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Dive into the research topics where Yoji Hirayama is active.

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Featured researches published by Yoji Hirayama.


Hypertension | 2006

Synergistic Acceleration of Arterial Stiffening in the Presence of Raised Blood Pressure and Raised Plasma Glucose

Hirofumi Tomiyama; Hideki Hashimoto; Yoji Hirayama; Minoru Yambe; Jiko Yamada; Yutaka Koji; Kazuki Shiina; Yoshio Yamamoto; Akira Yamashina

Arterial stiffness is recognized as a marker of arterial damage and an indicator of cardiovascular risk. This observational study was conducted to examine the synergistic effect of raised blood pressure (RBP; ≥130/85 mm Hg) and raised plasma glucose (RPG; ≥110 mg/dL) even at levels below those conventionally used to define hypertension and diabetes on the rate of increase of the pulse wave velocity (PWV) over a 3-year period in 2080 Japanese men (age 42±9 years). First, the subjects were classified into 4 groups based on the presence at the first examination of RBP, RPG, both abnormalities, or neither abnormality. The estimated annual rate of increase of the PWV was higher in subjects with both the abnormalities than in those with either abnormality alone or neither of the 2 abnormalities. Second, the subjects were also classified based on the evolutional status of these abnormalities during the study period; persistence of both of the abnormalities synergistically accelerated the rate of increase of the PWV (68.3±7.1 cm/s per year), as compared with the persistence of either abnormality alone (persistence of RBP alone: 18.2±1.6 cm/s per year; persistence of RPG alone: 21.2±7.4 cm/s per year) or persistence of neither abnormality (11.1±0.8 cm/s per year; P<0.01). Thus, blood pressure and fasting plasma glucose levels even below those defining hypertension and diabetes may synergistically lead to progression of arteriosclerotic arterial damage. This synergistic progression may contribute to the additive increases in the risk of cardiovascular events, at least in part.


Cardiovascular Research | 1996

The beneficial effects of atrial natriuretic peptide on arrhythmias and myocardial high-energy phosphates after reperfusion

Yoshifumi Takata; Yoji Hirayama; Sadamichi Kiyomi; Takashi Ogawa; Kentaro Iga; Toshikazu Ishii; Yoshikazu Nagai; Chiharu Ibukiyama

OBJECTIVES The aim of this investigation was to test whether the administration of atrial natriuretic peptide (ANP) has cardioprotective effects against ischaemic and reperfusion injury. METHODS Thoracotomized dogs underwent a 30 min left circumflex coronary artery occlusion and 60 min of reperfusion (control group; n = 16). The ANP group (n = 9) received a 20 micrograms bolus injection of synthetic alpha human ANP (SUN 4936) followed by infusion at a dose of 0.1 microgram/kg/min from the beginning of coronary occlusion to the end of the procedure. RESULTS Administration of exogenous ANP increased plasma ANP immediately and maintained levels at 3000 pg/ml, resulting in an 8-fold increase in plasma cyclic guanosine monophosphate (cGMP) levels. Plasma ANP and plasma cGMP levels did not change at all in controls. There were no significant differences in haemodynamic parameters during ischaemia and reperfusion between the groups. In the ANP group, the prevalence and frequency of ventricular extrasystoles within 10 min after reperfusion decreased markedly [ANP 22% vs. control 100%, P < 0.01, and ANP 1 (1) vs. control 92 (50), P < 0.05, respectively]. No dog in the ANP group had ventricular fibrillation (VF), but the incidence of VF was not statistically significant between the groups [ANP 0% vs. control 25%]. ATP content in the inner layers of the ischaemic myocardium in the ANP group was higher than in controls (P < 0.05) [1.92 (0.28) vs. 1.18 (0.13) mumol/g wet weight]. There was no significant difference in the content of myocardial tissue angiotensin II between the groups. CONCLUSIONS These data show that the infusion of ANP has cardioprotective effects on myocardial ischaemia and reperfusion in this model. These beneficial effects are probably due to direct effects through cGMP rather than haemodynamic changes.


Hypertension Research | 2006

Concurrent Presence of Metabolic Syndrome in Obstructive Sleep Apnea Syndrome Exacerbates the Cardiovascular Risk: A Sleep Clinic Cohort Study

Kazuki Shiina; Hirofumi Tomiyama; Yoshifumi Takata; Yasuhiro Usui; Kihiro Asano; Yoji Hirayama; Takeshi Nakamura; Akira Yamashina

This cross-sectional study was conducted to examine whether the obstructive sleep apnea syndrome (OSAS) is associated with elevation of the pulse wave velocity (PWV) and increase in the plasma levels of C-reactive protein (CRP), both of which are known markers of cardiovascular risk, and also to determine if the concurrent presence of the metabolic syndrome might exacerbate this elevation in the levels of these cardiovascular risk markers in subjects with OSAS. With these objectives, the PWV and serum CRP were measured in 184 subjects attending a sleep clinic. It was found that the PWV and CRP were higher in the subjects with OSAS (n=94) than in those without OSAS (n=90). Furthermore, among the subjects with OSAS, the PWV and CRP were higher in those with the concurrent presence of the metabolic syndrome (n= 41; PWV=1,562±19 cm/s; CRP=1.8±0.2 mg/l) than in those without metabolic syndrome (n=53; PWV=1,432±21 cm/s; CRP=1.2±0.1 mg/l) (p<0.05). A general linear model analysis demonstrated that OSAS and metabolic syndrome were independently associated with elevated PWV and increase of the plasma levels of CRP. OSAS appears to be associated with increased cardiovascular risk, as reflected by both elevated PWV and increase of the plasma CRP. The concurrent presence of metabolic syndrome may exacerbate this increase in cardiovascular risk in subjects with OSAS. Therefore, the concurrent presence of metabolic syndrome may constitute an additive cardiovascular risk factor in subjects with OSAS.


