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Biomedical subjects

A C von Houwelingen

Publications and source records attributed to A C von Houwelingen.

10 recordsLinked to original sources
PubMed1997

Effects of storage on venous and capillary blood samples: the influence of deferoxamine and butylated hydroxytoluene on the fatty acid alterations in red blood cell phospholipids.

Fatty acid concentrations in plasma and red blood cell phospholipids isolated from paired venous and capillary blood samples were compared and the effect of storage at -20 degrees C was evaluated as well. Plasma fatty acid profiles from venous and capillary blood were found to be comparable and not affected by up to four weeks of storage, while fatty acid profiles of venous and capillary red blood cells were no longer comparable after four weeks. Substantial losses of long-chain polyunsaturated fatty acids were observed in capillary red blood cells. To investigate whether the observed long-chain polyunsaturated fatty acids loss could be prevented, capillary red blood samples were stored for up to one year at -50 degrees C in the presence of the iron-binding agent deferoxamine or the free radical scavenger butylated hydroxytoluene. Both compounds protected the long-chain polyunsaturated fatty acids. Similarly, storage of red blood cell lipid extracts at -50 degrees C for up to one year was not associated with reduced levels of long-chain polyunsaturated fatty acids. In conclusion, the lipid loss from capillary red blood cells can be reduced for at least one year during storage at -50 degrees C with prior addition of either a metal chelating compound or a free radical scavenger, or by preparing lipid extracts of the samples within one week of blood collection.

Blood Preservation↗
PubMed1996

Fat intake of women during normal pregnancy: relationship with maternal and neonatal essential fatty acid status.

OBJECTIVE: To study the relationships between the essential fatty acid (EFA) composition of maternal diet, maternal EFA status and the EFA status of healthy newborn infants. METHODS: A prospective longitudinal study was performed in which 176 pregnant women completed a food frequency questionnaire (FFQ) before 13, at 22, and at 32 weeks of gestation, so that changes in nutrient intake throughout pregnancy could be recorded. Around 22 weeks, a dietary history was performed and a maternal blood sample was collected. Immediately after delivery, a blood sample from the umbilical vein and a piece of the umbilical cord were collected. Fatty acid compositions were determined for phospholipids (PLs) isolated from maternal and umbilical plasma and from umbilical vein and artery vessel walls. RESULTS: No significant differences in the mean daily intake of total fat, saturated fat, mono-unsaturated fat, polyunsaturated fat and linoleic acid (18:2(n-6), LA) were observed between the three trimesters. Maternal LA intake was positively associated with LA levels in maternal and umbilical plasma and negatively associated with 20:3(n-9), 18:3(n-3), 20:4(n-3) and 22:5(n-3) levels in maternal plasma, with 20:5(n-3) levels in umbilical plasma and with 22:6(n-3) levels in umbilical vein vessel walls. Significant positive correlations for almost all (n-6) and (n-3) fatty acids were observed between maternal and umbilical plasma levels. CONCLUSIONS: The maternal dietary fat composition appears to be consistent during pregnancy. A high maternal LA intake may have a lowering effect on the maternal as well as on the neonatal (n-3) fatty acid status. Finally, neonatal EFA status is strongly related to maternal EFA status.

Adult↗
PubMed1995

Some aspects of neonatal essential fatty acid status are altered by linoleic acid supplementation of women during pregnancy.

To study the effect of maternal linoleic acid [18:2(n-6), LA] supplementation during pregnancy on neonatal essential fatty acid status, pregnant women with relatively low plasma linoleic acid concentrations before 16 wk of gestation (n = 21) were supplied with foods rich in linoleic acid, resulting in an additional intake of 10 g/d of linoleic acid from the 20th week of gestation until delivery. One of the two control groups consisted of pregnant women with comparably low plasma linoleic acid concentrations at the start of the study (LL-control group, n = 22); the other consisted of women with habitually high plasma linoleic acid concentrations (HL-control group, n = 21). The neonatal essential fatty acid status was assessed by determining the fatty acid composition of phospholipids (PL) isolated from umbilical plasma and umbilical vessel walls. The maternal linoleic acid status in the LA-supplemented group increased to a level comparable to that of the HL-control group, but the neonatal linoleic acid status did not differ from that of either control group. Linoleic acid supplementation did result in slightly, but significantly, higher total amounts of (n-6) long-chain polyenes in umbilical plasma and vein vessel wall phospholipids compared with the LL-control group. This increase was associated with significantly lower total amounts of (n-3) long-chain polyenes. In the HL-control group, the concentration of (n-3) long-chain polyenes in umbilical plasma and vessel walls was significantly lower than in the LA-supplemented and the LL-control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Release of thromboxane A2 and beta-thromboglobulin during in-vivo plug formation following standardized skin incisions: effect of a moderate fish intake.

