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This study was designed to determine the role of dietary organic and inorganic sulfur on 3'-phosphoadenosine 5'-phosphosulfate (PAPS) homeostasis. Organic sulfur was altered by adding various amounts of methionine (0.15, 0.3, 0.6, or 1.2%) to a sulfhydryl-deficient diet. Inorganic sulfur was altered by providing rats w... | US |
Debrisoquin undergoes oxidative metabolism to 4-hydroxydebrisoquin, catalyzed by cytochrome CYP2D1 in rats and CYP2D6 in humans. Cytochrome CYP2D6 also plays a major role in dextromethorphan O-demethylation. In preliminary studies in perfused Lewis rat livers, we observed a difference in repeat clearance experiments us... | US |
Obese human patients and obese overfed rats treated chronically with gentamicin suffer greater renal injury than nonobese patients and control animals. To understand the mechanism of this heightened susceptibility to the nephrotoxic effects of gentamicin, this study examines the plasma-time course and renal uptake of g... | US |
This study was conducted to determine if soluble CD4 (ST4) altered the pharmacokinetics of 2',3'-dideoxycytidine (ddC) in nonhuman primates. Each of six monkeys received 5 mg/kg of ddC iv in the absence and presence of two different iv regimens of ST4. The ST4 regimens produced steady-state plasma concentrations of 10.... | US |
Sulfation is a major pathway in humans for the biotransformation of estrogens. However, the nature of the enzymes that catalyze the sulfation of estrone (E1) and 17 beta-estradiol (E2) in human liver is unclear. Human liver contains at least three well-characterized cytoplasmic sulfotransferases, the thermostable (TS) ... | US |
The effect of dose on the dermal absorption of 2- and 4-chloronitrobenzene (2- and 4-CNB) has been investigated in rats following nonocclusive protective dermal application on an area of 4 cm2 per animal at approximately 0.0325, 0.325, and 3.25 mg/cm2 (0.65, 6.5, and 65 mg/kg, respectively). At the three-dose levels, 3... | US |
Amphotericin B (Am-B), an antifungal drug, has been used for the treatment of most disseminated fungal infections. The current therapeutic regimens for this drug are complex, at least in part as a result of limited pharmacokinetic information. In this study, we examined the disposition of Am-B as a function of dose in ... | US |
Receptor binding assays using [3H]DAGO ([D-Ala2,MePhe4-Gly5-ol]enkephalin) (mu), [3H]DPDPE ([D-Pen2,D-Pen5]enkephalin) (delta) and [3H]U-69593 (kappa) were done in guinea pig whole brain membranes. Agonist activity was determined in norbinaltorphimine or beta-funaltrexamine (beta-FNA) treated guinea pig ileum (mu and k... | US |
In order to investigate adhesive interactions between photoreceptor and pigment epithelial cells, we have mechanically separated neural retinas from Xenopus laevis eyecups and then recombined the tissues in vitro. When tissue pairs are incubated in a defined medium, cell-cell contact is achieved within 3 hr. However, t... | US |
Recognition of tardive dyskinesia (TD) and other neuroleptic, drug-induced, extrapyramidal side effects presents a major challenge in modern clinical psychopharmacology. Failure to recognize these disorders can lead to poor patient care and may contribute to societal pressure for external control of psychiatric practic... | US |
Two new human cholangiocarcinoma (CC) cell lines (CC-SW-I and CC-LP-I) were established and maintained in culture for 2 years. Histologically, both original liver tumors were adenocarcinomas, and the cell lines exhibited morphologic features of moderately differentiated adenocarcinoma. Immunohistochemistry showed that ... | US |
The World Health Organization recommends the use of fixed reference periods for quantification of the incidence and severity of vaginal bleeding when patients use various forms of contraception. Ninety- and 110-day reference periods were used in the analysis of data from daily menstrual diaries kept by 72 healthy women... | US |
We describe the characterization of two genes, fimF and fimG (also called pilD), that encode two minor components of type 1 pili in Escherichia coli. Defined, in-frame deletion mutations were generated in vitro in each of these two genes. A double mutation that had deletions identical to both single lesions was also co... | US |
Delineation of apical and basolateral membrane domains is a critical step in the epithelialization of the outer layer of cells in the embryo. We have examined the initiation of polarized membrane traffic in Xenopus and show that membrane traffic is not polarized in oocytes but polarized membrane domains appear at first... | US |
