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Biomedical subjects

G De Backer

Publications and source records attributed to G De Backer.

At least 127 records · Page 7Linked to original sources
PubMed1992

Plasma lipoprotein(a) values and severity of coronary artery disease in a large population of patients undergoing coronary angiography.

To determine possible associations between lipoprotein(a) [Lp(a)] and the severity of coronary artery lesions, we measured lipid, apolipoprotein, and Lp(a) in a large population of Belgian patients (n = 1054) undergoing coronary angiography. In both women and men, univariate analysis demonstrated significant differences in the Lp(a) concentrations according to the severity of the coronary stenosis. However, after adjustment for possible confounding factors, many of these differences were attenuated, indicating that other variables that differentiate patients from control subjects also influence Lp(a) distribution. Differences in lipid, apolipoprotein, and Lp(a) concentrations between male and female patients are discussed.

Adult↗
PubMed1991

Platelet fatty acids and function in two distinct regions of Belgium: relationship to age and dietary habits.

We compared the dietary habits, fatty acid composition of plasma and platelet phospholipids, and platelet function in two groups of healthy Belgian male subjects, known to differ in their mortality rate from coronary heart disease (CHD). In the Walloon subjects, there was a larger intake of saturated and a lower intake of (n-6) polyunsaturated fats, confirmed by the fatty acid composition of plasma and platelet phospholipids. While plasma HDL and total cholesterol were similar in the present samples of the two communities, platelet aggregation to epinephrine was significantly higher in the Walloon subjects. When the two populations were divided into younger (28-54 years) and older (55-73 years) age groups, the older Walloon subjects exhibited platelet hyper-aggregability to most of the agonists, compared to the other three groups. In addition to dietary fats, alcohol and smoking habits, age was an important determinant of platelet phospholipid fatty acids and platelet reactivity. The present results reinforce those of previous studies, indicating that platelet behaviour is significantly affected by the main risk factors for CHD.

Aging↗
PubMed1990

Determinants of fat consumption in a general population.

In a random sample of the adult population (aged 25-64 years) from Ghent and Charleroi in Belgium, dietary fat consumption was estimated using both qualitative and quantitative dietary methods. A fat consumption score (FCS) was constructed from the qualitative method, and it correlated significantly with the dietary polyunsaturated/saturated fatty acids (P/S) ratio calculated from the quantitative method (r = -0.48; p less than 0.001). Differences in FCS were then studied using univariate and multivariate analyses. In both men and women, FCS was higher in Charleroi than in Ghent. In men, FCS was inversely related with educational level and with age. In women, significant correlations were observed with marital status. No differences were found in FCS by smoking behaviour. With the coronary risk factors, low-order relationships were found, but only in men. In the middle-aged group, significant correlations were found between FCS and the fatty acid composition of the serum cholesteryl esters, in particular with the linoleate/oleate ratio.

Adult↗
PubMed1989

Relationship between serum cholesteryl ester composition, dietary habits and coronary risk factors in middle-aged men.

Serum cholesteryl palmitate, oleate, linoleate and arachidonate were measured using high performance liquid chromatography in 134 men aged 45-64 years, randomly selected from the population of Ghent, Belgium. No relationship was observed between these cholesteryl esters, expressed as a percentage of their total, and age, serum cholesterol, arterial blood pressure, smoking habits and body mass index. Dietary habits were assessed using a 3-day diary method. No relationship was found between dietary habits and serum lipids. Highly significant correlations were observed between diet and the serum cholesteryl esters. In multivariate analyses dietary variables account for significant proportions of the variances of the serum cholesteryl esters. The results indicate that measurements of cholesteryl esters can be used to differentiate on the population level between subgroups with different dietary habits particularly with respect to fat consumption.

Age Factors↗
PubMed1989

Quantitation of plasma free cholesterol and cholesteryl esters by high performance liquid chromatography. Study of a normal population.

We describe a convenient method for the separation and quantitation of plasma free cholesterol and cholesteryl esters by high performance liquid chromatography (HPLC). After extraction of 100 microliters plasma with isopropanol the plasma cholesteryl esters were resolved on a Zorbax ODS reversed-phase column by isocratic elution with acetonitrile/isopropanol (50:50, v/v). Baseline separation of the plasma cholesteryl esters including the internal standard was obtained within a 25-min run. The intra- and interassay CV was less than 4%. The results obtained by HPLC show good agreement with enzymatic and gas-liquid chromatographic methods. High performance liquid chromatography provides a simple method for the quantitation of individual cholesteryl esters avoiding tedious chromatographic and derivatisation steps inherent to GLC. Our HPLC method was applied to the monitoring of plasma cholesteryl esters in a normal population and can also be used for the study of cholesteryl esters from lipid extracts of biological samples.

