Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “IFA”

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 55 records · Page 3Linked to original sources

Levels of detection of Cryptosporidium oocysts in mussels (Mytilus galloprovincialis) by IFA and PCR methods.

Cryptosporidium spp. are monoxenous protozoan parasites that cause gastrointestinal diseases in humans and animals. Shellfish harvesting areas can become contaminated by the infectious stage of the parasite and humans are therefore at risk of infection either by consumption of shellfish, or by taking part in recreational activities in these areas. In the present study we determined the levels of detection, by IFA and PCR techniques, of Cryptosporidium oocysts in mussels experimentally contaminated with a theoretical number of oocysts. There was a significant correlation between the results obtained by both techniques (P<0.05). IFA and PCR were also applied to a total of 222 samples of mussels (Mytilus galloprovincialis) destined for human consumption. In the naturally contaminated samples, we detected a 31.1% of contamination and only Cryptosporidium parvum (previously denominated C. parvum genotype II) was identified.

Animals↗

Seroprevalence of Babesia equi among horses in Israel using competitive inhibition ELISA and IFA assays.

Sera from 361 horses were tested by indirect immunofluorescence antibody test (IFA) and by competitive inhibition ELISA (cELISA), to detect antibodies to Babesia equi. The concordance between the assays was 95.7%. Application of a cutoff based on a calculated percent inhibition of < 20% gave a total of 22 discrepant results, while only 8 sera negative by the cELISA were found positive by the IFA when a cutoff of > 20% inhibition was used. Approximately one-third of all the horses tested were found serologically positive to B. equi, with more horses testing positive from northern Israel. Among horses raised with access to pasture there was a significant difference in the percentage of seropositive reactors (76.6% in the north and 20.1% in the central region), compared with horses without access to pasture (14.3 and 10.3%, respectively). Nineteen percent of stallions were found to be positive, which was significantly less than the proportions of seropositive mares and geldings: 38 and 42%, respectively. No significant association was found between the mean age of horses and seroreactivity to B. equi.

Animals↗

Immunofluorescence assays (IFA) and enzyme-linked immunosorbent assays (ELISA) in autoimmune disease diagnostics--technique, benefits, limitations and applications.

Autoimmune diseases are relatively frequent disease complexes, affecting approximately five to seven percent of the population. After cardio-vascular and malignant diseases they come third in mortality. As the clinical diagnosis of rheumatic autoimmune diseases is difficult, laboratory tests are helpful in differential diagnosis and for verification of the clinical diagnosis. The most commonly used assay is the determination of ANAs (anti nuclear antibodies) by indirect immunofluorescence (IFA). However, this method lacks reliable standardisation and is very dependable on the qualification of the observer. Enzyme Immunoassays (EIA) and Immunoblotting techniques, on the contrary, attain good standardisation and comparability. However, the latter methods are limited to the presentation of defined autoantibodies only. There is a need to select a suitable strategy for the use of laboratory parameters in order to support the clinical diagnosis more efficiently. A possible strategy is to replace IFA as a first line screening-step by second-generation ANA-EIA kits.

Antibodies, Antinuclear↗

Degradation of fluoranthene by Pasteurella sp. IFA and Mycobacterium sp. PYR-1:isolation and identification of metabolites.

The findings from a biodegradability study of fluoranthene using two pure bacterial strains, Pasteurella sp. IFA (B-2) and Mycobacterium sp. PYR-1 (AM) are reported. Of total fluoranthene, 24% (B-2) and 46% (AM) was biodegraded in an aqueous medium during 14 d of incubation at room temperature. During this period the bacteria were capable of mineralizing approximately two-thirds (B-2) and four-fifths (AM) of biodegraded fluoranthene to CO2, while one-third (B-2) and one-fifth (AM) of the original fluoranthene remained as stable metabolic products. These metabolites were isolated using liquid-liquid extraction and identified using gas chromatography-mass spectrometry (GC-MS) and derivatization techniques. Two metabolites (9-fluorenone-1-carboxylic acid and 9-fluorenone) were identified by GC-MS directly, while the metabolites 9-fluorenone-1-carboxylic acid, 9-hydroxyfluorene, 9-hydroxy-1-fluorene-carboxylic acid, 2-carboxybenzaldehyde, benzoic acid and phenylacetic acid were determined in their derivatized forms. From the identified metabolites, a fluoranthene biodegradation pathway was proposed for Pasteurella sp. IFA.

