Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Complement Fixation Tests”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,387 records · Page 77Linked to original sources
PubMed1988

Immunochemical studies of polyspecific natural autoantibodies: charge, lipid reactivity, Fab'2 fragments activity and complement fixation.

Polyspecific natural autoantibodies (NAAb) are antibodies present in normal unimmunized animals and are able to react with very dissimilar antigens (Ag). To better delineate the characteristics of polyspecificity, we subjected monoclonal NAAb to four different immunochemical studies: (1) Two-dimensional gel electrophoresis performed on eight NAAb did not reveal any obvious relationship between charge and antigen specificities; (2) NAAb widely polyspecific on proteins and nucleic acid were reactive with lipids bearing either phosphate, sulfate or carboxyl polar groups; (3) pepsin digestion of polyspecific IgM NAAb yielded Fab'2 fragments which maintained their multireactivities, but exhibited a decrease in reactivity as compared to that seen with monospecific mAb (induced); (4) two different assays were used to analyse the complement fixation ability of IgM NAAb. While very weak or no complement fixation was observed with a classical complement fixation test (fluid phase), when a complement enzyme immunoassay was used where Ag is immobilized on a solid phase, polyspecific NAAb fixed reproducible and easily detectable amounts of complement.

Animals↗
PubMed1986

Distinct fixation of defined amounts of complement by the Brucella abortus antigen and bovine antibodies under different incubation conditions in the CFT.

Different times and temperatures of the 1st phase incubation of the complement fixation test (CFT) were used. It was found that a similar decrease in complement (C') activity occurred after 2 h at 37 degrees C, after 8 h at 20 degrees C and after 18 h at 4 degrees C. Simultaneously, in the same periods a double increase in standard serum titre at 4 and 20 degrees C was noted in comparison with titre at 37 degrees C. This increase of sensitivity of the CFT at 4 and 20 degrees C appeared to be a simulating one and resulted from the different pattern of reaction in each temperature in the block titration of antigen. The positive reactions in the range from the lowest to the highest dilutions of antigen were appearing and increasing and then disappearing in sequence at 4, 20 and 37 degrees C, creating the typical C' fixation area for each temperature. Similar results were obtained in four different C' fixation techniques, most frequently used in diagnosis of animal brucellosis. On the basis of our own examination results and literature data the warm and short C' fixation (37 degrees C, 30 min) was chosen in the standard technique of the CFT used in routine diagnostic survey for animal brucellosis in Poland.

Animals↗
PubMed1987

Comparison of TRACK XI fluorometric immunoassay system with other serologic tests for detection of serum antibody to Brucella abortus in cattle.

The TRACK XI system (TRACK) is a commercially available fluorometric immunoassay system that has been adapted for the detection of antibodies to several antigens in various animal species. Serum antibodies to Brucella abortus were detected by TRACK and compared with those obtained from two primary binding assays (a fluorometric immunoassay [FIAX] and an enzyme-linked immunosorbent assay) and three standard serological tests (complement fixation, Rivanol precipitation, and CARD tests). A total of 298 serum samples were tested by each serological test. Of these serum samples, 134 were negative controls, 43 were from cattle 1 month after vaccination with B. abortus 19, and 121 were from cattle 10 to 12 weeks after a midgestational, intraconjunctival challenge with B. abortus 2308. The results of this study indicated that TRACK is both reproducible and accurate. The results compared favorably with those of other serological methods. TRACK is more rapid than either the enzyme-linked immunosorbent assay or FIAX system. TRACK was the most sensitive (96.3%) test, with a specificity of 100%.

Animals↗
PubMed1978

A simple, rapid syncytial-inhibition test for antibodies to bovine leukemia virus.

Cocultivation of equal numbers of cells from a fetal lamb kidney line infected with bovine leukemia virus and African green monkey (Vero) cells results in the rapid production of syncytia. The effect was blocked or inhibited by serum containing antibodies to bovine leukemia virus. A serological test based on syncytial inhibition was compared to the agar gel immunodiffusion test and the modified direct complement fixation test for the detection of bovine leukemia virus antibodies in sera from leukosis-free cattle, cases of adult enzootic bovine lymphosarcoma and cattle from herds in contact with enzootic lymphosarcoma. The results showed the syncytial inhibition test to react positively with sera from all cases of adult enzootic lymphosarcoma, but to be much less sensitive than the other tests in detecting bovine leukemia virus antibodies in sera of exposed animals.

Animals↗
PubMed1998

Babesia equi field isolates cultured from horse blood using a microcentrifuge method.

