Network


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

Hotspot


Dive into the research topics where Rika Yonezawa is active.

Publication


Featured researches published by Rika Yonezawa.


American Journal of Physiology-endocrinology and Metabolism | 2012

Central versus peripheral impact of estradiol on the impaired glucose metabolism in ovariectomized mice on a high-fat diet

Rika Yonezawa; Tsutomu Wada; Natsumi Matsumoto; Mayuko Morita; Kanae Sawakawa; Yoko Ishii; Masakiyo Sasahara; Hiroshi Tsuneki; Shigeru Saito; Toshiyasu Sasaoka

Age-related loss of ovarian function promotes adiposity and insulin resistance in women. Estrogen (E(2)) directly enhances insulin sensitivity and suppresses lipogenesis in peripheral tissues. Recently, the central actions of E(2) in the regulation of energy homeostasis are becoming clearer; however, the functional relevance and degree of contribution of the central vs. peripheral actions of E(2) are currently unknown. Therefore, we prepared and analyzed four groups of mice. 1) CONTROL: sham-operated mice fed a regular diet, 2) OVX-HF: ovariectomized (OVX) mice fed a 60% high-fat diet (HF), 3) E2-SC: OVX-HF mice subcutaneously treated with E(2), and 4) E2-ICV: OVX-HF mice treated with E(2) intracerebroventricularly. OVX-HF mice showed increased body weight with both visceral and subcutaneous fat volume enlargement, glucose intolerance, and insulin resistance. Both E2-SC and E2-ICV equally ameliorated these abnormalities. Although the size of adipocytes and number of CD11c-positive macrophages in perigonadal fat in OVX-HF were reduced by both E(2) treatments, peripherally administered E(2) decreased the expression of TNFα, lipoprotein lipase, and fatty acid synthase in the white adipose tissue (WAT) of OVX-HF. In contrast, centrally administered E(2) increased hormone-sensitive lipase in WAT, decreased the hepatic expression of gluconeogenic enzymes, and elevated core body temperature and energy expenditure with marked upregulation of uncoupling proteins in the brown adipose tissue. These results suggest that central and peripheral actions of E(2) regulate insulin sensitivity and glucose metabolism via different mechanisms, and their coordinated effects may be important to prevent the development of obesity and insulin resistance in postmenopausal women.


PLOS ONE | 2014

Intestinal microbiota is different in women with preterm birth: results from terminal restriction fragment length polymorphism analysis.

Arihiro Shiozaki; Satoshi Yoneda; Noriko Yoneda; Rika Yonezawa; Takamichi Matsubayashi; Genichiro Seo; Shigeru Saito

Preterm birth is a leading cause of perinatal morbidity and mortality. Studies using a cultivation method or molecular identification have shown that bacterial vaginosis is one of the risk factors for preterm birth. However, an association between preterm birth and intestinal microbiota has not been reported using molecular techniques, although the vaginal microbiota changes during pregnancy. Our aim here was to clarify the difference in intestinal and vaginal microbiota between women with preterm birth and women without preterm labor. 16S ribosomal ribonucleic acid genes were amplified from fecal and vaginal DNA by polymerase chain reaction. Using terminal restriction fragment length polymorphism (T-RFLP), we compared the levels of operational taxonomic units of both intestinal and vaginal flora among three groups: pregnant women who delivered term babies without preterm labor (non-PTL group) (n = 20), those who had preterm labor but delivered term babies (PTL group) (n = 11), and those who had preterm birth (PTB group) (n = 10). Significantly low levels of Clostridium subcluster XVIII, Clostridium cluster IV, Clostridium subcluster XIVa, and Bacteroides, and a significantly high level of Lactobacillales were observed in the intestinal microbiota in the PTB group compared with those in the non-PTL group. The levels of Clostridium subcluster XVIII and Clostridium subcluster XIVa in the PTB group were significantly lower than those in the PTL group, and these levels in the PTL group were significantly lower than those in non-PTL group. However, there were no significant differences in vaginal microbiota among the three groups. Intestinal microbiota in the PTB group was found to differ from that in the non-PTL group using the T-RFLP method.


American Journal of Reproductive Immunology | 2015

Accurate Prediction of the Stage of Histological Chorioamnionitis before Delivery by Amniotic Fluid IL-8 Level.

Satoshi Yoneda; Arihiro Shiozaki; Mika Ito; Noriko Yoneda; Kumiko Inada; Rika Yonezawa; Mika Kigawa; Shigeru Saito

To estimate the stage of histological chorioamnionitis (h‐CAM) antenatally using clinical data.


Journal of Obstetrics and Gynaecology Research | 2013

Kami‐shoyo‐san, Kampo (Japanese traditional medicine), is effective for climacteric syndrome, especially in hormone‐replacement‐therapy‐resistant patients who strongly complain of psychological symptoms

Takao Hidaka; Rika Yonezawa; Shigeru Saito

Aim:  Hormone replacement therapy (HRT) for climacteric symptoms is effective for vasomotor symptoms, such as hot flushes and sweating, but not for various psychological symptoms, such as anxiety, depression, and irritability. In such cases, prescribing Kampo, traditional herbal medicine, is sometimes considered. However, the effectiveness of Kampo has not been clearly shown. We examined the clinical effect of Kami‐shoyo‐san, a herbal formula commonly prescribed for climacteric symptoms in a Japanese Kampo clinic.


