Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Tomoyo Yasui is active.

Publication


Featured researches published by Tomoyo Yasui.


Proceedings of the National Academy of Sciences of the United States of America | 2003

A high-frequency polymorphism in exon 6 of the CD45 tyrosine phosphatase gene (PTPRC) resulting in altered isoform expression

Tara Stanton; Sally Boxall; Kouzo Hirai; Ritu Dawes; Susan Tonks; Tomoyo Yasui; Yasushi Kanaoka; Nadira Yuldasheva; Osamu Ishiko; Walter F. Bodmer; Peter C. L. Beverley; Elma Z. Tchilian

CD45 (leukocyte common) antigen is a hemopoietic cell-specific tyrosine phosphatase essential for antigen receptor-mediated signaling in lymphocytes. The molecule undergoes complex alternative splicing in the extracellular domain, and different patterns of CD45 splicing are associated with distinct functions. Lack of CD45 leads to severe combined immunodeficiency, and alterations of CD45 splicing, because of a polymorphism in exon 4, have been associated with altered immune function. Here we describe a polymorphism in exon 6 (A138G) of the gene encoding CD45 that interferes with alternative splicing. The polymorphism results in an amino acid substitution of Thr-47 to Ala in exon 6, a potential O- and N-linked glycosylation site. This exon 6 A138G variant is present at a frequency of 23.7% in the Japanese population but is absent in Caucasoids. Peripheral blood T cells from individuals carrying the A138G variant show a significant decrease in the proportion of cells expressing the A, B, and C CD45 isoforms and a high frequency of CD45R0+ cells. These phenotypic alterations in the A138G carriers may lead to changes in ligand binding, homodimerization of CD45, and altered immune responses, suggesting the involvement of natural selection in controlling the A138G carrier frequency.


Nutrition and Cancer | 1999

Lipolytic activity of anemia-inducing substance from tumor-bearing rabbits.

Osamu Ishiko; Tomoyo Yasui; Kouzo Hirai; Ken-ichi Honda; Toshiyuki Sumi; Sadako Nishimura; Sachio Ogita

Anemia-inducing substance (AIS) is a protein of approximately 50,000 molecular weight secreted by malignant tumor tissue that depresses erythrocyte and immuno-competent cell functions; in this study, its biological effects on adipocytes were examined. Changes in body weight, total body fat, and food intake were investigated in rabbits after VX2 carcinoma transplantation, and the results showed reductions of 11%, 24%, and 30%, respectively, at 40 days after transplantation compared with baseline values (before transplantation). The values were even more markedly reduced 70 days after transplantation. When cyclic plasma perfusion (2 times/wk) was started at 40 days after transplantation, the values at 70 days after transplantation (30 days after beginning plasma perfusion) recovered to 91%, 84%, and 87%, respectively, of the baseline values. AIS fractions were isolated from rabbit plasma by using a phenyl-Sepharose column before transplantation, 40 and 70 days after transplantation, and 30 days after start of plasma perfusion, and AIS activity and lipolytic activity were measured. The results showed enhancement of AIS activity and lipolytic activity as the tumors grew. Lipolytic activity also returned to baseline value as AIS was removed by adsorption by plasma perfusion, and there was a high correlation between lipolytic activity and AIS kinetics. These results strongly suggest that AIS might be one of the substances involved in the enhanced lipolytic activity in advanced tumor-bearing subjects.


Japanese Journal of Cancer Research | 1999

Metabolic and Morphologic Characteristics of Adipose Tissue Associated with the Growth of Malignant Tumors

Osamu Ishiko; Sadako Nishimura; Tomoyo Yasui; Toshiyuki Sumi; Kouzo Hirai; Ken-ichi Honda; Sachio Ogita

Changes in total body fat and the metabolic and morphologic characteristics of adipose tissue were sequentially investigated in individual rabbits implanted with VX2 tumors to elucidate the pathology of the fat reduction in animals with malignant tumors as compared with that of diet‐restricted rabbits. Lipogenesis in normal, VX2–implanted, and diet‐restricted rabbit groups on day 40 after the start of the experiments was 19.1±2.9, 13.3±3.5, and 41.7±6.0×l05 cpm/g/h, respectively, and glycerol liberation by their adipose tissue was 199±21, 528±94, and 301±45 nmol/g/h, respectively. In addition, apoptotic cells were noted in the adipose tissue of VX2–implanted rabbits on days 20–30 after implantation, but not in diet‐restricted rabbits. The results showed clear differences between the total body fat reduction profiles of VX2–implanted rabbits and diet‐restricted rabbits, suggesting a characteristic lipid metabolism with enhanced lipolysis and diminished lipogenesis in VX2–implanted rabbits. The results strongly suggest that adipocyte apoptosis might be involved in these phenomena.