Biodegradation, Environmental↗

The mouse IFN-alpha (Ifa) locus: correlation of physical and linkage maps by in situ hybridization.

The physical location of the mouse IFN-alpha locus (Ifa) on chromosome 4 was defined by in situ hybridization of a cloned mouse IFN-alpha probe to metaphase spreads in which one chromosome 4 was present as part of a single metacentric chromosome, all other chromosomes being acrocentric. (This approach greatly facilitates analysis and can be used even when it is difficult to obtain good banding). Using unbanded chromosomes, the grains were localized over the chromosome 4 part of the metacentric, in a region 0.61 +/- 0.07 (SD) of the distance from the centromere to the telomere. In Giemsa-banded spreads, the majority of the grains were in the region 4C3----C6. Consideration of these results and of the known linkage maps for mouse and man indicates that the Galt - Aco-1 - Ifa syntenic group spans a distance of approximately 14 cM and suggests that the same group on human 9p will also occupy a similarly sized region, with GALT proximal and IFL distal to the centromere.

Animals↗

[Construction of the immunoenzyme test system "IFA-AtEBV-Strip" for detecting antibodies of the Epstein-Barr virus].

The first home immunoenzyme test-system for finding antibodies to the Epstein-Barr virus (EBV) has been created. The test-system laboratory prototype was called "IFA-AtEBV-strip". Production technology has been developed for specific components of immunoenzyme test system and all the analysis stage conditions have been optimized: the antigen sorption on plates, its interaction with the studied serum, finding out of the formed immune complex. The test system "IFA-AtEBV-strip" sensitivity made up 96%, specificity--100%.

Antibodies, Viral↗

Comparative study on ELISA, IFA and direct methods in diagnosis of giardiasis.

A total of 200 cases aged 1-13 years complaining of symptoms suggestive of giardiasis in addition to thirty normal healthy children as a control group was examined clinically and laboratory using stool examination and detection of Giardia coproantigen in faeces by Dot ELISA and direct IFA. Stool examination detected 39 cases (19.5%) while Dot ELISA and direct IFA detected 49 cases (24.5%) with 100% sensitivity and 93.8% specificity. The common clinical findings were diarrhea, abdominal cramps, anorexia, underweight, pallor and manifestations of vitamin deficiency. The results were discussed.

Adolescent↗

Serological diagnosis of parainfluenza virus infections: verification of the sensitivity and specificity of the haemagglutination-inhibition (HI), complement-fixation (CF), immunofluorescence (IFA) tests and enzyme immunoassay (ELISA).

Using four serological tests paired sera were examined of 117 patients with acute respiratory diseases, in whom parainfluenza viruses (PIV) infection was demonstrated by virus isolation, and of 41 patients with typical clinical mumps symptoms. Comparative analysis showed the high sensitivity of IFA and ELISA. A significant rise of antibodies in convalescent sera with homologous antigen of PIV was found in nearly 100 percent of cases. Only the sera of youngest children with high titres of persisting maternal antibodies remained without seroconversion. Cross heterologous antibody responses could be found by means of ELISA in 45% and by IFA in 10%, of patients who in the past experienced infection with one or more PIV or mumps virus--apart from homologous antibody reaction. HI and CF test proved to be less sensitive for detection of postinfections antibodies, especially in primoinfections with PIV types 1 and 2.

Antibodies, Viral↗

Detection of typhoid fever by Widal and indirect fluorescent antibody (IFA) tests. A comparative study.

