Effects of dietary long-chain polyunsaturated fatty acids on plasma amino acids and indices of protein metabolism in infants: Results from a randomized clinical trial

Background/Aim: Previous studies in vitro and in animals in vivo found that alpha-linolenic acid (C18:3 omega 3) may enhance oxidative damage of essential amino acids. We investigated whether the addition of the long-chain polyunsaturated fatty acids (LCPUFA) arachidonate (C20:4 omega-6; AA) and docosahexaenoate (C22:6-omega 3; DHA) in the form of egg phospholipids to infant formula affects plasma amino acid concentrations and indices of protein metabolism in term infants. Methods: In a double-blind, randomized clinical trial, healthy infants were fed from day 5 of life formula with or without preformed LCPUFA (n = 10 and 12, respectively). At the age of 5 days and 1, 2, 3 and 4 months, blood samples were obtained and analyzed for plasma amino acids by high-performance liquid chromatography and for plasma phospholipid fatty acid composition by gas chromatography. Results: At the age of 3 months, plasma threonine concentrations were significantly lower in infants receiving dietary LCPUFA than in controls (124 +/- 16 vs. 216 +/- 28 mu mol/l, p < 0.05). Values of other plasma essential amino acids, total protein, albumin, creatinine and urea nitrogen did not differ between the two feeding groups throughout the study. At the age of 5 days, plasma phospholipid AA and DHA concentrations were inversely correlated with histidine concentrations (AA: r = -0.60, p = 0.01; DHA: r = -0.53, p < 0.05). At the age of 3 months, DHA concentrations were inversely related to plasma histidine, methionine and threonine concentrations (r = -0.66, -0.62, and -0.64, respectively, p < 0.05). Conclusions: The dietary LCPUFA supplementation of infant formula used in this study has no adverse effects on infant plasma amino acid concentrations and indicators of protein metabolism. Nonetheless, the apparent interaction of LCPUFA with some amino acids in formula-fed infants warrants further investigation

Alacsony frekvenciás AC szuszceptométer mágneses folyadékok komplex szuszceptibilitásának mérésére: Low frequency AC susceptometer for measuring complex susceptibility of magnetic fluids

A device was designed and built for measuring frequency dependent complex magnetic susceptibility of magnetic fluids in the range from 1 Hz to 100 kHz. The base of the device is a balanced differential transformer, where the induced voltage on the secondary coils are measured with a lock-in amplifier. Magnetic susceptibility of two ferrofluids and one magnetorheological fluid were measured to verify the correct operation of the device. Debye relaxation in one of the three fluids were observed in the frequency range of the device. Kivonat Megterveztünk és megvalósítottunk egy mérőeszközt, amellyel mágneses folyadékok frekvenciafüggő komplex szuszceptibilitását tudjuk mérni az 1 Hz – 100 kHz tartományban. Az eszköz alapja egy differenciáltranszformátoros kapcsolás, amelyen a szekunder tekercsekben indukált feszültséget egy lock-in erősítővel mérjük. Az eszköz helyes működésének ellenőrzésére mértük két ferrofluidum és egy magnetoreológiai folyadék mágneses szuszceptibilitását. A vizsgált folyadékok közül egy ferrofluidum Debye relaxációja figyelhető meg a rendelkezésre álló méréstartományban

Feasibility of real-time available transfer capacity calculations with PSSE

A new procedure is reviewed in this article that offers the possibility of the precision enhancement of intra-day network capacity calculations. The main advantages of the new procedure are the calculation capability of potential Emergency Assistance Service in reasonably short time and the enhancement of the intra-day trading activities

Dietary Intake of Natural Sources of Docosahexaenoic Acid and Folate in Pregnant Women of Three European Cohorts

