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Transgenic mice were produced containing the adipocyte-specific regulatory region from the adipocyte P2 (aP2) gene linked to the simian virus 40 transforming genes. Most of the transgenic mice developed brown fat tumors (hibernomas) in their interscapular brown adipose tissue. Hibernoma formation was noticeable in some... | US |
The designed peptide 1-methylimidazole-2-carboxamide netropsin (2-ImN) binds specifically to the sequence 5'-TGACT-3'. Direct evidence from NMR spectroscopy is presented that this synthetic ligand binds DNA as a 2:1 complex, which reveals that the structure is an antiparallel dimer in the minor groove of DNA. This is i... | US |
The control of gene transcription requires specific protein-protein and protein-DNA interactions. c-Myc, the protein product of the c-myc protooncogene, is a member of the basic helix-loop-helix leucine-zipper class of transcription factors. Although c-Myc is able to bind to a specific core hexanucleotide DNA sequence ... | US |
Certain class I major histocompatibility complex molecules expressed on live cells have been shown to bind exogenous peptide ligands. However, it remains controversial whether this binding occurs by peptide exchange or to empty surface class I molecules. In this report we compare the surface binding and dissociation of... | US |
Epstein-Barr virus (EBV) genomes in the P3J-HR-1 (HR-1) Burkitt lymphoma cell line rearrange at a high rate. Previously described deletions and rearrangements in HR-1 cells have been found at sites of EBV replication in vivo, suggesting that DNA rearrangement may be an integral aspect of EBV biology and pathogenesis. W... | US |
The dietary supplementation of normal guinea-pig diet with moderate levels of vegetable oils containing gamma-linolenic acid (GLA) is associated with elevation of epidermal levels of dihomo-gamma-linolenic acid (DGLA) and 15-hydroxyeicosatrienoic acid (15-lipoxygenase product of DGLA). However, supplementation of diet ... | US |
Glutamate is now recognized as a major excitatory neurotransmitter in the vertebrate CNS, participating in a number of physiological and pathological processes. The importance of glutamate in the mobilization of intracellular Ca2+ as well as the relationship between excitatory and toxic properties has made it important... | US |
The x-ray structures of a murine MHC class I molecule (H-2Kb) were determined in complex with two different viral peptides, derived from the vesicular stomatitis virus nucleoprotein (52-59), VSV-8, and the Sendai virus nucleoprotein (324-332), SEV-9. The H-2Kb complexes were refined at 2.3 A for VSV-8 and 2.5 A for SEV... | US |
Class I major histocompatibility complex (MHC) molecules interact with self and foreign peptides of diverse amino acid sequences yet exhibit distinct allele-specific selectivity for peptide binding. The structures of the peptide-binding specificity pockets (subsites) in the groove of murine H-2Kb as well as human histo... | US |
We studied the effects of intraosseous (IO) infusion of a standard fluid bolus and resuscitative drugs on long-term bone growth and epiphyseal closure in the "pediatric" swine model. Eighteen weanling pigs were randomly assigned to six groups as follows: three animals received two normal saline boluses, 20 mL/kg IO ove... | US |
The effects of acute i.v. administration of several sigma ligands on the single-unit activity of nigrostriatal and mesoaccumbal dopaminergic (DA) neurons were evaluated in chloral hydrate-anesthetized rats. DTG (1,3-di(o-tolyl)guanidine) did not alter DA neuronal activity at nontoxic doses and JO 1784 [(+)-N-cyclopropy... | US |
The type II cAMP-dependent protein kinase (PKA) is localized in certain cellular compartments through association with specific A-kinase anchoring proteins (AKAPs). A variety of blotting and electrophoresis techniques have been developed to study the protein-protein interactions that occur between the regulatory (R) su... | US |
The endogenous peptide bradykinin is found in plasma and inflammatory exudates and has been implicated as a chemical mediator of inflammatory pain and hyperalgesia. Two subtypes of bradykinin receptors, B1 and B2, have been described, and antagonists for the receptor subtypes have been synthesized. The bradykinin analo... | US |
Neuroendocrine challenge paradigms have been used to asses serotonergic systems in depression, but limitations in the specificity of many of these tests have been noted. In this study, the neuroendocrine responses to acute intravenous administration of the serotonin (5-HT) reuptake inhibitor clomipramine were assessed ... | US |
