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At least 109 records · Page 6Linked to original sources
PubMed1972

Equine infectious anemia: activity of liquid antigen extracts in the agar-gel immunodiffusion and complement-fixation tests.

Twenty-nine lots of acetone-ether extracted liquid antigen were prepared from the pulp of 11 spleens collected from horses at the acute phase of experimental infection. The lots prepared from the highly reactive pulp resulted in general in a liquid antigen of greater activity than those extracted from weakly reactive pulps. Some variations in activity between lots of antigen prepared from the same spleen were also observed. No matter what the results, given a wide enough variation, all results were reproducible. The procedure permitted production of a greater number of antigen test doses from reactive spleens and rendered usable the spleens which failed to give sufficient reactivity when used as pulp antigen in the agar-gel immunodiffusion test. The activity of each lot of liquid antigen was standardized, first by the complement-fixation test and finally by matching with a reference antiserum in the agar-gel immunodiffusion test.

Animals↗
PubMed1992

Evaluation of five commercial tests: complement fixation, microparticle agglutination, indirect immunofluorescence, enzyme-linked immunosorbent assay and latex agglutination, in comparison to immunoblotting for Mycoplasma pneumoniae serology.

A panel of 68 serum specimens from 41 subjects exhibiting various immunological patterns to Mycoplasma pneumoniae as determined by detection of a 180 kDa protein in immunoblotting was used to compare five commercially available tests based on different methods: complement fixation test (CFT), microparticle agglutination (MAG), indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (Elisa), and latex agglutination (LA). The tests were performed according to the manufacturers' instructions. For the determination of immunity to M pneumoniae, the five tests were in good accordance with immunoblotting: sensitivity was 100% for all the five assays, specificity ranged from 95.6% (MAG) to 82.6% (Elisa) and overall agreement ranged from 98.2% (MAG) to 92.8% (Elisa). The comparisons of antibody rates obtained by the four quantitative tests (CFT, MAG, IFA, Elisa) showed correlation coefficients ranging from 0.87 (CFT-IFA) to 0.67 (CFT-Elisa). Six significant antibody rises demonstrated by immunoblotting patterns were detected by all the tests but Elisa in one case. As a whole, the commercial assays gave satisfactory results for routine determination of immune status to M pneumoniae: CFT was the cheapest test and MAG and LA were the easiest to perform.

Adolescent↗
PubMed1976

[Comparison of the sensitivity of complement-fixation test and latex-fixation test in the demonstration of a migration phase of ascariasis (Ascaris suum) in a non-specific host].

The authors compared the sensitiveness of the complement-fixation reaction and the latex-fixation test in the demonstration of a migration phase of ascariasis in a non-specific host (rabbit). The sensitiveness of the latex-fixation test was higher by the value of one dilution of the geometric series, on an average.

Animals↗
PubMed1986

Comparison of an enzyme-linked immunosorbent assay using monoclonal antibodies and a complement fixation test for cattle vaccinated and infected with Brucella abortus.

A competitive enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody conjugated to horseradish peroxidase MA(A) and a complement fixation test (CFT) were applied to sera collected over a two-year period from 60 cattle challenged with Brucella abortus strain 544. Forty-eight of the cattle were previously vaccinated with B. abortus strain 19 (S19) or B. abortus strain 45/20 (45/20). After challenge 33 of the cattle remained uninfected and nine of the 27 infected cattle showed aberrant reactions by the CFT. The performance of the MA(A) ELISA was as follows: after vaccination, the MA(A) ELISA, like the CFT, was unable to differentiate infected cattle from those recently vaccinated with S19. After challenge the MA(A) ELISA gave results comparable with the CFT for those cattle with aberrant reactions. For the non-infected cattle there was a similar number of weeks after challenge when both tests were negative. It is suggested that the main advantage of the MA(A) ELISA when compared with the CFT lies in its relatively simple test procedure.

Animals↗
PubMed1975

[Study of the indirect complement fixation test for use in the differentiation of foot-and-mouth disease viruses and the determination of immunity].

