gebhart/patrepeval huggingface dataset:
Neurosteroid analogues. Part 5.1 Enantiomers of neuroactive steroids and benz[e]indenes: total synthesis, electrophysiological effects on GABAA receptor function and anesthetic actions in tadpoles (1997)

The synthesis of (3β,5β,8α,9β,10α,13α,14β,17α)-3-hydroxypregnan-20-one 2, (3β,5β,8α,9β,10α,13α,14β,17α)-3-hydroxyandrostane-17-carbonitrile 4,† [3R-(3α,3aα,5aβ,7α,9aα,9bβ)]-1-[dodecahydro-7-(2-hydroxyethyl)-3a-methyl-1H-benz[e]inden-3-yl]ethanone 6 and [3R-(3α,3aα,5aβ,7α,9aα,9bβ)]-dodecahydro-7-(2-hydroxyethyl)-3a-methyl-1H-benz[e]indene-3-carbonitrile 8 is reported.‡ Steroids 2 and 4 have been used previously to investigate the enantioselectivity of steroid action on GABAA receptor function and to correlate steroid action at this receptor with the anesthetic actions of the compounds. The enantioselective actions of benz[e]indenes 6 and 8 have been evaluated for the same reasons in this study. Similar correlations between the enantioselective effects of both classes of compounds on GABAA receptor function and anesthetic potency in tadpoles have been observed.
Protein Transduction: Generation of Full‐Length Transducible Proteins Using the TAT System (2003)

This unit describes the technology that allows an investigator to transduce full-length proteins by utilizing a minimal, eleven-amino acid, HIV-TAT transduction domain that can be fused to a protein of choice using the pTAT or pTAT-HA protein expression plasmids. Bacterial expression, followed by solubilization of protein aggregates with a denaturing agent, affords high yields of transducible fusion protein. The fusion protein, once added to the culture medium, can cross the cell membrane and then be degraded or refolded by the cellular machinery. Correct targeting and function of the fusion protein can be easily examined by fluorescent microscopy or immunohistochemistry. This strategy was established and improved to its current state by the purification and transduction of a multitude of fusion proteins. Because the pool of fusion proteins spans many different functions, the protocols cover a wide variety of commonly used protein isolation and characterization methods.
Differential Regulation of HIV-1 Fusion Cofactor Expression by CD28 Costimulation of CD4 + T Cells (1997)

Activation of CD4(+) T lymphocytes from human immunodeficiency virus-type 1 (HIV-1)-infected donors with immobilized antibodies to CD3 and CD28 induces a virus-resistant state. This effect is specific for macrophage-tropic HIV-1. Transcripts encoding CXCR4/Fusin, the fusion cofactor used by T cell line-tropic isolates, were abundant in CD3/CD28-stimulated cells, but transcripts encoding CCR5, the fusion cofactor used by macrophage-tropic viruses, were not detectable. Thus, CD3/CD28 costimulation induces an HIV-1-resistant phenotype similar to that seen in some highly exposed and HIV-uninfected individuals.
Domain structure of mitochondrial and chloroplast targeting peptides (1989)

Representative samples of mitochondrial and chloroplast targeting peptides have been analyzed in terms of amino acid composition, positional amino acid preferences and amphiphilic character. No highly conserved 'homology blocks' are found in either class of topogenic sequence. Mitochondrial-matrix-targeting peptides are composed of two domains with different amphiphilic properties. Arginine is frequently found either at position -10 or -2 relative to the cleavage site, suggesting that some targeting peptides may be cleaved twice in succession by two different matrix proteases. In stroma-targeting chloroplast transit peptides three distinct regions are evident: an uncharged amino-terminal domain, a central domain lacking acidic residues and a carboxy-terminal domain with the potential to form an amphiphilic beta-strand. Targeting peptides that route proteins to the mitochondrial intermembrane space or the lumen of chloroplast thylakoids have a mosaic design with an amino-terminal matrix- or stroma-targeting part attached to a carboxy-terminal extension that shares many characteristics with secretory signal peptides.
In vitro mutagenesis and overexpression of the Escherichia coli trpA gene and the partial characterization of the resultant tryptophan synthase mutant alpha-subunits. (1986)

