Haim Yavetz

Increased rate of nondisjunction in sex cells derived from low-quality semen

Abstract 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.

Fertility of men following inguinal hernia repair.

Summary. Among 8500 patients attending the fertility clinic due to infertility, 565 men (6.65%) reported an incidence of inguinal hernioplasty with or without subsequent atrophy of the testis. Semen quality (sperm concentrations, motility, and morphology) of these patients was markedly reduced in comparison to that of fertile men. In cases where hernioplasty was followed by atrophy of the testis, damage to sperm characteristics and Sertoli cell function was found to be far greater. This was also reflected in significant serum follicle stimulating hormone elevation (P< 0.0025). No changes in luteinizing hormone and testosterone were found. No correlation was found between age of hernioplasty and semen quality following operation. The reasons for testicular damage may be due to ischaemic orchitis or immunological reactions.

The hemizona assay is of good prognostic value for the ability of sperm to fertilize oocytes in vitro

OBJECTIVES To assess the prognostic value of hemizona assay (HZA) in predicting the success of IVF. DESIGN Samples from 133 patients, who were referred for semen evaluation, were tested by HZA. Thirty samples were tested twice to assess interassay variation. Seventy couples were also referred for IVF. Results of HZA were compared with standard parameters of sperm quality, fertilization rates, and pregnancies. RESULTS The intra-assay and interassay coefficient of variation were 8% and 14%, respectively. Hemizona assay results had the highest correlation with sperm morphology (r = 0.60). Of all parameters evaluated, fertilization rates were best predicted by hemizona index (HZI) (r = 0.75). The assay was found to have high sensitivity and specificity rates, at a threshold HZI of 23%. CONCLUSIONS The HZA is a valuable prognostic test for IVF. With a threshold HZI of 23%, it has a good predictive value for fertilization rates in IVF, and may thus be used for patient preselection before IVF.

Cryptorchidism: incidence and sperm quality in infertile men.

Summary. In a population of 8500 men attending the andrology outpatient clinic, 200 men (2.35%) were recorded as having some disturbances with the descent of the testes into the scrotum. Medical history of the patients revealed that 51 underwent unilateral orchidopexy; 40 bilateral orchidopexy; and 24 were treated with human chorionic gonadotropin in order to induce descent of their testes. In addition, 6 patients reported spontaneous descent of the testes, and 13 others were found to be unilaterally cryptorchid upon physical examination. Results of semen analysis, hormonal profile, testes position, and testicular volume were compared to those of 105 proven fertile men. The major finding of this study shows that post‐partum undescended testes suffer from primary Sertoli cell malfunction as reflected by elevated serum follicle stimulating hormone levels. Serum luteinizing hormone and testosterone levels were within the normal range. Surgical descent of the testes did not improve sperm production, proved by low sperm quality of all the study groups, compared to the cryptorchid group. Among the patients who were operated on, no correlation was found between age at operation and semen variables. All groups showed poor sperm quality which can be defined as oligoteratoasthenozoospermia. The degree of spermatogenic damage was in the following order of diagnosis or treatment: bilateral orchidopexy > cryptorchid testes > hormonal treatment > unilateral orchidopexy > late spontaneous descent of the testes. Thus, it is advisable to postpone surgical treatment of cryptorchidism and apply this only after a waiting period, and if the hormonal approach has failed to descend the testis.

Prerequisites for successful human sperm cryobanking: sperm quality and prefreezing holding time

Frozen-thawed donor semen was used in artificial inseminations and in vitro fertilization programs. Semen accepted for donation was characterized (mean +/- SE) by sperm concentration of 150 +/- 18.6 x 10(6)/mL, normal morphology of 57% +/- 1.4%, good progressive motility at 1 hour of 57% +/- 1.0%, and post-thaw motility of 45% +/- 1.0%. Delay of the freezing process for greater than 1 hour after semen delivery caused a deleterious effect to the freezability of sperm. The average monthly fecundability for the 1st 6 months after inseminations was 13.6%. This value decreased dramatically to 2.6% from the 7th month onward. In 74 IVF/embryo transfer (ET) cycles, the fertilization rate was 55.3% +/- 3.8%, pregnancy rate (PR) per ET was 39.6%, and the PR per woman was 42.8%.

Sertoli cell maturation in men with azoospermia of different etiologies

OBJECTIVE To evaluate the involvement of Sertoli cell in different spermatogenic disorders. DESIGN Retrospective case-control study. SETTING Teaching hospital. PATIENT(S) Azoospermic men who underwent testicular biopsy for sperm recovery in preparation for intracytoplasmic sperm injection. INTERVENTION(S) Testicular biopsy evaluation by quantitative immunohistochemistry for the immature Sertoli cell markers anti-Müllerian hormone and cytokeratin 18 (CK-18). MAIN OUTCOME MEASURE(S) Relative area of immature Sertoli cells in testes with focal spermatogenesis, spermatocyte maturation arrest, or normal spermatogenesis. RESULT(S) The relative area occupied by immature Sertoli cells, as revealed by anti-Müllerian hormone and CK-18 expression, was highest in the 11 men with focal spermatogenesis. In the group representing normal spermatogenesis (obstructive azoospermia, 6 men) and in the group characterized by spermatocyte maturation arrest (6 men), the areas occupied by anti-Müllerian hormone- and CK-18-positive cells were minimal. CONCLUSION(S) Different etiologies underlie the spermatogenic disorders reported in this study. In focal spermatogenesis with high anti-Müllerian hormone and CK-18 expression, the spermatogenic impairment is associated with the presence of immature Sertoli cells. The detection of normal mature Sertoli cells in the spermatocyte maturation arrest group indicates that the spermatogenic defect that is accompanied by an impairment of meiosis is intrinsic to the germ line without affecting Sertoli cell differentiation.

