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pubmed23n0001_1200 | [Analysis of sheep blood serum haptoglobin]. | Three types of haptoglobin (Hp), differing in the number of bands of Hp--Hb complex on polyacrylamide gel electrophoregramm are found in sheep blood serum. HpA, HpB and HpC fractions included one, two-three and six-eight bands respectively. A modified procedure for the HpC isolation is described. Effects of urea, sodium dodecylsulpate, beta-mercaptoethanol, pH and maleinization on the behaviour of HpC under polyacrylamide gel electrophoresis is studied. The data obtained suggest that the HpC molecule consists of two subunits (of alpha and beta types), bound with S--S bounds in an alphabeta-dimer, which form a whole HpC molecule for the expense of non-covalent bonds. | [Analysis of sheep blood serum haptoglobin]. Three types of haptoglobin (Hp), differing in the number of bands of Hp--Hb complex on polyacrylamide gel electrophoregramm are found in sheep blood serum. HpA, HpB and HpC fractions included one, two-three and six-eight bands respectively. A modified procedure for the HpC isolation is described. Effects of urea, sodium dodecylsulpate, beta-mercaptoethanol, pH and maleinization on the behaviour of HpC under polyacrylamide gel electrophoresis is studied. The data obtained suggest that the HpC molecule consists of two subunits (of alpha and beta types), bound with S--S bounds in an alphabeta-dimer, which form a whole HpC molecule for the expense of non-covalent bonds. | 2,330 |
pubmed23n0001_1201 | [Reaction ability and alkylation kinetics of sulfhydride groups of soluble succinate dehydrogenase]. | Inhibition kinetics of succinate--an acceptor of oxidoreductase activity of soluble succinate dehydrogenase by N-ethylmaleimide is studied. The alkylation reaction is described by the kinetic equation of the first order, its stechiometric coefficient being 1. The binding of enzyme sulphhydride groups by p-chloromercuriumbenzoate blocks the enzyme alkylation and its inhibition by oxaloacetate. Succinate protects succinate dehydrogenase from the inhibitory effect of N-ethylmaleimide. The reaction of the enzyme with an alkylating agent in the presence of different substrate concentrations corresponds kinetically to the model, according to which a sulphhydride group acts in the active site of the enzyme. pKa of this group is 7.0 at 20degreesC. The dependency of the maximal substrate oxidation reaction rate and that of the enzyme alkylation rate on pH coinside at the pH range 5.8--7.8. The presence of anions in the alkylation medium decreases the reaction ability of the active site with respect to N-ethylmaleimide. A mechanism of the initial stage of succinate oxidation with the cooperation of the sulphhydride group of the enzyme active site is postulated. | [Reaction ability and alkylation kinetics of sulfhydride groups of soluble succinate dehydrogenase]. Inhibition kinetics of succinate--an acceptor of oxidoreductase activity of soluble succinate dehydrogenase by N-ethylmaleimide is studied. The alkylation reaction is described by the kinetic equation of the first order, its stechiometric coefficient being 1. The binding of enzyme sulphhydride groups by p-chloromercuriumbenzoate blocks the enzyme alkylation and its inhibition by oxaloacetate. Succinate protects succinate dehydrogenase from the inhibitory effect of N-ethylmaleimide. The reaction of the enzyme with an alkylating agent in the presence of different substrate concentrations corresponds kinetically to the model, according to which a sulphhydride group acts in the active site of the enzyme. pKa of this group is 7.0 at 20degreesC. The dependency of the maximal substrate oxidation reaction rate and that of the enzyme alkylation rate on pH coinside at the pH range 5.8--7.8. The presence of anions in the alkylation medium decreases the reaction ability of the active site with respect to N-ethylmaleimide. A mechanism of the initial stage of succinate oxidation with the cooperation of the sulphhydride group of the enzyme active site is postulated. | 2,331 |
pubmed23n0001_1202 | [Effect of IAA on the photophosphorylation of pea isolated chloroplasts]. | Effect of IAA (10(-10)-10(-3) M) on photophosphorylation, NADP reduction and the oxygen exchange is investigated. It is shown that low concentrations of IAA (10(-10)-10(-7) M) increase the photophosphorylation reaction and the flow of electrones to NADP under the phosphorylation conditions in the chloroplasts, and their effect on the O2 exchange is not the same in different types of photophosphorylation. It is supposed that the effect of IAA on the photophosphorylation is connected with H292 metabolism in chloroplasts and with catalase and peroxidase functions. | [Effect of IAA on the photophosphorylation of pea isolated chloroplasts]. Effect of IAA (10(-10)-10(-3) M) on photophosphorylation, NADP reduction and the oxygen exchange is investigated. It is shown that low concentrations of IAA (10(-10)-10(-7) M) increase the photophosphorylation reaction and the flow of electrones to NADP under the phosphorylation conditions in the chloroplasts, and their effect on the O2 exchange is not the same in different types of photophosphorylation. It is supposed that the effect of IAA on the photophosphorylation is connected with H292 metabolism in chloroplasts and with catalase and peroxidase functions. | 2,332 |
pubmed23n0001_1203 | [Purification, molecular multiplicity and kinetic properties of "biosynthetic" L-threonine dehydratase from E. coli K-12]. | "Biosynthetic" L-threonine dehydratase was purified to homogeneous state with yield 29% of total activity from E. coli K-12. The cells were disrupted by means of ultra sound. Nucleic acids and nucleoproteins were precipitated with protamine sulphate, the proteins were fractioned with (NH4)2SO4, by gel filtration through Sephadex G-25 followed by chromatography on DEAE-cellulose using stepways elution by changing the pH-values. The homogenity of the enzyme was shown by polyacrylamide gel disc electrophoresis in the presence of dodecylsulphate. The enzyme consists of equal subunits having a molecular weight about 57000. The polyacrylamide gel disc electrophoresis had shown that the native enzyme consists of a set of oligomeric forms. The multiplisity of molecular organization of the enzyme was relfected in complicated kinetic behavior: at pH greater than 9 on the plots of initial reaction rate (upsilon) versus initial substrate concentration ([S]0) there were four inflexion points (two intermediate plateaux) the position and deepness of which depended on enzyme concentration. Kinetic properties of the highly purified enzyme and the enzyme in crude cell extracts at pH 9.3 and 7.4 were identical. At pH 8,3 on the upsilon versus [S]0 plots appeared two inflexion points (one intermediate plateau), the position of which practically did not depend on enzyme concentration in the reaction mixture but strongly depended on the enzyme concentration in the stock solution. Repeated polyacrylamide gel disc electrophoresis of several oligomeric forms isolated by the first electrophoresis had shown that oligomeric forms underwent a slow polymerization. It is suggested that "biosynthetic" L-threonine dehydratase from E. coli K-12 is a set of multiple oligomeric forms having different kinetic parameters. Probably, each form of the enzyme has a "simple" kinetics characterized by hyperbolic or sigmoidal shape of upsilon versus [S]0 plots. The rate of equilibrium between the oligomeric forms is small in comparison with the enzyme reaction velosity, that lead to the complex kinetic curves appearing as a result of summing up the kinetics inherent to the individual forms. | [Purification, molecular multiplicity and kinetic properties of "biosynthetic" L-threonine dehydratase from E. coli K-12]. "Biosynthetic" L-threonine dehydratase was purified to homogeneous state with yield 29% of total activity from E. coli K-12. The cells were disrupted by means of ultra sound. Nucleic acids and nucleoproteins were precipitated with protamine sulphate, the proteins were fractioned with (NH4)2SO4, by gel filtration through Sephadex G-25 followed by chromatography on DEAE-cellulose using stepways elution by changing the pH-values. The homogenity of the enzyme was shown by polyacrylamide gel disc electrophoresis in the presence of dodecylsulphate. The enzyme consists of equal subunits having a molecular weight about 57000. The polyacrylamide gel disc electrophoresis had shown that the native enzyme consists of a set of oligomeric forms. The multiplisity of molecular organization of the enzyme was relfected in complicated kinetic behavior: at pH greater than 9 on the plots of initial reaction rate (upsilon) versus initial substrate concentration ([S]0) there were four inflexion points (two intermediate plateaux) the position and deepness of which depended on enzyme concentration. Kinetic properties of the highly purified enzyme and the enzyme in crude cell extracts at pH 9.3 and 7.4 were identical. At pH 8,3 on the upsilon versus [S]0 plots appeared two inflexion points (one intermediate plateau), the position of which practically did not depend on enzyme concentration in the reaction mixture but strongly depended on the enzyme concentration in the stock solution. Repeated polyacrylamide gel disc electrophoresis of several oligomeric forms isolated by the first electrophoresis had shown that oligomeric forms underwent a slow polymerization. It is suggested that "biosynthetic" L-threonine dehydratase from E. coli K-12 is a set of multiple oligomeric forms having different kinetic parameters. Probably, each form of the enzyme has a "simple" kinetics characterized by hyperbolic or sigmoidal shape of upsilon versus [S]0 plots. The rate of equilibrium between the oligomeric forms is small in comparison with the enzyme reaction velosity, that lead to the complex kinetic curves appearing as a result of summing up the kinetics inherent to the individual forms. | 2,333 |
pubmed23n0001_1204 | [Purification and some properties of electrophoretic variants of 6-phosphogluconate dehydrogenase from rat erythrocytes]. | Purification procedure of electrophoretic variants FF and SS of 6-phosphogluconate dehydrogenase (6-PGD) is described. The method includes (NH4)2SO4 fractionation and chromatography on DEAE- and CM-celluloses. Isoenzymes were purified about 5000 fold, and were found to be homogenous by disc electrophoresis in 7% polyacrylamide gel. It was found by comparative studies of activities of variants FF and SS, that pH optimum was 8.2 for variant FF and 8.8 for variant SS. Km for 6-phosphogluconate were found to be 17,5-10(-5) M for variants SS and FF respectively. | [Purification and some properties of electrophoretic variants of 6-phosphogluconate dehydrogenase from rat erythrocytes]. Purification procedure of electrophoretic variants FF and SS of 6-phosphogluconate dehydrogenase (6-PGD) is described. The method includes (NH4)2SO4 fractionation and chromatography on DEAE- and CM-celluloses. Isoenzymes were purified about 5000 fold, and were found to be homogenous by disc electrophoresis in 7% polyacrylamide gel. It was found by comparative studies of activities of variants FF and SS, that pH optimum was 8.2 for variant FF and 8.8 for variant SS. Km for 6-phosphogluconate were found to be 17,5-10(-5) M for variants SS and FF respectively. | 2,334 |
pubmed23n0001_1205 | [Comparative study of glutamate dehydrogenases of Chlorella]. | The kinetic properties of the constitutive double specific glutamate dehydrogenase (NAD(P)--GDH) and the inducible NADP-specific glutamate dehydrogenase (NADP--GDH) of Chlorella pyrenoidosa Pringsheim 82T (thermophilic strain) in a deaminating reaction have been studied. NAD(P)-GDH behaves in a deamination as a Michaelis-Menten enzyme. NADP-GDH displays some lag-period before a steady-state phase. The duration of this lag depends on a substrate concentration. Besides that, an effect of all the substrates on a heat inactivation of both GDH and a product inhibition have been studied. All the substrates except the reduced co-factors protect effectively GDH from the heat inactivation, especially the thermolabille NADP-GDH. On the contrary, NAD(P)-H promote the heat inactivation of both GDH. The product inhibition analysis shows that the inducible NADP-GDH acts in vivo as a synthetic enzyme. In the previous paper (V. R. Shatilov et all., 1974, Dokl. Acad. Nauk USSR, 216,223) it was shown for the constitutive GDH that p-CMB strongly inhibited a desamination and slightly (if any) affect an amination. It this paper it is shown that action of p-CMB on the amination depends on the presence of NAD+ (not NADP+ or L-glutamate). p-CMB and NAD+ affect tha amination in a strongly sunergetic manner. Some suggestions about the intracellular localization of chlorella GDH are made. | [Comparative study of glutamate dehydrogenases of Chlorella]. The kinetic properties of the constitutive double specific glutamate dehydrogenase (NAD(P)--GDH) and the inducible NADP-specific glutamate dehydrogenase (NADP--GDH) of Chlorella pyrenoidosa Pringsheim 82T (thermophilic strain) in a deaminating reaction have been studied. NAD(P)-GDH behaves in a deamination as a Michaelis-Menten enzyme. NADP-GDH displays some lag-period before a steady-state phase. The duration of this lag depends on a substrate concentration. Besides that, an effect of all the substrates on a heat inactivation of both GDH and a product inhibition have been studied. All the substrates except the reduced co-factors protect effectively GDH from the heat inactivation, especially the thermolabille NADP-GDH. On the contrary, NAD(P)-H promote the heat inactivation of both GDH. The product inhibition analysis shows that the inducible NADP-GDH acts in vivo as a synthetic enzyme. In the previous paper (V. R. Shatilov et all., 1974, Dokl. Acad. Nauk USSR, 216,223) it was shown for the constitutive GDH that p-CMB strongly inhibited a desamination and slightly (if any) affect an amination. It this paper it is shown that action of p-CMB on the amination depends on the presence of NAD+ (not NADP+ or L-glutamate). p-CMB and NAD+ affect tha amination in a strongly sunergetic manner. Some suggestions about the intracellular localization of chlorella GDH are made. | 2,335 |
pubmed23n0001_1206 | [Fibril formation in solutions of solubilized collagen]. | Influence of the preparations of bacterial proteinases, protorisine and prototerrisine, was studied on the stability of the mature collagen of beef skin. The chemical composition of the tissue has been shown to be changed by these enzymes inconsiderably. The tissue treated by orisine and terrisine is completely dissolved in 0.5 M acetic acid (solubilized collagen). When the solutions of such collagen are heated to 37 degrees within the pH range from 4 to 10 at the ionic strength of 0.25 fibrils are formed. Under electron microscope fibres are cross-striated that is typical of native collagen fibres with periodicity of about 640 A. After chilling to 4 degrees, a part of fibrils is dissolved again. Nephlometry was used to study the rate of fibril formation as a function of pH and temperature values. A conclusion has been drawn that the mature collagne dissolved after incubation with bacterial proteinases is close to the acid-soluble collagen fraction in the ability to produce fibres upon heating. | [Fibril formation in solutions of solubilized collagen]. Influence of the preparations of bacterial proteinases, protorisine and prototerrisine, was studied on the stability of the mature collagen of beef skin. The chemical composition of the tissue has been shown to be changed by these enzymes inconsiderably. The tissue treated by orisine and terrisine is completely dissolved in 0.5 M acetic acid (solubilized collagen). When the solutions of such collagen are heated to 37 degrees within the pH range from 4 to 10 at the ionic strength of 0.25 fibrils are formed. Under electron microscope fibres are cross-striated that is typical of native collagen fibres with periodicity of about 640 A. After chilling to 4 degrees, a part of fibrils is dissolved again. Nephlometry was used to study the rate of fibril formation as a function of pH and temperature values. A conclusion has been drawn that the mature collagne dissolved after incubation with bacterial proteinases is close to the acid-soluble collagen fraction in the ability to produce fibres upon heating. | 2,336 |
pubmed23n0001_1207 | PAH clearance, sodium excretion, and PAH extraction ratio in acidotic near-term lambs treated with hypertonic sodium bicarbonate. | The electrolyte changes and renal hemodynamic adjustment to hypertonic sodium bicarbonate (NaHCO3) correction of a metabolic acidosis were studied in 4 neonatal lambs and in 2 controls. PAH clearance increased from 0.92 to 1.65 ml/min/kg (p less than 0.05), urine flow from 0.37 to 0.61 ml/min/kg (p less than 0.05), and Na excretion from 8.4 to 23.7 muEq/min/kg (p less than 0.05) during the NaHCO3 infusion. These increases were transient and returned to pre-infusion levels following NaHCO3 infusion. Calculation of Na intake and output revealed a net retention of 5.1 mEq/kg in the study lambs which was reflected in a rise of serum Na and osmolarity (Osm) during the post-NaHCO3 -infusion period. The extraction ratio of sodium p-aminohippurate (EPAH) and its relationship to arterial pH were studied in 4 additional lambs. The EPAH did not change with metabolic acidosis but for unknown reasons, the infusion of NaHCO3 resulted in a temporary depression of EPAH (p less than 0.001). | PAH clearance, sodium excretion, and PAH extraction ratio in acidotic near-term lambs treated with hypertonic sodium bicarbonate. The electrolyte changes and renal hemodynamic adjustment to hypertonic sodium bicarbonate (NaHCO3) correction of a metabolic acidosis were studied in 4 neonatal lambs and in 2 controls. PAH clearance increased from 0.92 to 1.65 ml/min/kg (p less than 0.05), urine flow from 0.37 to 0.61 ml/min/kg (p less than 0.05), and Na excretion from 8.4 to 23.7 muEq/min/kg (p less than 0.05) during the NaHCO3 infusion. These increases were transient and returned to pre-infusion levels following NaHCO3 infusion. Calculation of Na intake and output revealed a net retention of 5.1 mEq/kg in the study lambs which was reflected in a rise of serum Na and osmolarity (Osm) during the post-NaHCO3 -infusion period. The extraction ratio of sodium p-aminohippurate (EPAH) and its relationship to arterial pH were studied in 4 additional lambs. The EPAH did not change with metabolic acidosis but for unknown reasons, the infusion of NaHCO3 resulted in a temporary depression of EPAH (p less than 0.001). | 2,340 |
pubmed23n0001_1208 | On the proteolytic acitivity of ribosomes. | The presence of a proteinase on polysomes, isolated from rat liver has been demonstrated. The proteinase was not removed from polysomes upon treatment of the latter with 0,5 M ammonium chloride. The pH optimum of the enzymes is at pH 7,0. | On the proteolytic acitivity of ribosomes. The presence of a proteinase on polysomes, isolated from rat liver has been demonstrated. The proteinase was not removed from polysomes upon treatment of the latter with 0,5 M ammonium chloride. The pH optimum of the enzymes is at pH 7,0. | 2,337 |
pubmed23n0001_1209 | [Correction of plasma hemoglobin measurements in calculating a hemolysis index]. | A "haemolysis index" may be defined from plasma haemoglobin concentration. This is useful in evaluating the consequences of the artificial kidneys and lungs (pumps and circuitry). Measurements must be taken repeatedly, and corrections made for variations in plasma volume from standard conditions (haematocrit or total haemoglobin) to obtain meaningful comparisons. The "haemolysis index" must take into account the number of passages through the circuit. | [Correction of plasma hemoglobin measurements in calculating a hemolysis index]. A "haemolysis index" may be defined from plasma haemoglobin concentration. This is useful in evaluating the consequences of the artificial kidneys and lungs (pumps and circuitry). Measurements must be taken repeatedly, and corrections made for variations in plasma volume from standard conditions (haematocrit or total haemoglobin) to obtain meaningful comparisons. The "haemolysis index" must take into account the number of passages through the circuit. | 2,343 |
pubmed23n0001_1210 | [Study of the osmotic behaviour of human platelets]. | Observation of the behaviour of platelets in hypotonic media affords an approach to the evaluation of their fragility. It should be possible to apply such a test to various fields such as the study of rheological properties of platelets, the investigation of certain pathological cases and eventual alterations during storage. The curve obtained reflects a continuous distribution of platelet osmotic fragility. | [Study of the osmotic behaviour of human platelets]. Observation of the behaviour of platelets in hypotonic media affords an approach to the evaluation of their fragility. It should be possible to apply such a test to various fields such as the study of rheological properties of platelets, the investigation of certain pathological cases and eventual alterations during storage. The curve obtained reflects a continuous distribution of platelet osmotic fragility. | 2,344 |
pubmed23n0001_1211 | Oxygen transport by haemoglobin. A comparison of whole blood, washed erythrocytes and haemoglobin solution. | The properties of haemoglobin oxygen transport were compared under three different conditions: red cell in its natural medium, i.e. plasma (whole blood), washed red cell and haemoglobin A, the former suspended, the latter solved in an iso-osmotic tris buffer. The oxygen haemoglobin affinity (expressed as P50) and the respiratory Bohr effect variations were studied with modified media and unchanged pH and 2,3-diphosphoglycerate (2,3-DPG) concentration. Provided they are refered to intra-erythrocytic pH, none of these values were changed when varying environment. These results suggest that the three major ligands (H+ ions, 2,3-DPG and CO2) interaction with haemoglobin is largely predominant upon other factors which would interfere, and can completely account for oxygen transport by haemoglobin. | Oxygen transport by haemoglobin. A comparison of whole blood, washed erythrocytes and haemoglobin solution. The properties of haemoglobin oxygen transport were compared under three different conditions: red cell in its natural medium, i.e. plasma (whole blood), washed red cell and haemoglobin A, the former suspended, the latter solved in an iso-osmotic tris buffer. The oxygen haemoglobin affinity (expressed as P50) and the respiratory Bohr effect variations were studied with modified media and unchanged pH and 2,3-diphosphoglycerate (2,3-DPG) concentration. Provided they are refered to intra-erythrocytic pH, none of these values were changed when varying environment. These results suggest that the three major ligands (H+ ions, 2,3-DPG and CO2) interaction with haemoglobin is largely predominant upon other factors which would interfere, and can completely account for oxygen transport by haemoglobin. | 2,345 |
pubmed23n0001_1212 | Kinetics of the disordered chain-to-beta transformation of poly(L-tyrosine) in aqueous solution. | The kinetics of the transformation of poly(L-tyrosine) from the disordered chain to the intramolecular beta structure in aqueous solution has been studied. The reaction is induced by an isothermal pH jump and is followed by conventional circular dichroism methods. Upon application of curve-fitting procedures, it is found that the kinetics are poorly represented by a single first-order process, but a two-step sequential first-order equation is adequate. Sharp pH-dependent maxima in the phenomenological rate constants and in the fractional amplitude of the rapid step were found. It is proposed to attribute these phenomena to a transition in initial states which is shown to occur over the same pH range within the domain of the disordered-to-beta transition. No sigmoid transient curves were observed, indicating that no slow nucleation events are discernible in this system. These observations contrast strikingly with the mechanism elaborated for beta formation in (Lys)n [R. Hartman et al., J. Mol. Biol. 90 (1974) 415]. | Kinetics of the disordered chain-to-beta transformation of poly(L-tyrosine) in aqueous solution. The kinetics of the transformation of poly(L-tyrosine) from the disordered chain to the intramolecular beta structure in aqueous solution has been studied. The reaction is induced by an isothermal pH jump and is followed by conventional circular dichroism methods. Upon application of curve-fitting procedures, it is found that the kinetics are poorly represented by a single first-order process, but a two-step sequential first-order equation is adequate. Sharp pH-dependent maxima in the phenomenological rate constants and in the fractional amplitude of the rapid step were found. It is proposed to attribute these phenomena to a transition in initial states which is shown to occur over the same pH range within the domain of the disordered-to-beta transition. No sigmoid transient curves were observed, indicating that no slow nucleation events are discernible in this system. These observations contrast strikingly with the mechanism elaborated for beta formation in (Lys)n [R. Hartman et al., J. Mol. Biol. 90 (1974) 415]. | 2,346 |
pubmed23n0001_1213 | Thermodynamic investigations of proteins. I. Standard functions for proteins with lysozyme as an example. | A direct method is proposed for obtaining thermodynamic standard functions for native and denatured proteins using experimental data from scanning calorimetry, isothermal calorimetry and potentiometric titrations. The possibility of this approach is demonstrated on the example of lysozyme in the range of pH 1.5-7.0 and temperature 0-100 degrees C. Tests for the validity of the obtained functions of enthalpy and entropy are presented in the form of cyclic processes using experimental data obtained from thermodynamically different pathways. The Gibbs function is checked by comparison with results of an independent method. The methodic problems in determining and checking standard functions for proteins are discussed in detail. | Thermodynamic investigations of proteins. I. Standard functions for proteins with lysozyme as an example. A direct method is proposed for obtaining thermodynamic standard functions for native and denatured proteins using experimental data from scanning calorimetry, isothermal calorimetry and potentiometric titrations. The possibility of this approach is demonstrated on the example of lysozyme in the range of pH 1.5-7.0 and temperature 0-100 degrees C. Tests for the validity of the obtained functions of enthalpy and entropy are presented in the form of cyclic processes using experimental data obtained from thermodynamically different pathways. The Gibbs function is checked by comparison with results of an independent method. The methodic problems in determining and checking standard functions for proteins are discussed in detail. | 2,347 |
