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F RAPP

Publications and source records attributed to F RAPP.

At least 19 recordsLinked to original sources
PubMed1965

DIFFERENTIAL EFFECTS OF INHIBITORS ON THE STEPS LEADING TO THE FORMATION OF SV40 TUMOR AND VIRUS ANTIGENS.

The effect of DNA antagonists and various antibiotics on steps in the synthesis of SV40 virus in green monkey kidney cells was investigated. Both the early forming tumor (T) antigen, as well as the later synthesized virus (V) antigen, were synthesized in the presence of fluorouracil and iododeoxyuridine. Cytosine arabinoside (and fluorodeoxyuridine in starved cells) prevented synthesis of V antigen but not T antigen. The synthesis of T antigen therefore does not require synthesis of virus DNA. Virus particles formed only in the presence of the iododeoxyuridine and they were non-infectious. Actinomycin D inhibited synthesis of both tumor and virus antigens, suggesting that the synthesis of these antigens involves DNA-dependent RNA. Puromycin allowed synthesis of the T antigen which remained localized at the nucleolar membrane. This finding with puromycin suggests that the T antigen is a protein of low molecular weight. Virus antigen forming in the presence of mitomycin C, p-fluorophenylalanine, iododeoxyuridine, or fluorouracil was distributed atypically. These inhibitors caused the V antigen to be diffusely spread throughout the nucleus, or to be concentrated at the nuclear membrane.

Animals↗
PubMed1965

TUMOR AND VIRUS ANTIGENS OF SIMIAN VIRUS 40: DIFFERENTIAL INHIBITION OF SYNTHESIS BY CYTOSINE ARABINOSIDE.

Cells infected with the papovavirus SV40 not only synthesize viral antigen but also synthesize the specific nonviral antigen found in SV40-induced tumors. In the presence of the DNA antagonist cytosine arabinoside, infected cells fail to make viral antigen but still synthesize the tumor antigen. Iododeoxyuridine does not inhibit the synthesis either of tumor or of virus antigen but does prevent the development of infectious virus.

Antigens↗
PubMed1964

INCOMPLETE SIMIAN PAPOVAVIRUS SV40. FORMATION OF NON-INFECTIOUS VIRAL ANTIGEN IN THE PRESENCE OF FLUOROURACIL.

A study was made of the effects of 5-fluorouracil (FU) and 5-fluorodeoxyuridine (FUDR) on the replication of the simian papovavirus SV40 in cercopithecus monkey kidney cells and on the production of virus antigen by these cells. Both drugs markedly suppressed the production of new infectious virus by SV40-infected cells. Synthesis of viral protein was also markedly suppressed by FUDR, but not by FU. In the presence of FU, infected cells produced large amounts of viral protein which were detected by the fluorescent antibody technique. The antigen was not distributed in a particulate fashion as in untreated cells. Diffuse virus antigen was observed in the nuclei of FU-treated cells, resembling the distribution of antigen near the end of the eclipse period in untreated, infected cultures. This stage of antigen production presumably preceded viral assembly. Virus particles with or without cores were rarely seen with the electron microscope in infected FU-treated cells, although large numbers of SV40 particles were readily visualized in untreated, infected cells. It appears that at least one antigenic protein of this papovavirus is synthesized abundantly in FU-treated cells, but is not assembled into virus shells in the presence of the inhibitor.

Animals↗
PubMed1964

PLAQUE DIFFERENTIATION AND REPLICATION OF VIRULENT AND ATTENUATED STRAINS OF MEASLES VIRUS.

Rapp, Fred (Baylor University College of Medicine, Houston, Tex.). Plaque differentiation and replication of virulent and attenuated strains of measles virus. J. Bacteriol. 88:1448-1458. 1964.-Plaque formation by strains of measles virus in a stable line of African green monkey kidney cells (BSC-1) is characterized by development of large plaques (>1 mm) within 4 days after inoculation of the cultures with the virulent Edmonston strain or by small plaques (<1 mm) after inoculation with the attenuated Edmonston strain of virus. Plaque formation by measles virus is not influenced by iododeoxyuridine, cytosine arabinoside, isatinthiosemicarbazone, streptonigrin, actinomycin D, or mitomycin C. The predominant cytopathic effect observed with both strains is the formation of large, multinucleated giant cells. Development of the giant cells is correlated with development of virus antigen and synthesis of infectious virus. Synthesis of virus is similar at 34 and at 37 C. Appearance of intracellular virus precedes release, and is later in the attenuated virus-infected cells than in cells infected with the virulent strain. With the virulent strain, equal concentrations of intra- and extracellular virus are found but, with attenuated virus, only a small fraction reaches the extracellular fluids, and more than 95% of the newly synthesized virus remains cell-associated.

Animals↗