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Biomedical subjects

M Corbett

Publications and source records attributed to M Corbett.

At least 37 records · Page 2Linked to original sources

Antibodies to Klebsiella and Proteus microorganisms in ankylosing spondylitis and rheumatoid arthritis patients measured by ELISA.

Antibodies to Klebsiella oxytoca and Proteus mirabilis in 21 active ankylosing spondylitis (AS), 13 active rheumatoid arthritis (RA), 19 inactive RA patients and 18 healthy controls were measured using enzyme-linked immunosorbent assay (ELISA). Elevated anti-Klebsiella antibodies were demonstrated in active AS patients compared to active RA (p less than 0.01), inactive RA patients (p less than 0.001) and controls (p less than 0.005). When measuring antibodies to Proteus, active RA patients showed higher levels of antibodies compared to active AS patients (p less than 0.005) and healthy controls (p less than 0.05). Further investigations are required to assess the role of Klebsiella and Proteus microorganisms in AS and RA respectively.

Adult↗

IgA and IgM rheumatoid factors as markers of later erosive changes in rheumatoid arthritis (RA).

Stored samples from within the first year of disease of 119 patients with rheumatoid arthritis (RA) enrolled in a long-running prospective study have been studied for the presence of IgM and IgA rheumatoid factors (RF), using agglutination of rabbit IgG-coated red blood cells to detect IgMRF and an ELISA technique using rabbit IgG coated on the microtitre plates and labelled F(aB)2 fragment of goat anti-IgA. Outcome measures at a mean follow-up of 10.1 years (range 3-20) included the Steinbrocker functional grade and grading of erosive changes on hand and feet Xrays using a modification of Lawrence's method. Both IgA and IgG levels at presentation correlated significantly with outcome measured by erosive changes and functional grade at a mean of 10 years and with the time of first appearance of erosions. In patients who are IgMRF negative early in the disease, IgARF positivity indicates a greater chance of developing both erosions and impaired function than when both tests are negative. IgARF positivity seems to precede IgMRF.

Adult↗

Dysgonic Fermenter-type 2: an emerging zoonosis. Report of two cases and review.

We report Dysgonic Fermenter-type 2 septicaemia presenting in two previously healthy individuals, and review 52 cases of infection with Dysgonic Fermenter-type 2 reported in the English language literature. This zoonosis is usually acquired through contact with dogs and cats. Infection often presents with little warning to patient or physician and carries a high mortality. The immunosuppressed patient, those without a spleen, alcoholics and those with chronic disease appear to be most susceptible, although the healthy individual is also prone to infection. The infection is probably underdiagnosed due to difficulties in isolating Dysgonic Fermenter-type 2 by conventional blood culture techniques. Clinical and microbiological awareness is of prime importance in the early diagnosis of this potentially lethal infection.

Animals↗

A prospective study of early onset rheumatoid arthritis over fifteen years: prognostic features and outcome.

A total of 218 patients with early onset rheumatoid arthritis were entered into a prospective study over fifteen years. Of these, 151 remained in the study at three years (of whom 14 died), and a further 39 (23 deaths) defaulted after this time. The severity of disease was assessed by four different methods. Although persistently active joint disease was recorded in 26% of patients, only 13% had severe functional impairment, and only 14% developed severe erosions. An episode of RA lasting two to three years followed by complete remission with none or minimal sequelae ("non recurrent" RA) was present in 34%. Using discriminant analysis, which selected rheumatoid factor, haemoglobin level and platelet count from a number of clinical and laboratory variables measured at onset, it was possible to predict three mutually exclusive outcome categories correctly in 50-60% of patients depending on the method of assessment of outcome.

Adolescent↗

The longitudinal arch. A survey of eight hundred and eighty-two feet in normal children and adults.

Both feet of 441 normal subjects, who ranged in age from one to eighty years, were studied to document the configuration of the longitudinal arch. The findings showed that flat feet are usual in infants, common in children, and within the normal range of the observations made in adult feet. Documentation and observation is the recommended management of the flexible flat foot that falls within the normal range.

Adolescent↗

HLA and rheumatoid arthritis: a combined analysis of 440 British patients.

