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Biomedical subjects

K Hirosawa

Publications and source records attributed to K Hirosawa.

At least 127 records · Page 7Linked to original sources
PubMed1985

[Digital perfusion images for evaluating patients with mitral valve replacement].

To determine whether the distribution of pulmonary perfusion can be applied as a noninvasive means of evaluating patients with mitral valve replacement (MVR), computerized Tc-99m MAA pulmonary perfusion images (digital perfusion images: DPI) were obtained for 32 patients in the preoperative, early postoperative and late postoperative (18 months mean) periods. DPI consisted of isocount areas, and a 100-70% area was defined as a hyperperfusion area. The distribution of pulmonary perfusion was evaluated using patterns of hyperperfusion area in anterior DPI. In 32 patients above-mentioned had the hyperperfusion areas in the upper lung fields preoperatively, the perfusion of the lung base was investigated. In 21 patients hyperperfusion area appeared in the lung base in the late follow-up period (group A), and all patients improved clinically. In 11 patients, the DPI improved to nearly normal patterns. In five patients, the DPI improved after one year postoperatively. In 11 patients, hyperperfusion areas did not appear in the lung base in the late follow-up period (group B). Six of the 11 patients did not improve clinically. There were no significant hemodynamic differences between groups A and B except for slight differences in the postoperative pulmonary vascular resistance. These results suggested significant correlations between the clinical improvement and the normalization of the DPI. The use of DPI patterns may facilitate quantitative and objective estimations of postoperative states. Since DPI are easy to perform noninvasively, DPI may comprise a useful graphic diagnostic method for evaluating patients with MVR.

Adolescent↗
PubMed1985

[Do giant negative T waves represent apical hypertrophic cardiomyopathy? Left ventriculographic and cardiac biopsy studies].

Whether giant negative T waves (GNT) of 1 mV or greater represent the electrocardiographic characteristics of idiopathic cardiomyopathy, particularly apical hypertrophic cardiomyopathy, is controversial. To clarify this point, a comparative study was conducted for 57 persons with GNT (GNT+ group) and 57 persons of hypertrophic cardiomyopathy with either asymmetric septal hypertrophy or diffuse hypertrophy of the ventricular wall in the absence of GNT (GNT- group). Patients with cerebral vascular accidents, myocardial infarctions, valvular heart disease, myopericarditis, and implanted pacemakers were excluded from the study because these patients' ECGs may show GNT. Left ventriculograms were investigated at end-diastole in the right anterior oblique projection. The GNT+ group showed a spade-like configuration indicating a marked reduction in the lumen of the apical cavity in 25 cases (43.9%); a kidney or banana-like configuration indicating the inferior wall bulging into the left ventricular cavity in its mid-zone in eight cases (14.0%), and an oval configuration which indicated no deformity of the left ventricular cavity in 24 (42.1%). The spade-like configuration was also seen in four cases (7.0%) of the GNT- group. A study of ventricular wall thicknesses based on left ventriculography showed that 25.5% of cases with GNT did not have concomitant apical hypertrophy. Generally, the GNT+ group cases had a significantly thicker anterior left ventricular wall and apical hypertrophy compared to the GNT- group. The hypertrophic states of the apical wall and anterior wall of the left ventricle correlated well. The GNT+ group included a significantly larger percentage of patients who were middle aged and older than did the GNT- group, and the frequency of accompanying hypertension was significantly higher in the former. The confirmed or suspected familial occurrence of cardiomyopathy (CM) was observed in 32 cases (56.1%) of the GNT- group, and in 18 cases (31.6%) of the GNT+ group, i.e., the incidence was significantly lower in the GNT+ group. In an endomyocardial biopsy study, 40 cases (70.1%) of HCM without GNT had bizarre myocardial hypertrophy with disorganization (BMHD). The incidence of BMHD in the GNT+ group was 21/57 (36.8%)-significantly lower than in the GNT- group. In the GNT- group, there was no significant difference in the incidence of BMHD between relatively young and old patients or between patients with and without accompanying hypertension; whereas, in the GNT+ group, it was significantly lower among those with accompanying hypertension and in older patients than in those without accompanying hypertension and in younger patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1984

Development of the vitamin A-storing cell in mouse liver during late fetal and neonatal periods.

