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Biomedical subjects

R Ohuchi

Publications and source records attributed to R Ohuchi.

29 records · Page 2Linked to original sources
PubMed1987

Characterization of the measles virus isolated from the brain of a patient with immunosuppressive measles encephalitis.

Two strains of measles virus with different biologic properties were isolated from the brain of a patient with immunosuppressive measles encephalitis. One strain (Oita-1) grew extremely slowly in Vero cells and did not produce any cell-free virions. The other strain (Oita-2) replicated well, and a small amount of cell-free virus was detected from the culture medium and the freeze-thawed homogenate. Neurovirulence of the Oita-1 strain to mice was, however, stronger than that of the Oita-2 strain. Synthesis of the M protein by the Oita-2 strain was not demonstrable in the infected cells when they were labeled for 24 hr; however, a new protein moiety that was smaller in molecular weight than the M protein and that was not precipitated with monoclonal antibody to M protein was demonstrated by pulse-labeling for 1 hr. Antibodies to the M protein, as well as to other proteins, were detected (by immunoprecipitation) in the serum and cerebrospinal fluid of the patient.

Animals↗
PubMed1986

Protective effect of measles virus inoculation on subacute sclerosing panencephalitis virus-infected mice.

The Biken strain of subacute sclerosing panencephalitis (SSPE) virus caused a fatal neurologic disease in adult mice after intracerebral inoculation. However, the mice were completely protected from the disease when a high dose of measles virus was given intracerebrally after the SSPE virus infection. The measles virus inoculation induced interferon production and immune responses. An experiment with athymic nude mice showed that interferon and anti-measles antibody were able to prolong the incubation period of the disease but not to protect the SSPE virus-infected nude mice from death. For complete protection, T lymphocytes appeared to be essential. The present study suggested that the protective effect of measles virus inoculation is basically due to the induction of immune responses and that SSPE virus infection in mice is susceptible to immune reactions.

Animals↗
PubMed1984

Slow development of measles virus (Edmonston strain) infection in the brain of nude mice.

The Edmonston strain of measles virus caused neurologic disease in athymic nude mice by intracerebral inoculation. The incubation periods of the disease, however, were extremely long, ranging from 59 to 140 days when the mice were inoculated with 10(4) plaque forming units (PFU) of the virus. The Edmonston strain was highly infectious in the nude mouse brain since virus infection was established even with 1 PFU of the virus. Virus titers in the brains of infected mice increased with the time of incubation. These results indicate that the extremely long incubation period of the disease is ascribed to very slow development of virus infection in the mouse brain. On the other hand, the incubation periods of the Biken strain of SSPE virus were very short (generally within 2 weeks) even with inoculations of 1 PFU of the virus. However, the extent of the dissemination of infection in brains was not significantly different between the two viruses as examined by immunofluorescent staining.

Animals↗
PubMed1982

Demonstration of hemolytic and fusion activities of influenza C virus.

Influenza C virus showed a marked hemolytic activity when incubated with murine erythrocytes at 37 degrees C in acidic medium. The virus-specific hemolysis was most efficient at pH 5.0. Extensive cell fusion also occurred when the erythrocytes were treated with the virus at acidic pH. When propagated in MDCK cells, the virus had an extremely low infectivity and did not display hemolytic activity in any pH range. When the inactive virus was subjected to mild trypsin treatment, hemolytic activity was drastically manifested, accompanying a drastic increase in infectivity. The glycoprotein in the inactive virus was cleaved into smaller components by trypsin treatments. These results indicated that the envelope of influenza C virus can fuse with the cellular membrane under acidic conditions and that the activation of influenza C virus by cleavage was due to the appearance of this envelope fusion activity.

Animals↗
PubMed1981

Mode of subacute sclerosing panencephalitis (SSPE) virus infection in tissue culture cells. III. Neurovirulence of cell-free SSPE viruses of Niigata-1, Kitaken-1, and Biken strains.

Cell-free viruses recovered from virus-carrying cultures of the Niigata-1, Kitaken-1, and Biken strains of SSPE virus were examined for neurovirulence. The cell-free viruses were prepared by freezing and thawing or by EDTA treatment of the virus-carrying cultures and inoculated into adult mice intracerebrally. A considerable number of the inoculated mice showed clinical signs about 1 to 5 weeks after the inoculation. The first symptom was hyperreactivity, which was followed by paresis and myoclonus. All of the affected mice fell in paralysis and finally died. The virus could be recovered from the moribund mice by cocultivation of the brain cells with Vero cells. Immunofluorescence staining of the brain tissue revealed that infected cells containing viral antigens were distributed sparsely. No inflammatory feature, however, was observed in the brain as far as examined and neutralizing antibody against SSPE virus was not detected in sera from the mice inoculated with the cell-free SSPE viruses.

Animals↗
PubMed1980

Mode of subacute sclerosing panencephalitis (SSPE) virus infection in tissue culture cells. II. Cell-free viruses in cell cultures infected with Kitaken-1 and Biken strains of SSPE virus.

Cell-free infectious viruses were successfully recovered by the aid of freezing and thawing from cultures infected with the Kitaken-1 and Biken strains of subacute sclerosing panencephalitis (SSPE) virus. Our results including those in a previous report which dealt with the Niigata-1 strain of SSPE virus show that cell-free viruses can be detected from all of the SSPE virus-carrying cultures established in Japan. It was also found that cell-free infectious viruses can be recovered efficiently by dispersing the virus-carrying cultures with EDTA. The inclusion of trypsin in the EDTA solution, however, caused a poor recovery of the infectious viruses. Infection of cells with the cell-free viruses readily established the virus-carrying cultures that have characteristics comparable to those of their original cultures. The culture infected with the Kitaken-1 strain produced infectious viruses in about ten times the amount of the other two infected cultures. The buoyant densities of the cell-free infectious viruses were almost the same among the three strains, the values being 1.120 to 1.132, but significantly less than that of 1.164 of measles virus. The low density can be ascribed to one of the characteristics of these SSPE viruses.

Cell Line↗
PubMed1979

[A quantitative analysis of urinary 17-KS by GC-MS (author's transl)].

A quantitative analysis of seven components of 17-KS in human urine was successfully carried out by GCMS. The sample including deuterated 17-KS was introduced into TMS derivatives by BSTFA in pyridine. The derived TMS derivatives were analysed using the GC-MS system equipped with the column of 0.5% NPGS Chromosorb W AW DMCS, and the temperature was programmed from 180 degrees C to 240 degrees C at 3 degrees C/min. increment. Seven components were well separated, and each fraction was analysed by MS spectrum. Normal human urine was analysed by this method, the result of which is summarized in Table 3.

17-Ketosteroids↗
PubMed1979

Mode of subacute sclerosing panencephalitis (SSPE) virus infection in tissue culture cells. I. Detection of infectious virions from cells infected with Niigata-1 strain of SSPE virus.

By the aid of freezing and thawing, cell-free infectious virions were detected from an apparently nonproductive Vero cell line infected with Niigata-1 strain of subacute sclerosing panencephalitis virus. The production of infectious virions was limited in amount and such virions were detectable only during a limited period after cell subculture. The infectious virions were filtrable through a 0.65 mu membrane filter and neutralized completely by an antiserum against measles virus. The virions were banded at the density of 1.132, while Edmonston strain of measles virus banded at 1.164 in potassium tartrate density gradients. Infectious virions were also released from infected Vero cells by treatment of the cells in a hypotonic solution to an amount comparable to that obtained by freezing and thawing. Infection of normal culture of Vero cells with the infectious virions readily established a virus-cell interaction identical to that in the original infected culture from which the virions were recovered.

Animals↗