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Neutrophils (PMNs) initiate production of toxic oxygen metabolites through stimulation of an NADPH oxidase resulting in the reduction of oxygen to superoxide anion (O2-). The activity of this enzyme system may be primed by a variety of compounds. This laboratory investigated the possibility that stored blood components...
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A monoclonal antibody, PAb 2000, has been derived which recognizes the large T protein of JC virus (JCV), but not the corresponding proteins of the related polyomaviruses BK virus (BKV) and SV40. The epitope bound by PAb 2000 was localized to the amino-terminal 81 amino acids of this multifunctional protein. As observe...
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Every picornavirus studied thus far has a sequence within the 5'-non-coding region that is required for internal ribosome binding and translation of the polyprotein. In an attempt to identify this region in hepatitis A virus we constructed a truncated hepatitis A virus (HAV) cDNA clone that contains the entire 736 bp 5...
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Computer simulations are being performed to model the temperature patterns produced during ultrasonically induced hyperthermia of ocular tumours. The software package for these simulations incorporates operator interaction and uses tissue geometry obtained from B-mode data. Previous studies used geometric approximation...
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Lens epithelial and other ocular cells contain complex arrays of actin filaments which might be expected to allow them to migrate following injury: specifically into the capsular sac in cases of extracapsular cataract extraction or traumatic cataract. To test the possibility, a culture system was developed using a mela...
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The expression of the neural cell adhesion molecule NCAM and its polysialic acid (PSA) moiety was documented during embryonic development and adult differentiation of chicken lens cells. In both the embryo and adult, NCAM is predominantly found in the epithelium and the zone of young elongating cells of the annular pad...
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A lens growth factor was identified that is present in the anterior chamber of the embryonic chicken eye. The mitogen is similar to an embryo-specific activity found in embryo serum. Several purified growth factors, applied singly or in combination, did not stimulate cell division in embryonic lens cells. The serum mit...
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The preparation of milligram quantities of three vitamin D3 isomers, previtamin D3, lumisterol3 and tachysterol3, were carried out in a laboratory scale first by irradiating 7-dehydrocholesterol in a phototherapy chamber equipped with UVB lamps, followed by using a two-step high performance liquid chromatography (HPLC)...
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Parathyroid hormone-related protein (PTHrP) is a potent bone-resorbing protein that frequently mediates the humoral hypercalcemia of malignancy syndrome. Since prostaglandins may mediate the bone-resorptive action of certain hormones, we examined the effect of PTHrP on prostaglandin E2 (PGE2) secretion by human osteobl...
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Alcoholic clients were given role-play tests, involving various social and drinking-related scenarios, before and after two types of aftercare treatment. The assessments were used both to evaluate the effects of treatment and to determine whether any dimensions of pretreatment role-play performance interact with treatm...
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The use of responding to drug-related stimuli as a dependent measure for studies of anticraving medications was assessed. Cocaine-dependent subjects receiving either amantadine hydrochloride, a putative anticraving agent, or placebo were exposed to drug-related cues prior to and 7 days after the initiation of the medic...
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Our current incomplete picture of the earliest events in HSV infection may be summarized as follows. The initial interaction of virus with cells is the binding of virion gC to heparan sulfate moieties of cell surface proteoglycans. Stable binding of virus to cells may require the interaction of other virion glycoprotei...
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Though the existence of disease associated with HPV has been documented for centuries, it has been only within the past 2 decades that we have recognized the clinical diversity and significant morbidity and mortality associated with HPV infections. The original lack of interest and nonavailability of in vitro culture s...
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In a prospective study of 169 tenants of senior citizen housing in New Jersey in 1986-1987, the relations between tests of peripheral sensory and motor functions in the lower extremities and the rate of first falls were evaluated. The mean age of the cohort was 79.8 years. Fifty-seven persons fell at least once during ...
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To assess the efficacy and toxicity of orally administered itraconazole in the treatment of nonmeningeal, nonlife-threatening forms of blastomycosis and histoplasmosis.
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To determine the mechanisms by which calcium channel blockade with verapamil causes hyperprolactinemia, the authors investigated the effects of this blockade on the prolactin (PRL) responses to stimulation by thyrotropin releasing hormone (TRH) and inhibition by dopamine, using L-dopa and bromocriptine. Verapamil, give...
