Prp24

Prp24 (precursor RNA processing, gene 24) is a protein part of the pre-messenger RNA splicing process and aids the binding of U6 snRNA to U4 snRNA during the formation of spliceosomes. Found in eukaryotes from yeast to "E. coli", fungi, and humans, Prp24 was initially discovered to be an important element of RNA splicing in 1989. Mutations in Prp24 were later discovered in 1991 to suppress mutations in U4 that resulted in cold-sensitive strains of yeast, indicating its involvement in the reformation of the U4/U6 duplex after the catalytic steps of splicing.
Biological Role.
The process of spliceosome formation involves the U4 and U6 snRNPs associating and forming a di-snRNP in the cell nucleus. This di-snRNP then recruits another member (U5) to become a tri-snRNP. U6 must then dissociate from U4 to bond with U2 and become catalytically active. Once splicing has been done, U6 must dissociate from the spliceosome and bond back with U4 to restart the cycle.
Prp24 has been shown to promote the binding of U4 and U6 snRNPs. Removing Prp24 results in the accumulation of free U4 and U6, and the subsequent addition of Prp24 regenerates U4/U6 and reduces the amount of free U4 and U6. Naked U6 snRNA is very compact and has little room to form base pairs with other RNA. However, when U6 snRNP associates with proteins such as Prp24, the structure is much more open, thus facilitating the binding to U4. Prp24 is not present in the U6/U4 duplex itself, and it has been suggested that Prp24 must leave the complex in order for proper base pairs to be formed. It has also been suggested that Prp24 may play a role in destabilizing U4/U6 in order for U6 to pair bases with U2.
Structure.
Prp24 has a molecular weight of 50 kDa and has been shown to contain four RNA recognition motifs (RRMs) and a conserved 12-amino acid sequence at the C-terminus. RRMs 1 and 2 have been shown to be important for high-affinity binding of U6, while RRMs 3 and 4 bind at lower affinity sites on U6. The first three RRMs interact extensively with each other and contain canonical folds that contain a four-stranded beta-sheet and two alpha-helices. The electropositive surface of RRMs 1 and 2 is a RNA annealing domain while the cleft between RRMs 1 and 2 including the beta-sheet face of RRM2 is a sequence-specific RNA binding site. The C-terminal motif is required for association with LSm proteins and contributes to substrate (U6) binding and not the catalytic rate of splicing.
Interactions.
Prp24 interacts with the U6 snRNA via its RRMs. It has been shown through chemical modification testing that nucleotides 39–57 of U6 (40–43 in particular) are involved in binding Prp24.
The LSm proteins are in a consistent configuration on the U6 RNA. It has been proposed that the LSm proteins and Prp24 interact both physically and functionally and the C-terminal motif of Prp24 is important for this interaction. The binding of Prp24 to U6 is enhanced by the binding of Lsm proteins to U6, as is binding of U4 and U6. It was revealed by electron microscopy that Prp24 may interact with the LSm protein ring at LSm2.
Homologs.
Prp24 has a human homolog, SART3. SART3 is a tumor rejection antigen (SART3 stands for "squamous cell carcinoma antigen recognized by T cells, gene 3). The RRMs 1 and 2 in yeast are similar to RRMs in human SART3. The C-terminal domain is also highly conserved from yeast to humans. This protein, like Prp24, interacts with the LSm proteins for the recycling of U6 into the U4/U6 snRNP. It has been proposed that SART3 target U6 to a Cajal body or a nuclear inclusion as the site of assembly of the U4/U6 snRNP. SART3 is located on chromosome 12, and a mutation is likely the cause of disseminated superficial actinic porokeratosis.


3-MeO-PCE

3-Methoxyeticyclidine (3-MeO-PCE), also known as methoxieticyclidine, is a dissociative anesthetic that is qualitatively similar to PCE and PCP and has been sold online as a designer drug.
On October 18, 2012 the Advisory Council on the Misuse of Drugs in the United Kingdom released a report about methoxetamine, saying that the "harms of methoxetamine are commensurate with Class B of the Misuse of Drugs Act (1971)", despite the fact that the act does not classify drugs based on harm. The report went on to suggest that all analogues of methoxetamine should also become class B drugs and suggested a catch-all clause covering both existing and unresearched arylcyclohexamines, including 3-MeO-PCE.
This report also described the receptor binding profile of methoxetamine and three additional dissociatives 3-MeO-PCP, 4-MeO-PCP, and 3-MeO-PCE, showing them to have significant affinity for the PCP site of the NMDA receptor (NMDAR) and was later published in more detail.
3-MeO-PCE has Ki values of 61 nM for the NMDAR, 743 nM for the dopamine transporter, 2097 nM for the histamine H2 receptor, 964 nM for the alpha-2A adrenergic receptor, 115 nM for the serotonin transporter, 4519 nM for the σ1 receptor, and 525 nM for the σ2 receptor.
Legal status.
3-MeO-PCE is banned in Sweden and Switzerland.
As per Chile's Ley de drogas, aka Ley 20000, all esters and ethers of PCE are illegal. As 3-MeO-PCE is an ether of PCE, it is thus illegal.


Novosphingobium lentum

Novosphingobium lentum is a Gram-negative, rod-shaped, non-spore-forming, psychrotolerant and non-motile bacterium from the genus of Novosphingobium which has been isolated from chlorophenol-contaminated groundwater in Finland. "Novosphingobium lentum" has the ability to degrade chlorophenol.


List of adrenergic drugs

This is a list of adrenergic drugs. These are pharmaceutical drugs, naturally occurring compounds and other chemicals that influence the function of the neurotransmitter epinephrine (adrenaline).
Receptor ligands.
α1-adrenergic receptor ligands.
Antagonists.
Many tricyclic antidepressants, tetracyclic antidepressants, antipsychotics, ergolines, and some piperazines like buspirone, trazodone, nefazodone, etoperidone, and mepiprazole antagonize α1-adrenergic receptors as well, which contributes to their side effects such as orthostatic hypotension.
α2-adrenergic receptor ligands.
Antagonists.
Many atypical antipsychotics and azapirones like buspirone and gepirone (via metabolite pyrimidinylpiperazine) antagonize α2-adrenergic receptors as well.
Enzyme inhibitors.
Catabolism.
Monoamine oxidase (MAO) inhibitors.
MAO-B inhibitors also influence norepinephrine/epinephrine levels since they inhibit the breakdown of their precursor dopamine.


Bacterial effector protein

Bacterial effectors are proteins secreted by pathogenic bacteria into the cells of their host, usually using a type 3 secretion system (TTSS/T3SS), a type 4 secretion system (TFSS/T4SS) or a Type VI secretion system (T6SS). Some bacteria inject only a few effectors into their host’s cells while others may inject dozens or even hundreds. Effector proteins may have many different activities, but usually help the pathogen to invade host tissue, suppress its immune system, or otherwise help the pathogen to survive. Effector proteins are usually critical for virulence. For instance, in the causative agent of plague ("Yersinia pestis"), the loss of the T3SS is sufficient to render the bacteria completely avirulent, even when they are directly introduced into the bloodstream. Gram negative microbes are also suspected to deploy bacterial outer membrane vesicles to translocate effector proteins and virulence factors via a membrane vesicle trafficking secretory pathway, in order to modify their environment or attack/invade target cells, for example, at the host-pathogen interface.
Diversity.
Many pathogenic bacteria are known to have secreted effectors but for most species the exact number is unknown. Once a pathogen genome has been sequenced, effectors can be predicted based on protein sequence similarity, but such predictions are not always precise. More importantly, it is difficult to prove experimentally that a predicted effector is actually secreted into a host cell because the amount of each effector protein is tiny. For instance, Tobe et al. (2006) predicted more than 60 effectors for pathogenic "" but could only show for 39 that they are secreted into human Caco-2 cells. Finally, even within the same bacterial species, different strains often have different repertoires of effectors. For instance, the plant pathogen "Pseudomonas syringae" has 14 effectors in one strain, but more than 150 have been found in multiple different strains.
Mechanism of action.
Given the diversity of effectors, they affect a wide variety of intracellular processes. The T3SS effectors of pathogenic "E. coli, Shigella, Salmonella", and "Yersinia" regulate actin dynamics to facilitate their own attachment or invasion, subvert endocytic trafficking, block phagocytosis, modulate apoptotic pathways, and manipulate innate immunity as well as host responses.
Phagocytosis. Phagocytes are immune cells that can recognize and "eat" bacteria. Phagocytes recognize bacteria directly [e.g., through the so-called scavenger receptor A which recognizes bacterial lipopolysaccharide (LPS) ] or indirectly through antibodies (IgG) and complement proteins (C3bi) which coat the bacteria and are recognized by the Fcγ receptors and integrinαmβ2 (complement receptor 3). For instance, intracellular "Salmonella" and "Shigella" escape phagocytic killing through manipulation of endolysosomal trafficking (see there). "Yersinia" predominantly survives extracellularly using the translocation of effectors to inhibit cytoskeletal rearrangements and thus phagocytosis. EPEC/EHEC inhibit both transcytosis through M cells and internalization by phagocytes. "Yersinia" inhibits phagocytosis through the concerted actions of several effector proteins, including YopE which acts as a RhoGAP and inhibits Rac-dependent actin polymerization.
Endocytic trafficking. Several bacteria, including "Salmonella" and "Shigella", enter the cell and survive intracellularly by manipulating the endocytic pathway. Once internalized by host cells "Salmonella" subverts the endolysosome trafficking pathway to create a "Salmonella"-containing vacuole (SCV), which is essential for its intracellular survival. As the SCVs mature they travel to the microtubule organizing center (MTOC), a perinuclear region adjacent to the Golgi, where they produce "Salmonella" induced filaments (Sifs) dependent on the T3SS effectors SseF and SseG. By contrast, internalized "Shigella" avoids the endolysosome system by rapidly lysing its vacuole through the action of the T3SS effectors IpaB and C although the details of this process are poorly understood.
Secretory pathway. Some pathogens, such as EPEC/EHEC disrupt the secretory pathway. For instance, their effector EspG can reduce the secretion of interleukin-8 (IL-8), and thus affect the immune system (immunomodulation). EspG functions as a Rab GTPase-activating protein (Rab-GAP), trapping Rab-GTPases in their inactive GDP bound form, and reducing ER–Golgi transport (of IL-8 and other proteins).
Apoptosis (programmed cell death). Apoptosis is usually a mechanism of defense to infection, given that apoptotic cells eventually attract immune cells to remove them and the pathogen. Many pathogenic bacteria have developed mechanisms to prevent apoptosis, not the least to maintain their host environment. For instance, the EPEC/EHEC effectors NleH and NleF block apoptosis. Similarly, the "Shigella" effectors IpgD and OspG (a homolog of NleH) block apoptosis, the former by phosphorylating and stabilizing the double minute 2 protein (MDM2) which in turn leads to a block of NF-kB-induced apoptosis. "Salmonella" inhibits apoptosis and activates pro-survival signals, dependent on the effectors AvrA and SopB, respectively.
Induction of cell death. In contrast to inhibition of apoptosis, several effectors appear to induce programmed cell death. For instance, EHEC effectors EspF, EspH, and Cif induce apoptosis.
Inflammatory response. Human cells have receptors that recognize pathogen-associated molecular patterns (PAMPs). When bacteria bind to these receptors, they activate signaling cascades such as the NF-kB and MAPK pathways. This leads to expression of cytokines, immunomodulating agents, such as interleukins and interferons which regulate immune response to infection and inflammation. Several bacterial effectors affect NF-kB signaling. For instance, the EPEC/EHEC effectors NleE, NleB, NleC, NleH, and Tir are immunosuppressing effectors that target proteins in the NF-kB signaling pathway. NleC has been shown to cleave the NF-kB p65 subunit (RelA), blocking the production of IL-8 following infection. NleH1, but not NleH2, blocks translocation of NF-kB into the nucleus. The Tir effector protein inhibits cytokine production. Similarly, YopE, YopP, and YopJ (in "Yersinia enterocolitica", "Yersinia pestis", and "Yersinia pseudotuberculosis" respectively) target the NF-kB pathway. YopE inhibits activation of NF-kB, which in part prevents the production of IL-8. YopJ family members are acetyltransferases that modify lysine, serine or threonine residues with an acetyl group, leading to protein aggregation, blockage of phosphorylation or inhibition of ATP binding. In plants, this kind of protein acetylation can be removed through activity of the SOBER1/TIPSY1 deacetylase family.


