gebhart/patrepeval huggingface dataset:
Adenosine causes cAMP-dependent activation of chick embryo red cell carbonic anhydrase and 2,3-DPG synthesis (1996)

In late chick embryos, coordinate activation of red cell carbonic anhydrase II (CAII) and 2,3-diphosphoglycerate (2,3-DPG) synthesis is initiated by hypoxia. The effects are mediated by unidentified hormonal effectors resident in chick plasma. In the present investigation, we have analyzed the effect of adenosine receptor stimulation on embryonic red cell CAII and 2,3-DPG synthesis. We find that primitive and definitive embryonic red blood cells from chick have an A2a adenosine receptor. Stimulation of the receptor with metabolically stable adenosine analogues causes a large increase of red cell adenosine 3',5'-cyclic monophosphate (cAMP) and subsequent activation of red cell CAII and 2,3-DPG production in definitive red blood cells and of CAII synthesis in primitive red blood cells. Direct stimulation of adenylyl cyclase with forskolin has the same effect. Analysis of red cell protein pattern after labeling with [35S]methionine shows that stimulation of red cell cAMP levels activates synthesis of several other proteins aside from CAII. Presence of actinomycin D inhibits cAMP-dependent changes of protein synthesis, indicating that cAMP-dependent transcriptional activation is required. In contrast to the stable adenosine receptor analogues, adenosine itself was a very weak agonist, unless its metabolism was significantly inhibited. Thus, besides adenosine, other effectors of the adenylyl cyclase system are likely to be involved in the O2 pressure-dependent regulation of red cell metabolism in late development of avian embryos.
Navigation Using X-Ray Pulsars (1981)

Approximately one dozen X-ray pulsars are presently known which emit strong stable pulses with periods of 0.7 to approximately 1000 s. By comparing the arrival times of these pulses at a spacecraft and at the Earth (via an Earth orbiting satellite), a three dimensional position of the spacecraft can be determined. One day of data from a small onboard X-ray detector yields a three dimensional position accurate to approximately 150 km. This accuracy is independent of spacecraft distance from the Earth. Present techniques for determining the two spacecraft coordinates other than range measure angles and thus degrade with increasing spacecraft range. Thus navigation using X-ray pulsars will always be superior to present techniques in measuring these two coordinates for sufficiently distant spacecraft. At present, the break even point occurs near the orbit of Jupiter. The Crab pulsar can also be used to obtain one transverse coordinate with an accuracy of approximately 20 km.
The flexibility in the proline ring couples to the protein backbone (2005)

In proteins, the proline ring exists predominantly in two discrete states. However, there is also a small but significant amount of flexibility in the proline ring of high-resolution protein structures. We have found that this side-chain flexibility is coupled to the backbone conformation. To study this coupling, we have developed a model that is simply based on geometric and steric factors and not on energetics. We show that the coupling between phi and chi1 torsions in the proline ring can be described by an analytic equation that was developed by Bricard in 1897, and we describe a computer algorithm that implements the equation. The model predicts the observed coupling very well. The strain in the C(gamma)-C(delta)-N angle appears to be the principal barrier between the UP and DOWN pucker. This strain is relaxed to allow the proline ring to flatten in the rare PLANAR conformation.
Ebola Virus VP35-VP40 Interaction Is Sufficient for Packaging 3E-5E Minigenome RNA into Virus-Like Particles (2006)

The packaging of viral genomic RNA into nucleocapsids and subsequently into virions is not completely understood. Phosphoprotein (P) and nucleoprotein (NP) interactions link NP-RNA complexes with P-L (polymerase) complexes to form viral nucleocapsids. The nucleocapsid then interacts with the viral matrix protein, leading to specific packaging of the nucleocapsid into the virion. A mammalian two-hybrid assay and confocal microscopy were used to demonstrate that Ebola virus VP35 and VP40 interact and colocalize in transfected cells. VP35 was packaged into budding virus-like particles (VLPs) as observed by protease protection assays. Moreover, VP40 and VP35 were sufficient for packaging an Ebola virus minigenome RNA into VLPs. Results from immunoprecipitation-reverse transcriptase PCR experiments suggest that VP35 confers specificity of the nucleocapsid for viral genomic RNA by direct VP35-RNA interactions.
Segregation analysis of the specific response to allergens: A recessive major gene controls the specific IgE response to Timothy grass pollen (1999)

