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O2-induced impairment of mitochondrial energy generation was examined in intact lungs isolated from rats after 18-30 h exposure to either air or 100% O2 in vivo. Mitochondrial metabolic rates were determined by separate measurements of 14CO2 production from [1-14C]pyruvate and [U-14C]palmitate, perfused under normal an... | US |
Changes in the activity of the brush-border Na-H antiporter are accompanied by parallel changes in the activity of the Na-HCO3 cotransporter. Adenosine 3',5'-cyclic monophosphate (cAMP) and calmodulin inhibit the Na-H antiporter, whereas protein kinase C (PKC) stimulates it. We hypothesized that cAMP, calmodulin, and P... | US |
The spontaneous hyperpolarizing shift in Na+ channel kinetics that occurs during a series of voltage-clamp recordings was characterized in single canine cardiac Purkinje cells at 10-13.5 degrees C. The change in the half-point of voltage-dependent availability, in the half-point of peak conductance, in the voltage depe... | US |
We tested for direct G protein regulation of delayed rectifier K+ (IK) channels, by measuring IK currents in guinea pig ventricular cells using patch-clamp procedures. In excised inside-out patches, IK was enhanced by adding guanosine triphosphate or guanosine 5'-O-(3-thiotriphosphate) to the cytoplasmic side, even in ... | US |
Drugs that exhibit use-dependent Na channel blockade, including antiarrhythmic agents, tricyclic antidepressants, opiate-like analgesics, and cocaine, are linked with an increased susceptibility to cardiac arrhythmias and sudden death. Computer simulations indicate that Na channel blockade retards recovery of excitabil... | US |
The objective of this study was to ascertain the mechanism by which electrical field stimulation (EFS) of bovine pulmonary arterial rings causes endothelium-dependent smooth muscle relaxation. Like acetylcholine-elicited relaxation, EFS-elicited relaxation was endothelium-dependent and accompanied by accumulation of gu... | US |
Using enzyme histochemistry and in vitro electrophysiological recordings in brain slices, we studied 1) the relative activity of cytochrome c oxidase (Cytox) and hexokinase (HK) and 2) cellular function by examining ionic homeostasis across cell membranes in the turtle and newborn (5 days old) and adult rat central ner... | US |
In contrast to mammalian brain, which exhibits rapid degeneration during anoxia, the brains of certain species of turtles show an extraordinary capacity to survive prolonged anoxia. The decrease in energy expenditure shown by the anoxic turtle brain is likely to be a key factor for anoxic survival. The "channel arrest"... | US |
Little is known about the organization and performance of outpatient substance abuse treatment (OSAT) centers. We examine several performance measures of OSAT units, including clients treated, services provided, revenue sources, financial performance, and access to care, in relation to ownership of the center. | US |
The present study evaluates the action of volatile anesthetics on the voltage-dependent Ca2+ channels in isolated rat brain membranes, measured as changes in binding of the Ca2+ channel blocker [3H]isradipine to these membranes. Equilibrium binding studies with increasing concentrations of [3H]isradipine (0.01-1 nM) in... | US |
The immunogenicity and reactogenicity of live and heat-inactivated varicella vaccine were evaluated in 95 healthy seropositive adults (mean age, 32 yrs). Live-attenuated vaccine containing 28,000 pfu, 2800 pfu, or 280 pfu of Oka/Merck strain virus (8.4, 0.84, and 0.08 antigen units, respectively) or heat-inactivated va... | US |
Mice infected with various tumor retroviruses have been used as models for evaluating therapeutic substances for the treatment of some cancers, and more recently, for human immunodeficiency virus (HIV) infection, the causative agent of acquired immune deficiency syndrome (AIDS). Consequently, there is a need to determi... | US |
