Electrochemical Sensor Based on Glassy Carbon Electrode Modified with Carbon Nanohorns (SWCNH) for Determination of Cr(VI) via Adsorptive Cathodic Stripping Voltammetry (AdCSV) in Tap Water.

In this study, a new and simple glassy carbon electrode modified with carbon nanohorns (SWCNH/GCE) was used for the determination of Cr(VI) in aqueous matrices via adsorptive cathodic stripping voltammetry (AdCSV). The modified electrode was characterized via field emission scanning electron microscopy and cyclic voltammetry, which revealed a homogeneous distribution of spherical agglomerates of SWCNH on the electrode surface. The modification increased the electrochemically active area from 0.10 cm2 ± 0.01 (GCE) to 0.16 cm2 ± 0.01 (SWCNH/GCE). The optimized analytical conditions were as follows: a supporting electrolyte (0.15 mol L-1 HCl), an accumulation potential of 0.8 V versus Ag/AgCl, and an accumulation time of 240 s. Validation of the analytical methodology was performed, obtaining a linear range between 20 and 100 µg L-1, a limit of detection of 3.5 µg L-1, and a limit of quantification of 11.6 µg L-1 with good accuracy and precision. The method was applied to the analysis of spiked tap water samples, and the results were compared using a flame atomic absorption spectrophotometer (FAAS) with no significant statistical differences.

A simple graphene modified electrode for the determination of antimony(III) in edible plants and beverage.

Antimony(III) is a rare electroactive specie present on Earth, whose concentration is not typically determined. The presence of high concentrations of antimony is responsible for a variety of diseases, which makes it desirable to find convenient and reliable methods for its determination. We have developed a convenient glassy carbon modified electrode with electroreduced graphene oxide GC/rGO for the first time determination of Sb(III) in commercial lettuce, celery, and beverages. The surface of the electrode was characterized by scanning electron microscopy (SEM) and cyclic voltammetry, indicating a heterogeneous and rough surface with a real area of 0.28 cm2, which is ~2.5 times the area of GC. The optimal chemical and electrochemical parameters used were: sodium acetate buffer (pH = 4.3), an accumulation potential of -1.0 V and an accumulation time of 150 s. The analytical validation was developed evaluating the linear range (10-60 µg L-1), limit of detection (2.5 µg L-1), accuracy, repetibility and reproducibility with satisfactory results (relative standard deviation (RSD) values lower than 10%). All the analyzes performed in real samples by stripping voltammetry were compared with GF-AAS, showing statistically similar values, demonstrating that GC/rGO could be effectively applied in the analysis of food samples.

Ulva compressa from Copper-Polluted Sites Exhibits Intracellular Copper Accumulation, Increased Expression of Metallothioneins and Copper-Containing Nanoparticles in Chloroplasts.

In order to analyze the mechanisms involved in copper accumulation in Ulva compressa, algae were collected at control sites of central and northern Chile, and at two copper-polluted sites of northern Chile. The level of intracellular copper, reduced glutathione (GSH), phytochelatins (PCs), PC2 and PC4, and transcripts encoding metallothioneins (MTs) of U. compressa, UcMT1, UcMT2 and UcMT3, were determined. Algae of control sites contained around 20 µg of copper g-1 of dry tissue (DT) whereas algae of copper-polluted sites contained 260 and 272 µg of copper g-1 of DT. Algae of control sites and copper-polluted sites did not show detectable amounts of GSH, the level of PC2 did not change among sites whereas PC4 was increased in one of the copper-polluted sites. The level of transcripts of UcMT1 and UcMT2 were increased in algae of copper-polluted sites, but the level of UcMT3 did not change. Algae of a control site and a copper-polluted site were visualized by transmission electron microscopy (TEM) and the existence of copper in electrodense particles was analyzed using energy dispersive x-ray spectroscopy (EDXS). Algae of copper-polluted sites showed electrodense nanoparticles containing copper in the chloroplasts, whereas algae of control sites did not. Algae of a control site, Cachagua, were cultivated without copper (control) and with 10 µM copper for 5 days and they were analyzed by TEM-EDXS. Algae cultivated with copper showed copper-containing nanoparticles in the chloroplast whereas control algae did not. Thus, U. compressa from copper-polluted sites exhibits intracellular copper accumulation, an increase in the level of PC4 and expression of UcMTs, and the accumulation of copper-containing particles in chloroplasts.

