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Biomedical subjects

T Oda

Publications and source records attributed to T Oda.

At least 811 records · Page 45Linked to original sources
PubMed1980

Complete in vitro DNA replication of SV40 chromatin in digitonin-treated permeable cells.

A permeable cell system has been developed by treatment with digitonin for studying in vitro DNA replication of chromatin. DNA replication of simian virus 40 nucleoprotein complexes (SV40 chromatin) in digitonin-treated permeable cells was analyzed by electrophoresis in agarose-gel. Autoradiography of the agarose-gel revealed that [32P]dCTP was incorporated in SV40 DNA I, II and replicating intermediates. The time course of the incorporation indicated the complete replication of SV40 DNA and chromatin with a full number of nucleosomes. The digitonin-treated permeable cell system will serve as a useful system for studying in vitro DNA replication of chromatin.

Animals↗
PubMed1980

Finestructure and template activities of DNA-histone complexes reconstituted in the presence and absence of urea.

Several DNA-histone complexes were reconstituted in the presence and absence of urea. The fiber size of DNA-histone H1 complex was about 20 A in width with knobs 100 to 250 A in diameter interspersed at an average interval of about 1,100 A. H1-was associated with DNA segments corresponding to a DNA size of fewer than 100 base pairs. DNA-histones H2A, H2B, H3 and H4 complex consisted of globular subunits 100 to 150 A in diameter alternating with thin strands, like beads on a string. DNA-whole histones complex was 200 to 250 A in width and had a condensed configuration. The nuclease digestion pattern of the complexes containing histones H2A, H2B, H3 and H4 was regular, similar to that of chromatin, and was disrupted by urea. The complex containing H1 was inactive for in vitro RNA synthesis by escherichia coli RNA polymerase, whereas the other complexes were active. The complexes reconstituted in the absence of urea had template activities slightly less than in the presence of urea.

Animals↗
PubMed1980

Alcoholic hyalins (Mallory bodies) in a case of Weber-Christian disease: electron microscopic observations of liver involvement.

A 32-yr-old female who suffered from typical Weber-Christian disease developed hepatosplenomegaly and hepatic dysfunction. A liver biopsy specimen displayed many fat droplets and alcoholic hyalins (Mallory bodies). Electron microscopic hepatic injury was indicated by many fat droplets, alcoholic hyalins, marked deformities of the rough endoplasmic reticulum, and by some deformed nuclei and nuclear bodies. There has been no other report describing alcoholic hyalins in the hepatic changes of Weber-Christian disease. Additionally, based on electron microscopic observation, we assume that fatty changes were due to a relative reduction in lipoprotein synthesis in the deformed rough endoplasmic reticulum.

Adult↗
PubMed1980

Effect of BCG on hepatocarcinogenesis of the rat induced by 3'-methyl-4-(dimethylamino)azobenzene.

The effect of BCG, an immunopotentiator, on the hepatocarcinogenesis of the rat induced by 3'-methyl-4-(dimethylamino)azobenzene (3'-Me-DAB) was investigated. After administration of 3'-Me-DAB for 6 weeks, BCG was injected to the rats at 2-week intervals for 50 weeks and the serial determinations of serum alpha-fetoprotein and morphological examination of the liver were made. In the control group, the second rise of serum alpha-fetoprotein, which reflected the occurrence of hepatoma, was seen at about 12 weeks after discontinuance of 3'-Me-DAB. On the other hand, the second rise of serum alpha-fetoprotein in the group treated with BCG was delayed about 10 weeks compared to control group, although there was no significant difference in the final incidence of hepatomas between these two groups. Infiltration of the lymphocytes was observed in the liver of rats treated with BCG without hepatoma. BCG seems to have an inhibitory effect on 3'-Me-DAB carcinogenesis of the rat, possibly by stimulating the cell-mediated immunity, although it is not strong enough to prevent the occurrence of hepatoma completely.

Animals↗
PubMed1980

Effect of phorbol esters and hormones on rat hepatoma cells producing alpha-fetoprotein.

Effect of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on rat AH66 hepatoma cells was studied with a reference to that of insulin and the epidermal growth factor (EGF). In a short term cell incubation, TPA and EGF caused an approximately 2-fold increase in the production of alpha-fetoprotein (AFP) and other acid-precipitable materials, while the same concentration of insulin brought a 3-fold increase. In a long term culture using a low serum medium, TPA as well as insulin and EGF caused remarkable proliferation of AH66 cells, but the increase in cell number was not accompanied by a proportional increase in the levels of AFP of the culture media. These biological effects of TPA, insulin and EGF appeared to resemble each other, and subsequent hormone binding studies showed that TPA inhibited 125I-EGF binding to its membrane receptors without affecting 125I-insulin binding. Scatchard analysis of TPA effect on EGF binding indicated that TPA altered the affinity of the membrane receptors for EGF without changing the total number of available receptors per cell. From these data, it is suggested that some of the biological effects of TPA on AH66 cells may result from alterations in the functions of cell membrane.

