Hiroto Tajima

Green tea extracts attenuate doxorubicin-induced spermatogenic disorders in conjunction with higher telomerase activity in mice

PurposeThe aim of this study was to investigate the protective effect of green tea extracts against doxorubicin-induced damage in the mouse testes correlating with telomerase activity.MethodsGreen tea extracts were administered orally. Doxorubicin was coadministered intraperitoneally. These testes were evaluated histologically and the telomerase activity was analyzed. Additional immunostaining was carried out.ResultsBoth the sperm density and sperm motility were significantly increased in green tea extracts coadministration groups as compared to the doxorubicin-treated groups. By histological analysis, germ cell damage was greatly attenuated by green tea extracts coadministration. Telomerase activity significantly increased in association with the coadministration of green tea extracts as compared to that of doxorubicin-only groups. In all groups, human telomerase reverse transcriptase signals were mainly observed in the spermatocytes and spermatids.ConclusionsThese findings suggest that green tea extracts exert protective effects against doxorubicin-induced spermatogenic disorders in conjunction with higher telomerase activity levels.

The development of novel quantification assay for mitochondrial DNA heteroplasmy aimed at preimplantation genetic diagnosis of Leigh encephalopathy

Purpose: To perform preimplantation genetic diagnosis (PGD) of Leigh encephalopathy, we developed a rapid and reliable quantification assay for the percentage of T8993G mtDNA mutation and analyzed various specimens. Methods: We prepared the standard curve by measuring serial proportion of 8993T/G cloned plasmid DNA using real-time PCR, and measured (1) mutant DNA (known proportions by PCR-RFLP), (2) single lymphocytes from 46% mutant carrier, (3) 123 blastomeres from 20 abnormal embryos. Results: (1) These were within −5∼+6% error range, (2) mean 44.3%(11–70%), (3) Five embryos harbored T8993G mutation (4–22%). Embryos from same person indicated different degrees of heteroplasmy, and blastomeres from same embryo demonstrated limited dispersion of heteroplasmy (2–11%). Conclusions: (1) This method provides rapid and reliable PGD for Leigh encephalopathy. (2) The variable heteroplasmy with somatic mitosis was suggested. (3) T8993G mutation was existed in undeveloped embryo, and the bottleneck theory was supported. The limited heteroplasmy dispersion of blastomeres from same embryo also supported reliability of PGD for T8993G mutation.

C‐kit expression in spermatogonia damaged by doxorubicin exposure in mice

The purpose of this study was to assess the relationship between chronically impaired spermatogenesis induced by exposing mice to doxorubicin (DXR) and expression of the infertility factor c‐kit.

A nationwide survey on gynecologic endoscopic surgery in Japan, 2014–2016

Since 2014, Japan Society of Gynecologic and Obstetric Endoscopy and minimally invasive therapy (JSGOE) conducted a nationwide survey on gynecologic endoscopic surgery. We aimed to evaluate the current status and complications associated with endoscopic surgery by Japan gynecologic and obstetric endoscopy‐database registry system (JOE‐D).

Incidental deviation of short and long CAG repeats in the androgen receptor gene for Japanese male infertility

AimThe present study investigated whether the CAG repeat length in exon 1 of the androgen receptor gene on the X chromosome is associated with male infertility.MethodsThe CAG repeat length between the two groups of 143 idiopathic infertile Japanese men with severe oligozoospermia or non-obstructive azoospermia and 100 fertile men were analyzed. The azoospermia factor deletions were also analyzed.ResultsAlthough there was no significant difference in the mean length between the two groups observed (P = 0.055), the distribution in the infertile men was wider than that in the fertile men. Similar results were detected in the combined data from previous Japanese reports and our present data including 261 infertile and 235 fertile men. We detected 12 and 34 CAG repeats in the present study that were the shortest and the longest repeats in Japan, respectively.ConclusionsThese results suggest that excessive expansion or reduction of CAG repeats might be related to impaired spermatogenesis.