Contaminant emissions as indicators of chemical elements in the snow along a latitudinal gradient in southern Andes.

The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 µm and 10 µm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.

Evaluation of Antarctic Ozone Profiles derived from OMPS-LP by using Balloon-borne Ozonesondes.

Predicting radiative forcing due to Antarctic stratospheric ozone recovery requires detecting changes in the ozone vertical distribution. In this endeavor, the Limb Profiler of the Ozone Mapping and Profiler Suite (OMPS-LP), aboard the Suomi NPP satellite, has played a key role providing ozone profiles over Antarctica since 2011. Here, we compare ozone profiles derived from OMPS-LP data (version 2.5 algorithm) with balloon-borne ozonesondes launched from 8 Antarctic stations over the period 2012-2020. Comparisons focus on the layer from 12.5 to 27.5 km and include ozone profiles retrieved during the Sudden Stratospheric Warming (SSW) event registered in Spring 2019. We found that, over the period December-January-February-March, the root mean square error (RMSE) tends to be larger (about 20%) in the lower stratosphere (12.5-17.5 km) and smaller (about 10%) within higher layers (17.5-27.5 km). During the ozone hole season (September-October-November), RMSE values rise up to 40% within the layer from 12.5 to 22 km. Nevertheless, relative to balloon-borne measurements, the mean bias error of OMPS-derived Antarctic ozone profiles is generally lower than 0.3 ppmv, regardless of the season.

Tree decay modulates the functional response of lichen communities in Patagonian temperate forests.

Epiphytic and epixylic lichens respond negatively to forest degradation, climate change and pollution, but those effects may depend on functional traits or interact with the stage of tree decay. Disentangling the main drivers of lichen communities remains a challenge in regions where lichens are diverse and poorly known, as the case of Patagonian temperate forests. We used a multi-scale approach to evaluate the relationship between environmental variables, tree decay stage and lichens. We sampled lichens across three increasing scales (tree â‰ª site â‰ª landscape) by selecting 19 landscape units, where trees in four decay stages (snags, logs, cavity trees and healthy trees) were selected within sampling plots. A total of 35 predictors were measured over different scales, including 25 remote sensing indices of forest conditions, climate and air pollutants. Structural Equation Models were used to test the causal linkages of predictors with lichens, distinguishing functional categories (size, growth and reproductive strategy). A total of 69 lichen species were recorded. Cavity trees and logs supported the largest diversity, while snags and healthy trees had the lowest diversity. Functional lichen groups responded differently to fine-scale variables, including the diameter, height, density and pH of trees. Air pollutants affected species with sexual and mixed strategies. Lichens were sensitive to precipitation, temperature and wind speed, with foliose and sexual species responding positively to the latter. The abundance of all species and macrolichens increased with tree senescence and decreased with canopy continuity. Lichens occupying snags and logs responded negatively to primary productivity and tree senescence, but positively to soil organic matter. Our findings suggest: i) the functional structure of lichen communities varies non-linearly with the wood decay process; ii) the reproductive strategy influences the sensitivity to air pollutants, iii) climate variables influence dispersal and colonization of woody substrates; and iv) forest structure/succession interacts with tree decay.

COVID-19: la pandemia por el nuevo virus SARS-CoV-2.

During the first weeks of 2020, cases of SARS-CoV-2 began to be reported outside of China, with a rapid increase in cases and deaths worldwide. SARS-CoV-2 is a positive single-stranded RNA virus, encased in a lipid bilayer derived from the host cell membrane and consists of four structural proteins (S, M, E and N), plus a haemagglutinin-sterase. The binding of the S protein to the ECA2 receptor allows the entry of the virus into the host cell and is a potential therapeutic target. 81% of patients develop mild symptoms, 14% have severe symptoms and 5% require intensive care management. Fever is the most frequent symptom, followed by cough and dyspnea. Most patients do not present leukocytosis, but they do present lymphopenia with sputum cultures that do not show other pathogens. In lung biopsies of severe patients, the most noticeable finding is diffuse alveolar damage. Radiologically, ground glass and alveolar patterns are observed; the lesions being predominantly basal, subpleural, and posterior, with a multifocal peripheral distribution, more affecting the right lower lobe. There is a marked inflammatory response, up to the cytokine storm, in which anti-inflammatory treatment with pulse therapy with methylprednisolone would be indicated. Although there are no large-scale studies regarding the use of chloroquine / hydroxychloroquine, due to the global situation, its use has been authorized for its anti-SARS-CoV-2 and anti-inflammatory effect, which can be potentiated with the use of azithromycin.

