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Biomedical subjects

F Rapp

Publications and source records attributed to F Rapp.

At least 181 records · Page 10Linked to original sources
PubMed1976

In vitro viral transformation of human prostatic carcinoma.

Cell cultures derived from fetal human and prostatic adenocarcinoma were inoculated with SV40 virus. Within 6 weeks in vitro morphologic transformation occurred, after which the cells proliferated rapidly. They exhibited the SV40 T-antigen by immunofluorescence and survived propagation beyond the limited lifespan of uninfected cultures. We suggest that this may be a useful technique in establishing stable cell lines of human prostate.

Adenocarcinoma↗
PubMed1976

Induction of cellular DNA synthesis and increased mitotic activity in syrian hamster embryo cells abortively infected with human cytomegalovirus.

The effect of human cytomegalovirus (CMV) on cell DNA synthesis and mitotic activity in hamster embryo fibroblasts was examined. The results indicated that CMV infected cells had increased rates of cell DNA replication and mitotic activity. Detection of the effect of CMV on these two parameters necessitated arrest of cells prior to infection with low serum concentrations. This lowered the background levels of DNA synthesis and cell division so that the effect of virus infection could be detected. The data indicate that cells arrested prior to infection demonstrate increased susceptibility to virus infection. It was also observed that the effect of CMV on both DNA replication and mitotic activity could be enhanced by irradiation with ultraviolet light of the virus prior to infection.

Animals↗
PubMed1976

Host range temperature-sensitive mutants of herpes simplex virus type 2.

Two small-plaque mutants of herpes simplex virus type 2 (HSV-2) (strain 333), whose growth at 39 C was blocked in certain cell types (cell-dependent temperature sensitivity), were compared compared with parental virus in a number of biological assays. One mutant (no. 69) was found to produce a large number of morphologically normal, but noninfectious, particles; under nonpermissive conditions, these mutant particles were able to interfere with the replication of wild-type HSV-2. The other mutant (no. 74), which is known to belong to a different complementation group, appeared to direct little virus DNA synthesis, even at the permissive temperature. Progeny production and virus DNA synthesis in cells infected by mutant 74 were delayed in comparison with wild-type virus-infected cells. Both mutants were found to be more sensitive to UV irradiation than the parental virus; this was especially marked in the case of mutant 74. Moreover, this mutant was found to have a high transforming efficiency at much lower doses of irradiation than those needed to abolish the cytopathic effect of wildtype HSV-2.

Animals↗
PubMed1976

Herpes simplex virus DNA in transformed cells: sequence complexity in five hamster cell lines and one derived hamster tumor.

Analyses of the hybridization kinetics of labeled herpes simplex virus 2 (HSV-2) DNA with DNA from five hamster cell lines transformed by UV light-irradiated HSV-2 revealed the following. (i) Viral DNA sequences were detected in all five cell lines tested. (ii) None of the cell lines contained the full complement of HSV-2 DNA. (iii) The amount of viral DNA present in the cells varied in different transformed cell lines and ranged from 8 to 32% of the HSV-2 DNA genome in 1 to 3 copies/cell. (iv) Two parallel passages of the same cell line (333-2-29) differed in the amount of viral DNA they contained. We also compared the viral DNA sequences present in (i) one transformed cell line (333-8-9) propagated serially in culture for 80 passages, (ii) a tumor produced by inoculation of a newborn hamster with the 333-8-9 cells, and (iii) a cell line derived from a hamster tumor as above and propagated in culture for 32 passages. The results show that viral DNA present in the hamster tumor and in the cells derived from the tumor had a lower sequence complexity than that present in the original serially passaged 333-8-9 cell line.

Animals↗
PubMed1976

Induction of murine p30 by superinfecting herpesviruses.

The interaction of endogenous type C viruses with superinfecting herpes simplex virus type 2 (HSV-2) was investigated in two murine cell lines. Replication of HSV-2 was suboptimal in random-bred Swiss/3T3A cells and, in initial experiments, infection with a low virus-to-cell ratio resulted in carrier cultures with enhanced murine leukemia virus (MuLV) p30 expression. Immunofluorescence tests with Swiss/3T3A cells productively infected with HSV-2 also showed HSV-associated cytoplasmic antigens and enhanced MuLV p30 expression when compared with uninfected controls. Inactivation of HSV-2 with UV light did not abolish this reaction, although the number of cells expressing p30 was reduced. HSV-2 replicated more efficiently in a line of NIH Swiss cells (N c1 A c1 10). These cells are not readily inducible for type C expression by conventional methods; however, untreated and UV-inactivated HSV-2 induced both HSV-2-associated antigens and MuLV p30 in these cells. Although the Birch strain of human cytomegalovirus induced MuLV p30, neither mouse cytomegalovirus nor vesicular stomatitis virus induced MuLV p30 in either cell line.

Animals↗
PubMed1976

Distinguishing cytomegalovirus, mycoplasma, and cellular DNA polymerases.

