A new method for HDL particle sizing by polyacrylamide gradient gel electrophoresis using whole plasma.

Low plasma levels of HDL cholesterol have been associated with an increased risk of coronary heart disease. HDL particles are heterogeneous with respect to size and apolipoprotein content. The objective of the present study was to develop a method to generate lipid-stainable calibrators that would allow the assessment of HDL particle size from whole plasma, using polyacrylamide gradient gel electrophoresis (PAGGE). Lipid-stainable HDL calibrators were obtained by subjecting isolated red blood cells to hemolysis either by freezing at -20 or -80 degrees C overnight or by rapid exposure to liquid nitrogen and mixing of the hemolysis products with plasma aliquots. All three methods were highly reproducible in producing Sudan black lipid-stainable HDL calibrators ranging from 75 to 200 A. The assessment of HDL particle size with these lipid-stainable HDL calibrators was also highly reproducible, with a coefficient of variation below 5.5%. These lipid-stainable HDL calibrators simplify the assessment of HDL particle size by PAGGE using whole plasma, without the need for costly, time-consuming ultracentrifugation procedures.

Psychological stress and incidence of ischaemic heart disease.

BACKGROUND: We assessed the relationship between psychological stress and ischaemic heart disease (IHD) incidence in a population of 868 men over a 10-year follow-up period. METHODS: In 1981, 869 men aged 42-60, free from IHD and living around Quebec City completed a questionnaire assessing the presence of psychological stress in different areas of their life. They also underwent a medical examination and provided information on IHD risk factors. From 1981 to 1991, the incidence of IHD events was ascertained. The relationship between 13 stress dimensions and IHD incidence was investigated using Cox regression while controlling for important IHD risk factors. Cross-sectional analyses were also performed to investigate the relationship between stress dimensions and IHD risk factors. RESULTS: Between 1981 and 1991, 79 men (9%) experienced a first IHD event. The following risk factors were associated with the risk of IHD: age, (rate ratio (RR) = 1.93, 95% CI: 1.21-3.09), hypertension (RR = 1.90, 95% CI: 1.22-2.98), triglycerides (RR = 1.87, 95% CI: 1.19-2.95) and high density lipoprotein (HDL) cholesterol (RR = 1.64, 95% CI: 1.05-2.55). After controlling for risk factors, not one of the psychological stress dimensions significantly altered the risk of IHD. CONCLUSIONS: While confirming the influence of hypertension, age, triglycerides and HDL cholesterol on IHD incidence, this study suggests that there is no important connection between the explored stress dimensions and IHD incidence. It is unlikely that this lack of association is due to the stress questionnaire since the 13 stress dimensions were rigorously developed through independent evaluation of the questions by three specialists and many statistically significant relationships were observed between stress dimensions and IHD risk factors.

[The organization of work in hospitals and its effect on nurses health.]. / L'organisation du travail en milieu hospitalier et ses effets sur la santé des infirmières.

This article covers the actual knowledge on the organization of infirmary work and its effects on nurses' physical and mental health. Then it proposes a conceptual model to study the question. This model is concerned with the relationship between the work load, a potential source of health problems and the autonomy and the social support which may relieve the load or its effects.