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Biomedical subjects

K Nishida

Publications and source records attributed to K Nishida.

At least 541 records · Page 30Linked to original sources
PubMed1980

Lipids of plasma membranes from rat thymic lymphoid cells: deficiency of sphingomyelin.

Plasma membranes were isolated from normal thymocytes of Wistar-King-A rats and from Moloney virus-induced rat thymic leukemias (RML11 and RML30 cells) using a simplified method developed by us. All the isolated plasma membranes were electron-microscopically pure and enriched in the specific activities of (Na+ + K+)-ATPase, Mg2+-ATPase and 5'-nucleotidase in comparison with those of the corresponding whole cell homogenates. These plasma membranes as well as the original cells were analyzed for phopholipid composition and contents of phospholipid, cholesterol and plasmalogen. There was no difference in the phospholipid composition among the three plasma membranes. However, all the plasma membranes were deficient in sphingomyelin, namely, 1.8% for the normal thymocytes, 2.2% for the RML11 cells and 1.9% for the RML30 cells as percentage of the total phospholipid phosphorus. The contents of phospholipid (mumol per mg protein), cholesterol (mumol per mg protein) and plasmalogen (mol% to phospholipid) of the plasma membranes from both lines of malignant cells were lower than those of the normal thymocyte membranes. The molar ratio of cholesterol to phospholipid of the malignant cell membranes was also lower than that of the normal membranes, because in the former membranes the degree of decrease in the cholesterol content was higher than that in phospholipid content.

Animals↗
PubMed1980

Lipid analysis of isolated plasma membranes of lymphoid cells in benign thymomas of Buffalo/Mna rats.

Plasma membranes were isolated from lymphoid cells of benign thymomas obtained from inbred BUF/Mna rats (21 mo old) and from normal thymocytes obtained from young rats (7 wk old) of the same strain. The isolated plasma membranes were electron microscopically pure, and the specific activities of Na+, K+-ATPase, and 5'-nucleotidase were enhanced. The lipid compositions of the plasma membranes from these two sources were analyzed and compared. The cholesterol and plasmalogen contents of membranes from both sources were similar, but the phospholipid content of the benign thymoma lymphoid cell membranes was slightly lower than that of the normal thymocytes, resulting in a somewhat higher molar ratio of cholesterol to phospholipid. The plasma membranes of the thymoma lymphoid cells also exhibited a slightly higher microviscosity as measured with fluorescence polarization. No significant differences were observed in the phospholipid compositions of the two membrane preparations.

Animals↗
PubMed1980

Increase of antitumor effect on bleomycin by reduced nicotinamide adenine dinucleotide phosphate and microsomes in vitro and in vivo.

The DNA chain breakage effect of bleomycin A2 on isolated nuclei was enhanced over 150-fold by the reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent electron transport system of isolated microsomes. The enhancement of bleomycin A2-induced DNA chain breakage by NADPH was also shown at the level of the intact AH66 cells. Furthermore, it was found that the simultaneous administration of bleomycin and NADPH apparently inhibited the growth of Erhlich tumors in mice compared with the administration of bleomycin alone. These results indicate that the action of bleomycin on DNA is stimulated by the microsomal NADPH-dependent electron transport system not only in vitro but also in vivo.

Animals↗
PubMed1980

Immunological diagnosis of pancreatic cancer by assaying carcinoembryonic antigen (CEA) in pure pancreatic juice.

Carcinoembryonic antigen (CEA) levels in the pure pancreatic juice collected endoscopically were measured in a total of 102 cases including 18 with pancreatic cancer using radioimmunoassay. CEA levels in the pancreatic juice were significantly higher (p less than 0.001) in patients with pancreatic cancer than in those with pancreatitis or with other miscellaneous diseases and in normal controls. Despite the elevated CEA level in the pancreatic juice from patients with pancreatic cancer without liver metastasis, their serum CEA did not necessarily reveal a high value. In contrast, CEA in the pancreatic juice from patients with an advanced stage with liver metastasis, did not show a high value, although some of them had high CEA in their sera. It is concluded that the estimation of CEA levels in the pancreatic juice provides important diagnostic information in the detection of pancreatic cancer in the early stage.

