Summary of the OA biomarkers workshop 2010 – genetics and genomics: new targets in OA

SummaryOn November fourth and fifth 2010 a group of more than 100 international investigators gathered in Atlanta for the second Osteoarthritis (OA) Biomarkers Global Initiative workshop titled “Genetics and Genomics: New Targets in OA”. The first workshop took place in April 2009 and focused on in vitro (soluble) biomarkers whilst the third and final workshop will take place in 2012 and will focus on imaging biomarkers. The OA Research Society International (OARSI) has organized the workshops. In addition to OARSI, the National Institute of Arthritis, Musculoskeletal and Skin Diseases, the Arthritis Foundation, Amgen, Genzyme, the American Orthopaedic Society for Sports Medicine and Pfizer sponsored the second meeting. It was clear from this meeting that experiments in the genetics, epigenetics and genomics of OA, are yielding valuable insights into the etiology of this heterogeneous disease but that much still needs to be learnt. Combining genetic insights with conventional biomarkers and imaging modalities may provide scientists with the enhanced tools to understand this complex disease. With those tools in hand, clinicians and industry can develop protocols to ultimately improve patient care

Relationship of global assessment of change to AUSCAN and pinch and grip strength among individuals with hand osteoarthritis

SummaryObjectiveThis study assessed the utility and construct validity of a new patient global assessment of symptom change for hand osteoarthritis (OA) by examining its associations with change over time in grip strength, pinch strength, and AUStralian CANadian Osteoarthritis Hand Index (AUSCAN).MethodsParticipants (N=531, 80% female, mean age=68) were part of a study on the Genetics of Generalized Osteoarthritis (GOGO) and completed two assessments (average 4 years apart). At the second assessment, participants described change in their right and left hand pain, aching, and stiffness on a 15-point scale with descriptors ranging from “Great deal worse” to “Great deal better”. Linear regression models examined associations of global change scores with changes in hand strength and AUSCAN, controlling for age, gender, number of hand joints with OA, and time between assessments.ResultsBoth right and left hand global assessment of change scores were significantly associated with change in AUSCAN, grip strength, and right hand pinch strength (P<0.05), and approached significance for left hand pinch strength (P=0.06). The strongest associations were between global change scores and AUSCAN change (right hand: β=0.29, P<0.001; left hand: β=0.27, P<0.001). Associations of change scores with grip and pinch strength were stronger among participants with greater radiographic OA severity at baseline.ConclusionResults support the validity of this new global assessment of symptom change. This measure is particularly useful for assessing change over time when no baseline data are available. Additional research should examine this measure's responsiveness in the context of clinical trials

Pulse Shape Analysis with scintillating bolometers

Among the detectors used for rare event searches, such as neutrinoless Double Beta Decay (0$\nu$DBD) and Dark Matter experiments, bolometers are very promising because of their favorable properties (excellent energy resolution, high detector efficiency, a wide choice of different materials used as absorber, ...). However, up to now, the actual interesting possibility to identify the interacting particle, and thus to greatly reduce the background, can be fulfilled only with a double read-out (i.e. the simultaneous and independent read out of heat and scintillation light or heat and ionization). This double read-out could greatly complicate the assembly of a huge, multi-detector array, such as CUORE and EURECA. The possibility to recognize the interacting particle through the shape of the thermal pulse is then clearly a very interesting opportunity. While detailed analyses of the signal time development in purely thermal detectors have not produced so far interesting results, similar analyses on macro-bolometers ($\sim$10-500 g) built with scintillating crystals showed that it is possible to distinguish between an electron or $\gamma$-ray and an $\alpha$ particle interaction (i.e. the main source of background for 0$\nu$DBD experiments based on the bolometric technique). Results on pulse shape analysis of a CaMoO$_4$ crystal operated as bolometer is reported as an example. An explanation of this behavior, based on the energy partition in the heat and scintillation channels, is also presented.Comment: Presented at the 14th International Workshop on Low Temperature Detectors, proceedings to be published in the Journal of Low Temperature Physic

Optimization of the fixed-flexion knee radiograph

SummaryPurposeTo develop a user-friendly method of achieving optimal radiographs for measurement of joint space width of the knee with minimal radiation exposure. In order to accomplish this the X-ray technologist must (1) be able to identify the anterior and posterior rims of the tibial plateau at a variety of X-ray head angles and (2) be able to choose the direction to adjust the head angle to get a better view based on the criteria for acceptable radiographs.MethodsWe have developed a training manual and materials to instruct investigators and radiology technologists in a method that uses a commercially available Plexiglas positioning frame (Synaflexer™) and standard X-ray equipment to achieve optimal X-rays with regard to tibial plateau alignment of the knee. This should be accomplished with four or fewer radiographs.ResultsOptimized radiographs for joint space width measurements are achieved without the need for fluoroscopy or foot maps.ConclusionsThis method is readily understood and instituted by radiology technologists in the field