Recently, microdeletions in the azoospermic factor region of the Y chromosome, in addition to chromosomal anomalies, have been detected in men with azoospermia or severe oligozoospermia. In this study we evaluated the molecular and cytogenetic defects of infertile men. The frequency of Y microdeletions among 105 azoospermic, 28 oligozoospermic and 32 fertile men was tested on lymphocyte DNA using a series of 20 sequence-tagged sites. In addition, microdeletions were evaluated on testicular-derived DNA among 26 azoospermic patients who underwent testicular biopsy and in whom no sperm cells could be identified. Karyotype analysis was performed on 72 of the infertile patients. Deletions were detected in 6.7% azoospermic and 3.6% oligozoospermic men. No deletions were identified among the fertile men. Identical results were obtained with DNA derived either from lymphocytes or testicular tissue. The frequency of chromosomal aberrations in the 72 infertile patients tested (62 azoospermic, 10 oligozoospermic) was 16.6%, with a high percentage of gonosome anomalies. Additional andrological parameters (hormone values, cryptorchidism) failed to identify men at risk for having microdeletions before the test. Our findings support the recommendation to perform genetic defect screening among infertile men before their enrollment in an intracytoplasmic injection/in-vitro fertilization programme.

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The relationship between chromosomal nondisjunction and semen quality was studied in two groups of males who differ highly in their semen quality: 12 individuals with low-quality semen caused by varicocele, and 8 subjects with high-quality semen, selected from sperm donors for in vitro fertilization. Chromosomal nondisjunction was inferred from the rate of disomy found in mature sperm cells. To determine the rate of disomy, we applied fluorescence in situ hybridization using satellite-specific probes for chromosomes 1, 15, 18, X and Y. In sperm cells of males with low-quality semen, the mean rate of disomy for each of the autosomes and of hetero-disomy for the sex chromosomes (XY) was significantly higher than that observed in the high-quality semen samples: more than 15-fold higher for chromosomes 1 and 15, and 7-fold higher for chromosomes 18 and XY. Yet, the homo-disomy rate for each of the sex chromosomes (XX and YY) was almost the same in both types of semen. The large discrepancy between the low- and high-quality semen in the rate of sex chromosome hetero-disomy versus the similar rate of homo-disomy strongly suggests that the abnormal chromosomal segregation in meiocytes of males with low-quality semen resulted from chromosomal nondisjunction at the first meiotic division. The results indicate that men showing poor semen quality are at an increased risk for meiotic nondisjunction, similar to women at the end of their reproductive years.

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We report the presence of protein kinase C (PKC) in ejaculated human sperm as revealed by enzymatic activity assay and indirect immunohistochemistry. PKC is localized in the equatorial segment and in the principal piece of the tail. Addition of phorbol 12-myristate 13-acetate resulted in increased flagellar motility that was blocked by known PKC inhibitors such as sphingosine, staurosporine, and 1-(5-isoquinoylinylsulfonyl)-2-methylpiperazine. A very good correlation (r = 0.9, P < 0.001) was found between the percentage of PKC-stained sperm cells and motility. We propose that PKC is involved in the regulation of flagellar motility in human sperm.

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Lymphomas are a group of diseases, prevalent at reproductive age. Fertility is notoriously reduced among lymphoma patients. This study evaluates pre- and post-treatment semen concentration and motility, and factors associated with semen quality deterioration. We followed-up 33 patients with non-Hodgkin's lymphoma or with Hodgkin's disease during the years 1987-1997 who were referred for semen cryopreservation. Pretreatment semen analysis, and hormonal profile were recorded at diagnosis and at least 1 year after completion of the treatment, and compared. Medical records for disease type, disease stage and treatment protocols were related to long-term sperm outcome. Hormonal concentrations were not predictive of post-treatment sperm concentration. In patients with localized disease, initial sperm concentration and motility tended to be preserved, compared with patients with widespread disease (P: = 0. 016). In Hodgkin's disease patients, treatment with the adriamycin, bleomycin, vinblastine and dacarbazine (ABVD) protocol was superior to the mechloretamine, vincristine, procarbazine and prednisone with ABV protocol regarding germinal toxicity (P: = 0.0008). The post-treatment sperm outcome was better in patients treated with local irradiation than in those who did not undergo irradiation (P: = 0.0027). No predictive tools for post-treatment fertility were found and, therefore, every patient with a lymphoma should have his semen cryopreserved at diagnosis.