Brain food for babies

How does a mother supply a key building block of the brain required for neurodevelopment to her fetus in pregnancy? The critical requirement of docosahexaenoic acid (DHA) for fetal brain development, and the poor efficiency of its synthesis in humans, is a tricky metabolic problem to be overcome in pregnant women. Supplying this unique fatty acid to the fetus requires exquisite specificity and timing, processes that can unravel in disease conditions such as pre-eclampsia

Maternal plasma docosahexaenoic acid (DHA) concentrations increase at the critical time of neural tube closure

No abstract available

Intercellular communication in normal and regenerating rat liver: a quantitative analysis

We have compared intercellular communication in the regenerating and normal livers of weanling rats. The electrophysiological studies were conducted at the edge of the liver, and we have found that here as elsewhere in the liver there is a dramatic decrease in the number and size of gap junctions during regeneration. The area of hepatocyte membrane occupied by gap junctions is reduced 100-fold 29-35 h after hepatectomy. By combining observations made with the scanning electron microscope with our freeze fracture data we have estimated the number of "communicating interfaces" (areas of contact between hepatocytes that include at least one gap junction) formed by hepatocytes in normal and regenerating liver. In normal liver a hepatocyte forms gap junctions with every hepatocyte it contacts (approximately 6). In regenerating liver a hepatocyte forms detectable gap junctions with, on average, only one other hepatocyte. Intercellular spread of fluorescent dye and electric current is reduced in regenerating as compared with normal liver. The incidence of electric coupling is reduced from 100% of hepatocyte pairs tested in control liver to 92% in regenerating liver. Analysis of the spatial dependence of electronic potentials indicates a substantial increase in intercellular resistance in regenerating liver. A quantitative comparison of our morphological and physiological data is complicated by tortuous pattern of current flow and by inhomogeneities in the liver during regeneration. Nevertheless we believe that our results are consistent with the hypothesis that gap junctions are aggregates of channels between cell interiors

Australian children are not consuming enough long chain omega-3 polyunsaturated fatty acids for optimal health

Objectives: To determine children’s polyunsaturated fatty acid (PUFA) intakes, compare these with adequate intake and adjusted suggested dietary targets, and determine if intakes between children of different body weight and physical activity levels differed. Methods: The necessary data files were obtained from the Australian Social Science Data Archive and were merged for 4486 children 2 to 16 y old, with physical activity data collected only for children 5 to 16 y old. Results: The median (interquartile range) PUFA intakes at 2 to 3, 4 to 8, 9 to 13, and 14 to 16 y were 4.7 g (3.1–6.2), 6.0 g (4.4–8.1), 7.1 g (5.3–9.7), and 8.5 g (6.0–11.3), respectively, for linoleic acid; 0.75 g (0.57–1.0), 0.91 g (0.67–1.2), 1.02 g (0.73–1.42), and 1.15 g (0.81–1.62), respectively, for a-linolenic acid; and 56 mg (29–104), 68 mg (37–128), 88 mg (46–159), and 98 mg (49–190), respectively, for long-chain (LC) u-3 PUFAs. Most children met the adequate intakes for linoleic acid and a-linolenic acid, but only 50% to 60% of children met the adequate intake for LC u-3 PUFAs. Furthermore, only 6% of children met the adjusted suggested dietary target for LC u-3 PUFA per day. Comparison of LC u-3 PUFA tertile intakes showed no differences in intakes in different weight categories and physical activity levels. Conclusion: Most Australian children are not consuming enough LC u-3 PUFAs for optimal health

Condensins Regulate Meiotic DNA Break Distribution, thus Crossover Frequency, by Controlling Chromosome Structure

SummaryMeiotic crossover (CO) recombination facilitates evolution and accurate chromosome segregation. CO distribution is tightly regulated: homolog pairs receive at least one CO, CO spacing is nonrandom, and COs occur preferentially in short genomic intervals called hotspots. We show that CO number and distribution are controlled on a chromosome-wide basis at the level of DNA double-strand break (DSB) formation by a condensin complex composed of subunits from two known condensins: the C. elegans dosage compensation complex and mitotic condensin II. Disruption of any subunit of the CO-controlling condensin dominantly changes DSB distribution, and thereby COs, and extends meiotic chromosome axes. These phenotypes are cosuppressed by disruption of a chromosome axis element. Our data implicate higher-order chromosome structure in the regulation of CO recombination, provide a model for the rapid evolution of CO hotspots, and show that reshuffling of interchangeable molecular parts can create independent machines with similar architectures but distinct biological functions