Generalized mutilating recessive dystrophic epidermolysis bullosa (RDEB) is characterized by extreme skin fragility owing to loss of dermal-epidermal adherence. Immunohistochemical studies have implicated type VII collagen, the major component of anchoring fibrils, in the etiology of RDEB. In this study, we demonstrate... | US |
Bacteria can bind specifically to phagocytic cells via lectin-carbohydrate interactions and such binding is often followed by activation and degranulation of the phagocytes, as well as uptake and killing of the bacteria, a phenomenon designated lectinophagocytosis. Although extensively studied in vitro, no direct evide... | US |
1. Excitatory inputs to amacrine cells in the salamander retinal slice preparation were examined using whole-cell patch pipette voltage-clamp techniques. In strychnine (500 nM) and bicuculline (100 microM), two types of amacrine cell were easily distinguished by their light-evoked excitatory responses: transient and su... | US |
There are numerous reports of oral lesions in HIV-infected individuals. However, few correlate the oral lesions with laboratory parameters. This study examined oral candidiasis and hairy leukoplakia, the two most common HIV-associated oral lesions, in relation to T-cell counts, p24 core antigen levels and salivary flow... | US |
The present study was conducted to investigate the presence of expression products of c-erbB-1 and c-erbB-2/HER2 genes on mammalian sperm cell, and study the effects of their antibodies on fertilization. The mature sperm cells from various mammalian species (human, mouse, rabbit and rat) were found to have EGF-receptor... | US |
Oral vaccines offer great promise as public-health measures to prevent disease in less-developed countries. CVD 103-HgR, a genetically engineered, attenuated, Vibrio cholerae O1 strain has proved effective in industrialised countries. We have assessed the safety, immunogenicity, and excretion of this live cholera vacci... | US |
To investigate the pathophysiological process of transient ischaemic events in a clinically relevant model, we produced transient focal cerebral ischaemia in five baboons using endogenously generated platelet microemboli. Thrombogenic segments of Dacron vascular graft were incorporated as unilateral carotid arterio-art... | US |
We have examined the morphology of neurons in layer 1 by injecting them intracellularly with lucifer yellow in lightly fixed brain slices (250 microns thick) taken from the medial bank of area 17 in adult cats. Of 22 neurons with well-filled dendrites, 16 had smooth dendrites, two had sparsely spiny dendrites (less tha... | United Kingdom |
Heterologous radioimmunoassays (RIAs) for the mammalian prodynorphin end products, alpha-neo-endorphin, dynorphin A(1-17), dynorphin A(1-8), and dynorphin B(1-13) were used to screen brain extracts obtained from representatives of the major surviving orders of reptiles: Chelonia (Pseudemys scripta), Squamata (Anolis ca... | US |
This study examined contractile responses of the in vitro rabbit whole-bladder preparation to field stimulation, bethanechol and KCl in Tyrode's solution and minimum essential medium (MEM). We found frequency-dependent increases in intravesical pressure in bladders incubated in Tyrode's solution and MEM. However, bladd... | US |
The behavioral responsiveness to challenge doses of the D2 agonist quinpirole was examined in 21-day-old normal offspring (experiment 1) as well as offspring exposed gestationally to cocaine (experiment 2). In both experiments weanling rats received a subcutaneous injection of 0 (0.9% saline), 0.04, 0.08, 0.5, or 1.0 m... | US |
Buspirone and gepirone were evaluated as potential pharmacotherapies for cocaine abuse by studying the effects of acute and repeated treatment on IV cocaine self-administration in rhesus monkeys. Chlorpromazine was also evaluated as a positive control. Effects of IV drug pretreatments were tested during daily 60-min se... | US |
The effects of oral administration of the alpha 2 adrenergic receptor antagonists idazoxan (20 mg, 40 mg, 80 mg) and yohimbine (20 mg) were compared using a placebo-controlled within-subjects design. Healthy subjects completed 5 test days during which medication effects on mood and anxiety states, physiologic indices, ... | US |
After a single dose of the butyrophenone neuroleptic haloperidol, behavioral effects and detectable drug levels in rat brain can last for several weeks. To determine if such persistence is a general property of neuroleptics, we compared drug levels and effects after IP administration of two butyrophenones (haloperidol ... | US |
