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Biomedical subjects

H Uematsu

Publications and source records attributed to H Uematsu.

At least 91 records · Page 5Linked to original sources
PubMed1983

Distribution of abnormal Q waves on body surface in relation to left ventricular wall motion abnormalities in myocardial infarction.

This study was undertaken to determine the possible one-to-one relationship between each site of asynergy of the left ventricle and the body surface area to which ensuing abnormal electrical phenomena are reflected. In 140 post-myocardial infarction (MI) patients, distribution of abnormal Q waves on the body surface was correlated with the abnormal segments of LV wall motion identified by left ventriculography (LVG). Unipolar lead electrocardiograms (ECGs) were recorded from 87 lead points over the precordium and the back with Wilson's central terminal as the reference point. Data acquisition and mapping was accomplished through a mapping system HPM 5100 microcomputer. In all cases, coronary arteriography (CAG) and LVG were performed at least 2 months after the acute episode of MI. The LVG findings were evaluated separately in seven wall segments in accordance with the American Heart Association (AHA) reporting system. Sensitivity, specificity, diagnostic accuracy, positive predictive value, and negative predictive value of the abnormal Q wave in each lead point were obtained in cases with abnormal wall motion in segments 2, 3, and 6, respectively, and in infero-posterior segments 4 or 5. Statistical analysis was performed by comparing two groups of patients with or without asynergy of each wall segment concerned. Results of the study revealed some abnormal Q areas of high diagnostic accuracy that correlated highly with the site of abnormal contractility.

Journal Article↗
PubMed1982

The role of macrophages in demyelination in experimental allergic neuritis.

The role of macrophages and serum factors in demyelination in experimental allergic neuritis (EAN) was examined by a simple in vitro method. Cultivated rabbit peritoneal macrophages, preincubated with serum obtained from rabbit EAN produced by sensitization with bovine spinal nerve roots, could agglutinate and phagocytize purified bovine or rabbit peripheral nerve myelin. Sera from normal animals or from controls given adjuvant alone could not. Adhesion and phagocytosis were inhibited if EAN sera were absorbed with peripheral nerve myelin. Rabbit red blood cells were not phagocytized by macrophages exposed to EAN serum. Concomitant to these observations, three lysosomal acid hydrolases: acid proteinase, acid phosphatase and beta-glucuronidase, were assayed with respect to their topographical and chronological distribution. In the group examined at clinical onset, increases in the specific activities were 1.5-3.0-fold in the spinal roots and 1.0-1.5-fold in the sciatic nerves compared with control. The degree of increase in total activities per whole root or sciatic nerve was much higher for specific activities. The topographical distribution of the increase closely corresponded to the histological distribution of EAN lesions. These observations suggested that the increased lysosomal activity originated from lysosomal-rich infiltrating cells. These observations strongly indicated the significant role of macrophages activated by EAN serum in the demyelination of EAN.

Acid Phosphatase↗
PubMed1982

Electron microscopic visualization of cathepsin D using mercury-labeled pepstatin as an enzyme inhibitor.

Pepstatin, a specific inhibitor of pepsin, cathepsin D (E), renin, etc., was used in a new method to demonstrate the sites of enzymes. Pepstatin (Pst) was covalently attached to glutathione (GSH), using a dicyclohexylcarbodiimide, and CH3Hg+ was then put in the residue of SH for electron microscopic observation. Pst-GS-HgCH3 thus obtained was nonisotopical, had a very low molecular weight (about 1,200 daltons), and still almost completely retained its inhibitory activity. Sections of rat liver (less than 1 mm3 thick), prefixed by glutaraldehyde, were incubated in the prepared reaction medium. Cathepsin D, located in the lysosomes, was demonstrated by this compound, but when the sections were preincubated with pepstatin, this was not the case. These results demonstrate that mercury-labeled pepstatin is a useful reagent for the histochemical staining of acid proteases for electron microscope.

Animals↗
PubMed1981

Identification of the site of origin of ventricular premature beats and its activation sequence by body surface isopotential map.

