研究者総覧

鈴木 達也 (スズキ タツヤ)

  • 生殖医学センター 准教授
Last Updated :2021/12/04

研究者情報

学位

  • 医学博士(自治医科大学)

ホームページURL

J-Global ID

研究キーワード

  • 精子   超活性化   プロテインフォスファターゼ   リン酸化   タンパク質   透明帯   発生・分化   免疫性不妊症   生理学   シグナル伝達   受精   プロテオーム   

研究分野

  • ライフサイエンス / 産婦人科学

経歴

  • 2013年12月 - 現在  自治医科大学医学部准教授

学歴

  • 1991年04月 - 1997年03月   新潟大学   医学部   医学科

所属学協会

  • 日本卵子学会   日本産科婦人科内視鏡学会   日本受精着床学会   日本生殖医学会   日本産科婦人科学会   日本アンドロロジー学会   日本がん・生殖医療学会   

研究活動情報

論文

  • Yoshimitsu Wada, Hironori Takahashi, Hirotada Suzuki, Mai Ohashi, Manabu Ogoyama, Shiho Nagayama, Yosuke Baba, Rie Usui, Tatsuya Suzuki, Akihide Ohkuchi, Hiroyuki Fujiwara
    European journal of obstetrics, gynecology, and reproductive biology 260 1 - 5 2021年05月 
    OBJECTIVE: To clarify the natural history of retained products of conception (RPOC) following abortion at less than 22 weeks of gestation, and those who show major bleeding during course observation. STUDY DESIGN: We retrospectively reviewed 640 patients who had spontaneous or artificial abortion at less than 22 weeks of gestation between January 2011 and August 2019 in our institute. Of those, patients with RPOC were included. The maternal background, RPOC characteristics, and subsequent complications including additional interventions were reviewed. RESULTS: Fifty-four patients with RPOC were included. The incidence of RPOC was 6.7 %. The median (interquartile range: IQR) RPOC length was 29 (20-38) mm. RPOC hypervascularity was observed in 26 (48 %) patients. The median (IQR) periods of RPOC flow disappearance and RPOC disappearance on ultrasound from abortive treatment were 50 (28-76) and 84 (50-111) days, respectively. Of the 54, 44 patients were selected for expectant management. Of the 44, 34 (77 %) patients were observed without intervention (recovery group); the other 10 (23 %) patients required additional interventions associated with subsequent bleeding (intervention group). Compared with the recovery group, heavy bleeding (> 500 mL) at abortion (6/10: 60 %) and RPOC hypervascularity (8/10: 80 %) were more frequently observed in the intervention group. CONCLUSION: Expectant management was successful in almost 80 % of patients with RPOC following abortion. The additional interventions were required in patients with heavy bleeding at abortion and RPOC hypervascularity.
  • Yasushi Yumura, Akira Tsujimura, Hiroshi Okada, Kuniaki Ota, Masahumi Kitazawa, Tatsuya Suzuki, Toshiyuki Kakinuma, Chie Watanabe, Seido Takae, Nao Suzuki, Teruaki Iwamoto
    International journal of clinical oncology 24 1 94 - 102 2019年01月 [査読有り][通常論文]
     
    BACKGROUND: Treatment advancements have improved young cancer patients' survival rate considerably. Fertility preservation has become a very important tool in the prevention of treatment-induced gonadal toxicity. This study aimed to examine hematologists' awareness of its necessity and importance. METHODS: Questionnaires were mailed to the directors of 230 institutes that treated hematological malignancies in adults. The directors were asked to provide information regarding their institutes, collaboration with sperm banks, the number of patients treated per year, selection criteria for patients providing information, and their awareness of and attitudes toward sperm preservation. RESULTS: The response rate was 40.0%. Municipal and private hospitals treated patients significantly less frequently relative to university hospitals (p = .002). Of the 92 participating hematology institutions, 17 included sperm banks and 69 collaborated with sperm banks in neighboring institutions. Many participants stated that sperm preservation should be performed before chemotherapy; however, only 38% provided sperm preservation information to all patients. Participants in facilities without sperm banks exhibited significantly lower levels of knowledge regarding sperm preservation, relative to those from institutions with sperm banks, and found discussing fertility preservation burdensome. This trend was identical to that observed in a survey conducted 10 years earlier. CONCLUSION: Many hematologists did not appear to possess sufficient knowledge regarding fertility preservation. Moreover, few institutions included sperm banks, and a considerable burden was exerted on hematologists. The introduction of support systems is required to promote sperm preservation before cancer treatment.
  • Matsubara S, Takahashi H, Suzuki T
    Archives of gynecology and obstetrics 298 3 459 - 460 2018年09月 [査読有り][通常論文]
  • Yumura Y, Tsujimura A, Okada H, Ota K, Kitazawa M, Suzuki T, Kakinuma T, Takae S, Suzuki N, Iwamoto T
    Asian journal of andrology 20 4 336 - 341 2018年07月 [査読有り][通常論文]
  • Shigeki Matsubara, Tatsuo Morita, Shigeaki Muto, Tatsuya Suzuki
    Journal of Obstetrics and Gynaecology 38 4 587  2018年05月 [査読有り][通常論文]
  • Matsubara S, Takahashi H, Suzuki T
    Archives of gynecology and obstetrics 297 1 269 - 270 2018年01月 [査読有り][通常論文]
  • Yoichi Ishida, Akihide Ohkuchi, Tatsuya Suzuki, Toshihiro Takizawa, Hironori Takahashi, Shigeki Matsubara
    JOURNAL OF REPRODUCTIVE IMMUNOLOGY 124 82 - 82 2017年11月 [査読有り][通常論文]
  • Shigeki Matsubara, Shiho Nagayama, Risa Narumi, Rie Usui, Tatsuya Suzuki
    ACTA OBSTETRICIA ET GYNECOLOGICA SCANDINAVICA 96 7 898 - 899 2017年07月 [査読有り][通常論文]
  • Junko Koriyama, Hiroaki Shibahara, Tomoe Ikeda, Yuki Hirano, Tatsuya Suzuki, Mitsuaki Suzuki
    Reproductive Medicine and Biology 12 1 21 - 25 2013年 [査読有り][通常論文]
     
    Purpose: There is a need to improve our understanding of the cut-off value of the direct immunobead test (D-IBT). Methods: The subjects were 26 D-IBT-positive and 140 D-IBT-negative males. The results of post coital tests (PCTs) for each subject were examined. Results: A significant difference was observed in abnormal PCTs between values < 20 % and those ≥20 % (P = 0.02). However, there was no significant difference in abnormal PCTs between values < 50 % and those ≥50 % (P = 0.084). Conclusions: A cut-off value of 20 % was correlated with the possibility of conception on treatment with IUI. The D-IBT is a screening test, and the value of 20 % initially suggested by Bronson et al. seems to be more appropriate than that of 50 % in the criteria defined by the World Health Organization. © 2012 Japan Society for Reproductive Medicine.
  • Shibahara Hiroaki, Ikeda Tomoe, Shimada Kazuhiko, Hirano Yuki, Suzuki Tatsuya, Suzuki Mitsuaki
    16TH WORLD CONGRESS ON IN VITRO FERTILIZATION AND THE 5TH WORLD CONGRESS ON IN VITRO MATURATION 5 - 10 2011年 [査読有り][通常論文]
     
