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Glycoprotein and process for producing the same |
A process for producing a lysosomal enzyme having a mannose-6-phosphate-containing acidic sugar chain, wherein the process comprising: culturing in a medium yeast cells obtained by introducing a lysosomal enzyme gene into a sugar chain biosynthetic enzyme gene mutant strain of yeast, collecting a lysosomal enzyme having a phosphate-containing sugar chain from the culture, and then treating the enzyme with α-mannosidase; and pharmaceutical compositions for treatment of human lysosomal enzyme deficiencies produced by the process. The genetic engineering technique using the yeast according to the present invention allows large-amount and high-purity production of a glycoprotein having a phosphate-containing acidic sugar chain which can serve as a labeling marker for transporting into lysosomes in cells of mammals such as human. The glycoprotein having a phosphate-containing acidic sugar chain according to the invention may be utilized as a drug effective in treatment of human lysosomal enzyme deficiencies, etc. |
1. A process for producing an active form of glycoprotein, by using yeast, wherein the active form of glycoprotein has an acidic sugar chain having a mannose-6-phosphate at a non-reducing end. 2. The process of claim 1, wherein the acidic sugar chain having a mannose-6-phosphate may bind to mannose-6-phosphate receptor. 3. A process for producing an active form of glycoprotein, by using yeast, wherein the active form of glycoprotein has a high mannose-type sugar chain having a mannose-6-phosphate at a non-reducing end, wherein the high mannose-type sugar chain is shown in the following structural formulas I to VIII: 4. The process of any one of claims 1 to 3, wherein the yeast contains an acidic sugar chain, and at least the α-1,6-mannosyltransferase gene has been disrupted in the yeast strain to be used. 5. The process of any one of claims 1 to 3, wherein the yeast contains an acidic sugar chain, and at least the α-1,6-mannosyltransferase gene and the α-1,3-mannosyltransferase gene have been disrupted in the yeast strain to be used. 6. The process of claim 4 or 5, wherein the α-1,6-mannosyltransferase gene is the OCH1 gene of S. cerevisiae and the α-1,3-mannosyltransferase gene is the MNN1 gene of S. cerevisiae. 7. The process of any one of claims 1 to 6, wherein the yeast is a highly phosphorylated sugar chain-containing mutant. 8. The process of claim 7, wherein the yeast is S. cerevisiae strain HPY21. 9. The process of any one of claims 1 to 8, wherein the active form of glycoprotein having an acidic sugar chain having a mannose-6-phosphate is a lysosomal enzyme. 10. The process of claim 9, wherein the lysosomal enzyme is α-galactosidase. 11. The process of claim 10, wherein a structural gene for the α-galactosidase is a gene from human. 12. The process of claim 11, wherein the structural gene for the α-galactosidase has the nucleotide sequence represented by SEQ. ID. No: 5. 13. The process of any one of claims 10 to 12, wherein the yeast producing the β-galactosidase is strain HPY21G. 14. The process of any one of claims 1 to 13, by allowing α-mannosidase to act on a glycoprotein produced by the yeast as defined in any one of claims 4 to 8 to remove mannose residues from mannose-1-phosphate linkages in sugar chain. 15. The process of claim 14, wherein the α-mannosidase has an activity which removes mannose residues from mannose-1-phosphate linkages. 16. The process of claim 14 or 15, wherein the α-mannosidase has an activity which non-specifically breaks down α-1,2-mannoside linkages, α-1,3-mannoside linkages and α-1,6-mannoside linkages. 17. The process of claim 16, wherein the α-mannosidase activity is exo-type activity, and comprises no endo-type activity. 18. The process of claim 17, wherein the α-mannosidase is α-mannosidase from Cellulomonas bacteria. 19. The process of claim 18, wherein the Cellulomonas bacteria is Cellulomonas SO-5. 20. A glycoprotein, which is produced by yeast and has an acidic sugar chain having a mannose-6-phosphate at a non-reducing end. 21. The glycoprotein of claim 20, which is a lysosomal enzyme. 22. The glycoprotein of claim 20 or 21, which is produced by the process of any one of claims 1 to 19. 23. The glycoprotein of claim 21 or 22, which is α-galactosidase. 24. The glycoprotein of claim 23, which is α-galactosidase encoded by a gene from human. 25. The glycoprotein of claim 20, which has a sugar chain with high mannose-type sugar chain structure having a mannose-6-phosphate at a non-reducing end, wherein the sugar chain is shown in the following structural formulas I to VIII: 26. A pharmaceutical composition for treatment and/or prevention of lysosomal disease, comprising a glycoprotein according to any one of claims 20 to 25. 27. The pharmaceutical composition of claim 26, for treatment of Fabry disease, wherein the glycoprotein is human α-galactosidase. |
<SOH> BACKGROUND ART <EOH>It has become evident that naturally occurring proteins fail to exhibit their inherent biological activity when their sugar chains are removed (A. Kibata, Tanpakushitsu Kakusan Koso 36, 775-788 (1991)). This suggests that sugar chains play an important role in developing biological activity. However, because the correlation between sugar chain structure and biological activity is not always apparent, the development of techniques allowing flexible modification and control of the structures (the types of sugars, the linked positions, chain lengths, etc.) of sugar chains attached to proteins is needed. Glycoprotein sugar chains are largely classified as Asn-linked types, mucin types, O-GlcNAc types, GPI anchored types and proteoglycan types (M. Takeuchi, Glycobiology Series 5, Glycotechnology; edited by A. Kibata, S. Hakomori, K. Nagai, Kodansha Scientific, 191-208 (1994)), each of which have unique routes of biosynthesis and carry out different physiological functions. The biosynthesis pathway for Asn-linked sugar chains has been widely studied and analyzed in detail. Biosynthesis of Asn-linked sugar chains begins with synthesis of a precursor consisting of N-acetylglucosamine, mannose and glucose on a lipid carrier intermediate, and its transfer to a specific sequence (Asn-X-Ser or Thr) of the glycoprotein in the endoplasmic reticulum (ER). It then undergoes processing (cleavage of the glucose residue and a specific mannose residue) to synthesize an M8 high mannose-type sugar chain composed of 8 mannose residues and 2 N-acetylglucosamine residues (Man8GlcNAc2). The protein including the high mannose-type sugar chain is transported to the Golgi apparatus where it undergoes various modifications, and these modifications at the Golgi apparatus differ significantly between yeast and mammals (Kukuruzinska et al., Ann. Rev. Biochem., 56, 915-944 (1987)). In mammalian cells, one of three different pathways are taken, depending on the type of protein undergoing the sugar chain modification. The three pathways are cases 1) where the core sugar chain is not altered, 2) where the N-acetylglucosamine-1-phosphate moiety (GlcNAc-1-P) of UDP-N-acetylglucosamine (UDP-GlcNAc) is added at the 6-position of Man of the core sugar chain producing Man-6-P-1-GlcNAc, after which only the GlcNAc moiety is removed, for conversion to a glycoprotein having an acidic sugar chain, and 3) where five molecules of Man are removed in order from the core sugar chain, leaving Man3GlcNAc2 onto which almost simultaneously GlcNAc, galactose (Gal) and N-acetylneuraminic acid (also known as sialic acid (NeuNAc)) are added in order, resulting in a mixture of diverse hybrid and complex sugar chains [R. Kornfeld and S. Kornfeld, Ann. Rev. Biochem., Vol. 54, p.631-664 (1985)] ( FIG. 1 ). Thus, it has been found that mammalian sugar chains have a variety of structures which are closely related to the functions of glycoproteins. On the other hand, it has been found that yeast produce mannan-type sugar chains, or “outer chains”, having several to a hundred mannose residues on the above-mentioned core sugar chain (Man8GlcNAc2), while acidic sugar chains are also produced having mannose-1-phosphate added to the core sugar chain moiety and outer chain moiety (see FIG. 2 ). This modification differs from that of animal cells, and it has been reported that in yeast it does not function as a sorting signal for localization of glycoproteins to vacuoles (organelles corresponding to lysosomes in animal cells). The physiological function of phosphorylated sugar chains in yeast has therefore remained a mystery [Kukuruzinska et al, Ann. Rev. Biochem., Vol.56, p915-944 (1987)]. As shown in FIG. 2 , the phosphorylation sites of mannose phosphate-containing sugar chains in yeast are sometimes added to the α-1,3 branch side and α-1,6 branch side of the Man8GlcNAc2 core sugar chain synthesized in the ER, and are sometimes added to the α-1,2 branches abundantly present on mannose outer chains synthesized in the Golgi apparatus, or to the non-reducing ends of mannose outer chains [Herscovics and P. Orlean, FASEB J., Vol. 7, p540-550 (1993)]. Biosynthesis of outer chains in Saccharomyces yeast is believed to occur along the pathway shown in FIG. 2 [Ballou et al., Proc. Natl. Acad. Sci. USA, Vol.87, p3368 (1990)]. Specifically, an elongation initiating reaction occurs wherein mannose is added to the M8 high mannose-type sugar chains at the α-1,6 linkages ( FIG. 2 , Reactions I, B). It has been shown that the enzyme responsible for this reaction is a protein encoded by the OCH1 gene (Nakayama et al., EMBO J., 11, 2511-2519 (1992)). Also, a reaction of successive elongation of mannose by α-1,6 linkages ( FIG. 2 : II) forms poly α-1,6-linked mannose as the skeletons of the outer chains ( FIG. 2 : E). The α-1,6-linked mannose has α-1,2-linked mannose branches ( FIG. 2 : C, F, H), and α-1,3-linked mannose is often added to the ends of the branching α-1,2-linked mannose ( FIG. 2 : D, G, H, I). The addition of these α-1,3-linked mannoses is performed by MNN1 gene product (Nakanishi-Shindo et al., J. Biol. Chem., 268, 26338-26345 (1993)). It has also become evident that some acidic sugar chains are produced having mannose-1-phosphate added to the high mannose-type sugar chain moieties ( FIG. 2 : *) and outer chain moieties. This reaction has been shown to depend on a protein encoded by the MNN6 gene (Wang et al., J. Biol. Chem., 272, 18117-18124 (1997)), while a gene (MNN4) has also been identified which codes for a protein which positively controls this transfer reaction (Odani et al., Glycobiology, 6, 805-810 (1996); Odani et al., FEBS letters, 420, 186-190 (1997)). In most cases, outer chains result in heterogeneous protein products, both complicating protein purification and lowering specific activity (Bekkers et al., Biochim. Biophys. Acta, 1089, 345-351 (1991)). Moreover, because of the vast differences in sugar chain structures, glycoproteins produced in yeast do not exhibit the same biological activity as those from mammals, and are strongly immunogenic in mammals. For example, it is known that the α-1,3 mannoside linkages produced by the MNN1 gene in S. cerevisiae have strong immunogenicity (Ballou, C. E., Methods Enzymol., 185, 440-470 (1990)). It has been also reported that yeast inherently possess mannose-6-phosphate (Man-6-P) in the form of mannose-6-phosphate-α-1-mannose (Man-6-P-1-Man), which do not bind to Man-6-P receptors (Kukuruzinska et al., Annu. Rev. Biochem., 56, 915-944 (1987); Faust and Kornfeld, J. Biol. Chem., 264, 479-488 (1989); Tong et al., J. Biol. Chem., 264, 7962-7969 (1989)). Thus, yeast are considered unsuitable as hosts for production of useful mammalian glycoproteins. It has been a desire in both academia and industry to develop yeast that can produce glycoproteins with sugar chains having mammalian-equivalent biological activity, i.e., mammalian-type sugar chains. The present inventors have previously succeeded in creating mutants lacking outer chains and yeast with mammalian-type sugar chains (Japanese Patent Application No. 11-233215). As mentioned above, yeast produce acidic sugar chains having mannose-1-phosphate added to the core sugar chain moiety and outer chain moiety by the action of the MNN4 gene and MNN6 gene. It has been demonstrated that sugar chains of glycoproteins produced by mutants which produce the core sugar chain and are deficient in the genes for the outer chain synthetic enzymes, include both neutral sugar chains ( FIG. 3 : Structural Formula I) and acidic sugar chains ( FIG. 3 : Structural Formulas II to IV) (Proceedings of the 12th Biotechnology Symposium, p.153-157, Oct. 14, 2004, Biotechnology Developmental Technology Research Society). Such acidic sugar chains have a structure not found in mammalian sugar chains. Specifically, in mammalian cells it is not mannose-1-phosphate but rather N-acetylglucosamine-1-phosphate which is added, after which the N-acetylglucosamine moiety alone is removed to produce the final acidic sugar chain marked as “*” in FIG. 1 . As will be further explained below and is taught in Methods in Enzymology, [Vol.185, p.440-470 (1990)], this sugar chain serves as a lysosome transport signal in mammalian cells. Lysosomes are intracellular organelles containing numerous acidic hydrolases which decompose substances taken into the lysosomes both from within and without the cell. Most of the enzyme groups localized in human lysosomes, once biosynthesized and transported to the Golgi apparatus, undergo addition of phosphate groups at the 6-positions of mannose residues at the non-reducing ends of high mannose-type sugar chains, being thereby converted to acidic sugar chain-bearing glycoproteins, and the phosphate groups serve as lysosomal enzyme-specific recognition markers. They are distinguished from other proteins through binding with high affinity mannose-6-phosphate receptors (MPRs), and are carried into prelysosomes where they dissociate from the MPRs in the acidic environment and are then transported to lysosomes (von Figura and Hasilik, Annu. Rev. Biochem., 54, 167-193 (1984)). The binding with mannose-6-phosphate receptors (MPRs) requires that each sugar chain contain one or more mannose-6-phosphate molecules. This lysosomal enzyme-specific phosphate group addition is accomplished by two separate enzyme reactions. W. Canfield et al. have succeeded in cloning the genes for two enzymes (GlcNAc-phosphotransferase, GlcNAc-phosphodiester-GlcNAc′ase) involved in mannose-6-phosphate synthesis (Abstract of the XV International Symposium on Glycoconjugates. Glycoconjugate Journal Vol. 16 No. 4/5 S41 (1999)). Genetic defects in these lysosomal enzymes, in enzymes involved in the phosphate-addition reaction or in factors contributing to activation or stabilization of the lysosomal enzymes causes a group of diseases characterized by blockage of the enzyme reactions and accumulation of intracellular substrates, such diseases being referred to collectively as “lysosomal disease” (Leroy and DeMars, Science, 157, 804-806 (1967)). Over 30 different types of lysosomal disease are known in humans and together they constitute an important disease group in pediatric and internal medicine. Strategies for developing basic treatments for such diseases have included bone marrow transplantation and gene therapy. Enzyme supplementation therapy using lysosomal enzymes has also been attempted, but poor uptake by target organs has been a major obstacle and at the current time the only satisfactory results have been seen with enzyme supplementation for Gaucher disease. Gaucher disease results from a mutation in the gene for glucocerebrosidase, a glucosylceramide-degrading lysosomal enzyme, leading to accumulation of its substrate glucosylceramide mainly in bone marrow macrophage-derived cells, and manifested as notable hepatosplenomegaly as well as hematopoietic dysfunction including anemia and hemorrhage. As mentioned above, treatment methods for this disease include enzyme supplementation therapy, which has produced favorable treatment results, but such therapy must be continued for life and the enzyme preparations are extremely expensive. Glucocerebrosidase preparations are produced by modifying the ends of the sugar chains of human recombinant glucocerebrosidase expressed by CHO cells, to a form with the mannose exposed. Since the morbid cells in this disease are primarily macrophages, glucocerebrosidase is presumably transported to lysosomes after being taken up into the cells via mannose receptors on macrophages. Glucocerebrosidase is known to be transported into lysosomes regardless of whether it has mannose-6-phosphate on its sugar chains. It is therefore conjectured that the enzyme is transported to lysosomes by a mannose-6-phosphate receptor (MPR) non-dependent transport mechanism. However, the deficient enzymes in most other lysosomal diseases are transported to lysosomes by mannose-6-phosphate receptor-mediated systems, and therefore the lysosomal enzymes used for enzyme supplementation therapy must having mannose-6-phosphate-containing sugar chains as the lysosome migration signals necessary for binding with mannose-6-phosphate receptors (MPRs). Addition of mannose-6-phosphate to these lysosomal enzyme chains is therefore a key strategy. Currently, the reported methods for obtaining lysosomal enzymes include methods of purification from placenta, production methods utilizing cultured cells such as fibroblasts or melanoma cells, recombinant methods using cultured cells such as insect cells or Chinese hamster ovary (CHO) cells, and methods of obtaining the enzymes from transgenic rabbit milk. However, these methods are associated with the disadvantages of 1) low content of lysosomal enzymes with phosphate-added sugar chains and therefore poor uptake efficiency into lysosomes, and 2) low productivity/high culturing cost. Disadvantage 1) therefore requires high-dose administration, while disadvantage 2) leads to high treatment costs. Moreover, production by recombinant methods using yeast cells has not yet been achieved. Thus, enzymes having mannose-6-phosphate on the sugar chains and having high uptake activity into lysosomes have been a desired goal. One of the lysosomal disease known as Fabry disease is an X-chromosomal genetic disease characterized by reduced α-galactosidase activity and accumulation of its in vivo substrate globotriosylceramide in the body. Fabry disease patients in the classic type of the disease typically suffer extremity pain, cutaneous hemangioma and impaired sweating beginning from youth or adolescence, and exhibit nephropathy or cardiovascular and cerebrovascular disorders with increasing age. In recent years, a relatively mild Fabry disease “subtype” has been identified which is marked by cardiomyopathy in late middle age or thereafter, and it has been reported that such patients may be hidden among patient groups falsely diagnosed with cardiomyopathy. α-Galactosidase differs from the aforementioned glucocerebrosidase in that it is transported to lysosomes by a mannose-6-phosphate receptor-mediated system. Consequently, it must have mannose-6-phosphate-containing sugar chains in order to be taken up efficiently by the target cells. However, the technology has not existed for mass production of high-purity α-galactosidase with mannose-6-phosphate-containing sugar chains, suitable for use in therapy. For example, the proportion of mannose-6-phosphate sugar chains is thought to be about 20% in fibroblast-derived glycoprotein (α-galactosidase), which has shown superiority as an enzyme supplementation infusion in 9 out of 10 human patients (Pro. Natl. Acad. Sci. USA, 97:365-370 (2000)). Since the structures of the sugar chains added to proteins differ in yeast and mammalian cells, useful human or other mammalian glycoproteins produced in yeast by genetic engineering methods do not exhibit identical activity as those derived from mammals, or they may have different antigenicities due to the different sugar chains. It has been difficult to produce mammalian glycoproteins in yeast for this reason. Furthermore, while useful phosphate-containing acidic sugar chains having the identical sugar chain structures as are added in human and other mammalian cells would be of benefit in functioning as labeling markers for transport of the glycoproteins to lysosomes in human or other mammalian cells, it is currently difficult to supply such acidic sugar chain-having glycoproteins in uniform, large amounts. The development of such technology has therefore been greatly desired. The present inventors have previously proposed a method composing using a sugar chain synthesis mutant (ΔOCH1 mnn1) to produce a glycoprotein, allowing the MNN6 gene product to act thereon either in vivo or in vitro to obtain mannose-1-phosphate-added acidic sugar chains, and carrying out acid treatment to obtain mammalian-like sugar chains which are effective as lysosome transport signals (Japanese Unexamined Patent Publication HEI No. 9-135689). However, due to the extreme denaturing conditions used for this method (0.01 N hydrochloric acid, 100° C., 30 minutes), virtually all of the glycoprotein becomes denatured. It has therefore been unsatisfactory as a method for obtaining glycoproteins with physiological activity. |
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 illustrates the general biosynthesis pathway for N-linked sugar chains in mammals (konfeld et al.). FIG. 2 illustrates the biosynthesis pathway for N-linked sugar chains in yeast ( S. cerevisiae ). FIG. 3 shows the structures of the core sugar chains and the acidic sugar chains produced by yeast strain HPY21 (Δoch1 Δmnn1). FIG. 4 shows a strategy diagram according to the invention. FIG. 5 is a photograph of Western blot analysis for a culture supernatant of the α-galactosidase gene-introduced strain HPY21G. 1) Vector alone-introduced strain (HPY21) 2) α-Galactosidase gene-introduced strain (HPY21G) FIG. 6 shows the results of structural analysis of α-galactosidase sugar chains separated by Blue Sepharose from a culture supernatant concentrate of the α-galactosidase gene-introduced strain HPY21G. FIG. 7 shows the results of structural analysis of α-galactosidase sugar chains purified with an Asahi-Pak NH2-P column from a culture supernatant concentrate of the α-galactosidase gene-introduced strain HPY21G. 1) Sugar chains of α-galactosidase purified from culture supernatant (containing one phosphate molecule in each sugar chain). 2) Sugar chains from the α-mannosidase-treated foregoing 1). 3) Sugar chains from the alkaline phosphatase-treated foregoing 2). 4) Sugar chains from the α-mannosidase and alkaline phosphatase-treated sugar chain moieties of α-galactosidase purified from culture supernatant (containing two phosphate molecules in each sugar chain) treated with α-mannosidase and. FIG. 8 is a photograph of Western blot analysis for the purified α-galactosidase which has been further treated with Cellulomonas SO-5 strain-produced α-mannosidase. 1) untreated with α-Mannosidase 2) treated with α-Mannosidase FIG. 9 shows the results of structural analysis of sugar chains obtained from α-galactosidase treated with Cellulomonas SO-5 strain-produced α-mannosidase, using an Asahi-Pak NH2-P column. FIG. 10 shows the results of an uptake experiment (enzyme activity assay) of purified α-galactosidase obtained according to the invention, using cultured skin fibroblasts derived from a Fabry disease patient. FIG. 11 is a photograph showing the effects on substrate accumulation by administration of purified α-galactosidase obtained according to the invention to cultured fibroblasts obtained from a Fabry disease patient. detailed-description description="Detailed Description" end="lead"? |
High-ductility aluminium alloy part cast under pressure |
A safety or structural part cast under pressure made of high-ductility aluminum alloy containing, by weight: Si 2-6%; Mg<0.40%; Cu<0.30%; Zn<0.30%; Fe<0.50%; Ti<0.30%, at least one element for reducing adherence to the mold such as Mn (0.3-2%), Cr (0.1-0.3%), Co (0.1-0.3%), V (0.1-0.3%) or Mo (0.1-0.4%), and at least one element for modifying eutectics, such as Sr (50-500 ppm), Na (20-100 ppm) or Ca (30-120 ppm). Other elements may be present in an amount <0.05 each and <0.10 in total, the balance being aluminum. The part exhibits, after T5 tempering at a temperature less than 220° C., a yield strength Rp0.2>110 MPa and an elongation A>10%. |
1. Die-cast safety or structural part made of ductile aluminum alloy consisting essentially of, by weight: Si: 2-6%; Mg<0.40%; Cu<0.30%; Zn<0.30%; Fe<0.50%; Ti<0.30%; at least one element for reducing adherence to a mold selected from the group consisting of Mn 0.3, 2%, Cr 0.1, 0.3%, Co 0.1-0.3%, V 0.1-0.3% and Mo 0.1-0.4%, and at least one eutectic modifying element, selected from the group consisting of Sr 50-500 ppm, Na 20-100 ppm and Ca 30-120 ppm, other elements <0.05% each and <0.10% in total, the remainder being aluminium aluminum, said part having after artificial ageing T5 at a temperature below 220° C., a yield strength Rp0.2>100 MPa and an elongation A>10%. 2. Part according to claim 1, characterised in that the silicon content is between 3.5 and 5%. 3. Part according to claim 1, characterised in that the magnesium content is between 0.05 and 0.25%. 4. Part according to claim 1, characterised in that the titanium content is between 0.05 and 0.15%. 5. Part according to claim 1, characterised in that the copper content is less than 0.10%. 6. Part according to claim 1, characterised in that the iron content is less than 0.20%. 7. Part according to claim 1, characterised in that the zinc content is less than 0.10%. 8. Part according to claim 1, characterised in that the manganese content is between 0.7 and 1.5%. |
<SOH> FIELD OF THE INVENTION <EOH>The invention relates to the field of aluminium alloys intended for the manufacture of relatively thin aluminium-silicon alloy parts cast by means of die-casting and particularly automobile structural or safety parts. |
Method for Acaricidal and Microbicidal Treatment of Textile Materials |
The present invention concerns a method of agaricidal and microbicidal treatment of textile materials, a Neem oil microcapsule composition specifically for said treatment and a bioactive textile material obtained. More particularly, the present invention concerns the industrial and commercial areas of the treatment of fabrics and like products and is of particular application to textile materials produced from natural fibers such as cotton, feathers or down, or synthetic fibers such as polyester, nylon, acrylic or the like, or mixed fibers such as polyester-cotton. The present invention concerns a method of agaricidal and microbicidal treatment of a textile material, in which microcapsules containing Neem oil are fixed on said textile material. |
