Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PRECIPITIN 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 523 records · Page 29Linked to original sources
PubMed2004

Methods of choice for diagnostic antinuclear antibody (ANA) screening: benefit of adding antigen-specific assays to immunofluorescence microscopy.

OBJECTIVES: To evaluate and compare the performances of three enzyme-immunoassays (EIAs) and a double radial immunodiffusion (DRID) test in addition to immunofluorescence (IF) microscopy for routine laboratory screening of patient sera sent for antinuclear antibody (ANA) analysis. METHODS: 3079 consecutive patient sera sent for routine testing of ANA were analysed by IF microscopy on HEp-2 cells (IF-ANA), three different ANA-EIAs, and a DRID test for antibodies against extractable nuclear antigens. The IF-ANA and DRID tests were regarded as reference methods. RESULTS: By IF-ANA and/or DRID, 375 sera (12%) turned out ANA-positive. A further 171 sera (6%) were positive by EIA, but could not be confirmed either by IF microscopy or DRID. 32 of the 375 ANA-positive (9%) sera were negative by IF microscopy, but had precipitating antibodies against Ro/SS-A (52 and/or 60 kD). CONCLUSIONS: Different assays for ANA analysis give overlapping results to a certain extent, but are by no means interchangeable. Thus, different ANA tests reflect different aspects of these autoantibodies. The diagnostic utility of ANA testing still mainly refers to IF-microscopy and precipitin tests. IF-ANA should not be abandoned as the golden standard in clinical routine, until diagnostic and classification criteria for systemic lupus erythematosus and other systemic inflammatory autoimmune diseases have been revised. However, in addition we strongly advocate that a specific test for anti-Ro/SS-A antibodies is always included.

Adolescent↗
PubMed1964

AGAR-GEL PRECIPITIN TECHNIQUE IN ANTHRAX ANTIBODY DETERMINATIONS.

A modification of the agar-gel precipitation inhibition technique of Thorne and Belton for detecting anthrax antibodies reduces inconsistency of visually determined end points on the same sera observed by different technicians. Determination of the minimal reacting concentrations of the anthrax antigen and antibody reagents, modifications of the visualization apparatus, methods for combining reagents, and length of incubation periods contribute to the ease of the end-point determinations and the uniformity of results. When compared with the previous technique, the modified procedure is less time-consuming while retaining satisfactory reproducibility, simplicity, specificity, and sensitivity.

Agar↗
PubMed2000

Serological properties of Abiotrophia and Granulicatella species (nutritionally variant streptococci).

Serological variations were examined among 12 type or reference strains and 91 oral isolates of vitamin B6-dependent Abiotrophia and Granulicatella spp. Rabbits were immunized with whole cells of 12 selected strains and 10 typing antisera were obtained, which were unreactive with the Lancefield group A to G antigen preparations. The reactivity of the antisera and autoclaved cell surface antigen extracts was tested by double diffusion in agar gel and a capillary precipitin test. These typing antisera categorized all Abiotrophia defectiva strains, all except one Granulicatella elegans strain, three-quarters of the Granulicatella adiacens, and half of the Granulicatella paraadiacens into 8 serotypes and 2 subserotypes. The Granulicatella balaenopterae type strain was unserotypable. All A. defectiva strains were serotype I, some of which were divided into subserotype I-1 and/or I-5. The G. adiacens strains generally belonged to serotype II or III, and the G. paraadiacens strains to serotype IV, V or VI. All G. adiacens or G. paraadiacens serotype II strains were also subserotype I-5. The G. elegans strains were serotype VII or VIII. These Abiotrophia and Granulicatella serotypes were undetectable among 33 strains of the other 11 species including the bacteriolytic enzyme-producing but vitamin B6-independent strains of Streptococcus, Enterococcus, Dolosigranulum and Aerococcus. The proposed serotyping system for Abiotrophia and Granulicatella spp. would be helpful in the identification and classification of these unique coccal isolates in ecological and epidemiological studies.

Animals↗
PubMed1967

Soluble antigens for immunofluorescence detection of Histoplasma capsulatum antibodies.

Soluble antigens from Histoplasma capsulatum in the mycelial and yeast phase were purified by gel filtration, fixed onto paper discs, and employed in an indirect immunofluorescence procedure to detect antibody in sera from individuals infected with H. capsulatum. The elution patterns of crude histoplasmin passed through Sephadex G-200 revealed two minor peaks of protein showing immunofluorescence, complement fixing, and precipitating-antigen activity. A large peak containing the pigment and other low molecular weight materials showed no serological activity. A polysaccharide antigen obtained from fragmented, deproteinized yeast-phase cells was reactive in the fluorescent-antibody test but showed no antigen activity in complement fixation or precipitin tests. Although certain sera from culturally proven cases of blastomycosis, coccidioidomycosis, and cryptococcosis reacted with the purified Histoplasma antigens, preliminary evaluation indicated that the immunofluorescence technique may be of value as a screening procedure for the serodiagnosis of histoplasmosis.

