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Biomedical subjects

C M van Gent

Publications and source records attributed to C M van Gent.

At least 37 records · Page 2Linked to original sources
PubMed1979

Xanthomatosis and other clinical findings in patients with elevated levels of very low density lipoproteins.

Forty-six patients with xanthomatosis and elevated very low density lipoproteins (VLDL) levels (in different types of hyperlipoproteinaemia) were classified on the basis of the WHO criteria and the cholesterol/triglyceride ratio in VLDL. A large majority (31/46) of the patients referred to the Department of Dermatology could be classified as hyperlipoproteinaemia type III, only 8/46 as type IIB and 7/46 as type IV/V. This distinction seems to be relevant as the xanthomatous lesions differed distinctly between these three types of hyperlipoproteinaemia. Xanthochromia striata palmaris was present in 29/31 cases of hyperlipoproteinaemia type III and was not found in type IV/V patients, who had distinctive papuloeruptive xanthomas. During a follow-up in 35/46 patients all xanthomas disappeared within 2 years except the xanthelasma palpebrarum and tendinous xanthomas. All type IV/V patients (7/7) but only one type III patient (1/31) had abnormal glucose tolerance. Only 2/18 type III patients less than 45 years showed claudication and none of the young type III patients had angina pectoris. In contrast, all four type IIB patients less than 45 years had clinical signs of atherosclerosis. However, angina pectoris and/or claudication were present in 5/13 type III patients over 45 years old. The mean serum cholesterol level was equally elevated in both groups but the cholesterol was mainly present in VLDL in type III and in low density lipoproteins (LDL) in type IIB. In 9/31 type III patients the LDL level was also elevated but was easily normalized by a diet low in carbohydrate, whereas the elevated LDL level in type IIB was therapy-resistant. The recognition of xanthomatous lesions, specifically xanthochromia striata palmaris, as an early sign of type III hyperlipoproteinaemia, can lead to the early diagnosis and successful treatment of these patients, and thus possibly prevent the development of premature atherosclerosis.

Adult↗
PubMed1979

Influence of meal frequency on diurnal lipid, glucose and insulin levels in normal subjects on a high fat diet; comparison with data obtained on a high carbohydrate diet.

Diurnal levels of serum triglyceride (TG) were measured in six normal persons consuming a fixed solid 65% fat diet under steady state conditions in a metabolic unit. The food was divided into either three or eight similar portions, differently spaced over the day and night. The diurnal TG-profiles on this diet were practically identical to those found under comparable conditions on a 65% carbohydrate diet [1]. Mean diurnal TG values did not significantly differ with varying meal frequency. Free fatty acid levels, however, were significantly higher on a high fat diet. Post-prandial glucose and insulin reponses did not significantly differ whether a high fat diet or a high carbohydrate diet was consumed. We conclude that the composition of the diet is of little importance in determining diurnal TG patterns when the diet consists of normal food stuffs, but that these patterns are dependent on meal frequency and distribution.

Blood Glucose↗
PubMed1979

Influence of hydrochlorothiazide on the plasma levels of triglycerides, total cholesterol and HDL-cholesterol in patients with essential hypertension.

The influence of hydrochlorothiazide (HCT) treatment on the plasma levels of triglycerides, total cholesterol and high density lipoprotein cholesterol (HDL-cholesterol) was studied in 10 patients with essential hypertension. After a placebo period of 4 weeks, 50 mg HCT twice daily was given for a period of 9 months, followed by a second placebo period of 4 weeks. Triglycerides, total cholesterol and HDL-cholesterol were determined at the end of both placebo periods and after 1, 3, 6 and 9 months of HCT. For the whole group, there were no significant changes in triglycerides or HDL-cholesterol, whereas total cholesterol significantly increased during HCT. In 6 patients, plasma triglycerides were higher during HCT as compared to both placebo periods. In only 4 patients did HDL-cholesterol increase during HCT. Changes in triglycerides, total cholesterol and HDL-cholesterol were not related and no correlation was found with changes in blood pressure, body weight or serum potassium. In conclusion, this study confirms a possible adverse effect of diuretic treatment on plasma lipids, which should be considered when determining therapeutic regimens for hypertension.

Adult↗
PubMed1978

Methods for the estimation of high density cholesterol, comparison between two laboratories.

The determination of HDL by quantification of HDL-cholesterol was investigated using different methods and employing the Abell method as reference. The routinely applied direct method of Huang (calibrated on Abell standardized sera) and the enzymatic method of Röschlau were tested. Results show that with the Huang method, as compared to Abell values, a total laboratory error of less than 4.5 mg/100 can be achieved in 95% of the cases. The enzymatic method gave rise to erroneous results. Comparisons between two laboratories in experiments using random and pool sera are presented.

Chemical Phenomena↗
PubMed1978

Reduced high-density lipoprotein in women aged 40-41 using oral contraceptives. Consultation Bureau Heart Project.

In a survey of risk factors for coronary heart-disease (C.H.D.) in a Leiden population aged 40-41 years, mean serum-high-density-lipoprotein (H.D.L.)-cholesterol was significantly higher in 447 women (47.94 mg/dl) than in 471 men (42.40 mg/dl). No association was found between serum-H.D.L.-cholesterol and systolic or diastolic blood-pressure, obesity, or electrocardiographic changes. Cigarette smoking with use of oral contraceptives were strongly associated with reduced serum-H.D.L.-cholesterol. The difference in mean serum-H.D.L.-cholesterol concentrations between women who were on oral contraceptives and those who were not was independent of the effect of smoking. The finding of a low mean serum-H.D.L.-cholesterol concentration in pill users who smoke (i.e., similar to that in men of the same age; 43.0 mg/dl and 42.4 mg/dl in women and men, respectively) is disturbing since low serum-H.D.L.-cholesterol is a major C.H.D. risk factor and because of the reported increase in mortality from circulatory diseases in women using oral contraceptives.

