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Biomedical subjects

T Sakamoto

Publications and source records attributed to T Sakamoto.

At least 1,099 records · Page 61Linked to original sources
PubMed1983

Computed tomography for diagnosis and assessment of cerebral fat embolism.

A patient with cerebral fat embolism was followed by computed tomography (CT). For the first few days after injury, CT revealed no abnormality. About a week later, multiple low density areas appeared in the white matter of the frontal region. They disappeared within the subsequent 2 weeks while subdural effusions developed in the fronto-parieto-temporal regions. As neurologic recovery progressed, the subdural effusions gradually diminished and cerebral atrophy was seen.

Adolescent↗
PubMed1983

Serum folic acid levels and antipyrine clearance rates in smokers and non-smokers.

Serum folic acid (FA) levels and antipyrine clearance rates were determined in 15 healthy male subjects who had not been administered any drug and alcohol for a month preceding the study. Eight of the 15 subjects smoked cigarettes daily while the remaining seven did not. The serum FA levels were measured by Lactobacillus casei bioassay. The antipyrine clearance rates were estimated in plasma or saliva obtained after oral administration of antipyrine for evaluating the activity of hepatic microsomal oxidase. The serum FA levels in the smokers were significantly lower than those in the non-smokers and the antipyrine clearance rates were significantly higher in the smokers compared with the non-smokers. The increase of the antipyrine clearance rates in the smokers was supposed to be caused by an increase in the activity of hepatic microsomal oxidase since it has been established that polycyclic aromatic hydrocarbons contained in cigarette smoke induce these enzymes. The association of the decrease in the serum FA levels and the increase of the antipyrine clearance rates was investigated.

Adult↗
PubMed1983

Echophonocardiographic study of the initial low frequency component of the first heart sound.

To investigate the genesis of the initial low frequency component of the first heart sound that precedes the high frequency vibrations associated with closure of the atrioventricular valves, echophonocardiograms of 36 persons were recorded. These included 10 normal subjects and 26 patients with various types of heart disease including mitral valve replacement. Electrocardiograms demonstrated normal sinus rhythm in 23 subjects, atrial fibrillation in 9, complete atrioventricular block in 2 and atrial flutter in 2. In the phonocardiogram, the low frequency component of the first heart sound followed the onset of the QRS complex and preceded the first high frequency component of this sound. The low frequency component occurred simultaneously with the beginning of the final fast closing movement of the mitral valve on the echocardiogram and was found both in normal rhythm and in arrhythmias. However, in arrhythmias its intensity varied on a beat to beat basis, being loudest after a short RR interval or when atrial systole occurred very close to the expected time of ventricular systole. In patients in whom apexcardiograms were recorded, the low frequency component was coincident with or very close to the onset of ventricular systole. It is concluded that the low frequency component of the first heart sound represents vibrations caused by contraction of the left ventricle and deceleration of antegrade blood flow across the mitral valve. Neither atrial contraction nor mitral valve tension is necessary for the production of this soft initial component.

Adolescent↗
PubMed1983

[Studies on platelet function in toxemia of pregnancy].

This study evaluated the role of platelets in the pathogenesis of toxemia. The findings were: (1) Thrombocytopenia and macrothrombocytosis are characteristic of toxemia. (2) ADP induced platelet aggregation increases during pregnancy, but decreases in severe toxemia significantly. (3) beta-thromboglobulin levels in both plasma and urine rise during pregnancy, and are significantly high in toxemia, especially in a severe type. (4) The plasma TxB2/6-keto-PGF1 alpha ratio markedly increase in severe toxemia due to the increase in the amount of TxB2. And in the IInd trimester, the ratio in the toxemia onset group in which toxemic pregnancy occurred in the IIIrd trimester showed a significantly higher value than the control group. These findings suggest that, in toxemic patients, platelets are in a hyperactive state and there is rapid turnover caused by selective consumption in organs such as the kidneys and placenta, and that platelet aggregation decreases due to the relative increase in the number of exhausted platelets as the toxemic state is impending. Furthermore, the TxA2/PGI2 balance shifts to TxA2 dominant and measurement of the plasma TxB2/6-keto-PGF1 alpha ratio was considered to help prediction of toxemia in the latter term of pregnancy.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Mitral valve prolapse in five members of a family including the identical twins.

A family in which the five members including the identical twins had a mitral valve prolapse was described. None of these members had any known stigmata of Marfan syndrome and their auscultatory findings were different each other. M-mode echocardiograms disclosed a midsystolic buckling of the mitral valve in the identical twins, their parents and the mother's brother, but all were asymptomatic. Electrocardiograms revealed a wandering pacemaker in two members. The index case was a 13-year-old girl whose apical late systolic murmur was detected incidentally by the mass screening examination for cardiac diseases. Both the inhalation of amyl nitrite and injection of methoxamine induced the augmentation of this murmur and made it holosystolic. The identical twin of the index case had multiple apical non-ejection clicks. However, a mitral regurgitant murmur was not induced by pharmacological provocations. Two-dimensional echocardiograms revealed prolapse of both the anterior and posterior mitral valve leaflets in both of them. Their mother had a late systolic click and the mother's brother had a cardiopulmonary murmur. The abnormal auscultatory findings were not observed in their father. This familial study suggested the genetic background and the various clinical manifestations of mitral valve prolapse.

Adolescent↗