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P A Fernandes

Publications and source records attributed to P A Fernandes.

20 records · Page 2Linked to original sources
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Y body association with morphologic heterogeneity of human sperm.

OBJECTIVE: The purpose of this study was to determine a possible association between the Y body and sperm head shape, since sperm head shape may be a factor that influences the rate of migration of X- and Y-bearing sperm cells. MATERIALS: Sperm cell (n = 1,065) preparations from seven donors were fluorochrome stained for the Y body, and area and shape of Y body-positive and -negative cells were measured from digitized images. The distributions of the segregated cell population measurements were statistically analyzed nonparametrically. RESULTS: Of the total cells, 528 were Y body-positive and 537 were not, and the ratio (0.983) of the two cell categories, both within and between donors, was equivalent to the theoretical ratio of 1.0 expected for the X:Y sperm cell population. Sperm head area distributions were equal between the two populations. However, the length-width ratios of Y-bearing cells were significantly higher (P < .0001) and calculated roundness was significantly (P = .006) less than non Y body-bearing cells. CONCLUSIONS: The Y body may represent the Y chromosome. Furthermore, the Y body may impart a more ellipsoidal shape to sperm cells. Sperm shape may influence the migration rate of cells through cervical mucus such that differences in the male-to-female sex ratio of conceptuses, and at birth, may reflect a shape-imparted advantage in the migration rate of Y-bearing sperm in reaching the oocyte.

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Maternal prolactin secretion is phasic during induced term and post-term labor.

OBJECTIVE: We hypothesized that regimens of labor induction do not alter the biphasic secretion of maternal prolactin (PRL) seen during spontaneous labor. METHODS: Serial blood samples drawn from 12 women before, during, and after induced labor were assayed for PRL and hCG and compared with cervical dilatation and uterine contraction frequency (UCF). Induction methods were cervical ripening with dinoprostone gel (Prepidil) followed by oxytocin infusion (n = 1), amniotomy followed by oxytocin (n = 4), oxytocin followed by amniotomy (n = 3), amniotomy only (n = 2), and oxytocin only (n = 2). RESULTS: Regardless of the induction method, PRL decreased with advancing cervical dilatation during the first stage of labor and reached a nadir at full dilatation. Prolactin levels then increased rapidly during the second stage, correlating significantly with the increase in UCF, and peaked at 1 hour postpartum before decreasing. Levels of hCG increased during labor and peaked just before or at delivery before rapidly decreasing. CONCLUSIONS: The biphasic secretion of maternal PRL is a fundamental characteristic of active term labor and occurs regardless of the method used to induce labor.

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