    Since Stein and Leventhal reported that all women menstruated regularly post ovarian wedge resection and some of them conceived, ovarian surgery has been used to induce ovulation following unsuccessful medical induction of ovulation. Because of the rapidly expanding use of techniques involving laparoscopy, laparoscopic ovarian drilling (LOD) by the trans-abdominal approach has been widely used to induce ovulation in women with PCOS after failure of treatment with clomiphene citrate (CC). In 1998, to minimize the invasiveness of laparoscopy for diagnostic purposes, transvaginal hydrolaparoscopy (THL) was introduced as the first line procedure in the exploration of the adnexal structures in infertile women. Moreover, operative THL such as ovarian drilling for unovulatory women with PCOS to induce ovulation has also appeared to be as effective as that by LOD. This procedure is named transvaginal hydrolaparoscopic ovarian drilling (THLOD). This review article describes the usefulness of THLOD for the treatment of infertile women with PCOS.
  • Tatsuya Suzuki, Masakatsu Fujinoki, Hiroaki Shibahara, Mitsuaki Suzuki
    REPRODUCTION 139 5 847 - 856 2010年05月 [査読有り][通常論文]
     
    It has been widely accepted that serine/threonine protein phosphatases (PPPs) are associated with the regulation of sperm hyperactivation. In the present study, we examined the types of PPPs associated with the regulation of hamster sperm hyperactivation. Protein phosphatases PPP1CA, PPP1CC, PPP2, and PPP3 are present in hamster sperm. In the experiments using several inhibitors, sperm hyperactivation was enhanced when PPP2 was inhibited at least, although inhibition of PPP1 also enhanced sperm hyperactivation. Interestingly, sperm were hyperactivated after PPP2 became an inactive form. And then, PPP1CA became an active form after sperm were hyperactivated. It has also been widely accepted that tyrosine phosphorylation is closely associated with the regulation of sperm hyperactivation. When PPP2 was inhibited, tyrosine phosphorylation was not enhanced at all. On the other hand, inhibition of PPP1 enhanced tyrosine phosphorylation. From the results, it is likely that PPP2 is closely associated with the regulation of sperm hyperactivation, although it is not associated with the regulation of tyrosine phosphorylation. Reproduction (2010) 139 847-856
  • Takashi Watanabe, Shigeki Matsubara, Yosuke Baba, Hitoshi Tanaka, Tatsuya Suzuki, Mitsuaki Suzuki
    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH 35 3 562 - 564 2009年06月 [査読有り][通常論文]
     
    Segawa disease is an autosomal dominant trait characterized by progressive dystonia with marked diurnal fluctuation. Levodopa therapy dramatically improves the symptoms. We present the case of a pregnant woman with Segawa disease with a successful outcome. At the age of ten, bilateral clubfeet appeared as her first symptom. She was diagnosed as having Segawa disease and levodopa was administered with complete disappearance of the symptoms. She became pregnant and received levodopa throughout the pregnancy, and delivered a healthy male infant. A literature review and the present case indicated that out of nine pregnancies in six women with Segawa disease, all six pregnancies treated with levodopa monotherapy resulted in an uneventful obstetrical course and healthy infants; however, the remaining three pregnancies, two with levodopa and carbidopa and one without medication, resulted in fetal loss. Women with Segawa disease may be able to give birth to healthy infants with levodopa monotherapy.
  • Hiroaki Shibahara, Kazuhiko Shimada, Kumiko Kikuchi, Yuki Hirano, Tatsuya Suzuki, Satoru Takamizawa, Hiroyuki Fujiwara, Mitsuaki Suzuki
    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH 33 5 705 - 709 2007年10月 [査読有り][通常論文]
     
    Aim: Transvaginal hydrolaparoscopy (THL) has recently been developed as a less invasive alternative to conventional laparoscopy. There are some reports that described the usefulness and prognostic value of diagnostic THL in infertile women. Moreover, operative THL such as ovarian drilling for unovulatory women with polycystic ovarian syndrome (PCOS) to induce ovulation has also been found to be as effective as that by conventional laparoscopy. The risk of bowel injury and sepsis by transvaginal access with culdoscopy was higher than that with laparoscopy in the previous reports. The purpose of the present study was to examine the risk of diagnostic and operative THL according to two case studies with a literature review. Methods: The authors carried out diagnostic or operative THL in 177 infertile women, aged 22-43 years. Major complications during THL and a review of the literature were analyzed. Results: Two cases of bowel injury were diagnosed during diagnostic THL. No complication occurred during operative THL. In total, the incidence of bowel injury was 1.1%. The injuries were diagnosed during THL and treated expectantly under strict conditions in both cases. Ten studies in the literature reported a total of 4232 procedures, including 26 bowel injuries (0.61%) and one perforation of a retroflexed uterus (0.02%). Conclusions: The usefulness of THL for diagnostic and operative purposes is in no doubt. However, informed consent should be obtained and vigilance before and during THL should be maintained, although it can be done on an outpatient clinic basis.
  • Hiroaki Shibahara, Yuki Hirano, Takeshi Okajima, Kazuhiko Shimada, Kumiko Kikuchi, Tatsuya Suzuki, Satoru Takamizawa, Mitsuaki Suzuki
    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH 33 4 501 - 505 2007年08月 [査読有り][通常論文]
     
    Aim: Elective transfer of two good-quality embryos has been used to avoid triplet or high-order multiple pregnancies. However, the rate of twin pregnancies has remained fairly unchanged. In the present study, criteria for elective single embryo transfer (eSET) at day 2 or day 3 were established by analyzing cases with successful implantation of all embryos transferred. Methods: A total of 685 fresh or frozen-thawed embryo transfers following in vitro fertilization/intracytoplasmic sperm injection between April 2002 and March 2006 were performed. Only embryo transfers at day 2 or day 3, but not at blastocyst stage, were. included. Successful implantation of all embryos transferred was obtained in 17 pregnancy cycles. Results: Thirty-one gestational sacs with fetal heartbeats were obtained by a total of 31 embryo transfers in 17 infertile women. The average age was 32.6 years (23-38), and 14 (82.3%) of the 17 women were <36 years old. Fifteen (88.2%) of the 17 pregnancies were established at the first attempt of assisted reproductive technology (ART). Of the 17 women, eight (47.1%) women were multigravida and four (23.5%) women were multipara. The indications for ART or insemination methods did not seem to be related to the pregnancy results. Twenty-nine (93.5%) of 31 embryos implanted were considered good-quality embryos. Of the 17 fresh embryos transferred at day 2, 15 were at the 4-cell stage and two were at the 5-cell stage. Of the 11 fresh embryos transferred at day 3, one was at the 6-cell stage, two were at the 7-cell stage and eight were at the 8-cell stage. Conclusion: The criteria for eSET at day 2 or day 3 were established as follows: <36 years of age, a first treatment cycle and more than two good-quality embryos developed at least to the 4-cell stage at day 2, or 6-cell stage at day 3. Additionally, the past history of pregnancy or delivery should be considered, as patients positive for such history might have better implantation ability. eSET can be highly recommended to avoid twin pregnancies in subjects with the established criteria.
  • Hiroaki Shibahara, Kumiko Kikuchi, Yuki Hirano, Tatsuya Suzuki, Satoru Takamizawa, Mitsuaki Suzuki
    FERTILITY AND STERILITY 87 6 1487 - 1490 2007年06月 [査読有り][通常論文]
     
