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Biomedical subjects

V Wunderlich

Publications and source records attributed to V Wunderlich.

70 records · Page 4Linked to original sources
PubMed1976

[Elimination of a paramyxo-type virus from oncornavirus-producing human cell lines (author's transl)].

A virus of the paramyxo-type was eliminated from cell-free material of human oncornavirus-producing cell lines (PMF). After transmission of this paramyxovirus-free inoculum to a human permanent cell strain (Tu 197/Tr 1) oncornaviruses were permanently formed and no paramyxoviruses could be detected. The paramyxovirus-free, oncornavirus-producing PMF-39 cell line could be established after inoculation of the TU 197/Tr 1 line with cell-free material containing both oncorna- and paramyxovirus diluted 1 to 1000. A second way of elimination of the paramyxovirus was the treatment of cell-free material containing both viruses with antisera against paramyxovirus. In the Tu 197/Tr 1 line inoculated with such material only oncornaviruses were formed. The second paramyxovirus-free oncornavirus-producing cell line was designated PMF 50.

Animals↗
PubMed1975

Serological analysis of an oncornavirus (PMF virus) detected in malignant permanent human cell lines.

Immunodiffusion analysis of the PMF virus which was detected in malignant permanent human cell lines revealed positive reactions with antisera against the Mason-Pfizer monkey virus (MPMV). No cross-reactivity was demonstrated with murine leukemia virus (MuLV), rat leukemia virus (RaLV), hamster leukemia virus (HaLV), feline leukemia virus (FeLV), simian (woolly monkey) sarcoma virus (SSV-1) and mouse mammary tumor virus (MTV). The cross-reactive antigens of the PMF virus and the MPMV are considered as evidence for the human origin of the PMF virus.

Animals↗
PubMed1970

Preferential alkylation of mitochondrial deoxyribonucleic acid by N-methyl-N-nitrosourea.

The reaction of the carcinogen N-methyl-N-nitrosourea with mitochondrial DNA from various rat tissues was examined in vivo and in vitro. After incubation of isolated mitochondria or cell nuclei with N[(14)C]-methyl-N-nitrosourea in vitro and subsequent isolation and purification of the DNA the specific radioactivity of the mitochondrial DNA was 3-7 times that of the nuclear DNA. The incorporation of (14)C into embryonic mitochondrial DNA in vitro was about twice that into the liver mitochondrial DNA. Identical incorporation rates, however, were found for the reaction of isolated mitochondrial DNA or nuclear DNA respectively with N[(14)C]-methyl-N-nitrosourea. After intraperitoneal injection of 43.3-58.5mg of N[(14)C]-methyl-N-nitrosourea/kg body wt. to adult rats the labelling of the mitochondrial DNA was on average 5 times that of the nuclear DNA. A smaller specific labelling was observed for the ribosomal RNA, transfer RNA, and mitochondrial RNA as well as for the mitochondrial protein as compared with the mitochondrial DNA. After hydrolysis of the alkylated nucleic acids with hydrochloric acid, fractionation was carried out on Dowex 50 cation-exchange columns. In most experiments 70-80% of the input (14)C radioactivity was eluted in the 7-methylguanine fraction. The preferential alkylation of the mitochondrial DNA by N-methyl-N-nitrosourea in situ is discussed in connexion with the cytoplasmic-mutation hypothesis of carcinogenesis.

Alkylation↗
PubMedDate not supplied

Reverse transformation of human mammary carcinoma cells.

Exposure of cells derived from human mammary carcinoma cell line, MaTu, to daunorubicin started a selection process which reproducibly gave rise to sublines with different phenotypes. One subline exhibited a fibroblast-like morphology (MaTu/c7), while others retained the epitheloid phenotype of the parental cells (MaTu/p). Among the latter was clone 8 (MaTu/c8) which displayed piling-up structures not seen in MaTu/p cells. Striking differences were detected on immunocytochemistry using the anti-cytokeratin 19 antibody A53-B/A2 which positively reacted with cells from MaTu/c7, but not with those of MaTu/c8 and MaTu/p. In contrast, the anti-blood group H 2 antibody A46-B/B10 positively stained cells from MaTu/c8 and MaTu/p, but not those of MaTu/c7. Assays for tumorigenicity in nude mice demonstrated that MaTu/c7 is far less tumorigenic than MaTu/p, while MaTu/c8 showed a pattern distinguishing it from MaTu/p cells. Cross-resistance assays showed decreasing drug resistance in the order MaTu/c8 > MaTu/c7 > MaTu/p. These data suggest drug-induced differentiation with reversion of the neoplastic phenotype in MaTu/c7 and some form of malignant progression in MaTu/c8. This model system may be helpful for understanding cancer development, especially its relation to differentiation.

Animals↗