Vitamin D and disability in relapsing-remitting multiple sclerosis in patients with a Mexican background.

Previous studies of multiple sclerosis (MS) patients have reported an inverse correlation between disability, the number of relapses and vitamin D levels in mostly white patients. It is unclear if this relationship has the same behavior in individuals with Hispanic backgrounds. To determine the relationship between vitamin D serum levels and disability in a sample of Hispanics of a Mexican background with relapsing-remitting multiple sclerosis (RRMS). A cross-sectional study was conducted on 50 RRMS individuals of Mexican background. The Expanded Disability Status Scale (EDSS) score, progression index (PI) and annual relapse rate (ARR) were recorded for each patient. Vitamin D levels were assessed during the summer. Pearson's test was used to evaluate the relationship between vitamin D and EDSS, PI, ARR, and duration of disease evolution. Most patients were females (n = 29, 58%). The mean vitamin D level was 22.3 (± 6.4) ng/ml; the mean EDSS score was 2.2 (± 0.7), ARR 1.3 (± 0.5) and PI1.08 (± 0.6). No correlation was found between vitamin D levels and EDSS scores, ARR, PI or duration of disease. Moderate negative association between vitamin D levels and EDSS was found just in females (<0.0001). No correlation between vitamin D levels and disability was found in this sample of RRMS Mexicans. Longitudinal studies are needed to better understand the impact of Vitamin D in disability and multiple time points.

Comparison of a high-performance liquid chromatography method for quantification of carbamazepine with chemiluminescent microparticle immunoassay.

Carbamazepine is an antiepileptic drug widely used for the treatment of epilepsy. In the National Institute of Neurology, monitoring has been performed using the technique chemiluminescent microparticle immunoassay (CMIA) in an automated way during the last five years. The aim of this study was to develop a simple and rapid HPLC analytical method coupled to DAD-UV detection for the determination of plasma concentrations of carbamazepine and compare its feasibility with those used in routine analysis. The developed HPLC method was fully validated and the applicability of the proposed method was verified through the analysis of plasma samples of patients and later compared with the quantification of the same plasma samples with the CMIA method. The limit of quantification obtained was 0.5 µg/mL. The mean value for recovery was 99.05% and the coefficient of variation (CV) was 5.6%. The precision and accuracy of this method were within the acceptable limits; inter- and intraday CV values were <10%. The correlation between the CMIA method and the developed HPLC method was very good (r ≈ 0.999). A Bland-Altman plot showed no significant bias between the results. The HPLC-DAD method may be an alternative to determine and monitoring the carbamazepine levels in human plasma or serum. Copyright © 2015 John Wiley & Sons, Ltd.

Prenatal exposure to ozone disrupts cerebellar monoamine contents in newborn rats.

Ozone (O3) is widely distributed in environments with high levels of air pollution. Since cerebellar morphologic disruptions have been reported with prenatal O3 exposure, O3 may have an effect on some neurotransmitter systems, such as monoamines. In order to test this hypothesis, we used 60 male rats taken from either, mothers exposed to 1 ppm of O3 during the entire pregnancy, or from mothers breathing filtered and clean air during pregnancy. The cerebellum was extracted at 0, 5, and 10 postnatal days. Tissues were processed in order to analyze by HPLC, dopamine (DA) levels, 3,4 dihydroxyphenilacetic acid (DOPAC) and homovanillic acid (HVA), norepinephrine (NA), serotonin, and 5-hydroxy-indole-acetic acid (5-HIAA) contents. Results showed a decrease of DA, NA, DOPAC and HVA mainly in 0 and 5 postnatal days. There were no changes in 5-HT levels, and 5-HIAA showed an increase after 10 postnatal days. DOPAC + HVA/DA ratio showed changes in 0 and 10 postnatal days, while 5-HIAA/5-HT ratio showed a slight decrease in 0 days. The data suggest that prenatal O3 exposure disrupts the cerebellar catecholamine system rather than the indole-amine system. Disruptions in cerebellar NA could lead to ataxic symptoms and also could limit recovery after cortical brain damage in adults. These finding are important given that recovery mechanisms observed in animals are also observed in humans.

Brain thiobarbituric acid-reactive substances in rats after short periods of ozone exposure.

It has been proposed that molecules derived from reactions that occur between the ozone and the lung tissue mediate nonpulmonary effects caused by ozone exposure. Free radicals are among those proposed molecules that flow throughout the bloodstream to other organs producing lipid peroxidation. In order to elucidate on aspect of ozone toxicity mechanisms, we measured the thiobarbituric acid-reactive products (TBARS), as an index of lipid peroxidation, in a variety of brain regions in rats exposed to 1 ppm of ozone for 1, 3, 6, and 9h. Another group exposed to 9h of O(3) plus 3h of clean-air exposure was also included. The results showed an important increase in TBARS content in all the studied structures. Such effect seems to be transient. These findings indicates that acute ozone exposure can produce cerebral peroxidation as it has been found in rats exposed chronically, suggesting an involvement of free radicals in brain effects of ozone exposure.