Model building of disulfide bonds in proteins with known three-dimensional structure

As an aid in the selection of sites in a protein where a disulfide bond might be engineered, a computer program has been developed. The algorithm starts with the generation of Cβ positions from the N, Cα and C atom coordinates available from a three-dimensional model. A first set of residue pairs that might form a disulfide bond is selected on the basis of Cβ-Cβ distances between residues. Then, for each residue in this set, Sγ positions are generated, which satisfy the requirement that, with ideal values for the Cα-Cβ and Cβ-Sγ bond lengths and for the bond angle at Cβ, the distance between Sγ of residue 1 and Cβ of residue 2 in a pair (determined by the bond angle at Sγ2) is at, or very close to its ideal value. Usually two acceptable Sγ positions are found for each half cystine, resulting in up to four different conformations for the disulfide bond. Finally, these conformations are subjected to an energy minimization procedure to remove large deviations from ideal geometry and their final energies are calculated. User input determines which final conformations are energetically acceptable. These conformations are written to a file to allow further analysis and e.g. inspection on a computer graphics device

The IMPACT study: A clustered randomized controlled trial to assess the effect of a referral algorithm for axial spondyloarthritis

BACKGROUND: A substantial number of patients with chronic low back pain (CLBP) have axial spondyloarthritis (axSpA), but early recognition of these patients is difficult for general practitioners (GPs). The Case Finding Axial Spondyloarthritis (CaFaSpA) referral strategy has shown to be able to identify patients with CLBP at risk for axSpA, but its impact on clinical daily practice is yet unknown. OBJECTIVE: To assess the effect of the CaFaSpA referral strategy on pain caused by disability in primary care patients with CLBP. METHODS: Within this clustered randomized controlled trial 93 general practices were randomized to either the CaFaSpA referral model (intervention) or usual primary care (control). In each group primary care patients between 18 and 45 years with CLBP were included. The primary outcome was disability caused by CLBP, measured with the Roland Morris Disability Questionnaire (RMDQ) at baseline and four months. Secondary outcome was the frequency of new axSpA diagnosis. Descriptive analyses were performed, and a linear mixed-effects model was used. RESULTS: In total 679 CLBP patients were included of which 333 patients were allocated to the intervention group and 346 to the control group. Sixty-four percent were female and mean age was 36.2 years. The mean RMDQ score at baseline was 8.39 in the intervention group and 8.61 in the control group. At four months mean RMDQ score was 7.65 in the intervention group and 8.15 in the control group. This difference was not statistically significant (p = 0.50). Six (8%) out of the 75 finally referred patients, were diagnosed with axSpA by their rheumatologist. CONCLUSIONS: The CaFaSpA referral strategy for axSpA did not have an effect on disability after four months caused by CLBP. However, the strategy is able to detect the axSpA patient within the large CLBP population sufficiently. Trial registration number: NCT01944163, Clinicaltrials.gov

The IMPACT study:A clustered randomized controlled trial to assess the effect of a referral algorithm for axial spondyloarthritis

Background A substantial number of patients with chronic low back pain (CLBP) have axial spondyloarthritis (axSpA), but early recognition of these patients is difficult for general practitioners (GPs). The Case Finding Axial Spondyloarthritis (CaFaSpA) referral strategy has shown to be able to identify patients with CLBP at risk for axSpA, but its impact on clinical daily practice is yet unknown. Objective To assess the effect of the CaFaSpA referral strategy on pain caused by disability in primary care patients with CLBP. Methods Within this clustered randomized controlled trial 93 general practices were randomized to either the CaFaSpA referral model (intervention) or usual primary care (control). In each group primary care patients between 18 and 45 years with CLBP were included. The primary outcome was disability caused by CLBP, measured with the Roland Morris Disability Questionnaire (RMDQ) at baseline and four months. Secondary outcome was the frequency of new axSpA diagnosis. Descriptive analyses were performed, and a linear mixed-effects model was used. Results In total 679 CLBP patients were included of which 333 patients were allocated to the intervention group and 346 to the control group. Sixty-four percent were female and mean age was 36.2 years. The mean RMDQ score at baseline was 8.39 in the intervention group and 8.61 in the control group. At four months mean RMDQ score was 7.65 in the intervention group and 8.15 in the control group. This difference was not statistically significant (p = 0.50). Six (8%) out of the 75 finally referred patients, were diagnosed with axSpA by their rheumatologist. Conclusions The CaFaSpA referral strategy for axSpA did not have an effect on disability after four months caused by CLBP. However, the strategy is able to detect the axSpA patient within the large CLBP population sufficiently

Non-adherence to disease-modifying antirheumatic drugs is associated with higher disease activity in early arthritis patients in the first year of the disease

Introduction: Non-adherence to disease-modifying antirheumatic drugs (DMARDs) hampers the targets of rheumatoid arthritis (RA) treatment, obtaining low disease activity and decreasing radiological progression. This study investigates if, and to what extent, non-adherence to treatment would lead to a higher 28-

X-ray crystallographic studies on structure and fucntion of hemocyanins.

Hemocyanin is the oxygen transport pigment in many arthropods and molluscs. In this respect, hemocyanin has the same function as hemoglobin has in many other organisms. This functional homology has resulted in the development of a number of special properties in both protein classes, e.g. cooperative oxygen binding, regulation by several allosteric effectors and the aggegation into muli-meric complexes. However, the molecular basis by which hemocyanins and hemoglobins achieve these properties is completely different. ... Zie: Summary