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At least 19 recordsLinked to original sources
PubMed1994

Immunological neutralization of cobrotoxin by its homologous precipitin and non-precipitin antibodies.

Anti-cobrotoxin antibodies can be separated into precipitin and non-precipitin antibodies. The precipitin antibody possesses the same binding affinity to cobrotoxin as non-precipitin antibody, but the neutralizing capability of the latter is superior to that of the former in blocking cobrotoxin binding to nicotinic acetylcholine receptor (nAChR). After preincubation with antibodies, cobrotoxin completely lost its binding activity to nAChR. The dissociation of cobrotoxin-nAChR complex by the antibodies was low, and 60% of the complex formation appeared to be irreversible. These results indicate that the neutralization of cobrotoxin by the antibody may predominantly involve unbound, receptor-free cobrotoxin. The relationships of neutralization capacity and binding affinity as well as bond strength between cobrotoxin and its antibodies are incongruous. Different local conformational changes of a unique Trp in cobrotoxin on binding with the precipitin and non-precipitin antibodies seem to lead to different accessibility for fluorescence quenchers. Characterization of the binding domains by immunoprecipitation with the antibodies correlated with the quenching results. Thus, the binding topography of cobrotoxin may play an important role over the binding affinity and bond strength in neutralization by cobrotoxin antibody.

Animals↗
PubMed1967

Agar-gel precipitin-inhibition test for coccidioidomycosis. I. Preliminary evaluation of the complement-fixation and agar-gel precipitin tests in the serodiagnosis of human coccidioidomycosis.

The agar-gel precipitin-inhibition serological test for coccidioidomycosis was a more sensitive indicator of Coccidioides immitis antibodies than the tube precipitin, the agar-gel immunodiffusion, in the complement-fixation tests in assaying monkey sera, whether these sera were from prechallenge-vaccinated or postchallenged animals. When applying this technique to the assay of human sera, an analogous finding generally persisted. However, some human sera were positive by the complement-fixation test and negative by the agar-gel precipitin-inhibition test. These sera were diffused in agar-gel against various coccidioidin complement-fixation, tube precipitin, and agar-gel precipitin-inhibition test antigens with essentially negative results.

Animals↗
PubMed1989

Immunoaffinity isolation and partial characterization of the Coccidioides immitis antigen detected by the tube precipitin and immunodiffusion-tube precipitin tests.

The antigen participating in the tube precipitin (TP) serologic test for coccidioidomycosis was isolated from mycelial-phase antigen (coccidioidin) by immunoaffinity and characterized by various analytical procedures. This was accomplished by first preparing the antigen-antibody precipitate by using antigen and human serum positive for TP (immunoglobulin M) antibody and then liberating the antigen by digestion with pronase. This protease destroyed the antibody and left the antigen intact as indicated by immunodiffusion-TP. The coccidioidal antigen was isolated from the proteolytic digest by using size exclusion chromatography. DEAE chromatography of this antigen yielded two fractions with immunodiffusion-TP reactivity which had average molecular sizes of 225 and 140 kilodaltons, respectively. The presence of carbohydrate and amino acids indicated that the antigen(s) is a glycopeptide. Compositional analysis showed that one fraction contained 3-O-methylmannose, mannose, and glucose in a ratio of 8:1.2:1, whereas the second fraction contained 3-O-methylmannose, mannose, glucose, and galactose in a ratio of 1:1:1:1. The amino acids glycine, alanine, serine, threonine, aspartic acid plus asparagine, and glutamic acid plus glutamine constituted 60 to 70% of the amino acids in both glycopeptides. Neither antigen could be detected entering the gel in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Lectin affinity provided evidence of a high-mannose asparagine-linked glycopeptide in the first peak and an asparagine-linked glycopeptide with a biantennary complex-type structure in the second peak.

Amino Acids↗
PubMed1980

Circumoval precipitin antigens for the diagnosis of schistosomiasis. I. Development of an antiserum reactive with Schistosoma mansoni eggs by the circumoval precipitin test.

A serum was developed which reacts with Schistosoma mansoni eggs by the circumoval precipitin (COP) test. This antiserum to COP antigens was prepared by coupling the COP immune complexes to protein A-Sepharose, isolating the complex with acid buffer, and immunizing rabbits with the eluate. The antiserum reacted with S. mansoni eggs, forming globular bleb and septate precipitates. It also reacted in gel diffusion with a soluble egg antigen preparation of S. mansoni (SEA). Of four SEA antigenic components precipitated one was clearly MSA1. The antiserum to the COP antigens had anti-parasite antibodies absorbable with lyophilized cercariae or eggs. Three human immunoglobulins (IgG, IgM, and IgA) were involved in the COP reaction.

Animals↗
PubMed1989

[Comparison of immunoenzymatic staining technique (IEST), double gluing strip circumoval precipitin test (DGS-COPT) and conventional circumoval precipitin test (CV-COPT) for diagnosis of schistosomiasis japonica].

