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Contreras-Medina R.,National Autonomous University of Mexico | Contreras-Medina R.,Simon Bolivar University of Mexico | Luna-Vega I.,National Autonomous University of Mexico | Rios-Munoz C.A.,National Autonomous University of Mexico
Revista Chilena de Historia Natural | Year: 2010

Taxus globosa is a gymnosperm inhabiting Mexican and northern Central American temperate forests, and it has been considered as threatened by Mexican and international conservancy agencies. In Mexico, habitat loss is oneof the main threats for most of the cloud forest species including this taxon, being human-induced land use change a key issue. We obtained the potential distribution of this species through Maxent algorithm based on 73 herbarium records. Also the modification of vegetation cover for three time periods (1976, 1996 y 2000) was analyzed upon the potential distribution of this species. The known and potential geographical distribution was evaluated in relation to the current Mexican National System of Natural Protected Areas at federal level (ANPs) and Mexican Priority Regions for Conservation (RTPs), in order to determine the role of these areas in its conservation andmanagement. Potential distribution models show an important reduction (until 84 %) of the distribution area related with land use change. This speciesis scarcely represented in the ANPs, because less than 10 % of its potential distribution occurs within these areas of federal protection. This approach represents an important tool in biogeography and conservation, as well as in other areas of biology, due to its predictive ability. Our results highlight the urgency to preserve the remaining Mexican temperate forest patches, mainly cloud forest ones, to guarantee the existence of this species. © Sociedad de Biología de Chile. Source

Palomares-Alonso F.,Laboratorio Of Neuropsicofarmacologia | Rojas-Tome I.S.,Laboratorio Of Neuropsicofarmacologia | Rojas-Tome I.S.,Simon Bolivar University of Mexico | Juarez Rocha V.,Laboratorio Of Neuropsicofarmacologia | And 7 more authors.
Experimental Parasitology | Year: 2015

In the search of new alternatives for neurocysticercosis treatment, the cysticidal activity of organic extracts of Teloxys graveolens was evaluated. The in vitro activity of hexane, ethyl acetate and methanol extracts against Taenia crassiceps cysts was tested and the selectivity index relative to human fibroblasts was determined. Subsequently, the in vivo efficacy of the methanolic extract at doses of 200 and 500 mg/kg in the murine cysticercosis model was evaluated. The ultrastructural effects in vitro and in vivo of the methanolic extract were also investigated using scanning electron microscopy. Additionally, a bioassay-guided fractionation for the isolation of the cysticidal components was performed. Our in vitro findings revealed that all extracts exhibited good cysticidal activity with EC50 values from 44.8 to 67.1 μg/mL. Although the ethyl acetate and methanolic extracts displayed low cytotoxicity, the methanolic extract was the most selective. The methanolic extract also showed in vivo efficacy which was similar to that obtained with ABZ. Significant alterations were found on the germinal layer of the cysts, with a high accumulation of granules of glycogen and vacuoles. The bioguided fractionation of methanolic extract led to the isolation of three flavonoids: chrysin, pinocembrin and pinostrobin; among them, pinocembrin was the compound that displayed cysticidal activity. This is the first study which reveals that T. graveolens could be a potential source for cysticidal and non-toxic compounds. © 2015 Published by Elsevier Inc. Source

Escobar Francisco S.A.,Dermatologo | Cecilia Rodriguez Ruiz X.,Simon Bolivar University of Mexico
Dermatologia Cosmetica, Medica y Quirurgica | Year: 2013

Temporary bioimplants used for correcting facial defects must be inert easily manipulated, durable and immunologically well tolerated to ensure safe and effective results. This study evaluates both the effectiveness and biosafety of a new collagen-PVP-perhydrosqualene combination during a follow-up period of 6 months to assess the intensity of dermal response and aesthetic results. Source

Miguel-Perez G.,Simon Bolivar University of Mexico | Maya G.,National Autonomous University of Mexico | Flores-Marquez A.R.,National Autonomous University of Mexico | Amador-Munoz O.,National Autonomous University of Mexico | And 4 more authors.
Boletin Medico del Hospital Infantil de Mexico | Year: 2013

Background. PM2.5 are components of the atmosphere of Mexico City and contain polycyclic aromatic hydrocarbons (PAH), which induce toxic effects. Due to different compositions of the PM2.5 in all zones of Mexico City and the lack of information about their effects, the main purpose of this study was to evaluate the cytotoxicity and genotoxicity due to soluble organic fractions (SOFs), which contains PAH isolated from the PM2.5 collected from several monitoring stations in Mexico City (northeast, downtown, and southwest) in a cell culture of human line NL-20 during a 24-h period. Methods. We extracted the soluble organic fraction of PM2.5 filters from the different monitoring stations. Human bronchial cells were cultured and subsequently assays were performed on the exposure of SOFs to evaluate the effect on the viability and induction of genotoxicity. Results. Results show that 0.1 μg/μl of SOF from the downtown station was more cytotoxic, reducing cell viability to 52.4% and 54.2% in both dry and rainy periods, respectively. Also, cellular anomalies were induced such as multinucleation and nuclear atypia. These percentages of cytotoxicity contrasted against those obtained from SOFs from the northeast area that were 91.2% and 85% at the same concentration during both dry and rainy periods, respectively (p <0.05). Only at 0.1 μg/μl SOF were the results genotoxic from the northeast and downtown (p <0.05). Conclusions. SOFs from the downtown zone were the most cytotoxic due to the high concentration of automobiles as the main sources of PAH. Source

Villeda-Cuevas D.,Hospital Infantil de Mexico Federico Gomez | Villeda-Cuevas D.,Simon Bolivar University of Mexico | Quintero-Casas D.,Hospital Infantil de Mexico Federico Gomez | Quintero-Casas D.,Simon Bolivar University of Mexico | And 5 more authors.
Inhalation Toxicology | Year: 2012

Inorganic fibers form part of the complex mixture of environmental pollutants in Mexico City and in general locations. Upon entering the lungs, some of those fibers are transformed into ferruginous bodies (FB) that can be used as biological markers of exposure to fibers. Hence, the objectives of this study were, first, to describe the most frequent types of FB found in the lungs, and second, to determine the elemental composition of the cores of some of those FB. A total of 264 lung samples collected from autopsies performed at the National Institutes of Health in Mexico City were analyzed. The FB were obtained by digesting the samples in commercial bleach and all the FB were then collected in 0.45 m Millipore membranes. All the FB obtained from each case were counted directly under bright field microscopy, and then classified by morphology. Results showed from 14.5 FB/g in Category 1 (housewives), to 50.2 FB/g for samples from Category 5 (construction workers), and 152 FB/g for Category 6 (miners). Significant differences were found upon comparing samples from Categories 5/6 to Category 1 (p < 0.05). Type 1 FB were the most frequent ones seen in the samples from Categories 1 to 5. Elemental analyses of the cores of several FB found aluminosilicates, fiberglass, tremolite and amosite asbestos among others. In conclusion, residents of Mexico show exposures to a variety of fibers that induce FB including asbestos. © 2012 Informa Healthcare USA, Inc. Source

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