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Biomedical subjects

T Chiba

Publications and source records attributed to T Chiba.

At least 613 records · Page 34Linked to original sources
PubMed1984

[Experimental studies on splenic autotransplantation in rats].

To determine if splenic implants in the body regain vascularization and grow, and to determine the effects of any interaction between implant and remnant on growth of these spleen fragments, we conducted experiments on rats. 1) Spleen fragments were implanted in the omentum (20 cases), in the subcutaneous space (20 cases), or in the liver (10 cases), and the weight of splenic portions and its histological findings were observed 12 and 24 weeks after operation. The best splenic growth was observed in the group of implant in the omentum. 2) Total, 4/5, 2/3, 1/3 and 1/5 spleen were implanted in the omentum and the weight of implants were measured 6 weeks after the operation. The rate of growth of implanted spleen was the highest in the group of 1/5 and was the lowest in the group of whole spleen. 3) Two groups of rats underwent 1/3 splenectomy, and the 1/3 spleen portions was implanted in the omentum. One group had the remaining 2/3 spleen removed, the other group had the remaining 2/3 spleen left in place. In group at 6, 12 and 24 weeks postoperatively the splenic portions was weighed. The implants regenerate with time in rats of both groups. The rate of weight-gain was, however, slow in the group with 2/3 spleen and there was no regeneration on the remaining 2/3 spleen.

Animals↗
PubMed1984

[Histogenesis of uterine corpus carcinoma--relation to atypical endometrial hyperplasia].

We have studied the histogenesis of uterine corpus carcinoma with special reference to the relation to endometrial atypical hyperplasia. The summary of the results is as follows. The subjects of the study were 113 cases of operated uterine corpus cancer and 2,440 of noncorporeal (uterine) cancer. Atypical hyperplasia of the residual endometrium in corpus carcinoma was revealed in 42 of the 113 cases (37.2%). Among 19 premenopausal patients, the residual endometrium was in the secretory phase in 3 and in the proliferative phase in the others. The site of its appearance was either in the functional or non-functional layers with diffuse (16) and localized (26) types. A malignant change from the atypical hyperplastic (hormone dependent ?) and atrophic endometrium (hormone independent ?) was suggested.

Adult↗
PubMed1984

[Experimental studies on the rat-model for partial splenectomy and on spleen regeneration].

Partial splenectomy is often preferred to total splenectomy as a method to prevent serious post-operative sepsis. However, most of the previous researches on spleen function following partial splenectomy have failed to provide accurate data on the minimum increase of residual spleen in weight necessary for protection against postoperative sepsis. This is not only to the lack of appropriate model but also to the negligence of the effects of spleen regeneration after partial splenectomy. To produce an accurate model for partial splenectomies, and to know how the spleen regenerates following partial resection, about 500 rats underwent partial splenectomies. From these experiments, the following results were obtained. These partial splenectomies based on length of the spleen were satisfactory models as partial splenectomy. Absolute volume of regenerated spleen was finally almost the same in every model. However, the less the remnant spleen was the longer period was necessary until the spleen regeneration completed.

Animals↗
PubMed1983

Effect of an exogenous energy source and amino acids on DNA synthesis in regenerating rat liver.

Rats on a protein-free diet synthesized less DNA after partial hepatectomy than rats on a normal diet. In regenerating livers of animals on the protein-free diet, induction of several enzymes involved in the DNA precursor synthetic pathway, and especially ribonucleotide reductase, were depressed. When young rats were maintained solely by parenteral nutrition after partial hepatectomy, exogenous amino acids were more important than the exogenous energy source for induction of enzymes involved in synthesis of DNA and its pyrimidine nucleotide precursors. In particular, induction of ribonucleotide reductase appeared to be controlled by exogenous amino acids. Tryptophan, methionine, phenylalanine, leucine, valine, isoleucine and threonine seemed to stimulate the induction of this enzyme most after partial hepatectomy.

Amino Acids↗
PubMed1983

Effects of prostaglandin E2 and D2 on gastric somatostatin and gastrin secretion.

The effects of PGE2 and PGD2 on gastric somatostatin and gastrin releases were investigated using the isolated perfused rat stomach. In the presence of 5.5 mM glucose, the infusion of PGE2 elicited a significant augmentation in somatostatin release, but suppressed gastrin secretion from the perfusate. On the other hand, PGD2 did not affect somatostatin release, although the gastrin secretion decreased significantly, the same as after PGE2 infusion. These results suggest that PGE2 and PGD2 may be important in the regulation of gastric endocrine function, but that PGD2 does not affect gastric somatostatin secretion.

