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Biomedical subjects

H Takezawa

Publications and source records attributed to H Takezawa.

At least 91 records · Page 5Linked to original sources

[Detectability of stress-induced ischemic lesion in previous myocardial infarction using 201T1 myocardial single photon emission computed tomography].

The purpose of this study was to evaluate the detectability of stress-induced ischemic lesion in patients with previous myocardial infarction using single photon emission computed tomography (SPECT) producing thallium-201 (T1-201) myocardial perfusion imagings (MPI). Seventy patients underwent stress SPECT by symptom-limited graded bicycle ergometer exercise using a dual-headed rotating gamma camera (Toshiba GCA70A) equipped with a computer system (GMS90). After intravenous administration of 2.5 mCi of T1-201, stress SPECT data at 10 minutes and delayed SPECT data at 3 hours after the injection were collected in the 64 X 64 matrix form covering 360 degrees directions by camera sweep of 180 degrees in 6 minutes, which were immediately followed by conventional planar imagings (PL). Transaxial tomographic image reconstruction was performed by convolution method using a Shepp-Logan's filter. Thereafter, sagittal and coronal tomographic images were reconstructed for about 2 minutes. Image interpretation was assessed visually. The results were as follows: Sensitivity and specificity in detecting the affected vessel with more than 75% stenosis by segmental analysis of myocardial images were higher by SPECT than by PL (LAD 89% and 65%, LCX 68% and 56%, RCA 89% and 76% in sensitivity and LAD 94% and LCX 75%, 92% and 94%, RCA 81% and 59% in specificity, respectively). Sensitivity in detecting both single (82%) and multivessel disease (76%) was fairly high. Detectability of stress-induced ischemia (i.e. occurrence of a new defect in patients with previous myocardial infarction and ST-segment depression in ECG) was significantly higher in SPECT (67%) than in PL (39%, p less than 0.005) and in ECG (39%, p less than 0.005). A perfusion defect in the extensive anterior wall, marked left ventricular dilatation and the widening of the angle toward the apex composed of septal and anterolateral walls in transaxial images were the findings characteristic of anterior myocardial infarction with severe dyskinesis. We conclude that stress SPECT is a useful noninvasive technique for the documentation of the number of vessels affected and severe wall motion abnormality of the LV and for the detection of stress-induced ischemia in previous myocardial infarction.

Electrocardiography↗

[Serum and urinary level of sodium piperacillin in patients with liver disease (author's transl)].

Serum and urinary levels of PIPC (sodium piperacillin) in patients with liver disease were investigated. Serum and urinary levels of PIPC are affected by the degree of liver disease which is estimated most exactly by KICG, and it is available for determination of dose and administration interval. When PIPC was administered intravenously at a dose of 2 g, serum level in patients with liver disease was showed high and prolonged. Therefore this is convenient for PIPC of which biological half life is comparatively short. In patients with serious liver cirrhosis, PIPC is probably cumulated by continuous administration and in this case, dose and administration interval will be needed to regulate.

Aged↗

A study on the relationship between the prognosis of chronic active hepatitis and the HBV associated antigen/antibody systems.

The relationship between the prognosis of the disease based on liver histology and HB virus (HBV) associated antigen/antibody systems was investigated in twenty seven patients with chronic active hepatitis (CAH). These patients were followed up over extended periods with mean duration of 44.3 months. On initial liver biopsy five of twelve patients with CAH with spotty or focal necrosis were HBs antigen (HBsAg) positive, as were also five of six patients with sublobular necrosis and six of nine patients with lobular disorganization. Most of the HBsAg negative patients were anti-HBs or anti-HBc positive: HBV associated antigen or antibody was completely undetectable in only three of the twenty seven patients. There was no difference in the frequency of progression to liver cirrhosis (LC) between the sixteen HBsAg positive and the eleven HBsAg negative patients with CAH. On the other hand, progression to LC occurred in only one of seven HBe antigen (HBeAg) negative patients, compared to four of nine HBeAg positive patients, who were HbsAg positive. There were four patients who were HBeAg positive initially but then became HBeAg negative in the course of observation. LC developed in two of these four patients. These results suggest that in HBsAg positive patients with CAH the presence or absence of HBeAg and the variation in its level can provide useful indicators of the prognosis of the disease.

Adolescent↗

Left ventricular performance in chronic renal failure before and after hemodialysis assessed by systolic time intervals.

