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Biomedical subjects

M Onuma

Publications and source records attributed to M Onuma.

At least 235 records · Page 13Linked to original sources

Monoclonal antibodies against a paramyxovirus isolated from Japanese Sparrow-Hawks.

Five monoclonal antibodies against the haemagglutinin-neuraminidase (HN) molecule of Taka virus, a variant of Newcastle disease virus (NDV), were established to compare the antigenicities of several avian paramyxoviruses including NDV. From the results of the cross haemagglutination-inhibition (HI) test with the monoclonal antibodies, the HN molecule of Taka virus seemed to have at least three different antigenic determinants; one was specific for all NDV strains tested, the second was for Taka virus and Komarov strain of NDV and the third was for Taka virus, Komarov strain, Bangor and Yucaipa. Furthermore, the differences in the ratio of HI to neuraminidase-inhibition titers suggested that the separate active sites involved in haemagglutinin and neuraminidase activities might exist at least in close proximity.

Animals↗

Molecular cloning of bovine leukemia virus DNA integrated into the bovine tumor cell genome.

The bovine leukemia virus (BLV) DNA harbored in the bovine tumor cell genome was cloned in lambda Charon 4A phage. Using either representative or 3' half-enriched BLV cDNA as a blot hybridization probe, clone lambda BLV-1 was shown to carry 9 kb of the BLV genome, flanked by cellular sequences at both ends. Restriction mapping with twelve endonucleases and hybridization of the DNA fragments to BLV cDNA representing a 3'-end portion of the viral genome revealed the presence and precise location of two long terminal repeats (LTRs) and virus-cell junctions. Thus, lambda BLV-1 appears to contain the complete BLV genome and flanking tumor cellular sequences. The restriction map of the cloned BLV proviral DNA closely resembles that previously reported for unintegrated linear proviral DNA, but differs significantly from that of the integrated provirus of another BLV isolate, the difference occurring preferentially in the putative gag and pol genes.

Animals↗

Isolation of ortho- and paramyxoviruses from migrating feral ducks in Hokkaido. Brief Report.

A total of 18 hemagglutinating agents were isolated from 14 of 278 migrating feral ducks In Hokkaido during the surveillance studies conducted from 1978 to 1981. Seven of the 18 isolates belonged to paramyxovirus and the rest to influenza A virus. Five isolates of paramyxovirus reacted specifically with antiserum to duck/HK/199/77 and 7 isolates of influenza A virus possessed the antigenic configuration of H10N3. Three of the isolates possessed an hemagglutinin that has no antigenic relation to any of the 26 known strains of avian, swine, equine and human influenza A viruses.

Animals↗

Integration of bovine leukemia virus DNA in the genomes of bovine lymphosarcoma cells.

Integration of bovine leukemia virus (BLV) in the genomes of infected cells was investigated in cattle with enzootic bovine leukosis (EBL) and sporadic bovine leukosis (SBL). Southern blot hybridization of BLV cDNA to Eco RI and Xba I restriction fragments of EBL tumor DNAs revealed that: 1) one to four or more copies of proviral DNA were integrated per genome; 2) the restriction pattern of the integrated proviral DNA was the same in two or three different tumors from the same animals; and 3) different patterns were observed among tumors from four different animals. These findings suggest the monoclonal origin of different tumors in an individual animal and the existence of multiple chromosomal integration sites of BLV provirus. DNAs from several SBL tumors were also analyzed with the same restriction enzymes, but with both representative and cDNA3'-enriched's of BLV RNA. No hybridization bands reactive with representative BLV cDNA could be detected, while several bands appeared to hybridize with cDNA3'-enriched.

Animals↗

Enhancement of antibody activity to bovine leukemia virus by complement.

Cocultivation of fetal lamb kidney cells infected with bovine leukemia virus (BLV) and the cat cells containing murine sarcoma virus genome resulted in the rapid production of syncytia. This syncytia formation was inhibited by serum containing antibodies to glycoprotein antigen of BLV. When rabbit complement was added to the antiserum for early syncytia inhibition (ESI) test, a significant enhancement of ESI activity of the antiserum was observed. This enhancement was associated with IgG fraction but not with IgM fraction of the antiserum. The results of the comparative serological tests showed that the ESI test with complement was much more sensitive than either immunodiffusion or complement fixation tests in the detection of BLV antibodies.

Animals↗