Segregation analysis of the specific response to allergens (SRA) was performed in a sample of 234 randomly selected Australian families using the regressive models. Various SRA phenotypes were considered using broad and narrow definitions of these phenotypes, according to the type of test used, skin test or RAST test, and the specificity of the response to allergen. Strong evidence for familial dependencies among blood relatives was shown for most SRA phenotypes, especially when using a broad definition. There was no evidence for a Mendelian factor accounting for the familial transmission of these broadest phenotypes, which may involve multiple factors preventing the clear detection of a major effect with Mendelian transmission. However, segregation of a Mendelian recessive major gene was detected for one SRA sub-phenotype, the IgE response to a single allergen, Timothy grass pollen, measured by the RAST test. Identification of a specific SRA phenotype controlled by a major gene may have important implications for further linkage studies.
Crystalline Silver Nanowires by Soft Solution Processing (2002)

This paper describes a soft, solution-phase approach to the large-scale synthesis of uniform nanowires of bicrystalline silver whose lateral dimensions could be controlled in the range of 30−40 nm, and lengths up to ∼50 μm. The first step of this procedure involved the formation of platinum nanoparticles by reducing PtCl2 with ethylene glycol heated to ∼160 °C. Due to their close match in crystal structure and lattice constants, these platinum nanoparticles could serve as seeds for the heterogeneous nucleation and growth of silver that was produced in the solution via the reduction of AgNO3 with ethylene glycol. When surfactants such as poly(vinyl pyrrolidone) (PVP) were present in this solution, the silver could be directed to grow into uniform nanowires with aspect ratios as high as ∼1000. Measurements of transport property at room temperature indicated that these nanowires were electrically continuous with a conductivity of approximately 0.8 × 105 S/cm.
In Vivo Three-Dimensional High-Resolution Imaging of Rodent Retina with Spectral-Domain Optical Coherence Tomography (2007)

High-resolution spectral-domain OCT provides unprecedented high-quality 2D and 3D in vivo visualization of retinal structures of mouse and rat models of retinal diseases. With the capability of 3D quantitative information extraction and precise spatial registration, the OCT system made possible longitudinal study of ocular diseases that has been impossible to conduct.
Purification, crystallization and properties of porphobilinogen deaminase from a recombinant strain of Escherichia coli K12 (1988)

Porphobilinogen deaminase has been purified and crystallized from an overproducing recombinant strain of Escherichia coli harbouring a hemC-containing plasmid which has permitted the purification of milligram quantities of the enzyme. Determination of the Mr of the enzyme by SDS/polyacrylamide-gel electrophoresis (35,000) and gel filtration (32,000) agrees with the gene-derived Mr of 33,857. The enzyme has a Km of 19 +/- 7 microM, an isoelectric point of 4.5 and an N-terminal sequence NH2-MLDNVLRIAT. The substrate, porphobilinogen, binds to the active-site dipyrromethane cofactor to form three intermediate complexes: ES, ES2 and ES3. The gene-derived primary structure of the E. coli deaminase is compared with that derived from the cDNA of the human enzyme.
Interleukin 5, a T-cell-derived B-cell differentiation factor also induces cytotoxic T lymphocytes. (1987)

We describe an interleukin, termed interleukin 5, that is the recombinant product previously referred to as T-cell-replacing factor (TRF), B-cell growth factor II (BCGF II), or killer-helper factor (KHF). TRF has been defined as a T-cell-derived lymphokine that acts on activated B cells as a B-cell differentiation factor. We have previously demonstrated that TRF is identical to BCGF II and induces expression of receptors for interleukin 2 (IL-2) on activated B cells. We also have reported that KHF can induce not only expression of IL-2 receptors on peanut agglutinin-binding (PNA+) thymocytes but also generation of cytotoxic T lymphocytes (CTL) in PNA+ thymocytes in the presence of IL-2. We show here that culture supernatants of T-cell hybridomas that produce TRF as well as TRF purified by high-pressure liquid chromatography (HPLC-TRF) have KHF activity and generate CTL in PNA+ thymocytes in the presence of stimulator cells and IL-2. Moreover, translation products (recombinant TRF) of Xenopus oocytes injected with cDNA encoding for murine TRF (BCGF II) also exert KHF activity. A rat monoclonal anti-TRF antibody TB13 can block generation of CTL by HPLC-TRF or recombinant TRF. These results indicate that TRF acts not only on B cells as BCGF II but also on PNA+ thymocytes as KHF. In view of the diverse activities and targets of TRF, we propose that TRF refers to a different interleukin, interleukin 5.
Peroxo-complexes of vanadium(V); a vanadium-51 nuclear magnetic resonance study (1979)