pubmed23n0001_1214 | Thermodynamic investigations of proteins. III. Thermodynamic description of lysozyme. | Standard functions of enthalpy, entropy and the Gibbs energy of native and denatured lysozyme in the range of 0-100 degrees C and pH 1.5-7.0 are represented in three-dimensional projections. The denaturational Gibbs energy change reaches 16 kcal mol-1 at conditions of maximal protein stability (0 degrees C, pH 4.5-7.0) and equals 14.5 kcal mol-1 at 25 degrees C and neutral pH. This result was found to be in agreement with the data reported from guanidine hydrochloride denaturation studies. Partial thermodynamic functions of the conformational and ionizational changes of the protein are obtained from entropy and Gibbs-energy changes in denaturation. The conformational partial entropy and Gibbs-energy change are found to be independent of pH. The pH-dependent partial ionizational entropy and Gibbs-energy changes are induced by normalization of the ionization behaviour of buried groups and cause a decrease of protein stability. | Thermodynamic investigations of proteins. III. Thermodynamic description of lysozyme. Standard functions of enthalpy, entropy and the Gibbs energy of native and denatured lysozyme in the range of 0-100 degrees C and pH 1.5-7.0 are represented in three-dimensional projections. The denaturational Gibbs energy change reaches 16 kcal mol-1 at conditions of maximal protein stability (0 degrees C, pH 4.5-7.0) and equals 14.5 kcal mol-1 at 25 degrees C and neutral pH. This result was found to be in agreement with the data reported from guanidine hydrochloride denaturation studies. Partial thermodynamic functions of the conformational and ionizational changes of the protein are obtained from entropy and Gibbs-energy changes in denaturation. The conformational partial entropy and Gibbs-energy change are found to be independent of pH. The pH-dependent partial ionizational entropy and Gibbs-energy changes are induced by normalization of the ionization behaviour of buried groups and cause a decrease of protein stability. | 2,348 |
pubmed23n0001_1215 | The self-association of adenosine-5'-triphosphate studied by circular dichroism at low ionic strengths. | The self-association of adenosine-5'-triphosphate (ATP) was studied as a function of pH, additional counterions, concentration and temperature. Circular dichroism measurements were employed as a measure of the base-stacking. The self-association of ATP is pH dependent with the protonation of the adenine ring helping stabilize the association. Highly charged counterions alter this aggregation. At pH 2.8 and 20 degrees C, a dimerization constant of 88 M-1 is obtained, while an isodesmic model leads to an equilibrium constant of 158 M-1. With increasing pH, the association constants decrease. At pH 2.8 there is a very strong temperature dependence of the CD amplitude. These results indicate the existence of additional electrostatic stabilization for the stacking of the adenine rings. At acidic pHs, models are proposed to explain this high degree of stability and a calculation of the approximate electrostatic contribution to the aggregation shows it to be of the proper magnitude. | The self-association of adenosine-5'-triphosphate studied by circular dichroism at low ionic strengths. The self-association of adenosine-5'-triphosphate (ATP) was studied as a function of pH, additional counterions, concentration and temperature. Circular dichroism measurements were employed as a measure of the base-stacking. The self-association of ATP is pH dependent with the protonation of the adenine ring helping stabilize the association. Highly charged counterions alter this aggregation. At pH 2.8 and 20 degrees C, a dimerization constant of 88 M-1 is obtained, while an isodesmic model leads to an equilibrium constant of 158 M-1. With increasing pH, the association constants decrease. At pH 2.8 there is a very strong temperature dependence of the CD amplitude. These results indicate the existence of additional electrostatic stabilization for the stacking of the adenine rings. At acidic pHs, models are proposed to explain this high degree of stability and a calculation of the approximate electrostatic contribution to the aggregation shows it to be of the proper magnitude. | 2,349 |
pubmed23n0001_1216 | Studies on immobilized trypsin in high concentrations of organic solvents. | Trypsin was covalently immobilized on porous glass in the presence and absence of a specific substrate and reacted in various organic solvents of different dielectric constants. Optimum solvent concentration, pH profile, Km(app), Vmax(app), productivity versus temperature, activity, and reaction rates were determined. Reaction rates of six lysyl dipeptides were compared. Crystalline trypsin was dansylated for studies by nanosecond fluorescence techniques to determine the effects of introducing high concentrations of organic solvents on the molecule. The results indicated that greater reaction rates were observed with dipeptides having more acidic carboxyl terminal groups. The data also indicated that greater reaction rates were observed in higher concentrations of solvents of lower dielectric constants. Nanosecond fluorescence spectroscopy of trypsin in high concentrations of a low dielectric constant solvent indicated major dehydration even though maximal enzyme activity was achieved under these conditions. | Studies on immobilized trypsin in high concentrations of organic solvents. Trypsin was covalently immobilized on porous glass in the presence and absence of a specific substrate and reacted in various organic solvents of different dielectric constants. Optimum solvent concentration, pH profile, Km(app), Vmax(app), productivity versus temperature, activity, and reaction rates were determined. Reaction rates of six lysyl dipeptides were compared. Crystalline trypsin was dansylated for studies by nanosecond fluorescence techniques to determine the effects of introducing high concentrations of organic solvents on the molecule. The results indicated that greater reaction rates were observed with dipeptides having more acidic carboxyl terminal groups. The data also indicated that greater reaction rates were observed in higher concentrations of solvents of lower dielectric constants. Nanosecond fluorescence spectroscopy of trypsin in high concentrations of a low dielectric constant solvent indicated major dehydration even though maximal enzyme activity was achieved under these conditions. | 2,353 |
pubmed23n0001_1217 | Enzyme immobilization on fibrin. | The following conclusions can be drawn concerning the utilization of fibrin to immobilized enzyme systems. Fibrin can be used both as a powder or membrane, to covalently immobilize trypsin with retention of activity. Carbon-14 labeled trypsin can be used to estimate the amount of immobilized enzyme on a proteinaceous support. Significant amounts of noncovalently coupled (adsorbed) enzyme are present on the surface of the support. Esterase activity of the immobilized labeled trypsin was inversely proportional to the amount of attached enzyme. Optimum TAME hydrolysis occurred at pH 8-8.4. The storage stability of trypsin was enhanced. Inhibition of trypsin esterase activity occurred at substrate concentrations greater than 30mM. | Enzyme immobilization on fibrin. The following conclusions can be drawn concerning the utilization of fibrin to immobilized enzyme systems. Fibrin can be used both as a powder or membrane, to covalently immobilize trypsin with retention of activity. Carbon-14 labeled trypsin can be used to estimate the amount of immobilized enzyme on a proteinaceous support. Significant amounts of noncovalently coupled (adsorbed) enzyme are present on the surface of the support. Esterase activity of the immobilized labeled trypsin was inversely proportional to the amount of attached enzyme. Optimum TAME hydrolysis occurred at pH 8-8.4. The storage stability of trypsin was enhanced. Inhibition of trypsin esterase activity occurred at substrate concentrations greater than 30mM. | 2,354 |
pubmed23n0001_1218 | [Neuro-muscular synapse ultrastructure in the Lambert-Eaton myasthenic syndrome]. | A study was made of the ultrastructure of the neuro-muscular synapses in the patients with the myasthenic Lambert-Eaton syndrome. Most of the synapses displayed an increased content of synaptic vesicles in the axon terminals, and the anastomosing synaptic folds were increased in number and depth. Local destructive changes were found in the terminals of some synapses. The data obtained confirmed the fact that this syndrome was underlied by disorder of the transmitter release from the presynaptic structures. | [Neuro-muscular synapse ultrastructure in the Lambert-Eaton myasthenic syndrome]. A study was made of the ultrastructure of the neuro-muscular synapses in the patients with the myasthenic Lambert-Eaton syndrome. Most of the synapses displayed an increased content of synaptic vesicles in the axon terminals, and the anastomosing synaptic folds were increased in number and depth. Local destructive changes were found in the terminals of some synapses. The data obtained confirmed the fact that this syndrome was underlied by disorder of the transmitter release from the presynaptic structures. | 2,356 |
pubmed23n0001_1219 | Prostaglandins in pyometrial fluid from the cow, bitch and ferret. | 1 Pyometra is a disorder of the uterus usually associated with bacterial infection plus obstruction. 2 Large quantities of fluid often collect in the uterus during this condition. 3 Pyometrial fluid obtained from three species was found to contain prostaglandin F2alpha, usually in large quantities. 4 Prostaglandin E2 was present in smaller quantities in five of the six samples. 5 These findings are discussed in relation to the known occurrence of prostaglandins in inflammatory fluid, and to the problem of infertility. | Prostaglandins in pyometrial fluid from the cow, bitch and ferret. 1 Pyometra is a disorder of the uterus usually associated with bacterial infection plus obstruction. 2 Large quantities of fluid often collect in the uterus during this condition. 3 Pyometrial fluid obtained from three species was found to contain prostaglandin F2alpha, usually in large quantities. 4 Prostaglandin E2 was present in smaller quantities in five of the six samples. 5 These findings are discussed in relation to the known occurrence of prostaglandins in inflammatory fluid, and to the problem of infertility. | 2,358 |
pubmed23n0001_1220 | Assessment in the guinea-pig ileum and mouse vas deferens of benzomorphans which have strong antinociceptive activity but do not substitute for morphine in the dependent monkey. | 1 Four benzomorphans which have potent antinociceptive activity in the hot-plate and writhing tests in the mouse but do not suppress or precipitate withdrawal symptoms in the morphine-dependent monkey, have been examined for their pharmacological actions in the guinea-pig ileum and mouse vas deferens. 2 In the guinea-pig ileum their agonist potencies are 1.5 to 400 times greater than that of normorphine of morphine whereas in the mouse vas deferens their potencies relative to morphine are 0.3 to 100. They exhibit no antagonist activity in either preparation. Benzomorphans which substitute for morphine in the morphine-dependent monkey do not show such differences between their relative potencies in the guinea-pig ileum and mouse vas diferens. 3 The relative potencies of the four benzomorphans to inhibit stereospecific [3H]-dihydromorphine binding by membrane fragments from rat brain, are more closely related to their relative agonist potencies in the mouse vas deferens than to those found in the guinea-pig ileum. 4 In order to antagonize the agonist actions of these benzomorphans, naloxone is required in concentrations which are 3 to 7 times higher than those needed for the antagonism of normorphine or morphine or of benzomorphans which suppress abstinence in morphine-dependent monkeys. 5 It may be possible to use the three assays, namely, ratio of relative agonist potency in mouse vas deferens to that in guinea-pig ileum, ratio of relative agonist potency to relative affinity to opiate receptors and the concentration of nalozone required for antagonism, for the prediction of the potential of new compounds to produce physical dependence. | Assessment in the guinea-pig ileum and mouse vas deferens of benzomorphans which have strong antinociceptive activity but do not substitute for morphine in the dependent monkey. 1 Four benzomorphans which have potent antinociceptive activity in the hot-plate and writhing tests in the mouse but do not suppress or precipitate withdrawal symptoms in the morphine-dependent monkey, have been examined for their pharmacological actions in the guinea-pig ileum and mouse vas deferens. 2 In the guinea-pig ileum their agonist potencies are 1.5 to 400 times greater than that of normorphine of morphine whereas in the mouse vas deferens their potencies relative to morphine are 0.3 to 100. They exhibit no antagonist activity in either preparation. Benzomorphans which substitute for morphine in the morphine-dependent monkey do not show such differences between their relative potencies in the guinea-pig ileum and mouse vas diferens. 3 The relative potencies of the four benzomorphans to inhibit stereospecific [3H]-dihydromorphine binding by membrane fragments from rat brain, are more closely related to their relative agonist potencies in the mouse vas deferens than to those found in the guinea-pig ileum. 4 In order to antagonize the agonist actions of these benzomorphans, naloxone is required in concentrations which are 3 to 7 times higher than those needed for the antagonism of normorphine or morphine or of benzomorphans which suppress abstinence in morphine-dependent monkeys. 5 It may be possible to use the three assays, namely, ratio of relative agonist potency in mouse vas deferens to that in guinea-pig ileum, ratio of relative agonist potency to relative affinity to opiate receptors and the concentration of nalozone required for antagonism, for the prediction of the potential of new compounds to produce physical dependence. | 2,359 |
pubmed23n0001_1221 | The actions of flupenthixol upon 5-hydroxytryptamine-induced aggregation and the uptake of 5-hydroxytryptamine and dopamine by human blood platelets. | The effects of the alpha- and beta-isomers of flupenthixol on 5-hydroxytryptamine (5-HT)-induced platelet aggregation and on 5-HT and dopamine uptake were investigated. Alpha-Flupenthixol was 185 times more potent than the beta-isomer as an inhibitor of platelet aggregation. In contrast both isomers were equipotent as inhibitors of uptake of 5-HT and dopamine. The data suggest that 5-HT-induced aggregation and uptake are separate processes. | The actions of flupenthixol upon 5-hydroxytryptamine-induced aggregation and the uptake of 5-hydroxytryptamine and dopamine by human blood platelets. The effects of the alpha- and beta-isomers of flupenthixol on 5-hydroxytryptamine (5-HT)-induced platelet aggregation and on 5-HT and dopamine uptake were investigated. Alpha-Flupenthixol was 185 times more potent than the beta-isomer as an inhibitor of platelet aggregation. In contrast both isomers were equipotent as inhibitors of uptake of 5-HT and dopamine. The data suggest that 5-HT-induced aggregation and uptake are separate processes. | 2,360 |
pubmed23n0001_1222 | Evolution of functional respiratory disorders in different types of pneumoconiosis. | Three homogeneous groups of patients with silicosis, coal workers' pneumoconiosis and arc welders' pneumoconiosis had been reexamined after an interval of six years. The same examinations were repeated on each occasion with the purpose of evaluating the evolution of radiographic and functional changes. The clinical course, roentgenographic findings and results of function tests differed in the three groups. In silicosis and coal workers' pneumoconiosis the roentgenographic changes showed distinct progression. This progression was less evident in coal workers' pneumoconiosis, but deterioration of pulmonary function was more pronounced than in silicosis, apparently due to emphysema. In pneumoconiosis of welders roentgenographic changes showed a clear tendency to regression and respiratory function was not impaired. | Evolution of functional respiratory disorders in different types of pneumoconiosis. Three homogeneous groups of patients with silicosis, coal workers' pneumoconiosis and arc welders' pneumoconiosis had been reexamined after an interval of six years. The same examinations were repeated on each occasion with the purpose of evaluating the evolution of radiographic and functional changes. The clinical course, roentgenographic findings and results of function tests differed in the three groups. In silicosis and coal workers' pneumoconiosis the roentgenographic changes showed distinct progression. This progression was less evident in coal workers' pneumoconiosis, but deterioration of pulmonary function was more pronounced than in silicosis, apparently due to emphysema. In pneumoconiosis of welders roentgenographic changes showed a clear tendency to regression and respiratory function was not impaired. | 2,357 |
pubmed23n0001_1223 | Developmental variations of tyrosine hydroxylase and acetylcholinesterase in embryonic and post-hatching chicken sympathetic ganglia. | The developmental variations of tyrosine hydroxylase (TH) and of acetylcholinesterase (AChE) were studied in embryonic and post-hatching chicken sympathetic ganglia. Different levels of TH activity were found in two different flocks of White Leghorn chicken, which are probably dependent on genetic differences. These enzymatic differences, however, do not become apparent before hatching and may indicate a combined effect of genetic variation and functional demands. During the period of incubation, TH activity is characterized by a pronounced and steady increase from the twelfth day of incubation up to day 2 after hatching. This corresponds to a period of intense maturation of the sympathetic neuron. In the period following hatching, the 'fourth day fall phenomenon' previously described by us for DOPA decarboxylase (DDC), dopamine-beta-hydroxylase (DBH), and monoamine oxidase (MAO) is not seen in the TH curve. Instead, TH activity tends to remain constant between days 2 and 14 after hatching (ah). Both ganglionic protein and weight remain constant in this period, indicating a phase of general pause in protein synthesis. AChE activity increases steadily from the eighth until the twenty-first day of incubation. A sudden and significant drop in AChE activity was found at day 2 ah followed by a period of rapid increase at day 3 ah and a levelling of activity up to day 30 ah. Comparing the present variations to those observed in our previous studies on DBH, a temporal relationship between TH and DBH activity is observed during the phases of synaptogenesis and maturation but not during the phase of intense functional activity. Our results strongly suggest that before hatching in chick embryo sympathetic ganglia, the cholinergic presynaptic terminals play a role in regulating the development of the adrenergic neurons. In the period following hatching, however, the DBH and TH levels in cell bodies seem to be principally regulated by the functional activity. This results in depletion of DBH, but not TH, through liberation along with the neurotransmitter at the periphery. Depletion of DBH at the terminals may result in increased transport and thereby depletion in the cell body. This mechanism is probably responsible for the difference in the profiles of activity of DBH and TH in the cell bodies observed in the first week after hatching. | Developmental variations of tyrosine hydroxylase and acetylcholinesterase in embryonic and post-hatching chicken sympathetic ganglia. The developmental variations of tyrosine hydroxylase (TH) and of acetylcholinesterase (AChE) were studied in embryonic and post-hatching chicken sympathetic ganglia. Different levels of TH activity were found in two different flocks of White Leghorn chicken, which are probably dependent on genetic differences. These enzymatic differences, however, do not become apparent before hatching and may indicate a combined effect of genetic variation and functional demands. During the period of incubation, TH activity is characterized by a pronounced and steady increase from the twelfth day of incubation up to day 2 after hatching. This corresponds to a period of intense maturation of the sympathetic neuron. In the period following hatching, the 'fourth day fall phenomenon' previously described by us for DOPA decarboxylase (DDC), dopamine-beta-hydroxylase (DBH), and monoamine oxidase (MAO) is not seen in the TH curve. Instead, TH activity tends to remain constant between days 2 and 14 after hatching (ah). Both ganglionic protein and weight remain constant in this period, indicating a phase of general pause in protein synthesis. AChE activity increases steadily from the eighth until the twenty-first day of incubation. A sudden and significant drop in AChE activity was found at day 2 ah followed by a period of rapid increase at day 3 ah and a levelling of activity up to day 30 ah. Comparing the present variations to those observed in our previous studies on DBH, a temporal relationship between TH and DBH activity is observed during the phases of synaptogenesis and maturation but not during the phase of intense functional activity. Our results strongly suggest that before hatching in chick embryo sympathetic ganglia, the cholinergic presynaptic terminals play a role in regulating the development of the adrenergic neurons. In the period following hatching, however, the DBH and TH levels in cell bodies seem to be principally regulated by the functional activity. This results in depletion of DBH, but not TH, through liberation along with the neurotransmitter at the periphery. Depletion of DBH at the terminals may result in increased transport and thereby depletion in the cell body. This mechanism is probably responsible for the difference in the profiles of activity of DBH and TH in the cell bodies observed in the first week after hatching. | 2,367 |
pubmed23n0001_1224 | [Erythrocyte stroma included in polyacrylamide gel. Applications to affinity chromatography]. | Stromata prepared with human or animal red blood cells are suspended in acrylamide solution. Gel as prepared for electrophoresis is dispersed, before use, and can be used in chromatographic columns for the retention of agglutinins. Lectins, e.g., where first absorbed and then eluted with solution of inhibitory sugar or with acid buffer. Some applications are mentioned. | [Erythrocyte stroma included in polyacrylamide gel. Applications to affinity chromatography]. Stromata prepared with human or animal red blood cells are suspended in acrylamide solution. Gel as prepared for electrophoresis is dispersed, before use, and can be used in chromatographic columns for the retention of agglutinins. Lectins, e.g., where first absorbed and then eluted with solution of inhibitory sugar or with acid buffer. Some applications are mentioned. | 2,369 |
pubmed23n0001_1225 | [Value of the "gastric chamber", new technic performed ex vivo, for the study of the gastric mucosa of the rat]. | The "gastric chamber" technique, performed in the anaesthetised rat, enables the study of gastric mucosal fragility induced by doses of phenylbutazone, which do not themselves cause ulceration or exulceration. The perfusion of buffered solution at pH 2-8 into the gastric chamber shows that prior oral administration of phenylbutazone 50 mg/kg increases the fragility of the mucosa. The optimal delay separating this administration from the time of experimentation is 6 hours. The effects seen are essentially vascular disorders. | [Value of the "gastric chamber", new technic performed ex vivo, for the study of the gastric mucosa of the rat]. The "gastric chamber" technique, performed in the anaesthetised rat, enables the study of gastric mucosal fragility induced by doses of phenylbutazone, which do not themselves cause ulceration or exulceration. The perfusion of buffered solution at pH 2-8 into the gastric chamber shows that prior oral administration of phenylbutazone 50 mg/kg increases the fragility of the mucosa. The optimal delay separating this administration from the time of experimentation is 6 hours. The effects seen are essentially vascular disorders. | 2,370 |
pubmed23n0001_1226 | [Dopamine of the caudate nucleus in Perodictious potto, Macaca mulatta and Macaca fascicularis]. | The dopamine, dopac and tyrosinehydroxylase contents of the caudate nucleus in the prosimian Perodicticus potto and in the simii Macaca mulatta and M. fascicularis have been estimated. The results do not support the hypothesis according to which the sluggishness of the potto is somehow related to a low dopamine content of part of the extrapyramidal system as found in the Parkinson-syndrome. | [Dopamine of the caudate nucleus in Perodictious potto, Macaca mulatta and Macaca fascicularis]. The dopamine, dopac and tyrosinehydroxylase contents of the caudate nucleus in the prosimian Perodicticus potto and in the simii Macaca mulatta and M. fascicularis have been estimated. The results do not support the hypothesis according to which the sluggishness of the potto is somehow related to a low dopamine content of part of the extrapyramidal system as found in the Parkinson-syndrome. | 2,371 |
pubmed23n0001_1227 | [The effect of activator on the esterase activity of plasmin obtained by streptokinase]. | In the esterasic dosage of plasminogen, the authors aim to determine the optimal ratio between the amount of streptokinase to add and of plasminogen itself. It is essential that the activator formation be reduced, which explains the dissociations obtained with other methods. | [The effect of activator on the esterase activity of plasmin obtained by streptokinase]. In the esterasic dosage of plasminogen, the authors aim to determine the optimal ratio between the amount of streptokinase to add and of plasminogen itself. It is essential that the activator formation be reduced, which explains the dissociations obtained with other methods. | 2,372 |
