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Biomedical subjects

S Weiss

Publications and source records attributed to S Weiss.

At least 307 records · Page 17Linked to original sources
PubMed1991

Platelet alpha-2 adrenoreceptor activity pre-treatment and post-treatment in major depressive disorder with melancholia.

Changes in alpha-2 adrenoreceptor density and affinity during antidepressant treatment were studied using 3H-yohimbine binding to human platelet membranes. Baseline measurements were conducted in 21 patients diagnosed as having major depressive disorder with melancholia, and an equal number of age and sex matched normal controls. No differences were observed in receptor density or binding between pre-treatment subject groups and normal matched controls. Subjects participated for 6 weeks in a trial of placebo, adinazolam, or amitriptyline. Alpha-2 adrenoreceptor binding was not significantly changed from baseline following antidepressant treatment.

Adult↗
PubMed1991

Pharmacokinetics of 18F-labeled fluconazole in rabbits with candidal infections studied with positron emission tomography.

[4-18F]Fluconazole was used to measure the pharmacokinetics of fluconazole in normal and infected animals. The biodistribution of fluconazole was determined after administration of the 18F-tracer with/without a pharmacological dose of unlabeled drug by radioactivity measurements on excised tissues. In normal rabbits and rabbits with candidal infection of the thigh, tissue concentrations of drug were determined by serial positron emission tomographic imaging. In rats, coinjection of tracer quantities of [4-18F]fluconazole with a pharmacological dose of unlabeled drug resulted in a relatively uniform distribution of radioactivity in most organs, whereas, when the 18F-tracer was injected alone, spleen, muscle and heart accumulation was decreased and liver accumulation was increased. In rabbits, this effect was less pronounced. Early accumulation of [4-18F]fluconazole was greater in infected muscle. The areas under the 2-hr uptake curves were 4.30 and 6.05 micrograms.hr.ml-1 for normal and infected tissue. A mathematical model was used to summarize the kinetics of fluconazole in normal and infected muscle. The model hypothesizes that fluconazole is compartmentalized in blood and tissue, with rate constants describing the transition between compartments. Direct measurement of the partition coefficient of fluconazole in muscle and predictions of the kinetic model were in close agreement, suggesting that fluconazole enters muscle via a passive transport mechanism. Transport rates of fluconazole, into (Kin) and out of tissue (kout), were increased in infected compared with normal muscle, possibly due to increased capillary permeability (Kin: 0.064 +/- 0.001 vs. 0.0270 +/- 0.0002, kout: 0.063 +/- 0.002 vs. 0.035 +/- 0.001).

Animals↗
PubMed1991

Diverticulitis: an evaluation by computed tomography and contrast enema.

The role of a contrast enema and computed tomography (CT) was evaluated in 228 patients with a discharge diagnosis of acute diverticulitis. Forty-nine percent of these patients eventually required surgery. In the surgical group, 90% of contrast enemas and 69% of CT examinations reported either diverticulitis or findings compatible with diverticulitis. In patients treated medically, the negative results were higher with both modalities, although it is believed that a number of these patients were misdiagnosed. The contrast enema and CT influenced the decision for surgery in 17% and 6%, respectively, in patients undergoing these examinations.

Aged↗
PubMed1991

Alcohol drinking habits of Israeli Jewish, Moslem and Druze adolescents in the north of Israel in 1990.

The article describes research conducted in the north of Israel on the drinking and smoking habits of 2,763 Moslem, Druze, Kibbutz and urban Jewish adolescents from a big city and a development town. It compares alcohol drinking frequencies (alcohol drunk on a single occasion) and amounts of these four youth populations, as well as cigarette smoking, and hashish use. Also students were asked about the drinking patterns of parents and best friends.

Adolescent↗
PubMed1990

Muscarinic receptors and second-messenger responses of neurons in primary culture.

