8 research outputs found
Investigations into the biology of bovine coronavirus and the infections it causes.
Bovine coronavirus (BCV) has been previously detected in the enteric and respiratory tracts of cattle and is specifically associated with enteritis and diarrhoea in neonatal calves. Two diagnostic tests, an ELISA and an immunogold EM technique for the detection of BCV in faeces, were developed, optimised and compared with direct EM, immunosorbent EM and haemadsorption-elution-haemagglutination (HEHA). The immunogold EM technique was found to be the most sensitive test followed by the ELISA, HEHA, immunosorbent EM and direct EM. An IF test for detecting BCV in the respiratory tract and a neutralization test for quantifying anti-BCV antibody titres in serum and milk were also developed. Using the immunogold EM technique BCV was demonstrated in 39 of 123 field samples of bovine diarrheic faeces. From 25 of these samples 2 isolates were successfully adapted to grow in HRT 18 cells following initial isolation in bovine fetal tracheal organ culture. These, and three other strains of BCV and a human coronavirus (HCV) strain obtained from other laboratories, were compared in immunofluorescence (IF), haemagglutination inhibition (HAI) and neutralization tests. Polyclonal antisera against these 6 viruses were raised in rabbits. No significant differences between viruses were detected by IF incorporating homologous and heterologous antisera but HCV could be distinguished from the bovine coronaviruses in a cross neutralization test. In this test all BCV isolates were determined to be of one serotype. In the HAI test however, the HCV strain was distinguishable from the 5 BCV strains and differences between the BCV strains were shown. Two monoclonal antibodies prepared against one of the BCV strains distinguished the HCV from the BCV strains in all three tests. These monoclonal antibodies did not distinguish between the 5 BCV strains in the IF or HAI test but did so in the neutralization test. The various strains were also compared at the molecular level using the Western blotting technique. This technique showed no significant differences between the molecular weights or serological reactivity of the structural proteins of these strains. Experimental infection of a gnotobiotic calf with BCV resulted in diarrhoea and fever, but no clinical evidence of disease was seen when 4 conventionally reared colostrum fed calves and 4 gnotobiotic lambs were similarly infected. The oral infection of suckling mice with BCV produced diarrhoea in some animals but a full investigation is required to optimise this model. A prospective epidemiological survey on one farm was carried out and showed Cryptosporidium and BCV to be associated with diarrhoea. Additionally this survey showed that the detection of BCV in the respiratory tract was associated significantly with respiratory symptoms
Investigations into the biology of bovine coronavirus and the infections it causes.
Bovine coronavirus (BCV) has been previously detected in the enteric and respiratory tracts of cattle and is specifically associated with enteritis and diarrhoea in neonatal calves. Two diagnostic tests, an ELISA and an immunogold EM technique for the detection of BCV in faeces, were developed, optimised and compared with direct EM, immunosorbent EM and haemadsorption-elution-haemagglutination (HEHA). The immunogold EM technique was found to be the most sensitive test followed by the ELISA, HEHA, immunosorbent EM and direct EM. An IF test for detecting BCV in the respiratory tract and a neutralization test for quantifying anti-BCV antibody titres in serum and milk were also developed. Using the immunogold EM technique BCV was demonstrated in 39 of 123 field samples of bovine diarrheic faeces. From 25 of these samples 2 isolates were successfully adapted to grow in HRT 18 cells following initial isolation in bovine fetal tracheal organ culture. These, and three other strains of BCV and a human coronavirus (HCV) strain obtained from other laboratories, were compared in immunofluorescence (IF), haemagglutination inhibition (HAI) and neutralization tests. Polyclonal antisera against these 6 viruses were raised in rabbits. No significant differences between viruses were detected by IF incorporating homologous and heterologous antisera but HCV could be distinguished from the bovine coronaviruses in a cross neutralization test. In this test all BCV isolates were determined to be of one serotype. In the HAI test however, the HCV strain was distinguishable from the 5 BCV strains and differences between the BCV strains were shown. Two monoclonal antibodies prepared against one of the BCV strains distinguished the HCV from the BCV strains in all three tests. These monoclonal antibodies did not distinguish between the 5 BCV strains in the IF or HAI test but did so in the neutralization test. The various strains were also compared at the molecular level using the Western blotting technique. This technique showed no significant differences between the molecular weights or serological reactivity of the structural proteins of these strains. Experimental infection of a gnotobiotic calf with BCV resulted in diarrhoea and fever, but no clinical evidence of disease was seen when 4 conventionally reared colostrum fed calves and 4 gnotobiotic lambs were similarly infected. The oral infection of suckling mice with BCV produced diarrhoea in some animals but a full investigation is required to optimise this model. A prospective epidemiological survey on one farm was carried out and showed Cryptosporidium and BCV to be associated with diarrhoea. Additionally this survey showed that the detection of BCV in the respiratory tract was associated significantly with respiratory symptoms
Diagnosis and Management of Epilepsies in Children and Young People: A National Clinical Guideline
No abstract available
The Immune-Modulating Cytokine and Endogenous Alarmin Interleukin-33 Is Upregulated in Skin Exposed to Inflammatory UVB Radiation
The cellular and molecular mechanisms by which UV radiation modulates inflammation and immunity while simultaneously maintaining skin homeostasis is complex and not completely understood. Similar to the effects of UV, IL-33 has potent immune-modulating properties that are mediated by the downstream induction of cytokines and chemokines. We have discovered that exposure of mice in vivo or human skin samples ex vivo to inflammatory doses of UVB induced IL-33 expression within the epidermal and dermal skin layers. Using a combination of murine cell lines and primary human cells, we demonstrate that both UV and the oxidized lipid platelet activating factor induce IL-33 expression in keratinocytes and dermal fibroblasts. Highlighting the significance of these results, we found that administering IL-33 to mice in vivo suppressed the induction of Th1-mediated contact hypersensitivity responses. This may have consequences for skin cancer growth because UV-induced squamous cell carcinomas that evade immunological destruction were found to express significantly higher levels of IL-33. Finally, we demonstrate that dermal mast cells and skin-infiltrating neutrophils closely associate with UV-induced IL-33–expressing fibroblasts. Our results therefore identify and support a role for IL-33 as an important early danger signal produced in response to inflammation-inducing UV radiation