Babesia equi, a causative agent of equine piroplasmosis, was isolated from horses in the Chaco Province of Argentina, a known piroplasmosis endemic region. Fifteen B. equi field isolates were acquired by culture from 23 actively working horses from 2 ranches. The horses appeared healthy with no clinical signs or histories indicative of equine piroplasmosis. All 23 horses had B. equi-specific antibody activity by the indirect fluorescent antibody test and 18 were also complement fixation test positive for B. equi. Equine erythrocytes were prepared for parasite culture using a microcentrifuge tube method. This method greatly reduces the time involved in cell handling and parasite exposure to ambient conditions. By this method, B. equi cultures can be initiated from very small quantities of blood.

Animals↗
PubMed1970

Chronic biological false-positive reactions to serological tests for syphilis in blood donors.

Problem sera from 375 blood donors were investigated for biological false-positive reactions to serological tests for syphilis. Problem sera are those sera in which submitting laboratories have found a reactive result to a screening test for syphilis. On each serum a cardiolipin Wassermann reaction, a Venereal Disease Research Laboratory test, a Reiter protein-complement fixation test, a Treponema pallidum immobilization test, and a fluorescent treponemal antibody absorption test were performed. Of the sera 49.9% were found to be non-reactive in all five tests, 28.8% gave results indicating a diagnosis of syphilis, and 21.3% showed biological false-positive reactions. There were 80 sera from blood donors which gave biological false-positive reactions. A further specimen of serum from 67 of these donors was tested after an interval of a minimum of six months. Sixty-six of the sera showed chronic biological false-positive reactions. Some donors were only found reactive for the first time after they had given very many donations of blood. It is concluded that sudden blood loss, as in blood donation, appears to stimulate the production of excess reagin in certain individuals, causing a chronic biological false positive reaction to serological tests for syphilis. This may only appear after several blood donations have been made.

Blood Donors↗
PubMed1978

Antibody assays for varicella-zoster virus: comparison of enzyme immunoassay with neutralization, immune adherence hemagglutination, and complement fixation.

An enzyme immunossay (EIA) was adapted for detection of antibody to varicella-zoster virus, and its sensitivity and specificity were compared with those of neutralization, immune adherence hemagglutination (IAHA), and complement fixation tests. Test sera showed little nonspecific reactivity in the EIA system, and valid results could usually be obtained at serum dilutions as low as 1:8. Demonstration of the presence or absence of varicella-zoster viral antibody by EIA showed 94% correlation with results obtained in neutralization tests, but EIA titers were 2- to 16-fold higher than neutralizing antibody titers. Results by IAHA showed 87% correlation with those obtained by neutralization. No false positive IAHA results were seen, but a number of false negative IAHA results were seen at the 1:8 serum dilution, particularly in older individuals. With increasing age (>40 years), and presumably increased time from varicella infection, neutralizing antibody levels generally declined to 1:8 or 1:16, EIA levels fell to 1:128 or 1:256, and IAHA and complement fixation antibody titers were usually <1:8 or 1:8. EIA and IAHA were as reliable as the neutralization and complement fixation tests for serodiagnosis of varicella and zoster infections. All tests demonstrated heterotypic varicella-zoster antibody titer rises in selected patients with initial herpes simplex virus infections, but fewer heterotypic responses were seen by EIA than by the other methods. EIA offers a rapid, sensitive, and specific method for varicella-zoster antibody assay that is applicable to use in a clinical setting.

Adolescent↗
PubMed1995

Improved competitive enzyme immunoassay for the diagnosis of bovine brucellosis.

A modification of the competitive enzyme-linked immunosorbent assay (C-ELISA) for differentiating the antibody response of cattle vaccinated with Brucella abortus strain 19 and B. abortus infected cattle is described. This assay utilizes lipopolysaccharide as the antigen, immobilized on a polystyrene matrix, and a monoclonal antibody (M84) with specificity for an epitope of the O-polysaccharide. A goat anti-mouse IgG antibody-enzyme conjugate is used for detection. The specificity of the modified assay was 99.7% when 1446 sera from brucellosis free herds were tested and it correctly identified 636 sera from B. abortus infected cattle as positive, using a cut-off of 30% inhibition, for a sensitivity estimate of 100%. No reactions were noted among 261 sera from vaccinated cattle. However, in testing 1147 sera that gave positive reactions in the buffered plate antigen test, the indirect ELISA, the complement fixation test or a combination of these tests from the serum bank, 31 gave positive reactions. Twenty-seven of the 31 sera originated from recently vaccinated cattle. The overall specificity for sera from vaccinated cattle was 97.3%. Because of the sensitivity and specificity of this procedure and its ease of performance, it would be a reasonable alternative as a single assay for serological diagnosis of brucellosis.

