The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
John T. Roehrig - One of the best experts on this subject based on the ideXlab platform.
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Detection of West Nile Virus Antigen in Mosquitoes and Avian Tissues by a Monoclonal Antibody-Based Capture Enzyme Immunoassay
Journal of clinical microbiology, 2002Co-Authors: Ann R. Hunt, Roy A. Hall, Amy J. Kerst, Roger S. Nasci, Harry M. Savage, Nicholas A. Panella, Kristy L. Gottfried, Kristen L. Burkhalter, John T. RoehrigAbstract:An Antigen capture immunoassay to detect West Nile (WN) Virus Antigen in infected mosquitoes and avian tissues has been developed. With this assay purified WN Virus was detected at a concentration of 32 pg/0.1 ml, and Antigen in infected suckling mouse brain and laboratory-infected mosquito pools could be detected when the WN Virus titer was 10(2.1) to 10(3.7) PFU/0.1 ml. In a blindly coded set of field-collected mosquito pools (n = 100), this assay detected WN Virus Antigen in 12 of 18 (66.7%) TaqMan-positive pools, whereas traditional reverse transcriptase PCR detected 10 of 18 (55.5%) positive pools. A sample set of 73 organ homogenates from naturally infected American crows was also examined by WN Virus Antigen capture immunoassay and TaqMan for the presence of WN Virus. The Antigen capture assay detected Antigen in 30 of 34 (88.2%) TaqMan-positive tissues. Based upon a TaqMan-generated standard curve of infectious WN Virus, the limit of detection in the Antigen capture assay for avian tissue homogenates was approximately 10(3) PFU/0.1 ml. The recommended WN Virus Antigen capture protocol, which includes a capture assay followed by a confirmatory inhibition assay used to retest presumptive positive samples, could distinguish between the closely related WN and St. Louis encephalitis Viruses in Virus-infected mosquito pools and avian tissues. Therefore, this immunoassay demonstrates adequate sensitivity and specificity for surveillance of WN Virus activity in mosquito vectors and avian hosts, and, in addition, it is easy to perform and relatively inexpensive compared with the TaqMan assay.
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west nile Virus recombinant dna vaccine protects mouse and horse from Virus challenge and expresses in vitro a noninfectious recombinant Antigen that can be used in enzyme linked immunosorbent assays
Journal of Virology, 2001Co-Authors: Brent S Davis, Gwongjen J Chang, Bruce C Cropp, Denise A Martin, John T. Roehrig, Carl J. Mitchell, Richard A. Bowen, Michel L BunningAbstract:Introduction of West Nile (WN) Virus into the United States in 1999 created major human and animal health concerns. Currently, no human or veterinary vaccine is available to prevent WN viral infection, and mosquito control is the only practical strategy to combat the spread of disease. Starting with a previously designed eukaryotic expression vector, we constructed a recombinant plasmid (pCBWN) that expressed the WN Virus prM and E proteins. A single intramuscular injection of pCBWN DNA induced protective immunity, preventing WN Virus infection in mice and horses. Recombinant plasmid-transformed COS-1 cells expressed and secreted high levels of WN Virus prM and E proteins into the culture medium. The medium was treated with polyethylene glycol to concentrate proteins. The resultant, containing high-titered recombinant WN Virus Antigen, proved to be an excellent alternative to the more traditional suckling-mouse brain WN Virus Antigen used in the immunoglobulin M (IgM) antibody-capture and indirect IgG enzyme-linked immunosorbent assays. This recombinant Antigen has great potential to become the Antigen of choice and will facilitate the standardization of reagents and implementation of WN Virus surveillance in the United States and elsewhere.
Visith Sitprija - One of the best experts on this subject based on the ideXlab platform.
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Detection of Rabies Virus Antigen in Dog Saliva Using a Latex Agglutination Test
Journal of clinical microbiology, 2000Co-Authors: Songsri Kasempimolporn, Wachiraporn Saengseesom, Boonlert Lumlertdacha, Visith SitprijaAbstract:Dog bites are responsible for more than 90% of human rabies deaths in Asia. We developed a simple and inexpensive test based on latex agglutination (LA) for rabies Virus Antigen detection in dog saliva. Rabies Virus Antigen could be detected by agglutination on a glass slide using latex particles coated with gamma globulin. By evaluation of paired saliva-brain specimens from 238 dogs, the LA test using saliva was 99% specific and 95% sensitive compared to the fluorescent antibody test (FAT) on brain smears. The advantages of the LA test over the standard FAT are that it is comparatively simple and there is no need to kill the animal before examination.
Ann R. Hunt - One of the best experts on this subject based on the ideXlab platform.
