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Biomedical subjects

G Cazzolato

Publications and source records attributed to G Cazzolato.

At least 37 records · Page 2Linked to original sources
PubMed1991

Characterization of a more electronegatively charged LDL subfraction by ion exchange HPLC.

Low density lipoproteins (LDL), collected from 32 normal male subjects (aged 30-60), were subfractionated by high resolution ion exchange chromatography (IE-HPLC). By this procedure two LDL subfractions were eluted. The first corresponds to normal LDL (nLDL); while the second one corresponds to a more electronegative subfraction, called LDL-. The mean percentage contribution of LDL- to native plasma LDL was of 3.9% (range 0.5-9.8%). The percentage concentration of LDL- in total native LDL did not correlate with plasma total cholesterol, triglycerides, and LDL cholesterol, whereas a significant negative correlation with high density lipoprotein cholesterol was found (r = -.38; p less than .05). LDL- was negatively correlated with LDL phospholipids (r = -.59; p less than .001), and with the LDL vitamin E content (r = -.63; p less than .001), and positively correlated with LDL proteins (r = -.35; p less than .05) and the content of thiobarbituric acid reactive substances (TBARS) in total LDL (r = .43; p less than .05). The TBARS molar content of LDL- was three times higher than in nLDL, with a mean concentration in LDL- of 7.3 mol/mol lipoprotein. By preparative IE-HPLC significant differences of the LDL- chemical composition were observed. The percentage content of cholesterol esters and of phospholipids was decreased, whereas proteins and free cholesterol were increased. Analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis revealed that besides apolipoprotein B-100 there was evidence of peptides with a higher molecular weight in LDL-.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

A cross-over controlled study on beclobrate versus bezafibrate in the treatment of type IIb hyperlipoproteinaemia.

The effects of the new fibric acid derivative beclobrate (100 mg) on some plasma lipidic and apoproteic parameters in 20 patients with type IIb hyperlipoproteinaemia were matched in a randomized cross-over study to a sustained release formulation of bezafibrate (400 mg). Inclusion criteria were: total cholesterol (TC) plasma levels greater than 260 mg/dl and triglyceride (TG) levels greater than 200 mg/dl, after a 2-month period of isocaloric diet. The drugs were administered once a day for 8 weeks, and then crossed-over after 8 weeks of wash-out for another 8 week period of treatment. Both drugs were significantly effective in reducing TC and TG, and in increasing HDL-C plasma levels, but only beclobrate significantly decreased Apo B and LDL-C whereas bezafibrate seemed to be more active in increasing HDL-C levels. The electrophoretic pattern of LP in patients treated with beclobrate revealed a decrease of VLDL, a normalization of the LDL fraction and an increase of HDL. The tolerability was generally good.

Adult↗
PubMed1986

Plasma malondialdehyde in coronary patients and in "normal" people at rest and after exercise.

The behavior of plasma lipid peroxides, expressed as plasma malondialdehyde, was studied in 27 patients with documented coronary artery disease and 17 volunteers without coronary artery disease (henceforth designated "normal"), after a standardized exercise on a bicycle ergometer. In the control group, the basal values of malondialdehyde were significantly lower than in coronary patients. Persons in the control group did not show any significant variation of malondialdehyde after exercise and recovery, whereas patients with coronary artery disease showed malondialdehyde levels significantly higher than the baseline, both after exercise and after recovery. In the control group, a significant inverse correlation between the malondialdehyde variations during the exercise and the total work produced was ten times lower than in coronary patients. It seems probable that the higher levels of lipid peroxides in these patients may leave some long-term unwanted effects. Furthermore, the increased values of lipid peroxides after exercise may be regarded as a possible trigger of fatal myocardial malfunction occurring during physical activity.

Journal Article↗
PubMed1985

Effects of pantethine on in-vitro peroxidation of low density lipoproteins.

The effects of pantethine on LDL peroxidation in vitro are reported. LDL isolation by density gradient ultracentrifugation from 12 normal subjects were dialyzed 48 h under conditions allowing oxidation. The LDL peroxides were assayed for the presence of malondialdehyde (MDA) on the lipoprotein. The effect of peroxidation on the LDL protein moiety (apo B) was studied by SDS-gel electrophoresis. The presence in the dialysis buffer of 1 mM reduced glutathione or of an equimolar concentration of pantethine markedly inhibited the MDA formation in LDL. Less effective were 0.5 and 2 mM pantethine, while 10 mM pantethine did not prevent the LDL peroxidation. Both glutathione and pantethine (1 or 2 mM) preserved the original LDL electrophoretic mobility. The electronegative charge of LDL was correlated to the MDA production during the dialysis procedures. Freshly prepared LDL showed a single apo B band by SDS-gel electrophoresis (apo B-100). Following peroxidation 2 or 3 bands with higher molecular weight appeared. Both glutathione and pantethine (1 or 2 mM) strongly inhibited the appearance of higher molecular weight peptides. In appropriate concentrations therefore pantethine inhibits the LDL peroxidation in vitro, thus preserving the molecular integrity of apo B.

