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A J MacGregor

Publications and source records attributed to A J MacGregor.

At least 55 records · Page 3Linked to original sources
PubMed1994

Influence of previous exposure to human parvovirus B19 infection in explaining susceptibility to rheumatoid arthritis: an analysis of disease discordant twin pairs.

OBJECTIVES: To assess the association between exposure to parvovirus B19 and susceptibility to rheumatoid arthritis (RA). METHODS: One hundred and fifty five twin pairs (76 monozygotic (MZ) and 79 dizygotic (DZ)), discordant for RA, were tested for the presence of IgG antiparvovirus antibodies using ELISA. The data obtained were analysed using conditional logistic regression, from which odds ratios and 95% confidence intervals were calculated. RESULTS: Overall, there was no association between exposure to parvovirus and RA (OR = 1.2, 95% CI: 0.7-1.7). However, in two subgroups there was a suggestion of an association. These were: (1) pairs where the affected twin was rheumatoid factor (RF) seronegative (OR = 2.0, 95% CI: 0.9-12.4) and (2) in opposite-sexed twin pairs where the affected twin was female (OR = 3.0, 95% CI: 0.9-11.6). CONCLUSION: Previous exposure to parvovirus infection did not explain disease susceptibility in both MZ and DZ discordant pairs with rheumatoid arthritis. This infection, however, might be relevant in some subgroups.

Antibodies, Viral↗
PubMed1994

Low prevalence of rheumatoid arthritis in black-Caribbeans compared with whites in inner city Manchester.

OBJECTIVE: To compare the prevalence of rheumatoid arthritis (RA) in Black-Caribbeans and Whites living in the same urban area. METHODS: Cases of inflammatory joint disease were ascertained initially from a postal screening survey of 1851 Black and 1829 age and sex-matched non-Blacks identified from general practice age-sex registers of seven general practices in the Moss Side and Hulme districts of Manchester. The ethnicity of respondents was confirmed using data from a postal screening questionnaire. Those reporting joint swelling or a history of arthritis were reviewed by a rheumatologist at surgeries held in each practice. The clinical records of the questionnaire non-responders and questionnaire-positive non-attenders at surgery were reviewed. RESULTS: In an adjusted denominator population of 1046 Black-Caribbeans and 997 Whites, the cumulative prevalence of RA was 2.9/1000 in Black-Caribbeans and 8/1000 in Whites, representing a prevalence in Black-Caribbeans of 0.36 times that found in Whites (95% confidence interval 0.1-1.3). CONCLUSIONS: Rheumatoid arthritis occurs less commonly in Black-Caribbeans than in Whites. The findings are consistent with published studies showing a low RA prevalence in rural African Black populations.

Adult↗
PubMed1994

A comparison of the performance of different methods of disease classification for rheumatoid arthritis. Results of an analysis from a nationwide twin study.

OBJECTIVE: We have assessed the importance of the distinction between classification criteria for rheumatoid arthritis (RA) that recognize the presence of currently active disease from those that, in addition, incorporate evidence of past disease activity in ascertaining disease occurrence. We applied 7 classification schemes to a population of twins with inflammatory arthritis to determine (a) the number of individuals classified as RA positive by each scheme and hence the effect on the estimate of disease concordance in the twins and (b) their performance in correctly assigning a diagnosis compared with a physician's opinion. METHODS: The schemes assessed were the 1958 ARA (Rome) criteria which detect active disease, the 1966 New York (using both the 2/4 and 3/4 published cutoffs) which detect "ever" disease and 4 variants of the 1987 ARA criteria. These were the 4/7 and decision tree approaches applied on the basis of the relevant features (1) being present at the time of the study and (2) being present ever and allowing current joint deformity to substitute for absent joint swelling. RESULTS: In all, 283 individuals with a history of joint swelling were assessed, 255 of whom were considered to have RA by their physician. Criteria used to recognize "current" RA identified only about 70% of those which recognized RA ever. These differences in ascertainment level produced a marked effect on the monozygotic twin RA concordance estimates with percentages ranging from 10 to 18%. The results from receiver operating curves confirmed that criteria used to assess only current RA were too insensitive to be of value. Of the criteria that recognized RA status ever the 1987 ARA performed best overall. CONCLUSION: The use of classification methods that incorporate past as well as current evidence of disease activity is essential to avoid important misclassification in epidemiological and family studies. The 1987 criteria, applied retrospectively and allowing joint deformity to substitute for swelling, are of enhanced value over other existing schemes.

