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Biomedical subjects

A Afshar

Publications and source records attributed to A Afshar.

At least 55 records · Page 3Linked to original sources
PubMed1987

Comparison of competitive and indirect enzyme-linked immunosorbent assays for detection of bluetongue virus antibodies in serum and whole blood.

An indirect (I) enzyme-linked immunosorbent assay (ELISA) and a competitive (C) ELISA, using a group-specific monoclonal antibody against bluetongue virus (BTV), are described for the detection of antibodies to BTV in cattle and sheep sera. The performance of these assays in detecting anti-BTV antibody in sequential serum samples and eluates from whole blood (WB) dried on filter paper from three calves and four sheep experimentally infected with type 10 BTV was evaluated. The C-ELISA was superior to the I-ELISA in the detection of anti-BTV antibody in the sera and WB samples from both cattle and sheep early after infection with BTV. BTV antibodies were demonstrable by C-ELISA in all the bovine and ovine sera and WB eluates by 9 days postinfection; whereas the I-ELISA results for sheep sera and WB eluates were similar, anti-BTV antibody was not detected in bovine serum and WB eluates until 26 and 14 days postinfection, respectively. While both ELISAs proved reliable, under the present test conditions involving detection of early postinfection reactions of experimentally infected animals, the C-ELISA was always as sensitive or more sensitive than the standard agar gel immunodiffusion test, the modified complement fixation test, and the plaque neutralization tests in the detection of anti-BTV antibodies. Unlike observations with the immunodiffusion test, no reaction was seen between BTV antigen and bovine epizootic hemorrhagic disease virus antiserum in either ELISA. The results suggest that either ELISA may be suitable for routine diagnostic testing and may have the potential to replace other tests for detection of anti-BTV group-specific antibodies and that the C-ELISA may have the most potential.

Animals↗
PubMed1987

Specificity of the indirect enzyme-linked immunosorbent assay for detection of pseudorabies virus antibodies in pigs exposed to bovine herpesvirus-1.

Six 5-week-old pigs were inoculated intranasally (IN) with 10(7.6) TCID50 of bovine herpesvirus-1 (BHV-1). Three of the pigs also were inoculated IV with a similar dose of BHV-1. Clinical responses were not observed in these 6 pigs before oronasal challenge exposure with 10(7.8) TCID50 of virulent pseudorabies virus (PRV) at postinoculation day 42. Two pigs inoculated IN with BHV-1 and challenge exposed with PRV remained healthy, whereas the remaining 4 pigs developed severe clinical signs of pseudorabies and were moribund at postinoculation day 50 (8 days after challenge exposure). Anti-BHV-1 antibodies were demonstrable by ELISA in all 6 pigs and by serum neutralization (SN) in 5 pigs before challenge exposure with PRV. Anti-PRV antibody was not detected by ELISA or SN before challenge exposure to PRV. After challenge exposure to PRV, pigs with humoral antibody to BHV-1 responded anamnestically, and anti-PRV antibody activity was demonstrable by ELISA and SN in the 2 surviving pigs.

Animals↗
PubMed1987

Evaluation of an enzyme immunoassay for detection of antibodies to pseudorabies virus in porcine field sera.

The performance of an indirect enzyme-linked immunosorbent assay and the standard serum neutralization test for detection of antibodies to pseudorabies virus in porcine field sera were compared, using 304 sera from pseudorabies-free pigs in Canada, and 1082 and 580 swine sera from the USA and England, respectively. The sensitivity and specificity of the ELISA relative to the serum neutralization test were in the order of 97 to 98%, with the higher agreement between the tests when a 1:40 dilution of serum samples was used for the ELISA. The indirect ELISA was considered to be a rapid and convenient procedure, offering many advantages over the serum neutralization test for routine serodiagnostic use.

Animals↗
PubMed1986

Simple and rapid dot-enzyme immunoassay for visual detection of rinderpest antibodies in bovine and caprine sera.

