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Biomedical subjects

Y Okuno

Publications and source records attributed to Y Okuno.

At least 343 records · Page 19Linked to original sources
PubMed1981

Neutralization antibody responses induced by Japanese encephalitis virus vaccine.

Single doses of Japanese encephalitis (JE) vaccine of the Nakayama strain were given to members of the staffs of a hospital and 99 paired-sera were obtained. Neutralization antibody titers of the sera were determined against the Nakayama strain and E-50 strain, isolated from wild Culex tritaeniorhynchus using clone C6/36 of Singh's Aedes albopictus mosquito cell culture. Post-vaccination sera showed a significant neutralizing antibody response against both the Nakayama and E-50 strain. The geometrical mean neutralization titers of post-vaccination sera against the Nakayama and E-50 strains were in the same order, although the geometrical mean neutralization titer against the Nakayama strain was the higher in pre-vaccination sera. The antibody responses against the Nakayama strain and E-50 strain were somewhat different in detail: 7 individuals with a pre-vaccination neutralization titers of less than 10 showed antibody responses to the Nakayama strain, whereas 3 individuals of the same group did not show any detectable response to the E-50 strain.

Antibody Formation↗
PubMed1980

Production of an attenuated influenza A (H3N2) strain "KO-1" by recombination with A/Okuda/57 (H2N2) followed by selection of inhibitor-resistant virus.

A live attenuated influenza A (H3N2) strain "KO-1" was developed by recombination of wild influenza A/Kumamoto/22/76 (H3N2) with attenuated A/Okuda/57 (H2N2) followed by passage in developing chick eggs in the presence of horse serum inhibitor. The virus strain "KO-1" obtained is inhibitor-resistant, and has hemagglutinating (HA) and neuraminidase (NA) antigenicity derived from the wild parent virus. RNA analysis revealed that one RNA segment (corresponding to M protein) was derived from the A/Okuda/57 strain. The "KO-1" strain shows restricted growth in the lungs of Syrian hamsters as compared with that of the parent A/Kumamoto/76 strain and no transmission of virus from the hamsters infected with "KO-1" strain by inhalation ot untreated hamsters housed in the same cage was detected serologically. In contrast, the parent wild A/Kumamoto/76 strain induced contact infection under the same condition. The attenuated "KO-1" strain was administered by inhalation to a few children of 3 to 4 years old in a preliminary clinical trial. A good antibody response was observed with no clinical reaction.

Animals↗
PubMed1980

Serological and virological studies on patients with dengue hemorrhagic fever (DHF) in Chanthaburi province, Thailand. I. Serological studies on paired sera from DHF patients by neutralization (N), hemagglutination inhibition (HI) and staining tests.

Twenty paired sera were collected from DHF patients admitted to the provincial hospital of Chanthaburi, Thailand in 1978. They were tested by the N and HI tests and a newly developed staining test against all four serotypes of dengue (DEN) virus and Japanese encephalitis (JE) virus. Four patients were demonstrated to be cases of primary DEN infection and the other 16 to be cases of secondary DEN infection. The serotypes of recent DEN infections were easily determined by the N test in cases of primary infection, but were difficult to determine in cases of secondary infection because of the strong cross reactions among DEN serotypes. These cross reactions seemed to be due to subgroup-specific antibody, which reacts with all 4 serotypes of DEN virus in the N test. However, acute phase sera from some patients with the secondary type of antibody response reacted monospecifically in the N test, indicating the serotype of the primarily infecting viruses.

Adolescent↗
PubMed1980

Serological and virological studies on patients with dengue hemorrhagic fever (DHF) in Chanthaburi province, Thailand. II. Serological characteristics of viruses isolated from DHF patients using a clone of Singh's Aedes albopictus cells.

Four strains of dengue (DEN) virus were isolated using C6/36 cells, a clone of Singh's Aedes albopictus cells, from acute phase sera of DHF patients in Thailand in 1978. The isolates grown and passaged in C6/36 cells were not neutralized appreciably by standard rabbit antisera against each of the 4 types of DEN virus, but their serotypes could be identified by complement fixation (CF) tests. After the 4th or 10th passage in suckling mouse brain (SMB), however, three of the four strains showed type-specific reactions in neutralization (N) tests against the standard antisera. In cases of secondary infection, the highest N titer in the convalescent phase sera was demonstrated not against the isolated serotype, but against the serotype considered to have caused primary infection. Moreover in cases of secondary infection, the convalescent phase sera showed a significantly lower N titer against the newly isolated strain derived from the same patient than against the corresponding prototype standard virus. This phenomenon was not observed in a single case of primary infection.