    Metformin appears to be an effective medicine to induce ovulation in women with polycystic ovary syndrome and insulin resistance. After the introduction of metformin treatment for such cases, the use of gonadotropin in combination with metformin significantly increased the incidence of multiple pregnancies.
  • Masakatsu Fujinoki, Tatsuya Suzuki, Takeshi Takayama, Hiroaki Shibahara, Hideki Ohtake
    Reproductive medicine and biology 5 2 123 - 135 2006年06月 [査読有り][通常論文]
     
    Background and Aims:  It has been widely accepted that sperm hyperactivation is regulated by protein phosphorylations. But, the sperm hyperactivation phosphorylation pathway is not well understood yet because several different proteins have been detected in other studies. In order to understand the phosphorylation pathway that regulates hyperactivation, we established how to extract sperm protein completely and detected proteins that were phosphorylated during hyperactivation. Methods:  Protein phosphorylation of hamster spermatozoa was detected by western blotting using antiphospho-amino acid monoclonal antibodies or the SELDI ProteinChip system with IMAC-Ga(III). Results:  We detected 75 protein/peptide phosphoryations using the method established in the present study. Tyrosine phosphorylations occurred during hyperactivation. Serine or threonine phosphorylations occurred for 30 min. Furthermore, four of the serine or threonine phosphorations were phosphorylated by A-kinase. As for peptides, 15 peptides were dephosphorylated for 30 min. Other peptides were phosphorylated during hyperactivation. Conclusions:  Because most of the proteins detected in the present study have been described previously, we could detect comprehensive protein phosphorylations. Moreover, we also detected many novel phosphopeptides. Although we did not understand the role of peptide, it was likely that motility was basically regulated by serine/threonine phosphorylations and hyperactivation was mainly regulated by tyrosine phosphorylations. (Reprod Med Biol 2006; 5: 123-135).
  • H Shibahara, Y Hirano, K Kikuchi, T Suzuki, S Takamizawa, M Suzuki
    FERTILITY AND STERILITY 85 1 244 - 246 2006年01月 [査読有り][通常論文]
     
    Transvaginal hydrolaparoscopic ovarian drilling (THLOD) appears to be an effective minimally invasive procedure to induce ovulation in women with polycystic ovary syndrome (PCOS). Postoperative endocrinological alterations following THLOD show significant decrease of serum LH and testosterone concentrations.
  • Hiroaki Shibahara, Yuki Hirano, Yasuko Shiraishi, Kazuhiko Shimada, Kumiko Kikuchi, Tatsuya Suzuki, Satoru Takamizawa, Mitsuaki Suzuki
    Reproductive Medicine and Biology 5 2 137 - 143 2006年 [査読有り][通常論文]
     
    Aims: It has been shown that supplementation of patients' sera that contains sperm-immobilizing antibodies results in failure of fertilization and embryo development in vitro. The present study was carried out to investigate if exposing retrieved eggs to a high number of sperm-immobilizing antibodies in the follicular fluid (FF) in vivo affected subsequent fertilization and embryo development in vitro, even if they were washed with an antibody-free culture medium. Methods: Patients' sera and their FF were collected in 15 in vitro fertilization-embryo transfer (IVF-ET) or intracytoplasmic sperm injection-embryo transfer (ICSI-ET) treatment cycles from 11 infertile women with sperm-immobilizing antibodies in their sera. Quantitative sperm-immobilizing antibody titers (SI50 titers) in the sera and FF were evaluated. The fertilization rate, good-quality embryo rate and implantation rate by IVF-ET were compared between infertile patients having higher (10≤) SI50 titers and lower (< 10) SI50 titers in their FF. Results: There was a significant correlation in the SI50 titers between the patients' sera and their FF (P < 0.0001). After thoroughly washing the collected eggs in culture medium without the patient's serum before IVF, there was no difference in the fertilization rate in the patients with high (10≤) and low (< 10) SI50 titers in their FF (P = 0.62). However, the good-quality embryo rate in the patients with a high SI50 titer was significantly lower than patients with a low antibody titer (P < 0.05). There was no significant difference in the implantation rate between the two groups (P = 0.33). Conclusions: Similar amounts of sperm-immobilizing antibodies existed in the patients' FF and in their sera. ICSI did not seem to be necessary in patients having the antibodies if their sera were not supplemented in the culture media. Even with careful manipulation of eggs, it might be suggested that the harmful effects of sperm-immobilizing antibodies on embryo development cannot be completely avoided, especially in patients with high SI50 titers in the FF. © 2006 The AuthorsJournal compilation © 2006 Japan Society for Reproductive Medicine.
  • H Shibahara, T Suzuki, K Kikuchi, Y Hirano, M Suzuki
    AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY 54 4 186 - 192 2005年10月 [査読有り][通常論文]
     
    Problem Matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) play important roles throughout various stages of pregnancy, including embryo implantation, trophoblastic invasion, placentation in early gestation, and cervical dilatation in later gestation, and feto-maternal membrane lysis. It would be beneficial if assessment of serum concentrations of MMP and TIMP could predict successful implantation following in vitro fertilization-embryo transfer (IVF-ET). This study was performed to compare serum MMP and TIMP concentrations between patients with and without the establishment of pregnancy following ET. Method of study Ten patients who conceived and 10 patients who did not after IVF-ET were entered in the present study. Only intra-uterine single pregnancies with uneventful courses to term were included in the study subjects. Blood samples were obtained at 7, 14 and 21 days after oocyte retrieval. Serum concentrations of MMP-1, MMP-2, MMP-3, and TIMP-1 were measured using enzyme-linked immunosorbent assay. These variables were compared with estradiol (E-2), progesterone (P-4), and beta hCG levels in the patients' sera. Clinical pregnancies were diagnosed only when fetal heartbeat was visualized on ultrasound. Results There were no significant differences in serum MMP concentrations between the pregnant group and the non-pregnant group. However, serum TIMP-1 concentrations on Days 14 and 21 in the pregnant group were significantly higher than those in non-pregnant group [Day 14: 223.1 +/- 11.9 versus 177.5 +/- 20.6 ng/mL (P = 0.004); Day 21: 215.4 +/- 27.8 versus 181.5 +/- 27.4 ng/mL (P = 0.03)]. Serum TIMP-1 concentrations were also correlated with serum E-2 and P-4 levels (P < 0.0001), but not with those of the MMPs. None of MMP nor TIMP-1 were correlated with serum beta hCG level. Conclusions It was demonstrated that the patients who successfully conceived after IVF-ET showed significantly higher levels of TIMP-1 at 14 and 21 days after IVF-ET, but not at day 7; further work will be required to determine if serum TIMP-1 can be used to improve prediction of pregnancy outcome in these patients.
  • T Suzuki, H Shibahara, Y Hirano, H Fujiwara, S Takamizawa, M Suzuki
    JOURNAL OF MINIMALLY INVASIVE GYNECOLOGY 12 5 420 - 425 2005年09月 [査読有り][通常論文]
     