A genetic disease observed in certain Quarter horses is hyperkalaemic periodic paralysis (HYPP). This disease causes attacks of paralysis which can be induced by ingestion of potassium. Recent studies have shown that HYPP in humans is due to single base changes within the adult skeletal muscle sodium channel gene. A la... | US |
To determine the prevalence of antibodies to hepatitis C virus (anti-HCV) and HCV RNA among cadaver organ donors and to correlate these results with donor liver histologic abnormalities and evidence for transmission of disease through organ transplantation. | US |
The beta-lactamase gene from a periodontal strain of Eikenella corrodens, resistant to penicillins and streptomycin, was inserted into pBGS9 and transformed into Escherichia coli DH5 alpha. A 4.7-kb insert of pJML1, one of the transformants, was partially sequenced and found to contain the right section of transposon T... | US |
A previous study (M.J. Robinson, B.A. Martin, T.D. Gootz, P.R. McGuirk, M. Moynihan, J.A. Sutcliffe, and N. Osheroff, J. Biol. Chem. 266:14585-14592, 1991) demonstrated that novel 6,8-difluoroquinolones were potent effectors of eukaryotic topoisomerase II. To determine the contribution of the C-8 fluorine to drug poten... | US |
The nucleotide sequence of the tetracycline resistance determinant tet(M), located on conjugative transposon Tn916 of Enterococcus faecalis, was determined and found to encode a 72,486-dalton protein exhibiting a high degree of homology with other tet(M) determinants. A short open reading frame corresponding to a 28-am... | US |
A cut or crush injury to a peripheral nerve results in the degeneration of that portion of the axon isolated from the cell body. The rapid degeneration of this distal segment was for many years believed to be a process intrinsic to the nerve. It was believed that Schwann cells both phagocytosed degenerating axons and m... | United Kingdom |
Post-transfusion CMV infection most frequently results in asymptomatic seroconversion. Among immunocompetent patients only seronegative pregnant women require such products because of the risk of fetal CMV infection. In selected groups of immunocompromised patients, significant disease can occur. It is desirable to pro... | US |
A role for viruses in the etiopathogenesis of human autoimmune diseases has long been suspected but has not yet been proven. In Sjögren's syndrome (SS), there is continuing experimental support for the possible involvement of Epstein-Barr virus. Since the advent of AIDS, there is also great interest in retroviruses and... | US |
Keratinocytes immortalized by human papillomaviruses (HPV) 16 and 18 are partially resistant to the inhibition of proliferation exerted by transforming growth factor-beta (TGF-beta). To determine if this finding reflects a generalized resistance to inhibitory cytokines, we studied the effect of tumor necrosis factor-al... | US |
Rats were exposed to either 80 escapable shocks or yoked inescapable shocks and then injected with several hypnotic doses of sodium pentobarbital, midazolam, or ethanol; their sleep-time duration was compared with that of naive controls. Inescapable shock exposure resulted in a significant increase in ethanol-induced s... | US |
Peripheral gustatory mechanisms that may contribute to the expression of sodium (Na) appetite have been a focus of interest for many years. Because amiloride-sensitive Na transport is involved in the generation of neural signals in response to NaCl stimulation, the present study assessed whether changes in amiloride se... | US |
To evaluate the efficacy and otologic effects of recombinant interferon beta serine for experimental rhinovirus colds, 38 healthy adults received nasal drops of recombinant interferon beta serine, 12 x 10(6) U, or placebo three times daily for 4.3 days beginning 36 hours after infection. Illness rates and severity did ... | US |
Murine models with type C murine leukemia viruses have been used to develop major new prophylactic and therapeutic strategies in vaccination, drug therapy of acute virus exposure and chronic viremia, combination therapy, prevention of maternal transmission, and therapy targeted to the central nervous system. Transgenic... | US |
The hepatic alpha 1-adrenergic receptor mediates a variety of hepatic functions including respiration, glycogenolysis, gluconeogenesis, and growth. We have utilized a rat primary hepatocyte culture system to show that the alpha 1-adrenergic receptor can be activated in a stereoselective manner by a series of phenethyla... | US |
