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Biomedical subjects

D L Levy

Publications and source records attributed to D L Levy.

80 records · Page 5Linked to original sources

The specificity of gonadotropin binding by the human corpus luteum.

The specificity of gonadotropin binding was studied in fresh and frozen human corpora lutea. Ovine, bovine, and porcine luteinizing hormone (LH) competed with 125I-labeled human LH (125I-hLH) and 125I-labeled human chorionic gonadotropin (125I-hCG) for binding to tissue receptors in homogenates of human corpora lutea frozen for 3 to 12 months. In contrast, oLH, bLH, and pLH competed minimally for 125I-hLH and 125I-hCG binding sites in homogenates of fresh human corpora lutea. Ovine follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH) did not compete in homogenates of fresh or frozen tissue. Competition of oLH and hCG for 125I-hCG binding sites at several dose levels in a homogenate of a fresh corpus luteum was studied. One hundred micrograms of oLH and ten nanograms of hCG gave an equivalent competition--a 10,000-fold difference in competitive potency. Only hCG competed with 125I-hCG for binding when the competition of oLH, bLH, pLH, oFSH, oTSH, hCG and hCG subunits, and hCG were compared at the 10-mug level in a homogenate of fresh human corpus luteum. The binding of 125I-labeled homologous human hormones by the corpus luteum was examined in a limited fashion. 125I-Prolactin did not bind to preparations of fresh stroma from a patient with polycystic ovaries nor did it bind to three separate preparations of fresh corpora luteum which did bind 125I-hCG. 125I-hTSH did not show significant binding to a fresh human corpus luteum preparation which did bind 125I-hCG. These studies indicate that the gonadotropin receptor of the fresh human corpus luteum possesses a unique species specificity and illustrate the importance of working with human corpora lutea in their most native state.

Binding, Competitive↗

Smooth-pursuit eye movements, and diazepam, CPZ, and secobarbital.

This study examined the effects on smooth-pursuit eye tracking of single doses of CPZ (0.667 and 1.334 mg/kg), diazepam (0.071, 0.142, and 0.284 mg/kg), and secobarbital (100 mg). Only the barbiturate significantly affected the ability to follow a moving target with smooth-pursuit eye movements. In repeated testing of a single subject, 130 mg of secobarbital disrupted smooth-pursuit movements at least until 24 hrs after ingestion.

Adult↗

Season of birth and obstetrical complications in schizophrenics.

Many studies indicate that both obstetrical complications (OCs) and birth in winter or early spring are risk factors for schizophrenia, but few studies have examined how these risk factors covary in the same subjects. We assessed pre- and perinatal OCs, while blind to diagnosis, using medical data recorded at the time of subjects' births, in 29 probands with DSM-III schizophrenia or schizoaffective disorder and 39 of their unaffected adult sibs. Pre- and perinatal OCs were both significantly more common in probands than sibs. Schizophrenics not born during the winter or early spring had significantly more total and perinatal OCs than schizophrenics born in other months, but did not differ for prenatal OCs. Results indicate that OCs increase risk for schizophrenia, but also suggest the possibility that the impact of OCs on this risk may be affected by season of birth.

Adult↗

Fetoplacental and uteroplacental Doppler blood flow velocity analysis in premature rupture of membranes.

The value of Doppler velocimetry in predicting fetal distress or perinatal infection was investigated in 60 patients with premature rupture of the membranes (PROM) between 25 and 38 weeks of gestation. Studies were performed in the umbilical and uterine arteries after admission to the hospital and repeated every 24 to 76 hours until delivery. Results of the last study, performed less than 24 hours before delivery and comparison between longitudinal studies in the same patient, failed to disclose statistical differences between patients who did or did not develop the perinatal complications under study. We conclude that Doppler velocimetry is not a sensitive enough means of predicting fetal distress or infection in PROM.

Arteries↗