Prevalence of multivalvular regurgitation in athletes

To assess the effects of exercise training on the prevalence of valvular regurgitation, 2-dimensional echocardiography and Doppler flow mapping were performed in 45 athletes and 26 sedentary control subjects of similar age and sex. Mitral, tricuspid, aortic and pulmonic regurgitations were sought in all possible views and mitral and tricuspid flow velocities were recorded. Mitral and tricuspid anulus diameters and the maximal areas of regurgitant flow were planimetered. Regurgitation of at least one of the cardiac valves was found in 91% of athletes but in only 38% of control subjects (p less than 0.001). Mitral and tricuspid regurgitation occurred more commonly in athletes than in control subjects (mitral 69 vs 27%; tricuspid 76 vs 15%). The prevalence of aortic and pulmonic regurgitation was similar. Although athletes and sedentary normal subjects differed with respect to heart rate, right and left ventricular filling patterns and tricuspid and mitral anulus diameters, none of these variables was related to the presence or severity of regurgitation. Thus, exercise training is associated with an increased prevalence of mitral and tricuspid regurgitation and altered ventricular inflow patterns. The mechanism of these findings is unclear. Multivalvular regurgitation is common in athletes and does not imply structural valvular abnormalities.     

Evaluation of a novel automated non-invasive pulse pressure variation algorithm

In mechanically ventilated patients, Pulse Pressure Variation (PPV) has been shown to be a useful parameter to guide fluid management. We evaluated a real-time automated PPV-algorithm by comparing it to manually calculated PPV-values. In 10 critically ill patients, blood pressure was measured invasively (IBP) and non-invasively (CNAP^® Monitor, CNSystems Medizintechnik, Austria). PPV was determined manually and compared to automated PPV values: PPV_manIBP vs. PPV_autoIBP was ?0.19±1.65% (mean bias±standard deviation), PPV_manCNAP vs. PPV_autoCNAP was ?1.02±2.03% and PPV_autoCNAP vs. PPV_manIBP was ?2.10±3.14%, suggesting that the automated CNAP^® PPV-algorithm works well on both blood pressure waveforms but needs further clinical evaluation.     

A role for TASK2 channels in the human immunological synapse

The immunological synapse is a transient junction that occurs when the plasma membrane of a T cell comes in close contact with an APC after recognizing a peptide from the antigen-MHC. The interaction starts when CRAC channels embedded in the T cell membrane open, flowing calcium ions into the cell. To counterbalance the ion influx and subsequent depolarization, K_v1.3 and KCa3.1 channels are recruited to the immunological synapse, increasing the extracellular K⁺ concentration. These processes are crucial as they initiate gene expression that drives T cell activation and proliferation. The T cell-specific function of the K_2P channel family member TASK2 channels and their role in autoimmune processes remains unclear. Using mass spectrometry analysis together with epifluorescence and super-resolution single-molecule localization microscopy, we identified TASK2 channels as novel players recruited to the immunological synapse upon stimulation. TASK2 localizes at the immunological synapse, upon stimulation with CD3 antibodies, likely interacting with these molecules. Our findings suggest that, together with K_v1.3 and KCa3.1 channels, TASK2 channels contribute to the proper functioning of the immunological synapse, and represent an interesting treatment target for T cell-mediated autoimmune disorders.