Animals↗
PubMed2004

[Infection with Chlamydophila pneumoniae as a cause of female infertility of tubal origin?].

OBJECTIVE: A contribution to the role of Chlamydophila pneumoniae in women from the IVF program. DESIGN: A serological study proving the antibodies against the antigens of Chlamydophila pneumoniae (C. pneumoniae) and Chlamydia trachomatis (C. trachomatis) in women from the IVF program suffering from different factor of infertility. SETTING: Veterinary Research Institute, Brno. METHODS: The complement fixation test with chlamydial antigen and ELISA tests proving IgA and IgG antibodies against genus-specific antigen (cLPS) and species-specific chlamydial major outer membrane protein (cMOMP) of C. trachomatis and C. pneumoniae in the blood serum of 32 females being in the fertilization program due the tubal factor infertility have been estimated and the results compared with those obtained in 26 females being in the fertilization program due the ovarian factor and in 42 female with andrological factor, respectively. RESULTS: The frequency of positive complement fixation test proved in the group of women with tubal factor infertility was significantly higher than in the groups with ovarial and andrological factor, respectively. The number of the strongly positive reactions (with high titres) in the group with tubal factor infertility was higher than in two remaining groups. The occurrence of species-specific IgG antibodies (anti-C. trachomatis) and chlamydia genus-specific IgA antibodies proved by means of ELISA in the group with tubal factor was statistically more frequent. The difference of the species-specific anti-C. pneumoniae antibodies in all three groups examined was not significant. The simultaneous occurrence of species-specific antibodies against anti-C. pneumoniae and C. trachomatis in the group with tubal factor was higher than in other groups (in comparing with the group with andrological factor statistically significant). CONCLUSION: The opinion of the authors being in agreement with the view of most specialists is that the most important agent in the pathogenesis of tubal factor fertility is C. trachomatis. C. pneumoniae is above all a respiratory pathogen with a high prevalence and its impact for fertility disorders may be in the synergismus with C. trachomatis. The serological examination of both chlamydial infections should be a standard part of diagnostic algorithm.

Adolescent↗
PubMed1988

Serologic response of Babesia equi-infected horses as measured by complement-fixation and indirect fluorescent antibody tests.

Both the complement-fixation test (CFT) and the indirect fluorescent antibody test (IFAT) were conducted on weekly serum samples from nine Arab geldings for 28 days before and 256 days after their exposure to Babesia equi of European origin. On an average the IFAT became positive 8 days before the CFT and showed higher relative serum titer increases. Both test procedures successfully detected infection and neither showed an appreciable drop in titer during this time frame, with the exception of the CFT, which showed a transient drop immediately following treatment with imidocarb. A test conducted 540 days after infection showed four of the eight surviving, and presumably infected, horses to be negative on CFT, where as all eight were still positive on IFAT. Comparisons made with the IFAT, on horse sera from B. equi infection of both European and North American origin, utilizing homologous and heterologous antigens, showed significantly higher titers with homologous antigens.

Animals↗
PubMed1976

[Use of specific anti-T-lymphocyte globulin (sATG) for the diagnosis of lymphoproliferative diseases (author's transl)].

Difficulties in the production of specific antisera against T-lymphocytes could be overcome by a stepwise absorption and purification procedure of anti-human thymocyte serum. Specific anti-T lymphocyte globulin (sATG) reacted with thymocytes, thymus-derived lymphocytes and a lymphoblastoid cell line of T-cell type whereas no activity was found against lymphoblastoid cell lines of B-cell type. Five chronic and three acute lymphatic leukemias were characterized using sATG in the cytotoxic test, electron microscopy, complement fixation test and quantitative immunoautoradiography, and compared with lymphocyte populations of normal individuals. Three chronic lymphatic leukemias with low numbers of spontaneous rosettes and high percentages of membrane-Ig-positive lymphocytes showed only few T-cell-antigen-positive lymphocytes and were therefore classified as B-cell leukemias. The cells of two chronic lymphatic leukemias with high numbers of spontaneous rosettes carried T-cell-antigen. The T-cell-antigen concentration, however, was lower than that of normal peripheral blood T-lymphocytes. The T-cell nature of two acute lymphatic leukemias with high numbers of spontaneous rosettes was confirmed by a positive reaction of the cells with sATG. In one case of acute lymphatic leukemia most leukemic cells carried T-cell-antigen although these cells did not form spontaneous rosettes. In the first two cases the T-cell-antigen concentration on the cell surface exceeded that of normal blood-T-lymphocytes, in the latter case it was slightly below that. The advantages of the characterization of leukemias with sATG in comparison with the spontaneous rosette formation and the relevance for prognosis are discussed.

