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Biomedical subjects

M Matumoto

Publications and source records attributed to M Matumoto.

At least 73 records · Page 4Linked to original sources

Antigenic relationships between rotaviruses from different species as studied by neutralization and immunofluorescence.

Antigenic relationships between the Wa, Hochi, Ito, Hosokawa and Nemoto strains of human rotavirus, the SA-11 strain of simian rotavirus, the Lincoln strain of bovine rotavirus, the OSU strain of porcine rotavirus and the R-2 strain of lapine rotavirus, which were all established in cell culture, were studied by neutralization (NT) and immunofluorescence (IF) using guinea pig antisera against these strains. The strains could not be distinguished by indirect IF staining of infected cells because of marked cross reactions. On the other hand, the NT test clearly distinguished these strains, although there was a one-way antigenic relationship between some of them. The five strains of human rotavirus were clearly distinguished from each other by NT test. These human strains exhibited much higher homologous titers than heterologous titers, the former being at least eight-fold higher than the latter. The presence of at least five serotypes of human rotavirus was indicated.

Animals↗

Experimental parainfluenzavirus infection in mice: fatal illness with atrophy of thymus and spleen in mice caused by a variant of parainfluenza 3 virus.

Intracerebral inoculation of the YN strain of parainfluenza 3 virus was found to induce an acute fatal illness characterized by marked thymic and splenic atrophy in newborn mice. Previously we showed that the YN strain contains three distinct plaque-type variants, LT, SC, and M. Of these, the M-type variant induced this fatal illness, whereas the other two variants induced hydrocephalus.

Animals↗

Comparative measurement of equine influenza virus antibodies in horse sera by single radial hemolysis, neutralization, and hemagglutination inhibition tests.

Single radial hemolysis (SRH), neutralization (NT), and hemagglutination inhibition (HI) tests were carried out on sera from horses immunized against the Prague and Miami strains of equine influenza virus. The HI and NT tests demonstrated good sensitivity; the sensitivity of the SRH test was somewhat lower. The NT titers of individual sera were correlated very closely with the HI titers, although the NT titers were higher. SRH zone diameters of individual sera also showed significant correlation with the NT and NI titers. The SRH test appears to be suitable for large-scale serological surveys and offers the advantages of rapidity and simplicity.

Animals↗

Parainfluenza 3 virus: plaque-type variants lacking neuraminidase activity.

Virus clones lacking detectable neuraminidase activity (SC-YN and M-YN) as well as those possessing it (LT-910N and LT-YN) were isolated from bovine strains of parainfluenza 3 virus. LT-910N and LT-YN viruses produced large turbid plaques in MDBK cells, and SC-YN virus produced small clear plaques. Incorporation of a bacterial neuraminidase in agar overlay medium made SC-YN virus form large turbid plaques, whereas it made M-YN virus form large clear plaques. However, M-YN virus formed only pinhole plaques or no plaques in the absence of neuraminidase. The exogenous neuraminidase had little effect on the plaque formation of LT-910N and LT-YN viruses. M-YN virus induced extensive syncytial formation, and SC-YN virus produced less extensive syncytial formation. The exogenous neuraminidase enhanced replication of SC-YN and M-YN viruses and reduced syncytial formation by these viruses. The enzyme had little effect on replication and cytopathic effect of LT-910N and LT-YN viruses. The reason for these effects of the exogenous neuraminidase is discussed.

Animals↗

Serological relation between calf diarrhea coronavirus and hemagglutinating encephalomyelitis virus.

Neutralizing (NT) and hemagglutination-inhibiting (HI) antibodies to calf diarrhea coronavirus (CDCV) and hemagglutinating encephalomyelitis virus of swine (HEV) (strain 67N) were detected in high proportions of normal adult cattle and pigs in Japan. Since comparison of NT and HI titers in the serum samples suggested in antigenic difference between the viruses, cross NT and HI tests of these viruses were carried out with antisera raised in rabbits. The homologous NT titers were markedly higher than the heterologous titers. In HI tests essentially the same results were obtained. These findings indicate the presence of a marked difference in antigenic make-up between CDCV and HEV. NT and HI tests can clearly differentiate the viruses, although there is some cross reaction.

Animals↗

Enhanced production of virus-inhibiting factor (interferon) in human diploid cells by ultraviolet irradiation and temperature shift-down after stimulation with Newcastle disease virus.

The production of the virus-inhibiting factor or interferon (IF) was highest in cells incubated at 37 C after inoculation with Newcastle disease (ND) virus and decreased as the incubation temperature was lowered. Shift-down of incubation temperature to 32 C or 34 C after incubation at 37 C for 4--7 hr enhanced IF production in cell cultures stimulated with ND virus, as compared with cultures incubated continuously at 37 C. Shift-down to 32 C after incubation at 37 C for 6 hr was optimal for this enhancement of IF yield. Enhanced IF production was also observed in cell cultures irradiated by ultraviolet light 4--7 hr after stimulation with ND virus.

Cell Line↗