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Dive into the research topics where Michihisa Shiro is active.

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Featured researches published by Michihisa Shiro.


International Journal of Gynecological Cancer | 2014

Diagnostic value of preoperative SUVmax on FDG-PET/CT for the detection of ovarian cancer.

Yuko Tanizaki; Aya Kobayashi; Michihisa Shiro; Nami Ota; Rei Takano; Yasushi Mabuchi; Shigetaka Yagi; Sawako Minami; Masaki Terada; Kazuhiko Ino

Objective The objective of this study was to investigate the preoperative diagnostic value of 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography and computed tomography (PET/CT) in patients with ovarian cancer. Methods One hundred sixty patients suspected of having malignant ovarian tumors were included in this study. All patients underwent FDG-PET/CT scans before operation, and the maximum standardized uptake value (SUVmax) of the primary tumor was measured. We evaluated the diagnostic accuracy of SUVmax for detecting malignancy and its relationship with histological findings. Results Postoperative pathological diagnoses showed that 67 were malignant, 14 were borderline malignant, and 79 were benign tumors. With the use of a cutoff SUVmax of 2.9 obtained from the receiver operating characteristic curve analysis, the sensitivity, specificity, positive predictive value, and negative predictive value for detecting malignancy were 80.6%, 94.6%, 91.5%, and 87.1%, respectively. Positive FDG accumulation (SUVmax ≥ 2.9) was shown in 89.5% of serous adenocarcinoma and in 92.3% of endometrioid adenocarcinoma. In contrast, lower frequencies of positive FDG accumulation were shown in clear cell adenocarcinoma (54.5%), mucinous adenocarcinoma (66.7%), and metastatic carcinoma (66.7%), and the median SUVmax of these 3 histological types were significantly lower than those of serous and endometrioid types. In addition, a positive FDG accumulation was shown in all patients with malignant transformation of mature cystic teratoma. Finally, of the 14 borderline malignant tumors, only 2 (14.3%) showed positive FDG accumulation. Conclusions The SUVmax on FDG-PET/CT is useful for differentiating ovarian cancer from borderline or benign tumor with a high specificity and positive predictive value. However, our data also demonstrated a lower FDG uptake value in clear cell or mucinous histological finding, suggesting that SUVmax may vary depending on the tumor histological subtype.Objective The objective of this study was to investigate the preoperative diagnostic value of 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography and computed tomography (PET/CT) in patients with ovarian cancer. Methods One hundred sixty patients suspected of having malignant ovarian tumors were included in this study. All patients underwent FDG-PET/CT scans before operation, and the maximum standardized uptake value (SUVmax) of the primary tumor was measured. We evaluated the diagnostic accuracy of SUVmax for detecting malignancy and its relationship with histological findings. Results Postoperative pathological diagnoses showed that 67 were malignant, 14 were borderline malignant, and 79 were benign tumors. With the use of a cutoff SUVmax of 2.9 obtained from the receiver operating characteristic curve analysis, the sensitivity, specificity, positive predictive value, and negative predictive value for detecting malignancy were 80.6%, 94.6%, 91.5%, and 87.1%, respectively. Positive FDG accumulation (SUVmax ≥ 2.9) was shown in 89.5% of serous adenocarcinoma and in 92.3% of endometrioid adenocarcinoma. In contrast, lower frequencies of positive FDG accumulation were shown in clear cell adenocarcinoma (54.5%), mucinous adenocarcinoma (66.7%), and metastatic carcinoma (66.7%), and the median SUVmax of these 3 histological types were significantly lower than those of serous and endometrioid types. In addition, a positive FDG accumulation was shown in all patients with malignant transformation of mature cystic teratoma. Finally, of the 14 borderline malignant tumors, only 2 (14.3%) showed positive FDG accumulation. Conclusions The SUVmax on FDG-PET/CT is useful for differentiating ovarian cancer from borderline or benign tumor with a high specificity and positive predictive value. However, our data also demonstrated a lower FDG uptake value in clear cell or mucinous histological finding, suggesting that SUVmax may vary depending on the tumor histological subtype.