5-MeO-DET

5-MeO-DET or 5-methoxy-"N,N"-diethyltryptamine is a hallucinogenic tryptamine.
Pharmacology.
5-MeO-DET inhibits serotonin reuptake with an IC50 value of 2.4 μM and activates 5-HT2A receptors with an EC50 value of 8.11 nM.
Effects.
Low dosages (0.5–1 mg) are reported to produce a relaxing body high and mild entheogenic effects. Shulgin reports in TiHKAL that higher dosages (1–3 mg) can produce very unpleasant reactions.


RNA polymerase I

RNA polymerase 1 (also known as Pol I) is, in higher eukaryotes, the polymerase that only transcribes ribosomal RNA (but not 5S rRNA, which is synthesized by RNA polymerase III), a type of RNA that accounts for over 50% of the total RNA synthesized in a cell.
Structure and Function.
Pol I is a 590 kDa enzyme that consists of 14 protein subunits (polypeptides), and its crystal structure in the yeast "Saccharomyces cerevisiae" was solved at 2.8Å resolution in 2013. Twelve of its subunits have identical or related counterparts in RNA polymerase II (Pol II) and RNA polymerase III (Pol III). The other two subunits are related to Pol II initiation factors and have structural homologues in Pol III.
Ribosomal DNA transcription is confined to the nucleolus, where about 400 copies of the 42.9-kb rDNA gene are present, arranged as tandem repeats in nucleolus organizer regions. Each copy contains a ~13.3 kb sequence encoding the 18S, the 5.8S, and the 28S RNA molecules, interlaced with two internal transcribed spacers, ITS1 and ITS2, and flanked upstream by a 5' external transcribed spacer and a downstream 3' external transcribed spacer. These components are transcribed together to form the 45S pre-rRNA. The 45S pre-rRNA is then post-transcriptionally cleaved by C/D box and H/ACA box snoRNAs, removing the two spacers and resulting in the three rRNAs by a complex series of steps. The 5S ribosomal RNA is transcribed by Pol III. Because of the simplicity of Pol I transcription, it is the fastest-acting polymerase and contributes up to 60% of cellular transcription levels in exponentially growing cells.
In "Saccharomyces cerevisiae", the 5S rDNA has the unusual feature of lying inside the rDNA repeat. It is flanked by non-transcribed spacers NTS1 and NTS2, and is transcribed backwards by Pol III, separately from the rest of the rDNA.
Regulation of rRNA transcription.
The rate of cell growth is directly dependent on the rate of protein synthesis, which is itself intricately linked to ribosome synthesis and rRNA transcription. Thus, intracellular signals must coordinate the synthesis of rRNA with that of other components of protein translation. Myc is known to bind to human ribosomal DNA in order to stimulate rRNA transcription by RNA polymerase I. Two specific mechanisms have been identified, ensuring proper control of rRNA synthesis and Pol I-mediated transcription.
Given the large numbers of rDNA genes (several hundreds) available for transcription, the first mechanism involves adjustments in the number of genes being transcribed at a specific time. In mammalian cells, the number of active rDNA genes varies between cell types and level of differentiation. In general, as a cell becomes more differentiated, it requires less growth and, therefore, will have a decrease in rRNA synthesis and a decrease in rDNA genes being transcribed. When rRNA synthesis is stimulated, SL1 (selectivity factor 1) will bind to the promoters of rDNA genes that were previously silent, and recruit a pre-initiation complex to which Pol I will bind and start transcription of rRNA.
Changes in rRNA transcription can also occur via changes in the rate of transcription. While the exact mechanism through which Pol I increases its rate of transcription is as yet unknown, evidence has shown that rRNA synthesis can increase or decrease without changes in the number of actively transcribed rDNA.
Transcription cycle.
In the process of transcription (by any polymerase), there are three main stages:
Initiation.
Pol I requires no TATA box in the promoter, instead relying on an upstream control element (UCE) located between −200 and −107, and a core element located between −45 and +20.
Note that this process is variable in different organisms.
Elongation.
As Pol I escapes and clears the promoter, UBF and SL1 remain-promoter bound, ready to recruit another Pol I. Indeed, each active rDNA gene can be transcribed multiple times simultaneously, as opposed to Pol II-transcribed genes, which associate with only one complex at a time. While elongation proceeds unimpeded in vitro, it is unclear at this point whether this process happens in a cell, given the presence of nucleosomes. Pol I does seem to transcribe through nucleosomes, either bypassing or disrupting them, perhaps assisted by chromatin-remodeling activities. In addition, UBF might also act as positive feedback, enhancing Pol I elongation through an anti-repressor function. An additional factor, TIF-IC, can also stimulate the overall rate of transcription and suppress pausing of Pol I. As Pol I proceeds along the rDNA, supercoils form both ahead of and behind the complex. These are unwound by topoisomerase I or II at regular intervals, similar to what is seen in Pol II-mediated transcription.
Elongation is likely to be interrupted at sites of DNA damage. Transcription-coupled repair occurs similarly to Pol II-transcribed genes and requires the presence of several DNA repair proteins, such as TFIIH, CSB, and XPG.
Termination.
In higher eukaryotes, TTF-I binds and bends the termination site at the 3' end of the transcribed region. This will force Pol I to pause. TTF-I, with the help of transcript-release factor PTRF and a T-rich region, will induce Pol I into terminating transcription and dissociating from the DNA and the new transcript. Evidence suggests that termination might be rate-limiting in cases of high rRNA production. TTF-I and PTRF will then indirectly stimulate the reinitiation of transcription by Pol I at the same rDNA gene.
In organisms such as budding yeast the process seems to be much more complicated and is still not completely elucidated.
Recombination hotspot.
Recombination hotspots are DNA sequences that increase local recombination. The HOT1 sequence in yeast is one of the most well studied mitotic recombination hotspots. The HOT1 sequence includes an RNA polymerase I transcription promoter. In a yeast mutant strain defective in RNA polymerase I the HOT1 activity in promoting recombination is abolished. The level of RNA polymerase I transcription activity that is dependent on the promoter in the HOT1 sequence appears to determine the level of nearby mitotic recombination.


GRIK3

Glutamate receptor, ionotropic kainate 3 is a protein that in humans is encoded by the "GRIK3" gene.
This gene encodes a protein that belongs to the ligand-gated ionic channel family. It can coassemble with either GRIK4 or GRIK5 to form heteromeric receptors and acts as an excitatory neurotransmitter at many synapses in the central nervous system. RNA editing in the mRNA has been reported.


CtRNA

In molecular biology ctRNA (counter-transcribed RNA) is a plasmid encoded noncoding RNA that binds to the mRNA of repB and causes translational inhibition.
ctRNA is encoded by plasmids and functions in rolling circle replication to maintain a low copy number. In "Corynebacterium glutamicum", it achieves this by antisense pairing with the mRNA of RepB, a replication initiation protein.
In "Enterococcus faecium" the plasmid pJB01 contains three open reading frames, copA, repB, and repC. The pJB01 ctRNA is coded on the opposite strand from the copA/repB intergenic region and partially overlaps an atypical ribosome binding site for repB.


Creative Diagnostics

Creative Diagnostics is an American biotechnology company that specializes in the research and manufacturing of antibodies, viral antigens, diagnostic components, critical assay reagents, and other biological services.
Founding.
Creative Diagnostics was founded in Shirley, New York, USA in 2005. The initial business was focused on monoclonal and polyclonal antibodies. Later, various kinds of antibodies, viral antigens, reagents, medical kits, and biological services were launched to broaden the company's activities.
Partnerships.
Creative Diagnostics has maintained a strategic commercial partner agreement with CD Genomics, Inc. since 2010. The two companies also began a platform license agreement in 2012.
Operations.
Creative Diagnostics provides contract research and manufacturing services. Additionally, the company conducts ELISA testing. Other products include:


R. K. Kamboj

Dr R. K Kamboj (Rajender K Kamboj, Rajender Kamboj, Raj Kamboj) is an Indian Pharmaceutical scientist in the area of drug discovery was born in 1955 to Sh.Karta Ram Kamboj at Village Fatehpur, Yamunanagar district, Haryana. He did his M.Sc in Biological Sciences in 1977. He joined the University of Adelaide, Australia in 1981 and completed his Ph.D in March 1986. During his doctoral studies at the University of Adelaide (1981–1986), Kamboj published his researches in "Plant Physiology", a highly cited peer-reviewed scientific monthly journal published by American Society of Plant Biologists, which publishes articles on the physiology, biochemistry, cellular and molecular biology, genetics, biophysics and environmental biology of plants. Kamboj's doctoral thesis was about "Biochemical Studies on pollen and pollen-pistil interaction in `Petunia hybrida`".
After completing his Ph.D, Dr Kamboj continued to work as research scientist in Australia till 1991. Thereafter, he moved to Canada to join Allelix Biopharmaceuticals Inc ("a part of NPS Pharmaceuticals, Inc, Toronto"), as its Vice President and Chief Scientific Officer. At Allelix, Kamboj was entrusted with the primary responsibility of managing its drug discovery programs. After working about 12 years with Allelix, Dr Kamboj joined "Xenon Genetics Inc, Vancouver" as its Vice President for Drug Discovery. In both the companies named above, Dr Kamboj was instrumental in taking the companies from the inception of the drug discovery group all the way to multiple licensing transactions and collaborations.
Dr Kamboj left Xenon Genetics Inc. in June 2008 to join Lupin Limited, a medium-sized, but aggressive transnational pharmaceutical company from India, where he was appointed President of "New Chemical Entity (NCE) Research" of Lupin Limited. In the same year, Kamboj was also appointed president of the "Novel Drug Discovery and Development of Lupin Limited".
Dr Kamboj has developed an extensive global network of contacts with pharmaceutical industry and academic scientific communities. His experience includes strong contribution to business development, licensing products and technologies, mergers and acquisitions and corporate development activities. He holds over forty (40) U.S. patent applications (filed and issued), covering the discovery and use of a number of human genes. He is the author/co-author of over 90 research articles/papers in the field of biomedical field. His career spans more than 29 years in research, 16 years of which is in pharmaceutical industrial R&D setting.
Dr Kamboj is currently a member of the working group on "New TB Drugs Team, India".
Dr Kamboj is also a member of the "Market Advisory Groups (MAG)" of the Asia Pacific Trade Council of British Columbia, Canada.