pubmed23n0001_1228 | [Oxidative metabolism of funicular tissue. II. Determination of the activity of certain Krebs cycle enzymes]. | Previous experiments have suggested that a partial metabolic block might restrain the oxidative metabolism of the cord tissue between the decarboxylation of pyruvate and the oxidation of succinate. Some of the dehydrogenases of the Kreb's cycle were assayed on acetone powders prepared from human cords. Isocitrate dehydrogenases (both NAD and NADP-specific) have much lower activities than the alpha-ketoglutarate- and malate dehydrogenases; a partial block might be located at this level. Moreover, the malic enzyme has a rather high activity, and might play a significant role by regenerating NADPH in a tissue where other sources of this coenzyme are practically absent. | [Oxidative metabolism of funicular tissue. II. Determination of the activity of certain Krebs cycle enzymes]. Previous experiments have suggested that a partial metabolic block might restrain the oxidative metabolism of the cord tissue between the decarboxylation of pyruvate and the oxidation of succinate. Some of the dehydrogenases of the Kreb's cycle were assayed on acetone powders prepared from human cords. Isocitrate dehydrogenases (both NAD and NADP-specific) have much lower activities than the alpha-ketoglutarate- and malate dehydrogenases; a partial block might be located at this level. Moreover, the malic enzyme has a rather high activity, and might play a significant role by regenerating NADPH in a tissue where other sources of this coenzyme are practically absent. | 2,373 |
pubmed23n0001_1229 | [The effect of amino acids on the excitability of identified autoactive giant neurons of Achatina fulica Férussac]. | Effects of the following amino acids were examined on the electrical activity of the two giant neurones (PON and TAN) identified in the subesophageal ganglia of Achatina fulica Férussac : L-Asp, L-Thr, L-Ser, L-Glu, L-Pro, Gly, L-alpha-Ala, beta-Ala, L-cysteine, L-cystine, L-Val, L-Met, L-Ileu, L-Leu, L-Tyr, L-Phe, L-Lys, L-His, L-Arg, L-Cit, L-Try, GABA and GABOB. Among these substances, we observed an inhibitory effect of GABA and GABOB on the TAN excitability. GABA showed stronger effect on the TAN than GABOB. This effect of GABA was due to producing hyperpolarization on the TAN membrane. GABA showed a slight excitatory effect on the PON. The effect of GABOB on the PON was very weak and unstable. | [The effect of amino acids on the excitability of identified autoactive giant neurons of Achatina fulica Férussac]. Effects of the following amino acids were examined on the electrical activity of the two giant neurones (PON and TAN) identified in the subesophageal ganglia of Achatina fulica Férussac : L-Asp, L-Thr, L-Ser, L-Glu, L-Pro, Gly, L-alpha-Ala, beta-Ala, L-cysteine, L-cystine, L-Val, L-Met, L-Ileu, L-Leu, L-Tyr, L-Phe, L-Lys, L-His, L-Arg, L-Cit, L-Try, GABA and GABOB. Among these substances, we observed an inhibitory effect of GABA and GABOB on the TAN excitability. GABA showed stronger effect on the TAN than GABOB. This effect of GABA was due to producing hyperpolarization on the TAN membrane. GABA showed a slight excitatory effect on the PON. The effect of GABOB on the PON was very weak and unstable. | 2,374 |
pubmed23n0001_1230 | [Rapid production of a biotin deficiency in mice]. | This work describes a rapid method for the production of a biotin-deficiency in mice. Besides classical morphological symptoms, a decrease of activities of some biotin-dependent enzymes was also observed. The biotin-enzymes are not inhibited at the same extent in a same organ and the metabolic changes do not always follow the enzymatic modifications. | [Rapid production of a biotin deficiency in mice]. This work describes a rapid method for the production of a biotin-deficiency in mice. Besides classical morphological symptoms, a decrease of activities of some biotin-dependent enzymes was also observed. The biotin-enzymes are not inhibited at the same extent in a same organ and the metabolic changes do not always follow the enzymatic modifications. | 2,375 |
pubmed23n0001_1231 | [Ciguatera: neurophysiologic and histoenzymologic studies of several fractions of ciguatoxic extracts]. | Two fractions of ciguatoxic extracts were isolated by chromatography. The first showed anticholinesterasic properties, while the other acted directly on the muscular fibre. These findings were histoenzymologically confirmed. Controls with non-toxic extracts of fishes from the coral benthos reinforce the theory of the ecological origins of ciguatoxins. | [Ciguatera: neurophysiologic and histoenzymologic studies of several fractions of ciguatoxic extracts]. Two fractions of ciguatoxic extracts were isolated by chromatography. The first showed anticholinesterasic properties, while the other acted directly on the muscular fibre. These findings were histoenzymologically confirmed. Controls with non-toxic extracts of fishes from the coral benthos reinforce the theory of the ecological origins of ciguatoxins. | 2,376 |
pubmed23n0001_1232 | Lorazepam as a premedication. | A double-blind random study compared the effects of lorazepam and pantopon an intra-muscular premedication in healthy women for uterine curettage (D & C). Anxiety, as assessed by a self-rating test by the patient and by a trained observer, showed a significant reduction at one and one-half hours after lorazepam and a smaller reduction after pantopon, which was not significant. Sedation was satisfactory with no significant difference between the two drugs in the change before and after the premedication. Lorazepam showed much more amnesia than pantopon (p less than 0.001). The patients who had lorazepam required higher doses of thiopentone for the operation, and this, in part, led to longer intervals in recovery times after lorazepam. However, it is suggested that lorazepam itself was partly responsible for the longer recovery. Pantopon was followed by more nausea, vomiting and headaches, than lorazepam. The intra-muscular injection of lorazepam hurt more patients than did pantopon, but other local complications were negligible and comparable in both groups. The results of this study show that lorazepam produces better reduction of anxiety and much more amnesia than pantopon, with comparable sedation and much less nausea and vomiting. The only disadvantage of lorazepam is the lack of analgesia and, therefore, the need for more anaesthesia during the operation. The conclusion is that lorazepam is a very satisfactory premedication and warrants more use as such. | Lorazepam as a premedication. A double-blind random study compared the effects of lorazepam and pantopon an intra-muscular premedication in healthy women for uterine curettage (D & C). Anxiety, as assessed by a self-rating test by the patient and by a trained observer, showed a significant reduction at one and one-half hours after lorazepam and a smaller reduction after pantopon, which was not significant. Sedation was satisfactory with no significant difference between the two drugs in the change before and after the premedication. Lorazepam showed much more amnesia than pantopon (p less than 0.001). The patients who had lorazepam required higher doses of thiopentone for the operation, and this, in part, led to longer intervals in recovery times after lorazepam. However, it is suggested that lorazepam itself was partly responsible for the longer recovery. Pantopon was followed by more nausea, vomiting and headaches, than lorazepam. The intra-muscular injection of lorazepam hurt more patients than did pantopon, but other local complications were negligible and comparable in both groups. The results of this study show that lorazepam produces better reduction of anxiety and much more amnesia than pantopon, with comparable sedation and much less nausea and vomiting. The only disadvantage of lorazepam is the lack of analgesia and, therefore, the need for more anaesthesia during the operation. The conclusion is that lorazepam is a very satisfactory premedication and warrants more use as such. | 2,377 |
pubmed23n0001_1233 | Studies on fazadinium bromide (ah 8165): a new non-depolarizing neuromuscular blocking agent. | Intravenous dose-response relationships were used to correlate neuromuscular paralysis with the effects of fazadinium (AH 8165) on autonomic mechanisms in anaesthetized cats and rhesus monkeys and with cardiovascular effects in man. In cats and monkeys neuromuscular paralysis of the twitch responses of the gastrocnemius muscle by fazadinium was accompanied by impairment of the vagally induced bradycardia, but cardiovascular disturbances were small. Blockade of sympathetic mechanisms and hypotension were only evident with supra-maximal doses. In man tachycardia was a common occurrence and in some patients hypertension occurred with doses of the drug needed for complete neuromuscular paralysis. Fazadinium was three to four times more potent in rhesus monkeys than in cats and its course of action was considerably longer. The potency of the drug in man corresponded more closely to that in cats than in rhesus monkeys but its course of action in patients was similar to that in monkeys. In man, dose-response curves were constructed for the contractions of the adductor pollicis muscles elicited by tetanic and single twitch stimuli applied to the corresponding ulnar nerves. The onset of paralysis of the tetanic contractions after the intravenous injection of fazadinium (0.4 mg/kg) occurred within two minutes, but recovery was slow and about 50 minutes were needed for its completion. Depression of the simultaneously recorded twitch responses was less marked, slower in onset and recovery was slightly more rapid. These effects were similar to those obtained with tubocurarine (0.2 mg/kg) but the action of fazadinium was slightly shorter. Tetanic-tension ratios were computed after 30 and 50 per cent recovery from neruomuscular blockade in man. These ratios were lower with fazadinium than with tubocurarine and indicated taht tetanic fade was greater and more persistent after fazadinium than after tubocurarine. | Studies on fazadinium bromide (ah 8165): a new non-depolarizing neuromuscular blocking agent. Intravenous dose-response relationships were used to correlate neuromuscular paralysis with the effects of fazadinium (AH 8165) on autonomic mechanisms in anaesthetized cats and rhesus monkeys and with cardiovascular effects in man. In cats and monkeys neuromuscular paralysis of the twitch responses of the gastrocnemius muscle by fazadinium was accompanied by impairment of the vagally induced bradycardia, but cardiovascular disturbances were small. Blockade of sympathetic mechanisms and hypotension were only evident with supra-maximal doses. In man tachycardia was a common occurrence and in some patients hypertension occurred with doses of the drug needed for complete neuromuscular paralysis. Fazadinium was three to four times more potent in rhesus monkeys than in cats and its course of action was considerably longer. The potency of the drug in man corresponded more closely to that in cats than in rhesus monkeys but its course of action in patients was similar to that in monkeys. In man, dose-response curves were constructed for the contractions of the adductor pollicis muscles elicited by tetanic and single twitch stimuli applied to the corresponding ulnar nerves. The onset of paralysis of the tetanic contractions after the intravenous injection of fazadinium (0.4 mg/kg) occurred within two minutes, but recovery was slow and about 50 minutes were needed for its completion. Depression of the simultaneously recorded twitch responses was less marked, slower in onset and recovery was slightly more rapid. These effects were similar to those obtained with tubocurarine (0.2 mg/kg) but the action of fazadinium was slightly shorter. Tetanic-tension ratios were computed after 30 and 50 per cent recovery from neruomuscular blockade in man. These ratios were lower with fazadinium than with tubocurarine and indicated taht tetanic fade was greater and more persistent after fazadinium than after tubocurarine. | 2,378 |
pubmed23n0001_1234 | Biology of large bowel cancer. Present status and research frontiers. | Man and laboratory rodents exposed to chemical carcinogens both show changes in growth characteristics of colonic epithelial cells during neoplastic transformation. Progressive phases of abnormal cell development appear in colonic epithelial cells which gain an increased ability to proliferate and accumulate in the mucosa. These phases in the expression of neoplastic transformation of colonic cells are best defined in the dominant inherited disease of man as adenomatosis of the colon and rectum. Individuals with inherited adenomatosis and those in lesser risk categories can be classified by cell phenotype based on changes in the proliferation and maturation of colonic and other cells. These classifications are leading to new predictive indices which identify heightened degrees of susceptibility of individuals who are at increased risk for colon cancer, and the stage of development of their disease. The indices also are being used to study the contribution of specific elements in the enviroment that modify or accelerate the progression of disease. | Biology of large bowel cancer. Present status and research frontiers. Man and laboratory rodents exposed to chemical carcinogens both show changes in growth characteristics of colonic epithelial cells during neoplastic transformation. Progressive phases of abnormal cell development appear in colonic epithelial cells which gain an increased ability to proliferate and accumulate in the mucosa. These phases in the expression of neoplastic transformation of colonic cells are best defined in the dominant inherited disease of man as adenomatosis of the colon and rectum. Individuals with inherited adenomatosis and those in lesser risk categories can be classified by cell phenotype based on changes in the proliferation and maturation of colonic and other cells. These classifications are leading to new predictive indices which identify heightened degrees of susceptibility of individuals who are at increased risk for colon cancer, and the stage of development of their disease. The indices also are being used to study the contribution of specific elements in the enviroment that modify or accelerate the progression of disease. | 2,379 |
pubmed23n0001_1235 | Laboratory aids to diagnosis--enzymes. | A summary is presented of those organ specific enzyme assays traditionally used in evaluation of the patient with cancer. In addition, the use of certain serum enzymes such as gamma-glutamyl transpeptidase, phosphohexose isomerase or 5'-nucleotidase as aids in following the course of the disease, particularly in patients with metastatic spread to the liver is outlined. Also considered is the utility of enzyme analysis in biopsy tissue, biologic fluids, and washings of body cavities. Newer enzymes are considered which might, in the future, be developed as diagnostic tools or as probes for the understanding of the etiology of cancer. | Laboratory aids to diagnosis--enzymes. A summary is presented of those organ specific enzyme assays traditionally used in evaluation of the patient with cancer. In addition, the use of certain serum enzymes such as gamma-glutamyl transpeptidase, phosphohexose isomerase or 5'-nucleotidase as aids in following the course of the disease, particularly in patients with metastatic spread to the liver is outlined. Also considered is the utility of enzyme analysis in biopsy tissue, biologic fluids, and washings of body cavities. Newer enzymes are considered which might, in the future, be developed as diagnostic tools or as probes for the understanding of the etiology of cancer. | 2,380 |
pubmed23n0001_1236 | Increase in alkaline phosphatase activity in the liver of mice bearing Ehrlich ascites tumor. | In mice bearing Ehrilich ascites tumors, alkaline phosphatase activity was increased fivefold in the liver and by 50% in the kidney. In mice bearing solid tumors caused by inoculation of tumor cells into the axillary region, the activity of this enzyme in the liver was increased 11-fold, whereas the activity in the kidney did not change. Alkaline phosphatase activities in the liver and kidney were not altered by administration of adrenal steroids. Adrenalectomy, fasting, and pregnancy did not affect the activity of alkaline phosphatase in the liver and kidney. Treatment with tumor extracts or ascites fluid of normal mice increased liver alkaline phosphatase activity. These findings suggested that the elevation of liver alkaline phosphatase activity was cuased primarily by the tumor itself, and not by hormonal imbalance provoked secondarily by the presence of the tumor. | Increase in alkaline phosphatase activity in the liver of mice bearing Ehrlich ascites tumor. In mice bearing Ehrilich ascites tumors, alkaline phosphatase activity was increased fivefold in the liver and by 50% in the kidney. In mice bearing solid tumors caused by inoculation of tumor cells into the axillary region, the activity of this enzyme in the liver was increased 11-fold, whereas the activity in the kidney did not change. Alkaline phosphatase activities in the liver and kidney were not altered by administration of adrenal steroids. Adrenalectomy, fasting, and pregnancy did not affect the activity of alkaline phosphatase in the liver and kidney. Treatment with tumor extracts or ascites fluid of normal mice increased liver alkaline phosphatase activity. These findings suggested that the elevation of liver alkaline phosphatase activity was cuased primarily by the tumor itself, and not by hormonal imbalance provoked secondarily by the presence of the tumor. | 2,381 |
pubmed23n0001_1237 | Monoamine storage sites in the rat superior cervical ganglion following synthesis inhibition. | Monoamine storage sites in paraganglionic (PG-) cells of the rat superior cervical ganglion were investigated by electron and fluorescence microscopy following treatment with p-chlorophenylalanine (pCPA), disulfiram or guanethidine respectively. Dense core vesicles in PG-cells are significantly decreased (p less than 0.001) in number following pCPA, and in the majority of these cells following disulfiram and guanethidine. However in a minor portion of PG-cells the latter agents cause an increase in number and in size of dense core vesicles, in parallel with structural alterations. In agreement with these electron microscopic findings fluorescence microscopic and cytophotometric evaluations reveal a general decrease in catecholamine content with few cells showing an increase. The findings provide a morphological basis for the assumption, that monoamine storage sites in PG-cells can be decreased by inhibition of monoamine synthesis, following administration of pCPA, disulfiram and guanethidine. However the two types of responses of PG-cells which occur after disulfiram and guanethidine demonstrate a functional heterogeneity of this cell system in the rat superior cervical ganglion which is discussed. | Monoamine storage sites in the rat superior cervical ganglion following synthesis inhibition. Monoamine storage sites in paraganglionic (PG-) cells of the rat superior cervical ganglion were investigated by electron and fluorescence microscopy following treatment with p-chlorophenylalanine (pCPA), disulfiram or guanethidine respectively. Dense core vesicles in PG-cells are significantly decreased (p less than 0.001) in number following pCPA, and in the majority of these cells following disulfiram and guanethidine. However in a minor portion of PG-cells the latter agents cause an increase in number and in size of dense core vesicles, in parallel with structural alterations. In agreement with these electron microscopic findings fluorescence microscopic and cytophotometric evaluations reveal a general decrease in catecholamine content with few cells showing an increase. The findings provide a morphological basis for the assumption, that monoamine storage sites in PG-cells can be decreased by inhibition of monoamine synthesis, following administration of pCPA, disulfiram and guanethidine. However the two types of responses of PG-cells which occur after disulfiram and guanethidine demonstrate a functional heterogeneity of this cell system in the rat superior cervical ganglion which is discussed. | 2,382 |
pubmed23n0001_1238 | Ultracytochemistry of the synaptic ribbons in the rat pineal organ. | The synaptic complexes of the rat pinealocytes are neither cholinergic nor adrenergic. In the synaptic vesicles, a neurotransmitter carrier substance of lipid nature reacting with OsO4-Zn I2 mixture (similar to that present in both cholinergic and adrenergic vesicles) was not found. In addition, there were no indications of glucose-6-phosphatase or thiamine-pyrophosphatase activity in the synaptic vesicles. Thus, it appears that the synaptic vesicles do not originate from the rough or smooth endoplasmic reticulum. The synaptic ribbons do not contain carbohydrates, are of protein nature and possess some chemical resemblance to microtubules and microtubular bouquets. Appropriate ultracytochemical reactions have not shown detectable quantities of sodium and calcium ions in pinealocyte synaptic complexes. | Ultracytochemistry of the synaptic ribbons in the rat pineal organ. The synaptic complexes of the rat pinealocytes are neither cholinergic nor adrenergic. In the synaptic vesicles, a neurotransmitter carrier substance of lipid nature reacting with OsO4-Zn I2 mixture (similar to that present in both cholinergic and adrenergic vesicles) was not found. In addition, there were no indications of glucose-6-phosphatase or thiamine-pyrophosphatase activity in the synaptic vesicles. Thus, it appears that the synaptic vesicles do not originate from the rough or smooth endoplasmic reticulum. The synaptic ribbons do not contain carbohydrates, are of protein nature and possess some chemical resemblance to microtubules and microtubular bouquets. Appropriate ultracytochemical reactions have not shown detectable quantities of sodium and calcium ions in pinealocyte synaptic complexes. | 2,383 |
pubmed23n0001_1239 | Afferent neural pathway in the regulation of cardiopulmonary responses to tissue hypermetabolism. | We studied the role of neural transmission from hypermetabolic peripheral tissues in the regulation of cardiac output and pulmonary ventilation in chloralose-anesthetized dogs. Cross-circulation techniques with femoral-femoral or femoral-aortic anastomoses were used to produce a vascularly isolated, but normally innervated, hindlimb or lower half-body, 2,4-Dinitrophenol (DNP) was infused into the arterial side of the perfusion circuit to triple oxygen consumption and to increase lactate production by the cross-perfused area. After infusion of DNP, cardiac output and mean systemic arterial blood pressure increased, but neither heart rate nor pulmonary artery wedge pressure changed significantly. Pulmonary minute ventilation and arterial pH also increased, while arterial PCO2 fell. These changes were abolished when the nerve connections between the perfused limb and its parent body were severed. Normal saline, when administered in a similar manner, did not increase either ventilation or cardiac output, and simple denervation without previous infusions of DNP also had no effect. These results indicate that there are receptors sensitive to metabolic changes in the tissue, and that neural transmission is an important afferent link in regulating the cardiopulmonary responses to increased tissue metabolism. | Afferent neural pathway in the regulation of cardiopulmonary responses to tissue hypermetabolism. We studied the role of neural transmission from hypermetabolic peripheral tissues in the regulation of cardiac output and pulmonary ventilation in chloralose-anesthetized dogs. Cross-circulation techniques with femoral-femoral or femoral-aortic anastomoses were used to produce a vascularly isolated, but normally innervated, hindlimb or lower half-body, 2,4-Dinitrophenol (DNP) was infused into the arterial side of the perfusion circuit to triple oxygen consumption and to increase lactate production by the cross-perfused area. After infusion of DNP, cardiac output and mean systemic arterial blood pressure increased, but neither heart rate nor pulmonary artery wedge pressure changed significantly. Pulmonary minute ventilation and arterial pH also increased, while arterial PCO2 fell. These changes were abolished when the nerve connections between the perfused limb and its parent body were severed. Normal saline, when administered in a similar manner, did not increase either ventilation or cardiac output, and simple denervation without previous infusions of DNP also had no effect. These results indicate that there are receptors sensitive to metabolic changes in the tissue, and that neural transmission is an important afferent link in regulating the cardiopulmonary responses to increased tissue metabolism. | 2,387 |
pubmed23n0001_1240 | Determination of the molar absorptivity of NADH. | The molar absorptivity of NADH at 340 nm has been determined by an indirect procedure in which high-purity glucose is phosphorylated by ATP in the presence of hexokinase, coupled to oxidation of the glucose-6-phosphate by NAD+ in the presence of glucose-6-phosphate dehydrogenase. The average value from 85 independent determinations is 6317 liter mol-1 cm-1 at 25 degrees C and pH 7.8. The overall uncertainty is -4.0 to +5.5 ppt (6292 to 6352 liter mol-1 cm-1), based on a standard error of the mean of 0.48 ppt and an estimate of systematic error of -2.6 to +4.1 ppt. Effects of pH, buffer, and temperature on the molar absorptivity are also reported. | Determination of the molar absorptivity of NADH. The molar absorptivity of NADH at 340 nm has been determined by an indirect procedure in which high-purity glucose is phosphorylated by ATP in the presence of hexokinase, coupled to oxidation of the glucose-6-phosphate by NAD+ in the presence of glucose-6-phosphate dehydrogenase. The average value from 85 independent determinations is 6317 liter mol-1 cm-1 at 25 degrees C and pH 7.8. The overall uncertainty is -4.0 to +5.5 ppt (6292 to 6352 liter mol-1 cm-1), based on a standard error of the mean of 0.48 ppt and an estimate of systematic error of -2.6 to +4.1 ppt. Effects of pH, buffer, and temperature on the molar absorptivity are also reported. | 2,388 |
