Bioactive Oxylipins Profile in Marine Microalgae.

Microalgae are photosynthetic microscopic organisms that serve as the primary food source in aquatic environments. Microalgae can synthesize a wide variety of molecules, such as polyunsaturated fatty acids (PUFAs) of the omega-3 and omega-6 series. Oxidative degradation of PUFA due to radical and/or enzymatic conversion leads to the formation of oxylipins, which are compounds known for their bioactive properties. In the present study, we aim to profile oxylipins from five microalgae species grown in 10-L photo-bioreactors under optimal conditions. During their exponential phase, microalgae were harvested, extracted and analyzed by LC-MS/MS to determine the qualitative and quantitative profile of oxylipins for each species. The five different selected microalgae revealed a high diversity of metabolites, up to 33 non-enzymatic and 24 enzymatic oxylipins present in different concentrations. Taken together, these findings highlight an interesting role of marine microalgae as a source of bioactive lipids mediators, which we hypothesize have an important function in preventive health measures such as amelioration of inflammation. The rich mixture of oxylipins may display advantages to biological organisms, especially by providing for human health benefits including antioxidant, anti-inflammatory, neuroprotective or immunomodulator activities. Some oxylipins are also well known for their cardiovascular properties.

In vitro evaluation of Pseudomonas aeruginosa chronic lung infection models: Are agar and calcium-alginate beads interchangeable?

Animal models of chronic lung infection with P. aeruginosa (PA) are useful tools to improve antibiotic (ATB) treatment. Two main models based on the pulmonary instillation of PA embedded in agar or calcium-alginate beads are currently used. However, these two polymers used to prepare the beads have different properties; for example, agar is a neutral polysaccharide while alginate is anionic. We hypothesized that the effect of an ATB on PA entrapped in agar or calcium-alginate beads depends on its physicochemical properties, including charge, and concentration. To test this hypothesis, PAs were entrapped in agar or calcium-alginate beads dispersed in a growth medium containing either tobramycin (TOB), selected as a cationic ATB, or ciprofloxacin (CIP) selected as a neutral zwitterionic ATB. In vitro, time-kill curves evaluating the efficacy of ATBs over time were performed by measuring the light emitted by a bioluminescent PA for 42 h in the presence of ATB concentrations ranging from 0 to 100 times the MIC. In the presence of CIP, time-kill curves obtained with PA trapped in agar or calcium-alginate beads were comparable, whatever the CIP concentration used. In the presence of TOB, a clear difference was observed between the kill curves obtained with PA embedded in agar or calcium-alginate beads. While PA trapped within agar displayed the same susceptibility than the planktonic one, it was unresponsive to TOB for concentrations up to 1-fold MIC when trapped in calcium-alginate. At 10-fold the TOB's MIC, the luminescence emitted by PA01 in the agar beads was reduced by 95% after 40 h, whereas it returned to the same initial value for PA01 trapped in alginate-based beads. The reduction in TOB efficiency was even greater when alginate-based beads were dispersed in a mucus-simulating medium. These results show that the agar and alginate beads models can be interchangeable only for uncharged ATB, such as CIP, but not for cationic ATB, like TOB. In vitro experiments performed in this study could be a quick way to evaluate the effect of each model on a given ATB before performing animal experiments.

Ability of the Short Physical Performance Battery Frailty Index to Predict Mortality and Hospital Readmission in Patients with Liver Cirrhosis.

BACKGROUND/AIMS: Unplanned hospitalisation is a marker of poor prognosis and a major financial burden in patients with cirrhosis. Frailty-screening tools could determine the risk for unplanned hospital admissions and death. The study aims to evaluate the bedside frailty-screening tool (Short Physical Performance Battery (SPPB)) in prediction of mortality in patients with liver cirrhosis. METHODS: One hundred forty-five patients with liver cirrhosis were recruited from Cairo University Hospital. Clinical assessment and routine laboratory tests were performed, and the SPPB frailty index, Child score, and model for end-stage liver disease (MELD) score were calculated on admission. These metrics were compared to assess mortality outcomes over the course of 90 days. RESULTS: The mean age of the patients was 60 ± 7 years, and frailty index score (SD) was 6 ± 3. The overall 90-day readmission rate was 43.4%, while the overall 90-day mortality rate was 18.6%. SPPB scores differed significantly between survivors (4.1 ± 1.4) and nonsurvivors (6.47 ± 2.8) (P value ≤ 0.001) as well as between readmitted patients (7.5 ± 2.9) and patients who were not readmitted (4.5 ± 1.9) (P value ≤ 0.001), while the Child and MELD scores showed no associations with patient outcomes. SPPB performed better with a specificity of 72.3% and a sensitivity of 72.2% for predicting mortality. CONCLUSIONS: SPPB could be a screening tool used to detect frailty and excelled over traditional scores as a predictor of death. A low SPPB frailty score among hospitalised patients with cirrhosis is associated with poor outcomes.