Adult↗
PubMed1989

Interaction between the microtubule inhibitor tubulozole and gamma-irradiation in murine tumors in vivo.

The combined effect of the microtubule inhibitor tubulozole and gamma-irradiation has been investigated in vivo in subcutaneous MO4 fibrosarcomas and Lewis Lung carcinomas. A marked interactive effect on tumor growth was observed when 160 mg/kg tubulozole was orally administered before the tumors were treated with 10 Gy radiation. Dose dependency and optimal effect were obtained on tumor growth of MO4 tumor bearing animals when the drug treatment was given 6 hr prior to the irradiation. The optimal pretreatment time coincided with the time at which a peak mitotic index in the tumor tissue was observed. An enhancing effect is also noticed at other doses of radiation in MO4 tumors pretreated 6 hr before with 160 mg/kg tubulozole. The interactive effect is maintained in a clinically relevant dose fractionation schedule whereby 8 fractions of 2 Gy each were pretreated 6 hr before with 80 mg/kg tubulozole. Tubulozole-T, the stereo-isomer of tubulozole, neither exhibits any antimicrotubular action nor exerts an antitumoral effect on its own or in combination with gamma-irradiation. The possible mechanisms of interaction between tubulozole and gamma-irradiation in tumor tissue are discussed.

Animals↗
PubMed1989

[ECG abnormalities in the MONICA Gent-Charleroi study population].

In a survey of a random sample of the adult population (aged 25-64 yr) from Ghent and Charleroi (n = 1693), 103 (6.1%) showed ECG-abnormalities suggestive of coronary heart disease (Minnesota code I, IV, or V); prevalence was equal in men (6.2%) as in women (6.0%). In men, 30% of ECG-abnormalities suggested an old myocardial infarction as compared to 23.4% in women. Men with abnormal ECG had a positive history of acute myocardial infarction in 23%, as compared to 23.4% in women. Multivariate discriminant function analysis shows that men with abnormal ECG are older, have a higher systolic blood pressure and were more often married. Women with ECG abnormalities were significantly older, had a lower HDL-level and were less educated. So, although the prevalence of ECG abnormalities is almost similar between sexes, they correlate differently with antecedents of infarction and are poorly related to different sets of risk factors in men as compared to women.

Adult↗
PubMed1989

[Determinants of fat consumption in a general population].

In a random sample of the adult population (aged 25-64 yr) from Ghent and Charleroi in Belgium, dietary fat consumption was estimated using both qualitative and quantitative dietary methods. A fat consumption score (FCS) was constructed from the qualitative method and correlated significantly with the dietary P/S ratio calculated from the quantitative method. Differences in FCS were then studied using univariate and multivariate analyses. In both men and women FCS was higher in Charleroi than in Ghent. In men FCS was inversely related with educational level and with age and positively related with BMI. In women no significant correlations were observed. In the middle-aged group (aged 45-64 yr) significant correlations were found between FCS and the fatty acid composition of the cholesterol-esters, in particular with the linoleate/oleate ratio.

Adult↗
PubMed1988

Incidence and prognostic significance of asymptomatic ischaemia in patients with sustained ventricular arrhythmias.

The role of ischaemia in the natural history of sustained monomorphic ventricular tachycardia not related to acute myocardial infarction is not well documented. We examined 38 patients (mean age 60 years, mean ejection fraction 33%) with programmed electric stimulation and thallium scintigraphy to study the presence of perfusion defects and to assess its prognostic significance. Reversible perfusion defects (RPD), alone or in combination, were seen in 17 patients (44.7%), persistent perfusion defects (PPD) in 31 (81.5%), and RPD and PRD combined existed in 14 patients (37%). Normal scintigrams were obtained in only four patients. Segmental analysis gave a mean 'infarction score' (number of PPDs on a total of 15 segments) of 4.2; the mean 'ischaemia' score (number of RPDs) was 1.2. Recurrence of tachycardia or sudden death was observed in 14 patients during a follow-up of 17 +/- 13 months. The predictive value (PV) of the presence of a RPD for recurrence was 63%, the PV of its absence was 82%; the predictive accuracy was 74% (P = 0.0069). This was as important as the data obtained with the drug studies (+PV 83%; -PV 86%; overall PV 83%, P = 0.002). The mean ischaemia score was 3.3 in the group with recurrence and 2 in the patients without recurrence. As pharmacological studies are only feasible in a subgroup with inducible tachycardia, thallium scintigraphy is of benefit to a larger group for predicting effective drug therapy and the risk of recurrence.

