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Biomedical subjects

K Toyama

Publications and source records attributed to K Toyama.

At least 487 records · Page 27Linked to original sources
PubMed1984

Effects of 2,4-dinitrophenol and other metabolic inhibitors on the thermograms of Ehrlich ascites carcinoma cells registered with a microcalorimeter.

The heat produced by Ehrlich ascites carcinoma cells was measured microcalorimetrically to investigate the characteristics of the energetics of these cells. 2,4-Dinitrophenol and other inhibitors were used to obtain the standard thermograms. The heat level of starved Ehrlich ascites carcinoma cells (endogenous) was almost constant and linear and depended on the cell number used in the experiments (about 1 cal/1 X 10(8) cells/hr). The endogenous heat generation was suppressed strongly by potassium cyanide but not by iodoacetic acid or 2,4-dinitrophenol. On the other hand, heat evolution was directly related to the amount of glucose added to the medium but not to the number of cells (19 cal/mmol of glucose). The addition of iodoacetic acid markedly suppressed heat generation, but potassium cyanide did not. In contrast, glucose with dinitrophenol increased heat production markedly to about 10% higher than that of the control, possibly due to the uncoupled energy from oxidative phosphorylation. Malonic acid (1 mM) suppressed slightly the endogenous heat but caused a 15% reduction in exogenous heat. The amount of heat produced by the addition of glucose (19 cal/mmol) was equivalent to 40% of the theoretical value of energy released through glycolysis (47 cal/mmol). Thus, the heat produced by exogenous glucose appears to be mainly dependent on glycolysis.

2,4-Dinitrophenol↗
PubMed1983

Eye movement-related activities in cells of the lateral suprasylvian cortex of the cat.

Investigation of eye movement-related activities and photic responsiveness using behaving cats demonstrated distinctive representations of eye movement signals in different areas of the lateral suprasylvian cortex: visual reafference in the medial bank of the middle suprasylvian sulcus and non-visual signals (proprioceptive reafference or efference copy) in the lateral bank.

Animals↗
PubMed1983

Risk factors of cerebro-cardiovascular disorders in mild diabetes.

The previous history of maturity onset diabetics is often difficult to piece together since most of the patients, being asymptomatic in the early stages, are not predisposed to undergo routine examinations. We made a prognostic study of such asymptomatic mild diabetics in order to examine the relationship between diabetes and cerebro-cardiovascular disorders. The subjects consisted of 5,170 individuals who had undergone biennial routine examinations at the Nagasaki RERF since 1958. Of these, 424 persons were diagnosed during the follow-up period as having diabetes. Eliminating those receiving insulin or oral hypoglycemic agents, there were 392 patients. It is shown that 49% of these mild diabetics died from cerebro-cardiovascular disorders. The mortality rate for mild asymptomatic diabetics due to CVD and CHD was significantly higher than that for non-diabetics. To elucidate the risk factors of these disorders, we studied the effects of age, blood pressure (BP), serum total cholesterol (TC), relative body weight and four other factors. In CVD as well as in CHD, age and systolic blood pressure were the major risk factors of statistical significance. It was also noted that diabetes, however mild, was an important factor. Consequently, Bp is felt to be the greatest of the four risk factors above, and the maintenance of normal BP as well as glucose control is important even in mild asymptomatic diabetics.

Blood Pressure↗
PubMed1983

[Effects of various antibiotics and natural mycotoxins on the hematopoietic stem cells of the bone marrow in normal and adjuvant-treated rats].

This experiment was carried out, in order to investigate the effect of antibiotics and natural mycotoxin on the hematopoietic stem cells at the normal and inflammatory condition. Adjuvant-treated rats (Aj-rats) are considered as a model of human rheumatoid arthritis. We measured the CFU-C and CFU-E of bone marrow of normal and Aj-rats which were injected with large (1.0 g/kg X 3) and small doses (0.5 g/kg X 3) of ampicillin (ABPC), cefazolin (CEZ), chloramphenicol (CP) and fusarenon-X (F-X). In Aj-rats the number of CFU-C was 1.5 times higher and CFU-E 60% less than normal. Injection of large doses of ABPC enhanced markedly the numbers of CFU-C in Aj-rats and suppressed slightly CFU-E in normal rats. Large doses of CEZ inclined to increase CFU-C and decreased CFU-E in normal and Aj-rats. Injection of small doses of CP tended to increase CFU-C and to decrease CFU-E, and large doses of CP to suppress both CFU-C and CFU-E levels in normal or Aj-rats. F-X, natural mycotoxin suppressed markedly both CFU-C and CFU-E levels of normal rats, and slightly the CFU-E in Aj-rats. These results suggest that one should pay attention to the fact that some doses of antibiotics or natural mycotoxin might be harmful on the bone marrow hematopoietic stem cells.

Ampicillin↗
PubMed1982

Responses of Clare-Bishop neurones to three dimensional movement of a light stimulus.

Responsiveness of Clare-Bishop (CB) neurons to movement of a visual stimulus and to changes in stimulus disparity and size that associated with movements in depth were studied by using a three dimensional visual stimulator. (1) About a half of them (28/54) were sensitive to disparity- and size-stimuli. (2) the other half (20/54) were activated only by movement-stimulus, and (3) the remaining minority (6/54) responded equally well to all types of stimuli. These observations suggest that CB neurons encode movements in three dimensional space on the basis of their responsiveness to stimulus disparity and size.

Animals↗