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Biomedical subjects

T Horiuchi

Publications and source records attributed to T Horiuchi.

At least 595 records · Page 33Linked to original sources
PubMed1980

Real-time sound spectroanalysis for diagnosis of malfunctioning prosthetic valves.

A newly developed real-time sound spectroanalyzer was found to be capable of diagnosing malfunction of prosthetic heart valves. Sound spectroanalysis is believed to be superior to other methods such as phonocardiography and echocardiography. This system, developed in our institute, allows display on a cathode ray oscilloscope of five different modes of the valvular click, including the sound spectrograph and section pattern. Analysis of the section pattern allows measurement of the high-frequency components of the valvular click, which is normalized so as to be applicable to a click of any intensity. This parameter is called normalized maximal frequency (NMF). Sound spectroanalyses were carried out 228 times on 127 patients having a prosthetic heart valve. NMF values of normally functioning valves differed characteristically according to the type of valve, but did not change during the postoperative time course. Three of seven patients who had cerebral embolism showed significantly lower NMF values than normal, as did all four patients whose valve had become thrombosed.

Atrial Fibrillation↗
PubMed1980

Indication for total correction of complete transposition of the great arteries with pulmonary hypertension.

Pulmonary vascular disease (PVD) was histologically evaluated and its severity was expressed as an index of PVD in 14 autopsied and eight biopsied cases of complete transposition of the great arteries (TGA) in patients more than 6 months of age. The index varied from 1.0 to 2.3 in six patients who had survived complete surgical repair and ranged from 2.3 to 3.3 in five patients who had died of PVD postoperatively. Consequently, an index of 2.2 could be regarded as an upper limit of PVD for complete surgical repair. The index was significantly correlated to some hemodynamic factors. From the regression equation, the value 2.2 of histologic index could be translated into the clinical factors concerning hemodynamics. We consider that patients with pulmonary vascular resistance of less than 10.6 units . m2, and pulmonary arterial mean pressure less than 51 mm Hg, are suitable candidates for complete surgical repair in TGA, if more than 6 months of age. Thus histologic assessment of PVD in a lung biopsy as an indication for total correction of TGA with pulmonary hypertension appears to be useful in patients who are in borderline hemodynamic condition or in whom the hemodynamics could not be evaluated although pulmonary hypertension was suspected.

Autopsy↗
PubMed1980

Low tumor incidence in rats with long-term feeding of fusarenon-X, a cytotoxic trichothecene produced by Fusarium nivale.

In order to examine tumorigenic effects of fusarenon-X, a trichothecene compound produced by Fusarium nivale, feeding experiments on 151 male Donryu rats were carried out. Daily dose of 105 micrograms (7 ppm in the diet) or 50 micrograms (3.5 ppm)/animal of fusarenon-X was given for 1 or 2 years. Although the animals of the experimental groups showed lower body weight than controls and were more liable to be afflicted by pulmonary infections, tumor incidences were as low as that of the control group. However, several unusual tumors as follows were observed only in the experimental groups: 1 adenocarcinoma of the stomach, 2 papillary carcinomas of the urinary bladder, 1 adrenocortical adenoma, and 1 leukemia.

Animal Feed↗
PubMed1979

Action of human pancreatic and salivary alpha-amylases on maltooligosaccharides: evaluation of kinetic parameters.

The kinetic studies on the reactions of human pancreatic and salivary alpha-amylases with several maltooligosaccharides (maltotetraose, maltopentaose, maltohexaose, and maltoheptaose) were carried out. The susceptibility to hydrolysis with human pancreatic alpha-amylase decreased in the order of maltopentaose, maltohexaose, maltotetraose, and maltoheptaose, while with human salivary alpha-amylase maltopentaose was hydrolysed slightly slower than maltohexaose but fairly faster than maltotetraose or maltoheptaose from a viewpoint of the rates of reactions based on the amount of substrate changed. The relative rates of production of substrates, utilized in the coupled yeast alpha-glucosidase reaction, increased in the order of maltoheptaose, maltohexaose, maltotetraose, and maltopentaose with human pancreatic alpha-amylase, while with human salivary alpha-amylase in the order of maltoheptaose, maltotetraose, maltohexaose, and maltopentaose. Thus, maltopentaose was considered to be the best substrate over maltotetraose, maltohexaose or maltoheptaose for the alpha-glucosidase coupled method of alpha-amylase determination.

Adult↗
PubMed1979

Korean haemorrhagic fever in staff in an animal laboratory.