N-Methylated beta-carbolinium compounds (N-Me-BCs), including 2-N-methyl and 2,9-N,N-dimethyl analogs, structural analogs of 1-methyl-4-phenylpyridinium (MPP+), may be endogenously bioactivated, MPP(+)-like toxins, capable of inducing parkinsonism. Both MPP+ and selected N-Me-BCs inhibit NADH-linked mitochondrial respi... | US |
In this report we describe the purification and characterization of recombinant porcine prorelaxin expressed in Escherichia coli. Nucleotide sequence encoding porcine prorelaxin was inserted into an E. coli expression vector, pOTS, and the recombinant plasmid was transformed into the E. coli host (AR120). Upon inductio... | US |
Vertebrate ferredoxins function in the transfer of reducing equivalents from NADPH:ferredoxin oxidoreductase to cytochrome P450 enzymes involved in steroid metabolism. We report here the expression of human mitochondrial ferredoxin in the yeast Saccharomyces cerevisiae. The full-length ferredoxin protein containing the... | US |
Leupeptin is a small peptide microbially derived inhibitor of certain proteolytic enzymes. Using N-alpha-benzoyl-DL-arginine 4-nitroanilide as substrate, we found a novel leupeptin-sensitive proteolytic enzyme in N-methyl-N-nitrosourea(MNU)-induced rat mammary adenocarcinoma. This enzyme was apparently different from u... | US |
Calmodulin is the major intracellular Ca(2+)-binding protein, providing Ca(2+)-dependent regulation of numerous intracellular enzymes. The phosphorylation of calmodulin may provide an additional mechanism for modulating its function as a signal transducer. Phosphocalmodulin has been identified in tissues and cells, and... | US |
Infusion of 50 microM-Ins(1,3,4,5)P4 in addition to 500 microM-Ins(1,4,5)P3 into mouse lacrimal cells via a patch-clamp pipette promoted sustained activation of the Ca(2+)-dependent Cl- current, which could not be achieved with 500 microM-Ins(1,4,5)P3 alone. It has been proposed that Ins(1,3,4,5)P4 facilitates Ca2+ inf... | United Kingdom |
Light-activated cyclic GMP-phosphodiesterase (PDE) is the key effector enzyme of vertebrate photoreceptor cells which regulates the level of the internal transmitter cyclic GMP. PDE consists of catalytic P alpha and P beta subunits, and two copies of inhibitory P gamma subunit. The two P gamma subunits block the enzyme... | US |
Endogenous neutrophil formylpeptide receptors do not inhibit adenylylcyclase activation. The ability of a cloned and transfected human formylpeptide receptor to mediate the inhibition of adenylylcyclase was assessed in the human embryonic kidney 293 TSA cell line. Inclusion of 1 microM fMetLeuPhe resulted in a ca. 50% ... | US |
Acting through hormonal and/or autocrine/paracrine mechanisms, the insulin-like growth factors (IGFs) stimulate the differentiation of muscle cells. Previous studies have suggested that one mechanism by which IGFs stimulate muscle cell differentiation is by increasing the expression of myogenin, a DNA binding protein t... | US |
Treatment of cultured rat Sertoli cells with FSH or dibutyryl cAMP for 30 min resulted in phosphorylation of the same Sertoli cell proteins. Different Sertoli cell proteins were phosphorylated after calcium ionophore A23187 and 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment. A23187 stimulated the phosphorylation ... | US |
A full-length cDNA for the type II human activin receptor was cloned by hybridization from a human testis cDNA library. The sequence encodes a 513 amino acid protein that is 99% identical, at the amino acid level, with the mouse type II activin receptor. The type II human activin receptor consists of an extracellular d... | US |
Based on RII autophosphorylation, photoaffinity labeling with 8-N3[32P]cAMP, and Western blot analysis we have identified the RII isoform found in rabbit corpora lutea as RII beta. The RII beta subunit found in rabbit corpora lutea differs from the RII beta found in rat follicles and corpora lutea in that it migrates a... | US |
Polyclonal antipeptide antisera have been utilized to quantitate the amount of retinal rod outer segment cGMP phosphodiesterase alpha and beta catalytic subunits present in retinas from C57BL/6J mice which are normal or carriers for the rd gene defect. Results suggest that the quantity of PDE-beta subunit is reduced in... | US |