Journal of Endocrinology | 2015

Teneligliptin improves metabolic abnormalities in a mouse model of postmenopausal obesity

Azusa Sameshima; Tsutomu Wada; Tetsuo Ito; Ayaka Kashimura; Kanae Sawakawa; Rika Yonezawa; Hiroshi Tsuneki; Yoko Ishii; Masakiyo Sasahara; Shigeru Saito; Toshiyasu Sasaoka

A decrease in serum estrogen levels in menopause is closely associated with the development of visceral obesity and the onset of type 2 diabetes in women. In the present study, we demonstrated the therapeutic effects of the novel DPP4 inhibitor, teneligliptin, on the features of postmenopausal obesity in mice. In the control group, female C57BL/6 mice were sham-operated and maintained on a standard diet. In the postmenopausal obese group, ovariectomized (OVX) mice were maintained on a high-fat diet, and were referred to as OVX-HF. In the treated group, teneligliptin at 60 mg/kg per day was administrated to OVX-HF, and were referred to as Tene. After a 12-week food challenge, the metabolic phenotypes of these mice were analyzed. Body weight, fat accumulation, and glucose intolerance were greater in OVX-HF than in control, while these abnormalities were markedly improved without alterations in calorie intake in Tene. Teneligliptin effectively ameliorated the characteristics of metabolic abnormalities associated with postmenopausal obesity. Regarding chronic inflammation in visceral adipose tissue, the numbers of F4/80(+)CD11c(+)CD206(-) M1-macrophages in flow cytometry, crown-like structure formation in immunohistochemistry, and proinflammatory cytokine expression were significantly attenuated in Tene. Hepatic steatosis was also markedly improved. Furthermore, decreased energy consumption in the dark and light phases, reduced locomotor activity in the dark phase, and lowered core body temperature in OVX-HF were ameliorated in Tene. Since obesity and reduced energy metabolism are a common physiology of menopause, teneligliptin appears to be beneficial as a treatment for type 2 diabetes in postmenopausal obesity.


Placenta | 2013

A triploid partial mole placenta from paternal isodisomy with a diploid fetus derived from one sperm and one oocyte may have caused angiogenic imbalance leading to preeclampsia-like symptoms at 19 weeks of gestation

Noriko Yoneda; Arihiro Shiozaki; Kiyonori Miura; Rika Yonezawa; K. Takemura; Satoshi Yoneda; H. Masuzaki; Shigeru Saito

Partial hydatidiform mole with a normal fetus is extremely rare. A 30-year-old woman presented at 19 weeks gestation with clinical manifestations of severe preeclampsia. The fetus revealed a normal 46,XX karyotype and the placenta revealed triploid 69,XXX from paternal isodisomy. Microsatellite analysis revealed that the fetus and the triploid partial mole were derived from one sperm and one oocyte, followed by duplication of paternal chromosomes in only a trophectodermal cell. The maternal serum levels of angiogenic factors were extremely high compared with those reported in preeclampsia, suggesting an angiogenic imbalance may have caused preeclampsia-like symptoms before 20 weeks of gestation.


Journal of Obstetrics and Gynaecology Research | 2011

Stage I ovarian cancer cases during early, mid and late pregnancy periods: Three case reports and review of the literature

Toru Hasegawa; Yoko Ishii; Rika Yonezawa; Noriko Yoneda; Tomoko Shima; Akitoshi Nakashima; Takao Hidaka; Shigeru Saito

Since ovarian cancer during pregnancy is rare, the decisions regarding pregnancy discontinuation or fertility preservation are often difficult. We report three ovarian cancer cases detected at early, mid and late pregnancy periods in which both babies and mothers were saved. In particular, case 2 is the first reported instance of a sertoliform endometrioid carcinoma of the ovary during pregnancy. In addition, we review the clinical characteristics of previously reported patients with stage I ovarian cancer diagnosed during pregnancy.


Ejso | 2007

Omission of lymphadenectomy is possible for low-risk corpus cancer

Takao Hidaka; Kiyoshi Kato; Rika Yonezawa; Tomoko Shima; Akitoshi Nakashima; Kiyofumi Nagira; Takafumi Nakamura; Shigeru Saito


日本産科婦人科學會雜誌 | 2016

ISP-36-2 Effect of the dipeptidyl peptidase-4 inhibitor teneligliptin on glucose metabolism in ovariectomized mice on a high-fat diet(Group 36 Women's Health 1,International Session Poster)

Azusa Sameshima; Tsutomu Wada; Rika Yonezawa; Toshiyasu Sasaoka; Shigeru Saito


Placenta | 2013

A case of PMD with the high maternal serum levels of sFlt-1

Sameshima Azusa; Noriko Yoneda; Msahito Morijiri; Rika Yonezawa; Satoshi Yoneda; Arihiro Shiozaki; Ritsuko K. Pooh; Masahiro Nakayama; Hidenobu Soejima; Shigeru Saito

Collaboration


Dive into the Rika Yonezawa's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge