PubMed Health⌕ Search

Biomedical subjects

A Afshar

Publications and source records attributed to A Afshar.

At least 37 records · Page 2Linked to original sources
PubMed1992

Simultaneous screening of bovine sera for antibodies to bluetongue and epizootic hemorrhagic disease of deer viruses by enzyme-linked immunosorbent assay.

An indirect enzyme-linked immunosorbent assay (I-ELISA) is described for simultaneous screening of bovine sera for detection of antibodies to bluetongue (BT) and epizootic hemorrhagic disease of deer (EHD) viruses (V). Optimal dilutions of BTV and EHDV antigens were combined and allowed to absorb on to the wells of microtiter plates. Appropriately diluted (1:100) bovine sera were allowed to incubate and the bound antibodies were detected by a murine monoclonal antibody (MAb) to bovine immunoglobulin (H-Chain) conjugated with horseradish peroxidase. The performance of the combined (C) I-ELISA in detecting antibodies to BTV and EHDV in sequential serum samples from calves experimentally inoculated with BTV, serotype 10, EHDV, serotype 1 (New Jersey) or EHDV serotype 2 (Alberta) was evaluated. Comparable antibody profiles were demonstrable by the CI-ELISA and separate I-ELISAs using either BTV or EHDV antigens. The results suggest that the CI-ELISA offers many advantages over the standard agar gel immunodiffusion (AGID) test and has potential application as a rapid, sensitive, inter-group-specific and inexpensive test for simultaneous screening of bovine sera for antibodies to BTV and/or EHDV.

Animals↗
PubMed1992

Competitive ELISA for serodiagnosis of bluetongue: evaluation of group-specific monoclonal antibodies and expressed VP7 antigen.

The performance of 2 competitive enzyme-linked immunosorbent assays (C-ELISA) was compared with the reference C-ELISA I for the detection of antibodies to bluetongue virus (BTV). One of the assays (C-ELISA II) used a group-specific monoclonal antibody (MAb) to BTV, obtained from the American Type Culture Collection (8A3B-6) and tissue culture (TC)-derived BTV antigen (Ag), and the other assay (C-ELISA III) used BTV core protein VP7 (expressed in yeast) and the reference MAb (Pirbright Laboratory, 3-17-A3). Test sera were obtained by sequential blood samples from 22 calves, each inoculated with a different serotype (T) of BTV (South African [SA] T-1-T-16 and T-18-T-20 and USA T-11, T-13, and T-17). Sera were also obtained from 4 calves and 4 sheep inoculated with USA BTV T-10 and from several groups of calves exposed to single or multiple doses of epizootic hemorrhagic disease virus (EHDV) T-1-T-4 grown in TC (BHK-21) or suckling mouse brain (SMB). A total of 618 bovine and ovine field sera collected from BT-free and BT-endemic areas were also tested. The C-ELISA III was more sensitive than the C-ELISA II in the detection of anti-BTV antibody in sera from cattle and sheep early after infection with BTV. Seroconversion was demonstrated by the 3 C-ELISAs in all animals inoculated with BTV by 20 days postinfection (DPI), except in calves that received SA T-3 or USA T-13, which became positive at 40 DPI.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Development and evaluation of an enzyme-linked immunosorbent assay for detection of bovine antibodies to epizootic hemorrhagic disease of deer viruses.

An indirect enzyme-linked immunosorbent assay (I.ELISA) is described for detection of bovine serum antibody to epizootic hemorrhagic diseases of deer virus (EHDV). Serum samples, at a dilution of 1:200, were incubated with group-specific EHDV antigens, pre-adsorbed to microtiter plates. Bound antibodies were detected by a murine monoclonal antibody to bovine immunoglobulin (Ig)G1 (heavy-chain specific) conjugated with horseradish peroxidase. The performance of the I.ELISA in detecting antibodies to EHDV in sequential serum samples from calves experimentally infected with serotypes 1,2,3 and 4 was evaluated. The I.ELISA detected EHDV antibodies from 14 days postinfection when seroconversion by the standard agar gel immunodiffusion (AGID) test was also evident. The group-specific antibodies to EHDV increased exponentially during the first two to four weeks postinfection and remained relatively stable for about 12 months in some calves. Unlike observations with the AGID test, no reaction was seen in the I.ELISA between blue-tongue virus (BTV) antigen and sera from calves given a single dose of EHDV. The performance of the I.ELISA and AGID were compared using 3,135 AGID negative bovine field sera from herds in Ontario, Alberta and British Columbia and 130 AGID positive samples collected from cattle in 1987 and 1988 during and after outbreaks of EHD in the Okanagan Valley, British Columbia. The specificity and sensitivity of the assay relative to the AGID test were 99.3% and 91.5% respectively, with an overall agreement of 99.0% between the tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Dot immunoperoxidase assay using monoclonal antibody for detection of bluetongue virus antigens.