In the present study the relationship between changes in tyrosine aminotransferase (TAT) enzyme activity, cytoplasmic mRNA levels, and gene transcription in response to both short- and long-term exposure to insulin was investigated. Insulin acutely inhibited transcription of the TAT gene by 50% in serum-deprived rat H4... | US |
This paper reports the results of a series of laboratory experiments to determine the infectivity and pathogenesis of iridescent virus type 22 (IV 22) for six species of mosquitoes, phlebotomine sand flies and triatomid bugs. Following inoculation, IV 22 replicated in all of the species tested, without producing notice... | US |
The effects of acute subcutaneous injections of methylenedioxy-substituted phenylalkylamines in rats were tested in an unconditioned motor behavior paradigm using the Behavioral Pattern Monitor (BPM). Based on a previously developed scaling hypothesis and the associated temporal and spatial scaling exponents (alpha and... | US |
The steady-state flow of fluid across the wall of the isolated rabbit common carotid artery has been measured in the presence and absence of flow within the lumen of the vessel. The perfusate solution contained either 10 or 40 mg ml-1 albumin and transmural flux was measured by monitoring the rate of movement of fluid ... | US |
Genes containing a homeobox can be divided into classes based on the distinctive peptide sequences of their diverged homeodomains. Many of these classes, including Antennapedia, engrailed and paired, are strongly conserved in higher multicellular animals, but have not previously been found in platyhelminths, the flatwo... | US |
Two members of the murine labial (lab) subfamily of Antennapedia-like homeobox-containing genes, Hox-1.6 and Hox-2.9, have been identified previously. Here we describe a third member genetically linked to the Hox-4 cluster on chromosome 2. This gene, designated Hox-4.9, is similar in structure to the other lab subfamil... | US |
The feasibility of using a trans-dominant interfering human immunodeficiency virus type 1 (HIV-1) envelope mutant for inducible gene therapy of HIV infection was investigated. Genes encoding wild-type or mutant glycoproteins were introduced into CD4+ cells, where they were stably maintained but not expressed until indu... | US |
The postural stability of four adult populations was examined through force platform methods. The four groups were classified as: (1) developmentally disabled (severely and profoundly mentally retarded) with tardive dyskinesia; (2) developmentally disabled but with no history of neuroleptic medication; (3) tardive dysk... | US |
Feline hyperthyroidism bears a strong clinical and pathologic resemblance to toxic nodular goiter in humans. To evaluate whether the observed thyroid growth might be due to circulating thyroid antibodies, as has been postulated in humans, we studied the effect of purified immunoglobulin (Ig) G preparations on a rat thy... | US |
Autoimmune thyroid disease is a generic term that includes Graves' disease and Hashimoto's thyroiditis. In the former, there is overactivity of the thyroid due to the action of a thyroid-stimulating antibody (TSAb). Pathogenesis of Hashimoto's thyroiditis is largely cell-mediated immune destruction of the thyroid. None... | US |
Calretinin and calbindin-D28k are two calcium-binding proteins which are present in separate populations of interneurons in cerebral cortex and hippocampus. To identify these cells with the populations expressing different transmitters, two-colour immunofluorescence was done with antibodies against the calcium-binding ... | United Kingdom |
The concentration of somatostatin-like immunoreactivity (SS-LI) was determined by radioimmunoassay in neocortical tissue resected from 20 patients with pharmacologically intractable complex partial seizures. Most resections included either the anterior temporal pole neocortex (15 cases) or cingulate gyrus neocortex (3 ... | US |
We recorded extracellular responses from rat amygdaloid neurons in vivo after electrical stimulation of the basal forebrain and hippocampal formation. Iontophoretic application of the GABAA receptor antagonist, bicuculline, lead to the appearance of short latency evoked bursts after stimulation of either region. This o... | US |
Many dopaminergic cells of the substantia nigra are known to contain the calcium-binding proteins calretinin and calbindin-D28k. Catecholaminergic cell groups throughout the rat brain were therefore examined by two-colour immunofluorescence to determine whether they too contained these calcium-binding proteins as well ... | United Kingdom |
The effect on food intake of adrenergic agonists administered into the third cerebral ventricle was studied in Zucker fatty and lean rats. The alpha 2 agonist, clonidine, produced a larger dose-related increase in food intake in lean rats than in the fatty rats. Dose-response curves show similar sensitivity, but decrea... | US |
