The enzyme group of matrix metalloproteinases (MMPs) and their inhibitors, so-called tissue inhibitors of matrix-metalloproteinases (TIMPs), are crucial mediators responsible for wound repair after parenchymal damage. Little is known about the role of MMPs and TIMPs in severe sepsis. The aim of the present study was therefore to investigate their levels in patients with severe sepsis and to examine their association with prognosis. MMP-2, MMP-9, TIMP-1, TIMP-2 and interleukin-6 (IL-6) plasma levels were measured by ELISA methods in 37 patients on day 1 of severe sepsis. 37 healthy volunteers served as controls. Levels of MMP-9, TIMP-1, TIMP-2 and IL-6 in septic patients were significantly higher compared to healthy controls (p<0.001), whereas MMP-2 levels were not different in patients and controls. TIMP-1 levels were significantly higher in non-survivors (4675+/-435 ng/ml, mean+/-SEM) compared to survivors of severe sepsis (3201+/-249 ng/ml; p<0.01). Septic patients with TIMP-1 values >3200 ng/ml were 4.5 times more likely to die than patients with lower values (RR = 4.5; 95% CI 1.14-17.6, p = 0.014). Our results indicate that MMP-9, TIMP-2 and TIMP-1 are elevated in severe sepsis. Furthermore, TIMP-1 may serve as a useful laboratory marker to predict the clinical outcome of patients presenting with severe sepsis.

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IntroductionFever can increase the susceptibility to supraventricular and ventricular arrhythmias, in which sodium channel dysfunction has been implicated. Whether fever influences the efficacy of sodium channel blocking drugs is unknown. The current study was designed to investigate the temperature dependent effects of distinct sodium channel blocking drugs on the sodium currents in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).Methods and ResultshiPSC-CMs were generated from human skin fibroblasts of a healthy donor. The peak and late sodium currents (INa), steady-state activation, inactivation and recovery from inactivation of INa in hiPSC-CMs were analyzed using the whole-cell patch clamp technique. The effects of different concentrations of the antiarrhythmic drugs flecainide, lidocaine, ajmaline and the antianginal drug ranolazine on INa were tested at 36°C and 40°C. Increasing the temperature of the bath solution from 36°C to 40°C enhanced the inhibition of peak INa but reduced the inhibition of late INa by flecainide and lidocaine. By contrast, increasing the temperature reduced the effect of ajmaline and ranolazine on the peak INa but not late INa. None of the tested drugs showed temperature-dependent effects on the steady-state activation and inactivation as well as on the recovery from inactivation of INa in hiPSC-CMs.ConclusionsTemperature variation from the physiological to the febrile range apparently influences the effects of sodium channel blockers on the sodium currents. This may influence their antiarrhythmic efficacy in patients suffering from fever.