pubmed23n0001_1241 | Molar absorptivities of beta-NADH and beta-NADPH. | Re-investigating the accuracy of the commonly used values for molar absorptivities (epsilon) of beta-NADH and beta-NADPH at Hg 334, Hg 365, or 340 nm, we obtained the following results: The maximum of absorbance of NADH is shifted from about 340 nm at 0 degrees C to about 338.5 nm at 38 degrees C; the corresponding maxima of NADPH are located at about 0.5-nm longer wavelengths. In addition, the absorption curves of both coenzymes broaden with increasing temperature. For these reasons, the epsilon-values of NADH and NADPH are generally different from each other, and are temperature-dependent. Only at 334 nm are they almost identical and nearly independent of temperature. Therefore this wavelength is recommended for precise measurements. The epsilon-values of these coenzymes are influenced by ionic strength and pH. To determine the absolute values of the molar absorptivities, we performed the glutamate dehydrogenase or lactate dehydrogenase assay with carefully purified 2-oxoglutaric acid or pyruvic acid in the presence of excess coenzyme. The purity of the substrates was checked through differential scanning calorimetry, moisture analysis, gas-liquid chromatography, gas chromatography in combination with mass spectrometry, and nuclear magnetic resonance spectroscopy. The epsilon-values observed under the various conditions are about 1-7% higher than those currently used. | Molar absorptivities of beta-NADH and beta-NADPH. Re-investigating the accuracy of the commonly used values for molar absorptivities (epsilon) of beta-NADH and beta-NADPH at Hg 334, Hg 365, or 340 nm, we obtained the following results: The maximum of absorbance of NADH is shifted from about 340 nm at 0 degrees C to about 338.5 nm at 38 degrees C; the corresponding maxima of NADPH are located at about 0.5-nm longer wavelengths. In addition, the absorption curves of both coenzymes broaden with increasing temperature. For these reasons, the epsilon-values of NADH and NADPH are generally different from each other, and are temperature-dependent. Only at 334 nm are they almost identical and nearly independent of temperature. Therefore this wavelength is recommended for precise measurements. The epsilon-values of these coenzymes are influenced by ionic strength and pH. To determine the absolute values of the molar absorptivities, we performed the glutamate dehydrogenase or lactate dehydrogenase assay with carefully purified 2-oxoglutaric acid or pyruvic acid in the presence of excess coenzyme. The purity of the substrates was checked through differential scanning calorimetry, moisture analysis, gas-liquid chromatography, gas chromatography in combination with mass spectrometry, and nuclear magnetic resonance spectroscopy. The epsilon-values observed under the various conditions are about 1-7% higher than those currently used. | 2,389 |
pubmed23n0001_1242 | Analysis for indole compounds in urine by high-performance liquid chromatography with fluorometric detection. | We describe a chromatographic system involving a high-performance chemically-bonded reverse-phase column and fluorescence detection for measurement of indoles in urine. We controlled retention and selectivity by optimizing the methanol content and pH of the mobile phase. Six reference indoles were separated in less than 20 min; three 5-hydroxyindoles were eluted in less than 7 min. About 5-15 ng of aqueous solutions of these compounds can be detected. The combination of selectivity (from use of the chromatographic column) and fluorescence detection permitted analysis for five of the six indoles after a single urine-deproteinization step. | Analysis for indole compounds in urine by high-performance liquid chromatography with fluorometric detection. We describe a chromatographic system involving a high-performance chemically-bonded reverse-phase column and fluorescence detection for measurement of indoles in urine. We controlled retention and selectivity by optimizing the methanol content and pH of the mobile phase. Six reference indoles were separated in less than 20 min; three 5-hydroxyindoles were eluted in less than 7 min. About 5-15 ng of aqueous solutions of these compounds can be detected. The combination of selectivity (from use of the chromatographic column) and fluorescence detection permitted analysis for five of the six indoles after a single urine-deproteinization step. | 2,390 |
pubmed23n0001_1243 | Effect of halothane anesthesia on muscle, liver, thyroid, and adrenal-function tests in man. | Seven healthy men volunteers received 6.6 +/- 1.3 (SD) percent-hours of halothane oxygen anesthesia without surgery. Serum bilirubin, alanine aminotransferase, and aspartate aminotransferase significantly increased after anesthesia, which may indicate subclinical liver-cell damage. Creatine kinase of skeletal muscle origin increased above 90 U/liter in six subjects, indicating subclinical muscle-cell damage. Cortisol, triiodothyronine uptake, thyroxine, and free thyroxine index increased significantly immediately after anesthesia. Serum bromide concentrations had increased by fivefold on the second day after anesthesia, and on the ninth day was still elevated fourfold. Oral temperatures increased 0.7 degrees C 6 h post-anesthesia, possibly because of increased thyroxine activity. Lactate dehydrogenase, hydroxybutyrate dehydrogenase and gamma-glutamyltransferase activities did not change significantly. No drugs administered during the course of this study chemically interfered with any of the test methods used. | Effect of halothane anesthesia on muscle, liver, thyroid, and adrenal-function tests in man. Seven healthy men volunteers received 6.6 +/- 1.3 (SD) percent-hours of halothane oxygen anesthesia without surgery. Serum bilirubin, alanine aminotransferase, and aspartate aminotransferase significantly increased after anesthesia, which may indicate subclinical liver-cell damage. Creatine kinase of skeletal muscle origin increased above 90 U/liter in six subjects, indicating subclinical muscle-cell damage. Cortisol, triiodothyronine uptake, thyroxine, and free thyroxine index increased significantly immediately after anesthesia. Serum bromide concentrations had increased by fivefold on the second day after anesthesia, and on the ninth day was still elevated fourfold. Oral temperatures increased 0.7 degrees C 6 h post-anesthesia, possibly because of increased thyroxine activity. Lactate dehydrogenase, hydroxybutyrate dehydrogenase and gamma-glutamyltransferase activities did not change significantly. No drugs administered during the course of this study chemically interfered with any of the test methods used. | 2,391 |
pubmed23n0001_1244 | Improved assay for urinary 17-hydroxycorticosteroids. | We describe a simple, rapid, reliable method for determining urinary 17-hydroxycorticosteroids. A neutral resin (Amberlite XAD-2), which is a non-ionic cross-linked polystyrene, is used to extract and concentrate the steroids, which are then quantitatively determined with the Porter-Silber reaction. Use of the resin eliminates the need for enzymatic hydrolysis and n-butanol extractions, thereby decreasing analysis time considerably; results can be obtained within 3 h of receipt of specimens. Most of the nonsteroidal Porter-Silber chromogens are removed, resulting in a method that is highly specific and sensitive, even at low concentrations (0.6 mg/liter), and so more accurate and reproducible than currently used methods. | Improved assay for urinary 17-hydroxycorticosteroids. We describe a simple, rapid, reliable method for determining urinary 17-hydroxycorticosteroids. A neutral resin (Amberlite XAD-2), which is a non-ionic cross-linked polystyrene, is used to extract and concentrate the steroids, which are then quantitatively determined with the Porter-Silber reaction. Use of the resin eliminates the need for enzymatic hydrolysis and n-butanol extractions, thereby decreasing analysis time considerably; results can be obtained within 3 h of receipt of specimens. Most of the nonsteroidal Porter-Silber chromogens are removed, resulting in a method that is highly specific and sensitive, even at low concentrations (0.6 mg/liter), and so more accurate and reproducible than currently used methods. | 2,392 |
pubmed23n0001_1245 | Radioimmunoassay of plasma renin activity. | We describe a sensitive, simplified radioimmunoassay method for determination of plasma renin activity. Plasma was acidified to the optimal pH (6.0) of angiotensin l generation with the least possible dilution, by using a single addition of hydrochloric acid and the enzyme inhibitor hydroxyquinoline. Recovery of unlabeled angiotensin l added to plasma was 92-97%; that of monoiodinated angiotensin l exceeded 90%, indicating satisfactory protection from proteolytic enzymes. Plasma constituents interfered little with the radioimmunoassay. Bland values for plasma kept at 0 degrees C were 10.7 +/- 2.3 (mean +/- SD) percent of the activity values for samples kept at +37 degrees C (n equals 63). In the routine setting, 6.25 pg of angiotensin l or 10(-6) Goldblatt units of Standard Human Renin was detected. We report results of plasma renin activity measurements and a comparison with seven renin kits, and with bioassay for plasma renin activity. | Radioimmunoassay of plasma renin activity. We describe a sensitive, simplified radioimmunoassay method for determination of plasma renin activity. Plasma was acidified to the optimal pH (6.0) of angiotensin l generation with the least possible dilution, by using a single addition of hydrochloric acid and the enzyme inhibitor hydroxyquinoline. Recovery of unlabeled angiotensin l added to plasma was 92-97%; that of monoiodinated angiotensin l exceeded 90%, indicating satisfactory protection from proteolytic enzymes. Plasma constituents interfered little with the radioimmunoassay. Bland values for plasma kept at 0 degrees C were 10.7 +/- 2.3 (mean +/- SD) percent of the activity values for samples kept at +37 degrees C (n equals 63). In the routine setting, 6.25 pg of angiotensin l or 10(-6) Goldblatt units of Standard Human Renin was detected. We report results of plasma renin activity measurements and a comparison with seven renin kits, and with bioassay for plasma renin activity. | 2,393 |
pubmed23n0001_1246 | P-Hydroxybenzoic acid hydrazide procedure for serum glucose adapted to the Technicon "SMA 12/60," and compared with other glucose methods. | We adapted the p-hydroxybenzoic acid hydrazide procedure for serum glucose for use with the Technicon SMA 12/60 AutoAnalyzer. Like the o-toluidine method, this method is based on a general carbohydrate reaction except that it occurs in a mildly alkaline medium and the intense yellow color formed is measured at 400 nm. Advantages of this reagent over o-toluidine include lower cost, less toxicity, and higher purity. Aside from those carbohydrates that are present in serum in insignificant quantities, there are no interferences from various physiological compounds or drugs (hypoglycemic agents) found either in normal persons or diabetics. Within-run and day-to-day values had coefficients of variation of 1.39% and 3.44%, respectively; recoveries ranged from 100 to 102% (mean, 101%). Comparative data showed excellent agreement with the hexokinase (r equals 0.998; y equals 0.950x + 5.91) and glucose oxidase (r equals 0.996; y equals 0.986x + 5.34) enzymatic ("true") glucose methods, and with the o-toluidine procedure (r equals 0.998; y equals 0.979x + 3.14). | P-Hydroxybenzoic acid hydrazide procedure for serum glucose adapted to the Technicon "SMA 12/60," and compared with other glucose methods. We adapted the p-hydroxybenzoic acid hydrazide procedure for serum glucose for use with the Technicon SMA 12/60 AutoAnalyzer. Like the o-toluidine method, this method is based on a general carbohydrate reaction except that it occurs in a mildly alkaline medium and the intense yellow color formed is measured at 400 nm. Advantages of this reagent over o-toluidine include lower cost, less toxicity, and higher purity. Aside from those carbohydrates that are present in serum in insignificant quantities, there are no interferences from various physiological compounds or drugs (hypoglycemic agents) found either in normal persons or diabetics. Within-run and day-to-day values had coefficients of variation of 1.39% and 3.44%, respectively; recoveries ranged from 100 to 102% (mean, 101%). Comparative data showed excellent agreement with the hexokinase (r equals 0.998; y equals 0.950x + 5.91) and glucose oxidase (r equals 0.996; y equals 0.986x + 5.34) enzymatic ("true") glucose methods, and with the o-toluidine procedure (r equals 0.998; y equals 0.979x + 3.14). | 2,394 |
pubmed23n0001_1247 | Lipoamide dehydrogenase in serum: a preliminary report. | Lipoamide dehydrogenase was identified in serum and the optimal conditions for its assay at 30 degrees C were defined. The pH optimum in tris(hydroxymethyl)aminomethane buffer is 7.8, and activity is inhibited if buffer concentration exceeds 100 mmol/liter. Saturating concentrations of the substrates NAD+ and lipoamide are 3 mmol/liter and 5 mmol/liter, respectively. Activity is decreased eightfold when lipoic acid is substituted for lipoamide. Activity is linearly related to enzyme concentration up to limiting absorbance change of 0.300 at 340 nm, and both within-day and day-to-day precision are satisfactory. Data suggest a normal range (2 SD) of 3-19 kU/liter. The highest value measured in serum was 473 kU/liter. A correlation with direct bilirubin concentrations (r equals 0.435, P less than 0.01) was found. | Lipoamide dehydrogenase in serum: a preliminary report. Lipoamide dehydrogenase was identified in serum and the optimal conditions for its assay at 30 degrees C were defined. The pH optimum in tris(hydroxymethyl)aminomethane buffer is 7.8, and activity is inhibited if buffer concentration exceeds 100 mmol/liter. Saturating concentrations of the substrates NAD+ and lipoamide are 3 mmol/liter and 5 mmol/liter, respectively. Activity is decreased eightfold when lipoic acid is substituted for lipoamide. Activity is linearly related to enzyme concentration up to limiting absorbance change of 0.300 at 340 nm, and both within-day and day-to-day precision are satisfactory. Data suggest a normal range (2 SD) of 3-19 kU/liter. The highest value measured in serum was 473 kU/liter. A correlation with direct bilirubin concentrations (r equals 0.435, P less than 0.01) was found. | 2,395 |
pubmed23n0001_1248 | Direct radioimmunoassay of plasma cortisol. | The simplification of the measurement of circulating cortisol by direct radioimmunoassay of plasma samples sets the problem of inhibiting the carrier proteins competing with antibodies. This was accomplished by exploiting the much higher effectiveness of pH and temperature variations on steroid binding to carrier proteins than to antibody sites. A solid-phase system was set up, using antisera to cortisol-21-BSA conjucates coupled to CNBr-activated cellulose. The standardized procedure consisted of an incubation at pH 3.5 and room temperature, directly assaying 10 mul of plasma. A methodological and clinical validation of the measurement was carried out through a series of tests aimed at assessing the reliability of results (assay of steroid-deprived plasma, recovery test and serial dilution of samples, comparison between different antisera and with different methods including extraction, responsiveness to well-established physiological situations). The results obtained are reported and the validity of the method discussed in terms of more general applicability to steroid assay. | Direct radioimmunoassay of plasma cortisol. The simplification of the measurement of circulating cortisol by direct radioimmunoassay of plasma samples sets the problem of inhibiting the carrier proteins competing with antibodies. This was accomplished by exploiting the much higher effectiveness of pH and temperature variations on steroid binding to carrier proteins than to antibody sites. A solid-phase system was set up, using antisera to cortisol-21-BSA conjucates coupled to CNBr-activated cellulose. The standardized procedure consisted of an incubation at pH 3.5 and room temperature, directly assaying 10 mul of plasma. A methodological and clinical validation of the measurement was carried out through a series of tests aimed at assessing the reliability of results (assay of steroid-deprived plasma, recovery test and serial dilution of samples, comparison between different antisera and with different methods including extraction, responsiveness to well-established physiological situations). The results obtained are reported and the validity of the method discussed in terms of more general applicability to steroid assay. | 2,396 |
pubmed23n0001_1249 | Methodological simplifications in radioimmunoassay of urinary aldosterone. | Simplification of radioimmunoassay procedures of urinary aldosterone-18-glucuronide was attempted, taking into consideration the aspects implied by the hydrolysis of urine and the assay itself. The procedure standardized for the hydrolysis step (samples diluted with a two-fold volume of 0.2 N HCl and incubated at 30 degrees C for 16-24 h) proved suitable in terms of practicability and accuracy. Aldosterone antisera, raised in the rabbit against an aldosterone-3-bovine albumin conjugate, were selected according to their specificity towards competing steroids. Depending on the characteristics of the antisera used, an assay of extracts, or even direct measurements of hydrolyzed urines excluding any extraction, were found to yield reliable results. In the case of a high-quality antiserum, evidence for the adequacy of assay on non-hydrolyzed urine extracts for the measurement of the excretion of unconjugated aldosterone was provided by some preliminary data. The results of the experiments, directed at the methodological and clinical validation of the simplified procedures, are reported and discussed in this paper. | Methodological simplifications in radioimmunoassay of urinary aldosterone. Simplification of radioimmunoassay procedures of urinary aldosterone-18-glucuronide was attempted, taking into consideration the aspects implied by the hydrolysis of urine and the assay itself. The procedure standardized for the hydrolysis step (samples diluted with a two-fold volume of 0.2 N HCl and incubated at 30 degrees C for 16-24 h) proved suitable in terms of practicability and accuracy. Aldosterone antisera, raised in the rabbit against an aldosterone-3-bovine albumin conjugate, were selected according to their specificity towards competing steroids. Depending on the characteristics of the antisera used, an assay of extracts, or even direct measurements of hydrolyzed urines excluding any extraction, were found to yield reliable results. In the case of a high-quality antiserum, evidence for the adequacy of assay on non-hydrolyzed urine extracts for the measurement of the excretion of unconjugated aldosterone was provided by some preliminary data. The results of the experiments, directed at the methodological and clinical validation of the simplified procedures, are reported and discussed in this paper. | 2,397 |
pubmed23n0001_1250 | [Studies on the activities of peptidases from human leucocytes, and human and guinea pig alveolar macrophages (author's transl)]. | Peptidases activities were compared in human leucocytes, guinea pig and human alveolar macrophages. Seversl endo- and exopeptides were characterized; some of them were active at acid pH and others at neutral and alkaline pH. Leucocytes and alveolar macrophages had proteolygic activity for hemoglobin, fibrinogen, collagen and elastin. Using synthetic substrates, several enzymes were characterized: arylamidase, aminopeptidase, carboxypeptidases A and B and cathepsins A and C. The enzymatic activities were much higher in alveolar macrophages than in leucocytes. | [Studies on the activities of peptidases from human leucocytes, and human and guinea pig alveolar macrophages (author's transl)]. Peptidases activities were compared in human leucocytes, guinea pig and human alveolar macrophages. Seversl endo- and exopeptides were characterized; some of them were active at acid pH and others at neutral and alkaline pH. Leucocytes and alveolar macrophages had proteolygic activity for hemoglobin, fibrinogen, collagen and elastin. Using synthetic substrates, several enzymes were characterized: arylamidase, aminopeptidase, carboxypeptidases A and B and cathepsins A and C. The enzymatic activities were much higher in alveolar macrophages than in leucocytes. | 2,398 |
pubmed23n0001_1251 | Experience with a simple method for estrogen receptor assay in breast cancer. | A simple procedure for the assay of specific estrogen receptors in breast cancer tissue is described. Estrogen receptors were detected in 74% of primary tumors, 71% of skin metastases and 63% of lymph node metastases. Postmenopausal patients and younger oophorectomized women had estrogen receptor-containing tumors more frequently, and at higher levels, than uncastrated, premenopausal, patients. The stability of estrogen receptors was not affected by the transportation of samples from distant hospitals, providing that they were kept frozen in Tris buffer, pH 8.0, at all times. | Experience with a simple method for estrogen receptor assay in breast cancer. A simple procedure for the assay of specific estrogen receptors in breast cancer tissue is described. Estrogen receptors were detected in 74% of primary tumors, 71% of skin metastases and 63% of lymph node metastases. Postmenopausal patients and younger oophorectomized women had estrogen receptor-containing tumors more frequently, and at higher levels, than uncastrated, premenopausal, patients. The stability of estrogen receptors was not affected by the transportation of samples from distant hospitals, providing that they were kept frozen in Tris buffer, pH 8.0, at all times. | 2,401 |
pubmed23n0001_1252 | Immunological detection of isoferritins in normal human serum and tissue. | A method is described which permits the detection of isoferritins in normal human serum and tissues. The technique makes use of 125I-labelled monospecific anti-human-liver-ferritin antibody to demonstrate the isoferritins after isoelectric focussing of the purified ferritin in polyacrylamide gels. The organ-specific variation in tissue isoferritin profile previously reported in normal subjects has been confirmed by this technique using only 50 ng of each ferritin sample. Serum ferritin from normal healthy subjects was also shown to exhibit a microheterogeneity on isoelectric focussing; six clearly defined isoferritin peaks were detected in the pH range of 5.04 to 5.62. This isoferritin profile of normal serum contained isoferritins over the whole range of the various tissue isoferritins suggesting that a number of organs may contribute to the normal serum ferritin pool. | Immunological detection of isoferritins in normal human serum and tissue. A method is described which permits the detection of isoferritins in normal human serum and tissues. The technique makes use of 125I-labelled monospecific anti-human-liver-ferritin antibody to demonstrate the isoferritins after isoelectric focussing of the purified ferritin in polyacrylamide gels. The organ-specific variation in tissue isoferritin profile previously reported in normal subjects has been confirmed by this technique using only 50 ng of each ferritin sample. Serum ferritin from normal healthy subjects was also shown to exhibit a microheterogeneity on isoelectric focussing; six clearly defined isoferritin peaks were detected in the pH range of 5.04 to 5.62. This isoferritin profile of normal serum contained isoferritins over the whole range of the various tissue isoferritins suggesting that a number of organs may contribute to the normal serum ferritin pool. | 2,402 |
pubmed23n0001_1253 | Acceleration of autoimmunity in NZB/NZW F1 mice by graft-versus-host disease. | Chronic graft-versus-host (GVH) disease was induced in NZB/NZW F1 (B/W) hybrid female mice by the weekly injection of parental NZB spleen cells. Control mice received injections of syngeneic spleen cells only. The mice were assayed for antibodies to [3H]DNA and [3H]polyadenylic-polyuridylic acid by a cellulose ester filter radioimmunoassay, and for antibody to thymocytes by a cytotoxicity method. GVH disease accelerated the development of all three antibodies in B/W mice. In addition, sucrose density gradient ultracentrifugation of pooled sera suggested that an accelerated switch from 19S to 7S anti-DNA production may be an early effect of GVH. The mechanism of acceleration is discussed in terms of immunological and viral factors generated by the GVH reaction. | Acceleration of autoimmunity in NZB/NZW F1 mice by graft-versus-host disease. Chronic graft-versus-host (GVH) disease was induced in NZB/NZW F1 (B/W) hybrid female mice by the weekly injection of parental NZB spleen cells. Control mice received injections of syngeneic spleen cells only. The mice were assayed for antibodies to [3H]DNA and [3H]polyadenylic-polyuridylic acid by a cellulose ester filter radioimmunoassay, and for antibody to thymocytes by a cytotoxicity method. GVH disease accelerated the development of all three antibodies in B/W mice. In addition, sucrose density gradient ultracentrifugation of pooled sera suggested that an accelerated switch from 19S to 7S anti-DNA production may be an early effect of GVH. The mechanism of acceleration is discussed in terms of immunological and viral factors generated by the GVH reaction. | 2,403 |
pubmed23n0001_1254 | Lymphocyte subpopulations. Human red blood cell rosettes. | Human red blood cells (HRBC) even without prior neuraminidase treatment, could form rosettes with human peripheral blood lymphocytes in vitro. The optimum conditions for forming these rosettes were a pH of 7-0 and a medium with 5% bovine serum albumin (BSA). Rosette proportions became much less at a different pH or using lower concentrations of BSA, or replacing BSA with foetal calf sera (FCS) or human sera. Rosette formation was also promoted by prior treatment of HRBC or lymphocytes with neuraminidase. Mixed rosettes of HRBC and sheep red blood cells (SRBC) showed that HRBC receptors were detectable only on lymphocytes that possessed SRBC receptors, suggesting that HRBC rosette-forming cells were probably thymus-derived (T) cells. Next, the properties of human red blood cell (HRBC) and sheep red blood cell (SRBC) rosette-forming cells were investigated by comparing the ability of human peripheral blood lymphocytes to form these two types of rosettes after treatment with various inhibitory reagents. HRBC rosettes were relatively more resistant to inhibition with: (1) proteolytic agents, such as trypsin, alpha-chymotrypsin and pronase; (2) anti-thymocyte serum (ATS); (3) metabolic inhibitors, such as sodium azide and 2,4-dinitrophenol (DNP); (4) cytochalasin B. On further incubation after trypsinization, the lymphocytes recovered some ability to form SRBC rosettes, but continued to lose more of their capability to form HRBC rosettes. All these results were regarded as circumstantial evidence that the HRBC rosettes might represent a subpopulation of human T lymphocytes. | Lymphocyte subpopulations. Human red blood cell rosettes. Human red blood cells (HRBC) even without prior neuraminidase treatment, could form rosettes with human peripheral blood lymphocytes in vitro. The optimum conditions for forming these rosettes were a pH of 7-0 and a medium with 5% bovine serum albumin (BSA). Rosette proportions became much less at a different pH or using lower concentrations of BSA, or replacing BSA with foetal calf sera (FCS) or human sera. Rosette formation was also promoted by prior treatment of HRBC or lymphocytes with neuraminidase. Mixed rosettes of HRBC and sheep red blood cells (SRBC) showed that HRBC receptors were detectable only on lymphocytes that possessed SRBC receptors, suggesting that HRBC rosette-forming cells were probably thymus-derived (T) cells. Next, the properties of human red blood cell (HRBC) and sheep red blood cell (SRBC) rosette-forming cells were investigated by comparing the ability of human peripheral blood lymphocytes to form these two types of rosettes after treatment with various inhibitory reagents. HRBC rosettes were relatively more resistant to inhibition with: (1) proteolytic agents, such as trypsin, alpha-chymotrypsin and pronase; (2) anti-thymocyte serum (ATS); (3) metabolic inhibitors, such as sodium azide and 2,4-dinitrophenol (DNP); (4) cytochalasin B. On further incubation after trypsinization, the lymphocytes recovered some ability to form SRBC rosettes, but continued to lose more of their capability to form HRBC rosettes. All these results were regarded as circumstantial evidence that the HRBC rosettes might represent a subpopulation of human T lymphocytes. | 2,404 |