Imiloxan

Imiloxan is a drug which is used in scientific research. It acts as a selective antagonist for the α2B adrenergic receptor, and has been useful for distinguishing the actions of the different α2 adrenergic subtypes.
Synthesis.
The imidazole portion of imiloxan is prepared by the reaction of an imidate with the diethyl acetal of aminoacetaldehyde. "N"-Alkylation of the imidazole with ethyl iodide gives imiloxan.


Biomatrica

Biomatrica is a United States-based biotechnology company, and subsidiary of Exact Sciences Corporation, that develops chemicals for ambient temperature preservation of biological materials for the purpose of expanding the availability and accuracy of medical diagnostics and research. Specifically, the company focuses on improving the stability of biological materials, such as DNA, RNA, proteins, cells from patient samples used in research, and diagnostic testing reagents. Company scientists have developed alternatives to existing preservation technologies, such as cold storage and lyophilization (freeze-drying), to prevent degradation of perishable biological materials. Biomatrica's technologies are used in applications such as pre-analytic sample collection, diagnostic assays, biobanking, forensics, and basic research.
History.
Biomatrica was founded by scientists, Judy Müller-Cohn, PhD, and Rolf Müller, PhD, in 2004. Prior to founding Biomatrica, both had worked many years in San Diego's biotechnology industry. Müller-Cohn had previously worked at Digital Gene Technologies and Mycogen/ Dow Agrosciences, whilst Müller had worked on the HIV Core Program Project Grant at San Diego's Scripps Research Institute.
Biomatrica initially developed ambient temperature storage reagents for DNA and RNA. The company's core technology was inspired by the phenomenon of anhydrobiosis, the ability of some organisms to hibernate in a desiccated state during dry periods, and then reanimate upon contact with water. Focusing on microscopic, desert-dwelling creatures called Tardigrades, which undergo anhydrobiosis for up to 120 years, Biomatrica identified how to chemically mimic the mechanism of anhydrobiosis. Following stabilization at room temperature with Biomatrica's chemical reagents, biological specimens could be rehydrated for subsequent studies with the addition of a few drops of water.
Since 2012, the company has become increasingly focused on its pre-analytic collection and assay stabilization service businesses described below.
In October 2018 Biomatrica was acquired by the Madison, Wisconsin-based molecular diagnostics and cancer screening company Exact Sciences Corporation for $20 million.
Products and Services.
The company's first product was a dry, synthetic polymer, "DNAstable" (originally “SampleMatrix”), a chemical formulation that stabilized purified DNA at ambient temperature. The company later released RNAstable and CloneStable, dry chemical reagents optimized for stabilizing purified RNA and bacterial plasmid DNA, respectively.
In 2007, the German biotechnology company, Qiagen, licensed DNAstable for sale under the trade name QIAsafe. Biomatrica and Qiagen subsequently co-developed QIAsafe Blood, an ambient temperature stabilization reagent for unpurified DNA in whole blood. Later in 2007, Biomatrica released molecular assay enhancement products, PCRboost and STRboost, for enhancement of PCR performed on degraded and trace DNA samples. Liquid versions of DNAstable and RNAstable were launched as DNAstable LD and RNAstable LD in 2011 and 2012, respectively. These liquid products provide more flexibility for diverse experimental formats, including those utilizing automated instrumentation.
Biomatrica began commercialization of preanalytical products in 2009 with the launch of its “gard” product line. These products include RNAgard Blood, DNAgard Blood, and DNAgard Tissue and Cells, products designed to stabilize biological samples from collection to analytical testing. In 2013, the company launched a device, DNAgard Saliva, for the collection of salivary DNA samples to be used in a variety of research studies. In 2015, a completely redesigned and improved version of this device was launched under the name DNAgard Saliva "HT". This new version is designed and optimized for use by high-throughput laboratory automation instruments. In 2017, the company launched LBgard Blood Tubes, which allow collection and preservation of cfDNA for 14 days, and CTCs and WBCs for 4 days, for liquid biopsy and NIPT applications.
In 2012, the company began offering custom stabilization services to diagnostic assay manufacturers under the trade name, AssayStable. This service allowed improved manufacturing and stability of diagnostic test kits. After completing several successful contracts with large diagnostic manufacturers, the company launched a related service, PCRstable, that focused specifically on improving stability of PCR-based, molecular diagnostic assays, including those using microfluidic chips and specialized cartridges and cassettes. To facilitate testing and adoption of the company's stabilizers, Biomatrica launched the ReadyDry PCR Stabilizer Screening Kit in 2016.
Partnerships and Agreements.
Licensing agreements for Biomatrica technologies were signed with Qiagen in 2007 and 2009.
Following the launch of DNAstable, the company gained the interest of law enforcement organizations, such as the California Department of Justice, which sought to stabilize DNA samples from crime scenes for forensics purposes. Other law enforcement organizations, including sheriffs’ departments in Orange County, CA Los Angeles, CA, and Palm Beach, FL, have adopted ambient temperature forensic sample management systems based on Biomatrica's technologies.
Also in 2010, Biomatrica signed a collaborative research and development agreement (CRADA) with United States Army Medical Research Institute for Infectious Diseases (USAMRIID) to develop and test new technologies for ambient temperature stabilization of clinical and biological samples.
The same year, Biomatrica began a partnership agreement with the U.S. National Cancer Institute (NCI) for biomarker stabilization and SAIC-Frederick to improve molecular analysis of tumors.
In 2011, the company announced a partnership agreement with In-Q-Tel, an investment firm that identifies technologies to support the mission of the U.S. intelligence community.
In 2014, Biomatrica and American Type Tissue Culture (ATCC) signed a licensing agreement for Biomatrica to supply its DNA & RNA stabilization reagents to the ATCC for use in the latter company's DNA and RNA standards. In the same year, Biomatrica and Sigma-Aldrich signed an agreement for the worldwide distribution of Biomatrica's stabilization reagents.


Echinops (mammal)


Vladimir Torchilin

Vladimir Petrovich Torchilin (, born 1946) is a Soviet, Russian and American biochemist, pharmacologist , and an expert in medical nanotechnology.
Since 1991 lives in the USA. Since 1993-1999 he was with Massachusetts General Hospital and Harvard Medical School as the Head of Chemistry
Program, Center for Imaging and Pharmaceutical Research, and Associate Professor of Radiology. Since 1998 he is with Northeastern University, Boston, Massachusetts, in 1998-2008 as Chair of the Department of Pharmaceutical Sciences, and as of 2005, Distinguished Professor and as of 2013, University Distinguished Professor and Director of Center for Pharmaceutical Biotechnology and Nanomedicine of Northeastern University.
PhD, DSc, MS, Moscow State University
Scientific work.
V.Torchilin has published over 350 original papers, over 150 reviews, wrote and edited 10 books and holds over 40 patents. According to Google Scholar, his H index is 103 with more than 50,000 citations. Times Higher Education ranked V.Torchilin as #2 among world top scientists in pharmacology for the years 2001-2010.
Prose.
In addition to his scientific work, Torchilin publishes essays and short stories in Russian and American magazines and newspapers.


Tree wrap

A tree wrap or tree wrapping is a wrap of garden tree saplings, roses, and other delicate plants to protect them from frost damage (e.g. frost cracks or complete death). In the past it was made of straw (straw wrap) . Now there are commercial tree wrap materials, such as crepe paper or burlap tapes. Tree wrapping is also used to prevent saplings from sunscald and drying of the bark. A disadvantage of tape wrapping is dampness under the wrapping during rainy seasons.


LivK RNA motif

The "livK" RNA motif describes a conserved RNA structured that was discovered using bioinformatics. The "livK" motif is detected only in the species "Pseudomonas syringae". It is found in the potential 5' untranslated regions (5' UTRs) of "livK" genes and downstream "livM" and "livH" genes, as well as the 5' UTRs of amidase genes. The "liv" genes are predicted to be transporters of branched-chain amino acids, i.e., leucine, isoleucine or valine. The specific reaction catalyzed the amidase genes is not predicted.


