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Biomedical subjects

S Mizuno

Publications and source records attributed to S Mizuno.

At least 613 records · Page 34Linked to original sources
PubMed1978

Estrogen withdrawal in chick oviduct. Characterization of RNA synthesized in isolated nuclei using a mercurated precursor.

1. As a prerequisite for analyzing the effect of estrogen on transcription in chick oviduct, we describe suitable methods for the synthesis (under conditions restricting reinitiation), and isolation of RNA transcripts from oviduct nuclei in vitro, utilizing mercurated UTP (Hg-UTP) as an RNA precursor and chromatography on sulphydryl-Sepharose (SH-Sepharose) to recover mercurated RNA (Hg-RNA). The techniques described include treatment of Hg-RNA with p-hydroxymercuribenzoate, to improve the efficiency of binding to SH-Sepharose, and elution of Hg-RNA from SH-Sepharose after treatment with 60% formamide at 90 degrees C, to eliminate contamination by aggregated nucleic acid. 2. RNA synthesized by endogenous form B RNA polymerase (using either UTP or Hg-UTP as precursor) was recovered in nuclear lysates in the form of 30--85-S heterogeneous RNA . protein complexes, and after removal of protein, was 10--12 S in size. 3. The nature of RNA transcripts synthesized in vitro was examined by hybridization. More than 90% of the RNA was complementary to "unique" DNA sequences, and 50--60% of the hybridized RNA could be competed with homologous, steady-state nuclear RNA, indicating a significant degree with homologous, steady-state nuclear RNA, indicating a significant degree of homology between in vitro transcripts and in vivo RNA. The level of homology was similar whether RNA synthesis was performed in low salt, or in high salt in the presence of heparin. Possible reasons for only partial competition in these experiments are discussed. 4. Withdrawal of estrogen from chicks leads to a 50% reduction in endogenous RNA polymerase activities in nuclei within 48 h. Similar levels of competition with Hg-RNA transcripts for "unique" DNA were obtained using oviduct nuclear RNAs isolated before or after estrogen withdrawal, and even with liver nuclear RNA. Thus, in oviduct, those sequences present in primary transcripts, and analyzed under our experimental conditions, are present in different hormonal states and also in other chick tissues.

Amanitins↗
PubMed1978

Studies on the subpopulation and function of peripheral lymphocytes, and lymphocyte reactivity to colonic mucosal antigen and bacterial antigen in patients with ulcerative colitis and Crohn's disease.

Immunological studies were carried out in fifteen cases of ulcerative colitis, three cases of tuberculous colitis, four cases of Crohn's disease and one case of Behcet's disease diagnosed by X-ray, endoscopy or biopsy mainly from the standpoint of cellular immunity. In patients with ulcerative colitis the T-cell population and PHA responsiveness of peripheral lymphocytes were both depressed more than in the control group. At different stages of the disease, the deviation of the values of PHA responsiveness of lymphocytes showed a rather wide range in the active stage and there was also immunological instability. However, when the disease entered remission, the immunological conditions settled down and the pathological condition appeared stable. In contrast to the nonspecific immunological conditions mentioned above, characteristically, there were many examples of a positive lymphocyte response to colonic mucosal and bacterial antigens. In all cases of Crohn's disease the lesions are in the small intestine and there was a reduced response to PHA lymphocytic stimulation which was more pronounced than that in patients with ulcerative colitis. PHA response was also high in tuberculous colitis cases.

Adult↗
PubMed1978

Susceptibilities of normal and malignant human lung cells in culture to the cytocidal action of antitumor agents.

Cultured normal and malignant human lung cells were examined for their different sensitivities to the cytocidal action of nine antitumor and three non-antitumor agents. The malignant cells were killed preferentially at lower concentrations and in a shorter time with each antitumor agent, Adriamycin, neocarzinostatin, bleomycin, actinomycin D, mitomycin C, carboquone, 1-beta-D-arabinofuranosylcytosine, 5-fluorouracil, and 5-fluorodeoxyuridine. Among these, Adriamycin, 5-fluorouracil, and 5-fluoro-deoxyuridine exhibited a higher differential lethal action on the malignant cells than did the other antitumor agents. The two cell lines exhibited little difference in cytolytic sensitivity to non-antitumor cytotoxic agents such as amphotericin B, G-strophanthin, and alph-amanitin.

Antineoplastic Agents↗