Peroxovanadium(V) species of notional formula [VO(OO)]+, [HVO2(OO)2]2–, [H2VO2(OO)2]–, [VO(OO)3]3–, [HVO(OO)3]2–, [V(OO)4]3–, [H{VO(OO)2}2O]3–, and [VO(NH3)(OO)2]– have been identified in aqueous solution by 51V n.m.r. spectroscopy; species [HVO3(OO)]2–, [VO2(OO)2]3–, and [{V(OH2)(OO)2}2O] are also indicated. The chemical shifts and pKa values indicate that peroxo-ligands bind to vanadium less covalently than oxo-ligands, provided that at least one oxo-ligand remains co-ordinated.
Effects of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate on neurite outgrowth from chick embryo sensory ganglia. (1984)

The addition of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) to defined growth medium stimulated an intense neurite outgrowth from chick sensory ganglia explants. The development of radial neurites was concentration dependent. At low concentrations of TPA (1.6 to 16 nM), neurites were long but moderate in numbers. At higher concentrations (160 to 480 nM), TPA produced dense, short neurites that formed thick fascicles. This reduced outgrowth in length was not related to cytotoxicity and was found to be reversible when the tumor-promoting agent was removed. Neurite outgrowth was also accompanied by an increase in proliferation of nonneuronal cells. Blocking the proliferation of nonneuronal components by the mitotic inhibitor 1-beta-D-arabinofuranosylcytosine did not inhibit neurite outgrowth, suggesting that the TPA-induced neurite differentiation was independent of nonneuronal cells. When TPA was tested in the presence of nerve growth factor, the induction of neurite differentiation was not affected. Other active tumor promoters including phorbol-12,13-didecanoate and mezerein also elicited neurite outgrowth, while nonpromoting agents such as phorbol and 4 alpha-phorbol-12,13-didecanoate were ineffective.
Development of splenic natural suppressor (NS) cells in ehrlich tumor‐bearing mice (1989)

Spleen cells from C57BL/6J mice bearing Ehrlich carcinoma growing as a solid tumor show progressive unresponsiveness to concanavalin A (Con A) and lipopolysaccharide (LPS) mitogens. This is accompanied by striking spleen enlargement with marked hematopoietic activity. Lymphoproliferative assays of normal spleen cells in co-culture with tumor-bearing spleen cells (TBSC) show that: (a) TBSC contain non-specific suppressor cells able to abrogate both Con A and LPS responses, or mixed lymphocyte reaction, of normal spleen cells and (b) suppression by TBSC is MHC-unrestricted, non-prostaglandin-mediated and greatly enhanced by Con A supernatants. Suppressor cells associated with TBSC are large, low-density cells without markers of mature B or T lymphocytes or of the mononuclear phagocyte system. Most appear to be asialo-GM1-negative, as suppression was only partially inhibited by treatment with anti-asialo-GM1 and complement. Since NK activity is lacking in TBSC, our data strongly suggest that these "null" suppressor cells are related to the natural suppressor (NS) cells found described in normal bone-marrow and neonatal spleens, or induced in adult spleens by total lymphoid irradiation, graft-vs.-host disease, or cyclophosphamide treatment.
School Organization and Persistent School Absenteeism: An Introduction to a Complex Problem (1982)

(1982). School Organization and Persistent School Absenteeism: An Introduction to a Complex Problem. School Organisation: Vol. 2, No. 1, pp. 45-51.
A general method for the synthesis of 2'-azido-2'-deoxy- and 2'-amino-2'-deoxyribofuranosyl purines (1977)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA general method for the synthesis of 2'-azido-2'-deoxy- and 2'-amino-2'-deoxyribofuranosyl purinesJ. B. Hobbs and F. EcksteinCite this: J. Org. Chem. 1977, 42, 4, 714–719Publication Date (Print):March 1, 1977Publication History Published online1 May 2002Published inissue 1 March 1977https://pubs.acs.org/doi/10.1021/jo00424a031https://doi.org/10.1021/jo00424a031research-articleACS PublicationsRequest reuse permissionsArticle Views400Altmetric-Citations38LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Novel Structure of the N Terminus in Yeast Fis1 Correlates with a Specialized Function in Mitochondrial Fission (2005)

