Mario Ikeda

Gene expression of gonadotrophin-releasing hormone, but not its receptor, in human endometrium and decidua

Gonadotropin-releasing hormone (GnRH) has been reported to exist in extrahypothalamic tissues such as the placenta, gonads and mammary glands. While we have reported the presence of GnRH-mRNA in the rodent uterus, there have been no reports concerning gene expression of GnRH and its receptor (GnRH-R) in human endometrial tissue. In order to investigate the role of GnRH as a local regulator in the human endometrium, we examined the gene for GnRH and GnRH-R in non-pregnant endometrium and decidua of early pregnancy. Using reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis we found GnRH-mRNA but not GnRH-R-mRNA transcripts in the human endometrium and decidua at 7-9 weeks gestation. This is the first report that suggests GnRH gene expression in the human endometrium/decidua.

In vitro culture of mouse GV oocytes and preantral follicles isolated from ovarian tissues cryopreserved by vitrification

Cryopreservation of ovarian tissues containing many immature oocytes occurs in both gamete/embryo research and clinical medicine. Using vitrification, we studied factors related to meiosis after cryopreservation using the COCs (cumulus oocyte complexes) and preantral follicles obtained from cryopreserved ovarian tissues.COCs were isolated and cultured for 17–19hr. Thereafter, Metaphase II stage (MII stage) oocytes and fertilized oocytes after IVF were observed at a rate of 76.5% and 60.0%, respectively. Preantral follicles (100–130μm in diameter) were isolated and cultured in α MEM containing hFSH, ITS, and FBS. HCG and EGF were added to the media to stimulate ovulation on the 12th day of culture. The survival rates of the follicles obtained from the frozen/thawed ovaries were 66.4%. After 12 days of culture, the diameter of the follicles isolated from fresh (620.2±11.3μm) and frozen/thawed ovaries (518.7±15.1μm) differed as did the estradiol concentrations (3474.2±159pg/ml vs. 1508.2/+-134pg/ml). After in vitro ovulation, MII stage oocytes were observed in 84.5% of the fresh group and 60.5% of the frozen/thawed group while the fertilization rate was 74.2% and 53.5%, respectively. These studies demonstrate that cryopreservation of mouse ovarian tissues by vitrification did not affect the oocyte’s ability to undergo meiosis. Thus, this technique may become a powerful tool for the preservation of the female gamete.

Gene expression of double-stranded RNA-dependent protein kinase in the human endometrium and decidua.

To clarify the biological significance of double-stranded RNA-dependent protein kinase (PKR), an interferon (INF)-inducible substance, we investigated (1) PKR gene expression and the (2) effect of IFN-gamma on PKR gene expression in human endometrium. By Northern blot analysis, PKR mRNA was detected as a 2.5 kb band in human endometrium throughout the menstrual cycle and decidua in early pregnancy. The addition of IFN-gamma to culture medium increased the PKR mRNA level in a dose-dependent manner in cultured endometrial stromal cells. These results suggest that IFN-gamma, which is reported to have an inhibitory effect on cell proliferation, plays an important role in human endometrial function by mediating PKR gene expression.

Laparoscopy for the treatment of unexplained infertility

AimTo determine the best treatment for unexplained infertility.MethodsA retrospective study was used to examine Japanese women with unexplained infertility that had undergone laparoscopy. The main outcome measure of the study was the rate of pregnancy after laparoscopy.ResultsOne hundred and thirty-eight women diagnosed with unexplained infertility received laparoscopy and as a result 55 women had their diagnosis of unexplained infertility confirmed. There were no statistically significant differences between the women who became pregnant after laparoscopy in terms of duration of infertility, duration of treatment or age. The pregnancy rate of women with unexplained infertility was 56.4%, with 90% of these pregnancies achieved within the first 6 months. There were 64 women with minor endometriosis considered to be suffering from unexplained infertility before laparoscopy. The characteristics of the patients in the unexplained infertility group and in the minor endometriosis group were similar, but patients with minor endometriosis were found to have a lower pregnancy rate compared to those with unexplained infertility (35.9%vs 56.4%;P= 0.02).ConclusionsThe effective period after laparoscopy appears to be 6 months. Assisted reproductive technology should be considered after that time. Pregnancy rates were low in women with minor endometriosis compared with unexplained infertility. It is important to clarify the cause of infertility using laparoscopy.