1. A method of agaricidal and microbicidal treatment of a textile material, wherein microcapsules containing Neem oil are fixed on said textile material. 2. A method according to claim 1, wherein said microcapsules are fixed onto said textile material such that a concentration of 0.1% to 3% by weight of Neem oil is obtained in said textile material. 3. A method according to claim 1, wherein the Neem oil is enriched in active molecules such that it contains the following proportions by weight: 1% to 30% of nimbin, preferably 1% to 25%; 1% to 30% of salanim, preferably 2% to 30%; and 0.15% to 20% of azadirachtin A, preferably 1% to 20%. 4. A method according to claim 1, wherein said microcapsules are constituted by a polymer selected from aminoplast resins, preferably a urea-formol type polymer. 5. A method according to claim 1, wherein said textile material is treated by soaking or spraying with a composition of said Neem oil microcapsules. 6. A method according to claim 5, wherein an initial soaking of said textile material is carried out with said Neem oil microcapsule composition followed, after using said textile material, by spraying or soaking again with a said Neem oil microcapsule composition, preferably at least every five washes of said textile material. 7. A method according to claim 5, wherein said Neem oil microcapsule composition comprises a dispersion of microcapsules mixed with dispersions of polymeric binders, said polymeric binders being selected to encourage attachment of said microcapsules to said textile material, and to increase the resistance of said microcapsules and said active molecules contained in the Neem oil to high temperature degradation, preferably at a temperature of more than 65° C., more preferably at a temperature of more than 150° C. 8. A method according to claim 7, wherein said polymeric binders comprise at least one polyurethane binder and/or polysiloxane binder. 9. A method according to claim 6, wherein said textile material is treated by soaking in an aqueous composition of Neem oil microcapsules containing the following concentrations by weight: at least 0.5%, preferably at least 5%, of said Neem oil microcapsules; at least 1.5%, preferably at least 10%, of polyurethane binders; at least 0.3%, preferably at least 2%, of polysiloxane binder. 10. A composition of Neem oil microcapsules for use in a method of agaricidal and microbicidal treatment of textile materials, the composition containing an effective quantity of Neem oil microcapsules as defined in claim 2. 11. A bioactive textile material obtained by the method according to claim 1. 12. A bioactive textile material, comprising Neem oil microcapsules, preferably with a Neem oil content of at least 0.1% by weight, more preferably at least 0.3%, said microcapsules preferably being coated with a film of polymeric binders encouraging fixing of said microcapsules in said textile material and increasing the degradation resistance of said microcapsules and active molecules contained in the Neem oil; more preferably, said polymeric binder endows the microcapsules with softening properties. 13. A textile material according to claim 12, comprising Neem oil microcapsules produced in an aminoplast polymer, preferably of the urea-formol type, and comprising a coating of at least one polymeric binder comprising at least a polyurethane and/or polysiloxane. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Mites are small arachnids that are known to flourish in dwellings and to proliferate in the constituent textile materials of bed linen, carpets and upholstery, for example, causing serious problems to man, especially respiratory problems characterized by allergies or asthma, the remedies for which must be taken continuously. Current agaricidal compounds are usually of the perithrenoid type. Said compounds have a certain level of toxicity and have deleterious ecological effects since they are not biodegradable. |
<SOH> OBJECTS AND SUMMARY OF THE INVENTION <EOH>A first aim of the present invention is to provide a method of agaricidal treatment of textile materials, which is non toxic and which is acceptable from an ecological viewpoint. The method of the present invention also proposes a novel treatment for the textile materials themselves by endowing them with bioactive, agaricidal/mite-inhibiting and microbicidal properties which are effective over time, in particular over a fairly long period, and which can resist several washes, in particular machine washes, without losing their efficacy. A product is known from European patent EP-A-0 436 257 which is an insecticide in the field of wood, agriculture, and animal welfare for controlling pest insects such as mosquitoes, tics, flies and fleas, as well as certain bacterial species. It is a natural vegetable oil extracted from Neem seeds. Neem ( Azadirachta indica ) is a tree belonging to the mahogany family which can reach 15 meters in height and is widespread in tropical and subtropical regions, more particularly in India, Africa, Indonesia, and South America. Neem oil can be extracted by cold pressing Neem seeds or by solvent extraction as described in EP-A-0 494 067 and International patent application WO-A-97/25867. Neem oil is a product which is biodegradable and neither toxic nor allergenic. Neem oil has never been proposed for the agaricidal treatment of textile materials, as it has a large number of disadvantages, including: 1/ a repugnant garlic odor; 2/ rapid oxidation, producing a beige-brown color; 3/ degradation of the active compounds under ultraviolet (UV) light and at a temperature higher than 65° C.; and 4/ degradation of the active compounds in contact with water. The above disadvantages constitute obstacles which have dissuaded the skilled person from using Neem oil in fabrics intended for household use. In particular, the physico-chemical properties of Neem oil are incompatible with resistance to the machine washing and drying which is unavoidable in the industrial utilization of fabrics and bed linen. Microencapsulating liquid or solid substances, imprisoning such substances in microcapsules with polymeric walls, is known. Protected by their microcapsules, the active agents are only released when the microcapsules burst when brought into contact with certain media or are subjected to certain conditions which cause them to split or rupture. Treating textile materials on an industrial scale with different finishes to endow them with different properties such as flame-retardant or stain-repellant properties, the application of fillers or even glazing, involves padding treatments followed by a drying step at temperatures of over 120° C. to obtain rapid drying. Such drying temperatures are incompatible with maintaining the active properties of Neem oil. The inventor has discovered that it is possible to carry out an agaricidal and microbicidal treatment on textile materials which satisfies the aims of the present invention and overcomes the various disadvantages of Neem oil described above, by treating said textile materials with Neem oil in the microencapsulated form, i.e., in the form of micro-droplets of Neem oil enveloped in a polymeric wall. Thus microencapsulated, the Neem oil endows said textile materials with agaricidal and microbicidal properties, with the active substances in the Neem oil being released by rupture of the microcapsules following a simple mechanical process of rubbing said textile material into which they have been incorporated. Said microcapsules act as a vehicle for fixing the Neem oil onto the textile material, improving the bioavailability of its active principles, masking the disagreeable odors of certain of its compounds, and increasing the lifetime of said substances. The active molecules act in the core of the fibers, blocking the growth and reproduction of the mite pests via enzymatic systems. The inventor has discovered that it is possible to produce Neem oil microcapsules that preserve the properties of the active substances in the Neem oil over time even after washing and high temperature drying treatments. Further, the microcapsules are stable over time and the agaricidal and microbicidal characteristics of said textile material treated with said microcapsules are maintained even after several washes. Thus, microencapsulation can solve the problems of many agaricides as regards application to textile materials and as regards long-term, effective release of active substances from textile materials. In particular in microcapsules, the color and odor of the Neem oil are overcome, even more so when the Neem oil is mixed with other agents, allowing a desired odor to be obtained. Thus, the present invention provides a method of agaricidal and microbicidal treatment of a textile material in which microcapsules containing Neem oil are fixed to a textile material. Advantageously, to obtain an effective treatment over time, a sufficient quantity of microcapsules is fixed to said textile material to obtain a concentration by weight of 0.1% to 3% of Neem oil in said textile material. Of the 200 active compounds in Neem oil, azadirachtin A, nimbin, and salanim are, in accordance with the invention, the principal compounds with an agaricidal action, acting against the development and reproduction of mites. Preferably, a specifically reformulated Neem oil is employed to obtain a concentration enriched in active molecules, containing the following proportions by weight: 1% to 30% of nimbin, preferably 1% to 25%; 1% to 30% of salanim, preferably 2% to 30%; 0.15% to 20% of azadirachtin A, preferably 1% to 20%. In one implementation, the microcapsules represent a good compromise between wash resistance, good attachment to textile materials, ability to burst or rupture by simple rubbing, and finally treatment efficacy; said microcapsules are constituted by a polymer selected from aminoplast resins, namely resins resulting from polycondensing an aldehyde with an amine or an amide, more particularly a urea-formol type polymer. Preferably again, said microcapsules are coated with a film of polymeric binders encouraging fixing of said microcapsules to said textile material and increasing the resistance of said microcapsules and the active molecules contained in the Neem oil to degradation; preferably again, said polymer binder provides softening properties. More particularly advantageously, in the method of the invention, said textile material is treated by soaking or spraying with a composition of said Neem oil microcapsules. Many microencapsulation means are known to the skilled person. However, because of the risks of degrading the active substances in Neem oil, a microencapsulation method is employed that does not involve temperatures of more than 65° C. More particularly, microencapsulation is carried out by in situ polymerization of said constituent polymers of the wall in a Neem oil formulation, said in situ polycondensation polymerization being carried out at a temperature of less than 65° C. This in situ polymerization method is particularly advantageous as it involves strong bonds between the molecules of the polymers constituting the wall, which can preserve the properties of the agaricidal substances long-term even after machine washing, and which can release said substances by rupture of the wall by rubbing. In a preferred implementation, in the method of the invention said textile material is initially soaked with said Neem oil microcapsules composition followed, after using said treated textile material, by spraying or soaking said textile material again with a said Neem oil microcapsule composition, preferably at least every five washes of said textile material. Preferably, said Neem oil microcapsule composition comprises a dispersion of microcapsules mixed with dispersions of polymeric binders, said binders being selected to encourage attachment of said microcapsules to said textile material, and to increase the resistance of said microcapsules and said active molecules contained in the Neem oil to high temperature degradation, preferably at a temperature of more than 65° C., more preferably at a temperature of more than 150° C. This type of soaking treatment involves industrial drying processes carried out at temperatures of the order of 150° C. which, according to the present invention, do not denature the active substances in the Neem oil, nor the microcapsules. The method of the invention thus consists of impregnating the textile material to be treated with a finish applied either by spraying or soaking in a bath, to incorporate into said fabric a concentration of Neem oil of 0.1% to 3% by weight. In a preferred implementation of the method of the invention, said binders are selected from polyurethane and polysiloxane binders. The polyurethane type binder encourages attachment of the microcapsules to the fabric and increases the resistance to machine washing, and the polysiloxane type binder also contributes to increasing the high temperature degradation resistance, this protective effect being paired with a softening effect. The use of a silicone polysiloxane—based binder provides softening properties; adding microcapsules to a fabric would otherwise roughen the fabric. More particularly, and especially when the microcapsules are produced with aminoplast resin walls, more particularly urea-formol in type, said textile material is treated by soaking in an aqueous composition of Neem oil microcapsules containing the following concentrations by weight: at least 0.5%, preferably at least 3%. of said Neem oil microcapsules; at least 1.5%, preferably at least 10%, of polyurethane binders; at least 0.3%, preferably at least 2%, of polysiloxane binder. Still more particularly, said Neem oil microcapsules composition for agaricidal and microbicidal treatment of textile materials contains an effective quantity of Neem oil microcapsules, as defined above, preferably as a mixture with polymeric binders as defined above. The use of said polymeric binders endows said treatment with good washing resistance, i.e., good attachment of the microcapsules to the fabric, in particular for up to five consecutive washes, and good microcapsule strength; the microcapsules can achieve a service life of three years and achieve long-term resistance to degradation, as well as protect against denaturing of the active substances they contain, up to temperatures of at least 150° C. The present invention also concerns a bioactive textile material obtained by a treatment method in accordance with the invention and, more particularly, a bioactive textile material which comprises Neem oil microcapsules, preferably with a Neem oil content of at least 0.1% by weight, more preferably at least 0.3%, said microcapsules preferably being coated with a film of polymeric binders encouraging fixing of said microcapsules in said textile material and increasing the degradation resistance of said microcapsules and the active molecules contained in the Neem oil; more preferably, said polymeric binder endows the microcapsules with softening properties. Still more particularly, a bioactive textile material in accordance with the invention comprises Neem oil microcapsules produced from an aminoplast polymer and comprising a coating of at least one polymeric binder comprising at least a polyurethane and/or polysiloxane. Laboratory experiments carried out on the most resistant and virulent dust mites as regards allergies, namely Dermaphagoïde pteronissimus, exhibited 90% mortality after three weeks (one reproductive cycle) and 100% mortality after four weeks. It was also shown that the treated textiles are provided with an ability to transfer the agaricidal/mite-inhibiting properties by diffusion of the released active principles onto untreated textile materials in contact with a treated textile. From a toxicological viewpoint, the tests carried out have shown that toxicologically, this finish is non toxic and inoffensive as regards mammals, fishes, birds, and bees. Furthermore, it is hypoallergenic, even after a long period of contact with the skin. It is possible to couple the Neem oil in the microcapsules with a further natural vegetable oil with similar physico-chemical properties to endow the bioactive materials with complementary properties; for example, Saint-John's wort oil can be coupled with the Neem oil in a ratio of 3%. This produces a material that is also bactericidal/bacteria-inhibiting. It is also possible to add perfumed or deodorizing essences to the microcapsules, selected as a function of the use of the product to be treated. The treated textile materials can be used in areas such as bed linen (manufacture of eiderdowns, duvets, pillows, sheets, pillowcases, etc.), and in certain textiles such as curtains or carpets. They can also be used in the manufacture of storage items such as furniture covers, garment covers, duvet covers, etc. The arrangement and combination of the various constituent elements of the invention maximizes its advantages, which have not until now been produced by similar methods. detailed-description description="Detailed Description" end="lead"? |
Wound dressing and method for controlling severe, life-threatening bleeding |
This invention is directed to advanced hemorrhage control wound dressings, and methods of using a producing same. The subject wound dressing is constructed from a non-mammalian material for control of severe bleeding. The wound dressing is formed of a biomaterial comprising chitosan for controlling severe bleeding. The kind of severe, life-threatening bleeding contemplated by this invention is typically of the type not capable of being stanched when a conventional gauze wound dressing is applied with conventional pressure to the subject wound. The wound dressing being capable of substantially stanching the flow of the severe life-threatening bleeding from the wound by adhering to the wound site, to seal the wound, to accelerate blood clot formation at the wound site, to reinforce clot information at the wound site and prevent bleed out from the wound site, and to substantially prohibit the flow of blood out of the wound site. |
1. A wound dressing which is formed of a biomaterial comprising chitosan, for controlling severe, life-threatening bleeding from a wound at a wound site of a person, said wound dressing being capable of substantially stanching the flow of said severe life-threatening bleeding from said wound by adhering to said wound site, to seal said wound, to accelerate blood clot formation at said wound site, to reinforce clot formation at said wound site and prevent bleed out from said wound site, and to substantially prohibit the flow of blood out of the said wound site. 2. The wound dressing of claim 1, wherein said severe, life-threatening bleeding is not capable of being stanched when a conventional gauze wound dressing is applied with conventional pressure to wound. 3. The wound dressing of claim 1, wherein said severe, life-threatening bleeding is not capable of being stanched when a conventional gauze wound dressing is applied with conventional pressure to wound and, if not controlled by other means, would result in the person lapsing into a state of hypotension. 4. The wound dressing of claim 1, wherein said severe, life-threatening bleeding is not capable of being stanched when a conventional gauze wound dressing is applied with conventional pressure to wound and, if not controlled by other means, would result in the systolic blood pressure of the person dropping to a level of less than about 90 mm Hg. 5. The wound dressing of claim 1, wherein said biomaterial comprises a non-mammalian material. 6. The wound dressing of claim 1, wherein said severe bleeding is a steady high flow of blood of more than about 90 ml of blood loss per minute, such that in about 20 minutes of bleeding a volume of more than about 40% of total blood from a 70 kg human male would be lost, said blood volume loss greatly reducing the likelihood of survival of the wounded person. 7. The wound dressing of claim 1, which is capable of stanching said severe bleeding which is caused by a substantial arterial wound or a substantial venous wound having a blood flow rate of at least about 90 ml/minute. 8. The wound dressing of claim 1, which is sterilized by gamma irradiation 9. The wound dressing of claim 1, which has antiseptic properties. 10. The wound dressing of claim 1, which prohibits the flow of blood And other fluids into said wound site. 11. The wound dressing of claim 1, which has an ultimate tensil breaking load of not less than about 1 kg. 12. The wound dressing of claim 1, which has an ultimate elongation of at least about 70%. 13. The wound dressing of claim 1, which has Young's modulus which Is less than about 5 MPa. 14. The wound dressing of claim 1, wherein said severe bleeding is caused by a ballistic projectile injury or a sharp perforation injury or a blunt traumatic injury. 15. The wound dressing of claim 1, wherein said biomaterial is formed by a freeze drying, non-woven spinning, conventional spinning, electro-spinning, freeze substitution, phase inversion solvent process, solution coating or a combination thereof. 16. The wound dressing of claim 1, which is capable of adhering to said wound site by the application of direct pressure to the wound dressing for a period of time of not more than about five minutes. 17. The wound dressing of claim 1, which facilitates substantial clotting and agglutinating of the severe bleeding from the wound site and stanches said severe bleeding which includes the temporary application of direct pressure to the wound dressing. 18. The wound dressing of claim 1, wherein said biomaterial comprises interconnected open porous structure, and/or an oriented open lamella structure, and/or an open tubular structure, and/or an open honeycomb structure, and/or a filamentous structure. 19. The wound dressing of claim 1, which has an available blood contacting surface area per base surface of said wound dressing of at least about 100 cm2 per cm2. 20. The wound dressing of claim 1, which has a mean rate of dissolution per base surface area of said wound dressing when adhered to said wound site, at a temperature of about 37° C., of not more than about 0.008 grams per min per cm2. 21. The wound dressing of claim 1, which has a density of at least about 0.05 g/cm3. 22. The wound dressing of claim 1, which has a number average molecular weight of at least about 50 kda, and a weight average molecular weight of at least about 100 kda. 23. The wound dressing of claim 1, which has a Brookfield LV DV-II+ viscosity of not less than about 100 cps. 24. The wound dressing of claim 1, which has an open pore diameter of at least about 15 microns up to about 150 microns. 25. The wound dressing of claim 1, which has a backing support layer attached thereto. 26. The wound dressing of claim 25, wherein the backing support layer is substantially blood insoluble and non-sticking to hands or gloves. 27. The wound dressing of claim 25, wherein the backing support layer is substantially blood impermeable. 28. The wound dressing of claim 1, wherein the degree of adhesion of the wound dressing to the wound site is at least about 40 kPa. 29. The wound dressing of claim 1, which comprises cationic chitosan salts for promoting tissue adhesion and tissue sealing. 30. The wound dressing of claim 1, which has an available mass of chitosan biomaterial per wound surface area which is at least about 0.02 g/cm2. 31. The wound dressing of claim 29, wherein said cationic chitosan salts are selected from a group consisting of chitosan formate, chitosan acetate, chitosan lactate, chitosan ascorbate, chitosan chloride and chitosan citrate. 32. The wound dressing of claim 1, wherein the chitosan has a degree of deacetylation of at least about 70%. 33. The wound dressing of claim 1, wherein the thickness of the biomaterial is not less than about 3.0 mm and not more than about 8.0 mm. 34. The wound dressing of claim 1, wherein said severe bleeding is caused by coagulopathy or internal trauma or surgical trauma. 35. The wound dressing of claim 1, which further includes a supplemental traction surface. 36. The wound dressing of claim 35, wherein said supplemental traction surface is in the form of a tread design. 37. The wound dressing of claim 1, which is capable of forming an adhesive material in combination with blood flowing from said wound at the wound dressing-blood interface, said adhesive material having a pH of not more than about 5 when the wound is sealed. 38. The wound dressing of claim 37, wherein the acid employed to adjust the pH of the adhesive material is selected from a group consisting of acetic acid, formic acid, lactic acid, ascorbic acid, hydrochloric acid, and citric acid. 39. The wound dressing of claim 37, wherein the mole ratio of acid anion to glucosamine functional groups in the chitosan cation/anion pair required to adjust the pH to the level described above is preferably about 0.9. 40. The wound dressing of claim 1, which is capable of being conformed to the configuration of the wound for engagingly contacting said wound and facilitating stanching of the flow of said severe life-threatening bleeding. 41. The wound dressing of claim 40, which is capable of being conformed into a tubular configuration and inserted into said wound. 42. A method for controlling severe, life-threatening bleeding from a wound at a wound site of a person, which comprises providing a wound dressing formed of a biomaterial comprising chitosan, adhering said wound dressing to said wound site and substantially stanching the flow of said severe life-threatening bleeding from said wound, sealing said wound and preventing bleed out from said wound site, and preventing bleeding and the flow of other fluids into and/or out of the said wound site, said bleeding not capable of being stanched when a conventional gauze bandage is used for purposes of stanching said severe, life-threatening bleeding. 43. A method for producing a wound dressing capable of controlling severe, life-threatening bleeding from a wound at a wound site of a person, comprising providing a chitosan biomaterial; degassing said chitosan biomaterial; and freezing said chitosan biomaterial; and forming a wound dressing from said frozen chitosan biomaterial, said wound dressing being capable of substantially stanching the flow of said severe life-threatening bleeding from said wound by adhering to said wound site, to seal said wound and prevent bleed out from said wound site, and to prevent the flow of bleeding and other fluids into and/or out of the said wound site, said severe, life-threatening bleeding not capable of being stanched when a conventional gauze bandage is applied to the wound site. 44. The method of claim 43, which further includes the step of freeze-drying said frozen chitosan biomaterial. 45. The method of claim 43, which further includes the step of heating said frozen biomaterial. 46. The method of claim 43, which further includes the step of compressing said wound dressing to reduce the thickness and increase the density of said wound dressing thereby increasing the adhesion strength and dissolution resistance of said wound dressing. 47. The method of claim 43, which further includes the step of irradiating said wound dressing to sterilize and improve mechanical, wetting and adhesion properties thereof. 48. The method of claim 43, wherein said degassing step comprises removing sufficient residual gas from the chitosan biomaterial so that, on undergoing a subsequent freezing operation, the gas does not escape and form unwanted voids or trapped gas bubbles in the subject wound dressing product. 49. The method of claim 43, wherein said degassing step comprises heating said chitosan biomaterial, and then applying a vacuum thereto. 50. The method of claim 43, wherein the freezing step is carried out by cooling the chitosan biomaterial and lowering the temperature thereof from room temperature to a final temperature below the freezing point. 51. The method of claim 43, wherein freezing step is carried out by cooling the chitosan biomaterial and lowering the temperature thereof from room temperature to a final temperature of not more than about −10° C. 52. The method of claim 43, wherein freezing step is carried out by cooling the chitosan biomaterial so that the temperature is gradually lowered over a predetermined time period. 53. The method of claim 43, which further includes the step of removing water from within the interstices of the frozen chitosan biomaterial. 54. The method of claim 53, wherein the step of removing water from within the interstices of the frozen chitosan biomaterial is achieved without damaging the structural integrity of the frozen chitosan biomaterial. 55. The method of claim 53, wherein during the step of removing water from within the interstices of the frozen chitosan biomaterial the water passes from a solid frozen phase into a gas phase without the substantial formation of an intermediate liquid phase. 56. The method of claim 53, wherein the step of removing water from within the interstices of the frozen chitosan biomaterial comprises freeze drying, or freeze substitution or a combination thereof. 57. The method of claim 46, wherein the compression temperature in not less than about 60° C. 58. The method of claim 46, wherein the compressed chitosan biomaterial is preconditioned by heating same to a temperature of preferably up to about 75° C. 59. The method of claim 46, wherein said preconditioning step is typically conducted for a period of time up to about 0.25 hours. 60. The method of claim 46, which further includes the step of irradiating the wound dressing at a level of at least about 5 kGy. |
