Stability of hepatoprotecting agent IFC-305 encapsulated into sol-gel titania nanoparticles and drug release evaluation: water and drug concentration effect.

IFC-305 was encapsulated into nanostructured titania and functionalized with OH groups by the sol-gel process using titanium n-butoxide, to be used in a drug delivery system for the treatment of liver cancer. Synthesis was carried out at different molar hydrolysis ratios: 4, 8, 16 and 24 mol of water; and drug concentration of 10, 20 and 30%. Characterization of IFC-titania reservoirs was carried out by Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal analysis (DTA-TGA), scanning electron microscopy (SEM), and N2 adsorption-desorption isotherms (BET), confirms that IFC-305 is entrapped and stabilized in the TiO2-OH matrix. Drug liberation in vitro was determined by UV spectrometry over a period of 1000 h. This study demonstrated that the higher water content and the higher amount of loaded IFC, favored hydrogen bonding between titania-OH surface and IFC-NH groups, increasing the rate of drug release.

Exacerbation of excitotoxic neuronal death induced during mitochondrial inhibition in vivo: relation to energy imbalance or ATP depletion?

During the past two decades a close relationship between the energy state of the cell and glutamate neurotoxicity has been suggested. We have previously shown that increasing the extracellular concentration of glutamate does not cause neuronal death unless a deficit in energy metabolism occurs. The mechanisms of glutamate-induced neuronal death have been extensively studied in vitro and it has been associated with a rapid and severe decrease in ATP levels, accompanied with mitochondrial dysfunction. In this study we aimed to investigate the time course of the changes in energy metabolites during glutamate-induced neuronal death, in the presence of a moderate inhibition of mitochondrial metabolism in the rat striatum in vivo. We also aimed to study whether or not, as reported in vitro, changes in ATP levels are related to the extension of neuronal death. Results show that glutamate-induced lesions are exacerbated when rats are previously treated with a subtoxic dose of the mitochondrial toxin 3-nitropropionic acid (3-NP). However, changes in nucleotide levels were similar in rats injected with glutamate alone and in rats injected with glutamate and previously treated with 3-NP. In spite of the presence of an extensive striatal lesion, nucleotide levels were recovered in 3-NP-treated rats 24 h after glutamate injection. Results show that 3-NP pre-treatment induced an imbalance in nucleotide levels that predisposed cells to glutamate toxicity; however it did not influence the bioenergetic changes induced by glutamate alone. Enhancement of glutamate neurotoxicity in 3-NP pre-treated rats is more related to a sustained nucleotide imbalance than just to a rapid decrease in ATP levels.

[Reliability of optic density at 650 nm in determining lung maturity in children of diabetic mothers]. / Confiabilidad de la densidad óptica a 650 nm en la determinación de madurez pulmonar en el hijo de madre diabética.

The Diabetes Mellitus is the pathology that frequently is associated to the pregnancy and it is responsible for perinatal mobility specially by the respiratory distress syndrome since exists delay in the conversion of myoinositol-phosphatidyl inositol-phosphatidyl glycerol. To demonstrate the reliability of the DO tho 650 nm with standard of 20 in the determination of fetal lung maturity of the infant of diabetic mother. There were included 143 patient with pregnancy > or = 37 weeks with amenorrhea reliable and gestational age confirmed by ultrasound, of those 94 corresponded to gestational Diabetes Mellitus, 49 to pregestational (46 non insulin-dependent and 3 insulin-dependent). In all of them amniotic fluid studies was perform at 37 week and the resolution of the pregnancy was when DO to 650 nm showed fetal lung maturity. It was found a correlation among the DO to 650 nm of 20 and absence of RDS in 130 cases (true positive); there were seven cases with immaturity results by DO that they did not express RDS (false negative) and six cases with results that showed immaturity by DO and there were manifestations of RDS (true negative). We did not find results of false positive. The frequency of RDS was of 4.9% with a positive predictive value of the 100% an negative predictive value of 46%, a specificity of 100% and a sensitivity of 94%. An interesting finding was the fact that six cases true negative cases had poor maternal metabolic control of different degrees. For our results can be deduced that DO to 650 nm with standard of .20 it is reliable for the diagnosis of fetal lung maturity in the pregnancies complicated with Diabetes Mellitus, in addition to be an easy elaboration test and low cost.