The pharmaco-economics of peri-operative beta-blocker and statin therapy in South Africa

We conducted a pharmaco-economic analysis of the prospective  peri-operative  studies of beta-blocker and statin administration for major  elective non-cardiac surgery, using the Discovery Health claims costs for 2004. This analysis shows that acute peri-operative beta-blockade and statin  therapy could result in a cost saving through a reduction in major   perioperative cardiovascular complications in patients with an expected  peri-operative major cardiovascular complication rate exceeding 10% following elective major non-cardiac surgery. The validity of these findings is dependent on whether the incidence of cardiovascular complications following major  noncardiac surgery reported in the international literature is found to be similar in South Africa

Are lipophilic beta-blockers preferable for peri-operative cardioprotection?

Atenolol has been proposed as a peri-operative cardioprotective agent in patients with coronary disease. However, recent reports have cast doubt over the cardioprotective efficacy of atenolol in patients with hypertension and coronary artery disease. There is therefore doubt whether atenolol is the correct cardioprotective drug in the surgical setting. It is possible that some of the physiochemical properties of atenolol (hydrophilic and cardioselective) may decrease it's efficacy in comparison to its more lipophilic congeners (such as propranolol, metoprolol, bisoprolol and carvedilol). The issue of prevention of perioperative cardiac events is complicated by many confounders. As a result, the role of the physicochemical properties of beta-blockers can only be determined in the simpler setting of myocardial infarction. Therefore, we conducted a restricted systematic review to evaluate the effect of initiating atenolol and metoprolol on the prevention of ventricular fibrillation following acute myocardial infarction. Neither atenolol nor metoprolol significantly decreased the incidence of in-hospital ventricular fibrillation following acute myocardial infarction. The number-needed-to-treat to prevent in-hospital ventricular fibrillation equals or exceeds 200 with metoprolol and atenolol respectively. Based on the findings of this systematic review and the recently published Clopidogrel and Metoprolol in Myocardial Infarction Trial (COMMIT), it can be concluded that the prevention of peri-operative myocardial ischaemia with a betablocker is clinically more important to peri-operative cardioprotection than whether the beta-blocker is lipo- or hydrophilic. Keywords: atenolol, metoprolol, myocardial infarction, ventricular fibrillation Southern African Journal of Anaesthesia and Analgesia Vol. 12(4) 2006: 141-14

Thickness-dependence of the electronic properties in V2O3 thin films

High quality vanadium sesquioxide V2O3 films (170-1100 {\AA}) were grown using the pulsed laser deposition technique on (0001)-oriented sapphire substrates, and the effects of film thickness on the lattice strain and electronic properties were examined. X-ray diffraction indicates that there is an in-plane compressive lattice parameter (a), close to -3.5% with respect to the substrate and an out-of-plane tensile lattice parameter (c) . The thin film samples display metallic character between 2-300 K, and no metal-to-insulator transition is observed. At low temperature, the V2O3 films behave as a strongly correlated metal, and the resistivity (\rho) follows the equation \rho =\rho_0 + A T^2, where A is the transport coefficient in a Fermi liquid. Typical values of A have been calculated to be 0.14 \mu\Omega cm K^{-2}, which is in agreement with the coefficient reported for V2O3 single crystals under high pressure. Moreover, a strong temperature-dependence of the Hall resistance confirms the electronic correlations of these V2O3 thin films samples.Comment: 4 pages, 4 figure

A New Window of Exploration in the Mass Spectrum: Strong Lensing by Galaxy Groups in the SL2S

The existence of strong lensing systems with Einstein radii (Re) covering the full mass spectrum, from ~1-2" (produced by galaxy scale dark matter haloes) to >10" (produced by galaxy cluster scale haloes) have long been predicted. Many lenses with Re around 1-2" and above 10" have been reported but very few in between. In this article, we present a sample of 13 strong lensing systems with Re in the range 3"- 8", i.e. systems produced by galaxy group scale dark matter haloes, spanning a redshift range from 0.3 to 0.8. This opens a new window of exploration in the mass spectrum, around 10^{13}- 10^{14} M_{sun}, which is a crucial range for understanding the transition between galaxies and galaxy clusters. Our analysis is based on multi-colour CFHTLS images complemented with HST imaging and ground based spectroscopy. Large scale properties are derived from both the light distribution of the elliptical galaxies group members and weak lensing of the faint background galaxy population. On small scales, the strong lensing analysis yields Einstein radii between 2.5" and 8". On larger scales, the strong lenses coincide with the peak of the light distribution, suggesting that mass is traced by light. Most of the luminosity maps have complicated shapes, indicating that these intermediate mass structures are dynamically young. Fitting the reduced shear with a Singular Isothermal Sphere, we find sigma ~ 500 km/s and an upper limit of ~900 km/s for the whole sample. The mass to light ratio for the sample is found to be M/L_i ~ 250 (solar units, corrected for evolution), with an upper limit of 500. This can be compared to mass to light ratios of small groups (with sigma ~ 300 km/s and galaxy clusters with sigma > 1000 km/s, thus bridging the gap between these mass scales.Comment: A&A Accepted. Draft with Appendix images can be found at http://www.dark-cosmology.dk/~marceau/groups_sl2s.pd

Plasma and neutrophil fatty acid composition in advanced cancer patients and response to fish oil supplementation

Metabolic demand and altered supply of essential nutrients is poorly characterised in patients with advanced cancer. A possible imbalance or deficiency of essential fatty acids is suggested by reported beneficial effects of fish oil supplementation. To assess fatty acid status (composition of plasma and neutrophil phospholipids) in advanced cancer patients before and after 14 days of supplementation (12±1 g day−1) with fish (eicosapentaenoic acid, and docosahexaenoic acid) or placebo (olive) oil. Blood was drawn from cancer patients experiencing weight loss of >5% body weight (n=23). Fatty acid composition of plasma phospholipids and the major phospholipid classes of isolated neutrophils were determined using gas liquid chromatography. At baseline, patients with advanced cancer exhibited low levels (<30% of normal values) of plasma phospholipids and constituent fatty acids and elevated 20 : 4 n-6 content in neutrophil phospholipids. High n-6/n-3 fatty acid ratios in neutrophil and plasma phospholipids were inversely related to body mass index. Fish oil supplementation raised eicosapentaenoic acid and docosahexaenoic acid content in plasma but not neutrophil phospholipids. 20 : 4 n-6 content was reduced in neutrophil PI following supplementation with fish oil. Change in body weight during the supplementation period related directly to increases in eicosapentaenoic acid in plasma. Advanced cancer patients have alterations in lipid metabolism potentially due to nutritional status and/or chemotherapy. Potential obstacles in fatty acid utilisation must be addressed in future trials aiming to improve outcomes using nutritional intervention with fish oils