    STUDY OBJECTIVE: To investigate the feasibility and clinical usefulness of transvaginal salpingoscopy (TS) during transvaginal hydrolaparoscopy (THL) in infertile women. DESIGN: Retrospective study (Canadian Task Force classification II-3). SETTING: Jichi Medical School, Tochigi, Japan. PATIENTS: One hundred thirty infertile women, aged 22 to 43 years, who underwent THL. INTERVENTIONS: Transvaginal salpingoscopy findings in comparison with THL findings. MEASUREMENTS AND MAIN RESULTS: Transvaginal salpingoscopy could be performed in 41.0% of the attempted tubes. In comparing rates of successful TS in relation to tubal patency, tubal morphology, and past Chlamydia trachomatis infection, patent tubes and normal-appearing tubes classified with normal morphology had a significantly higher TS success rate. However, past C trachomatis infection did not affect the success of TS. There was a significant correlation between salpingoscopic and laparoscopic findings; however, there were no significant correlations between salpingoscopic findings and C trachomatis antibody titers. CONCLUSIONS: These findings suggest that TS can be performed simultaneously in some infertile women undergoing THL especially those with patent tubes or with normal-appearing tubes. Further studies are required to show the usefulness of intratubal exploration in assessing tubal infertility. (c) 2005 AAGL. All rights reserved.
  • Hiroaki Shibahara, Kazuhiko Shimada, Yukako Morimatsu, Kumiko Kikuchi, Yuki Hirano, Tatsuya Suzuki, Satoru Takamizawa, Mitsuaki Suzuki
    Reproductive Medicine and Biology 4 4 265 - 269 2005年 [査読有り][通常論文]
     
    Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of ovulation induction for infertile women. It has been shown that patients suffering from OHSS are generally young because OHSS depends on the patient's ovarian reserve. Therefore, women ≥40 years of age seldom suffer from the severe form of OHSS. In the present study, we report a case of severe OHSS that occurred in a 42-year-old woman with a successful pregnancy after intracytoplasmic sperm injection (ICSI)-embryo transfer. She had been diagnosed as having polycystic ovary syndrome (PCOS). After 5 cycles of unsuccessful treatment with gonadotropins plus intrauterine insemination for her husband's asthenozoospermia, the treatment with assisted reproductive technology (ART) was indicated. In the third ART attempt, the patient was treated by ICSI-embryo transfer (ET) and she developed severe OHSS at 4 weeks' gestation. On admission, marked hemoconcentration, oligouria and hypo-albuminemia were diagnosed. A continuous autotransfusion system of ascites, which was developed to expand circulating plasma volume without exogenous albumin, was carried out for 5 h at a rate of 100-200 mL/h once a day for a total of 5 days. The course of the pregnancy was uneventful. At 37 weeks' gestation, a healthy baby boy weighing 3336 g was born by cesarean section when the patient was 43 years of age. The postoperative course was also uneventful. To the best of our knowledge, the present report describes the oldest woman showing severe OHSS.
  • Ayustawati, H Shibahara, Y Hirano, T Suzuki, S Takamizawa, M Suzuki
    FERTILITY AND STERILITY 82 3 579 - 585 2004年09月 [査読有り][通常論文]
     
    Objective: To investigate the changes in serum leptin concentration in the conception cycle of severe ovarian hyperstimulation syndrome (OHSS). Design: Prospective longitudinal study of 66 IVF-ET cycles between May 2000 and June 2002. Setting: Infertility outpatient clinic at a Japanese medical school. Patient(s): Infertile patients undergoing IVF-ET cycles at the infertility outpatient clinic were divided into three groups consisting of group I (conception-cycle patients with severe OHSS, n = 9), and group 2 (conception cycle, non-OHSS, n = 28), and group 3 (nonconception cycle, non-OHSS, n = 29). Intervention (s): Blood samples were collected at five different periods. Period 1, on the first day of ovarian stimulation with FSH; period II, at hCG administration before oocyte retrieval; period III, 7 days after oocyte retrieval; period IV, 14 days after oocyte retrieval; and period V, 21 days after oocyte retrieval. Main Outcome Measure(s): Serum leptin concentration. Result(s): The serum leptin concentration was low in the OHSS group compared with that of the non-OHSS groups in all serum samples, with significant levels at periods III (vs. groups 2 and 3; P<.05) and IV (vs. group 3; P<.01). A twofold increase of leptin concentration from period I to period II (P<.05) was observed in all groups. Conclusion(s): The change pattern in serum leptin concentration might provide a great contribution to the pathophysiology development of OHSS patients during assisted reproductive treatment. (C) 2004 by American Society for Reproductive Medicine.
  • H Shibahara, H Obara, Ayustawati, Y Hirano, T Suzuki, A Ohno, S Takamizawa, M Suzuki
    INTERNATIONAL JOURNAL OF ANDROLOGY 27 2 63 - 68 2004年04月 [査読有り][通常論文]
     
    This study was performed to predict pregnancy by intrauterine insemination (IUI) using computer-aided sperm analysis (CASA) estimates and strict criteria in patients with male factor infertility. IUI was performed in 682 cycles on 160 male factor infertile patients. Semen examinations were carried out by CASA and strict criteria before and after sperm preparation using continuous-step density gradient centrifugation. Receiver operating characteristics (ROC) curves were constructed for assessment of the effectiveness of each individual parameter in predicting pregnancy by IUI. A clinically acceptable threshold was calculated when sensitivity plus specificity were maximum. The average cycle of IUI performed was 4.3+/-2.4. Pregnancy rate per cycle and per patient were 7.2% (49/682) and 28.1% (45/160), respectively. Using ROC curve, it was shown that normal sperm morphology assessed by the strict criteria before sperm separation and five parameters after sperm separation including rapid, progressive motility, average path velocity (VAP), curvilinear velocity (VCL), and straight line velocity (VSL) were able to predict pregnancy by IUI. Correlation between sperm parameters and pregnancy outcome was examined by the logistic regression model. In a multivariate analysis normal morphology before sperm separation greater than or equal to15.5% [odds ratio (OR)=2.2, p=0.02], rapid after sperm separation greater than or equal to25.5% [OR=3.9, p=0.029], and VCL after sperm separation greater than or equal to102.65 mum/sec [OR=3.2, p=0.002] were the parameters of predictive value for pregnancy outcome. Adjustment of the model for female age, female infertility factors, and the methods of ovulation induction did not change this finding, and the final model still had the same covariates. Pregnancy rates per cycle according to the number (0, 1, 2 and 3) of variables satisfied with the three parameters were 0% (0/110), 1.6% (3/183), 9.7% (21/217) and 15.1% (23/151), respectively. Three semen parameters including normal morphology before sperm separation, rapid and VCL after sperm separation were identified as predictors of pregnancy by IUI. These variables would be helpful when counselling patients before they make the decision to proceed with in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI)-ET.
  • Tatsuya Suzuki, Hiroaki Shibahara, Yuki Hirano, Akiko Ohno, Satoru Takamizawa, Mitsuaki Suzuki
    Reproductive Medicine and Biology 3 2 99 - 104 2004年 [査読有り][通常論文]
     
