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B Hampil

Publications and source records attributed to B Hampil.

8 recordsLinked to original sources
PubMed1977

Lyophilized combination pools of enterovirus equine antisera: preparation and test procedures for the identification of field strains of 19 group A coxsackievirus serotypes.

This paper describes the preparation of seven combination pools of equine antisera, designated J though P, for identification of 19 coxsackievirus A immunotypes. Each pool is composed of 4 to 6 antisera; the serotypes included are A1-6, 8, 10-15, and 17-22. These pools, unlike the previously prepared A-H enterovirus pools, were lyophilized from volumes of 0.5 ml dispensed into 5-ml vials, and when rehydrated with 5 ml of diluent provide 50-antibody-unit material ready for use in identification tests without further dilution. Procedures for using the antiserum pools are given, and guidance is provided for interpreting the results of serum neutralization tests in identifying field isolates.

Animals↗
PubMed1973

Lyophilized combination pools of enterovirus equine antisera: preparation and test procedures for the identification of field strains of 42 enteroviruses.

This paper describes the preparation of 8 dried pools (designated A to H) of sera. Each pool is composed of 10 or 11 of 42 individual enterovirus equine sera and contains 500 antibody units of each serum component per 0.1 ml. Procedures for using the antiserum pools are given, and guidance is provided for interpreting the results of serum neutralization tests in identifying field isolates.

Animals↗
PubMed1973

WHO collaborative studies on enterovirus reference antisera; fourth report.

This paper summarizes the results of the fourth part of a comprehensive programme undertaken by the WHO International Reference Centre for Enteroviruses and other laboratories for the testing of enterovirus equine antisera prepared for long-term use as reference antisera. The studies were designed to appraise the specificity of the immune serum of horses inoculated with prototype enteroviruses (coxsackievirus types A2, 4, 8, 10, 11, 14-16, 18-21, and 24, and echoviruses E21, 27, 30, 31, and 33). Tests for neutralizing antibody were performed against the homologous viruses and against available regional homotypic strains. Heterotypic tests were performed against reoviruses 1-3, adenoviruses 1-31, and the entire series of enteroviruses (with the exception of enterovirus 68). The homologous geometric mean titre of the 5 echovirus antisera ranged from 3 000 to 10 000; the titre of 1 coxsackievirus antiserum (A24) was only about 400, but the titres of the others ranged from 1 500 to 14 000. All corresponding preinoculation sera were negative. Heterotypic antibody of significant titre was found in 4 antisera: E31 serum against E5 virus, CA8 serum against CA3 virus, CA13 serum against CA18 virus, and CA15 serum against CA2 virus. Information on other heterotypic antibody titres (where found) is recorded for guidance in the use of the sera. The results of homotypic tests with viruses isolated by the collaborating laboratories, though limited in number, were satisfactory.

Adenoviridae↗
PubMed1970

WHO collaborative studies on enterovirus reference antisera. Third report.

This paper smmarizes the results of the third part of co-operative studies undertaken by the WHO International Reference Centre for Enteroviruses and a number of WHO Regional Virus Reference Centres and WHO Virus Collaborating Laboratories and other laboratories in a comprehensive testing programme of enterovirus equine antisera prepared for long-term use as reference antisera. The studies were designed to appraise the specificity of the immune serum of horses inoculated with prototype enteroviruses (coxsackie-viruses A1, A5, A6, A12 and A22 and echoviruses 5, 6, 13-16, 18-20, 22-26, 29 and 32). Tests for neutralizing antibody were performed not only against the homologous viruses but also against regional homotypic strains. Tests for heterotypic antibody were made against the entire group of enteroviruses (except enterovirus 68), reoviruses 1-3, and adenoviruses 1-11, 13-17 and 19-22. Final vials of the dried serum were provided for the tests. Each serum sample represented a pool of the individual bleedings taken from a group of horses before and after immunization with each virus antigen. The results showed that the homologous geometric mean titres of 9 of 16 echovirus immune sera were 10 000 or above while the other 7 ranged from 2000 to 8000. The homologous antibody titre of one coxsackievirus type A serum was about 2000 while the titres of the other 4 type A sera ranged from about 5000 to 15 000. All corresponding pre-inoculation sera were negative. The results of the homotypic tests, though limited in number, showed the usefulness of the sera. Data on heterotypic antibody titres, if any, are recorded for gidance in the use of the sera. Co-operative testing of 19 additional enterovirus equine sera is now in progress.