Treatment of C-4II human cervical squamous carcinoma cells with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) gave a concentration-dependent increase in ethoxyresorufin O-deethylase (EROD) activity. The EC50 for this response was approximately 1 nM and the maximum induced activity was 27 pmol/min/mg protein. The molecular... | US |
To compare the cumulative effects of oral methotrexate (MTX) therapy (after 6-8 weeks) with the acute effects (24 hours after a dose) on arachidonic acid metabolism by the 5-lipoxygenase (5-LO) pathway in neutrophils from patients with active rheumatoid arthritis (RA) who were beginning therapy with MTX. | US |
We describe the transient expression of the rat skeletal muscle muI Na+ channel in human embryonic kidney (HEK 293) cells. Functional channels appear at a density of approximately 30 in a 10 microns 2 patch, comparable to those of native excitable cells. Unlike muI currents in oocytes, inactivation gating is predominan... | US |
In the hilar region of the rat hippocampus, large spontaneous excitatory postsynaptic currents (sEPSCs) mediated by non-NMDA glutamate receptors are present in both excitatory spiny mossy cells and inhibitory aspiny hilar interneurons, making these neurons ideal candidates for a comparative study using the tight seal w... | US |
The fast internal dynamics of human ubiquitin have been studied by the analysis of 15N relaxation of backbone amide nitrogens. The amide 15N resonances have been assigned by use of heteronuclear multiple-quantum spectroscopy. Spin lattice relaxation times at 60.8 and 30.4 MHz and the steady-state nuclear Overhauser eff... | US |
Proton NMR spectroscopy at 500 and 361 MHz has been used to characterize the noncovalent or electrostatic complexes of yeast cytochrome c peroxidase (CcP) with horse, tuna, yeast isozyme-1, and yeast isozyme-2 ferricytochromes c and the covalently cross-linked complexes of cytochrome c peroxidase with horse and yeast i... | US |
Escherichia coli cAMP receptor protein (CRP) is a homodimer in which each subunit is composed of two domains. The C-terminal domain is responsible for DNA recognition, whereas the larger N-terminal domain is involved in cAMP binding. Biochemical and genetic evidence suggests that both intersubunit and interdomain inter... | US |
The DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) repairs the promutagenic O6-methylguanine lesion by transferring the methyl group to a cysteine residue on the protein. A mechanism in which AGT activates the guanyl moiety as a leaving group by protonation of a heteroatom on guanine was probed by reacti... | US |
There is marked pH dependence of the rate constant (koff) for tetrahydrofolate (H4folate) dissociation from its ternary complex with human dihydrofolate reductase (hDHFR) and NADPH. Similar pH dependence of H4folate dissociation from the ternary complex of a variant of hDHFR with the substitution Phe31----Leu (F31L hDH... | US |
Tissue plasminogen activator (t-PA) is an exceptional serine protease, because unlike most other serine protease zymogens single-chain tissue plasminogen activator (sct-PA) possesses a substantial amount of proteolytic activity. The unusual reaction of sct-PA afforded the opportunity to directly compare the active site... | US |
A series of site-specifically plantinated, covalently closed circular M13 genomes (7250 bp) was constructed in order to evaluate the consequences of DNA template damage induced by the anticancer drug cis-diamminedichloroplatinum(II) (cis-DDP). Here are reported the synthesis and characterization of genomes containing t... | US |
We have prepared a series of deoxyoligonucleotide duplexes of the sequence d(G-C-A-T-C-G-X-G-C-T-A-C-G).d(C-G-T-A-G-C-C-G-A-T-G-C), in which X represents either one (A), two (A-A), or three (A-A-A) unpaired adenine basis. Using two-dimensional proton and phosphorus NMR spectroscopy, we have characterized conformational... | US |
We have synthesized an oligodeoxynucleotide duplex, d(G-C-A-T-C-G-A-T-A-G-C-T-A-C-G).d(C-G-T-A-G-C-C-G-A-T-C-G), with a three-base bulge loop (A-T-A) at a central site in the first strand. Nuclear Overhauser experiments (NOESY) in H2O indicate that the GC base pairs flanking the bulge loop are intact between 0 and 25 d... | US |