A mutagenesis approach was initiated in order to examine further the folding behavior of the alpha-subunit of the Escherichia coli tryptophan synthase. A random single base pair saturation mutagenesis procedure (Myers, R.M., Lerman, L.S., and Maniatis, T. (1985) Science 229, 242-247) was applied in vitro to subcloned fragments of the trpA gene, which codes for this polypeptide. Mutagenesis plasmid vectors were constructed containing three fragments of the trpA gene which together code for about half of the total amino acid residues of the alpha-subunit. The vectors were constructed such that each strand of each trpA fragment could be altered. These trpA fragments were mutagenized in vitro (using nitrous acid, formic acid, hydrazine, and potassium permanganate), and several thousands of mutants have been isolated. Thirty-two mutants, contained within the first two trpA fragments (which encompass the first 206 base pairs of the trpA gene and encode the first 63 residues of the alpha-subunit) have been sequenced. Of these, 20 (63%) contained single base pair alterations, 12 (37%) contained multiple alterations, and 17 (53%) of these base pair alterations resulted in single amino acid substitutions. Selected mutant trpA fragments were subcloned into an overexpression vector in which the trpA gene is controlled by the tac promoter and is inducible by lactose. The kinetics and extent of induction show that after 22 h of induction, the wild-type alpha-subunit constituted about 30% of the total protein. A simple one-step purification procedure for the alpha-subunit is described in which 15 mg of alpha-subunit can be obtained from 200 ml of fully induced cultures. The mutant trpA genes were induced for mutant alpha-subunit expression, and an initial examination of their properties in crude extracts was performed. Of the 17 mutant proteins examined, most were overproduced to levels comparable to that for the wild-type alpha-subunit. An analysis of the apparent stability, beta 2-subunit-activating activity, and intrinsic activity of this group of mutant alpha-subunits suggests that many amino acid alterations have no apparent effect; there is a variety of novel functional defects; and a sequence located near residues 28 through 54 may be particularly critical for the normal folding of the polypeptide.
Identification of PECAM-1 in solid tumor cells and its potential involvement in tumor cell adhesion to endothelium. (1993)

PECAM-1 (CD31/EndoCAM) is an adhesion molecule in the immunoglobulin supergene family that is expressed on endothelial cells, platelets, and some hematopoietic lineage cells. In this paper, using several polyclonal and monoclonal antibodies against PECAM-1, we identified PECAM-1 molecules on human, rat, and murine solid tumor cell lines. Immunocytochemical labeling and flow cytometric analysis using either polyclonal, monoclonal, or Fab portion of the antibodies against PECAM-1 detected a distinct distribution on tumor cell surface. Immunoblotting revealed proteins ranging from 120 to 130 kDa in tumor cells derived from different species. Immunoprecipitation and subcellular fractionation studies indicated that PECAM-1 is constitutively expressed on the surface of human tumor cells (i.e. colon adenocarcinoma). The specificity of a major polyclonal anti-PECAM-1 used in the current study (i.e. SEW-3) was confirmed by the preabsorption studies. PECAM-1 molecules on tumor cells appear to bear terminal carbohydrate moieties (i.e. sialic acid residues) different from those on platelets, since neuraminidase treatment of tumor cells, unlike platelets, did not result in a mobility shift. Polymerase chain reaction (PCR) analysis of genomic DNA derived from tumor cell lines of different species revealed the presence of PECAM-1 gene in the genome. The mRNAs of PECAM-1 in tumor cells were detected by reverse transcription-PCR followed by Southern hybridization. Screening of more than 20 human, rat, and murine solid tumor cell lines indicated that PECAM-1 is widely expressed, although the level of expression varies considerably among different cell lines. The expression of PECAM-1 message in tumor cells was confirmed by Northern blotting. DNA sequencing of the PCR fragment revealed that human tumor cell PECAM-1 matches 100% to the human endothelial cell counterpart. Finally, it was demonstrated that tumor cell PECAM-1 is involved in mediating tumor cell adhesion to endothelium, as evidenced by the ability of anti-PECAM-1 antibodies to decrease the adhesion of unstimulated tumor cells to microvascular endothelial cells.
Theory of domain wall nucleation in a two section magnetic wire (2001)

The energy barrier for thermally driven magnetization reversal in a two section nanowire is calculated, based on a mechanism for domain wall nucleation at the interface between sections. It is shown that this energy barrier is lower than that for end nucleation, and can be determined by choice of material for each section.
Structure and activity of trypsin in reverse micelles (1988)

