Biomedical subjects
Publications and source records attributed to M Okada.
Dissecting aneurysm of the left atrium is extremely rare. A patient with such an aneurysm, which developed after mitral valve replacement is described. The diagnosis was established by cineventriculography of the left ventricle and two-dimensional echocardiography. The aneurysm was successfully treated by closure of the communicating opening through the left thoracotomy incision.
Gastroduodenoscopy was performed in 25 patients with various disorders, such as liver cirrhosis, nephrotic syndrome, and ulcerative colitis, to assess the effects of corticosteroids on the stomach and duodenum. The main criterion for entry into the trial was the absence of open ulcer, healed ulcer, erosion, or bleeding from the stomach or duodenum on pretreatment endoscopy performed within 48 hours before administration of corticosteroids. Endoscopy repeated at 2 to 4 weeks disclosed gastroduodenal lesions in 11 cases (44%)and no lesion in 14 cases (56%). The gastroduodenal lesions observed in 11 cases are as follows: one gastric ulcer (4.0%), six gastric erosions (24.0%), two gastroduodenal erosions (8.0%), and two duodenal erosions (8.0%). A lack of correlation between the patients' subjective complaints and endoscopic findings indicates the unreliability of patients' complaints and the importance of endoscopy in assessing gastroduodenal lesions. There were no differences in the total and average daily doses of corticosteroid between a group with gastric and/ or duodenal lesions and a group without such lesions. Corticosteroids may produce gastroduodenal lesions, regardless of the dose.
The properties of crude and purified mitochondrial aspartate aminotransferase preparations from pyridoxine-deficient and control rat livers were compared. The preparations from the two sources showed very similar behaviors on heat treatment, electrophoresis and chromatofocusing, and had similar molecular weights, but their visible absorption spectra and circular dichroism properties were different. These results suggest that mitochondrial aspartate aminotransferase from pyridoxine-deficient and control rat livers have very similar properties, but differ somewhat in conformation in the region of the pyridoxal phosphate binding site.
myo-Inositol-1-phosphatase [EC 3.1.3.25] was purified from a cytosolic fraction of rat brain. The purified enzyme appeared homogeneous on SDS-polyacrylamide gel electrophoresis and its molecular weight was estimated to be 29,000. The molecular weight of the native enzyme was 55,000 as determined by molecular sieve chromatography. These values indicated that the native enzyme was composed of two identical subunits. The isoelectric point of the enzyme was 4.6. The enzyme hydrolyzed inositol-1-phosphate, 2'-AMP, 2'-GMP, beta-glycerophosphate, and alpha-glycerophosphate; the ratio of the reaction rates was 100 : 84 : 73 : 64 : 32. The Km values for inositol-1-phosphate, 2'-AMP, and beta-glycerophosphate were 1.2 X 10(-4) M, 1.9 X 10(-4) M, and 7.7 X 10(-4) M, respectively. Mn2+ and Ca2+ were strong competitive inhibitors against Mg2+, with Ki values of 3 microM and 20 microM, respectively. This result suggests that myo-inositol-1-phosphatase might be regulated by intracellular Ca2+ and/or Mn2+. Li+, which is known to show a therapeutic effect on manic-depressive disease and also to prolong the intrinsic periods of circadian rhythms in various organisms, was a potent uncompetitive inhibitor and inhibited 50% of the activity at 1 mM. The possibility that myo-inositol-1-phosphatase and inositol phospholipid metabolism are involved in circadian rhythm oscillation is discussed in terms of Li actions.
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We report two cases of ataxia telangiectasia in which a small number of T cells and a slightly diminished response to phytohaemagglutinin or concanavalin A were observed. In one case, serum IgA was undetectable. In spite of T and/or B cell involvement, natural killer activity and the percentage of natural killer cells determined by monoclonal antibodies Leu 7 were normal in both cases.
Ovalbumin was modified with alpha,beta-poly[(2-hydroxyethyl)-DL-aspartamide] which had been developed as a nontoxic plasma expander. Preadministration of the modified ovalbumin suppressed both primary and secondary anti-ovalbumin IgE responses.
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Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. A qualitative analysis was performed from five projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in the LV posterolateral or posterior wall (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle involvements or thoracic deformities assessed by transmission computed tomography. Extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. Progression of the myocardial scintigraphic abnormalities were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies over 2 to 3 years. It was concluded that thallium myocardial perfusion imaging is a useful clinical technique to assess myocardial involvement in Duchenne's progressive muscular dystrophy.
Pleomorphic adenoma of rat salivary gland is extremely rare, and culture of cells obtained from rat salivary gland tumors has not been reported. We have established a long-term cell line from a pleomorphic adenoma of a Sprague-Dawley rat submaxillary gland. The pleomorphic adenoma was composed of oval or spindle-shaped cells occasionally forming a small duct. Alcian blue-positive intercellular matrices, consisting mainly of glycosaminoglycans, were abundant. The cultured cells showed characteristics similar to those of the original tumor. This cell line should be useful for biological and biochemical studies of glycosaminoglycan-synthesis of pleomorphic adenoma cells.