A rapid, simple dot immunoperoxidase assay (DIPA) is described for visual detection and identification of bluetongue virus (BTV) antigens in samples of infected cell culture fluid. The assay was performed using nitrocellulose (NC) paper and 'dipsticks'. Dots of samples were adsorbed to the NC surface and the remaining non-specific binding sites were blocked with skim milk solution. BTV was detected with either of two murine monoclonal antibodies (4H4, 5G12) to the major group specific antigens of BTV, and the complex was reacted with a peroxidase conjugated anti-mouse immunoglobulin G (heavy- and light-chain specific). Positive reactions were easily visualized as brown spots after enzyme degradation of substrate containing H2O2 and diaminobenzidine (DAB). The DIPA was specific in detecting BTV in samples of cell culture fluid from baby hamster kidney (BHK-21) cells infected with U.S.A. isolates of the five BTV serotypes (2, 10, 11, 13 and 17) known to exist in the U.S.A., and South African isolates of 17 BTV serotypes (1-12, 14-16, 18 and 20), but not with two North American isolates of epizootic hemorrhagic disease of deer virus (EHDV) representing serotypes 1 and 2. Attempts to detect BTV directly in infected sheep blood cells and chick embryo tissue suspensions by DIPA were unsuccessful. Of 55 cell culture fluid samples examined from BHK-21 or Vero cell monolayers inoculated with 55 clinical specimens, propagated initially in embryonating chicken egg (ECE) 11 proved positive and 44 were negative by DIPA. The results were in complete agreement with the conventional ECE and tissue culture isolation systems. The DIPA appears to have potential application, especially as a 'dipstick' kit, for rapid and inexpensive laboratory diagnosis of bluetongue virus infection.

Animals↗
PubMed1991

Comparative evaluation of the fluorescent antibody test and microtiter immunoperoxidase assay for detection of bovine viral diarrhea virus from bull semen.

An indirect immunoperoxidase staining technique (IP) is described for the detection of bovine viral diarrhea virus (BVDV) in bovine semen. The performance of the IP was compared to the reference immunofluorescent staining test in its ability to detect BVDV in 23 coded field semen samples. The IP assay which can be applied with ease to a large number of samples and does not require expensive fluorescence microscope equipment, appears to be an alternative method for BVDV detection. The IP assay can be strongly recommended for certification of BVDV-free bovine semen for artificial insemination and trading purposes and for laboratories which are not equipped for performing the immunofluorescent test.

Animals↗
PubMed1991

A survey of cattle for antibodies against bluetongue and epizootic hemorrhagic disease of deer viruses in British Columbia and southwestern Alberta in 1987.

In 1987 a serological survey of cattle for antibodies (Ab) to bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) was undertaken in British Columbia and southwestern Alberta after infection with the viruses was diagnosed in wild and domestic ruminants in the Okanagan Valley. Of 4610 cattle tested, five had Ab only to BTV, 125 had antibodies only to EHDV and 16 had Ab to both viruses. The Ab were identified as specific for BTV type 11 (BT-11) or EHDV type 2 (EHDV-2). All but one of the seropositive cattle originated in the Okanagan Valley of British Columbia. The remaining one seropositive animal which had Ab to EHDV-2 was pastured with a bull purchased from the Okanagan Valley.

Alberta↗
PubMed1991

Gamma irradiation alters bluetongue virus protein antigen.

Bluetongue virus (BTV) antigen, prepared for a monoclonal antibody (MAb)-based competitive enzyme-linked immunosorbent assay (C-ELISA), was exposed to 1, 2, 3, 4, 5 and 6 Mrad of gamma irradiation. The major group-specific BTV protein (VP7) reactive with the Mab was altered at higher doses of radiation, as revealed by immunoblotting studies. As well, a reduction in immunoreactivity was noted when irradiated antigen was used in the ELISA.

