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Toshihiro Fujiwara

Publications and source records attributed to Toshihiro Fujiwara.

11 recordsLinked to original sources
PubMed2006

Combined phospho-Akt and PTEN expressions associated with post-treatment hysterectomy after conservative progestin therapy in complex atypical hyperplasia and stage Ia, G1 adenocarcinoma of the endometrium.

Young patients with complex atypical hyperplasia (CAH) or stage Ia, G1 adenocarcinoma (IaG1) of the endometrium, who desire to preserve fertility, can select the conservative therapy by oral progestin, medroxyprogesterone acetate (MPA). However, conservative treatments involve potential risks of progression and recurrence. In an attempt to find out molecular markers for sensitivity to MPA, we performed immunohistochemical analysis of PTEN, phospho-Akt, p53, ER and PgR in MPA-treated 31 cases with CAH or IaG1. Eleven of 12 cases (92%) with CAH and 15 of 19 cases (79%) with IaG1 demonstrated an initial complete response, while five patients underwent hysterectomy due to no response. Four of 11 responders (36%) with CAH and five of 15 responders (33%) with IaG1 later developed relapse. Five of nine patients (56%) with CAH and three of 11 patients (27%) with IaG1 became pregnant after infertility treatment. Immunohistochemical analysis revealed that phospho-Akt expression was significantly decreased by MPA administration (p=0.002). Furthermore, combination of two factors, weak phosho-Akt or PTEN-null expression, was found to be significantly associated with receiving hysterectomy (p=0.04), while each factor showed a trend without statistical significance (p=0.07 and 0.2, respectively). Strong expression of both ER and PgR significantly correlated with successful pregnancy after infertility treatment following complete response to MPA (p=0.02). Our observations in vivo suggest that anti-tumor action of MPA may be mediated by dephosphorylation of Akt, and that immunohistochemical evaluation of phospho-Akt and PTEN may be able to predict the outcome of MPA therapy.

Adenocarcinoma↗
PubMed2006

Elevated serum bisphenol A levels under hyperandrogenic conditions may be caused by decreased UDP-glucuronosyltransferase activity.

This study was performed to investigate the effect of androgen on the metabolism of bisphenol A (BPA), an endocrine disruptor, in order to clarify the mechanism of the higher levels of serum BPA in men and hyperandrogenemic women compared with normal women. Castrated female rats (OVX) were subcutaneously injected with testosterone propionate (TP) (0.01, 0.1, and 1 mg) every day for 2 weeks. Serum BPA concentrations in OVX rats showed a TP dose-dependent increase and were significantly higher at 0.1 and 1.0 mg of TP. The enzyme reaction of BPA glucuronidation in the rat liver microsomes showed that the ratio of glucuronide in the OVX rats was significantly reduced in a TP dose-dependent manner. Analysis of the mRNA expression of UDP-glucuronosyltransferase 2B1 (UGT2B1) by real-time quantitative RT-PCR revealed that the relative expression level of UGT2B1 mRNA showed a TP dose-dependent decrease. The results of enzyme analyses demonstrated that the ratio of BPA glucuronidation and the expression level of UGT2B1 mRNA were significantly lower under the hyperandrogenemic conditions. The clearance of BPA may be slowed in a TP dose-dependent manner, resulting in an increase of serum BPA concentration under hyperandrogenemic conditions.

Animals↗
PubMed2004

Cross-Talk between Fas/Fas ligand system and nitric oxide in the pathway subserving granulosa cell apoptosis: a possible regulatory mechanism for ovarian follicle atresia.

Recent studies have shown the involvement of Fas/Fas ligand (FasL) system and nitric oxide (NO) in ovarian follicle atresia. Here we asked whether Fas/Fas ligand system interacts with NO using rat granulosa cell culture. Soluble recombinant Fas ligand (rFasL), at 100 ng/ml, significantly decreased cell viability, as measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, in the presence of 200 U/ml interferon-gamma, whereas the concurrent addition of a caspase inhibitor, Z-VAD-FMK, at 20 microm, significantly inhibited rFasL-induced cytotoxicity. Hoechst 33342 staining and flow cytometric analysis confirmed the induction of apoptosis in granulosa cells by 100 ng/ml rFasL in the presence of interferon-gamma, which was blocked by the concomitant addition of an NO donor, S-nitroso-N-acetylpenicillamine. Western blot analysis demonstrated that rFasL significantly up-regulated caspase-3, -8, and -9 activities in granulosa cells, which were attenuated by concurrent treatment with S-nitroso-N-acetylpenicillamine. Real-time quantitative RT-PCR revealed a significant decrease in inducible NO synthase mRNA levels in rFasL-induced apoptotic granulosa cells. In conclusion, we demonstrated the involvement of Fas/FasL system in inducing apoptosis through activation of a caspase-mediated cascade in rat granulosa cells, which is coupled with a decrease in inducible NO synthase expression. We further showed that NO inhibited Fas/FasL system-induced apoptosis by suppressing activation of the caspases, pointing to a cross-talk between Fas/FasL system-induced apoptosis pathway and NO-mediated antiapoptotic pathway in ovarian follicle atresia.