Studies were carried out to establish the optimal conditions for the indirect complement-fixation test (ICFT) and explore the possibility to use the test in differentiating the foot-and-mouth disease (FMD) viruses and checking the immunity obtained in survivals or in animals that had been vaccinated against FMD. It was demonstrated that the proper use of ICFT necessitates in turn the use of a minimal amount of antigen, which in the presence of 1-2 E homologous hyperimmune serum completely binds the 1 E complement. Results showed that the sera of survived or vaccinated animals contain specific antibodies of titers of 1:4 up to 1:256. The latter depended on the type of vaccine, the amount of antigen in the vaccinal dose, and the time period from the immunization or survival up to the time of taking the serum samples. It is pointed out that ICFT is a sensitive and specific method for the differentiation of FMD viruses and the study of animals' immunity against FMD.

Animals↗
PubMed1969

Equine infectious anemia: preliminary investigation of the complement-fixation test for the demonstration of antibodies and antigen.

Clinical field cases of equine infectious anemia were studied and the disease was reproduced experimentally in horses. Attempts were made to adapt the complement-fixation test to the detection of antibodies in the serum of infected animals and to the demonstration of antigens in tissue extracts.A moderate complement-fixing antibody response was demonstrated in the serum of horses shortly after primary exposure to the infectious agent. However, this reactivity was of short duration and occurred with normal as well as with infected saline tissue extracts. It was therefore concluded that this reaction was not specific for equine infectious anemia. Possibly it is due to the appearance of auto-tissue antibodies. The value of this reaction in the diagnosis of the infection was limited because of its short duration and absence in chronic infection and following re-exposure to the infectious agent.

Animals↗
PubMed1977

The effects of IgG2 and of antigen concentration on prozoning in the complement fixation test for bovine brucellosis.

Addition of Brucella-specific IgG2 to solutions of Brucella-specific IgG1 initially induced prozoning and at higher concentrations prevented all reaction in the complement fixation test (CFT) for bovine brucellosis. Some infected cattle may be diagnosed as brucellosis-free due to a high ratio of specific IgG2 to IgG1. Increasing the concentration of antigen in the CFT reduced the tendency to prozone.

Animals↗
PubMed1986

[Standardization of the complement fixation test (CFT) in brucellosis. I. The Polish standard of anti-Brucella abortus serum].

The purpose of this paper was to prepare an indigenous standard of anti-Brucella abortus serum for the complement fixation test (CFT) as a homologue of the secon International Standard of anti-Brucella abortus Serum (ISABS-II), which contains 1000 international units of complement-fixing antibodies in 1 cm3. The indigenous Standard of anti-Brucella Abortus Serum (ISABAS) was prepared in 1975. The material used was the serum of a cow infected with Br.abortus, biotype 1, under natural conditions. The cow was beheaded on the 54th day after abortion. The serum obtained was filtered through a Seitz EK filter and appropriately diluted with normal bovine serum. The preparation was lyophilized in 8500 ampules, each of which contained 1 cm3 of serum. They were filled with nitrogen before closing them. It was shown that ISABAS activity in CFT was approximate to that of ISABS-II. The studies in CVL, Weybridge showed that one ampule contained 1115 international units of complement-fixing antibodies. ISABAS titres in the agglutination test (AT) and antiglobulin test (AGT) were 320+ + and 2560+ + + respectively. Reduction with 2-mercaptoethanol and separation on a column with Sephadex G-200 gel showed that anti-Brucella antibodies occurred in ISABAS mainly in IgG class. ISABAS lyophilizate is characterized by stability of CFT titre, good solubility and a low anticomplementary activity. The average weight of the lyophilizate in an ampule is 79.57 mg, standard deviation - 0.36%. ISABS may serve as the basis of antigen standardization and other elements of indigenous CFT technique in brucellosis.

Animals↗
PubMed1977

The complement-fixation test in the diagnosis of congenital toxoplasmosis.

