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Dive into the research topics where Hiromichi Ohsaka is active.

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Featured researches published by Hiromichi Ohsaka.


Circulation | 2010

Single Administration of α-Glucosidase Inhibitors on Endothelial Function and Incretin Secretion in Diabetic Patients With Coronary Artery Disease - Juntendo University Trial: Effects of Miglitol on Endothelial Vascular Reactivity in Type 2 Diabetic Patients With Coronary Heart Disease (J-MACH) -

Makoto Hiki; Kazunori Shimada; Takashi Kiyanagi; Kosuke Fukao; Kuniaki Hirose; Hiromichi Ohsaka; Yoshifumi Fukushima; Atsumi Kume; Rie Matsumori; Katsuhiko Sumiyoshi; Tetsuro Miyazaki; Hirotoshi Ohmura; Takeshi Kurata; Takashi Miida; Hiroyuki Daida

Background: Post-prandial hyperglycemia, hyperlipidemia, and endothelial dysfunction play an important role in the pathogenesis of atherosclerosis. Improvement in post-prandial hyperglycemia on α-glucosidase inhibitors (α-GIs) is associated with a risk reduction of cardiovascular diseases, but the post-prandial effects of α-GIs on endothelial function and incretin secretion in type 2 diabetic patients with coronary artery disease (CAD) remain unclear. Methods and Results: The post-prandial effects of a single administration of miglitol and voglibose on endothelial function and changing levels of glucose, insulin, lipids, glucagon-like peptide (GLP)-1, and gastric inhibitory polypeptide (GIP) were compared after a standard meal loading in 11 diabetic patients with CAD, using a placebo-controlled cross-over design. The changing levels of glucose, insulin and triglycerides at 60 min were significantly lower in the miglitol group than in the voglibose and placebo groups (all P<0.01). GLP-1 levels were significantly higher at 120 min (P<0.05) and GIP levels were significantly lower at 30 min and 60 min (P<0.05) in the miglitol group compared to other treatments. The reactive hyperemia duration at 120 min was significantly maintained in the miglitol group compared to the other groups. Conclusions: A single administration of miglitol significantly improved post-prandial glucose/lipid metabolism, incretin secretion, and endothelial dysfunction in diabetic patients with CAD, suggesting that miglitol may be a useful anti-atherogenic agent (UMIN000002264).  (Circ J 2010; 74: 1471 - 1478)


Cardiovascular Diabetology | 2011

Effects of calcium channel blockers on glucose tolerance, inflammatory state, and circulating progenitor cells in non-diabetic patients with essential hypertension: a comparative study between azelnidipine and amlodipine on glucose tolerance and endothelial function--a crossover trial (AGENT).

Kosuke Fukao; Kazunori Shimada; Makoto Hiki; Takashi Kiyanagi; Kuniaki Hirose; Atsumi Kume; Hiromichi Ohsaka; Rie Matsumori; Takeshi Kurata; Tetsuro Miyazaki; Hiroyuki Daida

BackgroundHypertension is associated with impaired glucose tolerance and insulin resistance. Medical treatment that interferes with various steps in the renin-angiotensin system improves glucose tolerance and insulin resistance. However, it remains unclear if long-acting calcium channel blockers (CCBs) such as azelnidipine and amlodipine affect glucose tolerance and insulin resistance in clinical practice.MethodsSeventeen non-diabetic patients with essential hypertension who had controlled blood pressure levels using amlodipine (5 mg/day) were enrolled in this study. After randomization, either azelnidipine (16 mg/day) or amlodipine (5 mg/day) was administered in a crossover design for 12-weeks. At baseline and the end of each CCB therapy, samples of blood and urine were collected and 75 g oral glucose tolerance test (OGTT) was performed. In addition, hematopoietic progenitor cells (HPCs) were measured at each point by flow cytometry and endothelial functions were measured by fingertip pulse amplitude tonometry using EndoPAT.ResultsAlthough blood pressure levels were identical after each CCB treatment, the heart rate significantly decreased after azelnidipine administration than that after amlodipine administration (P < 0.005). Compared with amlodipine administration, azelnidipine significantly decreased levels of glucose and insulin 120 min after the 75 g OGTT (both P < 0.05). Serum levels of high-sensitivity C-reactive protein (P = 0.067) and interleukin-6 (P = 0.035) were decreased. Although endothelial functions were not different between the two medication groups, the number of circulating HPCs was significantly increased after azelnidipine administration (P = 0.016).ConclusionsThese results suggest that azelnidipine treatment may have beneficial effects on glucose tolerance, insulin sensitivity, the inflammatory state, and number of circulating progenitor cells in non-diabetic patients with essential hypertension.


