Tadao Tanaka

The Jikei University School of Medicine, Tokyo, Tokyo-to, Japan

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Publications (74)177.49 Total impact

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    ABSTRACT: The pentaspan membrane glycoprotein CD133 (also known as prominin-1) has been widely used as a marker for both cancer and normal stem cells. However, the function of CD133 has not been elucidated. Here we describe a cancer stem cell line established from clear cell carcinoma of the ovary (CCC) and show that CD133 interacts with plakoglobin (also known as γ-catenin), a desmosomal linker protein. We further demonstrate that knockdown of CD133 by RNA interference (RNAi) results in the downregulation of desmoglein-2, a desmosomal cadherin, and abrogates cell-cell adhesion and tumorigenicity of CCC stem cells. We speculate that CD133 may be a promising target for cancer chemotherapy.
    PLoS ONE 01/2013; 8(1):e53710. · 3.73 Impact Factor
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    ABSTRACT: Despite the use of retroviral vectors, efficiently introducing target genes into immunocytes such as T cells is difficult. In addition, retroviral vectors carry risks associated with the oncogenicity of the native virus and the potential for introducing malignancy in recipients due to genetic carryover from immortalized cells used during vector production. To address these issues, we have established a new virus vector that is based on human herpesvirus 6 (HHV-6), a non-oncogenic lymphotropic herpesvirus that infects CD4(+) T cells, macrophages, and dendritic cells. In the present study, we have altered the cell specificity of the resulting recombinant HHV-6 by knocking out the U2-U8 genes. The resulting virus proliferated only in activated cord blood cells and not in peripheral blood cells. Umbilical cord blood cells produced replication-defective recombinant virus in sufficiently high titer to omit the use of immortalized cells during vector production. HHV-6 vectors led to high rates (>90%) of gene transduction in both CD4(+) and CD8(+) T cells. These viruses showed low-level replication of viral DNA that supported greater expression of the induced genes than that of other methods but that was insufficient to support the production of replication-competent virus. Furthermore, HHV-6 vectors containing short hairpin RNAs against CD4 and HIV Gag remarkably inhibited the production of these proteins and HIV particles. Here we demonstrate the utility of HHV-6 as a new non-carcinogenic viral vector for immunologic diseases and immunotherapy.
    PLoS ONE 01/2013; 8(2):e56027. · 3.73 Impact Factor
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    ABSTRACT: Cytokine expression in a tumor microenvironment can impact both host defense against the tumor and tumor cell survival. In this study, we sought to clarify whether the cytokine gene expression profile could have clinical associations with ovarian cancer. We analyzed the expression of 16 cytokine genes (IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12p35, IL-12p40, IL-15, IFN-γ, TNF-α, IL-6, HLA-DRA, HLA-DPA1 and CSF1) in 50 ovarian carcinomas. Hierarchical clustering analysis of these tumors was carried out using Cluster software and differentially expressed genes were examined between clear cell carcinoma (CCC) and other subtypes. Following this examination we evaluated the biological significance of IL-6 knockdown in CCC. Unsupervised hierarchical clustering analysis of cytokine gene expression revealed two distinct clusters. The relationship between the two clusters and clinical parameters showed statistically significant differences in CCC compared to other histologies. CCC showed a dominant Th-2 cytokine expression pattern driven largely by IL-6 expression. Inhibition of IL-6 in CCC cells suppressed Stat3 signaling and rendered cells sensitive to cytotoxic agents. The unique cytokine expression pattern found in CCC may be involved in the pathogenesis of this subtype. In particular, high IL-6 expression appears likely to be driven by the tumor cells, fueling an autocrine pathway involving IL-6 expression and Stat3 activation and may influence survival when exposed to cytotoxic chemotherapy. Modulation of IL-6 expression or its related signaling pathway may be a promising strategy of treatment for CCC.
    International Journal of Oncology 06/2012; 41(3):1094-100. · 2.66 Impact Factor
  • Nippon rinsho. Japanese journal of clinical medicine 06/2012; 70 Suppl 4:475-9.
  • Nippon rinsho. Japanese journal of clinical medicine 06/2012; 70 Suppl 4:695-8.
