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Biomedical subjects

S Weiss

Publications and source records attributed to S Weiss.

At least 325 records · Page 18Linked to original sources
PubMed1989

Co-expression of the subunits of the heterodimer of HIV-1 reverse transcriptase in Escherichia coli.

Expression of the 66-kDa form of human immunodeficiency virus, type 1 reverse transcriptase in Escherichia coli leads to isolation of small amounts of a 2 x 66-kDa homodimer and larger amounts of a heterodimer form of the enzyme in which the 66-kDa protein is complexed with its carboxyl-terminally truncated is complexed with its carboxyl-terminally truncated 51-kDa form. The latter arises via proteolysis by contaminating proteases. The heterodimer, which was characterized by gel filtration (apparent native molecular mass of 120-130 kDa), was the most active form of the enzyme (specific activity, 5000 units/mg, cf. less than 2000 for the 66-kDa fragment). The 66-kDa fragment alone was shown to be only partially dimerized, with the activity residing mainly in the dimer fraction. Proteolysis of the 66-kDa form resulting partially in the 51-kDa form led to an increase in reverse transcriptase activity. Expression of a truncated version of the protein containing the first 428 amino acids of the reverse transcriptase coding region led to a protein which had low but measurable reverse transcriptase activity (400-500 units/mg). Co-expression of the two proteins on a single plasmid led to expression in a 1:1 ratio. The 1:1 mixture behaved as a heterodimer, as shown by its chromatographic properties. It is likely that the mechanism for the production of heterodimers in vivo involves cleavage of 66-kDa monomers followed by rapid dimerization of the 51- and 66-kDa forms to give the heterodimeric form, which is stable toward further proteolysis.

Catalysis↗
PubMed1989

Two distinct quisqualate receptor systems are present on striatal neurons.

At concentrations at which it did not alter spontaneous release, quisqualate (QUIS) induced a dose-dependent (EC50, 0.5 microM) potentiation of KCl- or veratrine-evoked release of [3H]GABA from striatal neurons in primary culture. QUIS potentiation of KCl-evoked [3H]GABA release was mimicked by the selective agonist alpha-amino-3-hydroxy-5-methylisoxazole-propionic acid (AMPA), glutamate and kainate, and was blocked by kynurenic acid and gamma-D-glutamylglycine. QUIS also induced a dose-dependent (EC50, 0.2 microM) augmentation of [3H]inositol monophosphate production in striatal neurons. This action of QUIS was mimicked by glutamate, but not by AMPA nor by kainate. Furthermore, none of the antagonists tested (kynurenic acid, gamma-D-glutamylglycine, glutamic acid diethyl ester, and 4-aminophosphonobutanoic acid) could block QUIS-induced elevations in [3H]inositol monophosphate production. The results of the present study suggest that two QUIS receptor systems, distinguished on the basis of their pharmacological properties, may subserve specific roles in the regulation of striatal neuron function by excitatory amino acids.

Animals↗
PubMed1989

Sequence and linkage of the V kappa 21A and G germ-line gene segments in the mouse.

The germ-line V gene segments encoding the subgroups A and G of the BALB/c V kappa 21 family were cloned and assigned to the previously described 30-kb cluster of the V kappa 21 family. Sequence comparison revealed close homology between the two gene segments at the DNA and the predicted amino acid sequence level, indicating that V kappa 21A and V kappa 21G originated by a rather recent gene duplication.

Animals↗
PubMed1989

Alcohol drinking habits and attitudes of the adult Jewish population in Israel 1987.

The purpose of this article is to present attitudes towards alcohol drinking and non-ritual alcohol drinking habits among the general adult Jewish population in Israel, which have been revealed in the framework of a national survey. 1190 Israeli adults over the age of 20 were interviewed in June and July 1987. The findings, such as 3% daily drinkers, clearly indicated a worrisome prevalence of non-ritual alcohol use among Israelis and reinforced the position that the phenomenon of drinking is liable to develop into an important social and public health problem in the State of Israel. Various aspects of consumption of alcoholic beverages and attitudes towards drinking are described and a number of methodological issues (unique to this research) are discussed.

Adult↗
PubMed1989

The Israeli residential center for alcoholics 1982-1987.