Adult↗
PubMed1979

Elevation of serum lipid peroxide level associated with doxorubicin toxicity and its amelioration by [dl]-alpha-tocopheryl acetate or coenzyme Q10 in mouse (doxorubicin, toxicity, lipid peroxide, tocopherol, coenzyme Q10).

Elevations of serum lipid peroxide levels were demonstrated in mice after an equitoxic dose of doxorubicin. When BDF1 mice were injected with doxorubicin (20 mg/kg body weight, IP), lipid peroxide levels in sera were elevated 1 day after the injection and the levels declined on subsequent days. 5-Fluorouracil (400 mg/kg body weight, IP) never changed the peroxide levels in serum. Furthermore, it was found that the co-administration of [dl]-alpha-tocopheryl acetate or coenzyme Q10 IM strongly inhibited the doxorubicin-induced elevation of lipid peroxides in serum. The effectiveness of [dl]-alpha-tocopheryl acetate or coenzyme Q10 in reducing the lethality of doxorubicin in mice was also confirmed. These results indicate that the measurement of serum 2-thiobarbituric acid-reacting substances provided a useful measurement of lipid peroxide levels, which may be involved in some way with doxorubicin toxicity, and that the administration of antioxidants provide protection against some of the side effects of doxorubicin.

Animals↗
PubMed1979

Serum proteins and secretory component in human carious dentin.

By the use of the peroxidase-labeled antibody method, significant localization of IgG, IgA, albumin and transferrin was demonstrated in the deep lesion of 20 carious teeth, where the secretory component was absent. These serum proteins formed a distinct zone, surrounding the overlying, shallow lesion infected with bacteria.

Adolescent↗
PubMed1979

Increase of superoxide dismutase activity in various human leukemia cells.

(1) Superoxide dismutase activity in polymorphonuclear cells from human blood is considerably lower than that in lymphocytes. Macrophages from ascites show the middle level between the other two cells. (2) In myelocytic, monocytic, and lymphocytic leukemia cells, the enzyme activities are increased compared to those in the corresponding normal cells. (3) Gel electrophoresis patterns of all normal cells reveal bands corresponding to the cytosol and mitochondrial bands reported in previous studies. However, the mitochondrial Mn-containing superoxide dismutase activities are diminished or absent in leukemia cells. CN-insensitive superoxide dismutase activity in leukemia cells is not detected under the conditions.

Humans↗
PubMed1979

Effect of a streptococcal preparation on the complement system.

Streptococcal preparation OK-432 (Picibanil), clinically being used as an immunopotentiator, has been shown to activate the complement system either through the classical or the alternative pathway in vitro [15]. In this experiment, OK-432 was found to increase serum complement level in guinea pigs, and in human without malignancy, when investigated by hemolytic assay using sensitized sheep erythrocytes (EA) for the classical pathway activity and unsensitized rabbit erythrocytes (RaE) for the alternative pathway activity. Assay of complement components revealed a significant increase in C3, but decrease in Clq, while no specific tendency was observed in C4, C5, C9, properdin, C3 activator and Cl-inhibitor. These evidences suggested that OK-432 might potentiate immune response of the host by elevating serum complement level, in addition to activate the complement system.

Aged↗
PubMed1978

Enhancement of DNA chain breakage by bleomycin A2 in the presence of microsomes and reduced nicotinamide adenine dinucleotide phosphate.

Chain breakage in DNA induced by bleomycin A2 (BLM) was enhanced more than 150-fold by the reduced nicotinamide adenine dinucleotide phosphate-dependent electron transport system of rat liver microsomes. However, the enhancement effect on DNA was partially reduced by the preincubation of BLM with the microsomal systems. BLM-Cu2+ was found to stimulate considerably microsomal reduced nicotinamide adenine dinucleotide phosphate-dependent oxygen consumption and malondialdehyde formation, whereas BLM inhibited both of the effects. These findings suggest that the pharmacological action of BLM is strongly affected by a membrane system, such as microsomes, that produces free radicals.

Animals↗