Vitamin A-storing cells in perinatal mouse liver were studied by chemical and autoradiographic analyses of exogenous vitamin A. The amount of retinyl palmitate in the fetal liver increased significantly following oral administration of retinyl acetate to the mother, suggesting the existence of storage sites of the vitamin in fetal liver. Light microscope semi-serial autoradiography of the fetal liver on the 15th day of gestation showed that 3H-vitamin A administered to the mother was incorporated into cells distributed exclusively along the hepatic blood vessels and the blood islands. Mitotic figures of the labeled cells were frequently observed. Electron microscope autoradiography revealed that the vitamin was incorporated into lipid droplets, rough endoplasmic reticulum and Golgi apparatus of the fibroblast-like cells in close apposition to the endothelial cells. The labeled cells differed in their ultrastructure from the vitamin A-storing cells (Ito cells) of the adult liver. In the later gestational period, silver grains tended to be more concentrated in lipid droplets, and the cytological features of the labeled cells became similar to those of the vitamin A-storing cells. Both retinyl palmitate content and the labeling of lipid droplets increased rapidly in the liver of neonates after commencement of suckling. The labeled cells had the same appearance as the vitamin A-storing cells (Ito cells). It is concluded that vitamin A transported across the placenta is taken up in the fetal liver by the cells distributed along the blood vessels, and that these cells proliferate in accordance with vascular development and gradually take on the characteristics of vitamin A-storing cells during the perinatal period. A defensive role of the vitamin A-storing cell against the toxic effects of vitamin A is also suggested.

Animals↗
PubMed1984

Evaluation of tricuspid regurgitation by blood flow pattern in the hepatic vein using pulsed Doppler technique.

Evaluation of tricuspid regurgitation (TR) was attempted by observing the blood flow pattern in the hepatic vein (HV), inferior vena cava dimension (IVCD), and hepatic vein dimension (HVD), with the use of a combined system of pulsed Doppler technique and two-dimensional echocardiography in 60 patients with valvular heart disease. For comparison, all patients underwent right ventriculography, by which TR was classified as mild, moderate, or severe. IVCD and HVD of the group with severe TR were significantly larger than those of the other groups (p less than 0.005). Several types of abnormal blood flow patterns in the HV were demonstrated in patients with atrial fibrillation. By these flow patterns, the severe or moderate TR groups could be differentiated from the mild TR group, because 21 of the 26 patients (81%) in the former group showed reverse hepatic flow during systole. Also, the Doppler shifts from baseline in the sound spectrogram correlated well with right atrial pressure (RAP) and right ventricular end-diastolic pressure (RVEDP) (r = -0.72, -0.64, p less than 0.001, respectively). This method is useful for rapidly evaluating considerable TR and for estimating RAP and RVEDP noninvasively.

Adult↗
PubMed1984

Natural history of subarterial infundibular ventricular septal defect.

Development of aortic valvular deformities was studied retrospectively in 395 inpatients with subarterial infundibular ventricular septal defect (siVSD). Aortic valvular deformities included prolapse into siVSD without aortic regurgitation (77 patients), prolapse and aortic regurgitation (95 patients), and aneurysm of the sinus of Valsalva (36 patients). No aortic valvular deformity was found in 187 patients, and 111 of these 187 patients had associated pulmonary hypertension. Prolapse and regurgitation of the aortic valve developed most frequently at the age 5 to 8 years. Aneurysm of the sinus of Valsalva was not found before the age of 10 years but began to develop during the teens and was diagnosed most frequently in the twenties. Patients with pulmonary hypertension did not develop aortic valvular deformities except in one instance. All inpatients with siVSD and without pulmonary hypertension over the age of 30 years had developed some aortic valvular deformities.

Adolescent↗
PubMed1984

Morphological and functional development of plasma membranes of mouse hepatocytes: an autoradiographic study of asialoglycoprotein uptake during the postnatal period.

The morphological development of the postnatal mouse liver was studied with reference to the specialization of sinusoidal plasma membranes of hepatocytes. Numerous hemopoietic islands were distributed at random among hepatocytes at neonatal stages. The hemopoietic fronts of hepatocytes were flat and showed few structures indicating endocytotic and exocytotic activities. They gradually acquired structural characteristics of the sinusoidal region as the processes of the endothelial cells extended in the space between hemopoietic cells and hepatocytes. The degree of attenuation and fenestration of the sinusoidal endothelial cells increased as the postnatal day advanced. In the course of these changes, microvilli, pinocytotic pits, and vesicles of sinusoidal regions of hepatocytes increased as well. The functional development of sinusoidal regions of hepatocytes was investigated by the quantitative analysis of autoradiograms of [3H]asialoorosomucoid (ASOR). Silver grains were distributed only in the regions where the structural specializations of the sinusoidal region were observed. They increased as the maturation of sinusoidal structure advanced. These results suggest that the sinusoidal regions of hepatocytes specialize structurally and functionally, as regards ASOR-uptake capability, in correlation with the structural establishment of sinusoids.

Animals↗
PubMed1984

Histopathological findings of acute and convalescent myocarditis obtained by serial endomyocardial biopsy.