Diabetes Research and Clinical Practice | 2013

High levels of very long-chain saturated fatty acid in erythrocytes correlates with atherogenic lipoprotein profiles in subjects with metabolic syndrome

Rie Matsumori; Tetsuro Miyazaki; Kazunori Shimada; Atsumi Kume; Yohei Kitamura; Kyoichi Oshida; Naotake Yanagisawa; Takashi Kiyanagi; Makoto Hiki; Kosuke Fukao; Kuniaki Hirose; Hiromichi Ohsaka; Hiroshi Mokuno; Hiroyuki Daida

AIM Very long chain saturated fatty acid (VLCFA) levels in erythrocytes are associated with metabolic syndrome (MS). However, the relationship between levels of the VLCFA ligonoceric acid (C24:0) in erythrocytes and the atherogenic lipoprotein profiles and inflammatory state in MS remain unclear. METHODS Based on the International Diabetes Federation (IDF) definition of MS, 195 apparently healthy males were assigned to either an MS group (n=38) or a non-MS group (n=157). Fatty acid composition of erythrocytes was determined by gas liquid chromatography. RESULTS Erythrocytes from the MS group had a significantly higher level of C24:0 than cells from the non-MS group (4.06±0.48% versus 3.88±0.34%; p=0.03). C24:0 levels were significantly correlated with several components of MS. The C24:0 levels showed a significant negative correlation with LDL and HDL particle size. Multivariate linear regression analysis showed that C24:0 levels were independently correlated with LDL particle size after adjusting for age and each MS criterion. C24:0 levels were also positively correlated with log-transformed high-sensitivity CRP levels (p=0.04). CONCLUSION C24:0 levels in erythrocytes are associated with specific atherogenic lipoprotein profiles and inflammation status in subjects with MS.


Journal of Cardiology | 2014

Disease Duration and Severity Impacts on Long-term Cardiovascular Events in Japanese Patients with Rheumatoid Arthritis

Hiroshi Masuda; Tetsuro Miyazaki; Kazunori Shimada; Naoto Tamura; Ran Matsudaira; Takuma Yoshihara; Hiromichi Ohsaka; Eiryu Sai; Rie Matsumori; Kosuke Fukao; Makoto Hiki; Atsumi Kume; Takashi Kiyanagi; Yoshinari Takasaki; Hiroyuki Daida

BACKGROUND Rheumatoid arthritis (RA) increases the mortality and morbidity of cardiovascular disease (CVD). However, the relationship between RA and the risk of CVD in the Japanese population remains unclear. METHODS AND RESULTS This study comprised 571 RA patients who were admitted to Juntendo University Hospital from January 1990 to December 2000. Cardiovascular events (CVEs) were defined as cardiac death, acute coronary syndrome (ACS), symptomatic stroke, and congestive heart failure. During follow-up (mean 11.7 ± 5.8 years), 7.5% of the patients died from all causes and 11.0% experienced CVEs. The morbidity of stroke and ACS was 3.6 and 2.5 per 1000 person-years, respectively. The mean RA disease duration at enrolment was significantly longer in patients who experienced CVEs than in those who did not experience CVEs (15.0 ± 12.7 years vs. 10. 8 ± 9.7 years; p = 0.01). Physical disabilities due to RA were more severe in patients who experienced CVEs than in those who did not experience CVEs. Patients with a long RA disease duration showed significantly higher event rates (p = 0.033). Cox proportional hazards analysis identified a longer RA duration as an independent risk factor for CVD (hazard ratio 1.57, 95% CI 1.09-2.30, p = 0.02). CONCLUSION Japanese RA patients showed a relatively high incidence of CVD, despite the fact that they had few coronary risk factors. The RA disease duration was an independent risk factor for CVEs.


Journal of Cardiology | 2012

Clinical significance of the measurements of urinary liver-type fatty acid binding protein levels in patients with acute coronary syndrome

Rie Matsumori; Kazunori Shimada; Takashi Kiyanagi; Makoto Hiki; Kosuke Fukao; Kuniaki Hirose; Hiromichi Ohsaka; Tetsuro Miyazaki; Atsumi Kume; Atsushi Yamada; Atsutoshi Takagi; Hirotoshi Ohmura; Katsumi Miyauchi; Hiroyuki Daida