    Objective: The number of embryos transferred is very important to avoid multiple pregnancies without compromising pregnancy rates in in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI)-embryo transfer (ET). We established criteria for the elective transfer of two embryos (age < 40, first treatment cycle, good-quality embryos ≥3) to avoid high-order multiple pregnancies, and reported their usefulness. In the current study, we compared the clinical outcome of day 2 versus day 3 elective transfer of two good-quality embryos, in order to investigate the day of preferential transfer. Methods: A total of 228 cycles were treated with IVF/ICSI-ET from August 1999 to August 2002. From this total, 114 patients who were less than 40 years old and also had a first treatment cycle were enrolled in the present study (50.0%). The elective transfer of two good-quality embryos was carried out in 36 cycles (31.6%). Patients were randomized for transfer on either day 2 or day 3 after oocyte retrieval. Results: The pregnancy rate of women who received two good-quality embryos was 44.4% (16 out of 36). The multiple pregnancy rate was 12.5% (two out of 16) and all pregnancies outcomes were twins. There were no significant differences between day 2 and day 3 ET for the following criteria: the number of cycles (24, 12) age (32.8 ± 3.4 years, 32.5 ± 2.7 years) number of oocytes retrieved (10.0 ± 3.3, 9.0 ± 6.0) number of embryos developed (7.6 ± 3.5, 6.9 ± 3.7) and number of good-quality embryos cryopreserved (3.5 ± 2.7, 3.6 ± 2.1). Higher pregnancy and implantation rates were obtained in day 3 ET than day 2 ET (37.5 and 20.8% in day 2 ET vs 58.3 and 33.3% in day 3 ET) however, there were no significant differences. Conclusion: Day 3 ET appears to be preferable to achieve more viable embryos than day 2 ET.
  • Tatsuya Suzuki, Hiroaki Shibahara, Kumiko Kikuchi, Yuki Hirano, Satoru Takamizawa, Mitsuaki Suzuki
    Reproductive Medicine and Biology 3 4 217 - 221 2004年 [査読有り][通常論文]
     
    It is well known that Chlamydia trachomatis causes acute and chronic pelvic inflammatory disease including salpingitis. We describe a case of successful pregnancy following conservative treatment of massive ascites associated with acute Chlamydia trachomatis peritonitis. In this present case, we conservatively treated a woman with acute chlamydial salpingitis accompanied with marked ascites and an adnexal mass that simulated a malignant neoplasm. Elevated CA125 and CA19-9 also suggested a malignancy at the time of diagnosis, however following treatment they decreased to below the cut-off value, and were useful in identifying the efficacy of medical treatment. The patient subsequently became pregnant after infertility treatment and underwent a normal vaginal delivery. We conclude that the possibility of Chlamydia trachomatis peritonitis should be considered when a patient presents with ascites and an adnexal mass in sexually active women.
  • Kikuchi K, Shibahara H, Hirano Y, Kohno T, Hirashima C, Suzuki T, Takamizawa S, Suzuki M
    American journal of reproductive immunology (New York, N.Y. : 1989) 50 363 - 367 4 2003年10月 [査読有り][通常論文]
  • H Shibahara, H Yamanaka, Y Hirano, K Kikuchi, S Yamanaka, T Suzuki, S Takamizawa, M Suzuki
    INTERNATIONAL JOURNAL OF ANDROLOGY 26 4 211 - 214 2003年08月 [査読有り][通常論文]
     
    This study was carried out to analyse if some of the sperm parameters assessed by computer-aided sperm analysis (CASA) are associated with multinucleate formation in human in vitro fertilization (IVF). In the present study, 137 IVF-embryo transfer (ET) treatment cycles in which pronucleate formation could be observed were enrolled. Sperm parameters after swim-up were assessed using CASA and strict criteria. Thirty-two (2.3%) of 1368 oocytes fertilized were judged as multinucleate formation, which occurred in 25 of 137 IVF-ET treatment cycles, giving the incidence of 18.2%. The factors associated with multinucleate formation were analysed. There were significant differences of the numbers of oocytes collected (13.9 vs. 9.2; p = 0.028), fertilization rate (88.8% vs. 71.9%; p = 0.011), curvilinear velocity (VCL) (162.7 mum/sec vs. 149.1 mum/sec; p = 0.034), average path velocity (VAP) (100.3 mum/sec vs. 93.1 mum/sec; p = 0.016), and amplitude of lateral head displacement (ALH) (5.9 mum vs. 5.3 mum; p = 0.046) between 25 cycles with multipronucleate formation and 112 cycles with two pronucleate formations. However, there were no significant differences of women's age or the number of sperm inseminated between the two groups. These findings suggest that prediction of multinucleate formation in human IVF might be possible in patients when the number of oocytes collected is higher and sperm motility parameters after swim-up are faster. However, prevention of multinucleate formation seems to be unnecessary because a higher successful IVF-ET outcome is expected as a result of the excellent fertilization rate in these patients.
  • H Shibahara, T Onagawa, S Jorsaraei, Y Hirano, T Suzuki, S Takamizawa, M Suzuki
    INTERNATIONAL JOURNAL OF ANDROLOGY 26 4 236 - 241 2003年08月 [査読有り][通常論文]
     
    The aim of the present study is to clarify the clinical significance of the Acridine Orange (AO) test (a sperm function test) as a routine examination by investigating the relationships between chromatin decondensation assessed by the AO test and routine semen analysis. Totally 543 semen samples were obtained from 286 infertile men. The AO test was performed, and spermatozoa displaying green fluorescence were considered as mature. The threshold of green AO fluorescence as 50% was adopted and the values <50% were considered as positive in the test. Computer-aided sperm analysis (CASA) and strict criteria were used for routine semen analysis. Twenty-two (4.05%) of 543 semen samples were positive in the AO test. In 20 semen samples obtained from men with severe male infertility treated by intracytoplasmic sperm injections (ICSI), the positive rate was 30.0%, which was significantly higher than that (2.63%) treated by conventional in vitro fertilization (IVF) (p = 0.01). As for the basic sperm parameters, there were significant correlations between the AO test and sperm motility (p < 0.001), and between the AO test and normal sperm morphology (p = 0.02). However, there was no relationship between the AO test and sperm concentration (p = 0.585). Sperm motion parameters assessed by CASA, including amplitude of lateral head displacement (ALH), curvilinear velocity (VCL) and rapid sperm movement (Rapid), were significantly correlated with the AO test. The information obtained using the AO test was indicated to be useful in planning treatment strategy for infertile couples.
  • T Tsunoda, H Shibahara, Y Hirano, T Suzuki, H Fujiwara, S Takamizawa, S Ogawa, M Motoyama, M Suzuki
    GYNECOLOGICAL ENDOCRINOLOGY 17 4 281 - 286 2003年08月 [査読有り][通常論文]
     