<SOH> BACKGROUND OF THE INVENTION <EOH>An advanced hemorrhage control bandage and methods of its application would substantially augment available hemostatic methods. To date, the application of continuous pressure with gauze bandage remains the preferred primary intervention technique used to stem blood flow, especially that from severely bleeding wounds. However, this procedure neither effectively nor safely stanches severe blood flow. This has been, and continues to be, a major survival problem in the case of severe life-threatening bleeding from a wound. Furthermore, it is widely accepted that severe bleeding is the leading cause of death from wounds on the battlefield, accounting for approximately 50 percent of such deaths. It is estimated that one-third of these deaths may be preventable with enhanced hemorrhage control methods and devices. Such enhanced hemorrhage control would also prove most useful in the civilian population where hemorrhage is the second leading cause of death following trauma. Currently available hemostatic bandages, restricted to use in surgical applications, such as collagen wound dressings or dry fibrin thrombin wound dressings are not sufficiently resistant to dissolution in high blood flow nor do they have strong enough adhesive properties to serve any practical purpose in the stanching of severe blood flow. These currently available surgical hemostatic bandages are also delicate and thus prone to failure should they be damaged by bending or loading with pressure. There is prior art relating to chitosan and chitosan dressings. For example, U.S. Pat. No. 4,394,373 employs chitosan in liquid or powder form to agglutinate blood in microgram/ml quantities. Also, U.S. Pat. No. 4,452,785 is directed to a method of occluding blood vessels therapeutically by injecting chitosan directly into the vessels. U.S. Pat. No. 4,532,134 further relates to hemostatis, inhibiting fibroplasias, and promoting tissue regeneration by placing in contact with the tissue wound a chitosan solution or water-soluble chitosan. The chitosan forms a coagulum which prevents bleeding. Moreover, U.S. Pat. No. 5,858,350 relates to a process to make diatom derived biomedical grade, high purity chitin and chitin derivatives (so called protein-free even though this is not demonstrated by analysis in the patent). The proposed advantage of so called protein-free chitin/chitosan materials are that they should be significantly less antigenic than current shrimp and crab derived chitin materials. Mi, F L, et al, Fabrication and Characterization of a Sponge - Like Assymetric Chitosan Membrane as a Wound Dressing, Biomaterials, 22(2):165-173 (2001) describes the fabrication and wound healing function of an asymmetric chitosan membrane produced by a phase inversion method. Chan, M W, et al, Comparison of Poly - N - acetyl Glucosamine ( P - GlcNAc ) with Absorbable Collagen ( Actifoam ), and Fibrin Sealant ( Bolheal ) for Achieving Hemostasis in a Swine Model of Splenic Hemorrhage , J. Trauma, Injury, Infection, and Critical Care, 48(3):454-458 (2000) describes the testing of chitin/chitosan hemostatic patches under the moderate blood flow and oozing typical of the swine spleen capsular stripping test. Cole, D. J., et al, A Pilot Study Evaluating the Efficacy of a Fully Acetylated poly - N - acetyl glucosamine Membrane Formulation as a Topical Hemostatic Agent, Surgery 126(3):510:517 (1999) describes hemostatic agent testing in the swine spleen capsular stripping test. Sandford, Steinnes A., “Biomedical Applications of High Purity Chitosan” in Water Soluble Polymers, Synthesis, Solution Properties and Applications, ACS Series 467, Shalaby W S. McCormick C L. Butler G B. Eds. ACS, Washington, D.C. 1991, Ch 28, 431-445. This is a general review paper describing chitosan use with reference to a chitosan sponge. Mallette, W. G., et al, Chitosan: A New Hemostat, The Annals of Thoracic Surgery, 36(1), 55-58, (1983) See comments concerning the Malette patents above. Olsen, R., et al, In Chitin and Chitosan, Sources, Chemistry, Biochemistry, Physical Properties and Applications, Elsevier Applied Science, London and New York, 1989, 813-828. This paper concerns the agglutinating efficiency of chitosan. Japanese Patent 60142927 covers a chitosan medical band with improved tack Japanese patent 63090507 A2 describes a water insoluble and 2% acetic acid insoluble chitosan sponge for external hemostatic application or for protection of a wound. U.S. Pat. No. 5,700,476 describes collagen based structurally inhomogeneous sponges for wound dressings and/or implant applications formed by freeze drying techniques employing at least one pharmacological agent and at least one substructure. U.S. Pat. No. 2,610,625 relates to freeze dried sponge structures that are highly effective in stopping the flow of blood or other fluids and which will be absorbed after a time in the body. This patent describes collagen sponge preparation. U.S. Pat. No. 5,836,970 comprises a wound dressing formed of a blend or mixture of chitosan and alginate. |
<SOH> SUMMARY OF THE INVENTION <EOH>The invention is directed to a first-aid/primary intervention wound dressing for control of severe, life-threatenincg bleeding. The subject wound dressing is typically relatively low cost. Presently there are no low cost wound dressings that address or any wound dressings that are suitable for control of severe life-threatening bleeding. Such bleeding can be fatal in ballistic injuries and severe arterial lacerations. There is an urgent need for this type of dressing especially in the battlefield where typically 50% of all deaths are associated with an inability to immediately control severe bleeding. An advanced wound dressing for control of severe, life-threatening bleeding should preferably have the following properties: i) easily and quickly applied in one step after removal from package ii) rapid and strong blood clotting iii) rapid and strong tissue adhesion iv) strong internal cohesive properties v) rapid and strong wound sealing vi) resistant to dissolution under strong blood flow vii) able to be treated roughly without compromising efficacy This invention is directed to advanced hemorrhage control wound dressings, and methods of using and producing same. The subject wound dressing is constructed from a non-mammalian material for control of severe bleeding. The preferred non-mammalian material is poly [β-(1→4)-2-amino-2-deoxy-D-glucopyranose] more commonly referred to as chitosan. In general, the subject dressing is formed of a biomaterial comprising chitosan for controlling severe bleeding. Preferably, the biomaterial comprises a non-mammalian material. The kind of severe, life-threatening bleeding contemplated by this invention is typically of the type not capable of being stanched when a conventional gauze wound dressing is applied with conventional pressure to the subject wound. Alternatively, the nature of the severe, life-threatening bleeding is such that it is not capable of being stanched when a conventional gauze wound dressing is applied with conventional pressure to the wound and, if not controlled by other means, would result in the person lapsing into a state of hypotension. Stated another way, the severe, life-threatening bleeding is generally not capable of being stanched when a conventional gauze wound dressing is applied with conventional pressure to the wound and, if not controlled by other means, would result in the systolic blood pressure of the person dropping to a level of less than about 90 mm Hg. The severe, life-threatening bleeding can also be described as a steady high flow of blood of more than about 90 ml of blood loss per minute, such that in about 20 minutes of bleeding a volume of more than about 40% of total blood from a 70 kg human male would be lost, and the blood volume loss would substantially reduce the likelihood of survival of the person. In many cases, the severe bleeding is caused by a ballistic projectile injury or a sharp perforation injury or a blunt traumatic injury. In other cases, the severe bleeding is caused by coagulopathy or internal trauma or surgical trauma. The wound dressing is preferably capable of stanching said severe bleeding which is caused by a substantial arterial wound or a substantial venous wound having a blood flow rate of at least about 90 ml/minute. The wound dressing is also preferably capable of adhering to the wound site by the application of direct pressure to the wound dressing for a period of time of not more than about five minutes. The wound dressing also preferably acts quickly to seal the wound. The wound dressing also preferably facilitates substantial clotting and agglutinating of the severe bleeding from the wound site, and stanches the severe bleeding with the temporary application of direct pressure to the wound dressing. The wound dressing preferably has a high resistance to dissolution in high blood flow. The wound dressing preferably has good internal cohesion properties and thus has sufficient flexibility and toughness to resist rough handling. The wound dressing is typically produced from a chitosan biomaterial and formed into a sponge-like or woven configuration via the use of an intermediate structure or form producing steps. Such structure or form producing steps are typically carried out from solution and can be accomplished employing techniques such as freezing (to cause phase separation), non-solvent die extrusion (to produce a filament), electro-spinning (to produce a filament), phase inversion and precipitation with a non-solvent (as is typically used to produce dialysis and filter membranes) or solution coating onto a preformed sponge-like or woven product. In the case of freezing, where two or more distinct phases are formed by freezing (typically water freezing into ice with differentiation of the chitosan biomaterial into a separate solid phase), another step is required to remove the frozen solvent (typically ice), and hence produce the wound dressing without disturbing the frozen structure. This can be accomplished by a freeze-drying and/or a freeze substitution step. The filament can be formed into a non-woven sponge-like mesh by non-woven spinning processes. Alternately, the filament can be produced into a felted weave by conventional spinning and weaving processes. Other processes that may be used to make the said biomaterial sponge-like product include dissolution of added porogens from a solid chitosan matrix or boring of material from said matrix. The wound dressing is preferably formed of a biomaterial comprising an interconnected open porous structure, and/or an oriented open lamella structure, and/or an open tubular structure, and/or an open honeycomb structure, and/or a filamentous structure. The wound dressing has interconnected free-space domains or pores with pore diameters of preferably at least about 15 microns, more preferably at least about 30 microns, most preferably at least about 35 microns, preferably up to about 100 microns, more preferably up to about 125 microns, and most preferably up to about 150 microns. The wound dressing has an available blood contacting surface area per base surface of said wound dressing of preferably at least about 100 cm 2 per cm 2 , more preferably at least about 200 cm 2 per gram per cm 2 , and most preferably at least about 300 cm 2 per gram per cm 2 . The available mass of chitosan biomaterial per wound surface area is preferably at least about 0.02 g/cm 2 , more preferably at least about 0.04 g/cm 2 , and most preferably at least about 0.06 g/cm 2 . Furthermore, the wound dressing has a mean rate of dissolution per base surface area of said wound dressing when adhered to said wound site, at a temperature of about 37° C., of preferably not more than about 0.008 grams per minute per cm 2 , more preferably not more than about 0.005 grams per minute per cm 2 , and most preferably not more than about 0.002 grams per minute per cm 2 . The subject wound dressing preferably has a density of at least about 0.05 g/cm 3 , more preferably at least about 0.07 g/cm 3 , and most preferably at least about 0.11 g/cm 3 . It can have a compression loading preferably to a compression density at least about 0.05 g/cm 3 , more preferably at least about 0.07 g/cm 3 , most preferably at least about 0.095 g/cm 3 , and preferably of not more than about 0.14 g/cm 3 , more preferably not more than about 0.12 g/cm 3 , most preferably not more than about 0.10 g/cm 3 . A wound dressing of this invention typically contains chitosan with number average molecular weight of at least about 50 kda, preferably at least about 75 kda, more preferably at least about 100 kda, and most preferably at least about 150 kda (molecular weights determined by Gel Permeation Chromatography relative to polyethylene glycol standards in pH 5.5, 0.01 M sodium acetate). The chitosan also preferably has a weight average molecular weight of at least about 100 kda, more preferably at least about 150 kda, and most preferably at least about 300 kda (molecular weights determined by Gel Permeation Chromatography relative to polyethylene glycol standards in pH 5.5, 0.01 M sodium acetate). The chitosan in the wound dressing also has a Brookfield LV DV-II+ viscosity at 25° C. in 1% solution and 1% acetic acid (AA) with spindle LV1 at 30 rpm which is preferably not less than 100 centipoise, more preferably not less than 125 centipoise, most preferably not less than 150 centipoise, The molecular weights and viscosities referred to immediately above are in respect to substantially pure chitosan wound dressings and wound dressings formed with an adsorbed surface layer of chitosan. In the case of a wound dressing containing a covalently bound surface layer of chitosan, then lower viscosities and molecular weights of chitosan may be preferred. The wound dressing of the present invention can comprise cationic chitosan salts for promoting tissue adhesion and tissue sealing. Preferably, the cationic chitosan salts are selected from a group consisting of chitosan formate, chitosan acetate, chitosan lactate, chitosan ascorbate and chitosan citrate. The chitosan has a degree of deacetylation which is typically at least about 70%, preferably at least about 75%, more preferably at least about 80%, most preferably at least about 85%. In a preferred form of this invention, the wound dressing has a backing support layer attached thereto that provides for and that facilitates improved handling and mechanical properties. This backing layer can be attached or bonded to the dressing by direct adhesion with the top layer of chitosan, or an adhesive such as 3M 9942 acrylate skin adhesive, or fibrin glue or cyanoacrylate glue can be employed. This backing support layer is also preferably substantially blood insoluble. The backing support layer is also preferably substantially blood impermeable. The backing support layer is also preferably substantially biodegradable. The backing support layer is preferably a material which allows for firm handling of the bandage during application and non-sticking to hands once bandage has been applied. Preferably, the material which forms the backing support layer is a layer of polymeric material. Examples of preferred backing materials include low-modulus meshes and/or films and/or weaves of synthetic and naturally occurring polymers. Synthetic biodegradable materials include poly(glycolic acid), poly(lactic acid), poly(e-caprolactone), poly(β-hydroxybutyric acid), poly(β-hydroxyvaleric acid), polydioxanone, poly(ethylene terephthalate), poly(malic acid), poly(tartronic acid), polyphosphazene and the copolymers of the monomers used to synthesize the above-mentioned polymers. Naturally occurring biodegradable polymers include chitin, algin, starch, dextran, collagen and albumen. Non-biodegradable polymers for temporary external wound applications include polyethylene, polypropylene, metallocene polymers, polyurethanes, polyvinylchloride polymers, polyesters and polyamides. The wound dressing of this invention has the degree of adhesion to the wound site which is preferably at least about 40 kPa, more preferably at least about 60 kPa, and most preferably at least about 100 kPa. Also, the wound dressing has a thickness which is preferably not less than about 3.0 mm, more preferably not less than about 3.5 mm, and most preferably not less than about 4.0 mm, and preferably not more than about 8.0 mm, more preferably not more than about 7.0 mm, and most preferably not more than about 6.5 mm. A wound dressing (2.5 cm wide) of this invention preferably has an ultimate tensile breaking load of not less than 1 kg, more preferably at least 1.5 kg and most preferably at least 2.25 kg. This same dressing preferably has an ultimate elongation of at least 70%, more preferably at least 90% and most preferably at least 110%. The young's modulus of this dressing is preferably less than 5 MPa, more preferably less than 3 MPa and most preferably less than 1 MPa. The wound dressing preferably includes a supplemental traction surface which is particularly useful for the application of the wound dressing to a wound site which includes a significant amount of surface blood. The supplemental traction surface can comprise at least one outer surface which grips the wound site to avoid slipping of wound dressing, typically in a direction away from the wound site, during use. The supplemental traction surface is preferably in the form of a tread design. The subject wound dressing is preferably capable of forming an adhesive material in combination with blood flowing from said wound at the wound dressing-blood interface. In this case, the adhesive material preferably has a pH of not more than about 5.5, more preferably not more than about 4.5, more preferably not more than about 4, when the wound is sealed. Typical acids employed for purposes of adjusting the pH of the wound dressing are as follows: acetic acid, formic acid, lactic acid, ascorbic acid, hydrochloric acid and citric acid. The mole ratio of acid anion to glucosamine functional groups in the chitosan cation/anion pair to adjust the pH to the level described above is preferably about 0.90, more preferably about 0.75, and most preferably about 0.60. The wound dressing is preferably capable of being conformed to the configuration of the wound, for engagingly contacting the wound, and for facilitating stanching of the flow of the severe life-threatening bleeding. More particularly, the wound dressing is introduced into the interstices of the wound. More preferably, the wound dressing is capable of being conformed into a tubular configuration. Then, the reconfigured wound dressing is inserted into the wound. This invention also contemplates a method for controlling severe, life-threatening bleeding from a wound at a wound site of a person. The method comprises providing a wound dressing formed of a biomaterial comprising chitosan, adhering said wound dressing to the wound site and substantially stanching the flow of said severe life-threatening bleeding from said wound. Preferably, the wound is sealed and bleed out is prevented from said wound site. Also, bleeding and the flow of other fluids into and/or out of the said wound site are preferably prevented. It has been found that the dressing typically acts to rapidly produce a strong clot at the bleeding site by agglutinating red blood cels. It can also promote clotting by accelerating the normal platelet clotting pathway. A method can also be provided for producing a wound dressing capable of controlling severe, life-threatening bleeding from a wound at a wound site of a person. Such a method comprises the steps of providing a chitosan biomaterial as described above. Preferably, the chitosan biomaterial is degassed. Typically, degassing is removing sufficient residual gas from the chitosan biomaterial so that, on undergoing a subsequent freezing operation, the gas does not escape and form unwanted voids or trapped gas bubbles in the subject wound dressing product. The degassing step can be performed by heating a chitosan biomaterial, typically in the form of a solution, and then applying a vacuum thereto. For example, degassing can be performed by heating a chitosan solution to 60° C. immediately prior to applying vacuum at 500 mTorr for 5 minutes while agitating the solution. Next, the chitosan biomaterial, which is typically in solution form, is subjected to a freezing step. Freezing is preferably carried out by cooling the chitosan biomaterial solution and lowering the solution temperature from room temperature to a final temperature below the freezing point. In this way, the preferred structure of the wound-dressing product can be prepared. The final freezing temperature is preferably not more than about −10° C., more preferably not more than about −20° C., and most preferably not more than about −30° C. Preferably, the temperature is gradually lowered over a predetermined time period. For example, the freezing temperature of a chitosan biomaterial solution can be lowered from room temperature to −45° C. by application of a constant temperature cooling ramp of between −0.4° C./min to −0.8° C./min for a period of 90 minutes to 160 minutes. Preferably, the frozen chitosan biomaterial then undergoes water removal from within the interstices of the frozen material. This water removal step can be achieved without damaging the structural integrity of the frozen chitosan biomaterial. Typically, this is achieved without producing a substantial liquid phase which can disrupt the structural arrangement of the ultimate wound dressing. Thus, preferably, the chitosan biomaterial passes from a solid frozen phase into a gas phase without the substantial formation of an intermediate liquid phase. The preferred manner of implementing water removal is by employing a freeze-drying step. Freeze-drying of the frozen chitosan biomaterial can be conducted by further freezing the frozen chitosan biomaterial. Typically, a vacuum is then applied thereto. Next, it is preferred to heat the evacuated frozen chitosan material. Then, there can be a preferred step of drying the heated, evacuated, frozen chitosan material. More specifically, the frozen chitosan biomaterial can be subjected to subsequent freezing preferably at about −15° C., more preferably at about −25° C., and most preferably at about −45° C., for a preferred time period of at least about 1 hour, more preferably at least about 2 hour, and most preferably at least about 3 hour. This can be followed by cooling of the condenser to a temperature of less than about −45° C., more preferably at about −60° C., and most preferably at about −85° C. Next, a vacuum in the amount of preferably at most about 150 mTorr, more preferably at most about 100 mTorr, and most preferably at least about 50 mTorr, can be applied. Then, the evacuated frozen chitosan material can be heated preferably at about −25° C., more preferably at about −15° C., and most preferably at about −10° C., for a preferred time period of at least about 1 hour, more preferably at least about 5 hour, and most preferably at least about 10 hour. Finally drying can be conducted at preferably at a temperature of about 20° C., more preferably at about 15° C., and most preferably at about 10° C., for a preferred time period of at least about 36 hour, more preferably at least about 42 hour, and most preferably at least about 48 hour. Subsequently, the chitosan biomaterial as previously treated can be compressed, such as by using heated platens, to reduce the thickness and increase the density of said wound dressing. The compression temperature is preferably not less than 60° C., more preferably it is not less than 75° C. and not more than 85° C. Then, the pressed chitosan biomaterial is preferably preconditioned by heating same to a temperature of preferably up to about 75° C., more preferably to a temperature of up to about 80° C., and most preferably to a temperature of preferably up to about 85° C. Preconditioning is typically conducted for a period of time up to about 0.25 hours, preferably up to about 0.35 hours, more preferably up to about 0.45 hours, and most preferably up to about 0.50 hours, thereby increasing the adhesion strength and dissolution resistance of said wound dressing, as previously described above. The processed wound dressing can then be subjected to a sterilization step. The dressing can be sterilized by a number of methods. For example, a preferred method is by irradiation, such as by gamma irradiation, which can further enhance the blood dissolution resistance, the tensile properties and the adhesion properties of the wound dressing. The irradiation can be conducted at a level of at least about 5 kGy, more preferably a least about 10 kGy, and most preferably at least about 15 kGy. The sterilized wound dressing can be subsequently packaged for storage in a heat sealed pouch purged with an inert gas such as either argon or nitrogen gas. A wound dressing is produced from said chitosan biomaterial which is capable of substantially stanching the flow of severe life-threatening bleeding from a wound by adhering the wound dressing to the wound site. The wound dressing is preferably sealed to said wound and prevents bleed out from said wound site by adhering said wound dressing to said wound site employing clotting and agglutinating of the severe bleeding. This wound dressing preferably adheres strongly to the wound site, while clotting and agglutinating red blood cells from around the wound, so that pressure need only be employed preferably in the first five minutes of application. In one form of this invention, the device is designed to be a temporary dressing which is applied, even by unskilled practitioners, in order to keep the wounded person alive until expert medical intervention is possible. In certain applications, the dissolution rate of the subject wound dressing has been relatively slow compared to the agglutination rate, and this balance has produced good results (agglutination at high enough rate stops dissolution). Also it has demonstrated the importance of uniformity of the internal and surface structure of the wound dressing. If a substantial defect is present in the wound dressing, such as a channel caused by grain boundaries or minor cracking, then significant blood flow will channel its way along the defect and produce a highly undesirable bleed-through condition which can flush away the smaller less-viscous agglutination areas as they form. Also significant blood flow at pressure over the wafer surface appears to adversely affect wound adhesion of prior art wound dressing, but not the wound adhesion of the wound dressing of this invention. An important preferred attribute of this wound dressing herein is the means of combining the chitosan with the blood while achieving good mechanical integrity of the resultant “clot” and good binding of the clot to the surface immediately adjacent to the injury. The subject wound dressing preferably accelerates blood clot formation at the wound site, to reinforce clot formation at the wound site and prevent bleed out from the wound site, and to substantially prohibit the flow of blood and other fluids into and/or out of the wound site. The wound dressing of the present invention maintains it's extraordinary dual capability for clotting and adhesion to a wound site, as described above, while at the same time exhibiting a high level of resilience in an extreme environment. The exceptional resilience of this wound dressing is exemplified by the formidable physical properties thereof which are described herein. The subject wound dressing, unlike prior art products described above, also has an outstanding ability to conform to wound shape while maintaining structural resilience. This structural resilience is a capacity for the wound dressing to assume a preferred shape after deformation without any substantial loss of mechanical properties. The subject wound dressing, unlike prior art product described above, also has excellent structural memory. Structural memory comprehends the capacity of the wound dressing to substantially restore its previous shape after deformation. |