An expression system that utilized yeast copper metallothionein promoter and ubiquitin fusion technology to express the human estrogen receptor gene in yeast is described. We have studied the biochemical and transcriptional regulatory properties of the human estrogen receptor. The biochemical properties of the yeast ex... | US |
Several early (Phase I) and late (Phase II) estrogenic effects of 9-ene-tetrahydrocannabinol (THC) were examined in the adult mouse uterus. An injection of THC (2.5 or 10 mg/kg body wt) in ovariectomized mice neither stimulated uterine water imbibition or accumulation of [125I]bovine serum albumin (Phase I responses) a... | US |
Bombesin (BBS) exerts significant effects on the growth of a mouse colon cancer cell line (MC-26) in vitro. The presence of specific binding sites on MC-26 cells for gastrin-releasing peptide (GRP)/BBS-related peptides was recently reported by us. In the present study, we determined that the transcript size of the mRNA... | US |
Taurine, a sulfated beta-amino acid, is conditionally essential during development. A maternal supply of taurine is necessary for normal fetal growth and neurologic development, suggesting the importance of efficient placental transfer. Uptake by the brush-border membrane (BBM) in several other tissues has been shown t... | US |
We have purified and generated antisera to a 95 kDa skeletal muscle protein that constitutes the largest mass fraction of gelatin-agarose binding proteins in skeletal muscle. Preliminary results indicated that this 95 kDa chicken skeletal muscle protein bound strongly to gelatin-agarose and type IV collagen-agarose, su... | US |
We investigated the regulation of the activity of amino acid transport system L in the JAR human placental choriocarcinoma cell line by agents which are known to modulate the activities of three different classes of protein kinases, A-kinase, C-kinase and CaM-kinase. The system L activity was measured by determining th... | US |
The ideas discussed above clearly point to increasingly complex and interactive transduction mechanisms for the regulation of the neutrophil. The central challenges to be met include the following: 1. Better assays are needed for the study of physiological parameters such as adherence, aggregation, shape change, and cy... | US |
Several tritiated chlorinated dibenzo-p-dioxins and dibenzofurans have been prepared with specific activities in the range of 30-50 Ci/mmol in order to investigate the effects of structure on the kinetics of their association with the rat cytosolic Ah receptor. The compounds were 2,3,7-trichlorodibenzo-p-dioxin (TrCDD)... | US |
Recent research has shown that presentations of an unconditioned aversive stimulus, such as electric shock, can induce alterations of immune function in rats. Furthermore, it has been demonstrated that an innocuous stimulus paired with an unconditioned aversive stimulus can acquire immunomodulatory properties. Research... | US |
To discuss strategies available for the treatment of herpesvirus infections in individuals infected with HIV. | US |
1. Electrical field stimulation causes neurally-mediated relaxation of the ileocolonic sphincter that is due to activation of non-adrenergic and non-cholinergic (NANC) nerves. Recent studies have suggested that nitric oxide (NO) is the neurotransmitter that mediates relaxation. 2. Using intracellular recording techniqu... | US |
1. Prostaglandin E2 (PGE2) relaxes circular smooth muscle of the rabbit isolated jugular vein at very low concentrations (mean pIC50 against histamine-induced contraction = 9.34). This effect is not blocked by the EP1-receptor antagonist, AH 6809 (2 microM). 2. From a group of prostaglandin E analogues examined, 16,16-... | United Kingdom |
1. The purpose of the present experiments was to assess the activities of GABAB receptor antagonists in mammalian isolated melanotrophs. 2. Cytosolic free Ca concentration ([Ca2+]i) in rat melanotrophs in primary culture was monitored with the fluorescent probe, fura-2. 3. (-)-Baclofen lowered [Ca2+]i in a concentratio... | US |
1. The ability of BRL 38227 and nitrendipine to affect muscarinic agonist and histamine-stimulated [3H]-inositol phosphate accumulation in slices of bovine tracheal smooth muscle has been studied and compared with the established inhibitory effects of isoprenaline on this pathway. 2. Pre-addition of BRL 38227 (5 microM... | United Kingdom |
1. The effect of adenosine receptor-stimulation on inositol phospholipid hydrolysis and calcium mobilization has been investigated in the hamster vas deferens smooth muscle cell line DDT1 MF-2. 2. Adenosine receptor stimulation increased the accumulation of total [3H]-inositol phosphates in DDT1 MF-2 cells prelabelled ... | United Kingdom |