Cancer Science | 2014

Indoleamine 2,3-dioxygenase promotes peritoneal metastasis of ovarian cancer by inducing an immunosuppressive environment.

Yuko Tanizaki; Aya Kobayashi; Saori Toujima; Michihisa Shiro; Mika Mizoguchi; Yasushi Mabuchi; Shigetaka Yagi; Sawako Minami; Osamu Takikawa; Kazuhiko Ino

Indoleamine 2,3‐dioxygenase (IDO) is a tryptophan‐catabolizing enzyme that has immunoregulatory functions. Our prior study showed that tumoral IDO overexpression is involved in disease progression and impaired patient survival in human ovarian cancer, although its mechanism remains unclear. The purpose of the present study is to clarify the role of IDO during the process of peritoneal dissemination of ovarian cancer. Indoleamine 2,3‐dioxygenase cDNA was transfected into the murine ovarian carcinoma cell line OV2944‐HM‐1, establishing stable clones of IDO‐overexpressing cells (HM‐1‐IDO). Then HM‐1‐IDO or control vector‐transfected cells (HM‐1‐mock) were i.p. transplanted into syngeneic immunocompetent mice. The HM‐1‐IDO‐transplanted mice showed significantly shortened survival compared with HM‐1‐mock‐transplanted (control) mice. On days 11 and 14 following transplantation, the tumor weight of peritoneal dissemination and ascites volume were significantly increased in HM‐1‐IDO‐transplanted mice compared with those of control mice. This tumor‐progressive effect was coincident with significantly reduced numbers of CD8+ T cells and natural killer cells within tumors as well as increased levels of transforming growth factor‐β and interleukin‐10 in ascites. Finally, treatment with the IDO inhibitor 1‐methyl‐tryptophan significantly suppressed tumor dissemination and ascites with reduced transforming growth factor‐β secretion. These findings showed that tumor‐derived IDO promotes the peritoneal dissemination of ovarian cancer through suppression of tumor‐infiltrating effector T cell and natural killer cell recruitment and reciprocal enhancement of immunosuppressive cytokines in ascites, creating an immunotolerogenic environment within the peritoneal cavity. Therefore, IDO may be a promising molecular target for the therapeutic strategy of ovarian cancer.


Journal of Obstetrics and Gynaecology Research | 2014

Adverse perinatal and neonatal outcomes in patients with chronic abruption–oligohydramnios sequence

Aya Kobayashi; Sawako Minami; Yuko Tanizaki; Michihisa Shiro; Madoka Yamamoto; Shigetaka Yagi; Takahiro Okutani; Takeshi Kumagai; Ryuzo Higuchi; Kazuhiko Ino

Chronic abruption–oligohydramnios sequence (CAOS) is a clinical condition with lasting vaginal bleeding and oligohydramnios because of chronic placental abruption, which seems to cause preterm labor and neonatal chronic lung disease (CLD). This prompted us to explore the correlation between perinatal/neonatal outcomes and CAOS.


International Journal of Gynecological Cancer | 2015

Clinicopathologic Factors of Cervical Adenocarcinoma Stages IB to IIB.

Yasushi Mabuchi; Tamaki Yahata; Aya Kobayashi; Yuko Tanizaki; Michihisa Shiro; Nami Ota; Shigetaka Yagi; Sawako Minami; Kazuhiko Ino

