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Biomedical subjects

R Maeda

Publications and source records attributed to R Maeda.

At least 91 records · Page 5Linked to original sources
PubMed1984

Bile acid-induced gastric mucosal injury: significance of portal hypertension and mucosal capillary permeability.

Rats with portal vein occlusion (PVO) were studied to determine severity of taurocholate-induced gastric mucosal injury during portal hypertension and following its resolution by collaterals. During the portal hypertensive state, after intragastric taurocholate, PVO rats compared with sham-operated controls had significantly greater macroscopic damage (14 +/- 1 vs 3 +/- 1% of total mucosa) and histologic deep necrosis (25 +/- 4 vs 3 +/- 1% of mucosal length). Gastric mucosal capillary permeability was also significantly greater in PVO rats, as assessed by increased appearance of intravenous Evans blue dye in gastric wall and contents. After 21 days of PVO portal pressures returned to normal. At this time taurocholate-induced gastric mucosal damage and capillary leak became similar in PVO and sham-operated rats. It is concluded that the portal hypertensive state alone predisposes to severe gastric mucosal damage and capillary leak.

Animals↗
PubMed1984

The gastric mucosa in portal hypertension: effects of topical bile acid.

Clinical observations suggest that patients with portal hypertension are more prone to erosive gastritis. To test this hypothesis we investigated gastric mucosa of rats with portal hypertension (produced by staged portal vein occlusion) and sham-operated controls before and after intragastric taurocholate. Portal pressure was 36 +/- 3 cm saline in portal hypertensive rats compared with 16 +/- 2 cm in controls (P less than 0.01). Before taurocholate no macroscopic or histologic spontaneous mucosal damage was present, but portal hypertensive rats had extensive submucosal edema. Three hours after intragastric taurocholate (2 ml, 80 mM in 0.1 N HCl), macroscopic injury comprised 13.7 +/- 1.1% of mucosal surface in portal hypertensive rats compared with 3.6 +/- 0.6% in controls (P less than 0.01) confirmed also by histologic morphometry. H+ back-diffusion was 402 +/- 40 microEq/h in portal hypertensive rats and 217 +/- 30 microEq/h in controls (P less than 0.01). We conclude taurocholate induced gastric mucosal injury is enhanced by portal hypertension. Greater H+ back-diffusion in portal hypertensive rats suggests increased mucosal permeability contributed by submucosal edema. We confirm quantitatively in an experimental model that portal hypertension predisposes to gastric mucosal injury.

Animals↗
PubMed1983

An autopsy case of 17 alpha-hydroxylase deficiency with malignant hypertension.

This is the first autopsy case of male 17 alpha-hydroxylase deficiency with malignant hypertension. The subject had hypertension, hypokalemic alkalosis, and pseudohermaphroditism. At age 21, 17 alpha-hydroxylase deficiency was diagnosed by low urinary excretion of 17-hydroxysteroids, low secretion rate of cortisol, and low plasma testosterone level in association with high urinary excretion of pregnanediol and high plasma progesterone and corticosterone. Urinary excretion of aldosterone and PRA were suppressed, and plasma ACTH was elevated. Hypertension and hypokalemic alkalosis were normalized with dexamethasone therapy. After missing 5 yr of follow-up, malignant hypertension developed, and PRA and aldosterone were elevated. Histological examination revealed some characteristic arteriolar lesions as in malignant nephrosclerosis. Juxtaglomerular hyperplasia and an increase of renin granules were observed, which reflected high PRA. Abnormal histological findings of endocrine organs were observed in the breast, the pituitary gland, the adrenal glands, and the testis.

Adrenal Hyperplasia, Congenital↗
PubMed1983

Study of atrial contraction in sick sinus syndrome using conventional and esophageal echocardiography.

To evaluate the active systolic function of both atria in sick sinus syndrome (SSS), conventional and esophageal echocardiograms were recorded in 22 normal subjects (Normal), 5 patients (pts) with sinus bradycardia (Group I), 9 with sinoatrial block or sinus arrest (Group II), 10 with bradycardia-tachycardia syndrome (BTS, Group III) and 6 with transient atrial fibrillation (Group IV). Two pts in Group II and 8 in Group III had a history of syncope. Atrial filling fraction obtained by the left ventricular echogram (AFF by LV echo) and posterior wall excursion of the aorta during atrial contraction (Ea) were determined by the conventional echocardiogram. The excursion of the interatrial septum during atrial contraction (Eb) and the dimensional shortening of the right atrium during atrial contraction (Ec) were determined by the esophageal echocardiogram. Results were as follows: AFF was almost the same in Normal, and Group I, II and IV, but it was significantly lower in Group III. AFF was also decreased in 2 pts in Group II who had a history of syncope. Both Ea and Eb in Group III were significantly lower than those in the other groups. Ec was not significantly different among all groups, although one patient in Group III had markedly decreased Ec. There was a significant correlation between Ea and AFF (r = 0.638, p less than 0.001). We conclude that in a number of cases with SSS, especially BTS, left atrial active contraction is significantly impaired in addition to the electrophysiological abnormality.