The kinetic properties of trypsin have been studied in reverse micelles formed by two surfactant systems, namely bis(2-ethylhexyl) sodium sulfosuccinate (AOT) in isooctane, and hexadecyltrimethyl ammonium bromide (CTAB) in chloroform/isooctane (1:1, by vol.). Three substrates have been used, namely N alpha-benzoyl-L-Arg ethyl ester, N alpha-benzoyl-L-Phe-L-Val-L-Arg p-nitroanilide (BzPheValArg-NH-Np) in AOT and N alpha-benzyloxycarbonyl-L-Lys p-nitrophenyl ester (ZLysO-Np) in CTAB. One of the main aims of the work was to compare the behaviour of trypsin in reverse micelles with that of alpha-chymotrypsin, for which an enhancement of kcat had been observed with respect to aqueous solutions. The pH profile is not significantly altered in reverse micelles with respect to water, however the kinetic parameters (kcat and Km) differ widely from one another, and are markedly affected by the micellar conditions, in particular by the water content wo (wo = [H2O]/[AOT]). Whereas in the case of BzPheValArg-NH-Np kcat is much smaller than in water, in the case of ZLysO-Np at pH 3.2 (but not at pH 6.0) a slight enhancement with respect to water is observed. On the basis of rapid kinetic spectrophotometry (stopped-flow) and solvent isotope effect studies, this enhancement is ascribed to a change in the rate-limiting step (acylation rather than hydrolysis). As in the case of alpha-chymotrypsin, the maximal activity is found for all substrates at rather small wo values (below 12), which is taken to suggest that the enzyme works better when is surrounded by only a few layers of tightly bound water. Spectroscopic studies [ultraviolet absorption, circular dichroism (CD) and fluorescence] have been carried out as a function of wo. Whereas the absorption properties are practically unchanged, the CD spectrum in AOT micelles has a lower intensity than in water, which is interpreted as a partial unfolding. The intensity is partly restored when Ca2+ ions are added, indicating that the micellar environment may cause a partial denaturation by depleting it of calcium ions. Fluorescence data show that the emission properties of the protein in reverse micelles match those in aqueous solution at around wo = 13 approx., whereas lambda max shifts towards the red by increasing wo, indicating an exposure of the tryptophan residues and probably an unfolding of the whole protein, at wo values above 15. Finally the reaction between trypsin and its specific macromolecular Kunitz inhibitor from soybeans is studied.(ABSTRACT TRUNCATED AT 400 WORDS)
Effect of vagal nerve stimulation on auditory and visual event‐related potentials (2001)

Chronic unilateral vagal nerve stimulation (VNS) has been recently introduced into the therapy for intractable epileptic seizures. Its effect on cognitive functions in VNS-treated patients remains controversial. The aim of the present study was to evaluate the possible impact of therapeutic VNS on cognitive functions by means of event-related potentials analysis. Ten patients with medically intractable epilepsy, who had been implanted with VNS devices, participated in the study. Auditory and visual event-related potentials (ERPs) were repeatedly recorded, first just before the implantation of VNS devices, and then again 3-6 months after the device activation. The effect of lower intensity stimulation on the P3 component of ERPs was assessed. No significant differences were found in auditory ERPs; the latencies of P3 as well as N2/P3 peak-to-peak amplitudes were virtually identical. The same was true for mean P3 latencies of visual ERPs. However, higher visual N2/P3 peak-to-peak amplitudes were observed in the responses to targets that followed VNS, with a significant finding at the electrodes investigated. When comparing the effect of VNS on visual N2/P3 amplitude in each electrode separately, the most expressive differences were found in the frontal region. This observation supports the theory of a possible positive effect of low-intensity VNS on the cognitive functions.
Evolving Therapy for Celiac Disease (2019)