Device for delivering fixed quantity of liquid |
To deliver a liquid at high speed and with high accuracy. A device for delivering a fixed quantity of liquid, comprising a pump section for metering the delivered liquid to provide a desired amount consisting of a plunger chamber formed in a cylinder block, and a plunger reciprocating in the plunger chamber, a valve section for switching between liquid flow channels for suction and delivery, a reservoir section for reserving liquid adapted to communicate with the pump section depending upon the position of the valve section, and a delivery section having a delivery port for delivering liquid, the device being characterized in that the pump section and the valve section are disposed connected to each other and that the maximum advance position of the plunger is defined by a plane where the front end surface of the plunger contacts the valve section and pump section. The valve section is removably disposed in the pump section. The plunger chamber is made of a cylindrical chamber fitted in a hole formed in the cylinder block. The valve section is in the form of a switching valve provided with a valve block having a first flow channel communicating with a reservoir vessel and a second flow channel communicating with the delivery section. |
1. A device for delivering a fixed quantity of liquid, comprising a pump section for metering the delivered liquid to provide a desired amount, said pump section being consisted of a plunger chamber formed in a cylinder block and a plunger reciprocating in said plunger chamber, a valve section for switching between liquid flow channels for suction and delivery, a reservoir section for reserving the liquid and being communicable with said pump section depending upon the position of said valve section, and a delivery section having a delivery port for delivering the liquid, characterized in that said pump section and said valve section are disposed in an intimately joined relation, and that a maximum advance position of said plunger is defined by a plane where a fore end surface of said plunger contacts said valve section and said pump section. 2. A device for delivering a fixed quantity of liquid according to claim 1, wherein said valve section is installed removably from said pump section. 3. A device for delivering a fixed quantity of liquid according to claim 1, wherein said plunger chamber is defined by a cylindrical member fitted in a hole bored in said cylinder block. 4. A device for delivering a fixed quantity of liquid according to claim 1, wherein said valve section is in the form of a switching valve including a valve block provided with a first flow channel communicating with a reservoir vessel and a second flow channel communicating with said delivery section. 5. A device for delivering a fixed quantity of liquid according to claim 1, wherein said switching valve is a sliding switching valve. 6. A device for delivering a fixed quantity of liquid according to claim 1, wherein said switching valve is a rotary switching valve having a smooth sliding surface. 7. A device for delivering a fixed quantity of liquid according to claim 5, wherein said device includes a slide valve brought into close contact with said cylinder block under action of pressure. 8. A device for delivering a fixed quantity of liquid according to claim 1, wherein said device includes pressurizing means for pressurizing the liquid in a reservoir vessel. 9. A device for delivering a fixed quantity of liquid according to claim 1, wherein said device includes a plurality of pump sections, and a plurality of plungers constituting said pump sections are driven by one drive source. 10. A device for delivering a fixed quantity of liquid according to claim 1, wherein said device includes a plurality of pump sections, and a plurality of plungers constituting said pump sections are driven by drive sources independent of each other. 11. A device for delivering a fixed quantity of liquid according to claim 6, wherein said device includes a slide valve brought into close contact with said cylinder block under action of pressure. |
<SOH> BACKGROUND ART <EOH>Hitherto, various types of devices for delivering a fixed quantity of liquid have been developed; for example, (1) an air type delivering device in which compressed air is applied under regulated pressure to a liquid in a reservoir vessel for a predetermined time such that a desired amount of liquid is delivered through a delivery port at a nozzle fore end, (2) a plunger type delivering device in which a plunger is liquid-tightly disposed with respect to a liquid in a reservoir vessel and is moved to pressurize the liquid such that a desired amount of liquid is delivered through a delivery port at a nozzle fore end, and (3) a multi-plunger pump type delivering device having a mechanism in which a cylinder is disposed between a reservoir vessel and a nozzle, a plurality of penetration holes are formed in the cylinder and receive plungers in a one-to-one relation to be able to advance or retreat, and the liquid is sucked into the cylinder from the reservoir vessel with the retreat of the plunger and is delivered from the cylinder to the nozzle with the advance of the plunger, the plurality of plungers acting upon the liquid in sequence to pressurize the liquid such that a desired amount of liquid is delivered through a delivery port at a nozzle fore end. |
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a schematic view of Embodiment 1. FIG. 2 is an enlarged view of principal part of Embodiment 1. FIG. 3 is a schematic view of Embodiment 2. detailed-description description="Detailed Description" end="lead"? |
Chp for use as marker for sepsis-type inflammatory diseases |
Use of calcineurin B homologous protein (CHP) from body fluids or body tissues as a marker peptide for diagnosis, for prognosis and for monitoring the course of inflammations and infections and/or as a target for therapeutically influencing the course of inflammations and/or infections. |
1. Method for differential early diagnosis, diagnosis, prognosis, assessment of the severity, monitoring of the course of or therapy-accompanying assessment of the course of inflammations and/or infections in an animal or patient, comprising testing a biological fluid or a tissue sample from said animal or patient for the presence and/or amount of calcineurin B homologous protein (CHP) or a CHP fragment, wherein the presence and/or amount of said CHP or CHP fragment in said sample is indicative of the presence, severity, expected course or the success of the therapy for inflammations and/or infections. 2. Method according to claim 1, wherein the presence and/or amount of said CHP or CHP fragment in said sample is indicative of the presence, severity, expected course or the success of the therapy for sepsis, severe infections or sepsis-like systemic infections. 3. Method according to claim 1, wherein the presence and/or amount of a specific fragment of CHP is determined. 4. Method according to claim 1, wherein the presence and/or amount of said CHP or CHP fragment is determined by an immunodiagnostic method of determination. 5. Method for preventing, influencing the course of or treating inflammation, inflammatory diseases, infections, severe infections, sepsis, sepsis-like systemic infections or other stress reactions of the body, comprising administering to an animal or patient an effective amount of calcineurin B homologous protein (CHP). 6. Pharmaceutical composition comprising a pharmaceutically acceptable carrier and calcineurin B homologous protein (CHP), a functional CHP partial peptide or fragment thereof, processed CHP, CHP phosphorylated in a certain form, or an antibody produced against CHP, CHP partial peptides or fragments, processed CHP or CHP phosphorylated in a certain form. 7. Pharmaceutical composition according to claim 6, wherein said composition comprises an antibody produced against CHP, CHP partial peptides or fragments, processed CHP, or CHP phosphorylated in a certain form. 8. Method according to claim 3, wherein the specific fragment of CHP determined has the partial sequence of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:4 or SEQ ID NO:5. |
CHARACTERIZATION OF A MEMBRANE ESTROGEN RECEPTOR |
Abstract of the Disclosure The present invention discloses the identification of a novel membrane associated estrogen receptor, termed mER. The membrane associated receptor is involved in rapid signal transduction. Amino acid sequences, nucleic acid sequences, vectors, and host cells are also discussed. Additionally, methods of detecting agonists and antagonists for the receptor are disclosed herein. |
1. An isolated membrane estrogen receptor polypeptide, which membrane estrogen receptor polypeptide is present in a cellular P2 fraction, binds to an antibody specific for a nuclear ERα receptor antibody, and binds specifically to an estrogen compound. 2. The membrane estrogen receptor polypeptide of claim 1 wherein the estrogen compound is 17-β-estradiol or diethylstilbestrol. 3. The membrane receptor polypeptide of claim 1 or a fragment thereof, wherein the polypeptide or fragment has an apparent molecular weight of 67 kDa as determined by SDS-PAGE. 4. The membrane estrogen receptor polypeptide of claim 1 wherein the antibody is selected from the group consisting of ER21, H-184, H222, and MC-20. 5. The membrane estrogen receptor polypeptide of claim 1 wherein the receptor polypeptide is recognized by each of antibodies ER21, H-184, H222, and MC-20. 6. The membrane estrogen receptor polypeptide of claim 1 wherein the polypeptide is not recognized by nuclear ERα receptor antibody SRA1000. 7. The membrane estrogen receptor polypeptide of claim 1 wherein the membrane estrogen receptor polypeptide is not present in a cellular S2 fraction. 8. The membrane estrogen receptor polypeptide of claim 1 wherein binding of an estrogen compound to the receptor modulates calcium mobilization in a cell expressing the receptor. 9. An isolated membrane estrogen receptor polypeptide, which membrane estrogen receptor polypeptide is present in a cellular P2 fraction, binds to the nuclear ERα receptor antibodies ER21, H-184, H222, and MC-20, binds specifically to an estrogen compound, has an apparent molecular weight of 67 kDa, is not recognized by the nuclear ERα receptor antibody SRA1000 and is not present in the cellular S2 fraction. 10. A method for detecting a membrane estrogen receptor polypeptide, which method comprises detecting binding of a nuclear ERα receptor antibody to a polypeptide present in a membrane of a cell, wherein detection of such binding indicates the presence of a membrane estrogen receptor. 11. The method according to claim 10, wherein the membrane estrogen receptor is detected in a P2 cellular fraction. 12. The method according to claim 10, wherein the membrane estrogen receptor is detected in an intact cell. 13. The method of claim 10, wherein the nuclear ERα receptor antibody is selected from the group consisting of ER21, H-184, H222, and MC-20. 14. A method for detecting the membrane estrogen receptor polypeptide of claim 1, which method comprises detecting binding of an estrogen compound to a polypeptide in a sample containing the P2 cellular fraction, wherein detection of such binding indicates the presence of a membrane estrogen receptor polypeptide. 15. The method of claim 14 wherein the estrogen compound is 17-β-estradiol or diethylstilbestrol. 16. A method for identifying a compound that binds the membrane estrogen receptor of claim 1, which method comprises detecting binding of a test compound contacted with a cellular P2 fraction comprising a membrane estrogen receptor wherein binding of the test compound indicates that the test compound binds to the membrane estrogen receptor. 17. The method according to claim 16, wherein detection of binding of the test compound comprises detecting inhibition of binding of an estrogen compound to the cellular P2 fraction. 18. A method for identifying a compound that modulates the membrane estrogen receptor of claim 1, which method comprises detecting calcium mobilization in a cell comprising a membrane estrogen receptor contacted with a test compound, wherein mobilization of calcium indicates that the test compound binds the membrane estrogen receptor. 19. The method according to claim 18, which further comprises detecting genomic estrogen receptor activity; wherein alteration of genomic activity in the presence of the test compound indicates that the compound does not selectively modulate the membrane estrogen receptor. 20. A method of screening for an antagonist of the membrane estrogen receptor polypeptide of claim 1, which method comprises (i) contacting a cell that expresses the membrane estrogen receptor polypeptide of claim 1 with a test compound and an estrogen compound and (ii) detecting decreased calcium mobilization compared to contacting the cell with the estrogen compound alone. |
<SOH> BACKGROUND OF THE INVENTION <EOH>The physiological response to steroid hormones is proposed to be mediated by specific interaction of steroids with nuclear receptors. These receptors are part of a larger family of ligand-activated transcription factors that regulate the expression of target genes. Two different nuclear estrogen receptors have been identified to date and they are designated ERα and ERβ. These receptors consist (in an aminoterminal-to-carboxyterminal direction) of a hypervariable aminoterminal domain that contributes to the transactivation function; a highly conserved DNA-binding domain responsible for receptor dimerization and specific DNA binding; and a carboxyterminal domain involved in ligand-binding, nuclear localization, and ligand-dependent transactivation. Recently, estrogen and estrogen compounds have also been shown to induce very rapid changes in physiological activity in certain cell types. These changes can occur within minutes and therefore cannot be mediated through the classical genomic mechanism that causes changes in gene transcription. Rapid responses to estrogen are thought to be mediated via a non-genomic mechanism that can include stimulation of nitric oxide production in pulmonary endothelial cells (Russell et al. Proc. Natl. Acad. Sci. U.S.A., 97, 5930, 2000), and increased activation of mitogen-activated protein kinase in neuronal cells (Singer et al., Journal of Neuroscience, 19, 2455, 1999), osteoblasts (Kousteni, et al., Cell, 104, 719, 2001), and breast cancer cells (Razandi et al. , Molecular Endocrinology, 14, 1434, 2000). The genomic effects of estrogen and estrogen compounds is mediated through the estrogen receptor (ER) complex (ER receptor and ligand) which binds to DNA, triggering mRNA synthesis and subsequently, protein synthesis. Little, however, is known about the molecular basis of the non-genomic actions of estrogen and estrogen compounds. This diversity of effects can only partially be explained by our current understanding of ER structure and function. Previous models of ER interactions can be used to understand the slower, genomic signaling pathways by estrogen. However, these models fail to explain the rapid signaling effects now reported for the ER complex. These rapid effects of estrogens do not fit the classic concept of nuclear localization and genomic regulation by the ER complex. However, in some systems, activation of estrogen-induced signaling pathways can be blocked by the same synthetic ER antagonists that block transcriptional activation by classical ER (Aronica, et al. , Proc. Natl. Acad. Sci. U.S.A., 91, 8517, 1994). It has been suggested that the non-genomic actions of estrogen may be mediated by a plasma membrane estrogen receptor (mER). Membrane binding sites for 17-β-estradiol (E2) have been identified in several areas such as the brain, uterus, and liver; and various signal pathways have been implicated. |
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention contemplates an isolated membrane estrogen receptor polypeptide, which membrane estrogen receptor polypeptide is present in a cellular P2 fraction, binds to an antibody specific for a nuclear ERα receptor antibody and binds specifically to an estrogen compound. In an embodiment, the receptor polypeptide is recognized by each of antibodies ER21, H-184, H222, and MC-20. In yet another embodiment, the estrogen compound is 17-β-estradiol or diethylstilbestrol. In one embodiment, the antibody is selected from the group consisting of ER21, H-184, H222, and MC-20. In an additional embodiment, binding of an estrogen compound to the receptor modulates calcium mobilization. In another embodiment, the membrane estrogen receptor polypeptide or a fragment thereof has an apparent molecular weight of 67 kDa as determined by SDS-PAGE. Additionally, the present invention contemplates the receptor polypeptide wherein the polypeptide is not recognized by the ERα receptor antibody SRA1000. In a further embodiment, the membrane estrogen receptor polypeptide is not present in the cellular S2 fraction. The present invention also contemplates an isolated membrane estrogen receptor polypeptide, which membrane estrogen receptor polypeptide is present in a cellular P2 fraction, binds to the nuclear ERα receptor antibodies ER21, H-184, H222, and MC-20, binds specifically to an estrogen compound, has an apparent molecular weight of 67 kDa, is not recognized by the nuclear ERα receptor antibody SRA1000 and is not present in the cellular S2 fraction. The present invention also contemplates a method for detecting a membrane estrogen receptor polypeptide, which method comprises detecting binding of a nuclear ERα receptor antibody to a polypeptide present in a membrane of a cell. In one embodiment, the membrane estrogen receptor polypeptide is detected in the P2 cellular fraction. In another embodiment, the membrane estrogen receptor polypeptide is detected in an intact cell. In yet another embodiment, the nuclear ERα receptor antibody is selected from the group consisting of ER21, H-184, H222, and MC-20. The present invention further contemplates a method for detecting a membrane estrogen receptor polypeptide, wherein the polypeptide is detected upon binding of an estrogen compound to a polypeptide in a sample containing the P2 cellular fraction. In one embodiment, the estrogen compound is 17-β-estradiol or diethylstilbestrol. The present invention further contemplates a method for identifying a compound that binds the membrane estrogen receptor polypeptide, which method comprises detecting binding of a test compound contacted with a cellular P2 fraction wherein binding of the test compound indicates that the test compound binds to the membrane estrogen receptor. In one embodiment, detection of binding of the test compound comprises detecting inhibition of binding of an estrogen compound to the cellular P2 fraction. The present invention also contemplates a method for identifying a compound that modulates a membrane estrogen receptor polypeptide, which method comprises detecting calcium mobilization in a cell comprising a membrane estrogen receptor polypeptide contacted with a test compound. In one embodiment, the method for identifying a compound that modulates the polypeptide comprises detecting genomic estrogen receptor activity wherein alteration of genomic activity in the presence of the test compound indicates that the compound does not selectively modulate the polypeptide. The present invention also contemplates a method of screening for an antagonist of a membrane estrogen receptor polypeptide, which method comprises (i) contacting a cell that expresses the polypeptide with a test compound and an estrogen compound and (ii) detecting decreased calcium mobilization compared to contacting the cell with the estrogen compound alone. |
Synergistic combinations of nano-scaled fillers and hindered amine light stabilizers |
Polymer compositions comprising a polymeric substrate and an effective stabilizing amount of a synergistic mixture of a nano-scaled filler and at least one additive selected from the group consisting of the hindered amine light stabilizers are effectively stabilized against the deleterious effects of oxidative, thermal or light-induced degradation. |
1. A polymer composition, stabilized against the deleterious effects of oxidative, thermal or light-induced degradation, which composition comprises (a) a polymer substrate, (b) at least one nano-scaled filler, and (c) at least one additive selected from the group consisting of the hindered amine light stabilizers. 2. A composition according to claim 1, wherein the filler is an organophilic phyllosilicate, a naturally occuring phyllosilicate, a synthetic phyllosilicate or a mixture of such phyllosilicates. 3. A composition according to claim 1, in which component (b) is present in an amount of 0.5 to 10% by weight, based on the weight of component (a). 4. A composition according to claim 1, in which the hindered amine light stabilizers of component (c) are selected from the group consisting of hindered amine light stabilizers substituted on the N-atom by an alkoxy or cycloalkoxy moiety, hindered amines substituted on the N-atom by an alkoxy which is further substituted with an hydroxy group, and conventional hindered amines where the N-atom is substituted by hydrogen, alkyl or acyl. 5. A composition according to claim 1, in which component (c) is a 1:1 mixture of bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate and the polycondensation product of 2,4-dichloro-6-tert-octylamino-s-triazine and 4,4′-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine). 6. A composition according to claim 1, in which component (c) is present in an amount of 0.01 to 10% by weight, based on the weight of component (a). 7. A composition according to claim 1, further comprising (d) at least one additive selected from the group consisting of additional hindered amine light stabilizers, ultraviolet light absorbers, phenolic antioxidants, organic phosphorus stabilizers, aminic antioxidants, hydroxylamine stabilizers, nitrone stabilizers, benzofuranone stabilizers and amine oxide stabilizers. 8. A process for effectively stabilizing a polymeric substrate subject to the deleterious effects of oxidative, thermal or light-induced degradation, which process comprises incorporating therein an effective stabilizing amount of (b) at least one nano-scaled filler and (c) at least one additive selected from the groups consisting of the hindered amine light stabilizers. 9. A flame retardant polymer composition which comprises (a) a polymer substrate, (b) at least one nano-scaled filler, and (c) at least one compound selected from the group consisting of hindered amine stabilizers substituted on the N-atom by an alkoxy, hindered amine stabilizers substituted on the N-atom by a cycloalkoxy moiety, and hindered amine stabilizers substituted on the N-atom by an alkoxy which is further substituted with an hydroxy group. 10. A flame retardant composition according to claim 9, further comprising (d) at least one compound selected from the group consisting of brominated flame retardants, phosphorus containing flame retardants and inorganic flame retardants. 11. A composition comprising (a) at least one ethylenically unsaturated polymerizable compound or cationically polymerizable compound, (b) at least one nano-scaled fille, and (c) at least one photoinitiator suitable for curing ethylenically unsaturated polymerizable compounds or cationically polymerizable compounds. 12. A process for curing ethylenically unsaturated polymerizable compounds or cationically polymerizable compounds, which process comprises adding to said compounds (b) at least one nano-scaled filler, and (c) at least one photoinitiator suitable for curing ethylenically unsaturated polymerizable compounds or cationically polymerizable compounds, and irradiating the mixture so obtained with ultraviolet radiation or daylight or with light sources equivalent to daylight. |
Thin film optical detectors for retinal implantation and methods for making and using same |
The present invention provides a method for capturing optical micro detectors for improved surgical handling during implantation into an eye comprising the steps of providing an optically active thin film heterostructure on a soluble substrate; forming an array comprising individual optical microdetectors from the optically active thin film heterostructure; attaching the optical microdetector array onto a biodegradable polymer carrier membrane; and separating the optical microdetector array attached to the biodegradable polymer carrier membrane from the soluble substrate thereby capturing the optical microdetectors in the bio-polymer carrier membrane for improved handling of the optical micro-detectors during transfer and implantation into the eye. |