Widal test is a conventional method for the detection of typhoid fever. However, it takes 18-24 hours to complete the test. In the present study indirect fluorescent antibody test has been compared with the Widal test using single serum specimens and was found to be rapid, sensitive and specific. Serum specimens from 41 culture proven cases of typhoid fever, 14 clinically suspected cases and 22 normal individuals were collected. Whereas Widal test detected 63.41% positive cases, IFA test detected 87.80% from among culturally proven typhoid cases. Among the clinically suspected cases of typhoid fever, IFA test detected 85.71% (28.57 + 57.14%) while Widal test detected only 57.13% (35.71 + 21.42%) positive cases out of above 14 cases.

Agglutination Tests↗

An endemic focus of visceral leishmaniasis in Meshkin-Shahr, east Azerbaijan province, north-west part of Iran and IFA serological survey of the disease in this area.

The incidence of visceral leishmaniasis has being increased in Iran during the recent decade. Since 1980, more than 200 cases have been diagnosed from East Azerbaijan province, mostly, from Meshkin-Shahr area. It seems, that kala-azar has being endemic in this area for a long time. The majority (86%) of kala-azar cases were found among children up to 4 years. The sex incidence ratio of males/females was 1.27/1. In IFA serological survey, sero-positive rate in females was higher than males. However, geometric mean of leishmanial antibody titers in males was, slightly, more than females. These serological findings indicate that females are exposed to the infection at least as much as males. The cross-sectional IFA serological survey, relatively reflected the kala-azar status among different studied groups with various incidences of the disease in Meshkin-Shahr area. IFAT showed also a good efficiency in the assessment of the treatment in the treated kala-azar patients.

Adolescent↗

An immunofluorescence assay in microwell plate (IFA) for detecting serum antibodies to Chlamydia pneumoniae.

An indirect immunofluorescence assay using a 96 microwell cell culture plate (IFA) was developed for the detection of antibodies to C. pneumoniae. The results obtained by IFA on 230 sera of healthy subjects were compared with those obtained with the microimmunofluorescence test. The correlation coefficient for IgG detection with the two methods was 0.96 showing good agreement.

Adult↗

Incidence of Cryptosporidium in all patients submitting stool specimens for ova and parasite examination: monoclonal antibody IFA method.

The development of a monoclonal antibody to Cryptosporidium oocysts provides a more sensitive detection method than that seen using other diagnostic techniques. Incidence reports on this organism have been based on earlier, less-sensitive methods. In order to determine the numbers of positive patients and stool specimens, every stool specimen submitted for an ova and parasite examination was tested using the Merifluor IFA system (Meridian Diagnostics, Inc). Over a 12-mo period, 2,786 specimens were tested (1,516 patients). Positive specimens (23) were from nine known immunosuppressed patients and from four symptomatic immunocompetent patients. This represents an overall positive rate of 0.86% (patients). In those patients who were not suspected of having cryptosporidiosis (immunocompetent), diagnosis of this infection would not have been accomplished without the use of a sensitive screening method. This data, obtained over a 12-mo period, provides information for those laboratories considering the clinical relevance of screening all stool specimens for this infection. With the development of therapy, early detection of Cryptosporidium will become more important.

Animals↗

Anti-Trichinella antibodies detected in chronically infected horses by IFA and Western blot, but not by ELISA.

In the Balkan countries, where trichinellosis is a re-emerging zoonosis, it is of great importance to determine Trichinella infection prevalence among the major hosts, including horses. One method for monitoring prevalence is serological surveillance; however, the validity of serological methods in horses is not well understood. The dynamics of anti-Trichinella IgG production and circulating excretory/secretory (ES) antigens were investigated in three horses experimentally-infected with Trichinella spiralis. Horses were slaughtered at 32 week post infection (p.i.). Low worm burdens were found in all three animals. Anti-Trichinella IgG was detected up to 32 weeks p.i. by an indirect immunofluorescence assay (IFA) and by Western blot (Wb), but not by ELISA. The ELISA test detected antibodies for only a short period of time (up to 18 weeks p.i. using ES antigen or up to 20 weeks p.i. using tyvelose-BSA antigen). The presence of circulating muscle larvae ES antigen in sera of infected horses was observed by dot blot from the 4th week p.i. up to the 32nd week p.i.