Animals↗
PubMed1983

Effect of tolbutamide on insulin, glucagon, and somatostatin release from the diabetic rat pancreas with special reference to glucose concentration.

The effects of tolbutamide on insulin, glucagon, and somatostatin secretion were investigated in the isolated perfused pancreas from normal and diabetic rats under low (30 mg/dl), normal (100 mg/dl), and high (300 mg/dl) glucose conditions. In the normal rat pancreas, tolbutamide-induced insulin release was increased when the glucose concentration in the perfusion medium was increased from 30-300 mg/dl. Tolbutamide had an inhibitory effect on glucagon release at the low (30 mg/dl) glucose concentrations, although a stimulatory effect was observed under normoglycemic conditions. The total amount of somatostatin secretion above baseline during tolbutamide infusion was higher under the normal glucose than under the low glucose condition. However, further augmentation of somatostatin release was not found at the high glucose concentration. In the diabetic rat pancreas, insulin release was diminished and tolbutamide-induced somatostatin release was enhanced with increasing glucose concentrations. Glucagon release was stimulated at the normal glucose concentration, but inhibited temporarily at the high glucose concentration. The maximum somatostatin response in the early phase was significantly decreased in the diabetic pancreas under low and normal glycemic conditions, when expressed as an incremental change (percentage) above baseline. From these results, one can conclude: (1) tolbutamide has a stimulatory effect on the pancreatic D cell in both the normal and diabetic pancreas; (2) the early response of somatostatin is decreased in the diabetic pancreas, except under conditions of high glucose concentration; and (3) the pancreatic A cell response to tolbutamide was not uniform and was quite different from the response of the D cell.

Animals↗
PubMed1983

Unresponsiveness of GH and cortisol to insulin-hypoglycemia in a patient with sub-total pancreatectomy.

Responses of plasma growth hormone (GH) and cortisol to insulin-induced hypoglycemia were repeatedly examined during a therapy of diabetes mellitus in a sub-totally pancreatectomized patient. During a mild control period of diabetes mellitus without any hypoglycemic attacks, insulin-induced hypoglycemia evoked a remarkable increase in plasma GH as well as cortisol while neither GH nor cortisol responded to insulin hypoglycemia during the strict control period with frequent episodes of hypoglycemia. On the other hand, plasma GH and cortisol responses to all other endocrinological stimuli were normal. The mechanism of such impaired hormone secretion during the strict control period of diabetes mellitus in this patient remains unclear.

Glucagon↗
PubMed1983

Characterization of the vasodilator action of antihypertensive drug budralazine.

Intravenous injection of 1-[2-(1,3-dimethyl-2-butenylidene)hydrazino]phthalazine (budralazine) to anesthetized dogs resulted in an increase in cardiac output and regional blood flow in various vascular beds, and a fall in mean blood pressure with a decreased total and regional vascular resistance. Budralazine produced a dose-related increase in femoral blood flow in anesthetized dogs when injected into the femoral artery. The vasodilator drug relaxed either KCl(K+)- or noradrenaline (NA)-induced contractions of isolated rabbit aorta in a concentration-dependent manner. In the K+-depolarized aorta, it also produced a concentration-related inhibition of contractile response to cumulative addition of Ca2+. Intra-arterial injection of budralazine dilated dose-dependently the isolated perfused vascular bed of rabbit ear constricted by either K+ or NA. Budralazine, at effective antihypertensive oral dose, was without significant effect on cyclic nucleotide levels in the aorta of spontaneously hypertensive rats (SHR). These results indicate that budralazine, like hydralazine, produces vasodilation through a direct effect on vascular smooth muscle which may result at least in part from its inhibitory effect on vascular Ca2+ fluxes.

Anesthesia↗
PubMed1983

A case of brain atrophy after fulminant hepatic failure.

We report a 26-year-old woman who survived fulminant hepatic failure but later developed permanent brain atrophy. After her recovery from fulminant hepatitis, her personality changed and mental abnormalities became obvious. Four years after the onset of fulminant hepatitis an epileptic attack occurred. At that time CT-scanning revealed generalized brain atrophy.

Acute Disease↗