Hypertension Research | 2006

The effects of changes in the metabolic syndrome detection status on arterial stiffening: a prospective study.

Hirofumi Tomiyama; Yoji Hirayama; Hideki Hashimoto; Minoru Yambe; Jiko Yamada; Yutaka Koji; Kohki Motobe; Kazuki Shiina; Yoshio Yamamoto; Akira Yamashina

We conducted a prospective study to examine the effects of alterations of the metabolic syndrome detection status on the rate of progression of arterial stiffness, which is recognized as a marker of arterial damage and an indicator of cardiovascular risk. Brachial-ankle pulse wave velocity as an index of arterial stiffening was recorded twice over a 3-year period in 2,080 Japanese men (age, 42±9 years). At the start of the prospective study, pulse wave velocity was higher in the subjects with metabolic syndrome (n=125) than in those without metabolic syndrome (n=1,955) even after adjusting for mean blood pressure. The annual rate of increase of the pulse wave velocity was higher in the group with persistent metabolic syndrome (27±51 cm/s/year, n=71) than in the group with regression of metabolic syndrome (6±39 cm/s/year, n=54) or the group in which metabolic syndrome was absent (13±37 cm/s/year, n=1,843; p<0.05) after adjustment for changes in blood pressure. In conclusion, the changes in the metabolic syndrome detection status of the subjects during the study period affected the annual rate of progression of arterial stiffening, and persistent metabolic syndrome during the study period was associated with acceleration of arterial stiffening in middle-aged Japanese men. On the other hand, resolution of metabolic syndrome may be associated with attenuation of the progression of arterial damage. Therefore, the increased cardiovascular risk associated with the presence of metabolic syndrome may be at least partly mediated by acceleration of the progression of arterial stiffening.


Journal of Gastroenterology and Hepatology | 2014

Prevalence of Helicobacter pylori infection with healthy subjects in Japan.

Yoji Hirayama; Takashi Kawai; Junji Otaki; Kohei Kawakami

Only few large‐scale epidemiological studies have examined the prevalence of Helicobacter pylori (H. pylori) infection in Japan. The aim of the present study was to estimate the prevalence and incidence of H. pylori infection in Japan in terms of gender, age and region.


Journal of Hypertension | 2008

Plasma B-type natriuretic peptide level is associated with left ventricular hypertrophy among obstructive sleep apnoea patients

Yasuhiro Usui; Hirofumi Tomiyama; Hideki Hashimoto; Yoshifumi Takata; Yuichi Inoue; Kihiro Asano; Saiko Kurohane; Kazuki Shiina; Yoji Hirayama; Akira Yamashina

Objectives To examine whether increased plasma levels of B-type natriuretic peptide (BNP) are associated with cardiac structural and functional abnormalities in obstructive sleep apnoea (OSA) patients, taking into consideration the confounding effect of obesity. Measurements In a cross-sectional study, polysomnography, echocardiography and the measurement of the serum levels of BNP were performed in 235 consecutive subjects (age 52 ± 14 years) visiting our sleep clinic. Left ventricular hypertrophy (LVH) [left ventricular mass index (LVMI) ≥ 125 g/m2 in men, and ≥ 110 g/m2 in women] and cardiac diastolic function (E/A ratio) were determined by echocardiography. Results The LVMI, prevalence rate of LVH and body mass index (BMI) were higher, and the E/A ratio lower in the subjects with severe OSA (apnoea–hypopnoea index ≥ 30/h, n = 146, LVH 80%) than in those with mild to moderate OSA (n = 89, LVH 35%; P < 0.01), although plasma BNP levels were similar in the two groups. Although the log-transformed plasma BNP level showed a negative correlation with BMI, the results of binary logistic regression analysis demonstrated that the quintile value of BNP was an independent significant variable for the identification of LVH (adjusted odds ratio in quintile 5 = 4.01, 95% confidence interval 1.18–13.70, P < 0.01), even after adjusting for obesity and other risk factors. Conclusion An increased likelihood of cardiac structural and functional abnormalities was observed with increasing severity of OSA. Increased plasma levels of BNP do seem to reflect an increased likelihood of LVH in patients with severe OSA.


Geriatrics & Gerontology International | 2015

Prognosis-related factors concerning oral and general conditions for homebound older adults in Japan

Ryo Suzuki; Takeshi Kikutani; Mitsuyoshi Yoshida; Yoshihisa Yamashita; Yoji Hirayama

The present study examined the relationship between oral function, such as eating/swallowing, and life prognosis among a homebound elderly population, considering physical and mental function.