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The effects of pyridoxine and hydrocortisone administrations on the rate of synthesis of cytosolic aspartate aminotransferase in adrenalectomized pyridoxine-deficient rat livers were examined. Induction of cytosolic aspartate aminotransferase by hydrocortisone was observed 6 to 10 h after the injection. Treatment with pyridoxine daily for 6 days but not for the 2 days, resulted in suppression of the enzyme synthesis. Similar suppression of enzyme synthesis was observed in rats without hydrocortisone treatment. The activity of tryptophan oxygenase, which is known to be induced by glucocorticoid and does not contain pyridoxal phosphates, was higher in the livers of pyridoxine-deficient rats than in that of controls. The possible effects of pyridoxal phosphate on the action of glucocorticoid are discussed based on the results.
The hepatic and renal activities of ornithine aminotransferase (OAT) [L-ornithine 2-oxoacid aminotransferase, EC 2.6.1.13] were determined in male and female rats given diet with or without pyridoxine. OAT activities were measured in the presence of pyridoxal phosphate. Diet without pyridoxine caused a decrease in hepatic OAT activity in males and no change in females and an increase in renal OAT activity in males and a decrease in females. The increased renal OAT activity in males was associated with increased immunochemically recognizable OAT, and was due to increased synthesis of OAT as shown by measurement of [3H]leucine incorporation in vivo. Thus OAT is regulated by nutritional conditions in different ways in liver and kidney.
The usefulness of multigated cardiac blood pool imaging in evaluating left ventricular function and ventricular activation was studied in patients with cardiac arrhythmias. Subjects consisted of 12 patients with the Wolff-Parkinson-White (WPW) syndrome; 20 with ventricular premature contractions (VPC); 21 with various modes of artificial pacemakers; and two normal controls. Phase analysis was useful in localizing the bypass tract in patients with the WPW syndrome. In four patients with the WPW syndrome and five with VVI pacing, the phase difference between the posterolateral wall of the left ventricle (LV) and the right ventricular apex correlated significantly with the activation time difference between these two regions as assessed by endocardial electrograms (r = 0.94, p less than 0.001). Images of VPC were obtained using the bad beat rejection program in an ADAC computer system. The origin of VPCs evaluated by phase image coincided with results of standard 12-lead electrograms. It was in the right ventricle in four patients, the LV in one, and probably in the interventricular septum in one. The LV ejection fraction (LVEF) decreased significantly (p less than 0.001) after the injection of lidocaine (-3.7%) or disopyramide (-6.2%). The percent reduction in LVEF was significantly greater with disopyramide than with lidocaine (-15.1 vs -11.2%). The plasma concentration of disopyramide was higher in four patients with organic heart diseases than in 11 without. There was a significant correlation between the percent reduction in LVEF and the disopyramide plasma concentrations (r = -0.62, p less than 0.001). The influence of the pacing mode and exercise on LV function was studied in 21 patients with artificial pacemakers. In the VDD and DDD modes, end-diastolic volume (EDV) and cardiac output (CO) decreased after converting to VVI mode. CO increased markedly to approximately 250% of the control value in the VDD and DDD, and moderately in the VVI and AAI modes during ergometer exercise. In conclusion, multigated cardiac pool imaging is considered useful in diagnosing and managing patients with cardiac arrhythmias.
Interleukin 2 (IL 2) receptor (IL 2-R) is constitutively expressed on T cell lines established from the patients with adult T cell leukemia (ATL), which is a human T cell leukemia lymphoma virus (HTLV-1)(+) T4(+)-leukemia endemic in Japan, the United States, and other countries. Many of these cell lines continuously produce an acidic lymphokine, ATL-derived factor (ADF), which preferentially induces the synthesis and expression of IL 2-R on a sensitive HTLV-1(-) non-T cell line (YT). The induced IL 2-R was characterized by the binding of 125I-IL 2 and flow cytometry by using fluoresceinated anti-human IL 2-R monoclonal antibodies (anti-Tac). Scatchard analysis with 125I-IL 2 showed ADF induced high-affinity receptor sites on YT cells. To test the possibility that ADF produced by HTLV-1(+) T cells is involved in the abnormal expression of IL 2-R, we studied the effect of ADF on an HTLV-1(+) IL 2-dependent T cell line (ED) in which the beta-chain gene of the T cell antigen receptor (T beta) was rearranged. Unlike IL 2-independent HTLV-1(+) cell lines that constitutively expressed Il 2-R, the IL 2-R expression on ED cells declined in the absence of crude IL 2 or recombinant IL 2. When either ADF or recombinant IL 2 was added to the culture of ED cells, there was a dose-dependent enhancement of IL 2-R expression in 24 hr. ADF and IL 2 showed a synergism in the IL 2-R induction, and both factors were needed to induce the maximal receptor expression in these T cells. The lack of IL 2 production by ADF-treated YT, as well as ED cell line suggested IL 2 may not be involved in the IL 2-R induction by ADF. Northern blot hybridization with human IL 2-R cDNA probe showed the increase of IL 2-R mRNA in YT cells after ADF-treatment. ADF also enhanced IL 2-R expression of a rat T cell line transformed by HTLV-1(TARS-1), as demonstrated with anti-rat IL 2 receptor monoclonal antibodies (ART-18). An ADF-like IL 2-R-inducing factor was also detected in the conditioned medium of two HTLV-1(+) rat T cell lines (TARL-2 and TART-1), which constitutively expressed a higher number of Il 2-R than TARS-1 cells.(ABSTRACT TRUNCATED AT 400 WORDS)