Groundwater arsenic content in Raigón aquifer system (San José, Uruguay)

As a Medical Geology research issue, an environmental arsenic risk assessment study in the most important sedimentary aquifer in southern Uruguay is presented. The Raigón Aquifer System is the most exploited in Uruguay. It has a surface extent of about 1,800 square kilometres and 10,000 inhabitants in San Jose Department, where it was studied. Agriculture and cattle breeding are the main economic activities and this aquifer is the basic support. The groundwater sampling was done on 37 water samples of PRENADER (Natural Resources Management and Irrigation Development Program) wells. Outcropping sediments of Raigón Formation and the overlying Libertad Formation were also sampled in the Kiyú region. The analyses were performed by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS). The results showed 80% samples with arsenic levels exceeding the 10 μg/l of WHO as limit for waters, and 11% exceeds the 20 μg/l limit of uruguayan regulation. The median, maximum and minimum water arsenic concentrations determined have been 14.24, 24.19 and 1.44 μg/l, respectively. On the other hand, nine sediment samples of Raigón and Libertad Formations in Kiyú region were analysed and yielded median, maximum and minimum arsenic concentrations of 5.03, 9.82 and 1.18 ppm, respectively. This issue leads to the supposition that the population, as well as industrial and agricultural activities, are consuming water with arsenic concentrations over the national and international maximum recommended limit.Como una aproximación a la Geología Médica en Uruguay se presentan los resultados de un estudio sobre el estado del Sistema Acuífero Raigón en relación a la presencia de arsénico, en el entendido que es el acuífero más explotado en el país. En particular, el área cubierta por este trabajo es de unos 1800 km2 en un territorio con una población de unos 10,000 habitantes en el departamento de San José. La colecta de aguas del acuífero se realizó en perforaciones de la base de datos de PRENADER (Proyecto de Manejo de Recursos Naturales y Desarrollo del Riego) obteniéndose 37 muestras, y sobre 9 muestras de sedimentos tanto de la Formación Raigón como la suprayacente Libertad en afloramientos de la región de Kiyú. Los análisis fueron realizados mediante ICP-MS. Un 80% de las muestras de aguas analizadas mostraron contenidos mayores a los límites de la OMS (10 μg/l) y un 11% de las muestras superaron el límite de la OSE (20 μg/l). El valor medio, máximo y mínimo determinado en el caso del agua subterránea fue de 14.24, 24.19 and 1.44 μg/l, respectivamente. Por otro lado, las nueve muestras de sedimentos analizados mostraron concentraciones media, máxima y mínima de arsénico de 5.03, 9.82 and 1.18 ppm, respectivamente, descartándose en principio un origen geogénico.Cooperation between the University of the Republic (Uruguay) and CSIC from Spain (Ref. 2005UY0001). DINACYT-Uruguay, Project of the Technological Development Program PDT # 45/14 which included the doctoral thesis work of MSc. Rosario Guerequiz. CYTED Iberoarsen Network and the International Medical Geology Association contributed with scientific and technical support to improve the knowledge on environmental arsenic and health impacts, with a multidisciplinary approach in Uruguay. This work was performed under the Research Consolidated Groups SGR-2005-795 PEGEFA (Petrology and Geochemistry Basic and Applied) and SGR-2005-00589 (Mineral Resources), funded by AGAUR-DURSI, Generalitat de Catalunya.Peer reviewe

Using Chemical Modeling to Asses Water Quality in the Raigón Aquifer System in Southern Uruguay

The Raigón aquifer is an important groundwater system in southern Uruguay. The increasing use of groundwater resources in the last decades has provoked changes in the concentration of many elements which are strongly related to anthropogenic pollution sources. Concentration levels are useful to detect changes in reservoir status but it is also necessary to analyze their chemical significance in order to make an accurate assessment of the sources of contamination and the causes of changes. In this work we use the available thermodynamic data to calculate chemical speciation on these groundwater samples. Trace elements present as anions, in particular Se and Mo, are especially focused to show the chemical modeling possibilities. Both elements form anionic species, predominantly MoO42- and SeO42-. Results show that these anions interact in solution and are greatly influenced by the concentration of the abundant calcium ion. Localized changes in pH can strongly affect the situation. The same is observed with the pE parameter, but only in the case of Se. Chemical speciation of trace elements is in general highly dependent on pH, pE and concentration of major elements. In consequence, for a fixed analytical total concentration, these parameters can markedly change the situation, affecting the mobility, the bioavailability and environmental fate of these elements. The strategy employed in this work can also be extended to the study of many other environmental water scenarios.The authors are grateful to CSIC (Programa de Apoyo a Grupos) and ANII (Project FCE_2011_6491), Uruguayan organizations, for financial support.Peer Reviewe