Durante las primeras semanas de 2020 se comenzaron a informar casos de personas con SARS-CoV-2 fuera de China, con un rápido aumento de casos y muertes en todo el mundo. El SARS-CoV-2 es un virus ARN monocatenario positivo, envuelto en una bicapa lipídica derivada de la membrana celular del huésped y constituido por cuatro proteínas estructurales (S, M, E y N), además de una hemaglutinina-esterasa. La unión de la proteína S con el receptor de enzima convertidora de angiotensina 2 (ECA2) permite la entrada del virus a la célula huésped y es una potencial diana terapéutica. El 81% de los enfermos hace cuadro leve; el 14%, grave; y el 5% requiere cuidados intensivos. La fiebre es el síntoma más frecuente, seguido de tos y disnea. La mayoría de los pacientes no presentan leucocitosis pero sí linfopenia, con cultivos de esputo que no muestran otros patógenos. En las biopsias de pulmón de pacientes graves el hallazgo más llamativo es el daño alveolar difuso. Radiológicamente se aprecian patrones de vidrio esmerilado y alveolar, siendo las lesiones de predominio basal, subpleural y posterior, con una distribución periférica multifocal, afectando más el lóbulo inferior derecho. Hay una marcada respuesta inflamatoria, que llega hasta la tormenta de citoquinas, en la que el tratamiento antiinflamatorio con terapia de pulso con metilprednisolona estaría indicado. Aunque no existan estudios en gran escala respecto al uso de cloroquina/hidroxicloroquina, debido a la situación mundial se ha autorizado su uso por su efecto anti SARS-CoV-2 y anti-inflamatorio, el cual puede ser potenciado con el uso de azitromicina.

COVID-19: la pandemia por el nuevo virus SARS-CoV-2

RESUMEN Durante las primeras semanas de 2020 se comenzaron a informar casos de personas con SARS-CoV-2 fuera de China, con un rápido aumento de casos y muertes en todo el mundo. El SARS-CoV-2 es un virus ARN monocatenario positivo, envuelto en una bicapa lipídica derivada de la membrana celular del huésped y constituido por cuatro proteínas estructurales (S, M, E y N), además de una hemaglutinina-esterasa. La unión de la proteína S con el receptor de enzima convertidora de angiotensina 2 (ECA2) permite la entrada del virus a la célula huésped y es una potencial diana terapéutica. El 81% de los enfermos hace cuadro leve; el 14%, grave; y el 5% requiere cuidados intensivos. La fiebre es el síntoma más frecuente, seguido de tos y disnea. La mayoría de los pacientes no presentan leucocitosis pero sí linfopenia, con cultivos de esputo que no muestran otros patógenos. En las biopsias de pulmón de pacientes graves el hallazgo más llamativo es el daño alveolar difuso. Radiológicamente se aprecian patrones de vidrio esmerilado y alveolar, siendo las lesiones de predominio basal, subpleural y posterior, con una distribución periférica multifocal, afectando más el lóbulo inferior derecho. Hay una marcada respuesta inflamatoria, que llega hasta la tormenta de citoquinas, en la que el tratamiento antiinflamatorio con terapia de pulso con metilprednisolona estaría indicado. Aunque no existan estudios en gran escala respecto al uso de cloroquina/hidroxicloroquina, debido a la situación mundial se ha autorizado su uso por su efecto anti SARS-CoV-2 y anti-inflamatorio, el cual puede ser potenciado con el uso de azitromicina.

