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M Wintzerith

Publications and source records attributed to M Wintzerith.

At least 37 records · Page 2Linked to original sources
PubMed1980

Brain nucleic acids and protein in various neurological mutant mice.

A study was made to compare alterations in the cerebral contents of nucleic acids and protein of several mouse strains affected by different neurological mutations: jimpy, msd, quaking, reeler, weaver, and dwarf. In normal and affected jimpy and msd mice the brain components analyzed were very similar. On the other hand, the cerebral hemispheres of quaking mice showed significant decreases in total RNA and DNA, when compared with those of normal littermates. In the affected reeler and weaver mice, total protein, RNA, and DNA in the cerebellum differed markedly from controls. Protein decreased slightly, whereas nucleic acids showed no significant variation in the cerebral hemispheres of the same mutants. The cerebella and cerebral hemispheres of affected dwarf mice had wet weights and total protein contents that were about 20% lower than those of their controls; DNA did not vary significantly in the various brain regions analyzed. The decrease of DNA we report in reeler and weaver mutant cerebellum in toto quantifies the lack of cell number, in contrast to histological studies which give only semiquantitative information.

Animals↗
PubMed1980

Purification and characterization of a nicotinamide deamidase released into the growth medium of neuroblastoma in vitro.

Nicotinamide deamidase (nicotinamide amidohydrolase, EC 3.5.1.19) has been demonstrated in the conditioned growth medium of the M1 clonal cell line of mouse C1300 neuroblastoma. The enzyme has been purified 1200-1500-fold by Sephadex G25, hydroxyapatite, DEAE-cellulose, Sephadex G200 and NAD-Sepharose column chromatographies. The purified protein was characterized by polyacrylamide gel electrophoresis under non-denaturing and denaturing conditions. The apparent molecular weight has been estimated to be 230,000, and the subunits had respective molecular weights of 65,000 and 50,000. Histidine was the only NH2-terminal amino acid found. The enzyme is a glycoprotein; mannose and N-acetyl-glucosamine have been identified. The effects of various ions on its activity have been investigated. The enzyme has a Km for nicotinamide in the order of 10(-6) M, a pH optimum of 7.2 and a pHi of 5.4. It is inhibited by heating and by sulfhydryl reagents. The existence of a nicotinamide deamidase with a high affinity for nicotinamide favors the operation of the Preiss-Handler pathway in M1 cells cultured in vitro. We found an induction of nicotinamide deamidase and a cellular increase of NAD with a higher nicotinamide supply and a repression of the released enzyme with supplying NAD in the nutrition medium of M1 cell cultures.

Amidohydrolases↗
PubMed1980

Hybridization studies of poly A-RNA from 5'-bromodeoxyuridine treated neuroblastoma cells.

Hybridization studies were carried out to measure sequence complexity and relative complexity of poly A-RNA populations from M1 neuroblastoma cells cultivated under proliferating conditions and after BrdU treatment. BrdU treatment is known to induce morphological differentiation. Hybridization kinetics were performed with [3H] labelled complementary DNA synthetized by reverse transcriptase action. The total complexities and the complexities of three classes of sequences measured for the two developmental states differed significantly. In particular, the total complexities as well as the complexity of the rare sequences class were higher in the poly A-RNA population of morphological differentiated M1 cells. Heterologous hybridization between poly A-RNA of proliferating cells with cDNA of differentiated M1 cells was very close to the homologous hybridization of poly A-RNA and cDNA from differentiated cells, nevertheless significant differences, were found in the intermediate and in the rare sequences classes. On the other hand the inverse heterologous hybridization (poly A-RNA of differentiated state X cDNA of proliferating cells) showed a lower hybridization in the region of Rot higher than 1. The plateau reached only 87 per cent compared to that of the homologous hybridization, suggesting that certain sequences expressed in the differentiated state. Nevertheless the number of different poly A-RNA species present per cell (seen by homologous hybridization experiments) was higher in differentiated state indicating that selective transcription took place beside repression with morphological differentiation.

Animals↗
PubMed1978

RNA metabolism in M1 adrenergic neuroblastoma cells.

RNA metabolism of M1 adrenergic neuroblastoma cells was investigated in logarithmic proliferating, stationary and differentiated states. [3h] uridine labelling experiments showed that in the stationary phase (10 days of culture) the cells incorporated less radioactive precursors into RNA than in the logarithmic phase (3 days of culture). Cells differentiated by bromodeoxyuridine treatment were compared with proliferating cells. At short labelling time, the BrdU-treated cells incorporated more [3H] uridine in RNA than the controls. But when morphological differentiation became irreversible, the treated cells incorporated less [3H] uridine into RNA. Our results show that morphological differentiation by BrdU-treatment of neuroblastoma M1 cells is not accompanied by striking changes in RNA metabolism.

Adenosine↗
PubMed1977

Nuclear, nucleolar repair, or turnover of DNA in adult rat brain.

Labeled thymidine administered to adult rats is incorporated at a low level into brain DNA as shown by biochemical and autoradiographic methods. This incorporation takes place in part into neuronal nuclei and nucleoli and also into glial nuclei. While incorporation into glial nuclei is interpreted to represent known glial cell proliferation, incorporation into neuronal nucleoli may be related to nucleolar DNA synthesis, which in turn is responsible for the regulation of nucleolar RNA synthesis. It could also be due to DNA repair synthesis. Assuming this latter phenomenon, our results suggest that nucleolar DNA is more sensitive than chromosomal DNA to ionizing radiations and other factors.

Animals↗