Clot-promoting effect of platelet-vessel wall interaction:Influence of dietary fats and relation to arterial thrombus formation in rats

Abstract. A small piece of vascular tissue punched from a rat aorta is able to clot plasma. This coagulation plocess is promoted by blood platelets, especially after their activation. Thrombin, generated by this clotting process, plays a key role in vessel-wall induced platelet activation. Vascular prostacyclin inhibits vessel-wall-induced clotting of platelet-rich plasma, possibly by inhibiting platelet activation. Type and amount of dietary fats were shown to influence vessel-wall-induced clotting via at least four different mecha-nisms, namely: by modifying vascular prostacyclin formation; by affecting the clotting potency of the vascular tissue per sec; by an effect on some platelet property, probably connected with platelet activation; by influencing a plasma factor. Each of these mechanisms, as well as the nature of vessel-wall-induced coagulation, requires further investigation. lntroduction When investigating dietary influences on vascular prostacyclin formation, we noticed that a piece of tissue punch€d from a rat or rabbit aorta is able to clot platelet-rich plasma (PRP). Since this coagulation process may be important i

Effect of Dietary cis and trans fatty acids on serum lipoprotein[a] levels in humans

Serum lipoprotein[a] (Lp[a]) is a strong risk factor for coronary heart disease. We therefore examined the effect of dietary fatty acid composition on serum Lp[a] levels in three strictly controlled experiments with healthy normocholesterolemic men and women. In Expt. I, 58 subjects consumed a control diet high in saturated fatty acids for 17 days. For the next 36 days, 6.5% of total energy intake from saturated fatty acids was replaced by monounsaturates plus polyunsaturates (monounsaturated fatty acid diet; n = 29) or by polyunsaturates alone (polyunsaturated fatty acid diet; n = 29). Both diets caused a slight, nonsignificant, increase in median Lp[a] levels, with no difference between diets. In Expt. II, 10% of energy from the cholesterol-raising saturated fatty acids (lauric, myristic, and palmitic acid) was replaced by oleic acid or by trans-monounsaturated fatty acids. Each of the 59 participants received each diet for 3 weeks in random order. The median level of Lp[a] was 26 mg/l on the saturated fatty acid diet; it increased to 32 mg/l (P less than 0.020) on the oleic acid diet and to 45 mg/l (P less than 0.001) on the trans-fatty acid diet. The difference in Lp[a] between the trans-fatty acid and the oleic acid diets was also highly significant (P less than 0.001). Expt. III involved 56 subjects; all received 8% of energy from stearic acid, from linoleic acid, or from trans-monounsaturates, for 3 weeks each. All other nutrients were equal.

Memory performance, but not information processing speed, may be reduced during early pregnancy

Memory performance, but not information processing speed, may be reduced during early pregnancy. de Groot RH, Hornstra G, Roozendaal N, Jolles J. Department of Human Biology, Maastricht University, The Netherlands. [email protected] Several studies have investigated aspects of cognitive functioning during late pregnancy or in the period around delivery. The present paper describes a controlled study of neurocognitive functioning in an early phase of pregnancy (14 weeks). Seventy-one pregnant women and 57 control subjects matched for age and education were tested with a cognitive test battery. Intentional learning was tested with the Verbal Learning Test, retrieval from semantic memory with the Fluency Test, and speed of information processing with the Concept Shifting Test, the Stroop test, and the Letter Digit Substitution Test. Results show that performance on tests measuring intentional learning and retrieval from semantic memory were lower in the pregnant group during early pregnancy as compared to a closely matched nonpregnant group. In contrast, speed of information processing was not different between the two groups. The differences observed in memory performance were not large and further research is needed to establish their clinical significance. In addition, the results should be interpreted with care, because our study has a cross-sectional design, which has limitations concerning the fact that preexisting performance differences might be possible. Therefore, longitudinal studies are essential to ascertain clear associations between pregnancy and cognitive performanc

Assessing the communication level in people with Down syndrome: inventory and assessment of instruments

Verschillende facetten van (pre)linguïstische taalontwikkeling zijn bij mensen met downsyndroom (DS) vertraagd of minder ontwikkeld. Dit kan zorgen voor probleemgedrag en moeilijkheden in de communicatie.Passende ondersteunde communicatie is nodig, maar het is niet duidelijk hoe op een laagdrempelige manier een afgewogen keuze kan worden gemaakt. In de verstandelijk gehandicaptenzorg wordt daarom vaak gebruikgemaakt van trial-and-error. Dit literatuuronderzoek inventariseert en evalueert instrumenten voor het bepalen van het communicatieniveau van mensen met downsyndroom. Middels systematisch literatuuronderzoek is gezocht naar artikelen waarin relevante instrumenten worden genoemd. Deze instrumenten zijn beschreven en beoordeeld op basis van zes criteria die zijn opgesteld vanuit de literatuur over specifieke kenmerken bij downsyndroom. De instrumenten zijn beoordeeldop toepasbaarheid bij deze doelgroep. Van de 1480 gevonden artikelen zijn 35 artikelen geanalyseerd, waaruit 23 verschillende instrumenten zijn geïdentificeerd. Van de relevante artikelen zijn onder andere studiepopulatie,doel en gebruikte instrumenten beschreven. Daarnaast zijn per instrument gegevens verzameld over eigenschappen als doelgroep, materiaal, afnameduur, normering, betrouwbaarheid en validiteit.Na beoordeling van de 23 instrumenten op basis van de criteria bleek één instrument te voldoen aan alle zes criteria. Zes instrumenten voldeden aan vijf van de zes criteria. Er is geen instrument gevonden dat specifiek voor mensen met DS is ontwikkeld. De ComVoor lijkt het meest passende instrument. Voor deinzet bij mensen met DS worden aanpassingen aan het instrument wenselijk geacht