BACKGROUND Recently, much attention has been focused on cardio-renal interaction. Urinary liver-type fatty acid binding protein (U-L-FABP), which is produced in the proximal tubule by renal hypoxia and oxidative stress, has been identified as a useful marker for diagnosis of acute kidney disease and a predictor of future events in chronic kidney disease. However, the clinical significance of U-L-FABP measurements in patients with acute coronary syndrome (ACS) has not been completely evaluated. METHODS AND RESULTS This study included 50 consecutive patients with ACS [37 with acute myocardial infarction (AMI) and 13 with unstable angina pectoris (UAP)] and 47 subjects without coronary artery disease (control group). U-L-FABP levels, urinary albumin (U-Alb), and other serum parameters were measured at admission and at 24 h after percutaneous coronary intervention. RESULTS U-L-FABP levels in patients with AMI were significantly higher (p=0.0019), than in control subjects, while patients with UAP did not exhibit such an increase. U-L-FABP levels at admission were positively correlated with brain natriuretic protein levels (p=0.001) and duration of hospitalization (p=0.025). At follow-up angiography, patients with restenosis had significantly higher U-L-FABP (p=0.047) and U-Alb levels (p<0.0001) than those without restenosis. After a median follow-up of 42 months, U-L-FABP levels at second measurement in patients with major adverse cardiocerebrovascular events (MACCEs) were significantly higher than those in patients without MACCEs (p=0.028). After adjusting for confounding factors, high U-L-FABP levels at second measurement were found to be independent factors for MACCEs (p=0.019). CONCLUSIONS These data suggest that patients with ACS, especially those with AMI, have high U-L-FABP levels, and that U-L-FABP measurements may be useful in identifying high-risk patients for future cardiovascular events after ACS.


Air Medical Journal | 2014

Introduction of a Physician-Staffed Helicopter Emergency Medical Service in Eastern Shizuoka Prefecture in Japan

Kazuhiko Omori; Hiromichi Ohsaka; Kouhei Ishikawa; Mariko Obinata; Yasumasa Oode; Akio Kanda; Mitsuhiro Fujii; Mutsumi Sakurada; Yasuaki Nakao; Tetsu Suwa; Ken Okamoto; Youichi Yanagawa

OBJECTIVE To analyze the operating situation of a physician-staffed helicopter emergency medical service in eastern Shizuoka prefecture. METHODS A retrospective analysis was performed using the conveyance records reported by staff members of the physician-staffed helicopter. A comparison between 2007 (n = 619) and 2012 (n = 678) was performed. RESULTS There were no significant differences between the 2 groups with regard to the sex, ratio of cardiopulmonary arrest, and survival ratio. In contrast, the duration from the request of dispatch to arrival at the hospital in 2007 was significantly longer than that in 2012 (53.7 vs 48.2 minutes, P < 0.0001). The average age in 2007 was significantly younger than in 2012 (55.7 vs 59.4 years, P < 0.01). The ratio of trauma case in the 2012 was higher than that in 2007 (47 vs 37%, P < 0.001). The ratio of severe cases in 2007 was higher than in 2012 (45 vs 39%, P < 0.05). CONCLUSION Japan is an aging society. In eastern Shizuoka prefecture, the increase in the number of trauma and minor injury cases may have increased due to the emphasis on the importance of early medical intervention by the fire department.


Journal of Cardiology | 2011

Clinical significance of the measurements of plasma N-terminal pro-B-type natriuretic peptide levels in patients with coronary artery disease who have undergone elective drug-eluting stent implantation

Yoshiyuki Masaki; Kazunori Shimada; Takahiko Kojima; Katsumi Miyauchi; Kenji Inoue; Takashi Kiyanagi; Makoto Hiki; Kosuke Fukao; Kuniaki Hirose; Hiromichi Ohsaka; Atsumi Kume; Tetsuro Miyazaki; Hirotoshi Ohmura; Akimichi Ohsaka; Hiroyuki Daida

BACKGROUND N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a diagnostic biomarker for patients with congestive heart failure (CHF). However, the clinical significance of measurements of NT-proBNP levels in patients with coronary artery disease (CAD) who have undergone drug-eluting stent (DES) implantation has not been fully elucidated. METHODS AND RESULTS We recruited 280 patients with documented CAD who were scheduled for elective coronary intervention and also age- and gender-matched 140 healthy subjects. Subjects with acute coronary syndrome, ongoing CHF, and stage IV or V chronic kidney disease were excluded. We measured the plasma NT-proBNP levels and followed the CAD patients who have undergone DES implantation for up to 62 months until occurrence of major adverse cardiovascular events (MACE). Plasma NT-proBNP levels were significantly higher in CAD patients compared to control subjects (p<0.0001). In the CAD group, 25 patients developed MACE and the NT-proBNP levels in the MACE group were significantly higher compared to that in the non-MACE group (p=0.005). After adjusting for the confounding factors, high NT-proBNP levels were observed to be independent factors for CAD (p<0.0001) and MACE (p=0.021). CONCLUSIONS These results demonstrated that the measurements of NT-proBNP levels may be useful in identifying high-risk subjects among CAD patients who have undergone elective DES implantation.


Air Medical Journal | 2016

Management of a Mass Casualty Event Caused by Electrocution Using Doctor Helicopters

Kouhei Ishikawa; Kei Jitsuiki; Hiromichi Ohsaka; Toshihiko Yoshizawa; Mariko Obinata; Kazuhiko Omori; Yasumasa Oode; Motoki Takahashi; Youichi Yanagawa

OBJECTIVE This is the first report to show the use of doctor helicopters in a mass casualty event induced by electrocution. METHODS We performed a narrative review. RESULTS Two children obtained electrocution burns by breaking an electric fence. Five adults also received electrocution burns. Emergency medical technicians at the scene requested additional dispatch of an ambulance and the doctor helicopter. Two adult men with cardiopulmonary arrest were transported by 2 ambulances to a nearby hospital. One adult woman was in a restless confusional state, intubated, and transferred to another hospital using the doctor helicopter. One boy, who was initially in a coma, and his mother were transferred to our hospital by 1 ambulance. Another boy, who had finger amputation, was transferred to the other hospital by another doctor helicopter. A remaining elderly woman was transported to the other local hospital by ambulance. All the victims, except the 2 fathers who fell into cardiac arrest, survived. CONCLUSION Early confirmation of the safety of the scene, early establishment of command and control, early request for dispatch of other parties and the doctor Helicopter, appropriate triage, appropriate treatment at the scene, selecting appropriate medical facilities, and dispersion transportation were crucial.


American Journal of Emergency Medicine | 2015

Significance of the vacuum phenomenon in patients with trauma evaluated by whole-body computed tomography☆

Kazuhiko Omori; Kouhei Ishikawa; Mariko Obinata; Kentaro Mishima; Shin Fukusato; Hiromichi Ohsaka; Yasumasa Oode; Youichi Yanagawa

BACKGROUND Severely traumatized patients undergo whole-body computed tomography (WCT) to detect lethal anatomical injuries. When checking the images, we have sometimes recognized minute gas (the vacuum phenomenon [VP]) near the traumatized lesions. Accordingly, we investigated the significance of the VP in patients with trauma. BASIC PROCEDURES From April to October 2013, a medical record review was retrospectively performed for all patients with trauma. The exclusion criteria included an age more than 60 years, patients who did not receive the WCT, scan and those in cardiopulmonary arrest on arrival. The subjects were divided into 2 groups: a VP group (n=19), which included patients who had the VP, and a control group (n=49). MAIN FINDINGS There were no significant differences between the 2 groups with regard to age, the mechanism of injury, or the survival rate. In contrast, the ratio of women, the Injury Severity Score, and the duration of hospitalization in the VP group were significantly higher than those in the control group. The greatest number of the VP was located at or near rib fractures, followed by joint spaces that experienced a traumatic impact. PRINCIPAL CONCLUSION This study demonstrated that the VP tended to be observed most often in severely traumatized female cases. The VP is observed at locations that experience a traumatic impact, so an analysis of the VP may be useful to elucidate the mechanism of injuries. The presence of traumatic VP itself does not influence the final outcome.


American Journal of Emergency Medicine | 2017

A comparison between evacuation from the scene and interhospital transportation using a helicopter for subarachnoid hemorrhage

Kouhei Ishikawa; Kazuhiko Omori; Ikuto Takeuchi; Kei Jitsuiki; Toshihiko Yoshizawa; Hiromichi Ohsaka; Yasuaki Nakao; Takuji Yamamoto; Youichi Yanagawa

Purpose: We investigated the changes in the vital signs and the final outcomes subarachnoid hemorrhage (SAH) patients who were evacuated from the scene using the doctor‐helicopter (Dr. Heli) service and those who only underwent interhospital transportation using the doctor‐helicopter Dr. Heli service to investigate safety of this system. Methods: We retrospectively investigated all of the patients with non‐traumatic SAH who were transported by a Dr. Heli between January 2010 and March 2016. The subjects were divided into two groups: the Scene group included subjects who were evacuated from the scene by a Dr. Heli, while the Interhospital group included subjects who were transported by a ground ambulance to a nearby medical facility and then transported by a Dr. Heli to a single tertiary center. Results: The systolic blood pressure, ratio of cardiac arrest, and Fisher classification values of the patients in the Scene group were significantly greater than those in the Interhospital group. The Glasgow Coma Scale in the Scene group was significantly lower than that in the Interhospital group. After excluding the patients with cardiac arrest, the Glasgow Coma Scale scores of the patients in the two groups did not differ to a statistically significant extent during, before or after transportation. There were no significant differences in Glasgow Outcome Scores or the survival ratio of the two groups, even when cardiac arrest patients were included. Conclusion: The present study indirectly suggests the safety of using a Dr. Heli to evacuate SAH patients from the scene.

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