This paper touches upon three primary topics: description of the treatment methods and approaches that have proven to be most useful and successful in Israel's only residential center for alcoholics; summary of recent findings about the characteristics of alcoholics that have been treated at the residential center during the years 1982-1987 (the findings revealed a high percentage of married alcoholics and of unemployment) and some details about the follow-up investigation and the evaluation of the effectiveness of the center's treatment modality. The relatively high abstention rate - 40.9% of all patients (51.2% of those who completed treatment) - is the most important result of the study. Thus, this article integrates research data and relevant features of the Israeli residential treatment experience, in which the emphasis on involving the family is greater than elsewhere.

Adult↗
PubMed1989

B-lymphoma cells process and present their endogenous immunoglobulin to major histocompatibility complex-restricted T cells.

Antigen-presenting B-lymphoma cells were transfected with the gene encoding the immunoglobulin lambda 2 light chain of MOPC315 cells (lambda 2(315). The lambda 2 chain is expressed on the cell surface of the transfectants together with the endogenous heavy chain. The transfectants present an idiotope of the lambda 2(315) light chain to class II-restricted T-cell clones. Recognition by the T cells requires processing of the lambda 2(315) light chain. From these data we conclude that B-lymphoma cells constitutively process and present their immunoglobulins. Secretion and reuptake of the light chain was not necessary for the presentation. Thus, B cells bear two types of idiotypes on their membrane, a native form as surface immunoglobulin and a processed form in the context of products of the major histocompatibility complex.

Animals↗
PubMed1989

Translocation and activation of protein kinase C in striatal neurons in primary culture: relationship to phorbol dibutyrate actions on the inositol phosphate generating system and neurotransmitter release.

The actions of the tumor-promoting phorbol ester phorbol dibutyrate were examined, under identical physiological conditions, on three distinct cellular processes in striatal neurons: the distribution of protein kinase C, the carbachol-stimulated generation of [3H]inositol monophosphate, and the KCl-evoked release of gamma-[3H]aminobutyric acid ([3H]GABA). Phorbol dibutyrate induced a rapid (complete in 5 min), dose-dependent, entirely reversible (t0.5 = 15 min) translocation of protein kinase C from cytosol to membrane. On longer exposure to phorbol dibutyrate, membrane-associated protein kinase C returned toward the control level, and total cellular enzyme activity declined markedly. Phorbol dibutyrate also induced the dose-dependent attenuation of carbachol-stimulated [3H]inositol monophosphate production and potentiation of KCl-evoked release of [3H]GABA. The translocation of protein kinase C and the potentiation of KCl-evoked [3H]GABA release were both rapidly reversed following washout of phorbol dibutyrate. In addition, for both processes, the effect of a 1-h exposure to phorbol dibutyrate was markedly less than that observed following a 5-min exposure to the agent. In direct contrast, inhibition of carbachol-stimulated [3H]inositol monophosphate production was not rapidly reversed following washout of phorbol dibutyrate and was actually more pronounced following a 1-h exposure, compared with a 5-min exposure. These findings indicate that some, but not all, of the actions of phorbol dibutyrate are closely associated with the translocation of protein kinase C in striatal neurons in primary culture.

Animals↗
PubMed1989

Verbal and nonverbal right hemisphere processing by chronic alcoholics.

The theory that chronic alcoholism produces a right hemisphere deficit has generally been tested using visuospatial tasks. The present report tested the theory using three tasks that tap functions, other than visuospatial abilities, which have been failed by patients with right hemisphere damage. The first task assesses the ability to draw a correct inference by integrating information from two unrelated sentences. The second taps the patient's capacity to appreciate humor. The third requires the patient to interpret the emotion displayed in a face. On all three tasks, the pattern of responses of chronic alcoholics differed from that of patients with right hemisphere damage. Thus, the right hemisphere deficit theory fails to gain support from this investigation. On the other hand, the chronic alcoholics' performance was impaired relative to contemporary controls on the first two tasks, although not on the last. On the first two tasks, alcoholics' impairment approximated, and in one instance exceeded, that seen in normal elderly controls. Thus, a premature aging hypothesis received modest support from this study.

Aged↗
PubMed1989

Gross genetic differences among substrains of NZB mice.

