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Biomedical subjects

E A de Deckere

Publications and source records attributed to E A de Deckere.

18 recordsLinked to original sources
PubMed1999

Possible beneficial effect of fish and fish n-3 polyunsaturated fatty acids in breast and colorectal cancer.

Breast and colorectal cancer are main causes of death in industrialized countries. In these cancers dietary factors appear to play beneficial or adverse roles. One of the possible beneficial factors may be fish intake or the n-3 polyunsaturated fatty acids from fish, as found in epidemiological and clinical studies. In population studies, high intake of fish during many years is associated with reduced risks of breast and colorectal cancer. Prospective and case-control studies either do not show an association between fish intake and cancer risks or show reduced risks at high fish intakes. In these studies, fish consumption may have been too low or may not reflect fish consumption over a longer period. In population, case-control, and prospective studies, fish and fish n-3 polyunsaturated fatty acids were not found to increase cancer risks. Clinical studies on markers of colorectal cancer indicate that fish n-3 polyunsaturated fatty acids may reduce cancer risk. In several studies in which the effect of fish consumption on cancer risk was investigated, meat and meat products were positively related to cancer risk, suggesting that cancer risks might be reduced more effectively when meat and meat products in meals are replaced by fish. In conclusion, the existing knowledge suggests that an increase in the consumption of fish and fish n-3 polyunsaturated fatty acids in industrialized countries may contribute to lower breast and colorectal cancer risks.

Animals↗
PubMed1999

Effects of conjugated linoleic acid (CLA) isomers on lipid levels and peroxisome proliferation in the hamster.

Effects of the conjugated linoleic acid (CLA) isomers cis-9, trans-11 (c9,t11 CLA) and trans-10, cis-12 (t10,c12 CLA) on lipid metabolism and markers of peroxisome proliferation were investigated in hamsters fed on purified diets containing 30% energy as fat and 0.1 g cholesterol/kg for 8 weeks. Four groups (n 32 each) received diets without CLA (control), with a mixture of equal amounts of c9,t11 and t10,c12 CLA (CLA mix), with c9,t11 CLA, and with t10,c12 CLA. The total amount of CLA isomers was 1.5% energy of 6.6g/ kg diet. CLA was incorporated into glycerides and exchanged for linoleic acid in the diet. Compared with the control, the CLA mix and t10,c12 CLA decreased fasting values of LDL- (21 and 18% respectively) and HDL-cholesterol (8 and 11%), increased VLDL-triacylglycerol (80 and 61%, and decreased epididymal fat pad weights (9 and 16%), whereas c9,t11 CLA had no significant effects. All CLA preparations increased liver weight, but not liver lipids. However, the increase in liver weight was much less in the c9,t11 CLA group (8%) than in the other two groups (25%) and might have been caused by the small amount of t10,c12 CLA present in the c9,t11 CLA preparation. Liver histology revealed that increased weight was due to hypertrophy. Markers of peroxisome proliferation, such as cyanide-insensitive palmitoyl CoA oxidase (EC 1.3.3.6) and carnitine acetyl transferase (EC 2.3.1.7) activities, were not increased by CLA. Both c9,t11 CLA and t10,c12 CLA were incorporated into phospholipids and triacylglycerols, but t10,c12 CLA only about half as much as c9,t11 CLA. In addition, linoleic acid and linolenic acid concentrations were lower in lipids of the t10,c12 CLA group compared with the c9,t11 CLA group. These data suggest that t10,c12 CLA stimulated the oxidation of all C18 polyunsaturated fatty acids. The results indicate that the t10,c12 CLA isomer, and not the so-called natural CLA isomer (c9,t11), is the active isomer affecting lipid levels in hamsters.

Adipose Tissue↗
PubMed1998

Health aspects of fish and n-3 polyunsaturated fatty acids from plant and marine origin.

An expert workshop reviewed the health effects of n-3 polyunsaturated fatty acids (PUFA), and came to the following conclusions. 1. Consumption of fish may reduce the risk of coronary heart disease (CHD). People at risk for CHD are therefore advised to eat fish once a week. The n-3 PUFA in fish are probably the active agents. People who do not eat fish should consider obtaining 200 mg of very long chain n-3 PUFA daily from other sources. 2. Marine n-3 PUFA somewhat alleviate the symptoms of rheumatoid arthritis. 3. There is incomplete but growing evidence that consumption of the plant n-3 PUFA, alpha-linolenic acid, reduces the risk of CHD. An intake of 2 g/d or 1% of energy of alpha-linolenic acid appears prudent. 4. The ratio of total n-3 over n-6 PUFA (linoleic acid) is not useful for characterising foods or diets because plant and marine n-3 PUFA show different effects, and because a decrease in n-6 PUFA intake does not produce the same effects as an increase in n-3 PUFA intake. Separate recommendations for alpha-linolenic acid, marine n-3 PUFA and linoleic acid are preferred.