Cytomegalovirus-induced DNA polymerase can be distinguished from infected-cell enzymes by activity in 100 mM (NH4)2SO4. Virus polymerase is stimulated to 145% of control, whereas mock-infected cell polymerase is inhibited to 12% of control without added salt. Mycoplasmas induce a DNA polymerase in cell extracts that is stimulated to 130 to 180% by 25 mM (NH4)2SO4. Mycoplasma DNA polymerase may be mistaken for a virus-induced polymerase when virus stocks are contaminated. Identification of virus, cellular, and mycoplasma DNA polymerases in total cell extracts is described using sedimentation rate and effect of inhibitors on DNA polymerase activities.

Acetates↗
PubMed1976

Deoxycytidine kinase from rabbit kidney cells infected with herpes simplex virus type 1 or 2.

When rabbit kidney cells were infected with herpes simplex virus type 1 (strain Seibert) or herpes simplex virus type 2 (strain 316D), deoxycytidine kinase (CdR kinase) activity, assayed at 38 degrees, increased 5- to 15-fold relative to controls. The CdR kinase activity induced by type 2 virus was more thermolabile than the enzyme activity induced by type 1 virus. When CdR kinase activity was assayed at various temperatures between 0.5 and 38 degrees, maximum activity for type 1 enzyme was obtained at 16 degrees while maximum activities for host and type 2 enzymes were obtained at 38 degrees. Both type 1 and type 2 induced CdR kinase activities eluted at the same positions as deoxythymidine kinase activities on a Sephadex G-100 column. The estimated mol wt for HSV-1 (Seibert) and HSV-2 (316D) induced CdR kinases are 67,000 and 60,000, respectively.

Cell Line↗
PubMed1976

Experimental evidence for the oncogenic potential of herpes simplex virus.

The data presented in this review reveal the transforming potential and oncogenic capability of herpes simplex viruses in cultured cells and in experimental animals, respectively. Unfortunately, the role of these agents in human cancer, especially cervical, cannot be unequivocally established through the indirect approaches used, but circumstantial evidence that these viruses represent potential oncogens in the human population is mounting.

Animals↗
PubMed1976

The development by cytomegalovirus-infected cells of binding affinity for normal human immunoglobulin.

After infection with human cytomegalovirus (CMV), cells develop an affinity for normal human immunoglobulin G (IgG). This was demonstrated using 125iodine-labeled purified IgG. It was further demonstrated that the immunoglobulin molecule binds to CMV-infected cells via its Fc portion, and competition for binding to infected cells occurred between purified preparations of human IgG and the Fc fragment of human IgG. Whole sera from individuals with or without a high titer of anti-CMV antibody were labeled with 125iodine and it was demonstrated that serum from individuals with no anti-CMV antibody had an affinity for CMV-infected cells which probably reflected binding of IgG via its Fc fragment. The possible significance of these results in immunologic studies of human CMV is considered.

Antibodies, Viral↗
PubMed1976

Diseases associated with herpesviruses.

Human herpesviruses have been associated with numerous diseases throughout history (Table 3), but their ability to induce latent and recurrent infections, alongwith their oncogenic capabilities, is only beginning to be understood. Accordingly, our ability to deal with the diseases induced by herpesviruses is severely limited by our lack of information concerning the basic processes of virus-host cell interactions and systemic host factors; especially immune factors that are involved in the disease process.

Antiviral Agents↗
PubMed1975

Demonstration of oncogenic potential of mammalian cells transformed by DNA-containing viruses following photodynamic inactivation.

The oncogenic properties of hamster embryo cells transformed by herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) and SV40 virus following photodynamic inactivation using neutral red were determined by subcutaneous inoculation into newborn Syrian hamsters. Cells transformed by all three viruses produced palpable tumors after different latent periods. Histopathological examination showed that HSV-2 tumors were fibrosarcomas and metastases were often seen in the lungs. HSV-2 primary tumors were reinoculated subcutaneously into weanling hamsters; they developed palpable tumors within 2 weeks. HSV-specific antigens were detected in the cytoplasm and/or on the surface of both the HSV-1 and HSV-2 tumor-cell cultures by the indirect immunofluorescence technique. The same method revealed SV40 tumor antigen in the nuclei of the SV40 tumor cells. Sera from HSV or SV40 tumor-bearing hamsters gave positive reactions when tested against HSV-infected hamster cells or SV40-infected monkey cells, respectively. These results demonstrate that herpes simplex virus and SV40, whose infectivity was lost following photodynamic inactivation, retained the virus genetic information necessary for transformation of normal cells to an oncogenic phenotype.

Animals↗
PubMed1975

Measles virus: an unwanted variant causing hydrocephalus.

Mutagenization of measles virus with proflavine produced a temperature-sensitive mutant capable of inducing hydrocephalus following intracranial inoculation of newborn hamsters. Hydrocephalus was not produced by the parental strain or by other measles virus mutants. Thus, mutants can be the causative agents of disease not associated with the parental strain. The results dictate caution in the use and distribution of experimentally induced virus variants.

Acridines↗