Estudio preliminar del contenido en arsénico d las aguas subterráneas del suroeste de Uruguay

This work presents new results on the arsenic distribution in the groundwater from the SW of Uruguay.This preliminary study is based in 28 samples from the Aquifer Systems Chuy, Raigón and Mercedes. Thearsenic concentrations observed exceed some thresholds of the Uruguayan and other (e.g., WHO)regulations of water quality. The median, maximum and minimum determined have been 16.9, 58.0 and0.1 µg/l, respectively). There is a horizontal and vertical variation of the concentrations considering alltogether the studied aquifers and also within them. The higher values have been observed in the MercedesAquifer in areas near the Uruguay Rive

Chicamocha Canyon Geopark project: A novel strategy for the socio-economic development of Santander (Colombia) through geoeducation, geotourism and geoconservation

The proposed Chicamocha Canyon Geopark project is starting its way for nomination as a UNESCO Global Geopark under the recognition of the Global Geoparks Network. This paper aims to present the justifications of establishing this geopark. It also assesses the potential role of a geopark figure in Santander as an urgent measure to promote the geoconservation of the Chicamocha Canyon territory. The success of this project will not only improve the living conditions of local communities, but also will be a reference model in terms of geological conservation at national and international level. The Chicamocha Canyon, where is proposed to develop this project, has a great potential for the development of the tourism industry due to climatic conditions of the region, besides possessing a rich cultural and natural heritage that needs to be enhanced and protected. Undoubtedly, this initiative should satisfy all the requirements to be a UNESCO Global Geopark, which include a delimited area that defines a territory, the occurrence of geological features of international importance with scientific, educational and aesthetic value, the presence of other types of heritage such as archaeological sites, as well as a proper access infrastructure that favors the socio-economic development of the region. In order to guarantee the successful consolidation of the proposed geopark within the defined territory, this initiative must count the strong support of the local communities and must involve stakeholders such as government authorities, academic and research institutions, and local businesses

Differential Muc2 and Muc5ac secretion by stimulated guinea pig tracheal epithelial cells in vitro

BACKGROUND: Mucus overproduction is a characteristic of inflammatory pulmonary diseases including asthma, chronic bronchitis, and cystic fibrosis. Expression of two mucin genes, MUC2 and MUC5AC, and their protein products (mucins), is modulated in certain disease states. Understanding the signaling mechanisms that regulate the production and secretion of these major mucus components may contribute significantly to development of effective therapies to modify their expression in inflamed airways. METHODS: To study the differential expression of Muc2 and Muc5ac, a novel monoclonal antibody recognizing guinea pig Muc2 and a commercially-available antibody against human MUC5AC were optimized for recognition of specific guinea pig mucins by enzyme-linked immunosorbent assay (ELISA), Western blot, and immunohistochemistry (IHC). These antibodies were then used to analyze expression of Muc2 and another mucin subtype (likely Muc5ac) in guinea pig tracheal epithelial (GPTE) cells stimulated with a mixture of pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and interferon- γ (IFN-γ)]. RESULTS: The anti-Muc2 (C4) and anti-MUC5AC (45M1) monoclonal antibodies specifically recognized proteins located in Muc2-dominant small intestinal and Muc5ac-dominant stomach mucosae, respectively, in both Western and ELISA experimental protocols. IHC protocols confirmed that C4 recognizes murine small intestine mucosal proteins while 45M1 does not react. C4 and 45M1 also stained specific epithelial cells in guinea pig lung sections. In the resting state, Muc2 was recognized as a highly expressed intracellular mucin in GPTE cells in vitro. Following cytokine exposure, secretion of Muc2, but not the mucin recognized by the 45M1 antibody (likely Muc5ac), was increased from the GPTE cells, with a concomitant increase in intracellular expression of both mucins. CONCLUSION: Given the tissue specificity in IHC and the differential hybridization to high molecular weight proteins by Western blot, we conclude that the antibodies used in this study can recognize specific mucin subtypes in guinea pig airway epithelium and in proteins from GPTE cells. In addition, Muc2 is highly expressed constitutively, modulated by inflammation, and secreted differentially (as compared to Muc5ac) in GPTE cells. This finding contrasts with expression patterns in the airway epithelium of a variety of mammalian species in which only Muc5ac predominates