Animals↗
PubMed1995

Both raw and retrograded starch decrease serum triacylglycerol concentration and fat accretion in the rat.

Male Wistar rats were meal-fed on diets containing various amounts of resistant starch in the form of raw starch (either amylomaize starch, potato starch or modified high-amylose starch) or retrograded starch (prepared from each of the starches) for 6 weeks. Two diets containing normal maize starch were fed as diets poor in resistant starch. Energy absorption (energy consumption minus faecal energy loss), growth, weight of the epididymal fat pads, serum total cholesterol and triacylglycerol concentrations and a number of intestinal and faecal variables were determined. The resistant starches affected all the variables determined except the serum total cholesterol concentration. Relationships were found between energy absorption and both growth and the weight of the fat pads, and between the weight of the fat pads and both the serum triacylglycerol concentration and the serum total cholesterol concentration. No clear differences between the effects of the two types of resistant starch (raw starch v. retrograded starch) were found except that raw potato starch hardly stimulated H2 excretion and led to lower amounts of propionic and butyric acids in the caecal contents than the other starches. The results suggest that dietary resistant starch reduces energy absorption leading to less abdominal depot fat and lower serum triacylglycerol concentrations.

Adipose Tissue↗
PubMed1993

Resistant starch decreases serum total cholesterol and triacylglycerol concentrations in rats.

Rats were meal-fed semipurified diets containing a low (0.8 g/MJ) and a high (9.6 g/MJ) amount of resistant starch (RS) or various amounts of RS (0.8 to 9.6 g/MJ) and guar gum (0 to 8.8 g/MJ). In one experiment, rats were fed the low and high RS diets in three dietary regimens (ad libitum consuming, 12 h ad libitum/12 h food deprived, and meal fed). Effects of RS and guar gum on serum postprandial and postabsorptive concentrations of total cholesterol (TC) and triacylglycerol (TAG), growth, hydrogen excretion, tissue weights and contents of small intestine and cecum, and pH of cecal contents were investigated. In addition, effects of RS on food intake, de novo hepatic synthesis of fatty acids and neutral sterols, and on lipoprotein lipase activity and weight of epididymal fat pads were investigated. Compared with feeding the low RS diet, the high RS diet reduced the serum TC and TAG concentrations, with these effects observed after 1 and 2 wk of feeding, respectively. The dietary regimen did not influence the effect of RS on the serum TC and TAG concentrations, but it did affect the serum TAG concentration. Resistant starch had no effect on the hepatic synthesis of fatty acids and neutral sterols or on the lipoprotein lipase activity in epididymal fat pads. Guar gum also reduced the serum TC concentration, but it had no effect on serum TAG concentration. The tissue weights and contents of small intestine and cecum as well as hydrogen excretion increased with increasing amounts of dietary RS and guar gum, whereas the pH of cecal contents decreased. No effects of RS on food intake and total body weight gain were found, whereas guar gum decreased weight gain. Feeding the high RS diet also led to a lower weight of the epididymal fat pads. We conclude that dietary RS can reduce serum TC and TAG concentrations and fat accretion.

Animals↗
PubMed1993

Hepatic de novo fatty acid synthesis in the rat.

Generally, the rate of hepatic de novo fatty acid (FA) synthesis (lipogenesis) in vivo is determined by measuring the amount of newly synthesized FA present in the liver 1 h or less after injection of label (3H2O) for FA synthesis (1-hour value of labelled FA). Since this value may well be affected by momentary conditions, our objective was to investigate whether the amount of labelled FA present in the liver 24 h after injection of 3H2O can be used as a parameter of lipogenesis (24-hour value of labelled FA). To this end, effects of the amounts of dietary fat, sucrose and linoleic acid and the effect of meal feeding versus d libitum feeding on this 24-hour value were investigated. The 24-hour value decreased with the dietary fat level and was higher in rats fed a diet in which starch was partly replaced by sucrose [20% of metabolizable energy (E%)]. This is in accordance with literature data on the 1-hour value of labelled FA. No effect of meal feeding versus ad libitum feeding on the 24-hour value of labelled FA was found. Furthermore, no significant effect of the dietary linoleic acid level (1-10 E%) on the 24-hour value of labelled FA was found, although when lipogenesis was stimulated by feeding a diet containing 20 E% sucrose, the 24-hour value tended to be higher at 1 E% linoleic acid than at 2.5 E% linoleic acid or higher.

