Although fatigue has been implicated in cartilage failure, there are only two published studies in this area, by the same author. However, in these previous studies cartilage was tested in the direction parallel to that of collagen orientation in the superficial layer, where it possesses greater tensile strength. In the present work, articular cartilage was also tested along the direction perpendicular to that of the collagen. Furthermore, the study investigated topographic and zonal variations in the fatigue behaviour of cartilage from the human knee.

Therapeutic ultrasound is one of the most common treatments used in the management of soft tissue lesions, which constitute the majority of rheumatic complaints. Although many laboratory-based research studies have demonstrated a number of physiological effects of ultrasound upon living tissue, there is remarkably little evidence for benefit in the treatment of soft tissue injuries. This may be related to several confounding factors, including technical variables, the complexity and variety of underlying pathologies in soft tissue lesions, methodological limitations of clinical studies, or true lack of effect. In this review the scientific basis for the use of therapeutic ultrasound in soft tissue lesions and the existing evidence relating to its clinical effect are detailed.

We have studied immune reconstitution in a patient with paediatric-onset polyarteritis nodosa treated with high-dose immunosuppressive agents followed by stem cell rescue. The patient developed several new autoimmune phenomena over the 18 months after immunosuppression and stem cell rescue. Flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR) heteroduplex and isotype-specific RT-PCR analysis of immunoglobulin expression showed that the T- and B-cell repertoires were highly restricted in the first few months after treatment. The dominant T-cell clones seen after reconstitution were persistently expanded, were different from those which could be demonstrated before autologous stem cell transplantation, and were in the CD8(+) population. Our data also show that 12 months after treatment these expanded T-cell clones were within the CD45RA(+) population, suggesting that reversion from the CD45RO(+) to the CD45RA(+) phenotype had occurred in vivo.

Central nervous system (CNS) complications are rarely reported in either juvenile or adult onset inflammatory myositides, such as dermatomyositis and polymyositis. We report two children, aged 4 and 10 yr respectively, with a diagnosis of juvenile dermatomyositis, both of whom subsequently developed clinical features of severe CNS involvement, possibly consistent with cerebral vasculopathy. One child died from apparent brainstem involvement; the other developed seizures, pseudoseizures and clinical depression which responded to aggressive immunosuppression. Although the vasculopathy or vasculitis underlying this disorder is known to have a systemic distribution, CNS involvement has rarely been reported and may be under-recognized.

The reactive haemophagocytic syndrome (RHS) is a little-known life-threatening complication of rheumatic diseases in children. It reflects the extreme vulnerability of these patients, especially those with systemic-onset juvenile chronic arthritis (JCA). This immunohaematological process may be triggered by events such as herpes virus infection and non-steroidal anti-inflammatory drug therapy. Treatment has not been standardized.

Fetal cells have been demonstrated in the active lesions of adult women with systemic sclerosis. Because the juvenile idiopathic inflammatory myopathies (JIIM) share clinical and histopathological features with systemic sclerosis and graft-vs-host disease, we explored the possibility that maternal cells persist and play a role in the pathogenesis of JIIM.

Juvenile idiopathic arthritis (JIA) can affect a child's performance across a range of activities necessary to normal childhood development. Although there are now several available measures of disability in JIA, none have been validated for use with children in the UK. Consequently, a study was undertaken to compare and validate four such measures, together with a locally developed function test.

In order to develop a preliminary core set of disease outcome measures for use in clinical trials of idiopathic inflammatory myopathies (IIM), we evaluated those measures used in previous trials, assessed the validation of published instruments and discussed these at an international consensus conference. The initial proposals were further refined by a multidisciplinary group of adult and paediatric specialists experienced in IIM using the Delphi method. The proposed preliminary core set of disease activity measures consists of five domains: physician and patient/parent global assessments of disease activity; muscle strength; physical function; serum activity of muscle enzymes; and an assessment tool to capture extra-skeletal muscle disease activity. The group recommended further development of a core set of disease damage measures for assessment of persistent changes in anatomy, pathology and function of at least 6 months' duration. The group recommended that patient-reported outcomes should include generic health-related quality of life assessments using the Medical Outcomes Study 36-item Short Form (SF-36) health survey in adult IIM patients and a validated quality of life instrument for paediatric patients. We propose the core set of outcome measures as a minimum group of assessments to include in all IIM therapeutic studies. The use of this core set should assist in standardizing outcome measurement and in optimizing therapeutic trials in myositis.

To estimate the occurrence of peripheral arthritis (PA) 6 yr after diagnosis of inflammatory bowel disease (IBD).