Four hundred and forty unrelated British Caucasoid patients with rheumatoid arthritis (RA) have been HLA typed for class I and class II antigens. Analyses of HLA antigen associations were performed on the overall group and in patient subsets selected according to particular disease parameters or sex, or both. The results confirm previously reported positive associations of HLA-DR4, Dw4, and DRw53 and negative associations of HLA-DR2 and DR7 with RA. Patients subsets with severe erosions, seropositivity, and features of extra-articular disease showed a stronger association, also confirming earlier reports. The link between HLA and disease severity was emphasised by a significant trend of increased Dw4 frequency with increasing severity of radiological erosions. In addition, a positive association of RA with HLA-A2 was observed and a strong negative association with DR3. The frequency of HLA-B27 was significantly increased in patients with subluxation of the spine. Differences were observed between male and female patients in relation to the HLA association. In men an increase in the frequency of the haplotype HLA/Dw4/DR4/Bw62/Cw3/A2 was observed. This showed no relationship with parameters of disease severity other than extra-articular disease. In women only class II antigens (DRw53/Dw4/DR4) showed an increased frequency. This increase was strongly associated with disease severity. A significant decrease of this class II association was observed with increasing age of disease onset; this was not seen in men.

Adolescent↗

HLA antigen associations with radiological changes in the hands, feet, and cervical spines in early rheumatoid arthritis.

Clinical, laboratory, and genetic features measured at the onset of rheumatoid arthritis in 100 patients were compared with the severity of radiological changes in the hands and feet and in the cervical spines at a mean of 7.7 years. HLA-Dw4 was associated with more severe (p = 0.009) and HLA-Dw2 with less severe (p = 0.02)radiological changes in the hands and feet but the single strongest correlation with the severity of peripheral erosions was rheumatoid factor (p = less than 0.0001). Although none of the standard clinical or laboratory parameters correlated with severity of cervical spine changes, the presence of HLA-Dw2 and/or HLA B7 cross-reactive group were associated with more severe radiological changes in the cervical spine (p less than 0.02). Discriminant analysis selected certain standard laboratory parameters which in combination provided the most powerful prognostic index of radiological outcome in the hands and feet which was correct in 82 per cent. The addition of HLA data did not improve this figure. Conversely, the combination of the presence of HLA-Dw2, B27, and older age of onset of disease was found to be the most powerful predictor of the development of cervical spine changes and successfully predicted this complication of RA in 73 per cent.

Adult↗

HLA frequency and haplotype analysis in a family study of adult onset rheumatoid arthritis.

Twenty-five families with probands who have rheumatoid arthritis (RA) were studied for clinical evidence of disease and for HLA status. This confirmed an association between RA and DR4 in 19/25 probands (76 per cent, p = 0.008). These 19 probands carried 24 haplotypes which contained DR4. There was no significant increase of DR4 haplotypes bearing B15(Bw62) or B44 when compared with published control haplotype data. The rare complement allele C4 B3 was detected as part of the extended haplotype A2 Cw3 B15(Bw62) DR4 C4 A*3B*3 in three probands with severe RA. Further studies to examine disease severity and autoantibody expression are in progress.

Arthritis, Rheumatoid↗

Antibodies to proteus in rheumatoid arthritis.

Antibodies to proteus species were measured in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) and in healthy controls by a Coombs agglutination method. The titres to Proteus mirabilis were higher in 30 RA patients being treated with gold than in 24 patients with active AS (p less than 0.001), 28 patients with inactive AS (p less than 0.001), and 41 healthy control subjects (p less than 0.001). Control studies with Klebsiella pneumoniae var oxytoca showed high antibody titres only in active AS patients.

Adult↗

Reproducibility of multiple-observer scoring of radiologic abnormalities in the hands and wrists of patients with rheumatoid arthritis.

Forty-one coded radiographic films from 16 patients with rheumatoid arthritis were read by 13 observers, using 4 different methods for scoring abnormalities. Although absolute scores differed widely among individual observers, correlation coefficients were greater than 0.850 for approximately 2 of 3 comparisons. When films were ranked, using the median rank of all readers, 72% of individual ranks were within 10% of the median ranks. Among serial films on individual patients, 92% of comparisons between early and late films were interpreted as demonstrating progression of abnormalities when mean standardized scores showed an increase in scores of 15 units or greater. Films with lesser changes were interpreted inconsistently. This study shows good general agreement among readers in scoring radiologic abnormalities of hands and wrists, when applied to a film set showing a broad spectrum of severity, and defines the sensitivity of radiologic detection of disease progression.

Adult↗

How many joints in the hands and wrists should be included in a score of radiologic abnormalities used to assess rheumatoid arthritis?