List of A Certain Magical Index characters

The following is a list of characters from "A Certain Magical Index" light novel, manga and anime series, and its side-story manga and anime series titled "A Certain Scientific Railgun" and "A Certain Scientific Accelerator". The series primarily takes place in Academy City, a city filled with students who strived to become powerful espers and were brought into conflict by the appearance of sorcerers.
Academy City.
A Certain High School.
The unnamed high school that Tōma and his friends attended.
Nagatenjōki Academy.
 is one of the top five most prestigious schools in Academy City, where Accelerator attended. Unlike Tokiwadai Middle School, the school's admission is open for both espers and normal students with no powers. Last year, Nagatenjōki Academy defeated Tokiwadai Middle School at Daihasei Festival.
Tokiwadai Middle School.
 is an elite girl's middle school and one of the five prestigious schools in Academy City, which was located in District 7's School Garden. It is the school that Mikoto Misaka and Misaki Shokuhō attended. The school's admission requires espers to be a Level 3 or higher.
Kirigaoka Girls' Academy.
 is an all-girls academy and one of the prestigious schools in Academy City, housing the middle school, high school, and college facilities. It is located near the Elementary Particle Engineering Laboratory at District 18. The school's admission is only opened to espers with rare and unique powers.
Sakugawa Middle School.
 is a co-ed middle school in Academy City located at District 7, where the two protagonists of "A Certain Scientific Railgun" manga and anime series were enrolled.
Ryōran Maid School.
 is a girls' home economics school in Academy City where students received training to become maids.
Sekisho Junior High School.
 is one of the middle schools located in Academy City.
Level 5.
Level 5 is currently the highest esper level in Academy City. There are currently seven Level 5s out of 2.3 million espers who participated in the Power Curriculum Program. An esper's promotion to Level 5 is approved by the Board of Directors. The Level 5s are ranked based on their worth to Aleister's plan rather than their test of strength. According to the Tree Diagram simulation, Accelerator is currently the only Level 5 esper that could achieve Level 6. Tōma can fight or interact with all Level 5s.
Skill-Out.
 is an armed group of Level 0s who often used various means of fighting espers to compensate their lack of powers.
Sisters.
 is the collective term for Mikoto's clones produced by the Radio Noise Project (also known as Sisters Project). They are Level 2 or 3 espers with an ability called that allowed them to generate at least 50,000 V of electricity but it cannot track electrons, therefore they use special goggles instead. This ability also turns their brainwaves into electric signals, allowing them to share their thoughts and memories within their communication network called "Misaka Network". The Sisters are quiet and emotionless as they speak monotonously in third person narrative while ending their sentences with a description of themselves. Since the termination of their projects, the clones eventually develop self-esteem and individuality and begin showing feelings towards Tōma as they share their memories with him throughout the network.
The Sisters are originally produced as efficient Level 5 combat clones for the military but the project result shows that they only achieved Level 2 or 3 instead. The clones are then reused in the Level 6 Shift Project as experimental subjects needed for Accelerator's shift into Level 6 by killing them. In the third volume of "A Certain Magical Index" light novel series, 10,031 clones have been killed in the experiment until Tōma and Mikoto intervene to stop the project, saving the last subject (Misaka #10032) before its termination. At the end of the Sisters story arc, the remaining 9,959 clones are sent to research facilities around the world for the readjustment of their body's life span while 10 clones stay in Academy City under Heaven Canceller's care.
The following Sisters have the most prominence in the series:
City administration.
Board of Directors.
The Board of Directors consists of twelve people who held absolute authority in Academy City, with the Board Chairman ruling them. They govern the city's daily activities and contribute to the research, development, and welfare of its citizens.
Kihara Family.
The is a group of scientists who led twisted human experiments in the name of science.
Dark side organizations.
SCHOOL.
 is one of the dark side organizations in Academy City, which became responsible for stealing the Tweezers that served as a MacGuffin in "A Certain Magical Index" light novel series.
ITEM.
 is one of the dark side organizations in Academy City tasked to keep the Board of Directors in check. The team is the only one of the organizations involved in the Battle Royale story arc to remain active after World War III.
MEMBER.
 is one of the dark side organizations in Academy City tasked to perform odd jobs for the Board Chairman. The team is considered Aleister's "loyal dogs".
BLOCK.
 is one of the dark side organizations in Academy City tasked to keep an eye on the level of cooperation between the city and friendly outside institutions.
Scavenger.
 is one of the dark side organizations in Academy City tasked for clean-up and disposal on behalf of the Board of Directors. They make appearances in the manga and anime series "A Certain Scientific Accelerator" and "A Certain Scientific Railgun".
Freshmen.
 is one of the dark side organizations in Academy City tasked to eliminate intruders with supernatural powers that were not developed in the city. The team is first introduced in the "New Testament: A Certain Magical Index" light novel series.
United Kingdom.
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, is a constitutional monarchy located off the north-western coast of continental Europe. The country is currently ruled by three organizations: the British Royal Family, the Church of England, and the Knights of England. Due to the joint ruling between organizations, they have made the United Kingdom one of the most powerful magical organizations in the world, rivaling the Roman Catholic Church.
British Royal Family.
The British royal family is a family of close relatives of the monarch of the United Kingdom. Queen Elizard, based on the real-life British queen, is the current head of the monarch and Supreme Head of the Church of England. The members of the royal family are magic users for generations as they represent the magic nobility. The family resides in Buckingham Palace but they usually use Windsor Castle as their second home.
Church of England.
The Church of England (or Anglican Church) is one of the three largest Christian denominations in the magic world headed by the Archbishop of Canterbury. Its headquarters establishes in St. George's Cathedral in Lambeth, London. The current leader of the Church of England is Dion Fortune.
Necessarius.
 is the 0th Parish of the Church of England specialized in neutralizing and destroying magic in England, and tasked to investigate, arrest, and punish magicians. The Head of the Church of Necessary Evil is also the current Archbishop of Canterbury.
Knights of England.
The Knights of England is the order of magic knights in England headed by the Knight Leader. The Knights have served the United Kingdom since the Crusades and have become the basis of all magic knights over Europe, including Vatican City's Thirteen Knights of the Roman Catholic Church and France's Knights of Orléans. As one of the three magic organizations of the United Kingdom, the Knights represent the magic community within the country's military.
Magic Cabals.
New Light.
 is a pseudo-cabal reserve force specialized in Norse-based magic. The members wear jackets with the initials of their organization embroidered on them.
Dawn-colored Sunlight.
 is the largest Golden-style magic cabal in Europe led by Leivinia. Their goal is to unite the magic and science sides and rule over them.
Vatican City.
Vatican City is an enclaved city-state located in Rome, Italy, and the headquarters of the Roman Catholic Church. The country merely represents the magic side in contrast with Academy City that represented the science side.
Roman Catholic Church.
The Roman Catholic Church is one of the three religious organizations that ruled the magic side with two billion followers under the leadership of the Pope. The current leader of the church is Pietro Yogdis who served as a cardinal before his promotion.
Agnese Forces.
Agnese Forces is a religious paramilitary unit of the Roman Catholic Church with over 250 battle nuns that specialized in magic combat.
God's Right Seat.
God's Right Seat is a four-member secret magical organization within the Roman Catholic Church with members representing four Archangels of Catholicism. Their goal is to achieve "La Persona Superiore a Dio" ('The One Above God') by erasing the original sin.
Russia.
Russia is a transcontinental country located in the Eurasia continent where the majority of World War III in "A Certain Magical Index" light novel series took place.
Russian Orthodox Church.
The Russian Orthodox Church is one of the three largest religious organizations that ruled the magic side. Its headquarters is located in Moscow. According to Motoharu, the Russian Orthodox Church specializes in ghost-hunting, whereas the Church of England is known for witch-hunting.
Annihilatus.
 is the secret magical organization within the Russian Orthodox Church specialized in exterminating ghosts and other nonexistent beings.
Elizalina Alliance of Independent Nations.
The Elizalina Alliance of Independent Nations is an international alliance of smaller nations that gained independence from Russia. It is named after the current leader of the country.
Latin America.
Return of the Winged One.
 is an Aztec-based magic organization. This organization has almost complete control over Latin America, though not to the extent like the Christian churches which could influence the government.
France.
France is a European country that had a fictional conflict with the United Kingdom in "A Certain Magical Index" universe.
Nordic countries.
GREMLIN.
 is a group of magicians formed after World War III to oppose Academy City and the major group antagonist of "New Testament: A Certain Magical Index" light novel series. Their organization name is based on the folkloric creature of the same name. GREMLIN has several followers, including other magicians, who desired the destruction of Academy City.
Japan.
Amakusa-Style Remix of Church.
The Amakusa-Style Remix of Church is a secret order of Japanese warriors. The order was formed during the Edo period when Japan banned Christianity. To escape persecution, they merge Shintoism and Buddhism into their Catholic beliefs to hide their religion which led the Amakusas to create a unique fusion of magic. While skilled sorcerers, the Amakusas are also skilled with martial arts and fighting in groups.


Abortive transformation

The abortive transformation is a transformation of cells, which are unstable. A few generations after transformation the cells revert to normal.
This process has been visualized in species such as Saccharomyces cerevisiae, where abortive transformants become formed during homologous recombination.


Mycena luxaeterna

Mycena luxaeterna, common name eternal light mushroom, is a species of fungus in the family Mycenaceae. The mushrooms have parachute-shaped caps which start off darkly grayish-brown, changing to grayish-yellow or pale grayish-brown with a pale white ring at the edge when mature, and reach up to in diameter. Their thin, cylindrical, hollow, fragile stems up to in diameter are covered in a thick gel and emit a constant yellow-green bioluminescence (the caps do not glow). The gills are attached. The mushroom has a slightly radish-like smell and similar slightly bitter taste.
Habitat.
The mushroom was discovered in a very limited area of the Atlantic rain forest of São Paulo, Brazil and is known to exist only at this location. It grows on decomposing twigs, rarely on dead leaves or undergrowth, in clusters of two-to-twenty individuals. Dennis Desjardin is credited with the discovery.
Uses.
The eternal light mushroom has no known nutritional value, contains no known hallucinogens, and is not reported as having any particular cultural significance. Its extreme rarity means that it has never been common in cooking.


Alan Grodzinsky

Alan J. Grodzinsky is an American scientist and Professor of Electrical, Mechanical and Biological Engineering and Director of the Center for Biomedical Engineering at MIT. He graduated in Electrical Engineering from MIT in 1971, obtaining a doctorate three years later under the supervision of James Melcher, with a thesis on membrane electromechanics.
Grodzinsky is widely recognized for his research investigating the mechanical, chemical and electrical properties of connective tissue, including studies on cartilage tissue engineering, with implications for understanding and curing diseases such as osteoarthritis. He has published over 315 peer reviewed papers which have been cited almost 30,000 times in Google Scholar. He has supervised 25 post-doctoral candidates, 52 Ph.D./Sc.D. students, 2 M.D. students, 52 M.S. students and 63 B.S students. He has been honored with the 2018 Orthopaedic Research Society Outstanding Achievement in Mentoring Award for his lifelong commitment to excellence in mentoring trainees both in his lab and around the world.
Grodzinsky was a founding Fellow of the American Institute of Medical and Biological Engineering in 1993. He has served as the President of the Bioelectrical Repair and Growth Society (1986–87), Chairman of the Gordon Research Conference on Musculoskeletal Biology & Bioengineering (1990), President of the International Cartilage Repair Society (1998-2000) and President of the Orthopaedic Research Society (2007–08). He received a NIH Merit Award in 1994.
Grodzinsky is married to Gail Grodzinsky (née Meyer) and has a son Michael Grodzinsky and lives in Massachusetts.