A modified solid phase enzyme immunoassay (EIA) is described for visual detection of anti-rinderpest virus (RPV) antibodies in cattle and goat sera. Dots of RPV antigens were adsorbed to nitrocellulose (NC) paper (hence Dot-EIA) and the adsorptive reactive sites were blocked with skim milk powder. After immersion in bovine or caprine test serum bound antibodies were reacted with a peroxidase-conjugated anti-bovine or anti-caprine IgG (H & L), respectively. Positive reactions were easily visualized as red-brown dots after enzyme degradation of a substrate containing hydrogen peroxide and amino-ethylcarbazole (AEC). The Dot-EIA was comparable to the serum neutralisation (SN) test in its ability to detect antibody in bovine sera seven or ten days after experimental infection (DPI) with live attenuated Kabete "O" (RBOK) strain of RPV (grown in Vero cells) by a combination of subcutaneous (s/c), intravenous (i/v) or intranasal (i/n) routes. Early (seven DPI) RPV antibodies were detected in a serum sample from one goat experimentally infected with RPV by combined s/c-i/v routes but not in another goat only infected intranasally. The specificity of the Dot-EIA was equal to that of the SN test, as serum samples, collected from these experimental animals and those inoculated with non infected Vero cell culture fluid, with SN titres of 0.3 or lower were all negative by Dot-EIA. The Dot-EIA may have potential application as a rapid, simple and economical field test in diagnosis of rinderpest, vaccination surveillance and other seroepidemiological studies.

Animals↗
PubMed1986

Dot-enzyme immunoassay for visual detection of antibodies to pseudorabies virus in swine serum.

A modified solid-phase enzyme immunoassay (EIA) is described for the visual detection of anti-pseudorabies virus (anti-PRV) antibody in porcine serum. Dots of PRV antigens were adsorbed to nitrocellulose paper (hence the name dot-EIA), and the remaining nonspecifically reactive sites were blocked with bovine serum albumin or skim milk powder. After immersion in test serum, bound antibodies were reacted with a peroxidase-conjugated anti-porcine immunoglobulin G (H & L). Positive reactions were easily visualized as brown dots after enzyme degradation of a substrate containing hydrogen peroxide and diaminobenzidine. The dot-EIA was comparable to the serum neutralization test and the standard microtiter EIA in its ability to detect antibody in the sera of pigs 9 days after experimental infection and 12 days after contact with infected pigs. The sensitivity and specificity of the dot-EIA relative to the serum neutralization test and the standard EIA were determined from the testing of 856 field sera from the United Kingdom, the United States, and Canada. In all comparisons, both the relative sensitivity and specificity of the dot-EIA were in the order of 98 to 99%. The dot EIA appears to have potential application as a rapid and economical field test in the diagnosis of PRV infection.

Animals↗
PubMed1986

Immunoperoxidase plaque staining for the detection of pseudorabies virus.

A quantitative indirect immunoperoxidase plaque staining method was developed for the detection of pseudorabies virus infection in a pig kidney cell line (PK-15). The method is rapid and specific and foci of infection, represented by stained plaques, are easily counted by the unaided eye. Possible modification of this technique in a plaque reduction assay for the detection of antipseudorabies virus antibody is also discussed.

Animals↗
PubMed1986

Development and evaluation of an indirect enzyme immunoassay for detection of porcine antibodies to pseudorabies virus.

An indirect enzyme immunoassay is described for detection of porcine serum antibody to pseudorabies virus. The analytical sensitivity of the enzyme immunoassay was found to be approximately 4.5 log 4 X 10 (5120 times) greater than the serum neutralization test, based on parallel end point titrations. The diagnostic sensitivity of the enzyme immunoassay was comparable or superior to that of the serum neutralization, based on the earliest detectable antibody after infection of swine with pseudorabies virus by intranasal or intrauterine routes or by contact with infected pigs. The enzyme immunoassay, at a screening dilution of 1:20, gave 100% agreement with ELISA results provided with a U.S. Department of Agriculture-Animal and Plant Health Inspection Service proficiency panel of 40 sera. One serum having demonstrable antibody by the enzyme immunoassay was seronegative by the serum neutralization test.

Animals↗
PubMed1986

Imported cases of chloroquine-resistant falciparum malaria in Iran.

