Search PubMed⌕ Search

Biomedical subjects

M Usami

Publications and source records attributed to M Usami.

At least 289 records · Page 16Linked to original sources

Effect of acetylsalicylic acid on blood glucose and glucose regulatory hormones in mild diabetes.

In order to investigate the effect of acetylsalicylic acid (ASA) on glucose tolerance and glucose regulatory hormones, ASA was given to 14 diabetic patients for seven days by two different methods. A 50 g oral glucose tolerance test (OGTT) was performed before and after the treatment. Nine of 14 diabetics received a dosage of 1.5 g of ASA three times a day for seven days plus 1.5 g on the eighth day one hr before the test (group I). The other 5 patients had the same dosage of ASA as group I, but were not administered ASA prior to the second OGTT (group II). In group I the ASA treatment improved the glucose tolerance associated with sustained rise of plasma insulin significantly, whereas no significant change in glucose tolerance or plasma insulin was observed in group II compared the pretreatment level. The ASA had no significant effect on plasma glucagon or gastric inhibitory polypeptide in either group I or group II. These results suggest that ASA allievates glucose intolerance in maturity onset diabetics by a direct enhancement of insulin secretion, and, moreover, that it is important to maintain elevated ASA concentrations in their blood.

Adult↗

Effects of high protein diet on insulin and glucagon secretion in normal rats.

The effects of a high protein diet on blood glucose, insulin, and glucagon secretion was studied in the peripheral blood and isolated perfused pancreas of normal rats. A balanced diet (protein 27%, carbohydrate 61%, fat 12%) and a high protein diet (protein 55%, carbohydrate 30%, fat 15%) were given ad libitum to normal rats for 2 weeks. No significant difference in calorie intake or body weight changes were observed between the two groups. Fasting blood glucose and plasma insulin concentrations in rats fed the high protein diet were significantly higher than those in rats fed the balanced diet. The fasting plasma glucagon concentration, however, was the same in both groups. In the isolated perfused pancreas, the arginine-induced insulin secretion in rats fed the high protein diet was significantly higher than that in rats fed the balanced diet, whereas the arginine-induced glucagon secretion was not different in either group. The possible mechanism by which a high protein diet causes hypersecretion of insulin in vivo and in vitro are discussed.

Animals↗

Further studies on the mechanism of phosphorylase activation in rabbit liver in response to splanchnic nerve stimulation.

1. The mechanism of activation of liver phosphorylase after splanchnic nerve stimulation has been investigated in rabbits and compared with the effects of intraportal injections of noradrenaline.2. The increase in the activity of liver phosphorylase-a, the active form of this key glycogenolytic enzyme, in response to injections of noradrenaline was blocked by beta-adrenergic antagonists, but not by alpha-adrenergic antagonists, suggesting that the effect of noradrenaline is mediated mainly through beta-adrenoceptors in vivo. In contrast, the increase in phosphorylase activity in response to stimulation of the peripheral end of the splanchnic nerve was resistant to both alpha- and beta-adrenoceptor blockade.3. When diltiazem and verapamil, selective Ca(2+) antagonists that restrict calcium influx across the cell membrane, were infused intraportally, the phosphorylase response to splanchnic nerve stimulation was virtually abolished, while the response to noradrenaline was unaltered.4. Infusion of the prostaglandin-synthesis inhibitor indomethacin at a dose of 3.4 mug/min was found to block the activation of liver phosphorylase in response to stimulation of the splanchnic innervation.5. These results suggest that the mechanism whereby stimulation of the sympathetic innervation to the liver leads to activation of phosphorylase is not mediated by either alpha- or beta-adrenoceptors, but appears to depend upon prostaglandin formation and influx of Ca(2+) ions into the hepatocytes.

Adrenergic alpha-Antagonists↗

[Clinical application of futraful suppositories in malignant head and neck cancer--effects of the therapy combined with radiation].