The protein kinase inhibitors staurosporine and K252A inhibit some of the cellular actions of nerve growth factor (NGF). To explore the molecular mechanisms involved, we test the ability of these agents to block one of the earliest cellular responses to NGF, protein tyrosine phosphorylation. Concentrations of 10-100 nM... | US |
Albumins from several species activated the bifunctional, Zn2+ metalloenzyme amino-peptidase/leukotriene A4 hydrolase (EC 3.3.2.6). Bovine serum albumin, 1 mg/mL, increased hydrolysis of L-proline-p-nitroanilide and leucine-enkephalin by 12-fold and 7-fold, respectively. The apparent Km for L-proline-p-nitroanilide was... | US |
Oxidation-reduction titrations have been conducted to determine the midpoint potential (Em) values of the three electron-carrying prosthetic groups of the ferredoxin-linked glutamate synthase isolated from spinach leaves. Titrations using electron paramagnetic resonance (EPR) signals to monitor the oxidation state of t... | US |
Parvalbumin, aldolase and liver alcohol dehydrogenase (ADH), proteins exhibiting long-lived phosphorescence lifetimes at room temperature, were examined for their reactivity with ferricytochrome c (cytochrome c Fe3+) as an external electron acceptor. Illumination of a reaction mixture containing protein and cytochrome ... | US |
Rate constants of cyanide binding to 'fast' oxidase have been measured in the fully-oxidised (O), peroxy (P) and ferryl (F) states at pH 8.0. Values of 2.2, 8 and 10 M-1 s-1, respectively, were obtained. Thus, none of these states appears to exhibit a rate that would identify it as the species responsible for the extre... | United Kingdom |
The technique of distance measurement, utilizing spin relaxation enhancement by an external probe, has been extended to the study of intrinsic semiquinone radicals through the use of holmium-EDTA complexes and continuous wave electron paramagnetic resonance spectroscopy. This technique has been used to determine the di... | US |
Binding of scatter factor (SF) to the surface protein of Madin-Darby canine kidney (MDCK) cells was investigated. The factor has a specific affinity for membrane proteins of MDCK cells and could be purified 10-20-fold using a membrane protein-affinity chromatographic procedure. The binding was pH- and salt-dependent. T... | US |
The transmembrane distribution of spin-labeled phospholipids was measured in human erythrocytes before and after hypotonic hemolysis by electron paramagnetic resonance. With a first series of partially water soluble probes a complete randomization of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and... | US |
The effect of cAMP on active Ca2+ extrusion across the plasma membrane of intact human platelets was studied using quin2, a fluorimetric indicator of free Ca2+ in the cytoplasmic compartment ([Ca2+]cyt). Elevations of cAMP were achieved by incubation with dibutyryl-cAMP or by forskolin, which was found to selectively e... | US |
Elevation of intracellular cAMP is shown to increase the rate (V) and maximal extent of Ca2+ uptake by the dense tubules in intact human platelets. Elevation of [cAMP] was accomplished by preincubation with the adenylate cyclase activator forskolin or with dibutyryl-cAMP (Bt2-cAMP). The free concentration of Ca2+ in th... | US |
Sodium nitroprusside (SNP) and other agents that elevate cGMP levels are known to inhibit the aggregation of human platelets. Published data suggest that cGMP attenuation of agonist-induced Ca2+ transients is involved in this effect. The present study shows that elevation of cGMP increases the rate of the Ca2+ extrusio... | US |
Spin labeling methods were used to study the structure and dynamic properties of dimyristoylphosphatidylcholine (DMPC) membranes as a function of temperature and the mole fraction of polar carotenoids. The results in fluid phase membranes are as follows: (1) Dihydroxycarotenoids, zeaxanthin and violaxanthin, increase o... | US |