Animals↗
PubMed1969

Method for testing virus stocks for viral contaminants.

A practical method for testing the purity of virus stocks has been developed and applied to reference stocks of enteroviruses. The method requires the use of a reference antiserum that is substantially free from heterotypic antibody. When selected dilutions of this antiserum are reacted with high concentrations of virus, virus intentionally allowed to escape neutralization is recovered and then identified. A contaminating virus present as a minor component of the population has a far greater probability of being revealed under the conditions of this "breakthrough" test than under the commonly used virus identity tests which customarily employ approximately 100 TCD(50) of virus and, therefore, only identify the major component of the virus population. The breakthrough test described has been used for tests of 104 reference stocks of all the enteroviruses that propagate in monkey kidney cells and human amnion cells. Although all the materials had been previously tested and approved by the commonly employed virus identity test, the breakthrough test in two instances revealed contaminating heterotypic enteroviruses present at a very low titer in the stocks. Without resorting to the stringent, elaborate, and expensive tests for absolute purity, such as those that are required to assure safety of vaccines, the use of the breakthrough test described provides reasonable assurance of purity for stock viruses to be employed as diagnostic reagents or for general laboratory research purposes where a multiplicity of viral agents and antisera are required.

Culture Techniques↗
PubMed1968

WHO collaborative studies on enterovirus reference antisera: second report.

This paper summarizes the results of the second part of co-operative studies undertaken by the WHO International Reference Centre for Enteroviruses and a number of WHO Regional Virus Reference Centres, WHO Virus Collaborating Laboratories and other laboratories in a comprehensive testing programme of enterovirus equine antisera. The studies were designed to appraise the specificity of immune serum prepared in horses against 16 representative prototype enteroviruses (polioviruses 2 and 3, coxsackieviruses A7, B1, B2, B4, B5 and B6 and echoviruses 1, 2, 3, 5, 7, 9, 12 and 17). Tests for neutralizing antibody were performed not only against the homologous viruses but also against the homotypic strains available in each laboratory. Tests for heterotypic antibody were made against the entire group of enteroviruses, reoviruses 1-3 and adenoviruses 1-11, 13 and 17. Each serum sample represented a pool of the individual bleedings taken from a group of horses before and after immunization with each virus antigen. The results showed that the homologous geometric mean titres of the immune sera ranged from 7000 to 36 000, whereas the preinoculation sera were negative. Results of the homotypic tests showed the usefulness of the sera. The specificity of the haemagglutination-inhibiting antibody of the sera against coxsackieviruses A7, B1, B5, B6 and echoviruses 3, 7, 12 was demonstrated. The results of the tests performed in tissue culture and mice are discussed. Co-operative testing of other enterovirus equine antisera is now in progress.

Animals↗
PubMed1965

WHO collaborative studies on enterovirus reference antisera.

This paper summarizes the results of co-operative studies undertaken by the WHO International Reference Centre for Enteroviruses and a number of WHO Regional Reference Centres for viruses, WHO Virus Collaborating Laboratories, or other laboratories in a comprehensive testing programme of enterovirus equine antisera. The studies were designed to appraise the specificity of immune serum prepared in horses against five representative prototype enteroviruses (poliovirus 1, coxsackieviruses A9 and B3, and echoviruses 4 and 11). Tests for neutralizing antibody were performed not only against the homologous viruses, but also against a battery of heterotypic picornaviruses, comprising 63 enteroviruses, several rhinoviruses, and three reoviruses. Each serum sample represented a pool of the individual bleedings taken from groups of five or six horses before and after immunization with each virus antigen (except echovirus 4, for which three animals were immunized). The results showed that, whereas the homologous titres of the antisera (poliovirus 1, coxsackieviruses A9 and B3, echoviruses 4 and 11) were found to be within a useful range (700-8000), heterotypic antibodies of significant titre were not detected. All corresponding pre-inoculation sera were negative. The specificity of the haemagglutination-inhibiting antibody of the coxsackievirus B3 and echovirus 11 antisera was also demonstrated. This accumulated information played a major role in a decision to prepare in horses antisera to the rest of the enterovirus group. Co-operative testing of the other enterovirus equine antisera is now in progress.

Enterovirus↗