The purpose of the present study was to examine noninvasively the myocardial performance before and after hemodialysis in 40 patients of chronic renal failure. Using systolic time intervals, the following results were obtained. 1) Left ventricular ejection time was shortened significantly. The reduction of circulating blood volume estimated by the body weight change seemed to be responsible for this finding. 2) Pre-ejection period seemed to be a sensitive indicator of the left ventricular performance in hemodialysis. 3) The less the circulating blood volume, the less the suppression of cardiac performance. 4) Left ventricular function in patients without cardiomegaly was improved. 5) Left ventricular function tended to improve in the young age group. The present study demonstrated that the left ventricular performance tended to be suppressed in older age patients, in patients with cardiomegaly and in the cases with excessive removal of circulating blood volume during dialysis. The significance of noninvasively obtained left ventricular hemodynamic parameters in patients with hemodialysis was discussed.

Adult↗

A case of idiopathic hypothalamic hypothyroidism.

The availability of thyrotropin hormone (TRH) has made it possible to determine whether tropic hormone deficiency is caused by pituitary or hypothalamic dysfunction. A case of hypothalamic hypothyroidism was described ina a 17 year old woman. This patient was admitted for the evaluation of hypothyroidism and secondary amenorrhea. Her T3 and T4 were decreased, with an undetectable level of base line thyrotropin. the TRH test revealed normal but delayed response of TSH. Her base line prolactin and its response to TRH were normal. Adenocorticotropic hormone (ACTH), cortisol, growth hormone (GH), and urinary 17-hydroxysteroids were also normal. ACTH response to metyrapone was normal. Evaluation of the pituitary-gonadal axis revealed a normal increase in both lutenizing hormone (LH) and follicle stimulating hormone (FSH) following the intravenous administration of lutenizing hormone releasing hormone (LHRH). These results suggest that she had hypothalamic hypothyroidism as an isolated disturbance in the hypothalamic-pituitary axis. A deficiency of TRH is probably caused by a disorder of hypothalamic function of unknown etiology since the extensive studies did not reveal any secondary causes. It is recommended that patients with amenorrhea and hypothyroidism be evaluated for possible hypothalamic hypothyroidism.

Adolescent↗

[The echocardiographic study in 13 cases with infective endocarditis (author's transl)].

The echocardiographic study was performed in 13 cases with infective endocarditis including one case with annular subvalvular left ventricular (LV) aneurysm. The echocardiographic findings were compared with clinical as well as anatomical findings obtained by surgery or autopsy. The valvular vegetations were visualized echocardiographically in 6 cases (46%); 2 cases in aortic valve (AV), 2 in mitral valve (MV) and 2 in both valves. In 3 out of 4 cases with AV vegetation, the abnormal echo was seen in the LV outflow tract. Two out of these 3 cases indicated "flail aortic leaflet" with early closure of the MV, and immediate aortic valve replacement was performed. Unfortunately, one died 4 weeks after operation. The echocardiographic findings showed good correlation with anatomical findings in 4 cases with valve replacement. Out of 4 cases with MV vegetation, one developed the progressive growth with subsequent rupture of the chordae tendinae to the anterior mitral leaflet, which paralleled to the clinical deterioration. In another one case, the echocardiographic size of vegetation in the MV reduced significantly shortly after the episode of cerebral embolism. In a case of annular subvalvular LV aneurysm possibly due to infective endocarditis, echo free space was visualized in the interventricular septum, coinciding well with postmortem anatomical findings. It seemed to be reasonable to indicate surgical repair in cases with evident vegetation and considerable destruction of AV, in which congestive heart failure inevitably develops and the prognosis is poor.

Adult↗

Acid-base disturbance in patients with fulminant hepatic failure.

Forty-two arterial blood pH and gas determinations were carried out on 11 patients with fulminant hepatic failure. The most common type of acid-base disturbance was that of respiratory alkalosis in 22 cases (52.4%). This was partially compensated in 13 subjects (31.0%) while an accompanying metabolic alkalosis was present in 9 (21.5%). Partially compensated metabolic acidosis was observed on 15 occasions (35.7%), all of which were in patients with laboratory evidence of impaired renal failure. The mental status of the patients was evaluated in each of the categories of acid-base disturbances. Some degree of correlation was evident between the PCO2 and the magnitude of base excess and that of the severity of the encephalopathy. The lower PCO2 and greater negative base excess values tended to be nearly always present in totally comatose subjects. By contrast, there was no clear cut relationship between pH and mental state.

Acid-Base Imbalance↗