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Biomedical subjects

G Cazzolato

Publications and source records attributed to G Cazzolato.

At least 55 records · Page 3Linked to original sources
PubMed1981

Preparative isotachophoresis of human plasma high density lipoproteins HDL2 and HDL3.

HDL2 and HDL3 subclasses of human serum HDL were isolated by preparative ultracentrifugation and further analyzed by isotachophoraesis on polyacrylamide gel. The HDL2 divided into six subfractions and the HDL3 into ten subfractions differing in chemical composition and in apolipoproteinl content. The apoA-I/apoA-II ratios differed widely among the various subfractions. The subfractions with the highest apoA-I/apoA-II ratio appeared to have the greatest affinity for cholesterol. The preparative isotachophoresis, used for the first time in this type of investigation, has high resolving power and is reproducible and thus suitable for use in the study of the structure and metabolism of the lipoproteins.

Apolipoproteins↗
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

Relationship between apolipoproteins and chemical components of lipoproteins in survivors of myocardial infarction.

The relationship of VLDL-, LDL-, HDL-cholesterol, VLDL-triglycerides and of apolipoproteins A-I, A-II and apo-D has been studied in 89 survivors of myocardial infarction and in 80 age- and sex-matched controls. The two groups as a whole were analysed as well as sub-groups of subjects divided according to their lipid phenotype (normolipidaemic, IIA, IIB and IV). The data support the view that plasma levels of apo-B and apoA-I as well as their ratio and the TC/apo-B and LDL-C/apo-B ratios are better indicators of lipid derangement in survivors of myocardial infarction than the levels of LDL-cholesterol and HDL-cholesterol. Total cholesterol, total triglycerides, VLDL-cholesterol and VLDL-triglycerides are of no help in discriminating between the two series. The VLDL-C/VLDL-TG ratio in survivors is, however, very close to the ratio thought to be peculiar to type III hyperlipidaemia.

Adult↗
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↗
PubMed1979

Are apolipoproteins better discriminators than lipids for atherosclerosis?

Plasma-levels of major lipids (cholesterol, triglyceride, high-density-lipoprotein cholesterol), two major apolipoproteins (apo-B and apo-A1), and two ratios (total-cholesterol/apo-B and apo-A1/apo-B) were studied in 218 survivors of myocardial infarction and 160 controls. Apolipoproteins were as good as lipids as discriminators between the populations under the age of 50 and better in the sixth to eighth decades.. Furthermore, values of total-cholesterol/apo-B and apo-A1/apo-B obtained from controls and normolipaemic survivors of myocardial infarction gave a bimodal distribution. The protein moiety of lipoproteins is a better discriminator than lipids between atherosclerotic subjects and controls.

Adult↗
PubMed1979

Determination of high-density lipoproteins: screening methods compared.

Factors reflecting the concentration of high-density lipoproteins in serum were assessed for 108 men and 106 women participating in a Venetian screening program for hyperlipoproteinemia. The methods applied, optimized in our laboratory, were: (a) cholesterol in high-density lipoproteins, determined in the supernate after sedimentation of the very-low-density lipoproteins + low-density lipoproteins with dextran sulfate or sodium phosphotungstate; and (b) immunochemical quantitation of apolipoprotein A-I and apolipoprotein A-II by Laurell's "rocket" technique. The latter determinations were performed with total serum before and after delipidation with diispropyl ether/n-butanol (6/4 by vol). The dextran sulfate method gave about 5% higher values than did the phosphotungstate method, but the correlation between the two was excellent (r = 0.95). Results of the immunochemical quantitation indicate that delipidation of lipoproteins before Laurell electrophoresis may not be necessary if only freshly drawn sera are used.

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↗
PubMed1978

Variations in apolipoproteins B and A1 during the course of myocardial infarction.

The plasma apolipoproteins B and A1, and plasma lipids and lipoproteins, were studied in fifteen patients with acute myocardial infarction. In the days immediately after acute infarction there was a decrease in total cholesterol, low density lipoprotein-cholesterol, total apolipoprotein-B, low density lipoprotein apolipoprotein-B and high density lipoprotein apolipoprotein A1. High density lipoprotein-cholesterol remained unchanged. In the same period the total triglycerides, very low density lipoprotein-protein, very low density lipoprotein-cholesterol, very low density lipoprotein apolipoprotein-B and very low density lipoprotein apolipoprotein A1 were increased. A reduction of the apolipoprotein ratio CII/CIII occurred after the acute phase. After 25--30 days all these values regained their baseline values.

Aged↗
PubMed1977

Familial hyper-alpha-lipoproteinaemia. Further studies on serum lipoproteins and some serum enzymes.

Some new data are given concerning a family whose members are characterized by high levels of alpha-(HDL)-cholesterol. Data from the new members of the family, not previously studied, confirm that the defect is not associated with any cardiac or neurological defect nor with xanthomata. Studies performed to assess the polypeptide composition of HDL of the affected members resulted in completely normal results. The post-heparin lipolytic activity (PHLA), the liver lipase and the lecithin-cholesterol acyltransferase (LCAT) activities also proved to be within the normal limits.