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    ABSTRACT: Choriocarcinoma is a highly malignant tumor of trophoblastic origin. Most cases occur in association with preceding gestational events. However, on very rare occasions, nongestational choriocarcinoma arises from germ cell or trophoblastic differentiation in different types of carcinoma. This article reports the case of a 58-year-old woman with primary nongestational choriocarcinoma of the uterus that developed 19 years after her final pregnancy and 4 years after menopause. A total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed. Histopathological examination showed choriocarcinoma of the uterus without components of other germ cell tumors. Karyotype analysis of the tumor cells demonstrated XX. We confirmed its nongestational origin by DNA polymorphism analysis at 15 short tandem repeat loci. After surgery, the patient was given four courses of combination chemotherapy. She is still alive and there has been no evidence of recurrence 3 years after surgery.
    International journal of gynecological pathology: official journal of the International Society of Gynecological Pathologists 05/2012; 31(4):364-8. · 2.07 Impact Factor
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    ABSTRACT: Aim:  The optimal chemotherapy regimen for patients with endometrial cancer has not been established. We assessed the feasibility of paclitaxel plus carboplatin (TC) for postoperative chemotherapy in patients with endometrial cancer. Material and Methods:  Patients with newly diagnosed endometrial cancer received TC (paclitaxel 180 mg/m(2) , carboplatin AUC6 mg/mL/min) every three weeks. Treatment was continued until disease progression or completion of six cycles. Toxicities were evaluated every cycle according to NCI-CTCAE version 3.0. Results:  Sixty patients were registered from December 2005 through November 2006. Forty-four of 60 (73.3%) cases completed all of the planned six cycles. Grades 3 and 4 hematologic toxicities were observed as follows: leukopenia (61.7%), neutropenia (95.0%), anemia (21.7%), and thrombocytopenia (5.0%). There were six patients who dropped out from the protocol by neutropenia. Grade 3 non-hematologic toxicities were observed as follows: nausea (3.3%), vomiting (1.7%), neuropathy (5.0%), myalgia (6.7%) and constipation (1.7%). No grade 4 non-hematologic toxicity was observed. Conclusion:  This TC regimen is feasible for endometrial cancer patients.
    Journal of Obstetrics and Gynaecology Research 05/2012; · 0.84 Impact Factor
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    ABSTRACT: Aim:  Several previous reports showed that irinotecan hydrochloride plus cisplatin (CPT-P) was a candidate first-line chemotherapy regimen for clear cell adenocarcinoma of the ovary (CCC). However, long-term survival in CCC patients treated with CPT-P as first-line chemotherapy remains to be determined. The aim of the present study was to evaluate the long-term results of CPT-P as first-line chemotherapy for CCC. Material and Methods:  We performed a retrospective review of 31 patients with CCC who were treated with CPT-P between 1996 and 2004. Results:  The median follow-up period was 91 months. The estimated 8-year overall survival (OS) rate in all patients was 64.5%, while the rate in 18 stage I, 21 stage I/II, and 10 stage III/IV patients was 88.9%, 85.7%, and 20.0%, respectively. The estimated 8-year OS rate in patients with pT1/pT2 disease was 87.0%, while the 3-year OS rate in patients with pT3 disease was 0%. Univariate analysis using the log-rank test revealed that Eastern Cooperative Oncology Group performance-status 1, pT3 stage, and presence of residual disease (stage II-IV) were significantly correlated with shortened patient survival. Multiple regression analysis revealed that pT3 predicted worse OS in patients with CCC than pT1 (P < 0.001) or pT2 disease (P < 0.005). Conclusion:  The long-term results suggest CPT-P as a candidate in first-line chemotherapy for CCC in not only stage I, but also in optimally debulked stage II-IV patients with pT1/pT2 disease.
