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Biomedical subjects

N Baba

Publications and source records attributed to N Baba.

At least 163 records · Page 9Linked to original sources
PubMed1982

The pattern of myocardial degeneration in nonischemic congestive cardiomyopathy.

The histopathologic features of nonischemic congestive cardiomyopathy (CCM) include diffuse and focal fibrosis, vacuolar degeneration, and myofiber hypertrophy. Eleven patients with CCM and five controls were studied. Fibrosis and degree of vacuolization were quantified by means of stereologic techniques; myocardial cell diameter was measured with an ocular micrometer. Five levels of the left ventricular free wall were examined. Area I was immediately subepicardial, and area 5 was immediately subendocardial. In all areas, fibrosis, vacuolization, and fiber diameter were significantly greater in the experimental group than in the control group (P less than 0.05). In addition, fibrosis and vacuolization had an umbrella distribution, which peaked in area 4, the area adjacent to the subendocardium (P less than 0.01). The distributions of fibrosis and vacuolar degeneration suggest compromised blood flow to the inner myocardial layers, with relative sparing of the immediate subendocardial region owing to its proximity to the left ventricular cavity.

Adult↗
PubMed1982

Enhanced thermogenesis and diminished deposition of fat in response to overfeeding with diet containing medium chain triglyceride.

The mechanism whereby overfeeding with diet containing medium chain triglyceride (MCT) results in diminished body weight and fat was studied. Fifteen male Sprague-Dawley rats were fitted under anesthesia with gastrostomy tubes and divided into two groups. One group was fed MCT diet, the other an isocaloric diet containing long chain triglyceride (LCT) in excess (150%) of spontaneous calorie intake. Both diets, fed for 6 wk, derived 50% of calories from fat. Basal and norepinephrine (25 micrograms/100 g) stimulated 02 consumption and CO2 production, as well as metabolic rate were measured. After the rats were killed, total dissectible fat and fat cell size and number were determined. MCT rats gained 15% less weight than LCT controls (p less than 0.001). Total dissectible fat was significantly lower (p less than 0.001) in MCT group, as was mean adipocyte size (p less than 0.001). Resting and maximal norepinephrine-stimulated 02 consumptions were 39.7 and 22.1% higher in MCT than in LCT group, respectively. Resting and norepinephrine-stimulated metabolic rates were 38.8 and 22.2% higher in MCT than LCT fed rats, respectively. Overfeeding MCT diet results in decreased body fat related to increased metabolic rate and thermogenesis.

Adipose Tissue↗
PubMed1982

Digital processing methods for structural analysis of an electron micrograph.

Digital processing method using the scanning-densitometer with microcomputer provides a useful description system. It draws attention to the usefulness of local lattice averaging in clarifying images of periodic structures in crystals as well as crystalloids and para crystalline arrays in biological specimens. Digital processing of lattice images in crystal structures from the selected diffraction spots is successfully developed to the structural analysis of evaporated gold, graphitized carbon and human tooth enamel of hydroxyapatite. Furthermore, known microbody crystalloids in enzyme and icosahedral capsids in virus are confirmed and clarified by the procedure of selecting diffraction spectra transformed from the information taken with high resolution electron micrographs. The processed results can provide significant improvements in structural analysis of an electron micrograph.

Crystallography↗
PubMed1982

Digital processing methods using scanning densitometer and microcomputer for the structural analysis of a scanning electron micrograph.

The fundamental equation of image contrast with practical resolving power is shown taking account of the optical and specimen characteristics. Then, the structural factor which is used to indicate the scattering from the unit of structure to form the periodic object in a scanning electron microscopy can be derived straight-forwardly by digital processing. Based on the Fourier analysis, the reconstruction and subsequent interpretation of structural images such as biological specimens of rat microvilli have been successful. These microvilli must exhibit regularity of a hexagonal lattice consisting of rod-like crystalline arrays. Lattice defects are analysed by means of contrast enhancement, level slicing and histogram plotting techniques. The resolution of SEM can be tested from the granularity distance of coated films by the image sharpening by differentiation and subsequent superimposition of reconstructed images. Furthermore, the structural details in high brightness owing to reducing of the brightness level and filtering the high frequency component have been analysed.

Animals↗
PubMed1981

Biochemical and histologic correlates of ventricular end-diastolic pressure.

The associations of elevated left ventricular (LV) and right ventricular (RV) end-diastolic pressure (EDP) were evaluated in 28 patients with non-ischemic congestive cardiomyopathy. Right-sided endomyocardial biopsies from each patient were evaluated for ATP content, percent fibrosis and myocardial fiber diameter. The resting RVEDP and LVEDP and the post-angiographic LVEDP were correlated with the results from the biopsies. There was a correlation of the LVEDP with the RVEDP (r = 0.67, P less than 0.001) by a linear plot. There was no correlation of any EDP measurement with the percent fibrosis. There was, however, a rough correlation of the myocardial fiber diameter with RVEDP (r = 0.40, P less than 0.05). Myocardial ATP content correlated with the RVEDP (r = -0.53, P less than 0.005), the LVEDP (r = -0.65, P less than 0.001) and the post-angiographic LVEDP (r = -0.72, P less than 0.001). These data demonstrate that an elevated ventricular EDP correlates most closely with depressed levels of myocardial ATP. The myocardial cell diameter correlated less well and there was no correlation of EDP with fibrosis. Metabolic factors may be more important than histologic parameters in the elevated ventricular EDP of non-ischemic congestive cardiomyopathy.

Adenosine Triphosphate↗
PubMed1981

Alterations of circulatory responses to upright tilt in cardiac patients.

Circulatory responses to the upright tilt were studied in 20 normal subjects and 27 cardiac patients with ischemic heart disease or idiopathic cardiomyopathy. In normal subjects, the upright tilt caused obvious increases in heart rate and diastolic pressure, a slight decrease in systolic pressure and marked decreases in cardiac output and stroke volume. The circulatory changes during the tilt were less pronounced in the cardiac patients as compared with the normal subjects. The reductions of cardiac output and stroke volume and the increase in total peripheral resistance were all significantly diminished. A paradoxical increase in cardiac output during the tilt, an observation hitherto not well recognized, was observed in 5 cases with low cardiac index during the control period. Although several possibilities can be considered for the explanation of the diminished, sometimes paradoxical, circulatory responses to the tilt in cardiac patients, the improvement of the function of the diseased heart by preload reduction was proposed as an important factor. There was a significant negative correlation between the per cent changes of cardiac output and the per cent changes of PEP/LVET. It was suggested that the measurements of systolic time intervals during the tilt might be useful for evaluating the severity of the hemodynamic derangement in cardiac patients.

Adolescent↗
PubMed1981

Cardiovascular abnormalities in progeria. Case report and review of the literature.

The cardiovascular findings in cases of progeria are similar in many respects to the changes associated with aging. These changes include prominent atherosclerosis and calcification of the aortic and mitral valves, coronary arteries, and aorta. The coronary artery disease leads to ischemic changes in the myocardium, including well-defined infarcts. In addition, the present case demonstrates narrowing of the small intramural arteries, which may have contributed to myocardial fibrosis.

Adolescent↗