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Our objective was to evaluate a self-administered cervicovaginal irrigation apparatus (MY-PAP, Medtech, Bohemia, N.Y.) for the detection of cervicovaginal human papillomavirus infection.
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The purpose of our study was to develop new biologic systems for the treatment or diagnosis of patients with ovarian carcinoma through expansion of T-cell lines from the tumor-infiltrating lymphocytes of patients with ovarian carcinoma in low-dose recombinant interleukin-2 in sufficient numbers for treatment and human ...
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A chimeric model consisting of severe combined immune deficiency (SCID) mice populated with human peripheral blood leukocytes (PBL) has recently been described (bu-PBL-SCID mice). These reports indicated a limited reconstruction of the transferred human immune system and functionality of the human graft. Herein we desc...
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During the early phase of a human cytomegalovirus (HCMV) infection, the 2.7-kb early gene is by far the most abundantly transcribed RNA. Using strand-specific 32P or digoxigenin-labeled riboprobes derived from a subgenomic fragment of the HCMV Towne 2.7-kb early gene, we have performed Northern blot analysis and RNA in...
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A genetic dimorphism of sheep red blood cells characterized by differences in the intracellular K+ concentration of mature red blood cells (low-K+ or high-K+ cells) reflects differences in their Na-K pumps and is known to be linked to the ML blood group system. We investigated the relationship of Na-K pumps in red bloo...
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The vasoactive factors thrombin, bradykinin (BK), and ATP are released in response to tissue damage and inflammation and act on endothelium to modulate vascular perfusion. We have investigated the second messenger response of endothelium activated by these agonists and, in particular, the mechanism of desensitization t...
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Activation of protein kinase C (PKC) modulates the mobilization of intracellular Ca2+ induced by extracellular ATP in rat ventricular myocytes. Pretreatment of myocytes with PKC activators attenuated both the ATP-induced Ca2+ transient and the noradrenergic potentiation of the Ca2+ response. Various PKC activators decr...
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Entry of Ca through voltage-dependent Ca channels is an important regulator of the function of smooth muscle, cardiac muscle, and neurons. Although Ca channels have been extensively studied since the first descriptions of Ca action potentials (P. Fatt and B. Katz. J. Physiol. Lond. 120: 171-204, 1953), the permeation r...
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Estradiol-17 beta (E2 beta) produces uterine and systemic vasodilation in nonpregnant ewes without altering mean arterial pressure (MAP). Mechanisms responsible for maintaining MAP and thus uterine blood flow (UBF) may include activation of the renin-angiotensin and/or adrenergic systems. We therefore investigated the ...
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The present study investigated the effects of a number of oxoanion compounds on in vitro ovulation of goldfish follicles and ovarian second messenger activities. Significant levels of ovulation were induced by 0.1 mM sodium chromate, 0.1 mM sodium metavanadate, 10 mM sodium molybdate, 0.1 mM sodium orthovanadate, 5 mM ...
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Levels (by immunoblotting) and cell distribution (by immunofluorescence) of connexins (Cxs) and glucagon receptors (GRs) were studied during the ontogeny of the rat liver. Cx32, the main rat liver gap junction protein, was present in fetal hepatocytes, and its abundance increased between the 19th and 21st gestational d...
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Inhalation of silicates induces a variety of lung diseases in humans. The molecular mechanism(s) by which these dusts cause disease is not known. Because several naturally occurring mineral oxides have large amounts of transition metal ions on their surfaces, we tested the hypothesis that surface complexation of iron m...
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We examined the binding characteristics of the recently described thrombin receptor amino-terminal peptide, SFLLRNPNDKYEPF (T. K. H. Vu, D. T. Hung, V. I. Wheaton, and S. R. Coughlin. Cell 64: 1057-1068, 1991), termed TRP-14, and its effect in activating intracellular calcium transients in pulmonary vascular endothelia...
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The in vitro blood-perfused juxtamedullary nephron technique was utilized to determine the contribution of endothelium-derived relaxing factor (EDRF) to resting renal arteriolar caliber and to evaluate the interaction between EDRF and angiotensin II (ANG II) in renal microvascular control. Video microscopy was employed...
