Kondoh N

Spermatogenic ability is different among males in different Y chromosome lineage

AbstractIt is a controversial question whether sperm concentrations in humans are changing. Several researchers have reported on environmental factors affecting sperm quality, but the influence of genetic factors is still not fully understood. In this study, we examined the relationship between Y chromosome haplotypes and sperm concentration in fertile males. In addition, we determined the haplotypes of azoospermic patients. The results show that the mean sperm concentration correlates with Y chromosome type. Moreover, the occurrence of azoospermia is related to one particular Y chromosome lineage. Thus, males with a certain haplotype are at a disadvantage for fathering children. The difference of spermatogenic ability among men is important not only in pursuing male competition as in the past but also as relates to the future of modern human males.

The Y Chromosome Region Essential for Spermatogenesis

We analyzed DNA from 153 Japanese men with azoospermia or severe oligozoospermia whose Y chromosomes were cytogenetically normal. A total of 23 loci on the Y chromosome were examined: 15 loci within interval 6 including YRRM1 and DAZ, and 8 loci outside interval 6. Microdeletions were observed in 20 individuals. All deletions involved at least one locus within interval 6. The YRRM1 gene deletion was found in 4 patients, of whom 2 also lacked the SMCY gene. The remaining 16 individuals shared the absence of 10 loci between DYS7C and DYS239 including the DAZ gene. Among them, 13 were azoospermic while 3 showed a little sperm production, indicating that the common deletion resulted in phenotypic diversity. Since there is no region commonly deleted in all patients, azoospermia caused by deletion of the Y chromosome long arm may be genetically heterogeneous.

Chromosomal variants among 1790 infertile men

Abstract Background: The largest cytogenetic survey involving infertile men was undertaken to clarify whether chromosomal abnormalities, including autosomal abnormalities, affect semen qualities.

Serum HGF levels in acute renal rejection after living related renal transplantation

Hepatocyte growth factor (HGF), a long sought-after hepatotrophic factor, has recently been shown to act as a renotrophic factor in regeneration of the kidney. We investigated serum HGF levels in 16 renal transplant patients. In patients with acute rejection, the serum HGF level was markedly increased (over 1 ng/ml), and its elevation was accompanied by an increase in serum creatinine and blood urea nitrogen (BUN). In contrast, serum HGF levels were continuously low in patients without rejection. We conclude that serum HGF may become a clinically useful marker for the assessment of acute renal rejection.

Significance of Subclinical Varicocele Detected by Scrotal Sonography in Male Infertility: A Preliminary Report

To assess the clinical significance of subclinical right varicocele, we used scrotal sonography for a prospective study of 68 infertile patients with a clinical left varicocele. A significant difference was found in the improvement in postoperative semen characteristics between sonographically diagnosed bilateral and unilateral groups. We conclude that a subclinical right varicocele is also detrimental for spermatogenesis in patients with a clinical left varicocele.

Optimal Temperature for Synthesis of DNA, RNA, and Protein by Human Testis in Vitro

To determine the optimal temperature for DNA, RNA, and protein syntheses in the human testis, the levels of incorporation of 3H-thymidine, 14C-uridine, and 14C-leucine into testicular tissue were studied at 28 degrees C, 31 degrees C, 34 degrees C, and 37 degrees C in vitro. The results suggest that the DNA synthesis is at a maximum at 31 degrees C and shows delicate temperature sensitivity, whereas the RNA and protein syntheses are at a maximum at 34 degrees C or 37 degrees C and are temperature-dependent. It is concluded that the temperature sensitivity of DNA synthesis may be one of the primary causes of delicate thermal inhibition of human spermatogenesis.

SUSCEPTIBILITY TO IDIOPATHIC AZOOSPERMIA IN JAPANESE MEN IS LINKED TO HLA CLASS I ANTIGEN

PURPOSE Approximately 15 to 20% of infertile men have azoospermia. In the Y chromosome a deletion, termed the azoospermic factor, has been found in some cases of idiopathic azoospermia. We investigate the relationship of factors in autosomal chromosomes (HLA class I antigens) to spermatogenesis failure in idiopathic azoospermia. MATERIALS AND METHODS We evaluated 65 infertile Japanese men with idiopathic azoospermia. The frequency of the HLA allele reported in 1,216 healthy Japanese men was used as a control. HLA class I typing was performed by the National Institutes of Health standard serological method or polymerase chain reaction-sequence specific primer analysis. Allele frequencies were calculated. We determined statistical significance in the frequency of each allele in patients and controls using the chi-square test. The relationship of HLA antigens to idiopathic azoospermia was expressed as relative risk. RESULTS In Japanese men with idiopathic azoospermia the frequency of HLA-A33, B13 and B44 was significantly increased compared with controls. The relative risk of HLA-B44 was 8.4, an extremely high value compared with that of other diseases and HLA antigens. CONCLUSIONS We suggest that HLA class I antigens are important genetic markers that represent a risk factor for idiopathic azoospermia.

Induction of renin-angiotensin system in human testis in vivo.

To better understand the local renin-angiotensin system in Leydig cells of the human testis, the plasma renin activity (PRA) and plasma concentration of angiotensin II (PAII) in the left internal spermatic vein (ISV) and cubital vein (CV) were measured at the time of surgical repair of varicocele in 27 patients. Fourteen of the patients were given a single i.m. injection of hCG (10,000 IU/m2) 4 days before the operation, whereas the remaining 13 were not treated. Although the mean PRA or PAII levels in the CV in the treated and nontreated groups were similar, both levels in the ISV in the treated group were significantly higher than in the nontreated group (p less than 0.05). For PAII levels in the treated group, nine of 11 patients with an increased PRA level showed significantly higher levels than the normal peripheral PAII value. The serum testosterone levels in the same ISV were also much higher in the treated group than in the nontreated group (p less than 0.001). These results suggested the possibility that sex steroids might influence the renin-angiotensin system in Leydig cells.

Testicular steroids in spermatic and peripheral veins after single injection of hCG in patients with varicocele

To determine the function of Leydig cells in patients with varicocele, hCG-stimulated levels of progesterone (Prog), 17 alpha-Hydroxy-4-pregnene-3,20-dione (17OHP), 4-Androstene-3,17-dione (A-dione), testosterone (T), and estradiol-17 beta (E2) in both spermatic and peripheral veins were measured. Seventy-two patients with idiopathic varicocele were divided into four groups: patients in group 1 were untreated, whereas patients in groups 2, 3, and 4 were given a single i.m. injection of 10,000 IU hCG 24 h, 96 h, and 168 h before surgery, respectively. In the spermatic and peripheral veins, levels of Prog, 17OHP, and E2 showed peaks at 24 h, whereas levels of A-dione and T showed peaks at 96 h. Significant increases in the ratios of spermatic veins 17OHP to A-dione and 17OHP to T, and a significant decrease in the ratio of T to E2, was found 24 h following hCG treatment. These results demonstrate that, following hCG injection, there is a transient inhibition of testicular C17-20-lyase activity, probably mediated by E2, even in subfertile males with varicocele.

A PROSPECTIVE COMPARATIVE TRIAL OF A GONADOTROPIN-RELEASING HORMONE ANALOGUE WITH CLOMIPHENE CITRATE FOR THE TREATMENT OF OLIGOASTHENOZOOSPERMIA

Background: We undertook a prospective trial to compare the efficacy and adverse effects of a gonadotropin releasing‐hormone analogue (CnRHa) and clomiphene therapy for idiopathic normogonadotropic oligoasthenozoospermia (INOA).