Antilymphocyte Serum↗
PubMed1976

The incidence of Mycoplasma pneumoniae infections in Denmark over the past seventeen years: a review.

The variations in the incidence of Mycoplasma pneumoniae infections in Denmark over a period of 17 years could be demonstrated in the central serological laboratory which serves the whole of the population. This observation was made possible for the first and major part of this study by testing cold agglutinin (CA) positive sera, which had been kept frozen sine 1958, for antibodies to M.pneumoniae. The second part of the study is based upon results from routine tests for CA and M.pneumoniae antibodies on all samples which we receive. A statistical analysis of the total material indicates that four epidemics of M.pneumoniae antibodies on all samples which we receive. A statistical analysis of the total material indicates that four epidemics of M.pneumoniae infection had taken place from January 1958 to December 1974 and that these epidemics occurred at regular four and a half year intervals. By a follow-up of the study a fifth epidemic was demonstrated during the first eight months of 1975 which broke the regular periodicity by appearing two years earlier than expected. The consequences of including only CA positive sera in this study was investigated. Antibodies to M.pneumoniae were measured by either an indirect immunofluorescence test, an indirect haemagglutination test or a complement fixation test. The observed difference in sensitivity of these tests is discussed in relationship to a possible influence on the overall incidence.

Agglutinins↗
PubMed2005

Trypanosoma equiperdum: master of disguise or historical mistake?

After 100 years of research, only a small number of laboratory strains of Trypanosoma equiperdum exists, and the history of most of the strains is unknown. No definitive diagnosis of dourine can be made at the serological or molecular level. Only clinical signs are pathognomonic and international screening relies on an outdated cross-reactive serological test (the complement-fixation test) from 1915, resulting in serious consequences at the practical level. Despite many characterization attempts, no clear picture has emerged of the position of T. equiperdum within the Trypanozoon group. In this article, we highlight the controversies that exist regarding T. equiperdum, and the overlap that occurs with Trypanosoma evansi and Trypanosoma brucei brucei. By revisiting the published data, from the early decades of discovery to the recent serological- and molecular-characterization studies, a new hypothesis arises in which T. equiperdum no longer exists as a separate species and in which current strains can be divided into T. evansi (the historical mistake) and Trypanosoma brucei equiperdum (the master of disguise). Hence, dourine is a disease caused by specific host immune responses to a T. b. equiperdum or T. evansi infection.

Animals↗
PubMed2002

How to substantiate eradication of bovine brucellosis when aspecific serological reactions occur in the course of brucellosis testing.

Collaborative work was financed by the EU to develop and assess new diagnostic tools that can differentiate between bovine brucellosis and bovine infections due to Yersinia enterocolitica O:9 either in conjunction with, or as an alternative to, the classical serological, bacteriological or allergic skin tests. Sixteen heifers were experimentally infected with Brucella abortus biovar 1 (five heifers), Brucella suis biovar 2 (two heifers), Y. enterocolitica O:9 (six heifers) and Y. enterocolitica O:3 (three heifers). Four heifers, naturally infected with Y. enterocolitica O:9 that presented aspecific brucellosis serological reactions were also included in the experiment. A self-limited infection was induced in cattle by B. suis biovar 2. All the brucellosis serological tests used, i.e. the slow agglutination test (SAW), the Rose Bengal test (RB), the complement fixation test (CFT), indirect and competitive ELISA's, lacked specificity when used to analyze sera from Y. enterocolitica O:9 infected animals. A Yersinia outer membrane proteins (YOPs)-ELISA was also used and although the test is able to detect a Yersinia group infection, it provided no evidence of whether or not there is a possible brucellosis infection when dual infections are present. The brucellergen IFN-gamma test showed a lack of specificity also. The only test that was proven to be specific is the brucellergen skin test. All brucellosis serological tests, except the indirect ELISA, were limited in their ability to detect B. abortus persistently infected animals. Based on these experimental studies, a strategy was implemented as part of the year 2001 Belgian Brucellosis Eradication Program to substantiate the eradication of bovine brucellosis. Epidemiological inquiries have identified risk factors associated with aspecific serological reactions, possible transmission and infection of cattle by B. suis biovar 2 from infected wild boars; and both legal and administrative measures taken by the veterinary services. No cases of bovine brucellosis have been confirmed in Belgium since March 2000.