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Angiotensin II (ANG II) normally induces cellular hypertrophy in proximal tubular epithelium by engaging receptor systems that use a G-protein-signaling mechanism. The c-mas oncogene also encodes part of a superfamily of vasoactive peptide receptor-like moieties that couple to G proteins. To determine whether the stabl...
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Superoxide production was measured as the superoxide dismutase (SOD)-inhibitable portion of nitro blue tetrazolium (NBT) reduction after cerebral ischemia-reperfusion in anesthetized cats equipped with cranial windows. Significant superoxide production was found in the early reperfusion period and continued for more th...
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Regional blood flow patterns vary within myocardium to suggest that intrinsic regional differences occur in vasoregulation. Accordingly, we used standard in vitro methodology (isometric force transducer) to study adrenergic responses in epicardial left anterior descending (LAD) artery and right coronary arteries (RCA) ...
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We have demonstrated previously that in adult ferret heart two alpha-subunit isoforms of the Na(+)-K(+)-ATPase, alpha(+) and alpha, are expressed. The alpha(+)-isoform may comprise either alpha 2-, or alpha 3-, or both isoforms. The present studies further characterize the alpha(+)-isoform. The alpha(+)-isoform of ferr...
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We have examined the responses to endothelin (ET) in isolated adult cardiac myocytes from both rodent and feline species to assess whether endothelin may have a role in the induction or mediation of cardiac hypertrophy in the adult animal. We have evidence that ET acts by more than one mechanism to promote cell-signali...
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Dietary supplementation with marine oils may reduce the incidence of thromboembolism and decrease cardiac arrhythmias during myocardial ischemia. However, function of subcellular organelles isolated from hearts of these animals is impaired. In contrast to studies where marine oil was the sole source of dietary lipid in...
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We have shown that infusion of zymosan-activated plasma (ZAP) in sheep causes acute lung injury and downregulates peripheral blood neutrophils in that elicited superoxide release is reduced for at least 24 h after the infusion. The present study was designed to test the following hypotheses: 1) peripheral blood neutrop...
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The role of kinins in the natriuretic and papillary blood flow (PBF) responses to intravenous administration of 0.9% sodium chloride solution equal to 5% of body weight over 30 min was evaluated using a B1-kinin receptor antagonist (des-Arg9, [Leu8]bradykinin, 2.5 micrograms/min i.v.) and a B2-kinin receptor antagonist...
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Just before and 4 months after initiation of a condom giveaway program, a questionnaire regarding sexual behavior and condom acquisition was administered to 103 men attending an outpatient drug abuse treatment clinic. Jars filled with a variety of condoms were placed in every clinic room. Condom taking varied as a func...
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This report updates the bidirectional selective breeding of taste aversion (TA) prone (TAP) and TA resistant (TAR) rat lines from the 8th through the 22nd generations. A palatable saccharin solution and the aversive consequences of a cyclophosphamide injection are the respective conditioned stimulus (CS) and unconditio...
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This study was conducted to determine whether alcoholic and control subjects respond differently to manipulations that either enhance personal involvement (PI) or reduce negative affect (R, relaxation) on tests of neuropsychological function. In Phase 1, 48 male alcoholics and 36 male control subjects completed neurops...
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The equilibrium constant for the binding of a spectroscopically invisible ligand to its protein receptor can be determined in a competition experiment, by using a structural analog that contains a reporter group (fluorophor). A novel mathematical treatment of the multiple equilibria allows the analysis to be performed ...
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A method for the synthesis and purification of large quantities of four radiolabeled substrates for quantitation of uncovering enzyme is described. Four substrates, [3H]GlcNAc-alpha-P-Man alpha Me, [3H]GlcNAc-alpha-P-uteroferrin, [3H]GlcNAc alpha-P-Man alpha 1-2Man-O-Me, and [3H]GlcNAc alpha-P-Man9GlcNAc, were enzymati...
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A new, highly sensitive radioreceptor assay, which does not require high-performance liquid chromatography, has been developed for the determination of 1,25-dihydroxyvitamin D3 (1,25-(OH2)D3) in serum. The assay involves rapid extraction of serum, Sep Pak silica purification, and addition of 1,25-dihydroxyvitamin D3 re...
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We present here the physicochemical and biochemical properties of NBD-DFO, the 7-nitrobenz-2-oxa-1,3-diazole (NBD) derivative of the siderophore, desferrioxamine B (DFO) (Lytton et al., Mol. Pharmacol. 40, 584, 1991). Modification of DFO at its terminal amine renders it more lipophilic, imparts to it fluorescent proper...