We present serologic results on 26 patients with congenital toxoplasmosis and on 22 of their mothers. The infection was severe (central nervous system involvement) in 12 patients, 12 had only ocular manifestations, and two were asymptomatic. The dye test results were positive on all specimens, and were positive at a titer of 1:1,024 or higher if collected from patients younger than 2 years of age. The complement-fixation test (CFT) results were positive on all specimens from patients younger than 2 years of age and on 69% of specimens collected from older patients. These serologic results are contrasted with those obtained on two control groups: (1) 46 uninfected infants followed up after birth because of substantial antibody titers in their mothers during pregnancy; and (2) 190 infants and children tested because toxoplasmosis was tentatively included in the differential diagnosis of the current illness. In both control groups the positive results on the CFT were limited almost exclusively to cord blood specimens or specimens collected during the first 2 weeks of life. Lower CFT titers in follow-up specimens suggested that the antibodies were maternal in origin. These two tests are valuable in providing laboratory support for the diagnosis of congenital toxoplasmosis, particularly the test for the comparatively short-lived complement-fixing antibody.

Antibodies↗
PubMed1977

Antigenic relationship between human and bovine rotaviruses as determined by neutralization, immune adherence hemagglutination, and complement fixation tests.

Guinea pig antiserum to bovine rotavirus does not neutralize human rotavirus. Bovine and human rotaviruses were, however, extensively cross-reactive when examined by complement fixation and immune adherence hemagglutination tests with antiserum to either virus. The immune adherence hemagglutination test was 16- to 32-fold more sensitive than the complement fixation test in detecting rotavirus.

Animals↗
PubMed1986

The potency determination of human varicella-zoster immunoglobulin by enzyme-linked immunosorbent assay, complement-fixation test and indirect fluorescent antibody tests.

Traditionally, plasma for the production of the human varicella-zoster immunoglobulin (VZIG) has been selected on the basis of the complement-fixing antibody (CFA) titre. Since immune individuals may lack CFA to varicella-zoster virus (VZV), non-CFA may be of importance in protection. In a search for a simple and reliable method for potency determination, 24 VZIG preparations were quantified by enzyme-linked immunosorbent assay (ELISA), the complement-fixation test (CFT), the indirect fluorescent antibody test to acetone-fixed (IF) and viable (FAMA) VZV-infected cells, respectively. The antibody titres obtained by the various methods were compared. Arranged in order of decreasing agreement, the correlation coefficients (r) of the regression equations between the variables were 0.62 for CFT and FAMA, 0.50 for CFT and ELISA and 0.26 for CFT and IF in a log2 plot. There was complete agreement between the titres obtained by the commercially available Enzygnost Varicella/Zoster kits (Behring Institute, Marburg, F.R. Germany) and the ELISA microtitre plates produced at our institute (r = 1). The regression equation lines for ELISA/CFT and FAMA/CFT titres tended to be parallel to each other, while the line for IF/CFT titres had a less steep slope. Similar titration curves were obtained for VZIGs fractionated by two different methods. Furthermore, the titration curves of serum pools from varicella and zoster convalescents, respectively, had a similar shape below delta OD = 0.4. Generally, a steeper slope was observed above delta OD = 0.4. As antibody detectable by ELISA seems to correlate with protection and the method is sensitive, specific, reproduceable, simple to carry out and easily automated, it may be suitable for the potency determination of VZIGs.

Antibodies, Viral↗
PubMed1986

Detection of Campylobacter pyloridis in patients with antrum gastritis and peptic ulcers by culture, complement fixation test, and immunoblot.

The association of Campylobacter pyloridis with antrum gastritis and peptic ulcers was described. We investigated antral biopsies from 180 patients who underwent gastroscopy. By culture or Gram stain or both, we found overall 98 (54%) of them to be positive for C. pyloridis. In the various groups the following percentages were found to be positive: normal antral mucosa 3% (n = 30); moderate superficial antrum gastritis, 49% (n = 83); severe superficial antrum gastritis, 86% (n = 44); duodenal ulcer, 83% (n = 54); and gastric ulcer, 72% (n = 18). A serological screening that used a complement fixation test yielded the following results: highest rates of positive complement fixation titers were seen in patients with severe gastritis and those with duodenal ulcers, both with 79%; the lowest incidence was in a group of 20 blood donors, with 5%. Positive complement fixation titers in gastritis patients also correlated well with characteristic patterns on immunoglobulin G and A immunoblots, while there was no specific reactivity observed on immunoglobulin M immunoblots.