Serial endomyocardial biopsy findings in 20 cases with acute myocarditis of possible viral origin were analyzed. The histopathological findings were analyzed during the acute (0-10 days after the onset: 8.3 +/- 1.9 days; 6 cases), the subacute (11-21 days: 18.2 +/- 2.2 days, 6 cases), and the convalescent stages (22-167 days: 54.5 +/- 45.4 days; 8 cases). The incidence and severity of various changes of the cardiac myocytes and interstitial changes were analyzed and compared at each stage of the disease. In the acute stage, interstitial cell infiltrations were composed of fibroblasts, macrophages and lymphocytes, taken out in descending order. In the convalescent stage, interstitial cell infiltration showed a marked increase and was replaced by fibrocytes. In the subacute stage, transitional changes between the acute and convalescent stages were observable. A controlled myocardium in 21 cases with myocardial infarction which were compared at various stages revealed that in the acute stage, neutrophils were most prominent, and in the subacute and convalescent stages, macrophages were most prominent and plasma cells were most often observed. The time course changes of the histopathological findings in acute myocarditis were as follows: In the acute stage, Interstitial cell infiltration which is composed of fibroblasts, macrophages and lymphocytes, fragmentation of the muscle bundles, myocytolytic changes, swelling and scarcity of the cytoplasm and swelling of nuclei, variation in size of the myocytes, disarrangement of the muscle bundles, interstitial edema, increased glycogen deposition in the myocytes, abnormal branching of the myocytes, and interstitial fibrosis were observable. In the convalescent stage, most of the above described findings were still observable except for the myocytolytic change, swelling of myocytes and interstitial edema.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1984

Ultrastructural features of the endomyocardium in patients with eosinophilic heart disease. An endomyocardial biopsy study.

In a series of studies with endomyocardial biopsy, 7 adult cases with cardiac disease and eosinophilia were studied clinically and electro-microscopy. Degranulation of the eosinophils in the peripheral blood was observed ultrastructurally in 3 of the 4 cases studied. The clinical expression of the 7 patients were, restrictive cardiomyopathy in 2, dilated cardiomyopathy in 2 and sick sinus syndrome in 1 and others in 2. Endocardial thickening was observed in 5 cases, one of whom showed a marked cellular infiltration with macrophages, plasma cells, lymphocytes and mast cells. One other case showed cell debris of degranulated eosinophils. Degeneration of the myocytes was manifested by an increase in Z-bands of the myofibrils as well as streaming (1 case), disarrangement of the myofibrils, and mitochondrial change (1 case) which was characterized by giant mitochondria (1 case) as well as by a numerical increase in mitochondria. Increase of atrial granules and mitochondria in a right atrial biopsy of a case with sick sinus syndrome was noteworthy. Basal lamina layering of the capillaries of the myocardium and pyknosis of an endothelial cell cytoplasm were also noted in each case. These observations may reveal that various disease processes are taking place in the endocardium and adjacent myocardium.

Adult↗
PubMed1984

CCU network as primary care of acute myocardial infarction.

The early pre-hospital care of patients with acute myocardial infarction (AMI) is critical because of high mortality during acute phase of AMI. A CCU network has been established by the Metropolitan Tokyo CCU Communication Society and the help of the Ambulance Units through the Control Room of the Tokyo Fire Department, performing ECG telephone line transmission and telephone consultation. Out of 1439 patients admitted by means of CCU network during the 8-month period (Jan. 1982-Aug. 1982), 505 (30.3 percent) had AMI as a final cardiac diagnosis. Many patients were admitted directly to the CCU by ambulance from the place where the patient was located, with the shortest overall time of 7 hours 25 minutes. Fifty-three percent of patients with AMI were admitted within 6 hours after the onset of symptoms. The mean patients' decision time was 9 hours 48 minutes, which comprised one half of the overall period as well as physician delay of 6 hours 36 minutes on the average. Thus, community oriented educational programs to more fully inform the population and individual hospital evaluations to hospitalize patients with chest discomfort are needed in order to shorten the decision time and physician delay expediting the care of these patients.

Adolescent↗
PubMed1984

Defects in the growth plate of brachypodism in mice--light and electron microscopic findings and cell proliferation by the method of tritiated thymidine autoradiography.

The basic defect of the human chondrodystrophies with normal chondro-osseous histopathology is speculated to be quantitative decrease in the rate of ossification. Homozygous brachypodism (brp/brp), chondrodystrophic mutant in mice, is characterized by shortening long bones. The light and electron microscopic observations of the growth plate were essentially normal. The method of tritiated thymidine autoradiography showed that the rate of chondrocyte division in the mutant growth plate was decreased. These findings show that the failure of chondrocytes to divide at a normal rate can produce the growth disturbance of bone without abnormal chondro-osseous histopathology.

Animals↗