Animals↗
PubMed2004

Concentration of osteoprotegerin (OPG) in peritoneal fluid is increased in women with endometriosis.

BACKGROUND: Failure of apoptosis of refluxed endometrial cells within the peritoneal cavity is a possible etiologic factor for development of endometriosis. Osteoprotegerin (OPG) is a survival factor that exerts its effect by binding to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), thus preventing TRAIL from binding to the apoptosis receptors DR4 and DR5. In the present study, we addressed the possibility that the TRAIL/OPG system is involved in the pathogenesis of endometriosis. METHODS: Concentrations of OPG and TRAIL in the peritoneal fluid (PF) of women with or without endometriosis were measured using specific enzyme-linked immunoabsorbent assay. The expression of DR4 and DR5 in the endometriotic tissue was examined by reverse transcription-polymerase chain reaction. RESULTS: OPG concentrations in PF of women with endometriosis were significantly higher than those of women without endometriosis (P=0.006). With respect to the stages of the disease, the concentrations of OPG in women with stage III/IV endometriosis were significantly higher than in those without endometriosis and those with stage I/II endometriosis. On the other hand, the ratios of TRAIL/OPG concentrations were significantly lower in stage III/IV endometriosis compared to those in non-endometriosis and stage I/II endometriosis. DR5 mRNA expression was clearly detected in all the endometriotic tissues studied. CONCLUSIONS: These findings suggest that the TRAIL/OPG system is involved in the pathophysiology of endometriosis, possibly affecting the apoptosis of endometriotic cells.

Adult↗
PubMed2003

Concentrations of interferon-gamma-induced protein-10 (IP-10), an antiangiogenic substance, are decreased in peritoneal fluid of women with advanced endometriosis.

PROBLEM: To assess whether interferon-gamma-induced protein-10 (IP-10), a chemokine that has antiangiogenic activities, may be involved in the pathogenesis of endometriosis. METHOD OF STUDY: A total of 120 patients undergoing laparoscopy for pain and/or infertility were recruited, and peritoneal fluid (PF) and bone marrow derived cells in PF were collected. Concentrations of IP-10 in PF were measured with a specific enzyme-linked immunosorbent assay. Expression of IP-10 and IP-10 receptor, CXCR3, in bone marrow derived cells in PF, peritoneum and endometriotic cells was analyzed by reverse transcription-polymerase chain reaction. RESULTS: All of the PF samples examined contained detectable concentrations of IP-10. In women with advanced stages of endometriosis, IP-10 concentrations in PF were significantly lower than those of women in early stages (P = 0.02). The IP-10 concentrations in women with advanced endometriosis also appeared to be lower than those without endometriosis although the difference was statistically marginal (P = 0.06). The expression of both IP-10 and CXCR3 was clearly detected in the bone marrow derived cells in PF, peritoneum and endometriotic stromal cells. CONCLUSIONS: Decreased concentrations of IP-10 in PF from women with advanced stages of endometriosis may imply that the peritoneal environment of these women is permissive to the development of the disease by enhancing angiogenesis and/or modulating inflammatory/immunological responses.

Adult↗
PubMed2003

Upregulation of interleukin-8 by hypoxia in human ovaries.