    Journal of Obstetrics and Gynaecology Research 05/2012; · 0.84 Impact Factor
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    ABSTRACT: CD147 is a membrane glycoprotein that is expressed in various cancer cells and is involved in tumor invasion and metastasis by inducing stromal fibroblastic cells to produce matrix metalloproteinases. This study was carried out to evaluate the correlation between CD147 expression and various clinicopathologic parameters, including histological grade and prognosis in a small sample set of human ovarian cancer patients. Paraffin-embedded surgical tissue samples from 25 patients with ovarian serous and endometrioid adenocarcinoma were stained with anti-CD147 antibody (monoclonal antibody 12C3: MoAb 12C3) for immunohistochemical analysis. CD147 protein was expressed in 84.0% (21 of 25 cases) of cancerous lesions, but not in normal lesions. CD147 expression by ovarian cancer cells was inversely correlated with overall survival. There was no correlation between CD147 expression and histological grade. These results suggest that measurement of CD147 expression may enhance the understanding of the pathophysiology of epithelial ovarian cancer.
    Journal of Obstetrics and Gynaecology Research 05/2012; 38(9):1211-9. · 0.84 Impact Factor
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    ABSTRACT: Ovarian clear cell carcinoma (OCCC) has several significant characteristics based on molecular features that are distinct from those of ovarian high-grade serous carcinoma. Cellular glycogen accumulation is the most conspicuous feature of OCCC and in the present study its metabolic mechanism was investigated. The amount of glycogen in cells cultured under hypoxia increased significantly and approximately doubled after 48 h (P<0.01) compared to that under normoxic conditions. Periodic acid-Schiff positive staining also demonstrated intracellular glycogen storage. Western blot analysis revealed that HIF1α, which was overexpressed and stabilized under hypoxic conditions, led to an increase in the levels of cellular glycogen synthase 1, muscle type (GYS1), and conversely to a decrease in inactive phosphorylated GYS1 at serine (Ser) 641. Additional increases were observed in both protein phosphatase 1, which dephosphorylates and thereby induces GYS1 enzyme activity, and glycogen synthase kinase 3 beta (GSK3β) phosphorylated at Ser9, which is inactive on phosphorylation of GYS1 and subsequently induces its enzyme activity. By contrast, the level of PYGM-b decreased. These results indicated that the glycogen accumulation under a hypoxic environment resulted in the promotion of glycogen synthesis, but did not lead to inhibition of glycogen degradation and/or consumption. Under hypoxic conditions, HAC2 cells showed activation of the PI3K/AKT pathway caused by a mutation in exon 20 of PIK3CA, encoding the catalytic subunit p110α of PI3K. The resulting activation of AKT (phosphoSer473) also plays a role as a central enhancer in glycogen synthesis through suppression of GSK3β via phosphorylation at Ser9. Hypoxia decreased the cytocidal activity of cisplatin and doxorubicin to various degrees. In conclusion, the hypoxic conditions together with HIF1 expression and stabilization increased the intracellular glycogen contents and resistance to the anticancer drugs.
    International Journal of Oncology 03/2012; 40(6):2122-30. · 2.66 Impact Factor
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    ABSTRACT: Adenomyosis patients treated with dienogest are considered to be at higher risk of uterine bleeding; however, the mechanisms which cause severe uterine bleeding in those patients are unknown. This study aims to investigate the risk factors of uterine bleeding among adenomyosis patients treated with dienogest. Clinical data of 51 adenomyosis patients treated with dienogest were retrospectively collected from their medical records. The impact of potential risk factors (age, sagittal square area of the uterus before treatment, and estradiol at the third month of treatment) and confounders (hemoglobin before treatment and prior medical treatments) on the time to treatment discontinuation due to uterine bleeding was assessed using log-rank tests and a Cox proportional hazard model. Age (< 38 years, P = 0.004), hemoglobin before treatment (<12 g/dL, P = 0.047), and estradiol at the third month of treatment (≥ 60 pg/mL, P = 0.027) had statistically significant effects on the time to treatment discontinuation due to uterine bleeding. Age was still statistically significant after controlling for hemoglobin (P = 0.023). Adenomyosis patients treated with dienogest are at higher risk of treatment discontinuation due to uterine bleeding, especially when they are of younger age, have anemia before treatment, and/or have mildly suppressed or unsuppressed estradiol after they started dienogest treatment. Clinicians should pay special attention when they prescribe dienogest for such patients.