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N-hydroxy-2-thiopyridone (1), an established source of the hydroxyl radical (HO., Boivin, J., Crepon, E., and Zard, S. Z. (1990) Tetrahedron Lett. 31, 6869-6872), produced HO. under conditions directly applicable to biological studies. Generation of HO. by subjecting 1 to irradiation with visible light was monitored in...
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A simple procedure is presented for the enzymatic preparation of [2-3H]mannose 6-phosphate (Man 6-P) with purified yeast hexokinase and unlabeled ATP. The enzymatically synthesized [2-3H]Man 6-P is utilized as the radiolabeled substrate in a new rapid assay for glucose 6-phosphate (Glc 6-P) phosphatase. The principle o...
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The mechanism by which volatile anesthetics produce their direct effects on vascular smooth muscle remains unknown. The authors previously reported that volatile anesthetics decrease both Ca2+ and K+ currents, however the role of Ca(2+)-activated K+ channels during the vasorelaxation by anesthetics has not been investi...
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Besides its classical actions in calcium metabolism, it is clear that the hormonal form of vitamin D has many new functions, which have only been discovered as a result of following the appearance of its receptor. Furthermore, because of the vitamin D-based endocrine system, the use of vitamin D compounds in treating a...
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Candida albicans is an opportunistic pathogen responsible for life-threatening infections in persons with impaired immune systems. Topoisomerase I is a potential target for novel antifungal agents; however, in order for this enzyme to be a therapeutically useful target, it needs to be demonstrated that the fungal and h...
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The genetic determinant encoding gentamicin resistance (Gmr) on the beta-lactamase encoding plasmid pBEM10 of Enterococcus faecalis HH22 is carried on a transposon, termed Tn5281, that is highly related to the staphylococcal Gmr transposons Tn4001 found in Australian isolates of Staphylococcus aureus and Tn4031 found i...
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The purpose of this study was to develop a pharmacodynamic model to describe the dependency of the rate of Staphylococcus aureus killing upon the concentration of daptomycin. A range of free (unbound) daptomycin concentrations ranging from 0.12 to 27 times the MIC were simulated in the peripheral compartment of a two-c...
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We previously described the synthesis and in vitro antiviral activity of an acyclic thiosangivamycin analog (Gupta et al., 1989a). In order to extend these initial studies, a new, multi-gram synthesis of 4-amino-7-[(2-hydroxy- ethoxy)methyl]pyrrolo]2,3-d]pyrimidine-5-thiocarboxamide (compound 229) was achieved in 5 ste...
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The ability of several known anti-HIV substances to inhibit feline immunodeficiency virus (FIV) was tested. The results showed that FIV infection of feline T-cells was almost completely blocked in the presence of all of the agents tested. However, FIV-induced syncytium formation between a human T-cell line (MT-2 cells)...
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Treatment of African green monkey kidney cells with 1 microgram/ml of (S)-1-[(3-hydroxy-2-phosphonyl methoxy) propyl] cytosine (HPMPC) inhibited the release of infectious herpes simplex virus type 1 (HSV-1) by more than 90%. Electron microscopic observations of HPMPC-treated monkey kidney cells demonstrated few intrace...
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The combination 2'-nor-cGMP/DHPG at fixed ratios 1:5, 1:10 and 1:20 showed synergistic antiviral effects against GPCMV replication in vitro with CI value < 1. In vivo, a fixed ratio of 1:10 at three different dosage levels of 1.25/12.5 mg, 2.5/25 mg and 5/50 mg/kg/day 2'-nor-cGMP/DHPG combination showed only additive r...
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The primary aim of this study was to characterize the carbohydrate that would be supplied to the colon for fermentation under physiological conditions. Colectomized rats were fed fiber-free diets or diets containing 5% (wt/wt) gum arabic. Four (fucose, galactose, glucosamine, and galactosamine) of 11 analyzed sugars ac...
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An electron spin resonance (ESR) assay has been developed for peroxidase activity. The assay measures the formation of the paramagnetic nitroxide Tempol from the oxidation of its hydroxylamine derivative (TOLH) by short-lived radicals produced by peroxidase cycle intermediates, Compounds I and II. Using phenol as a per...
