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Biomedical subjects

Y Koga

Publications and source records attributed to Y Koga.

At least 631 records · Page 35Linked to original sources
PubMed1981

[Secondary atypical hypertrophy: hypertrophic cardiomyopathy with acquired risk factors (author's transl)].

New clinical concept of "secondary atypical hypertrophy" was proposed for hypertrophic cardiomyopathy (HCM) associated with an acquired risk factors such as hypertension, strenuous exercise, etc, based on the following findings. 1) Case-control study suggested that history of hypertension, physical labor and weight gain were thought to be risk factors of apical hypertrophy. History of hypertension was also demonstrated in 55% of older cases of HCM (greater than 35 yrs) with asymmetric septal hypertrophy, and this figure was appreciably higher than that in general population (around 26% in our population survey). Thus hypertension was suggested to have a causal relationship to HCM as an important risk factor in older cases. 2) Even in cases without hypertension, 29% of non-obstructive HCM exhibited a marked increase in systolic blood pressure on bicycle ergometer stress test, suggesting an important of transient hypertension during exercise as a risk factor of unusual hypertrophy. 3) The cases of HCM with definite family history and the cases of HCM with secondary atypical hypertrophy, with acquired risk factors such as hypertension, presented different clinical features. The latter is older and predominant in males. In the former, QRS pattern was les distorted, suggesting milder congenital defect of the myocardium. Left ventricular function was less impaired in cases with secondary atypical hypertrophy if judged from diastolic descent rate of the mitral valve, left ventricular enddiastolic pressure and functional aerobic impairment (FAI). On the other hand, no differences were observed between cases with ventricular septal hypertrophy and left ventricular outflow obstruction. 4) Follow-up study demonstrated rather favorable prognosis in cases with secondary atypical hypertrophy because of the absence of sudden death despite of their older age. These distinctive difference in clinical features, prognosis and then management in cases with HCM with acquired risk factors suggested a validity of the concept of secondary atypical hypertrophy in clinical practice.

Adult↗
PubMed1981

Self-mutilation. Plastic spherules in penile skin in yakuza, Japan's racketeers.

Despite the reduction in crime in Japan there is a problem with organized racketeer groups, or yakuza in Japanese. The members of the yakuza can be recognized by their speech and behavior and by their physical characteristics such as tattooing and digital amputations. Penile balls are unusual sexual devices that have been found on some yakuza. Nine cases of unusual way of identifying yakuza are reported. A survey of a detension house showed that 28 prisoners out of 130, or 21.5%, had penile balls. Penile balls and the yakuza are discussed in relation to forensic psychiatry.

Adult↗
PubMed1981

[Detection of exercise induced left ventricular asynergy by two-dimensional echocardiography (author's transl)].

In order to detect an exercise induced asynergy, cross-sectional echocardiography was performed during multistage maximal bicycle ergometer stress test in the supine position. 1) Left ventricular (LV) asynergy occurred earlier than or simultaneously with the appreciable ST segment change. 2) In patients with angina, LV asynergy appeared in the area of dominant coronary stenosis, while ST depression was seen in V3-6 as well as II, III and aVF, despite of the localized area of asynergy. 3) In patients with myocardial infarction, LV asynergy increased or extended over or around the infarcted area except one case, ST segment elevated in the leads over the infarction with abnormal Q waves and depressed in the reciprocal leads. These observations revealed that ST depression does not necessarily mean an occurrence of new ischemia over the corresponding area in myocardial infarction. Thus exercise cross-sectional echocardiography was demonstrated to be a good method to detect an exercise induced ischemia and would be particularly valuable in view of the coronary artery bypass.

Adult↗
PubMed1981

Ga-67 imaging with scintillation camera: the selection of collimator.

Ga-67 scintiphotos made with 300 and 360 keV collimators (LFOV) were compared to determine which collimator performed better. One target was a modified Rollo phantom; the other an Anger focal photon-deficient phantom. Three energy windows were used to bracket the 93-, 185-, and 300-keV peaks of Ga-67. The MTF and contrast efficiency functions of the 360 keV collimator were found higher than those of the 300 keV; on the other hand, the latter one was graded higher by a performance index. The modified Rollo phantom images were studied by four observers to determine how well photon-deficient lesions could be seen. From their findings the "lesion-detecting ability" of each collimator was calculated--i.e., the number of lesions with decreased activity detected divided by the number actually present in the phantom. This quotient was found higher for the 360 keV than for the other one. The advantage of the 360 keV collimator was also suggested by a study of clinical Ga-67 scintigrams of a liver with focal defects.

Densitometry↗
PubMed1980

Intra- and postoperative autotransfusion in open heart surgery under simple hypothermia in children.

A new autotransfusion unit was developed by the authors and the favorable results of 21 operations of open heart surgery under simple hypothermia were described. The patients were all children with simple congenital heart diseases. The amounts of autotransfused blood ranged from 2.8 to 15.5 ml/kg. Intraoperative autotransfusion proved to be an effective means of minimizing blood loss during surgery (range 3.2 to 12.8 ml/kg) and performing open heart surgery without donor blood transfusion. Postoperative autotransfusion (range 0 to 14.3 ml/kg) served as a supplementary means of avoiding homologous blood transfusion. Among the 21 autotransfused patients, there were no complications, while two patients developed hepatitis out of 19 patients who received homologous blood in the control group.

Adolescent↗
PubMed1980

Enhancement of cooling and rewarming by a jet water system in surface-induced deep hypothermia.

To shorten the time of cooling and rewarming in surface-induced deep hypothermia, we devised a jet water system for hypothermia which was constructed within the water bath of the operating-table. In the clinical applications for open heart surgery under surface-induced deep hypothermia, we found that the time required for cooling and rewarming, particularly the later, was significantly reduced without any adverse effects.

Adolescent↗
PubMed1980

Evaluation of scintillation cameras by spherical lesion detectability.

The lesion detectability with a scintillation camera as a function of count density was determined for the four spherical cold lesions with diameter 0.9-2.5 cm (in square root 2 step) within a uniform background activity. It can be seen from the curves that the lesion detectability increases with an increase in count density until 2 kcounts/cm2, however it does not appreciably improve for count densities above 2 kcounts/cm2. The curves also show that, for a giving count density, the lesion detectability decreases as the lesion size or object contrast decreases. From these curves minimum count density required for recognition of each cold lesion is deduced. This value is applied to the evaluation of scintillation camera system.

Background Radiation↗