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Direct effects of Pasteurella haemolytica lipopolysaccharide on bovine pulmonary endothelial cells in vitro.
1989
Paulsen D.B. | Mosier D.A. | Clinkenbeard K.D. | Confer A.W.
Bovine pulmonary artery cells in cell culture were exposed to lipopolysaccharide (LPS) purified from Pasteurella haemolytica serotype A1. This resulted in severe membrane damage, which caused a time- and dose-dependent release of lactate dehydrogenase that was first detected 4 hours after exposure and reached a maximal mean release of 67% after 24 hours of exposure to 1 microgram of LPS/ml. Mean release of 51chromium followed by a similar pattern and reached a maximum of 61% following 24 hours of exposure to 10 micrograms of LPS/ml. Morphologically, endothelial cells responded to LPS by marked cell membrane retraction, the formation of numerous cytoplasmic blebs, and ruffling of the cell membrane. Subsequently, the cells became round and detached. Cell detachment reached a mean of 95% following 8 hours of exposure to 1 microgram of LPS/ml. These studies demonstrated that P haemolytica LPS is capable of causing direct damage to bovine pulmonary arterial endothelial cells, which may be important in the pathogenesis of bovine pneumonic pasteurellosis.
Afficher plus [+] Moins [-]Infectious bovine keratoconjunctivitis epizootic associated with area-wide emergence of a new Moraxella bovis pilus type.
1989
Vandergaast N. | Rosenbusch R.F.
Pilus-mediated adherence is a virulence attribute of Moraxella bovis. Several pilus types have been shown to exist among strains of this bacterium, but correlation between pilus type and specific field cases of the disease has not been done. During the summer of 1987, an epizootic of infectious bovine keratoconjunctivitis was reported in 7 Iowa counties. Eight isolates of M bovis were secured from 12 episodes studied. All 8 of the isolates were nearly homogeneous in biochemical properties and had the same plasmid biotype. Pilus typing performed by immunofluorescence and immunogold electron microscopy identified a single new pilus type among 5 of the 8 isolates. This pilus type was identified in field cases that developed within a narrow time frame and over large distances. The implication of these findings is that infectious bovine keratoconjunctivitis epizootics may be associated with emergence of a novel pilus type, and that rapid dissemination over wide distances can occur, presumably by transportation of carrier cattle.
Afficher plus [+] Moins [-]Proteins specified by bovine herpesvirus-2.
1988
Adams S.W. | Balachandran N. | Hutt Fletcher L.M.
Use of viable-cell ELISA for detection of monoclonal antibodies recognizing tumor-associated antigens on bovine lymphosarcoma cells.
1987
Aida Y. | Onuma M. | Kasai N. | Izawa H.
Herd evaluation of Fasciola hepatica infection levels in Louisiana cattle by an enzyme-linked immunosorbent assay.
1987
Welch R.D. | Smith P.H. | Malone J.B. | Holmes R.A. | Geaghan J.P.
Pharmacokinetics of diacetoxyscirpenol in cattle and swine: effects of halothane.
1987
Coppock R.W. | Swanson S.P. | Gelberg H.B. | Koritz G.D. | Buck W.B. | Hoffmann W.E.
DNA homology studies of leptospires of serogroups Sejroe and Pomona from cattle and swine.
1986
Le Febvre R.B. | Thiermann A.B.
Scanning electron microscopy of bovine coreneas irradiated with sun lamps and challenge exposed with Moraxella bovis.
1986
Vogelweid C.M. | Miller R.B. | Berg J.N. | Kinden D.A.
Characterization of Tritrichomonas foetus antigens, using bovine antiserum.
1986
Hall M.R. | Huang J.C. | Ota R. | Redelman D. | Hanks D. | Taylor R.E.L.
Vaccination of cattle against ringworm caused by Trichophyton verrucosum.
1986
Gudding R. | Naess B.