The coupling of muscarinic receptors to second messenger responses was investigated in primary cultures of neurons from the fetal mouse brain. Neurons were maintained in monolayer culture, in serum-free medium; immunocytochemical studies found these cultures to be nearly exclusively neuronal. In striatal cultures, [3H]N-methylscopolamine (NMS) bound specifically and with high affinity (Kd = 70 pM) to a homogeneous population of receptors on intact neurons (320 fmol/mg cellular protein). Displacement of the binding of [3H]NMS by pirenzepine indicated the presence of heterogeneous sites (81% high affinity sites, Kh = 51 nM, K1 = 1.5 microM); AF-DX 116 showed the opposite selectivity (15% high affinity sites, Kh = 56 nM, K1 = 1.3 microM). The dopamine agonist SKF-38393 (1 microM) enhanced the accumulation of cyclic adenosine monophosphate (AMP) in these cultures 2.5-fold; addition of carbachol reduced cyclic AMP levels by 30% (EC50, 1.7 microM). In the presence of 1 mM lithium, carbachol stimulated the accumulation of inositol monophosphate 5-fold (EC50, 61 microM). Both responses were antagonized by pirenzepine (apparent Ki of 23 nM for the phosphoinositide response and 200 nM for the cyclic AMP response) and AF-DX 116 (apparent Ki 540 nM and 160 nM, respectively). In binding studies on brainstem cultures, AF-DX 116 indicated the presence of two sites of approximately equal abundance (Kh = 170 nM, K1 = 2.9 microM); data for pirenzepine were adequately fit by a one-site model (Kd = 630 nM).(ABSTRACT TRUNCATED AT 250 WORDS)

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1990

A stimulatory monoclonal antibody detecting T cell receptor diversity among idiotype-specific, major histocompatibility complex-restricted T cell clones.

A panel of independent BALB/c T cell clones responding to a peptide of the lambda 2(315) immunoglobulin light chain (residues 91-101), in the context of I-Ed, has previously been described. A monoclonal antibody (mAb; GB113) to the T cell receptor (TcR) of one of the clones, 4B2A1 (V alpha 1, J alpha 19; V beta 8.2, D beta 1.1, J beta 1.2) precipitates the alpha/beta heterodimer from 4B2A1. However, GB113 does not bind DO11-10.2 cells bearing a similar alpha/beta heterodimer (V alpha 1.1, J alpha TT11; V beta 8.2, D beta 1.1, J beta 1.1). GB113 does not cross-react with the TcR of the six other clones in the panel. Furthermore, the mAb does not bind polyclonal lambda 2(315)-specific T cell lines except 4.4% of cells of line 4 from which 4B2A1 was cloned. The mAb only binds a negligible number (0.5%) of BALB/c thymocytes and peripheral T cells. Therefore, the epitope detected by GB113 is very rarely expressed on 91-101. lambda 2(315)-specific TcR or on TcR of normal T cells. Soluble GB113 induces T cell activation [measured as proliferation and interleukin (IL) 2, IL3 and interferon-gamma production]. GB113-induced T cell activation is enhanced by soluble anti-CD4 and anti-Thy-1 mAb.

Animals↗
PubMed1990

Strategic and automatic priming of semantic memory in alcoholic Korsakoff patients.

To examine whether the organization of semantic memory is intact in alcoholic Korsakoff patients, three semantic memory tasks which do not require active search for stored information were administered to a group of Korsakoff patients and alcoholic controls. The first two tasks used a perceptual identification paradigm in which patients had to identify briefly presented targets preceded by associatively (experiment 1) or categorically (experiment 2) related primes. On both tasks, Korsakoff patients demonstrated intact priming effects. Because priming in these tasks was thought to reflect the operation of strategic processes, experiment 3 was designed to assess automatic spreading activation using a lexical decision task. Here as well, Korsakoff patients demonstrated intact priming. Taken together, these results support the view that the organization of semantic memory in Korsakoff patients has not been disrupted by their brain injury. The implications of these findings for understanding Korsakoff patients' impaired performance on semantic search tasks are discussed.

Aged↗
PubMed1990

Cultural differences in the perception of magazine alcohol advertisements by Israeli Jewish, Moslem, Druze and Christian high school students.

This article describes the Israeli part of an international comparative research project conducted simultaneously in 1988 also in Australia and in the U.S.A., in order to determine the attitudes of high school students from different nations and cultures toward alcohol advertising. The Israeli study used a set of 64 magazine alcohol advertisements from 10 countries and with the help of an open-ended questionnaire examined differences and similarities in the perception of Israeli and foreign advertisements by Jewish, Moslem, Druze and Christian teenagers. Each response was coded twice. The first code indicated the general tone of the response and the second code indicated its theme. The article presents selected general results and conclusions. The results have implications for designing alcohol abuse education messages and can aid alcohol advertisers interested in responsible advertising to find advertising standards suitable to each culture.