Futraful suppository 1.5 g per day was administered to 33 patients with head and neck malignancies. Among 33 cases which entered into the study, 16 cases were evaluated. Out of 16 evaluable cases, complete responses (CRs) were obtained in 4 cases and partial responses (PRs) in 7 cases, an overall response rate including 4 CRs and 7 PRs was 68.8%. Side effects due to FT-207 suppository were developed in 14 cases out of 33 patients (42.4%). Side effects such as anal pain, anorexia, diarrhea, pigmentation, exanthema and nail change were observed. No severe side effect was encountered.

Aged↗

Total retropubic prostatectomy for carcinoma of the prostate.

Total prostatectomy is an effective mode of therapy for early carcinoma of the prostate. This report deals with 74 patients who underwent total retropubic prostatectomy at our hospitals during a 23-year period. The 5-year survival rates of patients with stages A and B, C, and D carcinomas were 84.1, 40.1, and 12.7% respectively. The total 5-year survival rate was 56.1%. The 10-year survival rates compare favorably with those of any other mode of therapy. The histological grade was highly significant with respect to prognosis. Combined orchiectomy with total prostatectomy was effective. Operative mortality was 4.05% (3 patients), and the main complication was incontinence. We strongly believe that total prostatectomy is the only curative treatment for early carcinoma of the prostate. This procedure should be utilized more frequently.

Aged↗

Noninvasive detection of coronary artery disease by myocardial imaging with thallium-201--the significance of pharmacologic interventions.

We obtained myocardial imaging with Tl during pharmacologic interventions. Dipyridamole-loading myocardial imaging was performed in 38 patients with CAD. The diagnostic accuracy of this method was 66%. The combination of dipyridamole-loading and exercise stress myocardial imaging increased the diagnostic sensitivity of CAD from 71% (exercise stress imaging only) to 87%. In addition, dipyridamole-loading myocardial imaging was useful for the diagnosis of CAD in patients who could not perform exercise stress test. Chest pain and ST-segment depression were induced less often during dipyridamole administration than exercise stress test. Animal experiments showed that dipyridamole caused abnormalities in myocardial blood flow and myocardial Tl uptake distal to the critical coronary stenosis. And dipyridamole increased myocardial blood flow by 142% and myocardial Tl concentration by 62% in the normally perfused myocardial segments. Ergonovine-loading myocardial imaging was performed in 8 patients with resting angina and without significant coronary stenosis. And in all of them, ergonovine induced cold-spots on myocardial imaging with or without chest pain and ST-segment shift. Ergonovine-loading myocardial imaging was useful for the diagnosis of angina induced by coronary artery spasm. The combination of initial and delayed resting myocardial imaging was useful to differentiate the underperfused but viable myocardium from the scar. And by comparing with radionuclide angiography obtained before and after NTG administration, NTG-loading myocardial imaging and ECG findings in 20 patients with CAD, we demonstrated that the transient defective myocardial segments were underperfused but viable.

Adult↗

Regulation of liver phosphorylase phosphatase by glutathione disulfide.

The mechanism of inactivation of rabbit liver phosphorylase phosphatase by glutathione disulfide (GSSG) was investigated. The catalytic subunit of phosphorylase phosphatase was inactivated by GSSG and other disulfides. Inactivation by GSSG was a concentration-dependent process and resulted in the formation of an inactive, stable enzyme species. The inactivated enzyme could be reactivated by addition of various sulfhydryl compounds, including glutathione (GSH). Homogeneous phosphorylase phosphatase contains, per mol of catalytic subunit (Mr = 33,000), two sulfhydryl groups, one of which reacted with GSSG to form inactive enzyme. Binding studies with [glycine-2-3H]GSSG revealed simultaneous incorporation of 3H radioactivity into the catalytic subunit and stoichiometric loss of catalytic activity. Treatment of the 3H-labeled enzyme with GSH was accompanied by release of 3H radioactivity from the enzyme and restoration of enzyme activity. The results suggest that inactivation of phosphorylase phosphatase by GSSG results from the formation of a mixed disulfide between GSSG and one of the two sulfhydryl groups in the catalytic subunit.

Animals↗