Animals↗
PubMed1980

PGF2 alpha stimulates release of PGE2 and PGI2 in the isolated perfused rat heart.

The effect of prostaglandin F2 alpha on the release of PGI2 and PGE2 was investigated in isolated perfused rat heart. PGF2 alpha at concentrations of 1.7 nmoles liter-1 or higher increased the release of PGI2 and PGE2 alpha. The release of PGI2 was highest after 3 to 4 min of perfusion with PGF2 alpha. This phenomenon may be of physiological significance and might explain the observed variable effects of PGF2 alpha on vascular resistance.

Animals↗
PubMed1979

Effects of dietary fats on the coronary flow rate and the left ventricular function of the isolated rat heart.

Two groups of rats were fed diets containing large amounts (45-50% of the total digestible energy) of sunflower seed oil or hydrogenated coconut oil for 4-5 days. The left ventricular working capacity, the coronary flow rate, the oxygen consumption, the glucose uptake and the lactate release were determined in the isolated perfused heart. The fatty acid composition of the heart phospholipids was also determined. The left ventricular working capacity and the coronary flow rate of hearts of rats fed sunflower seed oil are higher (10-20%) than those of rats fed hydrogenated coconut oil. Feeding the two fats for 3-4 weeks instead of 4-5 days does not alter the results. There are no or only minor differences between the two dietary groups as to the other quantities mentioned. It is concluded that dietary fats affect the properties of the heart already after a short feeding time.

Animals↗
PubMed1978

The high yield of prostacyclin biosynthesis by the iris and its effects on the intraocular muscles.

Iris, and to a lesser extent ciliary body, from cat and rabbit produce considerable amounts of prostacyclin (PGI2) after incubation of the tissue with 1-14C arachidonic acid. These tissues also generate PGI2-like material after gentle squeezing. It is likely that major metabolites found previously in iris and aqueous humor actually were 6-keto-PGF1alpha. It is concluded that PGH2 and PGI2 are synthetized at the same location. PGI2 induces a contraction of the sphincter and dilator and a relaxation of the ciliary muscle if the tissues had been previously exposed to indomethacin. Thromboxane A2 (TxA2) has either no effect or may cause a slight relaxation of the sphincter.

Animals↗
PubMed1975

Influences of dietary fats on the coronary flow and oxygen consumption of the isolated rat heart.

The influence of various diets on the coronary flow (Qcor) and oxygen consumption (VO2m) of Langendorff-perfused rat hearts was studied. The diets contained 23 percent of the total amount of calories as proteins and sufficient amounts of minerals and vitamins, while the amounts of starch and type of fat were varied. In the Langendorff set-up, the perfusion pressure (Pp), and/or the developed left ventricular pressure (PD) were varied to change Qcor and VO2m. At Pp = 50 and 90 mm Hg, Qcor and VO2m of the isolated hearts of rats fed 50 percent of the total number of calories (cal%) as sunflower seed oil (50 SSO) or 50 cal% palm oil (50 PO) for 3 days were 10--20 percent higher than those of the hearts of rats fed pellets (11 cal% fat). At Pp = 80 mm Hg and at various levels of PD, Qcor of the isolated hearts of rats fed 50 SSO or 45 PO + 5 SSO for 3 months was about 20 percent higher than that of the isolated hearts of rats fed a high carbohydrate diet. No differences were found in VO2m or in the maximum obtainable value of PD. When rats were fed mixtures (total amount of fat 50 cal%) of SSO and hardened coconut oil (CO) for 3 days, Qcor increased with increasing dietary SSO. The value of Qcor of the isolated hearts of rats fed a high carbohydrate diet containing 5 cal% SSO was in between the values of the groups fed 50 SSO and 45 CO + 5 SSO. Perfusion of the latter two groups of hearts with substrate-free medium increased Qcor by about 35 percent. The total hypoxanthine + inosine output in these two groups of hearts was about 4.0 nmoles-min-1, and remained contstant during perfusion with substrate-free medium. We conclude that the composition of the diet influences the coronary flow of isolated perfused rat hearts. The amount and the type of dietary fat influence both the magnitude and the direction of the effects. The relationship between the type of dietary fat and its effects on coronary flow is complex.

Animals↗