International Journal of Infectious Diseases | 2016

Evaluation of the rapid influenza detection tests GOLD SIGN FLU and Quick Navi-Flu for the detection of influenza A and B virus antigens in adults during the influenza season.

Yu Akaishi; Tetsuya Matsumoto; Yoji Hirayama

As the characteristics and accuracy of rapid influenza detection tests (RIDTs) vary, the development of a high-performance RIDT has been eagerly anticipated. In this study, the new RIDT GOLD SIGN FLU and the existing RIDT Quick Navi-Flu were evaluated in terms of detecting the antigens of influenza viruses A and B in Japanese adults with influenza-like symptoms. The study was performed from December 2013 to March 2014. Among the 123 patients from whom nasopharyngeal swab specimens were collected, 59 tested positive by viral isolation as the gold standard method (influenza A, n=38; influenza B, n=21). For GOLD SIGN FLU, the sensitivities were 73.7% and 81.0%, and the specificities were 97.6% and 98.0% for influenza A and B, respectively. For Quick Navi-Flu, the sensitivities were 86.8% and 85.7%, and the specificities were 98.8% and 100% for influenza A and B, respectively. The time to the appearance of the line on the test strip was less than 3min for influenza A and less than 2min for influenza B with both RIDTs in more than 90% of cases. GOLD SIGN FLU was useful for diagnosing influenza A, and the result was readily available for influenza B particularly among adult patients. Quick Navi-Flu showed better sensitivities and specificities than GOLD SIGN FLU.


BMC Medical Education | 2016

How do case presentation teaching methods affect learning outcomes?-SNAPPS and the One-Minute preceptor

Masayasu Seki; Junji Otaki; Raoul Breugelmans; Takayuki Komoda; Shizuko Nagata-Kobayashi; Yu Akaishi; Jun Hiramoto; Iwao Ohno; Yoji Hirayama; Miki Izumi

BackgroundVarious techniques have been developed to enable preceptors to teach residents effectively in outpatient settings to promote active learning, including SNAPPS and the One-Minute Preceptor (OMP). This study aimed to ascertain the differences between SNAPPS and the OMP in case presentation content and learner evaluation when used to teach residents about case presentation.MethodsFrom 2011 to 2013, participants were 71 junior clinical residents employed in two hospitals for clinical training. They were randomly allocated to two groups, one using SNAPPS and the other the OMP. From recorded discussions, the “differential diagnoses”, “questions and uncertainties”, “treatment plans”, and “learning issues” were counted. Also, a self-evaluation form was distributed at the end of the study to evaluate the residents’ satisfaction with the case presentation.ResultsMembers of the SNAPPS group used significantly more meaning units related to questions and uncertainties compared with those of the OMP group (P < 0.001). Self-evaluation sheets revealed that members of the SNAPPS group had significantly higher positive responses than those of the OMP group in terms of the following evaluations: “It was easy to bring up questions and uncertainties” (P = 0.046), “It was easy to present the case efficiently” (P = 0.002), “It was easy to present the case in the sequence given” (P = 0.029), and “I was able to give an in-depth case presentation” (P = 0.005).ConclusionsSNAPPS may induce more meaning units related to questions and uncertainties and give more satisfaction to residents than the OMP.


Journal of Clinical Biochemistry and Nutrition | 2017

Effects of rikkunshito on quality of life in patients with gastroesophageal reflux disease refractory to proton pump inhibitor therapy

Takashi Kawai; Yoji Hirayama; Aiko Oguchi; Fumi Ishii; Masanao Matushita; Naoya Kitayama; Shinji Morishita; Noboru Hiratsuka; Ken Ohata; Hiroyuki Konishi; Maiko Kishino; Shinichi Nakamura

We investigated the effects of rikkunshito, in combination with a proton pump inhibitor, on symptoms and quality of life in patients with proton pump inhibitor-refractory gastroesophageal reflux disease. The subjects were 47 patients with gastroesophageal reflux disease with residual symptoms such as heartburn following 8 weeks of proton pump inhibitor therapy. We administered these subjects rikkunshito in combination with a proton pump inhibitor for 6–8 weeks. We scored their symptoms of heartburn, fullness, abdominal discomfort, and abdominal pain, and surveyed their quality of life using the Reflux Esophagitis Symptom Questionnaire, comprising questions concerning daily activities, meals (changes in amount and favorite foods), and sleep (getting to sleep and early morning waking). Improvement was seen in all symptoms, and quality of life scores for meals and sleep also improved. These results indicate that combination therapy with rikkunshito and a proton pump inhibitor improves quality of life related to eating and sleep in patients with patients with proton pump inhibitor-refractory gastroesophageal reflux disease.

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Kihiro Asano

Tokyo Medical University

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Kazuki Shiina

Tokyo Medical University

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Yasuhiro Usui

Tokyo Medical University

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Minoru Yambe

Tokyo Medical University

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Takashi Ogawa

Sapporo Medical University

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Teijin Sumi

Tokyo Medical University

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