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Biomedical subjects

D J Walker

Publications and source records attributed to D J Walker.

At least 91 records · Page 5Linked to original sources
PubMed1992

Effect of disease severity on rheumatoid arthritis concordance in same sexed siblings.

To assess the factors in a proband with rheumatoid arthritis (RA) that might predict the occurrence of the disease in siblings, 240 same sexed sibships (190 female, 50 male) in which the proband had classical or definite RA were clinically and immunologically documented. Sibship concordance rates were consistently higher for features of severe disease in the proband, reaching statistical significance for a clinical score of disease severity (the SS index). This trend for increasing disease severity to be associated with increasing sibship concordance rates could not be accounted for by age or disease duration of the proband. These results suggest that siblings of probands with severe RA are at greater risk of developing RA than those of probands with mild disease.

Age Factors↗
PubMed1992

Sex hormones in postmenopausal HLA-identical rheumatoid arthritis discordant sibling pairs.

Dehydroepiandrosterone sulfate (DHEAS), testosterone, androstenedione, 17-beta estradiol and sex hormone binding globulin have been assayed in 50 HLA-identical postmenopausal rheumatoid arthritis (RA) discordant sibling pairs. The only difference was for DHEAS, siblings with RA having a significantly lower level than their sisters. However, in 68 patients with RA, the level of DHEAS inversely correlated with disease duration, a radiographic grading score, the Health Assessment Questionnaire score, duration of morning stiffness, and a clinical score of disease activity and severity (the Spread/Severity index). These observations, taken with that of previous work on DHEAS, suggest that low levels may be a consequence of RA rather than predisposing to the disease. The role of sex hormones in RA will have to be approached in alternative ways.

Aged↗
PubMed1992

What factors distinguish probands from multicase rheumatoid arthritis same sex sibships from sporadic disease?

Thirty-two of 243 same sex sibships in which the proband had rheumatoid arthritis (RA) had at least one same sex sibling with RA ("familial" RA) and 211 did not ("sporadic" RA). The most important factors accounting for familial RA were the sibship size, and the proportion of siblings sharing both HLA haplotypes with the proband. Demographic and clinical details, autoantibodies and HLA-DR status were similar between the 2 groups, with the exceptions of regular use of artificial teardrops, and involvement of distal interphalangeal joints, which were both more prevalent in familial RA. The extrapolation of results from familial to sporadic RA appears to be justified.

Arthritis, Rheumatoid↗
PubMed1992

Histochemistry and ultrastructure of the metacercarial cyst of Bolbogonotylus corkumi (Trematoda: Cryptogonimidae).

Histochemical and ultrastructural studies were conducted on the metacercarial cyst of the cryptogonimid trematode Bolbogonotylus corkumi from the muscle tissue of fantail darters Etheostoma flabellare. The metacercarial cyst consisted of an outer host capsule and an inner parasite cyst. The host capsule was composed of an outer region of fibroblasts, collagen, macrophages, and unidentified cells, and an inner region containing degenerating cells. The parasite cyst was thin, homogenous, and noncellular in nature. The host capsule stained strongly for connective tissue and proteins and moderately for lipids, nucleic acids, nonspecific esterase activity, and acid and alkaline phosphatase activities. The parasite cyst stained intensely for acid mucopolysaccharides and moderately for acid phosphatase activity. A thick glycocalyx occurred between the parasite cyst and metacercarial tegument.

Animals↗
PubMed1991

Provision of medical and community services to people with severe arthritis; an audit.

We have identified severely disabled arthritics who live in the community through social service records. All had either rheumatoid arthritis (RA) or osteoarthritis (OA). The diagnosis influenced referral to hospital, those with RA being referred while only half of those with OA had been referred. Referral was important for both surgical and environmental intervention. Provision of social services and community occupational therapy services was greater if the patients had been seen in hospital departments irrespective of the diagnosis. Recipients of joint surgery had all gained temporary benefit although progression of arthritis or other disabling disease compromised this after several years. There was a substantial minority of people with severe OA living in the community who had not been considered for joint replacement and did not have optimal provision of aids, appliances and environmental adaptation.

Arthritis↗
PubMed1991

Referrals to a rheumatology unit: an evaluation of the views of patients, general practitioners, and consultants.

