The interaction of biotinylated human interleukin 5 ([BT]hIL5) with immobilized receptor was measured with a real-time biosensor, and these results were used as a basis for configuring an ELISA for screening antagonists of hIL5-receptor binding. The recombinant proteins used, hIL5 and shIL5R alpha-Fc (chimeric fusion receptor constructed by linking the soluble component of the hIL5 receptor alpha subunit to the constant domain (Fc) of immunoglobulin G), were produced by the expression of cloned vectors in Drosophila schneider (S2) cells. Initial attempts to develop a screening assay by direct immobilization of soluble IL5 receptor to microtiter plates proved unsatisfactory and led to use of the Fc chimera attached by oriented immobilization via protein A. Hence, shIL5R alpha-Fc was bound to protein A covalently immobilized on a carboxymethyl dextran (CM-5) biosensor chip. Specific binding was demonstrated of [BT]hIL5 to protein A/shIL5R alpha-Fc receptor complex. The binding was high affinity (Kdapp = 6 nM), reversible and saturable. The affinity of [BT]hIL5 was similar to that determined with the biosensor assay for unmodified hIL5. The observed kinetics of the interactions of Fc chimera with protein A (slow dissociation) and of [BT]hIL5 with immobilized Fc chimera (faster dissociation) were favorable for subsequently establishing a microtiter plate based ELISA assay. In the latter, Fc chimera was immobilized to the plate via protein A as in the biosensor experiment. Binding of [BT]hIL5 to immobilized Fc chimera in the ELISA was concentration dependent and was competed by both hIL5 and shIL5R alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Ossifying fibromyxoid tumour of soft parts.

Ossifying fibromyxoid tumour of soft parts (OFMT) is a recently described soft tissue tumour. Although rare it deserves recognition as a locally invasive but essentially benign neoplasm. Prior to its description in 1989 by Enzinger, ossifying fibromyxoid tumours of soft parts were classified as a wide variety of lesions, ranging from nodular fasciitis to osteosarcoma. We report a typical case of such a tumour and review current knowledge of this distinct neoplasm.

Aged↗

PubMedDate not supplied

Effect of nitric oxide synthase inhibitors on hypotension in patients with septic shock.

Hypotension during septic shock, which may reflect increased synthesis of the potent vasodilator nitric oxide (NO), is often refractory to vasoconstrictors. We describe the effects of NO synthase inhibition in two patients with life-threatening septic shock in whom conventional therapy had failed to restore blood pressure. NG-monomethyl-L-arginine (L-NMMA) caused dose-dependent increases in blood pressure and systemic vascular resistance in both patients, and a similar effect was observed in the second patient after treatment with NG-nitro-L-arginine methyl ester (L-NAME). These findings indicate that NO synthase induction contributes to the pathogenesis of septic shock, and that inhibition of NO synthase may represent a novel therapeutic option.

Amino Acid Oxidoreductases↗

PubMedDate not supplied

Antibodies to heat shock proteins in dogs with rheumatoid arthritis and systemic lupus erythematosus.

Antibodies to heat shock proteins of the 65 kDa group were demonstrated in canine sera and synovial fluid. This paper reports these antibody measurements in three groups of dogs with joint disease and compares them with those of a control population. Dogs with rheumatoid arthritis (RA) showed higher anti-heat shock proteins (HSP) antibody levels, in both their sera and synovial fluids, compared to the control dogs and these antibodies were predominantly of the IgG and IgM class; there was a significant correlation between IgM anti-HSP65 and IgM-rheumatoid factors. There was also a significant correlation between anti-HSP65 and antibodies to canine distemper virus, but only of the IgM class and the relevance of these antibodies to the overall pathogenesis of canine RA and, in particular, to the presence of canine distemper virus within the joint, are discussed.

Animals↗

PubMedDate not supplied

Analysis and significance of anti-nuclear antibodies in dogs.

Assays for detecting and measuring antinuclear antibodies (ANA) in dogs were compared. They included the indirect immunofluorescence test, using rat liver as substrate, and ELISAs for three nuclear antigens: double-stranded DNA, single-stranded DNA, and histone. There was no correlation between the ANA titre and antibodies to the three nuclear antigens. Analysis of ANA in different arthropathies showed no specific disease association. HEP-2 cells showed no fluorescence reaction with either ANA-positive or ANA-negative dog sera. Western blotting produced too complex a pattern to identify specific antigens. The antigens that reacted with ANA in dogs were not identified; there is either a broad range of reactivities or non-specific binding of immunoglobulins.

Animals↗