Adolescent↗
PubMed1990

Postoperative injuries of upper limb nerves.

Three cases of different types of nerve injuries following orthopedic and chest surgery are described. Recovery from these nerve injuries was prolonged and incomplete. By constant awareness of potential nerve damage during operation, it is possible to prevent such injuries.

Angina Pectoris↗
PubMed1990

Pharmacological properties of the N-methyl-D-aspartate receptor system coupled to the evoked release of gamma-[3H] aminobutyric acid from striatal neurons in primary culture.

The actions of a series of endogenous excitatory amino acid (EAA) agonists and synthetic antagonists at the N-methyl-D-aspartate (NMDA) receptor system coupled to the evoked release of gamma-[3H]aminobutyric acid (GABA) from purified populations of striatal neurons in primary culture were examined. EAA agonists displayed the following rank order of potency in evoking [3H]GABA release: glutamate greater than homocysteate greater than aspartate, NMDA greater than cysteine sulfinate. Glutamate, homocysteate and cysteine sulfinate were equieffective, whereas at saturating concentrations, aspartate and NMDA reached 75 and 65%, respectively, of the maximum efficacy of the former three agonists. The release of [3H]GABA evoked by 100 microM NMDA was attenuated in a dose-dependent manner by the following antagonists (IC50, micromolar): MK-801 (0.067), phencyclidine (0.151), CGS-19755 (3.31), 2-aminophosphonovalerate (18.8), kynurenate (100) and gamma-D-glutamylglycine (100). The antagonist properties of MK-801 and phencyclidine were not competitive with NMDA, whereas NMDA dose-response curves performed in the absence and presence of increasing concentrations of CGS-19755 resulted in parallel rightward shifts (pA2 = 5.95). CGS-19755 produced similar rightward shifts of the homocysteate dose-response curve (pA2 = 5.89). At glutamate concentrations less than 100 microM, CGS-19755 and 2-aminophosphonovalerate were potent antagonists of glutamate-evoked release; however, at glutamate concentrations greater than 100 microM these agents were ineffective blockers. The blockade of NMDA-evoked release of [3H]GABA by kynurenate was not competitive in nature.(ABSTRACT TRUNCATED AT 250 WORDS)

2-Amino-5-phosphonovalerate↗
PubMed1990

[Etiopathogenesis of adhesions. Aspects of analysis of the literature 1888 to 1989].

Despite surgical efforts over a century, peritoneal adhesions are still an unsolved problem. Pathogenetic aspects derived from an analysis of the literature (700 papers, 1888-1989) are discussed: Two basic mechanisms play a role. Inhibition of the physiological regeneration of mesothelial defects and depression of peritoneal fibrinolytic activity mainly by ischemia and inflammation. Fibrinolysis in due time prevents the fibrinous adhesions from being transformed into fibrous ones. - All prophylactic and therapeutic measures have to be evaluated regarding these factors.

Abdomen↗
PubMed1990

Kainate receptors coupled to the evoked release of [3H]-gamma-aminobutyric acid from striatal neurons in primary culture: potentiation by lithium ions.

