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Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 1,171 records · Page 65Linked to original sources
PubMed1976

Metabolism of threo-beta-methylmalate by a soil bacterium.

Studies on threo-beta-methylmalate metabolism in a soil bacterium of the genus Bacillus which can utilize threo-beta-methylmalate as a sole carbon source were carried out. When DL-threo-beta-methylmalate was incubated with a cell-free extract of the bacterium, citramalate was found to be formed. Similarly, formation of threo-beta-methylmalate from DL-citramalate was confirmed. These dicarbosylic acids were identified by gas chromatography-mass spectrometry. Examination of inducibility, substrate specificity, and cofactor requirement of the enzymes involved in the reactions showed the existence of two interconversion reactions between the threo-beta-methylmalate and citramalate. One was an interconversion reaction between L-threo-beta-methylmalate and L-citramalate via mesaconate and the other was an interconversion reaction between D-threo-beta-methylmalate and D-citramalate via citraconate. These reactions were both reversible and were catalyzed by distinct and inducible enzymes. It is suggested that the two reactions participate in the catabolism of threo-beta-methylmalate.

Bacillus↗
PubMed1976

Localization of E and EAC binding lymphocytes in human tonsils.

The localization of T and B lymphocytes in frozen sections of human tonsils was determined using E and EAC binding techniques. It was revealed that there were thymus-dependent areas with E binding lymphocytes in peri- and interfollicular zones. EAC binding lymphocytes were found mainly in the follicles. This suggests that B cells are produced in germinal centres. The present experiment confirmed that human tonsils contain two different kinds of lymphocytes demonstrating selective localizations in the tissues as similar to the lymph nodes.

Adolescent↗
PubMed1976

Non-infected false aneurysm of the ascending aorta eight years after aortic valve surgery.

In this report, the development of false aneurysm of the ascending aorta 8 years following the repair of congenital aortic stenosis is described. A 14-year-old male patient was found to have congenital aortic stenosis in 1966 after medical check-up and subsequently operated upon. In the postoperative period, he was complicated by remittent fever of 1 month's duration, which was finally controlled by antibiotics. Arterial blood cultures taken on a few occasions were negative. Eight years and 5 months after surgery, he was noticed to have a mediastinal mass around the base of the heart and the presence of false aneurysm was confirmed by aortography. Aneurysmectomy was carried out almost 9 years after the previous operation, and it was found that aneurysm was arising from the suture line of the aortotomy with communication to the aorta at the bottom of the aneurysm. Postoperatively, patient's recovery was uneventful and was discharged on the 23rd postoperative day. Etiology, timing of operation and techniques utilizing hypothermia and/or circulatory arrest are discussed.

Adolescent↗
PubMed1976

Surgical management of congenital cardiovascular anomalies with the use of profound hypothermia and circulatory arrest. Analysis of 180 consecutive cases.

An initial series of 180 patients subjected to definitive repair of cardiac malformations during infancy is presented. The operations were performed with profound hypothermia and circulatory stasis. Statistics relating to the entire series of patients are presented and discussed, after which the results among eleven individual groups of patients categorized by type of cardiovascular lesion are analyzed. There was 113 survivors, representing an over-all mortality rate of 37 per cent. The mortality rate was highest among patients severely ill preoperatively and among those with complex malformations. Deaths were also more frequent among infants under 6 months of age and less than 5 kilograms in weight. Analysis shows a steady increase in percentage of patient survival over the years reported from December, 1967, to April, 1975.

Heart Arrest, Induced↗
PubMed1975

Respiration-department uncoupler-stimulated ATPase activity in castor bean endosperm mitochondria and submitochondrial particles.

1. The uncoupler-stimulated ATPase activity of castor bean endosperm mitochondria and submitchondrial particles has been studied. The rate of ATP hydrolysis catalyzed by intact mitochondria was slow and little enhanced by addition of uncouplers at the concentration required for uncoupling the oxidative phosphorylation. ATP-ase activity was stimulated at higher concentrations of uncouplers. 2. 1-Anilinonaphthalene 8-sulfonate fluorescence was decreased when the mitochondria were oxidizing succinate. Carbonylcyanide-p-trifluoromethoxyphenylhydrazone and antimycin reversed the succinate-induced fluorescence diminution. ATP did not induce the fluorescence response. 3. The addition of succinate, NADH or ascorbate/N,N,N'-N'-tetramethyl-p-phenylenediamine as electron donor induced high ATPase activity in the presence of low concentrations of uncouplers. Stimulating effect of uncouplers was completely abolished by further addition of antimycin. 4. Submitochondrial particles were prepared by sonication. The particles catalyzed a rapid hydrolysis of ATP and carbonylcyanide-p-trifluoromethoxyphenylhydrazone at 10-8 M did not stimulate the ATPase activity. Addition of succinate induced uncoupler-stimulated ATPase activity. The effect of succinate was completely abolished by further addition of antimycin. 5. The treatment of submitochondrial particles by trypsin or high pH also induced uncoupler-stimulated ATPase activity. 6. The above results were interpreted to indicate that ATPase inhibitor regulated the back-flow reaction of mitochondrial oxidative phosphorylation.

Adenosine Triphosphatases↗
PubMed1975

Malignant hemangioendothelioma of the heart with hematological disorders.

An autposy case of a 30-year-old house wife with malignant hemangiothelioma of the heart was reported. This case was also accompanied by marked anemia, thrombocytopenia, leukoerythremoid reaction and hypofibrinogenemia. The spread of tumor was so wide that only the alimentary tract and the skin were free from metastases of the tumor. Many of the metastatic foci showed marked hemopoiesis intra tumori. A short discussion was made on the hematological abnormalities associated with vascular tumors.

Adult↗
PubMed1975

Vaccination against parainfluenza 1 virus (typus muris) infection in order to eradicate this virus in colonies of laboratory animals.

Parainfluenza 1 virus (typus muris), commonly known as Sendai virus, is still contaminating mouse colonies in Japan. This presents a serious problem to keep mouse colonies pathogen-free. It seems that the infection is spread by dust and the virus remains active a considerable time in the mouse breeding rooms after all mice are removed. In order to eradicate the infection of this virus, vaccination was attempted to inoculate newly born young mice successively for about six months and during and after these periods the movements of the infection were under observation. The vaccine used for this experiment was inactivated virus vaccine with mineral oil-Arlacel adjuvant. The induction of antibody level by the inoculation of this vaccine was evidenced to be very efficient and the duration of the immunity was also very satisfactory. However, after the cessation of the vaccination, the infection of the virus reappeared gradually after some period of temporary ease.

Animals↗