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Biomedical subjects

D Ayalon

Publications and source records attributed to D Ayalon.

101 records · Page 6Linked to original sources

Effect of diphenylhydantoin on patterns of insulin secretion in obese subjects.

The effect of short-term treatment with diphenylhydantoin (DPH) on the insulin secretion patterns during OGTT and on the daily insulin profile was studied in obese patients. DPH treatment for 3 days with a dose of 300 mg/die (100 mg, 3 times daily) significantly decreased the insulin release after glucose ingestion, but did not alter the basal insulin level. No effect on the fasting glucose concentration as well as on the glucose profiles during OGTT was observed after short-term DPH treatment. A smaller decrease of plasma free fatty acid concentration during OGTT performed after DPH administration confirmed the inhibitory effect of the drug on insulin release. Short-term DPH treatment was also shown to decrease markedly the postpradial insulin release in obese patients. No difference was noted between plasma 11-OHCS and serum HGH concentrations during OGTT before and after DPH treatment. The possible therapeutic role of DPH in obesity is discussed.

11-Hydroxycorticosteroids↗

Improved reliability of a serum alpha-fetoprotein enzyme immunoassay compared with a radioimmunoassay.

During the 6-month period between September 1982 and February 1983, serum samples were obtained from 850 pregnant women attending the municipal family clinics in Tel Aviv. All serum samples were tested by alpha-fetoprotein (AFP) enzyme immunoassay (EIA), and 650 samples were also tested by AFP radioimmunoassay (RIA). Comparisons were made between the absolute values, the medians, and the multiples of the median (MOM) obtained by each method. The ratios of the 90th percentile to the median and of the median to the 10th percentile were also compared. Inter- and intraassay variation were determined for both methods. Correlating the test results with the birth results showed that both methods detected the four fetuses with a neural tube defect (NTD) and three of nine twin pairs, when using a cutoff point of greater than or equal to 2.5 MOM. Elevated maternal serum AFP (MSAFP) levels were also noted in 32 normal singletons (3.8%). There were no false negative results during this phase of the study. Although the median values were similar for both methods, the mean of the ratios of the median to the 10th percentile and the 90th percentile to the median, showed a reduced spread for the EIA method.

Evaluation Studies as Topic↗

The effect of serum prolactin levels on ovarian steroidogenesis.

In order to assess the effect of hyperprolactinemia on ovarian steroidogenetic potential, a group of anovulatory hyperprolactinemic patients and a control group of anovulatory normoprolactinemic women were submitted to exogenous gonadotropin (hMG) stimulation under identical experimental conditions. Serum 17 beta-estradiol (E2) concentrations were determined before and after hMG stimulation. The mean basal serum E2 levels in the hyperprolactinemic group (22.7 +/- 3.3 pg/mL, mean +/- 1 SE) were significantly lower than in the normoprolactinemic control group (48.7 +/- 8.4 pg/mL, P less than .01). A significant negative correlation (r = -.6157, P less than .01) between basal serum E2 levels and basal serum prolactin (hPRL) concentrations was found. Following hMG stimulation, the serum E2 increment (delta E2) from basal E2 levels in the control group (491 +/- 91 pg/mL) was significantly higher than the increment in the hyperprolactinemic group (182 +/- 48 pg/mL, P less than .01), and a significant negative correlation was observed between basal serum hPRL levels and the logarithm of delta E2 (r = -.4744, P less than .05). Our results suggest that chronic hyperprolactinemia induces ovarian refractoriness to exogenous gonadotropin stimulation and substantially reduces its steroidogenetic potential.

Adult↗