NAD(P)H dehydrogenase (quinone)

In enzymology, a NAD(P)H dehydrogenase (quinone) () is an enzyme that catalyzes the chemical reaction
The 4 substrates of this enzyme are NADH, NADPH, H+, and quinone, whereas its 3 products are NAD+, NADP+, and hydroquinone.
This enzyme belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with a quinone or similar compound as acceptor. The systematic name of this enzyme class is NAD(P)H:quinone oxidoreductase. Other names in common use include menadione reductase, phylloquinone reductase, quinone reductase, dehydrogenase, reduced nicotinamide adenine dinucleotide (phosphate, quinone), DT-diaphorase, flavoprotein NAD(P)H-quinone reductase, menadione oxidoreductase, NAD(P)H dehydrogenase, NAD(P)H menadione reductase, NAD(P)H-quinone dehydrogenase, NAD(P)H-quinone oxidoreductase, NAD(P)H: (quinone-acceptor)oxidoreductase, NAD(P)H: menadione oxidoreductase, NADH-menadione reductase, naphthoquinone reductase, p-benzoquinone reductase, reduced NAD(P)H dehydrogenase, viologen accepting pyridine nucleotide oxidoreductase, vitamin K reductase, diaphorase, reduced nicotinamide-adenine dinucleotide (phosphate) dehydrogenase, vitamin-K reductase, NAD(P)H2 dehydrogenase (quinone), NQO1, QR1, and NAD(P)H:(quinone-acceptor) oxidoreductase. This enzyme participates in biosynthesis of steroids. It employs one cofactor, FAD. At least one compound, Dicumarol is known to inhibit this enzyme.
Structural studies.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .


Lipid bilayer characterization

Lipid bilayer characterization is the use of various optical, chemical and physical probing methods to study the properties of lipid bilayers. Many of these techniques are elaborate and require expensive equipment because the fundamental nature of the lipid bilayer makes it a very difficult structure to study. An individual bilayer, since it is only a few nanometers thick, is invisible in traditional light microscopy. The bilayer is also a relatively fragile structure since it is held together entirely by non-covalent bonds and is irreversibly destroyed if removed from water. In spite of these limitations dozens of techniques have been developed over the last seventy years to allow investigations of the structure and function of bilayers. The first general approach was to utilize non-destructive "in situ" measurements such as x-ray diffraction and electrical resistance which measured bilayer properties but did not actually image the bilayer. Later, protocols were developed to modify the bilayer and allow its direct visualization at first in the electron microscope and, more recently, with fluorescence microscopy. Over the past two decades, a new generation of characterization tools including AFM has allowed the direct probing and imaging of membranes "in situ" with little to no chemical or physical modification. More recently, dual polarisation interferometry has been used to measure the optical birefringence of lipid bilayers to characterise order and disruption associated with interactions or environmental effects.
Fluorescence Microscopy.
Fluorescence microscopy is a technique whereby certain molecules can be excited with one wavelength of light and will emit another longer wavelength of light. Because each fluorescent molecule has a unique spectrum of absorption and emission, the location of particular types of molecules can be determined. Natural lipids do not fluoresce, so it is always necessary to include a dye molecule in order to study lipid bilayers with fluorescence microscopy. To some extent, the addition of the dye molecule always changes the system, and in some cases it can be difficult to say whether the observed effect is due to the lipids, the dye or, most commonly, some combination of the two. The dye is usually attached either to a lipid or a molecule that closely resembles a lipid, but since the dye domain is relatively large it can alter the behavior of this other molecule. This is a particularly contentious issue when studying the diffusion or phase separation of lipids, as both processes are very sensitive to the size and shape of the molecules involved.
This potential complication has been given an argument against the use of one of fluorescence recovery after photobleaching (FRAP) to determine bilayer diffusion coefficients. In a typical FRAP experiment a small (~30 µm diameter) area is photobleached by exposure to an intense light source. This area is then monitored over time as the “dead” dye molecules diffuse out and are replaced by intact dye molecules from the surrounding bilayer. By fitting this recovery curve it is possible to calculate the diffusion coefficient of the bilayer. An argument against the use of this technique is that what is actually being studied is the diffusion of the dye, not the lipid. While correct, this distinction is not always important, since the mobility of the dye is often dominated by the mobility of the bilayer.
In traditional fluorescence microscopy the resolution has been limited to approximately half the wavelength of the light used. Through the use of confocal microscopy and image processing this limit can be extended, but typically not much below 100 nanometers, which is much smaller than a typical cell but much larger than the thickness of a lipid bilayer. More recently, advanced microscopy methods have allowed much greater resolution under certain circumstances, even down to sub-nm. One of the first of these methods to be developed was Förster resonance energy transfer (FRET). In FRET, two dye molecules are chosen such that the emission spectrum of one overlaps the absorption spectrum of the other. This energy transfer is extremely distance dependent, so it is possible to tell with angstrom resolution how far apart the two dyes are. This can be used for instance to determine when two bilayers fuse and their components mix. Another high resolution microscopy technique is fluorescence interference contrast microscopy (FLIC). This method requires that the sample be mounted on a precisely micromachined reflective surface. By studying the destructive interference patterns formed it is possible to individually resolve the two leaflets of a supported bilayer and determine the distribution of a fluorescent dye in each.
Electrical.
Electrical measurements are the most straightforward way to characterize one of the more important functions of a bilayer, namely its ability to segregate and prevent the flow of ions in solution. Accordingly, electrical characterization was one of the first tools used to study the properties of model systems such as black membranes. It was already known that the cell membrane was capable of supporting an ionic gradient and that this gradient is responsible for the ability of neurons to send signals via an action potential. Demonstrating that similar phenomena could be replicated "in vitro" was an important verification of the utility of model systems.
Fundamentally, all electrical measurements of bilayers involve the placement of an electrode on either side of the membrane. By applying a bias across these electrodes and measuring the resulting current, it is possible to determine the resistance of the bilayer. This resistance is typically quite high for intact bilayers, often exceeding 100 GΩ since the hydrophobic core is impermeable to charged hydrated species. Because this resistance is so large, the presence of even a few nanometer-scale holes results in a dramatic increase in current and can be easily determined. The sensitivity of this system is such that even the activity of single ion channels can be resolved. In such DC measurements, it is necessary to use electrochemically active electrodes to provide the necessary positive charges on one side and negative charges on the other. The most common system is the silver/silver chloride electrode since this reaction is stable, reversible, involves a single electron transfer and can produce large currents. In addition to simple DC current measurements it is also possible to perform AC electrical characterization to extract information about the capacitance and complex impedance of a bilayer. Because capacitance is inversely proportional to thickness and bilayers are very thin they typically have a very large capacitance, on the order of 2µF/cm2. Capacitance measurements are particularly useful when dealing with black lipid membranes, as they can be used to determine when the solvent/lipid plug thins down to a single bilayer.
Optical.
Lipids are highly polar molecules which when self assembled into bilayers creates a highly birefringent layer where the optical properties parallel are very different from those perpendicular. This effect, studied by dual polarisation interferometry has been used to measure dynamic reorganisation of the layer due to temperature, ionic strength, and molecular interactions with e.g. antimicrobial peptides.
Hydrated bilayers show rich vibrational dynamics and are good media for efficient vibrational energy transfer. Vibrational properties of lipid monolayers and bilayers has been investigated by ultrafast spectroscopic techniques and recently developed computational methods.
AFM.
Atomic force microscopy (AFM) has been used in recent years to image and probe the physical properties of lipid bilayers. AFM is a promising technique because it has the potential to image with nanometer resolution at room temperature and even underwater, conditions necessary for natural bilayer behavior. These capabilities have allowed direct imaging of the subtle ripple phase transition in a supported bilayer. Another AFM experiment performed in a tapping mode under aqueous buffer medium allowed (1) to determine the formation of transmembrane pores (holes) around nanoparticles of approximately 1.2 to 22 nm diameter via subtraction of AFM images from series recorded during the lipid bilayer formation and (2) to observe adsorption of single insulin molecules onto exposed nanoparticles. Another advantage is that AFM does not require fluorescent or isotopic labeling of the lipids, as the probe tip interacts mechanically with the bilayer surface. Because of this, the same scan can reveal information about both the bilayer and any associated structures, even to the extent of resolving individual membrane proteins. In addition to imaging, AFM can also probe the mechanical nature of small delicate structures such as lipid bilayers. One study demonstrated the possibility of measuring the elastic modulus of individual nano-scale membranes suspended over porous anodic alumina.
Although AFM is a powerful and versatile tool for studying lipid bilayers, there are some practical limitations and difficulties. Because of the fragile nature of the bilayer, extremely low scanning forces (typically 50pN or less) must be used to avoid damage. This consideration is particularly important when studying metastable systems such as vesicles adsorbed on a substrate, since the AFM tip can induce rupture and other structural changes. Care must also be taken to choose an appropriate material and surface preparation for the AFM tip, as hydrophobic surfaces can interact strongly with lipids and disrupt the bilayer structure.
Electron microscopy.
In electron microscopy a beam of focused electrons interacts with the sample rather than a beam of light as in traditional microscopy. Electrons have a much shorter wavelength than light so electron microscopy has much higher resolution than light microscopy, potentially down to the atomic scale. Because lipid bilayers are arranged on the molecular level, this higher resolution has been invaluable. In 1960, when the structure of the bilayer was still debated, it was electron microscopy that offered the first direct visualization of the two apposing leaflets. In conjunction with rapid freezing techniques, electron microscopy has also been used to study the mechanisms of inter- and intracellular transport, for instance in demonstrating that exocytotic vesicles are the means of chemical release at synapses. Often, electron microscopy is the only probe technique with sufficient resolution to determine complex nanometer-scale morphologies.
The limitations of electron microscopy in the study of lipid structures deal primarily with sample preparation. Most electron microscopes require the sample to be under vacuum, which is incompatible with hydration at room temperature. To surmount this problem, samples can be imaged under cryogenic conditions with the associated water frozen, or a metallic negative can be made from a frozen sample. It is also typically necessary to stain the bilayer with a heavy metal compound such as osmium tetroxide or uranyl acetate because the low atomic weight constituents of lipids (carbon, nitrogen, phosphorus, etc.) offer little contrast compared to water. If a Transmission electron microscope (TEM) is being used, it is also necessary to cut or polish the sample into a very thin (<1 micrometre) sheet, which can be difficult and time-consuming. Scanning Electron Microscopy (SEM) does not require this step, but cannot offer the same resolution as TEM. Both methods are surface-sensitive techniques and cannot reveal information about deeply buried structures.
Neutron and X-ray scattering.
Both X-rays and high-energy neutrons are used to probe the structure and periodicity of biological structures including bilayers because they can be tuned to interact with matter at the relevant (angstrom-nm) length scales. Often, these two classes of experiment provide complementary information because each has different advantages and disadvantages. X-rays interact only weakly with water, so bulk samples can be probed with relatively easy sample preparation. This is one of the reasons that x-ray scattering was the technique first used to systematically study inter-bilayer spacing. X-ray scattering can also yield information on the average spacing between individual lipid molecules, which has led to its use in characterizing phase transitions. One limitation of x-ray techniques is that x-rays are relatively insensitive to light elements such as hydrogen. This effect is a consequence of the fact that x-rays interact with matter by scattering off of electron density which decreases with decreasing atomic number. In contrast, neutrons scatter off of nuclear density and nuclear magnetic fields so sensitivity does not decrease monotonically with z. This mechanism also provides strong isotopic contrast in some cases, notably between hydrogen and deuterium, allowing researchers to tune the experimental baseline by mixing water and deuterated water. Using reflectometry rather than scattering with neutrons or x-rays allow experimenters to probe supported bilayers or multilayer stacks. These measurements are more complicated to perform an analyze, but allow determination of cross sectional composition, including the location and concentration of water within the bilayer. In the case of both neutron and x-ray scattering measurements, the information provided is an ensemble average of the system and is therefore subject to uncertainty based on thermal fluctuations in these highly mobile structures.