pubmed23n0001_1255 | Acetate intolerance during hemodialysis. | Acetate is frequently substituted for bicarbonate in hemodialysis solutions. Plasma acetate and bicarbonate concentrations were measured in nine patients with chronic renal failure undergoing hemodialysis with dialyzate containing acetate. In three patients (2 children and 1 adult) plasma acetate concentrations exceeded 15 mEq/liter during the dialysis. The mechanisms leading to acetate intolerance are probably multiple. It cannot be assumed that dialysis with acetate containing solutions will restore the buffer anion deficit characteristic of chronic renal failure. | Acetate intolerance during hemodialysis. Acetate is frequently substituted for bicarbonate in hemodialysis solutions. Plasma acetate and bicarbonate concentrations were measured in nine patients with chronic renal failure undergoing hemodialysis with dialyzate containing acetate. In three patients (2 children and 1 adult) plasma acetate concentrations exceeded 15 mEq/liter during the dialysis. The mechanisms leading to acetate intolerance are probably multiple. It cannot be assumed that dialysis with acetate containing solutions will restore the buffer anion deficit characteristic of chronic renal failure. | 2,405 |
pubmed23n0001_1256 | Effect of liver failure on the ventilatory response to hypoxia in man and the goat. | 1. The ventilatory responses to transient and steady-state hypoxia were measured in ten patients with hepatic cirrhosis and in ten healthy control subjects. Successive measurements of these responses were also obtained in six goats before and after the experimental production of liver failure. Changes in the effect of steady-state hypoxia on the ventilatory response to hypercapnia were evaluated by successive studies in another goat. 2. In spite of a respiratory alkalosis during liver failure, the response to transient hypoxia was greater in the patients than in the control subjects. This response was increased after the onset of liver failure in all the goats. 3. In healthy humans and goats the responses to transient and steady-state hypoxia were similar in magnitude. During liver failure there was a disparity between the size of these responses, since the ventilatory increment evoked by steady-state hypoxia was unchanged in spite of the increase in response to transient hypoxia. Steady-state hypoxia consistently enhanced the ventilatory response to hypercapnia in a healthy goat, but frequently depressed the response to hypercapnia during liver failure. 4. The findings suggest that liver failure heightens the sensitivity of the peripheral chemoreceptors to the hypoxic stimulus, but may increase the tendency of the medullary centres to become depressed in hypoxia. | Effect of liver failure on the ventilatory response to hypoxia in man and the goat. 1. The ventilatory responses to transient and steady-state hypoxia were measured in ten patients with hepatic cirrhosis and in ten healthy control subjects. Successive measurements of these responses were also obtained in six goats before and after the experimental production of liver failure. Changes in the effect of steady-state hypoxia on the ventilatory response to hypercapnia were evaluated by successive studies in another goat. 2. In spite of a respiratory alkalosis during liver failure, the response to transient hypoxia was greater in the patients than in the control subjects. This response was increased after the onset of liver failure in all the goats. 3. In healthy humans and goats the responses to transient and steady-state hypoxia were similar in magnitude. During liver failure there was a disparity between the size of these responses, since the ventilatory increment evoked by steady-state hypoxia was unchanged in spite of the increase in response to transient hypoxia. Steady-state hypoxia consistently enhanced the ventilatory response to hypercapnia in a healthy goat, but frequently depressed the response to hypercapnia during liver failure. 4. The findings suggest that liver failure heightens the sensitivity of the peripheral chemoreceptors to the hypoxic stimulus, but may increase the tendency of the medullary centres to become depressed in hypoxia. | 2,406 |
pubmed23n0001_1257 | Ventilatory response to carbon dioxide in tetanus. | 1. Ventilatory response to carbon dioxide was measured by the rebreathing technique in seven patients with mild tetanus during the disease state and after clinical recovery. 2. The ventilatory response to carbon dioxide was found to be decreased in the tetanus patients during the disease state with normal response after full clinical recovery. It is postulated that the restrictive ventilatory defect was responsible for the decreased ventilatory response to carbon dioxide. | Ventilatory response to carbon dioxide in tetanus. 1. Ventilatory response to carbon dioxide was measured by the rebreathing technique in seven patients with mild tetanus during the disease state and after clinical recovery. 2. The ventilatory response to carbon dioxide was found to be decreased in the tetanus patients during the disease state with normal response after full clinical recovery. It is postulated that the restrictive ventilatory defect was responsible for the decreased ventilatory response to carbon dioxide. | 2,407 |
pubmed23n0001_1258 | [Treatment of severe hypnotic poisoning with extracorporeal haemoperfusion (author's transl)]. | Four patients with severe hypnotic intoxication, twice after suicidal intake of barbital, once of barbital, methaqualone and carbromal, and once of carbromal, were treated with six activated charcoal haemoperfusions. Three patients showed rapid improvement in the level of consciousness followed by complete recovery. One female patient died in cerebral coma due to complete acute cerebromalacia following hypoxia. Serious complications due to the haemoperfusion did not occur. Correct use of activated charcoal haemoperfusion enriches the therapeutic spectrum of severe exogenous intoxications. | [Treatment of severe hypnotic poisoning with extracorporeal haemoperfusion (author's transl)]. Four patients with severe hypnotic intoxication, twice after suicidal intake of barbital, once of barbital, methaqualone and carbromal, and once of carbromal, were treated with six activated charcoal haemoperfusions. Three patients showed rapid improvement in the level of consciousness followed by complete recovery. One female patient died in cerebral coma due to complete acute cerebromalacia following hypoxia. Serious complications due to the haemoperfusion did not occur. Correct use of activated charcoal haemoperfusion enriches the therapeutic spectrum of severe exogenous intoxications. | 2,454 |
pubmed23n0001_1259 | Failure to monoaminergic and cholinergic receptor blockers to prevent prostaglandin E2-induced luteinizing hormone release. | Receptor blocking drugs were used to determine whether adrenergic, dopaminergic, serotoninergic, or cholinergic synapses are involved in mediating the LH release induced by intraventricularly injected PGE2. Prostaglandin E2 (5mug) was injected into the 3rd ventricle (3rd V) of ovariectomized rats, and plasma LH concentrations before and after treatment were determined by radioimmunoassay. Phentolamine, 20 or 30 mug, or pronethalol, 20 mug (alpha and beta adrenergic receptor blockers, respectively) injected into the 3rd V failed to alter the elevation of plasma LH evoked by PGE2 injected into the ventricle 10 min later. Likewise, LH release following PGE2 was not changed when a dopaminergic blocker, pimozide (0.63 mg/kg, SC), was injected 2 h prior to PGE2. Two antagonists of serotonin, methysergide maleate (3 mg/kg ip) or cinanserin HC1 (1 mg/kg iv) given 2 h or 45 min before PGE2, respectively, failed to alter the action of PGE2. Atropine (100 or 250 mug) injected into the 3rd V 10 min prior to PGE2 was also ineffective in blocking the increase in plasma LH following PGE2. The results of this study indicate that the effect of PGE2 on LH release is not mediated by adrenergic, dopaminergic, serotoninergic, or cholinergic receptors. They also suggest that PGE2 is not acting trans-synaptically but probably directly on the LHRH neuron to induce the discharge of LHRH into the hypophysial portal vessels which then evokes release of LH from the adenohypophysis. | Failure to monoaminergic and cholinergic receptor blockers to prevent prostaglandin E2-induced luteinizing hormone release. Receptor blocking drugs were used to determine whether adrenergic, dopaminergic, serotoninergic, or cholinergic synapses are involved in mediating the LH release induced by intraventricularly injected PGE2. Prostaglandin E2 (5mug) was injected into the 3rd ventricle (3rd V) of ovariectomized rats, and plasma LH concentrations before and after treatment were determined by radioimmunoassay. Phentolamine, 20 or 30 mug, or pronethalol, 20 mug (alpha and beta adrenergic receptor blockers, respectively) injected into the 3rd V failed to alter the elevation of plasma LH evoked by PGE2 injected into the ventricle 10 min later. Likewise, LH release following PGE2 was not changed when a dopaminergic blocker, pimozide (0.63 mg/kg, SC), was injected 2 h prior to PGE2. Two antagonists of serotonin, methysergide maleate (3 mg/kg ip) or cinanserin HC1 (1 mg/kg iv) given 2 h or 45 min before PGE2, respectively, failed to alter the action of PGE2. Atropine (100 or 250 mug) injected into the 3rd V 10 min prior to PGE2 was also ineffective in blocking the increase in plasma LH following PGE2. The results of this study indicate that the effect of PGE2 on LH release is not mediated by adrenergic, dopaminergic, serotoninergic, or cholinergic receptors. They also suggest that PGE2 is not acting trans-synaptically but probably directly on the LHRH neuron to induce the discharge of LHRH into the hypophysial portal vessels which then evokes release of LH from the adenohypophysis. | 2,457 |
pubmed23n0001_1260 | Neurotransmitter regulation of growth hormone and ACTH in the rhesus monkey: effects of biogenic amines. | In an attempt to clarify the role of central neurotransmitters in GH and ACTH regulation, chair-adapted unanesthetized adult male rhesus monkeys and chronic indwelling intratrial cannulae were given 30 min infusions of various agonists known to affect central amines, and plasma samples were withdrawn for GH and cortisol determinations. Infusion of acid-saline vehicle alone had no significant effect on plasma GH or cortisol (P less than 0.05). L-Dihydroxyphenylalanine (L-Dopa) (4.5 and 45 mg/kg), but not apomorphine (7 mug/kg), a specific dopaminergic agonist, produced significant elevations of GH. Both noradrenergic (clonidine HCl, 1.5, 15, and 150 mug/kg, and D,L-threodihydroxyphenylserine (D,L-threodops) 90 mg/kg) and serotoninergic (5-hydroxy-L-tryptophan (5-HTP), 45 mg/kg) agonists induced significant GH responses. These findings suggest that GH is regulated in the rhesus monkey by noradrenergic and serotoninergic neurons, whereas participation of dopaminergic neurons has not been established. Significant cortisol responses were only observed following infusion of 5HTP (45 mg/kg). Dopaminergic and noradrenergic agonists not only failed to alter resting cortisol levels but also did not affect the cortisol response to 5-HTP. In the rhesus monkey serotoninergic mechanisms appear to be responsible for the regulation of resting cortisol levels. A catecholamine inhibitory mechanism was not demonstrated in this species. | Neurotransmitter regulation of growth hormone and ACTH in the rhesus monkey: effects of biogenic amines. In an attempt to clarify the role of central neurotransmitters in GH and ACTH regulation, chair-adapted unanesthetized adult male rhesus monkeys and chronic indwelling intratrial cannulae were given 30 min infusions of various agonists known to affect central amines, and plasma samples were withdrawn for GH and cortisol determinations. Infusion of acid-saline vehicle alone had no significant effect on plasma GH or cortisol (P less than 0.05). L-Dihydroxyphenylalanine (L-Dopa) (4.5 and 45 mg/kg), but not apomorphine (7 mug/kg), a specific dopaminergic agonist, produced significant elevations of GH. Both noradrenergic (clonidine HCl, 1.5, 15, and 150 mug/kg, and D,L-threodihydroxyphenylserine (D,L-threodops) 90 mg/kg) and serotoninergic (5-hydroxy-L-tryptophan (5-HTP), 45 mg/kg) agonists induced significant GH responses. These findings suggest that GH is regulated in the rhesus monkey by noradrenergic and serotoninergic neurons, whereas participation of dopaminergic neurons has not been established. Significant cortisol responses were only observed following infusion of 5HTP (45 mg/kg). Dopaminergic and noradrenergic agonists not only failed to alter resting cortisol levels but also did not affect the cortisol response to 5-HTP. In the rhesus monkey serotoninergic mechanisms appear to be responsible for the regulation of resting cortisol levels. A catecholamine inhibitory mechanism was not demonstrated in this species. | 2,458 |
pubmed23n0001_1261 | Adrenergic binding sites and enzyme activities in the heart of hyperthyroid rats. | In present study interactions of some adrenergic drugs with the binding of 3H-norepinephrine (NE) and response of some enzymatic systems in the heart of rats with pharmacological hyperthyroidism have been investigated. Binding of NE to cardiac particles was inhibited by isoproterenol, propranolol and in lower concentrations by another beta-blocking drug trimepranol both in control and hyperthyroid hearts in the same degree. However, after addition of nonradioactive norepinephrine (10(-3) M) the degree of displacement was lower in hyperthyroid than in euthyroid group. Activity of adenylate cyclase was lower in hyperthyroid cardiac particles. This difference remained preserved after stimulation by norepinephrine or NaF. The activities of hormone-sensitive lipase and lipoprotein lipase were increased in preparation of hyperthyroid hearts. The phosphorylase "a" activity was also increased in hyperthyroid cardiac particles. There was no change in cardiac adrenergic binding sites properties in hyperthyroidism with the exception of less displacement of NE by nonlabelled hormone. The results indicate that the increased lipolytic and phosphorylase "a" activities in hyperthyroid hearts are not necessarily linked to elevated activity of adenylate cyclase. | Adrenergic binding sites and enzyme activities in the heart of hyperthyroid rats. In present study interactions of some adrenergic drugs with the binding of 3H-norepinephrine (NE) and response of some enzymatic systems in the heart of rats with pharmacological hyperthyroidism have been investigated. Binding of NE to cardiac particles was inhibited by isoproterenol, propranolol and in lower concentrations by another beta-blocking drug trimepranol both in control and hyperthyroid hearts in the same degree. However, after addition of nonradioactive norepinephrine (10(-3) M) the degree of displacement was lower in hyperthyroid than in euthyroid group. Activity of adenylate cyclase was lower in hyperthyroid cardiac particles. This difference remained preserved after stimulation by norepinephrine or NaF. The activities of hormone-sensitive lipase and lipoprotein lipase were increased in preparation of hyperthyroid hearts. The phosphorylase "a" activity was also increased in hyperthyroid cardiac particles. There was no change in cardiac adrenergic binding sites properties in hyperthyroidism with the exception of less displacement of NE by nonlabelled hormone. The results indicate that the increased lipolytic and phosphorylase "a" activities in hyperthyroid hearts are not necessarily linked to elevated activity of adenylate cyclase. | 2,459 |
pubmed23n0001_1262 | Determination of total insulin (TIRI) in plasma of insulin-treated diabetics and newborn infants of insulin-treated diabetic mothers. | Plasma of insulin-treated diabetics and of newborn infants of insulin-treated diabetic mothers contains insulin antibodies which invalidates the radioimmunoassay of insulin. Therefore, the endogenous insulin antibody complex must be splitted at a pH lower than 5 and the total IRI (TIRI) is separated by ethanol extraction. It was investigated the recovery rate in dependence upon plasma volume used for extraction. By reduction of used plasma volume from 500 to 200 mul per extraction the recovery rate was increased from 65.1 +/- 8.4 to 88.3 +/- 4.2% (mean +/- SEM). The low plasma volume of 200 mul for TIRI extraction made it possible to determine TIRI during glucose loads of newborn infants. To eliminate different conditions of incubation for standard and unknown plasma samples the TIRI levels were computed by means of so-called "extracted" standard curve, obtained with extracted insulin from standard insulin dilution in insulin-free pooled human plasma. Using the described method a temporary regeneration of insulin secretion of a newly diagnosed juvenile diabetic after insulin treatment could be shown. In contrast to newborn infants of healthy mothers a biphasic/insulin release was found during the intravenous glucose loads in newborn infants of insulin-treated diabetic mothers. | Determination of total insulin (TIRI) in plasma of insulin-treated diabetics and newborn infants of insulin-treated diabetic mothers. Plasma of insulin-treated diabetics and of newborn infants of insulin-treated diabetic mothers contains insulin antibodies which invalidates the radioimmunoassay of insulin. Therefore, the endogenous insulin antibody complex must be splitted at a pH lower than 5 and the total IRI (TIRI) is separated by ethanol extraction. It was investigated the recovery rate in dependence upon plasma volume used for extraction. By reduction of used plasma volume from 500 to 200 mul per extraction the recovery rate was increased from 65.1 +/- 8.4 to 88.3 +/- 4.2% (mean +/- SEM). The low plasma volume of 200 mul for TIRI extraction made it possible to determine TIRI during glucose loads of newborn infants. To eliminate different conditions of incubation for standard and unknown plasma samples the TIRI levels were computed by means of so-called "extracted" standard curve, obtained with extracted insulin from standard insulin dilution in insulin-free pooled human plasma. Using the described method a temporary regeneration of insulin secretion of a newly diagnosed juvenile diabetic after insulin treatment could be shown. In contrast to newborn infants of healthy mothers a biphasic/insulin release was found during the intravenous glucose loads in newborn infants of insulin-treated diabetic mothers. | 2,460 |
pubmed23n0001_1263 | Glutamine synthetase, glutaminase and phosphodiesterase activities in brain under hypoxia: in vitro effect of cortisol, GABA and serotonin on glutamine synthetase. | The effect of hypobaric hypoxia on the activities of glutamine synthetase, glutaminase and cyclic 3'5' AMP phosphodiesterase in rat brain was studied after exposure to 25,000' for 6 h. Glutamine synthetase activity was increased in all the regions of brain studied, and addition of gamma amino butyric acid, serotonin and cortisol in vitro produced a differential response. Glutaminase activity decreased in the whole brain. Cyclic 3'5' AMP phosphodiesterase activity decreased in cerebellum, medulla, hypothalamus and pituitary showing an accumulation of cyclic 3'5' AMP in these regions. The results suggest that glutamine synthesis and degradation are regulated in the central nervous system by cyclic AMP and cortisol: Gamma aminoburyric acid and other compounds can modulate the activity of glutamine synthetase and glutaminase. | Glutamine synthetase, glutaminase and phosphodiesterase activities in brain under hypoxia: in vitro effect of cortisol, GABA and serotonin on glutamine synthetase. The effect of hypobaric hypoxia on the activities of glutamine synthetase, glutaminase and cyclic 3'5' AMP phosphodiesterase in rat brain was studied after exposure to 25,000' for 6 h. Glutamine synthetase activity was increased in all the regions of brain studied, and addition of gamma amino butyric acid, serotonin and cortisol in vitro produced a differential response. Glutaminase activity decreased in the whole brain. Cyclic 3'5' AMP phosphodiesterase activity decreased in cerebellum, medulla, hypothalamus and pituitary showing an accumulation of cyclic 3'5' AMP in these regions. The results suggest that glutamine synthesis and degradation are regulated in the central nervous system by cyclic AMP and cortisol: Gamma aminoburyric acid and other compounds can modulate the activity of glutamine synthetase and glutaminase. | 2,463 |
pubmed23n0001_1264 | Intermediates in the interconversion of acid and alkaline ferrihemoglobin. Structural and kinetic aspects. | The acid-alkaline pH-jump in suspension of crystalline sheep hemoglobin has been studied in the range of 5.95 to 8.94. Crystals suspended in 3.8 M Cs2SO4 show a rapid optical transition of half-time equal to or less than 2 ms. As the ammonia concentration is increased in the Cs2SO4-suspended crystals, a second optical transition is observed as a pseudo-first-order reaction, with a rate constant of between 10 and 15 s-1. The alkaline-acid pH-jump proceeds through a very rapid shift of the alkaline-acid equilibrium and is followed by a first-order dissociation constant between 9 and 12 s-1. The dissociation of the ammonia is biphasic, and the ratio between the fast and slow phases is 9. | Intermediates in the interconversion of acid and alkaline ferrihemoglobin. Structural and kinetic aspects. The acid-alkaline pH-jump in suspension of crystalline sheep hemoglobin has been studied in the range of 5.95 to 8.94. Crystals suspended in 3.8 M Cs2SO4 show a rapid optical transition of half-time equal to or less than 2 ms. As the ammonia concentration is increased in the Cs2SO4-suspended crystals, a second optical transition is observed as a pseudo-first-order reaction, with a rate constant of between 10 and 15 s-1. The alkaline-acid pH-jump proceeds through a very rapid shift of the alkaline-acid equilibrium and is followed by a first-order dissociation constant between 9 and 12 s-1. The dissociation of the ammonia is biphasic, and the ratio between the fast and slow phases is 9. | 2,464 |
pubmed23n0001_1265 | The reaction kinetics of fluoride and ammonia with acid and alkaline ferrimyoglobin in a crystalline state. | Differences between the reactivity of amorphous and crystalline myoglobin have been studied by the rapid-flow method combined with dual-wavelength spectrophotometry. The binding of ammonia to the hydroxide compound has a half-time of 55 ms. The reverse reaction has a half-time of 70 ms. At pH 7.0 the relative half-times of combination and dissociation with fluoride are 10 min for crystalline and 1.8 min for amorphous materials. Reactivity of the crystals to fluoride at pH 6.0 greatly increased as compared with pH 8.7. Half-time at pH 8.7 is 10 min, while at pH 6.0 the half-time is 2.5 s for the crystalline material and 1.4 s for the amorphous material. The exchange of fluoride by azide at pH 6.0 is 3.1-fold faster in amorphous material than in crystalline material. | The reaction kinetics of fluoride and ammonia with acid and alkaline ferrimyoglobin in a crystalline state. Differences between the reactivity of amorphous and crystalline myoglobin have been studied by the rapid-flow method combined with dual-wavelength spectrophotometry. The binding of ammonia to the hydroxide compound has a half-time of 55 ms. The reverse reaction has a half-time of 70 ms. At pH 7.0 the relative half-times of combination and dissociation with fluoride are 10 min for crystalline and 1.8 min for amorphous materials. Reactivity of the crystals to fluoride at pH 6.0 greatly increased as compared with pH 8.7. Half-time at pH 8.7 is 10 min, while at pH 6.0 the half-time is 2.5 s for the crystalline material and 1.4 s for the amorphous material. The exchange of fluoride by azide at pH 6.0 is 3.1-fold faster in amorphous material than in crystalline material. | 2,465 |
