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Dive into the research topics where Jun Mohara is active.

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Featured researches published by Jun Mohara.


Journal of Heart and Lung Transplantation | 1999

Long-term heart preservation using a new portable hypothermic perfusion apparatus

Kiyohiro Oshima; Yasuo Morishita; Toshiharu Yamagishi; Jun Mohara; Toru Takahashi; Yutaka Hasegawa; Susumu Ishikawa; Koshi Matsumoto

OBJECTIVE Perfusion storage is not often used clinically compared with simple immersion because of complicated circuits and demanding management. We developed a new apparatus for preservation combined with simple immersion and continuous coronary perfusion. METHODS The main characteristics of this apparatus are as follows: (1) hypothermic storage, (2) does not require any energy source, (3) variable perfusion pressure, and (4) portability. The perfusion apparatus is composed of a storage chamber, a cooling chamber, and metal bars from which a perfusate bag is suspended. Adult mongrel dogs were divided into two groups: the coronary perfusion group (CP, n = 6) and the simple immersion group (SI, n = 6). Coronary vascular beds of the dog were washed out with a University of Wisconsin (UW) solution following cardiac arrest obtained using a GIK solution. The hearts were then excised. In the CP group, the heart graft, which was immersed in a 4 degrees C UW solution, was perfused with the same solution at a flow rate of 35 approximately 50 ml/hr. In the SI group, the heart graft was immersed in a 4 degrees C UW solution only. The heart graft was preserved for 12 hours in both groups. Beta-adenosine triphosphate (beta-ATP), phosphocreatine (Pcr), and inorganic phosphate (Pi) levels were measured immediately after excision of the heart, and at 3, 6, and 12 hours after preservation. Beta-ATP, Pcr, and Pi values were expressed as a percentage of control values, which had been obtained immediately after excision of the heart. Water content of the myocardium was measured prior to and after 12-hour preservation. The preserved graft was then evaluated through orthotopic transplantation. RESULTS Beta-ATP/Pi levels at 6 and 12 hours after preservation were significantly higher in the CP group than in the SI group (62 +/- 5 versus 39 +/- 7%, 48 +/- 5 versus 22 +/- 8%, respectively, p < 0.05). Pcr/Pi levels at 6 and 12 hours after preservation were 30 +/- 9% and 22 +/- 8%, respectively in the CP group, while Pcr/Pi levels in the SI group were detected in only one case. There was no significant difference in water content either prior to or after 12-hour preservation between the two groups. Histopathologically, irregular expansion and/or contraction of myocardial fibers were more severe in the SI group than in the CP group. The recovery rate of hemodynamic parameters 2 hours after heart transplantation was significantly (p < 0.05) higher in the CP group than in the SI group. CONCLUSION Stable and safe long-term canine heart preservation with continuous coronary perfusion associated with immersion is possible using this new apparatus, and may have broad clinical application.


Journal of Heart and Lung Transplantation | 1999

A comparative study of Celsior and University of Wisconsin solutions based on 12-hr preservation followed by transplantation in canine models.

Jun Mohara; Yasuo Morishita; Toru Takahashi; Kiyohiro Oshima; Toshiharu Yamagishi; Izumi Takeyoshi; Koshi Matsumoto

BACKGROUND Celsior is a recently developed extracellular-type preservation solution that is effective in organ preservation. This experimental study was designed to compare the effects of Celsior and University of Wisconsin (UW) solutions in myocardial protection, using 12-hour preservation followed by orthotopic transplantation. METHODS Fourteen pairs of adult mongrel dogs were divided into 2 groups. In the UW group (n = 7), UW solution at 4 degrees C was used for coronary vascular washout and storage following cardiac arrest with glucose-insulin-potassium (GIK) solution. In the Celsior group (n = 7), Celsior solution was used to produce cardiac arrest, for coronary vascular washout, and for storage. After 12-hour cold preservation, orthotopic transplantation was performed under cardiopulmonary bypass (CPB). The rate of recovery (%) of cardiac function of donor hearts was compared 1 and 2 hours after weaning from CPB, and then the transplanted hearts were harvested for histological study. RESULTS Hemodynamic parameters including cardiac output, left ventricular pressure (LVP), and the maximum rates of positive and negative increase of LVP after transplantation were significantly (p < 0.05) higher in the Celsior group than in the UW group 2 hours after weaning from CPB. The transmission electron microscopic study found that degeneration of the mitochondria in the Celsior group was less extensive than in the UW group. CONCLUSION Celsior solution enhanced the cardiac function of hearts preserved for 12 hours prior to transplantation compared to UW solution. Our results indicate that Celsior solution is equivalent or superior to UW solution for cardiac preservation.


The Annals of Thoracic Surgery | 2009

Aortic Valve Replacement for Aortic Regurgitation in a Patient With Left Ventricular Noncompaction

Satoshi Ohki; Yukinori Moriyama; Jun Mohara; Chieri Kimura; Naoyuki Sata; Kenkichi Miyahara

We present a case of a 61-year-old man who underwent aortic valve replacement for aortic regurgitation complicated with left ventricular noncompaction. The pathogenesis of this condition remains unknown. In advanced form, left ventricular noncompaction produces marked disability and carries a poor prognosis. We underscore that familiarity with this disease entity will help to stimulate early diagnosis and timely treatment when necessary.