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Myocytes prepared from rat heart have been studied by optical spectroscopy using a photodiode array spectrophotometer adapted to a stopped flow apparatus (PASF). The isolated cells were viable for 3-4 h (i.e., over the total time of the experiments), as tested employing morphological parameters of cell damage, reactivi...
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The metabolism and disposition of hydrazine and its effects on endogenous metabolites has been studied in rats by the use of high resolution proton NMR spectroscopy of urine. Several metabolites of hydrazine were detected, notably acetyl- and diacetylhydrazine and a cyclised metabolite which results from a hydrazone fo...
United Kingdom
In order to characterize agonist-dependent Ca2+ influx pathways, changes in cystolic Ca2+ (Ca2+i) during stimulation with multiple Ca(2+)-mobilizing agents were measured in rat pancreatic and submandibular gland acini loaded with fura-2. In pancreatic acini, maximal levels of carbachol and cholecystokinin octapeptide (...
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Porphyromonas gingivalis is a Gram-negative anaerobic bacterium associated with various forms of periodontal disease. Several characteristics of P. gingivalis are thought to contribute to its pathogenicity; these include haemagglutination and trypsin-like protease activity. Previous studies suggest an association betwe...
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Horse spleen ferritin will bind up to 16 protoporphyrin IX haem groups per 24 subunits in vitro [Kadir & Moore (1990) FEBS Lett. 276, 81-84] at a site that causes the haem to be low spin for both ferric and ferrous states. E.p.r. spectra at 10 K of the oxidized form of the resulting haemoferritin gives g values of 2.93...
United Kingdom
1H- and 31P-n.m.r. have been used to study the interaction of the bacterial chemotaxis protein, CheY, with ATP and a variety of other phosphates in the presence and absence of bivalent metal ions. In the metal-bound conformation, CheY will bind nucleotide phosphates and phosphates in general, while in the metal-free co...
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The ovary uses the cholesterol from high-density lipoproteins (HDL) as a substrate source for steroid hormone production. It is not clear, however, how ovarian cells acquire the lipoprotein cholesterol. This study describes the characterization and isolation of a high-affinity-binding protein for apolipoprotein E-free ...
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We have investigated the mechanisms by which type 1 plasminogen activator inhibitor (PAI-1) is regulated by transforming growth factor beta (TGF-beta) and by epidermal growth factor (EGF) in CCL64 mink lung epithelial cells, BSC-1 monkey kidney epithelial cells, mouse embryo fibroblast (AKR-2B 84A) cells and normal rat...
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Endothelin, a potent vasoactive peptide originally isolated from the vascular endothelial cells, exerts glycogenolytic and vasoconstrictive actions in the perfused rat liver. In this paper we demonstrate high-affinity binding sites for endothelin-1 (ET-1) on rat hepatocytes. Upon incubation at 37 degrees C, association...
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Of the many intracellular events that occur after mitogenic stimulation of cells, the phosphorylation of the retinoblastoma protein (RB) in early G1-phase appears to play a pivotal role in controlling cell-cycle progression. RB phosphorylation results in release from a proliferative block imposed by hypophosphorylated ...
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Because of the importance of pH homeostasis in bone and the current uncertainty about the mechanisms by which intracellular pH (pHi) is regulated in this tissue, we have investigated the roles of cytosolic free Ca2+ concentrations ([Ca2+]i) and protein kinase C on the activation of Na+/H+ exchange in human osteoblast-l...
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Platelet-activating factor (PAF) desensitizes as well as stimulates its various target cells, We find that human polymorphonuclear neutrophils (PMN) exposed to PAF became maximally unresponsive to a second PAF challenge within 15-90 s in assays of Ca2+ mobilization and degranulation. The cells regained full PAF-sensiti...
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Physiological experiments conducted over the last 60 years indicate that the plant hormone auxin regulates a diverse set of developmental processes via changes in cell division, cell elongation and cell differentiation. Recent studies using transgenic plants with altered auxin levels support these conclusions and promi...
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Parietal cell secretion can be stimulated by both histaminergic and cholinergic agonists. We have recently found that inhibition of calmodulin-dependent protein kinase II (CaMK II) activity can abolish cholinergic but not histaminergic stimulation of parietal cell secretion (Am. J. Physiol. 262:G118-122). We have inves...
