Kaoruko Mizuno

Analysis of the phospholipid hydroperoxide glutathione peroxidase mRNA in the rat spermatozoon and effect of selenium deficiency on the mRNA

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a selenium (Se)-dependent glutathione peroxidase. It is reported that the relative PHGPx mRNA levels are much higher in the testis than in the other tissues. We have analyzed the existence and structure of the PHGPx mRNA in rat sperm and the changes in the level of the PHGPx mRNA after feeding with Se-deficient diets. We used 8-wk-old male Wistar strain rats given Se-adequate feed (control group, n=5) and Se-deficient diets with marginal levels of Se (0.03 ppm or less) (Sedeficient group, n=5) for 4 wk. The existence and level of the PHGPx mRNA in the cauda epididymal sperm, testis, and liver from the Seadequate rats were analyzed by the reverse transcription-polymerase chain reaction and the Southern blotting method. As a result, the existence of the PHGPx mRNA was demonstrated in the cauda epididymal sperm as well as in the testis and liver. Moreover, the subtype of the PHGPx mRNA in the rat sperm was the mitochondrial-type mRNA, which included a region corresponding to the mitochondrial transfer leader sequence. These results imply that the intracellular localization of PHGPx may be regulated by the transcription level. On the other hand, there was no significant difference between the control group and the Se-deficient group in the Se level of the cauda epididymal sperm and the level of the PHGPx mRNA. In conclusion, it has been demonstrated that the PHGPx mRNA exists in rat sperm for the first time. The analysis of the PHGPx mRNA in the sperm would be a useful tool for investigating the disfunction caused by the disorder of the level or structure of the PHGPx in the sperm.

Mucinous Cystadenocarcinoma with Sarcoma‐like Mural Nodules Arising in a Mature Cystic Teratoma of the Ovary: A Case Report

Almost all cases with malignant transformation of a mature cystic teratoma of the ovary have been reported to be associated with squamous cell carcinoma. We describe a very rare case of mucinous cystadenocarcinoma with sarcoma‐like mural nodules arising in an ovarian teratoma.

Effect of Oocyte Retrieval from a Small Leading Follicle in Fixed-Schedule in vitro Fertilization Program

Objective: To evaluate the propriety of oocyte retrieval (OR) from a small leading follicle during a fixed‐schedule in vitro fertilization (IVF) program.

Life-table analysis of artificial insemination pregnancy rates for couples with male factor and idiopathic infertility

BackgroundIn the summer of 2002, standard guidelines for the application of assisted reproductive technology were reported by a research group of the Ministry of Health, Labor and Welfare. The present study aimed to examine the relationship between the number of cycles of artificial insemination and the cumulative pregnancy rates according to the cause of infertility.MethodsPatients who experienced their first cycle of artificial insemination during the period of January 1999-December 2002 were included in the study and were divided into a male factor infertility group and an idiopathic infertility group. Cumulative pregnancy rates resulting from artificial insemination with the husband’s semen were calculated by the life-table approach.ResultsDuring the study period, 139 couples entered the assisted reproduction program and underwent 581 cycles. Significant differences were observed in cumulative pregnancy rates between the two groups.ConclusionIt is recommended that couples with male factor infertility and who fail to conceive within six or seven cycles of intrauterine insemination, consider a modification of treatment strategy such asin vitro fertilization, because cumulative pregnancy rates of this group were reached at a plateau within six or seven cycles. In contrast, patients with idiopathic infertility, the cumulative pregnancy rates appeared to increase constantly with each subsequent cycle. It is important to consider modifications of treatment strategy in the light of the cause of infertility.

Oxidative state and zona-binding ability in mouse spermatozoa treated with reduced glutathione

Background and AimsNuclear proteins in mature mammalian spermatozoa nuclei are oxidized to form numerous disulfide bonds. Reduced glutathione (GSH) in the oocyte has been linked to spermatozoan nuclear decondensation after fertilization. In this study, we analyzed whether GSH reduced protamines in sperm nuclei in vitro, and examined the zona-binding ability of treated nuclei.MethodsThree groups of mouse cauda epididymal sperma-tozoa were prepared. The first group was cultured in Chatot-Tasca-Ziomek (CZB; control group), the second in 10 mmol/L GSH (GSH group), and the third group was the GSH group recultured in CZB (re-cultured group). Each sperm was stained with acridine orange, and the oxidative and reductive state of nuclei was analyzed by using fluorescence microscopy. Furthermore, we examined the zona-binding ability for each group by insemination to mouse oocytes after exposure to hyaluronidase.ResultsAll sperm nuclei from the control group displayed an oxidized pattern (green), and those from the GSH group displayed a reduced pattern (red), attributable to reduced protamines. Sperm nuclei from the re-cultured group displayed the oxidized pattern. Although the zona-binding ability of the GSH group was deteriorated compared with the control group sperm, no significant differences were observed between the control and re-cultured groups.ConclusionFrom these results, in vitro reduced sperm were shown to be oxidized in CZB. A reduction of mouse spermatozoa in vitro by GSH is, therefore, reversible, and the oxidative state of sperm nuclei exerts an effect on zona-binding ability.