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Dive into the research topics where Chiaki Nishimura is active.

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Featured researches published by Chiaki Nishimura.


Circulation | 2009

Anatomic Properties of Myocardial Bridge Predisposing to Myocardial Infarction

Yukio Ishikawa; Yoshikiyo Akasaka; Koyu Suzuki; Mieko Fujiwara; Takafumi Ogawa; Kazuto Yamazaki; Hitoshi Niino; Michio Tanaka; Kentaro Ogata; Shojiroh Morinaga; Yoshiro Ebihara; Yutaka Kawahara; Hitoshi Sugiura; Toshiro Takimoto; Akio Komatsu; Toshihito Shinagawa; Kazuhiro Taki; Hideaki Satoh; Kazuaki Yamada; Maki Yanagida-Iida; Reiko Shimokawa; Kazuyuki Shimada; Chiaki Nishimura; Kinji Ito; Toshiharu Ishii

Background— A myocardial bridge (MB) that partially covers the course of the left anterior descending coronary artery (LAD) sometimes causes myocardial ischemia, primarily because of hemodynamic deterioration, but without atherosclerosis. However, the mechanism of occurrence of myocardial infarction (MI) as a result of an MB in patients with spontaneously developing atherosclerosis is unclear. Methods and Results— One hundred consecutive autopsied MI hearts either with MBs [MI(+)MB(+) group; n=46] or without MBs (n=54) were obtained, as were 200 normal hearts, 100 with MBs [MI(−)MB(+) group] and 100 without MBs. By microscopy on LADs that were consecutively cross-sectioned at 5-mm intervals, the extent and distribution of LAD atherosclerosis were investigated histomorphometrically in conjunction with the anatomic properties of the MB, such as its thickness, length, and location and the MB muscle index (MB thickness multiplied by MB length), according to MI and MB status. In the MI(+)MB(+) group, the MB showed a significantly greater thickness and greater MB muscle index (P<0.05) than in the MI(−)MB(+) group. The intima-media ratio (intimal area/medial area) within 1.0 cm of the left coronary ostium was also greater (P<0.05) in the MI(+)MB(+) group than in the other groups. In addition, in the MI(+)MB(+) group, the location of the segment that exhibited the greatest intima-media ratio in the LAD proximal to the MB correlated significantly (P<0.001) with the location of the MB entrance, and furthermore, atherosclerosis progression in the LAD proximal to the MB was largest at 2.0 cm from the MB entrance. Conclusions— In the proximal LAD with an MB, MB muscle index is associated with a shift of coronary disease more proximally, an effect that may increase the risk of MI.


Clinical and Experimental Hypertension | 2009

Anti-Hypertensive Effect of γ-Aminobutyric Acid (GABA)-Rich Chlorella on High-Normal Blood Pressure and Borderline Hypertension in Placebo-Controlled Double Blind Study

Morio Shimada; Takashi Hasegawa; Chiaki Nishimura; Hiroko Kan; Toshihiro Kanno; Toshio Nakamura; Tsuneo Matsubayashi

The anti-hypertensive effect of GABA-rich Chlorella was studied after oral administration for 12 weeks in the subjects with high-normal blood pressure and borderline hypertension in the placebo-controlled, double-blind manner in order to investigate if GABA-rich Chlorella, a dietary supplement, is useful in control of blood pressure. Eighty subjects with Systolic blood pressure (SBP) 130–159 mmHg or diastolic blood pressure (DBP) 85–99 mmHg (40 subjects/group) took the blinded substance of GABA-rich Chlorella (20 mg as γ-aminobutyric acid) or placebo twice daily for 12 weeks, and had follow-up observation for an additional 4 weeks. Systolic blood pressure in the subjects given GABA-rich Chlorella significantly decreased compared with placebo (p < 0.01). Diastolic blood pressure had the tendency to decrease after intake of GABA-rich Chlorella. Neither adverse events nor abnormal laboratory findings were reported throughout the study period. Reduction of SBP in the subjects with borderline hypertension was higher than those in the subjects with high-normal blood pressure. These results suggest that GABA-rich Chlorella significantly decreased high-normal blood pressure and borderline hypertension, and is a beneficial dietary supplement for prevention of the development of hypertension.


Journal of Glaucoma | 2013

Ability of optical coherence tomography-determined ganglion cell complex thickness to total retinal thickness ratio to diagnose glaucoma.