Brain cell membrane function during and following single and repeated episodes of asphyxia was investigated. Asphyxia in 24 anesthetized, paralyzed, mechanically-ventilated newborn piglets was produced by stopping ventilation for 2-3 min followed by recovery with reventilation. Measurements of cerebral Na+,K(+)-ATPase ... | US |
Epstein-Barr virus (EBV) is associated with B-cell malignancy in immunosuppressed humans and SCID mice receiving human peripheral blood leukocyte grafts (hu-PBL-SCID). We have further characterized the process of lymphoma development in hu-PBL-SCID mice. We report that EBV-seropositive donors differ markedly in the cap... | US |
Glucocorticoid treatment dramatically inhibits growth of the wild-type DDT1MF-2 hamster smooth muscle tumor cell line (DDT-WT) but not that of a glucocorticoid-selected clonal variant (DDT-GR). Our objective was to further define the level of glucocorticoid resistance in DDT-GR cells. Glucocorticoid receptors were conf... | US |
A hybrid toxin targeted to melanotropin receptors and selectively cytotoxic to melanoma cell lines in vitro has recently been developed. The toxin, a recombinant fusion protein (designated DAB389-MSH), contains the peptide sequences of alpha-melanocyte-stimulating hormone (alpha-MSH) and the catalytic (cytotoxic; Fragm... | US |
Nerve growth factor (NGF), like many other growth factors and hormones, binds to two different receptor molecules on responsive cells. The product of the proto-oncogene trk, p140trk, is a tyrosine kinase receptor that has been identified as a signal-transducing receptor for NGF, while the role of the low affinity NGF r... | US |
Eighteen nuclear mutants of the yeast Saccharomyces cerevisae, each disturbed in the biosynthesis of the mitochondrially encoded cytochrome c oxidase subunit 1 (cox1) and each representing a distinct complementation group, have been examined to identify the level at which COX1 expression is affected. RNA blotting revea... | US |
High affinity agonist-binding (HAB) sites are formed from specific receptor interaction with guanine nucleotide-binding (Gi) proteins. To determine whether the release of endothelium-derived relaxing factor (EDRF) is regulated by specific receptor-Gi protein coupling, we treated bovine aortic endothelial cells with 100... | US |
Heparin is a potent inhibitor of arterial smooth muscle cell (SMC) migration and proliferation in vivo and in vitro. We propose that heparin affects these SMC functions by interfering with either the expression or the activity of secreted proteases required for cell movement. We have reported that heparin selectively i... | US |
Hearts with compensatory pressure-overload hypertrophy show an increased intracardiac activation of angiotensin II that may contribute to ischemic diastolic dysfunction. We studied whether pressure-overload hypertrophy in response to aortic banding would result in exaggerated diastolic dysfunction during low-flow ische... | US |
The purpose of this study was to examine whether neutral endopeptidase and angiotensin I-converting enzyme, two membrane-bound metalloenzymes that are widely distributed in the microcirculation, play a role in bradykinin-induced increase in vascular permeability in the hamster cheek pouch. Changes in vascular permeabil... | US |
We describe the clinical and pathologic features in four extended kindreds that are consistent with the hereditary flat adenoma syndrome (HFAS). This colon cancer susceptibility disorder is believed to be inherited as an autosomal dominant. The principal phenotypic marker is multiple colonic adenomas (usually less than... | US |
Restriction endonuclease mapping demonstrates a 3' end deletion of one erythropoietin receptor (EpoR) gene in TF-1 cells, a human erythroleukemia cell line that overexpresses the EpoR and proliferates in response to erythropoietin (Epo). EpoR mRNA transcripts are highly abundant and normal in size. These findings raise... | US |
Protein tyrosine kinases represent a subset of proteins that mediate signal transduction between the extracellular environment and the nucleus. We have previously described a coordinated upregulation between RNA transcripts of a tyrosine kinase, c-abl, and those of granulocyte-macrophage colony-stimulating factor (GM-C... | US |