1. In right ventricular papillary muscles from control ferrets, flosequinan (10(-7)-10(-4) M) produced a concentration-dependent positive inotropic effect (10(-5) M = 153 +/- 24, 10(-4) M = 198 +/- 44% increase in isometric tension; control tension = 100%; n = 11) associated with a corresponding increase in amplitude o... | US |
We have shown previously that chronic treatment of mice with a benzodiazepine agonist, flurazepam, increased the pharmacological actions of the partial inverse agonist, FG7142. We have investigated the neurophysiological basis for this using extracellular recordings of evoked field potentials in area CA1 of isolated hi... | United Kingdom |
Inwardly rectifying voltage-sensitive channels have been detected in the cell bodies and axons of a number of excitable cells. The question of whether similar channels exist at axon terminals has been a matter of speculation for some time. We now report the first direct evidence for the existence of inward rectifiers i... | US |
Mouse sensory dorsal-root ganglion (DRG) neurons chronically exposed to 1 microM D-Ala2-D-Leu5-enkephalin (DADLE) for greater than 1 week in culture become tolerant to opioid inhibitory effects, i.e. shortening of the duration of the calcium-dependent component of the action potential (APD). Acute application of higher... | US |
The area postrema (AP), a chemoreceptor trigger zone for nausea and vomiting, has been implicated in taste aversion conditioning with LiCl. In addition to taste aversion acquisition, the present studies indicate that a number of other responses to LiCl administration are eliminated by lesions of the AP. These include a... | US |
Lithium is known to potentiate the ability of pilocarpine to induce status epilepticus in rats. The goal of this study was to determine whether lithium could potentiate pilocarpine-induced seizures in developing animals. Behavioral, electroencephalographic (EEG), and histopathological changes induced by systemic admini... | US |
Antidromic stimulation of small caliber trigeminal axons causes neurogenic inflammation in the dura mater and tongue as evidenced by marked increases in mast cell activation, protein extravasation, as well as in the numbers of endothelial cytoplasmic vesicles, endothelial microvilli and platelet aggregates within ipsil... | US |
Current hypotheses of structural pattern formation in the mammalian somatosensory system are modeled on experimental findings from the trigeminal system of rodents. The present results show that, like rodents, the trigeminal nucleus principalis of humans contains a parcellated pattern of cytochrome oxidase dense patche... | US |
GABAA receptors are multisubunit inhibitory chloride channels in the brain which open in response to binding of gamma-aminobutyric acid (GABA) and are thought to be involved in some forms of seizures. We compare the sequence and expression of the GABAA receptor delta subunit in audiogenic seizure prone (DBA/2J) and sei... | US |
To determine whether changes in pituitary responsiveness might account for the lack of corticotropin (ACTH) stimulation following 6 consecutive days of continuous cocaine administration (5 or 25 mg/kg/day, via osmotic minipumps), the hormonal response of vehicle- or cocaine-pretreated male rats was compared. Intravenou... | US |
The in vitro and in vivo effects of alphaxalone, a steroid anesthetic, and two physiological steroids, tetrahydrodeoxycorticosterone (THDOC) and pregnenolone sulfate (PS), on GABAA receptor function were evaluated in long-sleep (LS) and short-sleep (SS) mice. In vitro, both alphaxalone and THDOC enhanced GABAergic inhi... | US |
Kinetoplast DNA is a network of interlocked minicircles and maxicircles. In situ hybridization, using probes detected by digital fluorescence microscopy, has clarified the in vivo structure and replication mechanism of the network. The probe recognizes only nicked minicircles. Hybridization reveals prereplication kinet... | US |
Nifedipine, which is unstable at light, is photolytically converted to the corresponding 4-[2'-nitrosophenyl]-pyridine (NTP). We reported earlier that NTP react with unsaturated lipids in a pseudo Diels-Alder reaction, thus forming stable nitroxide radicals. In this paper we report that superoxide is being generated in... | US |
Previously we have detected the occurrence of retinal lipid peroxidation initiated by phagocyte-derived oxygen radicals in experimental autoimmune uveitis (EAU). In the current studies, the confirmation of inflammation-mediated lipid peroxidation was proceeded further to include measurement of multiple parameters, incl... | US |