Bacterial one-hybrid system

The bacterial one-hybrid (B1H) system is a method for identifying the sequence-specific target site of a DNA-binding domain. In this system, a given transcription factor (TF) is expressed as a fusion to a subunit of RNA polymerase. In parallel, a library of randomized oligonucleotides representing potential TF target sequences are cloned into a separate vector containing the selectable genes HIS3 and URA3. If the DNA-binding domain (bait) binds a potential DNA target site (prey) "in vivo", it will recruit RNA polymerase to the promoter and activate transcription of the reporter genes in that clone. The two reporter genes, HIS3 and URA3, allow for positive and negative selections, respectively. At the end of the process, positive clones are sequenced and examined with motif-finding tools in order to resolve the favoured DNA target sequence.
Introduction.
Across all living organisms, regulation of gene expression is controlled by interactions between DNA-binding regulatory proteins (transcription factors) and cis-regulatory elements, DNA sequences in or around genes that act as target sites for DNA-binding proteins. By binding to cis-regulatory sequences and to each other, transcription factors fine-tune transcriptional levels by stabilizing/destabilizing binding of RNA polymerase to a gene's promoter.
But despite their importance and ubiquity, little is known about where exactly each of these regulatory proteins binds. Literature suggests that nearly 8% of human genes encode transcription factors and the functions and specificities of their interactions remain largely unexplored. We are on the brink of a convergence of high-throughput technologies and genomic theory that is allowing researchers to start mapping these interactions on a genome-wide scale. Only recently has a complete survey of DNA-binding specificities been attempted for a large family of DNA-binding domains. B1H is just one emerging technique among many that is useful for studying protein–DNA interactions.
Method overview.

Transformation of a bacterial host with two different plasmids is required. One is designed to express a DNA-binding protein-of-interest as a fusion construct with a subunit of RNA polymerase (bait). The other plasmid contains a region of randomized sequence representing potential binding sites (prey) which, if bound to by the chimeric fusion product, drives expression of downstream reporter genes. This reporter region facilitates both positive and negative selection by HIS3 and URA3, respectively, which together allow for isolation of the prey containing the true DNA target sequence. HIS3 and URA3 encode proteins required for biosynthesis of histidine and uracil.
Using a negative selectable marker is crucial for greatly reducing the incidence of false-positives. Self-activating prey, where the randomized region facilitate reporter expression in the absence of TF binding, are removed by transforming the reporter vector library into bacteria in the absence of bait and assaying for growth on plates containing 5-fluoro-orotic acid (5-FOA). The protein product of URA3 converts 5-FOA into a toxic compound, thereby allowing survival of only those colonies that contain reporter vectors which are not self-activating. Negative selection normally precedes positive selection so that a smaller, purified prey library can be subjected to the more rigorous positive selection process. Upon transformation of the purified prey library with the bait plasmid, positive selection is achieved by growing the host E. coli on minimal medium lacking histidine (NM selective medium) that is usually supplemented with varying concentrations of 3-amino-triazole (3-AT), a competitive inhibitor of HIS3. HIS3 encodes a protein required for histidine biosynthesis and thus only those cells containing bait-prey combinations that activate the reporter genes will be able to grow. Manipulating 3-AT concentrations allows for the characterization of binding stringencies. In this way, researches can gauge how strongly bait binds its prey (correlated with the level of expression of HIS3) and thus determines which nucleotide binding-sites have strong or weak preferences for a given base. In other words, if cells can grow despite a high concentration of 3-AT, bait-prey binding must be of high enough stringency to drive reporter gene expression (HIS3) at a sufficient level to overcome the resulting competitive inhibition. Finally, positive clones are sequenced and examined with preexisting motif-finding tools (ex, MEME, BioProspector).
History of method.
The bacteria one-hybrid system has undergone numerous modifications since its inception in 2005.
It ultimately arose as a variation of the bacteria two-hybrid system, conceived in 2000, which itself was inspired by the yeast one- and two-hybrid systems. Whereas the two-hybrid versions can assess both protein–protein interaction and protein–DNA interactions, the one-hybrid system specializes in the latter.
Meng et al.’s B1H system differs from the two-hybrid version in two key respects. It uses a randomized prey library consisting of many (<2x108) unique potential target sequences and also adds a negative selection step in order to purge this library of self-activating clones. Although these ideas were borrowed from the original yeast one-hybrid system, they had not yet been applied to a bacterial host before 2005.
As the technique grew in popularity, researchers amended their protocols to improve the B1H system. Designing the fusion construct (bait) to the omega, rather than the alpha, subunit of RNA polymerase has recently been favoured in order to improve the chimera’s stereochemistry and dynamic range.
A zinc-finger domain on the fusion construct and its corresponding DNA target site, adjacent to the randomized prey sequence, has also been added to the increases affinity and specificity of protein–DNA interactions. This increased overall binding affinity allows for the characterization of even those DNA-binding domain proteins which interact weakly with a target sequence.
Advantages.
The B1H system has significant advantages over other methods that investigate protein–DNA interactions. Microarray-based readout of chromatin immunoprecipitation (ChIP-chip) for high-throughput binding-site determination relies on specific antibodies which may not always be available. Methods that rely on protein-binding microarrays also require additional protein purification steps that are not required in the B1H system. Furthermore, these microarray-based techniques are often prohibitive in terms of requiring special facilities and expertise to analyze the resulting data. SELEX, another system commonly used to identify the target nucleic acids for DNA-binding proteins, requires multiple rounds of selection. In contrast, the bacterial one-hybrid system requires just one round of in vitro selection and also offers a low-tech alternative to microarray-based technologies. Antibodies are not required for studying the interactions of DNA-binding proteins in the B1H system. A further advantage is that the B1H system works not only for monomeric proteins but also for proteins that bind DNA as complexes.
The B1H system should be considered a specialized technique for studying DNA-protein interactions whereas the two-hybrid variations (B2H and Y2H) can assess both protein–protein and protein–DNA interactions. These two-hybrid systems are multi-purpose but are limited in terms of assaying only a single “prey” library. An advantage of the bacterial one-hybrid system over the yeast one-hybrid system (Y1H) lies in the higher transformation efficiency of plasmids into bacteria which allows for more complex “prey” libraries to be examined.
Limitations.
Despite its aforementioned advantages as a specialized tool, the B1H system does have some drawbacks. First, the B1H selection system is limited in its capacity to determine the binding specificities of transcription factors with lengthy binding sites. This arises from the fact that the number of randomized “prey” clones required to represent all possible target sequences increases exponentially with the number of nucleotides in that target sequence. Second, some eukaryotic factors may not express or fold efficiently in the bacterial system, attributed to differing regulatory networks and transcriptional machinery. Hence when working with DNA-binding proteins of eukaryotic origin, a yeast-based hybrid system may be beneficial. Third, the B1H system may not be ideally suited for transcription factors that recognize binding sites with low affinity. The logic here is that competition created by binding sites elsewhere in the bacterial genome may limit the signal that can be realized from a single binding site that is present upstream of the reporter.
Application.
B1H system provides a tool in our arsenal for identifying the DNA-binding specificities of transcription factors and thus predicting their target genes and genomic DNA regulatory elements. It also allows for examination of the effects of protein–protein interactions on DNA binding, which may further guide the prediction of cis regulatory modules based on binding-site clustering. Moreover, the B1H selection system has implications for the predicting regulatory roles of previously uncharacterized transcription factors.
Specific examples.
Using the bacterial one-hybrid system, one study has characterized 35 members of the Drosophilia melanogaster segmentation network which includes representative members of all the major classes of DNA-binding domain proteins. Implications for medical research are evident from another study that used the B1H system to identify the DNA-binding specificity of a transcriptional regulator for a gene in Mycobacterium tuberculosis. The B1H system has also been used to identify an important turnover element in Escherichia coli.


Linda C. Meade-Tollin

Linda Celida Meade-Tollin (16 August 1944-) is an American biochemist and cancer researcher. In her research at the University of Arizona, she studied DNA damage, angiogenesis, and cancer invasion & metastasis; directed the Office of Women in Science and Engineering there; and was the first female chairperson of the National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE).
Early life & education.
Meade-Tollin was born on August 16, 1944 in London, West Virginia, the daughter of Robert Alfred Meade, a dentist & community activist, and Virginia May Meade, a teacher & guidance counselor. She grew up in London and did well in school, skipping two grades and entering high school at a young age. Her first year of high school was also the school's first year of racial integration, and the first opportunity Meade-Tollin and her female peers to enroll in a science course.
At the age of 16, Meade-Tollin entered West Virginia State College. She studied chemistry, was a member of Alpha Kappa Alpha, and completed her Bachelor of Science in 1964 at age 19.
She continued to Hunter College where she completed a Master of Science in biochemistry in 1969. Meade-Tollin worked at both Harlem and Bellevue Hospitals before entering a Ph.D. program in chemistry at the City University of New York (CUNY) at age 21. After a year, she switched to biochemistry, completing her thesis on gene expression in E. coli and finishing her degree in 1972. Meade-Tollin may have been first Black woman to graduate from CUNY with a biochem Ph.D. but CUNY records don't indicate race and therefore cannot confirm this milestone.
Career.
Meade-Tollin accepted a faculty appointment at the College at Old Westbury, simultaneously serving as a visiting assistant professor at Rockefeller University, where she studied sickle cell anemia as part of Anthony Cerami's research team.
In 1975, she began a National Institutes of Health biochemistry research fellowship at the University of Arizona in Tucson. At the time, she was the only Black woman to head a biomedical research laboratory there, and her research focused on studying DNA damage, angiogenesis, and cancer invasion & metastasis.
Her angiogenesis research first used human microvascular endothelial cells to develop "a more physiologically relevant and highly reproducible rapid model angiogenesis assay", which researchers then used to screen desert plants and fungi for ingredients that could be used in cancer treatment drugs. Meade-Tollin worked with Leslie Gunatilaka & Luke Whitesell on this research.
At the University of Arizona, Meade-Tollin was the director of the Office of Women in Science and Engineering in the Department of Women's Studies, and she spent significant time planning and developing workshops and conferences that sought to encourage women to enter science and engineering fields. She also helped present American Association of Medical Colleges workshops for leaders in medical academia.
Meade-Tollin spent a year as faculty development fellow at the Morehouse School of Medicine in Atlanta and in 1993 became the first female national chairperson of the National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE).
She retired from the University of Arizona as a Research Assistant Professor Emerita in 2008.
Personal life.
While at Rockefeller University, Meade-Tollin met Gordon Tollin who was on sabbatical there.
During her tenure at the University of Arizona, Meade-Tollin was a caregiver for her aging parents. As of 2012, Meade-Tollin, who had divorced her husband, lived in Tucson.