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Gene amplification contributes to carcinogenesis by enhancing proto-oncogene activity and causing chromosomal instability. The ease of detecting amplified tumor-virus sequences has encouraged use of this system as a surrogate for studying the molecular events involved in endogenous gene amplification. We report here a ...
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Alterations in the motivation to ingest sucrose can be quantified by measuring the number and type of oral motor and somatic responses (i.e., taste reactivity [TR]) that are elicited by sucrose. In 2 experiments, rats had intraorally infused sucrose paired with LiCl injections for several trials, or they were injected ...
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The effect of transforming growth factor beta type 1 (TGF-beta 1) on DNA synthesis, anchorage-dependent and anchorage-independent proliferation, cytoskeletal organization, and gene expression in ras-transformed simian virus 40 (SV40)-immortalized hepatocyte cell lines was measured. An SV40-immortalized cell line (CWSV1...
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Activating the protein-tyrosine kinase activity of v-Fps leads to the rapid transcriptional activation of the Egr-1 gene, which encodes a mitogen-responsive transcription factor. Activation of Egr-1 by v-Fps was insensitive to protein kinase C depletion, suggesting that a protein kinase C-independent signal activated b...
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Antijunctions and mesojunctions are new classes of multistranded DNA complexes. They represent a generalization of DNA branched junction complexes, such as the Holliday recombination intermediate. Each strand of a conventional branched junction participates in two different double helices, and this is also true for mes...
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The DNA polymerase from the bacteriophage T4 is part of a multienzyme complex required for the synthesis of DNA. As a first step in understanding the contributions of individual proteins to the dynamic properties of the complex, e.g., turnover, processivity, and fidelity of replication, the minimal kinetic schemes for ...
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Pseudomonas mevalonii 3-hydroxy-3-methylglutaryl-CoA lyase has been expressed in an active form in Escherichia coli and purified to homogeneity. Enzyme activity in crude extracts is 30-fold higher than reported for a homologous expression system. After Q-Sepharose fast-flow anion-exchange chromatography, the enzyme, wh...
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Monoclonal antibody M7-PB-E9 binds the sheep kidney Na+,K(+)-ATPase alpha-subunit with high affinity (Kd = 3 nM) and inhibits enzyme turnover in competition with ATP, and, like ATP, in the presence of Mg2+, it stimulates the rate of ouabain binding [Ball, W. J. (1984) Biochemistry 23, 2275-2281]. In this study, covalen...
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15N and 1H resonance assignments for backbone and side-chain resonances of both equilibrium forms of rat ferrocytochrome b5 have been obtained, using 15N-1H heteronuclear correlation methods employing globally 15N-labeled protein. Unlike other cytochrome b5 species assigned to date (Guiles et al., 1990) the rat cytochr...
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Ubiquitin adopts a non-native folded structure in 60% methanol solution at low pH. Two-dimensional nuclear magnetic resonance (2D NMR) was used to measure the hydrogen-exchange rates of backbone amide protons of ubiquitin in both native and methanol forms, and to characterize the structure of ubiquitin in the methanol ...
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The stoichiometry of cytochrome b559 (one or two copies) per reaction center of photosystem II (PSII) has been the subject of considerable debate. The molar ratio of cytochrome b559 has a number of significant implications on our understanding of the functional role of cytochrome b559, the mechanism of electron donatio...
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The spectroscopic properties of a mutant cytochrome c peroxidase, in which Asp-235 has been replaced by an asparagine residue, were examined in both nitrate and phosphate buffers between pH 4 and 10.5. The spin state of the enzyme is pH dependent, and four distinct spectroscopic species are observed in each buffer syst...
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NMR experiments were carried out to study the interaction of thrombin with a synthetic peptide, ESKATNATLDPR, derived from the newly-identified platelet receptor for thrombin [Vu, T.-K. H., Hung, D. T., Wheaton, V. I., & Coughlin, S. R. (1991) Cell 64, 1057-1068]. On the basis of the observation of the thrombin-induced...
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A set of mutants of transcription factor IIIA (TFIIIA) have been prepared in which successive zinc-finger domains have been deleted from the carboxyl terminus of the protein. These have been analyzed by hydroxyl radical footprinting to map the location of contacts to DNA by individual zinc-finger domains of TFIIIA. The...
