Arsenic Distribution Assessment in a Residential Area Polluted with Mining Residues.

Mining is a major source for metals and metalloids pollution, which could pose a risk for human health. In San Guillermo, Chihuahua, Mexico mining wastes are found adjacent to a residential area. A soil-surface sampling was performed, collecting 88 samples for arsenic determination by atomic absorption. Arsenic concentration data set was interpolated using the ArcGis models: inverse distance weighting (IDW), ordinary kriging (OK), and radial basis function (RBF). For method validation purposes, a set of the data was selected and two tests were performed (P1 and P2). In P1 the models were processed without the validation data; in P2 the validation data were removed one by one, models were processed every time that a data point was removed. An arsenic concentration range of 22.7 to 2190 mg/kg was reported. The 39% of data set was classified as contaminated soil and 61% as industrial land use. In P1 the method of interpolation with the lowest RMSE was RBF (0.80), the highest coefficient of E was RBF (46.25), and the highest Ceff value was with RBF (0.48). In P2 the method with the lowest RMSE was OK (0.76), the highest E value was 50.65 with OK, and the Ceff reported the highest value with OK (0.52). The high arsenic contamination in soil of the site indicates an abundant dispersion of this metalloid. Furthermore, the difference between the models was not very wide. The incorporation of more parameters would be of interest to observe the behavior of interpolation methods.

Not so little differences: variation in hot weather risk to young children in New York City.

OBJECTIVES: High ambient temperatures are associated with significant health risk in the United States. The risk to children has been minimally explored, and often young children are considered as a single age group despite marked physiologic and social variation among this population from infancy through preschool. This study explored the heterogeneity of risk of heat among young children. STUDY DESIGN: Using a time-stratified, case-crossover design, we evaluated associations between maximum daily temperature (Tmax) and ED visits (n = 1,002,951) to New York City (NYC) metropolitan area hospitals for children aged 0-4 years in May-September, 2005-2011. METHODS: Conditional logistic regression analysis estimated risks for an interquartile range of Tmax for 0-6 lag days. Stratified analyses explored age strata by year, race/ethnic groups, and diagnostic codes. Sensitivity analyses controlled for same day ambient ozone, particulate matter <2.5 microns, and relative humidity and, separately, explored race groups without ethnicity and different diagnostic code groupings. RESULTS: Children ages 0-4 years had increased risk of emergency department visits with increased Tmax on lag days 0, 1, and 3. The association was strongest on lag day 0, when an increase in Tmax of 13 °F conferred an excess risk of 2.6% (95% confidence interval [CI]: 2.2-3.0). Stratifying by age, we observed significant positive associations for same-day exposures, for 1-4 year olds. Children less than 1 year of age showed a significant positive association with Tmax only on lag day 3. The race/ethnicity stratified analysis revealed a similar lag pattern for all subgroups. The diagnostic group analysis showed percent excess risk for heat-specific diagnoses (16.6% [95% CI: 3.0-31.9]); general symptoms (10.1% [95% CI: 8.2-11.9]); infectious (4.9% [95% CI: 3.9-5.9]); and injury (5.1% [95% CI: 3.8-6.4]) diagnoses. CONCLUSION: We found a significant risk of ED visits in young children with elevated Tmax. Risk patterns vary based on age with infants showing delayed risk and toddlers and preschoolers with same day risk. In addition, the finding of increased risk of injury associated with higher temperatures is novel. Altogether, these findings suggest a need for a tailored public health response, such as different messages to caregivers of different age children, to protect children from the effects of heat. Next steps include examining specific subcategories of diagnoses to develop protective strategies and better anticipate the needs of population health in future scenarios of climate change.

Conductometric measurement of the changes in humic substances caused by ozone oxidation.

Humic substances (HS), a broad category of organic compounds and a major constituent of soil, are responsible for serious problems during water purification processes. In particular, HS react with chlorine during disinfection processes to produce a variety of organochlorine compounds such as trihalomethanes (THMs), which are potentially carcinogenic to humans. The use of ozone as a disinfection method represents a potential solution to this problem; however, HS that are not completely oxidized may form by-products more reactive than the original molecules. The structural changes of HS during oxidation with ozone were evaluated through a replicated 2(2) design, where concentrations of 5 and 30 mg/L of two commercial HS (Aldrich and Fluka) were ozonized over different time intervals (0, 10, and 20 min). The ozone-treated HS were titrated with acid and base solutions, and the shifts of the slopes were then analyzed and finally related to the ionic alterations of the HS. The Aldrich HS (AHS) showed only protonated functional groups; the Fluka HS (FHS) showed only ionized groups; and in both cases, the amount of functional groups increased with increasing ozonation. For AHS and FHA, respectively, the maximum ozone exposure time (20 min) and the highest concentration of HS (30 mg/L) produced the greatest reductions in total organic carbon (TOC) (39 and 34 %), UV254 (50 and 60.8 %), and color (16.4 and 19.6 %). As for aromaticity, AHS showed removals of 39.6 % (from a starting concentration of 5 mg/L) and 17.2 % (from a starting concentration of 30 mg/L). FHS showed the opposite effect, with removals of 33.3 % (starting at 5 mg/L) and 40.1 % (starting at 30 mg/L). In this study, the structural changes of HS submitted to ozonation were inferred in a relatively quick and easy way by using a conductometric titration, thus demonstrating the applicability of the technique.