The effects of cyclooxygenase inhibitors flurbiprofen and indomethacin on the inflammatory response and immune reactions induced by S-antigen in the rat eye were studied. The treatment with flurbiprofen and indomethacin administered subcutaneously every 12 hours, commenced on the day of S-antigen injection and was cont... | US |
KDR (kinase insert domain receptor), a new type III receptor tyrosine kinase gene, maps to human chromosome 4q31.2----q32 by fluorescence in situ hybridization. This differs from the chromosomal locations of other members of this gene family. | US |
The present study was undertaken to determine whether dimethylthiourea (DMTU), a hydroxyl radical scavenger, could prevent gastric injury in the rat stomach induced by various noxious agents. Fasted rats (N = 6-8/group) were given a 1-ml oral bolus of saline or DMTU over the dose range 10-500 mg/kg. After 30 min, anima... | US |
The purpose of this study was to determine whether normal morphological development occurs in pituitary corticotrophs deprived of products of the hypothalamic paraventricular nucleus (PVN), e.g. corticotropin releasing hormone and arginine vasopressin (AVP), after PVN lesions. In addition, we have attempted to ascertai... | US |
We have examined the effects of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] on the phosphoinositol signal transduction pathway in the human colon cancer-derived cell line CaCo-2 and have studied the regulation of intracellular calcium ([Ca2+]i) and pH (pHi) by this secosteroid. CaCo-2 cells were prelabeled with [3H]myoinos... | US |
Studies were performed to compare the effects of 5 alpha-reductase inhibition and antiandrogen receptor blockade on differentiation of male internal and external genital structures and prostate in the rat. Dose-response studies were performed on male rats treated in utero during the period of sexual differentiation wit... | US |
Vasoactive intestinal peptide (VIP) is a widely distributed neuropeptide that has been considered a potential regulator of cell growth and differentiation in various tissues, including the gut. To examine this idea, we used a human colon carcinoma cell line (LoVo) as a model system and measured ornithine decarboxylase ... | US |
Specific thyroid hormone (T3) receptors are present in thyroid follicular cells, including the rat FRTL5 clonal line, but little is known about the effects of T3 on the growth and differentiated function of the thyroid. Unlike primary cultures of animal or human thyroid cells, FRTL5 do not secrete appreciable amounts o... | US |
Our previous studies implicated the involvement of protein kinase-A in the inhibitory effects of isoproterenol and relaxin on oxytocin-stimulated phosphoinositide turnover in rat myometrium. To understand the possible mechanisms involved, the properties and regulation of phospholipase-C (PLC) in purified myometrial pla... | US |
PTH stimulates mammalian renal proximal tubule cell synthesis and secretion of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] by a Ca-dependent process. In the present study regulation of 1,25-(OH)2D3 secretion by PTH, phorbol ester 12-O-tetradecanoylphorbol 13-acetate, the Ca ionophore A23187, and calcitonin was evaluated in... | US |
Calcitonin (CT) activates both the cAMP and the protein kinase C (PKC) pathways in the kidney cell line LLC-PK1. Although CT also activates cAMP in osteoclasts, its effects on PKC in this cell type are unknown. In order to determine whether the response of osteoclasts to CT also involves the PKC pathway, the effects of... | US |
Rat epididymal retinoic acid-binding protein (EP-RABP) has been purified to apparent homogeneity from extracts of the epididymis by HPLC. N-Terminal amino acid sequence analysis revealed that the HPLC-purified protein consisted of two molecular variants, in that one has three extra N-terminal amino acids of NH2-TEG. Th... | US |
The genomes of the four primate lentiviral groups are complex and contain several regulatory or accessory genes. Two of these genes, vpr and vpx, are found in various combinations within the four groups and encode proteins whose functions have yet to be elucidated. Comparison of the encoded protein sequences suggests t... | United Kingdom |
It has previously been shown that the mitochondrial DNA (mtDNA) of Saccharomyces cerevisiae becomes thermosensitive due to the inactivation of the mitochondrial DNA helicase gene, PIF1. A suppressor of this thermosensitive phenotype was isolated from a wild-type plasmid library by transforming a pif1 null strain to gro... | US |
We have purified the transposase of IS903 in three different ways. We find that transposase expressed as a fusion protein with either glutathione-S-transferase or maltose-binding protein is soluble and can be purified rapidly using affinity chromatography. The third purification requires extracting the native transposa... | US |