This paper describes a controlled study of the effects of a fish supplement on haemostasis. This was evaluated by measuring bleeding times from skin incisions, the volume of the emerging blood, the number of platelets taking part in the formation of the haemostatic plug (platelet retention), and the release of thromboxane B2 and beta-thromboglobulin in volunteers, before and after consuming a daily supplement of 100 g of fish (n = 20) or meat (n = 20) paste for 6 weeks. The fish supplement decreased the amount of thromboxane B2 released per platelet incorporated into the plug. Despite this, the skin bleeding times were hardly changed. There was also no difference in platelet retention, which was consistent with there being no difference in the release of beta-thromboglobulin. These results suggest that in the effect of marine diets on haemostasis, a reduced vascular reactivity plays a more important role than decreased plug formation.

Animals↗
PubMed1992

Replacement of dietary fat with palm oil: effect on human serum lipids, lipoproteins and apolipoproteins.

Thirty-eight male volunteers participated in a double-blind cross-over trial evaluating the effect of replacing the usual sources of saturated fat in the Dutch diet (animal fats and hydrogenated oils) by palm oil, which is virtually free of cholesterol and trans-fatty acids, on serum lipids, lipoproteins and apolipoproteins. Maximum (about 70%) replacement had no significant effect on serum total cholesterol or most lipoprotein fractions, but resulted in an 11% increase in serum high-density-lipoprotein (HDL)2-cholesterol relative to the control (P2 = 0.01). The palm-oil diet also caused an 8% decrease in low-density-lipoprotein (LDL):HDL2 + HDL3-cholesterol ratio (P2 = 0.02) as well as a 9% decrease in triacylglycerols in the low-density-lipoprotein fractions (P2 = 0.01). Palm oil consumption resulted in a 4% increase in serum apolipoprotein AI (P2 = 0.008) and a 4% decrease in apolipoprotein B (P2 = 0.01) relative to the control diet; the B:AI apolipoprotein ratio was decreased by 8% (P2 < 0.0001). These results were not significantly affected by the different lipoprotein E phenotypes of the volunteers. Although the observed differences were relatively modest, the present study, nonetheless, indicates that dietary palm oil, when replacing a major part of the normal fat content in a Dutch diet, may slightly reduce the lipoprotein- and apolipoprotein-associated cardiovascular risk profiles.

Adult↗
PubMed1989

Comparison between habitual intake of polyunsaturated fatty acids and their concentrations in serum lipid fractions.

To evaluate the validity of the cross-check dietary history method for the assessment of the habitual intake of polyunsaturated fatty acids, the relationship was investigated between the estimated intake of these fatty acids and their relative amounts in the various serum lipid fractions. Food intake data were obtained from a group of volunteers participating in a long-term epidemiological study in the Dutch town of Zutphen. The fatty acid composition of total lipids, phospholipids, triglycerides and cholesterol esters was determined in fasting serum samples from these volunteers. Although correlations between the calculated dietary intake of timnodonic acid (20:5(n-3), TA) and cervonic acid (22:6(n-3), CA), on the one hand, and the relative amounts of these fatty acids in the various serum lipid fractions, on the other, appeared to be statistically significant, no more than about 20 per cent of the variance in the serum values could be explained on the basis of dietary intake. For linoleic acid (18:2(n-6), LA) this was 55 per cent. It is concluded that the cross-check dietary history method is an acceptable technique for estimating the habitual intake of linoleic acid of a given individual. For the fish-related fatty acids, however, this method is less reliable. This discrepancy most probably results from the large differences in TA and CA contents in the same foods. In addition, a negative association with the calculated LA intake on the proportional amount of TA for most of the serum lipid fractions was demonstrated. This indicates an interference of dietary LA on the metabolism of TA.

Aged↗