ABSTRACT During the first weeks of 2020, cases of SARS-CoV-2 began to be reported outside of China, with a rapid increase in cases and deaths worldwide. SARS-CoV-2 is a positive single-stranded RNA virus, encased in a lipid bilayer derived from the host cell membrane and consists of four structural proteins (S, M, E and N), plus a haemagglutinin-sterase. The binding of the S protein to the ECA2 receptor allows the entry of the virus into the host cell and is a potential therapeutic target. 81% of patients develop mild symptoms, 14% have severe symptoms and 5% require intensive care management. Fever is the most frequent symptom, followed by cough and dyspnea. Most patients do not present leukocytosis, but they do present lymphopenia with sputum cultures that do not show other pathogens. In lung biopsies of severe patients, the most noticeable finding is diffuse alveolar damage. Radiologically, ground glass and alveolar patterns are observed; the lesions being predominantly basal, subpleural, and posterior, with a multifocal peripheral distribution, more affecting the right lower lobe. There is a marked inflammatory response, up to the cytokine storm, in which anti-inflammatory treatment with pulse therapy with methylprednisolone would be indicated. Although there are no large-scale studies regarding the use of chloroquine / hydroxychloroquine, due to the global situation, its use has been authorized for its anti-SARS-CoV-2 and anti-inflammatory effect, which can be potentiated with the use of azithromycin.

New aryloxy-quinone derivatives with promising activity on Trypanosoma cruzi.

Continuing with a program to develop new quinone derivatives as biologically active compounds, we designed and synthesized a new series of aryloxy-quinones, which were evaluated in vitro against Trypanosoma cruzi in epimastigote form. Chemical modifications in three specific moieties on the aryloxy-quinone core were considered for developing new anti-T. cruzi agents. The majority of our new quinones showed higher potency (IC50 values of <0.70 µM) than nifurtimox, a known pharmaceutical used as a baseline drug (IC50 values of 7.00 µM); however, only two of them elicited higher selectivity than nifurtimox against Vero cells. A structure-activity relationship analysis provided information about the stereoelectronic features of these compounds, which are responsible for an increase in trypanosomicidal activity. Using a pharmacophore model, we mapped the substitution patterns of the five pharmacophoric features of trypanosomicidal activity. We chose the Epc1 compounds and found no relationship with the trypanosomicidal effects. These results provided useful information about the structural characteristics for developing new aryloxy-quinones with higher potency against the protozoan parasite T. cruzi.

Elemental and Mineralogical Composition of the Western Andean Snow (18°S-41°S).

The snowpack is an important source of water for many Andean communities. Because of its importance, elemental and mineralogical composition analysis of the Andean snow is a worthwhile effort. In this study, we conducted a chemical composition analysis (major and trace elements, mineralogy, and chemical enrichment) of surface snow sampled at 21 sites across a transect of about 2,500 km in the Chilean Andes (18-41°S). Our results enabled us to identify five depositional environments: (i) sites 1-3 (in the Atacama Desert, 18-26°S) with relatively high concentrations of metals, high abundance of quartz and low presence of arsenates, (ii) sites 4-8 (in northern Chile, 29-32°S) with relatively high abundance of quartz and low presence of metals and arsenates, (iii) sites 9-12 (in central Chile, 33-35°S) with anthropogenic enrichment of metals, relatively high values of quartz and low abundance of arsenates, (iv) sites 13-14 (also in central Chile, 35-37°S) with relatively high values of quartz and low presence of metals and arsenates, and v) sites 15-21 (in southern Chile, 37-41°S) with relatively high abundance of arsenates and low presence of metals and quartz. We found significant anthropogenic enrichment at sites close to Santiago (a major city of 6 million inhabitants) and in the Atacama Desert (that hosts several major copper mines).

Black carbon and other light-absorbing impurities in snow in the Chilean Andes.

Vertical profiles of black carbon (BC) and other light-absorbing impurities were measured in seasonal snow and permanent snowfields in the Chilean Andes during Austral winters 2015 and 2016, at 22 sites between latitudes 18°S and 41°S. The samples were analyzed for spectrally-resolved visible light absorption. For surface snow, the average mass mixing ratio of BC was 15 ng/g in northern Chile (18-33°S), 28 ng/g near Santiago (a major city near latitude 33°S, where urban pollution plays a significant role), and 13 ng/g in southern Chile (33-41°S). The regional average vertically-integrated loading of BC was 207 µg/m2 in the north, 780 µg/m2 near Santiago, and 2500 µg/m2 in the south, where the snow season was longer and the snow was deeper. For samples collected at locations where there had been no new snowfall for a week or more, the BC concentration in surface snow was high (~10-100 ng/g) and the sub-surface snow was comparatively clean, indicating the dominance of dry deposition of BC. Mean albedo reductions due to light-absorbing impurities were 0.0150, 0.0160, and 0.0077 for snow grain radii of 100 µm for northern Chile, the region near Santiago, and southern Chile; respective mean radiative forcings for the winter months were 2.8, 1.4, and 0.6 W/m2. In northern Chile, our measurements indicate that light-absorption by impurities in snow was dominated by dust rather than BC.