    Dopamine treatment constitutes a mal I or advance towards the management of severe ovarian hyperstimulation syndrome (OHSS) by causing renal and mesenteric vasodilatation as well as diuretic and positive inotropic actions. Docarpamine, an oral dopamine prodrug, is converted into dopamine after enteral administration, and the generated dopamine causes renal vasoodilatation and diuresis. The purpose of this study was to assess whether docarpamine was taken every 8 h. In some cases, the plasma levels of free dopamine were measured. The daily urinary outputs before and 1, 2, 3, and 4 days after the docarpamine treatment were 839 +/- 424 ml, 1121 +/- 608 ml, 1168 +/- 504 ml, 1325 +/- 815 ml and 1133 +/- 509 ml, respectively. There were significant differences between the first and each of the others (p < 0.05). In 19 (86.4%) of 22 patients treated, clinical symptoms associated with ascites were gradually improved after administrating docarpamine. The plasma free dopamine concentration rose to as high as 55.9 +/- 33.2 mg/ml during the first hour, which corresponded to the usual intravenous drip infusion treatment with dopamine. Moreover, there were no major adverse effects of docarpamine in this study. This was the first demonstration of docarpamine treatment in patients with intravenous albumin-resistant OHSS. Although no effect was seen in pregnant women , diureseis was increased in some women, and ascites decreased. These findings indicate that oral docarpamine administration could be one the options in the management of patients with OHSS using dopamine therapy.
  • H Shibahara, Y Shiraishi, Y Hirano, T Suzuki, S Takamizawa, M Suzuki
    HUMAN REPRODUCTION 18 7 1469 - 1473 2003年07月 [査読有り][通常論文]
     
    BACKGROUND: The presence of anti-sperm antibodies (ASA) in males can reduce fecundity. However, it has been shown that there is a diversity of ASA bound to the sperm surface. This study was performed to investigate the inhibitory effects on fertilization by ASA in males. METHODS: ASA were detected using the direct-immunobead test (D-IBT) in 509 semen samples. In some cases, the direct-sperm immobilization test (D-SIT) was carried out. The fertilizing ability of infertile males with ASA was determined as follows; (i) an IVF fertilization rate of greater than or equal to50%, (ii) a hemizona index (HZI) of greater than or equal to50%, and (iii) pregnancy established without the use of ART. RESULTS: In total, 18 (3.54%) infertile males had ASA on the sperm surface. Except for one male with an absolute indication for ICSI because of severe asthenozoospermia and two males who dropped out of this study, fertilizing ability in 15 males could be determined. Four (26.7%) men did not satisfy the criteria. The existence of sperm immobilizing antibodies on the surface of ejaculated sperm had no impact on fertilization. In four (57.1%) of seven patients who had IB-bound sperm of greater than or equal to80%, fertilizing ability was inhibited, while none of the eight patients who had <80% IB-bound sperm had an inhibitory effect on fertilization. There was a significant difference between the two groups (P = 0.01). CONCLUSIONS: Some sperm-bound antibodies are related to the inhibitory effects on fertilization, indicating that a diversity of sperm-bound antibodies exists in males. This result might be one of the reasons for the controversy of the relationship between ASA and male immunological infertility. Based on the present study, a sperm-zona pellucida binding assay should be performed for appropriate decision making in infertile males with ASA.
  • H Fujiwara, H Shibahara, Y Hirano, T Suzuki, S Takamizawa, Sato, I
    FERTILITY AND STERILITY 79 1 186 - 189 2003年01月 [査読有り][通常論文]
     
    Objective: To evaluate the usefulness and prognostic value of transvaginal hydrolaparoscopy (THL) in infertile women. Design: Retrospective study. Setting: Jichi Medical School Hospital, Tochigi, Japan. Patient(s): Thirty-six patients who were followed up for 6 months or longer after THL was performed. Intervention(s): Transvaginal hydrolaparoscopy findings in comparison with hysterosalpingography (HSG). Main Outcome Measure(s): Transvaginal hydrolaparoscopy findings, HSG findings, treatment strategy, and prognosis. Result(s): Twenty of 36 patients (55.5%) became pregnant, including 7 by coitus, 7 by artificial insemination with the husband's semen, and 6 by assisted reproductive technology (ART). In 11 of these pregnant patients, information obtained during THL differed from findings on HSG. Conclusion(s): Transvaginal hydrolaparoscopy is useful in selecting a future treatment strategy.
  • Hiroaki Shibahara, Hiromi Obara, Kumiko Kikuchi, Seiji Yamanaka, Yuki Hirano, Tatsuya Suzuki, Satoru Takamizawa, Mitsuaki Suzuki
    Journal of Mammalian Ova Research 20 1 29 - 33 2003年 [査読有り][通常論文]
     
    Human sperm cannot fertilize oocytes immediately upon ejaculation, but must acquire the ability to bind and penetrate the zona pellucida. Hyperactivation, which is linked to the process of capacitation, is a vigorous pattern of sperm motility marked by wide-amplitude, high-velocity, whiplash movements of the flagellum. This study was performed to investigate the correlation between hyperactivated (HA) motility patterns assessed by computer-aided sperm analysis (CASA) and the fertilization rate (FR) in vitro. Swim-up sperm were collected in 135 IVF cycles with at least 3 oocytes collected. Because no cases satisfied the HA motility pattern of “Star-spin”, patients were divided into 3 groups: Sperm with curvilinear velocity (VCL) ≥ 100 μM/sec, linearity (LIN) < 60% and amplitude of lateral head displacement (ALH) ≥ 5 μM were “All HA”. Sperm with straight-line velocity (VSL) ≥ 40 μM/sec, LIN ≥ 60% and ALH < 5 μM were “Non-HA”. Others were defined as “Transition phase”. The FRs in 81 “All HA” cycles, 33 “Non-HA” cycles, and 21 “Transition phase” cycles were 79.5 ± 26.6%, 65.4 ± 32.5%, and 80.8 ± 27.3% respectively. There was a significant difference between “All HA” and “Non-HA” cycles in the FRs (P=0.018). In 27 (20.0%) of 135 IVF cycles, the FRs were ≤ 50% (“poor” group). Eleven (13.6%) of 81 “All HA” cycles, 12 (36.3%) of 33 “Non-HA” cycles, and 4 of 21 “Transition phase” cycles belonged to the “poor” group. There was a significant difference between “All HA” and “Non-HA” cycles (P=0.006) in these incidences. The better FRs were obtained in patients with “All HA” cycles, and lower FRs were obtained in those with “Non-HA” cycles. These findings suggest that the assessment of HA motility patterns by means of CASA could be one of the predictors of human sperm fertilizing ability. © 2003, JAPANESE SOCIETY OF OVA RESEARCH. All rights reserved.
  • H Shibahara, T Suzuki, H Obara, Y Hirano, T Onagawa, A Taneichi, S Takamizawa, Sato, I
    INTERNATIONAL JOURNAL OF ANDROLOGY 25 1 45 - 48 2002年02月 [査読有り][通常論文]
     