The pharmacological properties and modulation by lithium of the kainate (KA) receptor system coupled to the evoked release of [3H]-gamma-aminobutyric acid [( 3H]GABA) from purified populations of striatal neurons in primary culture were examined. KA evoked a dose-dependent (EC50, 100 microM) and saturable increase in [3H]GABA release from striatal neurons that was unaffected by the removal of extracellular calcium and resistant to the actions of tetrodotoxin. The release of [3H]GABA evoked by 100 microM KA was attenuated in a dose-dependent manner by the following excitatory amino acid antagonists (IC50):6-cyano-2, 3-dihydroxy-7-nitroquinoxaline (2 microM),2,3-dihydroxy-6,7-dinitroquinoxaline (2 microM), kynurenate (0.3 mM), and gamma-D-glutamylglycine (2 mM). The antagonist properties of 6-cyano-2,3-dihydroxy-7-nitroquinoxaline, kynurenate, and gamma-D-glutamylglycine were competitive in nature, inducing parallel rightward shifts of the KA dose-response curves. At concentrations at which it did not significantly increase basal levels of [3H]GABA release, quisqualate attenuated in a dose-dependent manner (IC50, 10 microM) the release due to 100 microM KA. The quisqualate receptor agonist alpha-amino-3-hydroxyisoxazolepropionic acid (AMPA), however, exerted a biphasic effect on 100 microM KA-evoked release of [3H]GABA. At lower concentrations of AMPA (0.1-10 microM), the release due to 100 microM KA was potentiated 25-50%; at higher concentrations (greater than 10 microM) AMPA induced a dose-dependent (IC50, 100 microM) attenuation of KA-evoked release. The release of [3H]GABA due to 100 microM KA was significantly potentiated by the replacement of sodium with lithium in the extracellular medium. A significant potentiation (20-30%) was detected with as little as 5-10 mM lithium, and maximal effects (100-110% increase) were obtained with 50-75 mM lithium. Replacement of sodium with choline or N-methyl-D-glucamine could not mimic the actions of lithium. Lithium (25 mM) also induced a 4-fold increase in the levels of endogenous GABA release due to 100 microM KA. Whole-cell voltage-clamp recordings of these striatal neurons indicated that the 100 microM KA-induced inward current was not significantly altered in the presence of 25 mM lithium. Lithium attenuated vasoactive intestinal polypeptide-stimulated cyclic AMP formation by 50%, with a dose dependence similar to that of its actions on KA-evoked release. The results of this study demonstrate a distinct pharmacological profile for the KA receptor system coupled to the evoked release of [3H]GABA from striatal neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Three national surveys on nonritual alcohol drinking practices of the Israeli Jewish adult population in the '80s: what are the trends?

The trends of alcohol consumption among the adult Jewish population in Israel from 1982 to 1987 were identified on the basis of three nation-wide epidemiological surveys carried out in 1982, 1983 and 1987 by the Israel Institute of Applied Social Research. Findings indicate that while present trends concerning general drinking characteristics of Jewish Israelis can calm fears--since 1982 there has been an increasing trend of abstaining from alcohol--beer drinking and drinking in pubs among young people, and drunkeness among the Israeli-born second generation has been on the increase. Furthermore, acquaintance with alcoholics was reported by religious more than nonreligious respondents in all the surveys.

Adult↗
PubMed1989

Kainate evokes the release of endogenous glycine from striatal neurons in primary culture.

The actions of 56 mM KCl and excitatory amino acid (EAA) agonists on the release of endogenous glycine (Gly) from striatal neurons in primary culture was examined. During a 3 min period, 2 x 10(6) striatal neurons released 743 +/- 51 pmol of Gly. In the presence of 56 mM KCl, an additional 492 +/- 52 pmol of Gly (+66%) were released, 75% of which was dependent upon the presence of extracellular calcium. When striatal neurons were exposed to 1 mM N-methyl-D-aspartate (NMDA) or quisqualate (QA), endogenous Gly released was increased by 370 +/- 71 (+50%) or 120 +/- 31 (+16%) pmol, respectively. In the presence of 1 mM kainate (KA), however, the release of endogenous Gly increased by 994 +/- 82 pmol (+135%). Interestingly, while KA (1 mM) was twice as effective as KCl (56 mM) in evoking the release of endogenous Gly, KCl was 5 times more effective than KA in evoking the release of endogenous gamma-aminobutyric acid (GABA). KA-induced increases of endogenously released Gly were dose-dependent (EC50, 100 microM), saturable and not significantly reduced in the absence of extracellular calcium. The actions of KA were blocked by coincubation with 6-cyano-2,3-dihydroxy-7-nitro-quinoxaline (CNQX), a competitive antagonist at the KA receptor. These data suggest that the release of endogenous Gly from striatal neurons in primary culture is regulated principally by EAA actions at the KA receptor system.

Animals↗
PubMed1989

Integration of the transposon-like element ETn upstream of V lambda 2 in the cell line P3X63Ag8.

The cell line P3X63Ag8 and hybridomas obtained with it contain two rearranged V lambda 2 EcoRI fragments--6.8 kb and 7.4 kb in size. Southern blot analysis, molecular cloning, and mapping revealed that the rearrangements are related to one another and are not due to normal VJ joining. Sequence analysis indicated that the rearrangement was due to the integration of the transposon like element ETn upstream of V lambda 2. Because a normal embryonic V lambda 2 is still retained in this cell line one of the rearranged fragments must be due to a secondary event after the aneuploidization of the plasmacytoma. RNA dot blot analysis showed that the transposon is strongly expressed not only in embryonic cells but also in plasmacytomas, B lymphomas and T cell lines.

Animals↗