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Biomedical subjects

F W Scott

Publications and source records attributed to F W Scott.

149 records · Page 9Linked to original sources
PubMedDate not supplied

Intervention in autoimmune diabetes by targeting the gut immune system.

BB rats and nonobese diabetic (NOD) mice spontaneously develop autoimmune insulin dependent diabetes and serve as models for human type I diabetes. During progression of the disease the cytokine pattern elaborated by islet infiltrating immune cells shifts from a Th2 or Th0 toward Th1 type. Only the latter is associated with "destructive" insulitis. We discuss here attempts to modulate disease progression by targeting the gut immune system with bacterial immunostimulants. Oral dosing of diabetes prone BB rats with lipopolysaccharide (LPS) or the Escherichia coli extract OM-89 lead to a Th2-shift of pancreatic mRNA expression. In vitro studies showed that repeated exposure toward LPS or OM-89 lead to downregulation of proinflammatory macrophage responses. In the NOD mouse, repeated oral dosing of OM-89 caused a Th2 shift in the gut cytokine gene expression, probably because of desensitization of macrophages and other antigen presenting cells. Concomitantly, diabetes prevention by oral insulin was improved. In conclusion, oral dosing with bacterial immunostimulants dampens Th1 type immune reactivities of the gut immune system and thereby promotes oral tolerance mechanisms. Downregulation of proinflammatory immune reactivities by repeated exposure to bacterial stimulants requires intact desensitization mechanisms in macrophages or other antigen presenting cells.

Adjuvants, Immunologic↗
PubMedDate not supplied

Raccoon poxvirus live recombinant feline panleukopenia virus VP2 and rabies virus glycoprotein bivalent vaccine.

A raccoon poxvirus (RCNV) recombinant for immunizing against feline panleukopenia and rabies was developed by homologous recombination with a chimeric plasmid for insertional inactivation of the RCNV thymidine kinase gene. The recombinant, RCN-FPV/VP2-rabG, coexpressed the feline panleukopenia virus (FPV) VP2 protein and the rabies virus spike glycoprotein (rabG) under oppositely oriented vaccinia virus P11 promoters. Cats vaccinated subcutaneously with the recombinant showed relatively high neutralizing antibody responses against rabies virus and FPV, and protection against an otherwise virulent FPV challenge with no drop in white blood cell count. Because of containment constraints, no rabies virus challenges were done, but the high concentrations (> 8 IU) of rabies neutralizing antibodies were consistent with levels that usually indicate an ability to counter the infection.

Animals↗
PubMedDate not supplied

Concurrent toxoplasmosis and feline infectious peritonitis in a cat.

A 13-year-old, 4-kg, neutered male Maine coon presented with ascites. Toxoplasma gondii tachyzoites were seen within neutrophils and macrophages, and free within the abdominal fluid. At necropsy, many abdominal organs were positive for feline infectious peritonitis (FIP) antigens using immunohistochemical staining. This apparently is the first report of concurrent toxoplasmosis and FIP in a domestic cat.

Animals↗