    The aim of the present study is to investigate the accuracy of the normal sperm morphology value by Sperm Quality Analyzer IIC (SQA IIC), which was developed to provide a rapid and low-cost quantitative evaluation of semen quality. Normal sperm morphology was assessed using SQA IIC in comparison with that by the strict criteria in 62 semen samples. Normal sperm morphology value by SQA IIC was based on the studies of three traditional sperm parameters from over 4000 fresh, untreated semen samples, while the strict criteria was based on the method by Kruger et al. The mean +/- SD of percent normal morphology by SQA IIC and the strict criteria were 37.6 +/- 10.9% (range 15-52) and 19.9 +/- 8.2 (range 1-34), respectively. There was a significant correlation of the sperm morphology assessment between the two methods (r = 0.454, p < 0.001). Using the cut-off value of >30% normal morphology by SQA IIC, the positive predictive value and the negative predictive value of the 'normal' strict criteria were 79.6% (39/49) and 46.2% (6/13), respectively. These results indicate that SQA IIC might be used as an initial screening test for the evaluation of sperm morphology. However, sperm morphological assessment by the strict criteria should be performed in order to make decisions in planning strategies for the treatment of infertile couples.
  • T Suzuki, H Shibahara, H Tsunoda, Y Hirano, A Taneichi, H Obara, S Takamizawa, Sato, I
    INTERNATIONAL JOURNAL OF ANDROLOGY 25 1 49 - 54 2002年02月 [査読有り][通常論文]
     
    Sperm Quality Analyzer (SQA) IIC, an upgrade version, is an inexpensive device and provides a quantitative estimation of sperm motility, whereas the use of computer-aided sperm analysis (CASA) provides high precision and provision of quantitative data on sperm kinetics. The aim of the present study was to evaluate if the SQA IIC variables correlated with the CASA estimates. Semen quality analysis of 71 fresh semen samples was performed using SQA IIC and CASA. Total sperm concentration, percentage of progressively motile sperm, percentage of normal morphology, motile sperm concentration, sperm motility index (SMI) and functional sperm count (FSC) determinations were performed using SQA IIC. Sperm concentration, sperm motility, and sperm motion variables including amplitude of lateral head displacement (ALH), beat cross frequency (BCF), curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN = VSL/VCL), and straightness (STR = VSL/VAP) were evaluated simultaneously on the same semen samples using CASA. The sperm characteristics were compared between SQA IIC and CASA. There were significant correlations of sperm concentration (r = 0.634, p < 0.0001), sperm motility (r = 0.697, p < 0.0001), and motile sperm concentration (r = 0.757, p < 0.0001) between the two devices. Both SMI and FSC significantly correlated with eight CASA estimates, including sperm concentration, sperm motility, motile sperm concentration, ALH, VCL, VSL, VAP, and Rapid. SQA IIC is simple and easy to use. Moreover, the SQA IIC variables well correlated with the CASA estimates. As a screening test for semen quality, SQA IIC is considered as useful in the management of male infertility.
  • Taneichi A, Shibahara H, Hirano Y, Suzuki T, Obara H, Fujiwara H, Takamizawa S, Sato I
    American journal of reproductive immunology (New York, N.Y. : 1989) 47 46 - 51 1 2002年01月 [査読有り][通常論文]
  • A Taneichi, H Shibahara, Y Hirano, T Suzuki, H Obara, H Fujiwara, S Takamizawa, Sato, I
    AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY 47 1 46 - 51 2002年01月 [査読有り][通常論文]
     
    PROBLEM: The effects of sperm immobilizing antibodies in the sera of infertile women on fertilization and embryo quality in vitro were investigated. METHOD OF STUDY: Before the introduction of sperm immobilization test (SIT) as a routine test for female infertility, 85 oocytes were collected in nine in vitro fertilization (IVF) cycles from four infertile women who were afterward found having had sperm immobilizing antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium containing the patient's serum. Fifty oocytes were collected in five IVF cycles from five infertile women possessing the antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium supplemented with human serum albumin (HSA). RESULTS: In the former group, 41 of 85 oocytes were fertilized, giving a fertilization rate of 48.2%. In the latter group, 43 of 50 oocytes were fertilized, giving a fertilization rate of 86.0%. There was a significant difference of the fertilization rate between the groups (P < 0.0001). Embryo quality was assessed by the Veeck's classification. The grade I and grade 2 embryos were considered good quality. Using this classification, 16 (39.0%) of 41 embryos incubated in the medium containing the patient's serum were good quality, while 34 (79.1%) of 43 embryos incubated in the medium supplemented with HSA were good quality. There was also a significant difference between the groups (P = 0.0003). CONCLUSIONS: These findings might indicate that sperm immobilizing antibodies in the sera of infertile women cause low fertilization rates and poor embryo quality in vitro. It is suggested that SIT in the sera of infertile women should be performed at least before proceeding IVF. The manipulation of gametes and embryos from patients having sperm immobilizing antibodies should be carefully carried out especially to avoid contaminating patient's serum and follicular fluid in the culture medium in order to have a better IVF result.
  • H Shibahara, H Fujiwara, Y Hirano, T Suzuki, H Obara, S Takamizawa, S Idei, Sato, I
    HUMAN REPRODUCTION 16 8 1690 - 1693 2001年08月 [査読有り][通常論文]
     
    BACKGROUND: A new technique called transvaginal hydrolaparoscopy (THL) was recently developed for the exploration of the tubo-ovarian structures in infertile patients without obvious pelvic pathology. This study was performed to investigate the usefulness of THL to evaluate Chlamydia trachomatis tubal infertility. METHODS: Forty-one women with primary and secondary infertility participated in this study. Fourteen had past C. trachomatis infection. In 38 (92.7%) of the 41, access to the pouch of Douglas was obtained. In total, 71 (93.4%) out of 76 adnexa were clearly visualized. Thirty-seven patients were analysed and compared their tubal passages and peritubal adhesions using both hysterosalpingography (HSG) and THL. Twenty-four tubes from 14 patients with past C. trachomatis infection and 44 tubes from 23 patients without a history of C. trachomatis infection were compared. RESULTS: For the diagnosis of the tubal passage, there were no significant differences in the discrepancy rates between HSG and THL, in patients with and without past C. trachomatis infection. In 14 (58.3%) of the 24 tubes from patients with past C. trachomatis infection and in eight (18.2%) of the 44 tubes from patients without infection, peritubal adhesion was diagnosed only by THL. There was a significant difference in the discrepancy rates of the diagnosis of peritubal adhesion between HSG and THL in the two groups (P = 0.0007). CONCLUSIONS: These results suggest that C. trachomatis infection is highly associated with peritubal adhesion which is difficult to diagnose by HSG. Therefore, in C. trachomatis antibody-positive patients, exclusion of tubal pathology by THL or standard laparoscopy should be carried out to consider appropriate treatments. Although THL is not a substitute for laparoscopy, it can be proposed as a first line procedure in the early stages of the infertility investigation.
  • Y Hirano, H Shibahara, H Obara, T Suzuki, S Takamizawa, C Yamaguchi, H Tsunoda, Sato, I
    JOURNAL OF ASSISTED REPRODUCTION AND GENETICS 18 4 213 - 218 2001年04月 [査読有り][通常論文]
     
