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Biomedical subjects

R L McGuire

Publications and source records attributed to R L McGuire.

11 recordsLinked to original sources
PubMed1984

Evidence for defective neutrophil function in lungs of calves exposed to infectious bovine rhinotracheitis virus.

Calves were exposed to an aerosol of infectious bovine rhinotracheitis (IBR) virus followed five days later by an aerosol of Pasteurella haemolytica. The animals were subjected to bronchoalveolar lavage before IBR and four days after, and again at 0, 4, 24, and 48 hours following Pasteurella haemolytica challenge. The results of these experiments suggest that neutrophil infiltration into the lung, in response to the presence of the bacteria was delayed thereby allowing the bacteria to become established in the lung. Neutrophils in infected animals displayed little random migration in vitro and did not respond to a chemotactic stimulus. It was also found that alveolar macrophages from virus-infected animals were not able to produce neutrophil chemotactic factors. These data suggest that the decrease in neutrophil chemotaxis and the lack of chemotactic factor production by the alveolar macrophage following infection with infectious bovine rhinotracheitis virus may predispose infected cattle to a secondary bacterial infection.

Animals↗
PubMed1983

Nonspecific suppressive effect of bovine herpesvirus type 1 on bovine leukocyte functions.

The effect of bovine herpesvirus type 1 on the specific and nonspecific immune response of calves was examined. Animals with or without prior aerosol exposure to Pasteurella haemolytica serotype A1 were aerosol challenged with 10(8) PFU of virus. Blood and serum samples were taken before and after virus challenge for determining cell-mediated, humoral, and neutrophil responses. A significant depression of the blastogenic responses to phytohemagglutinin, P. haemolytica, and Pasteurella multocida and of neutrophil chemotactic response was observed 4 to 7 days after challenge. However, the antibacterial activity of neutrophils was not significantly affected by virus exposure. Anti-bovine herpesvirus type 1 antibody responses were detected 11 days postchallenge. A significant elevation of the anti-P. haemolytica antibody response (day 0 versus day +11) was detected in animals previously exposed to P. haemolytica.

Animals↗
PubMed1979

Suppression of delayed hypersensitivity by the depletion of circulating monocytes.

The intraperitoneal injection of Marcol oil was previously reported to result in the depletion of circulating monocytes. The way in which this depletion affected guinea-pigs' ability to respond to challenge with antigen was tested by challenging with tuberculin after sensitization and examining the ability to respond to DNCB. It was found that the ability to respond to tuberculin was completely abrogated by the injection of Marcol and could be restored by removing the oil from the peritoneal cavity. The ability to respond to a secondary challenge with DNCB was not affected, while the ability to become sensitized was impaired. A normal inflammatory response was seen. The role of the circulating monocyte is discussed.

Animals↗
PubMed1977

Crude transfer-factor preparations stimulate trypsinized human lymphocytes to form rosettes with sheep red cells.

The binding sites for sheep red cells (E) on human lymphocytes are trypsin-sensitive but regenerate in vitro on incubation at 37 degrees C. The rate of this regeneration was increased in the presence of dialysates of human leucocyte extracts (DLE). Thus incubation of trypsinized lymphocytes for 3 hr in appropriate dilutions of DLE resulted in a 2- to 6-fold increase of E-binding activity above that observed in medium-incubated control lymphocytes. Dialysates prepared from human thymus and brain similarly accelerated recovery of E-binding activity whilst dialysates of human fibroblasts and liver cells were inactive. The regeneration of trypsinized membrane immunoglobulin was slightly delayed in the presence of DLE. These findings indicate that leucocyte dialysates contain an activity which preferentially stimulates the regeneration of a T-lymphocyte membrane component. It is suggested that this activity may account for the immunological restoration observed in some patients with T-lymphocyte deficiency after injection of leucocyte dialysates.

Humans↗
PubMed1976

Potentiation of the macrophage response to migration inhibition factor from fetal calf serum by blood group substances with human H activity.

Soluble blood group substances, with human H and A activity, have previously been shown to block the interaction between guinea pig peritoneal macrophages and migration inhibition factor from fetal calf serum (FCS-MIF). Conversely, incubation of macrophages at 37 degrees C for 1 h in the presence of 0.1% blood group substance, followed by thorough washing, potentiates the action of FCS-MIF. The sensitivity of the macrophages is markedly increased, allowing detection of subthreshold levels of FCS-MIF. Blood group substances (BGS) labeled with radioidine are taken up by macrophages, and a proportion remains on the surface. This radiolabeled BGS is lost from the surface spontaneously, and the rate of loss is increased by treatment with trypsin. It is suggested that the BGS mimic the natural macrophage receptor for FCS-MIF and potentiate its effect by incorporating new receptors into the macrophage membrane.

ABO Blood-Group System↗