Adult↗
PubMed1993

Twin concordance rates for rheumatoid arthritis: results from a nationwide study.

We report the concordance rate for RA in a nationwide study of 91 monozygotic (MZ) and 112 dizygotic (DZ) pairs. Twin pairs were recruited from both a national media campaign and a 2-month prospective inquiry of all UK rheumatologists. Disease status was established following a structured clinical and serological appraisal, together with radiological assessment where necessary. Zygosity was confirmed using DNA fingerprinting. In all, 14 (15.4%) of the MZ and four (3.6%) of the DZ pairs were disease concordant (risk ratio: 4.3 95% CI 1.5 to 12.6). There was no difference in the concordance between the media and clinical derived twins. Further the excess MZ concordance persisted after adjusting for age, age at disease onset, sex and rheumatoid factor status. Analysing the data in relation to the timing of disease onset in the first affected twin showed that subsequent disease risk in the initially unaffected co-twins of the MZ affected probands increased with increasing duration of follow-up. We conclude that the overall MZ concordance at 15% is lower than the 30% figure normally quoted from a study some 30 years ago and sets a ceiling at the potential genetic contribution to disease susceptibility.

Adult↗
PubMed1993

Lack of association of increased antibody levels to mycobacterial hsp65 with rheumatoid arthritis: results from a study of disease discordant twin pairs.

OBJECTIVES: To investigate the role of humoral immunity to mycobacterial hsp65 in the aetiology of rheumatoid arthritis. METHODS: Levels of IgG antibodies to recombinant mycobacterial hsp65 were measured by enzyme linked immunosorbent assay (ELISA) in serum samples of 152 twin pairs discordant for RA and in serum samples from 62 normal blood donors. RESULTS: No significant differences between antibody levels in the subjects with RA compared either with their unaffected twins or with a group of normal blood donors was observed. In the monozygotic twins there was a strong but negative association between levels of antibody to hsp65 and disease status. Zygosity, sex, and HLA status did not significantly affect levels of antibody to hsp65. CONCLUSION: Previous reports of an association between hsp65 and RA were not confirmed.

Antibodies, Bacterial↗
PubMed1992

Fasting lipids and anticardiolipin antibodies as risk factors for vascular disease in systemic lupus erythematosus.

Fasting cholesterol, triglyceride, low density lipoprotein cholesterol, high density lipoprotein cholesterol, apoprotein AI, and apoprotein B were measured in 64 patients with systemic lupus erythematosus to assess the risk factors for vascular disease. The relation between the lipid profile, steroid treatment, the presence of anticardiolipin antibodies, and the prevalence of vascular disease was examined. Raised concentrations of triglyceride and apoprotein B were seen in those patients treated with more than the equivalent of 10 mg prednisolone a day in the six months before testing. An increase in vascular disease was found only in the subgroup of patients with increased triglycerides who also expressed anticardiolipin antibodies. This study confirms the association between treatment with high doses of steroids in lupus and the development of an atherogenic plasma lipid profile. The presence of anticardiolipin antibodies compounds the risk of developing vascular disease.

Adult↗
PubMed1992

Analysis of antibody reactivity in the sera of 42 patients with paraproteinaemia.