pubmed23n0001_1266 | Circular-dichroism and absorption spectroscopic studies on specific aromatic residues involved in the different modes of aggregation of tobacco-mosaic-virus protein. | Conformational changes accompanying the different modes of aggregation of tobacco mosaic virus protein (TMV-protein) were investigated using circular dichroism (CD) and absorption difference spectra in the range of aromatic absorption. Comparing wild-type protein and mutant Ni 2068 (Tyr-139 leads to Cys-139) a tentative localization of aromatic amino acids in the three-dimensional structure is rendered possible. In all modes of aggregation the CD spectra are determined by intrasubunit interactions between aromatic residues, in particular Trp-17 and Trp-52 as well as Tyr-70, Tyr-72 and Tyr-139. The Trp-17-Trp-52 interaction was found to be highly sensitive towards changes of the quaternary structure especially with respect to helical aggregates. This suggests that the environment of the two tryptophan residues is of crucial importance in the three-dimensional structure of the subunit; in the course of aggregation intersubunit interactions compete with the specific intrasubunit Trp-17--Trp52 interactions. It is suggested that Try-70 and Tyr-72 form hydrogen bonds in a strongly hydrophobic environment. Formation of the double disc decreases the rotatory strength, pointing to an increase in conformational flexibility. Spectroscopic and chemical evidence prove that Tyr-70, Tyr-72 and Tyr-139 are in close neighbourhood. Double disc formation by lowering the pH (pH 8 LEADS TO 6.9, I = 0.1 M) or increasing the ionic strength (pH 8, I = 0.1 LEADS TO 0.6 M) is reflected by identical spectral effects in the environment of Tyr-70 - Tyr-72. However the interaction between Trp-17 and Trp-52 indicates significant differences in the conformation which may be important for the formation of higher aggregates, i.e. 'lockwashers', helices, and 'stacked discs'. | Circular-dichroism and absorption spectroscopic studies on specific aromatic residues involved in the different modes of aggregation of tobacco-mosaic-virus protein. Conformational changes accompanying the different modes of aggregation of tobacco mosaic virus protein (TMV-protein) were investigated using circular dichroism (CD) and absorption difference spectra in the range of aromatic absorption. Comparing wild-type protein and mutant Ni 2068 (Tyr-139 leads to Cys-139) a tentative localization of aromatic amino acids in the three-dimensional structure is rendered possible. In all modes of aggregation the CD spectra are determined by intrasubunit interactions between aromatic residues, in particular Trp-17 and Trp-52 as well as Tyr-70, Tyr-72 and Tyr-139. The Trp-17-Trp-52 interaction was found to be highly sensitive towards changes of the quaternary structure especially with respect to helical aggregates. This suggests that the environment of the two tryptophan residues is of crucial importance in the three-dimensional structure of the subunit; in the course of aggregation intersubunit interactions compete with the specific intrasubunit Trp-17--Trp52 interactions. It is suggested that Try-70 and Tyr-72 form hydrogen bonds in a strongly hydrophobic environment. Formation of the double disc decreases the rotatory strength, pointing to an increase in conformational flexibility. Spectroscopic and chemical evidence prove that Tyr-70, Tyr-72 and Tyr-139 are in close neighbourhood. Double disc formation by lowering the pH (pH 8 LEADS TO 6.9, I = 0.1 M) or increasing the ionic strength (pH 8, I = 0.1 LEADS TO 0.6 M) is reflected by identical spectral effects in the environment of Tyr-70 - Tyr-72. However the interaction between Trp-17 and Trp-52 indicates significant differences in the conformation which may be important for the formation of higher aggregates, i.e. 'lockwashers', helices, and 'stacked discs'. | 2,466 |
pubmed23n0001_1267 | Characterization of the oxygenase activity in a mutant of Chlamydomonas reinhardi exhibiting altered ribulosebisphosphate carboxylase. | A previously described Mendelian mutant of Chlamydomonas reinhardi, ac i72, exhibiting altered ribulosebisphosphate carboxylase activity and unable to grow on minimal medium is examined for changes in ribulosebisphosphate oxygenase activity. The ribulosebisphosphate oxygenase activity of the enzyme purified from both wild type and ac i72 is compared over a pH range from 7.0 to 9.5. Both enzymes exhibit maximum activity at pH 9.0. However, the ac i72 enzyme is twice as active as the wild type enzyme at a physiological pH of 7.0. The studies in vivo of the products of CO2 fixation of ac i72 and wild type cells in the presence of high and low O2 concentration shows that due to a lower level of carboxylation, the ac i72 cells fix CO2 at half the rate of wild type cells. In ac i72, 24% of the photosynthetically fixed 14C is channelled into the water-soluble fraction as opposed to 6% in wild type. Thin-layer chromatography of the water-soluble fraction showed extensive accumulation of components of the glycolate pathway in ac i72 as compared to wild type. This indicates that the oxygenase activity of the enzyme prevails in ac i72 in vivo. Since a high concentration of glycolate is toxic to cells of C. reinhardi, the high oxygenase activity of ac i72 provides an explanation for the inability of ac i72 to grow phototrophically even though its rate of CO2 fixation is half that of wild type. This toxicity to glycolate is overcome by growth under amber illumination or low O2 concentration. | Characterization of the oxygenase activity in a mutant of Chlamydomonas reinhardi exhibiting altered ribulosebisphosphate carboxylase. A previously described Mendelian mutant of Chlamydomonas reinhardi, ac i72, exhibiting altered ribulosebisphosphate carboxylase activity and unable to grow on minimal medium is examined for changes in ribulosebisphosphate oxygenase activity. The ribulosebisphosphate oxygenase activity of the enzyme purified from both wild type and ac i72 is compared over a pH range from 7.0 to 9.5. Both enzymes exhibit maximum activity at pH 9.0. However, the ac i72 enzyme is twice as active as the wild type enzyme at a physiological pH of 7.0. The studies in vivo of the products of CO2 fixation of ac i72 and wild type cells in the presence of high and low O2 concentration shows that due to a lower level of carboxylation, the ac i72 cells fix CO2 at half the rate of wild type cells. In ac i72, 24% of the photosynthetically fixed 14C is channelled into the water-soluble fraction as opposed to 6% in wild type. Thin-layer chromatography of the water-soluble fraction showed extensive accumulation of components of the glycolate pathway in ac i72 as compared to wild type. This indicates that the oxygenase activity of the enzyme prevails in ac i72 in vivo. Since a high concentration of glycolate is toxic to cells of C. reinhardi, the high oxygenase activity of ac i72 provides an explanation for the inability of ac i72 to grow phototrophically even though its rate of CO2 fixation is half that of wild type. This toxicity to glycolate is overcome by growth under amber illumination or low O2 concentration. | 2,467 |
pubmed23n0001_1268 | An intracellular endonuclease of Bacillus subtilis specific for single-stranded DNA. | We have fractionated from extracts of Bacillus subtilis the DNase activity specific for single-stranded DNA; the activity separates in two main fractions on Sephadex G-200, a larger one (Mr greater than 400 000) and a smaller one (Mr approximately 30 000). We have purified the smaller, more abundant fraction nearly 3000-fold. The purified enzyme has a pH optimum close to 8, is activated by Ca2+, and is inhibited by EDTA; the enzyme hydrolyses single-stranded DNA at a rate approximately 40 times greater than double-stranded DNA. The mode of action is endonucleolytic on both substrates, but the possiblility that the two activities may reside on different molecules is not ruled out. The products have 5'-P and 3'-OH ends. The enzyme is different from those purified from the culture media of the same organism in several respects; the latter are all extracellular enzymes, they are not specific for single-stranded DNA (except one) and have all an exonucleolytic mode of action. | An intracellular endonuclease of Bacillus subtilis specific for single-stranded DNA. We have fractionated from extracts of Bacillus subtilis the DNase activity specific for single-stranded DNA; the activity separates in two main fractions on Sephadex G-200, a larger one (Mr greater than 400 000) and a smaller one (Mr approximately 30 000). We have purified the smaller, more abundant fraction nearly 3000-fold. The purified enzyme has a pH optimum close to 8, is activated by Ca2+, and is inhibited by EDTA; the enzyme hydrolyses single-stranded DNA at a rate approximately 40 times greater than double-stranded DNA. The mode of action is endonucleolytic on both substrates, but the possiblility that the two activities may reside on different molecules is not ruled out. The products have 5'-P and 3'-OH ends. The enzyme is different from those purified from the culture media of the same organism in several respects; the latter are all extracellular enzymes, they are not specific for single-stranded DNA (except one) and have all an exonucleolytic mode of action. | 2,468 |
pubmed23n0001_1269 | Guanylate cyclase: assay and properties of the particulate and supernatant enzymes in mouse parotid. | A new, very sensitive, rapid and reliable assay for guanylate cyclase has been established based on conversion of [32P]GTP to [32P]guanosine 3':5'-monophosphate and its separation on Dowex 50 and aluminium oxide columns. The optimum conditions for the assay of mouse parotid guanylate cyclase have been established and using this procedure the properties of the enzyme have been investigated. The enzyme was found in both the particulate and supernatant fractions. The particulate enzyme was activated 12-fold by Triton X-100 and the supernatant enzyme activity increased 2-fold. In the presence of detergent guanylate cyclase activity was distributed 85% in the particulate and 15% in the supernatant fractions, respectively. The particulate activity was localised in a plasma membrane fraction. Guanylate cyclase activity was also assayed in a wide variety of other tissues. In all cases enzymatic activity was found in both the particulate and supernatant fractions. The distribution varied with the tissue but only the intestinal mucosa had a greater proportion of total guanylate cyclase activity in the particulate fraction than the parotid. The two enzymes showed some similar properties. Their pH optima were pH 7.4, both enzymes were inhibited by ATP, dATP, dGTP and ITP, required Mn2+ for activity and plots of activity versus Mn2+ concentration were sigmoidal. However, in many properties the enzymes were dissimilar. The ratios of Mn2+ to GTP for optimum activity were 4 and 1.5 for the supernatant and plasma-bound enzymes, respectively. The slope of Hill plots for the supernatant enzyme with varying Mn2+ was 2. The particulate enzyme plots also had a slope of 2 at low Mn2+ concentration but at higher concentrations (above 0.7 mM) the Hill coefficient shifted abruptly to 4. Calcium ions reduced sigmoidicity of the kinetics lowering the Hill coefficient, activated the enzyme at all Mn2+ concentrations but had no effect on the Mn2+:GTP ratio with the supernatant enzyme while with the plasma membrane enzyme Ca2+ had no effect on the sigmoid form of the kinetics at low Mn2+ but prevented the shift to a greater Hill coefficient at higher Mn2+, inhibited the activity at low Mn2+ and shifted the Mn2+:GTP optimum ratio to 4. For the particulate enzyme plots of activity versus GTP concentration were sigmoid (n = 1.3), while the supernatant enzyme exhibited hyperbolic kinetics. | Guanylate cyclase: assay and properties of the particulate and supernatant enzymes in mouse parotid. A new, very sensitive, rapid and reliable assay for guanylate cyclase has been established based on conversion of [32P]GTP to [32P]guanosine 3':5'-monophosphate and its separation on Dowex 50 and aluminium oxide columns. The optimum conditions for the assay of mouse parotid guanylate cyclase have been established and using this procedure the properties of the enzyme have been investigated. The enzyme was found in both the particulate and supernatant fractions. The particulate enzyme was activated 12-fold by Triton X-100 and the supernatant enzyme activity increased 2-fold. In the presence of detergent guanylate cyclase activity was distributed 85% in the particulate and 15% in the supernatant fractions, respectively. The particulate activity was localised in a plasma membrane fraction. Guanylate cyclase activity was also assayed in a wide variety of other tissues. In all cases enzymatic activity was found in both the particulate and supernatant fractions. The distribution varied with the tissue but only the intestinal mucosa had a greater proportion of total guanylate cyclase activity in the particulate fraction than the parotid. The two enzymes showed some similar properties. Their pH optima were pH 7.4, both enzymes were inhibited by ATP, dATP, dGTP and ITP, required Mn2+ for activity and plots of activity versus Mn2+ concentration were sigmoidal. However, in many properties the enzymes were dissimilar. The ratios of Mn2+ to GTP for optimum activity were 4 and 1.5 for the supernatant and plasma-bound enzymes, respectively. The slope of Hill plots for the supernatant enzyme with varying Mn2+ was 2. The particulate enzyme plots also had a slope of 2 at low Mn2+ concentration but at higher concentrations (above 0.7 mM) the Hill coefficient shifted abruptly to 4. Calcium ions reduced sigmoidicity of the kinetics lowering the Hill coefficient, activated the enzyme at all Mn2+ concentrations but had no effect on the Mn2+:GTP ratio with the supernatant enzyme while with the plasma membrane enzyme Ca2+ had no effect on the sigmoid form of the kinetics at low Mn2+ but prevented the shift to a greater Hill coefficient at higher Mn2+, inhibited the activity at low Mn2+ and shifted the Mn2+:GTP optimum ratio to 4. For the particulate enzyme plots of activity versus GTP concentration were sigmoid (n = 1.3), while the supernatant enzyme exhibited hyperbolic kinetics. | 2,469 |
pubmed23n0001_1270 | Influence of unsaturated fatty acids in chloroplasts. Shift of the pH optimum of electron flow and relations to deltapH, thylakoid internal pH and proton uptake. | Linolenic acid (C18:3) is the main endogenous unsaturated fatty acid of thylakoid membrane lipids, and seems in its free form to exert significant effects on the structure and function of photosynthetic membranes. In this investigation the effect of linolenic acid was studied at various pH values on the electron flow rate in isolated spinach chloroplasts and related to deltapH, the proton pump and the pH of the inner thylakoid space (pHi). The deltapH and pHi were estimated from the extent of the fluorescence quenching of 9-aminoacridine. Linolenic acid caused a shift (approximately one unit) of the pH optimum for electron flow toward acidity in the following systems: (a) photosystems II + I (from H2O to NADP+ or to 2,6-dichlorophenolindophenol) coupled or non-coupled; (b) photosystem II (from H2O to 2,6-dichlorophenolindophenol in the presence of dibromothymoquinone). In photosystem I conditions (phenazine methosulphate), the deltapH of the control increased as a function of external pHo with a maximum around pH 8.8. When linolenic acid was added, the deltapH dropped, but its optimum was shifted toward more acidic pHo. The same phenomena were also observed in photosytems II + I (from H2O to ferricyanide) and in photosystem II conditions (from H2O to ferricyanide in the presence of dibromothymoquinone). However, the deltapH was smaller and the sensitivity of the proton gradient toward linolenic acid was eventually higher than for photosystem I electron flow activity. The proton pump which might be considered as a measure of the internal buffering capacity of thylakoids was optimum at pHo, 6.7 in the controls. An addition of linolenic acid diminished the proton pump and shifted its optimum toward higher pHo. As a consequence, pHi increased when pHo was raised. At the optimal pHo 8.6 to 9, pHi were 5 to 5.5. Additions of increasing concentrations of linolenic acid displaced the curves toward higher pHi. A decrease of pHo was therefore required to maintain the pHi in the range of 5-5.5 for maximum electron flow. In conclusion, the electron flow activity seems to be delicately controlled by the proton pump (buffer capacity), deltapH, pHi and pHo. Fatty acids damage the membrane integrity in such a way that the subtile equilibrium between the factors is disturbed. | Influence of unsaturated fatty acids in chloroplasts. Shift of the pH optimum of electron flow and relations to deltapH, thylakoid internal pH and proton uptake. Linolenic acid (C18:3) is the main endogenous unsaturated fatty acid of thylakoid membrane lipids, and seems in its free form to exert significant effects on the structure and function of photosynthetic membranes. In this investigation the effect of linolenic acid was studied at various pH values on the electron flow rate in isolated spinach chloroplasts and related to deltapH, the proton pump and the pH of the inner thylakoid space (pHi). The deltapH and pHi were estimated from the extent of the fluorescence quenching of 9-aminoacridine. Linolenic acid caused a shift (approximately one unit) of the pH optimum for electron flow toward acidity in the following systems: (a) photosystems II + I (from H2O to NADP+ or to 2,6-dichlorophenolindophenol) coupled or non-coupled; (b) photosystem II (from H2O to 2,6-dichlorophenolindophenol in the presence of dibromothymoquinone). In photosystem I conditions (phenazine methosulphate), the deltapH of the control increased as a function of external pHo with a maximum around pH 8.8. When linolenic acid was added, the deltapH dropped, but its optimum was shifted toward more acidic pHo. The same phenomena were also observed in photosytems II + I (from H2O to ferricyanide) and in photosystem II conditions (from H2O to ferricyanide in the presence of dibromothymoquinone). However, the deltapH was smaller and the sensitivity of the proton gradient toward linolenic acid was eventually higher than for photosystem I electron flow activity. The proton pump which might be considered as a measure of the internal buffering capacity of thylakoids was optimum at pHo, 6.7 in the controls. An addition of linolenic acid diminished the proton pump and shifted its optimum toward higher pHo. As a consequence, pHi increased when pHo was raised. At the optimal pHo 8.6 to 9, pHi were 5 to 5.5. Additions of increasing concentrations of linolenic acid displaced the curves toward higher pHi. A decrease of pHo was therefore required to maintain the pHi in the range of 5-5.5 for maximum electron flow. In conclusion, the electron flow activity seems to be delicately controlled by the proton pump (buffer capacity), deltapH, pHi and pHo. Fatty acids damage the membrane integrity in such a way that the subtile equilibrium between the factors is disturbed. | 2,470 |
pubmed23n0001_1271 | Uronic acid dehydrogenase from Pseudomonas syringae. Purification and properties. | 1. Uronic acid dehydrogenase was purified to homogeneity. After a 338-fold purification a yield of 16% was achieved with a specific activity of 81 mumol NADH formed min-1 mg protein-1. 2. The purity of the enzyme was controlled by disc electrophoresis, sodium dodecylsulfate electrophoresis and ultracentrifugation. 3. A molecular weight of 60 000 was determined by gel chromatography and by ultracentrifugation. 4. The native enzyme is composed of two subunits, their molecular weight being 30 000 as estimated by sodium dodecylsulfate electrophoresis. The subunits as such are inactive. 5. The absorption spectrum with a maximum at 278 nm shows no evidence for a prosthetic group. 6. For catalytic activity no SH groups and no metals seem to be necessary. 7. The Michaelis constants determined with the pure enzyme are for glucuronic acid Km = 0.37 mM, galacturonic acid Km = 54 muM and NAD+ (with glucuronic acid) Km = 80 muM. 8. A weak reverse reaction could be observed with glucaric acid lactones at acidic pH. 9. NADH is competitive with NAD+. The inhibitor constant is Ki = 60 muM. 10. The NAD+ binding site seems to be of lower specificity than the uronic acid binding site. | Uronic acid dehydrogenase from Pseudomonas syringae. Purification and properties. 1. Uronic acid dehydrogenase was purified to homogeneity. After a 338-fold purification a yield of 16% was achieved with a specific activity of 81 mumol NADH formed min-1 mg protein-1. 2. The purity of the enzyme was controlled by disc electrophoresis, sodium dodecylsulfate electrophoresis and ultracentrifugation. 3. A molecular weight of 60 000 was determined by gel chromatography and by ultracentrifugation. 4. The native enzyme is composed of two subunits, their molecular weight being 30 000 as estimated by sodium dodecylsulfate electrophoresis. The subunits as such are inactive. 5. The absorption spectrum with a maximum at 278 nm shows no evidence for a prosthetic group. 6. For catalytic activity no SH groups and no metals seem to be necessary. 7. The Michaelis constants determined with the pure enzyme are for glucuronic acid Km = 0.37 mM, galacturonic acid Km = 54 muM and NAD+ (with glucuronic acid) Km = 80 muM. 8. A weak reverse reaction could be observed with glucaric acid lactones at acidic pH. 9. NADH is competitive with NAD+. The inhibitor constant is Ki = 60 muM. 10. The NAD+ binding site seems to be of lower specificity than the uronic acid binding site. | 2,471 |
pubmed23n0001_1272 | The purification and properties of the trimethoprim-resistant dihydrofolate reductase mediated by the R-factor, R388. | The R-factor R388 mediates the production of a trimethoprim-resistant dihydrofolate reductase. This enzyme has a different molecular weight and pH profile to the trimethoprim-sensitive enzyme of the Escherichia coli host. The R-factor mediated enzyme was separated completely from the host E. coli enzyme by DEAE-cellulose ion-exchange chromatography. The purified R-factor enzyme was about 20 000 times less susceptible to trimethoprim than the E. coli enzyme and although it was inhibited competitively by trimethoprim, its inhibitor constant (Ki) was 20 000 times greater than that of the host enzyme. The R388 and E. coli enzymes also differed in their substrate specificity requirements. In addition, the R388 enzyme suprisingly conferred high level resistance to the broad spectrum dihydrofolate reductase inhibitor, amethopterin. The possible origins of the R388 enzyme are discussed. | The purification and properties of the trimethoprim-resistant dihydrofolate reductase mediated by the R-factor, R388. The R-factor R388 mediates the production of a trimethoprim-resistant dihydrofolate reductase. This enzyme has a different molecular weight and pH profile to the trimethoprim-sensitive enzyme of the Escherichia coli host. The R-factor mediated enzyme was separated completely from the host E. coli enzyme by DEAE-cellulose ion-exchange chromatography. The purified R-factor enzyme was about 20 000 times less susceptible to trimethoprim than the E. coli enzyme and although it was inhibited competitively by trimethoprim, its inhibitor constant (Ki) was 20 000 times greater than that of the host enzyme. The R388 and E. coli enzymes also differed in their substrate specificity requirements. In addition, the R388 enzyme suprisingly conferred high level resistance to the broad spectrum dihydrofolate reductase inhibitor, amethopterin. The possible origins of the R388 enzyme are discussed. | 2,472 |
pubmed23n0001_1273 | Glycosaminoglycan biosynthesis in arterial wall. Hexosaminyltransferase and glucuronyltransferase in cell membranes of aortic media-intima. | Hexosaminyltransferase and glucuronyltransferase are well known for their role in the biosynthesis of proteoglycans. These two enzymes are characterized in rough and smooth membranes, obtained following subcellular fractionation of aortic media-intima. They require the presence of Mn2+ or Mg2+ for activity. The optimum concentration for these two cations is 5 mM. The optimum pH for hexosaminyltransferase and glucuronyltransferase is approximately 6.8 in Tris buffer, and their optimum temperature is 30 degrees C. Hexosaminyltransferase has an apparent Km of 0.27 nM. Glucuronyltransferase has an apparent Km of 0.21 nM. Uptake of labeled sugars by endogenous proteoglycans is inhibited by puromycin. Hexosaminyltransferase and glucuronyltransferase are present in both rough and smooth submicrosomal fractions. The different endogenous glycosaminoglycans are labeled during our incubation experiments. The greatest incorporation is noted for hyaluronic acid and heparan sulfate; the least is seen for chondroitin sulfate. The results obtained in vitro for incorporation of labeled precursors into endogenous proteoglycans are consistent with those observed during the study in vivo of the turnover of these macromolecules. | Glycosaminoglycan biosynthesis in arterial wall. Hexosaminyltransferase and glucuronyltransferase in cell membranes of aortic media-intima. Hexosaminyltransferase and glucuronyltransferase are well known for their role in the biosynthesis of proteoglycans. These two enzymes are characterized in rough and smooth membranes, obtained following subcellular fractionation of aortic media-intima. They require the presence of Mn2+ or Mg2+ for activity. The optimum concentration for these two cations is 5 mM. The optimum pH for hexosaminyltransferase and glucuronyltransferase is approximately 6.8 in Tris buffer, and their optimum temperature is 30 degrees C. Hexosaminyltransferase has an apparent Km of 0.27 nM. Glucuronyltransferase has an apparent Km of 0.21 nM. Uptake of labeled sugars by endogenous proteoglycans is inhibited by puromycin. Hexosaminyltransferase and glucuronyltransferase are present in both rough and smooth submicrosomal fractions. The different endogenous glycosaminoglycans are labeled during our incubation experiments. The greatest incorporation is noted for hyaluronic acid and heparan sulfate; the least is seen for chondroitin sulfate. The results obtained in vitro for incorporation of labeled precursors into endogenous proteoglycans are consistent with those observed during the study in vivo of the turnover of these macromolecules. | 2,473 |
pubmed23n0001_1274 | A study of the lysyl residues in the basic pancreatic trypsin inhibitor using 1H nuclear magnetic resonance at 360 Mhz. | Fourier transform 1H nuclear magnetic resonance (NMR) experiments at 360 MHz using convolution difference techniques to improve the spectral resolution were employed to investigate the resonances of the lysyl residues in bovine pancreatic trypsin inhibitor. The observations in both native protein and in chemically modified protein containing Nepsilon-dimethyllsysine show that three of the four lysines extend predominantly freely into the solvent, whereas lysine-41 is involved in an intramolecular interaction with tyrosine-10. Since in the single crystal structure tyrosine-10 is involved in an intermolecular interaction with arginine-42 of the neighboring protein molecule, the NMR data thus reveal a local conformation difference for bovine pancreatic trypsin inhibitor in solution and in the crystalline form which appears to result primarily from intermolecular interaction in the crystal lattice. | A study of the lysyl residues in the basic pancreatic trypsin inhibitor using 1H nuclear magnetic resonance at 360 Mhz. Fourier transform 1H nuclear magnetic resonance (NMR) experiments at 360 MHz using convolution difference techniques to improve the spectral resolution were employed to investigate the resonances of the lysyl residues in bovine pancreatic trypsin inhibitor. The observations in both native protein and in chemically modified protein containing Nepsilon-dimethyllsysine show that three of the four lysines extend predominantly freely into the solvent, whereas lysine-41 is involved in an intramolecular interaction with tyrosine-10. Since in the single crystal structure tyrosine-10 is involved in an intermolecular interaction with arginine-42 of the neighboring protein molecule, the NMR data thus reveal a local conformation difference for bovine pancreatic trypsin inhibitor in solution and in the crystalline form which appears to result primarily from intermolecular interaction in the crystal lattice. | 2,474 |