Objective The aim of this study was to clarify the clinicopathologic factors of stages IB to IIB cervical adenocarcinoma. Methods Several clinicopathologic factors were compared between 35 patients who underwent radical hysterectomy and pelvic lymphadenectomy due to cervical adenocarcinoma stages IB to IIB and 77 patients with squamous cell carcinoma (SCC). Results In patients with adenocarcinoma, univariate analysis demonstrated that International Federation of Gynecology and Obstetrics stage, tumor size, and lymphovascular space invasion were significantly associated with progression-free survival (PFS), whereas FIGO stage, lymphovascular space invasion, and lymph node metastasis were significantly associated with overall survival (OS). However, multivariate analysis revealed that FIGO stage was the only significant factor for PFS in patients with adenocarcinoma. In patients with SCC, univariate analysis demonstrated that FIGO stage and lymph node metastasis were significantly associated with PFS, whereas FIGO stage, lymphovascular space invasion, and lymph node metastasis were significantly associated with OS. Multivariate analysis revealed that lymph node metastasis was the only significant factor for PFS and OS in patients with SCC. In 26 patients who were positive for high-risk human papillomavirus (HPV), including both adenocarcinoma and SCC patients, univariate and multivariate analyses revealed that HPV18 was significantly associated with poorer PFS compared with non-HPV18. There was a significant difference in distribution of HPV genotype between adenocarcinoma and SCC. Conclusions Careful treatment may be necessary for the patients with lymphovascular space invasion in early-stage cervical adenocarcinoma. The presence of HPV18 may have an influence on the prognosis of early-stage cervical carcinoma.


Journal of Obstetrics and Gynaecology Research | 2017

Levels of serum-circulating angiogenic factors within 1 week prior to delivery are closely related to conditions of pregnant women with pre-eclampsia, gestational hypertension, and/or fetal growth restriction

Sakiko Nanjo; Sawako Minami; Mika Mizoguchi; Madoka Yamamoto; Tamaki Yahata; Saori Toujima; Michihisa Shiro; Aya Kobayashi; Yasuteru Muragaki; Kazuhiko Ino

We aimed to investigate maternal serum angiogenic marker profiles within 1 week prior to delivery in cases of gestational hypertension (GH), pre‐eclampsia (PE), and/or fetal growth restriction (FGR) with different clinical conditions.


Molecular and Clinical Oncology | 2016

Large uterine pyomyoma in a perimenopausal female: A case report and review of 50 reported cases in the literature

Naoyuki Iwahashi; Yasushi Mabuchi; Michihisa Shiro; Shigetaka Yagi; Sawako Minami; Kazuhiko Ino

Pyomyoma is a rare complication, which withoug antibiotics or surgical intervention, may cause sepsis and mortality. The present study reported a case of large uterine pyomyoma in a perimenopausal female. A 53-year-old multigravida woman was referred to the Department of Obstetrics and Gynecology (Wakayama Medical University, Wakayama, Japan) due to progressive abdominal distension. The patient presented with anemia gravis, severe inflammatory reaction and cachexia. Computed tomography revealed a large unilocular mass, 50 cm in size, with an irregular surface and thickened wall, occupying the entire abdomen. Following antibiotic medication, the patient underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy. Intraoperative findings demonstrated a solid tumor arising from the back of the uterine body. A total of 12 liters of purulent, malodorous fluid was drained from the tumor. The resected mass was 50 cm in size and 13.5 kg in weight. Cultures of the pus revealed the presence of Streptococcus agalactiae. Pathological findings revealed suppurative leiomyoma with no malignancy. Large pyomyoma is difficult to distinguish from a gynecological malignant tumor types, particularly in perimenopausal women with non-specific clinical presentation. Although pyomyoma is a benign tumor, care must be taken to discriminate these from large abdominal tumors.


Journal of Obstetrics and Gynaecology Research | 2018

Placental mesenchymal dysplasia with severe fetal growth restriction in one placenta of a dichorionic diamniotic twin pregnancy

Shoko Jitsumori; Michihisa Shiro; Fumiyoshi Kojima; Nami Ota; Sawako Minami; Kazuhiko Ino

We report a rare case of placental mesenchymal dysplasia (PMD) with fetal growth restriction (FGR) in one placenta of a dichorionic diamniotic (DD) twin pregnancy. A 24‐year‐old woman was referred to our hospital at 24 weeks’ gestation due to FGR and ipsilateral placental abnormality in DD twins. Ultrasound and magnetic resonance imaging showed one placenta of the FGR fetus was bulky and had multiple cysts, while the other fetus placenta appeared normal. Cesarean section was performed at 32 weeks’ gestation; the first and second neonates weighted 1799 and 1215 g, respectively. Macroscopically, chorionic vessels on the placental surface of the second neonate were prominently enlarged. Pathological findings demonstrated swelling stem villi with enlarged vessels and increased interstitial cells without trophoblast proliferation. Immunostaining for p57kip2 was negative in interstitial cells and cytotrophoblasts of the swelling stem villi. This suggested that PMD occurred in one placenta of the DD twin, leading to early‐onset FGR.