Animals↗
PubMed1990

Bacterial infections in suspected cutaneous leishmaniasis lesions.

In Iran, microscopic examination of skin scrapings from 2202 individuals with clinically diagnosed cutaneous leishmaniasis (CL) lesions revealed the presence of amastigotes in 1123 cases (51.0%). Bacteriological examinations of the lesions indicated that 788 individuals (35.7%) were also infected with one or more pathogenic bacteria, including coagulase-positive staphylococci (27.8%), beta-haemolytic streptococci (10.6%), and other opportunist pathogenic bacteria (total, 2.5%). The prevalence of bacterial infections in lesions in which leishmania parasites were detected was 26.5%, while for lesions in which no parasite was found the prevalence of such infections was significantly greater (45%). The results of this study show that bacterial infections should be considered in diagnosing and treating suspected CL lesions, particularly in areas where there is no facility for carrying out bacteriological examinations. Erythromycin can be used to treat the bacterial infections of the purulent sores.

Adolescent↗
PubMed1989

Comparison of competitive ELISA, indirect ELISA and standard AGID tests for detecting blue-tongue virus antibodies in cattle and sheep.

The performances of a competitive enzyme-linked immunosorbent assay (ELISA) using a group specific monoclonal antibody against bluetongue virus, an indirect ELISA and the standard agar gel immunodiffusion (AGID) test were compared in the detection of serum antibody against bluetongue virus. Test sera consisted of 1300 bovine, 530 ovine and 160 carpine samples from bluetongue-free areas of Canada, 605 bovine and ovine field samples from the USA and Barbados and 464 samples from 79 cattle and sheep experimentally infected with 19 South African and five USA serotypes of bluetongue virus. The diagnostic specificity of the competitive ELISA, as determined for the bluetongue virus-free cattle sera was superior (99.92 per cent) to that of the indirect ELISA (99.85 per cent) and the AGID (99.0 per cent). The specificities of the competitive ELISA for sheep (99.63 per cent) and goats (100.0 per cent) sera were also higher than those of the AGID test. The performance of the ELISA tests was similar whether a gamma-ray-irradiated (2.0 Mrad) or a non-irradiated bluetongue virus antigen preparation was used. The competitive ELISA results for bovine field sera from endemic areas demonstrated a relatively low level of agreement (92.04 per cent) with AGID test results, with 9.7 per cent false negatives. The possible presence in these sera of antibody to cross-reacting antigens or to other orbiviruses, eg, epizootic haemorrhagic disease virus, which react in the AGID but not in the competitive ELISA may account for this lack of agreement.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Application of peroxidase labelled antibody assays for detection of porcine IgG antibodies to hog cholera and bovine viral diarrhea viruses.

Rapid, sensitive peroxidase labelled antibody (PLA) assays using microtiter systems, were developed for detection of hog cholera virus (HCV) and cross-reacting bovine viral diarrhea virus (BVDV) antibodies in pig sera. HCV-infected pig kidney cell line (PK 15) prepared in microtiter plates were fixed and used in PLA assays. After inoculation with test serum, bound antibodies (HCV/BVDV) were reacted with either horseradish peroxidase (HRP) conjugated anti-porcine immunoglobulin (H & L) or biotinylated protein A (BPA) and subsequent HRP labelled avidin (A). Positive reactions were easily visualized under an inverted light microscope as foci of brown colored cells after enzyme degradation of hydrogen peroxidase in the presence of amino-ethylcarbazole (AEC). The PLA assays were superior to the indirect fluorescent antibody (IFA) test in detecting anti-HCV antibodies in porcine sera collected early after inoculation of pigs with a lapinized HCV vaccine. The performances of the PLA, IFA and FA neutralization (FAN) tests in measuring the immune response in the vaccinated pigs were comparable. Cross-reacting anti-BVDV antibody, as measured by a microtiter serum neutralization (MTSN) test, was not demonstrable in vaccinated pigs until they were challenged with a virulent HCV, 13 weeks later. The PLA assays relative to the IFA test detected more reactive samples among porcine field sera collected from HC-free pigs in Canada. Of 795 samples, 24 (3.01%) were reactive in the PLA employing HRP anti-porcine IgG, and 21 (2.6%) in the PLA, using BPA-HRP-A. When 324 of these sera were screened by the IFA test (using HC antigen), only one sample (0.30%) was found reactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

The response of Plasmodium falciparum to chloroquine and mefloquine in Bandar-Abbas and Minab areas, Hormozgan Province, southern Iran.

