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Biomedical subjects

T Okada

Publications and source records attributed to T Okada.

At least 1,009 records · Page 56Linked to original sources
PubMed1985

Chlorambucil central nervous toxicity: a significant side effect of chlorambucil therapy in childhood nephrotic syndrome.

Chlorambucil (CHL) was used in combination with prednisolone in the treatment of nine children with frequently relapsing nephrotic syndrome. Serial electroencephalograms were obtained to evaluate CHL central nervous toxicity, before, during and after treatment with this agent. EEG abnormalities were observed in two of the nine children during chlorambucil therapy. EEG changes were diffuse spike and wave complexes and disappeared after discontinuation of therapy. There were no other neurological abnormalities and more particularly, no seizures or myocloni were observed. According to the literature, chlorambucil central nervous toxicity is found almost exclusively in childhood nephrotic syndrome. Strict neurological supervision of patients treated with chlorambucil is recommended.

Brain↗
PubMed1985

Effects of dexamethasone on metallothionein induction by Zn, Cu, and Cd in Chang liver cells.

Metallothioneins (MTs) were induced in Chang liver cells by the metals, Zn, Cu and Cd, and the glucocorticoid hormone, dexamethasone. When 116 microM Zn, 32 microM Cu and 18 microM Cd, and 10(-7) M dexamethasone, respectively, were administered for 9 h, MTs induced by each inducer in the cells reached maximum levels. The maximum accumulation of MT level induced by dexamethasone was the lowest of the four inducers investigated; the levels induced by Zn, Cu and Cd were 4.7, 1.2 and 1.5 times of that induced by dexamethasone. When dexamethasone was added to the cells together with the heavy metals (Zn, Cu and Cd), dexamethasone had an additive effect on the maximum MT accumulations induced by heavy metals as compared to when induction was conducted using one of heavy metals alone or by dexamethasone alone. However, dexamethasone did almost not effect the metal accumulations in the cells, although the maximum MT levels induced by heavy metal increased by dexamethasone. These results suggest that the process of MT induction by heavy metals and that by dexamethasone are independent of one another. When dexamethasone was added to the cells together with a high concentration of Cu (32 microM) induced the maximum MT accumulation, Cu transport into the cells decreased by 20-40% of that into non-treated cells, which was statistically significant.

Adult↗
PubMed1985

Myocardial ischaemia produced by ergonovine-induced vasoconstriction during preexisting coronary stenosis: experimental conditions for the geometric theory.

Experiments were designed to determine the contribution of active vasomotor tone of a large coronary artery during a preexisting coronary stenosis to the production of myocardial ischaemia. The quantitative relations between ergonovine dose and systemic and coronary haemodynamic and electrocardiographic responses during various degrees of coronary stenosis were evaluated in 55 anaesthetised open-chest dogs. In the absence of coronary stenosis, intracoronary infusion of ergonovine (0.04 to 4 micrograms X min-1) had no systemic or coronary haemodynamic effects. In dogs with coronary stenosis created with intraluminal microballoon occluder, ergonovine produced marked decreases in coronary blood flow and distal coronary pressure followed by a decline in left ventricular dP/dt and ST-elevation in epicardial electrogram in the presence of moderate (28 +/- 1.1 mmHg in pressure gradient) and severe (41 +/- 1.4 mmHg), but not mild (15 +/- 0.9 mmHg) stenosis. These detrimental effects of ergonovine were dependent on its dose as well as the severity of preexisting coronary stenosis. Interventions such as aspirin pretreatment or endothelial denudation did not attenuate the coronary vasomotor response or ergonovine, but pretreatment with nifedipine (3 micrograms X kg-1 iv) prevented this response. Intravenous injection of ergonovine (4 to 15 micrograms X kg-1) in doses relevant to clinical usage during intraluminal obstruction resulted in similar changes in coronary haemodynamics as those of intracoronary ergonovine. In contrast, in dogs with various degrees of coronary stenosis produced with an externally applied constrictor device, ergonovine did not affect systemic and coronary haemodynamics. These experiments demonstrate that normal vasomotion superimposed on moderate and severe pliable coronary stenosis can cause transient myocardial ischaemia, which helps to clarify the conditions to produce myocardial ischaemia according to geometric theory.

Animals↗
PubMed1985

Comparison of the amino acid sequences of hen plasma-, yolk-, and white-riboflavin binding proteins.

