Soil bacteria are decomposer organisms crucial for the biodegradation of organic pollutants, mineralization of dead organic matter and the turnover of biogenic elements. In their environment they are constantly exposed to membrane-lytic enzymes emitted to the soil by other microorganisms competing for the same niche. Therefore, the composition and structure of their membranes is of utmost importance for survival in the harsh environment. Although soil bacteria species can be Gram-negative or Gram-positive and their membranes differ significantly, they are formed by phospholipids belonging mainly to three classes phosphatidylethanolamines (PE), phosphatidylglycerols (PG) and cardiolipins (CL). see more The correlation of the membrane phospholipid composition and its susceptibility to secretory membrane-lytic enzymes is widely unknown; thus, to shed light on these phenomena we applied the Langmuir monolayer technique to construct models of soil bacteria membranes differing in the mutual proportion of the main phospholipids. To characterize the systems we studied their elasticity, mesoscopic texture, 2D crystalline structure and discussed the thermodynamics of the interactions between their components. The model membranes were exposed to secretory phospholipase A2. It turned out that in spite of the structural similarities the model membranes differed significantly in their susceptibility to s-PLA2 attack. The membranes devoid of cardiolipin were completely degraded, whereas, these containing cardiolipin were much more resistant to the enzymatic hydrolysis. It also turned out that the sole presence of cardiolipin in the model membrane did not guarantee the membrane durability and that the interplay between cardiolipin and the zwitterionic phosphatidylethanolamine was here of crucial importance. Aging of red blood cells (RBCs) is associated with alteration in a wide range of RBC features, occurring each on its own timescale. A number of these changes are interrelated and initiate a cascade of biochemical and structural transformations, including band-3 clustering and phosphatidylserine (PS) externalization. Using specific band-3 clustering agents (acridine orange (AO) and ZnCl2), we examined whether treatment of RBCs with these agents may affects PS externalization and whether this process is Ca2+-dependent. RBCs were isolated from the blood of eight healthy donors upon obtaining their informed consent. The suspension was supplemented with increasing concentrations of AO or ZnCl2 (from 0.5 to 2.0 mM) and incubated at 25 °C for 60 min. To detect PS at the RBC surface, we used allophycocyanin-conjugated recombinant human Annexin V. We demonstrated, that treatment of RBCs with both clustering agents caused an elevation in the percent of cells positively labeled by Annexin-V (RBCPS), and that this value was not dependent on the presence of calcium in the buffer RBCs treated with AO in the presence of either EDTA, EGTA or calcium exhibited similar percentage of RBCPS. Moreover, the active influx of Zn2+ into RBCs induced by their co-incubation with both ZnCl2 and A23187 did not increase the percent of RBCPS as compared to RBCs incubated with ZnCl2 alone. Taken together, these results demonstrate that the band-3 clustering agents (AO or ZnCl2) induce PS externalization in a Ca2+ independent manner, and we hereby suggest a possible scenario for this phenomenon. BACKGROUND Diuretics have been reported as effective for reducing obstructive sleep apnea (OSA) severity by preventing fluid retention and reducing rostral fluid shift. The benefit of diuretics might vary depending upon the OSA clinical phenotype and comorbidities. To test this hypothesis, we conducted a propensity score-matched cohort analysis of data from the French national sleep apnea registry "Observatoire Sommeil de la Fédération de Pneumologie" (OSFP). METHODS A propensity score analysis was used to determine the impact of diuretics on OSA severity. Matching (ratio 14) was performed by using a 0.1 collider for the propensity score. Severe OSA was defined as an apnea-hypopnea index (AHI) > 30 events/h and the usefulness of diuretics was assessed using a logistic regression model. RESULTS The 69,564 OSA patients studied in the OSFP prospective observational cohort had a median age of 56.9 years [Interquartile range (IQR) 47.4; 65.6], 67% were men, and the median AHI was 28 [14; 43] events/h. Among them, 9,783 (14.1%) were treated with diuretics. Diuretics reduced OSA severity in overweight or moderately obese patients (p=0.03) and in patients with hypertension (p less then 0.01), particularly in hypertensives with a body mass index between 25 and 35 kg/m2 (p less then 0.01). Diuretics had no significant effect on OSA severity in patients with self-reported low physical activity or heart failure. CONCLUSIONS Diuretics appear to have a positive impact on OSA severity in overweight or moderately obese patients with hypertension. A prospective study is needed to confirm that diuretics are of interest in combined therapies for hypertensive patients with OSA. BACKGROUND Extracorporeal membrane oxygenation (ECMO) is rapidly becoming a mainstream technology for lung or heart/lung support. Current ECMO devices mostly consist of a power-driven centrifugal pump and a dedicated oxygenator. We studied the safety and efficacy of a novel, fully pneumatically-driven ECMO device, which could be used in both veno-venous or veno-arterial mode in an animal model. METHODS Six healthy, awake sheep were treated with the Mobybox ECMO device (Hemovent, Aachen, Germany) over a 7-day period in a veno-venous mode. Gas exchange, coagulation parameters and safety were assessed. RESULTS Using a blood flow rate of 2 L/min and a low sweep gas flow rate of 0.3 L/min, the PCO2 ranged from 38-44 mmHg pre oxygenator and dropped to 32-36 mmHg post oxygenator, whereas the PaO2 post oxygenator increased to 600 mmHg. Higher levels of sweep gas flow resulted in cessation of spontaneous breathing in some animals, consistent with high-efficiency carbon dioxide removal; thus, the sweep gas flow rate was maintained at a low level. Platelets dropped from 177±53/μL to 107±28/μL on day two, while returning to baseline by day seven (180±51/μL). Plasma-free hemoglobin remained low (2-9 mg/dl), whereas fibrinogen slightly increased, and then remained stable throughout the period. Neither the pump nor the oxygenator showed any visible clotting after 7 days. CONCLUSIONS The pneumatically-driven ECMO device provides excellent safety and physiologic efficacy in a 7-day sheep experiment without visible clotting, hemolysis, or sustained reductions in fibrinogen or platelets.