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Biomedical subjects

K Kojima

Publications and source records attributed to K Kojima.

At least 685 records · Page 38Linked to original sources
PubMed1984

[Effect of vagotomy on gastric wall autonomic responses, mucosal cholinesterase activity and gastric acid secretion in cats].

Adrenergic and cholinergic innervation of the stomach was investigated using histochemical techniques, and gastric mucosal cholinesterase (ChE) activity was measured by a calorimetric method. The effects of vagal nerve stimulation on gastric mucosal ChE activity was examined, and the following results were obtained. No differences in innervation and mucosal ChE activity were found between the lesser and greater curvatures of the stomach. High ChE activity and a wide and dense network of cholinergic nerve fibers were observed in the fundic mucosa, but in the antral mucosa the fibers were limited and ChE activity was low. The number of cholinergic fibers was markedly reduced in the intermediate zone. Mucosal ChE activity increased temporarily after truncal vagotomy, but after 6 months it returned to the original value. Antral mucosal ChE activity became elevated temporarily after vagal stimulation, but decreased rapidly thereafter. Denervation of hepatic, celiac and antral branches of the vagus caused a significant decrease in acid secretion. This suggests that these nerves are also involved in gastric secretion, and that the vagal nerve fibers are distributed to the greater curvature of stomach via these branches.

Adrenergic Fibers↗
PubMed1984

[Nutritional support in surgery: with special reference to fat emulsion and carnitine].

Energy metabolism of fat emulsion has been studied in rats with various conditions including postoperative catabolism, chronic and acute hepatic dysfunction, diabetes and sepsis. The results indicate that fat emulsion is rapidly eliminated from the blood stream and metabolized readily even in such conditions. Based on these findings, we have actively employed fat emulsion clinically as energy source. In septic rats, it was demonstrated that levels of carnitine decreased and that this decrease was based upon a decrease of synthesis. When carnitine was administrated together with fat emulsion, the energy metabolism returned to approximately normal level. This report also describes the tissue concentrations of carnitine in diabetic rats and the blood and urine concentrations of carnitine in postoperative patients.

Animals↗
PubMed1983

Aldosterone secretion: effect of phorbol ester and A23187.

The effects of the divalent ionophore, A23187, the phorbol ester, and/or 12-0-tetradecanoyl-phorbol-13-acetate on aldosterone secretion from adrenal glomerulosa cells were compared to those of angiotensin II (AII). AII causes a prompt and sustained increase in secretion. A23187 causes an initial increase followed by a gradual decline to values less than 25 percent of those seen with AII. TPA causes no initial increase but a slowly progressive rise in secretion rate to a less than maximal value. When TPA and A23187 act together, there is a prompt and sustained increase in aldosterone production rate similar to that seen after AII addition. The effect of TPA is dependent on the free Ca2+ concentration of the cell cytosol. These results are interpreted in terms of a model of cell activation in which two branches of the calcium messenger system operate to control respectively the initial and sustained phases of the secretory response. The first phase occurs as a consequence of amplitude modulation of the calmodulin branch of the system by a rise in [Ca2+]c, and the second phase as a consequence of the sensitivity modulation of the C-kinase branch by diacylglycerol.

Adrenal Medulla↗
PubMed1983

High-grade tumor-specific immunity induced by L1210 leukemia variants obtained from the culture of L1210 cells fused with Lesch-Nyhan fibroblasts.

A highly immunogenic variant of the murine L1210 leukemia cell (L1210/LN-1) for generation of tumor immunity has been obtained from culture of L1210 cells originally fused with human Lesch-Nyhan fibroblasts. In L1210/LN-1 cells, no human chromosomes were identified and chromosomes M1 and No. 1 carried by the parent L1210 cells were missing. L1210/LN-1 cells displayed an intermediate morphology between L1210 cells and Lesch-Nyhan fibroblasts. Most of the CDF1 mice that were inoculated with less than 2 X 10(6) L1210/LN-1 cells survived over 60 days without evidence of tumor, whereas the original L1210 cells killed all the mice tested in about 2 weeks. When inoculated with more than 5 X 10(6) L1210/LN-1 cells, CDF1 mice developed tumor. The CDF1 mice which rejected 2 X 10(6) L1210/LN-1 cells were protected very effectively against challenge of otherwise highly aggressive 1-5 X 10(5) L1210 leukemia cells; 40 out of 43 primed mice tested survived for 60 days or longer after the tumor challenge. Even the CDF1 mice primed with irradiated or mitomycin-treated L1210/LN-1 cells survived against a challenge of 10(5) L1210 leukemia cells. They were, however, not protected against P388 leukemia or Meth A sarcoma, indicating that the immunity was specific to L1210 leukemia. The immunity induced by L1210/LN-1 cells was transplantable by immune spleen cells into syngeneic recipients. Thus, the L1210/LN-1 cells we obtained seem to be very useful as an immunogen for generation of high-grade tumor-specific immunity against highly malignant L1210 leukemia.