To determine the more exact site of origin of ventricular premature beats (VPBs), body surface maps were recorded in 28 patients, aged 15 to 71 years (mean 52) with no cardiac disorders. The site of origin of VPBs was determined from 1) sequential isopotential maps, 2) ventricular activation time (VAT) map and 3) on the basis of maps during pacemaker stimulation at different ventricular areas. To get a three dimensional idea regarding the progression of the ventricular activation front, zero plane was constructed in the human torso by supposing the plane which includes zero potential line on body surface at each instance of ventricular activation. Unipolar lead electrocardiograms were recorded from 85 lead points over the body surface to obtain maps. The site of origin was determined to be from right ventricle in 15 patients, from top of interventricular septum in 10 patients, and from left ventricle in 3 patients. Of 15 patients with right ventricular premature beats, 3 were from outflow region, 4 were from posterobasal region, 6 were from inflow region and 2 were from apical region. Of 3 patients with left ventricular premature beats, 2 were from posterobasal region and 1 was from high lateral region.

Adolescent↗
PubMed1980

Increase in the susceptibility of hemoglobin to trypsin on treatment with glutathione or cysteine.

1. Native human hemoglobin A was digested with proteases after treatment with reduced or oxidized glutathione, cysteine, or cystine. 2. The treatment of hemoglobin with a 40-fold molar excess of reduced glutathione or cysteine at 37 degrees C for 4 enhanced its susceptibility to trypsin 4 or 6 times, respectively. However, oxidized glutathione and cystine had little or no effect on its susceptibility to the protease. 3. The enhanced susceptibility was not due to conformational change in hemoglobin, such as dissociation to dimers or monomers, or to unfolding of alpha-helical structure, but was due to dissociation of heme from the globin moiety, judging from measurements of the absorption spectrum and circular dichroism spectrum, and gel-filtration analysis.

Binding Sites↗
PubMed1980

Diagnostic value of body surface map in myocardial infarction: assessment of location, size and ejection fraction as compared with coronary cineangiography and 201Tl myocardial scintigraphy.

The diagnosis of the location and size of old myocardial infarction was made by the map and various indices obtained from the map were correlated with coronary arteriography, left ventriculography, and 201Tl myocardial scintigraphy. Diseased coronary arteries were presumed from Q30, Q40 area and/or peak voltage map and left ventricular wall motion was estimated from subtraction map. There were significant correlations between ejection fraction and sigma R in anterolateral MI (r = 0.51, p less than 0.001) and between ejection fraction and nQ30 in anterolateral (r = -0.47, p less than 0.001) and inferoposterior (r = -0.63, p less than 0.01) MI. Negative correlation was observed between myocardial uptake ratio (MUR) and nQ30 (r = -0.69, p less than 0.001) and positive correlation between MUR and sigma R (r = 0.50 p less than 0.01) in anterolateral MI. Those cases which could not be diagnosed by either ECG or 201Tl scintigraphy were correctly diagnosed by the map and it proved to have an excellent diagnostic accuracy for myocardial infarction.

Adult↗
PubMed1979

Limited proteolysis of p-chloromercuribenzoate-dissociated hemoglobin by trypsin.

p-Chloromercuribenzoate-treated hemoglobin was digested by trypsin. The hydrolysate was subjected to gel-filtration on Bio-Gel P-4 and Sephadex G-50 columns, ion-exchange chromatography on CM-Sephadex and DE 52 columns, and paper electrophoresis. Peptides obtained by this procedure were analyzed for amino acid compositions and amino-terminal amino acid sequences. The results showed that p-chloromercuribenzoate-treated hemoglobin was hydrolyzed to a limited extent by trypsin at the bonds involving the carboxyl group of a lysine or arginine residue in planes A--E in the parent hemoglobin, which represent the external region of the parent tetramer. It is concluded therefore that the slight modification of hemoglobin enhances the susceptibility of the protein to proteases and that the hydrolysis of the modified protein is limited.

Amino Acid Sequence↗