1. A method for capturing optical microdetectors for improved surgical handling during implantation into an eye comprising the steps of: providing an optically active thin film heterostructure on a removable substrate; forming an array comprising individual optical microdetectors from the optically active thin film heterostructure; attaching the optical microdetector array onto a biodegradable polymer carrier membrane; and separating the optical microdetector array attached to the biodegradable polymer carrier membrane from the removable substrate to form an implant comprising an array of microdetectors in or one a biodegradable bio-polymer carrier for improved surgical handling of the optical micro-detectors during implantation into the eye. 2. The method of claim 1, wherein said substrate is selected from the group consisting of magnesium oxide potassium bromide, potassium chloride, any other soluable substrate and mixtures or combinations thereof. 3. The method of claim 1, wherein the optically active heterostructure comprises a bottom electrode layer and an optically active layer thereon, where the bottom electrode layer comprises platinum, gold, LaSrCoO3, RuO2, or IrO2 doped CeO2 or mixtures or combinations thereof and where the optically active layer comprises an oxide or a nitride. 4. The method of claim 3, wherein the optically active oxide or nitride layer is selected from the group consisting of ferroelectric Perovskite oxides including PbZrTiO3, BaTiO3, BaSrTiO3, or ZnO, BiVMgO3, GaN, BN, and mixtures or combinations thereof. 5. The method of claim 4, wherein the perovskite is doped and is PbZrTiO3 wherein the dopant comprises La, Nb, Sb, Mn, or Ca or mixtures or combinations thereof. 6. The method of claim 3, wherein the optically active heterostructure further comprises a top electrode comprising platinum, gold, LaSrCoO3, RuO2, IrO2 doped CeO2, or other conducting oxide or mixtures or combinations thereof. 7. The method of claim 1, wherein the biodegradable polymer is polyglycolic acid, poly-1-lactide, poly-dl-lactide, caprolactane, dl-lactic-co-glycolic-acid or other co-polymers thereof or mixtures or combinations thereof. 8. The method of claim 1, wherein forming the array of individual optical microdetectors on the heterostructure comprises the steps of: patterning the array onto the heterostructure using negative or positive photoresist lithography; and removing areas of the heterostructure not patterned during the negative photoresist lithography or patterned during the positive photoresist lithography by ion milling thereby leaving the array of optical microdetectors on the substrate. 9. The method of claim 8, wherein each microdetector in the array has a diameter of about 5 microns to about 500 microns. 10. The method of claim 1, wherein attaching the optical microdetector array onto the biodegradable polymer carrier membrane comprises the steps of: pressing a layer of the biodegradable polymer carrier membrane onto the optical microdetector array; and wet etching or dry etching the substrate under conditions wherein the optical microdetector array is removed from the substrate such that the optical microdetector array is attached to the biodegradable polymer carrier membrane layer. 11. The method of claim 10, wherein the biodegradable polymer carrier membrane layer is pressed at a pressure of from 2000 Kg to about 2500 Kg and at a temperature of about 50° C. to about 85° C. and the biodegradable polymer carrier membrane layer is less than about 300 microns thick. 12. The method of claim 10, wherein the biodegradable polymer carrier membrane layer is formed by melting or liquefying the polymer, using standard spin-on techniques to coat the microdetectors and solidification to a biodegradable polymer carrier membrane layer less than about 200 microns thick. 13. The method of claim 10, wherein the conditions comprise wet etching in an about 20% by volume hydrochloric acid solution for about 24 hours to about 8 hours at room temperature. 14. A method for capturing optical microdetectors for improved surgical handling during implantation into an eye comprising the steps of: forming an optically active thin film heterostructure deposited on a removable support, where the heterostructure comprises a conductive layer and an optically active layer formed on top of the conductive layer; patterning an array of microdetectors on the heterostructure using negative photoresist lithography; removing those areas of the heterostructure not patterned during the negative photoresist lithography by ion milling to form an array of optical microdetectors on the substrate, where each microdetector has a diameter of about 5 microns to about 500 microns; forming a biodegradable carrierr layer on top of the array, where the bio-polymer is less than about 500 microns thick; and removing the substrate to form a retinal implant comprising an array of micro detectors on or in the carrier, where the implant has improved surgical handling characteristic for implantation into the subretinal region of an eye of an animal including a human. 15. The method of claim 13, wherein the active heterostructure further comprises a top conducting layer. 16. A method of surgically implanting optical microdetectors into an eye comprising the steps of: providing an implant comprising an array of optical microdetectors on or in a biodegradable carrier; implanting the implant into a subretinal implantation site on the eye; and biodegrading the carrier so that the optical microdetectors are surgically implanted at the site in a proper orientation and array configuration within the site, where the microdetectors are capable of converting light energy into electrical energy sufficient to activate at least one bipolar cell at the implantation site. 17. A method of converting light energy into electrical energy using an implant implanted in a retinal site of an eye of an animal including a human comprising the steps of: providing an implant comprising an array of optical microdetectors on or in a biodegradable carrier; implanting the implant into a subretinal implantation site on the eye; and biodegrading the carrier so that the optical microdetectors are surgically implanted at the site in a proper orientation and array configuration within the site, converting light energy absorbed by the microdetectors into electrical energy sufficient to activate at least one bipolar cell at the implantation site; communicating the activation to an optical center of a brain of the animal; and producing an optical response or sight. 18. An implant for communicating optical information to retinal neurons in an animal including a human, where the implant comprises a bio-erodible carrier and an optically active, thin film, heterostructure optical microdetector, where the microdetector is adapted to convert light energy into electrical energy sufficient to activate at least one bipolar cell of a retinal site resulting in the communication of optical information to retinal neurons for transmission to an optical center of the brain of the animal. 19. An implant for communicating optical information to retinal neurons in an animal including a human, where the implant comprises a bio-erodible carrier and a plurality of optically active, thin film heterostructure optical microdetectors, where each microdetector converts light energy into electrical energy sufficient to activate bipolar cells of a retinal site, thus communicating optical information to retinal neurons for transmission to the brain. 20. An implant for communicating optical information to retinal neurons in an animal including a human, where the implant comprising a bio-erodible carrier and a patterned plurality of optically active, thin film heterostructure optical microdetectors, where each microdetector converts light energy into electrical energy sufficient to activate bipolar cells of a retinal site for transmission of the optical information to the brain and where the pattern is designed to mimic a pattern of cones and/or rods in the retinal site. 21. An implant for communicating optical information to retinal neurons in an animal including a human, where the implant comprising a bio-erodible carrier and a patterned plurality of optically active, thin film heterostructure optical microdetectors, where the patterned microdetectors converts light energy into electrical energy sufficient to activate bipolar cells of a retinal site in a manner similar to how the cones and/or rods activate the bipolar cells in the retina. 22. An implant for communicating optical information to retinal neurons in an animal including a human, where the implant comprising a bio-erodible carrier including a first plurality of optically active, thin film heterostructure optical microdetectors sensitive to light in a low energy range or red range of the visible light energy range of the electromagnetic spectrum (RMDs), a second plurality of optically active, thin film heterostructure optical microdetectors sensitive to light in a medium energy range or green range of the visible light energy range of the electromagnetic spectrum (GMDs), a third plurality of optically active, thin film heterostructure optical microdetectors sensitive to light in a high energy range or blue range of the visible light energy range of the electromagnetic spectrum (BMDs), where the three microdetectors are arranged in a pattern with distributions of RMDs, GMDs and BMDs similar to a red, green, blue cone cell distributions in a retinal site into which the implant is to be implanted and where each microdetector converts light energy into electrical energy sufficient to activate bipolar cells in the retinal site in a manner similar to how the cones and/or rods activate the bipolar cells in the retina. 23. A method for capturing optical microdetectors in an implant for improved surgical handling during implantation into an eye comprising the steps of: (1) forming an optically active thin film heterostructure on a top surface of a removable substrate; (2) patterning the thin film heterostructure to form an array comprising individual optically active, thin film, heterostructure microdetectors; (3) contacting the top surface of the substrate with the array thereon with a biodegradable polymer carrier; and (4) removing the removable substrate to form an implant comprising an array of optical microdetectors in a biodegradable polymer carrier, where the implant has improved surgical handling characteristics for implantation into the eye, where the heterostructure comprises a uniform composition or the heterostructure comprises a pattern of different compositions, each composition absorbing light in a different region of the visible light spectrum. 24. The method of claim 22, wherein the compositions include a red sensitive composition, a green sensitive composition and a blue sensitive compositions. 25. The method of claim 23, wherein compositions are distributed in manner similar to the distribution of red, green and blue cone cells in the retina of an animal that have color vision. 26. A method for capturing optical microdetectors in a structure that allows for improved handling during transfer and implantation into an eye comprising the steps of: (1) depositing a conductive layer on a top surface of a removable substrate; (2) forming a first pattern on a surface of conductive layer using positive or negative photoresist lithograph; (3) depositing a first optically active material on exposed regions of the conductive layer to form a first thin film heterostructure of the top surface of the substrate, where the first heterostructure comprises the conductive layer and the first optically active layer and the first material is sensitive to light in a first region of the electromagnetic spectrum; (4) forming a second pattern on a surface of conductive layer using positive or negative photoresist lithograph; (5) depositing a second optically active material on exposed regions of the conductive layer to form a second thin film heterostructure of the top surface of the substrate, where the second heterostructure comprises the conductive layer and the second optically active layer and the second material is sensitive to light in a second region of the electromagnetic spectrum; (6) forming a second pattern on a surface of conductive layer using positive or negative photoresist lithograph; (7) depositing a third optically active material on exposed regions of the conductive layer to form a third thin film heterostructure of the top surface of the substrate, where the third heterostructure comprises the conductive layer and the third optically active layer and the third material is sensitive to light in a third region of the electromagnetic spectrum; (8) patterning the heterostructure using negative photoresist lithography to form a patterned heterostructure; (9) removing those areas of the heterostructure not patterned during the negative photoresist lithography to form an array of optical active microdetectors comprising pluralities of microdetectors composed of each of the three heterostructures on the top surface of the substrate; (10) forming a biodegradable polymer film onto the top surface of the substrate including the optical microdetector array thereon to secure each microdetector in the array to or in the film; and (11) removing the substrate to form an implant comprising an array of optical microdetectors in a biodegradable polymer carrier, where the implant has improved surgical handling characteristics for implantation into the eye. 27. The method of claim 25, wherein three optical region comprises a red, green and blue regions so that the heterostructures correspond to red, green and blue cone cells. 28. The method of claim 25, wherein the three patterns are constructed so that the distribution of red, green, and blue regions mimic the distribution found in the region of the retina in which the implant is intended. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to medical optically active implants to treat blindness and method for implanting these implants into an animal including a human to allow detection of visible light by the blind or to repair damaged areas of the retina to allow the animal to retain visual acuity in the damages areas. More particularly, the present invention relates to an implant including an array of optical microdetectors supported on or in a bio-absorbable substrate, where the microdetectors comprise a heterostructure. The present invention also relates to a method for making the implant, to a method for implanting the implant in an animal including a human and to methods for treating blindness, for replacing damaged retinal photo sensors and for ameliorating symptoms of diseases of the eye such as Retinitis Pigmentosa (RP) and Age-related Macular degeneration (AMD). 2. Description of the Related Art Recent efforts on external stimulation of retinal neuronal cells with electrical signals have resulted in visual brain sensation [1,3]. Several reports have established that stimulation of retinal neuronal cells with electrical signals can result in visual perception [2,15]. In view of this phenomenon, different approaches have been undertaken in order to restore the vision of a retinally blind person. This has been accomplished by either direct stimulation of the retina or direct retinal implant of an optical detector to stimulate retinal neuronal cells in a patient whose optical detectors are damaged [9,10,11,15]. Both epiretinal electrical stimulation [9,10] and retinal stimulation with implants placed in the subretinal space [11,15] have been investigated. The implants can consist of an encapsulated micro-photodiode array with thousands of micro-contacts for localized electrical stimulation of the bipolar cells in the subretinal approach [11,15], or they can use external processing of visual information before it is sent to implanted electrodes in the epiretinal or subretinal space [9,10]. The latter systems utilize video cameras that capture the image and convert it to an electrical signal. The electrical signal is coded, then sent as telemetry to an implant receiver that decodes the signal and generates the desired current to stimulate retinal neurons. By using a thin film optical device (TOD), it has been demonstrated that thin films of certain perovskite ferroelectric oxides show optical activities in the visible range of the electromagnetic spectrum [12]. These ceramic ferroelectric films are also shown to be stable in aqueous, basic or acidic solutions for long periods of time; while other photodetectors based on semiconductors require encapsulation and wire interconnects for integration into the eye. Human photoreceptor topography studies indicate that the photoreceptors are in the shape of cones and rods, with different densities in different parts of the retina [4,5]. The photoreceptors are nominally hexagonally close-packed with receptor size varying between 2 to 5 microns. Tissue or organ engineering develops functional devices such as microdetectors to substitute for the missing or malfunctioning tissues or organs in the human body. Bio-resorbable polymers that are fully degradable into the body's natural metabolites by simple hydrolysis under physiological conditions are the most desirable materials for the carrier of such functional substitutes in the human body. Biodegradable polymers are well known as bio-materials for applications in cell transplantation and drug delivery [6,7]. In vitro dissolution of thin layers made from these polymers in simulated body fluid has been characterized in terms of film thickness, molecular weight and time of degradation [7,8]. Among these materials, poly (dl-lactic-co-glycolic acid) (PLGA) polymers have been widely utilized as a template for tissue and cell transplantation. This strategy is widely used and investigated for transplantation of many cells including retinal pigment epithelium (RPE). The disadvantage associated with these polymers is the time it takes to degrade which depends on the nature and, also, the thickness of the polymer. Even though small microdetectors or other type of microdevices can be constructed using modem electronic fabrication techniques, the small size of such microdevices, which could approach the 5 micron size of human photo sensors, make the detector verifiably impossible to handle for individually implantation of such microdevices by current surgical techniques. Thus, surgical implantation is problematic for any micro-implantation of small devices, tissues or cell cultures. Despite complex engineering issues, these different approaches for restoring vision in retinally blind people have led to encouraging preliminary results [2,15]. However, several questions need to be answered in order to better define the parameters influencing the optimal performance of such artificial retinas such as sensitivity, long-term stability, and the degree of spatial resolution that might be achieved by these devices. Moreover, the design of reliable and reasonably safe surgical procedures for implantation as well as biocompatibility and long term function of implanted devices still remain in the forefront of ongoing investigations. The prior art is deficient in the lack of effective means of forming a surgically manipulable optical implant for replacement of damagee retinal photo sensor or for allowing the sightless to see. More specifically, the prior art is deficient in the lack of effective means for handling arrays of optical microdetector devices for implantation into the retina of the eye and for means of making suitable implants for implantation into the retina of an animal. Thus, there is a need in the art for implants that can be handled using standard surgical techniques, for implants that include optical detectors distributed in a similar manner to the photoreceptors of an animal including a human eye and to methods for making such implants and implanting such implants. |
<SOH> SUMMARY OF THE INVENTION <EOH>Implants The present invention provides an implant for communicating optical information to retinal neurons in an animal including a human, where the implant includes a bio-erodible carrier and an optically active, thin film, heterostructure optical microdetector, where the microdetector converts light energy into electrical energy sufficient to activate at least one bipolar cell of a retinal site, thus communicating optical information to retinal neurons for transmission to the brain. The term optical information means light of a sufficient intensity within a spectral range detectable by the microdetector. The present invention also provides an implant for communicating optical information to retinal neurons in an animal including a human, where the implant includes a bio-erodible carrier and a plurality of optically active, thin film heterostructure optical microdetectors, where each microdetector converts light energy into electrical energy sufficient to activate bipolar cells of a retinal site, thus communicating optical information to retinal neurons for transmission to the brain. The present invention also provides an implant for communicating optical information to retinal neuronal cells in an animal including a human, where the implant includes a bio-erodible carrier and a patterned plurality of optically active, thin film heterostructure optical microdetectors, where each microdetector converts light energy into electrical energy sufficient to activate bipolar cells of a retinal site for transmission of the optical information to the brain and where the pattern is designed to mimic a pattern of cones and/or rods in the retinal site. The present invention also provides an implant for communicating optical information to retinal neurons in an animal including a human, where the implant includes a bio-erodible carrier and a patterned plurality of optically active, thin film heterostructure optical microdetectors, where the patterned microdetectors converts light energy into electrical energy sufficient to activate bipolar cells of a retinal site in a manner similar to how the cones and/or rods activate the bipolar cells in the retina The present invention also provides an implant for communicating optical information to retinal neurons in an animal including a human, where the implant includes a bio-erodible carrier including a first plurality of optically active, thin film heterostructure optical microdetectors sensitive to light in a low energy range or red range of the visible light energy range of the electromagnetic spectrum (RMDs), a second plurality of optically active, thin film heterostructure optical microdetectors sensitive to light in a medium energy range or green range of the visible light energy range of the electromagnetic spectrum (GMDs), a third plurality of optically active, thin film heterostructure optical microdetectors sensitive to light in a high energy range or blue range of the visible light energy range of the electromagnetic spectrum (BMDs), where the three microdetectors are arranged in a pattern with distributions of RMDs, GMDs and BMDs similar to a red, green, blue cone cell distributions in a retinal site into which the implant is to be implanted and where each microdetector converts light energy into electrical energy sufficient to activate bipolar cells in the retinal site. Method for Making the Implants The present invention provides a method for capturing optical microdetectors in an implant for improved surgical handling during implantation into an eye comprising the steps of: (1) forming an optically active thin film heterostructure on a top surface of a removable substrate; (2) patterning the thin film heterostructure to form an array comprising individual optically active, thin film, heterostructure microdetectors; (3) contacting the top surface of the substrate with the array thereon with a biodegradable polymer carrier; and (4) removing the removable substrate to form an implant comprising an array of optical microdetectors in a biodegradable polymer carrier, where the implant has improved surgical handling characteristics for implantation into the eye. The heterostructure can comprise a uniform composition or the heterostructure can comprise a pattern of different compositions, each composition absorbing light in a different region of the visible light spectrum. Preferably, the compositions include a red sensitive composition, a green sensitive composition and a blue sensitive compositions. The preferred distribution of compositions is a distribution that is similar to the distribution of red, green and blue sensitive cone cells in the retina of an animal that has color vision. The present invention also provides a method for capturing optical microdetectors in an implant for improved surgical handling during implantation into an eye comprising the steps of: (1) depositing a conductive layer on a top surface of a removable substrate; (2) forming a first pattern on a surface of conductive layer using positive or negative photoresist lithograph; (3) depositing a first optically active material on exposed regions of the conductive layer to form a first thin film heterostructure of the top surface of the substrate, where the first heterostructure comprises the conductive layer and the first optically active layer and the first material is sensitive to light in a first region of the electromagnetic spectrum; (4) forming a second pattern on a surface of conductive layer using positive or negative photoresist lithograph; (5) depositing a second optically active material on exposed regions of the conductive layer to form a second thin film heterostructure of the top surface of the substrate, where the second heterostructure comprises the conductive layer and the second optically active layer and the second material is sensitive to light in a second region of the electromagnetic spectrum; (6) forming a second pattern on a surface of conductive layer using positive or negative photoresist lithograph; (7) depositing a third optically active material on exposed regions of the conductive layer to form a third thin film heterostructure of the top surface of the substrate, where the third heterostructure comprises the conductive layer and the third optically active layer and the third material is sensitive to light in a third region of the electromagnetic spectrum; (8) patterning the heterostructure using negative or positive photoresist lithography to form a patterned heterostructure; (9) removing those areas of the heterostructure not patterned during the negative or positive photoresist lithography to form an array of optical active microdetectors comprising pluralities of microdetectors composed of each of the three heterostructures on the top surface of the substrate; (10) forming a biodegradable polymer film onto the top surface of the substrate including the optical microdetector array thereon to secure each microdetector in the array to or in the film; and (11) removing the substrate to form an implant comprising an array of optical microdetectors in a biodegradable polymer carrier, where the implant has improved surgical handling characteristics for implantation into the eye. The three optical region can comprises a red, green and blue regions so that the heterostructures correspond to red, green and blue cone cells. Moreover, the three patterns can be constructed so that the distribution of red, green, and blue regions mimic the distribution found in the region of the retina in which the implant is intended. It should be obvious to an ordinary artisan that the formation of different optically active oxide layers to make different microdetectors can include additional compositions to allow detection of light in other regions of the electromagnetic spectrum. Implanting the Implants The present invention also provides a method for surgically implanting an optical implant into an eye of an animal including a human, the method comprising the steps of: implanting the optical implant of this invention at an implantation site in the eye so that the array of optical microdetectors within the implant are positioned to come into electrical contact with bipolar cells associated with the implant site after biodegradation of the biodegradable polymer carrier. Other and further aspects, features, and advantages of the present invention will be apparent from the following description of the presently preferred embodiments of the invention given for the purpose of disclosure. |
Device for wavelength conversion or optical computing |