Animals↗
PubMed1983

Alteration in sensitivity of transmural electrical response to propionate in rat colon after chronic luminal infusion of short-chain fatty acids.

The colon is always exposed to abundant short-chain fatty acids (SCFA) produced by gut fermentation. In order to know an effect of chronic load of SCFA on colonic functions, we studied that the acute and chronic effects of SCFA on transmural potential difference (p.d.) across the proximal colon of germ-free (GF), gnotobiotic (GB) and conventionalized (CV) rats in vivo. Intravenous administration of SCFA (acute effect), such as propionate, butyrate, valerate or caproate, caused a transient increase in the p.d. The acute effects of propionate were studied in detail. The dose-response curve of CV rats shifted markedly to the right compared to that of GF rats, suggesting that CV rats were less sensitive to the acute effects of propionate than GF rats. Decreased sensitivity also appeared in GB rats (monocontamination with Fusobacterium varium). By chronic luminal infusion of isotonic sodium propionate or butyrate (25.5 ml/day) into the proximal colon of GF rats for 7 days (chronic effect), the acute effects of propionate were reduced. Atropine reduced the p.d. increment produced by propionate and shifted the dose-response curve of propionate to the right. These results suggest that chronic luminal load of SCFA resulted in a type of chronic refractoriness.

Animals↗
PubMed1983

Effect of splenectomy and immunotherapy on advanced gastric cancer associated with total gastrectomy.

Immunotherapy with levamisole (LMS) and combined splenectomy were performed in the cases of stages III and IV gastric cancer of the upper and middle stomach and associated with total gastrectomy. The cell-mediated immunity and the survival rates for both groups were compared with controls. Combined splenectomy was not effective for cases of stage III gastric cancer, but was effective for those in stage IV. Comparing the cumulative survival rates of the immunotherapy group with the controls, cases of stages III and IV gastric cancer without splenectomy, the survival rate of those with immunotherapy was higher than that of the control group in the cases of the stage III, but the result was reverse in cases of stage IV gastric cancer. Changes in the cell-mediated immunity correlated with the survival rates.

Gastrectomy↗
PubMed1983

Studies on dental fluoride-releasing polymers. IV: Fluoridation of human enamel by fluoride-containing sealant.

An experimental fluoride-containing acrylic sealant was prepared using methacryloyl fluoride-methyl methacrylate copolymer as powder component. The in vitro fluoride acquisition by human enamel coated with the sealant after 11, 21, 41 and 84 days of incubation in a phosphate buffer of pH7 at 37 degrees C was determined. Fluoride penetration and uptake were increased by prolonging the exposure time of enamel to the sealant. Most of the fluoride retained in enamel was found to be present as fluorapatite. The discharge of fluoride in the sealant was about 12% of initial load after 84 days of immersion.

Apatites↗
PubMed1983

Characterization of tyrosine hydroxylase from bovine adrenal medulla.

Tyrosine hydroxylase purified to apparent homogeneity from the soluble fraction of bovine adrenal medulla had an apparent Mr of about 280,000 by Bio-Gel A-1.5m chromatography, and gave a single band with a Mr of 60,000 by sodium dodesyl sulfate polyacrylamide gel electrophoresis. The enzyme is considered to be composed of four identical subunits. Isoelectric point of purified enzyme was pH 6.0. The amino acid composition of the enzyme was characterized by fairly high contents of glutamic acid and alanine residues. The N-terminal amino acid was determined to be glutamic acid.

Adrenal Medulla↗