Animals↗

Efficient detection of intermediate filament proteins using a panspecific monoclonal antibody: anti-IFA.

Anti-IFA, a panspecific monoclonal antibody which was raised against human glial fibrillary acidic protein (GFAP), recognizes a determinant common to GFAP and all other intermediate filament proteins. This antibody can be used to identify intermediate filament proteins from both vertebrate and invertebrate tissues. Its utility in immunoblot studies of intermediate filament proteins is enhanced by using cytoskeleton extracts and protease treatment to facilitate the transfer of high molecular weight (greater than 70 000) proteins from gels to nitrocellulose membranes.

Animals↗

An indirect fluorescent antibody (IFA) test for the serodiagnosis of Kala-Azar.

The IFA test developed using Leishmania donovani promastigote and amastigote antigens showed very high antibody titre in clinically and parasitologically established cases (30) of kala-azar, the geometrical mean reciprocal titre (GMRT) being 870 +/- 5.4 and 5370 +/- 1.80 respectively with the two antigens. In contrast, the GMRT of normal subjects of endemic area was only 12.44 +/- 6.19 and 80.35 +/- 1.66 respectively with these antigens. None of the subjects from non-endemic area suffering with other parasitic diseases, such as malaria, filaria, amoebiasis, leprosy or tuberculosis (20 cases each) gave a positive response to any of the antigen. The test holds promise in the diagnosis of Kala-azar.

Animals↗

Indirect immunofluorescence (IFA) on kinetoplasts of Trypanosoma theileri for serological diagnosis of systemic lupus erythematosus (LES) in the dog.

An indirect immunofluorescence technique was developed to detect antibodies to ds-DNA in a dog affected by Systemic Lupus Erythematosus (LES). The assay was based upon the use of the antigen substrate Trypanosoma theileri, isolated from samples of bovine blood and maintained in culture tubes. Slides were prepared by the drop method and maintained at -20 degrees C until used. This T. theileri immunofluorescence test, evaluated with positive and discriminant results in a previous study on human sera affected by LES, was used for the first time in the diagnosis of canine LES. The results indicate that T. theileri IFA is specific and reliable.

Animals↗

Diffusion-in-gel enzyme-linked immunosorbent assay, ELISA and IFA test in the detection of malarial antibodies.

Malarial antibodies in 80 patients were measured using the diffusion-in-gel enzyme linked immunosorbent assay (DIG-ELISA), enzyme-linked immunosorbent assay (ELISA) and the indirect fluorescent antibody (IFA) test. Good correlations were obtained between all three tests in terms of sensitivity and reliability. DIG-ELISA has the advantage of being a rapid diagnostic tool for the detection of malarial antibodies.

Animals↗

Comparison of the dried blood on filter paper and serum techniques for the diagnosis of bovine babesiosis utilizing the indirect fluorescent antibody (IFA) test.

A comparison between the techniques of dried blood on filter paper and serum for the diagnosis of babesiosis utilizing the indirect fluorescent antibody (IFA) test was evaluated. Dried blood on filter paper was used as a method to detect B. bigemina and B. argentina antibodies of Colombian cattle under laboratory and field conditions and the technique was compared with the serum of the same animals. A high relationship was found between the results of the dried blood and the serum from calves experimentally infected with Babesia spp. and calves from enzootic hemoparasites-free zones in Colombia. There were no significant differences in the sensitivity and specificity of both techniques. The samples on filter paper could be practical for field use due to their easy management and storage at different temperatures. This indicates that the use of dried blood may be a valuable aid for the epizootiologic studies of Babesia spp. infections in bovines.

Animals↗