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Biomedical subjects

K Takebe

Publications and source records attributed to K Takebe.

At least 217 records · Page 12Linked to original sources
PubMed1982

Impaired insulin secretion in the spontaneous diabetes rats.

Dynamics of insulin and glucagon secretion were investigated by using a new model of spontaneous diabetes rats produced by the repetition of selective breeding in our laboratories. The perfusion experiments of the pancreas showed that the early phase of insulin secretion to continuous stimulation with glucose was specifically impaired, although the response of the early phase to arginine was preserved. The glucose-induced insulin secretion in the nineth generation (F8) which had a more remarkably impaired glucose tolerance was more reduced than in the sixth generation (F5). No significant difference of glucagon secretion in response to arginine or norepinephrine was noted between the diabetes rats and control ones. The present data indicate that the defective insulin secretion is a primary derangement in a diabetic state of the spontaneous diabetes rat. This defect in the early phase of glucose-induced insulin secretion suggests the specific impairment of the recognition of glucose by the pancreatic beta-cells. The spontaneous diabetes rats are very useful as a model of disease for investigating pathophysiology of non-insulin dependent diabetes mellitus.

Animals↗
PubMed1981

Peroneal nerve palsy due to fabella.

In general, the fabella has been considered to have a minor clinical significance, and has not been recognized as one of the causes of peroneal nerve palsy. Seven cases of peroneal nerve palsy due to the fabella are reported. The typical clinical features and the importance of electrophysiological examinations in making an accurate diagnosis are described. Of the seven cases mentioned above, three cases were treated by surgery and four cases by conservative methods.

Adult↗
PubMed1981

Degradation of insulin in perfused liver and skeletal muscle and insulin secretion in perfused pancreas of liver injury rat.

To study the mechanism of hyperinsulinism and glucose intolerance in liver disease, insulin removal rate by liver and muscle, glucose uptake by muscle and insulin secretion from pancreas were measured using the perfusion in rats with injured liver induced by carbon tetrachloride (liver injury rat). In the perfused liver, insulin removal rate of liver injury rat decreased to 62% of that of normal rat, but it did not alter in the perfused muscle. Insulin response to arginine by the perfused pancreas of liver injury rat was similar to that of normal rat. Before insulin infusion, glucose uptake by the perfused muscle was similar in liver injury rat and normal rat. In contrast, during insulin infusion, glucose uptake by the perfused muscle was 1.5 times higher in liver injury rat than in normal rat. These results suggested that the peripheral hyperinsulinism was solely due to decreased hepatic insulin degradation, but not hypersecretion of insulin from pancreas and furthermore, might suggest that the insulin resistance was related to appearance of biologically inactive endogenous insulin, because of exogenous insulin completely acting on peripheral target tissue.

Animals↗
PubMed1981

Structural properties of immature canine bone.

Structural properties of growing canine long bones were determined from three and four-point bending tests. Mechanical and geometric properties were found to follow a biphasic growth process, with a rapid increase in bending strength and moment of inertia from l to 24 wk of age and a substantially decreased rate thereafter to maturity. Predicted bone tissue material properties were also found to follow this biphasic developmental process.

Age Factors↗
PubMed1981

Degree of inhibition of ACTH release by glucocorticoids in adrenalectomized rats.

The inhibitory effects of corticosterone, dexamethasone and prednisolone on activity of the hypothalamus-pituitary-adrenal axis were investigated in adrenalectomized rats infused with glucocorticoids for 6 h. Infusion of 202 micrograms corticosterone did not inhibit the plasma ACTH concentration, but 504 micrograms corticosterone significantly suppressed plasma ACTH levels. Infusion of 20 micrograms dexamethasone suppressed markedly the plasma ACTH concentration. These data suggest that the degree of inhibition of dexamethasone on ACTH release is about 25 times greater than that of corticosterone. The CRF content of the hypothalamus was not decreased by the administration of 202 micrograms corticosterone over a 6-hour period, but it was significantly diminished by 504 micrograms corticosterone. Infusion of 504 micrograms dexamethasone did not decrease the hypothalamic CRF content; however, infusion of 5 mg dexamethasone effectively suppressed the hypothalamic CRF content. Infusion of 2.5 mg prednisolone did not either decrease the CRF content. These data suggest that the degree of inhibition of natural steroid at the hypothalamus level is stronger than that of synthetic steroids. In rats pretreated with a single injection of dexamethasone (25 micrograms/200 g body weight) 22 h prior to the experiments, continuous infusion of 318 micrograms of dexamethasone significantly suppressed the hypothalamic CRF content, whereas infusion of 504 micrograms of dexamethasone failed to decrease the hypothalamic CRF content in the rats not pretreated with dexamethasone. This finding suggests that a latent period after the injection of dexamethasone is needed for the appearance of the inhibitory action of synthetic steroids at the level of hypothalamus.

