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Biomedical subjects

K Ota

Publications and source records attributed to K Ota.

At least 721 records · Page 40Linked to original sources
PubMed1982

[Flow cytometric analysis of cell surface antigens on leukemia cells by monoclonal antibodies and its application].

Nine monoclonal antibodies against null cell ALL cells were obtained by mouse hybridoma technique. Using two antibodies, namely B-1 and D-22, out of these, cell surface antigens on various leukemia cells, normal bone marrow cells, spleen cells and cultured cells were analysed by means of flow cytometry. B-1 antibody was found to have reactivities against null cell ALL cells as well as some CML-blastic crisis cells. The antibody reacted against some cultured lymphoid cell lines and also several percent of bone marrow cells. The reactivities of B-1 antibody were quite similar to those of c-ALL by Greaves et al and J-5 by Ritz et al. Radioimmunoprecipitation experiment suggested that B-1 antibody define the same antigen as the other two do. Meanwhile, D-22 antibody reacted against null cell ALL cells, but did not react against any other types of leukemia cells or any other cultured cell lines, or bone marrow cells. Thus D-22 antibody was considered to have higher specificity for null cell ALL cells than any other antibodies reported. On the other hand, the analyses by flow cytometry were well correlated with the analysis by immune adherence assay and by immunofluorescent microscopy. Besides, the analysis by flow cytometry provided us precise quantitative data and histogram pattern of positive cells. Furthermore, detailed examination of subpopulation could be done using cell sorter or other biological features could be analysed simultaneously using another fluorescent dye. Although, it has a few limitations, flow cytometry could take over other methods which are currently used in this field. Finally, the possibility of this method for the clinical diagnosis of leukemia was discussed.

Antibodies, Monoclonal↗
PubMed1981

Rapid isolation and lipid characterization of plasma membranes from normal and malignant lymphoid cells of mouse.

A rapid isolation method was developed for plasma membranes from mouse lymphoid cells such as lymph node lymphocytes, thymocytes, radiation-induced thymoma cells and L1210 cells. Lysates of these lymphoid cells were prepared by Dounce homogenization under hypotonic conditions and directly layered on sucrose step density gradients containing 2 mM CaCl2 and 5 mM MgCl2, and centrifuged at 52 000 X g for 1 h. Plasma membrane fractions appeared at the interface between 20 and 42% sucrose in the gradients. The procedure permitted purified membranes from cells to be obtained within 3 h, and the preparations appeared to be uniform by electron microscopy. Specific activities of (Na+ + K+)-ATPase, Mg2+-ATPase and 5'-nucleotidase of the isolated plasma membranes were enriched 23- to 61-fold, 12- to 15-fold and 18- to 34-fold, respectively, in comparison with those of the corresponding cell homogenates. Cholesterol content of the malignant cell membranes was lower than that of the normal membranes and the molar ratio of cholesterol to phospholipid of the malignant cell membranes was also lower than that of the normal membranes. A decreased plasmalogen content was observed in the malignant plasma membranes, together with a higher percentage of phosphatidylethanolamine and a lower percentage of phosphatidylserine. In the normal cell membranes, thymocytes contained a higher percentage of phosphatidylcholine and a lower percentage of sphingomyelin than those of the lymph node lymphocytes. At all temperature ranges (5 to 40 degrees C) the plasma membranes of the malignant cells had lower microviscosity than those of the normal cells.

Animals↗
PubMed1981

A controlled study of maintenance chemoimmunotherapy vs immunotherapy alone immediately following palliative gastrectomy and induction chemoimmunotherapy for advanced gastric cancer. Tokai cooperative study group for adjuvant chemoimmunotherapy of stomach cancer.

A randomized trial of surgical adjuvant chemoimmunotherapy was conducted in patients who had undergone palliative gastrectomy for previously untreated advanced stomach cancer. First, all patients received the same induction chemoimmunotherapy with MFC (mitomycin C, 5-fluorouracil, and cytosine arabinoside) plus OK-432 for 6 weeks after surgery. The patients were then randomized to receive either chemoimmunotherapy with MFC plus OK-432 (group A) or immunotherapy with OK-432 alone (group B) for maintenance. The survival rate of patients was significantly higher in group B (44 cases) than in group A (39 cases) during the first 9 months after the start of induction therapy (P less than 0.05). A further division of patients in terms of carcinoma histology revealed a difference in survival rate only in patients with an undifferentiated histology (poorly differentiated adenocarcinoma and signet-ring cell carcinoma), and not in those with a differentiated histology (papillary, tubular, and mucinous adenocarcinomas). These results indicate that simple immunotherapy with Ok-432 is better for maintenance than chemoimmunotherapy involving MFC, particularly in patients with undifferentiated gastric carcinomas.

Antineoplastic Agents↗
PubMed1981

Poly(ADP-ribose) synthesis in human cervical cancer cell-diagnostic cytological usefulness.

Poly(ADP-ribose) synthetase activity in human cervical cancer cell nuclei was found to be approximately twice that of normal cervical cell nuclei. Using antipoly(ADP-ribose) antibody, frozen section of normal tissue were stained by indirect-immunofluorescence and it was demonstrated that the fluorescence of nuclei in squamous cells decreased during maturation. Correspondingly, superficial cells appearing in smear specimens had less nuclear fluorescence compared with parabasal cells in the same smear. However, cancer cells in cervical smears had marked nuclear fluorescence using immunostaining and were easily distinguished from normal cells.

Cell Nucleus↗
PubMed1981

Malignant tumours in dialysis patients: a nationwide survey.

A nationwide survey was made to find out patients with malignant tumours among the dialysis population. A total of 354 malignant tumours were detected during the time of survey. Consistent with the incidence in the Japanese general population, the most frequently detected malignant tumour was gastric cancer, accounting for about one third of the total. Overall the incidence of tumour death was 2.31 times higher in males and 4.3 times higher in females. However, the high incidence of gynaecological and urinary tract tumours would suggest that some of them might be causative factors for the development of renal failure.

Female↗
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

Gm allotypes in myasthenia gravis.

Gm typing and acetylcholine receptor antibody assay were performed on serum samples from 74 patients with myasthenia gravis (31 male, 43 female) and from 236 unrelated normal blood-donors. The haplotype Gm1,2,21 was significantly more common in patients with myasthenia gravis (relative risk = 3.24), especially those with thymoma (relative risk = 6.99). The frequency of haplotype Gm1,2,21 was further increased in patients with severe generalised myasthenia gravis (relative risk = 10.52). The frequency of Gm1,2,21 was also increased in patients with high acetylcholine receptor antibody titres (greater than 5 pmol/ml). The results indicate the presence of a pathogenic gene close to the IgG heavy-chain gene complex in the 6th chromosome in the patients with myasthenia gravis, especially those with thymoma.

Adolescent↗
PubMed1980

Cytosolic and microsomal epoxide hydrolases: differential properties in mammalian liver.

The epoxide hydrolase activities of the 100,000 g pellet (microsomal) and 100,00 g soluble (cystosolic) fractions of mouse, rat, and guinea pig liver were measured with three closely related compounds used as substrates. Differences between the species in the distribution of the cytosolic and microsomal hydrolases and in their substrate specificities and pH optima demonstrate why epoxide hydrolase activity in the cytosolic fraction was not detected earlier in spie of intensive work on the microsomal epoxide hydrolase.

Allyl Compounds↗
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↗