Numerous methods for reading abnormalities of rheumatoid arthritis in hand and wrist radiographs have been proposed over the past several decades. There are many differences among these methods, one of the more striking of which is the variation in the number of joints that are scored. In this study, we tested the number of joints that need to be read in order to represent abnormalities accurately and reproducibly, using the scores of multiple observers. Thirteen rheumatologists and radiologists each read a set of 41 hand and wrist films from patients with rheumatoid arthritis. Ten of 13 readers scored 27 joints in each hand and wrist; the other 3 readers scored fewer areas. Fourteen combinations of joints were selected based on the frequency of involvement and the technical adequacy of routine films in assessing a given area. After testing these 14 different combinations, 1 scheme, which included 17 areas read for erosions and 18 areas read for joint space narrowing, was tested further. The correlation coefficients for 10 intraobserver scores derived from this modified scheme compared with the original scores were between 0.981 and 0.997. Seventy-one of 78 interobserver comparisons were better using the new scheme than using the original scheme. These data indicate that the simplified scheme, using a combination of 17 joints to score erosions and 18 to score joint space narrowing, more accurately reflects the extent of abnormalities perceived by a panel of experts than does the original scheme. This abbreviated number of joints shortens the amount of time required to read a set of films and simplifies the scoring of films, since a number of areas that are difficult to read are eliminated from radiographic assessment.

Arthritis, Rheumatoid↗

Lower-extremity rotational problems in children. Normal values to guide management.

We studied 1,000 normal lower extremities of children and adults in order to establish normal values for the rotational profile. The intrauterine position of the fetus molds the femur by rotating it laterally and molds the tibia by rotating it medially. These molding effects usually resolve spontaneously during infancy, and then genetically determined individual differences are unmasked. Rotational problems should be clinically evaluated and the findings compared with the normal values provided by this study. Out-toeing in infants, medial tibial torsion in toddlers, and medial femoral torsion in young children are extremes of a normal developmental pattern. In the vast majority, these rotational variations fall within the broad range of normal and require no treatment.

Adolescent↗

Quantitative evaluation of the dermal vasculature of diabetics.

The dermal microvasculature has been compared in 51 diabetics and 51 matched non-diabetic controls using tissue measurement techniques and functional assessments of blood vessel reactivity. Blood vessel walls were thicker in different groups of diabetics than the controls (p less than 0.01) but the degree of thickness did not differ between patients with insulin-dependent diabetes mellitus and those with non-insulin-dependent diabetes mellitus or between diabetics with and without vascular complications. Vascular lumina were narrower in diabetics than in controls (p less than 0.01) and diabetics with vascular complications had a greater reduction in luminal area than those without such complications (p less than 0.001) but the luminal area did not differ between the insulin-dependent and the non-insulin-dependent groups. The luminal perimeter was also reduced in the diabetic group compared to controls. The weal and flare response to intracutaneous histamine acid phosphate (50 micrograms) was markedly decreased (p less than 0.001) in diabetic subjects compared with controls, as was the response to a topically applied vasodilator (Transvasin). The degree of reduction did not differ between patients with insulin-dependent diabetes mellitus and those with the non-insulin-dependent disease but diabetics with vascular complications show impaired responses as compared to those without. The maximum increase in skin temperature on the volar surface of the right middle finger during a period of reactive hyperaemia following 3 min of cuff-induced ischaemia was also markedly decreased in diabetics compared with control subjects. It did not differ between those with insulin-dependent diabetes mellitus and those with the non-insulin-dependent disease but did between diabetics with vascular complications as compared with those without. This study confirms that the cutaneous vasculature of diabetics differs markedly from that of matched control subjects. The results also indicate that there are significant differences between diabetics with vascular complications and those without. The quantitative approaches adopted may have predictive value.

Adult↗

Association of HLA-DR4/Dw4 and DR2/Dw2 with radiologic changes in a prospective study of patients with rheumatoid arthritis. Preferential relationship with HLA-Dw rather than HLA-DR specificities.

Patients admitted to a prospective study within a year of onset of suspected rheumatoid arthritis showed a positive correlation between HLA-Dw4 and the eventual severity of peripheral radiologic changes. Dw4 and DR4 were strongly associated with severity of erosions when analysis was restricted to each of the following: patients with erosions, those under 50 at onset, and all females. Relationships were consistently stronger with Dw4 than with DR4. Another D-related specificity, MT3, was positively correlated and Dw2/DR2 negatively correlated with erosions.

Age Factors↗