In-vivo and macro and micro in-vitro assessments of the response of P. falciparum to chloroquine and mefloquine were carried out in the malarious areas of Bandar-Abbas and Minab, Hormozgan Province, southern Iran, during 1986-1987. The susceptibility tests indicated a considerable resistance of P. falciparum to chloroquine in Bandar-Abbas but almost satisfactory sensitivity of the parasite to the drug in Minab. A rather high number of the chloroquine-resistant cases were found among Afghans and Pakistani immigrants and tourists who most probably have introduced and established the resistant strains of the parasite in such malarious areas in Iran. In the micro in-vitro test, P. falciparum was generally sensitive to mefloquine in both Bandar-Abbas and Minab. However, in a few sporadic cases the growth of the parasites occurred in the presence of rather higher doses of the drug, up to 3.2 mumol/l blood, which could be considered to result from innate mefloquine tolerant or resistant strains of P. falciparum in the areas studied.

Adolescent↗
PubMed1989

Porcine circovirus antigens in PK-15 cell line (ATCC CCL-33) and evidence of antibodies to circovirus in Canadian pigs.

Permanent infection of a PK-15 (ATCC CCL-33) cell line by the porcine circovirus was demonstrated. This virus appears to be common in the Canadian swine population as indicated by the presence of antibodies detected by indirect immunofluorescence or immunoperoxidase tests in the serum of culled sows and sows in commercial herds. One source of the PK-15 cell line was found to be free of circovirus antigen.

Animals↗
PubMed1988

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↗
PubMed1988

Experimental peste des petits ruminants (goat plague) in goats and sheep.

In order to study the pathomorphology and immunohistochemistry of peste des petits ruminants, four goats and two sheep were inoculated intranasally with the Malig-Yemen strain of peste des petits ruminants virus. The animals developed fever, nasal discharge, oral erosions, cough and diarrhea. One goat and one sheep died and one moribund goat was killed. Three animals survived the infection. At necropsy, erosive stomatitis, pneumonia and gastroenteritis were found. Histopathologically the pneumonocytes and epithelial cells of the ileum had eosinophilic cytoplasmic and nuclear inclusions. By an indirect immunoperoxidase method, the nuclei and cytoplasm of the ileal epithelial cells of one goat contained positively (brown) stained antigen, which corresponded to viral nucleocapsids by electron microscopy. Virus appeared to be released through the microvilli of the epithelial cells. We also confirmed the formation of giant cells due to peste des petits ruminants virus.

Animals↗
PubMed1987

Blocking dot-ELISA, using a monoclonal antibody for detection of antibodies to bluetongue virus in bovine and ovine sera.

A modified solid phase blocking enzyme immunosorbent assay (ELISA), using a monoclonal antibody (McAb) against the group specific bluetongue virus (BTV) antigen is described for detection of anti-BTV antibodies in cattle and sheep sera. Dots of an optimal dilution of BTV antigens were adsorbed to nitrocellulose (NC) paper (hence dot-ELISA) and then the remaining adsorptive sites were saturated with gelatin. After exposure to bovine or ovine test serum the NC strips were reacted with the McAb. The presence of McAb was detected with a peroxidase-conjugated anti-mouse IgG (H and L). In the absence of anti-BTV antibody in test sera, BTV antigen sites were reactive with McAb as indicated by a brown colored dot after enzyme degradation of hydrogen peroxide in the presence of diamino benzidine (DAB) or amino ethylcarbazole (AEC). In the presence of sufficient anti-BTV antibody no color reaction was observed. The blocking (B) dot-ELISA was superior to the agar gel immunodiffusion (AGID) in detecting anti-BTV antibodies in bovine and ovine sera early after experimental infection with BTV type 10. In 5 of 7 animals inoculated by combined intravenous and subcutaneous routes, anti-BTV antibodies in sera were detectable as early as 7 days post infection (DPI), all of which were AGID negative. Comparable B-dot-ELISA and AGID results were found in 23 paired sera (pre and 20 DPI) from cattle experimentally infected with different types of BTV and in 100 AGID negative sera from Ontario dairy and Alberta beef cattle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