Virtual Azoospermia and Cryptozoospermia—Fresh/Frozen Testicular or Ejaculate Sperm for Better IVF Outcome?

Men diagnosed as having azoospermia occasionally have a few mature sperm cells in other ejaculates. Other men may have constant, yet very low quality and quantity of sperm cells in their ejaculates, resulting in poor intracytoplasmic sperm injection (ICSI) outcome. It has not been conclusively established which source of sperm cells is preferable for ICSI when both ejaculate and testicular (fresh or frozen) sperm cells are available. It is also unclear whether there is any advantage of fresh over frozen sperm if testicular sperm is to be used. We used ejaculate, testicular (fresh or frozen) sperm cells, or both for ICSI in 13 couples. Five of these couples initially underwent ICSI by testicular sperm extraction, because the males had total azoospermia, and in later cycles with ejaculate sperm cells. Ejaculate sperm cells were initially used for ICSI in the other 8 patients, and later with testicular sperm cells. The fertilization rate was significantly higher when fresh or frozen-thawed testicular sperm cells were used than when ejaculated sperm cells were used. Likewise, the quality of the embryos from testicular (fresh and frozen) sperm was higher than from ejaculated sperm (65.3% vs 53.2%, respectively, P < .05). The use of fresh testicular sperm yielded better implantation rates than both frozen testicular sperm and ejaculate. Therefore, fresh testicular sperm should be considered first for ICSI in patients with virtual azoospermia or cryptozoospermia because of their superior fertility.

Expression of CDY1 may identify complete spermatogenesis

OBJECTIVE To investigate the expression of deleted in azoospermia (DAZ), RNA-binding motif (RBM), and chromodomain y1 (CDY1) genes in the testes of men with azoospermia with variable histopathologies. DESIGN Prospective study. SETTING Andrology laboratory of a university-affiliated maternity hospital. PATIENT(S) Sixty-six men with azoospermia. INTERVENTION(S) Testicular sperm extraction. MAIN OUTCOME MEASURE(S) The results of gene expression in testicular tissue tested by RT-PCR were correlated with those of histopathologically and microscopically examined minced testicular tissue. Y chromosome microdeletion testing and karyotyping were performed, as was direct sequencing of CDY1-PCR products. RESULT(S) CDY1-minor expression was detected in all biopsies in which mature spermatids/spermatozoa were observed by histological analysis and/or in the minced tissue. CDY1-minor expression was also detected in two biopsies with arrest at the spermatocyte stage during which no mature spermatids/spermatozoa were observed. A previously unreported CDY1-minor alternative splicing transcript was identified. DAZ and RBM gene expressions were detected in all biopsies in which at least a few germinal cells in early stages were found and in one biopsy histologically determined as Sertoli cell only. CONCLUSION(S) Our preliminary results suggest that CDY1-minor expression might increase the prospect for complete spermatogenesis, while RBM and DAZ expression can only be indicative of the presence of germinal cells.

Intrauterine insemination in male factor subfertility: significance of sperm motility and morphology assessed by strict criteria

Summary.  The study was conducted to evaluate the results of IUI treatment in a homogenous group with male factor infertility, and to assess the correlation of sperm variables, including sperm morphology by strict criteria, with pregnancy achievement after IUI. A total of 108 couples with no apparent female aetiology for infertility underwent 264 intrauterine insemination treatment cycles. A comparison was made between the sperm variables in two groups in which the achievement of pregnancy differed. The percentage of motile spermatozoa, degree of motility and normal morphology (by strict criteria) were significantly higher in the pregnant group compared with that of the nonpregnant group. A significant difference in pregnancy rates per couple after intrauterine insemination was demonstrated among three groups according to the percentage of sperm morphology, i.e. poor (< 4%), fair (4–14%) or good (> 14%) (11.1%; 36.1% and 50.0%, respectively). Intrauterine insemination is a valid mode of treatment in cases with male infertility, provided that normal morphology by strict criteria is higher than 4%.

Members of the CDY family have different expression patterns: CDY1 transcripts have the best correlation with complete spermatogenesis

The CDY family of genes is of special interest because some of them are included in chromosome-Y microdeletions detected among infertile men and are apparently involved in the spermiogenetic process. In this study, we employed the reverse transcriptase/polymerase chain reaction technique to test the RNA expression of the various transcripts of these genes in testicular biopsies of 84 azoospermic men who had been classified by comprehensive histology and cytology analyses. We also evaluated the feasibility of detecting CDY expression in biopsies taken by testicular sperm extraction versus acquisition by aspiration. There was a significant association between the type of testicular impairment and the expression of CDY1 and CDY2 transcripts. CDY2 was expressed whenever germ cells were present, but CDY1 major and especially CDY1 minor and short transcripts were identified almost exclusively when mature spermatids/spermatozoa were detected. The expression of CDY1 minor and short transcripts detected in aspirated specimens was less efficient than that in testicular tissue acquired by extraction. It is sugested that CDY2 is apparently required in the early stages of spermatogenesis, whereas CDY1 transcripts are required later on in the process. The findings of this study imply different functional roles for CDY isoforms during spermatogenesis. However, in consideration of the high levels of identity between CDY1 and CDY2 (98% at the protein level), the delayed up-regulation of CDY1 transcripts could be attributable to temporal changes in dosage requirements.