To study the role of protein phosphorylation in erythropoietin (EPO)-mediated signal transduction, we examined the effects of tyrosine phosphatase and tyrosine and serine-threonine kinase inhibitors as well as activators of serine kinases on DNA synthesis and cell proliferation in the murine EPO-dependent cell line HCD... | US |
Because of the potential significance of colonic bacteria and secondary bile acids in the pathogenesis of colon cancer, the present study investigated the effect of different types of dietary fiber on fecal bacterial enzymes, namely, beta-glucuronidase, 7 alpha-dehydroxylase, nitroreductase, and azoreductase, and on bi... | US |
Two models of colitis produced in rats that have received significant attention over the past few years are the acetic acid and trinitrobenzene sulfonic acid (TNBS) models. The objective of this study was to quantify and compare the temporal relationship among mucosal permeability, epithelial injury, and inflammation i... | US |
The aim of this study was to assess the effect of cell culture on the bradykinin receptor of rabbit colon myocytes. In longitudinal muscle strips prepared from distal colon, bradykinin stimulated dose-dependent contraction that was 62% of the maximal response to bethanecol. At 4 degrees C, [3H]bradykinin binding to fre... | US |
Ethanol is metabolized to acetaldehyde by hepatic microsomes in a reaction that requires cytochrome P-450, and a role for hydroxyl radicals has been implicated in this process. However, previous spin trapping experiments have failed to demonstrate the production of hydroxyl radicals by liver microsomes unless iron or o... | US |
This study examines the generation of superoxide anion by the perfused rat liver after ethanol intoxication and acute endotoxemia to assess the potential importance of oxygen-derived free radicals in the ethanol-induced hepatic pathological condition. Hepatic superoxide anion production of 0.65 +/- 0.06 nmol/min/gm liv... | US |
The uptake of tri-hydroxy conjugated bile salts by hepatocytes is principally by a sodium-dependent carrier. We examined the uptake kinetics of the high-specific-activity, hydroxylated, conjugated bile salt 125I-labeled cholyl-glycyl-tyrosine, to determine whether this synthetic bile salt was transported by the sodium-... | US |
A study of 149 light microscopic tissue slides from 147 patients with recorded initial diagnoses of small cell lung cancer (SCLC) (114 cases) and undifferentiated carcinoma (35 cases) was undertaken to test the reproducibility and prognostic impact of a new histopathologic subclassification of SCLC proposed by the Path... | US |
The adeno-associated virus 2 (AAV) genome can be rescued either from a recombinant plasmid upon transfection into human cells or from cells latently infected with AAV, following subsequent infection with adenovirus. Using human diploid fibroblasts as a model for a natural AAV infection, we observed increased efficiency... | US |
The genome of a papillomavirus isolated from a cutaneous lesion on the head of an African grey parrot (Psittacus erithacus timneh) was cloned into pBR322, and a restriction map was prepared. Several short portions of the DNA were sequenced allowing the genome to be aligned with HPV-la. In Southern blot hybridizations, ... | US |
The drive to breathe in exercise is thought to result from a combination of neural and humoral factors, but the exact nature of the controlling signals is controversial. This review examines evidence suggesting that potassium could be a signal that drives ventilation (VE) in exercise. Potassium is lost from working mus... | United Kingdom |
Expression of the Bacillus subtilis gene coding for SspC, a small, acid-soluble protein, caused both killing and mutation in a number of Escherichia coli B and K-12 strains. SspC was previously shown to bind E. coli DNA in vivo, and in vitro this protein binds DNA and converts it into an A-like conformation. Analysis o... | US |