[Venous tromboembolism in a patient with Crohn disease with ileal stenosis]. / Trombosis venosa profunda en un paciente con enfermedad de Crohnilealestenosante.

Inflammatory bowel disease is associated with extraintestinal manifestations. Among these manifestations is the venous tromboembolism which presents a risk three times more than that presented in general population. We report the case of a 61-year-old male with a history of abdominal pain, chronic diarrhea and fever, with leukocytosis, and fecal samples containing leukocytes, partial ileal stenosis with multiple ulcers in the enteroscopy, with histologic findings compatible with Crohn's disease. The patient has a good outcome with prednisone and maintenence azathioprine, presenting at the fifth month deep venous thrombosis of both lower extremities that resolvewith anticoagulation treatment.

Cooling and eutrophication of southern Chilean lakes.

Understanding the impacts of global warming and human-disturbances on lakes is required for implementing management strategies aimed at mitigating the decline of the quality and availability of water for humans. We assessed temporal trends in water parameters, and the contribution of land use to the eutrophication of the largest lakes of central-southern Chile. The mean values of water parameters varied seasonally, with lakes Chapo and Caburgua exhibiting lower pH, temperature, and N/P ratio values. Over the assessed period (19 years), we found a temporal reduction in water conductivity and temperature of the lakes. The concentration of NO3(-)-N, PO4(3-)-P and dissolved oxygen increased in all the lakes, but pH increased in eight out of the ten lakes. The negative temporal trend in temperature was more pronounced as the depth level increased. Lakes whose basins had a higher percentage of forest plantation and urban areas had larger values of Chlorophyll a and pH, as well as, smaller values of dissolved oxygen. Lakes whose basins included larger percentages of native forest had smaller nutrient (NO3(-)-N, PO4(3-)-P) concentrations. Our findings suggest that decreased rainfall in central-southern Chile due to climate change may cause a decrease of particulate material that is carried by tributaries into the lakes. The observed temporal decrease in temperature, especially at the deeper levels, may be explained by the rapid melting of glaciers. Although the studied lakes are classified as oligotrophic, deforestation and expansion of urban areas around the lakes have led to increased nutrient input, thus accelerating their eutrophication.

Características clínicas y patológicas de las pacientes diagnosticadas como tuberculosis de mama en un hospital general / Clinical and pathological features of patients diagnosed as breast tuberculosis at a general hospital

Objetivo: Describir las características clínicas y patológicas de pacientes diagnosticadas como TB de mama en un hospital general. Material y métodos: Se incluyeron los casos registrados en el Programa de Control de Tuberculosis (PCT) como TB de mama en cuyo informe anatomo-patológico figuraba "inflamación crónica granulomatosa". Se revisaron las historias clínicas y revaluaron las biopsias de mama. Resultados: Se incluyeron 69 mujeres con edad promedio 35,79+-7,94 años. Las manifestaciones más frecuentes fueron presencia de nódulo (89,86%), dolor (89,86%) y signos inflamatorios (40,58%). La revaluación de la biopsia mostró granulomas de tipo supurado, con células gigantes multinucleadas tipo Langhans y tipo cuerpo extraño, sin necrosis caseosa, localizados preferentemente a nivel de la unidad ducto lobular (UDL) y extra-UDL en 85,51% de los casos. Solo en 3 casos se observó bacilos ácido alcohol resistente en la secreción o tejido de mamá. Todos los casos recibieron tratamiento antituberculoso. Treinta y ocho casos tuvieron seguimiento, de ellos 73,68% presentó persistencia o recurrencia al menos un mes después del inicio de tratamiento antituberculoso. Conclusiones: Todos los casos estudiandos fueron mujeres, la mayoría presentaron nódulo, dolor o signo de inflamación en mama, sin síntomas o signos sistémicos y con presencia histológica de granulomas supurados, sin necrósis caseosa. A pesar de recibir tratamiento antituberculoso en todos los casos, cerca del 75% con seguimiento de al menos un mes presentaron persistencia o recurrencia clínica.