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Detection of West Nile Virus Antigen in Mosquitoes and Avian Tissues by a Monoclonal Antibody-Based Capture Enzyme Immunoassay
Journal of clinical microbiology, 2002Co-Authors: Ann R. Hunt, Roy A. Hall, Amy J. Kerst, Roger S. Nasci, Harry M. Savage, Nicholas A. Panella, Kristy L. Gottfried, Kristen L. Burkhalter, John T. RoehrigAbstract:An Antigen capture immunoassay to detect West Nile (WN) Virus Antigen in infected mosquitoes and avian tissues has been developed. With this assay purified WN Virus was detected at a concentration of 32 pg/0.1 ml, and Antigen in infected suckling mouse brain and laboratory-infected mosquito pools could be detected when the WN Virus titer was 10(2.1) to 10(3.7) PFU/0.1 ml. In a blindly coded set of field-collected mosquito pools (n = 100), this assay detected WN Virus Antigen in 12 of 18 (66.7%) TaqMan-positive pools, whereas traditional reverse transcriptase PCR detected 10 of 18 (55.5%) positive pools. A sample set of 73 organ homogenates from naturally infected American crows was also examined by WN Virus Antigen capture immunoassay and TaqMan for the presence of WN Virus. The Antigen capture assay detected Antigen in 30 of 34 (88.2%) TaqMan-positive tissues. Based upon a TaqMan-generated standard curve of infectious WN Virus, the limit of detection in the Antigen capture assay for avian tissue homogenates was approximately 10(3) PFU/0.1 ml. The recommended WN Virus Antigen capture protocol, which includes a capture assay followed by a confirmatory inhibition assay used to retest presumptive positive samples, could distinguish between the closely related WN and St. Louis encephalitis Viruses in Virus-infected mosquito pools and avian tissues. Therefore, this immunoassay demonstrates adequate sensitivity and specificity for surveillance of WN Virus activity in mosquito vectors and avian hosts, and, in addition, it is easy to perform and relatively inexpensive compared with the TaqMan assay.
T. J. Hill - One of the best experts on this subject based on the ideXlab platform.
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REACTIVATION OF HERPES SIMPLEX Virus TYPE 1 IN THE MOUSE TRIGEMINAL GANGLION : AN IN VIVO STUDY OF Virus Antigen AND IMMUNE CELL INFILTRATION
Journal of General Virology, 1996Co-Authors: C. Shimeld, Joanne L. Whiteland, Neil A. Williams, David L. Easty, T. J. HillAbstract:The corneas of latently infected mice were UV irradiated to induce reactivation of herpes simplex Virus type 1 (HSV-1) in the trigeminal ganglion (TG). On days 1 to 4 after irradiation, TG were removed, serially sectioned and double stained to identify immune cells and Virus Antigens. Virus Antigen was detected in small numbers (most commonly one) of neurons per ganglion as early as day 1, confirming the rapidity of reactivation and the neuron as the likely site of this event. The immune response was also rapid and effective since Virus Antigen was identified in immune cells at day 1 and by day 4 all samples were negative. The predominant infiltrating cells on days 1 and 2, when Virus Antigen was present and being cleared, were T cells, both CD4+ and CD8+. Later, large numbers of B cells appeared, suggesting that local antibody production may also be involved in controlling the reactivated infection. The observations suggest that a significant proportion of reactivation events do not result in disease of the eye or shedding of Virus in the tear film. However, they also suggest that as little as one reactivating neuron in the ganglion may be sufficient to lead to such disease and/or shedding.
Krawczynski Krzysztof - One of the best experts on this subject based on the ideXlab platform.
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Changes in hepatitis C Virus Antigen in liver with antiviral therapy
Gastroenterology, 1993Co-Authors: Adrian M. Di Bisceglie, Jay H. Hoofnagle, Krawczynski KrzysztofAbstract:Abstract Background: Although it has recently become possible to detect hepatitis C viral Antigens in liver biopsy specimens, the frequency and clinical significance of this finding remains uncertain. Therefore, 49 liver biopsy specimens from 35 patients with hepatitis C were studied to make these assessments. Methods: Hepatitis C Virus Antigen was detected by immunofluorescence staining of snap-frozen liver biopsy sections. Results: Hepatitis C Virus Antigen was present in 86% of patients; the amount and pattern of hepatitis C Virus Antigen staining did not correlate with the degree of hepatic injury as assessed by serum aminotransferase levels or liver histology or with the level of viral replication assessed by the titer of HCV RNA in serum. Patients who had a beneficial response to antiviral therapy had significantly less hepatitis C Virus Antigen staining in pretreatment liver biopsy specimens than those who did not respond. The degree of hepatitis C Virus Antigen staining decreased significantly following interferon alfa therapy but not after ribavirin therapy. Hepatic hepatitis C Virus Antigen became undetectable after therapy in those patients who had a long-term beneficial response to therapy. Conclusions: Hepatic hepatitis C Virus staining may be useful in predicting and monitoring the response to antiviral therapy.
