Biomedical subjects

R W Dorner

Publications and source records attributed to R W Dorner.

At least 37 records · Page 2Linked to original sources

PubMed1984

Precipitation of 19S IgM rheumatoid factor-IgG circulating immune complexes in patients with juvenile arthritis by polyethylene glycol and separation by immobilized protein A.

Immune complexes (IC) in sera and synovial fluid (SF) from patients with juvenile (rheumatoid) arthritis (JA) were isolated by making use of polyethylene glycol (PEG) to precipitate IC and then using staphylococcal protein A to separate the IC. The isolated IC were compared to IC in sera analysed by sucrose density gradients and measured by the C1q solid phase assay (ClqSPA). Isolated IC from sera of 10 of 16 JA patients demonstrated significant 19S IgM rheumatoid factor (RF) titres in their acid elutes utilizing the haemolytic assay. IgM and IgG were detected by low level radial immunodiffusion in the acid eluate of sera in all 10 patients who had significant RF titres. In isolated IC from SF, three of five JA patients had significant 19S IgM RF titres detected in their acid eluates. By sucrose density gradient analysis of these sera, elevated levels of IC detected by ClqSPA were found in the fractions of greater than or equal to 19S comparable to the previous isolated 19S IgM-IgG complexes. This detection of IC like material containing 19S IgM and IgG by the present method further supports the participation of classic and hidden 19S IgM RF in IC formation in JA patients.

Antigen-Antibody Complex↗

PubMed1983

Rapid determination of hidden rheumatoid factor.

A method for the determination of hidden 19S IgM rheumatoid factor based on separation by QAE-Sephadex A-50 chromatography followed by hemolytic assay is described. Hidden rheumatoid factor titers and IgM recoveries of sera were comparable to those obtained by the conventional acid gel filtration method. The QAE method saves time, requires only 250 microliters of serum and can be performed with a minimum of specialized equipment.

Arthritis, Juvenile↗

PubMed1983

Separation and characterization of immune complexes containing 19S IgM rheumatoid factor-IgG in juvenile arthritis.

Sera from 10 patients with juvenile arthritis (JA), 2 seropositive and 8 with hidden rheumatoid factor (RF), were subjected to affinity chromatography on a rabbit anti-human IgM column. Material retained by the column was eluted sequentially by 1M NH3 and 0.1M glycine-HCl buffer, pH 3.0. The affinity fractions contained both 19S IgM RF and IgG, while corresponding fractions from healthy controls contained neither. Sera from 15 patients with JA, 1 seropositive and 11 with hidden RF, were subjected to 4% polyethylene glycol precipitation followed by acid dissociation of the precipitate. Ten of 15 resultant fractions contained both IgM RF and IgG, while corresponding fractions from healthy controls contained only traces of IgG. Sera from 7 of these JA patients were subjected to sucrose density gradient centrifugation and the resultant fractions analyzed for the presence of immune complexes by the C1q solid-phase assay. Immune complexes were detected at and ahead of the IgM marker, as expected for IgM RF-IgG complexes. These combined data show that the majority of JA patients with classic or hidden 19S IgM RF have immune complexes containing IgM RF and IgG in their sera.

Antigen-Antibody Complex↗

PubMed1983

Glycosaminoglycan content in skin of the tight-skin mouse.

The tight-skin (TSK) mouse has cutaneous changes similar to those found in the skin of patients with progressive systemic sclerosis (PSS). Previous studies have shown that both have common abnormalities in skin thickness, dry weight, and hydroxyproline content. In this study, glycosaminoglycans (GAGs), major components of the ground substance, were quantitated in skins from TSK mice and compared with age-matched normal mice. Biochemical studies included determinations of hexosamines, uronic acids, and total GAGs by cetylpyridinium chloride precipitation. Dry weights and water-fat content of skin biopsy specimens from TSK mice were also compared with those of normal mice. Hexosamine, uronic acid, total GAGs, and dry weight were increased in TSK mouse skin when compared with normal mouse skin. The water-fat content did not differ significantly. These findings were similar to those known to occur in PSS skin, further suggesting that the TSK mouse might serve as an animal model for the skin changes found in PSS patients.

Animals↗

PubMed1981

Specificity of hidden 19S IgM rheumatoid factor in patients with juvenile rheumatoid arthritis.

