High Levels of Polypharmacy in Rheumatoid Arthritis-A Challenge Not Covered by Current Management Recommendations: Data From a Large Real-Life Study.

BACKGROUND: Rheumatoid arthritis (RA) is associated with high frequency of comorbidities and increased risk of polypharmacy. Although there is a great potential for complications, there is a gap in literature on polypharmacy in patients with rheumatic arthritis. OBJECTIVE: To evaluate the prevalence and factors associated with polypharmacy in a population in a real-life setting. METHODS: A cross-sectional multicenter study was conducted in Brazil. Patients underwent clinical evaluation and medical records analysis. Polypharmacy was considered as a dependent variable. To test independent variables, we used Poisson regression. RESULTS: We evaluated 792 patients (89% female, median age 56.6 years). Median duration of disease was 12.7 years, 78.73% had a positive rheumatoid factor. The median of disease activity score-28 was 3.5 (disease with mild activity), median of the clinical disease activity index score was 9, and median of health assessment questionnaire-disability index was 0.875; 47% used corticosteroids, 9.1% used nonsteroidal anti-inflammatory drugs, 90.9% used synthetic disease-modifying antirheumatic drugs, 35.7% used biologic disease-modifying antirheumatic drugs (DMARDs). In total, 537 (67.9%) patients used 5 or more drugs. Polypharmacy showed a relationship with a number of comorbidities and use of specific drugs (corticosteroids, methotrexate, and biological DMARDs). CONCLUSION: We found a high prevalence of polypharmacy (67.9%) in RA. Solutions to management this problem should be stimulated.

Multivariate statistical analysis of chemical and electrochemical oscillators for an accurate frequency selection.

The effect of experimental parameters on the frequency of chemical oscillators has been systematically studied since the first observations of clock reactions. The approach is mainly based on univariate changes in one specific parameter while others are kept constant. The frequency is then monitored and the effect of each parameter is discussed separately. This type of analysis, however, does not take into account the multiple interactions among the controllable parameters and the synergic responses on the oscillation frequency. We have carried out a multivariate statistical analysis of chemical (BZ-ferroin catalyzed reaction) and electrochemical (Cu/Cu2O cathodic deposition) oscillators and identified the contributions of the experimental parameters on frequency variations. The BZ reaction presented a strong dependence on the initial concentration of sodium bromate and temperature, resulting in a frequency increase. The concentration of malonic acid, the organic substrate, affects the system but with lower intensity compared with the combination of sodium bromate and temperature. On the other hand, the Cu/Cu2O electrochemical oscillator was shown to be less sensitive to changes in the temperature. The applied current density and pH were the two parameters which most perturbed the system. Interestingly, the frequency behaved nonmonotonically with a quadratic dependence. The multivariate analysis of both oscillators exhibited significant differences - while the homogenous oscillator displayed a linear dependence with the factors, the heterogeneous one revealed a more complex dependence with quadratic terms. Our results may contribute, for instance, in the synthesis of self-organized materials in which an accurate frequency selection is required and, depending on its value, different physicochemical properties are obtained.

Tuning Electrochemical Bistability by Surface Area Blocking in the Cathodic Deposition of Copper.

We report herein a precise control of the electrochemical bistability induced by surface area changes during the cathodic deposition of copper. Small additions of 1,10-phenanthroline (Phen) in the reaction media present an inhibiting effect on the global rate mainly due to the adsorption of protonated Phen. The increase of its concentration favors a shrinkage of the bifurcation (saddle-node) diagram and shifts it to less negative potentials. The dynamic instability is verified by impedance measurements, and a negative impedance is clearly found. We calculated the apparent molar mass of the adsorbents using in situ gravimetric monitoring in the electrochemical experiments, and the results indicate that mass changes occur mainly due to the reduction of copper from bivalent ions dissolved in the reaction media. Importantly, the adsorption of protonated Phen molecules does not show a considerable contribution in mass variations but prevents the formation of a copper course grained morphology over the surface. Imaging analysis indicates finer nodulations at the lower branch compared to the upper branch in the bistability domain. On the basis of these observations, a kinetic mechanism is proposed and a good agreement is obtained between the apparent molar mass extracted from experiments and the theoretical values. Altogether, our results contribute to a detailed physical chemical description of the nonlinear behavior, bringing new insights about this reaction and pointing out the possibility to design switchable surface electrodes by taking advantage of the bistable behavior.

Gut immunity in a protochordate involves a secreted immunoglobulin-type mediator binding host chitin and bacteria.

Protochordate variable region-containing chitin-binding proteins (VCBPs) consist of immunoglobulin-type V domains and a chitin-binding domain (CBD). VCBP V domains facilitate phagocytosis of bacteria by granulocytic amoebocytes; the function of the CBD is not understood. Here we show that the gut mucosa of Ciona intestinalis contains an extensive matrix of chitin fibrils to which VCBPs bind early in gut development, before feeding. Later in development, VCBPs and bacteria colocalize to chitin-rich mucus along the intestinal wall. VCBP-C influences biofilm formation in vitro and, collectively, the findings of this study suggest that VCBP-C may influence the overall settlement and colonization of bacteria in the Ciona gut. Basic relationships between soluble immunoglobulin-type molecules, endogenous chitin and bacteria arose early in chordate evolution and are integral to the overall function of the gut barrier.