Antibodies, Bacterial↗
PubMed1991

Comparison of the Johne's absorbed EIA and the complement-fixation test for the diagnosis of Johne's disease in cattle.

A commercially available absorbed ELISA for the diagnosis of Johne's disease (JD) (paratuberculosis) in cattle, the Johne's Absorbed EIA, was compared with the conventional complement-fixation test (CFT) used in Australia. Stored plasma from 3 Victorian dairy herds with a history of JD, sera from specimens submitted from animals showing clinical signs of JD and sera from the US National Repository for Paratuberculosis Specimens were used to determine the sensitivity of each test. The EIA detected 48.8% of 43 Australian animals with subclinical JD, while the CFT detected only 12 (21.4%) of 56 subclinically affected cattle. Of 150 subclinically infected US cattle, the EIA detected 47.3% and the CFT detected 52.0%. The EIA detected 59.7% of animals which at the time of sampling were shedding Mycobacterium paratuberculosis in their faeces, but showed no clinical signs of JD, while the CFT detected 57.3%. The EIA correctly identified 88.2% of 136 histologically confirmed clinical cases, and the CFT detected 83.4%. The specificity of each test was determined by testing sera collected at slaughter from animals residing in a known JD-free area of Australia, and from samples from the US National Repository of Paratuberculosis Specimens collected from certified-free herds in Wisconsin. The EIA was found to have a specificity of 99.8% when 998 Australian animals were used as the test population, and 99.0% when 196 US animals were used. The specificity of the CFT using Australian samples was 96.9% and 95.2% using American samples.

Animals↗
PubMed1977

Complement "specificity" and interchangeability: measurement of hemolytic complement levels and use of the complement-fixation test with sera from common domesticated animals.

The results from studies to measure lytic complement (C') in sera of different animal species were reviewed. The traditional system, using sheep red blood cells (RBC) and rabbit antibody, was confirmed as the most sensitive to measure C' levels in man, monkey, dog, guinea pig, and rat serums. Sera C' from horse, cow, and sheep were found to be best assayed using rabbit RBC, whereas C' from goat, cat, and rabbit were best assayed with human RBC. Antibodies and C' from the same species usually mediated lysis of foreign RBC, but this lysis occurred more readily with some RBC targets than with others and may be associated with the presence of natural antibodies in the test sera. The effects of the species origin of a C' source in immunologic reactions in vitro and in vivo are discussed.

Animals↗
PubMed1977

A complement fixation test for the detection of Eperythrozoon infection in sheep.

A method is described for preparation of an antigen from E. ovis-infected blood first lysed by freezing and thawing, and then followed by sonic disruption of the centrifuged deposit. It was then used in a complement fixation test to demonstrate antibodies in sheep infected with E. ovis. The antigen was not anti-complementary and it retained its potency for long periods when stored concentrated, at about -20 degrees C. Repeated freezing and thawing also has had no effect on the potency of the concentrated antigen. The testing of 668 serums from commercial flocks where E. ovis infection has been diagnosed microscopically has shown the CFT to be a valuable diagnostic aid mainly on a flock sample basis, though the test could be of value on an individual sample basis if the sample were taken from a recently infected sheep.

Anaplasmataceae Infections↗
PubMed1989

Comparison of the dot-immunobinding assay with the complement fixation test for the detection of Brucella antibodies in sheep.

A dot-immunobinding assay (DIA), using as antigen a sonic extract of Brucella abortus dotted on nitrocellulose bound to a plastic strip, was employed for the detection of Brucella antibodies in 666 sheep sera. The results were compared with the complement fixation test (CFT). All the 242 sera belonging to two flocks were found to be negative by DIA. CFT was negative in 239 cases, whereas three samples showed anti-complementary activity. Of the 424 sera from the remaining three flocks, 98 were positive by both tests and six were positive in DIA, but negative in CFT. In addition, 14 of the 19 anti-complementary sera were also positive by DIA.

Animals↗