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Biomedical subjects

G Bittolo Bon

Publications and source records attributed to G Bittolo Bon.

33 records · Page 2Linked to original sources
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↗
PubMed1980

Zonal rotor ultracentrifugation: a proposal for improving the effectiveness of the procedure.

A methodological variant of the zonal ultracentrifugation technique for the separation of plasma lipoproteins is described. The modification consists of (1) preloading the rotor with water and (2) using a different gradient former, and altering the gradient profile during the second step. This variant permits the detection of an intermediate lipoprotein even in healthy individuals and in cord blood.

Centrifugation, Zonal↗
PubMed1980

High and low high-density lipoproteins: clinical implications.

High-density lipoproteins (HDL) are macromolecular complexes of lipids and proteins which float in the ultracentrifuge between densities of 1.063 and 1.21 g/l. A major division of HDL into two subclasses according to their specific density as been proposed: HDL2 (d = 1.063-1.125) and HDL3 (d = 1.125-1.21). The division is supported by the different proportions of lipids and apoproteins in the two subclasses and by evidence suggesting that the protective effect of HDL lies mostly in the HDL2 subclasses. Recent epidemiological, experimental and clinical data have supported a probable role or HDL as an anti-risk factor due to their negative correlation with the prevalence of ischaemic heart disease. Some of these data are presented and discussed in this paper.

Adult↗
PubMed1979

Values of APO-1 and APO-B in humans according to age and sex.

Two series of 100 subjects each, males and females, have been studied for the determination of plasma values of apo-A1, the major peptide of HDL, and of apo-B, the major peptide of LDL. To minimize a possible influence of variations in plasma lipid levels, two series of subjects were selected with very similar mean values of plasma cholesterol and triglyceride. Despite this criterion of selection apo-A1 was significantly lower in males (127 +/- 18 mg/l) than in females (137 +/- 15 mg/l) while the reverse was true for apo-B (99 +/- 16 mg/l in males vs. 91 +/- mg/l in females). Both apo-B and apo-A1 showed a tendency to increase with advancing age with the greatest increase for apo-A1 (in both sexes) and for apo-B (only in males) from the 3rd to the 4th decade of age.

Adult↗
PubMed1978

HDL-cholesterol, apolipoproteins A1 and B. Age and index body weight.

Some data of previous literature have emphasized a negative correlation between plasma apo A1, HDL cholesterol and coronary heart disease. The present paper stresses a high negative correlation existing both in females and males between values of index body weight (IBW) and plasma levels of HDL cholesterol and apo A1. No correlation has been found between age and, respectively, HDL cholesterol, apo A1 and apo B.

Adolescent↗
PubMedDate not supplied

Lipids, lipoproteins and apolipoproteins in type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus.

Total plasma cholesterol, triglycerides, VLDL-C, VLDL-TG, HDL-C and the apoproteins A-I, A-II, B and D were measured in 111 male non-obese diabetic patients and in 90 male control subjects of similar age and body weight distribution. Forty-eight patients had Type 1 (insulin-dependent diabetes) and 63 had Type 2 (non-insulin-dependent diabetes); all were in stable metabolic control while following an appropriate diet and therapy with insulin or oral hypoglycemic agents. HDL-C, apoA-I, apoB and the apoA-I/apoA-II ratio were significantly increased in the Type 1 patients, whereas the VLDL-C/VLDL-TG and LDL-C/apoB ratios were decreased significantly. Type 2 diabetics showed low HDL-C and low apoA-I/apoA-II ratio, while the values of apoA-I, A-II, D and the VLDL-C/VLDL-TG ratio were significantly higher than in controls. Type 1 diabetics in 'fair' metabolic control presented higher values of TG, VLDL-C, VLDL-TG and apoB than patients in 'good' control: lower values of apoA-I and of the ratios apoA-I/apoA-II, apoA-I/apoB and LDL-C/apoB were recorded in the same subgroup. In Type 2 diabetics no significant differences were observed according to metabolic control, with the exception of a higher apo-D value in subjects in 'fair' control. The data obtained support the view that good metabolic control may be important for the prevention of a relevant derangement of lipoprotein components, particularly in Type 1 patients.

