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V Atger

Publications and source records attributed to V Atger.

42 records · Page 3Linked to original sources
PubMed1989

Rapid method for the isolation of two purified subfractions of high density lipoproteins by differential dextran sulfate-magnesium chloride precipitation.

We describe a rapid and reliable three-step precipitation procedure for the isolation of large amounts of the two major components of high density lipoproteins (HDL) in human serum. Precipitation was accomplished by means of dextran sulfate (DS) of mol. wt. 500,000 and MgCl2. First, all apoB-associated lipoproteins of any density were selectively precipitated with critical concentrations of reagents. Secondly, a subfraction of HDL was differentially precipitated from the apoB-depleted serum by increasing the concentration of both reagents. Eventually, the bulk of the remainder of HDL was precipitated by lowering the pH to 5.4. According to the precipitation patterns and the density profiles, the DS-Mg procedure provides a clear differentiation between the two HDL components. According to the compositional criteria and the ultracentrifugal characteristics, the two polyanion-precipitated subclasses are very similar to, if not identical with, the two density subclasses, the lighter HDL2 and the heavier HDL3, isolated by preparative ultracentrifugation after apoB-containing lipoproteins had been removed.

Chemical Precipitation↗
PubMed1989

Influence of end-stage renal failure on concentrations of free apolipoprotein A-1 in serum.

We determined, immunoturbidimetrically, the concentrations of apolipoprotein A-I (apo A-I) (a) in total serum, (b) in total lipoproteins, and (c) in the fraction of d greater than 1.21 kg/L (free apo A-I) in 31 uremic patients (16 on hemodialysis, HD, and 15 with end-stage renal failure, ESRF) and 14 control subjects. The concentration of free apo A-I in serum was significantly increased in both groups of uremic patients (0.27 +/- 0.07 g/L for HD and 0.22 +/- 0.08 g/L for ESRF, mean +/- SD), in comparison with the control group (0.14 +/- 0.04 g/L). The ratio of total apo A-I to high-density-lipoprotein cholesterol was significantly increased in sera from both uremic groups, whereas the apo A-I/HDL-chol ratio of total lipoproteins was similar in all three groups. No apo A-I could be detected in five ultrafiltrates of plasma, even after 100-fold concentration. Analysis of apo A-I isoforms by isoelectrofocusing revealed a significant relative increase in apo A-I3 and a decrease in apo A-I5 isoform in ESRF patients, but not in HD patients. Finally, we found no relationship between serum TG and free apo A-I concentration.

Adult↗
PubMed1989

Presence of Apo B48, and relative Apo CII deficiency and Apo CIII enrichment in uremic very-low density lipoproteins.

In the present study, lipid and apolipoprotein composition of very low density lipoprotein (VLDL) was analyzed in 39 patients with end-stage renal failure by comparison with 41 healthy subjects. Uremic patients had an increase of serum triglycerides (TG) concentration by comparison with control values. This increase of serum TG was associated with an increase of VLDL which had a normal percent amount of main components. Furthermore a mid-band between VLDL and low density lipoproteins (LDL) on polyacrylamide gel was observed in 22 out of 39 uremic patients but in only 1 out of 41 control subjects. In uremic VLDL Apo B48 was more frequently observed than in control VLDL (p less than 0.05). Furthermore, the content of Apo CII expressed as percent of total Apo C was significantly (p less than 0.001) decreased in uremic VLDL (19.13 +/- 4.54 p. cent) as compared to normal VLDL (23.57 +/- 4.40 p. cent). Apo CIII-O was significantly (p less than 0.001) increased (9.58 +/- 7.19 p. cent vs 5.55 +/- 6.12 p. cent, whereas Apo CIII-1 and Apo CIII-2 distribution was not modified in uremic VLDL. These anomalies were present in uremic patients even when no elevation of fasting serum TG was present. No significant change was observed in uremic patients before their fifth as compared to their first hemodialysis (HD) session, respectively, for any of the parameters studied. Advanced chronic renal failure is associated with a variety of anomalies of TG-rich lipoproteins isolated at d less than 1.006 g/ml which are not reflected by the degree of hypertriglyceridemia and are not corrected by the first four HD sessions.

Adult↗
PubMed1988

Anomalies in composition of uremic lipoproteins isolated by gradient ultracentrifugation: relative enrichment of HDL in apolipoprotein C-III at the expense of apolipoprotein A-I.

Using a discriminating gradient separation technique combined with careful analysis of lipid and apolipoprotein (apo) composition, serum lipoproteins of 20 chronically uremic patients have been compared with those of 19 normal controls matched for age and sex. In uremic subjects, serum VLDL concentration was markedly increased. These particles were enriched in protein and cholesterol and relatively poor in triglycerides (TG). They contained more frequently apo B-48, and a decreased proportion of apo E. Expressed in percent, total apo C was normal but the ratio of apo C-III2/apo C-III1 was elevated. Uremic IDL, whose serum concentration was markedly increased, were characterized by an increased proportion of protein. Total uremic LDL whose serum concentration was normal, contained less esterified cholesterol (EC) and more TG than normal LDL, their EC/TG ratio being very low. Moreover, the concentration of the mature subfraction of LDL having a mean density of 1.043 g/ml, was markedly decreased in uremic subjects. Taken together, these anomalies indicate a delayed transformation of VLDL into LDL in chronic renal failure. The decreased concentration of total HDL in uremic subjects was more marked in HDL2 (-46%) than HDL3 (-24%). Both uremic HDL2 and HDL3 were relatively enriched in TG, and uremic HDL3 were poorer in EC than normal HDL3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Polyacrylamide gel electrophoresis in quantification of high-density lipoprotein cholesterol.

We evaluated a method for quantifying high-density lipoprotein cholesterol in plasma, based on electrophoretic migration of the prestained (with Sudan Black III) sample through a discontinuous polyacrylamide++ gel and densitometric integration of the stain associated with each class of lipoprotein. With this method, operations can be carried out on all types of lipoproteins over a broad range of concentrations. Overloading with very-low and low-density lipoproteins did not affect reliability within a wide range of HDL concentrations (0.45 to 16.60 mmol/L). Results for 22 individual plasma samples from normal and dyslipemic subjects correlated well with those by ultracentrifugal analysis (r=0.96; Student's t= 0.90, p > 0.30). We conclude that this method is reliable, sensitive, and accurate, It may be used for simultaneously typing dyslipoproteinemias and assaying HDL cholesterol.

Cholesterol, HDL↗