Nutrition and Cancer | 1998

Body composition analysis of cachectic rabbits by total body electrical conductivity

Tomoyo Yasui; Osamu Ishiko; Toshiyuki Sumi; Ken-ichi Honda; Kouzo Hirai; Sadako Nishimura; Yoshinari Matsumoto; Sachio Ogita

A simple formula (1.536 x TOBEC + 475.146 = LBM, where TOBEC is total body electrical conductivity and LBM is lean body mass) to estimate LBM in grams was developed on the basis of the total body fat data obtained by ether extraction and TOBEC in normal rabbits. The formula was also applicable to rabbits with cachexia induced by inoculation of VX2 carcinoma or by starvation. We were able to assess the losses of body fat in the rabbits with cachexia at 10-day intervals by using TOBEC.


Journal of Obstetrics and Gynaecology Research | 2009

Uterine artery flow velocity waveforms during uterine contractions: Differences between oxytocin‐induced contractions and spontaneous labor contractions

Mie Tahara; Yuichiro Nakai; Tomoyo Yasui; Sachiyo Nishimoto; Akemi Nakano; Makiko Matsumoto; Hiroyuki Nobeyama; Rika Nishihara; Naoko Iwanaga; Osamu Ishiko

Aim:  To clarify the effects on uterine arterial flow velocity waveforms of uterine contractions following oxytocin infusion and during spontaneous labor.


Anti-Cancer Drugs | 2015

Chemotherapy-induced neutropenia and febrile neutropenia in patients with gynecologic malignancy

Yasunori Hashiguchi; Mari Kasai; Takeshi Fukuda; Tomoyuki Ichimura; Tomoyo Yasui; Toshiyuki Sumi

Chemotherapy-induced neutropenia is a common complication in cancer treatment. In this study, we investigated chemotherapy-induced neutropenia that was recently detected in all patients with gynecologic malignancy. Between January 2009 and December 2011, we examined cases of chemotherapy-induced neutropenia reported in our hospital. We analyzed the incidence and clinical features of chemotherapy-induced neutropenia and febrile neutropenia in patients with gynecologic malignancy. During the study period, we administered over 1614 infusions (29 regimens) to 291 patients. The median age of the patients was 60 years (range 24–84 years). Chemotherapy-induced neutropenia occurred in 147 (50.5%) patients over 378 (23.4%) chemotherapy cycles. Febrile neutropenia occurred in 20 (6.9%) patients over 25 (1.5%) cycles. The mean duration of neutropenia and fever was 3.6 days (range 1–12 days) and 3.4 days (range 1–9 days), respectively. The source of fever was unexplained by examination or cultures in 14 (56.0%) cycles. There were two cases of neutropenia-related death. Chemotherapy-induced neutropenia was associated with older age (over 70 years) (P<0.0001), less than five previous chemotherapy cycles (P=0.02), disseminated disease (P=0.03), platinum-based regimens (P<0.0001), taxane-containing regimens (P<0.0001), and combined therapy (P<0.0001). Febrile neutropenia was associated with poor performance status (P<0.0001), no previous chemotherapy (P<0.05), disseminated disease (P<0.0001), and distant metastatic disease (P=0.03). Neither chemotherapy-induced neutropenia nor febrile neutropenia was associated with bone marrow metastases or previous radiotherapy. By identifying risk factors for febrile neutropenia, such as performance status, no previous chemotherapy, disseminated disease, and distant metastatic disease, the safe management of chemotherapy-induced neutropenia may be possible in patients with gynecologic malignancy.


Oncology Letters | 2017

UCP2 expression may represent a predictive marker of neoadjuvant chemotherapy effectiveness for locally advanced uterine cervical cancer

Kenji Imai; Takeshi Fukuda; Takuma Wada; Masaru Kawanishi; Reiko Tasaka; Tomoyo Yasui; Toshiyuki Sumi

Concurrent chemoradiotherapy is the standard treatment for locally advanced uterine cervical cancer. However, effective neoadjuvant chemotherapy (NAC) can reduce tumor size and facilitate hysterectomy for locally advanced uterine cervical cancer. NAC treatment could improve the prognosis of patients with locally advanced cervical cancer. However, if NAC is ineffective, radiotherapy must be pursued. This causes a delay in initiating the core treatment and results in a worse prognosis. Therefore, the identification of predictive markers of whether NAC is likely to be effective for the treatment of locally advanced uterine cervical cancer could improve patient prognosis. Uncoupling protein 2 (UCP2) is broadly expressed in cancer cells, and suppresses mitochondrial reactive oxygen species (ROS) production. UCP2 contributes to both carcinogenesis and chemoresistance by reducing ROS. Downregulation of UCP2 results in significantly increased cell death following chemotherapy. The present study investigated the association between UCP2 expression and NAC effectiveness. A total of 58 patients with locally advanced uterine cervical cancer (stage IIIA or IIIB) treated at Osaka City University Hospital between April 1995 and March 2010 were examined. Tumor tissue samples were obtained by punch biopsy prior to NAC. UCP2 expression was examined immunohistochemically and scored using a weighted scoring system. Patients were divided into NAC effective (n=34) and ineffective (n=24) groups. Furthermore, UCP2 expression in human uterine cervical cancer cells was inhibited by genipin, and changes in cisplatin sensitivity were examined. UCP2 weighted score was higher in the NAC ineffective group than in the NAC effective group (P=0.038). Additionally, the low UCP2 expression group was more sensitive to NAC than the high UCP2 expression group (P=0.041). Sensitivity to cisplatin was significantly increased when UCP2 was inhibited in human uterine cervical cancer cells in vitro. UCP2 expression may become a predictive marker of whether NAC is effective for patients with locally advanced uterine cervical cancer, which could improve patient prognosis.