Adrenalectomy↗
PubMed1981

The site of inhibitory action of a natural (corticosterone) and synthetic steroid (dexamethasone) in the hypothalamic-pituitary-adrenal axis.

Only a few reports have appeared which have attempted to determine whether the naturally occurring steroid corticosterone, has the same site of action in the hypothalamus-pituitary-adrenal axis as the synthetic steroid, dexamethasone. The present studies help to define the site of inhibition of both corticosterone and dexamethasone on the hypothalamus-pituitary-adrenal axis. Infusion of 20 or 202 microgram corticosterone over 6 h significantly reduced hypothalamic CRF (corticotropin-releasing factor) content, whereas it did not reduce plasma ACTH levels in normal rats. The finding indicates the possibility that the infusion of corticosterone may decrease the hypothalamic CRF content by reducing CRF production or enhancing intracellular and/or extracellular CRF degradation. On the other hand, infusion of 20 microgram dexamethasone for 6 h to normal rats significantly decreased plasma ACTH levels, but did not alter the hypothalamic CRF content. This finding indicates that dexamethasone may inhibit the release and/or production of ACTH in the anterior pituitary. In addition, relatively large doses of corticosterone (504 microgram/rat) and dexamethasone (202 microgram/rat) may suppress CRF content and ACTH release at the level of both the hypothalamus and anterior pituitary.

Adrenalectomy↗
PubMed1981

Effect of theophylline on insulin, glucagon and somatostatin secretion from the isolated rat pancreatico-duodenal preparation.

In order to determine whether endogenous somatostatin has an inhibitory action on insulin and glucagon secretion, the isolated rat pancreas was perfused with 10mM theophylline, which strongly stimulated somatostatin release, under pretreatment or simultaneous administration of 8.3, 16.7 mM glucose and 20mM arginine with 4.4 mM glucose. 1) In the infusion of 10mM theophylline with 8.3 mM glucose, the first phase at the time corresponding with that of insulin release elicited by 8.3 mM glucose alone was suppressed by endogenous somatostatin stimulated by theophylline. 2) During the infusion of 16.7 mM glucose for 35 min, 10mM theophylline was interposed at from 15 to 25 min intervals. Its addition caused a rapid increase in somatostatin. Only at 15 min 30 sec and 16 min, insulin concentration went down and reached the levels of 70 and 74 per cent of the 15-min value, respectively. 3) During the infusion of 20 mM arginine with 4.4 mM glucose for 35 min, 10mM theophylline was added to the perfusate from 15 to 25 min. The addition of theophylline caused an increase in somatostatin and decrease in glucagon. At 15 min 30sec and 16 min, the levels of glucagon were 63 and 75 per cent of 15-min value, respectively. These results seem to support the idea that endogenous somatostatin suppressed glucose-induced insulin and arginine-induced glucagon secretion. However, the possibility of a direct effect of theophylline on the changes in insulin and glucagon secretion could not be excluded.

Animals↗
PubMed1981

[Laboratory and clinical studies on cefsulodin (author's transl)].

Laboratory and clinical studies on cefsulodin (CFS), a new antipseudomonal cephalosporin antibiotic, were carried out and the following results were obtained. 1. The MIC of CFS against P. aeruginosa showed the peak of susceptibility at 3.13 mcg/ml in the inoculum size of 10(8) cells/ml and at 1.56 mcg/ml in the inoculum size of 10(8) cells/ml. It has a higher superiority as compared with gentamicin or piperacillin and gentamicin-resistant strains of P. aeruginosa were sensitive to CFS. 2. CFS was given to 3 patients with acute pneumonia and 5 patients with chronic cystitis which were all due to P. aeruginosa. Clinical effects were good in 2 patients and poor in a patient with acute pneumonia, and those were good in 3 patients and poor in 2 patients with chronic cystitis. Side effects were not recognized at all.

Adult↗
PubMed1980

EMG biofeedback in tendon transplantation for foot drop.

EMG biofeedback training was used successfully to obtain the desired new function of dorsiflexion in the transplanted muscle for two patients with foot drop. The transplanted muscles are not working effectively, not only the active movement but also during a walk. It is concluded that EMG biofeedback training is useful in rehabilitation following tendon transplantation for foot drop.

Adolescent↗