Suchergebnisse

The hypothesis that the month-specific rate of return to ovarian cyclicity after childbirth is causally related to suckling pattern was tested for a population of New Mexican women recruited within the service area of New Mexico Highlands University and for a nationwide USA subpopulation of women recruited through membership of the Couple to Couple League (CCL). Survival analysis for time-dependent covariates was used, and significant predictors of the first postpartum menses were found. Important differences were detected in the suckling pattern for the two groups and a 5:2 differential was found in their respective rates of menstrual cycle recovery. Although the two groups were comparable perinatally, daily and time-windowed breast-feeding performance fell off at twice the rate for the New Mexico population when contrasted with the CCL sample. For both populations, the introduction of solid feeds was a strong and significant predictor of returning menstrual cyclicity, independent of suckling pattern.

Longitudinal data were analyzed for seminal characteristics of rhesus monkeys and beagles. The monkeys were exposed to DBCP; the beagles were exposed to acute or chronic whole body gamma irradiation. The semen was analyzed for volume and sperm concentration. Sperm were measured for percent motility, swimming speed, and head dimensions. Abnormalities of the sperm tail were also noted. All treatments resulted in measurable effects on the semen parameters. Sperm production, as evaluated by seminal sperm concentration or total sperm numbers in the ejaculate, was as informative of testicular toxicity as any other parameter or combination of parameters. A consistent finding was that changes in sperm output occurred concomitantly with changes in sperm motility.