Adult↗
PubMed1988

The Belgian Heart Disease Prevention Project: 10-year mortality follow-up.

The Belgian Heart Disease Prevention Project was a controlled, randomized multifactorial intervention trial in middle-aged men which lasted 6 years. Significant net differences between intervention and control groups were observed in change in risk profile, in total mortality and in CHD incidence. The net difference in risk profile change was greatest at two years, intermediate at four years and minimal at six years. Total and cause-specific mortality rates were systematically followed from the 6th to the 10th year. Follow-up at 10 years was 99.3% complete. The differences between intervention and control groups in total, coronary and cardiovascular mortality reduced from the 6th to the 10th year. The results suggest that changes in risk profile are rapidly followed by changes in cardiovascular mortality, but this applies in both directions. Thus risk reduction should be maintained in order to achieve a long-lasting preventive effect.

Adult↗
PubMed1988

Comparison of the attack rates of acute myocardial infarction in two Belgian towns.

Comparison of the attack rates for acute myocardial infarction in two Belgian towns AMI attack rates in two Belgian towns. Belgium is divided in two main regions: Flanders in the North with a Dutch-speaking population, and Wallonia in the South with a French-speaking community. From 1982 onwards, a register of acute myocardial infarction has been in operation in Ghent, a Flemish town, and in Charleroi in Wallonia, following the procedures of the MONICA (Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases) study. Annual attack rates of myocardial infarction are presented for a 5-year period. During this period, the annual attack rates for men are 10-20% higher in Charleroi than Ghent. In women, the ratio between the two cities is less clear. The results of this community registers confirms the regional differences observed previously in Belgium using other epidemiological techniques.

Adult↗
PubMed1988

Multicentre study of the efficacy and tolerance of acebutolol versus atenolol in the long term treatment of mild arterial hypertension.

The efficacy, tolerance and effect on serum lipids of acebutolol were compared with those of atenolol over a 6-month period in a large group of patients with mild arterial hypertension. Both drugs were equally effective in reducing blood pressure, and tolerance was generally excellent. High density lipoprotein (HDL)-cholesterol concentrations were reduced to a similar extent by both treatments at 2 months and this change was reflected in measurements of the total cholesterol concentrations. However, no significant changes occurred in serum triglyceride levels and at 6 months all serum lipid parameters had returned to baseline values. These observations suggest that cardioselective beta-blockers have no adverse effects on serum lipids at 6 months, after a temporary reduction of HDL-cholesterol at 2 months.

Acebutolol↗
PubMed1988

Blood pressure and excretion of sodium, potassium, calcium and magnesium in 8- and 9-year old boys from 19 European centres.

We have measured systolic and diastolic blood pressure and excretions of sodium, potassium, calcium and magnesium in groups of about 50 8- and 9-year-old boys from 19 European centres using standardized methods for the measurement of blood pressure and collection of urine, and by carrying out all analyses in one laboratory. Weight, height, pulse rate and environmental temperature were also studied. Mean systolic blood pressure ranged from 91 to 105 mm Hg and diastolic blood pressure from 51 to 66 mm Hg. Mean 24-h excretion of sodium was between 91 and 146 mmol/d, that of potassium between 29 and 60 mmol/d, that of calcium between 1.5 and 2.6 mmol/d and that of magnesium between 2.7 and 4.2 mmol/d. Mean sodium excretion tended to be lower and potassium excretion tended to be higher in the boys from the north-western parts of Europe. Relations between either systolic or diastolic blood pressure and electrolyte excretions were generally weak or absent. Most remarkable is that only the association between mean diastolic blood pressure and 24-h magnesium excretion (partial regression coefficient (b +/- s.e., -5.04 +/- 2.08 mm Hg/mmol/d) was statistically significant after adjusting for differences in creatinine excretion and environmental temperature. Mean systolic blood pressure was not significantly related with any of the variables measured. The partial regression coefficient (b +/- s.e.) for diastolic blood pressure on weight was 0.186 +/- 0.062 mm Hg/kg, on height 0.165 +/- 0.056 mm Hg/cm, on pulse rate 0.364 +/- 0.100 mm Hg/beats per min and on outside temperature -0.25 +/- 0.07 mm Hg/degrees C.

