Comparison of membrane filtration and nephelometry with analytical ultracentrifugation, for the quantitative analysis of low density lipoprotein fractions

A quantitative assessment of serum chylomicron by light scattering intensity: application to the intestinal fat absorption test

A novel fat absorption test to clarify the malabsorption syndrome was developed using a micronephelometric technique and compared with the classic conventional technique using 131I-triolein. An integrity of time-sequential light scattered from chylomicron-related turbidity in serum was determined between 0 and 300 min after butter fat load, being expressed in terms of the light scattering intensity (LSI). A good correlation was obtained between LSI and the serum level of chylomicron-triglyceride determined by an ultracentrifugation technique (r = 0.819, P < 0.001). The maximal LSI was consistently observed at 180 min after administration of a test meal in the normal group (n = 39), whereas the malabsorption syndrome group (n = 35) was distinctly different and could be further classified according to four patterns of LSI changes. In addition, an inverse correlation was found between this fat absorption test and the 131I-triolein absorption test. It was concluded that the micronephelometric technique which does not use a radionuclide is advantageous in its simple and safe evaluation of fat malabsorption syndrome.

Evaluation of the polyethylene glycol precipitation method for the estimation of high-density lipoprotein cholesterol

Treatment of fresh sera with polyethylene glycol 6000 at a final concentration of 100 g/l produced selective precipitation of low-density lipoproteins with only traces of contamination with high-density lipoproteins, as determined by electroimmunoassay using antisera to human alpha1-lipoprotein and human beta-lipoprotein. Supernatants collected for high-density lipoprotein-cholesterol estimation were free from low-density lipoproteins. Precipitates sedimented readily from specimens with high triglyceride contents, and secondary precipitation during enzymatic cholesterol determinations was absent. Values obtained by this method correlated well with those obtained by precipitation of low-density lipoproteins with heparin and manganous ions at concentrations optimal for discrete of lipoprotein classes (r = 0.975; p less than 0.001).

Selective precipitation of very low density lipoproteins from fasting sera by heparin and manganese ions

Complete and discrete precipitation of very low density lipoproteins (VLDL) from fasting sera required heating at 40 degrees C for 60 min in the presence of 0.05 M manganous ions and heparin in a concentration dependent upon the VLDL content. The minimum polyanion concentration, employed with VLDL contents less than 1.0 g/l, was 85 mg/l; an increment of 5 mg/l was required for each 1.0 g/l increase in VLDL content. The products isolated by this procedure had electrophoretic, immunochemical and ultracentrifugal characteristics skin to those of native VLDL and were slightly contaminated with albumin. The reaction conditions did not affect adversely the subsequent precipitation of low density lipoproteins.

The association between serum triglycerides and gamma glutamyl transpeptidase activity in diabetes mellitus

A study conducted on 228 diabetic patients has shown a significant positive association between serum gamma-glutamyl transpeptidase (GGT) and triglyceride levels. Both fall with treatment, the most marked reduction occurring in patients on insulin. We suggest that the association between serum GGT and triglyceride levels and also the higher incidence of raised GGT and triglyceride levels in new diabetics may reflect hepatic microsomal enzyme induction of the rate-limiting enzymes of triglyceride synthesis. Serum GGT does not seem to correlate with hepatomegaly in diabetes mellitus.

Changes in plasma nephelometry after oral fat loading in children with normal and abnormal small intestinal morphology

A standardized oral fat load has been given to 66 children having duodenal or jejunal biopsy, and to 10 children presumed normal. The rise in plasma light scattering intensity (LSI) measured by nephelometry between the fasting and 2-hour postload level (0-2 hour) showed good correlation with the small intestinal morphology in patients suspected of having coeliac disease. In those who had had recurrent diarrhoea and gastroenteritis, the fat load test did not predict small intestinal morphology. Serial studies in 5 treated patients with malabsorption showed increase in the 0-to 2-hour LSI, with corresponding improvement of small intestinal morphology and clinical state.

35 eggs per day in the treatment of severe burns

A regime involving the dietary management of 8 severely burned patients has been described, the main feature of this diet being the high egg intake. The eggs were given in a variety of forms without any untoward effects and without any distaste being developed. No pathological levels of serum lipoproteins or cholesterol were attained. Serum proteins from an initial low level reached normal values within a relatively short time. It is felt that a high egg diet is a valuable and safe addition in the management of severely burned patients.

Clinical, haemodynamic, rheological, and biochemical findings in 126 patients with intermittent claudication

Increased blood viscosity has been shown to be an important factor in reducing blood flow in a review and analysis of the history, clinical findings, and haemodynamic, rheological, radiological, and biochemical measurements in 126 patients with intermittent claudication. In some patients increased viscosity seemed to be the determining cause of claudication. A raised plasma fibrinogen was the most common single biochemical abnormality. The results of conventional serum lipid and lipoprotein estimations were abnormal in the series as a whole but did not correlate with clinical findings or flow measurements at individual patient level. There was, however, a significant correlation between some clinical findings and the susceptibility of the red cells to autoxidation.

Classification of lipoproteins and lipoprotein disorders

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