    Journal of Obstetrics and Gynaecology Research 03/2012; 38(4):639-44. · 0.84 Impact Factor
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    ABSTRACT: The objective of this study was to ascertain the evidence on ovarian cancer during pregnancy and compile recommendations derived from this information. This was a retrospective study, based on clinical histories from patients diagnosed and treated at 4 independent hospitals for ovarian cancer during pregnancy, between 1992 and 2009. The median age at diagnosis was 30 years (range, 24-41). Out of 10 cases of ovarian cancer, 2 patients showed either bleeding or abdominal pain, while 8 patients were asymptomatic. All 10 cases were diagnosed via ultrasound, and the masses were detected in the first trimester in 7 patients and in the second trimester in 2 patients. Of the diagnosed tumors, 8 cases were epithelial tumors including 6 adenocarcinomas and 2 borderline tumors, and 2 germ cell tumors. The primary ovarian malignancies were at stage I of the disease. Unilateral salpingo-oophorectomy was performed in 9 patients and cystectomy was performed in one patient. Chemotherapy was administered to 4 patients, in 1 case during pregnancy. Neonatal outcome analysis showed a full- or pre-term delivery in 6 cases, abortion in 1 case and therapeutic termination in 3 cases. The majority of cases of ovarian cancer in pregnancy were incidentally detected by ultrasound at an early stage, resulting in good prognosis for the mother and the neonate.
    Oncology letters 03/2012; 3(3):577-580. · 0.24 Impact Factor
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    Nagayoshi Umehara, Tadao Tanaka
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    ABSTRACT: Objective. To investigate the incidence of various antiphospholipid antibodies (aPLs), measured by commercial-based laboratory, with recurrent spontaneous abortion (RSA) patients and the impact of the species, isotype, titer, and number of positive aPLs on reproductive outcome in Japanese. Method. In this retrospective cohort study, 263 patients with RSA without possible causes were investigated. Of 131 patients with one or more positive aPL, 82 pregnant women under anticoagulant therapy were evaluated. Results. The incidence of various aPLs was almost consistent with previous report. Overall, successful pregnancy rate with anticoagulant therapy was 91.4% regardless of aPL profiles. There was no significant difference in the pregnancy maintenance rate between IgG and IgM groups or single positive and multiple positive groups, but there was a tendency for the rate with aspirin to be lower than with aspirin plus heparin in IgG group. Conclusion. aPL profile did not affect the pregnancy maintenance rate when anticoagulant therapy was actively introduced, however in IgG group, we recommend combination therapy with aspirin and heparin.
    ISRN obstetrics and gynecology 01/2012; 2012:819356.
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    ABSTRACT: Based on the evidences showing that serum deprivation provokes apoptosis in a variety of cells, we have investigated the effect of serum deprivation on drug sensitivity. After human ovarian cancer cells were preincubated in 0.5 % serum containing medium for 12 hours, cellular drug sensitivities were determined by colony-forming assay. Serum deprivation treatment resulted in significant increase in paclitaxel sensitivity by factors of mean ± SD, 148.6 ± 28.1 and 10.1 ± 1.0 (n = 3; P < 0.001) fold in platinum-resistant C13 and CP70 cells, respectively. Similarly, serum deprivation induced significant docetaxel sensitivity in these cell lines. However, no enhancement effect of serum deprivation was observed in platinum-sensitive 2008 and A2780 cells. Serum deprivation did not have any effect on the sensitivities to cisplatin, vincristin, and doxorubicin in all of these cells. More than 7-fold increase of apoptotic cells were observed in C13 or CP70 cells when they were treated by serum deprivation followed by paclitaxel compared with the treatment of either serum deprivation or paclitaxel alone. Confocal laser microscopy using rhodamine 123 and flow cytometric analysis with 3,3'-dihexyloxacarbocyanine iodide revealed that serum deprivation decreased mitochondrial membrane potential in C13 or CP70 cells, whereas no change was observed in 2008 and A2780 cells. This indicates that serum deprivation induced depolarization specifically in platinum-resistant cells. Electron microscopy revealed that serum deprivation caused regeneration of mitochondrial matrix structure in C13 or CP70 cells where mitochondria were usually destructed and disappeared. These results indicate that serum deprivation confers taxane hypersensitivity specifically in platinum-resistant cells by recovering their impaired mitochondrial functions. The evidence might be clinically beneficial for the development of new chemotherapeutic technology, particularly for the patients with platinum-resistant ovarian cancer.