Journal of Heart and Lung Transplantation | 2002

The optimal pressure for initial flush with UW solution in heart procurement

Jun Mohara; Hirofumi Tsutsumi; Izumi Takeyoshi; Masahiko Tokumine; Masahiro Aizaki; Susumu Ishikawa; Koshi Matsumoto; Yasuo Morishita

OBJECTIVE University of Wisconsin (UW) solution is widely used in organ preservation. Some investigators have reported that high pressure during initial flush with UW solution may induce vasoconstriction and endothelial damage, because of its high potassium content and high viscosity. However, using lower pressure during the initial flush may lead to irregular distribution of the solution and incomplete flushing of blood components from coronary vascular beds. This experimental study evaluated the effects of a range of initial flush pressures during heart procurement, followed by orthotopic transplantation of the graft after 12 hours of preservation. MATERIALS AND METHODS Twelve pairs of adult mongrel dogs, weighing 9 to 14 kg, formed the recipient-donor combinations. After determining hemodynamic status by measuring cardiac output, left ventricular pressure (LVP), and maximum positive and negative change in LVP (+/-LVdP/dt), donor hearts were excised. Coronary vascular beds were flushed with 4 degrees C UW solution at a pressure of 60 mm Hg in the low-pressure group (n = 6) and at 120 mm Hg in the high-pressure group (n = 6). After 12 hours of cold preservation, orthotopic transplantation was performed using cardiopulmonary bypass (CPB). The hemodynamics of the transplanted graft were assessed by comparing recovery rates (%) from donor hearts 2 hours after weaning from CPB. Endothelin-1 (ET-1) levels were measured in the blood obtained from the coronary sinus 30 minutes after reperfusion. The transplanted grafts were then harvested for histologic study and measurement of adenosine triphosphate (ATP) content. RESULTS Cardiac output, LVP, LVdP/dt and myocardial tissue ATP content were significantly better (p < 0.05) in the high-pressure group than in the low-pressure group. We found no significant differences in ET-1 levels between the groups. Transmission electron microscopic findings revealed that degeneration of the mitochondria was less extensive in the high-pressure group than in the low-pressure group. We observed no obvious ultrastructural damage to the endothelial cells in either group. CONCLUSION When using UW solution in heart procurement, high pressure is better to completely wash out the blood components and distribute the solution.


Surgery Today | 2004

Screening cost for abdominal aortic aneurysms: Japan-based estimates.

Susumu Ishikawa; Toru Takahashi; Yasushi Sato; Masao Suzuki; Satoshi Ohki; Kiyohiro Oshima; Jun Mohara; Taro Nameki; Yoshimi Otani; Yasuo Morishita

PurposeThe aim of this study was to evaluate the screening procedures in Japan economically focusing on the screening costs and the hospital costs for abdominal aortic aneurysm (AAA) surgery.MethodsA total of 10 057 residents, 60 years of age or older, including 4 247 men and 5 810 women, participated in the screening test for AAA using ultrasound.ResultsAneurysms were detected in 34 participants, including 32 men and 2 women. The detection rate of AAA was 0.8% in men, 0.03% in women, and 0.3% in total. It cost US


The Spine Journal | 2014

Gorham disease of the lumbar spine with an abdominal aortic aneurysm: a case report

Yohei Kakuta; Haku Iizuka; Ryoichi Kobayashi; Yoichi Iizuka; Toru Takahashi; Jun Mohara; Kenji Takagishi

8 to screen each participant, and the cost to detect each aneurysm was thus estimated at


Surgery Today | 1999

Assessment of the myocardial protective effect of antegrade warm blood cardioplegia by measuring the release of biochemical markers.

Koji Kawahito; Jun Mohara; Yoshio Misawa; Morito Kato; Katsuo Fuse

1 250 in men,


International Journal of Angiology | 1999

The Effect of FR167653 on Cerebral Ischemia-Reperfusion Injury After Retrograde Cerebral Perfusion in a Canine Model.

Kiyohiro Oshima; Yasushi Sato; Izumi Takeyoshi; Toshiharu Yamagishi; Jun Mohara; Susumu Ishikawa; Toru Takahashi; Yasuo Morishita

23 240 in women, and


Journal of Thoracic Oncology | 2011

Pulmonary Large Cell Carcinoma Mimicking an Infected Thoracoabdominal Aortic Aneurysm

Tetsuhiro Nakano; Kimihiro Shimizu; Toru Takahashi; Jun Mohara; Norimasa Koike; Osamu Kawashima; Mitsuhiro Kamiyoshihara; Masayuki Sugano; Takashi Ibe; Seiichi Kakegawa; Toshiteru Nagashima; Jun Atsumi; Izumi Takeyoshi

2 366 in total. The difference in the mean hospital cost between ruptured and nonruptured AAA was


Surgery Today | 2003

Pericardiectomy to treat constrictive pericarditis in a patient with hyperbilirubinemia: report of a case.

Kiyohiro Oshima; Yasushi Sato; Toru Takahashi; Jun Mohara; Toshio Fukusato; Susumu Ishikawa; Yasuo Morishita

21 833 in our recent cases. Obesity, male sex, and smoking habits were all significant risk factors for AAA.ConclusionScreening for AAA using ultrasound is useful not only for the early detection of AAA but also for a reduction in the overall medical cost.

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