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Biomedical subjects

T J Grier

Publications and source records attributed to T J Grier.

8 recordsLinked to original sources
PubMed1996

Intradermal reactivity to various insect and arachnid allergens among dogs from the southeastern United States.

OBJECTIVE: To compare cutaneous reactivity to insect and arachnid allergens in clinically normal (control) and allergic dogs in the southeastern United States. DESIGN: Prospective, controlled study. ANIMALS: 26 clinically normal dogs and 82 allergic dogs from the southeastern United States. PROCEDURE: Intradermal skin testing with various dilutions of 13 insect and arachnid allergens was performed on control dogs to establish skin threshold concentrations (ie, concentrations to which < 25% of the dogs had positive reactions). These established threshold concentrations were then used to test allergic dogs for reactivity. Prevalence of single and multiple insect and arachnid reactions were determined. RESULTS: Flea allergen was the only allergen that caused a significantly higher prevalence of positive reactions in allergic dogs than in control dogs. CLINICAL IMPLICATIONS: Flea hypersensitivity is the most important arthropod hypersensitivity in dogs. The importance of reactivity to insect and arachnid allergens other than flea allergen can be determined only when prevalence of positive reactivity has been determined in an appropriate regional control group of dogs.

Allergens↗
PubMed1996

Allergenic cross-reactivities in flea-reactive canine serum samples.

OBJECTIVES: To determine whether flea extract could be determined (via ELISA) to share allergenic epitopes with other insects, and to determine whether sera with different reactivities to insect extracts have different cross-reactivity patterns. SAMPLE POPULATION: 69 canine serum samples that were selected from samples submitted for routing ELISA allergy testing and had previously been found to have high reactivities to flea. PROCEDURE: Each serum sample was assessed by means of a direct ELISA for IgE binding to 11 common insects. Samples that were reactive primarily to flea extract alone were designated pool 1, samples that were reactive to small numbers of insects were designated pool 2, and samples that were reactive to all or almost all insects were designated pool 3. Samples that did not have any apparent patterns of cross-reactivity were not included in the rest of the study. Inhibition ELISA techniques were used with the 3 serum pools to determine whether multiple insect extracts inhibited reactivity on flea-coated ELISA plates. Those extracts were used to coat ELISA plates, and reciprocal inhibition studies were then performed. RESULTS: Black fly, black ant, and cockroach extracts were capable of > 50% inhibition of flea solid-phase IgE binding with all 3 serum pools. In the ELISA inhibition studies, flea extract was able to inhibit IgE binding to each extract with all pools, confirming reciprocal inhibition. CONCLUSIONS: Inhibition of IgE binding to solid-phase flea antigen by black ant, black fly, and cockroach extracts suggested sharing of allergenic epitopes among these species. Reciprocal inhibition studies further confirmed these findings. These results indicated in vitro cross-reactivity between flea, black ant, black fly, and cockroach extracts. These results need to be further investigated in vivo. CLINICAL RELEVANCE: It is possible that dogs may become sensitized to fleas via exposure to other insects, and flea allergenic dogs may have signs of pruritus, in the absence of fleas, if exposed to cross-reactive insects.

Animals↗
PubMed1987

The role of C-4-substituted mannose analogues in protein glycosylation. Effect of the guanosine diphosphate esters of 4-deoxy-4-fluoro-D-mannose and 4-deoxy-D-mannose on lipid-linked oligosaccharide assembly.

