May spa therapy be a valid opportunity to treat hand osteoarthritis? A review of clinical trials and mechanisms of action.

Osteoarthritis (OA) is the most common form of arthritis and its current treatment includes non-pharmacological and pharmacological modalities. Spa therapy represents a popular treatment for many rheumatic diseases. The aim of this review was to summarize the currently available information on clinical effects and mechanisms of action of spa therapy in OA of the hand. We conducted a search of the literature to extract articles describing randomized clinical trials (RCTs) in hand OA published in the period 1952-2015. We identified three assessable articles reporting RCTs on spa therapy in hand OA. Data from these clinical trials support a beneficial effect of spa therapy on pain, function and quality of life in hand OA. Spa therapy seems to have a role in the treatment of hand OA. However, additional RCTs are necessary to clarify the mechanisms of action and the effects of the application of thermal treatments.

Role of gamma carboxylated Glu47 in connexin 26 hemichannel regulation by extracellular Ca²âº: insight from a local quantum chemistry study.

Connexin hemichannels are regulated by several gating mechanisms, some of which depend critically on the extracellular Ca(2+) concentration ([Ca(2+)]e). It is well established that hemichannel activity is inhibited at normal (∼1 mM) [Ca(2+)]e, whereas lowering [Ca(2+)]e to micromolar levels fosters hemichannel opening. Atomic force microscopy imaging shows significant and reversible changes of pore diameter at the extracellular mouth of Cx26 hemichannels exposed to different [Ca(2+)]e, however, the underlying molecular mechanisms are not fully elucidated. Analysis of the crystal structure of connexin 26 (Cx26) gap junction channels, corroborated by molecular dynamics (MD) simulations, suggests that several negatively charged amino acids create a favorable environment for low-affinity Ca(2+) binding within the extracellular vestibule of the Cx26 hemichannel. In particular a highly conserved glutammic acid, found in position 47 in most connexins, is thought to undergo post translational gamma carboxylation (γGlu47), and is thus likely to play an important role in Ca(2+) coordination. γGlu47 may also form salt bridges with two conserved arginines (Arg75 and Arg184 in Cx26), which are considered important in stabilizing the structure of the extracellular region. Using a combination of quantum chemistry methods, we analyzed the interaction between γGlu47, Arg75 and Arg184 in a Cx26 hemichannel model both in the absence and in the presence of Ca(2+). We show that Ca(2+) imparts significant local structural changes and speculate that these modifications may alter the structure of the extracellular loops in Cx26, and may thus account for the mechanism of hemichannel closure in the presence of mM [Ca(2+)]e.

Short- and long-term effects of mud-bath treatment on hand osteoarthritis: a randomized clinical trial.

The aim of this study was to evaluate both the short-term and the long-term effectiveness of spa therapy in patients with primary hand osteoarthritis (OA). This was a prospective randomized, single blind controlled trial. Sixty outpatients with primary bilateral hand OA were included in the study and randomized to one of two groups. One group (n = 30) was treated with 12 daily local mud packs and generalized thermal baths with a sulfate-calcium-magnesium-fluorides mineral water added to usual treatment. The control group (n = 30) continued regular outpatient care routine (exercise, NSAIDs and/or analgesics). Each patient was examined at baseline, after 2 weeks, and after 3, 6, 9 and 12 months. Primary outcome measures were global spontaneous hand pain on a visual analogue scale (VAS) and the functional index for hand osteoarthritis (FIHOA) score; secondary outcomes were health assessment questionnaire (HAQ), duration of morning stiffness, medical outcomes study 36-item short form (SF-36) and symptomatic drugs consumption. Our results demonstrated that the efficacy of spa therapy was significant in all the assessed parameters, both at the end of therapy and after 3 months; the values of FIHOA, HAQ and drugs consumption continued to be significantly better after 6 months in comparison with baseline. There were no significant modifications of the parameters throughout the follow-up in the control group. Differences between the two groups were significant for all parameters at the 15th day and at 3 months follow-up; regarding FIHOA, HAQ, and symptomatic drugs consumption, the difference between the two groups persisted and was significant at 6month follow-up. Tolerability of spa therapy seemed to be good. In conclusion, our results confirm that the beneficial effects of spa therapy in patients with hand OA last over time.