25 research outputs found

    A compilation of field surveys on gaseous elemental mercury (GEM) from contrasting environmental settings in Europe, South America, South Africa and China: separating fads from facts

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    Mercury is transported globally in the atmosphere mostly in gaseous elemental form (GEM, Hg0 gas), but still few worldwide studies taking into account different and contrasted environmental settings are available in a single publication. This work presents and discusses data from Argentina, Bolivia, Bosnia and Herzegovina, Brazil, Chile, China, Croatia, Finland, Italy, Russia, South Africa, Spain, Slovenia and Venezuela. We classified the information in four groups: (1) mining districts where this contaminant poses or has posed a risk for human populations and/or ecosystems; (2) cities, where the concentration ofatmospheric mercury could be higher than normal due to the burning of fossil fuels and industrial activities; (3) areas with natural emissions from volcanoes; and (4) pristine areas where no anthropogenic influence was apparent. All the surveys were performed using portable LUMEX RA-915 series atomic absorption spectrometers. The results for cities fall within a low GEM concentration range that rarely exceeds 30 ng m-3, that is, 6.6 times lower than the restrictive ATSDR threshold (200 ng m-3) for chronic exposure to this pollutant. We also observed this behavior in the former mercury mining districts, where few data were above 200 ng m-3.We noted that high concentrations of GEM are localized phenomena that fade away in short distances. However, this does not imply that they do not pose a risk for those working in close proximity to the source. This is the case of the artisanal gold miners that heat the Au–Hg amalgam to vaporize mercury. In this respect, while GEM can be truly regarded as a hazard, because of possible physical–chemical transformations into other species, it is only under these localized conditions, implying exposure to high GEM concentrations, which it becomes a direct risk for humans.Grants CGL2009-13171 and CTM2012-33918 from the Spanish Ministry of Economy and Competitiveness and PII1I09-0142- 4389 from theCastilla-LaMancha (Spain)RegionalGovernment.Published713-7346A. Monitoraggio ambientale, sicurezza e territorioJCR Journalrestricte

    Radiosinovectomía de muñeca guiada por ultrasonido: Experiencia de un caso clínico y revisión del tema Ultrasound-guided wrist radiosynovectomy: Case report and topic review

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    La radiosinovectomía es una forma local de radioterapia utilizada como tratamiento de segunda línea en el manejo de artropatías inflamatorias y no inflamatorias con respuesta insatisfactoria a la terapia sistémica o local con corticoesteroides. Tiene una eficacia similar a la sinovectomía quirúrgica, con las ventajas de ser un tratamiento de menor costo, menos cruento y con menor tiempo de convalecencia. Su eficacia es mayor en artropatías inflamatorias caracterizadas por sinovitis, como la artritis reumatoide y artritis crónica juvenil, con compromiso mono u oligoarticular y en articulaciones de extremidades superiores. Existen múltiples isótopos que se pueden utilizar en suspensiones coloidales, siendo el sulfuro coloidal de renio-186 el utilizado para la articulación radiocarpiana. Una técnica de administración adecuada es fundamental para el éxito del tratamiento, siendo la inyección con guía ultrasonográfica adecuada para articulaciones de volumen pequeño, instancia en la que la colaboración del médico radiólogo entrenado es fundamental.<br>Radiosynovectomy is a local form of radiotherapy used as second-line treatment in the management of inflammatory and non-inflammatory arthropathies with unsatisfactory response to local or systemic corticosteroid therapy. Its efficacy is similar to that of surgical synovectomy, with the advantages of being a low-cost and minimally- invasive treatment that requires a shorter recovery time. Its efficacy is greater in the treatment of inflammatory arthritis characterized by synovitis, such as rheumatoid arthritis and juvenile chronic arthritis with mono/ oligoarticular involvement, especially in upper extremity joints. A number of isotopes can be used in colloidal suspensions. Rhenium-186-sulphide colloid is currently indicated for the treatment of medium-sized joints. The ultrasound-guided injection is suitable for small joints, such as wrist. For proper and safe use and administration of this technique the collaboration of a trained and experienced radiologist is critical to successful treatment