Taiwanese Journal of Obstetrics & Gynecology | 2016

Vasa previa evaluated by noncontrast time-of-flight magnetic resonance angiography

Naoyuki Iwahashi; Nami Ota; Michihisa Shiro; Shigetaka Yagi; Sawako Minami; Kazuhiko Ino

OBJECTIVE Vasa previa is a rare complication, and rupture of vasa previa during pregnancy may lead to significant perinatal mortality. Here, we report a case of vasa previa evaluated prenatally using noncontrast time-of-flight magnetic resonance angiography (TOF MRA). CASE REPORT A 22-year-old primiparous woman was referred to our hospital due to suspicion of vasa previa. Transvaginal ultrasonography showed two vessels running over the internal os. To obtain further information, magnetic resonance imaging (MRI) and TOF MRA were performed. Caesarean section was carried out, and macroscopic findings of the vascular distribution on the fetal membrane were consistent with those identified by TOF MRA. CONCLUSION TOF MRA in addition to MRI may be an option for prenatal identification of the precise three-dimensional vascular distribution in patients with vasa previa.


PLOS ONE | 2018

Effects of perinatal blood pressure on maternal brain functional connectivity

Hiromichi Kurosaki; Katsutoshi Nakahata; Tomohiro Donishi; Michihisa Shiro; Kazuhiko Ino; Masaki Terada; Tomoyuki Kawamata; Yoshiki Kaneoke

Perinatal hypertensive disorder including pre-eclampsia is a systemic syndrome that occurs in 3–5% of pregnant women. It can result in various degrees of brain damage. A recent study suggested that even gestational hypertension without proteinuria can cause cardiovascular or cognitive impairments later in life. We hypothesized that perinatal hypertension affects the brain functional connectivity (FC) regardless of the clinical manifestation of brain functional impairment. In the present study, we analyzed regional global connectivity (rGC) strength (mean cross-correlation coefficient between a brain region and all other regions) using resting-state functional magnetic resonance imaging to clarify brain FC changes associated with perinatal blood pressure using data from 16 women with a normal pregnancy and 21 pregnant women with pre-eclampsia. The rGC values in the bilateral orbitofrontal gyri were negatively correlated with diastolic blood pressure (dBP), which could not be explained by other pre-eclampsia symptoms. The strength of FC seeding at the left orbitofrontal gyrus was negatively correlated with dBP in the anterior cingulate gyri and right middle frontal gyrus. These results suggest that dBP elevation during pregnancy can affect the brain FC. Since FC is known to be associated with various brain functions and diseases, our findings are important for elucidating the neural correlate of cognitive impairments related to hypertension in pregnancy.


Journal of Obstetrics and Gynaecology Research | 2018

Perinatal outcome of vaginal delivery with epidural analgesia initiated at the early or late phase of labor period: A retrospective cohort study in the Japanese population

Michihisa Shiro; Katsutoshi Nakahata; Sawako Minami; Tomoyuki Kawamata; Kazuhiko Ino

We compared the perinatal outcomes of vaginal delivery with epidural analgesia initiated at the early versus late phase in a Japanese population.

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Kazuhiko Ino

Wakayama Medical University

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Sawako Minami

Wakayama Medical University

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Shigetaka Yagi

Wakayama Medical University

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Nami Ota

Wakayama Medical University

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Yasushi Mabuchi

Wakayama Medical University

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Aya Kobayashi

Wakayama Medical University

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Madoka Yamamoto

Wakayama Medical University

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Naoyuki Iwahashi

Wakayama Medical University

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Yuko Tanizaki

Wakayama Medical University

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Mika Mizoguchi

Wakayama Medical University

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