Biomedical subjects

M Pocovi

Publications and source records attributed to M Pocovi.

10 recordsLinked to original sources

PubMed1992

[Factors associated with hypoalphalipoproteinemia].

BACKGROUND: Hypoalphalipoproteinemia (HALP) is the most frequent lipid alteration found in patients with myocardial infarction at an early age. It is defined by amounts of lipid cholesterol at high density lipoproteins (cHDL) lower than 10% according to age and sex. The aim of this study was to know the frequency of main factors which reduce the levels of cHDL in a group of subjects with and without HALP. METHODS: Pathological antecedents, consumption of drugs, alcohol and cigarettes, the presence of obesity and levels of cholesterol, triglycerides, cHDL, glucose and urea were studied in a group of 1825 males. The study was performed in the course of medical examinations for workers. RESULTS: The consumption of cigarettes, the index of body mass (IBM) and the prevalence of diabetes mellitus were higher in the group of subjects with HALP. Hypertriglyceridemia (triglycerides > or = 200 mg/dl) was found in 31% of the subjects with HALP vs 10% in the control group (p < 0.001); hypocholesterolemia (cholesterol < or = 150 mg/dl) was also significantly greater (9.8% vs 4.3%, p < 0.01). Altogether, in 64% of the subjects with HALP, factors which may decrease cHDL were associated. Of the factors studied, the number of triglycerides, IBM and the number of cigarettes consumed per day were the independent factors which most significantly contributed to the decrease of cHDL in the regression analysis. CONCLUSIONS: Most of the subjects with hypoalphalipoproteinemia present other modifiable factors such as an elevated index of body mass, cigarette consumption and high amounts of triglicerydes, the correction of which constitutes the base for treatment of this disorder.

Adult↗

PubMed1992

The MspI restriction fragment length polymorphism 3' to the apolipoprotein A-II gene: relationships with lipids, apolipoproteins, and premature coronary artery disease.

In previous studies, a restriction fragment length polymorphism (RFLP) has been identified using MspI restriction endonuclease in the 3' region of the apo A-II gene. The rare variant site for this MspI (M2) has been reported to be associated with higher levels of HDL cholesterol and apo A-II. We have studied the frequency and lipid associations of this RFLP in a population of 168 coronary artery disease (CAD) male and female patients, who had more than 50% narrowing of one or more arteries prior to age 60 years, as well as 255 aged-matched males and females from the Framingham Offspring Study. We also studied 31 kindreds in which the proband had premature CAD. The frequency of the M2 allele was higher in CAD cases (0.20) than in the controls (0.13) (P less than 0.05). In general, those subjects carrying the M2 allele had lower HDL cholesterol and apo A-I plasma levels; however, this difference was only significant (P less than 0.02 and 0.002, respectively) in females with CAD. No cosegregation of the M2 allele with hypoalphalipoproteinemia was found in 31 kindreds studied. However, in both generations there was a trend for those subjects carrying the M2 allele to have lower HDL cholesterol levels than those carrying the M1 allele. Sequence analysis of the apo A-II gene of subjects homozygous for either the M1 (n = 1) or the M2 allele (n = 2) revealed that this RFLP is due to a T----C single base mutation 528 bp 3' to the apo A-II gene. In the subjects homozygous for the M2 allele no other mutations were found within the coding region of the apo A-II gene that could result in changes in the primary sequence of the protein. These data indicate that the MspI RFLP 3' to the apo A-II gene is somewhat more frequent in the CAD group. However, there was no significant association between this RFLP and any of the parameters examined. In conclusion, this DNA marker lacks the specificity to be clinically useful for CAD risk assessment in the population studied.

Adult↗

PubMed1991

Restriction fragment length polymorphisms of the apolipoprotein A-I, C-III, A-IV gene locus. Relationships with lipids, apolipoproteins, and premature coronary artery disease.

