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C Jungwirth

Publications and source records attributed to C Jungwirth.

54 records · Page 3Linked to original sources
PubMed1970

[Interferon].

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Acrylates↗
PubMed1969

Characterization of deoxyribonucleases induced by poxviruses.

Increases in deoxyribonuclease activity assayed at alkaline pH can be observed in poxvirus-infected cells when native or denatured deoxyribonucleic acid (DNA) is used as substrate. The deoxyribonuclease assayable with native DNA as substrate, induced in HeLa cells by cowpoxvirus or vaccinia virus WR, can be separated from the corresponding enzyme present in normal cells by chromatography on diethylaminoethyl cellulose. In addition, the two enzymes induced in the virus-infected cells differ from each other in their chromatographic properties. The two induced enzymes have been further characterized with respect to properties of enzymatic reaction.

Journal Article↗
PubMed1968

Effect of poxvirus infection on host cell deoxyribonucleic acid synthesis.

Deoxyribonucleic acid (DNA) synthesis was studied in poxvirus-infected cells by measuring (14)C-thymidine incorporation into viral and host cell DNA. A complete separation of the two species of DNA was achieved by combining the previously used "Dounce method" with a separation method based on different reannealing properties of viral and vertebrate DNA. Shortly after infection of HeLa cells with poxviruses, a burst of viral DNA synthesis occurred in the cytoplasm, but a rapid inhibition of host-cell DNA synthesis in the nucleus was observed. This inhibition of cellular DNA synthesis was also found if an accumulation of viral DNA was prevented. At high multiplicites, ultraviolet-irradiated virus inhibited host-cell DNA synthesis to the same extent as fully infectious poxvirus. Under the same conditions, heating at 60 C for 15 min caused a decrease in the ability of cowpox virus to inhibit host-cell DNA synthesis, but did not produce the same effect on vaccinia virus strain WR.

Carbon Isotopes↗
PubMed1967

Effect of interferon on deoxyribonuclease induction in chick fibroblast cultures infected with cowpox virus.

An exonuclease which degrades native deoxyribonucleic acid at pH 9.2 was induced in chick embryo fibroblast cultures and in human amnion cells by infection with cowpox virus. Highly purified chick embryo interferon suppressed the induction of the enzyme in the homologous cell system but not in the human amnion cell cultures. "Mock" interferon prepared from uninfected chicken eggs and purified in the same manner as biologically active interferon preparations had no effect on the induction of the enzyme.

Amnion↗
PubMedDate not supplied

In vitro translation of natural mRNAs in a cell-free system containing components from interferon-treated chicken fibroblasts and factor preparations from mouse ascites cells or rabbit reticulocytes.

The effect of interferon has been studied in a mixed cell-free protein synthesizing system. Hemoglobin (Hb) and Encephalomyocarditis virus (EMC)-RNA can be efficiently translated in vitro in a system containing S-30 lysates or run-off ribosomes from primary chick embryo fibroblasts (CEF) and a postmicrosomal supernatant from mouse ascites cells or a ribosomal-wash preparation from rabbit reticulocytes. Ribosomes prepared from CEF pretreated with high doses of homologous interferon (500 units/ml) were able to translate Hb-RNA in the presence of heterologous factors with the same efficiency as ribosomes prepared from control cells. Translation of EMC-RNAP WAS SLIGHTLY Reduced if ribosomes from interferon-treated cells were used in the mixed cell-free system, confirming previous reports. No inhibitory effect caused by interferon treatment of CEF cells could be detected on in vitro translation of natural mRNAs if the cells had, in addition to interferon treatment, been infected with vaccinia virus. Possible reasons for the different observations made with out cell-free protein synthesizing system from CEF and with cell-free systems prepared from mouse cells are discussed.

Animals↗