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Adenosine 5'-phosphosulfate (APS) kinase (ATP:APS 3'-phosphotransferase) catalyzes the ultimate step in the biosynthesis of 3'-phosphoadenosine 5'-phosphosulfate (PAPS), the primary biological sulfuryl donor. APS kinase from Escherichia coli is phosphorylated upon incubation with ATP, yielding a protein that can comple...
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The properties of the cationic locus within the recombinant (r) kringle 2 domain (residues 180-261) of tissue-type plasminogen activator ([K2tPA]) that are responsible for stabilization of its interaction with the carboxylate moiety of omega-amino acid ligands have been assessed by determination of the binding constant...
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We have determined the formal potential values for each electron transfer to electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO), in order to further characterize the thermodynamics of electron transport from various acyl-CoA thioesters to the mitochondrial ubiquinone pool. ETF-QO contains one [4Fe-4S]2+,...
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Exposure of cells to alkylating agents produces DNA lesions, most of which are repaired. However some alkyl lesions persist and play a role in inducing point mutations and the subsequent carcinogenic conversion. O6-Ethylguanine (e6G) is a relatively persistent alkylation lesion caused by the exposure of DNA to N-ethyl-...
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Site-directed mutagenesis was used to investigate which of the highly conserved methionine residues (M183 and M205) provides the sixth axial ligand to the heme Fe in the cyt c1 subunit of the bc1 complex from the bacterium Rhodobacter capsulatus. These residues were changed to leucine (cM183L) and valine (cM205V). Two ...
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The stable tyrosine radical in photosystem II, YD*, has been studied by ESR and ENDOR spectroscopies to obtain proton hyperfine coupling constants from which the electron spin density distribution can be deduced. Simulations of six previously published ESR spectra of PSII (one at Q band; five at X band, of which two we...
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Smooth muscle myosin light chain kinase is phosphorylated at two sites (A and B) by different protein kinases. Phosphorylation at site A increases the concentration of Ca2+/calmodulin required for kinase activation. Diphosphorylated myosin light chain kinase was used to determine the site-specificity of several forms o...
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The biochemical responses of intact human platelets to the monoclonal antibody (mAb) AG-1 were investigated. AG-1 is a murine IgG mAb that recognizes a series of platelet membrane glycoproteins (Gp) from M(r) 21,000 to 29,000, one of which is the M(r) 24,000 (p24) receptor for anti-CD9 mAbs. AG-1 causes platelet aggreg...
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Quantitative autoradiographic analysis of beta-adrenergic binding sites was conducted in human postmortem hypothalamus using the radioligand 125I-pindolol. The focus was on the hypothalamic nuclei most clearly involved in corticotropin-releasing hormone (CRH) release, the PVN and SON. For comparison, the distribution o...
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Tri-n-butyltin(TBT) compounds having the chemical formula (C4H9)3SnX are broad-spectrum biocidal agents whose toxic effect is primarily at the membrane level. Red blood cells (RBC) exposed to micromolar concentrations of tributyltin compounds (TBTX) undergo morphological changes and hemolysis. Determination of the mech...
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The purpose of the present study was to characterize opioid receptor-mediated regulation of incertohypothalamic dopaminergic (DA) neurons in the rat brain by examining the acute effects of selective mu or kappa opioid receptor agonists and antagonists on concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC) in the m...
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The neuroanatomical distribution of binding sites for [3H]imipramine and [3H]citalopram was assessed by in vitro autoradiography in select regions of the rat and human forebrain. To determine involvement of serotonin-containing terminals in the binding of [3H]imipramine and [3H]citalopram, binding of these compounds wa...
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[125I]Human calcitonin gene-related peptide ([125I]hCGRP) binding in the dorsal horn of the spinal cord exhibited differential changes among laminae over time in response to unilateral adjuvant-induced inflammation. In laminae I/II, 4 days after induction of inflammation, the binding decreased 36% on the side of the sp...
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The sulphydryl reagent, p-chloromercuribenzenesulfonic acid (PCMBS), irreversibly excites the carotid body in vivo. We tested the effects of PCMBS on ionic currents in isolated type I cells, using the whole-cell patch-clamp technique. PCMBS selectively and irreversibly inhibited the Ca(2+)-activated K+ current (IKCa) i...
United Kingdom