Objective: To describe clinical and pathological features of patients diagnosed as breast TB in a general hospital. Methods: Patients registered at the TCP with the pathological diagnosis of "chronic granulomatous mastitis" were included. Clinical records and pathological slides were reviewed. Results: A total of 69 women were included; mean age was 35.79+-7.94 years of age. The most common clinical manifestations were a nodular lesion (89.96%), pain (89.96%) and inflammatory signs (40.58%). Reevaluation of biopsies showed suppurated granulomas with Langhans' and foreign body type multinucleated giant cells without caseuous necrosis located at the duct-lobular (DL) and extra DL areas in 85.1% of cases. Acid-fast bacilli were seen in 3 cases. All cases received anti TB treatment. Thirty-eight patients had follow-up, 73.68% of them had recurrence or persistence at least one month after starting anti TB treatment. Conclusions: Nodular lesions with pain and inflammatory signs inabsence of systemic symptoms, and suppurated granulomas without caseuous necrosis were the most frequent findings. Despite receiving anti TB treatment, almost 75% of patients with follow-up had persistence or clinical recurrence.

[Secondary vasculitis to infection by Fasciola hepatica]. / Vasculitis secundaria a infección por Fasciola hepática.

There is a case of a 38 year-old male patient coming from an area where hepatic fascioliasis is endemic in Peru. He was hospitalized because he showed 4 weeks of symptoms like fever, intense myalgias, erythematous and painful injuries on limb extensions. The electromyography and nerve conduction velocity showed a global inflammatory myopathy. A skin biopsy showed polyarteritis nodosa-type vasculitis. During the evaluation process prior to the immunosuppressive therapy, hepatic Fasciola eggs were found in the parasitological examination of stools. The fascioliasis diagnosis was confirmed by fas2-ELISA: 0.46 (VN <0.20). Clinical symptoms started to subside after treatment with ticlabendazol. Contact with the patient was maintained for a year and there was no evidence of disease recurrence, and he was asymptomatic.

Vasculitis secundaria a infección por Fasciola hepática / Secondary vasculitis to infection by Fasciola hepatica

Se presenta el caso de un paciente varón de 38 años, procedente de una zona endémica para fascioliasis hepática en el Perú. Fue hospitalizado por presentar un cuadro de cuatro semanas de evolución; con fiebre, mialgias intensas, lesiones eritematosas y dolorosas en las regiones de extensión de las extremidades. La electromiografía y la velocidad de conducción nerviosa mostraron una miopatía inflamatoria global. La biopsia de piel evidenció una vasculitis de tipo poliarteritis nodosa. En el proceso de evaluación previa a la terapia inmunosupresora, se hallaron huevos de Fasciola hepática en el examen coproparasitológico. El diagnóstico de fascioliasis se confirmó con fas2-ELISA: 0,46 (VN <0,20). El cuadro clínico remitió luego del tratamiento con ticlabendazol. Se mantuvo contacto con el paciente durante un año y no se evidenció recurrencia de la enfermedad, manteniéndose asintomático.

There is a case of a 38 year-old male patient coming from an area where hepatic fascioliasis is endemic in Peru. He was hospitalized because he showed 4 weeks of symptoms like fever, intense myalgias, erythematous and painful injuries on limb extensions. The electromyography and nerve conduction velocity showed a global inflammatory myopathy. A skin biopsy showed polyarteritis nodosa-type vasculitis. During the evaluation process prior to the immunosuppressive therapy, hepatic Fasciola eggs were found in the parasitological examination of stools. The fascioliasis diagnosis was confirmed by fas2-ELISA: 0.46 (VN <0.20). Clinical symptoms started to subside after treatment with ticlabendazol. Contact with the patient was maintained for a year and there was no evidence of disease recurrence, and he was asymptomatic.

Heavy metals in northern Chilean rivers: spatial variation and temporal trends.

