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Dive into the research topics where Takehiro Nakao is active.

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Featured researches published by Takehiro Nakao.


Gynecologic and Obstetric Investigation | 2017

Expression of Angiotensin II Types 1 and 2 Receptors in Endometriotic Lesions

Takehiro Nakao; Fumihisa Chishima; Masahiko Sugitani; Ryusuke Tsujimura; Chuyu Hayashi; Tatsuo Yamamoto

Background/Aim: The aim of this study was to evaluate the gene and protein expression of angiotensin type (AT) 1, AT2 receptors in endometriotic lesions and its relation to prostaglandin (PG) synthases. Materials and Methods: Endometriosis samples were obtained from 32 patients with endometriotic cysts. Endometrial tissues were obtained during operations for benign gynecological conditions. The expression of the AT1 and AT2 receptor mRNA and that of PG-endoperoxide synthase 2 and microsomal PGE2 synthase-1 (mPGES-1) was examined by quantitative RT-PCR. Immunohistochemical staining was performed for these receptors. Results: AT1 and AT2 receptor proteins were mostly located in endometrial glandular epithelium and some stromal cells. Immunoreactivity of the receptor proteins was observed in both the eutopic endometrium and endometriotic lesions. The AT1/AT2 ratio in endometriotic cysts (median 7.29, range 1.88-187.60) was significantly increased compared with that in the eutopic endometrium in the proliferative-phase in controls (median 1.01, range 0.37-2.09, p < 0.001). There was a relationship between the AT1 mRNA expression and that of mPGES-1 mRNA in the endometriotic cysts (r = 0.394089, p < 0.05). There was a significant relationship between the mRNA expression of the AT2 receptor and that of mPGES-1 in eutopic endometrium of non-endometriotic control (r = 0.610714, p < 0.05). Conclusion: Renin-angiotensin system may play an important role in the pathophysiology of endometriosis.


Oncology Letters | 2018

Brachytherapy for cervical cancer in septate uterus: Dose-volume differences with tandem implant placement in right vs. left uterine canal: A case report

Naoya Ishibashi; Toshiya Maebayashi; Takuya Aizawa; Masakuni Sakaguchi; Takehiro Nakao; Masahiro Okada

Brachytherapy is a standard treatment modality for locally advanced cervical cancer. In patients with uterine anomalies, the radiation dose to the target volume and the organs at risk can vary depending on the positioning of the brachytherapy tandem implant. However, there have been few reports concerning the use of brachytherapy in patients with uterine anomalies. The present study reports the case of a 55-year-old woman with locally advanced squamous cell carcinoma of the cervix and complete septate uterus. The patient was treated with external-beam radiation therapy, cisplatin chemotherapy, and brachytherapy. Computed tomography-based planning was performed for image-guided brachytherapy with the tandem implant alternately in the right and left uterine canals and using the right and left point A. A comparison of the resulting dose-volume histograms revealed wide variations in the projected dose to the clinical target volume and organs at risk. Tandem implant positioning for brachytherapy was chosen to optimize the dose-volume distribution. At the point of writing, the patient has not experienced local recurrence.


Gynecologic oncology reports | 2018

Uterine corpus tumor with neuroectodermal differentiation and frequent ganglion-like cells in a postmenopausal woman

Taku Homma; Takehiro Nakao; Toshiya Maebayashi; Toshiyuki Ishige; Hiroyuki Hao

Highlights • Uterine neuroectodermal tumors (NETs) are uncommon malignant neoplasm with poor prognosis.• Ganglion-like cells with fibrillary background as major component of uterine NETs are extremely rare.• We present a patient affected by uterine NET with frequent ganglion-like cells, resembling ganglioneuroblastoma.• This case report is important to define the pathogenesis and establish better treatments for neuroectodermal tumors.