Blood Pressure↗
PubMed1988

Physical activity and psychosocial variables in atherosclerosis.

The clinical consequences of atherosclerosis differ substantially by time, by place and by person. The between population variation can largely be explained by differences in the classical risk factors. Within a population it becomes more difficult to predict atherosclerosis risk solely on the basis of blood pressure, serum cholesterol and smoking. On the individual level risk prediction becomes even more hazardous. Among the long list of less well documented or more controversial risk indicators physical activity and psychosocial variables are of prime importance. In epidemiological research the association between physical inactivity and atherosclerosis is modest compared to the classical risk factors. Physical inactivity does not necessarily precede the atherosclerosis process. However a majority of prospective epidemiological surveys performed has found physical inactivity to be a risk factor. The ability of physical inactivity or physical fitness to predict atherosclerosis events has been reproducible when applied crossculturally but the consistency with clinical pathological studies is poor. Regular exercise most likely helps to decrease other risk factors. Therefore the inclusion of regular exercise in one's life style makes good sense for many reasons. Concerning the psychosocial variables there is overwhelming evidence to accept that they play a role in the development of atherosclerosis as well as in the occurrence and recurrence of its clinical consequences. However major problems exist to quantify in a standardized way these psychosocial factors across or within populations and in a given individual. Various hypotheses relating atherosclerosis to stress, social support, personality pattern, psychological traits or life events have been tested in epidemiological, experimental and clinical studies. In a majority of these, significant associations were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Arteriosclerosis↗
PubMed1987

Distribution and composition of HDL subclasses in students whose parents suffered prematurely from a myocardial infarction in comparison with controls.

The purpose of this study was to analyze the distribution and composition of the HDL subclasses in students whose parents suffered from a premature coronary heart disease (CHD), in comparison with a control group without any familial history of CHD. In the first part of this study, we observed significantly lower apo A-I concentrations in the cases than in the controls. Since there was a significant difference in smoking habits between cases and controls, and since we wanted to study the effect of a parental history of premature CHD on the composition of the HDL subclasses independently of smoking, the present study was conducted on the 17 pairs of non-smokers male cases and controls. In agreement with the results on total serum, we observed lower apo A-I concentrations in the HDL2b and HDL2a + 3a fractions in the cases compared to the controls. The apo A-II and cholesterol levels in these fractions were not significantly different between the 2 groups. The selective decrease of apo A-I in the HDL subclasses with the lowest density might be due to a decreased number of particles containing only apo A-I, with which a protective effect against atherosclerosis might be associated.

Adult↗
PubMed1987

Protection against ischemic heart disease in the Belgian Physical Fitness Study: physical fitness rather than physical activity?

Occupational and leisure time physical activity and conventional risk factors were determined in the Belgian Physical Fitness Study, a prospective study of 2,363 healthy male factory workers who were aged 40-55 years at entry in 1976-1978 and who were followed for five years. Physical fitness, defined as the interpolated physical working capacity at heart rate 150 beats per minute, was measured in 2,109 subjects. In this subgroup, there were 31 myocardial infarctions and sudden deaths. Smoking, physical fitness, and high density lipoprotein cholesterol (HDL cholesterol) were independent risk indicators for subsequent ischemic heart disease, while both physical activity scores were not. It is concluded that in this healthy, predominantly sedentary population, the fitness level, but not the physical activity pattern, is an independent protective factor against ischemic heart disease.

Adult↗
PubMed1987

Restrictive cardiomyopathy caused by adipositas cordis.

Adipositas cordis is a very rare disorder, characterized by fatty infiltration of myofibers. It has been related to dilated or hypertrophic cardiomyopathy and obesity. In this report, however, we present a non-obese patient, presenting with a restrictive syndrome and showing massive infiltration of adipocytes in the interventricular septum, proving adipositas cordis.

Cardiomyopathies↗