Environmental refuges increase performance of juvenile mussels Mytilus chilensis: Implications for mussel seedling and farming strategies.

Estuarine ecosystems are characterized by a wide physical-chemical variation that in the context of global change scenarios may be exacerbated in the future. The fitness of resident organisms is expected to be influenced by such variation and, hence, its study is a priority. Some of that variation relates to water vertical stratification, which may create "environmental refuges" or distinct layers of water with conditions favoring the fitness of some individuals and species. This study explored the performance of juvenile mussels (M. chilensis) settled in two distinctive water depths (1 m and 4 m) of the Reloncaví fjord (southern Chile) by conducting a reciprocal transplants experiment. Salinity, saturation state and the contents of CO3 in seawater were among the factors that best explained the differences between the two layers. In such environmental conditions, the mussel traits that responded to such variation were growth and calcification rates, with significantly higher values at 4 m deep, whereas the opposite, increased metabolic stress, was higher in mussels raised and transplanted to the surface waters (1 m). Such differences support the notion of an environmental refuge, where species like mussels can find better growth conditions and achieve higher performance levels. These results are relevant considering the importance of M. chilensis as a shellfish resource for aquaculture and a habitat forming species. In addition, these results shed light on the variable responses exhibited by estuarine organisms to small-scale changes in the characteristics of the water column, which in turn will help to better understand the responses of the organisms to the projected scenarios of climate global change.

Partículas finas en el aire de locales gastronómicos con parrilla / Fine particles in the air of gastronomic places with grill

La exposición a humo ambiental en lugares cerrados es peligrosa para la salud. Las partículas de hasta 2,5 micras son marcadores del humo en los lugares cerrados. Este estudio monitoreó la calidad de aire en 4 locales gastronómicos de Asunción, Paraguay, y algunas condiciones que influyen en los niveles de exposición explorados. Los niveles más altos de partículas encontrados fueron 9,9 µg/m3. En ninguno de los locales estudiados se detectaron fumadores. Falta mayor investigación sobre contaminación del aire en lugares cerrados para una mejor protección de la salud.

Exposure to indoor smoke is hazardous to health. Particles up to 2.5 microns are smoke markers in enclosed places. This study monitored the air quality in 4 gastronomic places in Asunción, Paraguay, and some conditions that influence the levels of exposure explored. The highest levels of particles found were 9.3 µg / m3. In none of the premises studied were smokers detected. There is a lack of further research on indoor air pollution for better health protection.

Comportamientos sexuales y características personales según orientación sexual en adolescentes chilenos / Sexual behaviors and personal characteristics according to sexual orientation in Chilean adolescents

ANTECEDENTES: Los adolescentes y jóvenes lesbianas, gays y bisexuales (LGB) presentan desafíos adicionales en su desarrollo comparados con sus pares heterosexuales, lo cual los expone a altos niveles de estrés y angustia que pueden llevarlos a comportamientos sexuales de riesgo. OBJETIVO: Analizar los comportamientos sexuales y características personales según la orientación sexual en adolescentes consultantes en un centro de salud sexual y reproductiva. MÉTODO: Estudio transversal y analítico en una población adolescente. Los datos fueron recolectados entre 2000-2012. Se utilizó regresión logística múltiple para comparar variables personales, comportamientos sexuales y la orientación sexual. RESULTADOS: En total, 5.143 adolescentes (mediana de edad 16 años, 91,5% mujeres y 97,5% estudiantes) fueron estudiados; 127 reportaron orientación LGB. Los adolescentes LGB presentaron riesgo de tener más parejas sexuales en el grupo de adolescentes católicos, y en el grupo total inicio de la actividad sexual más temprana que sus pares heterosexuales, además los adolescentes LGB en el uso de métodos anticonceptivos no mostró ser un factor de riesgo en los adolescentes católicos pero si en los adolescentes con otra o sin religión. CONCLUSIONES: Los resultados de este estudio muestran que los adolescentes LGB y heterosexual no son idénticos en términos de riesgo sexual. La población LGB se compromete en comportamientos sexuales de más riesgo que su contraparte heterosexual. Los proveedores de salud como el sector educación necesitan estar más sensibilizados a estas diferencias y sus implicancias para la salud y consejería de los y las adolescentes.