Gynecologic and Obstetric Investigation | 2018

The Expression of MAS1, an Angiotensin (1–7) Receptor, in the Eutopic Proliferative Endometria of Endometriosis Patients

Takahiro Nakajima; Fumihisa Chishima; Takehiro Nakao; Chuyu Hayashi; Akiko Kasuga; Kaori Shinya; Takuo Nakayama; Hiromitsu Azuma; Go Ichikawa; Atsushi Komatsu; Tatsuo Yamamoto; Kei Kawana

Background/Aim: We demonstrated that AT1 and AT2 are expressed and both pathways balance the renin-angiotensin system in endometriosis. MAS1, a specific receptor of angiotensin (1–7), opposes AT1 pathway-associated tissue remodelling. It is not known whether MAS1 has an effect on the pathogenesis of endometriosis or not. Materials and Methods: Ovarian endometriotic tissues (endo-Ov) and eutopic endometrial tissues (endo-Em) were obtained from 29 patients with endometrial cysts. Normal endometrial tissues (cont-Em) were obtained from patients without endometriosis. Immunohistochemical staining was performed for MAS1, AT1 and AT2 in the endometriosis-associated tissues. The mRNA levels of these receptors were examined by quantitative reverse transcription PCR. Results: MAS1 was immune-positive at the apical side of the glandular epithelium in the endometriotic lesions. The MAS1 mRNA levels in endo-Ov were increased significantly, irrespective of the menstrual cycle phase. The MAS1 mRNA levels were significantly higher in the proliferative-tissues of the endometriosis patients than in those of the controls. The ratio of the MAS1 to the AT1 mRNA in the proliferative tissues was increased predominantly in the endometriosis patients compared with that in the controls. Conclusion: High MAS1 expression in the endometrium might promote the initiation of endometriosis via migration of proliferative tissue.


Journal of Mammalian Ova Research | 2017

The Inflammatory Process and Successful Implantation

Fumihisa Chishima; Takahiro Nakajima; Takehiro Nakao; Chuyu Hayashi; Go Ichikawa; Atsushi Komatsu; Kei Kawana

Abstract: Implantation is essential for successful reproduction. In humans, uterine receptivity is restricted to the mid-secretory phase, days 19 to 24 of the menstrual cycle; and this period is called the window of implantation (WOI). Large populations of decidual leukocytes infiltrate the implantation site, and the levels of cytokines, prostaglandins (PGs), and leukocytes are up-regulated in the endometrium during implantation. Implantation is like a local wound healing process which is characterized by a strong Th1, pro-inflammatory response in which high levels of pro-inflammatory cytokines such as IL-6, LIF, IL-8, and TNFα are involved. In addition, cyclooxygenase (COX)-2 expression increases between days 2 to 5, suggesting that PGs are necessary for the process of stromal cell decidualization in early pregnancy. Recently, it was reported that endometrial biopsies taken during spontaneous cycles that preceding IVF treatment improved the rate of implantation, clinical pregnancies, and live births in patients with recurrent implantation failure. These results suggest an ininflammatory environment is not adequately induced in some IVF patients with recurrent implantation failure in the absence of local injury provoked by biopsy treatment, further suggesting that uterine receptivity is mediated by the expression of molecules associated with a pro-inflammatory process.


Journal of Reproductive Immunology | 2018

Inflammation and hypercoagulability status in the patient with ovarian clear cell carcinoma

Kanoko Shoji; Fumihisa Chishima; Takahiro Nakajima; Takehiro Nakao; Hiromitsu Azuma; Chuyu Hayashi; Yuji Ikeda; Atsushi Komatsu; Chiaki Takeya; Mikiko Sato; Shinichi Takada; Kei Kawana


Journal of Reproductive Immunology | 2017

Expression of angiotensin 1-7 receptor (MAS1) in endometriotic lesions

Takahiro Nakajima; Fumihisa Chishima; Takehiro Nakao; Chuyu Hayashi; Akiko Kasuga; Kaori Shinya; Go Ichikawa; Shinichi Takada; Kei Kawana


Journal of Reproductive Immunology | 2016

Prorenin/renin-angiotensin system in local endometriosis lesions

Takahiro Nakajima; Fumihisa Chishima; Takehiro Nakao; Chuyu Hayashi; Motomi Yamazaki; Go Ichikawa; Kenji Sugita; Tatsuo Yamamoto; Kei Kawana


Journal of Reproductive Immunology | 2016

Expression of prorenin (REN) and angiotensin 1-7 receptor (MAS1) mRNA and in local endometriosis lesions

Takahiro Nakajima; Fumihisa Chishima; Takehiro Nakao; Chuyu Hayashi; Yoichi Aoki; Motomi Yamazaki; Go Ichikawa; Kenji Sugita; Tatsuo Yamamoto


Journal of Reproductive Immunology | 2015

Expressions of prostaglandin E2 synthases and its related factors in local lesions of endometriosis patients

Fumihisa Chishima; Takehiro Nakao; Chuyu Hayashi; Takahiro Nakajima; Tatsuo Yamamoto

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