Antibodies↗
PubMed2001

Secondary triatomine species in dwellings and other nearby structures in municipalities under epidemiological surveillance in the state of Paraná, Brazil.

OBJECTIVE: Since data are scarce regarding secondary triatomine species in the Brazilian state of Paraná, this study investigated infestations in inhabited and abandoned houses and in various other nearby structures in rural areas of that state. METHODS: Triatomines were manually captured in inhabited and uninhabited houses and other nearby structures in nine areas (eight municipalities and one district) of Paraná from June 1996 to February 2000. Testing for Trypanosoma cruzi infection was performed, as were also precipitin tests to determine the triatomines' food sources. RESULTS: While Triatoma infestans was not found in any of the nine areas of Paraná that were studied, three secondary triatomine species were detected: Triatoma sordida, Panstrongylus megistus, and Rhodnius neglectus. T. sordida was the most common species found, comprising 575 of the 658 triatomines captured (87.4%). The second-most common was P. megistus, with 82 specimens (12.5%). Of the various categories of structures investigated, uninhabited houses was the most frequently infested category (19/62, or 30.6%), followed by chicken coops (24/350, or 6.9%). The primary food source of the triatomines was the blood of birds. Nevertheless, in the municipality with the highest density of triatomines, the food sources included domestic animals and even humans. We found that 13.4% of the T. sordida and 13.5% of the P. megistus were infected with Trypanosoma cruzi. CONCLUSIONS: These results demonstrate the need to maintain entomological surveillance measures in the studied areas. This is especially important since Brazil and other countries of Latin America have affirmed the need to interrupt the vector-borne transmission of Chagas' disease.

Animals↗
PubMed2001

Response of herb processing workers to work-related airborne allergens.

A group of 51 herb processing workers employed in a big herb processing facility located in eastern Poland were examined by the skin and precipitin tests with, respectively, 4 and 17 extracts of microorganisms associated with organic dusts. Out of this number, 32 workers were examined by the skin test with 7 extracts of selected herbs processed in the facility. All the subjects were asked about the occurrence of work-related symptoms. 32 healthy office workers were examined with microbial extracts as a reference group. The herb processing workers showed a high proportion of early skin reactions (after 20 min) to the extract of Gram-negative bacterium Alcaligenes faecalis (41.2%), significantly higher compared to the reference group (p<0.01). At all time intervals (20 min, 8 hrs, 24 hrs), the workers responded with a high frequency to the extract of Bacillus subtilis (respectively 72.5%, 64.7%, and 15.7%), significantly greater compared to the reference group (respectively p<0.001, p<0.001, and p<0.05). No significant differences were found between the groups of herb processing workers and referents in skin response to the extracts of Streptomyces albus and Alternaria alternata and, except for the extract of Pantoea agglomerans, in the frequency of positive precipitin reactions to microbial antigens. In the skin test with herb extracts, the highest response among workers were caused by the extracts of chamomile flowers and nettle leaves which evoked 40-65% of positive skin reactions at all time intervals. 39 out of 51 interviewed herb processing workers (76.5%) reported the occurrence of work-related general, respiratory and skin symptoms. The positive skin reactions occurred more frequently among symptomatic workers which suggests that the specific immunologic response might be implicated in etiopathogenesis of work-related symptoms in examined workers. However, in most cases the differences did not attain a significance level which indicates that there is no direct relationship between a positive immunologic response and the appearance of symptoms caused by occupational exposure to herb dust, and that most probably a considerable part of these symptoms might be also due to non-specific immunologic and/or toxic mechanisms.

Adult↗
PubMed1992

[Detection of antibodies to infectious bronchitis of fowl using the ELISA, hemagglutination-inhibition test and agar-gel precipitation test].

Chicks of a conventional poultry flock, Shaver Starcross 288 hybrid, were vaccinated with infectious bronchitis (IB) virus H 120 at the age of 21 days. Three weeks later, the chicks were divided into three groups and separate groups were infected with infectious bronchitis viruses M 41 and D 274 or revaccinated with virus H 120. The content of specific antibodies to antigens prepared from homologous and heterologous viruses of infectious bronchitis used for chick vaccination and infection was investigated at regular intervals in the separate groups of chicks by means of an ELISA technique and haemagglutination-inhibition test (HIT). Serotype specificity of haemagglutination-inhibition test was documented by the results; the specificity was obvious mainly after the first vaccination and two weeks after infection, or after chick revaccination (Fig. 1). The dynamics of postinfective or postvaccinal antibodies, recorded by the ELISA technique, had analogical patterns in the separate groups of chicks, and there were no larger differences in the values determined on the basis of different antigens during the investigation (Fig. 2). A total of 52 group samples of fowl serum was examined by the ELISA technique and agar-gel precipitin test (AGPT) in another part of this study. Ten serums of identical origin represented the separate groups. The result of this examination was evaluated from the percentage of samples with precipitin activity in the group, or from the average value of ELISA. Mutual comparison of the mentioned values indicated that the precipitin activity was limited by the positivity degree of ELISA reaction (Fig. 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Health effects of exposure to herb dust in valerian growing farmers.

