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Biomedical subjects

S Paul

Publications and source records attributed to S Paul.

At least 307 records · Page 17Linked to original sources
PubMed1982

Generation of monoclonal antibodies against human spermatozoa and seminal plasma constituents.

Five mouse myeloma X splenocyte hybridoma cell lines synthesizing monoclonal antibody against human sperm were generated. Antibodies from three clones (VII 5, A-24 and B-20) exhibited high reactivity with sperm, as well as with seminal plasma in enzyme-lined immunoabsorbent assay (ELISA) tests, and two clones (VI 1 and VI 16) showed high reactivity only with sperm. Seminal plasma competitively inhibited binding of the monoclonal antibodies (VII 4, A-24 and B-20) to sperm in ELISA. Immunohistochemical studies revealed that the three monoclonal antibody types (VII 5, A-24 and B-20) stained only 5-30% of the sperm strongly, and the rest weakly. Monoclonal antibody types VI 1 and VI 16 showed weak staining of nearly all sperm. None of these monoclonal antibodies possessed sperm-agglutinating or sperm-immobilizing activity. As determined by ELISA the class and subclass specificity of the monoclonal antibodies was: A-24, IgG1 (kappa); B-20, IgG1 (kappa); VI 1, IgG3 (kappa); VI 16, IgG1 (kappa); and VII 5, IgG1 (kappa).

Animals↗
PubMed1981

Differential electrophysiological and behavioral responses to optically active derivatives of phencyclidine.

Dextro- and levorotatory isomers of 1-(1-phenylcyclohexyl)-3-methylpiperidine (PCMP) were synthesized. Both isomers inhibited spontaneous cerebellar Purkinje neuron firing when applied locally by pressure ejection. This effect was dose-dependent, with the (+)-isomer about 5--7 times more potent than the (-)-isomer. Both isomers also depressed rotarod performance in mice. Again, the (+)-isomer was about 5 times more potent than the (-)-isomer. Both rotarod performance and Purkinje cells discharge were depressed maximally 10--15 min after i.p. injection of drug. Our results suggest a correlation between behavioral performance and central neuron electrophysiological activity and suggest that the central actions of PCP or its derivatives are probably mediated at one locus, by a stereospecific mechanism.

Animals↗
PubMed1980

'Brain-specific' benzodiazepine receptors are localized in the inner plexiform layer of rat retina.

Saturable, high affinity binding sites for [3H] diazepam have recently been characterized in rat brain. A significant component of this binding was determined to occur to a population of receptors which is pharmacologically similar to receptors present in mammalian brain and spinal cord. Neonatal treatment of rats with monosodium glutamate (MSG), intraocular administration of kainic acid, and the use of pink-eyed, tan-hooded (PETH) rats with a genetic retinopathy (degeneration of photoreceptor cells) suggests that these 'brain-type' receptors are highly localized on neuronal elements of the inner plexiform layer and/or ganglion cells.

Animals↗
PubMed1980

Pharmacologic and behavioral effects of EMD 28422: a novel purine which enhances (3H) diazepam binding to brain benzodiazepine receptors.

A novel purine, (N6-2-(4-chlorophenyl)-bicyclo 2.2.2.-octyl-(3)-adenosine) EMD 28422 increases the binding of (3H) diazepam to benzodiazepine receptors in vivo within 10 min after intraperitoneal administration. This increase in (3H) diazepam binding is due to an increase in the number of benzodiazepine receptors (Bmax) rather than an altered affinity of the radioligand for receptor (Kd), EMD 28422 protects mice against pentylenetetrazole and caffeine-induced seizures and potentiates the anticonvulsant action of subeffective doses of diazepam in a dose-dependent fashion. Furthermore, EMD 28422 also produces a significant increase in punished responding in a conflict situation (rats), and a long-lasting, dose-dependent decrease in spontaneous motor activity (mice). In contrast, neither EMD 39011 nor adenosine (the two component molecules of EMD 28422) possess anticonvulsant properties at doses up to five mole-equivalents of EMD 28422. These data indicate that the purine EMD 28422 produces a spectrum of pharmacologic effects similar to the benzodiazepines, yet in contrast to the benzodiazepines (and other purines), increases benzodiazepine receptor number. Thus, EMD 28422 may represent the prototype of a class of synthetic purines exerting a unique neurochemical effect on benzodiazepine receptors and possessing several therapeutic actions of the benzodiazepines.

Adenosine↗
PubMed1980

Resistance of human syncytiotrophoblast to hypotonic and thermal stress.

Human placental syncytiotrophoblast was not lysed when exposed to acutely hypotonic environments (distilled water) or during repeated freeze-thawing. The ability of the syncytiotrophoblast to synthesize and secrete hCG was not blocked after exposure to hypotonic stress (0.055 osmol) and elevated temperature (47 degrees C), treatments which caused lysis of erythrocytes and lymphocytes. The stress-resistant property of the syncytiotrophoblast may be an important element in enabling its survival as a barrier between the maternal environment and the conceptus.

Chorionic Gonadotropin↗