Low prevalence of subclinical synovitis in patients with juvenile idiopathic arthritis (JIA) in long-term clinical remission on medication

Subclinical synovitis is highly prevalent in patients with JIA in clinical remission (CR) with a short duration. The objective was to evaluate its prevalence by ultrasound (US) in patients with JIA in long CR during a one-year follow-up. In this prospective and longitudinal study, we included 76 patients with JIA according to ILAR with CR by the Wallace modified criteria and JADAS27 and compared them with 22 patients with active disease. Clinical and demographic characteristics were recorded. US evaluation was by 10-joint count. Differences in US evaluations were analyzed by the Mann-Whitney U test. There were no differences among the two group with regard to disease duration at enrollment, and age (p = 0.540 and p = 0.080, respectively), but JADAS 27, CHAQ, and acute phase reactants were significantly higher (p < 0.001) in the clinically active group. The prevalence of subclinical synovitis at baseline and the end of the study in the CR group was 18.4% and 11.8%, respectively, while it was 100% and 40.9% in the active disease group. Subclinical synovitis at baseline was significantly more prevalent in the clinically active group (elbow, p = 0.01; wrist, p = 0.001; MCP 2, p = 0.001; knee, p = 0.001 and ankle p = 0.001; and PD only in the ankle, p = 0.002). The concordance of inter-reader reliability in all evaluated joints was excellent (p = 0.001). Although the prevalence of subclinical synovitis is low in patients with JIA with long-term clinical remission on medication, a percentage of patients continue to have subclinical involvement that could predict the risk of relapse and structural damage. Key Points • Subclinical synovitis is less prevalent in JIA in long-term clinical remission compared to patients in short-term remission. • The persistence of imaging signs of inflammation in a significant percentage of patients may indicate the need for ongoing medication.

Hydrochemical characterization of a mine water geothermal energy resource in NW Spain

Abandoned and flooded mine networks provide underground reservoirs of mine water that can be used as a renewable geothermal energy source. A complete hydrochemical characterization of mine water is required to optimally design the geothermal installation, understand the hydraulic behavior of the water in the reservoir and prevent undesired effects such as pipe clogging via mineral precipitation. Water pumped from the Barredo-Figaredo mining reservoir (Asturias, NW Spain), which is currently exploited for geothermal use, has been studied and compared to water from a separate, nearby mountain mine and a river that receives mine water discharge and partially infiltrates into the mine workings. Although the hydrochemistry was altered during the flooding process, the deep mine waters are currently near neutral, net alkaline, high metal waters of Na-HCO₃ type. Isotopic values suggest that mine waters are closely related to modern meteoric water, and likely correspond to rapid infiltration. Suspended and dissolved solids, and particularly iron content, of mine water results in some scaling and partial clogging of heat exchangers, but water temperature is stable (22°C) and increases with depth, so, considering the available flow (>100Ls^-1), the Barredo-Figaredo mining reservoir represents a sustainable, long-term resource for geothermal use.

Prediction of the flooding of a mining reservoir in NW Spain

Abandoned and flooded mines constitute underground reservoirs which must be managed. When pumping is stopped in a closed mine, the process of flooding should be anticipated in order to avoid environmentally undesirable or unexpected mine water discharges at the surface, particularly in populated areas. The Candín-Fondón mining reservoir in Asturias (NW Spain) has an estimated void volume of 8 million m³ and some urban areas are susceptible to be flooded if the water is freely released from the lowest mine adit/pithead. A conceptual model of this reservoir was undertaken and the flooding process was numerically modelled in order to estimate the time that the flooding would take. Additionally, the maximum safe height for the filling of the reservoir is discussed.

Immunopathology of polymorphous light eruption. T lymphocytes in blood and skin

Polymorphous light eruption (PLE; actinic prurigo) is a relatively common dermatologic disease. People suffering from it have a pruritic skin eruption on exposed areas. PLE may be an immunologically mediated disease. Sixteen patients with PLE were studied. T lymphocytes and the helper and suppressor-cytotoxic subsets were assessed in peripheral blood by an indirect immunofluorescent method with the use of monoclonal antibodies. Total T lymphocytes were significantly increased as compared to controls. By an indirect immunoperoxidase technic with the use of monoclonal antibodies, characterization of the dermal cell infiltrate was done. Predominance of T total, T helper, and cells marked with Ia antigen were found. These findings suggest that an abnormal immune response is responsible for the tissue damage in PLE.