When forming a periodically-poled structure on a nonlinear optical crystal 1 that permits wavelength conversion and/or optical computing, the group velocity matching conditions are determined to synchronize the group velocity of the incident light L1 with that of the outgoing light L2, and the polarization reversal period of the periodically-poled structure is determined to satisfy quasi-phase matching conditions for the aforementioned wavelength conversion and/or optical computing. As a result, the problems associated with wavelength conversion of the pulsed light due to difference in the group velocity are suppressed pulsed light and a preferable element for wavelength conversion and optical computing can be provided. |
1. An element for wavelength conversion or optical computing, which is a poled structure element comprising a periodically-poled structure formed on a nonlinear optical crystal, thereby to convert an incident light to an outgoing light by wavelength conversion and/or optical computing, wherein group velocity matching conditions are determined to synchronize the group velocity of the incident light with that of the outgoing light, and a polarization reversal period of the periodically-poled structure has been determined to satisfy quasi-phase matching conditions for the aforementioned wavelength conversion and/or optical computing. 2. The element of claim 1, wherein the nonlinear optical crystal is MgO doped LiNbO3. 3. The element of claim 1, wherein a nonlinear optical constant of the nonlinear optical crystal used to satisfy the above-mentioned quasi-phase matching conditions is an off-diagonal component of d tensor. 4. The element of claim 3, wherein the off-diagonal component of the d tensor is d31. 5. The element of claim 1, wherein the wavelength conversion and/or optical computing are/is performed by second harmonic generation, optical parametric oscillation, optical parametric generation, sum-frequency generation or difference frequency generation. 6. The element of claim 1, wherein the incident light is in a pulse train having a pulse width of 1 ps or below. |
<SOH> BACKGROUND ART <EOH>Nonlinear optical crystals such as LiNbO 3 , LiTaO 3 and the like have been preferably used as materials of elements used for wavelength conversion such as second harmonic generation (SHG), optical parametric oscillation, optical parametric generation (including amplification), difference frequency generation, sum-frequency generation and the like. As a means for satisfying the phase matching conditions for such wavelength conversion, quasi-phase matching (QPM) including formation of a periodically-poled structure (hereinafter to be also referred to as a “poled structure”) on a nonlinear optical crystal has been actively conducted in recent years. The quasi-phase matching is described in detail in, for example, a publication, Optical Second Harmonic Generation and Polarization Reversal, Kurimura, Solid-State Physics, 29(1994) 75-82) and the like. As shown in FIG. 2 , a poled structure element (wavelength conversion element) is an element wherein the polarizational direction (z direction in the Figure) of a nonlinear optical crystal 10 is periodically reversed (i.e., nonlinear optical constant has been modulated) to achieve a high wavelength conversion efficiency, and the nonlinear optical constant to be utilized is exclusively d 33 , because its value is the highest. That the nonlinear optical constant d 33 can be used is the advantageous aspect of the quasi-phase matching method. In conventional poled structure elements, what is called a z plate (crystal substrate processed to make the substrate surface perpendicular to the z-axis of optical crystal) is used and a polarization reversal period utilizing the nonlinear optical constant d 33 is formed. As shown in FIG. 2 , the polarized light direction of an incident light L 10 and the polarized light direction of a wavelength converted outgoing light L 20 are both parallel to the z-axis of the nonlinear optical crystal. In this way, only the utilization of the nonlinear optical constant d 33 has been conventionally taken note of and group velocity matching of the incident light and the outgoing light has not been considered at all. For wavelength conversion, a light having a pulse train (pulsed light) is sometimes used as an incident light. Examples thereof include conversion of, a pulsed light having a wavelength of 1.5 μm to a pulsed light having a wavelength of 0.78 μm by SHG, computing (e.g., sampling and gating for time-division multiplex communication, channel conversion and routing for wavelength multiplex communication) of a pulsed light having a wavelength of 1.5 μm and a pulsed light having a wavelength of 0.78 μm, and the like. However, when the present inventors studied wavelength conversion behavior of the above-mentioned conventional poled structure element, it was found that, when a pulsed light μs handled, the incident light and the outgoing light are separated in space and in time, along with the propagation of the light, due to a difference in the group velocity between the incident light and the outgoing light, and as a result, the following various problems such as those described below occur. For wavelength conversion of continuous light, for example, since incident light exists over the entire length of the element, the conversion efficiency and computing efficiency are expected to be improved by prolongation of the element length. In contrast, when a short pulsed light is to be handled, such as pulse-number 1 Tbit/sec or above (=pulse width 1 ps or below), the incident light and the outgoing light are separated due to a difference in the group velocity between them, posing a problem in that the conversion efficiency and computing efficiency are not improved even if the element length is prolonged. A problem also occurs in that, as a result of wavelength conversion, the pulse width of the outgoing light is extended depending on the difference in the group velocity, making retention of the pulse shape difficult, and accurate computing results cannot be obtained. In some cases, a problem also occurs in that pulses before and behind in the pulse train interfere with each other and produce serious errors in computing. Such problems are clearly recognized when the pulse width is shorter and the pulse-number is higher. In addition, since this difference in the group velocity depends on the wavelength of the incident light and the wavelength of the outgoing light (converted light), it becomes a factor that limits the wavelength band of the incident light. In a 1.5 μm band wavelength variable light source using 0.78 μm wavelength as an exciting-light source, moreover, the realizable wavelength band is limited due to the group velocity dispersion. |
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a schematic view showing the poled structure element of the present invention, wherein 1 is a nonlinear optical crystal, L 1 is an incident light and L 2 is an outgoing light. FIG. 2 is a schematic view showing a conventional poled structure element. detailed-description description="Detailed Description" end="lead"? |
Optically variable surface pattern |
An optically variable surface pattern (1) contains relief structures (9.1; 9.2; 9.3) for producing at least two representations (2; 3; 4). The relief structures (9.1; 9.2; 9.3) have a period length (L) of at least five micrometers and are sawtooth-shaped. The relief structures (9.1; 9.2; 9.3) associated with different representations (2; 3; 4) have different angles of inclination (α;β;γ). The angles of inclination are so selected that the representations (2; 3; 4) can be perceived separately by a viewer on the one hand and on the other hand when producing a copy by means of a color photocopier they are all transferred onto the copy. |
1. An optically variable surface pattern comprising surface portions with light-diffracting, reflecting structures and reflective surface portions for producing two or more representations which with lighting with light impinging perpendicularly onto the surface pattern are perceptible separately by a human viewer at a viewing distance of 30 cm at different angles of view, wherein the surface portions contain achromatically light-diffracting, sawtooth-shaped relief structures with angles of inclination of the sawtooth with respect to the plane of the surface pattern, the relief structures associated with different representations have different angles of inclination and the value of the largest angle of inclination is at most 25° so that the difference in the angles of view of the light beams reflected at the relief structures from at least two of the representations is smaller than an angle difference detected by the photoelectric sensor of a photocopier of 30°, whereby a copy produced by means of a photocopier reproduces at least two representations one over the other. 2. A surface pattern as set forth in claim 1, wherein the light-diffracting, reflecting structures are microscopically fine relief structures, and have a period length of at least five micrometers. 3. A surface pattern as set forth in claim 1, wherein the difference between the angles of inclination of two representations is at least 0.5°. 4. A surface pattern as set forth in claim 1, wherein the difference between the largest and the smallest angles of inclination is at most 20°. 5. A surface pattern as set forth in claim 1, wherein a when there are three representations, the mean angle of inclination is of the value of 15°. 6. A surface pattern as set forth in claim 1, wherein the differences of successive angles of inclination are of equal magnitude. 7. A surface pattern as set forth in claim 2, wherein the relief structures have a symmetrical profile shape. 8. (Cancelled) 9. A surface pattern as set forth in claim 1, wherein the grooves of the relief structures are wavy, circular or polygonal approximating a circle. 10. A surface pattern as set forth in claim 1, wherein the grooves of the relief structures are straight and the grooves of the various relief structures are approximately parallel. 11. A surface pattern as set forth in claim 1, wherein the reflective surface portions have cross grating with at least 3,000 lines per millimeter. 12. A surface pattern as set forth in claim 1, wherein the light-diffracting, reflecting structures are embodied in the form of a volume hologram. 13. An optically variable surface pattern comprising surface portions with light-diffracting, reflecting structures and reflective surface portions for producing two or more representations which with lighting with light impinging perpendicularly onto the surface pattern are perceptible separately by a human viewer at a viewing distance of 30 cm at different angles of view, wherein the surface portions contain achromatically light-diffracting sine-like relief structures with a period length of at least 5 μm, wherein the relief structures associated with the various representations differ in the period length and/or the structure depth so that the difference in the angles of the light beams reflected at the relief structures from at least two of the representations is smaller than an angle difference detected by the photoelectric sensor of a photocopier of 30°, whereby a copy produced by means of a photocopier reproduces at least two representations one over the other. 14. A surface pattern as set forth in claim 13, wherein the grooves of the relief structures are wavy, circular or polygonal approximating a circle. 15. A surface pattern asset forth in claim 13, wherein the grooves of the relief structures are straight and the grooves of the various relief structures are approximately parallel. 16. A surface patter as set forth in claim 13, wherein the reflective surface portions have cross gating with at least 3,000 lines per millimeter. |
Sheet accepting apparatus and recycler |
A sheet accepting apparatus comprises an inlet (210) for receiving one or more sheets. A transport system (217,350) extracts sheets from the inlet. A first detector (222) detects the passage of a foreign object with the transported sheet(s), the transport system being controllable to divert a detected foreign object to a foreign object collection position (215). One or more further detectors monitor sheets fed by the transport system. At least one store (205) is provided for storing accepted sheets. A controller is responsive to the detectors for controlling the transport system. |
1. A sheet accepting apparatus comprising an inlet for receiving one or more sheets; a transport system for extracting sheets from the inlet; a first detector for detecting the passage of a foreign object with the transported sheet(s), the transport system being controllable to divert a detected foreign object to a foreign object collection position; one or more further detectors for monitoring sheets fed by the transport system; at least one store for storing accepted sheets; a diverter for diverting unacceptable sheets to an output location; and a controller responsive to the detectors for controlling the transport system. 2. Apparatus according to claim 1, wherein the foreign object collection position is located adjacent the inlet. 3. Apparatus according to claim 1, wherein the inlet is defined by an inlet hopper having at least one opening through which foreign objects can fall into the foreign object collection position. 4. Apparatus according to claim 1, wherein a conveyor system is provided at the foreign object collection position on which foreign objects collect, the conveyor system being operable to feed foreign objects to a secure store. 5. Apparatus according to claim 4, wherein the feed system comprises a conveyor pivoted at one end so as to be movable between a collection orientation and a disposal orientation. 6. Apparatus according to claim 5, wherein the conveyor comprises one or more high friction belts. 6. (Canceled) 7. Apparatus according to claim 1, wherein the one or more further detectors detect one or more of the pattern on a sheet, the size and/or thickness of a sheet, and the stiffness of a sheet. 8. Apparatus according to claim 1, wherein the one or more further detectors are adapted to detect characteristics of banknotes such as limpness, tears and the like. 9. Apparatus according to claim 1, wherein the or each store comprises a roll storage module, cassette or storage box. 10. Apparatus according to claim 1, wherein, at the inlet, the transport system includes at least one roller defining a feed nip with another surface and which is biased in a direction to close the nip but which can be urged against the bias during passage of a foreign object. 11. Apparatus according to claim 10, wherein the roller can move by more than substantially 3mm against the bias to accommodate the passage of a foreign object. 12. Apparatus according to claim 1, wherein the output location is provided adjacent the inlet. 13. Apparatus according to claim 1, wherein the transport system defines a first feed system for extracting sheets from the inlet and a second feed system downstream of the first feed system for receiving sheets from the first feed system and for feeding them on to a further downstream location, whereby the second feed system defines a planar path such that foreign objects are substantially not bent as they are fed by the second feed system, the second feed system being pivotally mounted such that when a foreign object is detected, the controller causes the second feed system to pivot so that the foreign object is fed to the foreign object collection position. 14. A sheet accepting apparatus comprising an inlet for receiving one or more sheets; a transport system including a first feed system for extracting sheets from the inlet, the first feed system including a first detector for detecting the passage of a foreign object through the first feed system and a second feed system downstream of the first feed system for receiving sheets from the first feed system and for feeding them on to a further downstream location, whereby the second feed system defines a planar path such that sheets are substantially not bent as they are fed by the second feed system; and a controller connected to the first detector and the second feed system, the second feed system being pivotally mounted such that when a foreign object is detected, the controller causes the second feed system to pivot so that the foreign object is fed to a reject location. 15. Apparatus according to claim 14, wherein the second feed system is pivotally mounted at its downstream end with respect to the first feed system, the controller causing the second feed system to reverse its feed direction when feeding a foreign object to the foreign object collection position. 16. Apparatus according to claim 14, wherein the second feed system comprises juxtaposed feed belts defining a feed path therebetween. 17. Apparatus according to claim 14, wherein the first detector includes at least one roller of the first feed system, and a sensor for monitoring displacement of the at least one roller. 18. Apparatus according to claim 17, wherein the first detector comprises at least two laterally spaced rollers of the first feed system, and respective sensors for monitoring displacement of each roller. 19. Apparatus according to claim 18, wherein the controller is adapted to determine differences in the amounts by which the rollers are displaced so as to indicate the presence of a foreign object. 20. A sheet recycler comprising sheet accepting apparatus according to claim 1; and an output assembly to which sheets are fed from the store by the transport system, the output assembly being adapted to present the sheets at an output location. 21. A recycler according to claim 20, wherein the output assembly includes a tray on which the sheets are stacked. 22. A recycler according to claim 21, wherein the tray is movable from a stacking position to an output location. 23. A recycler according to claim 22, wherein the tray is supported on laterally spaced tracks along which it can be moved between the stacking position and the output location. 24. A recycler according to claim 22, wherein the tray is pivotally mounted to enable stacked sheets to be fed into a secure store. 25. A recycler according to claim 24, further comprising a diverting member actuable to cause the tray to pivot during movement of the tray from the output location towards the stacking position. 26-27. (Canceled) 28. A recycler according to claim 20, further comprising an escrow store to which accepted sheets are initially fed by the transport system. 29. A recycler according to claim 28, wherein the escrow store is provided by a roll storage module. 30. A sheet feeding assembly comprising an input hopper for receiving one or more sheets; and a first feed system for extracting sheets from the input hopper, the input hopper having at least one opening through which foreign objects deposited in the input hopper can fall. 31. An assembly according to claim 30, wherein the input hopper further includes a pusher member for pushing sheets away from a base of the input hopper so as to be correctly presented to the first feed system. 32. Apparatus according to claim 1, wherein the one or more detectors are provided downstream of the first detector. |
Automatic indexing of digital video recordings |
A digital television system includes service provider equipment for transmitting a digital television broadcast, a set-top box for receiving and recording and decoding the digital television broadcast and displaying the decoded broadcast and/or recording on an analog or digital television. A processor arranged in the set-top box or the user equipment includes an agent or computer program for extracting information transmitted with the digital television broadcast, selecting filtering alternatives based on the information and for providing to the recording indexes associated with the recording position of events filtered out using the selected filtering alternatives. |
1. A system for indexing events within a recording of a digital television broadcast, comprising a processor operatively arranged for receiving information transmitted with the digital television broadcast being recorded, the information comprising descriptor fields containing terms related to the broadcast, wherein said processor is further operatively arranged for selecting filtering alternatives based on the information and for providing to the recording indexes associated with the recording position of events filtered out using the selected filtering alternatives. 2. The system of claim 1, wherein the information transmitted with the digital television broadcast comprises service information. 3. The system of claim 1, wherein the information transmitted with the digital television broadcast comprises information transmitted in Advanced TV Enhancement Forum techniques. 4. The system of claim 1, wherein said processor is operatively arranged for determining the appropriate filter settings from information contained in descriptor fields of information transmitted with the DTV broadcast as Service Information (SI) defined in European Telecommunication Standard 300 468, “Digital Video Broadcasting; Specification for Service Information (SI) in DVB Systems”. 5. The system of claim 4, wherein the terms in the descriptor field of the information transmitted with digital television broadcast comprise at least one of a title of the broadcast, a subject of the broadcast, and keywords related to the broadcast. 6. The system of claim 1, wherein said processor is operatively arranged for selecting filter settings based on the information associated with an event selected for later recording upon time delayed automatic initiation of the recording. 7. The system of claim 1, wherein said processor is arranged in a set-top box of a digital television system. 8. The system of claim 1, wherein said processor is arranged in service provider equipment of a digital television system. 9. The system of claim 1, further comprising a computer connected between a set-top box and a display of the digital television system, wherein said processor is arranged in said computer. 10. The system of claim 1, further comprising means for displaying a list of filtering alternatives to the user, whereby the user may select any one of the filtering alternatives on the list to obtain the further information about the used filtering criteria and/or edit the filtering alternative in accordance with personal preferences. 11. A process for indexing events within a recording of a digital television broadcast, comprising the steps of: receiving information transmitted with the digital television broadcast, the information including descriptor fields including terms related to the digital television broadcast; selecting filtering alternatives based on the terms in the descriptor fields of the information; and providing to the recording indexes associated with the recording position of events filtered out using the selected filtering alternatives. 12. The process of claim 11, wherein said step of receiving comprises receiving service information transmitted with the digital television broadcast. 13. The process of claim 11, wherein said step of receiving comprises receiving information transmitted with the digital television broadcast in Advanced TV Enhancement Forum techniques. 14. The process of claim 11, wherein said step of selecting comprises selecting filtering alternatives using a manual input device. 15. The process of claim 14, wherein the information transmitted with digital television broadcast comprises at least one of a title of the broadcast and a subject of the broadcast. 16. The process of claim 11, wherein said step of selecting comprises selecting filtering alternatives based on the information associated with a event selected for later recording upon time delayed automatic initiation of the recording. 17. The process of claim 11, further comprising the step of inputting the terms into the descriptor fields by a provider of the digital television broadcast before said step of receiving. 18. The system of claim 11, further comprising the step of displaying the list of filtering alternatives in response to a user input. 19. A digital television system, comprising: a service provider equipment for transmitting digital television broadcasts; a set-top box for receiving and recording and decoding the digital television broadcasts; a display for displaying the decoded digital television broadcasts and recordings; a user input for selecting a channel of the digital television broadcasts to be displayed and/or recorded; and a processor operatively arranged for receiving information transmitted with the digital television broadcast, the information including descriptor fields containing terms related to the broadcast, wherein said processor is further operatively arranged for selecting filtering alternatives based on the information and for providing to the recording indexes associated with the recording position of events filtered out using the selected filtering alternatives. 20. The system of claim 19, wherein said processor is arranged in said set-top box. 21. The system of claim 19, wherein said processor is arranged in said service provider equipment. 22. The system of claim 19, further comprising a computer arranged between said set-top box and said display, wherein said processor is arranged in said computer. 23. The system of claim 19, further comprising means for displaying the list of filtering alternatives on said display in response to said user input. 24. A computer program product directly loadable into the internal memory of a digital computer comprising software code portions for performing the following steps when said product is run on a computer: extracting information transmitted with a digital television broadcast, the information including descriptor fields including terms related to the digital television broadcast; selecting filtering alternatives based on the terms in the descriptor fields of the information; and filtering out events corresponding to the selected filtering alternatives; and providing to a recording of the digital television broadcast indexes associated with the recording position of events filtered out using the selected filtering alternatives. 25. A computer program product stored on a computer readable storage medium, comprising computer readable program code means for causing a computer to perform the following steps: extracting information transmitted with a digital television broadcast, the information including descriptor fields including terms related to the digital television broadcast; selecting filtering alternatives based on the terms in the descriptor fields of the information; and filtering out events corresponding to the selected filtering alternatives; and providing to a recording of the digital television broadcast indexes associated with the recording position of events filtered out using the selected filtering alternatives. |
Image guided implantology methods |
A method for correcting inherent distortions in a CT or MRI imaging process, or distortions arising from excessive patient movement during the scan by means of a registration device inserted into the mouth of the patient at the time the scan is being performed. The registration device incorporates a set of fiducial markers disposed in a predetermined three-dimensional pattern. The exact positions of the fiducial markers are known with respect to each other, thus providing a three-dimensional reference against which the resulting images can be compared. Additionally, a method whereby three-dimensional CT or MRI images taken prior to an operation, are accurately registered and integrated with real-time tracking positional data of the patient's body part and instruments operating thereon. Application is described for the drilling of a patient's jaw for the placement of dental implants. |