Background: Folic acid plays a fundamental role in cell division and differentiation. Docosahexaenoic acid (DHA) has been associated with infantile neurological and cognitive development. Thus, optimal intrauterine development and growth requires adequate supply of these nutrients during pregnancy. Methods: Healthy pregnant women, aged 18-41 years, were recruited in Granada (Spain; n = 62), Munich (Germany; n = 97) and Pecs (Hungary; n = 152). We estimated dietary DHA and folate intake in weeks 20 (w20) and 30 of gestation (w30) using a food frequency questionnaire with specific focus on the dietary sources of folate and DHA. Results: Both w20 and w30 Spanish participants had significantly higher daily DHA intakes (155 +/- 13 and 161 +/- 9 mg/1,000 kcal) than the German (119 +/- 9 and 124 +/- 12 mg/1,000 kcal; p = 0.002) and Hungarian participants (122 +/- 8 and 125 +/- 10 mg/1,000 kcal; p = 0.005). Hungarian women had higher folate intakes in w20 and w30 (149 +/- 5 and 147 +/- 6 mu g/1,000 kcal) than Spanish (112 +/- 2 and 110 +/- 2 mu g/1,000 kcal; p < 0.001) and German participants (126 +/- 4 and 120 +/- 6 mu g/1,000 kcal; p < 0.001), respectively. Conclusion: Dietary DHA and folate intake of pregnant women differs significantly across the three European cohorts. Only 7% of the participants reached the recommended folate intake during pregnancy, whereas nearly 90% reached the DHA recommended intake of 200 mg per day. Copyright (C) 2008 S. Karger AG, Base

Az esszenciális zsírsavak metabolizmusának zavarai és terápiás befolyásulásuk lehetőségei a gyermekgyógyászati gyakorlatban = Disturbances of essential fatty acid metabolism and potential therapeutic interventions in the paediatric praxis

Szignifikáns fordított korrelációt találtunk a női tej arachidonsav- és dokozahexénsavtartalma valamint a 18 szénatomot tartalmazó transz izomér zsírsavak között, ami arra utal, hogy az anyai étrendbe bekerülő transz izomér zsírsavak károsan befolyásolhatják az újszülött esszenciális zsírsavellátottságát. Szignifikánsan magasabb arachidonsav és a dokozahexénsav értékeket találtunk a szoptatás első hónapjában a koraszülöttet szült anyák tejében, mint az időre született újszülöttet szült anyákéiban. Megfigyelésünk újabb szemponttal támasztja alá a saját anya tejének fontosságát a koraszülöttek táplálásában. Szignifikáns összefüggéseket találtunk a köldökzsinór véna és artéria falának a megszületéskor meghatározott zsírsavösszetétele, valamint a csecsemők mind 3 hónapos, mind pedig 18 hónapos életkorban megítélhető fejlődésneurológiai statusa között. Ez a megfigyelésünk arra utal, hogy a várandós anyák zsírsavellátottsága a megszületés utáni legalább másfél éves időszakra szólóan befolyásolhatja a gyermek neurológiai fejlődését. Megállapítottuk, hogy az uncoupling protein gén -866 G/A polimorfizmusa szignifikánsan összefüggésben van elhízott gyermekek zsírsavellátottságával, amit célszerű figyelembe venni az elhízottak étrendje zsírsavösszetételét befolyásoló vizsgálatok tervezésekor. Újabb adatokat szolgáltattunk a hosszú szénláncú, többszörösen telítetlen zsírsavak a diabetes mellitus és a gyulladásos bélbetegségek kórképeiben betöltött szerepére vonatkozóan. | We found significant inverse correlations between human milk arachidonic and docosahexaenoic acid values, on the one hand, and values of 18-carbon trans isomeric fatty acids, on the other hand. This observation indicates that maternal dietary intake of trans isomeric fatty acids may untowardly influence the availability of essential fatty acids for the infant. We found significantly higher values of arachidonic and docosahexaenoic acids in milk samples of mothers of preterm than in those of full-term infants. This observation provides further ground for the utilisation of the own mothers' milk in the nutrition of preterm infants. We revealed significant correlations between long-chain polyunsaturated fatty acids in cord vessel wall lipids and neurodevelopment of the offspring both at the age of 3 and 18 months. These data indicate that fatty acid status of expecting women may influence the neurodevelopment of their children at least up to the age of 1.5 years. We demonstrated significant correlations between the -866 G/A polymorphism of uncoupling protein gene and fatty acid status in obese children; this relationship should be taken into consideration at planning studies on modifying fatty acid intake in obese subjects. We published further data on the role of long-chain polyunsaturated fatty acids in diabetes mellitus and inflammatory bowel disease

Inverse Association between trans Isomeric and Long-Chain Polyunsaturated Fatty Acids in Pregnant Women and Their Newborns: Data from Three European Countries

