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Biomedical subjects

H Kurogi

Publications and source records attributed to H Kurogi.

At least 37 records · Page 2Linked to original sources
PubMed1978

Development of inactivated vaccine for Akabane disease.

Virus inactivated by formalin or beta-propiolactone was superior to that inactivated by ether and heating in immunogenicity to mice. There were no significant differences in the antibody response of mice among such adjuvants as aluminum phosphate gel, aluminum hydroxide gel, and sodium arginate gel. When cattle were immunized with vaccine inactivated by formalin and adsorbed to aluminum phosphate gel, an excellent effect was obtained by injection with two doses of 3 ml each given at a 4-week interval. It was also suggested that mice and guinea pigs might be available for the potency test of vaccine. When calves and pregnant goats were injected with vaccine in the same manner as mentioned above, they were prevented from viremia and fetal infection caused by challenge virus. Even when stored at 4 degrees C for 12 months, vaccine was found to retain its stabilized immunogenicity. When pregnant cows were injected with vaccine in the field, the positive rate of neutralizing antibody was 88.5% in the 2 months after the first injection. When other pregnant cows were injected twice with vaccine, this rate was 34.6, 100, 65.4, and 45.8% in the 1, 2, 6, and 10 months, respectively, after the first injection. In another experiment, the antibody levels attained declined rather rapidly in several months. A single dose of vaccine given one year later provoked a rapid antibody response. The vaccination caused no clinical symptoms, abnormal birth, or decrease in milk yield in these cows.

Animals↗
PubMed1977

Congenital abnormalities in newborn calves after inoculation of pregnant cows with Akabane virus.

A fresh isolate of Akabane virus was inoculated intravenously into 11 seronegative pregnant cows at 62 to 96 days of gestation. Two of the cows were slaughtered 18 days post-inoculation, and the fetuses were examined; the remaining cows were allowed to give birth. All the inoculated cows developed viremia and neutralizing antibody for the virus, indicating that the cows were actually infected with the virus, although fever or any other clinical abnormalities were not noted. The virus further infected the fetuses. This was proved by virus isolation in one of the two fetuses from the slaughtered cows, and polymyositis was noted in both fetuses. Six of seven calves born alive had anti-Akabane antibody in their precolostral sera, indicating that in utero infection with the virus took place in these calves. Some of the in utero-infected calves demonstrated congenital abnormalities such as cerebral defect, hydranencephaly, and arthrogryposis. These findings provide additional evidence that Akabane virus is the etiological agent of epizootic abortion and congenital arthrogryposis-hydranencephaly syndrome in cattle.

Abortion, Veterinary↗
PubMed1977

Experimental infection of pregnant goats with Akabane virus.

Ten pregnant goats were inoculated intravenously with a newly isolated strain of Akabane virus. As a result, vertical infection and experimental reproduction of congenital morphological abnormality were accomplished. Fetuses were removed from two of them 10 days after inoculation and used for recovery of the virus. Clinically, the goats were free from any abnormal sign. Mild viremia was demonstrated in one of them inoculated with the virus at 30 days of pregnancy, but the fetus removed from this goat was negative for virus recovery. No viremia was demonstrated in the other one inoculated with the virus at 55 days of pregnancy, but two fetuses removed from it were positive for virus recovery. No abnormal clinical signs were observed in eight goats inoculated with the virus at 40 approximately 115 days of pregnancy, but leukopenia was noticed in five of these goats. Viremia was demonstrated in all the goats. It persisted for 2 to approximately 4 days. Seven goats were held under observation up to the time of spontaneous parturition. Ten neonatal kids were obtained. All of them were normal, except three which were particularly weak and one which was mummified fetus. When precolostral serum was examined, it contained neutralizing antibody against Akabane virus in five of eight neonatal kids. Two fetuses (120 days of intrauterine life) were removed from the remaining one pregnant goat 80 days after inoculation. Congenital morphological anomaly was reproduced in one of them. The other was a normal fetus. Serum collected from the umbilical cord was positive for neutralizing antibody against Akabane virus in both fetuses.

Animals↗
PubMed1977

Complement fixation test of Nebraska calf diarrhea virus with calf serum.