Substrains of NZB mice have been compared by Southern blot analysis using several probes. The restriction fragment length polymorphism of probes derived from the Igh-V, Igk-V, Tcr alpha-C loci and of the long terminal repeat of the mouse mammary tumour virus revealed that NZB/BlLwPtIbm were grossly different from NZB/BlNJ and NZB/BlOla. Comparison with mouse strains of the Igk-V haplotypes a and d suggested that NZB/BlLwPtIbm contain genetic material of the C58 mouse strain.

Animals↗
PubMed1989

Projected incidence of cardiovascular disease in male firefighters based on current risk factor prevalence.

The projected incidence of cardiovascular disease (CVD) in male firefighters was determined by the prevalence of current CVD risk factors and the use of the Framingham Study general cardiovascular risk profile in a probability sample of firefighters from two municipal fire departments. Hypercholesterolemia (60.9%) and obesity (56.0%) were the most prevalent risk factors. Significant age-related trends were observed for the prevalence of all CVD risk factors, except glucose intolerance (P = .21) and an abnormal resting electrocardiogram (P = .07). The projected incidence of CVD in firefighters did not differ from that of the general male population (relative risk, 1.0; 95% confidence interval, 0.7 to 1.4); similar risk estimates were observed in age-specific analyses. These findings are in accord with previous incidence and mortality studies that used circulatory diseases as an end point. The present method should be viewed primarily as a hypothesis-generating tool because of its limitations in assessing cause and effect.

Adolescent↗
PubMed1988

Forskolin attenuates the evoked release of [3H]GABA from striatal neurons in primary culture.

The actions of the diterpene forskolin, and cyclic AMP analogues, on the evoked release of [3H]GABA (gamma-aminobutyric acid) was examined in intact striatal neurons in primary culture, generated from the fetal mouse brain. Exposure of striatal neurons to forskolin (100 microM) resulted in a 40-55% attenuation of [3H]GABA release evoked by either KCl (30 mM) or veratrine (2 micrograms/ml), while baseline levels of release were unaffected. The dose-dependence for forskolin attenuation of KCl-evoked release of [3H]GABA was virtually identical to the dose-dependent elevation of cyclic AMP levels by forskolin in striatal neurons. Exposure of striatal neurons to membrane-permeable analogues of cyclic AMP, such as p-chlorophenylthio cyclic AMP (0.5 mM) and dibutyryl cyclic AMP (1 mM), resulted in a 25 and 26% attenuation of [3H]GABA release, respectively; dibutyryl cyclic GMP (1 mM) was without effect. The similarity between the actions of forskolin and the cyclic AMP analogues suggests that, in striatal neurons in primary culture, the elevation of cyclic AMP levels results in the attenuation of the evoked release of [3H]GABA. The greater effectiveness of forskolin, compared to the cyclic AMP analogues, may be related to the recently reported, additional direct actions of forskolin on neuronal membrane ion channels.

Animals↗
PubMed1988

A collaborative intercampus model for graduate studies in primary care nursing.

A feasibility study was conducted to determine the appropriateness of developing an intercampus curriculum for graduate studies in nursing with collaboration between a School of Medicine at one campus and a School of Nursing at another. Methods of data collection included interviews with a broad scope of administrators, faculty and students, synthesis of survey data and other documentation, and a consultation visit by a representative of the United States national accreditation body for nursing. From these data, an advisory committee of faculty administrators from each campus jointly determined the most appropriate criteria upon which to base an intercampus program. A curriculum preparing students in the specialties of either midwifery or family practice was created. The advantages and disadvantages of this collaborative effort are described, along with conclusions regarding factors influencing the effectiveness of the program.

Curriculum↗
PubMed1988

POEMS syndrome associated with cryoglobulinemia, lymphoma, multiple seborrheic keratosis, and ichthyosis.

The case of a patient with POEMS syndrome is presented. The characteristic features of the disorder were associated with the apparently unique and undescribed findings of multiple seborrheic keratosis, ichthyosis, livedo reticularis, and vasculitis, combined with IgM/IgG cryoglobulinemia. Analysis of the cryoprecipitate revealed monoclonal IgM, with kappa light chains. Six years later an immunoblastic lymphoma developed. Notably, the paraneoplastic cutaneous signs were present 6 years before the development of the immunoblastic lymphoma.