Gluten is known to be the main triggering factor for celiac disease (CeD), an immune-mediated disorder. CeD is therefore managed using a strict and lifelong gluten-free diet (GFD), the only effective treatment available currently. However, the GFD is restrictive. Hence, efforts are being made to explore alternative therapies. Based on their mechanisms of action on various molecular targets involved in the pathogenesis of CeD, these therapies may be classified into one of the following five broad approaches. The first approach focuses on decreasing the immunogenic content of gluten, using strategies like genetically modified wheat, intra-intestinal gluten digestion using glutenases, microwave thermal treatment of hydrated wheat kernels, and gluten pretreatment with either bacterial/ fungal derived endopeptidases or microbial transglutaminase. The second approach involves sequestering gluten in the gut lumen before it is digested into immunogenic peptides and absorbed, using binder drugs like polymer p(HEMA-co-SS), single chain fragment variable (scFv), and anti- gluten antibody AGY. The third approach aims to prevent uptake of digested gluten through intestinal epithelial tight junctions, using a zonulin antagonist. The fourth approach involves tissue transglutaminase (tTG) inhibitors to prevent the enhancement of immunogenicity of digested gluten by the intestinal tTG enzyme. The fifth approach seeks to prevent downstream immune activation after uptake of gluten immunogenic peptides through the intestinal mucosal epithelial layer. Examples include HLA-DQ2 blockers that prevent presentation of gluten derived- antigens by dendritic cells to T cells, immune- tolerizing therapies like the vaccine Nexvax2 and TIMP-Glia, cathepsin inhibitors, immunosuppressants like corticosteroids, azathioprine etc., and anti-cytokine agents targeting TNF-α and interleukin-15. Apart from these approaches, research is being done to evaluate the effectiveness of probiotics/prebiotics, helminth therapy using <i>Necator americanus</i>, low FODMAP diet, and pancreatic enzyme supplementation in CeD symptom control; however, the mechanisms by which they play a beneficial role in CeD are yet to be clearly established. Overall, although many therapies being explored are still in the pre-clinical phase, some like the zonulin antagonist, immune tolerizing therapies and glutenases have reached phase II/III clinical trials. While these potential options appear exciting, currently they may at best be used to supplement rather than supplant the GFD.
Rilopirox ‐ a New Hydroxypyridone Antifungal with Fungicidal Properties (1990)

Rilopirox, 6-[[p-chlorophenoxy)phenoxy]methyl]-1hydroxy-4-methyl-2(1H)-pyrido ne, is a new fungicidal antimycotic with very low water solubility. It was designed to meet the demand for an intravaginal antifungal with a long skin retention time and a strong killing effect on pathogenic yeasts. In addition, it inhibits all common fungal pathogens in the range 0.98 to 15.6 micrograms/ml. Fungicidal rates vis-à-vis Trichophyton mentagrophytes and Candida albicans under proliferative and non-proliferative conditions are higher than those achieved with common azole and allylamine antifungals. Rilopirox is affected by Fe3+ ions and high concentrations of human serum owing to its chelating activity. The peptone source is of utmost importance to the inhibitory activity of rilopirox whereas the pH value seems to be unimportant so long as it is within the range 5-8.5. Rilopirox appears to meet the demand for an intravaginal antifungal as a result of its very low water solubility of 50 ng/ml and its immediate fungicidal action even under non-proliferative conditions.
Reactions of niobium and tantalum pentafluorides with trimethylsilyldiethylamine and with trimethylsilyl chloride (1972)

The diethylamido-niobium and -tantalum fluorides, MF4NEt2 and MF3(NEt2)2 are formed from the pentafluorides and Me3SiNEt2 at 20 °C. They are weaker Lewis acids than the pentafluorides and are thought to be fluoro-bridged polymers from their i.r. spectra. Niobium pentafluoride reacts with Me3SiCl in Et2O to give labile niobium chlorofluoride species and finally NbCl5, OEt2.
Optical Resolution of a Series of Potential Cholecystokinin Antagonist 4(3H)-Quinazolone Derivatives by Chiral Liquid Chromatography on 1-Acid Glycoprotein Stationary Phase (2000)

Optical resolution of the enantiomers of new 4(3H)-quinazolone derivatives is investigated using the alpha1-acid glycoprotein chiral stationary phase (Chiral-AGP). Stereoselective separation of the model compounds can be controlled by varying the pH and adding uncharged organic modifiers (acetonitrile and 2-propanol) to the mobile phase. For the majority of quinazolone derivatives, Chiral-AGP is proved to be an excellent enantioselector, because optimized chromatographic conditions allow for the baseline separation of the enantiomers. Separation factors between 1.19 and 1.85 are obtained. The effects of acetonitrile and 2-propanol on the chromatographic behavior of the model compounds are quite different because of their different hydrophobic- and hydrogen-bonding properties. The eluent pH and organic modifier concentration also contributes to the chiral recognition by altering the protein environment. The analysis of the experimental results leads to new information about the chromatographic mechanism on a Chiral-AGP surface.
Growth hormone is produced within the hippocampus where it responds to age, sex, and stress (2006)

