Surfactant properties of low molecular weight phospholipids

Surface tensions, critical micelle concentrations (CMCs), contact angles on hydrophobic polyethylene, and foaming characteristics of phosphatidic acids, phosphatidylcholines, phosphatidylethanolamines, and phosphatidylglycerols were measured to determine their suitability as substitutes for traditional surfactants. These phospholipids have fatty acid chains of 5 to 12 carbon atoms, a range over which they are soluble at room temperature. Their surface tensions decrease with increasing concentrations until their CMCs are reached, above which their plateau surface tensions are as low as 21 mN/m, indicating excellent surface activities. In general, plateau surface tensions decrease with increasing chain length within each phospholipid type. The classical relationship for In CMC vs. chain length is followed with slopes typical of anionic surfactants for phosphatidic acids and phosphatidylglycerols and resembling zwitterionic surfactants for phosphatidylcholines and phosphatidylethanolamines, consistent with the charge on the hydrophilic group. The wetting capabilities of aqueous solutions on polyethylene are good and foam heights and stabilities are high, the latter two properties being comparable to traditional anionic (sodium dodecylsulfate) and nonionic (octylphenol polyethoxylate) surfactants. Some anomalies are observed regarding the effect of chain length on wetting and foaming, probably due to the depletion effect. Many phospholipids slowly degrade in aqueous solution. We conclude that short-chain phospholipids exhibit excellent surfactant properties and may be useful in many applications.This is a post-print of an article from Journal of Surfactants and Detergents, 8, no. 1 (2005): 65–72, doi: 10.1007/s11743-005-0332-8.</p

Microbial Community Analysis of a Coastal Salt Marsh Affected by the Deepwater Horizon Oil Spill

Conceived and designed the experiments: MJB RJM BM PAS. Performed the experiments: MJB RJM SR JP YMP LMT JDVN. Analyzed the data: MJB RJM YMP LMT GLA TCH JDVN JZ PAS. Contributed reagents/materials/analysis tools: GLA TCH JZ BM PAS. Wrote the paper: MJB RJM PAS.Coastal salt marshes are highly sensitive wetland ecosystems that can sustain long-term impacts from anthropogenic events such as oil spills. In this study, we examined the microbial communities of a Gulf of Mexico coastal salt marsh during and after the influx of petroleum hydrocarbons following the Deepwater Horizon oil spill. Total hydrocarbon concentrations in salt marsh sediments were highest in June and July 2010 and decreased in September 2010. Coupled PhyloChip and GeoChip microarray analyses demonstrated that the microbial community structure and function of the extant salt marsh hydrocarbon-degrading microbial populations changed significantly during the study. The relative richness and abundance of phyla containing previously described hydrocarbon-degrading bacteria (Proteobacteria, Bacteroidetes, and Actinobacteria) increased in hydrocarbon-contaminated sediments and then decreased once hydrocarbons were below detection. Firmicutes, however, continued to increase in relative richness and abundance after hydrocarbon concentrations were below detection. Functional genes involved in hydrocarbon degradation were enriched in hydrocarbon-contaminated sediments then declined significantly (p<0.05) once hydrocarbon concentrations decreased. A greater decrease in hydrocarbon concentrations among marsh grass sediments compared to inlet sediments (lacking marsh grass) suggests that the marsh rhizosphere microbial communities could also be contributing to hydrocarbon degradation. The results of this study provide a comprehensive view of microbial community structural and functional dynamics within perturbed salt marsh ecosystems.Yeshttp://www.plosone.org/static/editorial#pee

PROTECTION AND REVASCULARIZATION OF BRONCHIAL ANASTOMOSES BY THE INTERCOSTAL PEDICLE FLAP

We used an improved method for preparation of the intercostal pedicle flap for encircling bronchial anastomoses, and we studied its vascular supply after the operation. The flap was used in 56 patients undergoing various types of sleeve resection and in three patients undergoing single lung transplantation. The technique is simple, fast, and causes neither extra surgical trauma nor complications. It allows satisfactory isolation and sealing of the bronchial anastomosis. Even if complete anastomotic dehiscence occurs (one case), the flap preserves the continuity of the airway, thus avoiding bronchopleural fistulas or other complications. The postoperative arteriographic study of the intercostal artery supplying the flap (performed in 14 patients) demonstrated the full patency of the vessel in all cases. It also showed that a fine vascular network develops around the anastomosis early in the postoperative period

014 Atorvastatin protects human myocardium from lethal ischaemia-reperfusion injury by activating the risk pathway

Background Previous animal studies have demonstrated that acute treatment with atorvastatin at reperfusion reduces myocardial infarct size by up-regulating the Akt and Erk1/2 components of the Reperfusion Injury Salvage Kinase (RISK) pathway. Whether this cardioprotective strategy applies to human cardiac tissue is unknown.Objective To determine whether atorvastatin, administered at reperfusion, protects human atrial tissue from ischaemia-reperfusion injury (IRI) via activation of the RISK pathway.Methods Local UCLH/UCL Ethical Committee approval was granted. Human atrial trabeculae were isolated from right atrial appendage tissue harvested from consenting adult patients undergoing elective cardiac surgery. The atrial trabeculae were subjected to 90 min of hypoxia followed by 120 min reoxygenation as simulated ischaemia-reperfusion injury. Following this, recovery of contractile function was determined and compared to baseline. Atrial trabeculae were randomised to the following groups: 1. Control (N=14); 2. Hypoxic preconditioning positive control (N=4); 3. Atorvastatin (25 μM) at reperfusion (N=9); 4. Atorvastatin plus UO126 (10 μM), a MEK1/2-Erk1/2 inhibitor (N=4); 5. Atorvastatin plus LY294002 (15 μM), a PI3K-Akt inhibitor (N=4); 6. Atorvastatin plus L-NAME (100 μM), a non-specific nitric oxide synthase inhibitor (N=7); 7. Atorvastatin plus 1400W (5μM), a specific inducible nitric oxide synthase inhibitor (N=5); 8. Inhibitor-only controls (N=18).Results Control atrial trabeculae recovered 37.5±1.6% of baseline contractile function following simulated IRI. Treatment with atorvastatin 25 μM at reperfusion significantly improved the recovery of contractile function (61.1±3.8%,