Adolescent↗
PubMed1979

Attenuated mumps virus therapy of carcinoma of the maxillary sinus.

This paper presents treatment of carcinoma of the maxillary sinus with an attenuated mumps virus. The mumps virus was inoculated into two cases of very advanced carcinoma of the maxillary sinus by local and general injection. Shortly after injection, relief from severe cancer pain and growth inhibition or necrosis of tumor were observed in both cases. In this communication, we discuss a possible mechanism of antitumor effect of mumps virus by utilizing immunologic tests and interferon assay.

Carcinoma, Squamous Cell↗
PubMed1979

A modified PAP (peroxidase-anti-peroxidase) staining technique using sera from patients with dengue hemorrhagic fever (DHF): 4 step PAP staining technique.

BHK-21 cells infected with dengue virus type 1 were stained by a newly developed 4 step PAP (peroxidase-anti-peroxidase) technique using sera from patients with dengue hemorrhagic fever as anti-virus antibody. The intensity of staining of the sera was proportional to the hemagglutination inhibition and neutralization titers. With this new technique using sera from patients it should be possible to use the PAP technique of virus infections.

Animals↗
PubMed1979

Etiological relation between Korean hemorrhagic fever and epidemic hemorrhagic fever in Japan.

The first case of epidemic hemorrhagic fever in Japan was seen in Osaka in 1960. The etiologic agent of this disease has not yet been isolated, but a close etiologic relation between Korean hemorrhagic fever and epidemic hemorrhagic fever in Japan has been suspected because of similarities in the clinical and pathological pictures of the two diseases. This relation has now been confirmed serologically by demonstrating specific immunofluorescent antibodies to Korean hemorrhagic fever virus in 19 of 20 sera obtained from subjects 7 to 17 years after an acute attack of epidemic hemorrhagic fever.

Adolescent↗
PubMed1979

Hemagglutinin prepared from cells of Aedes albopictus, clone C6/36, infected with type 1 dengue virus.

A high titer of hemagglutinin (HAnin) was found in culture fluids of cells of Aedes albopictus, clone C6/36, infected with type 1 dengue virus. The HAnin (TC antigen) was associated with complete virions and no appreciable small-sized HAnin was produced, in contrast to the case in an infected suckling mouse brain (SMB) homogenate, in which most of the HAnin is smaller than complete virions. Extraction of the TC antigen with Tween 80-ether disrupted the HAnin into smaller-sized particles, resulting in complete loss of infectivity (TE-TC antigen), but it did not affect the titer or reactivity of the HAnin. Comparative hemagglutination-inhibition (HI) assay of human sera using TC antigen, TE-TC antigen or standard antigen extracted from infected SMB (SMB antigen) showed that TC or TE-TC antigen could be used for routine diagnostic or epidemiological HI tests instead of SMB antigen, which is rather hard to prepare.

Aedes↗
PubMed1978

Neutralization tests for dengue and Japanese encephalitis viruses by the focus reduction method using peroxidase-anti-peroxidase staining.

Neutralization tests were made on 4 types of dengue (DEN) virus and Japanese encephalitis (JE) virus by incubation of serially diluted antisera and constant amounts of the viruses and then focus assay of surviving virus infectivity with peroxidase-anti-peroxidase (PAP) staining. Neutralization reactions were virtually completed in 2 hr on incubation of serum-virus mixtures at 28 C. A straight regression line was obtained on a probit chart by plotting the focus reduction rates at various dilutions of a given serum against the logarithm of the serum dilution used in the test. The slopes of the probit regression lines for the neutralization for DEN types 1 and 3 were similar, but differed somewhat from those for DEN type 2 and type 4. The slope of the line for JE virus was quite different from those for DEN viruses. Using these relations, the fifty percent focus reduction titer (FR50) of neutralizing antibodies of a given serum could be estimated from the focus reduction rates at several dilutions of the test serum when the latter was between 25-75% of the value of the control.

Animals↗