Search PubMed⌕ Search

Biomedical subjects

B R Hecht

Publications and source records attributed to B R Hecht.

22 records · Page 2Linked to original sources
PubMed1989

The luteinizing hormone surge: timing and characteristics in the plasma and urine after clomiphene citrate treatment.

Clomiphene citrate (CC) has been used to influence the timing of ovulation. To evaluate the effects of CC on the timing of the luteinizing hormone (LH) surge, we examined the LH surge in 10 cycling normal women for 3 cycles each, during an untreated cycle (control) and during treatment with 50 mg CC (CC 50) and 150 mg CC (CC 150) daily on days 5 to 9. Length of control cycles (mean +/- standard error of the mean) was 28.5 +/- 1.1 days and was not significantly different from either CC 50 (28.2 +/- 0.6 days) or CC 150 cycles (29.0 +/- 0.4 days). LH surge occurred on day 16.4 +/- 1.2 in control, 16.5 +/- 0.5 in CC 50, and 17.1 +/- 0.7 in CC 150 cycles. Similarly, luteal phase lengths were not significantly affected by CC treatment. Individually, however, the effect of CC on the timing of the LH surge depended on when the LH surge occurred in corresponding control cycles. If the control cycle LH surge occurred on day 16 or earlier, CC significantly delayed it. If the normal LH surge occurred on day 18 or later, CC advanced it. During CC 50 treatment, the LH surge was advanced by 1 to 7 days in 3 cycles, unchanged in 2, and delayed in 5 cycles by 1 to 9 days. Detection of urinary LH surge was reliable in CC-treated cycles and correlated well with the day of plasma LH surge.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Determination of laboratory specific percent normal sperm morphology value based on prevasectomy ("fertile") ejaculates.

Semen assessments were performed on ejaculates from 25 men with proven fertility requesting vasectomy. Multiple cytological slides were made simultaneously from each ejaculate and analyzed by a single technician. The morphology data obtained were analyzed for repeatability. The mean +/- SD for normal sperm morphology was 30.6+/-7.3, and the within-subject repeatability was < or =1 SD of the mean for 17 of 25 ejaculates. Technician and laboratory specific criteria for the percent normal sperm morphology component of a semen analysis report (that are clinically meaningful) can be developed using the approach described herein.

Ejaculation↗
PubMedDate not supplied

Current practices of commercial cryobanks in screening prospective donors for genetic disease and reproductive risk.

OBJECTIVE: To determine how the screening practices of commercial semen banks vary from published guidelines, which factors influence cryobanks to exclude prospective semen donors for genetic reasons, and the current role of clinical geneticists/genetic counselors in evaluating prospective semen donors. DESIGN: The genetic screening of prospective donors by commercial semen banks was evaluated using written questionnaires completed by bank directors. Responses were analyzed to determine exclusion criteria, adherence to published guidelines, and contribution of genetic professionals. SETTING AND PARTICIPANTS: Semen banks were selected on the basis of membership in the American Association of Tissue Banks and commercial use of semen for artificial insemination by donor. MAIN OUTCOME MEASURE: Semen bank practices as reported by commercial semen bank directors. RESULTS: Of 37 eligible banks, 16 responded. All screen prospective donors by medical/family history and physical examination, 94% have upper age limits; 63% examine for minor physical defects; 56% routinely karyotype; 81% screen men of ethnic groups at risk for Tay Sachs disease, sickle cell disease and thalassemia; 19% screen all donors; 25% screen all donors for cystic fibrosis and 50% only screen if family history positive. Donor rejection was based on three criteria: mode of inheritance of familial disorder, severity of disease, and availability of carrier/confirmatory testing of donor genotype. Ten of 16 banks have no genetic professional on staff. CONCLUSION: Commercial semen banks primarily rely on family history as the major exclusion criterion in genetic screening of donors. Considerable differences exist among semen bank practices in accordance with guidelines published by national agencies. Genetic professionals have a minimal effect overall on evaluation of semen donors.

Adult↗