PubMed Health⌕ Search

Biomedical subjects

V Erfle

Publications and source records attributed to V Erfle.

At least 163 records · Page 9Linked to original sources
PubMed1981

ELISA for the detection and quantification of C-type viral glycoprotein (gp70) using antibodies that recognize the protein moieties of the glycoproteins.

The enzyme-linked immunosorbent assay (ELISA) technique was applied to the detection and quantification of simian sarcoma-associated virus (SiSV)-glycoprotein gp70 in virus preparations and cells and compared to the RIA competition technique. By detecting 0.1 ng of retroviral glycoprotein, its sensitivity is comparable to that of the RIA technique. It was further shown that the antibodies used recognize the protein and not the sugar components of the glycoprotein.

Animals↗
PubMed1980

Time course of C-type retrovirus expression in mice submitted to osteosarcomagenic doses of 224radium.

Virus particles with the biochemical properties of C-type retroviruses appeared transiently in bone tissues of (C3H x 101) f1 hybrid mice early after treatment with 224 Radium; such particles were then again detected in the bones of the irradiated animals at the onset of osteosarcoma formation and in the osteosarcomas. Antibodies against a murine retrovirus isolated from a 224 Ra-induced osteosarcoma were produced and detected in the serum of the 224 Ra-treated animals within a month after treatment began. The antibody levels plateaued to a maximum after about 2 months and remained elevated until the tumors started to develop. The antibody concentration in the serum of these irradiated animals decreased then progressively to reach levels similar to those observed in untreated controls. It thus appears that the imminence of osteosarcoma development can be predicted by monitoring the anti-C-type virus antibody levels in the serum of the irradiated mice. These experiments also strongly suggest that treatment with 224Radium induces expression of endogenous viruses in the animals.

Animals↗
PubMed1980

Dermal dysplasia, hypotrichosis, and dorsal skin ulcers in adult NMRI-mice after X-irradiation in utero.

Prenatal X-irradiation in mice leads to a marked incidence of hypotrichosis and alopecia in offspring, when irradiation occurs during the stage of late organogenesis (day 11-13 p.c.). In addition, severe ulcerative dermatitis occurs in offspring starting at 2 months of age, with marked preference for those animals, which have been irradiated at least during days 11-13 p.c. This occurs without any dose dependence; application of doses between 2.4 Gy and 7.2 Gy results in approximately similar incidence rates of skin ulcers (range between 39.1 and 48.0%). There is no sex preference and no dependence on housing. At autopsy no special abnormalities were found in the internal organs with the exception of frequent signs of amyloidosis. This disease pattern could also be produced in germ-free animals. The intracutanous administration of skin extracts from affected animals into unirradiated mice leads to a marked infiltration of leukocytes. It is therefore suggested that prenatal X-irradiation induces a distinct dysplasia of the epidermis, which is followed by an endogenous leukotactic activity.

Alopecia↗
PubMed1980

Detection and quantification of type C viral proteins in tissues and sera with an enzyme immunoassay.

The detection and quantification of retroviral proteins in cells, tumors, and sera by an enzyme immunoassay technique (enzyme-linked immunosorbent assay [ELISA]) is described. The ELISA technique has been applied to three viral systems: murine leukemia virus, baboon endogenous virus, and simian sarcoma virus. By detecting 0.1 nf of retroviral antigen, the sensitivity of the ELISA is comparable to that of the competition radioimmunoassay technique.

Absorption↗
PubMed1980

Bacteriological examination of specified-pathogen-free animals: a procedure for small rodents.

Organs of 10 mice or 5 rats were pooled and homogenized. A portion of the homogenate was cultured on several selective and enrichment media. The method was tested by adding various pathogenic organisms to organ homogenates. 10(3)-10(4) microorganisms in homogenates of 10 organs were readily detected. This procedure allows even a small microbiological laboratory to detect a low frequency of infected animals in a colony.

Animals↗
PubMed1979

Establishment and characterization of C-type RNA virus-producing cell lines from radiation-induced murine osteosarcomas.

Eight cell lines were established from murine osteosarcomas induced in vivo with the radionuclides 224Ra and 227Th. They have been compared by light and electron microscopy, by karyology, and by their growth properties. The morphology, the growth pattern, and the ability to induce tumors in mice indicate that five of them are tumor cell lines. Chromosome studies demonstrated that the five cell lines have marker chromosomes. The other cell lines only showed some criteria generally used to score for transformation of fibroblasts and they may be derived from stromal cells. All cell lines release virus particles in the culture fluid which have the typical properties of RNA tumor viruses. They possess C-type morphology, a density of 1.16--1.18 g/cm3, a 60--70 S RNA, a RNA dependent DNA polymerase and they induce syncytia in rat XC cells. The possible significance of these virus particles in radiation osteosarcomagenesis is discussed.

Animals↗
PubMed1978

Biochemical studies on RNA tumor virus information and its transmission in B16 murine melanoma.

The mouse melanoma B16 contains particles encapsulating a high molecular weight RNA of 60--70S size associated with a reverse transcriptase. The particles possess a density of 1.14--1.18 g/cm3. The RNA shares sequences with the 70S RNAs of several mammalian C-type RNA tumor viruses. The nuclear DNA of the mouse melanoma B16 possesses particle-related sequences not present in the genome of normal C57BL mice.

Animals↗
PubMedDate not supplied

Target cells for HIV in the central nervous system: macrophages or glial cells?

Infection of foetal or embryonic brain cells and cell lines from human astrocytomas and gliomas with HIV1 derived from T-lymphoma cultures leads to the expression of HIV in about 1 to 2% of the cells in culture. Single-cell cloning of astrocytoma cells shortly after infection resulted in the establishment of persistently HIV1-infected cell lines. These cultures were characterized by low production of virus and moderate intra- and extracellular expression of structural proteins. However, high expression of the nef regulatory protein was found. The virus could be rescued by cocultivation with T cells and primary macrophages giving rise to typical syncytia formation. In contrast to infection with HIV-infected T-lymphoma lines, cocultivation with HIV1-infected primary macrophages or monocytic cell lines induced a reduction in the growth of astrocytes and failed to induce productive infection. These in vitro observations support the hypothesis that astrocytes and glial cells may be a reservoir for HIV in the central nervous system and that macrophages may not carry the virus to the brain, but rather may be infected in the brain after having penetrated the blood-brain barrier.

Astrocytes↗
PubMedDate not supplied

Restricted expression of HIV1 in human astrocytes: molecular basis for viral persistence in the CNS.

Besides macrophages and microglial cells, cells of astroglial origin are thought to be targets of HIV1 in the brain. HIV1 infection of astroglial cells results in restricted production of the virus. To analyse the molecular basis of this restricted infection phenotype, we established a chronically HIV1-infected low-producer astrocytoma cell line. These cells show only low levels of mRNA encoding structural proteins, due to a cell-determined blockage in the Rev/RRE regulatory axis. The low-producer state could not be overcome by treatment with known stimulators of virus expression such as phorbol ester, (12-O-tetradecanoylphorbol-13-acetate), tumour necrosis factor alpha or sodium butyrate. This indicates that the molecular mechanisms involved in restricting virus production in astroglial cells differ from those in latently infected T cells and monocytes.

Astrocytes↗