Marrow stromal fibroblasts (FBs) likely play an important role in the regulation of hematopoiesis within the marrow microenvironment. Infection of these cells by feline leukemia virus (FeLV) might not only contribute to the pathogenesis of FeLV-induced hematologic diseases, but could provide a reservoir for virus in th... | US |
Zymosan, which is composed primarily of alpha-mannan and beta-glucan polymers, is a well recognized activator of macrophages. The type receptor by which unopsonized zymosan induces arachidonic acid release was investigated. It was found that particulate beta-glucan and zymosan stimulated an identical dose-dependent rel... | US |
The electron paramagnetic resonance (EPR) and near-infrared magnetic circular dichroism (MCD) spectra of the azide and cyanide adducts of nitrimyoglobin and hydroperoxidase II from Escherichia coli have been measured at cryogenic temperatures. For the first time, ligand-to-metal charge-transfer transitions in the near-... | US |
Mutant aminoglycoside 3'-phosphotransferase II enzymes were produced in which Tyr218 was changed to serine, aspartic acid, or phenylalanine. In each case the mutation resulted in increased bacterial susceptibility to neomycin and kanamycin, while simultaneously increasing the Km values for these substrates. For the Ser... | US |
Ethanol reportedly is immunosuppressive, interfering with lymphocyte proliferation. To investigate the basis for this immunosuppression, the effects of acute treatment with ethanol were studied on Ca2+ mobilization in tonsillar B lymphocytes and the human lymphoblastoid B-cell line, Ramos. The level of intracellular Ca... | US |
We used the osteogenic sarcoma cell line, UMR-106-01, to determine whether the rise in free cytosolic Ca2+ concentration ([Ca2+]i) and cellular cAMP following PTH stimulation are able to be regulated independently. For this purpose, we compared the effect of a PTH antagonist, stimulation of protein kinase C, augmentati... | US |
Autophagic vacuoles (AVs) arise when membranes of the ER sequester parts of the cytoplasm, forming a new, double-membraned vacuole, to which lysosomal enzymes are then delivered. To investigate the mechanism of lysosomal enzyme delivery to nascent AVs, amino acid (AA) starvation and glucagon treatment were used to indu... | US |
Regional CBF was measured with the 133Xe inhalation technique before and thrice after smoking marijuana of two strengths and placebo in 20 physically and mentally healthy male volunteers with a previous history of exposure to marijuana. They were drug-free at the time of the study. Blood pressure, pulse rate, end-tidal... | US |
Changes in intra- and extracellular [Ca2+] and [H+], together with alterations in tissue PO2 and local blood flow, were measured in areas CA1 and CA3 of the hippocampus during recovery (up to 8 h) after an 8-min period of low-flow ischemia. Restoration of blood supply was followed by an immediate rise in flow and tissu... | US |
Previous studies utilizing crude brain homogenates have shown that forebrain ischemia results in inhibition of calcium/calmodulin-dependent protein kinase II (CaM kinase II) activity without large-scale proteolysis of the enzyme. In this report, a monoclonal antibody (1C3-3D6) directed against the beta- (60-kDa) subuni... | US |
The three approved nucleoside analogues are fairly well tolerated, and only a few patients have to discontinue therapy permanently. However, because clinical experience is limited, especially with ddI and ddC, delayed toxicities are likely to emerge over time. In addition, physicians should be vigilant for overlapping ... | US |
T cell hybridomas respond to conventional peptide Ag associated with self major histocompatibility restriction elements, as well as to alloantigens, activating lectins, and stimulatory forms of mAb by producing lymphokines and undergoing programmed cell death (PCD). We show here that the level of PCD and IL-2 productio... | US |
C57BL/6 mice, after immunization and secondary in vitro restimulation with AKR/Gross murine leukemia virus (MuLV)-induced tumors, generate AKR/Gross MuLV-specific CTL. After similar immunization protocols, AKR-H-2b mice fail to generate CTL specific for AKR/Gross MuLV. The basis for nonresponsiveness in AKR.H-2b mice i... | US |
Bovine, non-pigmented, ciliary body epithelial cells were isolated and grown in culture to determine whether timolol maleate might affect the activity of their plasma membrane ATPases. The possible effects were tested in drug concentrations in a range of 5 x 10(-19) to 5 x 10(-5) M over an incubation period of 30 min a... | US |