Yoshiyuki Kita; Ritsuko Kita; Asuka Takeyama; Seiji Takagi; Chiaki Nishimura; Goji Tomita

Purpose:To evaluate the usefulness of the spectral-domain optical coherence tomography (SD OCT)–determined ganglion cell complex thickness to total retinal thickness ratio (G/T ratio) in diagnosing glaucoma. Methods:A total of 99 eyes with primary open-angle glaucoma and 35 normal eyes were enrolled in the study. SD OCT (RTVue-100) was used to measure the macular ganglion cell complex thickness, total retinal thickness, outer retinal thickness, and circumpapillary retinal nerve fiber layer (RNFL) thickness. A new macular parameter, the G/T ratio, was also calculated. The ability of each parameter to diagnose glaucoma was examined by analyzing the area under the receiver operating characteristics curve (AUROC) and the sensitivity at fixed specificity. Results:The G/T ratio was 36.0±1.5% in normal eyes, 31.8±1.7% in early glaucoma, and 30.2±2.6% in advanced glaucoma. These decreases in the ratio were statistically significant. For the AUROC, the individual SD OCT parameters were 0.982 for the G/T ratio, 0.968 for the macular ganglion cell complex thickness, 0.942 for the RNFL thickness, and 0.841 for the total retinal thickness. The AUROC for the G/T ratio was significantly higher than that seen for the total retinal and RNFL thicknesses (P<0.05). Analyses of the sensitivity at a specificity of >90% indicated that the G/T ratio (sensitivity, 93.94%) was the best diagnostic parameter. Conclusions:Decreases in the G/T ratio occur during the early stages of glaucoma. When using SD OCT to diagnose glaucoma, the G/T ratio may improve the diagnostic ability of the macular parameter.


American Journal of Clinical Pathology | 2007

Significance of lymphatic invasion on regional lymph node metastasis in early gastric cancer using LYVE-1 immunohistochemical analysis

Ai Fujimoto; Yukio Ishikawa; Yuri Akishima-Fukasawa; Kinji Ito; Yoshikiyo Akasaka; Seiichi Tamai; Tadaaki Maehara; Hideko Kiguchi; Kentaro Ogata; Chiaki Nishimura; Kazumasa Miki; Toshiharu Ishii

It has been reported that lymphatic invasion is a predictor for lymph node metastasis in early gastric cancer (EGC); however, it has been impossible to differentiate between lymphatic invasion and blood vessel invasion using current staining techniques. We studied the significance of lymphatic invasion on regional lymph node metastasis in EGC by using human lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) antibody, specific to lymphatic vessels, and von Willebrand factor (vWF) antibody, specific to the blood vessels, to clearly distinguish these vascular tissues.EGC tissues were obtained from 66 node-positive and 66 node-negative subjects and were matched by age and sex. These tissues were immunostained with antibodies against LYVE-1 and vWF. Multivariate logistic regression analysis demonstrated that lymphatic invasion was a significant independent predictor for regional lymph node metastasis (odds ratio, 4.667; P = .0094), whereas blood vessel invasion was not. Thus, lymphatic invasion identified by LYVE-1 antibody could predict the existence of regional lymph node metastasis in EGC.


Japanese Journal of Ophthalmology | 2011

Glaucomatous eye macular ganglion cell complex thickness and its relation to temporal circumpapillary retinal nerve fiber layer thickness

Yoshiyuki Kita; Ritsuko Kita; Ai Nitta; Chiaki Nishimura; Goji Tomita

PurposeTo clarify the correlation between temporal circumpapillary retinal nerve fiber layer (RNFL) thickness and macular ganglion cell complex (mGCC) thickness in glaucomatous eyes.MethodsSeventy-seven eyes of 77 subjects were categorized as normal, early glaucoma and moderate-to-advanced (moderate) glaucoma. After the circumpapillary RNFL thickness and mGCC thickness were measured, the temporal mean RNFL and mean mGCC were compared within the three groups. The study also investigated whether there was any correlation between the temporal RNFL and mGCC thicknesses.ResultsIn the glaucoma groups, significant thinning of the temporal RNFL and mGCC thicknesses was noted. With the exception of the papillomacular bundle (r = −0.078), correlations were seen in each of the early glaucoma mGCC and temporal RNFL sectors (r = 0.38–0.753). Correlations were also noted for the mGCC and all temporal RNFL sectors in the moderate glaucoma group (r = 0.425–0.809).ConclusionsFrom the early stage of glaucoma, similar decreases of the mGCC and RNFL occured, and a high correlation existed between the two. Therefore, like RNFL, mGCC can potentially be used to detect the early stages of glaucoma. However, in early glaucoma eyes, the papillomacular bundle of the RNFL may be spared, even though mGCC thinning is present.