The aim of the present study was to determine the health status of farmers cultivating valerian (Valeriana officinalis L.) and occupationally exposed to dust from this plant. A group of 75 valerian growing farmers were examined. As a reference group, 50 urban dwellers, not exposed to any kind of organic dust were examined. All people were interviewed for the presence of work-related symptoms and subjected to physical and spirometric examinations. Skin prick tests were conducted with 4 microbial antigens associated with organic dust and 3 herbal extracts, precipitin tests with 12 microbial antigens and 4 herbal extracts and tests for specific inhibition of leukocyte migration with 4 microbial antigens. 30.7 % of the valerian farmers reported occurrence of work-related symptoms. No significant differences were found between the spirometric values in the group of valerian farmers and the reference group. Valerian farmers showed a low frequency of positive skin reactions to all tested antigens (0-4.0 %), not significantly greater compared to reference group. The frequency of positive precipitin reactions to the antigen of Gram-negative bacterium Pantoea agglomerans was very high in valerian farmers (45.5 %) with 3-fold concentrated sera and significantly greater compared to the reference group (p < 0.001). The positive precipitin response of valerian farmers to other microbial and herbal antigens was much lower or absent and did not show any difference compared to reference group. In the test for specific inhibition of leukocyte migration, the highest frequencies of positive reactions in valerian farmers were noted with Pantoea agglomerans and Saccharopolyspora rectivirgula (15.0 % each), in both cases significantly greater compared to reference group (p < 0.05). In conclusion, the farmers growing valerian showed a moderate frequency of work-related symptoms and low reactivity to most microbial and herbal allergens. They exhibited an increased immunologic response to Gram-negative bacterium Pantoea agglomerans which appears to be the most important risk factor associated with valerian dust.

Adolescent↗
PubMed1976

The value of amoebic serology in an area of low endemicity.

One hundred sera from army patients who had had amoebiasis in the past and 113 sera from coloured immigrants attending a venereal diseases clinic were examined by four serological techniques. The indirect haemagglutination and the latex agglutination tests showed almost complete correlation; they are useful epidemiological tools but too sensitive and the antibodies on which they depend are too persistent for clinical use. The indirect fluorescent antibody test is a good clinical screening test, and in an area of low endemicity the gel diffusion precipitin test shows a close correlation with clinical disease.

Amebiasis↗
PubMed1977

Immunological procedure for the rapid and specific identification of Coccidioides immitis cultures.

An immunological procedure for the rapid and specific identification of Coccidioides immitis isolates has been developed. The specificity of the procedure is based on the fact that C. immitis produces antigens that are not produced by morphologically similar fungi. The procedure involved the transfer of heavy mold-form inocula to flasks that contained small volumes of brain heart infusion broth. Shake cultures were grown at 25 degrees C on a gyratory shaker at 150 rpm. The concentrated supernatant antigens so obtained from broth cultures were tested in parallel with coccidioidin by a microimmunodiffusion technique against C. immitis antiserum. The ability of the immunological procedure to identify C. immitis cultures was evaluated by testing the supernatant antigens of 166 unknown isolates, many of which, by gross or microscopic examination or both, resembled C. immitis or belonged to the family Gymnoascaceae. Each culture was also identified by conventional laboratory procedures. Comparative evaluation showed that the immunological test for C. immitis was 100% sensitive and specific. The diagnostic precipitin bands that were produced by the interaction of the C. immitis supernatants and antisera were shown to consist of (i) a heat-stable antigen comparable to that active in the tube precipitin test and (ii) two heat-labile antigens, one of which was associated with complement fixation reactivity. With pure cultures, this immunological procedure permitted the identification of C. immitis isolates within 5 days.

Antigens, Fungal↗
PubMed1990

Prevalence and characterization of Pasteurella multocida in rabbits and their environment in Japan.

Prevalence and some properties of Pasteurella multocida in rabbits kept at laboratory animal facilities and commercial rabbitries, and in their environment were investigated. A total of 1,147 nasal swab samples from 1,147 rabbits and 126 samples from their environment were subjected to the isolation of P. multocida. The bacteria were isolated from 199 (29.8%) of 668 rabbits in laboratory animal facilities and from 1 (0.2%) of 479 rabbits in the rabbitries. Isolation rate of P. multocida was low (0.9%) or high (44.9%) in the facilities with or without the monitoring for the presence of the bacteria, respectively. The highest rate of the isolation from rabbits was recorded at 10 to 12 months of their housing time. Thirty-nine cultures (31.0%) of air and the surfaces of floors, tips of water bottles, and cages were positive for P. multocida and isolation rate of the bacteria was high (78.6%) in the air. Biological and biochemical properties of the isolates were identical except for indole production and raffinose fermentation. The isolates were susceptible to antibiotics tested except for clindamycin, serologically similar in the gel-diffusion precipitin test and weakly virulent for mice. The present results suggested that these P. multocida isolates were the causal agent of rabbits rhinitis (snuffles) in Japan.

Animals↗