Recent studies by our group and others have demonstrated that growth hormone (GH) is produced endogenously within the hippocampal formation, a brain structure associated with learning and aspects of emotional experience. Here, we demonstrate that this endogenously produced GH is modulated by age and sex differences and the presence of estrogen. GH mRNA levels were higher in females than males, especially during proestrus, a stage of estrus when estrogen levels are elevated. Moreover, GH expression was increased in ovariectomized females that were treated with estradiol. This increase in GH mRNA in response to estrogen was followed by the appearance of GH protein and was negatively correlated with the expression levels of insulin-like growth factor-I mRNA, suggesting a feedback relationship between insulin-like growth factor-I and GH in the brain. GH mRNA levels were also elevated in primary neuronal cultures exposed to 17-beta-estradiol in vitro, further confirming the direct influence of estrogen on GH expression. Finally, exposure to an acute stressful event increased the expression and production of GH in both males and females. However, the stress-induced increase of GH in females depended on the stage of the estrous cycle in which they were exposed to the stressful event. Together, these data further demonstrate that GH is endogenously produced in the adult hippocampal formation, where it is regulated by age, estrogen, and exposure to environmental stimuli. These results suggest that GH may be involved in functions ascribed to the hippocampus, such as learning and the response to stressful experience.
P-selectin Cell Adhesion Molecule in Inflammation, Thrombosis, Cancer Growth and Metastasis (2004)

P-selectin (CD62P) is a member of the selectin family of cell adhesion molecules. It is expressed on stimulated endothelial cells and activated platelets and mediates leukocyte rolling on stimulated endothelial cells and heterotypic aggregation of activated platelets onto leukocytes. It also mediates heterotypic aggregation of activated platelets to cancer cells and adhesion of cancer cells to stimulated endothelial cells. Using P-selectin knockout mice, the importance of P-selectin-mediated cell adhesive interactions in the pathogeneses of inflammation, thrombosis, growth and metastasis of cancers has been clearly demonstrated. Here we will summarize the current knowledge and highlight the important progress in the biomedical research of P-selectin biology, providing a suitable target for therapeutic interventions developed through both experimental and bioinformatic approaches.
Immune-type receptor genes in zebrafish share genetic and functional properties with genes encoded by the mammalian leukocyte receptor cluster (2001)

An extensive, highly diversified multigene family of novel immune-type receptor (nitr) genes has been defined in Danio rerio (zebrafish). The genes are predicted to encode type I transmembrane glycoproteins consisting of extracellular variable (V) and V-like C2 (V/C2) domains, a transmembrane region and a cytoplasmic tail. All of the genes examined encode immunoreceptor tyrosine-based inhibition motifs in the cytoplasmic tail. Radiation hybrid panel mapping and analysis of a deletion mutant line (b240) indicate that a minimum of approximately 40 nitr genes are contiguous in the genome and span approximately 0.6 Mb near the top of zebrafish linkage group 7. One flanking region of the nitr gene complex shares conserved synteny with a region of mouse chromosome 7, which shares conserved synteny with human 19q13.3-q13.4 that encodes the leukocyte receptor cluster. Antibody-induced crosslinking of Nitrs that have been introduced into a human natural killer cell line inhibits the phosphorylation of mitogen-activated protein kinase that is triggered by natural killer-sensitive tumor target cells. Nitrs likely represent intermediates in the evolution of the leukocyte receptor cluster.
The Global Impact of Scaling Up HIV/AIDS Prevention Programs in Low- and Middle-Income Countries (2006)

A strong, global commitment to expanded prevention programs targeted at sexual transmission and transmission among injecting drug users, started now, could avert 28 million new HIV infections between 2005 and 2015. This figure is more than half of the new infections that might otherwise occur during that period in 125 low- and middle-income countries. Although preventing these new infections would require investing about U.S.$122 billion over this period, it would reduce future needs for treatment and care. Our analysis suggests that it will cost about U.S.$3900 to prevent each new infection, but that this will produce a savings of U.S.$4700 in forgone treatment and care costs. Thus, greater spending on prevention now would not only prevent more than half the new infections that would occur from 2005 to 2015 but would actually produce a net financial saving as future costs for treatment and care are averted.