Individual variation of the percentage of Y-chromosome bearing sperm content in human ejaculates.

The study aimed to determine the variation of Y-chromosome-bearing sperm content among individual ejaculates. A real-time polymerase chain reaction (qPCR) with unique primers was developed and used to calculate the percentage of Y-chromosome-bearing sperm in individual ejaculates from 50 randomly selected men. There was a significant difference in the overall mean ± SD between the proportion of Y-chromosome-bearing sperm and X-chromosome-bearing sperm (45.36 ± 7.88 vs. 54.42 ± 7.88). Of the 50 ejaculates, 17 had more than, and 14 had less than the 99% confidence interval of the mean of the Y-chromosome-bearing sperm (45.58 ± 2.87). These results suggest that the inconsistency in sperm-based sex-selection outcomes appears to be a function of differences in the ejaculates and highlights the need for further study in environmental and genetic factors contributing to X or Y bearing spermatozoan instability.Abbreviations: qPCR: real-time polymerase chain reaction; ROS: reactive oxygen species; DTT: dithiothreitol; SRY: sex-determining region Y.

A novel laboratory procedure to validate American Urological Association guideline on vasectomy success and to diagnose obstructive azoospermia.

The objective was to develop a laboratory procedure to validate American Urological Association (AUA) Guideline on vasectomy success when nonmotile spermatozoa are found in the post-vasectomy ejaculate. The neutral α-glucosidase (NAG) an epididymal protein assay modified to determine the activity at 30 and 90 min of incubation from 24 pre- and 47 post-vasectomy ejaculates. The difference between the two points in the relative activity was calculated and if the difference was nonsignificant will confirm vasectomy success. The mean differences in the relative NAG activity were significantly different in pre- and post-vasectomy ejaculates, respectively. The mean differences in the relative NAG activity were similar in post-vasectomy ejaculates with and without nonmotile spermatozoa. No difference in relative NAG activity in post-vasectomy ejaculates between two time points of incubation may be a reliable method to confirm occlusion of the vas deferens. It also validates the recommendation by AUA Guideline on vasectomy success in the presence of few nonmotile spermatozoa.

The relevance of neutral alpha-glucosidase activity in andrology.

To assess the usefulness of routine determination of neutral alpha-glucosidase (NAG) in andrology, 216 ejaculates were analyzed for NAG activity and semen quality. A correlation between NAG activity and semen volume and sperm concentration was determined; however, no correlation was observed between NAG activity and sperm motility or sperm morphology. The number of azoospermic ejaculates that had NAG activity below acceptable levels was significantly higher than the number of non-azoospermic ejaculates with similarly low NAG levels. Routine determination of NAG activity is not practical; however, when an epididymal pathology leading to a physiological or anatomical functional alteration is suspected, the determination of NAG activity is a valuable tool in the diagnosis, and would also aid in the prognosis.

Interleukin 1 receptor antagonist gene polymorphisms are not risk factors for recurrent pregnancy loss: evaluation of couples.

PROBLEM: The interleukin-1 system has been implicated in pregnancy outcome. Fetal carriage of interleukin-1 receptor antagonist (IL-1Ra) specific alleles has been associated with adverse pregnancy outcomes including spontaneous abortion and pre-term labor. This study was undertaken to compare the frequency of IL-1RN 2 alleles among both male and female partners of couples experiencing recurrent pregnancy loss with that of fertile control couples. METHOD OF STUDY: Buccal swabs were obtained from 42 couples experiencing recurrent pregnancy loss and from 20 fertile control couples. DNA was extracted from the buccal swabs and analyzed for the presence of IL-1RN variable number tandem repeat. RESULTS: No significant differences were found when the frequency of IL-1RN 2 polymorphisms were compared between fertile control couples and couples experiencing recurrent pregnancy loss. Similar results were also obtained when comparing women or men respectively from each group. CONCLUSION: IL-1RN 2 allele is not a risk factor for recurrent pregnancy loss.