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The objective of this paper is to review the extent and mechanisms of lipoprotein alterations in pregnancy, present new data relating to placental lipid transport in. normal humans and diabetic animals and consider possible effects on fetal growth and development in normal and diabetic pregnancy. The concentration of all lipoprotein fractions increases during pregnancy. VLDL cholesterol and triglyceride increase 2.5-fold over prepregnancy levels and LDL cholesterol increases 1.6-fold, all with peak levels at term. HDL cholesterol is maximally increased in midgestation by 1.45-fold and subsequently declines to 1.15-fold at term. The mechanisms of these lipoprotein changes have not been studied in humans but the hypertriglyceridemia in animal models is related to enhanced VLDL entry into the circulation. In addition, diminished adipose tissue lipoprotein lipase (LPL) activity in late gestation may cause a rerouting of triglyceride fatty acids to other tissues such as muscle and uterus for oxidation, rather than storage, since triglyceride transport is not reduced in pregnancy. All of these changes appear to be sex hormone mediated. In diabetic pregnancies, the available data indicate that triglyceride concentrations are increased and HDL cholesterol concentrations are decreased with reference to lipoproteins in nondiabetic pregnant women. Previously unpublished data show that a transplacental FFA gradient exists across the umbilical circulation in the direction of the fetus and is proportional to the maternal FFA concentration. No gradient is seen for triglyceride or total plasma cholesterol. However, transport of unmeasured amounts of triglyceride fatty acids may still occur via placental LPL and be exaggerated in diabetes where LPL declines in adipose tissue but not in placenta. The mechanism of transplacental cholesterol transport remains to be defined. Preliminary studies suggest that it depends on HDL as well as LDL since both can provide cholesterol for placental progesterone synthesis. In addition, fetal weight and length are associated with maternal apoproteins A-I and A-II, both major apoproteins of HDL. By lowering HDL in pregnancy, diabetes mellitus could negatively affect these relationships. In conclusion, sex hormone mediated modifications of lipoprotein physiology are described in pregnancy which may enhance triglyceride fatty acid transport to muscle for oxidation and LDL and HDL cholesterol delivery to growing maternal and fetal tissues, a process that diabetes could globally disrupt.

Epidemiological research on the relationship between diet and asthma has increased in the last decade. Several components found in foods have been proposed to have a series of antioxidant, anti-allergic and anti-inflammatory properties, which can have a protective effect against asthma risk. Several literature reviews and critical appraisals have been published to summarize the existing evidence in this field. In the context of this EAACI Lifestyle and asthma Task Force, we summarize the evidence from existing systematic reviews on dietary intake and asthma, using the PRISMA guidelines. We therefore report the quality of eligible systematic reviews and summarize the results of those with an AMSTAR score ≥32. The GRADE approach is used to assess the overall quality of the existing evidence. This overview is centred on systematic reviews of nutritional components provided in the diet only, as a way to establish what type of advice can be given in clinical practice and to the general population on dietary habits and asthma.

The extent to which human discrimination learning is based on elemental or configural stimulus representations was examined in 7 experiments. In Experiments la and 1b, participants were able to learn nonlinear discrimination problems in a food-allergy task. In unique-cue theories, such learning is explained by individual stimulus elements acquiring independent connections with the outcome and also combining to form unique cues that function elementally. In Stage 1 of Experiments 2, 3, and 4a-c, Food A signaled an allergy outcome (O) (A -O) when presented alone but signaled no allergy (AB -no 0) when paired with Food B. In Stage 2, Food B was paired with the allergy (B -»O). In a test phase, the original discrimination between A and AB was found to be intact, at variance with the unique-cue theory. By contrast, in Experiments 5a, 5b, and 6, an effect of the B -* O trials on the A-AB discrimination was observed with training procedures previously found by D. A. Williams (1995) to encourage elemental processing. Experiment 7 showed that the influence of B -* O trials on the A-AB discrimination was unaffected by pretreatments designed to foster an elemental processing strategy. Overall, these results are problematic for unique-cue theories and instead imply that, by default, configurations of elements form the representational basis of simple discrimination learning in humans.

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