Adult↗
PubMed1982

Partial purification and characterization of glycylprolyl dipeptidyl aminopeptidase in porcine pancreas.

This study reports the presence of glycylprolyl dipeptidyl aminopeptidase in porcine pancreas, and its partial purification and some properties. Crude enzyme preparation was obtained by extraction from acetone-dried powder of the pancreas at pH 7.6. For solubilization of enzyme, freezing and thawing were carried out. Crude enzyme extract was fractionated with ammonium sulfate precipitation, gel filtration on Sephadex G-200 column and ion-exchange chromatography on DEAE-cellulose. Partially purified enzyme showed 2897-folds purification. The enzyme activity on polyacrylamide gel electrophoresis showed good agreement with a main protein band stained with Coomassie brilliant blue. Molecular weight of this enzyme from the pancreas was estimated to be 300000 by gel filtration on Sephacryl S-300 column. Optimum pH was between 8.5 and 9.0, and Km value for glycylproline-p-nitroanilide tosilate was 0.33 mM. This enzyme from the pancreas was a serine enzyme and was relatively stable to heat at 60 degrees C for 10 min.

Aminopeptidases↗
PubMed1982

[Antibody to 1-24 ACTH and hypofunction of the adrenal cortex in a patient who was unilaterally adrenalectomized for Cushing's syndrome (author's transl)].

We report here on a patient who was unilaterally adrenalectomized for Cushing's syndrome, and who developed antibodies to 1-24 ACTH. A 49-year-old nurse had undergone right adrenalectomy for adrenal adenoma. After surgery, she was treated with 0.5 mg of 1-24 ACTH-Z together with glucocorticoid replacement therapy for 40 days. Thereafter she was given 0.25-0.5 mg of ACTH-Z every other day for 4 months. ACTH-Z was then stopped for a year but glucocorticoid therapy was continued. About one year prior to this admission, 1 mg of ACTH-Z was again initiated 1 to 2 times a week. Glucocorticoid therapy was not withdrawn during the four years after adrenalectomy. She was admitted for the purpose of withdrawal of glucocorticoids. Her serum was found to bind labeled ACTH. This labeled ACTH was competitively displaced from binding by unlabeled hormones. Finally, reaction with specific antihuman Ig demonstrated an antibody of the IgG class. The titer of the antibodies gradually decreased after the discontinuation of ACTH-Z, but it is still present in measurable quantity in her serum. The clinical significance of the circulating anti-ACTH antibody in her serum is discussed.

Adrenal Insufficiency↗
PubMed1981

Biosynthesis of prostaglandins from arachidonic acid by the rat ovary.

Biosynthesis of prostaglandins (PGs) from 14C-arachidonic acid was studied using homogenates of the ovaries from immature rats. In ascending order of metabolizing potency were, the ovaries from untreated rats, from rats treated with pregnant mare's serum gonadotropin (PMS), and from PMS-human chorionic gonadotropin (hCG) treated rats. Among the radioactive metabolites extracted, PGE2 and 6-keto PGF1 were purified and identified by silicic acid column-, thin layer-, reversed phase partition chromatographies, and radiogaschromatography. Production of PGE2 and 6-keto PGF1 was observed in homogenates of the ovaries of intact and PMS-hCG treated rats at conversion rates of 0.72; 0.43% and 7.62; 2.31%, but not by PMS treated rat ovaries. Treatment with PMS-hCG activated metabolism of arachidonic acid into radioactive metabolites including PGE2 and 6-keto PGF1 to a large extent. Accordingly, it is concluded that luteinizing hormone and hCG play a significant role in the biosynthesis of PGs by the rat ovarian follicle.

6-Ketoprostaglandin F1 alpha↗
PubMed1979

[Intracranial hemorrhage in autopsy cases with occlusion of the circle of Willis (author's transl)].

Seventeen autopsy cases with occlusion of the circle of Willis were examined clinicopathologically. These patients ranged in age from 8 years to 64 years and consisted of 6 males and 11 females. The following results were obtained. 1. Fresh and massive intracerebral hemorrhage was confirmed in 13 of 17 patients and cerebral infarct in 4 of 17 patients. 2. Among these 13 patients, massive hemorrhage was found in basal ganglia, thalamus and hypothalamus of 9 patients, and in thalamus, cerebral peduncle and midbrain of 4 patients. 3. Rupture of the dilated muscular-type arteries was noted in the thalamus and basal ganglia in 2 of 13 patients. Ruptured arteries with organization of the lumen were found in the old hemorrhagic foci in one of them. 4. Overgrown and dilated arteries, branching off from the circle of Willis, were confirmed in 11 patients. These arteries consisted of "perforating" arteries well developed as collateral circulation. 5. No ruture in these arteries of the subarachnoidal spaces was found in 11 patients. In one of them, a small saccular aneurysm was found. These findings strongly suggest that in patients with occlusion of the circle of Willis intracerebral rupture of overgrown "perforating" arteries as collateral circulation may be the main cause of intracranial hemorrhage and intracerebral hemorrhage due to rupture of the arteries may be repeated.

Adolescent↗