Pseudomonas syringae pv. coronafaciens, a pathogen of oats, was mutagenized with Tn5 to generate mutants defective in tabtoxin production. From a screen of 3,400 kanamycin-resistant transconjugants, seven independent mutants that do not produce tabtoxin (Tox-) were isolated. Although the Tn5 insertions within these sev... | US |
The lemA gene of the plant pathogen Pseudomonas syringae pv. syringae is required for disease lesion formation on bean plants. Cosmid clones that complemented a lemA mutant in trans were isolated previously. The lemA gene was localized by subcloning and transposon mutagenesis. The lemA region and flanking DNA were sequ... | US |
The cytoplasmic domain of murine CD45 has been expressed using an in vitro transcription/translation system. The recombinant protein was isolated by immunoprecipitation with a specific rabbit antiserum and was shown to have protein tyrosine phosphatase (PTPase) activity. Oligonucleotide-directed mutagenesis was then us... | US |
We have previously shown that glucocorticoids regulate the trafficking and processing of mouse mammary tumor virus (MMTV) proteins in viral-infected M1.54 rat hepatoma cells. To examine the role of intracellular membrane integrity on MMTV protein maturation, brefeldin A (BFA) was utilized to disrupt membrane flow betwe... | US |
It has been suggested that the catabolite gene activator protein (CAP) uses an "acidic activating region" transcription activation mechanism and that Glu171 of CAP is the critical amino acid of the "acidic activating region" of CAP (Irwin, N., and Ptashne, M. (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 8315-8319). In this... | US |
We used lactoperoxidase-mediated iodination to investigate the lumenal polypeptide composition of rat hepatocyte endosomes. A chemical conjugate of asialoorosomucoid and lactoperoxidase that binds specifically to hepatocyte asialoglycoprotein receptors was perfused through isolated rat livers at 16 degrees C in the pre... | US |
Using the electron spin resonance/spin trapping system, 4-pyridyl 1-oxide N-tert-butylnitrone (4-POBN)/ethanol, hydroxyl radical was detected as the alpha-hydroxyethyl spin trapped adduct of 4-POBN, 4-POBN-CH(CH3)OH, from phorbol 12-myristate 13-acetate-stimulated human neutrophils and monocytes without the addition of... | US |
The two fundamental parameters of corticotropin (ACTH) secretion are the number of secreting corticotropes and the amount of ACTH secreted by each cell. We have measured these parameters in rat corticotropes in response to increasing concentrations of corticotropin-releasing factor (CRF) or arginine vasopressin (AVP). ... | US |
Tumor necrosis factor alpha (TNF alpha), 12-O-tetradecanoylphorbol-13-acetate and cAMP stimulate hexose transport in quiescent 3T3-L1 preadipocytes by stabilizing the relatively labile mRNA coding for the basal glucose transporter, GLUT-1. The 3'-UTR of GLUT-1 mRNA contains a single copy of the destabilizing AUUUA moti... | US |
We investigated the specificity of CAAX box-related isoprenylation of rod photoreceptor cGMP phosphodiesterase (PDE) subunits expressed in bacteria and the consequences of this modification on rod disk membrane association. Full-length cDNA sequences of the alpha and beta subunits of mouse PDE, inserted into bacterial ... | US |
Cross-regulation from the stimulatory to the inhibitory adenylylcyclase pathways has been described (Hadcock, J. R., Ros, M., Watkins, D. C., and Malbon, C. C. (1990) J. Biol. Chem. 265, 14784-14790). More recently, persistent activation (48 h) of the inhibitory adenylylcyclase pathway has been shown to cross-regulate ... | US |
The massive nonselective and reversible phosphorylation of histone H1 during mitosis is a universal phenomenon among eukaryotes. The growth-associated kinase responsible for this phosphorylation is identical to the maturation promoting factor, a key regulator of the cell cycle. Here we showed that growth-associated kin... | US |
The 4-azasteroid 17 beta-(N-t-butyl)carbamoyl-4-aza-5 alpha-androst-1-en-3-one (finasteride) is 100-fold more potent as a competitive inhibitor of the rat NADPH:delta 4-3-oxosteroid-5-alpha- oxidoreductase (steroid 5 alpha-reductase) type 1 enzyme (Ki = 3-5 nM) than of the human type 1 enzyme (Ki greater than or equal ... | US |