PROBLEM: To evaluate the effect of hypoxia on interleukin (IL)-8 expression in human ovarian follicles. METHOD OF STUDY: Follicular fluid (FF) from each follicle was separately collected from women undergoing in vitro fertilization and embryo transfer. Concentrations of oxygen, progesterone, estradiol, IL-1alpha/beta, IL-8, and tumor necrosis factor (TNF)-alpha in FF were measured. Isolated granulosa-lutein cells (GLC) from obtained FF were cultured under normoxic or hypoxic conditions, and concentrations of IL-8 in culture media were measured. RESULTS: Simple regression analysis demonstrated a significant negative correlation between the concentrations of IL-8 and oxygen in FF (r = 0.50, P < 0.0001). However, none of the concentrations of progesterone, estradiol, IL-1beta, and TNF-alpha in FF showed a significant correlation with IL-8 concentrations. Hypoxia stimulated the secretion of IL-8 by cultured GLC over twofolds compared with a normoxic control (P < 0.05). CONCLUSIONS: These findings suggest that IL-8, like other angiogenic factors, is upregulated under hypoxic condition, which argues that hypoxia in the ovarian follicles comes into play in ovarian functions by inducing a range of proangiogenic and chemoattractive substances.

Adult↗
PubMed2002

Bisphenol A induces apoptosis and G2-to-M arrest of ovarian granulosa cells.

We investigated the impact of bisphenol A (BPA) on murine ovarian granulosa cells. Ovarian granulosa cells were cultured with 100 fM to 100 microM BPA for 24 h to 72 h. BPA decreased granulosa cell viability in a dose- and time-dependent manner. The lowest concentration that induced a significant decrease was 100 pM (89.2 +/- 4.0% of the control). TUNEL analysis demonstrated that treatment with BPA increased apoptosis of granulosa cells in a dose- and time-dependent manner. In addition, flow cytometry analyses revealed that treatment with BPA resulted in G2-to-M arrest, which was most prominent at 48 h. BPA increased the expression of Bax and concomitantly decreased the expression of Bcl2 at both protein and mRNA levels of granulosa cells. These findings suggest that low, presumably environmentally relevant doses of BPA, decrease the viability of granulosa cells by inducing apoptosis and G2-to-M arrest. Up-regulation of Bax and down-regulation of Bcl2 were suggested to be involved in this apoptotic effect.

Animals↗
PubMed2002

Human chorionic gonadotropin combined with progesterone for luteal support improves pregnancy rate in patients with low late-midluteal estradiol levels in IVF cycles.

PURPOSE: To investigate how late-midluteal estradiol levels relate to the pregnancy outcome in IVF cycles, and to assess whether human chorionic gonadotropin (hCG) for luteal support benefits the pregnancy outcome of patients with low late-midluteal estradiol levels. METHODS: The pregnancy rate of 436 women undergoing first IVF cycles with long protocol and luteal support with progesterone alone were analyzed. Unsuccessful women with low late-midluteal estradiol levels (< 100 pg/mL) proceeded with the exploratory second IVF cycles where they were randomly given with either progesterone alone (P protocol) or hCG +progesterone (P+hCG protocol) for luteal support. RESULTS: Pregnancy rate in women with low late-midluteal estradiol levels was significantly lower compared to that with medium (100-500 pg/mL) and high (> 500 pg/mL) levels (13.3, 26.8, and 36.3%, respectively). P+hCG protocol increased late-midluteal estradiol levels and produced a significantly higher pregnancy rate (31.7%) than P protocol (13.7%). CONCLUSIONS: hCG in combination with progesterone for luteal support was suggested to benefit women undergoing IVF with low late-midluteal estradiol levels.

Adult↗
PubMed2002

The activity of bisphenol A depends on both the estrogen receptor subtype and the cell type.

Bisphenol A (BPA), a monomer of plastic used in consumer products, is abundant in the environment and enters the body by ingestion or adsorption. In order to characterize the estrogenic effect of BPA, we performed luciferase assay on three independent cell lines derived from different tissues transfected with either human ERalpha cDNA or ERbeta cDNA. The estrogenic activities of BPA were detectable in all cell lines via both ERalpha and ERbeta. In 293T cells and Hec-1 cells, the estrogenic activities were significantly decreased when cells expressing ERalpha were incubated with 10(-6) M BPA in the presence of 10(-8) M 17beta-estradiol (E2) while the activities via ERbeta were essentially unchanged in the same conditions. Interestingly, no reduction of estrogenic activity was detected in HOS-TE85 cells via either ERalpha or ERbeta. Our results indicate that BPA only acts as an agonist of estrogen via ERbeta whereas it has dual actions as an agonist and antagonist in some types of cells via ERalpha. Thus, the activity of BPA may depend on the ER subtype and the tissue involved.

Benzhydryl Compounds↗