One hundred and twelve randomly selected patients referred to a rheumatology unit were studied, using structured questionnaires, to gain the views of patients, general practitioners (GPs), and the consultants. There were differences in perception between these respondents on the reason for referral. Major diagnostic changes were made in less than 10% of cases. Nearly all patients claimed that some aspect of their disease had been improved as a result of the appointment. Satisfaction with the communication aspects of the appointment contributed more to patients' overall satisfaction than did improvement in pain or disability. General practitioners' objectives were also met if communication with patients was satisfactory. In the management of chronic disease communication is important and should be recognised as such.

Attitude of Health Personnel↗
PubMed1990

The regulation of resistance to Schistosoma mansoni by auto-anti-idiotypic immunity. III. An analysis of effects on epitopic recognition, idiotypic expression, and anti-idiotypic reactivity at the clonal level.

Auto-anti-idiotypic mechanisms can regulate the protective immune response against Schistosoma mansoni. Anti-idiotypic responses were stimulated by immunization of mice either with nonspecifically induced lymphoblasts, produced with Con A, or with Ag-induced lymphoblasts bearing specific idiotypic receptors. The effect of the induced anti-idiotypic response upon clonotypic cellular reactivity was assessed in vitro through the suppression of antigen-mediated blast transformation by cloned T cells and in vivo by suppression of resistance to S. mansoni and delayed-type hypersensitivity responses against specific Ag. Differential regulation of humoral immune responses was studied at the levels of specific epitopic recognition, the expression of specific Id, and the production of anti-idiotypic responses directed against mAb bearing specific Id. Anti-idiotypic sensitization resulted in variable (10 to 90%) suppression of the immune response to discrete antigenic epitopes, the expression of specific idiotypic phenotypes, and anti-idiotypic, antiparatopic responses against T cell clonotypes and antibody idiotypic phenotypes. In vitro admixture and in vivo challenge studies resulted in consonant differential suppression. Thus idiotypic regulation can mold the fine specificities of the protective immune response to S. mansoni at the clonal level and may provide an approach to optimize the expression and assessment of resistance.

Animals↗
PubMed1990

The regulation of resistance to Schistosoma mansoni by auto-anti-idiotypic immunity. II. Global qualitative and quantitative regulation.

These studies explore the suppression of resistance to schistosomiasis mansoni through interactions of autologous immune functions derived from an induced anti-idiotypic response. This anti-clonotypic response is induced by immunization with syngeneic L3T4+ receptor-bearing lymphoblasts and for the sake of description is termed "auto-anti-idiotypic". It is antigenically restricted and cannot be induced by allogeneic cells. Anti-idiotypic immunization profoundly suppressed the development of protective immunity after exposure to irradiated cercariae and altered a wide variety of functional humoral and cellular immune responses to the parasite. In addition to quantitative suppressive effects, the anti-idiotypic network also regulated qualitative aspects of the immune response by increasing the heterogeneity and reducing the functional binding avidity of antibody for Ag. These effects also were reflected in analogous alterations in cellular reactivity, using the criteria of the Ag mediated blast transformation and delayed type hypersensitivity. Thus idiotypic regulation can mold the specificity and sensitivity of the immune response to Schistosoma mansoni by affecting quantitative and qualitative responses. Manipulation of idiotypic recognition provides an approach to optimize the expression of protective resistance to schistosomiasis.

Animals↗
PubMed1989

Outcome from multiple joint replacement surgery to the lower limbs.

All patients who had three or more major joints (hips or knees) replaced were identified from operation records at one hospital and reviewed to assess outcome. Forty-three were found to suffer from rheumatoid arthritis, four from osteoarthritis and three from psoriatic arthritis. Eight patients had died an average of 2.6 years (range 1-7 years) after their last operation and this was higher than expected, even for RA. Average follow-up in the 36 surviving RA sufferers was 1.8 years, with a minimum of 6 months since last operation. Range of joint movement, pain relief, satisfaction, mobility, disability and social outcomes were assessed and are reported. Patients were satisfied with outcome because of pain relief and functional improvement. No patient required permanent in-patient care, although they still represented a very disabled group with mean HAQ score of 2.75.

Aged↗
PubMed1989

The contribution of HLA to rheumatoid arthritis.

The contribution of genes within the major histocompatibility complex to rheumatoid arthritis has been calculated (Rotter & Landaw 1984). Separate data from hospital- and population-based studies of monozygotic twin concordance rates and sibling recurrence risks have been used, along with material from published haplotype-sharing studies. Using either source of information gives the same result, a contribution of 37%.

Arthritis, Rheumatoid↗