    International Journal of Gynecological Cancer 11/2011; 21(9):1547-54. · 1.94 Impact Factor
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    ABSTRACT: Myeloid sarcoma can involve any anatomic site, but involvement of the gynecologic tract is uncommon. In particular, vulvar myeloid sarcoma is extremely rare, with only 1 case report in the English-language medical literature. A 21-year-old, normally developed Japanese woman presented with a hard, gradually growing mass that involved the patient's right labia majora and whole right vulva. The mass was resected and histologically diagnosed as vulvar myeloid sarcoma, poorly differentiated type on the basis of the immunohistochemical studies. She had no history or simultaneous involvement of any other myeloid neoplasm. The patient had a complete remission (CR) after induction chemotherapy with cytarabine and daunorubicin, and she received another course of the same combination chemotherapy as a consolidation therapy and an allogeneic hematopoietic stem cell transplantation from an human leukocyte antigen-matched related donor. But a first medullar relapse of acute myeloid leukemia (AML) developed, and she needed salvage chemotherapy with daunomycin and cytarabine. She achieved a second CR after the salvage therapy and received a second allogeneic hematopoietic stem cell transplantation from the same donor. However, AML relapsed again and she received reinduction chemotherapy, which consisted of behenoyl cytarabine and aclarubicin, which resulted in a third remission of AML. Three years after the initial resection, the patient is alive, without any evidence of recurrent extramedullary disease. To the best of our knowledge, this is the second report of the vulvar myeloid sarcoma in the English-language medical literature. The correct diagnosis of myeloid sarcoma particularly on an isolated mass is important so that appropriate therapy can be instituted.
    Clinical Ovarian Cancer 06/2011; 4(1):49–51.
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    ABSTRACT: We previously reported that cyclin E (CCNE1) amplification is strongly associated with resistance to treatment in serous ovarian cancer by high-resolution oligonucleotide copy number analysis. Dysregulation of cell cycle control has been implicated as the key event in human oncogenesis, and aberrant expression of G1-S phase-related genes in particular has been reported in epithelial ovarian cancer (EOC). Nevertheless, there are conflicting results concerning the prognostic values of these abnormalities in EOC. This study focused on advanced serous EOC cases and investigated the association between the expression of G1-S phase-regulatory proteins and clinicopathological parameters. The utility of these proteins as prognostic factors was assessed, and whether these targets reflect chemoresistance of advanced serous EOC was investigated. A total of 66 patients treated by primary surgery were evaluated in this study. Immunohistochemical analysis for cyclin D1, pRb, p16, p53, p27(Kip1), p21(Waf1/Cip1) and cyclin E was performed on formalin-fixed tissue sections collected from primary surgical specimens. The correlations between the expression of these proteins and the clinicopathological parameters, including progression-free survival (PFS), overall survival (OS) and chemosensitivity, were examined. Upon univariate analysis, overexpression of cyclin D1 was positively correlated with reduced PFS (p=0.00062) and OS (p=0.00037). Reduced expression of p27(Kip1) was associated with shorter OS (p=0.064). Upon multivariate analysis, overexpression of cyclin D1 (p=0.0019), reduced expression of p27(Kip1) (p=0.042) and residual tumor volume (p=0.0092) were identified as independent predictors of OS. Overexpression of cyclin D1 (p=0.011) as well as residual tumor volume (p=0.006) were significantly associated with first-line chemosensitivity. In advanced serous EOC, overexpression of cyclin D1 contributed largely to poor prognosis, and this may have been in part mediated by chemoresistance. Cyclin D1 is a possible target for overcoming the refractory nature of advanced serous EOC.
