Biomedical subjects

P Suphavilai

Publications and source records attributed to P Suphavilai.

3 recordsLinked to original sources

PubMed1978

Indirect complement fixation test with foot-and-mouth disease virus antigen concentrated by polyethylene glycol precipitation.

To a BHK-21 cell culture fluid infected with the O, A, or Asia 1 type of foot-and-mouth disease (FMD) virus was added polyethylene glycol 16000 to a concentration of 10% (w/v). Then the fluid was concentrated to one-tenth of the original volume. The resulting concentrated virus antigens showed a complement fixation (CF) titer ranging from 12 to 14. The rate of recovery of CF activity was in a range of 40 approximately 80%. Each antigen was applied to the indirect complement fixation (ICF) test with serum from cattle infected experimentally with the respective type of virus to estimate antibody titers. When antibody was examined for a rise and fall, it began to be detected 4 approximately 7 days after inoculation and was detectable even 63 days after inoculation. It showed a tendency to exhibit a rise and fall parallel with that of neutralizing antibody, although it was always lower in titer than this antibody. ICF antibody corresponding to one type of virus was type-specific, presenting little crossing with a heterologous antigen. As a result, it was clarified that such antigen as prepared from an infected cell culture fluid after concentration with polyethylene glycol was applicable to the ICF test for the estimation of the titer of antibody against FMD virus.

Animals↗

PubMed1978

Inactivated-concentrated virus antigen for indirect complement fixation test of foot-and-mouth disease.

To the culture fluids of BHK-21 cells infected with each of types O, A, and Asia 1 of foot-and-mouth disease virus was added acetylethyleneimine to 0.05% (v/v). The mixtures were incubated at 37 degrees C for 24 hours. To them were then added polyethylene glycol 6000 to 10% (w/v), and the mixtures concentrated to one-tenth of the initial volume. The resulting inactivated-concentrated virus antigens showed a complement fixation (CF) titer ranging from 12 to 24. The recovery rate of CF activity was 40 approximately 60%. This activity of each antigen was maintained at 4 degrees C or -70 degrees C for 6 months at least. Experimentally infected cattle were examined for the development of antibody by the aid of the indirect complement fixation (ICF) test with those antigens. As a result, ICF antibody began to be detected 3 approximately 5 days after inoculation. Its titer reached a maximum 10 approximately 14 days after inoculation and decreased gradually thereafter. It was detected even 232 days after inoculation. There was a tendency for the development of ICF antibody to be parallel with that of neutralizing antibody. It was suggested that ICF antibody might be type-specific. In conclusion, the antigens prepared had such high activity that they could be used for the determination of antibody by ICF. In addition, they were of great practical value because of their sufficient keeping quality and safety.

Animals↗

PubMed1977

Antibody estimation by indirect complement fixation test for foot-and-mouth disease in cattle.

Antibody against foot-and-mouth disease (FMD) virus was measured by the indirect complement fixation (ICF) test. For this test serum samples were collected from cattle experimentally infected with FMD virus of O, A and Asia 1 types, as well as cattle infected in the field. Two types of antigen were used. One was antigen derived from infected lingual epithelial culture prepared by Frenkel's method with each type of the virus. The other was antigen derived from the lingual epithelium of cattle infected by virus inoculation. ICF antibody began to be dectected about 4 5 days after inoculation. It reached a maximum titer 10 14 days after inoculation, remaining at this titer for about a week or two, and then decreased gradually. It was, however, detectable even 63 days after inoculation. The rise and fall of ICF antibody was parallel with that of neutralizing antibody, although that antibody was always lower in titer than this. ICF antibody was detected type-specifically from cattle infected experimentally and naturally. These results indicated that the ICF test was available for the routine serological diagnosis and epizootiological investigation and research.

Animals↗