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At least 253 records · Page 14Linked to original sources
PubMed1976

The standardization of Cl. perfringens antigens and antisera.

The preparation of laboratory standard antitoxins against Cl. perfringens beta and epsilon toxins is described. These antitoxins are suitable for the quantitative determination of the corresponding antigens by means of the flocculation test. The flocculation test was, however, shown to be more suitable for determining the antigenic value of fresh toxoid rather than toxoid stored without neutralization of excess formalin. A maximal immunity response to alum-precipitated epsilon toxoid was obtained in sheep with two injections containing 90 Lf per dose. The interval between these injections may vary from 2 to 6 weeks. The serum-antibody titres after the primary and secondary injections or after a booster dose given before 12 months after the primary injection did not remain above the protective level in most of the sheep injected for longer than about 5 months. When a sound basic immunity is established the degree of protection following on a booster dose given 12 months later is complete for at least 12 months. An alum-precipitated vaccine containing 25 Lf epsilon toxoid per dose is adequate. The decline in the serum-antibody titre during the first year of vaccination could be eliminated by the use of the antigen in water-in-oil emulsion. Lambs from immune dams were protected for at least up to 13 weeks of age. A satisfactory level of circulating antitoxin against Cl. perfringens beta toxin could be produced in ewes by vaccinating them with APT containing 6.25 Lf beta toxoid per dose. The primary and secondary injections could be separated by 2, 3, 4 or 5 weeks without changing the end result. A booster dose given 2 months before parturition was satisfactory.

Animals↗
PubMed1975

[Value of TPHA in the serological screening of lues].

In the present work, 21,400 not selected sera were tested with hemagglutination test (TPHA) and flocculation test (VDRL) with cardiolipin for screening of syphilis; sera that gave negative results against both tests showed remarkable agreement (97,81%). 468 sera gave positive results to least one of the tests employed in screening and were tested with the following procedures: fluorescent Treponemal antibody-absorption (FTA/ABS) test, complement fixation (by Kolmer, modified) with proteic (KP) and lipidic (KL) antigen; 100 of these sera were also tested with T. pallidum immobilizaiton (TPI) test. The agreement among the before mentioned tests and sera that gave positive results only to VDRL was significatively low; on the contrary, the agreement was remarkable in the case of those positive only to TPHA (99% with FTA/ABS, 83% with TPI, 52,5% with KP and 21,5% with KL). The results obtained in attesting sensitivity and specificity of TPHA indicate that it is a very valuable screening test, and suggest to the AA. to emphasize that TPHA/VDRL association a definitive conclusion in syphilis serological negativity.

Antibody Formation↗
PubMed1990

Quantitative estimation of diphtheria and tetanus toxoids. 4. Toxoids as international reference materials defining Lf-units for diphtheria and tetanus toxoids.

The Lf-unit, which is used in the control of diphtheria and tetanus toxoid production and in some countries also to follow immunization of horses for production of antitoxins, has hitherto been defined by means of antitoxin preparations. A diphtheria toxoid and a tetanus toxoid preparation, both freeze-dried, were examined in an international collaborative study for their suitability to serve as reference reagents in the flocculation tests and for defining the Lf-units. It was shown that flocculation tests using the reference toxoids are very reproducible and reliable and the WHO Expert Committee on Biological Standardization established: the toxoid called DIFT as the International Reference Reagent of Diphtheria Toxoid for Flocculation Test with a defined content of 900 Lf-units of diphtheria toxoid per ampoule; and the toxoid called TEFT as the International Reference Reagent of Tetanus Toxoid for Flocculation Test with a defined content of 1000 Lf-units of diphtheria toxoid per ampoule.

Animals↗
PubMed1977

Serological responses in experimental bovine tuberculosis.

Five two-year-old heifers were each inoculated intravenously with 0.02 mg M. bovis strain AN5. Clinical, haematological and microbiological observations were made during the course of the experiment and antibody levels were measured before and after infection by means of the indirect immunofluorescent antibody (IFA) and bentonite flocculation tests. All cattle developed M. bovis infection varying in severity from peracute tuberculous pneumonia resulting in death within 33 days to chronic progressive generalised tuberculosis. Only cattle developing peracute or acute forms of tuberculosis showed marked haematological changes characterised by leucopenia with lymphopenia. Bacteraemia was detected in the two cattle with peracute tuberculosis 22 days after infection. Anti-mycobacterial antibody was detected after infection in all cattle but fluctuated markedly during the course of the disease. Of a total of 61 serum samples examined from all cattle after inoculation with M. bovis, only 38 were positive to the IFA test and 30 to the bentonite flocculation test. Only 18 were positive to both tests at any one time. IgM was the predominant type of anti-mycobacterial antibody detected by the IFA test and this was found to cross-react with M. avium in almost every sample.

Animals↗
PubMedDate not supplied

[The passive hemagglutination test in the diagnosis of syphilis].

Studies were carried out on the comparative value of passive haemaglutination, cardiolipin and treponema tests in a total number of 4327 sera syphilitic patients in various stages of the disease and apparently normal subjects or free of syphilis. The results demonstrated the specificity and sensitivity of passive haemagglutination in all the stages of syphilis. In view of the qualities and simplicity of the test, the author recommends it as a screening test combined with a micromethod using the cardiolipin antigen (flocculation test).

Complement Fixation Tests↗