Adult↗
PubMedDate not supplied

Distribution and concentration of apolipoprotein E in high and low density lipoproteins.

An electroimmunoassay of apolipoprotein E (Apo E) in total human plasma and in the supernatant following precipitation with sodium phosphotungstate in the presence of MgCl2 of the apolipoprotein B (Apo B)-containing lipoproteins is described. The assay is specific and sensitive enough to record also low levels of Apo E found in isolated lipoprotein fractions. In 30 normal male subjects, the method gave a total plasma Apo E concentration of 6.67 +/- 1.92 mg/dl and a HDL Apo E concentration of 2.58 +/- 0.91 mg/dl. Total Apo E is positively correlated with total plasma triglycerides. The values of Apo E in the lipoproteins obtained by ultracentrifugation were lower than the corresponding values obtained by a precipitation procedure, with a mean Apo E loss of 12.1% in the low density lipoproteins (VLDL + LDL) and of 34.3% in HDL. After ultracentrifugation, a substantial amount of Apo E was detected in the d greater than 1.210 g/ml fraction. The proposed method allows to study the Apo E concentration and distribution between low and high density lipoproteins in large samples, avoiding the problems connected with high salt concentrations and centrifugal forces.

Apolipoproteins↗
PubMedDate not supplied

Concentration, composition and apolipoprotein B species of very low density lipoprotein subfractions from normolipidemic and hypertriglyceridemic humans.

Lipoproteins in the d less than 1.006 g/ml density range obtained form 13 healthy normolipidemic subjects and from 15 patients affected by primary endogenous hypertriglyceridemia after 14-h fasting were subfractionated by filtration in Biogel A-15 M columns. The mass values and chemical composition of very low density lipoprotein (VLDL) subfractions 1 and 2 thus obtained were studied. In each subfraction the behavior of apolipoprotein B (Apo B) was tested by sodium dodecyl-sulfate polyacrylamide gel electrophoresis. VLDL2 was higher and richer in cholesterol and proteins than VLDL1, while the percentage content of triglycerides was lower. In hypertriglyceridemic patients both VLDL1 and VLDL2 were higher than in normolipidemic subjects, the difference being particularly evident for VLDL1. In both VLDL1 and VLDL2 of nearly all the subjects studied the presence in electrophoretic gels of a large Apo B-100 band and of a minor Apo B-48 band with the appropriate mobility of lymph chylomicrons was detected. The Apo B-100/Apo B-48 ratio was about 6 in VLDL1 and 24 in VLDL2. A trend of a reduced Apo B-100/Apo B-48 ratio was observed in VLDL1 of hypertriglyceridemic patients.

Adult↗
PubMedDate not supplied

Apoprotein B-48 is a constant finding in very low density lipoproteins of humans.

The results of this study indicate that very low density lipoprotein (VLDL) from the plasma of fasting normolipidemic or slightly hypertriglyceridemic subjects contains two apo B species. In SDS gel electrophoresis, the VLDL shows the presence of a major band corresponding to low density lipoprotein (LDL) apo B (apo B-100) and a minor band with the appropriate mobility of the lymph chylomicron apo B (apo B-48). The reactivity of monoclonal antibodies directed against opportunely selected human apo B suggests that the protein with the lower molecular weight corresponds to apo B-48. This finding was confirmed by using immunoadsorbants and affinity chromatography with monoclonal antibodies that react only with apo B-100. Through this method, VLDL were separated into two fractions: one that had only apo B-100 and one with both apo B-100 and apo B-48. Hepatic and intestinal VLDL may constitute different particles. The ratio of apo B-100 to apo B-48 in VLDL decreased as the mass of fasting plasma VLDL increased. This may improve our understanding of the metabolism of triglyceride-rich lipoproteins. The investigation of the new subspecies of apo B may be relevant in understanding the atherogenetic process and better defining the hyperlipidemic states.

Adult↗