High glucose concentrations induce TNF-α production through the down-regulation of CD33 in primary human monocytes.

BACKGROUND: CD33 is a membrane receptor containing a lectin domain and a cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM) that is able to inhibit cytokine production. CD33 is expressed by monocytes, and reduced expression of CD33 correlates with augmented production of inflammatory cytokines, such as IL-1ß, TNF-α, and IL-8. However, the role of CD33 in the inflammation associated with hyperglycemia and diabetes is unknown. Therefore, we studied CD33 expression and inflammatory cytokine secretion in freshly isolated monocytes from patients with type 2 diabetes. To evaluate the effects of hyperglycemia, monocytes from healthy donors were cultured with different glucose concentrations (15-50 mmol/l D-glucose), and CD33 expression and inflammatory cytokine production were assessed. The expression of suppressor of cytokine signaling protein-3 (SOCS-3) and the generation of reactive oxygen species (ROS) were also evaluated to address the cellular mechanisms involved in the down-regulation of CD33. RESULTS: CD33 expression was significantly decreased in monocytes from patients with type 2 diabetes, and higher levels of TNF-α, IL-8 and IL-12p70 were detected in the plasma of patients compared to healthy donors. Under high glucose conditions, CD33 protein and mRNA expression was significantly decreased, whereas spontaneous TNF-α secretion and SOCS-3 mRNA expression were increased in monocytes from healthy donors. Furthermore, the down-regulation of CD33 and increase in TNF-α production were prevented when monocytes were treated with the antioxidant α-tocopherol and cultured under high glucose conditions. CONCLUSION: Our results suggest that hyperglycemia down-regulates CD33 expression and triggers the spontaneous secretion of TNF-α by peripheral monocytes. This phenomenon involves the generation of ROS and the up-regulation of SOCS-3. These observations support the importance of blood glucose control for maintaining innate immune function and suggest the participation of CD33 in the inflammatory profile associated with type 2 diabetes.

Government conservation policies on Mexican coastal areas: is "top-down" management working?

Marine and terrestrial ecosystems are declining globally due to environmental degradation and poorly planned resource use. Traditionally, local government agencies have been responsible of the management of natural reserves to preserve biodiversity. Nonetheless, much of these approaches have failed, suggesting the development of more integrative strategies. In order to discuss the importance of a holistic approach in conservation initiatives, coastal and underwater landscape value and biological/environmental indicators of coral reef degradation were assessed using the study case of Zihuatanejo, Guerrero coastal area. This area shelters representative coral reef structures of the Eastern Pacific coast and its terrestrial biodiversity and archaeology enhance the high value of its coastal area. This study explored the landscape value of both terrestrial and marine ecosystems using the geomorphosite approach in two sites on the Zihuatanejo coastal area: Caleta de Chon and Manzanillo Beach. Sedimentation rate, water transparency, chlorophyll and total suspended solids were recorded underwater in each site for environmental characterization. 50 photo-quadrants on five transects were surveyed between 3-4m depth to record coverage (%) of living corals, dead corals, algae, sand and rocks. The conservation status of coral reefs was assessed by the coral mortality index (MI). Landscape values showed that both terrestrial and marine ecosystems had important scientific and aesthetic values, being Manzanillo Beach the site with the highest potential for conservation initiatives (TtV=14.2). However, coral reefs face elevated sedimentation rates (up to 1.16kg/m2d) and low water transparency (less of 5m) generated by coastal land use changes that have increased soil erosion in the adjacent coastal area. High coverage of dead corals (23.6%) and algae (up to 29%) confirm the low values in conservation status of coral reefs (MI=0.5), reflecting a poorly-planned management. Current conditions are the result of "top-down" conservation strategies in Zihuatanejo, as Federal and Municipal authorities do not coordinate, disregard local community in coral reef management, and ignore the intimate relationship between the coastal and marine realms. This work confirms the importance of conservation strategies with a holistic approach, considering both terrestrial and marine ecosystems in coastal areas; and that these initiatives should include local coastal communities in management and decision-taking processes done by government authorities. Rev. Biol. Trop. 59 (4): 1487-1501. Epub 2011 December 01.