The effects of administration of antibodies against dynorphin1-17 (DYN1-17-AB) and dynorphin1-8 (DYN1-8-AB) were examined on the activity of dopaminergic (DA) neurons comprising the nigrostriatal, mesolimbic, tuberoinfundibular and periventricular-hypophysial systems in the male rat brain. DA neuronal activity was esti... | US |
Benzodiazepines (BZ) and steroid hormone derivatives can potentiate the inhibitory actions of GABA through interactions with the GABAA/BZ/chloride ionophore complex. The present study examines whether the in vivo hormone milieu of rats modulates GABA/BZ receptors and/or benzodiazepine responses. The influences of gende... | US |
The present experiments examined glutamate-dopamine interactions within the nucleus accumbens in rats. It has been hypothesized that dopaminergic nerve terminals exert a modulatory influence on glutamate-mediated signals from corticolimbic areas. In the present studies, the effect of the selective NMDA (n-methyl-d-aspa... | US |
Gene amplification occurs at high frequency in transformed cells (10(-3)-10(-5)), but is undetectable in normal diploid fibroblasts (less than 10(-9)). This study examines whether alterations of one or both p53 alleles were sufficient to allow gene amplification to occur. Cells retaining one wild-type p53 allele mimick... | US |
Lymphoid cells from scid mice initiate V(D)J recombination normally but have a severely reduced ability to join coding segments. Thymocytes from scid mice contain broken DNA molecules at the TCR delta locus that have coding ends, as well as molecules with signal ends, whereas in normal mice we previously detected only ... | US |
Evaluation of the outcome of successful bone marrow transplantation and indepth studies of transplantation biology rely increasingly upon detection and enumeration of donor hemopoietic cells in the transplanted recipients. The ability to detect and enumerate low levels of donor engraftment in interphase cell subpopulat... | US |
Dendritic cells (DC) isolated from various lymph node (LN) groups of pre-diabetic non-obese diabetic (NOD) (4-20 weeks of age) and age-sex-matched control mice were analysed for their surface antigen phenotype and their ability to cluster lymphocytes. The draining LN of the pancreas (PLN) of 8-week-old NOD mice with ac... | US |
Transcription of the ornithine decarboxylase (ODC) gene is rapidly elevated by activation of protein kinase A (PKA). The additive influence of three cis-acting elements is responsible for this regulation in an adrenal carcinoma cell line. Two sites, CRE2 at -48 base pairs (bp) relative to the start of transcription and... | US |
The goal of this study was to develop an alternative to silver intensification for visualizing small colloidal gold particles by light and electron microscopy. The isolated goldfish retina was labeled with rabbit antiserum to tyrosine hydroxylase and 1-nm colloidal gold-conjugated goat anti-rabbit IgG. The gold particl... | US |
Taxol, a microtubule stabilizing agent, exhibits promise in the treatment of breast and ovarian tumors. Recently, this novel drug has been shown to activate murine macrophages to express TNF-alpha and to down-regulate TNF-alpha receptors, activities shared by bacterial LPS. Our study sought to determine if taxol could ... | US |
We evaluated the effect of H-ras oncogene expression on resistance to ionizing radiation in cultured rat fibroblasts. The Rat-1 cell line, and two Rat-1 derivatives, MR4 and MR7, carrying a ZN-regulatable metallothionein-rasT24 fusion gene were used to study the effects of the ras oncogene on radiation sensitivity. Cel... | US |
Postirradiation cellular recovery kinetics for delayed plating, araA, hypertonic saline (HS) treatments and their combinations, were analysed in the framework of the previously developed dsb model (Ostashevsky 1989). Two possible types of DNA double-strand break (dsb) repair kinetics were considered: cooperative, where... | US |
Antipsychotic drugs are known to block dopamine receptors soon after their administration, resulting in an increase in dopamine neuron firing and dopamine turnover. Nonetheless, antipsychotic drugs must be administered repeatedly to schizophrenics before therapeutic benefits are produced. Recordings from dopamine neuro... | US |
Coronal brain slices from 21-50-d-old hooded rats were used to characterize intracellular responses of cells in both the external and dorsal cortices of the inferior colliculus (IC). These cells could generate both sodium and calcium spikes. Depending on current amplitude, depolarizing current pulses could elicit eithe... | US |