Dietary Shiitake mushroom (Lentinus edodes) prevents fat deposition and lowers triglyceride in rats fed a high-fat diet

High-fat diet (HFD) induces obesity. This study examined the effects of Shiitake mushroom on the prevention of alterations of plasma lipid profiles, fat deposition, energy efficiency, and body fat index induced by HFD. Rats were given a low, medium, and high (7, 20, 60 g/kg = LD-M, MD-M, HD-M) Shiitake mushroom powder in their high-fat (50% in kcal) diets for 6 weeks. The results showed that the rats on the HD-M diet had the lowest body weight gain compared to MD-M and LD-M groups (P \u3c 0.05). The total fat deposition was significantly lower (-35%, P \u3c 0.05) in rats fed an HD-M diet than that of HFD group. Interestingly, plasma triacylglycerol (TAG) level was significantly lower (-55%, P \u3c 0.05) in rats on HD-M than HFD. This study also revealed the existence of negative correlations between the amount of Shiitake mushroom supplementation and body weight gain, plasma TAG, and total fat masses

Dietary intake and food sources of EPA, DPA and DHA in Australian children

Secondary analysis of the 2007 Australian National Children\u27s Nutrition and Physical Activity survey was undertaken to assess the intake and food sources of EPA, DPA and DHA (excluding supplements) in 4,487 children aged 2-16 years. An average of two 24-h dietary recalls was analysed for each child and food sources of EPA, DPA and DHA were assessed using the Australian nutrient composition database called AUSNUT 2007. Median (inter quartile range, IQR) for EPA, DPA and DHA intakes (mg/day) for 2-3, 4-8, 9-13, 14-16 year were: EPA 5.3 (1.5-14), 6.7 (1.8-18), 8.7 (2.6-23), 9.8 (2.7-28) respectively; DPA 6.2 (2.2-14), 8.2 (3.3-18), 10.8 (4.3-24), 12.2 (5-29) respectively; and DHA 3.9 (0.6-24), 5.1 (0.9-26), 6.8 (1.1-27), 7.8 (1.5-33) respectively. Energy-adjusted intakes of EPA, DPA and DHA in children who ate fish were 7.5, 2 and 16-fold higher, respectively (P \u3c 0.001) compared to those who did not eat fish during the 2 days of the survey. Intake of total long chain n-3 PUFA was compared to the energy adjusted suggested dietary target (SDT) for Australian children and 20 % of children who ate fish during the 2 days of the survey met the SDT. Fish and seafood products were the largest contributors to DHA (76 %) and EPA (59 %) intake, while meat, poultry and game contributed to 56 % DPA. Meat consumption was 8.5 times greater than that for fish/seafood. Australian children do not consume the recommended amounts of long chain omega-3 fatty acids, especially DHA, which could be explained by low fish consumption

Maternal plasma DHA levels increase prior to 29 days post-LH surge in women undergoing frozen embryo transfer: a prospective, observational study of human pregnancy

Context: Docosahexaenoic acid (DHA) is an important fatty acid required for neurological development but its importance during early fetal neurological organogenesis is unknown. Objective: To assess plasma fatty acid changes in early pregnancy in women undergoing natural cycle-frozen embryo transfer as a means of achieving accurately-timed periconceptual sampling. Design: Women undergoing frozen embryo transfer were recruited and serial fasting blood samples were taken pre-luteinising hormone (LH) surge, and at days 18, 29 and 45 post-LH surge and fatty acids were analysed using gas chromatography. Setting: Assisted Conception Unit, Glasgow Royal Infirmary, Scotland Main outcome measures: Plasma fatty acid concentrations, influence of twin pregnancies on DHA plasma concentration. Results: In pregnant women, there was a rapid, early increase in the maternal rate of change of plasma DHA concentration observed by 29 days post-LH surge (mean±SD, from 0.1±1.3 to 1.6±2.9 nmol DHA per mL plasma per day). This early pressure to increase plasma DHA concentration was further emphasised in twin pregnancies where the increase in DHA concentration over 45 days was two-fold higher than in singleton pregnancies (mean±SD increase, 74±39 nmol/mL versus 36±40 nmol/mL). An index of delta-6 desaturase activity increased 30% and positively correlated with the rate of change of DHA concentration between day 18 and 29-post LH surge (R-squared adjusted = 41%, P=0.0002). DHA was the only fatty acid with a continual accelerated increase in plasma concentration and a positive incremental area under the curve (mean±SD, 632±911 nmol/mL x day) over the first 45 days of gestation. Conclusions: An increase in maternal plasma DHA concentration is initiated in human pregnancy prior to neural tube closure which occurs at 28 days' gestation