Immunohistochemical analysis of structural changes in collagen for the assessment of osteoarthritis.

Collagen fibrillation within articular cartilage (AC) plays a key role in joint osteoarthritis (OA) progression and, therefore, studying collagen synthesis changes could be an indicator for use in the assessment of OA. Various staining techniques have been developed and used to determine the collagen network transformation under microscopy. However, because collagen and proteoglycan coexist and have the same index of refraction, conventional methods for specific visualization of collagen tissue is difficult. This study aimed to develop an advanced staining technique to distinguish collagen from proteoglycan and to determine its evolution in relation to OA progression using optical and laser scanning confocal microscopy (LSCM). A number of AC samples were obtained from sheep joints, including both healthy and abnormal joints with OA grades 1 to 3. The samples were stained using two different trichrome methods and immunohistochemistry (IHC) to stain both colourimetrically and with fluorescence. Using optical microscopy and LSCM, the present authors demonstrated that the IHC technique stains collagens only, allowing the collagen network to be separated and directly investigated. Fluorescently-stained IHC samples were also subjected to LSCM to obtain three-dimensional images of the collagen fibres. Changes in the collagen fibres were then correlated with the grade of OA in tissue. This study is the first to successfully utilize the IHC staining technique in conjunction with laser scanning confocal microscopy. This is a valuable tool for assessing changes to articular cartilage in OA.

Consumer views on the potential use of mobile phones for the delivery of weight-loss interventions.

BACKGROUND: The surge in the incidence of obesity and being overweight demands new options to extend the reach of weight-loss interventions. Mobile phones provide a medium for reaching large numbers of people in a cost-effective manner. The present study aimed to explore the potential for weight-loss interventions to be delivered via mobile phone. METHODS: A mixed methods approach was employed. A telephone survey was conducted with 306 randomly selected participants, and 10 focus groups were undertaken with 54 purposively selected participants. The telephone survey comprised questions exploring the nature and acceptability of any potential weight-loss programme that might be delivered via mobile phones. The focus groups were conducted to explore issues of acceptability in more depth than was possible in the survey. RESULTS: Two-thirds of participants reported support for a mobile phone weight-loss intervention, with greater levels of support amongst younger age groups and rural Maori (the indigenous population in New Zealand). Participants liked the idea of ready access to weight-loss information, and associated feedback and encouragement. The results suggest that interventions would need to include aspects of social support, use tailored and personalised content, and be practical and relevant so that they appeal to consumers. Appropriate methods of providing social support using a mobile phone require further exploration. CONCLUSIONS: Mobile phones may provide a novel but acceptable way to deliver a weight-loss intervention. They have the potential to be automatically personalised and tailored to the needs of the individual, at the same time as being delivered at a population level.

An alternative technique for the induction of autoimmune valvulitis in a rat model of rheumatic heart disease.

We currently use a rat model in our investigations into human rheumatic heart disease (RHD). This model traditionally involves footpad immunization with antigen emulsified in complete Freund's adjuvant (CFA). Trials to find an alternative adjuvant to CFA which produced a Th1 type response in the rats resulting in carditis were unsuccessful. However, hock immunization was found to produce the desired valvular pathology without the adverse inflammatory side-effects associated with CFA. We therefore consider the hock an ideal site for immunization, particularly when using CFA.

Subtle hydrophobic interactions between the seventh residue of the zinc finger loop and the first base of an HGATAR sequence determine promoter-specific recognition by the Aspergillus nidulans GATA factor AreA.

A change of a universally conserved leucine to valine in the DNA-binding domain of the GATA factor AreA results in inability to activate some AreA-dependent promoters, including that of the uapA gene encoding a specific urate-xanthine permease. Some other AreA-dependent promoters become able to function more efficiently than in the wild-type context. A methionine in the same position results in a less extreme, but opposite effect. Suppressors of the AreA(Val) mutation mapping in the uapA promoter show that the nature of the base in the first position of an HGATAR (where H stands for A, T or C) sequence determines the relative affinity of the promoter for the wild-type and mutant forms of AreA. In vitro binding studies of wild-type and mutant AreA proteins are completely consistent with the phenotypes in vivo. Molecular models of the wild-type and mutant AreA-DNA complexes derived from the atomic coordinates of the GATA-1-AGATAA complex account both for the phenotypes observed in vivo and the binding differences observed in vitro. Our work extends the consensus of physiologically relevant binding sites from WGATAR to HGATAR, and provides a rationale for the almost universal evolutionary conservation of leucine at the seventh position of the Zn finger of GATA factors. This work shows inter alia that the sequence CGATAGagAGATAA, comprising two almost adjacent AreA-binding sites, is sufficient to ensure activation of transcription of the uapA gene.