Six imported cases of chloroquine-resistant Falciparum malaria have been studied since October 1984. In five cases including two Iranian men, returned from India, two Afghan and one Bengalee immigrants came to Iran through Pakistan, recrudescence occurred following treatment with chloroquine. In these five cases resistance of P. falciparum to chloroquine was clinically (by the in vivo test) at R1 level in all patients. The resistance was also confirmed by the macro in vitro susceptibility test which was carried out in four of them. These five chloroquine-resistant cases were treated, one with Sulfadiazine-Pyrimethamine, three with Quinine-Sulfadiazine-Pyrimethamine and one with Sulfadoxine-Pyrimethamine (Fansidar) successfully. In the sixth case who was a Pakistani tourist the parasites showed resistance in the macro in vitro test, but apparently responded to chloroquine treatment in three days. It seems the resistance in this case was also at R1 level as other cases.

Adolescent↗
PubMed1985

IFA serological surveys of malaria in north, north-west and south-west parts of Iran.

In the IFA serological surveys of malaria carried out in north, north-west and south-west parts of Iran during 1975-1982 altogether 9,132 subjects were studied for malaria antibodies and parasitaemia. Serological data indicated probable malaria transmission in a consolidation area where the autochthonous cases of malaria were reported a year after this serological study. Asymptomatic parasite carriers of P. malariae were found by IFA and parasite concentration techniques among the professional blood donors and the residents of a village without any recent malaria history. IFA results with P. falciparum antigen reflected the malaria histories in the studied areas of west Azerbaijan better than P. vivax antigen. The serological and parasitological findings in the nomads of Bakhtiary tribes showed that the nomads are more exposed to malaria infection in the winter quarters of Izeh area and they are also more under malaria control programme when they are living in this area. In comparison of IFA results of 438 paired plasma and dried blood samples tested with P. vivax and P. falciparum antigens, there was no significant difference between SPR in plasma and dried blood samples, however in the dried blood samples collected by malaria surveillance agents on filter paper SPR and GMRT were considerably low.

Adolescent↗
PubMed1983

Animal toxoplasmosis in Iran.

A latex agglutination slide test for Toxoplasma antibodies was used on serum samples collected from various animals (111 cats, 113 dogs, three jackals, 393 sheep, 272 goats, 69 cows) in different parts of Iran. The sero-positive rate in titres 1:2-1:256 in different animals ranged from 12.6 to 56.0%; the highest (56.0%) was found in the stray dogs. Suspensions of the brains of 120 sero-positive animals (17 cats, 14 dogs, one jackal, 66 sheep, 22 goats) as well as 13 sero-negative animals (11 dogs, two jackals) and four black kites (Milvus migrans) not serologically tested were inoculated intraperitoneally into mice for isolation of Toxoplasma gondii. Altogether 16 strains of T. gondii were isolated from cats (47.0%) dogs (14.2%), sheep (7.5%) and a bird (black kite).

Animals↗
PubMed1981

Serological survey of human toxoplasmosis in mountainous regions of the north-west and south-west parts of Iran (1976-77).

A total of 3,370 plasma samples, collected from residents of three mountainous regions, located in Azerbaijan and Khuzestan provinces, north-west and south-west Iran, were tested for Toxoplasma antibodies by the indirect fluorescent antibody technique. The over-all sero-positive rate was 12.8%, with a general increase in positivity with increasing age. The distribution of antibodies to Toxoplasma was found to be different in different ethnic groups in the regions studied. The Toxoplasma sero-positive rate in these mountainous areas was considerably lower than that in the Caspian Sea littoral, in northern Iran, obtained in our previous study.

Age Factors↗
PubMed1981

Experimental Escherichia coli and rotavirus infection in lambs.

Colostrum-deprived lambs were infected with either enteropathogenic Escherichia coli(O9:K30:K99) or rotavirus or a mixture of the E coli and rotavirus. E coli doses of 10(6) and above consistently produced diarrhoea, as did experimental rotavirus infection. When both of the agents were administered, the mortality rate was higher, although the duration of diarrhoea was no greater than that observed when either of the two agents was administered alone.

Animals↗