Data from various laboratories have indicated associations of various alleles determined by RFLPs within or adjacent to several apolipoprotein genes with abnormalities in plasma lipids and/or premature coronary artery disease (CAD). In order to assess such relationships we have examined allele frequencies of 8 different RFLPs within or adjacent to the apo A-I, C-III and A-IV gene complex on the long arm of chromosome 11 (MspI, 5' to the apo A-I gene; MspI, within the apo A-I gene; PstI, 3' to the apo A-I gene; SstI, 3' to the apo C-III gene; PvuII, within the apo C-III gene; PvuII, 5' to the apo C-III gene; XbaI, within the apo A-IV gene; and XbaI, 3' to the apo A-IV gene) in 202 patients with CAD (50% narrowing of one or more coronary arteries) prior to age 60 and 145 normal controls. None of the allele frequencies of these RFLPs were significantly different in cases as compared to controls. With regard to associations with plasma lipids and apolipoprotein levels, the rare allele determined by the absence of the PstI site was associated with elevated triglyceride levels (P less than 0.05) in cases, but not in controls. In contrast, the rate MspI allele 5' to the apo A-I gene was associated with elevated triglyceride levels (P less than 0.05) in controls but not in cases. In both cases and controls, subjects with the uncommon SstI allele had triglyceride levels that were 9 and 38% higher than in those without this allele. These differences were significant (P less than 0.05) only in controls. Our data indicate that the rare allele determined by the SstI site within this gene complex deserves further study in order to understand its association with elevated triglycerides in Caucasian populations. However, at the present time all these DNA markers lack sufficient specificity to be clinically useful for CAD risk assessment.

Age Factors↗

PubMed1989

Cord blood lipoprotein-cholesterol: relationship birth weight and gestational age of newborns.

Umbilical plasma levels of lipoproteins-cholesterol were measured in 60 premature (less than 37 weeks), 60 small for gestational age (SGA, greater than 37 weeks), and 60 full term newborns (greater than 37 weeks) to ascertain the relationship between gestational age, infant's weight and concentration of plasma lipoprotein cholesterol. Umbilical levels of total cholesterol (TC), unesterified cholesterol (UC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) in premature newborns were significantly higher (P less than .001) than in term infants. The levels of TC, UC, HDL-C and very low density lipoprotein cholesterol (VLDL-C) were substantially higher (P less than .05) in umbilical cord plasma of SGA newborns than in cord plasma of full term newborns. Lecithin:cholesterol acyltransferase activity in cord plasma was indirectly assessed by measuring the ratio of esterified cholesterol to unesterified cholesterol (CE/UC). This ratio was significantly lower (P less than .01) in preterm and SGA than in full term newborns. In addition, plasma TC, UC, LDL-C and HDL-C levels were inversely correlated with gestational age of newborns. By contrast, CE/UC ratio had an inverse correlation with gestational age and HDL-C of the newborns. These findings suggest that the levels of TC in newborns are regulated by the uptake of LDL-C by the fetal adrenal and, additionally, by the lecithin:cholesterol acyltransferase (LCAT) activity of newborn plasma. Only by careful follow-up of hyperlipidemic neonates can the true incidence of familial hyperlipoproteinemia and the value of early diagnosis be assessed.

Birth Weight↗

PubMed1989

[Keratoacanthoma centrifugum of Miedzinski and Kozakiewicz].

We describe the case of one patient, 54-year-old male, with a keratoacanthoma centrifugum situated on the right auricular pavilion. The injury begins as a small nodule with a keratotic innermost part that rapidly is excavated, grows centrifugally, appearing as a new lesion, an expansion of the primary one, in the posterior higher region, with the same characteristics. These lesions join and perforate the auricular cartilaginous tissue.

Ear Cartilage↗

PubMed1988

Longitudinal study of plasma lipids and lipoprotein cholesterol in normal pregnancy and puerperium.