Mitochondrial fission is facilitated by a multiprotein complex assembled at the division site. The required components of the fission machinery in Saccharomyces cerevisiae include Dnm1, Fis1, and Mdv1. In the present study, we determined the protein structure of yeast Fis1 using NMR spectroscopy. Although the six alpha-helices, as well as their folding, in the yeast Fis1 structure are similar to those of the tetratricopeptide repeat (TPR) domains of the human Fis1 structure, the two structures differ in their N termini. The N-terminal tail of human Fis1 is flexible and unstructured, whereas a major segment of the longer N terminus of yeast Fis1 is fixed to the concave face formed by the six alpha-helices in the TPR domains. To investigate the role of the fixed N terminus, exogenous Fis1 was expressed in yeast lacking the endogenous protein. Expression of yeast Fis1 protein rescued mitochondrial fission in delta fis1 yeast only when the N-terminal TPR binding segment was left intact. The presence of this segment is also correlated to the recruitment of Mdv1 to mitochondria. The conformation of the N-terminal segment embedded in the TPR pocket indicates an intra-molecular regulation of Fis1 bioactivity. Although the TPR-like helix bundle of Fis1 mediates the interaction with Dnm1 and Mdv1, the N terminus of Fis1 is a prerequisite to recruit Mdv1 to facilitate mitochondrial fission.
Alpha-adrenergic mechanisms in myocardial ischemia. (1990)

alpha-Adrenoceptor-mediated effects of sympathetic activation on the heart and coronary circulation are reviewed with emphasis on the pathophysiology of myocardial ischemia. A classification of alpha-adrenoceptor subtypes is presented, and the effects of alpha-adrenoceptor activation on presynaptic sympathetic nerve terminals, cardiomyocytes, endothelium, platelets, and coronary smooth muscle cells are discussed. alpha-Adrenergic coronary vasoconstriction at rest and during situations of sympathetic activation such as exercise and excitement is analyzed for the segmental, transmural, and regional distribution of coronary blood flow. Evidence for a significant contribution of alpha-adrenergic coronary vasoconstriction to experimental and clinical myocardial ischemia is provided. Cardiomyocyte alpha-adrenoceptor activation may be involved in ischemic and reperfusion arrhythmias. The participation of presynaptic and postsynaptic alpha-adrenoceptors, as well as of alpha 1- and alpha 2-adrenoceptors, in experimental and clinical myocardial ischemia will require further investigation.
High pressure HC1 conversion of cellulose to glucose (1981)

The production of ethanol from glucose by means of fermentation represents a potential long-range alternative to oil for use as a transportation fuel. Today's rising oil prices and the dwindling world supply of oil have made other fuels, such as ethanol, attractive alternatives. It has been shown that automobiles can operate, with minor alterations, on a 10% ethanol-gasoline mixture popularly known as gasohol. Wood has long been known as a potential source of glucose. Glucose may be obtained from wood following acid hydrolysis. In this research, it was found that saturating wood particles with HCl gas under pressure was an effective pretreatment before subjecting the wood to dilute acid hydrolysis. The pretreatment is necessary because of the tight lattice structure of cellulose, which inhibits dilute acid hydrolysis. HCl gas makes the cellulose more susceptible to hydrolysis and the glucose yield is doubled when dilute acid hydrolysis is preceded by HCl saturation at high pressure. The saturation was most effectively performed in a fluidized bed reactor, with pure HCl gas fluidizing equal volumes of ground wood and inert particles. The fluidized bed effectively dissipated the large amount of heat released upon HCl absorption into the wood. Batch reaction times of one hour at 314.7 p.s.i.a. gave glucose yields of 80% and xylose yields of 95% after dilute acid hydrolysis. A non-catalytic gas-solid reaction model, with gas diffusing through the solid limiting the reaction rate, was found to describe the HCl-wood reaction in the fluidized bed. HCl was found to form a stable adduct with the lignin residue in the wood, in a ratio of 3.33 moles per mole of lignin monomer. This resulted in a loss of 0.1453 lb. of HCl per pound of wood. The adduct was broken upon the addition of water. A process design and economic evaluation for a plant to produce 214 tons per day of glucose from air-dried ground Populus tristi gave an estimated glucose cost of 15.14 cents per pound. This would correspond to $2.54 per gallon of ethanol if the glucose were fermented. Key factors contributing to the cost of glucose production were unrecovered HCl, which contributed 5.70 cents per pound of glucose, and the cost of wood, which at $25 per ton contribute 4.17 cents per pound.
HIV-1–Associated Dementia: A Metabolic Encephalopathy Perpetrated by Virus-Infected and Immune-Competent Mononuclear Phagocytes (2002)