The mechanisms associated with the neurotoxic responses caused by prolonged exposure (48 hr) to norepinephrine (NE) were examined in cultures of brain stem of 18-day-old rat fetuses. Two separate components of NE neurotoxicity were identified and differentiated according to dose dependency, sensitivity to catalase and ... | US |
Biliary excretion of glutathione disulfide (GSSG) is used as an index of oxidative stress. Analysis of endogenous thiols and disulfides in rat bile by reverse phase high performance liquid chromatography with electrochemical detection revealed an unknown disulfide which eluted immediately after GSSG. This disulfide was... | US |
The effect of chlorethylclonidine (CEC) on arterial blood pressure and heart rate (HR) has been evaluated in the conscious rat. CEC injection (25 mg/kg i.p.) caused a statistically significant decrease in mean arterial blood pressure (MAP) that was seen 24 hr after treatment. CEC also induced a decrease in HR that was ... | US |
The primary pathophysiologic finding of the viral disease known as Korean hemorrhagic fever, the etiological agent of which is Hantaan virus (HTV), is vascular instability. To investigate whether HTV was able to infect cells derived from human vascular tissue and alter their behavior, we infected in vitro primary adult... | US |
The scrapie prion protein (PrPSc) is derived from a cellular isoform (PrPC) that acquires protease resistance posttranslationally. We have used several different experimental approaches in attempts to reconstitute in vitro the processes leading to protease-resistant PrPSc molecules. In the first study, we performed mix... | US |
Wild-type p53 has recently been shown to repress transcription from several cellular and viral promoters. Since p53 mutations are the most frequently reported genetic defects in human cancers, it becomes important to study the effects of mutations of p53 on promoter functions. We, therefore, have studied the effects of... | US |
Maple syrup urine disease (MSUD) is an autosomal recessive inherited disease due to a deficiency of any of the subunits, E1 alpha, E1 beta or E2, of the branched-chain alpha-ketoacid dehydrogenase complex (BCKDH). A large Mennonite kindred of MSUD has been studied in Pennsylvania, USA. In the present investigation, gen... | US |
The mechanisms underlying the accelerated hepatic consumption of glutamine that occurs during endotoxemia were investigated in rats 12 hr after treatment with Escherichia coli lipopolysaccharide. Hepatic glutamine delivery and consumption were calculated from measurements of hepatic blood flow and blood glutamine level... | US |
These experiments combined electrophysiological recordings from hippocampal slices with application of drugs to and sampling of extracellular fluid from a restricted region of the slice using a push-pull cannula placed under the slice in an interface chamber. Stable and apparently normal extracellular and intracellular... | United Kingdom |
Monoclonal antibodies that target T cells have shown some benefit in rheumatoid arthritis although responses have not been long lasting. This is partly due to insufficient therapy consequent upon antibody immunogenicity. Use of humanised antibodies, which are expected to be less foreign to man than conventional rodent ... | United Kingdom |
Pulmonary capillaries have extremely thin walls to allow rapid exchange of respiratory gases across them. Recently it has been shown that the wall stresses become very large when the capillary pressure is raised, and in anaesthetised rabbits, ultrastructural damage to the walls is seen at pressures of 40 mm Hg and abov... | US |
The introduction of exogenous glutamate to normally respiring hippocampal slices produced substantial reductions in ATP, phosphocreatine (PCr) and intracellular pH (pHi) when the concentration exceeded 1 mM. These changes were not prevented by addition of MK-801 (an NMDA receptor antagonist), nor were they mimicked by ... | US |
Norepinephrine (NE) content, release and uptake by brain synaptosomes are reduced in chronic renal failure (CRF), and this has been attributed to the state of secondary hyperparathyroidism. The decrease in NE content in CRF could not be explained by changes in NE uptake or release since in normal circumstances, NE cont... | US |
The effects of microinfusing L-glutamate, serotonin (5-HT), (+-)-8-hydroxy-2-(di-N-propylamino) tetralin (8-OH DPAT; a 5-HT1A agonist), and muscimol (a GABAA agonist) into the dorsal raphe nucleus on the extracellular levels of 5-HT, dopamine (DA) and their metabolites in the nucleus accumbens were studied in unanesthe... | US |