Antioxidants↗
PubMed1984

Total plasma apo E and high density lipoprotein apo E in survivors of myocardial infarction.

Total apo E in plasma and the amount of apo E-HDL were measured in 40 normolipidemic male survivors of myocardial infarction and in 40 controls. LDL-C, Lp(a) and apo B were significantly higher and HDL-C and apo A-I were significantly lower in survivors than in controls. Total plasma apo E did not differ between patients and controls, but HDL-E and the ratio HDL-E/apo A-I were lower in survivors. The data support the view that atherosclerotic patients are often characterized by abnormalities in the concentration and distribution of lipoproteins as well as of apoproteins, even in the presence of normal total plasma lipids.

Adult↗
PubMed1983

The determination of lipoprotein Lp(a) by rate and endpoint nephelometry.

Rate nephelometry is a fast and convenient method for Lp(a) quantification. The linearity in the range of the physiological serum concentrations is good and there is good correlation with other immunochemical methods. The antibody consumption is some 50% higher when compared to the Laurell procedure if light scatter is measured in the RU mode. Measurements in the SU mode on the other hand consume less antibody than the Laurell procedure. The endpoint method, however, is more time-consuming and considered to be less accurate. In addition, only clear samples should be used. Lipemic sera should be cleared by lipase treatment or by high speed centrifugation. The treatment of samples with detergents causes a pronounced reduction of the immunochemical response and thus should be avoided.

Electrophoresis, Agar Gel↗
PubMed1983

Variations in lipids and proteins of lipoproteins by fenofibrate in some hyperlipoproteinaemic states.

A total of 28 hyperlipoproteinaemic patients (8 type IIA, 12 type IIB and 8 type IV) were studied. Each patient was put on a 'prudent' isocaloric diet (50% carbohydrate, 30% fat, 20% protein) following a 2-month period of wash-out. Fenofibrate (300 mg/day) was then given for 2 periods of 2 months, each separated by a 2-month period in which only the dietary treatment was continued. Fenofibrate induced a significantly beneficial effect on the abnormal plasma levels of lipids and apolipoproteins A-I and B in all three phenotypes. Total cholesterol significantly decreased in type IIA and IIB; total triglycerides decreased significantly in all three types. HDL-C increased in all the patients but significantly only in those presenting types IIB and IV. ApoB significantly decreased in the 3 groups while apoA-I increased. The ratio apoA/apoB increased significantly in the three groups. Enzymatic parameters did not vary during the drug treatment. However, 6 patients (16%) dropped out because of gastro-intestinal side effects.

Adult↗
PubMed1983

Changes of apolipoprotein B molecular weight and immunoreactivity in malondialdehyde-modified low density lipoproteins.

ApoB molecular weight by SDS polyacrylamide gel electrophoresis and its immunoreactivity by either electroimmunoassay or radial immunodiffusion has been recorded in human malondialdehyde-modified low density lipoproteins. Malondialdehyde treatment of LDL leads to a reduction of the typical B-100 band and to the appearance of two heavier peptides that can be designated as B-126 and B-151 according to the centile nomenclature. A significant increase of the height of apoB rockets by electroimmunoassay and of the immunoprecipitates diameter by radial immunodiffusion was also recorded.

Apolipoproteins↗
PubMed1982

Serum concentrations of Lp(a) and other lipoprotein parameters in heavy alcohol consumers.

The serum concentration of lipoprotein Lp(a) and of other lipoproteins of 64 individuals consuming more than 200 g of ethanol per day for several years was measured. 42 of the propositi with no clinical signs of alcoholic liver cirrhosis (ALC) had an apoAI/apoAII ratio twice as high as the control group. The apoAI values of the consumers of alcohol were higher and the HDL-C and Lp(a) levels were lower than those of the control group. 22 alcohol drinkers with ALC exhibited strikingly reduced values of all serum lipids and lipoproteins and the lowest Lp(a) concentrations of all. It is suggested that alcohol drinking lowers serum Lp(a) what might be an additional reason why this group of people seems to be a lower risk of atherosclerosis.

Adult↗