Helicobacter pylori Infection of Gastrointestinal Epithelial Cells in vitro Induces Mesenchymal Stem Cell Migration through an NF-κB-Dependent Pathway

The role of bone marrow-derived mesenchymal stem cells (MSC) in the physiology of the gastrointestinal tract epithelium is currently not well established. These cells can be recruited in response to inflammation due to epithelial damage, home, and participate in tissue repair. In addition, in the case of tissue repair failure, these cells could transform and be at the origin of carcinomas. However, the chemoattractant molecules responsible for MSC recruitment and migration in response to epithelial damage, and particularly to Helicobacter pylori infection, remain unknown although the role of some chemokines has been suggested. This work aimed to get insight into the mechanisms of mouse MSC migration during in vitro infection of mouse gastrointestinal epithelial cells by H. pylori. Using a cell culture insert system, we showed that infection of gastrointestinal epithelial cells by different H. pylori strains is able to stimulate the migration of MSC. This mechanism involves the secretion by infected epithelial cells of multiple cytokines, with a major role of TNFα, mainly via a Nuclear Factor-kappa B-dependent pathway. This study provides the first evidence of the role of H. pylori infection in MSC migration and paves the way to a better understanding of the role of bone marrow-derived stem cells in gastric pathophysiology and carcinogenesis

Selective Targeting of TRPV1 Expressing Sensory Nerve Terminals in the Spinal Cord for Long Lasting Analgesia

Chronic pain is a major clinical problem and opiates are often the only treatment, but they cause significant problems ranging from sedation to deadly respiratory depression. Resiniferatoxin (RTX), a potent agonist of Transient Receptor Potential Vanilloid 1 (TRPV1), causes a slow, sustained and irreversible activation of TRPV1 and increases the frequency of spontaneous excitatory postsynaptic currents, but causes significant depression of evoked EPSCs due to nerve terminal depolarization block. Intrathecal administration of RTX to rats in the short-term inhibits nociceptive synaptic transmission, and in the long-term causes a localized, selective ablation of TRPV1-expressing central sensory nerve terminals leading to long lasting analgesia in behavioral models. Since RTX actions are selective for central sensory nerve terminals, other efferent functions of dorsal root ganglion neurons can be preserved. Preventing nociceptive transmission at the level of the spinal cord can be a useful strategy to treat chronic, debilitating and intractable pain

Effect of synthetic thymic humoral factor (THF-gamma 2) on T cell activities in immunodeficient ageing mice.

Immunodeficient ageing (C57BL/10 x DBA/2)F1 mice were treated by a single injection of synthetic thymic hormones and 4 days later their thymus and spleen cells were assayed in vitro for T cell activities. A few nanograms of THF-gamma 2 were found to raise the frequency of mitogen-responsive T cells in thymus and spleen cell populations as well as the frequency of cytokine-producing splenic T cells, up to the levels observed in young mice. Moreover, injection of THF-gamma 2 was found to restore T cell growth factor (TCGF) production by mitogen-stimulated spleen cells. Also, the helper activity of spleen cells was enhanced by this treatment and increased with increasing the THF-gamma 2 dose over a wide range. Similarly, the effects of thymopentin and thymosin-alpha 1 on T helper cell activity increased with increasing the injected dose, but the efficiencies of THF-gamma 2 and thymopentin were, respectively, 400-fold and eight-fold greater than that of thymosin-alpha 1