Previous reports have shown that among the markers for the nigro-striatal dopamine (DA) system measured in the striatum, dopamine uptake seems to be more severely affected than the others in the weaver mutant mouse. In the present study we examined DA levels, tyrosine hydroxylase (TH) activity, and high-affinity DA upt... | US |
Neurotransmitter turnover of biogenic monoamines (dopamine, norepinephrine, and serotonin) and amino acids (glutamate, aspartate, and gamma-aminobutyric acid) was evaluated in rats exposed to the conditioned emotional response (CER) paradigm in the absence (total suppression) or presence of acute 5 mg/kg i.p. diazepam ... | US |
Irreversible inactivation of striatal D2 dopamine (DA) autoreceptors with N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) or inactivation of striatal guanine nucleotide binding proteins (G proteins) with pertussis toxin (PT) shifted the dose-response curve for N-n-propylnorapomorphine (NPA)-mediated inhibition of... | US |
The possibility that mu-opioid-induced tachycardia and bradycardia could be mediated by different subtypes of the mu-receptor was studied in conscious Sprague-Dawley rats. The selective mu-receptor agonist dermorphin and its analog, TAPS (Tyr-D-Arg-Phe-sarcosine), a putative mu 1-receptor agonist, were given centrally.... | US |
Treatment of ovariectomized rats with both estradiol and progesterone in vivo resulted in a marked enhancement of glutamate-induced release of newly synthesized [3H]gamma-aminobutyric acid (GABA) from synaptosomes of the preoptic area in vitro. With this treatment, as little as 0.01 nM glutamate, in vitro, enhanced rel... | US |
Quantitative receptor autoradiography was used to map the distribution of N-methyl-D-aspartate (NMDA) receptors in the developing rat spinal cord. Three different specific ligands, which label partially overlapping subpopulations of NMDA receptors, were used: an agonist (L-[3H]glutamate), a noncompetitive antagonist ([... | US |
We modified a previously published PCR-RFLP for DQA1 typing (1) and examined the predictive value of HLA-DQA1 in mixed lymphocyte cultures (MLC) among matched (HLA generic types) pairs of unrelated individuals. There were 61/102 (60%) pairs with positive MLC, one-third of which could be predicted by DQA1* typing alone.... | US |
We have used a PCR-RFLP method with one generic amplification of HLA-DPB1 second exon and 6 endonucleases to differentiate the 19 HLA-DPB1 alleles and 171 heterozygous combinations. The set of primers used in our studies produced fragment sizes different from those published before (1). The HLA-DPB1 alleles in Caucasia... | US |
The strains of Epstein-Barr virus (EBV) were characterized in epithelial and lymphoid malignancies from geographic regions with high or low incidence. The predominant strains in nasopharyngeal carcinoma (NPC) from regions with elevated incidence were EBV type 1 in southeast Asia and Mediterranean Africa. In Alaskan Esk... | US |
We previously isolated an avian erythroblastosis virus, AEV-GEE35, in which the complete extracellular and transmembrane domains of the v-erbB oncoprotein were replaced with sequences from the gag and env proteins. The GEE35 virus was capable of transforming both fibroblasts and erythroblasts as efficiently as wild-typ... | US |
Neuroblastomas are heterogeneous in terms of both their genotype and their clinical behavior. Recent studies suggest that these two features are related, and that the genotype frequently is predictive of response to treatment or the outcome of the patient. The genetic abnormalities that are characteristic of certain ne... | US |
The allelic association of the human dopamine D2 receptor gene and alcoholism was evaluated in 20 male alcoholics and 20 controls (sex, race, and geographic place of birth matched). This study further examines the issue of alcoholism severity and A1 allele frequency. No difference in A1 allele frequency was observed be... | US |
This study used transient transfection analysis to determine the DNA regions which mediate basal and insulin-sensitive transcription from the gene encoding tyrosine aminotransferase (TAT; EC 2.6.1.5). Basal expression requires at least parts of two regions: a region at -3600 and a region from -208 to + 62. Insulin sens... | US |
The overexpression of P-glycoprotein (PGP) and alterations in DNA topoisomerase II (TOPO II) were evaluated in mouse leukemia P388 cells selected in vivo for mitoxantrone (MTT) resistance (P388/MTT) and compared to doxorubicin (DOX) resistant (P388/DOX) or vincristine (VCR) resistant (P388/VCR) models. Among a panel of... | US |
To determine (1) whether there were differences in cognition between HIV-1-seropositive and HIV-1-seronegative homosexual men and (2), if so, whether these differences could be explained by the degree of immunosuppression [i.e., CD4 cell count and immunoglobulin A (IgA) levels]. | US |