Animals↗
PubMed1999

Validation of enzyme-linked immunosorbent assays for the diagnosis of bovine brucellosis.

The purpose of this study was to evaluate the performance of the indirect enzyme immunoassay (IELISA) and the competitive enzyme immunoassay (CELISA) for the diagnosis of bovine brucellosis in comparison to conventional serological tests routinely used in Argentina. Serum samples (n = 3500), from Brucella-free herds, from vaccinated cattle and from naturally infected cattle, were tested by the following tests: buffered antigen agglutination test (BPAT), rose bengal test (RBT), 2-mercaptoethanol test (2-ME), complement fixation test (CFT), IELISA and CELISA. Sensitivity and specificity of the BPAT, RBT, IELISA and CELISA were determined relative to the 2-ME and the CFT. The CELISA was considered suitable for eliminating most serological reactions of vaccinated animals and was more specific than the other tests. The results indicate the potential use of the CELISA as a complementary assay in the brucellosis control and eradication program in Argentina and other countries, where Brucella abortusstrain 19 vaccination is mandatory.

Animals↗
PubMed1982

[Ocular histoplasmosis].

Reports of ocular histoplasma mycosis demonstrated serologically and in tissue are rare in Europe. This is principally due to the fact that histoplasmosis is not endemic in Europe (in contrast to the USA). A second reason is that it is hard to find laboratories which have experience in the differential diagnosis of histoplasmosis and forms of uveitis. In cases of uveitis it would be desirable to include histoplasmosis in the differential diagnosis and to use more staining methods (silver nitrate methenamine, fluorescein serology) and immunologic tests (intracutaneous test with histoplasmin, complement fixation test, countercurrent immuno-electrophoresis) for histoplasmosis. Report on a case of ocular histoplasmosis, positive in the skin test and in immunodiffusion, contracted 19 years previously in Mississippi, USA.

Adult↗
PubMed2001

Fluorescence polarization assay for the diagnosis of brucellosis: a review.

Fluorescence polarization assay (FPA) is based on the rotational differences between a small soluble antigen molecule in solution (labelled with a fluorochrome) and the antigen molecule complexed with its antibody. A small molecule will rotate randomly at a rapid rate, resulting in rapid depolarization of light, while a larger complex molecule will rotate slower and depolarize light at a reduced rate. The rate change in depolarization can be measured. The FPA is a homogeneous assay which does not require removal of unreacted reagents and can, therefore, be performed very quickly and, given portable equipment, in the laboratory and in the field. The latter obviates the need for shipping samples and eliminates waiting for results, as well as reducing test costs. The FPA technology has been developed and validated for the serological diagnosis of brucellosis in cattle, swine, sheep, goats, bison, and cervids. Sufficient cross reactivity of the common epitopes of Brucella abortus, B. melitensis and B. suis O-polysaccharide (OPS) allowed for the use of a single antigen for all species of smooth Brucella and animals. The OPS prepared from B. abortus S1119.3 was conjugated with fluorscein isothiocyanate (FITC). The FPA was initially developed for testing serum; however, the technology has been extended to testing whole blood and milk from individual animals or bulk tank samples pooled from 2000 or fewer animals. The accuracy of the FPA equalled or exceeded those obtained using other serological tests such as the buffered antigen plate agglutination test (BPAT), the milk ring test (MRT), the complement fixation test (CFT), the indirect enzyme immunoassay (IELISA), and the competitive enzyme immunoassay (CELISA).

Animals↗
PubMedDate not supplied

Isolation of herpes simplex virus from sexually transmitted disease patients in Ibadan, Nigeria.

BACKGROUND AND OBJECTIVES: Despite the public health importance of herpes simplex virus infection in Nigeria, attempts have not been made to isolate and identify the virus. GOAL OF THE STUDY: To isolate, identify, and type the virus from patients attending a sexually transmitted disease (STD) clinic in Ibadan, Nigeria. STUDY DESIGN: One hundred fifty-three clinical samples from 116 patients were taken and inoculated into tissue culture for virus isolation. The isolates were identified and typed using chloroform sensitivity test, histocytological study, Complement Fixation Test (CFT), and indirect immunofluorescent antibody technique (IFAT). RESULT: Virus was isolated from seven of the 153 samples. Two of the seven were HSV-1, and five were HSV-2. CONCLUSION: This is the first documented isolation of the herpes simplex virus in Nigeria. The study has provided baseline data for future studies on genital herpes in Nigeria. These results may have interesting implications with respect of HIV transmission and other related sexually transmitted diseases in Nigeria.

Female↗