Kapilláris gázkromatográfiás módszer biológiai anyagok szeléntartalmának 4,6-dibróm-piazszelenol formában történő meghatározására

Szerzők kapilláris gázkromatográfiás meghatározási eljárást dolgoztak ki különböző biológiai anyagok szeléntartalmának meghatározására. A szerves mátrix elroncsolását magnézium-nitrát —salétromsav keverékkel végezték. A roncsolmány sósavas feloldása, majd redukció után a szelén (IV)-ből 4,6-dibróm-piazszelenol származékot képeztek. Az ehhez szükséges 3,5-dibróm-orto-fenilén-diamin reagenst maguk állították elő. A szelénszármazék meghatározását gázkromatográfiásán végezték, „wide bore” kapilláris kolonna alkalmazásával. A módszer érzékenysége 0,003 mg szelén/kg minta, variációs koefficiense 3% körüli érték. Az eljárás ellenőrzését standard addíciós módszerrel végezték el különböző állati szervek és takarmányok esetében. The authors developed capillary gaschromatographic method for the determination of Selenium content in different biological matters. The organic substance were broken down by compound of magnesium-nitrate-nitric acid. They formed from the Selenium (IV) the derivative of 4,6-dibromo-piazselenol after the hydrochloric solving and reduction of the decompositioned matter. The required 4,6- dibromo-ortho-phenylene-diamine reagent was produced by themselves. They made the determination of Selenium derivate by gaschromatography on wide bore capillary column. The sensitivity of the method is 0,003 mg Selenium/kg sample, coefficient of variation is about 3%. They performed the control of the method by standard additive method in case of different animal organs and feeds. Verfasser haben ein kapillarschromatogaphisches Verfahren für die Bestimmung des Selengehaltes von verschiedenen biologischen Materialen ausgearbeitet. Die Zerstörung des organischen Materials wurde m it einem Gemisch von Magnesiumnitrat und Salpetersäure durchgeführt. Nach der Auflösung des Rückstandes m it Salzsäure und der Reduktion wurde aus dem Selen (IV) eine 4,6-Di'orompiazselenol-Verbindung gebildet. Die dazu notwendige 3,5-DibromortophenylendiaminReagenz haben die Verfasser selbst hergestellt. Die Selenverbindung wurde gaschromatographisch mit einer Kapillarkolonne “ wide bore” bestimmt. Die Empfindlichkeit der Methode liegt bei 0,003 mg Se/kg Probe, wobei der Variationskoeffizient etwa 3% beträgt. Das Verfahren wurde m it der Standardadditionsmethode mit Hilfe von verschiedenen tierischen Organen und Futtermitteln überprüft

Birth Outcomes of Newborns after Folic Acid Supplementation in Pregnant Women with Early and Late Pre-Eclampsia: A Population-Based Study

Objective. To evaluate the rate of preterm birth and low birth weight in the newborns of pregnant women with early and late onset pre-eclampsia according to folic acid supplementation. Study design. Birth outcomes of newborns were evaluated in 1,017 (2.7%) pregnant women with medically recorded pre-eclampsia and 37,134 pregnant women without pre-eclampsia as reference in the Hungarian Case-Control Surveillance System of Congenital Abnormalities, 1980–1996, in addition these study groups were differentiated according to the supplementation of high dose of folic acid alone from early pregnancy. Results. Pregnant women with pre-eclampsia associated with a higher rate of preterm birth (10.2% versus 9.1%) and low birthweight (7.9% versus 5.6%). There was a lower risk of preterm birth (6.8%) of newborn infants born to pregnant women with early onset pre-eclampsia after folic acid supplementation from early pregnancy though the rate of low birthweight was not reduced significantly. There was no significant reduction in the rate of preterm birth and low birthweight in pregnant women with late onset pre-eclampsia after folic acid supplementation. Conclusion. The rate of preterm birth in pregnant women with early onset pre-eclampsia was reduced moderately by high doses of folic acid supplementation from early pregnancy

Gelatin content governs hydration induced structural changes in silica-gelatin hybrid aerogels – Implications in drug delivery

Silica-gelatin hybrid aerogels of varying gelatin content (from 4 wt.% to 24 wt.%) can be conveniently impregnated with hydrophobic active agents (e.g. ibuprofen, ketoprofen) in supercritical CO2 and used as drug delivery systems. Contrast variation neutron scattering (SANS) experiments show the molecular level hybridization of the silica and the gelatin components of the aerogel carriers. The active agents are amorphous, and homogeneously dispersed in these porous, hybrid matrices. Importantly, both fast and retarded drug release can be achieved with silica-gelatin hybrid aerogels, and the kinetics of drug release is governed by the gelatin content of the carrier. In this paper, for the first time, a molecular level explanation is given for the strong correlation between the composition and the functionality of a family of aerogel based drug delivery systems. Characterization of the wet aerogels by SANS and by NMR diffusiometry, cryoporometry and relaxometry revealed that the different hydration mechanisms of the aerogels are responsible for the broad spectrum of release kinetics. Low-gelatin (4–11 wt.%) aerogels retain their open-porous structure in water, thus rapid matrix erosion dictates fast drug release from these carriers. In contrast to this, wet aerogels of high gelatin content (18–24 wt.%) show well pronounced hydrogel-like characteristics, and a wide gradual transition zone forms in the solid-liquid interface. The extensive swelling of the high-gelatin hybrid backbone results in the collapse of the open porous structure, that limits mass transport towards the release medium, resulting in slower, diffusion controlled drug release