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Biomedical subjects

H Ashida

Publications and source records attributed to H Ashida.

At least 163 records · Page 9Linked to original sources
PubMed1983

CD-resolved secondary structure of bovine plasma albumin in acid-induced isomerization.

Bovine plasma albumin (BPA) showed the acid-induced two-step transition, the N-F transition and acid-expansion. Changes in fractions of alpha-helix (f alpha), beta-form (f beta) and unordered form (fR) in the acid-induced isomerization of BPA were studied using the method of Chen et al. (1972) with two constraints: sigma fi = 1, 0 less than or equal to fi less than or equal to 1. pH-profiles of f alpha and fR showed the two-step change, one corresponding to the N-F transition and the other to the acid-expansion in 0.10 M KCl and in 0.02 M NaClO4. pH-profile of f beta showed one-step change, correlating to the later part (lower pH side) of the N-F transition. The N-F transition might thus involve the helix leads to beta and helix leads to coil transitions.

Animals↗
PubMed1983

Cation transport of red blood cells from hypertensive patients in Japan.

This study was performed to determine whether there is any difference in cation transport of red blood cells from normotensive subjects and hypertensive patients in Japan. Net Na+ efflux and net K+ influx rates were measured in sodium-loaded red cells from 19 normotensive subjects, 22 essential hypertensive patients, and 8 secondary hypertensive patients. The ratio of Na+/K+ net fluxes and the net cation flux rate were compared between these groups. The ratio of Na+/K+ net fluxes was significantly lower in essential hypertensive patients than in normotensive subjects. Parameters such as age, sex, blood pressure, plasma renin activity, and plasma aldosterone concentration were also examined in 2 groups of essential hypertensive patients, divided on the basis of their Na+/K+ net fluxes. However, there is no significant difference between the groups. These results suggest that the ratio of cation flux is related to hypertension independently of these parameters.

Adolescent↗
PubMed1982

Effects of Ca ions on action potentials in immature cultured neurons from chick cerebral cortex.

Action potentials evoked by depolarizing pulses were studied in immature cultured cerebral cortical neurons from chick embryos. The majority of action potentials were rather small, and they were still elicited in the presence of 10(-7) gm/ml tetrodotoxin (TTX), but were almost completely abolished in NA+-free solution or by 10(-5) gm/ml TTX in Tyrode's solution. The elevation of external Ca2+ concentration not only increased the maximum rates of rise of action potentials in normal Tyrode's solution with and without low (10(-7) gm/ml) TTX but also regenerated action potentials in high (10(-5) gm/ml) TTX-containing Tyrode's solution or in Na+-free solution. These high Ca2+ effects were blocked by Mn2+ or Co2+. These results suggest that action potentials, which were predominantly Na-dependent, are partially contributed by Ca ions in immature chick cerebral cortical neurons.

Action Potentials↗
PubMedDate not supplied

Acute mesenteric ischemia. CT and plain radiographic analysis of 26 cases.

The purpose of this study was to assess the computed tomography (CT) and plain radiographic findings of acute mesenteric ischemia, in an effort to elucidate its poor prognostic signs. The study group consisted of 26 cases with pathologically or angiographically proven mesenteric ischemia. The pathologically proven longitudinal extent of the bowel ischemia was graded using six degrees, and correlated with the radiographic findings. The mortality of the patients depended primarily on the extent of infarctions and the age of the patient. Patients with bowel dilation or abnormal gas in the bowel wall or portal system were prone to have wider extents of ischemia.

Acute Disease↗
PubMedDate not supplied

CT appearance of implanted esophageal stents.

Three different types of esophageal stents, the Z-stent, Ultraflex, and Wall-stent, exhibit different shapes on CT, which may suggest a difference in the radial forces applied by each of the stents. CT is useful for displaying the relationship between an esophageal stent and adjacent structures and complications.

Esophageal Neoplasms↗