GRIN2A

Glutamate [NMDA] receptor subunit epsilon-1 is a protein that in humans is encoded by the "GRIN2A" gene.
Function.
N-methyl-D-aspartate (NMDA) receptors are a class of ionotropic glutamate receptors. NMDA channel has been shown to be involved in long-term potentiation, an activity-dependent increase in the efficiency of synaptic transmission thought to underlie certain kinds of memory and learning. NMDA receptor channels are heteromers composed of the key receptor subunit NMDAR1 (GRIN1) and 1 or more of the 4 NMDAR2 subunits: NMDAR2A (GRIN2A), NMDAR2B (GRIN2B), NMDAR2C (GRIN2C), and NMDAR2D (GRIN2D).
Associations.
Variants of the gene are associated with the protective effect of coffee on Parkinson's disease.
Mutations in GRIN2A are associated to refractory epilepsy.
Whole exome/genome sequencing has led to the discovery of an association between mutations in GRIN2A and a wide variety of neurological diseases, including epilepsy, intellectual disability, autism spectrum disorders, developmental delay, and schizophrenia.
Interactions.
GRIN2A has been shown to interact with:


Pronethalol

Pronethalol (Alderlin, Nethalide) was an early non-selective beta blocker clinical candidate. It was never used clinically due to carcinogenicity in mice, which was thought to result from formation of a carcinogenic naphthalene epoxide metabolite.


Paula Booth

Paula Jane Booth is an English chemist who holds the Daniell Chair of Chemistry at King's College London and is Head of Department. Booth was awarded a Philip Leverhulme Prize in 2003, a Royal Society Wolfson Research Merit Award in 2008 and an ERC Advanced grant in 2012 for her novel work on investigating the mechanisms of biological self-assembly.
Education and academic career.
Booth studied for a BA Hons in Chemistry at St John’s College, Oxford. Booth undertook a PhD to study the thermodynamic properties of electron transfer in Photosystem 2 reaction centres, at Imperial College, London, under the supervisor of George Porter and James Barber. Following a short fellowship at the Centre D-Etudes de Saclay outside Paris, Booth set up her own research group at the University of Oxford, whilst holding a Research Fellowship at Corpus Christi College. After this, Booth moved to Imperial College and then the University of Bristol where she was appointed professor in 2005. In 2014 Booth was appointed Daniell Chair and Head of Department at King's College London. She is also on the academic staff at The London Centre for Nanotechnology.
Research interests.
At the University of Bristol, Booth investigated the minimal lipid composition which allows insertion of membrane proteins. Booth's current research studies how membrane lipids impact on membrane protein folding and activity. Booth also investigates the design of artificial membrane proteins and lipids to develop synthetic biology systems to apply to useful applications. Techniques from many disciplines are put to use by Booth to measure and alter properties of membrane lipids and proteins.


Establishment of sister chromatid cohesion

Sister chromatid cohesion refers to the process by which sister chromatids are paired and held together during certain phases of the cell cycle. Establishment of sister chromatid cohesion is the process by which chromatin-associated cohesin protein becomes competent to physically bind together the sister chromatids. In general, cohesion is established during S phase as DNA is replicated, and is lost when chromosomes segregate during mitosis and meiosis. Some studies have suggested that cohesion aids in aligning the kinetochores during mitosis by forcing the kinetochores to face opposite cell poles.
Cohesin loading.
Cohesin first associates with the chromosomes during G1 phase. The cohesin ring is composed of two SMC (structural maintenance of chromosomes) proteins and two additional Scc proteins. Cohesin may originally interact with chromosomes via the ATPase domains of the SMC proteins. In yeast, the loading of cohesin on the chromosomes depends on proteins Scc2 and Scc4.
Cohesin interacts with the chromatin at specific loci. High levels of cohesin binding are observed at the centromere. Cohesin is also loaded at cohesin attachment regions (CARs) along the length of the chromosomes. CARs are approximately 500-800 base pair regions spaced at approximately 9 kilobase intervals along the chromosomes. In yeast, CARs tend to be rich in adenine-thymine base pairs. CARs are independent of origins of replication.
Establishment of cohesion.
Establishment of cohesion refers to the process by which chromatin-associated cohesin becomes cohesion-competent. Chromatin association of cohesin is not sufficient for cohesion. Cohesin must undergo subsequent modification ("establishment") to be capable of physically holding the sister chromosomes together. Though cohesin can associate with chromatin earlier in the cell cycle, cohesion is established during S phase. Early data suggesting that S phase is crucial to cohesion was based on the fact that after S phase, sister chromatids are always found in the bound state. Tying establishment to DNA replication allows the cell to institute cohesion as soon as the sister chromatids are formed. This solves the problem of how the cell might properly identify and pair sister chromatids by ensuring that the sister chromatids are never separate once replication has occurred.
The Eco1/Ctf7 gene (yeast) was one of the first genes to be identified as specifically required for the establishment of cohesion. Eco1 must be present in S phase to establish cohesion, but its continued presence is not required to maintain cohesion. Eco1 interacts with many proteins directly involved in DNA replication, including the processivity clamp PCNA, clamp loader subunits, and a DNA helicase. Though Eco1 contains several functional domains, it is the acetyltransferase activity of the protein which is crucial for establishment of cohesion. During S phase, Eco1 acetylates lysine residues in the Smc3 subunit of cohesin. Smc3 remains acetylated until at least anaphase. Once cohesin has been removed from the chromatin, Smc3 is deacetylated by Hos1.
The Pds5 gene was also identified in yeast as necessary for the establishment of cohesion. In humans, the gene has two homologs, Pds5A and Pds5B. Pds5 interacts with chromatin-associated cohesin. Pds5 is not strictly establishment-specific, as Pds5 is necessary for maintenance of cohesion during G2 and M phase. The loss of Pds5 negates the requirement for Eco1. As such, Pds5 is often termed an "anti-establishment" factor.
In addition to interacting with cohesin, Pds5 also interacts with Wapl (wings apart-like), another protein that has been implicated in the regulation of sister chromatid cohesion. Human Wapl binds cohesin through the Scc cohesin subunits (in humans, Scc1 and SA1). Wapl has been tied to the loss of cohesin from the chromatids during M phase. Wapl interacts with Pds5 through phenylalanine-glycine-phenylalanine (FGF) sequence motifs.
One model of establishment of cohesion suggests that establishment is mediated by the replacement of Wapl in the Wapl-Pds5-cohesin complex with the Sororin protein. Like Wapl, Sororin contains an FGF domain and is capable of interacting with Pds5. In this model, put forward by Nishiyama "et al"., Wapl interacts with Pds5 and cohesin during G1, before establishment. During S phase, Eco1 (Esco1/Esco2 in humans) acetylates Smc3. This results in recruitment of Sororin. Sororin then replaces Wapl in the Pds5-cohesin complex. This new complex is the established, cohesion-competent cohesin state. At entry to mitosis, Sororin is phosphorylated and replaced again by Wapl, leading to loss of cohesion. Sororin also has chromatin binding activity independent of its ability to mediate cohesion.
Meiosis.
Cohesion proteins SMC1ß, SMC3, REC8 and STAG3 appear to participate in the cohesion of sister chromatids throughout the meiotic process in human oocytes. SMC1ß, REC8 and STAG3 are meiosis specific cohesin proteins. The STAG3 protein is essential for female meiosis and fertility.
Ties to DNA replication.
A growing body of evidence ties establishment of cohesion to DNA replication. As mentioned above, functional coupling of these two processes prevents the cell from having to later distinguish which chromosomes are sisters by ensuring that the sister chromatids are never separate after replication.
Another significant tie between DNA replication and cohesion pathways is through Replication Factor C (RFC). This complex, the "clamp loader," is responsible for loading PCNA onto DNA. An alternative form of RFC is required for sister chromatin cohesion. This alternative form is composed of core RFC proteins RFC2, RFC3, RFC4, and RFC5, but replaces the RFC1 protein with cohesion specific proteins Ctf8, Ctf18, and Dcc1. A similar function-specific alternative RFC (replacing RFC1 with Rad24) plays a role in the DNA damage checkpoint. The presence of an alternative RFC in the cohesion pathway can be interpreted as evidence in support of the polymerase switch model for cohesion establishment. Like the non-cohesion RFC, the cohesion RFC loads PCNA onto DNA.
Some of the evidence tying cohesion and DNA replication comes from the multiple interactions of Eco1. Eco1 interacts with PCNA, RFC subunits, and a DNA helicase, Chl1, either physically or genetically. Studies have also found replication-linked proteins which influence cohesion independent of Eco1. The Ctf18 subunit of the cohesion-specific RFC can interact with cohesin subunits Smc1 and Scc1.
Polymerase switch model.
Though the protein was originally identified as a Topoisomerase I redundant factor, the TRF4 gene product was later shown to be required for sister chromatid cohesion. Wang "et al". showed that Trf4 is actually a DNA polymerase, which they called Polymerase κ. This polymerase is also referred to as Polymerase σ. In the same paper in which they identified Pol σ, Wang "et al". suggested a polymerase switch model for establishment of cohesion. In this model, upon reaching a CAR, the cell switches DNA polymerases in a mechanism similar to that used in Okazaki fragment synthesis. The cell off-loads the processive replication polymerase and instead uses Pol σ for synthesis of the CAR region. It has been suggested that the cohesion-specific RFC could function in off-loading or on-loading PNCA and polymerases in such a switch.
Ties to DNA damage pathways.
Changes in patterns of sister chromatid cohesion have been observed in cases of DNA damage. Cohesin is required for repair of DNA double-strand breaks (DSBs). One mechanism of DSB repair, homologous recombination (HR), requires the presence of the sister chromatid for repair at the break site. Thus, it is possible that cohesion is required for this process because it ensures that the sister chromatids are physically close enough to undergo HR. DNA damage can lead to cohesin loading at non-CAR sites and establishment of cohesion at these sites even during G2 phase. In the presence of ionizing radiation (IR), the Smc1 subunit of cohesin is phosphorylated by the ataxia telangiectasia mutated (ATM) kinase. ATM is a key kinase in the DNA damage checkpoint. Defects in cohesion can increase genome instability, a result consistent with the ties between cohesion and DNA damage pathways.
In the bacterium "Escherichia coli", repair of mitomycin C-induced DNA damages occurs by a sister chromatid cohesion process involving the RecN protein. Sister chromatid interaction followed by homologous recombination appears to significantly contribute to the repair of DNA double-strand damages.
Medical relevance.
Defects in the establishment of sister chromatid cohesion have serious consequences for the cell and are therefore tied to many human diseases. Failure to establish cohesion correctly or inappropriate loss of cohesion can lead to missegregation of chromosomes during mitosis, which results in aneuploidy. The loss of the human homologs of core cohesin proteins or of Eco1, Pds5, Wapl, Sororin, or Scc2 has been tied to cancer. Mutations affecting cohesion and establishment of cohesion are also responsible for Cornelia de Lange Syndrome and Roberts Syndrome. Diseases arising from defects in cohesin or other proteins involved in sister chromatid cohesion are referred to as cohesinopathies.
Cornelia de Lange Syndrome.
Genetic alterations in genes "NIPBL", "SMC1A", "SMC3", "RAD21" and "HDAC8" are associated with Cornelia de Lange Syndrome. The proteins encoded by these genes all function in the chromosome cohesion pathway that is employed in the cohesion of sister chromatids during mitosis, DNA repair, chromosome segregation and the regulation of developmental gene expression. Defects in these functions likely underlie many of the features of Cornelia de Lang Syndrome.