Glycosyl phosphoinositol (GPI) anchors on proteins can be modified by palmitoylation of their inositol residue, which makes such anchors resistant to cleavage by phosphatidylinositol-specific phospholipase C (PI-PLC) (Roberts, W. L., Myher, J. J., Kuksis, A., Low, M. G., and Rosenberry, T.L. (1988) J. Biol. Chem. 263, ... | US |
Vaccinia virus DNA topoisomerase I forms a 3'-phosphoryl intermediate with duplex DNAs containing the conserved binding/cleavage motif 5'CCCTT decreases. Covalently bound enzyme is capable of transferring the incised DNA strand to a heterologous DNA acceptor containing a 5'OH terminus. Both intramolecular and intermole... | US |
Endothelins (ET) are potent vasoconstrictor peptides that also function as mitogens for numerous cell types. Although regulation of second messenger pathways by ET peptides has been extensively investigated, little is known about the pathways of nuclear signaling by which ET controls gene expression. The present experi... | US |
The relationship between the concentration of cAMP-dependent protein kinase (PKA) activity and the induction of alkaline phosphatase (AP) was examined in transfected L cell lines with altered PKA levels. C alpha 12 cells were generated by transfecting mouse L cells with an expression vector coding for the mouse C alpha... | US |
The role of epidermal growth factor (EGF) receptor autophosphorylation sites in the regulation of receptor functions has been studied using cells transfected with mutant EGF receptors. Simultaneous point mutation of 4 tyrosines (Y1068, Y1086, Y1148, Y1173) to phenylalanine, as well as removal of these sites by truncati... | US |
The osteoconductive nature of calcium phosphate ceramics (CPC) follows from several proven effects, such as a direct bone attachment and enhanced bone tissue formation. Mechanisms leading to these phenomena are still largely undiscovered. Specifically, little is known about the CPC surface and cell-driven reactions. Th... | US |
The effect of biomaterials on the superoxide-producing ability of neutrophils was studied. Human peripheral blood neutrophils were incubated with cobalt-base alloy (F-75) or polystyrene beads of a nonphagocytosable size. Respiratory burst activity was studied by measuring superoxide dismutase inhibitable reduction of c... | US |
Skin explants were placed in plastic dishes coated with fibronectin (FN), fibrinogen (FGN) or collagen. Explants were cultured for 16 h in serum-free medium containing calcium (Ca) and magnesium (Mg), or in medium containing either Ca-only, Mg-only or manganese (Mn)-only. In Ca/Mg, migrating keratinocytes on all test s... | US |
To characterize the recovery of the hypothalamic-pituitary-adrenal axis from suppression by short-term glucocorticoid treatment, we examined the responses to ovine CRH (oCRH) before and after prednisolone administration. Eight normal male volunteers were studied before (control) and after administration of 25 mg predni... | US |
With a two-step purification procedure employing sequential affinity chromatography with insulin receptor monoclonal antibody followed by wheat germ agglutinin, we isolated from the plasma of two healthy individuals a material that reacted in a specific RIA for insulin receptors. This material produced dilution curves ... | US |
Generalized resistance to thyroid hormones results from diverse mutations in the T3-binding domain of the c-erbA beta thyroid hormone receptor, and different kindreds have variable phenotypes. However, the T3-binding affinities of these mutant receptors studied in vitro have all been severely reduced compared to wild t... | US |
Mild heating of human neutrophils inactivates the respiratory burst oxidase, producing a defect in superoxide production and bacterial killing comparable to that seen in patients afflicted with chronic granulomatous disease (CGD). We have now investigated the mechanism and specificity of this inactivation by examining ... | US |
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