    Purpose: Some studies have suggested that computer-aided sperm analysis (CASA) estimates of concentration and movement characteristics of progressively motile spermatozoa are related to fertilization rates in vitro. However, it has also been suggested that the greater number of motility parameters assessed by CASA does nor imply more precision in predicting fertility. This study was carried out to investigate the relationships between the CASA estimates and fertilization rates in vitro. Methods: Semen quality analysis M,ns performed using CASA in 136 in vitro fertilization-embryo transfer (IVF-ET) cycles with at least 3 oocytes collected. The CASA estimates before and after swim-up were compared between 108 cycles with fertilization rate > 50% ("good" group) and 28 cycles with fertilization rate less than or equal to 50% ("poor" group). Results: Before swim-up, there were significant correlations between fertilization rates anti CASA estimates, including amplitude of lateral head displacement (ALH) (r = .269), curvilinear velocity (VCL) (r = .297), straight line velocity (VSL) (r = .266), and rapid sprm movement (Rapid) (r = .243). There was also a significant correlation between the fertilization rates and straightness (STR) after swim-up (r = -0.178). As for sperm movement characteristics there were significant differences of ALH (p < .005), VCL (p < .001), VSL (p < .005), and Rapid (p < .01) between "good" and "poor" groups before swim-up. After swim-up, there were significant differences of VCL (p < .005), average path velocity (VAP) (p < .005), and Rapid (p < .05) between the two groups. Conclusions These results indicate that some of the CASA estimates provide reliable estimation of the fertilizing ability of human sperm. There were significant differences of th e two sperm movement characteristics, including VCL and Rapid (before and after swim-up), indicating that the total distance traveled by unpin sperm movement might be important in human sperm fertilizing abilities.

MISC

共同研究・競争的資金等の研究課題

  • 文部科学省:科学研究費補助金(基盤研究(C))
    研究期間 : 2011年 -2013年 
    代表者 : 鈴木 達也, 柴原 浩章
     
    抗透明帯抗体を保有する不妊女性が存在する。その場合、精子は卵子と結合して受精することができず不妊症となる。本研究は抗透明帯抗体を保有する免疫学的不妊女性の不妊機序を血中及び卵胞液中の抗体のクラス分類を利用して明らかにするものである。透明帯の構造は、ZPA、ZPB、ZPCの3種類の糖タンパクから構成される。我々は抗透明帯抗体がそれらのいずれに対応するか、分子量および等電点の違いを利用し、患者毎に抗体のクラス分類を行った。そしてその抗体のクラス分類および抗体比を解析することにより、免疫学的不妊女性の受精率や妊娠率の向上を期待できるのかを解明することを目的とした。 体外受精予定患者70名の血清を精製し夾雑物を除去後に、各々の血清を用いてmicro dot assayを行い、抗体陽性者4名を選別した。その後、抗透明帯抗体陽性血清を用いてウエスタンブロッティングを行い、ZPA,ZPB,ZPCのどの部分にバンドが出現するのかを確認後、画像解析ソフトを用いてバンドの分析および定量を行った。 その結果、3種類の抗体のうち、1種類(ZPB)にのみ反応を示した。精子と透明帯の結合様式は3段階に分類でき、第1段階のprimary bindingとは、精子の先体外膜表面上の透明帯認識分子であるリガンドと、透明帯上の精子レセプターであるZPCの結合を示すので、我々は、抗体陽性患者で受精障害を伴う場合はZPC抗体の量比が高いと考えていた。しかし今回は抗ZPB抗体にのみ反応を示しており、各患者の体外受精の結果との関係を検討し、抗体のクラスと受精及び着床等への影響との関係を検討している。 不妊女性における受精率や妊娠率を向上できるよう、この二次元電気泳動システムを使用する抗体検出は重要であり、引き続きこのシステムを使用し、本研究を継続する予定である。
  • 文部科学省:科学研究費補助金(若手研究(B))
    研究期間 : 2008年 -2010年 
    代表者 : 鈴木 達也
     
    精子超活性化の調節にはPPP(phosphoprotein phosphatase)と呼ばれる脱リン酸化酵素が関与すると考えられている。本研究では、PPPのどの型がハムスター精子超活性化の調節に関与するのかを調査した。その結果、PPP2が精子超活性化の調節に密接に関与した。しかしながら、PPP2は精子タンパク質のチロシンリン酸化の調節とは関与しなかった。
  • 文部科学省:科学研究費補助金(若手研究(B))
    研究期間 : 2005年 -2007年 
    代表者 : 鈴木 達也
     
    男性不妊症に対する治療法を開発するためには、精子の運動性・受精能力を獲得するメカニズムを明らかにする必要がある。これまで、精子の運動性・受精能力の獲得はCa^<2+>やAMP、Aキナーゼによるタンパク質リン酸化によって調節されることが示されている。おもにハムスターを用い精子のcapacitationに関与するリン酸化タンパク質・それに関与するキナーゼ・フォスファターゼを検索することにより、精子のcapacitationを調節するリン酸化経路を明らかにすることを目的とした。プロテインフォスファターゼ(PP)阻害剤(オカダ酸およびカリキュリンA:PP1およびPP2Aに対する阻害剤)を添加することにより、ハムスター精子の超活性化が早まることが明らかとなった。さらにPP2AのIC50濃度でも超活性化が早まっており、精子超活性化にはPP2Aが関与していることが示唆された。また、PP阻害剤添加精子抽出タンパク質のチロシンリン酸化にはコントロール精子と差がなく、今まで報告されているリン酸化カスケードと異なる系に作用していることが示唆される(現在投稿中)。現在進行中の研究においてはプロテインフォスファターゼ2Bによる脱リン酸化も精子capacitationにおける運動性変化に関与するpreliminaryのデータを得ている。さらにキナーゼに関しても順次確認する。動物実験と平行し、将来的なヒトでの臨床応用をめざし、動物実験で得られた成果をヒト精子においても再現可能であるかを確認する予定である。

委員歴

  • - 現在   日本受精着床学会   ART生涯研修コース委員会
  • - 現在   日本卵子学会   胚培養士認定委員会
  • 日本生殖医学会   学術委員会


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