Infection of the nervous system by HIV-1 commonly causes a broad range of cognitive, behavioral, and motor abnormalities called, in its most severe form, HIV-1-associated dementia (HAD). HAD is a metabolic encephalopathy caused by productive viral infection of brain mononuclear phagocytes (MPs) (perivascular and parenchymal brain macrophages and microglia) and sustained by paracrine-amplified, inflammatory, neurotoxic responses. MP neurotoxins are, in large measure, homeostatic secretory products that can have a negative effect on neuronal cell function when produced in abundance. Proinflammatory cytokines, chemokines, platelet-activating factor, arachidonic acid and its metabolites, nitric oxide, quinolinic acid, progeny virions, and viral structural and regulatory proteins are all included as part of these cellular and viral toxic elements. In addition, neuronal damage can occur directly by engaging specific receptors or through inducing widespread inflammatory activities in brain tissue that ultimately induce neuronal demise. The mechanisms for immune-and viral-mediated neural injury in HAD are made more striking by the effects of abused drugs on cognitive function. Ultimately, linkages between neuronal function and disordered MP immunity will provide insights into how HIV-1 infection of the brain leads to compromised mental function as well as providing clues into the pathogenesis of other neurodegenerative disorders.
Phage Particle-Mediated Gene Transfer to Cultured Mammalian Cells (1982)

Recombinant phage particles carrying the thymidine kinase (TK) gene of herpes simplex virus type 1, coprecipitated with calcium phosphate, efficiently transformed mouse Ltk − cells to the TK + phenotype. The conditions necessary to achieve high efficiency of transfer of the TK gene by phage particle-mediated gene transfer were investigated. Of the parameters examined, the pH of the buffer used for coprecipitation of phage particles with calcium phosphate, the length of time of coprecipitation, and the length of the adsorption period were found to alter the transfer efficiency significantly. The optimal pH was 6.87 at 25°C. The other optimal values for these parameters were as follows: coprecipitation time, 7 to 20 min; adsorption time, 18 to 30 h. Treatment with dimethyl sulfoxide, glycerol, or sucrose did not enhance gene transfer. The optimal conditions yielded about 1 transformant per 10 5 phage particles per 10 6 cells without carrier DNA. An increase in the dosage of phage particles, up to at least 5 × 10 7 phage particles per 100-mm dish, resulted in a linear increase in the number of transformants. Addition of carrier phage, up to 10 10 phage particles per dish, did not significantly affect the number of transformants.
Phosphopantethenylated Precursor Acyl Carrier Protein Is Imported into Spinach (Spinacia oleracea) Chloroplasts (1994)

Acyl carrier protein (ACP) is an essential cofactor of fatty acid synthase. In plants, ACP is synthesized in the cytosol as a larger precursor protein and then is imported into the plastid where it is processed to a smaller mature form. The active form of ACP uses a covalently linked 4[prime]-phosphopantetheine prosthetic group derived from coenzyme A to covalently bind the acyl intermediates during fatty acid synthesis. The prosthetic group is added to ACP by holoACP synthase. This enzyme activity is associated with both the plastidial subcellular fraction and the soluble, or cytoplasmic, fraction. To gain further insight into potential in vivo pathways for the synthesis and maturation of ACP, in this study we examined whether precursor holoACP can be imported by isolated spinach (Spinacia oleracea) chloroplasts. Precursor holoACP containing a [35S]phosphopantetheine prosthetic group was prepared, and the radiolabel was used to demonstrate import of the phosphopantethenylated protein into isolated chloroplasts. In addition, timed chloroplast import assays indicated that in vitro import of the phosphopantethenylated protein is at least as efficient as import of the precursor apoprotein. Evidence was also obtained for a low level turnover of the prosthetic group among endogenous plastidial ACPs when coenzyme A was supplied exogenously.