Modern Rheumatology | 2012

Serum adipokine profiles in Kawasaki disease

Tsutomu Saji; Natsuko Kusunoki; Nahoko Tanaka; Chiaki Nishimura; Akira Ishiguro; Shinichi Kawai

Adipokines are cytokines derived from adipose tissue. Recently it has been established that adipokines are closely linked to the pathophysiology of not only metabolic diseases, such as diabetes mellitus, obesity, and atherosclerosis, but also to inflammation and immune diseases. In this study we measured serum levels of adipokines in patients with acute Kawasaki disease to investigate the role of adipokines in the pathophysiology of Kawasaki disease. Serum resistin, high-molecular-weight (HMW) adiponectin, leptin, and visfatin levels were measured by enzyme-linked immunosorbent assay in a total of 117 subjects: 56 patients with acute Kawasaki disease, 30 healthy children, and 31 patients with acute infectious diseases. Serum resistin levels in patients with Kawasaki disease were significantly higher than those of healthy children and patients with acute infectious diseases. In contrast, mean serum HMW adiponectin, leptin, and visfatin levels in patients with Kawasaki disease exhibited no statistically significant differences compared with those in healthy children and patients with infectious diseases. Serum resistin levels decreased significantly after administration of intravenous immune globulin. Serum resistin levels on admission were significantly higher in nonresponders compared with responders to intravenous immune globulin therapy. A multivariate model revealed that C-reactive protein was a factor that was significantly related to elevated serum resistin level in patients with Kawasaki disease. In patients with Kawasaki disease, serum resistin levels were elevated, but decreased to nearly normal after intravenous administration of immune globulin. In contrast, serum HMW adiponectin, leptin, and visfatin levels showed no statistically significant changes. These findings suggest that resistin plays an important role, while other adipokines do not play a major role, in the pathogenesis of Kawasaki disease.


American Journal of Clinical Pathology | 2007

Significance of Lymphatic Invasion and Proliferation on Regional Lymph Node Metastasis in Renal Cell Carcinoma

Yukio Ishikawa; Shinsuke Aida; Seiichi Tamai; Yoshikiyo Akasaka; Hideko Kiguchi; Yuri Akishima-Fukasawa; Masamichi Hayakawa; Shigehiro Soh; Kinji Ito; Masayo Kimura-Matsumoto; Shigeki Ishiguro; Chiaki Nishimura; Itaru Kamata; Reiko Shimokawa; Toshiharu Ishii

We studied the associations of lymphatic invasion and lymphatic vessel density around tumors with lymph node (LN) status in renal cell carcinoma (RCC) by immunohistochemical analysis using D2-40 antibody as a lymphatic marker. Surgically removed specimens from 76 cases with RCC, including 16 cases with LN metastasis, were used. Lymphatic vessel density around the tumor increased compared with normal kidneys but was not significant by LN status. Tumor size, tumor cell types, patterns of tumor growth, nuclear grade of tumor cells, venous invasion, lymphatic invasion, and primary tumor stage were predictive factors for LN metastasis. Based on multivariate regression analysis, only lymphatic invasion was an independent risk factor for LN metastasis. The immunohistochemical detection of lymphatics was useful for identifying the lymphatic invasion of RCC, and the presence of lymphatic invasion around RCC was an independent predictive factor for LN metastasis.


Virchows Archiv | 2009

Histopathological predictor for regional lymph node metastasis in gastric cancer

Hiroshi Morita; Yukio Ishikawa; Yuri Akishima-Fukasawa; Kinji Ito; Yoshikiyo Akasaka; Chiaki Nishimura; Yoshinori Igarashi; Kazumasa Miki; Toshiharu Ishii

Regional lymph node metastasis in gastric cancer is a definitive indicator of the patient’s prognosis. The goal of this study was to identify the predictors for lymph node metastasis among all the possible histopathological parameters, especially by conducting an objective discrimination of the lymphatic and blood vessels. A total of 210 resected primary gastric cancers with or without lymph node metastasis were evaluated based on the conventional histopathological parameters together with immunohistochemistry using antisera-recognizing lymphatic endothelial hyaluronan receptor-1 (LYVE-1), von Willebrand factor, and lymphangiogenesis promoter vascular endothelial growth factor-C (VEGF-C) antibodies. A multivariate regression analyses of the results indicated that only lymphatic invasion was a significant independent predictor of lymph node metastasis at any stage of cancer invasion. VEGF-C expression was partially related to lymph node metastasis in early gastric cancer. The identification of lymphatic invasion by LYVE-1 antibody is therefore useful to predict regional lymph node metastasis in gastric cancer.


Journal of Atherosclerosis and Thrombosis | 2011

Influence of Fatty Liver on Plasma Small, Dense LDL- Cholesterol in Subjects with and without Metabolic Syndrome

Ikumi Sugino; Koji Kuboki; Tomoko Matsumoto; Eiichi Murakami; Chiaki Nishimura; Gen Yoshino


Journal of Atherosclerosis and Thrombosis | 2010

Small, dense LDL and high-sensitivity C-reactive protein (hs-CRP) in metabolic syndrome with type 2 diabetes mellitus.

Saburo Nakano; Koji Kuboki; Tomoko Matsumoto; Chiaki Nishimura; Gen Yoshino

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Reiko Shimokawa

Tokyo Medical and Dental University

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