Acyltransferases↗
PubMed1977

Chemical composition of ultracentrifugal fractions in different patterns of human atheroslcerosis.

The chemical composition of ultracentrifugal fractions of VLDL (d less than 1006), LDL (d 1006-1063) and HDL (d less than 1063) has been studied in males affected by atherosclerosis of different vascular beds. Thirty-seven subjects affected by post-infarction cardiopathy (M.I.) showed significantly higher values of total-C, VLDL-C and LDL-C when compared to 52 controls. Twenty-three patients affected by non-occlusive ischaemic heart disease (I.H.D.) showed higher values than controls of total-C, VLCL-C, LDL-C, total TG, VLDL-TG, and GDL-TG. Twenty-three patients with atherosclerosis of the inferior limbs (P.A.) were characterized by increased levels of total-TG, VLDL-TG, VLDL-C, HDL-C. A group of patients who had suffered a stroke from cerebro-vascular disease (C.V.D.) did not show any significant difference from controls. In the M.I. group, 56% of the patients had a high level of C-VLDL. Patients with I.H.D. were characterized mostly by an increase in C-LDL, Patients with P.A. showed the highest values of total -TG, VLDL-TG and LDL-TG. Some of the observed differences are probably due to different metabolic backgrounds. Some other differences may be due to variations in dietary habits after heart infarction. Patients with levels of plasma cholesterol and triglyceride beyond the 90th percentile of the normal group showed many abnormalities in the chemical composition of their lipoproteins. It is noteworthy that increased amounts of cholesterol may collect in lipoprotein classes different from LDL while increased amounts of triglyceride may collect in classes different from VLDL.

Adult↗
PubMed1975

"Sinking" lipoprotein in normal, hyperlipoproteinaemic and atherosclerotic patients.

The presence of a "sinking" lipoprotein (SLP), demonstrated by combining electrophoretic and ultracentrifugal methods, has been recorded in 13.6% of 44 normal subjects, in 62.2% of 37 hyperlipoproteinaemic patients with types IIA, IIB and IV and in 39.8% of 107 atherosclerotic patients. The recorded data suggest that the "sinking" lipoprotein may be related to human atherosclerosis and to hyperipoproteinaemic states. A pre-beta (S band in the fraction with density greater than 1.006 appeared in 2 out of 20 subjects receiving as isocaloric hyperglucidic diet (CHO, 80; F, 5;P, 15) for 8 days and in 3 out of 10 subjects receiving an acute ethanol oral load. The nature of the nutritionally determined lipoprotein is doubtful. It seems improbable that the newly synthetized lipoprotein is the "true" sinking lipoprotein as this considered to be a genetically determined marker. These data may signify that other "sinking" lipoproteins unrelated to LP-Berg system may exist or may be determined. It is also probable that the new synthetized lipoprotein may have some relationship with the "intermediate" lipoprotein.

Adult↗
PubMed1975

Changes in the composition and physico-chemical characteristics of serum lipoproteins during ethanol-induced lipaemia in alcoholic subjects.

The effect upon serum lipids and lipoproteins of a large intake of ethanol (180 g in 6 hr) has been studied during the ensuing 24 hr in 21 subjects. These were all men who were habituated to heavy drinking but who were shown to be normolipaemic when maintained on a normal diet with a restricted intake of alcohol. In all the subjects studied, ingestion of this amount of ethanol induced an acute hypertriglyceridaemia which varied in intensity between individuals, with increases ranging from 26% to 377% above the basal value. On the other hand, no significant change occurred in plasma cholesterol. In addition to measurements of triglycerides and cholesterol, the plasma from all the subjects were examined by electrophoresis in agarose and polyacrylamide gels with photometric scanning of the gels. In a subgroup of ten of the subjects, the plasma lipoproteins were separated into very low density (VLDL), low-density (LDL), and high-density (HDL) fractions, which were also analyzed biochemically and by electrophoresis. Following ethanol ingestion, a mean increase of about twofold in triglyceride content, and a decrease in the cholesterol/triglyceride ratio was observed in VLDL, LDL, and HDL. The triglyceride/protein ratio decreased in VLDL and increased in LDL. On electrophoresis of the intact sera following ethanol ingestion visible particulate fat and a band which failed to permeate the gel ('chylomicron-like band') was observed in five out of ten subjects and eight out of these ten subjects showed a prominent prebetalipoprotein (pre-beta) band. This component was found to be present in the lipoprotein fraction of density greater than 1.006 Kg/1. Examination of this fraction from basal specimens revealed a pre-beta band in only two of the ten subjects and the intensity of this band increased in the corresponding fractions from the same subjects after ethanol ingestion. In an additional four subjects no pre-beta was detected in this fraction before ethanol but appeared after ethanol ingestion. No attempt has been made to characterize further the component with these characters but it is suggested that it is probably an intermediate lipoprotein (ILDL), that is, a lipoprotein with characteristics intermediate between VLDL and LDL.

Adult↗