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Biomedical subjects

H Vera

Publications and source records attributed to H Vera.

8 recordsLinked to original sources
PubMed1997

Melatonin and testicular function: characterization of binding sites for 2-[125I]-iodomelatonin in immature rat testes.

Melatonin-binding sites in membrane preparation immature rat testes were demonstrated by utilizing 2-[125I]-iodomelatonin as a radioligand. Binding at these sites was found to be reversible, saturable, specific and of, high affinity. Scatchard analysis of the specific binding revealed an equilibrium binding constant (kd) of 215 +/- 23 pmol/L and a total number of binding sites (Bmax) of 0.94 +/- 0.1 fmol/mg protein. The Hill coefficient of 1.0 suggests a single class of 2-[125I]-iodomelatonin-binding site in the rat testes. The Kd value determined from kinetic analysis was 179 pmol/L, which is in close agreement with the value determined from equilibrium studies. In competition studies, the order of pharmacological affinity for 2-[125I]-iodomelatonin binding sites in the rat membrane testes was: melatonin > 6-hydroxymelatonin > N-acetylserotonin > 5-hydroxyindole-3-acetic acid > 5-hydroxytryptamine > 5-hydroxy-L-tryptophan > tryptamine > > 5-methoxytryptamine, 5-methoxyl-DL-tryptophan, D-L-tryptophan. The 2-[125I]-iodomelatonin binding was markedly reduced by guanine nucleotides; treatment with nonhydrolyzable GTP analog guanosine 5'-O-(3-thiotriphosphate) caused a 10-fold decrease in receptor affinity. In this paper, we report evidence indicating the presence of binding sites in immature rat tests, suggesting a possible direct role of melatonin on testicular steroidogenesis.

Animals↗
PubMed1993

Melatonin binding sites in interstitial cells from immature rat testes.

Melatonin binding sites in rat testes interstitial cells were identified using 2-[125I]-iodomelatonin. Saturation studies of cells revealed a single class of high affinity binding sites, with an apparent equilibrium dissociation constant (Kd) of 100 +/- 20 pM, and a total binding capacity (B max) of 3.0 +/- 0.2 x 10(3) melatonin molecules per cell. Binding was reversible and inhibited by non radioactive melatonin. These results suggest that interstitial cells from immature rat testes have specific receptors for melatonin.

Animals↗
PubMed1979

The intelligence of rapists: new data.

IQs of violent sexual offenders (rapists) were compared to those of alleged nonviolent sexual offenders, nonsexual violent offenders, and nonsexual nonviolent offenders. Data were gathered from defendants referred to the medical coauthor for pretrial psychiatric evaluation. Rapists scored lower in the IQ test, but this difference did not appear to be significant in the pairwise X2 comparisons. This held true after controlling for the race of the defendant.

Humans↗
PubMedDate not supplied

The client's view of high-quality care in Santiago, Chile.

The meaning of quality of care for the women who receive reproductive health services at a family planning and maternal and infant care clinic in Santiago, Chile, was examined to describe the clinic's service from the women's point of view. A participatory research project with the staff of the clinic was conducted. The central part of that study, reported here, consisted of interviews with 60 of the 330 women who came to the clinic during two weeks in June 1991. The women defined high quality of care as "being treated like a human being." Among specific elements of care they identified were cleanliness, promptness and availability of service, time made available for consultation, learning opportunities for themselves and their partners, and cordial treatment. Clients' view of quality of care must be supplemented by professional judgments about how well services meet clients' needs. But the client's view is determinant if improvements are to result in greater acceptance and sustained use of the services offered. The issues identified by the clients involve only minor costs for the clinic.

Child Health Services↗