Aged↗
PubMed1988

Clinical comparison of systemic methylprednisolone acetate versus topical budesonide in patients with seasonal allergic rhinitis.

Thirty patients with seasonal allergic rhinitis entered a double blind study comparing budesonide (nasal spray, 400 micrograms/d) and i.m. injection of 80 mg methylprednisolone acetate. Symptoms were assessed over a "run in" period of 3-7 days followed by a treatment period of 3 weeks. Pollen counts were evaluated daily. Both the systemic and topical corticosteroid treatment resulted in a significant improvement of nasal and ocular symptoms and were accompanied by reduced antihistamine intake. A comparison of the two treatments in relation to the pollen count yielded statistically significantly fewer nasal symptoms, such as itching, secretion, and sneezing in the budesonide-treated group. Nasal blockage and ocular symptoms remained unchanged, but the use of eyedrops was significantly reduced in the methylprednisolone-treated group. Side effects of both treatments were mild and the incidence negligible. Methylprednisolone-treated patients had a significantly lower cortisol value after 7 days but still had a normal response to ACTH-stimulation. We conclude that the acute symptoms of allergic rhinitis are at least as well ameliorated by regular topical application of budesonide as by a single injection of methylprednisolone acetate. The accompanying allergic conjunctivitis may require additional treatment.

Administration, Intranasal↗
PubMed1988

Excitatory amino acid-evoked release of gamma-[3H]aminobutyric acid from striatal neurons in primary culture.

The actions of excitatory amino acids on the release of previously incorporated gamma-[3H]aminobutyric acid ([3H]GABA) were examined in purified (greater than 93%) striatal neurons derived from the fetal mouse brain and differentiated in primary culture. Glutamate, KCl, and veratrine evoked a dose-dependent, saturable, and reversible release of [3H]GABA from striatal neurons. Glutamate actions were not reduced in the absence of calcium, and were insensitive to tetrodotoxin. The dose-response relationships of excitatory amino acids demonstrated the following rank order of potency: glutamate greater than aspartate = N-methyl-D-aspartate greater than kainate much greater than quisqualate. Kainate, however, was the most effective agonist, evoking an eightfold increase over baseline levels of [3H]GABA release. Aspartate- and N-methyl-D-aspartate-evoked release was abolished in the presence of either 2-aminophosphonovaleric acid or gamma-D-glutamylglycine. Release due to glutamate and kainate was partially or ineffectively attenuated by these agents. Glutamate-, aspartate-, and N-methyl-D-aspartate-evoked GABA releases were augmented when calcium was omitted from the bathing medium and reduced when sodium was replaced with choline or lithium. Kainate-evoked release was unaffected when calcium was omitted, virtually unchanged when choline replaced sodium, and markedly potentiated when lithium was substituted for sodium. These findings suggest that at least two distinct receptor systems for excitatory amino acids mediate the evoked release of [3H]GABA from striatal neurons in primary culture. These two systems, aspartate/N-methyl-D-aspartate- and kainate-preferring, are distinguishable on the basis of their pharmacological and ionic properties.

Amino Acids↗
PubMed1988

Neurotransmitter-induced inositol phosphate formation in neurons in primary culture.

Inositol-1,4,5-trisphosphate, produced in cells as a breakdown product of phosphatidylinositol-4,5-bisphosphate, induces, in many cell types, release of calcium from intracellular stores. In murine striatal neurons, differentiated in primary culture, carbachol, norepinephrine, glutamate, and neurotensin stimulate 3H-labeled inositol phosphate (3H-IP) production. The glutamate response was recently characterized as being mediated primarily by receptors of the quisqualate subtype. In the present study, we found that major differences exist between glutamate-stimulated 3H-IP formation and those stimulated by the other neuromediators. The maximal response to glutamate occurred before and during synaptogenesis and declined thereafter, whereas the maximal response to either carbachol or norepinephrine required complete neuronal differentiation. Although the glutamate response appears to be mediated exclusively by direct interaction with the neurotransmitter receptors, responses to carbachol, norepinephrine, and neurotensin were partially or completely blocked by tetrodotoxin.

Animals↗