Oncology Letters | 2016

Expression of epidermal growth factor‑like domain 7 may be a predictive marker of the effect of neoadjuvant chemotherapy for locally advanced uterine cervical cancer

Makoto Yamauchi; Takeshi Fukuda; Takuma Wada; Masaru Kawanishi; Kenji Imai; Reiko Tasaka; Tomoyo Yasui; Toshiyuki Sumi

Neoadjuvant chemotherapy (NAC) followed by hysterectomy may be effective for the treatment of locally advanced uterine cervical cancer and improve patient prognosis. It is important to identify markers that are able to predict whether NAC may be successful. Epidermal growth factor-like domain 7 (EGFL7) regulates vascular sprouting in blood vessel formation. In numerous types of human cancer, EGFL7 is upregulated and inhibits endothelial cell adhesion molecules, decreasing vascular tightness and, thus, increasing vascular permeability. It is considered that the overexpression of EGFL7 is able to inhibit drug delivery, resistance to apoptosis and the epithelial-to-mesenchymal transition. In the current study, 63 patients with locally advanced uterine cervical cancer were reviewed and classified as stage IIIA-IIIB using the International Federation of Gynecology and Obstetrics criteria. These patients (aged <70 years) were treated at Osaka City University Medical School Hospital, Japan, between 1995 and 2010. Tumor tissue samples were obtained by biopsy prior to NAC. The tissue samples were classified as group 1 or 2 depending on the efficacy of NAC. Surgery and radiotherapy were administered in group 1 (n=36), for which NAC was effective. In the patients of group 2 NAC was not effective, and radiotherapy alone was administered (n=27). The expression of EGFL7 and Snail was examined in paraffin-embedded tissue sample sections using the avidin-biotin peroxidase complex method. The results indicated that EGFL7 expression levels were significantly higher in group 2, as compared with group 1 (P<0.001). A similar result was observed for the expression levels of Snail (P=0.001). Group 1 exhibited significantly longer overall survival times compared with group 2 (P=0.001). The patients were also classified into a low EGFL7 expression level group (weighted score of ≤6) and a high EGFL7 expression level group (weighted score of ≥8). NAC was observed to be significantly more effective in the low EGFL7 expression level group (P<0.001), as compared with the high expression level group. The results suggest that the expression levels of EGFL7 may be a potential predictive marker of the efficacy of NAC for the treatment of locally advanced uterine cervical cancer.


Oncology Letters | 2014

Minimal deviation mucinous adenocarcinoma of the uterine cervix that proved difficult to differentiate from endometrial cancer: A case report

Yuko Nishii; Takeshi Fukuda; Kenji Imai; Makoto Yamauchi; Yasunori Hashiguchi; Tomoyuki Ichimura; Tomoyo Yasui; Toshiyuki Sumi

Minimal deviation adenocarcinoma (MDA), also known as adenoma malignum of the uterine cervix, accounts for only ~1% of uterine cervical adenocarcinomas. Adenoma malignum of the uterine cervix was initially described by Gusserow in 1870. Using magnetic resonance imaging (MRI), MDA appears as multilocular lesions with solid components that extend from the endocervical glands to the deep cervical stroma. Cytological evaluation and biopsies have low detection rates, therefore, it is difficult to diagnose MDA accurately prior to treatment. The current study describes a rare case of MDA that was difficult to differentiate from endometrial adenocarcinoma of the corpus uteri preoperatively, as the endometrial biopsy results suggested a well-differentiated endometrioid adenocarcinoma and MRI did not show typical images for MDA. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed under the diagnosis of endometrial cancer, and the mass was subsequently diagnosed as MDA of the uterine cervix by pathological examination of the hysterectomy specimen. Postoperatively, although two types of adjuvant chemotherapy were performed, the remaining tumor continued to grow, causing obstruction of the bilateral ureters and leading to bilateral hydronephrosis. The patient is currently alive with the disease 10 months following the surgery.


International Journal of Gynecology & Obstetrics | 2012

Outcomes of traditional prolapse surgery for pelvic organ prolapse repair at a single center.

Takeshi Fukuda; Toshiyuki Sumi; Tomoyo Yasui; Masayasu Koyama; Osamu Ishiko

To evaluate the clinical outcomes of traditional surgical approaches to pelvic organ prolapse.

Collaboration


Dive into the Tomoyo Yasui's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Hiroyuki Yoshida

Osaka Prefecture University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge