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Biomedical subjects

H Akashi

Publications and source records attributed to H Akashi.

At least 163 records · Page 9Linked to original sources
PubMed1982

The complete sequence and coding content of snowshoe hare bunyavirus small (S) viral RNA species.

The complete sequence of the small (S) viral RNA species of snowshoe hare (SSH) bunyavirus has been determined, principally from a DNA copy of the RNA cloned in the E.coli plasmid pBr322. The viral S RNA (negative sense strand) is 982 nucleotides long (3.3 x 10(5) daltons) with complementary 5' and 3' end sequences. It has a base composition of 30.5%U, 25.8%A, 24.9%C and 18.7%G. In the viral complementary (plus sense) strand there are two overlapping open reading frames initiated by methionine codons. One reading frame codes for a 26.8 x 10(3) dalton protein, the other for a 10.5 x 10(3) dalton protein. The larger gene product is presumably related to the viral nucleoprotein (N) that is coded by the S RNA (Gentsch and Bishop (1978) J. Virol. 28, 417-419). The smaller gene product is probably related to the recently identified S RNA coded nonstructural protein (NSS) induced in virus infected cells (Fuller and Bishop (1982) J. Virol. 41, 643-648).

Amino Acid Sequence↗
PubMed1982

The 3' terminal RNA sequences of bunyaviruses and nairoviruses (Bunyaviridae): evidence of end sequence generic differences within the virus family.

The 3' terminal nucleotide sequences of the three virus RNA species of viruses representing eight serogroups of bunyaviruses (genus Bunyavirus, Bunyaviridae) and six serogroups of nairoviruses (genus Nairovirus, Bunyaviridae) have been characterized. Members of the Bunyavirus genus have conserved 3' end sequences (generally, 3' UCAUCACAUGA...) that differ from the conserved 3' end sequences of members of the Nairovirus genus (generally, 3' AGAGUUUCU...).

Base Sequence↗
PubMed1982

Nucleotide sequence analyses and predicted coding of bunyavirus genome RNA species.

We performed 3' RNA sequence analyses of [(32)P]pCp-end-labeled La Crosse (LAC) virus, alternate LAC virus isolate L74, and snowshoe hare bunyavirus large (L), medium (M), and small (S) negative-stranded viral RNA species to determine the coding capabilities of these species. These analyses were confirmed by dideoxy primer extension studies in which we used a synthetic oligodeoxynucleotide primer complementary to the conserved 3'-terminal decanucleotide of the three viral RNA species (Clerx-van Haaster and Bishop, Virology 105:564-574, 1980). The deduced sequences predicted translation of two S-RNA gene products that were read in overlapping reading frames. So far, only single contiguous open reading frames have been identified for the viral M- and L-RNA species. For the negative-stranded M-RNA species of all three viruses, the single reading frame developed from the first 3'-proximal UAC triplet. Likewise, for the L-RNA of the alternate LAC isolate, a single open reading frame developed from the first 3'-proximal UAC triplet. The corresponding L-RNA sequences of prototype LAC and snowshoe hare viruses initiated open reading frames; however, for both viral L-RNA species there was a preceding 3'-proximal UAC triplet in another reading frame that was followed shortly afterward by a termination codon. A comparison of the sequence data obtained for snowshoe hare virus, LAC virus, and the alternate LAC virus isolate showed that the identified nucleotide substitutions were sufficient to account for some of the fingerprint differences in the L-, M-, and S-RNA species of the three viruses. Unlike the distribution of the L- and M-RNA substitutions, significantly fewer nucleotide substitutions occurred after the initial UAC triplet of the S-RNA species than before this triplet, implying that the overlapping genes of the S RNA provided a constraint against evolution by point mutation. The comparative sequence analyses predicted amino acid differences among the corresponding L-, M-, and S-RNA gene products of snowshoe hare virus and the two LAC virus isolates.

Base Sequence↗
PubMed1982

Pathological studies on encephalitis in mice experimentally inoculated with bovine coronavirus.

One- to 21-day-old mice were examined pathologically after inoculated intracerebrally or subcutaneously with the Kakegawa strain of bovine coronavirus. In 1- to 4-day-old mice inoculated intracerebrally, the brain contained a small number of neutrophils and lymphocytes having infiltrated diffusely and perivascularly and some degenerative neurons. In mice inoculated intracerebrally at 7 to 21 days of age, severe necrosis of pyramidal cells was shown in Ammon's horn. Perivascular infiltrations of neutrophils and lymphocytes were moderate to severe. Some neurons were degenerative in the cerebral cortex, thalamus and midbrain. Degeneration of some neurons and mild infiltration of neutrophils and lymphocytes were observed in the brain of mice inoculated subcutaneously at 1 to 7 days of age. Perivascular infiltration of neutrophils and lymphocytes was prominent in the cerebral cortex of mice inoculated subcutaneously at 14 days of age. Cellular infiltration was also seen in the thalamus, Ammon's horn, midbrain, cerebellum and medulla oblongata. All the mice, except one, inoculated subcutaneously at 21 days of age were free from neural changes. Electron-microscopically, virus particles were observed in and outside of the degenerative neurons. They had a core 70 nm in diameter and an envelope with spikes.

Aging↗
PubMed1982

Seroepizootiological survey on bluetongue virus infection in cattle in Japan.

Bovine sera collected in various parts of Japan were subjected to seroepizootiological tests with bluetongue virus type 1 (BTV1), type 12 (BTV12), and type 20 (BTV20). All these viruses have been widely disseminated among cattle in the southern part of Japan in 1974. Relatively high incidences of neutralizing (NT) antibody against the three viruses were shown among cattle in the Kyushu district, including Okinawa Prefecture, or the southern part of Japan, but extremely low or incidences in Hokkaido, or the northern part of Japan. The incidence of reactors was higher in old animals. Cattle in Okinawa Prefecture showed a high rate of seroconversion for all the viruses during the summer of 1979. None of the animals seroconverted, however, manifested any sign of disease. Seroepizootiological investigation made it clear that BTV1, BTV12 and BTV20 had existed in Japan and that the epizootic of bluetongue virus infection started during a period from summer through early autumn.

Age Factors↗
PubMed1981

Propagation of the Kakegawa strain of bovine coronavirus in suckling mice, rats and hamsters.

The Kakegawa strain of bovine coronavirus was easily propagated in suckling mice. Infected animals died with nervous symptoms, and serial passage was readily accomplished by intracerebral inoculation with brain emulsions. The 3rd passage viral material from infected mice evoked the same disease in suckling mice, rats and hamsters inoculated by the intracerebral or by the subcutaneous route. Viruses recovered from mice, rats and hamsters could be clearly differentiated from mouse hepatitis virus strain 2 by the neutralization test.

Animal Population Groups↗
PubMed1981

Hemagglutination of epizootic hemorrhagic disease virus.

Hemagglutination of epizootic hemorrhagic disease virus (EHDV) with a variety of erythrocyte species at 4 degrees C, room temperature and 37 degrees C was dependent on the NaCl molarity and the pH of the diluent. The hemagglutination inhibition test was used to identify EHDV serotypes.

Animals↗
PubMed1979

An attenuated strain of Akabane virus: a candidate for live virus vaccine.

An attempt was made to attenuate the high virulent OBE-1 strain of Akabane virus by adaptation to low temperature. In it the virus was subjected to passage through HmLu-1 cell cultures at 30 degrees C. Cloning was carried out on the virus which had undergone 20 passages through these cultures to select a strain adapted to low temperature. Finally, ten clones were obtained. As a result, nine strains of clone in which virus replication was poor in HmLu-1 cell cultures at 40 degrees C were obtained. Of them, five strains of clone produced uniform plaques. Of these strains, one, or the TS-C2 strain, was selected. It was considerably lower both in peripheral infectivity to suckling mice and in intracerebral infectivity to 3-week-old mice than the OBE-1 strain. Calves and pregnant cows inoculated with the TS-C2 strain by the intracerebral, intravenous, or subcutaneous route were free from pyrexia, leukopenia, and viremia. Virus recovery was negative from various organs and fetuses. All the animals inoculated, however, were found to have neutralizing antibody produced. The results mentioned above suggested that the TS-C2 strain might have been so attenuated as to be available as a candidate strain for a live virus vaccine.

Animals↗
PubMed1979

Immune response of various animals to Akabane disease live virus vaccine.

When various animals and routes of inoculation were examined for antibody response to Akabane disease live virus vaccine, the intracerebral (ic) inoculation of mice induced a better antibody response than the subcutaneous (sc) inoculation of calves, guinea pigs, hamsters, mice, or rats. Immunogenicity was compared among lots of this vaccine by performing ic inoculation of mice and sc inoculation of calves and guinea pigs. As a result, there was no distinct significant difference between any two lots of the vaccine, regardless of the animal species used. There was a tendency that the larger the dose of inoculation of the virus, the earlier the production of neutralizing (NT) antibody took place in calves inoculated with the vaccine, and the higher the antibody titer and the rate of taking a turn for positivity for antibody became in these calves. When calves immunized with the vaccine and cows in the field possessing NT antibody were given booster inoculation with the vaccine, the antibody titer showed a significant increase in almost all the calves and cows that exhibited an NT antibody titer of 4 or less at the time of booster inoculation. There were, however, no changes in antibody titer in such calves and cows as presenting an NT antibody titer of 8 or more. Calves and pregnant cows immunized with the vaccine were prevented from viremia and fetal infection when challenged by inoculation with virulent virus.

Animals↗