The effects of the guanosine diphosphate esters of 4-deoxy-4-fluoro-D-mannose (GDP-4FMan) and 4-deoxy-D-mannose (GDP-4dMan) on reactions of the dolichol pathway in chick-embryo cell microsomal membranes were investigated by studies with chick-embryo cell microsomal membranes in vitro and in baby-hamster kidney (BHK) cells in vivo. Each nucleotide sugar analogue inhibited lipid-linked oligosaccharide biosynthesis in a concentration-dependent manner. GDP-4FMan blocked in vitro the addition of mannose to Dol-PP-(GlcNAc)2Man from GDP-Man (where Dol represents dolichol), but did not interfere with the formation of Dol-P-Man, Dol-P-Glc and Dol-PP-(GlcNAc)2. Although GDP-4FMan and Dol-P-4FMan were identified as metabolites of 4FMan in BHK cells labelled with [1-14C]4FMan, GDP-4FMan was a very poor substrate for GDP-Man:Dol-P mannosyltransferase and Dol-P-4FMan could only be synthesized in vitro if the chick-embryo cell membranes were primed with Dol-P. It therefore appears that the inhibition of lipid-linked oligosaccharide formation in BHK cells treated with 4FMan [Grier & Rasmussen (1984) J. Biol. Chem. 259, 1027-1030] is due primarily to a blockage in the formation of Dol-PP-(GlcNAc)2Man2 by GDP-4FMan. In contrast, GDP-4dMan was a substrate for those mannosyltransferases that catalyse the transfer of the first five mannose residues to Dol-PP-(GlcNAc)2. In addition, GDP-4dMan was a substrate for GDP-Man:Dol-P mannosyltransferase, which catalysed the formation of Dol-P-4dMan. As a consequence of this, the formation of Dol-P-Man, Dol-P-Glc and Dol-PP-(GlcNAc)2 may be inhibited through competition for Dol-P. In BHK cells treated with 10 mM-4dMan, Dol-PP-(GlcNAc)2Man9 was the major lipid-linked oligosaccharide detected. Nearly normal extents of protein glycosylation were observed, but very little processing to complex oligosaccharides occurred, and the high-mannose structures were smaller than in untreated cells.

Animals↗
PubMed1984

4-Deoxy-4-fluoro-D-mannose inhibits the glycosylation of the G protein of vesicular stomatitis virus.

The effect of 4-deoxy-4-fluoro-D-mannose (4F-Man), a synthetic analog of D-mannose, on the synthesis of the glycoprotein (G) of vesicular stomatitis virus was examined. Nearly confluent monolayers of cultured BHK21 cells infected with vesicular stomatitis virus were incubated for 2 h with 4F-Man (0-10 mM) or for 1 h with tunicamycin (2 micrograms/ml) and then pulse-labeled with [35S]methionine or [3H]glucosamine. After a 90-min chase period, the cells were lysed and the viral proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. The 35S-labeled G protein from cells exposed to greater than or equal to 1 mM 4F-Man migrated more rapidly than G protein isolated from control cells and with the same electrophoretic mobility as the glycoprotein produced by cells treated with tunicamycin. When infected cells were labeled with [3H]glucosamine, little or no radioactivity was associated with G protein synthesized in the presence of greater than or equal to 1 mM 4F-Man. The conclusion that 4F-Man blocks the glycosylation of the G protein was supported by experiments which demonstrated that the fluorosugar inhibits the synthesis of lipid-linked oligosaccharides.

Animals↗
PubMed1983

Metabolism of 3-deoxy-3-fluoro-D-mannose and 4-deoxy-4-fluoro-D-mannose by Saccharomyces cerevisiae S288C.

Incubation of Saccharomyces cerevisiae S288C with 4-deoxy-4-fluoro-D-[1-14C]-mannose resulted in the formation of three metabolites that were characterized as 4-deoxy-4-fluoro-D-[1-14C]mannose 1,6-bisphosphate, 4-deoxy-4-fluoro-D-[1-14C]-mannose 6-phosphate and GDP-4-deoxy-4-fluoro-D-[1-14C]mannose. In addition, radioactive material was incorporated into a particulate fraction composed primarily of cell-wall polysaccharides. Compared with the 4-fluoro sugar, 3-deoxy-3-fluoro-D-[1-14C]mannose was not transported into yeast cells as well, and its conversion into sugar nucleotide was much less efficient. Metabolites that were isolated after incubation with the 3-fluoro analogue were identified as 3-deoxy-3-fluoro-D-[1-14C]mannose 1,6-bisphosphate, 3-deoxy-3-fluoro-D-[1-14C]mannose 6-phosphate and GDP-3-deoxy-3-fluoro-D-[1-14C]mannose. Little radioactivity was transferred into the cell-wall fraction.

Carbon Radioisotopes↗