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Biomedical subjects

H Imagawa

Publications and source records attributed to H Imagawa.

At least 73 records · Page 4Linked to original sources

Induction of immune response and protection from equine viral arteritis (EVA) by formalin inactivated-virus vaccine for EVA in horses.

Thirty-nine horses included 3 pregnant mares were examined by inoculating with formalin inactivated-virus vaccine for EVA. Antibody response of horses after one dose vaccination was somewhat poor and 50% effective inoculum dose of the vaccine should be included 10(8.4) pfu of virus before inactivation. After 2 doses given at an interval of 4 weeks, the horses developed such high titer of SN antibody as up to 1:5,120. The SN titer declined rather rapidly, but supplemental administration of the vaccine at an interval of more than 2 months elicited a prompt antibody response and SN titers persisted as 1:80 to 1:320 at 6 months after the administration. Therefore, supplemental administration of the vaccine as booster every 6 months or 1 year would be capable of maintaining high titer of SN antibody. The inactivated-virus vaccine prevented horses from clinical disease of EVA and protected pregnant mares from abortion by challenge exposure with virulent virus. Fifty percent protective dose in SN titer of 1:43 was confirmed by clinical signs and viremia.

Animals↗

Isolation of Clostridium perfringens from foals.

Clostridium perfingens was isolated from four of 29 healthy foals and from all twelve foals with gastrointestinal diseases. The range of viable counts of C. perfringens in the faeces was 10(1)-10(5)/g and in the intestinal specimens 10(1)-10(7)/g. Of 41 isolates of C. perfringens, 37 were considered to be type A. Enterotoxin of the organism was demonstrated in the intestinal contents of five of eight foals with enteric diseases. These findings suggested that C. perfringens is a likely pathogen of foal intestinal diseases.

Animals↗

[Clinical experience of mechanical ventricular support with centrifugal pump for severe ventricular failure after open heart surgery].

Five adult patients (pts) with age 15-67 (mean 43) received mechanical circulatory support with centrifugal pump (Biomedicus, BP-80, Sarns centrifugal pump) for postcardiotomy profound shock. Three pts underwent left ventricular support (LVS) alone, and the other 2 required biventricular support (BVS). Duration of the LVS ranged from 33 to 240 hours (mean 126 hours) and the right ventricular support 92, 120 hrs. Pump flow rate was 1.1 to 2.5 (mean 1.9) L/min/m2. Sixteen pumps were used and the pump exchange was performed 9 times in five pts and an average perfusion time per pump was 57 hrs. Two of 3 pts with LVS alone survived and one died of multiorgan failure associated with right heart dysfunction. In two pts with BVS, one survived and the other died of persistent low cardiac output early after pump removal. As the complication during mechanical support, bleeding was seen in 3 pts and cerebral infarction in one. Although centrifugal pump has potential limitation in antithrombogenicity and durability, this device provides a simple and effective mechanical circulatory support.

Adolescent↗

[Evaluation of the effects of coronary artery bypass grafting on left ventricular function in patients with previous myocardial infarction].

The present study was designed to assess a left ventricular function following coronary artery bypass grafting (CABG) in patients with previous myocardial infarction (MI). The subject was consisted of 10 patients with MI (MI(+) group) and 6 without it (MI(-) group). Both groups underwent complete revascularization. Stroke index (SI), ejection fraction (EF), systolic pressure/end-systolic volume index (SP/ESVI) and end-diastolic volume index (EDVI) were evaluated utilizing radionuclide angiography at rest and during exercise (Ex) before and after CABG. The influence of size of myocardial infarction on left ventricular function were also analyzed. Preoperatively during Ex, EF showed decrease, SP/ESVI no change and EDVI increase in both MI(+) and MI(-) group compared with those at rest. Postoperatively during Ex, SI, EF and EDVI showed no change and SP/ESVI increase in both MI(+) and MI(-) group compared with those at rest. Ejection fraction and SP/ESVI during Ex in MI(+) group had significant differences compared with those in both MI(-) group and control group. Ejection fraction and SP/ESVI during Ex in MI(-) showed no difference compared with those in control group. The size of MI suggested by ECG scoring system (proposed by Wagner GS et al, Circulation '82) had negative correlations with both Ex-induced increment of postoperative EF and Ex-induced increase ratio of postoperative SP/ESVI. These data indicated that complete revascularization improved EF and SP/ESVI in patients with MI, and moreover normalized those in patients without MI. But in the case of extensive MI, even complete revascularization might not recover poor functional reserve during Ex.

Adult↗

Evaluation of coronary revascularization for ischemic heart disease: in the consecutive 200 cases.

The elective simple coronary revascularization in the last consecutive 200 patients were analyzed in this study. Despite of the increase in older patients who have more high risk factors, including low left ventricular ejection fraction (LVEF) and multiple vessel disease, there were no operative deaths in the second 100 patients. The use of calcium antagonist in patients with a history of spastic angina eliminated episodes of spastic angina in the perioperative period. In the late postoperative period, there were no cardiac deaths during the 7-year follow-up period. Angina remained in two of three patients with the patent grafts, who had a history of spastic angina. Hyperlipidemia and diabetes mellitus influenced occlusion of the grafts and progression of atherosclerosis of native coronary arteries and then four of five reoperations. Exercise tolerance in patients, even those with preoperative low LVEF, has been improved although their was some increment of left ventricular end-diastolic pressure during exercise. Patency rate in sequential grafting with saphenous vein grafts or internal mammary artery grafts were 92% in the average follow-up period of 11 months. The increase of flow rate with nitroglycerine and atrial pacing in internal mammary artery grafts (IMAG) were comparable with saphenous vein grafts.

Aged↗