Animals↗
PubMed1980

Fusion of transformed human cells by simian retroviruses.

Mason-Pfizer monkey virus (MPMV), baboon endogenous virus (BaEV) and simian sarcoma virus associated virus (SSAV) induced fusion in cultured human cells derived from tumors or transformed in vitro. Not only virus-transformed cells, but also cells transformed spontaneously by 4-nitroquinoline 1-oxide (4-NQO) treatment or by 60Co-gamma ray irradiation were fused by these simian retroviruses. Non-transformed cells derived from normal human embryos were not fused by any of these viruses. Of these tumor or transformed cells, cells carrying Rous sarcoma virus (RSV) genome were most extensively fused by these simian retroviruses. Anti-MPMV, anti-BaEV and anti-SSAV sera blocked the cell fusion mediated by MPMV, BaEV and SSAV, respectively, and not that by other viruses, indicating that the cell fusion was virus-specific.

Avian Sarcoma Viruses↗
PubMed1980

Antitumor effect of neocarzinostatin entrapped in liposomes.

Antitumor effect against mouse Ehrlich ascites carcinoma was examined on Neocarzinostatin (NCS) entrapped in sonicated liposomes (neutral and negatively or positively charged forms) in comparison with free NCS. In the intraperitoneal inoculation-intraperitoneal medication system, NSC entrapped in negatively charged liposomes, which was most unstable in aqueous solution, showed statistically significant prolongation of survival days in mice compared to free NCS. In contrast, survival days of the animals given NCS entrapped in positively charged liposomes were shorter than those of the corresponding groups given free NCS. On the other hand in the intraperitoneal inoculation-intravenous medication system, survival days were not prolonged markedly by administration of free NCS, BUT WHEN NCS was entrapped in positively charged or neutral liposomes, prolongation of survival was apparent compared to the corresponding groups given free NCS. The most marked effect was seen when NCS was entrapped in positively charged liposomes, which show the best stability in aqueous solution.

Animals↗
PubMed1980

Report of the survey of hepatitis antigens in the Asian-Pacific region.

The aim of the study was to determine the prevalence of Hepatitis antigens e.g. Hepatitis B surface antigen (HBsAg), anti-HBsAg Hepatitis A and non A and B in liver diseases and in blood donors, hospital staff, specific population and general population in various countries in the Asian Pacific Region through published data and questionnaires. The study confirmed previous data indicating a high prevalence of Hepatitis B in certain areas of the Asian Pacific region. The problem of chronic hepatitis, non A, non B hepatitis will become clearer with more sensitive assays.

Blood Donors↗
PubMed1980

Alkaline phosphatase isoenzymes in intestinal metaplasia and carcinoma of rat stomach induced by N-methyl-N'-nitro-N-nitrosoguanidine.

Intestinal metaplasia and carcinoma of the stomach were produced in Wistar strain rats by oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Alkaline phosphatase (AlP) isoenzymes of tissues from intestinal metaplastic mucosa and carcinoma of the stomach were studied. The ALP activity from all carcinoma tissues was several times higher than that of the surrounding gastric mucosa, and two of the tissues has over 100 times higher activity. An AlP zymogram from carcinoma tissues of the stomach showed one broad active band on 5% polyacrylamide-gel disc electrophoresis. This band was separated into 2 sharp active bands after treatment with neuraminidase: A-band (Rf = 19%) and B-band (Rf = 32%). From the enzymological and immunological study, B-band had properties similar to those of AlP isoenzyme from the intestinal metaplastic mucosa of the stomach, as well as intestinal AlP isoenzyme, while A-band had different ones. Anm AlP zymogram from glandular mucosa of the stomach showed 2 types of active band (A and B band) after treatment with neuraminidase, which were identical with those appearing in carcinoma tissues. The properties of AlP isoenzyme from the intestinal metaplastic mucosa of rat stomach induced by MNNG were similar to those of humans, and the carcinoma tissues of rat stomach were suspected of producing high amounts of AlP, especially the intestinal-type AlP isoenzyme.

Alkaline Phosphatase↗