The clinical expression of disease in patients with conditions in which autoimmunity is thought to contribute to the pathogenesis of disease is the result of an unfortunate combination of predisposing and environmental factors. The presence of autoantibodies showing a variety of antigen specificities in sera from many of these patients has been closely correlated with particular spectra of organ involvement or tissue destruction. Their precise role in the disease process is as yet unclear. Sera from patients with paraproteinaemia also often contain autoantibodies to a variety of cell components, although symptoms of autoimmune disease are rarely found in this group of individuals. In this study of 42 sera from patients with paraproteinaemia we have confirmed the presence of autoantibodies in 33% (13/42) of samples. Amongst the autoantibodies detected were those to human neutrophils (3), U1RNP (8) and cardiolipin (4). In five sera, the immunoglobulin class of autoantibody did not correlate with that of the monoclonal band. This study extends previous reports of the repertoire of autoantibodies present in sera from patients with paraproteinaemia.

Antibodies, Anticardiolipin↗
PubMed1991

Updating practices among Yorkshire general dental practitioners.

Ninety-eight per cent was the response achieved by a June 1989 postal survey to determine how general dental practitioners (GDPs) in Yorkshire Region maintain their professional knowledge. Such a good response adds confidence to the survey's findings which show many GDPs are educationally active and use a variety of media to keep up to date. Nevertheless, there remains a substantial proportion who should be doing more and need encouragement.

Education, Dental, Continuing↗
PubMed1991

IDEA: an index of dental educational activity.

This paper reports on the construction of an index of dental educational activities (IDEA) developed as part of an exploration of continuing professional development activities among a sample of general dental practitioners (GDPs) in the Yorkshire Region in Britain. To assist in the interpretation of the index scores an analogy is drawn to an academic examination. Only 50% of the GDPs passed, 31% achieving scores of 40% or less and 9% distinctions. Higher IDEAS were achieved by practitioners who spent a lot on their dental education, those who intended to attend continuing education events next year practice principals, those who worked in larger practices and men GDPs. Little difference in the scores was observed by the age of the practitioner, experience of working in hospital or distance from the central continuing education centre. Discussion centres on the utility of the index as a summary of updating practices and its potential as a comparative measure across health professions. High levels of continuing professional development and thus high IDEAs must be encouraged, but they need to be accompanied by high quality care and effective job performance.

Education, Dental, Continuing↗
PubMed1990

Reduction in morbidity in the surgery of the third molar removal.

No single regime has proved to be totally successful in reducing the pain and swelling that frequently follow extraction of wisdom teeth. In this review the author examines the regimes that are currently used, assesses the evidence for their efficacy, and makes some practical recommendations.

Edema↗
PubMed1986

Increased resistance to penicillin of oral viridans streptococci in dental students.

Salivary samples were taken annually in October from 48 dental students as they progressed from pre-clinical studies to final year. The MICs of penicillin for the viridans streptococci were determined. Over the three years these organisms became progressively more resistant but not to a level of clinical significance. The findings were confirmed by a cross-sectional study of 57 pre-clinical and 37 final year students. The increase in resistance might have been related to age, but a further study of 20 postgraduate chemistry students of the same age as the final year dental students showed that the former had a population of streptococci similar to that found in the pre-clinical students. Whether the increase in resistance is a result of the dental students working in the clinic or having penicillin more frequently prescribed for them personally is a matter for speculation.

Adult↗
PubMed1986

The effect of a single large dose of amoxycillin on oral streptococci.

Salivary samples were examined for a period three weeks before, and three weeks after the administration of 3 g of amoxycillin in ten volunteers. There was a marked drop in the concentration of streptococci in all subjects in the first 4 h but most had substantially recovered within 48 h. All had recovered at seven days. No strains were resistant to 1 mg/l amoxycillin in the pre-treatment control series, and no resistant streptococci emerged.

Amoxicillin↗
PubMed1985

The response of the peripheral branches of the trigeminal nerve to trauma.

56 patients were monitored for a period of 26 weeks following injury to one of the peripheral branches of the trigeminal nerve. A further 10 patients were followed up after periods of 1 to 9 years suffering impaired facial sensation. Tests showed that 50% of the patients returned to normal in 3 months and 60% in 6 months. The fine sensations of touch and temperature recovered first and the response to pricking and two-point discrimination occurred later. Not all patients recovered normal sensation. A small proportion continued to suffer disturbing sensations such as tingling, burning and formication.

Adolescent↗