Adult↗
PubMed1978

A simplified method for the determination of steroids in diets and faeces.

A simplified method for the quantitative isolation and determination of sterols and bile acids for application in sterol balance studies in humans consuming mixed general food is described. The recovery of steroids from diets and from faeces was found to be quantitative. By application of temperature programmed gas-liquid chromatography (GLC), thin-layer chromatographic (TLC) pre-separation could be omitted from the multistep analytical procedure. Furthermore, it was possible to use simple internal standards, 5alpha-cholestane and/or 5beta-cholanic acid, instead of labeled compounds for the calculation of overall recoveries.

Bile Acids and Salts↗
PubMed1978

The influence of dietary mackerel oil on the condition of organs and on blood lipid composition in the young growing pig.

A feeding experiment was carried out in which piglets were fed to a diet enriched with either mackerel oil or olive oil. The oil consumption amounted to about 100 g per animal per day. The aim of this experiment was to study the effect of feeding high amounts of fish oil rich in polyunsaturated and long-chain monoenoic acids in order to determine if any morbid changes occurred in the animals as a result of this addition. The piglets fed olive oil served as controls. After 4 weeks, blood hemoglobin, plasma glucose, and serum triglycerides were significantly lower in the mackerel oil group as compared with the control group. There was no difference in serum cholesterol and serum lipid composition. Very low density lipoproteins were lower in the mackerel oil group. The fatty acid composition of blood serum, heart muscle, and liver showed considerable differences, omega3 acids being higher and both omega6 and omega9 acids being lower in the mackerel oil group than in the control group. Some increase in the amount of triglycerides in the heart muscle was observed in the mackerel oil group. Some characteristics of "yellow fat disease" developed in the mackerel oil group. This type of vitamin E deficiency seems to be the result of the considerable amount of omega3 fatty acids present in the mackerel oil. No clinical symptoms due to ingestion of long-chain monoenoic acids were observed.

Animals↗
PubMed1978

The effect of a fish diet on serum lipids in healthy human subjects.

A cross-over study was done with 19 male and 23 female volunteers living in a monastery and a convent, respectively. The effect of a fat gish (mackerel) diet on the blood serum lipid composition was studied. As the normal diet of these volunteers was of the lacto-ovo-vegetarian type, a control diet in which the fish was replaced by full-fat cheese was used. Subjects consuming the fish diet had a daily uptake of polyunsaturated acids of the omega3 family of about 8 g; comparable amounts of linoleic acid were ingested with both diets. Both diets were consumed for a period of 3 weeks. Serum cholesterol was slightly but significantly (7.5%) lower and serum triglycerides considerably lower (35%) on the fish diet, whereas high density lipoprotein cholesterol increased slightly. Lipoprotein analysis showed a strong very low density lipoprotein decrease by the fish diet while, in the men, both low and high density lipoproteins increased. The fatty acid composition of serum lipids showed considerable differences; C20:5omega3 increased in all fractions and C22:6omega3 was found in the triglycerides and the phospholipids, but not in the sterol esters. These increases occurred chiefly at the expense of C18:1omega9 and, in particular, C18:2omega6, which indicates a replacement of omega6 by omega3 acids. Long-chain monoenoic acids which are abundant in the mackerel were not detected in any serum lipid fraction.

Adult↗
PubMed1977

Cholesterol determinations. A comparative study of methods with special reference to enzymatic procedures.

Two enzymatic methods for the determination of cholesterol in serum have been modified for automatic use. These methods utilize the colour reactions according to Kageyama or Trinder to measure the hydrogen peroxide resulting from the enzymatic reaction. The procedures have been compared with the classical methods according to Abell and to Huang. Details regarding the procedures are given. Comparisons made during routine analysis of a large number of different sera have been expressed in the form of regression equations. The standard errors of the methods are given along with the standard deviations for differences between methods. Some conversions of values from one method into another are also given. It appears that the automated Kageyama method can be used for large scale practice. The manual Kageyama method is not very satisfactory because of its large experimental error. A disadvantage of the Kageyama methods is the necessity of having blank corrections for haemolytic sera. The Trinder method avoids the problem and has some additional advantages.

Autoanalysis↗
PubMed1977

Cerebrotendinous cholestanolosis in relation to other cerebral xanthomatoses.

A synopsis is given of 37 reported patients with cerebrotendinous xanthomatosis; divided in 11 possible, but not proven cases of C.T.Ch (cerebrotendinous cholestanolosis), and 26 proven cases. An increased content of cholestanol in serum or tissue, was used as the main criterion. The ophthalmological and neurological signs are tabulated. Attention is drawn to the fact that cholestanol is not mentioned in the extensive literature on related diseases with possible cerebrospinal xanthomas, such as eosinophilic granulomatosis and hyperlipoproteinemia. The importance of a possible role of cholestanol in these diseases is stressed. A hypothetical form of cerebrotendinous cholesterolosis is discussed. A family with a sibship of parents and twelve children, three of which showed C.T.Ch is described. The development of the clinical picture confirmed the variable expression of the autosomal recessive disease. Two patients showed disturbances of steroid metabolism. A first contribution to the search for linkage with the H.L.A. system is presented. Cholestanol over cholesterol ratio, appeared to be independent of the type of lipoprotein. In search for therapy we found in patients with hyperlipoproteinemia type II A, that cholestyramine alone gave dangerously high blood levels of cholestanol; in combined treatment of cholestyramine with clofibrate cholestanol, levels were comparable to those of the controls. The possibilities of therapy are discussed.

Adult↗