Potamogale


Acebutolol

Acebutolol, sold under the brand names Sectral among others, is a beta blocker for the treatment of hypertension and arrhythmias.
It was patented in 1967 and approved for medical use in 1973.
Side effects.
The development of anti-nuclear antibodies (ANA) has been found in 10 to 30% of patients under treatment with acebutolol. A systemic disease with arthralgic pain and myalgias has been observed in 1%. A lupus erythematosus-like syndrome with skin rash and multiforme organ involvement is even less frequent. The incidence of both ANA and symptomatic disease under acebutolol is higher than under propranolol. Female patients are more likely to develop these symptoms than male patients. Some few cases of hepatotoxicity with increased liver enzymes (ALT, AST) have been seen. Altogether, 5 to 6% of all patients treated have to discontinue acebutolol due to intolerable side effects. When possible, the treatment should be discontinued gradually in order to avoid a withdrawal syndrome with increased frequency of angina and even precipitation of myocardial infarction.
Pharmacology.
Acebutolol is a cardioselective beta-1 blocker which also considered a partial agonist due to its intrinsic sympathomimetic activity (ISA); this means it provides low-grade beta stimulation at rest but acting as typical beta-blockers when sympathetic activity is high. Due to its cardioselectivity, Acebutolol is more suitable than non-cardioselective beta-blockers, in a patient with asthma or chronic obstructive pulmonary disease (COPD) who needs treatment with a beta-blocker. (For these reasons, it may be a beta-blocker of choice in inclusion in Polypill strategies). In doses lower than 800 mg daily its constricting effects on the bronchial system and smooth muscle vessels are only 10% to 30% of those observed under propranolol treatment, but there is experimental evidence that the cardioselective properties diminish at doses of 800 mg/day or more.
The drug has lipophilic properties and therefore crosses the blood–brain barrier. Acebutolol has no negative impact on serum lipids (cholesterol and triglycerides). No HDL decrease has been observed. In this regard, it is unlike many other beta-blockers which have this unfavourable property.
The drug works in hypertensive patients with high, normal, or low renin plasma concentrations, although acebutolol may be more efficient in patients with high or normal renin plasma concentrations. In clinically relevant concentrations, a membrane-stabilizing effect does not appear to play an important role.
Pharmacokinetics.
Acebutolol is well absorbed from the GI tract, but undergoes substantial first-pass-metabolization, leading to a bioavailability of only 35% to 50%. Peak plasma levels of acebutolol are reached within 2 to 2.5 hours after oral dosing. Peak levels of the main active metabolite, diacetolol, are reached after 4 hours. Acebutolol has a half-life of 3 to 4 hours, and diacetolol a half-life of 8 to 13 hours.
Acebutolol undergoes extensive hepatic metabolization resulting in the desbutyl amine acetolol which is readily converted into diacetolol. Diacetolol is as active as acebutolol (equipotency) and appears to have the same pharmacologic profile. Geriatric patients tend to have higher peak plasma levels of both acebutolol and diacetolol and a slightly prolonged excretion. Excretion is substantially prolonged in patients with renal impairment, and so a dose reduction may be needed. Liver cirrhosis does not seem to alter the pharmacokinetic profile of the parent drug and metabolite.


Psychrobacter vallis

Psychrobacter vallis is a Gram-negative, psychrophilic, halotolerant, nonmotile bacterium of the genus "Psychrobacter", which was isolated from cyanobacterial mat samples from the McMurdo Dry Valley region of Antarctica.


Thiocoraline

Thiocoraline is a microbial natural product of the depsipeptide class. Thiocoraline was isolated from the mycelium cake of a marine actinomycete strain L-13-ACM2-092. "In vitro", thiocoraline causes an arrest in G1 phase of the cell cycle and decreases the rate of S phase progression towards G2/M phase. Thiocoraline is likely to be a DNA replication inhibitor. Thiocoraline is produced on a nonribosomal peptide synthetase (NRPS) assembly line.


Gliadorphin

Gliadorphin (also known as gluteomorphin) is an opioid peptide that is formed during digestion of the gliadin component of the gluten protein. It is usually broken down into amino acids by digestion enzymes. It has been hypothesized that children with autism have abnormal leakage from the gut of this compound. This is partly the basis for the gluten-free, casein-free diet. Abnormally high levels of gliadorphin have been found in the urine of autistic children via mass spectrometry testing.


Leemor Joshua-Tor

Leemor Joshua-Tor is the W.M. Keck Professor of Structural Biology at Cold Spring Harbor Laboratory and a Howard Hughes Medical Institute Investigator. Her research focuses on the role of argonaute in RNA interference.
Early life and education.
Leemor Joshua-Tor was born in Rehovot, Israel. She received a B.S. from Tel-Aviv University in chemistry, then served for three years in the Israeli Defense Forces. She earned a PhD in chemistry in the lab of Joel Sussman from the Weizmann Institute of Science in 1991, then did postdoctoral research at CalTech.
Career.
Joshua-Tor joined the faculty at Cold Spring Harbor Laboratory in 1995 and was promoted to full professor in 2005.
She was Dean of the Watson School of Biological Sciences from 2007 to 2012. She is a faculty advisor of CSHL's Women in Science and Engineering group. She has been an HHMI investigator since 2008.
In 2005, her lab published the structure of argonaute, helping to demonstrate its role in RNA interference, and she is known for her research on argonaute's "slicer". She has collaborated extensively with Greg Hannon. Joshua-Tor's research has shed light on how the proteins responsible for RNA interference function.


Neonothopanus gardneri

Neonothopanus gardneri, locally known as flor de coco, is a bioluminescent fungus native to Goiás, Piauí and Tocantins states in Brazil.
The fungus was first discovered in 1839 by the English botanist George Gardner, after he came across some youths playing with glowing material in the streets of Villa de Natividade in Goiás state in Brazil. Initially thinking it was a firefly, he then discovered it was a mushroom—known as "Flor de Coco" locally—that was common locally and found on decaying palm leaves. Gardner sought to call it "Agaricus phosphorescens". However, his colleague Miles Joseph Berkeley opined that the attribute was not unique, and hence described it with the specific name "A. gardneri". Gardner thought it resembled members of the genus "Pleurotus" in structure, while Berkeley felt it was more akin to the genus "Panus" but conceded spores were necessary for further classification.
It was rediscovered in February 2005 by scientists Patricia Izar, Elisabetta Visalberghi and Dorothy Fragaszy, with the aid of Marino Gomes de Oliveira. It is larger and brighter than other known bioluminescent fungi. Marina Capelari and colleagues investigated its relationships by analysing it and close relatives genetically, and found that it was the sister taxon to "Neonothopanus nambi" rather than members of the genus "Omphalotus" and placed it in the genus "Neonothopanus".
The fleshy yellow mushrooms have caps that are darker in the centre fading to paler yellow or cream at the margins. Measuring wide, the cap is initially convex with a central umbo before becoming flat or even funnel-shaped with age. The decurrent and widely spaced gills are the same colour as the cap. The fibrous stipe is long by wide. The cap and gills glow with a green light at night, more strongly than most other bioluminescent fungi.
"Neonothopanus gardneri" grows at the base of the palm trees, including the pindoba palm ("Attalea humilis"), piaçava ("A. funifera") and babaçu ("A. speciosa").


Frances Ligler

Frances S. Ligler (born June 11, 1951) is a biochemist and bioengineer who was a 2017 inductee of the National Inventors Hall of Fame. Ligler's research dramatically improved the effectiveness of biosensors while at the same time reducing their size and increasing automation. Her work on biosensors made it easier to detect toxins and pathogens in food, water, or when airborne.
In a 2017 interview, Ligler summarized her work: "Optical biosensors is a whole field where biological molecules are being used for recognition and transduce an optical signal to a small device. My teams and I demonstrated the use of optical biosensors for detection of pathogens in food, infectious diseases in people, biological warfare agents, environmental pollutants, explosives and drugs of abuse — things that can kill you." Ligler's interests include microfluidics, tissue on chips, optical analytical devices, biosensors and nanotechnology. Ligler holds 35 patents and has authored over 400 scientific papers.
Biography.
Ligler received a B.S. from Furman University and a D.Phil. and D.Sc. from Oxford University. In 1986, she joined the US Naval Research Laboratory, where she developed sensors to detect anthrax and botulinum toxin that were deployed during Operation Desert Storm.
In 2013, she left the US Naval Research Laboratory to become the Lampe Distinguished Professor of Biomedical Engineering in the Joint Department of Biomedical Engineering at North Carolina State University and the University of North Carolina at Chapel Hill. She received honorary doctorates from the Agricultural University of Athens, Greece in 2014 and from Furman University in 2018.


Mirabamide

Mirabamides are sea sponge isolates that inhibit HIV-1 fusion.