    Experimental and therapeutic medicine 01/2011; 2(2):213-219. · 0.34 Impact Factor
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    ABSTRACT: PurposeTo investigate potential indicators of in vitro fertilization (IVF) treatment outcome for female infertility patients aged ≥ 40years based on the clinical course. MethodsWe retrospectively examined results of 111 female infertility patients aged ≥ 40years undergoing IVF treatment. We investigated the relationship between treatment cycle cancellation and the final outcome of IVF treatment in female infertility patients aged ≥ 40years. ResultsA total of 44 pregnancies were achieved. Overall pregnancy rate per initiated treatment cycle was 12.1%, and 24 spontaneous abortions occurred (54.5%). No woman aged ≥ 45years achieved pregnancy. No patients conceived after 10 treatment cycles while 42 (11.5%) oocyte pick-up cycles and 120 (33.0%) embryo transfer cycles were canceled. Investigation of correlation with treatment cycle cancellation revealed that patients who experienced embryo transfer cancellation had a high spontaneous abortion rate while only a few patients who experienced oocyte pick-up cancellation achieved pregnancy and even fewer achieved a successful outcome. ConclusionsOur study suggests that, in addition to patient age and number of treatment cycles, cancellation of treatment cycle also provides another useful indicator for pregnancy outcome. KeywordsCancellation–Embryo transfer–Female infertility patients aged 40years or older–IVF–Oocyte pick up
    Reproductive Medicine and Biology 01/2011; 10(3):179-184.
  • Nippon rinsho. Japanese journal of clinical medicine 08/2010; 68 Suppl 8:489-93.
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    ABSTRACT: Clinical practice guidelines for gynecologic cancers have been published by the National Comprehensive Cancer Network and the National Cancer Institute. Whereas these guidelines form the basis for the standard of care for gynecologic malignancies in the United States, it has proven difficult to institute them in Japan due to differences in patient characteristics, health-care delivery systems, and insurance programs. Therefore, evidence-based guidelines for treating cervical cancer specifically in Japan have been under development. The Guidelines Formulation Committee and Evaluation Committee were independently established within the Committee for Treatment Guidelines for Cervical Cancer. Opinions from within and outside the Japan Society of Gynecologic Oncology (JSGO) were incorporated into the final draft, and the guidelines were published after approval by the JSGO. These guidelines are composed of ten chapters and comprise three algorithms. Each chapter consists of a clinical question, recommendations, background, objectives, explanations, and references. The objective of these guidelines is to clearly delineate the standard of care for cervical cancer treatment in Japan in order to ensure equitable care for all Japanese women diagnosed with cervical cancer.
    International Journal of Clinical Oncology 03/2010; 15(2):117-24. · 1.41 Impact Factor
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    ABSTRACT: Phthalates may act as an estrogen and are a potential risk factor for estrogen-related diseases such as endometriosis. We assessed the association between phthalate exposure and endometriosis in 166 consecutive women who presented at a university hospital for consultation regarding infertility. The subjects were interviewed and provided a urine specimen prior to a laparoscopic diagnosis of endometriosis. They were then categorized by the severity of endometriosis as controls (stages 0-I) and cases (stages II-IV). Urinary concentrations of the phthalate metabolites monoethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate, and mono(2-ethyl-5-hydroxyhexyl) phthalate were measured in 57 cases and 80 controls using high-performance liquid chromatography isotope-dilution tandem mass spectrometry. Adjusted odds ratios for endometriosis in relation to dichotomized individual phthalate metabolites (standardized for creatinine) were calculated. No significant association between endometriosis and any urinary creatinine-adjusted phthalate monoester was seen. Adjusted odds ratio (95% confidence interval) for higher dichotomized MEHP by endometriosis was 1.57 (0.74-3.30). No monotonic trend was seen in urinary creatinine-adjusted concentration of phthalate metabolites by endometriosis stage (p=0.23-0.90). Our results do not support the hypothesis that higher urinary concentrations of phthalate metabolites are associated with the risk of endometriosis in infertile Japanese women.
    Science of The Total Environment 10/2009; 408(1):37-42. · 3.26 Impact Factor

Publication Stats

2k Citations
177.49 Total Impact Points

Institutions

  • 1999–2012
    • The Jikei University School of Medicine
      • Department of Obstetrics and Gynecology
      Tokyo, Tokyo-to, Japan
  • 2005–2009
    • National Cancer Center, Japan
      • Research Center for Cancer Prevention and Screening
      Edo, Tōkyō, Japan