Different macrophage preparations were compared for functional capacity in conditions of high prostaglandin E2 (PGE2) or low L-arginine concentrations. Macrophages derived in vitro from bone marrow progenitor cells (bone marrow-derived macrophages, BMDMs) using colony-stimulating factor 1 (CSF-1) as the myelopoietic st... | US |
The conformational preferences of the kappa-selective opioid agonist U50488 have been studied using MM2-87 calculations and nuclear magnetic resonance (NMR) spectroscopy. The calculations were performed for the protonated form with a dielectric constant of 80 and the unprotonated form with dielectric constants of 1.5 a... | US |
Surprisingly, both of the synthetic 1-(hydroxymethyl)-25-hydroxyvitamin D3 diastereomers (-)-2 and (+)-3 retained the antiproliferative activity of natural calcitriol in murine keratinocytes. Preliminary studies indicated, however, that both of these synthetic diastereomers were less than 0.1% as effective as calcitrio... | US |
The mechanism of the Cre recombinase of bacteriophage P1 in Escherichia coli cells was analyzed by topological methods in order to determine the important features of the in vivo reaction. Lambda infection was used to introduce the cre gene into cells containing plasmid substrates. The products of Cre resolution on sub... | US |
A strain of Vibrio cholerae, which had been engineered to express high levels of the non-toxic B subunit (EtxB) of Escherichia coli heat-labile enterotoxin, was subjected to transposon (TnphoA) mutagenesis. Two chromosomal TnphoA insertion mutations of the strain were isolated that showed a severe defect in the amount ... | United Kingdom |
Transcriptional cascades that specify cell fate have been well described in invertebrates. In mammalian development, however, gene hierarchies involved in determination of cell lineage are not understood. With the recent cloning of the MyoD family of myogenic regulatory factors, a model system has become available with... | US |
The hepatocyte nuclear factor 3 (HNF-3) gene family is composed of three proteins (alpha, beta, and gamma) that are transcription factors involved in the coordinate expression of several liver genes. All three proteins share strong homology in their DNA binding domains (region I) and are able to recognize the same DNA ... | US |
The complex and diverse biological effects of retinoic acid (RA) are mediated through specific receptors that are members of the steroid hormone family of nuclear transcription factors. The RA receptor family consists of multiple structurally distinct RA receptors, which diverge primarily at the NH2-terminal domain. Th... | US |
rad5 (rev2) mutants of Saccharomyces cerevisiae are sensitive to UV light and other DNA-damaging agents, and RAD5 is in the RAD6 epistasis group of DNA repair genes. To unambiguously define the function of RAD5, we have cloned the RAD5 gene, determined the effects of the rad5 deletion mutation on DNA repair, DNA damage... | US |
Dicentric chromosomes are genetically unstable and depress the rate of cell division in Saccharomyces cerevisiae. We have characterized the effects of a conditionally dicentric chromosome on the cell division cycle by using microscopy, flow cytometry, and an assay for histone H1 kinase activity. Activating the dicentri... | US |
BALB/c3T3 cells are exquisitely growth regulated and require platelet-derived growth factor, epidermal growth factor (EGF), and insulinlike growth factor 1 (IGF-1) for growth. When BALB/c3T3 cells are transfected with plasmids constitutively expressing both EGF and the human IGF-1 receptor mRNAs, the cells are capable ... | US |
Eight terminally deleted Drosophila melanogaster chromosomes have now been found to be "healed." In each case, the healed chromosome end had acquired sequence from the HeT DNA family, a complex family of repeated sequences found only in telomeric and pericentric heterochromatin. The sequences were apparently added by t... | US |
Mutations in the Saccharomyces cerevisiae alpha-factor receptor that lead to improved response to Saccharomyces kluyveri alpha-factor were identified and sequenced. Mutants were isolated from cells bearing randomly mutagenized receptor gene (STE2) plasmids by an in vivo screen. Five mutations lead to substitutions in h... | US |
Tunicamycin (TM)-resistant Leishmania amazonensis has been found previously to contain amplified chromosomal DNA, existing exclusively as extrachromosomal circles of 63 kb. Fragments of this DNA cloned into plasmids were functionally analyzed by transfection of wild-type cells. A clone with a 15-kb fragment of the 63-k... | US |
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