Las estrategias integrales son clave para lograr efectividad en la conservación de las áreas costeras. Para discutir la importancia de las estrategias holísticas en iniciativas de conservación, usamos como caso de estudio los arrecifes coralinos de Zihuatanejo Guerrero. En primer lugar, analizamos el valor paisajístico terrestre y marino de la zona costera y posteriormente usamos indicadores biológicos y ambientales de degradación en arrecifes coralinos. El valor paisajístico mostró que Manzanillo Beach tiene el mayor potencial para desarrollar iniciativas de conservación (TtV=14.2). No obstante, ambos arrecifes se enfrentan a elevados niveles de sedimentación (hasta 1.16kg/m2d) y baja transparencia del agua (<5m) causados por el aumento de la erosión de la costa, como consecuencia del cambio de uso del suelo. La alta cobertura de corales muertos (23.6%) y algas (hasta un 29%) en los arrecifes reflejan su manejo inadecuado. Estas condiciones son resultado de las estrategias de conservación usadas principalmente por las autoridades gubernamentales, que en muchos casos no se encuentran coordinadas y no consideran a la población local en el manejo de los recursos. Estos resultados confirman la importancia de las estrategias de conservación con una visión holística del ecosistema terrestre-marino en las áreas costeras. Estas iniciativas deben incluir a la población local en el manejo y la toma de decisiones.

Government conservation policies on Mexican coastal areas: is "top-down" management working?

Marine and terrestrial ecosystems are declining globally due to environmental degradation and poorly planned resource use. Traditionally, local government agencies have been responsible of the management of natural reserves to preserve biodiversity. Nonetheless, much of these approaches have failed, suggesting the development of more integrative strategies. In order to discuss the importance of a holistic approach in conservation initiatives, coastal and underwater landscape value and biological/environmental indicators of coral reef degradation were assessed using the study case of Zihuatanejo, Guerrero coastal area. This area shelters representative coral reef structures of the Eastern Pacific coast and its terrestrial biodiversity and archaeology enhance the high value of its coastal area. This study explored the landscape value of both terrestrial and marine ecosystems using the geomorphosite approach in two sites on the Zihuatanejo coastal area: Caleta de Chon and Manzanillo Beach. Sedimentation rate, water transparency, chlorophyll and total suspended solids were recorded underwater in each site for environmental characterization. 50 photo-quadrants on five transects were surveyed between 3-4m depth to record coverage (%) of living corals, dead corals, algae, sand and rocks. The conservation status of coral reefs was assessed by the coral mortality index (MI). Landscape values showed that both terrestrial and marine ecosystems had important scientific and aesthetic values, being Manzanillo Beach the site with the highest potential for conservation initiatives (TtV = 14.2). However, coral reefs face elevated sedimentation rates (up to 1.16 kg/m2d) and low water transparency (less of 5m) generated by coastal land use changes that have increased soil erosion in the adjacent coastal area. High coverage of dead corals (23.6%) and algae (up to 29%) confirm the low values in conservation status of coral reefs (MI = 0.5), reflecting a poorly-planned management. Current conditions are the result of "top-down" conservation strategies in Zihuatanejo, as Federal and Municipal authorities do not coordinate, disregard local community in coral reef management, and ignore the intimate relationship between the coastal and marine realms. This work confirms the importance of conservation strategies with a holistic approach, considering both terrestrial and marine ecosystems in coastal areas; and that these initiatives should include local coastal communities in management and decision-taking processes done by government authorities.

Mycobacterium tuberculosis effects on fibroblast collagen metabolism.

BACKGROUND: Type I collagen synthesis and degradation are important events during Mycobacterium tuberculosis (MTb) granuloma or cavity formation, and fibroblasts are cells involved in these processes. OBJECTIVE: We examined the MTb effects on fibroblast collagen metabolism to understand the virulence factors involved in tuberculosis pathogenesis. METHODS: Human lung fibroblasts were incubated with culture medium or sonicated MTb H37Ra (avirulent) or H37Rv (virulent) strains. The effects on collagen synthesis, fibroblast proliferation and collagenase activity were examined. Matrix metalloproteinase-1 (MMP-1), MMP-13 and tissue inhibitors of metalloproteinases (TIMP-1) mRNA levels were analyzed by quantitative real-time PCR amplification. Protein expression was explored by Western blot technique. RESULTS: Collagen synthesis and fibroblast proliferation were significantly increased by H37Ra medium. In contrast, cells incubated with H37Rv medium showed an increase in collagenase activity. MMPs quantitative real-time PCR amplification revealed an increase on MMP-13 mRNA levels in fibroblasts cultured with H37Rv medium, with little effect observed on MMP-1 expression. Western blot assay demonstrated that H37Rv medium stimulated MMP-1 and MMP-13 proenzyme synthesis. This medium had a large effect on MMP-1 activation. TIMP-1 transcription was increased in cells incubated with medium and sonicated from H37Ra, although the highest TIMP-1 protein expression was found in fibroblasts cultured with sonicated H37Rv. CONCLUSIONS: These results suggest that MTb had direct effects on fibroblast collagen turnover, with differences in collagen synthesis and degradation depending on the strain.

Alteraciones hidrocarbonadas por insulinorresistencia en la edad pediátrica / Metabolic glucose alterations in relation with insulin resistance in pediatric age

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