Plasma lipids and lipoprotein cholesterol distribution were measured in 60 normal pregnancies studied longitudinally at 12, 20, 28, and 36 weeks of gestation and 3 and 40 days postpartum. Total cholesterol, unesterified cholesterol, phospholipids, triglycerides and cholesterol in low- and very-low-density lipoproteins rose progressively during pregnancy. Maximal values were reached at 36 weeks for total cholesterol, unesterified cholesterol and low-density lipoprotein cholesterol and at partum for triglycerides, very-low-density lipoprotein cholesterol and phospholipids. High-density lipoprotein cholesterol was hardly affected by pregnancy. During the second half of pregnancy and postpartum period, high-density lipoprotein cholesterol was consistently and negatively correlated with triglycerides and very-low-density lipoprotein cholesterol. In each period studied total cholesterol showed very high positive correlation with low-density lipoprotein cholesterol but a weak correlation with high-density lipoprotein cholesterol.

Cholesterol↗

PubMed1984

Plasma lipids and cholesterol esterification rate during pregnancy.

Total plasma cholesterol, cholesterol in high-density lipoproteins, unesterified cholesterol, total plasma triglycerides, and plasma cholesterol esterification rate were measured in three groups of subjects, including 176 pregnant, 22 nonpregnant, and 22 postpartum women. Total cholesterol levels showed a 49% increase during pregnancy, reaching a maximum at 33 to 36 weeks. Triglycerides showed a three-fold increase over the levels in nonpregnant women by 37 to 40 weeks' gestation. However, unesterified cholesterol percentage and high-density lipoprotein cholesterol were hardly affected by pregnancy. The hyperlipidemia of pregnancy is accompanied by an increase in the plasma cholesterol esterification rate for the first half of gestation. During the second half of gestation there is little change in the plasma cholesterol esterification rate, in the presence of a continuing increase in plasma lipid levels.

Adolescent↗

PubMed1983

Rate and equilibrium constants of the tetramerization process of phosphorylase b. Influence of AMP and Mg2+.

The association-dissociation equilibrium of phosphorylase b at different enzymatic concentrations has been studied at 25 degrees C in this paper, pointing out how this equilibrium is affected by both AMP and Mg2+ concentrations. It has also been proved that association of phosphorylase b in the presence of AMP and Mg2+ follows second-order and first-order rate laws in the direction of tetramerization and dimerization, respectively. Rate constants have also been calculated and their dependence upon protein, AMP and Mg2+ concentrations studied thoroughly.

Adenosine Monophosphate↗

PubMed1982

[Cholesterol esterification in human plasma].

The initial rates of the reaction catalized by the lecithin: cholesterol acyltransferase, were measured in the plasmas of two groups of normal subjects (20 males and 20 females) of the same age (average 20 years). The determination of the initial rate of lecithin: cholesterol acyltransferase reaction in human plasma was measured by a method based on the determination of plasma unesterified cholesterol by gas-liquid chromatography. With this technique the plasma esterification reaction is linear to approx. 75 min. The influence of sex, concentration of cholesterol total, high density lipoprotein cholesterol and unesterified cholesterol on the initial rate of plasma cholesterol esterification has been shown.

Adult↗

PubMed1980

Regulation of phosphorylase b by AMP. The effects of enzyme concentration.

The enthalpies of binding of AMP to phosphorylase b have been measured as a function of enzyme concentration in glycylglycine buffer, pH 6.9. The results show how a conformational transition, which takes place in the concentration range of 1.7 to 2.5 mg/ml of phosphorylase b, affects the enthalpies of the two binding sites per monomer for the allosteric activator AMP. The enthalpies of the AMP interaction with its higher and lower affinity binding sites are -220 and -640 kJ (mol monomer)-1 at an enzyme concentration of 1 mg/ml, and -120 and -360 kJ (mol monomer)-1 at 2.7 mg/ml. The conformational transition of phosphorylase b alters the reactivity of the slow -SH groups of the enzyme with 5,5'-dithiobis(2-nitrobenzoic acid), suggesting that the environment of these groups are affected by the process. On the other hand, kinetic data show that the saturation of both classes of AMP binding sites affects the catalytic behavior and that their specific effects on the catalytic process are altered by the enzymatic transition dependent on the enzyme concentration. Thus, a strong inhibition is associated with the saturation of the weaker affinity AMP binding sites at 3 mg/ml while the saturation of these weaker affinity binding sites at 1 mg/ml produces an important activation of the enzyme.

Adenosine Monophosphate↗