The amino acid sequence of hen egg yolk-riboflavin binding protein (yolk-RBP) was determined by conventional methods. The sequence was identical with that of hen egg white-riboflavin binding protein except that their carboxyltermini were different, that of yolk-RBP lacked 11 or 13 amino acid residues, while hen plasma-RBP had the same C-terminal sequence as white-RBP. This indicated that the C-terminal 11 or 13 amino acid residues in plasma-RBP might be cleaved off during the incorporation from the blood into the oocyte or in the yolk fluid. Yolk-RBP had the same characteristics as white-RBP, such as N-terminal pyroglutamic acid, polymorphism in the amino acid sequence (Lys/Asn) at the fourteenth residue from the N-terminal end, carbohydrate chains attached to both Asn(36) and Asn(147) residues, and phosphate groups bound to some serine residues in the sequence of Ser(185) to Ser(197) as a cluster. These results led us to the conclusion that yolk- and white-RBPs are bio-synthesized from the same gene in the different organs (liver and oviduct). The carbohydrate composition of yolk-RBP was identical to that of plasma-RBP but different from that of white-RBP showing that the processing of the carbohydrate chains in the liver was different from that in the oviduct.

Amino Acid Sequence↗
PubMed1985

Anti-tumor activity of 1-acetyl-3-o-toluyl-5-fluorouracil against murine hepatoma MH134 and its effects on tissue weights following subcutaneous and oral administration.

Anti-tumor activity of 1-acetyl-3-o-toluyl-5-fluorouracil (A-OT) against MH134 solid tumors in mice was studied following subcutaneous and oral administration and compared with that of 5-fluorouracil (5-FU) administered subcutaneously at doses of 0.2, 0.4 and 0.6 mmol/kg/d. Oral administration of A-OT demonstrated a remarkable effect on MH134 solid tumors, the effect being more marked than that of subcutaneous administration of A-OT. Anti-tumor activity of oral administration of A-OT at a dose of 0.2 mmol/kg/d was comparable to that of subcutaneous administration of 5-FU at the same dose. The level of decrease in thymus weight and the magnitude of increase of spleen weight following oral administration of A-OT at any dose were smaller than those by subcutaneous administration of 5-FU (0.2 mmol/kg/d).

Administration, Oral↗
PubMed1985

Revascularization of the anterior cerebral artery. Report of two cases.

Intracranial anastomosis between the distal anterior cerebral arteries (ACA's) was performed on two patients. One patient had isolated occlusion of the proximal ACA on one side causing monoparesis in the leg, and the other patient suffered from occlusion of the internal carotid artery and a small anterior communicating artery. The weakness of the legs improved immediately after surgery and cerebral angiography revealed a good filling of the bilateral ACA's. Technical aspects and indications for the procedure are discussed.

Arterial Occlusive Diseases↗
PubMed1985

Increase of mast cells in the alopecia lesion of mice.

A histological investigation was made of the quantitative behavior of mast cells in bald areas on mice and in human alopecia areata. C57BL,W/Wv and +/+ mice with alopecia lesions were examined. In C57BL mice and +/+ mice, the number of dermal mast cells (per square mm) in the bald areas was greater than that in controls. The mean number of mast cells was slightly higher in human alopecia areata than in the controls. Since W/Wv mice lacking mast cells developed alopecia lesions, it seems that mast cells are not necessary for the onset of alopecia areata but could play some part in regrowth.

Alopecia Areata↗
PubMed1985

Results of prifinium bromide therapy in irritable bowel syndrome.

An open clinical trial with prifinium bromide, an anticholinergic agent, was carried out in 21 patients with irritable bowel syndrome showing clear psychosomatic characteristics. The clinical efficacy was evaluated by comparing the symptomatic severity before, during, and after treatment with prifinium bromide, 90 mg/day for four weeks. Of these 21 patients, 18 patients were allowed to take antacids or lactobacillus preparations concomitantly only when necessary. As a result, marked or moderate improvement in symptoms such as diarrhea and constipation was seen in 43% after two weeks and 86% after four weeks. Prifinium bromide's efficacy in the treatment of abnormal bowel movements was most evident in patients with diarrhea and slightly less evident in patients with alternation of diarrhea and constipation, and in constipated patients. Side effects attributable to the drug were encountered in four (19%) of the patients. None were serious enough to require that use of the drug be discontinued. All laboratory test values were within normal ranges before and after therapy. Overall, prifinium bromide was judged to be useful in 14 (67%) of the 21 patients studied.

Aged↗
PubMed1985

Ultracytochemical study of the stria vascularis of the guinea pig cochlea.

The localization of the K-NPPase, ALPase and Mg-ATPase activities in the stria vascularis of the guinea pig cochlea was ultracytochemically studied. The K-NPPase reflecting the Na-K-ATPase activity was localized on the cytoplasmic side of the deeply infolded basolateral plasma membrane of the marginal cells. On the other hand, activities of ALPase and Mg-ATPase were found in the intercellular spaces between the marginal and the intermediate or the basal cells. The surface of the stria vascularis facing to endolymph showed only the Mg-ATPase activity. The ALPase activity localized also around the capillaries. The mechanism of the K and Na transport was discussed.

4-Nitrophenylphosphatase↗