Hidden 19S IgM rheumatoid factors (RF)-i.e., RF detected in the IgM-containing fraction after separation of the serum at an acid pH-have been found in 68% of patients with seronegative juvenile rheumatoid arthritis (JRA). Inhibition studies utilizing a hemolytic assay for RF were performed to determine the specificity of hidden 19S IgM RF. Sera from 14 children with JRA were separated by gel filtration at pH 4.05. Two were seropositive for RF and 12 were seronegative; the latter had high titer hidden 19S IgM RF. The IgM-containing fractions were preincubated with monomeric human IgG, rabbit IgG, or bovine IgG, and the complement-dependent hemolytic assay ws performed. The RF in the IgM fraction from the 2 seropositive patients were inhibited most strongly by rabbit IgG, whereas hidden RF in the IgM fraction of 9 seronegative patients were inhibited markedly by human IgG (homologous IgG equal to autologous IgG), poorly by rabbit IgG, and not at all by bovine IgG. Further inhibition studies with the hidden 19S IgM RF demonstrated inhibition by the human IgG1 subclass in all patients and only minimal inhibition by the IgG3 subclass in 3 patients. Inhibition with IgG1 Fc fragments produced by papain and thermolysin digestion demonstrated inhibition by only those fragments that contained the G1m (a) antigenic area which is found in the C gamma 3 homology area of the IgG1 molecule. These data indicate that hidden 19S IgM RF possibly circulate as immune complexes bound to the IgG1 molecule and the binding chiefly occurs in th G1m (a) homology area.

Arthritis, Juvenile↗

PubMed1981

Plasma and synovial fluid as solvents for monosodium urate.

In-vitro differences in monosodium urate (MSU) crystal dissolution in paired plasma and synovial fluid samples from patients with various arthritides were studied. Plasma was a significantly better solvent for MSU than synovial fluid (overall difference 6.3 mg/dl (0.37 mmol/l); significant at P less than 0.001). Attempts to correlate the solubility differentials with the principal compositional differences between the 2 fluids were only partially successful. (1) A tendency towards higher MSU solubility at higher protein levels was observed, but it was too slight to reach statistical significance. (2) Hyaluronidase treatment of synovial fluid significantly enhanced its ability to dissolve MSU (overall difference 2.2 mg/dl (0.13 mmol/l); significant at P less than 0.01) but not sufficiently to explain wholly the plasma-synovial fluid differential.

Arthritis↗

PubMed1980

19S IgM Forssman-type heterophile antibodies in juvenile rheumatoid arthritis.

Fifty-four sera from children with juvenile rheumatoid arthritis (JRA) were separated by gel filtration at pH 4.05. The serum and IgM- and IgG-containing fractions were analyzed for heterophile antibodies by subjecting them to a hemolytic assay in tubes with the target cell a 1% washed sheep erythrocyte (SRBC) or beef erythrocyte (BRBC) in suspension. Thirty-three of 54 sera showed hemolytic antibody titers > 1:640 against SRBC alone and 4 of 54 had titers > 1:320 against SRBC and BRBC. All positive titers against SRBC and BRBC were associated with the IgM fraction. Differential absorption with SRBC, BRBC, and tissue sediment of homogenized guinea pig kidney revealed a Forssman specificity in 33 sera and Forssman and Hanganutziu-Deicher specificity in 4. The presence of heterophile antibodies in JRA correlated with the presence of hidden rheumatoid factor. There was also an increased incidence in patients with positive antinuclear antibodies and in teenaged females with polyarticular disease.

Animals↗

PubMed1980

Hidden 19S IgM rheumatoid factor in juvenile rheumatoid arthritis.

One-hundred twenty-five serum samples from 82 patients with juvenile rheumatoid arthritis (JRA) were studied for the presence of hidden rheumatoid factor (RF) in an effort to find a better serologic marker to define JRA. Hidden 19S IgM RF was detected by means of a hemolytic assay utilizing the IgM-containing fraction of serum. The IgM fraction was obtained after acid separation of serum on a Sephadex G-200 column. Hidden 19S IgM RF was present in 68% of patients with seronegative JRA with a mean titer of 1:63. The mean titer for the polyarticular JRA group was 1:83, for the pauciarticular JRA group, it was 1:32, and for the systemic type-onset JRA patients, it was 1:32. When disease was active, the mean titer for all JRA patients was 1:108, for the active polyarticular JRA group it was 1:119, for the active pauciarticular JRA, it was 1:97, and for the active systemic JRA patients, it was 1:64. All values were significant at the P less than or equal to 0.001 when compared to disease and normal controls. The hemolytic assay for RF on the IgM-containing fraction of serum thus enhances the serologic capabilities of defining JRA.

Adolescent↗

PubMed1974