1. A method of compensating for distortions generated in an imaging process, comprising the steps of: providing a registration device with a plurality of markers disposed in a predetermined three-dimensional pattern, said markers being rendered visible in said imaging process; producing a scanned image of an object of interest in the presence of said registration device; and correcting the data of said scanned image such that the image of said markers accurately reproduces said predetermined three-dimensional pattern. 2. The method according to claim 1 wherein said plurality of markers are disposed within said registration device. 3. The method according to claim 1 wherein said plurality of markers are disposed within a body attached to said registration device. 4. The method according to claim 1 wherein said imaging process is selected form a group consisting of computerized tomography and an MRI process. 5. The method according to claim 1 wherein said object is at least part of a jaw of a subject. 6. The method according to claim 5 wherein said registration device is adapted to fit in a reproducible position in said at least part of said jaw. 7. A method for correlating positional data relating to an object, obtained by means of a tracking system, with a scanned image of said object, comprising the steps of: producing a scanned image of said object in the presence of a registration device having markers which are visible in said scanned image, said markers being located in fixed positions in said registration device; locating said registration device at a position remote from said object, and determining said position such that the location of said markers is known to said tracking system; obtaining positional data relating to said object by means of said tracking system; and adjusting the relationship between said scanned image of said object and said positional data of said object such that the position of said markers on said scanned image coincides with the location of said markers known to said tracking system. 8. The method according to claim 7 wherein said step of determining said position is performed using a manually directed position sensing device. 9. The method according to claim 7 wherein said step of determining said position is performed by inserting said registration device into a registration jig which accommodates said registration device in a known position, and recording the position of said jig with said tracking system. 10. The method according to claim 7 wherein said object is at least part of a jaw of a subject. 11. The method according to claim 7 wherein said scanned image is selected from a group consisting of a CT image and an MRI image. 12. The method according to claim 7 wherein said registration device is adapted to fit in a reproducible position in said at least part of a jaw of said subject. 13. The method according to claim 12 wherein said registration device is split into parts, such that only part of said registration device need be in the mouth of said subject during dental treatment. 14. The method according to claim 13 wherein said part of said registration device in the mouth of said subject during dental treatment is adapted such that it does not interfere with the progress of said dental treatment. 15. The method according to claim 12 wherein said registration jig is located remote from said subject. 16. The method according to claim 12, and wherein said step of obtaining positional data about said at least part of a jaw of a subject is performed by providing said registration device with trackability by said tracking system, and also comprising the steps of: juxtaposing said registration device in a reproducible manner with at least one tooth of said subject; tracking the position of said registration device; and compensating said positional data of said at least part of a jaw of a subject according to the tracked position of said registration device, such that said relationship between said scanned image of said object and said positional data of said object is maintained during movement of said subject. 17. The method according to claim 16, and wherein said step of providing said registration device with trackability by said tracking system is performed by attaching to said registration device a body adapted to be tracked by said tracking system. 18. The method according to claim 16, and also comprising the step of providing a drill with trackability by said tracking system, such that the position of said drill in relation to said at least one tooth of said subject can be determined. 19. A registration device for positional determination of at least part of a jaw of a subject, comprising: a portion incorporating markers, identifiable by an imaging method; and a trackable position sensor, associated with said registration device, for determining the three-dimensional position of said registration device; wherein said registration device is demountable into at least two component parts for mounting in said at least part of a jaw of a subject. 20. A registration device according to claim 19, and wherein said component parts are adapted to be sufficiently small that they do not interfere with a procedure to be performed in the oral cavity of said subject. 21. A registration device according to claim 19, and wherein said portion incorporating markers is demountable from said registration device. 22. A registration device according to claim 19, and wherein at least one of said component parts comprises a splint being adaptable to conform to a shape within the oral cavity of said subject. 23. A method for correlating positional data relating to an object, obtained by means of a tracking system, with a scanned image of said object, comprising the steps of: providing a registration device having markers, visible in said scanned image, located in known positions, and also having a reference tracking body located in a known position relative to said registration device, the position of said reference tracking body being tracked by said tracking system; producing a scanned image of said object in the presence of said registration device, such that said markers are visible in said image; determining the position of said registration device with said tracking system, such that the location of said markers is known to said tracking system; obtaining positional data relating to said object by means of a known positional relationship between said registration device and said object; and adjusting the relationship between said scanned image of said object and said positional data of said object such that the position of said markers on said scanned image coincides with the location of said markers known to said tracking system. 24. The method according to claim 23, and wherein said reference tracking body is part of said registration device itself. 25. The method according to claim 23, and wherein said object is at least part of a jaw of a subject. 26. The method according to claim 24, and wherein said object is at least part of a jaw of a subject. 27. The method according to claim 23, and wherein said scanned image is selected from a group consisting of a CT image and an MRI image. 28. The method according to claim 24, and wherein said scanned image is selected from a group consisting of a CT image and an MRI image. |
<SOH> BACKGROUND OF THE INVENTION <EOH>The use of threaded inserts, generally made of titanium, has become the dominant technology currently used for dental implant surgery. Such inserts must be precisely located in the tooth in order to provide optimum aesthetic and beneficial results. Bone preparation must be precise and should preferably be carried out with the implant site and shape in constant view of the dental surgeon. In particular, during the drilling phase of the bone preparation, great care must be taken to avoid causing injury to the patient. Examples of such potential damage include inadvertent entry into the mandibular nerve canal, possible perforation of the cortical plates, or damage to adjacent teeth. In order to achieve these objectives, exact knowledge of the bone topology of the jaw must be on hand. Such information is today obtainable from computer-generated panoramic and oblique radiographic CT scans of the jaw, which provide the cross-sectional shape of the jaw at every point throughout the arch on a 1:1 scale. In order to use the information on such CT images optimally, the dental surgeon should be provided with a continuous, real-time, three-dimensional image of the location and direction of the drill during the drilling procedure into the bone at all times during its execution. As a result, there should be optimal correlation between the implantation planning and the actual surgical performance, and accurate placement of the insert, even by less experienced clinicians, and additionally, reduction to a minimum of any danger of damage to vital anatomical structures, such as the inferior alveolar nerve, the maxillary antrum, the nasal cavity, adjacent teeth, or cortical plates. However, the successful and accurate implementation of a system providing such information is dependent on the accuracy of the initial input data of the CT imagery provided to the system computer. Such data as supplied by the CT scanner may generally be distorted, whether because of imperfections in the algorithms used in the scanner software, or because of interpolations made in areas where exact measurements are not performed, or simply because of inaccuracies due to excessive patient movement during the CT scan. Very high accuracy is required in dental implantology, where even a fraction of a millimeter of excess penetration or a degree or two of misalignment, can mean the difference between a successful procedure and an unsatisfactory one, or even between a safe procedure and injury to the patient. Consequently, the distortion inherent in generally available CT scans is such that such scans cannot be used as supplied, for accurate image-guided dental implantology. There therefore exists a serious need for a method of compensating or correcting for such CT distortion for use in image-guided implantation surgery. In addition, such a method would also be applicable and necessary for use in other accurate, image-guided surgical or industrial procedures which utilize scanned image information for determining an exact overall picture of the imaged subject or object. Furthermore, even if such accurately corrected CT imagery were available, it is necessary to relate the computer-generated virtual images of the patient's jaw with the actual teeth in the patient's jaw, and with the position of the dental surgeon's hand and drill. Thus, it is necessary to correlate a definite point on a CT scan with its matching point in the patient's jaw, and a stereometric angle on the scan with the corresponding angle in the patient's jaw. Without such correlation, even the most accurate and undistorted CT scan is of very limited use for guiding any sort of real time surgical procedure, such as implant preparation. Furthermore, the correlation must take into account and track any motion of the patient's jaw during the procedure. In U.S. Pat. No. 5,842,858 to M Truppe, for “Method of Imaging a Person's Jaw and a Model thereof”, there is described a method whereby such correlation and tracking are performed using a 3-D sensor attached, for instance by means of screws, to the outside of the jaw of the patient, which is referenced by means of a tracking system to another 3-D sensor temporarily located inside the jaw. Such a referencing method may be considered disadvantageous since it entails subject involvement, and may also be dependent on operator skill in attachment of the 3-D sensor to the outside of the patient's jaw. Furthermore, physiological changes taking place in the tissue and muscle of the patient's jaw during the course of the procedure may induce inaccuracies in the position of the sensor. These factors may compromise the high accuracy required for an accurate implant procedure. There therefore exists a serious need for a method of correlating virtual CT images previously obtained of a patient's jaw with the actual situation being followed by the drill in real time in the patient's jaw during a dental surgical procedure. The method should ideally be performed with minimal interaction with the patient's jaw, in order to reduce subjective inaccuracies as much as possible. Furthermore, it should be simple enough to be executable by personnel other than the dental surgeon himself, such as a dental technician. It is to be understood that such a method would also be useful and applicable in other accurate, image-guided surgical or industrial procedures which utilize scanned image information for determining the overall picture of a real-time procedure being performed. The disclosures of all publications mentioned in this section and in the other sections of the specification, are hereby incorporated by reference, each in its entirety. |
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention seeks to provide new methods for ensuring the accurate use of CT or MRI scanned images in surgical procedures, such as image-guided implantology. There is thus provided according to a first preferred embodiment of the present invention, a method whereby inherent distortions in the CT or MRI imaging process, or distortions arising from excessive patient movement during the scan are corrected by means of a registration device inserted into the mouth of the patient at the time the scan is being performed. To this registration device is attached in a reproducible manner, a device known as a distortion body which contains a set of fiducial markers disposed in a predetermined three-dimensional pattern, and whose location is registered on the images during the scanning. The exact positions of the fiducial markers are known with respect to each other, thus providing a three-dimensional reference against which the resulting images can be compared. This provides accurate spatial position information for correcting any distortion present in the scanning and image-processing procedure. Calculations are then performed for determining the exact location of the fiducials in the CT data, the distortion between the three dimensional image obtained and the known true location of the fiducials, and for producing a correction function for use in interpreting the CT or MRI data such that it provides accurate positional data. There is also provided according to another preferred embodiment of the present invention, a method whereby the three-dimensional, pre-operative CT or MRI images are accurately registered and integrated with the real-time intra-operative tracking positional data. The latter are defined by two characteristic activities. Firstly, the position and orientation of the drill is supplied to the system, preferably by means of LED's attached to the drill body. The position of these LED's is preferably tracked by means of a triangulation tracking and measurement technique, or any other suitable tracking and measurement technique, such that the drill's spatial position and orientation is known at all times. Secondly, the position of the tooth being drilled in the patient's jaw is tracked preferably by means of a reference tracking body the position of which is defined relative to the patient's jaw. The reference tracking body preferably incorporates a set of LED's, which are tracked by the tracking system. Thus, the real-world positions both of the drill and of the tooth can be spatially and definitively tracked by the system. These images are then spatially and angularly related to the pre-operative images by means of a pre-registration procedure performed according to another preferred embodiment of the present invention, in which a registration body containing fiduciary markers is inserted in a predefined manner into a registration jig, prior to commencement of any work on the patient. The position of the jig together with the inserted registration body is tracked by the tracking system preferably by means of LED's mounted on the jig. Alternatively and preferably, the position of the registration body can be made known to the tracking system by any other suitable positional determining device, such as by a manually held stylus which is touched onto a reference point of the registration body, or even onto the fiducial markers themselves. Since the fiducial markers are the same ones as were incorporated in the scans previously made with the registration body in the patient's mouth, and thus bear a predefined and fixed spatial and angular relationship to the registration body, and the registration body to the patient's teeth, this correlation enables the virtual-world CT scans to be related to the functional world of the tooth and drill as tracked in real time by the system. Since this registration procedure is performed outside of the patient's mouth, it has a number of advantages over prior art registration procedures performed involving the patient's jaw. In the first place, since the registration procedure is performed outside of the patient's mouth, and without patient involvement, the accuracy and the reliability of the registration process is increased, as is the patient comfort level, for the reasons stated hereinabove. Secondly, the registration process can be performed at any time before the procedure on the patient, and requires less skill and time than an intra-oral registration procedure, as in the prior art, with all the advantages thereby engendered. The term registration device as used and claimed throughout this application, is understood to include any form of device operative for acquiring positional determination data of the object to be imaged. Likewise, the term reference tracking body as used and claimed throughout this application, is understood to include any form of sensor device operative for providing 3-D information about the position of the tracked body. There is also provided in accordance with another preferred embodiment of the present invention, a a method of compensating for distortions generated in an imaging process, comprising the steps of (a) providing a registration device with a plurality of markers disposed in a predetermined three-dimensional pattern, the markers being rendered visible in the imaging process, (b) producing a scanned image of an object of interest in the presence of the registration device, and (c) correcting the data of the scanned image such that the image of the markers accurately reproduces the predetermined three-dimensional pattern. The plurality of markers are preferably disposed either within the registration device, or within a body attached to the registration device. The above-described method can preferably be used for computerized tomography or for MRI imaging. Furthermore, the method can preferably be used when the object is at least part of a jaw of a subject, in which case the registration device is adapted to fit in a reproducible position in the at least part of the jaw. In accordance with yet another preferred embodiment of the present invention, there is provided a method for correlating positional data relating to an object, obtained by means of a tracking system, with a scanned image of the object, comprising the steps of (a) producing a scanned image of the object in the presence of a registration device having markers which are visible in the scanned image, the markers being located in fixed positions in the registration device, (b) locating the registration device at a position remote from the object, and determining the position such that the location of the markers is known to the tracking system, (c) obtaining positional data relating to the object by means of the tracking system, and (d) adjusting the relationship between the scanned image of the object and the positional data of the object such that the position of the markers on the scanned image coincides with the location of the markers known to the tracking system. In accordance with still another preferred embodiment of the present invention, in the above-mentioned method, the step of determining the position may be preferably performed either using a manually directed position sensing device, or by inserting the registration device into a registration jig which accommodates the registration device in a known position, and recording the position of the jig with the tracking system. The above-described method can be preferably used for computerized tomography or for MRI imaging. Furthermore, the method can preferably be used when the object is at least part of a jaw of a subject. If the object is at least part of a jaw of a subject, the registration device is preferably adapted to fit in a reproducible position in the at least part of the jaw of the subject. In accordance with a further preferred embodiment of the present invention, for dental use, the registration device may be split into parts, such that only part of the registration device need be in the mouth of the subject during treatment. In such a case, the part of the registration device in the mouth of the subject during treatment is preferably adapted such that it does not interfere with the progress of the dental treatment. In the above methods, the registration jig is preferably located remote from the subject. Furthermore, in accordance with yet another preferred embodiment of the present invention, in the above-mentioned method in which the registration device is adapted to fit in a reproducible position in the at least part of the jaw of the subject the step of obtaining positional data about the at least part of a jaw of a subject may preferably be performed by providing the registration device with trackability by the tracking system, and may also comprise the additional steps of: (a) juxtaposing the registration device in a reproducible manner with at least one tooth of the subject, (b) tracking the position of the registration device, and (c) compensating the positional data of the at least part of a jaw of a subject according to the tracked position of the registration device, such that the relationship between the scanned image of the object and the positional data of the object is maintained during movement of the subject. In this method, the step of providing the registration device with trackability by the tracking system may be performed by attaching to the registration device a body adapted to be tracked by the tracking system. Furthermore, the method may comprise the additional step of providing a drill with trackability by the tracking system, such that the position of the drill in relation to the at least one tooth of the subject can be determined. There is even further provided in accordance with another preferred embodiment of the present invention a registration device for positional determination of at least part of a jaw of a subject, comprising (a) a portion incorporating markers, identifiable by an imaging method, and (b) a trackable position sensor, associated with the registration device, for determining the three-dimensional position of the registration device, wherein the registration device is demountable into at least two component parts for mounting in the at least part of a jaw of a subject. Preferably, the component parts are adapted to be sufficiently small that they do not interfere with a procedure to be performed in the oral cavity of the subject. Furthermore, the portion incorporating markers may preferably be demountable from the registration device, and at least one of the component parts may preferably comprise a splint adapted to conform to a shape within the oral cavity of the subject. Furthermore, in accordance with yet another preferred embodiment of the present invention, there is provided a method for correlating positional data relating to an object, obtained by means of a tracking system, with a scanned image of the object, comprising the steps of: (a) providing a registration device having markers, visible in the scanned image, located in known positions, and also having a reference tracking body located in a known position relative to the registration device, the position of the reference tracking body being tracked by the tracking system, (b) producing a scanned image of the object in the presence of the registration device, such that the markers are visible in the image, (c) determining the position of the registration device with the tracking system, such that the location of the markers is known to the tracking system, (d) obtaining positional data relating to the object by means of a known positional relationship between the registration device and the object, and (e) adjusting the relationship between the scanned image of the object and the positional data of the object such that the position of the markers on the scanned image coincides with the location of the markers known to the tracking system. In the last-described method, the reference tracking body may be the registration device itself. Furthermore, the object may be at least part of a jaw of a subject. Finally, the scanned image may preferably be a CT image or an MRI image. |
2-Heteroaryl-imidazotriazinones and their use in the treatment of inflammatory or immune diseases |
The invention relates to 2-Heteroaryl-imidazotriazinones, processes for their preparation and their use in medicaments, esp. for the treatment and/or prophylaxis of inflammatory processes and/or immune diseases. The present invention relates to compounds of the general formula (I) in which R1 denotes 5- to 10-membered heteroaryl, which is optionally substituted by identical or different residues selected from the group consisting of halogen, (C1-C4)-alkyl, trifluoromthyl, cyano, nitro und trifluoromethoxy, denotes 3- to 10-membered carbocyclyl or carbon-bonded, 4- to 10-membered heterocyclyl, whereby carbocyclyl and heterocyclyl are optionally substituted by identical or different residues selected from the group consisting of (C1-C6)-aldyl, (C1-C6)-aldoxy, hydroxy, halogen, trifluoromethyl and oxo, or denotes (C2-C10)-alkyl, which is optionally substituted by identical or different residues selected from the group the group consisting of (C1-C6)-alkoxy, hydroxy, halogen, 3- to 10-membered carbocyclyl and oxo. |
1. A compound of the general formula (I) in which R1 denotes 5- to 10-membered heteroaryl, which is optionally substituted by identical or different residues selected from the group consisting of halogen, (C1-C4)-alkyl, trifluoromethyl, phenyl, cyano, nitro und trifluoromethoxy, and R2 denotes 3- to 10-membered carbocyclyl or carbon-bonded, 4- to 10-membered heterocyclyl, whereby carbocyclyl and heterocyclyl are optionally substituted by identical or different residues selected from the group consisting of (C1-C6)-alkyl, (C1-C6)-alkoxy, hydroxy, halogen, trifluoromethyl and oxo, or denotes (C2-C10)-alkyl, which is optionally substituted by identical or different residues selected from the group consisting of (C1-C6)-alkoxy, hydroxy, halogen, 3- to 10-membered carbocyclyl and oxo, and its salts, hydrates and/or solvates. 2. A compound according to claim 1, whereby R1 denotes furanyl, thiophenyl, thiazolyl, pyridyl, chinolyl or isochinolyl, which are optionally substituted by identical or different residues selected from the group consisting of halogen, (C1-C4)-alkyl, trifluoromethyl, cyano, nitro und trifluoromethoxy. 3. A compound according to claim 1 or 2, whereby R2 denotes (C4-C7)-cycloalkyl, which is optionally substituted up to two times by identical or different (C1-C5)-alkyl residues, or denotes (C3-C8)-alkyl, which is optionally substituted by a (C4-C7)-cycloalkyl. 4. A process for the preparation of the compounds according to claim 1, characterized in that, compounds of the general formula (IV), in which R1 and R2 have the meaning indicated in claim 1, are reacted with a dehydrating agent. 5. A compound of the general formula (IV) according to claim 4. 6. (canceled) 7. Pharmaceutical composition containing at least one compound according to any one of claims 1 to 3 and a pharmacologically acceptable diluent. 8. A process for preparing a medicament, wherein a compound according to any one of claims 1 to 3 is converted into a medicament. 9. (canceled) 10. (canceled) 11. The process of claim 8 wherein the medicament is a medicament for the treatment and/or prophylaxis of inflammatory processes and/or immune diseases. 12. The process of claim 8 wherein the medicament is a medicament for the treatment and/or prophylaxis of chronic obstructive pulmonary disease and/or asthma. 13. A method of preventing or treating an inflammatory process and/or immune disease, comprising administering to a patient in need thereof an effective amount of a compound of claim 1. |