Rivers of central-northern Chile are exposed to pollution from different sources, including mining activities, natural orogenic process, volcanic activity, and geology. In order to determine the contribution of mining to river pollution, the spatio-temporal dynamics of chemical species dissolved in 12 rivers of central-northern Chile was assessed. Of all the rivers studied, the Elqui showed the highest historical mean concentrations of As, Cu and Pb. The Aconcagua had the highest concentration of Hg and a large Cr concentration, while the Rapel showed elevated concentrations of Cu and Mo. The Elqui and the Aconcagua were clustered as distinct groups by a cluster analysis based on two independent principal components. Hierarchical Bayesian models showed annual trends but no seasonal effects in heavy metal concentrations. As and Cu in the Elqui had positive annual slopes. Sulphate concentration exceeded 100 mg L(-1) in nine rivers, and in seven of them it had positive annual slopes. Our findings suggest that mining pollution is the main process contributing to this increasing annual trend in As, Cu and SO(4)(2-). Therefore, in order to improve the water quality of these rivers it is necessary to identify the main sources of heavy metals associated with mining activities.

Equinococcosis cardiaca y obesidad mórbida: consideraciones quirúrgicas / Cardiac echinoccocosis and morbid obesity: surgical considerations

Presentamos el informe de una paciente de 49 años de edad con obesidad mórbida a quien se le detectó mediante tomografía torácica un quiste hidatídico en el ventrículo cardiaco izquierdo. El quiste fue extraído a través de una toracotomía submamaria anterior izquierda sin usar circulación extracorpórea. Los estudios de anatomía patológica mostraron presencia de escólex en la membrana hidatídica. Un año después de la cirugía la paciente está sin molestias cardiorrespiratorias y sin evidencia de hidatidosis torácica.

We report the case of a 49-year-old patient with morbid obesity in whom a hydatid cyst in the left ventricle was detected by means of a thoracic CT scan. The cyst was excised through a left submammary thoracothomy without using extracorporeal circulation. Pathological anatomy studies evidenced the presence of scolices on the hydatid membrane. After being followed-up for one year, the patient does not have any cardiac-respiratory symptom, and there is no evidence of cardio-thoracic hydatidosis.

Health risk estimation due to carbon monoxide pollution at different spatial levels in Santiago, Chile.

The Metropolitan Region of Santiago has been declared as nonattainment area for carbon monoxide (CO). The data was based on seven air monitoring stations that do not necessarily represent the real population exposure. Usually, a series of coefficients that relates the concentration of pollutants with health effects (betas of the concentration-response equations) are used. For the calculation of these betas, normally, a city average air pollution concentration is used; nevertheless, these betas do not necessarily represent the real risk of exposure that the inhabitants are experimented. For this reason, this study estimates two aspects that are unknown and that are necessary to policymakers in public health decisions. First, estimate the exposure at a lower spatial resolution level and, second, estimate a concentration-response curve that differs spatially and depends on the proportion of susceptible groups. We followed the Air Pollution and Health, European Approach/Spanish Multicenter Study on the Relationship Between Air Pollution and the Mortality methodology for the determination of the short-term health effect due to CO population exposure at the three spatial levels (city, zone, and county). We found that there are different risks in cardiorespiratory mortality in the group over 64 years old associated to an unequal exposure to CO in Santiago city. The higher risks are in counties located to the south-east of the city. These finding confirm the necessity to face, in a different way, the approach when evaluating control strategies and policy decision to control air pollution in Santiago.

Nutrients dynamics in the main river basins of the centre-southern region of Chile.

Chilean basins have long been exposed to nutrient discharges from human activities and land use changes. A historical seasonal NO(3)(-)-N and PO(4)(3-)-P database of the last 23 years of the main nine rivers of central-southern region of Chile was analysed. Generalized additive models indicated that annual trends in NO(3)(-)-N and PO(4)(3-)-P are nonlinear. River basins such as Bío-Bío, Bueno, Imperial, Maule, Rapel and Valdivia showed a clear increase in NO(3)(-)-N, while PO(4)(3-)-P increased only in the Rapel and Maule basins. Although no seasonal difference in NO(3)(-)-N and PO(4)(3-)-P was found in the analysed basins, there was a negative relation between these nutrients and water flow. Sampling stations with high NO(3)(-)-N concentration were found mostly in sub-basins located in the "central valley" of central Chile, while several PO(4)(3-)-P "over-concentrated" sampling stations were located mostly upstream. If NO(3)(-)-N emissions into Chilean river basins continue at current rates it is probable that the concentration of this nutrient will tend to match that of the most "polluted" rivers around the world.