Effects of pravastatin on coronary events in 2073 patients with low levels of both low-density lipoprotein cholesterol and high-density lipoprotein cholesterol: results from the LIPID study

Aims Fibrates or nicotinic acid are usually recommended for secondary prevention of coronary heart disease in patients with low plasma levels of both low-density tipoprotein cholesterol (LDL-C) less than or equal to140 mg/dL (less than or equal to3.6 mmol/L) and high-density lipoprotein cholesterol (HDL-C) less than or equal to40 mg/dL (less than or equal to1.03 mmol/L). The LIPID trial, a randomised, placebo-controlled trial in 9014 patients at 87 centres in Australia and New Zealand, provided an opportunity to investigate the effects of an HMG-CoA reductase inhibitor in patients with tow LDL-C and tow HDL-C. Methods and results Participants in this post hoc substudy were 2073 patients aged 31-75 years with baseline LDL-C less than or equal to140 mg/dL (less than or equal to3.6 mmoL/L), HDL-C less than or equal to40 mg/dL (less than or equal to1.03 mmol/L), and triglyceride less than or equal to300 mg/dL (less than or equal to3.4 mmol/L). The relative risk reduction with pravastatin treatment was 27% for major coronary events (95% Cl 8-42%), 27% for coronary heart disease mortality (95% CI 0-47%), 21% for all-cause mortality (95% Cl 0-38%), and 51% for stroke (95% CI 24-69%). The number needed to treat to prevent a major coronary event over 6 years was 22. Conclusions Treatment with pravastatin in patients with both low LDL-C and low HDL-C significantly reduced major coronary events, stroke, and all-cause mortality. The level of HDL-C is crucial to the risk of recurrent CHD events and, consequently, the benefit of lowering LDL-C. (C) 2004 Published by Elsevier Ltd on behalf of The European Society of Cardiology.

Investigation of the low-density lipoprotein receptor gene and cholesterol as a risk factor for migraine

The Low-Density Lipoprotein Receptor (LDLR) gene is a cell surface receptor that plays an important role in cholesterol homeostasis. We investigated the (TA)n polymorphism in exon 18 of the LDLR gene on chromosome 19p13.2 performing an association analysis in 244 typical migraine-affected patients, 151 suffering from migraine with aura (MA), 96 with migraine without aura (MO) and 244 unaffected controls. The populations consisted of Caucasians only, and controls were age- and sex-matched. The results showed no significant difference between groups for allele frequency distributions of the (TA)n polymorphism even after separation of the migraine-affected individuals into subgroups of MA and MO affected patients. This is in contradiction to Mochi et al. [Mochi M, Cevoli S, Cortelli P, Pierangeli G, Scapoli C, Soriani S, Montagna P. Investigation of an LDLR gene polymorphism (19p13.2) in susceptibility to migrane without aura. J Neurol Sci 2003; 213 (1-2): 7-10.] who found a positive association of this variant with MO. Our study discusses possible differences between the two studies and extends this research by investigating circulating cholesterol levels in a migraine-affected population. (C) 2004 Elsevier B.V. All rights reserved.

Kinetic study of the thermal degradation of high density polyethylene

The thermal degradation of high density polyethylene has been modelled by the random breakage of polymer bonds, using a set of population balance equations. A model was proposed in which the population balances were lumped into representative sizes so that the experimentally determined molecular weight distribution of the original polymer could be used as the initial condition. This model was then compared to two different cases of the unlumped population balance which assumed unimolecular initial distributions of 100 and 500 monomer units, respectively. The model that utilised the experimentally determined molecular weight distribution was found to best describe the experimental data. The model fits suggested a second mechanism in addition to random breakage at slow reaction rates. (c) 2005 Elsevier Ltd. All rights reserved.

The effect of residence time and aeration on coal recovery within the high density zone of a flotation machine

The high intensity zone within the Jameson Cell is the downcomer. It is largely external and separated from the flotation tank. This, together with operation of the downcomer under vacuum, rather than at elevated pressure and the absence of moving parts, allows ready access to the high intensity zone for measurement and analysis. Experimentation was conducted allowing measurements of recovery for residence times of between 20 milliseconds and ten seconds within the downcomer of a Jameson Cell. The affect of aeration rate on the recovery of different particle sizes was also studied.

Expression of caveolin-1 enhances cholesterol efflux in hepatic cells

HepG2 cells were stably transfected with human caveolin-1 (HepG2/cav cells). Transfection resulted in expression of caveolin-1 mRNA, a high abundance of caveolin-1 protein, and the formation of caveolae on the plasma membrane. Cholesterol efflux from HepG2/cav cells was 280 and 45% higher than that from parent HepG2 cells when human plasma and human apoA-I, respectively, were used as acceptors. The difference in efflux was eliminated by treatment of cells with progesterone. There was no difference in cholesterol efflux to cyclodextrin. Cholesterol efflux from plasma membrane vesicles was similar for the two cell types. Transfection led to a 40% increase in the amount of plasma membrane cholesterol in cholesterol-rich domains ( caveolae and/or rafts) and a 67% increase in the rate of cholesterol trafficking from intracellular compartments to these domains. Cholesterol biosynthesis in HepG2/cav cells was increased by 2-fold, and cholesterol esterification was reduced by 50% compared with parent HepG2 cells. The proliferation rate of transfected cells was significantly lower than that of non-transfected cells. Transfection did not affect expression of ABCA1 or the abundance of ABCA1 protein, but decreased secretion of apoA-I. We conclude that overexpression of caveolin-1 in hepatic cells stimulates cholesterol efflux by enhancing transfer of cholesterol to cholesterol-rich domains in the plasma membrane.