Two critical amino acids in the visual pigment rhodopsin are Lys-296, the site of attachment of retinal to the protein through a protonated Schiff base linkage, and Glu-113, the Schiff base counterion. Mutation of Lys-296 or Glu-113 results in constitutive activation of opsin, as assayed by its ability to activate tran... | US |
Synaptic connections between the sensory and motor neurons of Aplysia in culture undergo long-term facilitation in response to serotonin (5-HT) and long-term depression in response to FMRFamide. These long-term functional changes are dependent on the synthesis of macromolecules during the period in which the transmitte... | US |
The involvement of synaptophysin, a synaptic vesicle-specific protein, in transmitter release at neuromuscular synapses was studied by intracellular application of synaptophysin antibodies into presynaptic neurons. Polyclonal antibodies or their Fab fragments were loaded into spinal neurons by injection into one of the... | US |
There is now considerable evidence that peroxisomes not only have a role in cholesterol oxidation but also in cholesterol biosynthesis. Specifically, peroxisomes contain at least two enzymes necessary for the initial steps in cholesterol synthesis, i.e., thiolase and mevalonate kinase. The rate-limiting enzyme in chole... | US |
The CpG islands found at the 5' ends of many mammalian genes are typically unmethylated despite being both exposed to diffusible protein factors in nuclei and rich in CpG, the target site for DNA methyltransferase. We show here that the CpG islands associated with the human Thy-1 and profilin genes are inherently resis... | US |
Studies of three keratinocyte differentiation markers are described. First, the involucrins of several mammals are identified, facilitating use of this marker in animal models of human disease. The rapid evolution of involucrin has prevented its routine immunochemical identification beyond the primates, but its unusual... | US |
Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in brain, opens chloride channels through actions on GABAA receptors. We now report base and amino acid sequences of the alpha 1, alpha 2, and alpha 3 subunits from GABAA receptors of audiogenic seizure-prone (DBA/2J) and -resistant (C57BL/6J) inbred... | US |
T lymphocytes and neutrophils accumulate in psoriatic epidermis. To determine whether the epidermis plays an active role in this process through the production of cellular adhesion factors, leucocyte adherence to lesional psoriasis was compared with normal skin in a modified frozen-section adhesion assay. Lymphocyte an... | United Kingdom |
The expression of multidrug resistance (mdr) genes was investigated in the livers of transgenic mice that express the human hepatitis B virus large envelope polypeptide under the transcriptional control of a liver-specific promoter. These mice develop a storage disease due to the accumulation of a nonsecretable form of... | US |
Immunocytochemical and autoradiographic methods were used to identify neurons in the pure cone retina of the lizard (Anolis carolinensis) that are likely to employ glutamate (GLU) or aspartate (ASP) as a neurotransmitter. GLU immunocytochemistry demonstrated high levels of endogenous GLU in all cone types and numerous ... | US |
Rapid activation of transcription factor genes is thought to play a key role in stimulus-induced neuronal plasticity. To help understand the genomic response that may underlie long-term effects of cocaine and amphetamine, we have investigated the effect of these agents on Zif268, a transcription regulatory factor that ... | US |
The mammalian 70-kilodalton heat shock cognate protein (Hsc70) is an abundant, cytosolic molecular chaperone whose interactions with protein substrates are regulated by ATP hydrolysis. In vitro, purified Hsc70 was found to have a slow, intrinsic ATPase activity in the absence of protein substrates. The addition of an u... | US |
The multicatalytic proteinase complex (MPC), also referred to as proteasome, is a large molecular mass intracellular particle (approximately 700 kDa), which exhibits three distinct proteolytic activities designated as chymotrypsin-like, trypsin-like, and peptidylglutamyl-peptide hydrolyzing (PGPH), all sensitive to inh... | US |
The glycophospholipid-linked, amphiphilic form of acetylcholinesterase (AChE) from Torpedo californica and the hydrophilic form from mouse were overexpressed in Sf9 insect cells using the baculovirus expression system. Recombinant baculovirus, constructed by inserting AChE cDNA's into the genome of Autographa californi... | US |
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