pubmed23n0001_1275 | Effect of triiodothyronine on rat liver chromatin protein kinase. | 1. Injection of triiodothyronine to rats stimulates protein kinase activity in liver chromatin nonhistone proteins. A significant increase was found after two daily injections. A 4-fold increase was observed with the purified enzyme after eight daily injections of the hormone. No variations were observed in cytosol protein kinase activity. Electrophoretic pattern, effect of heat denaturation, effect of p-hydroxymercuribenzoate seem to indicate that the enzyme present in treated rats is not identical to the enzyme in control animals, which suggests that thyroid hormone has induced nuclear protein kinase. Diiodothyronine, 3, 3', 5'-triiodothyronine have no effect on protein kinase. 2. Chromatin non-histone proteins isolated from rats injected with triiodothyronine incorporated more 32P when incubated with [gamma-32P]ATP than the chromatin proteins from untreated rats. Thyroidectomy reduced the in vitro 32P incorporation. It is suggested that some of the biological activity of thyroid hormone could be mediated through its effect on chromatin non-histone proteins. | Effect of triiodothyronine on rat liver chromatin protein kinase. 1. Injection of triiodothyronine to rats stimulates protein kinase activity in liver chromatin nonhistone proteins. A significant increase was found after two daily injections. A 4-fold increase was observed with the purified enzyme after eight daily injections of the hormone. No variations were observed in cytosol protein kinase activity. Electrophoretic pattern, effect of heat denaturation, effect of p-hydroxymercuribenzoate seem to indicate that the enzyme present in treated rats is not identical to the enzyme in control animals, which suggests that thyroid hormone has induced nuclear protein kinase. Diiodothyronine, 3, 3', 5'-triiodothyronine have no effect on protein kinase. 2. Chromatin non-histone proteins isolated from rats injected with triiodothyronine incorporated more 32P when incubated with [gamma-32P]ATP than the chromatin proteins from untreated rats. Thyroidectomy reduced the in vitro 32P incorporation. It is suggested that some of the biological activity of thyroid hormone could be mediated through its effect on chromatin non-histone proteins. | 2,475 |
pubmed23n0001_1276 | Subcellular distribution of histone-degrading enzyme activities from rat liver. | Chromatin prepared from liver tissue contains a histone-degrading enzyme activity with a pH optimum of 7.5-8.0, whereas chromatin isolated from purified nuclei is devoid of it. The histone-degrading enzyme activity was assayed with radioactively labelled total histones from Ehrlich ascites tumor cells. Among the different subcellular fractions assayed, only lysosomes and mitochondria exhibited histone-degrading enzymes. A pH optimum around 4.0-5.0 was found for the lysosomal fraction, whereas 7.5-8.0 has been found for mitochondria. Binding studies of frozen and thawed lysosomes or mitochondria to proteinase-free chromatin demonstrate that the proteinase associated with chromatin isolated from frozen tissue originates from damaged mitochondria. The protein degradation patterns obtained after acrylamide gel electrophoresis are similar for the chromatin-associated and the mitochondrial proteinase and different from that obtained after incubation with lysosomes. The chromatin-associated proteinase as well as the mitochondrial proteinase are strongly inhibited by 1.0 mM phenylmethanesulfonyl fluoride. Weak inhibition is found for lysosomal proteinases at pH 5. Kallikrein-trypsin inhibitor, however, inhibits lysosomal proteinase activity and has no effect on either chromatin-associated or mitochondrial proteinases. The higher template activity of chromatin isolated from a total homogenate compared to chromatin prepared from nuclei may be due to the presence of this histone-degrading enzyme activity. | Subcellular distribution of histone-degrading enzyme activities from rat liver. Chromatin prepared from liver tissue contains a histone-degrading enzyme activity with a pH optimum of 7.5-8.0, whereas chromatin isolated from purified nuclei is devoid of it. The histone-degrading enzyme activity was assayed with radioactively labelled total histones from Ehrlich ascites tumor cells. Among the different subcellular fractions assayed, only lysosomes and mitochondria exhibited histone-degrading enzymes. A pH optimum around 4.0-5.0 was found for the lysosomal fraction, whereas 7.5-8.0 has been found for mitochondria. Binding studies of frozen and thawed lysosomes or mitochondria to proteinase-free chromatin demonstrate that the proteinase associated with chromatin isolated from frozen tissue originates from damaged mitochondria. The protein degradation patterns obtained after acrylamide gel electrophoresis are similar for the chromatin-associated and the mitochondrial proteinase and different from that obtained after incubation with lysosomes. The chromatin-associated proteinase as well as the mitochondrial proteinase are strongly inhibited by 1.0 mM phenylmethanesulfonyl fluoride. Weak inhibition is found for lysosomal proteinases at pH 5. Kallikrein-trypsin inhibitor, however, inhibits lysosomal proteinase activity and has no effect on either chromatin-associated or mitochondrial proteinases. The higher template activity of chromatin isolated from a total homogenate compared to chromatin prepared from nuclei may be due to the presence of this histone-degrading enzyme activity. | 2,476 |
pubmed23n0001_1277 | Anion and amine uptake and uncoupling in submitochondrial particles. | 1. Unlike chloroplasts, submitochondrial particles are not uncoupled by nigericin + KCl or NH4Cl. Also the uncoupling effect of lipophilic anions is largely independent of the addition of weak bases. 2. Low concentrations of permeant anions cause a shift of the steady-state energy level rather than a cycle of energy utilization. The degree of inhibition of ATP synthesis by tetraphenylboron is larger than required for the uptake of the anion. 3. Lipophilic anions such as bromthymolblue, bromcresolpurple, and 8-anilino-1-napthalene sulphonate cause a pH-independent, 50% uncoupling in submitochondrial particles at concentrations of 3, 30 and 30 muM, respectively. The passive interaction of bromthymolblue and bromcresolpurple appears as a pH-dependent distribution between two pHases. ATP causes a pH-independent slight shift in the anion distribution, with negligible anion accumulation. 4. Addition of amines to energized submitochondrial particles results in two types of effects; uptake of amines and uncoupling. While in chloroplasts amine uptake and uncoupling are closely associated, this is not the case in submitochondrial particles. The uncoupling effect is observed only with lipophilic and not with hydrophilic amines, and the degree of uncoupling increases with the lipophilicity of the amines. The amine uptake, on the other hand, is accompanied by negligible uncoupling. 5. While the uptake of amines is dependent on the presence of non-permeant anions, such as Cl-, the uncoupling effect is independent of Cl-. Furthermore the amine uncoupling is markedly enhanced by lipophilic anions. 6. The view is discussed that the uncoupling effect of lipophilic anions and lipophilic amines in submitochondrial particles is due to a catalytic energy dissipation rather than to a stoichiometry energy utilization. The molecular mechanism of uncoupling presumably involves a cycling of charges after a perturbation of the membrane structure. | Anion and amine uptake and uncoupling in submitochondrial particles. 1. Unlike chloroplasts, submitochondrial particles are not uncoupled by nigericin + KCl or NH4Cl. Also the uncoupling effect of lipophilic anions is largely independent of the addition of weak bases. 2. Low concentrations of permeant anions cause a shift of the steady-state energy level rather than a cycle of energy utilization. The degree of inhibition of ATP synthesis by tetraphenylboron is larger than required for the uptake of the anion. 3. Lipophilic anions such as bromthymolblue, bromcresolpurple, and 8-anilino-1-napthalene sulphonate cause a pH-independent, 50% uncoupling in submitochondrial particles at concentrations of 3, 30 and 30 muM, respectively. The passive interaction of bromthymolblue and bromcresolpurple appears as a pH-dependent distribution between two pHases. ATP causes a pH-independent slight shift in the anion distribution, with negligible anion accumulation. 4. Addition of amines to energized submitochondrial particles results in two types of effects; uptake of amines and uncoupling. While in chloroplasts amine uptake and uncoupling are closely associated, this is not the case in submitochondrial particles. The uncoupling effect is observed only with lipophilic and not with hydrophilic amines, and the degree of uncoupling increases with the lipophilicity of the amines. The amine uptake, on the other hand, is accompanied by negligible uncoupling. 5. While the uptake of amines is dependent on the presence of non-permeant anions, such as Cl-, the uncoupling effect is independent of Cl-. Furthermore the amine uncoupling is markedly enhanced by lipophilic anions. 6. The view is discussed that the uncoupling effect of lipophilic anions and lipophilic amines in submitochondrial particles is due to a catalytic energy dissipation rather than to a stoichiometry energy utilization. The molecular mechanism of uncoupling presumably involves a cycling of charges after a perturbation of the membrane structure. | 2,477 |
pubmed23n0001_1278 | Oral antipyretic therapy: evaluation of benorylate, an ester of acetylsalicylic acid and paracetamol. | The capacity of benorylate, an ester of acetylsalicylic acid and paracetamol, to reduce fever in children was compared with that of the components as such or as a combination. The series of cases studied consisted of 66 patients between the ages of 4 months and 12 years with rectal temperatures above 38.5 degrees C. Temperatures were recorded at 15 and 20 min and 1, 2, 4 and 6 hrs after the administration of the drug. The antipyretic effect of combined acetylsalicylic acid (11 mg/kg) and paracetamol (14 mg/kg) was superior to the effect of benorylate with a dose of 25 mg/kg and even of 50 mg/kg as well as better than the effect of either drug alone. Acetylsalicylic acid (10 mg/kg) and paracetamol (12.5 mg/kg) alone produced a significantly greater antipyretic effect than benorylate with a dose of 25 mg/kg. Given in a dose of 35--40 mg/kg, benorylate seems to have a significant antipyretic effect. However, this effect is clearly smaller than that of either of its components, acetylsalicylic acid or paracetamol. Therefore benorylate is probably not suitable to be used as a general antipyretic agent in children. | Oral antipyretic therapy: evaluation of benorylate, an ester of acetylsalicylic acid and paracetamol. The capacity of benorylate, an ester of acetylsalicylic acid and paracetamol, to reduce fever in children was compared with that of the components as such or as a combination. The series of cases studied consisted of 66 patients between the ages of 4 months and 12 years with rectal temperatures above 38.5 degrees C. Temperatures were recorded at 15 and 20 min and 1, 2, 4 and 6 hrs after the administration of the drug. The antipyretic effect of combined acetylsalicylic acid (11 mg/kg) and paracetamol (14 mg/kg) was superior to the effect of benorylate with a dose of 25 mg/kg and even of 50 mg/kg as well as better than the effect of either drug alone. Acetylsalicylic acid (10 mg/kg) and paracetamol (12.5 mg/kg) alone produced a significantly greater antipyretic effect than benorylate with a dose of 25 mg/kg. Given in a dose of 35--40 mg/kg, benorylate seems to have a significant antipyretic effect. However, this effect is clearly smaller than that of either of its components, acetylsalicylic acid or paracetamol. Therefore benorylate is probably not suitable to be used as a general antipyretic agent in children. | 2,478 |
pubmed23n0001_1279 | Effect of ischemic anoxia on electrical and mechanical activity of the totally isolated porcine stomach. | Electrical and mechanical activity were recorded from totally isolated whole porcine stomachs perfused with homologous blood. Stagnant, complete ischemia was then produced by closing the gastric artery and vein for various periods of time up to 3 h. After a given period of ischemia, blood was recirculated for 10 min and then pentagastrin was injected into the gastric artery. The vagus nerve was also electrically stimulated at various stages of anoxia and recirculation. After up to 90 min of ischemia, stomachs were able to demonstrate electrical control activity of low frequency after 10 min of blood recirculation. After injection of pentagastrin, electrical control activity rapidly became normal. When ischemia lasted 120 min or longer, recirculation of blood did not induce reappearance of electrical control activity, but pentagastrin injection produced a normal response. After ischemia of 240 min duration or longer, recirculation and pentagastrin had no effect. In previously ischemic stomachs the response to vagal stimulation occurred only in the stomachs responding to pentagastrin. | Effect of ischemic anoxia on electrical and mechanical activity of the totally isolated porcine stomach. Electrical and mechanical activity were recorded from totally isolated whole porcine stomachs perfused with homologous blood. Stagnant, complete ischemia was then produced by closing the gastric artery and vein for various periods of time up to 3 h. After a given period of ischemia, blood was recirculated for 10 min and then pentagastrin was injected into the gastric artery. The vagus nerve was also electrically stimulated at various stages of anoxia and recirculation. After up to 90 min of ischemia, stomachs were able to demonstrate electrical control activity of low frequency after 10 min of blood recirculation. After injection of pentagastrin, electrical control activity rapidly became normal. When ischemia lasted 120 min or longer, recirculation of blood did not induce reappearance of electrical control activity, but pentagastrin injection produced a normal response. After ischemia of 240 min duration or longer, recirculation and pentagastrin had no effect. In previously ischemic stomachs the response to vagal stimulation occurred only in the stomachs responding to pentagastrin. | 2,479 |
pubmed23n0001_1280 | Combined azaperone and metomidate anaesthesia in liver transplantation in the pig. | Combined azaperone and metomidate anaesthesia has been used in 86 surgical procedures on 84 piglets, either as such or deepened and prolonged. 51 animals were sacrificed at the end of the procedure as planned before. The anesthesia allowed the performance of various short and long operations. Out of the 33 remaining pigs, submitted to 35 operations, 4 died during the procedure of a technical fault; 2 did not recover from a deep hypothermia (below 10 degrees C); 1 died from the hepatic coma induced through the operative procedure. The other 26 awoke and recovered spontaneous breathing within 1-4 h following the type of anaesthesia and operating procedure they had submitted, which dured from 15 to 330 min. | Combined azaperone and metomidate anaesthesia in liver transplantation in the pig. Combined azaperone and metomidate anaesthesia has been used in 86 surgical procedures on 84 piglets, either as such or deepened and prolonged. 51 animals were sacrificed at the end of the procedure as planned before. The anesthesia allowed the performance of various short and long operations. Out of the 33 remaining pigs, submitted to 35 operations, 4 died during the procedure of a technical fault; 2 did not recover from a deep hypothermia (below 10 degrees C); 1 died from the hepatic coma induced through the operative procedure. The other 26 awoke and recovered spontaneous breathing within 1-4 h following the type of anaesthesia and operating procedure they had submitted, which dured from 15 to 330 min. | 2,480 |
pubmed23n0001_1281 | Cardiovascular and beta-adrenergic blocking effects of timolol. | The haemodynamic effects of timolol and its inhibiting action on the cardiovascular and bronchial effects of isoproterenol have been studied. Splanchnic nerve activity was recorded. The antiarrhythmic action of timolol was studied on guinea pig isolated atria, using arrhythmias induced by epinephrine, ouabain or coronary ligation in the dog. Timolol is a very potent beta-adrenoceptor blocking agent, without specificity on beta1- or beta2-receptors. No intrinsic beta-stimulating or depressant effects were found. Timolol reduced splanchnic discharges. The antiarrhythmic effect of timolol was limited to epinephrine-induced arrhythmias. | Cardiovascular and beta-adrenergic blocking effects of timolol. The haemodynamic effects of timolol and its inhibiting action on the cardiovascular and bronchial effects of isoproterenol have been studied. Splanchnic nerve activity was recorded. The antiarrhythmic action of timolol was studied on guinea pig isolated atria, using arrhythmias induced by epinephrine, ouabain or coronary ligation in the dog. Timolol is a very potent beta-adrenoceptor blocking agent, without specificity on beta1- or beta2-receptors. No intrinsic beta-stimulating or depressant effects were found. Timolol reduced splanchnic discharges. The antiarrhythmic effect of timolol was limited to epinephrine-induced arrhythmias. | 2,481 |
pubmed23n0001_1282 | Effects on rectal temperature in rats of gamma-aminobutyric acid; possible mediation through putative transmitters. | The rectal temperature of male rats was measured in a thermoneutral environment (25 degrees C) and at ambient temperatures of 15 and 35 degrees C. Unless otherwise specified all drugs were administered intracerebroventricularly (i.c.v.) and all results are reported for the thermoneutral environment. Exposure to 15 degrees C did not affect the rectal temperature but exposure to 35 degrees C produced hyperthermia. At 15 and 25 degrees C, 20 mug GABA produced hyperthermia which was longer lasting at the former ambient temperature. GABA (20 mug) prevented the hyperthermic effect of exposure to 35 degrees C and produced hypothermia in animals maintained at this temperature for 1 hr. A low dose (1 mug) of NA produced hyperthermia and a higher dose (mug) hypothermia. In rats pretreated with sodium salicylate (i.p.), 20 mug GABA and 1 mug NA produced hypothermia instead of hyperthermia, suggesting the release of PGE in mediating hyperthermia. The hypothermic effect of 10 mug NA and of GABA observed at 35 degrees C was blocked by phentolamine, an indication of the possibility of alpha-adrenoceptor mediation. | Effects on rectal temperature in rats of gamma-aminobutyric acid; possible mediation through putative transmitters. The rectal temperature of male rats was measured in a thermoneutral environment (25 degrees C) and at ambient temperatures of 15 and 35 degrees C. Unless otherwise specified all drugs were administered intracerebroventricularly (i.c.v.) and all results are reported for the thermoneutral environment. Exposure to 15 degrees C did not affect the rectal temperature but exposure to 35 degrees C produced hyperthermia. At 15 and 25 degrees C, 20 mug GABA produced hyperthermia which was longer lasting at the former ambient temperature. GABA (20 mug) prevented the hyperthermic effect of exposure to 35 degrees C and produced hypothermia in animals maintained at this temperature for 1 hr. A low dose (1 mug) of NA produced hyperthermia and a higher dose (mug) hypothermia. In rats pretreated with sodium salicylate (i.p.), 20 mug GABA and 1 mug NA produced hypothermia instead of hyperthermia, suggesting the release of PGE in mediating hyperthermia. The hypothermic effect of 10 mug NA and of GABA observed at 35 degrees C was blocked by phentolamine, an indication of the possibility of alpha-adrenoceptor mediation. | 2,482 |
pubmed23n0001_1283 | Analysis of cardiac chronotropic responses to diazepam and bromazepam in conscious trained dogs. | In conscious trained dogs, administration of bromazepam (0.3 mg/kg p.o.) or diazepam (0.3 and 1.0 mg/kg p.o.) had no influence on heart rate. A higher dose (10 mg/kg p.o.) of two benzodiazepines elicited a positive chronotropic effect which was rapid in onset and of long duration. The beta-adrenoceptor blocking agent practolol (2.5 mg/kg i.v.) did not revert heart rate after the benzodiazepines to the same level as in controls, indicating that the tachycardia was not produced by an increase in sympathetic outflow to the heart. For diazepam, a sympathetic--parasympathetic interaction cannot be excluded. However, diazepam and bromazepam significantly reduced the tachycardia which is normally observed after administration of methylatropine (0.5 mg/kg i.v.) alone or in combination with practolol. In anaesthetized dogs, bromazepam failed to modify the heart rate responses to electrical stimulation of cardiac vagal or sympathetic nerves, excluding an action on this compound on ganglionic transmission and cardiac cholinoceptors and adrenoceptors. It is concluded that high doses of diazepam and bromazepam influence the heart rate of conscious dogs in a biphasic way. Firstly, they cause a central reduction of vagal tone to the heart resulting in tachycardia. Secondly, the two drugs decrease the cardiac pacemaker rate directly. Since the overall effect is tachycardia, the central action is more pronounced. | Analysis of cardiac chronotropic responses to diazepam and bromazepam in conscious trained dogs. In conscious trained dogs, administration of bromazepam (0.3 mg/kg p.o.) or diazepam (0.3 and 1.0 mg/kg p.o.) had no influence on heart rate. A higher dose (10 mg/kg p.o.) of two benzodiazepines elicited a positive chronotropic effect which was rapid in onset and of long duration. The beta-adrenoceptor blocking agent practolol (2.5 mg/kg i.v.) did not revert heart rate after the benzodiazepines to the same level as in controls, indicating that the tachycardia was not produced by an increase in sympathetic outflow to the heart. For diazepam, a sympathetic--parasympathetic interaction cannot be excluded. However, diazepam and bromazepam significantly reduced the tachycardia which is normally observed after administration of methylatropine (0.5 mg/kg i.v.) alone or in combination with practolol. In anaesthetized dogs, bromazepam failed to modify the heart rate responses to electrical stimulation of cardiac vagal or sympathetic nerves, excluding an action on this compound on ganglionic transmission and cardiac cholinoceptors and adrenoceptors. It is concluded that high doses of diazepam and bromazepam influence the heart rate of conscious dogs in a biphasic way. Firstly, they cause a central reduction of vagal tone to the heart resulting in tachycardia. Secondly, the two drugs decrease the cardiac pacemaker rate directly. Since the overall effect is tachycardia, the central action is more pronounced. | 2,483 |
pubmed23n0001_1284 | The amphetamine-induced inhibition of dopamine biosynthesis in rat striatum. | The dopamine biosynthetic machinery of intact synaptosomes of rat striatum showed a 5-fold increase in development from 3-day-old neonates to adults, and it was fully developed between 2-3 weeks after birth. Concurring with this development was the appearance 2 weeks after birth of a regulatory mechanism(s) through which amphetamine in vivo induced an inhibition of dopamine biosynthesis. The inhibition was not appreciably reversed when haloperidol, in addition to amphetamine, was administered. | The amphetamine-induced inhibition of dopamine biosynthesis in rat striatum. The dopamine biosynthetic machinery of intact synaptosomes of rat striatum showed a 5-fold increase in development from 3-day-old neonates to adults, and it was fully developed between 2-3 weeks after birth. Concurring with this development was the appearance 2 weeks after birth of a regulatory mechanism(s) through which amphetamine in vivo induced an inhibition of dopamine biosynthesis. The inhibition was not appreciably reversed when haloperidol, in addition to amphetamine, was administered. | 2,484 |
pubmed23n0001_1285 | Toxicological aspects of dimethyl-ether. | The authors report the results of a series of investigations on the toxic effects produced in mice and rabbits by inhalation of Dimethyl-ether. Median lethal concentration (LC50) and Median lethal time (LT50) were determined in the mouse. Also the effects of DME inhalation on some physiological parameters (blood pressure, heart rate, blood gas and pH data) were evaluated in the rabbit. | Toxicological aspects of dimethyl-ether. The authors report the results of a series of investigations on the toxic effects produced in mice and rabbits by inhalation of Dimethyl-ether. Median lethal concentration (LC50) and Median lethal time (LT50) were determined in the mouse. Also the effects of DME inhalation on some physiological parameters (blood pressure, heart rate, blood gas and pH data) were evaluated in the rabbit. | 2,485 |
pubmed23n0001_1286 | [Gastric irrigation and secretion in the ligatured or fistuled pylorus rat upon influence of intra-duodenal olive oil (author's transl)]. | Pylorus ligature hides the inhibitory effects of endogenous cholecystokinine-pancreozyme (CCK-PZ) on gastric mucosal secretion and irrigation, whereas the juice collected through transduodenal pyloric fistula makes this phenomenon obvious. It appears that the pyloric fistula encourages inhibition of gastrinic secretion, so that the CCK-PZ can achieve its effects. | [Gastric irrigation and secretion in the ligatured or fistuled pylorus rat upon influence of intra-duodenal olive oil (author's transl)]. Pylorus ligature hides the inhibitory effects of endogenous cholecystokinine-pancreozyme (CCK-PZ) on gastric mucosal secretion and irrigation, whereas the juice collected through transduodenal pyloric fistula makes this phenomenon obvious. It appears that the pyloric fistula encourages inhibition of gastrinic secretion, so that the CCK-PZ can achieve its effects. | 2,489 |