In March, 1975, and January, 1978, there were outbreaks of Korean haemorrhagic fever (K.H.F.) among staff in the animal laboratory of the clinical research building of Tohoku University hospital. 13 doctors and 1 veterinarian had K.H.F., and all except 1 had a mild but typical clinical course. K.H.F. antibody titres were significantly raised in all 14 patients. 12 other doctors working in the same room had no symptoms and no K.H.F. antibody. K.H.F. antibody was also detected in 3 animal technicians who had not been ill, but who had worked in the same room. Antibody was not detected in any of the 4 technicians who worked in different animal rooms in another building. Epidemiological studies suggest that laboratory rats were the source of the infection. High titres of K.H.F. antibody were most common in rats reared in the animal laboratory associated with the outbreak.

Adult↗
PubMed1979

Quantitative analysis of postoperative changes in the pulmonary vasculature of patients with complete transposition of the great arteries and pulmonary hypertension.

Postoperative changes in the medial thickness of the small pulmonary arteries and the degree of pulmonary vascular disease were estimated histometrically and histopathologically in three cases of late death after total correction of complete transposition of the great arteries with large ventricular septal defect and pulmonary hypertension. In the postoperative course of two of the three cases extreme medial hypertrophy of the small pulmonary arteries as well as severe pulmonary vascular disease were found. In the third case, the thickening of the media was mild and pulmonary vascular disease had not progressed owing to a residual ventricular septal defect. Examination of three additional cases of late death and 15 autopsy cases of complete transposition of the great arteries revealed that hypertrophy of pulmonary arterial media after radical surgery for complete transposition of the great arteries is a common phenomenon. In cases of complete transposition of the great arteries with severe pulmonary hypertension, the deveopment of marked hypertrophy of the media accompanied by pulmonary vascular disease after total correction is usually seen and seems to be the most likely cause of death in the postoperative period.

Autopsy↗
PubMed1979

Recent experiences with the Mustard procedure for the complete transposition of the great arteries by means of "bypass hypothermia".

This paper presents our recent results of the Mustard procedure (intra-artrial baffle operation) for the complete transposition of the great arteries performed in 24 infants and children during the past 6 years at the Tohoku University Hospital. All intracardiac repairs were performed using "bypass hypothermia" (surface-induced deep hypothermia, circulatory arrest, and limited cardiopulmonary bypass). The hospital mortality rate was 8% in patients with simple transposition without pulmonary hypertension (Group I, one death in 12 patients), 50% in patients with ventricular septal defect (VSD) and pulmonary hypertension (Group II, 3 deaths in 6 patients), and 20% in patients with VSD and pulmonary stenosis (Group III, one death in 5 patients). Various types of longstanding dysrhythmia were found in 6 out of 18 long-term survivors, and subsequent pace-maker implantation was necessary in one infant. Postoperative pulmonary venous obstruction occurred in 3 infants, and surgical relief of the obstruction was successfully undertaken in 2 of them. Prevention of postoperative dysrhythmia, pulmonary venous obstruction, and possible brain damage are also discussed.

Cardiopulmonary Bypass↗
PubMed1979

Pathological changes of experimental polychlorinated biphenyl poisoning in chickens.

Two experiments were carried out to study pathological changes of polychlorinated biphenyl (PCB) "KC 400" poisoning. In them chickens were administered with this agent for a relatively short time. Eleven experimental diets were prepared to contain 11 different PCB concentrations, 4,800 ppm being the highest, respectively. They were given to broiler chickens in initial feeding and later. All the chickens fed 300 ppm and higher concentrations of PCB died, showing the serious dilatation of uriniferous tubules and involution of the bursa of Fabricius, by the time when they reached 12 days of age. All the chickens, except a very few, fed 100 ppm remained alive at the end of the experimental period, when they were 41 days of age and exhibited such edematous changes as hydropericardium. Few chickens fed 50 ppm and less manifested pathological changes until the end of the experimental period, when they were 22 days of age. Two experimental diets were prepared to contain 600 and 200 ppm of PCB, respectively. They were given to layer chickens in initial feeding and later. These layers were sacrificed for autopsy every fourth day. A gain in body weight was retarded mostly in those fed 600 ppm. Dilatation of uriniferous tubules and involution of the bursa of Fabricius began in the very early stage of experimental feeding in both groups. Hydropericardium occurred to many of the chickens fed 200 ppm in the late stage of the experimental period. The results of both experiments indicated that there was no essential difference in changes of PCB poisoning between broiler and layer chickens. The principal changes of the poisoning were dilatation of uriniferous tubules, involution of the bursa of Fabricius, and edematous alterations. They appeared in a relatively early stage of the experimental period of PCB feeding. Their severity was strongly dependent upon the concentration of PCB contained in the diet.

Animals↗