Background: trans unsaturated fatty acids are thought to interfere with essential fatty acid metabolism. To extend our knowledge of this phenomenon, we investigated the relationship between trans isomeric and long-chain polyunsaturated fatty acids (LCPUFA) in mothers during pregnancy and in their infants at birth. Methods: Fatty acid composition of erythrocyte phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was determined in Spanish (n = 120), German (n = 78) and Hungarian (n = 43) women at the 20th and 30th week of gestation, at delivery and in their newborns. Results: At the 20th week of gestation, the sum of trans fatty acids in PE was significantly (p < 0.01) lower in Hungarian [0.73 (0.51), % wt/wt, median (IQR)] than in Spanish [1.42 (1.36)] and German [1.30 (1.21)] women. Docosahexaenoic acid (DHA) values in PE were significantly (p < 0.01) higher in Hungarian {[}5.65 (2.09)] than in Spanish [4.37 (2.60)] or German [4.39 (3.3.2)] women. The sum of trans fatty acids significantly inversely correlated to DHA in PCs in Spanish (r = -0.37, p < 0.001), German (n = -0.77, p < 0.001) and Hungarian (r = -0.35, p < 0.05) women, and in PEs in Spanish (r = -0.67, p < 0.001) and German (r = -0.71, p < 0.001), but not in Hungarian (r = -0.02) women. Significant inverse correlations were seen between trans fatty acids and DHA in PEs at the 30th week of gestation (n = 241, r = -0.52, p < 0.001), at delivery (n = 241, r = -0.40, p < 0.001) and in cord lipids (n = 218, r = -0.28, p < 0.001). Conclusion: Because humans cannot synthesize trans isomeric fatty acids, the data obtained in the present study support the concept that high maternal trans isomeric fatty acid intake may interfere with the availability of LCPUFA both for the mother and the fetus. Copyright (C) 2011 S. Karger AG, Base

Biomimetikus katalizátorok fejlesztése mikrofluidikai reaktorokhoz: Development of Biomimetic catalysts for microfluidic reactors

During discovery of drug molecules, metabolism studies are important topic, which are usually carried out in vivo or in vitro using cell based systems. Instead of using living organism-based methods biomimetic systems can offer a promising alternative. Synthetic metalloporphyrins as biomimetic catalysts have strong structural similarity to the active site of the CYP enzymes responsible for the oxidative metabolism of drugs. The applicability and robustness of the porphyrin catalysts can be improved by immobilization techniques involving rationally functionalized solid carriers. The use of magnetic nanoparticles (MNPs) as catalyst carrier provides unique benefits, while the trapping, isolation or separation of the particles from the reaction mixture can be achieved with magnetic field. During my research, MNPs were prepared, modified with reactive function groups for immobilization of porphyrin catalyst, and inert groups which can influence the function group density. The fine-tuned immobilized catalyst was chosen and applied for continuous-flow microfluidical experiment. By the application of the developed biomimetic catalyst and reactor system, drug metabolites can be produced in very rapid way for further stages of drug discovery.&nbsp; &nbsp;Kivonat A gyógyszervegyületek kifejlesztése során az egyik kritikus fontosságú terület a metabolizmus kutatás, mely során jellemzően in vivo és in vitro májsejt alapú rendszereket használnak, melyek számos hátránnyal rendelkeznek. Az ún. biomimetikus eljárások ígéretes alternatívát jelenthetnek, melyek a kiemelkedő katalitikus hatással bíró szintetikus metalloporfirinekkel megvalósíthatók. A porfirinek alkalmazása a szerkezeti hasonlóságukon alapszik a metabolizmusban részvevő CYP enzimek aktív helyén található hem csoporttal. Az érzékeny porfirin katalizátor alkalmazhatóságát, stabilitását nagyban javíthatjuk, ha valamilyen szilárd hordozó felületére rögzítjük. Mágneses nanorészecskék alkalmazása előnyös katalizátor hordozóként, mivel helyhez rögzítésük vagy elválasztásuk a reakcióelegytől mágneses erőtérrel megvalósítható. Munkám során mágneses nanorészecskék szintézisét és felületmódosítását valósítottam meg. A részecskék felületén a porfirin rögzítésére szolgáló reaktív funkcióscsoportokat, valamint a funkcióscsoport sűrűségét befolyásoló inert csoportokat alakítottam ki. Az ily módon finomhangolt katalizátort sikeresen alkalmaztam folyamatos áramú mikrofluidikai reaktorokban gyógyszermetabolitok szintézisére