pubmed23n0001_1287 | Properties of glutamine aminohydrolases in subcellular fractions of liver of tumour bearing mice. | Glutamine aminohydrolase is found to be present in microsomal and soluble supernatant in liver of EAC-bearing mice. Enzymes obtained from these two sources were characterized and found to behave differently from the mitochondrial glutaminase of both normal and tumour-bearing mice. | Properties of glutamine aminohydrolases in subcellular fractions of liver of tumour bearing mice. Glutamine aminohydrolase is found to be present in microsomal and soluble supernatant in liver of EAC-bearing mice. Enzymes obtained from these two sources were characterized and found to behave differently from the mitochondrial glutaminase of both normal and tumour-bearing mice. | 2,490 |
pubmed23n0001_1288 | [Ability of adrenergic nerves to accumulate exogenous noradrenaline under some pharmacological influences]. | By employing spectrofluorometry and quantitative fluorescent histochemistry the norepinephrine (NE) content in the tissue and in the adrenergic nerves of Vas deferens of the rat after depletion of the transmitter's reserves with tyramine and their subsequent replenishment through incubation of the tissue with exogenous NE was measured. The object of investigations was also the influence of antidepressants (phthoracizine and imipramine) and of the cholinolytic spasmolytin (diphacyl) on processes of the NE accumulation. Phthoracizine, impramine and spasmolytin were found to capable of inhibiting accumulation of the exogenous NE in the tissue and in the adrenergic nerves of Vas deferens, provided the mediator is present in the extraneuronal medium in a concentration of 0.5 gamma/ml. When the neurotransmitter was introduced into the medium in higher concentrations (10 gamma/ml) the antidepressents and cholinolytic did not produce the said effect. A correlation of spectrofluorometric and quantitative fluorescent-histochemical findings was observed in cases when the tissue contained less than 50% (i.e. less than 9 gamma/ml) of the total NE reserves. | [Ability of adrenergic nerves to accumulate exogenous noradrenaline under some pharmacological influences]. By employing spectrofluorometry and quantitative fluorescent histochemistry the norepinephrine (NE) content in the tissue and in the adrenergic nerves of Vas deferens of the rat after depletion of the transmitter's reserves with tyramine and their subsequent replenishment through incubation of the tissue with exogenous NE was measured. The object of investigations was also the influence of antidepressants (phthoracizine and imipramine) and of the cholinolytic spasmolytin (diphacyl) on processes of the NE accumulation. Phthoracizine, impramine and spasmolytin were found to capable of inhibiting accumulation of the exogenous NE in the tissue and in the adrenergic nerves of Vas deferens, provided the mediator is present in the extraneuronal medium in a concentration of 0.5 gamma/ml. When the neurotransmitter was introduced into the medium in higher concentrations (10 gamma/ml) the antidepressents and cholinolytic did not produce the said effect. A correlation of spectrofluorometric and quantitative fluorescent-histochemical findings was observed in cases when the tissue contained less than 50% (i.e. less than 9 gamma/ml) of the total NE reserves. | 2,494 |
pubmed23n0001_1289 | [Possible participation of potassium ions in the regulation of local cerebral blood flow]. | The microinjections of mock spinal fluid with various potassium concentrations into the cat and monkey brain tissue were made in acute and chronic experiments. The vascular reactions as studied with the microphotography and H-clearance method were found to be linearly related to the potassium concentrations within the range of 0--12 mEq/1, being constrictory below 5 mEq/1 and dilatory above that. An interaction between MSF potassium and pH seems to be weak if any, since the slope of the potassium vascular activity diagram remains unchanged within 6.8--7.8 pH change. The data obtained suggest that potassium ions take part in rCBF control since potassium is known to escape from stimulated nerve cells and thus substantially increase an extracellular potassium concentration. | [Possible participation of potassium ions in the regulation of local cerebral blood flow]. The microinjections of mock spinal fluid with various potassium concentrations into the cat and monkey brain tissue were made in acute and chronic experiments. The vascular reactions as studied with the microphotography and H-clearance method were found to be linearly related to the potassium concentrations within the range of 0--12 mEq/1, being constrictory below 5 mEq/1 and dilatory above that. An interaction between MSF potassium and pH seems to be weak if any, since the slope of the potassium vascular activity diagram remains unchanged within 6.8--7.8 pH change. The data obtained suggest that potassium ions take part in rCBF control since potassium is known to escape from stimulated nerve cells and thus substantially increase an extracellular potassium concentration. | 2,506 |
pubmed23n0001_1290 | The alternate complement pathway in inflammatory bowel disease. Quantitation of the C3 proactivator (factor B) protein. | A component of the complement system's alternate pathway was investigated in ulcerative colitis and Crohn's disease. The mean C3PA (Factor B) titer in normals was 74 +/- 15%; in ulcerative colitis, 92 +/- 18%; and in Crohn's disease, 119+/- 24%. Significance was at the P less than 0.001 level when the mean values for the ulcerative colitis and the Crohn's disease groups were compared to normal subjects. Titers did not change significantly with exacerbation or amelioration of the diseases or when patient groups were analyzed according to the mode of treatment received. | The alternate complement pathway in inflammatory bowel disease. Quantitation of the C3 proactivator (factor B) protein. A component of the complement system's alternate pathway was investigated in ulcerative colitis and Crohn's disease. The mean C3PA (Factor B) titer in normals was 74 +/- 15%; in ulcerative colitis, 92 +/- 18%; and in Crohn's disease, 119+/- 24%. Significance was at the P less than 0.001 level when the mean values for the ulcerative colitis and the Crohn's disease groups were compared to normal subjects. Titers did not change significantly with exacerbation or amelioration of the diseases or when patient groups were analyzed according to the mode of treatment received. | 2,509 |
pubmed23n0001_1291 | Measurement of gastric functions during digestion of ordinary solid meals in man. | A method of measuring gastric secretions and emptying rates after ingestion of an ordinary (solid-liquid) meal has been developed and validated. The technique quantifies movements of volume across the pylorus using constant duodenal perfusion with a nonabsorbable marker, polyethylene glycol (PEG), which, in turn, quantifies emptying into the duodenum of another marker, [14C]PEG, incorporated in the meal. Acid and pepsin outputs can be determined without manipulation of the intragastric pH. Employing this method, we have simultaneously quantified acid, pepsin, and total secretory outputs; rates of gastric emptying of meal and secretions; and serum gastrin levels during digestion. These data characterize physiological responses to ordinary food in health. | Measurement of gastric functions during digestion of ordinary solid meals in man. A method of measuring gastric secretions and emptying rates after ingestion of an ordinary (solid-liquid) meal has been developed and validated. The technique quantifies movements of volume across the pylorus using constant duodenal perfusion with a nonabsorbable marker, polyethylene glycol (PEG), which, in turn, quantifies emptying into the duodenum of another marker, [14C]PEG, incorporated in the meal. Acid and pepsin outputs can be determined without manipulation of the intragastric pH. Employing this method, we have simultaneously quantified acid, pepsin, and total secretory outputs; rates of gastric emptying of meal and secretions; and serum gastrin levels during digestion. These data characterize physiological responses to ordinary food in health. | 2,510 |
pubmed23n0001_1292 | A dopamine receptor in esophageal smooth muscle of the opossum. | We examined the possibility that dopamine may play a role in nerve-mediated "off" responses of esophageal body (EB) and relaxations of lower esophageal spincter (LES) smooth muscle. The effects of dopamine, epinine, and dopamine antagonists on EB and LES smooth muscle were studied on these responses. Dopamine and epinine caused a dose-related fall in basal LES muscle tension and in amplitude of EB muscle "off" responses. Threshold dose for both was about 10(-7) M, and maximal dose was about 10(-4) M. At high concentrations, they also caused repetitive transient contractions of both LES and EB muscle after the period of inhibition. These effects were antagonized by haloperidol, 10(-5) M, and bulbocapnine, 10(-5) M, but were not influenced by propranolol, 10(-5) M, nor by phenoxybenzamine, 10(-5) M. Neither haloperidol nor bulbocapnine influenced responses to electrical field stimulation. Tetrodotoxin 10(-7) M abolished the responses to electrical field stimulation but did not antagonize the effects of dopamine and epinine. EB and LES smooth muscle contain a dopamine receptor. It is unlikely that dopamine is involved in responses to electrical field stimulation. | A dopamine receptor in esophageal smooth muscle of the opossum. We examined the possibility that dopamine may play a role in nerve-mediated "off" responses of esophageal body (EB) and relaxations of lower esophageal spincter (LES) smooth muscle. The effects of dopamine, epinine, and dopamine antagonists on EB and LES smooth muscle were studied on these responses. Dopamine and epinine caused a dose-related fall in basal LES muscle tension and in amplitude of EB muscle "off" responses. Threshold dose for both was about 10(-7) M, and maximal dose was about 10(-4) M. At high concentrations, they also caused repetitive transient contractions of both LES and EB muscle after the period of inhibition. These effects were antagonized by haloperidol, 10(-5) M, and bulbocapnine, 10(-5) M, but were not influenced by propranolol, 10(-5) M, nor by phenoxybenzamine, 10(-5) M. Neither haloperidol nor bulbocapnine influenced responses to electrical field stimulation. Tetrodotoxin 10(-7) M abolished the responses to electrical field stimulation but did not antagonize the effects of dopamine and epinine. EB and LES smooth muscle contain a dopamine receptor. It is unlikely that dopamine is involved in responses to electrical field stimulation. | 2,511 |
pubmed23n0001_1293 | [Continuous subcutaneous pH monitoring in newborns with abnormal metabolism (author's transl)]. | In newborns with postpartum acidosis the subcutaneous interstitiel space pH was monitored continuously with the special electrode of Stamm and Moeller. This was compared with intermittent determinations of the pH in the capillary blood from the heel of the infant. The severity of the metabolic disturbance can be recognized in all test cases with both methods. The correction of the acidosis develops in a concordant manner, in a concordant magnitude and at a largely synchronous rate. The observations show that it is possible to monitor the postpartum adaptation phase by continuous pH monitoring in the interstitial space of the subcutaneous tissue and to observe the efficiency of the treatment of acidosis, administration of oxygen, or a buffer infusion. | [Continuous subcutaneous pH monitoring in newborns with abnormal metabolism (author's transl)]. In newborns with postpartum acidosis the subcutaneous interstitiel space pH was monitored continuously with the special electrode of Stamm and Moeller. This was compared with intermittent determinations of the pH in the capillary blood from the heel of the infant. The severity of the metabolic disturbance can be recognized in all test cases with both methods. The correction of the acidosis develops in a concordant manner, in a concordant magnitude and at a largely synchronous rate. The observations show that it is possible to monitor the postpartum adaptation phase by continuous pH monitoring in the interstitial space of the subcutaneous tissue and to observe the efficiency of the treatment of acidosis, administration of oxygen, or a buffer infusion. | 2,513 |
pubmed23n0001_1294 | [The significance of gestational age in evaluating the antepartal cardiotokogram (author's transl)]. | The influence of gestational age on the probable meaning of features in the antepartal CTG which are not clearly pathological was investigated in 232 births in 1973/74. The umbilical artery pH was significantly lower among premature infants exhibiting abnormal, than among those exhibiting normal CTG patterns. No similar difference was found in term or overdue births. The clinical diagnosis of neonatal condition using the Apgar scheme confirmed biochemical findings: The frequency of depressed babies is in turn clearly higher in cases with abnormal antepartal CTG patterns. It is assumed that the reason for this is the higher sensitivity of premature babies to haemodynamic disturbances. Thus, it follows that premature babies exhibiting antepartal patterns which are not completely normal require close observation. | [The significance of gestational age in evaluating the antepartal cardiotokogram (author's transl)]. The influence of gestational age on the probable meaning of features in the antepartal CTG which are not clearly pathological was investigated in 232 births in 1973/74. The umbilical artery pH was significantly lower among premature infants exhibiting abnormal, than among those exhibiting normal CTG patterns. No similar difference was found in term or overdue births. The clinical diagnosis of neonatal condition using the Apgar scheme confirmed biochemical findings: The frequency of depressed babies is in turn clearly higher in cases with abnormal antepartal CTG patterns. It is assumed that the reason for this is the higher sensitivity of premature babies to haemodynamic disturbances. Thus, it follows that premature babies exhibiting antepartal patterns which are not completely normal require close observation. | 2,514 |
pubmed23n0001_1295 | Characteristics of lipopolysaccharides of Salmonella typhi isolated from carriers and patients suffering from typhoid fever. | Lipopolysaccharides (LPS) of Salmonella typhi strains, isolated from carriers and patients suffering from typhoid fever, were characterised according to their biochemical properties, morphological structure and degree of aggregation of complexes. All preparations of LPS, regardless of their origin, were morphologically heterogeneous. Free electrophoresis and immunoelectrophoresis demonstrated that LPS preparations were composed of components possessing different mobilities in electric fields. LPS of bacterial strains isolated from both carriers and patients, split upon reaction in immunoelectrophoresis with specific antiserum 73, rabbit antiserum to Salmonella typhi Vi Bhatnagar and 0-901 split into anodic and cathodic fractions. The anodic fraction reacted similarly as Vi antigen. LPS from Salmonella typhi Ty-2 yielded only the cathodic fraction, typical for O antigen. LPS from strains which were passaged twice in nutritional medium possessed identical properties as LPS from fresh cultures of Salmonella typhi. Electron microscopy revealed that LPS appears as long bands, rods, ellipsoid forms and amorphous material. Contrary to amorphous material, the bands, rods and ellipsoid forms possessed three-layer structure. | Characteristics of lipopolysaccharides of Salmonella typhi isolated from carriers and patients suffering from typhoid fever. Lipopolysaccharides (LPS) of Salmonella typhi strains, isolated from carriers and patients suffering from typhoid fever, were characterised according to their biochemical properties, morphological structure and degree of aggregation of complexes. All preparations of LPS, regardless of their origin, were morphologically heterogeneous. Free electrophoresis and immunoelectrophoresis demonstrated that LPS preparations were composed of components possessing different mobilities in electric fields. LPS of bacterial strains isolated from both carriers and patients, split upon reaction in immunoelectrophoresis with specific antiserum 73, rabbit antiserum to Salmonella typhi Vi Bhatnagar and 0-901 split into anodic and cathodic fractions. The anodic fraction reacted similarly as Vi antigen. LPS from Salmonella typhi Ty-2 yielded only the cathodic fraction, typical for O antigen. LPS from strains which were passaged twice in nutritional medium possessed identical properties as LPS from fresh cultures of Salmonella typhi. Electron microscopy revealed that LPS appears as long bands, rods, ellipsoid forms and amorphous material. Contrary to amorphous material, the bands, rods and ellipsoid forms possessed three-layer structure. | 2,523 |
pubmed23n0001_1296 | Reduction of blood platelet monoamine oxidase activity in schizophrenic patients on phenothiazines. | A newly developed assay for monoamine oxidase (MAO) activity in blood platelets (serotonin used as substrate) was applied for the measurement of the enzyme activity in 76 schizophrenic patients. No significant reduction was found in the blood platelet MAO activity in a group of 33 untreated schizophrenic patients, as compared to that in the normal controls. Male patients revealed to have lower enzyme activity than females in the schizophrenic group, as we described previously in the normal subjects. Treatment with phenothiazines caused significant reduction of blood platelet MAO activity, while platelet serotonin content and platelet count appeared to be not affected by the drug treatment. The authors suggest that blood platelet MAO activity may be related to hormonal factors but not to psychiatric diagnosis of schizophrenia or constitution liable to schizophrenic illnesses. | Reduction of blood platelet monoamine oxidase activity in schizophrenic patients on phenothiazines. A newly developed assay for monoamine oxidase (MAO) activity in blood platelets (serotonin used as substrate) was applied for the measurement of the enzyme activity in 76 schizophrenic patients. No significant reduction was found in the blood platelet MAO activity in a group of 33 untreated schizophrenic patients, as compared to that in the normal controls. Male patients revealed to have lower enzyme activity than females in the schizophrenic group, as we described previously in the normal subjects. Treatment with phenothiazines caused significant reduction of blood platelet MAO activity, while platelet serotonin content and platelet count appeared to be not affected by the drug treatment. The authors suggest that blood platelet MAO activity may be related to hormonal factors but not to psychiatric diagnosis of schizophrenia or constitution liable to schizophrenic illnesses. | 2,524 |
pubmed23n0001_1297 | [Inflammatory cerebro-vascular disease: angiographic findings and distribution patterns (author's transl)]. | Although cerebral angiography should be approached with caution in the diagnosis of inflammatory cerebro-vascular disease there are some characteristic angiographic findings which may be helpful for classification and differential diagnosis. The proximal cerebral arteries are favourably affected by basal meningitis and thrombangiitis obliterans with resulting stenoses and occlusions. Whereas those inflammations originating from neighbouring skull structures mostly involve the intracavernous parts of the carotid artery, the tuberculous and mycotic arteritis prefer the supraclinoid carotid siphon. Peripheral vascular changes are found in luetic endangiitis, necrotizing and toxic angiitis and in collagenoses. Simultaneous involvement of the temporal arteries is of great diagnostic importance demonstrating the systemic character of the inflammatory process; in Horton's arteritis it can be a pathognomonic finding. Infectious endocarditis, some mycoses and malaria may lead to embolic occlusion of cerebral vessels. Mycotic aneurysms mostly have a broad base or a fusiform shape and do not prefer the localizations of congenital aneurysms. Angiographically, abscesses, tuberculomas and viral encephalitis may result in circumscribed hypervascularized areas. The characteristic angiographic findings are exemplified and discussed on the basis of 8 cases of inflammatory cerebro-vascular disease (tuberculosis, pneumococcal and unspecific bacterial meningitis, syphilis, mycosis, Takayasu-syndrome, panarteritis nodosa, temporal arteritis). | [Inflammatory cerebro-vascular disease: angiographic findings and distribution patterns (author's transl)]. Although cerebral angiography should be approached with caution in the diagnosis of inflammatory cerebro-vascular disease there are some characteristic angiographic findings which may be helpful for classification and differential diagnosis. The proximal cerebral arteries are favourably affected by basal meningitis and thrombangiitis obliterans with resulting stenoses and occlusions. Whereas those inflammations originating from neighbouring skull structures mostly involve the intracavernous parts of the carotid artery, the tuberculous and mycotic arteritis prefer the supraclinoid carotid siphon. Peripheral vascular changes are found in luetic endangiitis, necrotizing and toxic angiitis and in collagenoses. Simultaneous involvement of the temporal arteries is of great diagnostic importance demonstrating the systemic character of the inflammatory process; in Horton's arteritis it can be a pathognomonic finding. Infectious endocarditis, some mycoses and malaria may lead to embolic occlusion of cerebral vessels. Mycotic aneurysms mostly have a broad base or a fusiform shape and do not prefer the localizations of congenital aneurysms. Angiographically, abscesses, tuberculomas and viral encephalitis may result in circumscribed hypervascularized areas. The characteristic angiographic findings are exemplified and discussed on the basis of 8 cases of inflammatory cerebro-vascular disease (tuberculosis, pneumococcal and unspecific bacterial meningitis, syphilis, mycosis, Takayasu-syndrome, panarteritis nodosa, temporal arteritis). | 2,527 |
pubmed23n0001_1298 | Oxidative deamination of biogenic amines by intestinal amine oxidases: histamine is specifically inactivated by diamine oxidase. | The ability of the gut to inactivate various amines by oxidative deamination was tested with a 130-fold purified amine oxidase preparation from dog small intestine. Of 34 amines tested, putrescine, benzylamine, cadaverine, and serotonin were the most favourable substrates. Histamine was inactivated rapidly by this enzyme preparation, too. Histamine derivatives methylated at the imidazole nucleus were also deaminated, whereas Nalpha-methylhistamine was only a poor substrate and Nalpha, Nalpha-dimethylhistamine was not a substrate at all. Using a second procedure for the purification of amine oxidases from gut, the separation of a soluble monoamine oxidase from diamine oxidase was achieved by gel filtration on Sephadex G-200. The diamine oxidase deaminated putrescine (Km = 1.3 x 10(-4)M) and histamine (Km = 6.6 x 10(-5)M), but not serotonin, and was inhibited by aminoguanidine, but not by pargyline. The soluble monoamine oxidase inactivated serotonin (Km = 4.5 x 10(-4)M), but not histamine and putrescine and was inhibited by pargyline, but not by aminoguanidine. It was concluded that in dog small intestine (as well as in rabbit small intestine) only diamine oxidase was capable of inactivating histamine by oxidative deamination. | Oxidative deamination of biogenic amines by intestinal amine oxidases: histamine is specifically inactivated by diamine oxidase. The ability of the gut to inactivate various amines by oxidative deamination was tested with a 130-fold purified amine oxidase preparation from dog small intestine. Of 34 amines tested, putrescine, benzylamine, cadaverine, and serotonin were the most favourable substrates. Histamine was inactivated rapidly by this enzyme preparation, too. Histamine derivatives methylated at the imidazole nucleus were also deaminated, whereas Nalpha-methylhistamine was only a poor substrate and Nalpha, Nalpha-dimethylhistamine was not a substrate at all. Using a second procedure for the purification of amine oxidases from gut, the separation of a soluble monoamine oxidase from diamine oxidase was achieved by gel filtration on Sephadex G-200. The diamine oxidase deaminated putrescine (Km = 1.3 x 10(-4)M) and histamine (Km = 6.6 x 10(-5)M), but not serotonin, and was inhibited by aminoguanidine, but not by pargyline. The soluble monoamine oxidase inactivated serotonin (Km = 4.5 x 10(-4)M), but not histamine and putrescine and was inhibited by pargyline, but not by aminoguanidine. It was concluded that in dog small intestine (as well as in rabbit small intestine) only diamine oxidase was capable of inactivating histamine by oxidative deamination. | 2,528 |
pubmed23n0001_1299 | Comparative toxicology in vitreous humor and blood. | Drug and toxic substances were detected in blood and vitreous humor in fifty-six cases, in which causes of death were both from an overdose of the particular substances and from other unrelated causes. Five instances are reported in which two drug substances were detected in blood and vitreous humor from the same subject. Patients having long survival times, as well as those dying from unrelated causes, reveal drug values to approach unity, when the blood and vitreous concentrations are compared. The ratios reached at equilibrium probably depend on solubility of the drug in vitreous humor, lipid solubility and the percentage protein-bound in the blood. The vitreous humor provides another parameter of testing and may be useful in studies of survival time. | Comparative toxicology in vitreous humor and blood. Drug and toxic substances were detected in blood and vitreous humor in fifty-six cases, in which causes of death were both from an overdose of the particular substances and from other unrelated causes. Five instances are reported in which two drug substances were detected in blood and vitreous humor from the same subject. Patients having long survival times, as well as those dying from unrelated causes, reveal drug values to approach unity, when the blood and vitreous concentrations are compared. The ratios reached at equilibrium probably depend on solubility of the drug in vitreous humor, lipid solubility and the percentage protein-bound in the blood. The vitreous humor provides another parameter of testing and may be useful in studies of survival time. | 2,525 |
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