    Proapoptotic effect of endocannabinoids in prostate cancer cells

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    Artículo de publicación ISIIn the early stages, prostate cancer is androgendependent; therefore, medical castration has shown significant results during the initial stages of this pathology. Despite this early effect, advanced prostate cancer is resilient to such treatment. Recent evidence shows that derivatives of Cannabis sativa and its analogs may exert a protective effect against different types of oncologic pathologies. The purpose of the present study was to detect the presence of cannabinoid receptors (CB1 and CB2) on cancer cells with a prostatic origin and to evaluate the effect of the in vitro use of synthetic analogs. In order to do this, we used a commercial cell line and primary cultures derived from prostate cancer and benign prostatic hyperplasia. The presence of the CB1 and CB2 receptors was determined by immunohistochemistry where we showed a higher expression of these receptors in later stages of the disease (samples with a high Gleason score). Later, treatments were conducted using anandamide, 2-arachidonoyl glycerol and a synthetic analog of anandamide, methanandamide. Using the MTT assay, we proved that the treatments produced a cell growth inhibitory effect on all the different prostate cancer cultures. This effect was demonstrated to be dose-dependent. The use of a specific CB1 receptor blocker (SR141716) confirmed that this effect was produced primarily from the activation of the CB1 receptor. In order to understand the MTT assay results, we determined cell cycle distribution by flow cytometry, which showed no variation at the different cell cycle stages in all the cultures after treatment. Treatment with endocannabinoids resulted in an increase in the percentage of apoptotic cells as determined by Annexin V assays and caused an increase in the levels of activated caspase-3 and a reduction in the levels of Bcl-2 confirming that the reduction in cell viability noted in the MTT assay was caused by the activation of the apoptotic pathway. Finally, we observed that endocannabinoid treatment activated the Erk pathway and at the same time, produced a decrease in the activation levels of the Akt pathway. Based on these results, we suggest that endocannabinoids may be a beneficial option for the treatment of prostate cancer that has become nonresponsive to common therapies.Vicerrectoria de Investigacion y Desarrrollo of Universidad de Chile (VID) DI MULT 05/36-2 FONDECYT 1060500 1110269 1140417 Grant DI MULT 05/36-2. Grants FONDECYT, 1060500 (H.C.), 1110269 (H.C.) and 1140417 (E.C.)

    Socioemotional wealth, entrepreneurial orientation and international performance of family firms

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    This paper analyses the relationships between the socioemotional wealth, entrepreneurial orientation and international performance of family firms. This research is pioneering in that it seeks to explain the international performance of family firms from the non-economic perspective of entrepreneurial orientation determined by socioemotional wealth. Second generation structural equation modelling (PLS-SEM) using SmartPLS 3.2.8 software was applied to data from 106 Spanish family firms. The study shows that considering socioemotional wealth substantially improves the capacity of entrepreneurial orientation to explain variation in the international performance of family firms. When only entrepreneurial orientation is included in the model, the explained variance of international performance is 34.2%. However, when socioemotional wealth is included in the model as an antecedent of international performance, the explained variance increases to 42.6%

    Assessing malaria transmission in a low endemicity area of north-western Peru

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    Abstract Background Where malaria endemicity is low, control programmes need increasingly sensitive tools for monitoring malaria transmission intensity (MTI) and to better define health priorities. A cross-sectional survey was conducted in a low endemicity area of the Peruvian north-western coast to assess the MTI using both molecular and serological tools. Methods Epidemiological, parasitological and serological data were collected from 2,667 individuals in three settlements of Bellavista district, in May 2010. Parasite infection was detected using microscopy and polymerase chain reaction (PCR). Antibodies to Plasmodium vivax merozoite surface protein-119 (PvMSP119) and to Plasmodium falciparum glutamate-rich protein (PfGLURP) were detected by ELISA. Risk factors for exposure to malaria (seropositivity) were assessed by multivariate survey logistic regression models. Age-specific antibody prevalence of both P. falciparum and P. vivax were analysed using a previously published catalytic conversion model based on maximum likelihood for generating seroconversion rates (SCR). Results The overall parasite prevalence by microscopy and PCR were extremely low: 0.3 and 0.9%, respectively for P. vivax, and 0 and 0.04%, respectively for P. falciparum, while seroprevalence was much higher, 13.6% for P. vivax and 9.8% for P. falciparum. Settlement, age and occupation as moto-taxi driver during previous year were significantly associated with P. falciparum exposure, while age and distance to the water drain were associated with P. vivax exposure. Likelihood ratio tests supported age seroprevalence curves with two SCR for both P. vivax and P. falciparum indicating significant changes in the MTI over time. The SCR for PfGLURP was 19-fold lower after 2002 as compared to before (λ1 = 0.022 versus λ2 = 0.431), and the SCR for PvMSP119 was four-fold higher after 2006 as compared to before (λ1 = 0.024 versus λ2 = 0.006). Conclusion Combining molecular and serological tools considerably enhanced the capacity of detecting current and past exposure to malaria infections and related risks factors in this very low endemicity area. This allowed for an improved characterization of the current human reservoir of infections, largely hidden and heterogeneous, as well as providing insights into recent changes in species specific MTIs. This approach will be of key importance for evaluating and monitoring future malaria elimination strategies
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