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Biomedical subjects

M Urade

Publications and source records attributed to M Urade.

82 records · Page 5Linked to original sources
PubMed1978

Isolation and characterization of a new rubella variang with DNA polymerase activity.

A rubella variant (HPV-RV) was isolated from high passage rubella virus preparations propagated at 37 degrees C in baby hamster kidney BHK21/WI-2 cells. HPV-RV formed clear plaques in HeLa cells and primary cells of the Rhesus monkey kidney although wild type rubella virus did not produce plaques in these cells. Cells persistently infected with rubella virus were insensitive to infection by HPV-RV at both 34 degrees and 39.5 degrees C. HPV-RV agglutinated one day old chick, human group O and sheep erythrocytes. This hemagglutinating activity was inhibited by anti-BHK latent virus serum but not by anti-rubella virus serum. The plaque forming ability of HPV-RV was neutralized by anti-BHK latent virus serum although the same antiserum did not affect the plaque forming ability of wild type rubella virus. Furthermore, HPV-RV was found to have the complement fixation antigen of rubella virus and DNA polymerase activity. From these findings, it is concluded that HPV-RV is a hybrid between rubella virus and a latent virus of BHK21/WI-2 cells.

Antigens, Viral↗
PubMed1978

Metastatic choriocarcinoma involving the gingiva.

A case of metastatic choriocarcinoma involving the mandible is reported. This case is analyzed for the potentiality of immunologic defense by utilizing tuberculin test and scoring the rate of blast formation of peripheral blood lymphocytes by phytohemagglutinin, resulting in a greatly decreased ability of cellular immunity.

Adult↗
PubMedDate not supplied

Hybrids between rubella virus and a latent virus of baby hamster kidney cell line BHK21: characterization of rubella virus and type 2 hybrid virus genomes and determination of their physical homology.

The biochemical nature of rubella virus and type 2 hybrid virus, which is a recombinant between rubella virus and a latent retrovirus of BHK21 cells, has been characterized. Type 2 hybrid virus carries DNA polymerase able to copy exogenous DNA. However, disrupted type 2 hybrid virions do not synthesize detectable amounts of DNA using the endogenous viral RNA or synthetic poly(rA)/oligo(dT) primed as a template. Thus, the type 2 hybrid virus DNA polymerase has no detectable reverse transcriptase activity. Rubella virus and type 2 hybrid virus RNA can serve as templates for avian myeloblastosis virus (AMV) reverse transcriptase, although they are inefficient. The addition of oligo(dT) to these viral RNA showed no significant stimulation of their template activity for AMV reverse transcriptase. The oligo(dT)-cellulose affinity column bound neither rubella virus nor type 2 hybrid virus RNA. This suggests that both RNA genomes have a very short poly(A) tail at their 3' end. Thus, complementary DNA (cDNA) synthesis by AMV reverse transcriptase using oligo(dT) primers showed no preferential reverse transcription from the genomic 3' terminus and produced only short cDNA fragments (about 200 nucleotides). We cross-hybridized these short cDNA fragments with their viral RNA, assuming that they are copies of random sites of the genome. These cDNA-RNA hybridization analyses of physical homology between type 2 hybrid virus and rubella virus genomes revealed that about 70% of the type 2 hybrid virus genome is derived from about an 85% portion of the rubella virus genome. These values indicate that the size of the type 2 hybrid virus genome is about 21% larger than that of the rubella virus genome. Co-sedimentation studies of these viral RNA by sucrose density gradient centrifugation confirmed that the molecular weight of type 2 hybrid virus RNA is 20% higher than that of rubella virus RNA. We propose a genomic structure of the type 2 hybrid virus taking into account both physical and biochemical data.

Animals↗
PubMedDate not supplied

Structural gene products and morphogenesis of a hybrid between rubella virus and a hamster latent retrovirus.

We studied the structural gene products and morphogenesis of the hybrid between rubella virus (RV) and a latent retrovirus (R-type virus or R virus) of a baby hamster kidney cell line, BHK21/WI-2. In electron microscopic analysis, the rubella virion measures 80 nm in diameter and has a round nucleoid form with an electron-lucid centre, while R-type virus is 110 nm in diameter and has a round nucleoid with radial spokes. The type 2 hybrid (H2) virion is pleomorphic, ranging from 85 to 110 nm in diameter, and has a nucleoid structure similar to R virus, with short spokes. Indirect immunofluorescence staining of H2-infected cells with polyclonal and monoclonal antibodies (mAb) against the RV structural proteins demonstrated expression of the homologous RV gene products. SDS-PAGE of 35S-methionine-labelled proteins in RV- and H2-infected cells revealed that they both produce four major immunoprecipitable proteins, three of which (E2a, E2b and C) are products of the two genetic homologous loci (e2 and c). In nonhomologous regions, RV-infected cells exhibited E1 protein, while H2-infected cells produced the Env protein of R virus. Western immunoblotting analysis of RV and H2 viral proteins with mAb confirmed that H2 virions carry rubella viral E2 and C proteins and that E1 protein is carried by RV but not H2 virion. These results explained the absence of serological cross-neutralization of haemagglutination and plaque-forming ability of RV and H2 viruses.

Animals↗