Review for the generalist: evaluation of pediatric hip pain

Hip pathology may cause groin pain, referred thigh or knee pain, refusal to bear weight or altered gait in the absence of pain. A young child with an irritable hip poses a diagnostic challenge. Transient synovitis, one of the most common causes of hip pain in children, must be differentiated from septic arthritis. Hip pain may be caused by conditions unique to the growing pediatric skeleton including Perthes disease, slipped capital femoral epiphysis and apophyseal avulsion fractures of the pelvis. Hip pain may also be referred from low back or pelvic pathology. Evaluation and management requires a thorough history and physical exam, and understanding of the pediatric skeleton. This article will review common causes of hip and pelvic musculoskeletal pain in the pediatric population

Cooperation of local motions in the Hsp90 molecular chaperone ATPase mechanism

The Hsp90 chaperone is a central node of protein homeostasis activating a large number of diverse client proteins. Hsp90 functions as a molecular clamp that closes and opens in response to the binding and hydrolysis of ATP. Crystallographic studies define distinct conformational states of the mechanistic core implying structural changes that have not yet been observed in solution. Here, we engineered one-nanometer fluorescence probes based on photo-induced electron transfer into yeast Hsp90 to observe these motions. We found that the ATPase activity of the chaperone was reflected in the kinetics of specific structural rearrangements at remote positions that acted cooperatively. Nanosecond single-molecule fluorescence fluctuation analysis uncovered that critical structural elements that undergo rearrangement are mobile on a sub-millisecond time scale. We identified a two-step mechanism for lid closure over the nucleotide-binding pocket. The activating co-chaperone Aha1 mobilizes the lid of apo Hsp90, suggesting an early role in the catalytic cycle

Hsps are up-regulated in melanoma tissue and correlate with patient clinical parameters

Heat shock proteins (hsps) have been studied in numerous cancer types, but a clear view of their clinical relevance in melanoma remains elusive. Therefore, the aim of this study was to investigate the expression of hsps in melanoma with respect to patient clinical parameters. Using Western immunoblotting, hsps 90, 70, 60, 40 and 32 were observed to be widely expressed in metastatic melanomas (n = 31), while immunofluorescence demonstrated that in the majority of samples these hsps, apart from hsp32, were increased in expression in melanoma cells compared with surrounding non-melanoma cells in situ (n = 8). Correlating hsp expression with patient clinical parameters indicated that greater hsp90 (P < 0.02) and hsp40 (P < 0.03) expression correlated with advanced stage (stage III Vs stage IV), while in the case of hsp40, this was additionally associated with reduced patient survival (P < 0.05). In contrast, higher hsp32 expression was associated with improved patient survival (P < 0.007). On the other hand, the expression of the other hsps did not correlate with any obtainable patient clinical parameters. This study provides further evidence for the importance of hsps in melanoma and for their use as therapeutic targets and biomarkers, but larger-scale follow-up studies are required to confirm these results. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12192-012-0363-1) contains supplementary material, which is available to authorized users

Understanding of the Hsp90 molecular chaperone reaches new heights

Heat shock protein 90 (Hsp90) was the focus of a recent meeting in the Swiss Alps, where the Hsp90 community met to discuss the operation and functions of this ubiquitous and essential molecular chaperone