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Biomedical subjects

S Teramoto

Publications and source records attributed to S Teramoto.

At least 361 records · Page 20Linked to original sources
PubMed1988

Oxygenated perfluorocarbon, recombinant human superoxide dismutase, and catalase ameliorate free radical induced myocardial injury during heart preservation and transplantation.

The effect of free radical scavengers on free radical-induced myocardial injury during heart preservation and transplantation was examined. Four groups of nine hearts each were harvested from mongrel dogs (12.5 to 16.5 kg) and orthotopically transplanted to size-matched recipients. All hearts received a continuous perfusion of oxygenated modified Collins' solution (group A). In addition, groups B, C, and D received Fluosol DA and albumin. Preservation perfusion was performed for 18 hours, at 4 degrees C, pH = 7.4, and 20 mm Hg. In group C, recombinant human superoxide dismutase (4,080 U/mg, 20 mg/kg) and bovine catalase (46,200 U/mg, 20 mg/kg) were administered only during preservation perfusion. In group D, these scavengers were administered just before and during reperfusion for 1 hour. Hemodynamic studies were performed before excision of the donor hearts and 1 hour after the termination of cardiopulmonary bypass. Creatinine kinase MB isoenzyme and thiobarbituric acid reactive substance levels in the coronary effluent were determined during preservation perfusion and reperfusion. Only group A showed a significant heart weight gain (p less than 0.05) and a decline in passive compliance (p less than 0.05) during preservation. Lactate release was higher in group A than in the groups receiving Fluosol DA. In contrast, pyruvate levels in group A were lower than in other groups. The generation of free radicals stayed at a low level during preservation, but significantly increased during reperfusion and was associated with a corresponding increase in creatinine kinase MB isoenzyme. Perfusion with a perfluorochemical solution (group B) inhibited the sharp rise in levels of thiobarbituric acid reactive substances and of creatinine kinase MB isoenzyme and improved cardiac function during reperfusion (versus group A). Exogeneous free radical scavengers administered just before and during reperfusion (group D) significantly ameliorated thiobarbituric acid reactive substances and creatinine kinase MB isoenzyme levels and also induced a significant hemodynamic improvement during reperfusion. However, administration of scavengers during preservation did not. This study demonstrates that the generation of free radicals is primarily significant during reperfusion and reoxygenation after ischemia. Thus the best time for administration of scavengers is just before and just after the onset of reperfusion. Furthermore, perfusion with perfluorochemicals effectively maintains aerobic metabolism and ameliorates free radical damage during this period.

Animals↗
PubMed1988

[A review of post-operative multiple organ failure in peripheral arterial diseases].

Two-hundred- and-fifty-one patients of peripheral arterial diseases underwent 281 operations for past 11 years in our institute, and multiple organ failure (MOF) occurred in 10 patients (4.0%). These patients were reviewed and were compared with in other diseases. Survival rate was 50% and all the patients with 4 or more organ disorders died. Incidence and survival rate were not significantly different from operative time, blood loss and blood transfusion. Significant difference was observed between elective operation (3.0%) and emergent operation (20.0%). Compared with other diseases, MOF occurred more rarely in peripheral arterial diseases than in aortic aneurysms, but occurred 1.4 times of digestive diseases. While the gastro-intestinal bleeding as the initial failure organ occurred more frequently in peripheral arterial diseases than in other diseases, heart and respiratory failures were rare. MOF occurred after peripheral arterial intervention as well as other abdominal and thoracic surgery. To avoid MOF it is important to avoid MOF that the emergent surgery should be kept out and that general status, especially the grade of diabetes mellitus should be evaluated sufficiently.

Adult↗
PubMed1988

Prevention of free radical-induced myocardial injury by allopurinol. Experimental study in cardiac preservation and transplantation.

To determine the role of free radical-induced injury during heart preservation and transplantation, we harvested hearts from 28 mongrel dogs (12.5 to 16.5 kg), divided them into four groups, and orthotopically transplanted them. A group of seven hearts were orthotopically transplanted immediately after excision (group A). A second group of seven animals received allopurinol pretreatment (50 mg/kg/day) for 72 hours, and the hearts were orthotopically transplanted immediately after excision (group B). A third group of seven hearts were transplanted after continuous perfusion with oxygenated modified Collins solutions at 4 degrees C, pH 7.4, and a pressure of 20 mm Hg for 18 hours (group C). A fourth group of seven animals received allopurinol pretreatment (50 mg/kg/day) for 72 hours, and the hearts were orthotopically transplanted after perfusion with modified Collins solutions in the same manner as group C hearts (group D). The generation of free radicals, estimated by measurement of thiobarbituric acid reactive substances (malondialdehyde) in the coronary effluent, stayed at low levels during perfusion in groups C and D and also remained at low levels during operational ischemia in group A and B. During reperfusion, their levels abruptly and significantly increased and were associated with a corresponding increase in creatinine kinase MB isoenzyme (malondialdehyde levels at 30 minutes' reperfusion: A, 2.25 +/- 0.43; B, 1.55 +/- 0.25 nmol/ml/100 gm wet weight [p less than 0.05 versus group A]; C, 2.67 +/- 0.28; D, 1.77 +/- 0.27 nmol/ml/100 gm wet weight [p less than 0.05 versus group C]). In the allopurinol pretreatment groups, allopurinol significantly slowed the appearance of malondialdehyde and the release of creatinine kinase MB isoenzyme during reperfusion. Furthermore, cardiac functions during reperfusion, expressed as percent of control (mean +/- standard deviation), were significantly better in the allopurinol pretreatment groups than in the untreated groups: maximum first derivative of left ventricular pressure: A, 76.4 +/- 9.5; B, 99.7 +/- 14.3 [p less than 0.05 versus group A]; C, 25.2 +/- 2.6; D, 42.7 +/- 7.9 [p less than 0.05 versus group C]). These results indicate that (1) the generation of oxygen free radical is not significant during perfusion with modified Collins solutions nor during operational ischemia, but only during reperfusion, and (2) allopurinol reduces free radical-induced injury during reperfusion. Allopurinol has potential application in the prevention of reperfusion injury during heart transplantation.

Allopurinol↗