A complement fixation (CF) test for neonatal calf diarrhea has been developed with Nebraska calf diarrhea virus (NCDV) as antigen. The CF antigenicity of NCDV appeared in BK cell cultures for the first time 3 days after inoculation. Usually, the unconcentrated BK cell culture fluid infected with NCDV possessed poor CF antigenicity. The fluid concentrated by ultracentrifugation and ultrafiltration and with polyethylene glycol 6000 revealed a high-titered CF antigenicity to antiserum against NCDV. The antigen was not sensitive to lipid solvents, but was relatively resistant to heating. It was recognized that the concentrated fluid of cell culture infected with NCDV was available as antigen in the CF test for the serological demonstration of infection with a calf reovirus-like agent. The wide prevalence of diarrhea among Japanese calves with the calf reovirus-like agent was revealed from the results of CF and neutralization tests of NCDV.

Animals↗
PubMed1976

Epizootic congenital arthrogryposis-hydranencephaly syndrome in cattle: isolation of Akabane virus from affected fetuses.

Previous serolgoical studies strongly suggested Akabane virus to be the etiologic agent of epizootic abortion and congenital arthrogryposis-hydranencephaly in cattle, and this view was further corroborated in this study by the isolation of the virus from an aborted fetus in an epizootic of the disease and from a fetus extracted froma cow which was suggested by serologic tests to have a recent infection with the virus. The latter fetus had histological changes of encephalomyelitis and polymyositis, and specific antigens of Akabane virus was shown by the immunofluorescent technique in brain tissues as well as skeletal muscular tissues. The virus was recovered from various fetal tissues and fluids, and in relatively large amounts from brain, spinal cord, cerebral fluid, skeletal muscles and fetal placenta. The intracranial inoculation of suckling mice, 1-2 days of age, was the most sensitive system for Akabane virus isolation and HmLu-1, a continuous cell line from hamster lung, seemed almost as sensitive as suckling mice.

Abortion, Veterinary↗
PubMed1976

Isolation and properties of reovirus from cattle in an outbreak of acute respiratory disease.

A cytopathogenic virus was isolated in the primary culture of bovine kidney cells from a nasal swab of affected calves in an outbreak of acute respiratory disease in Japan in 1971. It agglutinated human type O erythrocytes and produced cytoplasmic inclusion bodies. Viral replication was inhibited by 5-iodo-2'-deoxyuridine, indicating that the viral nucleic acid was RNA. The virus was resistant to ether, chloroform, sodium deoxycholate, and acid, and passed readily through Sartorius' membrane filter 100 nm in pore size, but not through the filter 50 nm in pore size. Electron microscopy showed many spherical particles 60 approximately 75 nm in diameter with a double-layered capsid in a sample taken at a buoyant density of 1.34 produced by CaCl equilibrium centrifugation. The virus suspended in 1M MgCl2 solution was stable against heating at 50 degrees C for 30 minutes, but not against freezing at -20 degrees C for 60 minutes. The virus was resistant to, and increased in infectivity after, treatment with 0.063 approximately 1.0% trypsin. These properties were consistent with those established for the reoviruses. Most affected cattle showed a significant rise of antibody titer against reovirus and bovine respiratory syncytial virus, whereas only a few of them presented a serological evidence for recent infection with parainfluenza virus type 3, bovine adenovirus type 7, and bovine parovirus.

Acute Disease↗
PubMed1976

Separation and properties of enterovirus and reovirus recovered from a fecal sample of calf with diarrhea.

In April, 1971, a disease with pyrexia and diarrhea as main symptoms broke out collectively among calves. Fecal samples were collected from calves involved and inoculated into bovine kidney (BK) cell cultures. As a result, the diarrheal feces of one calf were suspected to contain two agents simultaneously. One agent (C-121 E strain) was isolated from the primary infected BK cell culture fluid by terminal dilution passages. It had been predominant in replication and shown a cytopathic effect which gave rise to a granular appearance in the early stage of culture. The other agent (C-121 R strain) was isolated from the primary infected BK cell culture fluid by neutralizing the C-121 E strain contained in this fluid with antiserum against this strain. It caused cytoplasmic inclusion bodies to form. On the basis of their physico-chemical properties, the C-121 E strain was identified as bovine enterovirus and the C-121 R strain as reovirus. Serological tests indicated that some of the affected calves had been infected not only with the two strains isolated, but also with bovine viral diarrhea virus, bovine adenovirus type 7, and bovine parvovirus.

Animals↗
PubMed1975

Serologic evidence for etiologic role of Akabane virus in epizootic abortion-arthrogryposis-hydranencephaly in cattle in Japan, 1972-1974.

In the outbreak of abortions, premature births, stillbirths and congenital arthrogryposis-hydranencephaly (AH) syndrome in Japan during the summer through winter of 1972-73 and 1973-74, precolostral sera from calves with congenital AH syndrome and normal calves were tested for neutralizing antibodies against some arboviruses, i.e. Akabane, Aino, Getah and Japanese encephalitis (JE) viruses. The incidence of antibody for Akabane virus was very high in calves with AH syndrome (49/59 or 83 per cent) as compared with normal calves (3/11 or 27 per cent), indicating an intimate correlation between the AH syndrome and precolostral anti-Akabane antibody. Three stillborn fetuses also had anti-Akabane antibody. On the other hand, no precolostral serum antibody for the other viruses was detected in any of the calves tested. The mothers of these calves, normal and with AH syndrome, had anti-Akabane antibody in high percentages (44/52 or 85 per cent and 7/8 or 88 per cent), whereas a few of the mothers had antibodies for the other viruses. Serological surveys indicate a wide dissemination of Akabane virus in epizootic areas during the summer months of 1972 and 1973. Thus, 8 groups of cattle in epizootic areas showed high rates of seroconversion for Akabane virus during the 1972 or 1973 summer. Very high incidences of Akabane antibody were shown among cattle in epizootic areas but extremely low incidences in near-by non-epizootic areas. The geographic distribution of anti-Akabane antibody among cattle throughout the country in the 1973 spring generally agrees with the pattern of case distribution in the 1972--73 outbreak. All these findings strongly suggest that Akabane virus is the etiological agent of the outbreaks. Further studies are needed, particularly isolation of the virus, demonstration of infection with the virus in lesions by immunofluroescence and production of intrauterine infection by experimental infection of pregnant cows.

Abortion, Veterinary↗
PubMed1975

Rolling round bottle culture of HmLu-1 cells and the production of bovine ephemeral fever virus.

An attempt was made to cultivate HmLu-1 cells in a rolling round bottle. As a result, the optimum conditions of cultivation were found to consist in the number of cells transplanted per bottle being 1 X 10(8), the volume of growth medium per bottle being 250 ml, and the velocity of rolling being 6 revolutions per hour. It was possible to make a monolayer of cells develop all over the glass surface under these conditions. A preliminary experiment was carried out to clarify the production of virus in the tube culture. In it, the highest virus titer was obtained two days after inoculation of a 4-day-old culture with a 1:100 dilution of stock virus. On the other hand, when the 4-day-old culture cells in the rolling round bottle were inoculated with virus suspension and when 100, 500, or 800 ml of maintenance medium was added to each bottle, there was little difference in virus titer obtained among the culture bottles. Then the virus yield per cell was compared between the rolling round bottle culture method and the stationary square bottle culture method. The highest virus titer was reached two days after virus inoculation, regardless of the culture method. The virus yield was 1.9 times as high in the rolling method as in the stationary method. From the results mentioned above, it was clarified that the rolling round bottle culture method made it possible to obtain a large amount of bovine ephemeral fever virus at a high titer in a labor-saving manner.

Animals↗
PubMed1975

Diagnosis of bovine respiratory syncytial virus infection by complement fixation test.

The complement fixation test by the microtiter method was applied to the serological diagnosis of bovine respiratory syncytial (RS) virus infection. When used as complement fixing antigens, untreated infected cell culture fluid, fluorocarbon-treated, and ether-treated materials showed no differences in antigenicity among them. The complement fixing antigenicity of bovine RS virus appeared in bovine kidney and Vero cell cultures for the first time 4 days after inoculation. Both the infectivity and complement fixing antigenicity reached a maximum 6 days after inoculation. In detecting complement fixing antibody from infected cattle, the most outstanding specific reaction was obtained when 5% fresh normal calf serum had been added to the diluent of complement. Neutralizing and complement fixing antibodies were examined in serum samples from two cattle in the course of experimental infection. It was found that both antibodies turned to be positive 2 weeks after inoculation. There was a linear correlation between neutralizing and complement fixing antibody titers, when serum samples from 40 natural cases were tested in the acute and convalescent stages. In addition, common antigenicity was demonstrated between the virus of bovine origin and the Long strain of human RS virus by complement fixation test.

Animals↗