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Biomedical subjects

S Sasson

Publications and source records attributed to S Sasson.

64 records · Page 4Linked to original sources
PubMed1982

Simulated public speaking as a model of clinical anxiety.

Normal male volunteers took single acute doses of either diazepam or placebo under double-blind conditions in three simulated public speaking experiments. Measures of palmar sweating and subjective anxiety showed that anticipation of speaking in public increased anxiety relative to baseline and prestress conditions, and performance of public speaking further increased anxiety. A dose-related anxiolytic effect of diazepam on subjective anxiety supported the model's clinical relevance. Moreover, the intensity of the subject's public speaking phobia predicted both degree of prestress anxiety relief from 10 mg diazepam and overall anxiety level, regardless of medication, throughout the experimental session. A measure of traditionalism predicted placebo and 5 mg diazepam response during prestress: As in previous clinical trials, high traditionalism scorers reported more relief from placebo, whereas low scorers showed more relief from diazepam.

Adolescent↗
PubMed1981

Antiglucocorticoid activity of androgens in rat thymus lymphocytes.

The potent androgens testosterone and 5 alpha-dihydrotestosterone, but not the inactive androgens etiocholanolone and androsterone, display antiglucocorticoid activity in rat thymus-derived lymphocytes. At a concentration of 10(-5) M, the potent androgens markedly lower the in vitro cytolytic response of isolated thymic lymphocytes to 10(-8) M dexamethasone. AT 2.5 X 10(-5) M, these androgens completely prevent the inhibition produced by 5 X 10(-8) M dexamethasone on 2-deoxyglucose uptake and uridine uptake and incorporation in isolated thymic lymphocytes. In the cytosol fraction obtained from rat thymus homogenate, the active androgens competitively inhibit the binding of [3H]dexamethasone to glucocorticoid-specific receptors with Ki values of 1.2 X 10(-6) and 2.5 X 10(-6) M for testosterone and 5 alpha-dihydrotestosterone, respectively. Thymus-derived lymphocytes and nuclei isolated from these cells exhibit binding of [3H]dexamethasone. The bound dexamethasone is avidly displaced by an excess of nonradioactive dexamethasone as well as by nonradioactive testosterone or 5 alpha-dihydrotestosterone. In contrast to their antiglucocorticoid activity in vitro, these androgens fail to elicit antiglucocorticoid activity when administered in vivo. This work shows that androgens are potent antiglucocorticoids in vitro due to competition with the active glucocorticoid on binding to cytoplasmic and nuclear receptor sites.

Androgens↗
PubMed1981

Semisynthetic cephalosporins. IV. Synthesis and structure activity relationships of parenterally active 7-[4-(substituted methyl)phenyl]-acetamido-3-cephem-4-carboxylic acids.

A group of novel 4-substituted phenylacetic acids were prepared and coupled with several 7-amino-delta-3-cephems to afford a family of parenterally active cephalosporins. A compound designated 13I had the broadest spectrum of activity and the highest potency of the group against both Gram-positive and Gram-negative bacteria. The activity of 13I included high potency against penicillinase-producing staphylococci and activity against anaerobes, including Bacteroides fragilis.

Anti-Bacterial Agents↗
PubMed1978

Photochemical dehydrogenation of 5, 6-dihydropyrimidines.

5, 6-Dihydropyrimidines can be oxidized photochemically to the original pyrimidines with light of lambda greater than 300 nm in the presence of transition metal salts which act as sensitizers. A hydrogen atom abstraction by hydroxyl radical is suggested as the reaction mechanism.

Copper↗
PubMed1975

Improvement of fertility and semen quality in men treated with a combination of anticongestive and antibiotic drugs.

The effects of a combined therapy of antibiotics and antiinflammatory drugs was evaluated in 344 men referred to our clinic for treatment of infertility. Physical signs of congestion, usually not severe, were detected in 244 men. The treatment caused significant improvement in semen quality, especially in sperm concentration, morphology and motility. Forty percent of the wives became pregnant. There was a striking relationship between increase in morphologically normal spermatozoa and incidence of pregnancy. It is speculated that the therapy had its major effect at the level of the epididymis and/or testis.

Adult↗
PubMedDate not supplied

Paradoxical interactions among estrogen receptors, estrogens and SERMS: mutual annihilation and synergy.

The phenomenon of mutual annihilation of action between 17beta estradiol (E(2)) and a selective estrogen receptor modulator (SERM), previously described in prepubertal rat diaphysis, epiphysis and uterus, has been investigated in ROS 17/2.8 rat osteoblastic cells and in transiently co-transfected cells in culture. In ROS 17/2.8 cells, the estrogen-induced marker enzyme creatine kinase B (CKB) was stimulated by raloxifene, tamoxifen and tamoxifen methiodide to a specific activity equal to or greater than that induced by 10 nM E(2). However, when a fully inhibitory dose of any of these SERMS was given simultaneously with E(2), no stimulation of CK activity resulted. Therefore, SERMS can be full agonists when acting alone, but complete antagonists to a super-physiological dose of estrogen. It is expected that excess tamoxifen would prevent the action of a SERM, but that the agonist activity of a SERM is abolished by 1000-fold less estrogen is a phenomenon without obvious explanation by classical pharmacology of competitive inhibition. To probe the mechanism of this interaction further, a ckb-CAT reporter plasmid, plus the human receptor expression plasmid, HEO, was transfected transiently into several cell types. In MCF-7 cells, a 1:10 ratio of E(2) to tamoxifen produced mutual annihilation, but the same ratio in ROS 17/2.8 or HeLa cells led to synergistic stimulation. In HeLa cells, co-transfected with the more efficient wild-type estrogen receptor plasmid, HEGO, synergy was demonstrated only at sub-saturation levels of HEGO. We speculate that, in the presence of estradiol and a SERM, not only active homodimers would be formed, but also hetero-dimers of estrogen-liganded and tamoxifen-liganded receptor monomers, depending on the molar ratio of their ligands and their relative affinities. The resulting hetero-dimer conformation would change the specific receptor surface for interactions with the growing number of co-activators and co-repressors, structural changes which could help to explain the mutual annihilation and synergy phenomena and their cell selectivity.

Antineoplastic Agents, Hormonal↗