Biological and materials properties of various cholesterol based systems

Liposomes composed of cationic lipids have become very popular gene delivery vehicles. A great deal of research is being pursued to make efficient vectors by varying their molecular architecture. Cholesterol being ubiquitous component in most of the animal cell membranes is increasingly being used as a hydrophobic segment of synthetic cationic lipids. In this review we describe various cholesterol based cationic lipids and focus on the effect of modifying various structural segments like linker and the head group of the cationic lipids on gene transfection efficiency with a special emphasis on the importance of ether linkage between cholesteryl backbone and the polar head group. Interaction of cationic cholesteryl lipids with dipalmitylphosphatidycholine membranes is also discussed here. Apart from cholesterol being an attractive scaffold in the drug/gene delivery vehicles, certain cholesteryl derivatives have also been shown to be attractive room temperature liquid-crystalline materials

Novel polyquinanes from a caged hexacyclic [4.4.2]propellane system

This article does not have an abstract

Process review of a departmental change from conventional coronary artery bypass grafting to totally arterial coronary artery bypass and its effects on the incidence and severity of postoperative stroke

Background: We evaluated the process of changing from conventional coronary artery bypass grafting (CABG) to totally arterial off-pump coronary artery bypass (TOPCAB) at a single heart center in Germany. Methods: We (1) used multivariate statistical methods to assess real-time monitoring of OPCAB effects, (2) conducted a case review to assess preventable deaths and identify areas of improvement, (3) conducted a team survey, and (4) evaluated benchmarking results. Results: All surgeons and assistants (n = 18) at this center were involved and were guided by the department head and one of the consultants, who was trained in this procedure in 2004 at the Leuven OPCAB school. The frequency of OPCAB operations increased abruptly in 2005 from 5% to 43% and then increased gradually to 67% (n = 546) by 2008 (total, 1781 OPCAB cases and 1563 on-pump cases). The in-hospital and 30-day mortality rates for OPCAB surgeries (n = 10 [0.6%] and 21 [1.2%], respectively) were lower than for on-pump surgeries (n = 27 [1.7%] and 26 [1.7%], respectively). Stroke rates were also lower for OPCAB surgeries (7 cases [0.4%] versus 15 cases [1%]). The lower risk of stroke in the OPCAB group was significant (P < .05) after risk adjustment. Monitoring curves and case reviews demonstrated a preventable death percentage of at least 30%.The attitude of the team was mostly positive because of the promising results (eg, fewer strokes, increasing TOPCAB popularity, and a top national rank). Conclusions: The change from conventional CABG to TOPCAB was effective in decreasing the incidence and severity of stroke, in developing a team routine and a positive team attitude, and in producing excellent benchmarking results. The presence of a training and communication deficiency at the beginning of the study suggested an area for further improvement. After 6 years TOPCAB had largely replaced conventional CABG