Ceramic components having multilayered architectures and processes for manufacturing the same |
The present invention relates to multilayered ceramic components (10) and methods of fabricating such multilayered architectures. More particularly, the present invention relates to multilayered components having a plurality of dielectric (12) and electrode material (14, 15) layers. The multilayered components are manufactured by coextrusion processes. |
1. A method of manufacturing components having multi-layer architectures comprising the steps of: (a) combining a dielectric ceramic material with a first additive composition to form a first composite blend; (b) combining an electrically conductive material with a second additive composition to form a second composite blend; (c) forming a dielectric body from the first composite blend; (d) forming an electrode body from the second composite blend; (e) arranging a plurality of dielectric bodies and electrode bodies to form a feed rod having a patterned array of alternating dielectric and electrode layers; and (f) extruding the feed rod to form a component product having multi-layered architecture. 2. The method of claim 1 further comprising a step of sectioning the extruded feed rod to provide a plurality of individual component products of predetermined dimensions and having multi-layered architecture. 3. The method of claim 1 wherein the patterned array of dielectric and electrode layers of the feed rod is maintained during extrusion to provide a component product having essentially the same patterned array of layers. 4. The method of claim 1 wherein the dielectric ceramic material is a ferroelectric compound. 5. The method of claim 1 wherein the dielectric material is selected from the group consisting of titanate compounds, niobate compounds tantalate compounds and combinations thereof. 6. The method of claim 1 wherein the dielectric ceramic material is selected from the group consisting of MgTiO3, BaTiO3, BaTi4O9, TiO2, SrTiO3, CaTiO3, Al2O3, MgO and combinations thereof. 7. The method of claim 1 wherein at least one of the first and second additive compositions includes a thermoplastic binder. 8. The method of claim 1 wherein at least one of the first and second additive compositions includes a plasticizer. 9. The method of claim 1 further comprising steps of: (a) stacking the extruded component product to form a second feed rod; and (b) extruding the second feed rod to form a second component product having multi-layered architecture. 10. The method of claim 1 further comprising a step of heating the component product to burn out the first and second additive compositions. 11. The method of claim 10 wherein heating occurs in a nitrogen atmosphere. 12. The method of claim 1 further comprising a step of densifying the component product wherein densifying includes heating to a temperature and for a time effective for densifying the dielectric and electrode materials of the component product. 13. The method of claim 12 wherein densifying occurs in a nitrogen atmosphere. 14. The method of claim 1 wherein the step of extruding includes consolidating through the application of heat and pressure. 15. The method of claim 1 wherein the electrically conductive material is a metallic material. 16. The method of claim 15 wherein the electrically conductive material is selected from the group consisting of base metals, precious metals and combinations thereof. 17. The method of claim 1 wherein the component product includes repeated structural units having an ordered microstructure, the structural units being disposed across a working surface of the component. 18. The method of claim 1 wherein the component product is a multi-layer ceramic capacitor. 19. The method of claim 1 wherein the composite product is a microwave dielectric filter. 20. The method of claim 1 wherein the composite product is an ultrasonic motor. 21. The method of claim 1 wherein the composite product is a piezoelectric component. |
<SOH> BACKGROUND OF THE INVENTION <EOH>The most common method for manufacturing multi-layer ceramic capacitors (MLCCs) involves tape-casting technologies. Unfortunately, tape-casting processes pose severe handling problems as the thickness of the tape decreases. Although there has been a strong desire for a more versatile process than tape casting for fabricating MLCCs, other possible fabrication methods, such has vapor deposition techniques and sol-gel techniques, have shortcomings that have impeded their commercial success. For instance, chemical and physical vapor deposition techniques are limited by their inherently slow deposition rates. In addition, sol-gel techniques are limited because sol-gel based components must undergo large shrinkages during drying and firing. In electronic circuitry, the demand for greater board densities and improved volumetric efficiency in components is continuously escalating. In the case of MLCCs, smaller component parts and thinner dielectric layers are required for improving the performance of electronic devices. This trend has driven the thickness of MLCC chips down from 0.120 inches in the 1980s to 0.080 inches in the late 1990s. Presently, the industry is heading towards 0.060, 0.040, and even 0.020-inch thick MLCCs. These numbers translate into dielectric layer thicknesses of approximately 20 μm in the 1980s, layer thicknesses of 13-15 μm in the mid-1990s, and less than 7.5 μm layer thicknesses in the late 1990s. The technology push worldwide has now seen the fabrication of dielectric layers of less than 5 μm and thicknesses will continue to decrease. In turn trends in manufacturing will require new methods of MLCC fabrication with more automated production for large quantities of components. Therefore, there remains a need for a versatile method for preparing these thin film ceramic components for the electronics industry. |
<SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide methods of manufacturing electronic components having multi-layered structures, including components having layer thicknesses of 4 μm or less. It is another object of the present invention to provide multi-layered components that include one or more dielectric material layers and one or more electrode material layers, the layers having controlled and uniform thicknesses. It is yet another object of the present invention to provide cost-effective and efficient extrusion processes for forming multilayer components. According to the present invention provides, a multilayer ceramic component includes alternately stacked dielectric layers and internal electrode layers. Methods of fabricating such components having multilayered architectures include combining a dielectric ceramic material with a first additive composition to form a first composite blend, combining an electrically conductive material with a second additive composition to form a second composite blend, forming a dielectric body, such as a sheet, from the first composite blend, forming an electrode body, such as a sheet, from the second composite blend, arranging a plurality of dielectric bodies and electrode bodies to form a feed rod having a patterned array of alternating dielectric and electrode layers, and extruding the feed rod to form a “green” component product having multi-layered architecture. The “green” component product then is cut into individual component pieces which are then finished. Finishing steps include a binder bake out step and a densification step to provide a fully consolidated and densified finished component product. The finished components have improved durability and strength as compared to monolithic ceramic components. By varying the materials selected for the dielectric and electrode layers, desired mechanical strengths and electrical properties can be obtained. |
Beta-secretase substrates and uses thereof |
The present invention provides synthetic β-secretase peptide substrates useful in various assays for measuring β-secretase activity. Antibodies that recognize the synthetic substrates and uses of the antibodies in various assays are disclosed. The herein disclosed peptide substrates are hydrolyzed at rates substantially faster than the attendant Swedish mutant APP from which the substrate sequences are derived. |
1. A substantially pure peptide comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 1-256, 258-263, and 264. 2. An antibody specific for the peptide of claim 1. 3. The antibody of claim 2, wherein said antibody is a monoclonal antibody 4. The antibody of claim 2, wherein said antibody is a humanized antibody 5. An antibody composition comprising antibody molecules that specifically recognize an amino-terminal fragment of the peptide of claim 1, wherein said amino terminal fragment results from cleavage of the peptide by β-secretase. 6. An antibody composition comprising antibody molecules that specifically recognize a cleavage product of the peptide of claim 1, wherein said cleavage product is the C-terminal fragment that results from cleavage of the peptide by β-secretase. 7. An antibody that is specific for the synthetic β-secretase cleavage site of the peptide of claim 1, said site corresponding to Leu596 and Asp597 of the Swedish Mutant APP numbered according to the 695 isoform. 8. An antibody that specifically binds the peptide of claim 1 characterized by its ability to be cleaved by human β-secretase at a site corresponding to amino acids 596 and 597 of a Swedish mutant APP numbered according to the 695 isoform. 9. A method for assaying β-secretase activity, comprising the step of measuring cleavage of the peptide of claim 1 by β-secretase. 10. The method of claim 9, wherein said measuring comprises the use of an antibody that binds to the amino terminus of the β-secretase peptide related product produced by said cleavage. 11. The method according to claim 6, wherein said method is performed in the presence of one or more compounds that inhibit β-secretase activity. 12. A method for measuring the activity of a test compound to effect β-secretase activity comprising the steps of: a. combining together the peptide of claim 1, said test compound, and a preparation having β-secretase activity, under conditions allowing for β-secretase activity to occur; and b. measuring β-secretase activity. 13. The method according to claim 8, where step b. comprises measuring amounts of cleavage product produced by action of said β-secretase on said peptide substrate. 14. A method for detecting human β-secretase cleavage of a peptide substrate, said method comprising: providing a reaction system including human β-secretase, and the peptide substrate of claim 1, wherein the peptide substrate comprises a β-secretase cleavage site of β-amyloid precursor protein (APP) under conditions which permit β-secretase cleavage of the peptide substrate into β-secretase cleavage products; and detecting the amount of at least one of the β-secretase cleavage products produced as a result of β-secretase cleavage of the substrate relative to a control by binding at least one of an amino terminal end of a carboxyl terminal fragment and a carboxy terminal end of an amino terminal fragment of the peptide substrate with an antibody specific for said end. 15. A method for monitoring in vivo processing of a peptide of claim 1, said method comprising specifically detecting the presence of the peptide in a specimen from a non-human animal transformed to express the peptide, wherein the amino terminal fragment has been cleaved at the β-cleavage site of the peptide. 16. A method as in claim 15, wherein the presence of the peptide is detected by reaction of the specimen with a binding substance specific for an epitope at the carboxy terminus of the peptide. 17. A method as in claim 15, wherein the presence of the peptide is detected by reaction of the specimen with a binding substance specific for an epitope at the amino terminus of the peptide. 18. A peptide cleavage product resulting from cleavage of the peptide of claim 1 when acted upon by a β-secretase. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Few subjects in medicine today arouse the interest of the scientific community and the lay community as does Alzheimer's disease (AD). AD has emerged as the most prevalent form of late-life mental failure in humans. AD is a common dementing brain disorder of the elderly. The key features of the disease include progressive memory impairment, loss of language and visuospatial skills, and behavior deficits. These changes in cognitive function are the result of degeneration of neurons in the cerebral cortex, hippocampus, basal forebrain, and other regions of the brain. Neuropathological analyses of postmortem Alzheimer's diseased brains consistently reveal the presence of large numbers of neurofibrillary tangles in degenerated neurons and neuritic plaques in the extracellular space and in the walls of the cerebral microvasculature. The neurofibrillary tangles are composed of bundles of paired helical filaments containing hyperphosphorylated tau protein (Lee & Trojanowski, 1992, Curr. Opin. Neurobiol. 2:653-656). The neuritic plaques consist of deposits of proteinaceous material surrounding an amyloid core (Selkoe, 1994, Annu. Rev. Neurosci. 17:489-517). AD has been estimated to affect more than 4 million people in the United States alone and perhaps 17 to 25 million worldwide. Moreover, the number of sufferers is expected to grow as the population ages. The pathology of AD has been studied extensively for the last 20 years, but it was not until about 15 years ago that the first molecular handle in understanding this complex degenerative disease was obtained, when the protein sequence of the extracellular amyloid was determined. The effort to decipher the mechanism of AD has attracted the interest of investigators from diverse biological disciplines, including biochemistry, cell biology, molecular genetics, neuroscience, and structural biology. The eclectic nature of research approaches to AD and the intensity of scientific interest in the problem have made it increasingly likely that AD will become a premier example of the successful application of biological chemistry to the identification of rational therapeutic targets in a major human disease. Much of the recent progress in elucidating the pathogenesis of AD has centered on the apparent role of the 40-42-residue amyloid-protein (AP) as a unifying pathological feature of the genetically diverse forms of this complex disorder. AD is divided into 2 classes: Familial AD, (FAD) which has an early onset and is heritable, and “non-familial”, or sporadic AD (SAD), which has no identifiable cause. Although FAD is rare (less than 10% of all AD), the characteristic clinicopathological features—amyloid plaques, neurofibrillary tangles, synaptic and neuronal loss, and neurotransmitter deficits are apparently indistinguishable from the more common SAD. The defining neuropathological characteristic of AD is the accumulation of insoluble proteinacious deposits, known as amyloid plaques, in the brains of those affected. The presence of these amyloid plaque deposits is the essential observation underpinning the amyloid hypothesis. Evidence suggests that deposition of amyloid-β peptide (AD) plays a significant role in the development of amyloid plaques and the etiology of AD. For example, individuals with mutations in the gene encoding the β-amyloid precursor protein (APP) from which the AP protein is derived invariably develop Alzheimer's disease (Goate et al., 1991, Nature 353:844-846; Mullan et al., 1992, Nature Genet. 1:345-347; Murrell et al., 1991, Science 254:97-99; Van Broeckhoven, 1995, Eur. J. Neurol. 35:8-19). Likewise, autopsies have shown that amyloid plaques are found in the brains of virtually all Alzheimer's patients and that the degree of amyloid plaque deposition correlates with the degree of dementia (Cummings & Cotman, 1995, Lancet 326:1524-1587). That increased expression and/or abnormal processing of APP is associated with the formation of amyloid plaques and cerebrovascular amyloid deposits, which are one of the major morphological hallmarks of AD has been corroborated from least two sources. The first is that transgenic mice which express altered APP genes exhibit neuritic plaques and age-dependent memory deficits (Games et al., 1995, Nature 373:523-525; Masliah et al., 1996, J. Neurosci. 16:5795-5811; Hsiao et al., 1996, Science 274:99-103). The second body of evidence comes from study of patients suffering from Down's syndrome, who develop amyloid plaques and other symptoms of Alzheimer's disease at an early age (Mann & Esiri, 1989, J. Neurosci. 89:169-179). Because the APP gene is found on chromosome 21, it has been hypothesized that the increased gene dosage which results from the extra copy of this chromosome in Down's syndrome accounts for the early appearance of amyloid plaques (Kang et al., 1987, Nature 325:733-736; Tanzi et al., 1987, Science 235:880-884). Taken together with the evidence derived from cases of familial Alzheimer's disease, the current data suggest that genetic alterations which result in an increase in Aβ production can induce Alzheimer's disease. Accordingly, since Aβ deposition is an early and invariant event in Alzheimer's disease, it is believed that treatment which reduces production of Aβ will be useful in the treatment of this disease. Among the processes regulating APP metabolism, the proteolytic cleavage of APP into amyloidogenic or nonamyloidogenic fragments is of special interest. The strongest evidence implicating Aβ in the pathogenesis of AD comes from the observation that Aβ peptides are toxic to neurons in culture and transgenic mice that overproduce Aβ in their brains show significant deposition of Aβ into amyloid plaques and significant neuronal toxicity (Yankner et al., 1989, Science 245:417420; Frautschy et al., 1991, Proc. Natl. Acad. Sci. USA 88:8362-8366; Kowall et al., 1991, Proc. Natl. Acad. Sci. USA 88:7247-7251). This toxicity is enhanced if the peptides are “aged” (incubated from hours to days), a procedure that increases amyloid fibril formation. As well, injection of the insoluble, fibrillar form of AD into monkey brains results in the development of pathology (neuronal destruction, tau phosphorylation, microglial proliferation) that closely mimics Alzheimer's disease in humans (Geula et al., 1998, Nature Medicine 4:827-831). See Selkoe, 1994, J. Neuropathol. Exp. Neurol. 53:438-447 for a review of the evidence that amyloid plaques have a central role in Alzheimer's disease. While abundant evidence suggests that extracellular accumulation and deposition of Aβ is a central event in the etiology of AD, recent studies have also proposed that increased intracellular accumulation of Aβ or amyloid containing C-terminal fragments may play a role in the pathophysiology of AD. For example, over-expression of APP harboring mutations which cause familial AD results in the increased intracellular accumulation of C100 in neuronal cultures and Aβ42 in HEK 293 cells. Aβ42 is the 42 amino acid long form of AD that is believed to be more efficacious at formed amyloid plaques than shorter forms of Aβ. Moreover, evidence suggests that intra- and extracellular Aβ are formed in distinct cellular pools in hippocampal neurons and that a common feature associated with two types of familial AD mutations in APP (“Swedish” and “London”) is an increased intracellular accumulation of Aβ 42 . Thus, based on these studies and earlier reports implicating extracellular Aβ accumulation in AD pathology, it appears that altered APP catabolism may be involved in disease progression. APP is an ubiquitous membrane-spanning (type 1) glycoprotein that undergoes a variety of proteolytic processing events. (Selkoe, 1998, Trends Cell Biol. 8:447-453). APP is actually a family of peptides produced by alternative splicing from a single gene. Major forms of APP are known as APP 695 , APP 751 , and APP 770 , with the subscripts referring to the number of amino acids in each splice variant (Ponte et al., 1988, Nature 331:525-527; Tanzi et al., 1988, Nature 331:528-530; Kitaguchi et al., 1988, Nature 331:530-532). APP is expressed and constitutively catabolized in most cells. APP has a short half-life and is metabolized rapidly down two pathways in all cells. The dominant catabolic pathway appears to be cleavage of APP within the Aβ sequence by α-secretase, resulting in the constitutive secretion of a soluble extracellular domain (sAPPα) and the appearance of a nonamyloidogenic intracellular fragment (approximately 9 kD), referred to as the constitutive carboxy-terminal fragment (cCTFα). cCTFα is a suitable substrate for cleavage by γ-secretase to yield the p3 fragment. This pathway appears to be widely conserved among species and present in many cell types (Weidemann et al., 1989, Cell 57:115-126; Oltersdorf et al., 1990, J. Biol. Chem. 265:4492-4497; and Esch et al., 1990, Science 248:1122-1124). In this pathway, processing of APP involves proteolytic cleavage at a site between residues Lys 16 and Leu 17 of the AO region while APP is still in the trans-Golgi secretory compartment (Kang et al., 1987, Nature 325:773-776). Since this cleavage occurs within the Aβ portion of APP, it precludes the formation of Aβ. sAPPα has neurotrophic and neuroprotective activities (Kuentzel et al., 1993, Biochem. J. 295:367-378). In contrast to this non-amyloidogenic pathway involving α-secretase described above, proteolytic processing of APP by β-secretase exposes the N-terminus of Aβ, which after γ-secretase cleavage at the variable C-terminus, liberates Aβ. This Aβ-producing pathway involves cleavage of the Met 671 -Asp 672 bond (numbered according to the 770 amino acid isoform) by β-secretase. The C-terminus is actually a heterogeneous collection of cleavage sites rather than a single site since γ-secretase activity occurs over a short stretch of APP amino acids rather than at a single peptide bond. In the amyloidogenic pathway, APP is cleaved by β-secretase to liberate sAPPβ and CTFβ, which CTFβ is then cleaved by γ-secretase to liberate the harmful Aβ peptide. Of key importance in this Aβ-producing pathway is the position of the γ-secretase cleavage. If the γ-secretase cut is at residue 711-712, short Aβ (Aβ40) is the result; if it is cut after residue 713, long Aβ (Aβ42) is the result. Thus, the γ-secretase process is central to the production of Aβ peptide of 40 or 42 amino acids in length (Aβ40 and Aβ42, respectively). For a review that discusses APP and its processing, see Selkoe, 1998, Trends Cell. Biol. 8:447453; Selkoe, 1994, Ann. Rev. Cell Biol. 10:373-403. See also, Esch et al., 1994, Science 248:1122. Aβ, the principal component of amyloid plaques, is a 3943 amino acid peptide which is capable of forming β-pleated sheet aggregates. These aggregating fibrils are subsequently deposited in the brain parenchyma or in the cerebrovasculature of the Alzheimer's disease victim (Glenner et al., 1984, Biochem. Biophys. Res. Comm. 120:885-890; Masters et al., 1985, Proc. Natl. Acad. Sci. USA 82:4245-4249). Reports show that soluble β-amyloid peptide is produced by healthy cells into culture media (Haass et al., 1992, Nature 359:322-325) and in human and animal CSF (Seubert et al., 1992, Nature 359:325-327). Cleavage of APP can be detected in a number of convenient manners, including the detection of polypeptide or peptide fragments produced by proteolysis. Such fragments can be detected by any convenient means, such as by antibody binding. Another convenient method for detecting proteolytic cleavage is through the use of a chromogenic β-secretase substrate whereby cleavage of the substrate releases a chromogen, e.g., a colored or fluorescent, product. Various groups have cloned and sequenced cDNA encoding a protein that is believed to be β-secretase (Vassar et al., 1999, Science 286:735-741; Hussain et al., 1999, Mol. Cell. Neurosci. 14:419427; Yan et al., 1999, Nature 402:533-537; Sinha et al., 1999, Nature 402:537-540; Lin et al., 2000, Proc. Natl. Acad. Sci. USA 97:1456-1460). β-secretase has been called various names by these groups, e.g., BACE, Asp2, memapsin2. Much interest has focused on the possibility of inhibiting the development of amyloid plaques as a means of preventing or ameliorating the symptoms of Alzheimer's disease. To that end, a promising strategy is to inhibit the activity of at least one of β- and γ-secretase, the two enzymes that together are responsible for producing Aβ. This strategy is attractive because, if the formation of amyloid plaques as a result of the deposition of Aβ is a cause of Alzheimer's disease, inhibiting the activity of one or both of the two secretases would intervene in the disease process at an early stage, before late-stage events such as inflammation or apoptosis occur. Such early stage intervention is expected to be particularly beneficial (see, e.g., Citron, 2000, Molecular Medicine Today 6:392-397). Thus, it is believed that a drug that could interfere with β-amyloid plaque formation or toxicity may delay or halt the progression of Alzheimer's disease. At present, few suitable in vitro systems or methods exist for screening candidate drugs for the ability to inhibit or prevent the production of β-amyloid plaque. The scarcity of such screening methods may, at least in part, result from insufficient understanding of the pathogenic mechanism(s) which cause the conversion of amyloid precursor protein to the β-amyloid peptide, and ultimately to the amyloid plaque. In view of the anticipated benefits of modulating APP catabolism as a treatment for diseases such as AD, compositions and methods for modulating APP catabolism in APP-containing cells which do not substantially alter the viability of those cells, have been desired and are addressed by the present invention. For these reasons, it would be desirable to provide methods and systems for screening test compounds for the ability to inhibit or prevent the production of Aβ from APP. In particular, it would be desirable to base such methods and systems on a metabolic pathway which is involved in such conversion, where the test compound would be able to interrupt or interfere with the metabolic pathway which leads to conversion. In particular, initial methods should utilize in vitro systems rather than animal models, so that the methods are particularly suitable for initial screening of test compounds to identify suitable candidate drugs. |
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