IEST, DGS-COPT and CV-COPT using lyophilized ova of schistosoma japonicum were performed on sera from 120 cases of schistosomiasis japonica, 120 cases of schistosomiasis japonica 3-8 years after being cured with praziquantel and 120 healthy individuals by single-blind method. The sensitivity and specificity of IEST was 91.7% and 95.8% respectively which were significantly higher than that of both DGS-COPT and CV-COPT. The negative conversion rate of cured patients was 70.8% with IEST, 80.8% with DGS-COPT and 81.7% with CV-COPT. The results showed that IEST has higher diagnostic value for schistosomiasis than both COPT. DGS-COPT has the same diagnostic value as CV-COPT, however, it was easy to perform and time-saving, thus it might be applied in the fields for practical purposes.

Animals↗
PubMed1992

Precipitins and specific IgG antibody to Aspergillus fumigatus in a chest unit population.

BACKGROUND: The enzyme linked immunosorbent assay (ELISA) for detecting IgG antibodies to Aspergillus fumigatus is more sensitive than the measurement of Aspergillus precipitins. The relation of the results from both techniques to the clinical pattern of disease in a large unselected group of patients from a large referral centre is unknown. METHODS: The clinical relation of precipitins to Aspergillus fumigatus to clinical disease was determined retrospectively in 98 patients attending a primary referral centre. Precipitin results were compared with the specific IgG antibody to A fumigatus in 88 of the sera. Precipitins were determined by the agar gel double diffusion test and specific IgG antibody to A fumigatus by a quantitative ELISA. RESULTS: Precipitins were detected in the unconcentrated serum of 51 patients. Thirty nine of these had a mycetoma or allergic bronchopulmonary aspergillosis, 34 having specific IgG antibody to A fumigatus more than the control range. Forty seven patients had precipitins only after threefold concentration of serum or to only one of the four A fumigatus antigen extracts. Most of these had specific IgG in or near the control range. Thirty of these had A fumigatus skin test negative asthma or bronchiectasis, in which aspergillus was probably not pathogenic. There was a close relation between the level of antibody detected by the ELISA and the number of precipitin lines. CONCLUSIONS: This study reaffirmed the supportive role of aspergillus precipitins in the diagnosis of pulmonary aspergillosis. No additional benefit in the routine use of the ELISA was seen. It also showed that care should be taken in interpreting positive precipitin results from concentrated serum and that using several rather than one A fumigatus antigen extract is helpful for identifying allergic aspergillosis.

Antibodies, Fungal↗
PubMed1975

Incidence of serum anti-DNA precipitins in patients with systemic lupus erythematosus by counterimmunoelectrophoresis.

The technique of counterimmunoelectrophoresis (CIE) has been adapted for detection of serum precipitins to calf thymus (CT) DNA in patients with SLE, discoid LE, miscellaneous connective tissue and infectious diseases, and control populations. Of seventy-eight LE patients, 58% demonstrated anti-ss DNA precipitins, and 20% exhibited anti-ds DNA precipitins. Good correlation was noted between the presence of ss DNA precipitins and ss DNA binding values determined by the more sensitive ammonium sulphate precipitation assay. Depressed total serum haemolytic complement activity in CH50 mu/ml was noted in 64% of sera exhibiting ss DNA precipitins and 38% of those with negative ss DNA precipitins. There was a strong association, however, between ds DNA precipitins and depressed serum complement levels. Although less sensitive than primary binding assays, CIE can be used as a rapid and simple screening test for detection of circulating anti-native and denatured CT DNA precipitins. CT DNA serum precipitins are present in a significantly higher percentage of SLE patients when compared with other disease states and normal control populations.

Ammonium Sulfate↗
PubMed1974

Candida precipitins in pregnant women: validity of the test systems used.

Sera from 200 pregnant women, with symptoms suggestive of vaginitis and harbouring yeast in the vagina, were examined for precipitating antibodies to three antigens of C. albicans, using a gel double diffusion test. A high overall incidence of precipitin-positive sera (47.5%) was found compared with an incidence of 18% in the unselected pregnant population previously studied (Stanley, Hurley, and Carroll 1972). Using the clinicopathological criteria of Carroll, Hurley, and Stanley (1973), a final aetiological diagnosis of C. albicans mycosis was reached in 75 cases and precipitins were demonstrated in 64%. Forty-eight women harbouring C. albicans responded favourably to a single course of antifungal treatment, and probably had mycotic vaginitis. The incidence of precipitins in this group was 42%. C. albicans was isolated from a further 55 of 62 patients, in whom the incidence of precipitins was 32%.;Booking' sera were investigated from 50 of the 200 women studied. Sixty-four per cent of women had symptoms of vaginitis at booking and 32% were precipitin positive. Twenty-eight per cent had precipitins on both occasions, and a further 24% acquired candida precipitins during pregnancy. None of the seven newborn with oral or skin thrush had precipitins to C. albicans.The results indicate that the detection of precipitating antibodies to C. albicans, particularly to all three of the antigens described in this paper, would be a useful additional criterion in the diagnosis of candida vaginitis, particularly if the vaginitis were persistent, recurrent, or unresponsive to therapy. The sensitivity of the test system used was 64%, and its specificity 87%; as such, the test is valid and may be reasonably useful as a screening procedure.

Antigens↗