Loss of immune tolerance to IL-2 in type 1 diabetes

Type 1 diabetes (T1D) is characterized by a chronic, progressive autoimmune attack against pancreas-specific antigens, effecting the destruction of insulin-producing β-cells. Here we show interleukin-2 (IL-2) is a non-pancreatic autoimmune target in T1D. Anti-IL-2 autoantibodies, as well as T cells specific for a single orthologous epitope of IL-2, are present in the peripheral blood of non-obese diabetic (NOD) mice and patients with T1D. In NOD mice, the generation of anti-IL-2 autoantibodies is genetically determined and their titre increases with age and disease onset. In T1D patients, circulating IgG memory B cells specific for IL-2 or insulin are present at similar frequencies. Anti-IL-2 autoantibodies cloned from T1D patients demonstrate clonality, a high degree of somatic hypermutation and nanomolar affinities, indicating a germinal centre origin and underscoring the synergy between cognate autoreactive T and B cells leading to defective immune tolerance.

Type 1 diabetes is driven by T-cell autoimmunity to pancreatic islet cells. Here the authors show that autoreactive anti-IL-2 T and B cells are present in type 1 diabetes patients, and that anti-IL-2 antibodies precede diabetes onset in mice, suggesting their potential as a diagnostic marker.

Trials in primary care: statistical issues in the design, conduct and evaluation of complex interventions

Trials carried out in primary care typically involve complex interventions that require considerable planning if they are to be implemented successfully. The role of the statistician in promoting both robust study design and appropriate statistical analysis is an important contribution to a multi-disciplinary primary care research group. Issues in the design of complex interventions have been addressed in the Medical Research Council's new guidance document and over the past 7 years by the Royal Statistical Society's Primary Health Care Study Group. With the aim of raising the profile of statistics and building research capability in this area, particularly with respect to methodological issues, the study group meetings have covered a wide range of topics that have been of interest to statisticians and non-statisticians alike. The aim of this article is to provide an overview of the statistical issues that have arisen over the years related to the design and evaluation of trials in primary care, to provide useful examples and references for further study and ultimately to promote good practice in the conduct of complex interventions carried out in primary care and other health care settings. Throughout we have given particular emphasis to statistical issues related to the design of cluster randomised trials.

An interference technique for the measurement of in-plane displacements of opaque surfaces

A laser interferometer system is used to record two mutually perpendicular diffraction gratings on a photoresist coated specimen. When either grating is re-illuminated by the fringe pattern used to form it, real-time observations can be made of moiré fringes corresponding to surface displacements which occur as a tensile load is applied to the specimen. The technique has been used to study the in-plane deformations of carbon-fibre composites, and typical results are given.

The Ilizarov procedure: limb lengthening and its implications

The purpose of this article is to provide a historical and clinical perspective on the Ilizarov method of external fixation for limb lengthening and deformity correction of the lower extremity. Though relatively new in the United States, the technique has been applied for orthopedic problems with great success for over three decades in Russia and Europe. Physical therapy management is discussed from the preoperative planning phase to removal of the apparatus.