BACKGROUND: Adolescents and young lesbian, gay and bisexual (LGB) present additional challenges in their development compared to their heterosexual peers which exposes them to high levels of stress and distress that can lead to sexual risk behaviors. AIM: To analyze the sexual behavior, personal characteristics and sexual orientation in adolescents that attended in a center of sexual and reproductive health. METHODS: Analytical cross-sectional study conducted in an adolescent population. Data were collected in 2000-2012. Multiple logistic regression was used to quantify comparisons of sexual behaviors and personal variables between LGB and heterosexual adolescents. RESULTS: In total, 5,143 adolescents (median age 16 years, 91.5% women and 97.5% students) were studied, 127 were LGB teenagers. LGB adolescents reported risk having more sexual partners and sexual debut earlier than their heterosexual peers. This risk increased by catholic teenagers. Using contraception methods showed no risk in catholic teenagers but adolescents as-signed to another religion or no religion which was a risk factor. CONCLUSIONS: The results of this study show that the LGB and heterosexual adolescents are not identical in terms of sexual risk. LGB engages in riskier sexual behaviors than heterosexual counterparts. Healthcare providers and the education sector need to be sensitive to these differences and their implications for health and counseling of adolescents.

Revisión de técnica y utilidades de la tomosíntesis digital de tórax en la actualidad / A review of current techniques and usefulness of digital chest tomosynthesis

Digital tomosynthesis (DTS) of the chest is an imaging technique composed of similar components to digital radiography (DR). Its advantages over DR: more precise diagnosis of the thoracic structure alterations, useful for confirming or ruling out suspected nodules, detection of patients at high risk of lung cancer and the monitoring of known lesions. The DTS creates coronal thoracic reconstructions with resolution superior to CT; however it is limited by its depth resolution and sensitivity to movement, occasionally hiding lesions adjacent to the pleura, diaphragm and mediastinum. The radiation dose of DTS and the cost is much lower than CT. More specific applications as well as the pulmonary nodules are under investigation, such as mycobacterial infection, cystic fibrosis and others. A basic understanding of the usefulness of thoracic DTS and its technique may be useful for the radiologist.

La Tomosíntesis digital (TSD) de tórax es una técnica de imagen compuesta por piezas similares que la radiografía digital (RD). Sus ventajas de sobre RD: diagnóstico más preciso de las alteraciones estructuras torácicas, útil para confirmar o descartar la sospecha de nódulos, detección de los pacientes de alto riesgo de cáncer pulmonar y seguimiento de lesiones conocidas. La TSD crea reconstrucciones coronales torácicas con resolución superior a TC. Sin embargo, está limitada por su resolución de profundidad y susceptibilidad al movimiento, ocultando ocasionalmente lesiones adyacentes a pleura, diafragma y mediastino. La dosis de radiación de TSD y el costo son más bajos que la TC. Más aplicaciones específicas además de los nódulos pulmonares están bajo investigación, como la infección por micobacterias, fibrosis quística y otras. Una comprensión básica de la utilidad de TSD torácica y su técnica puede ser útil para el radiólogo.

[Part V. Laboratory diagnosis of Chagas disease]. / Parte V. Diagnóstico de laboratorio.

In this fifth part of Guidelines for Chagas disease, diagnostic techniques for Trypanosoma cruzi infection in humans are reviewed, the interpretation of laboratory results and an algorithm for laboratory diagnosis in immunocompetent hosts are presented. Chagas disease may be diagnosed by three kinds of techniques: direct, which allow detect the presence of the parasite in different kind of samples; indirect, based on the search of immune specific response against T. cruzi antigens and molecular, which detect parasite genetic material. Direct techniques are utilized mainly in acute phase of disease, as the parasite is present in blood of infected host. These techniques do not require be confirmed by other methods. For chronic undetermined phase and for symptomatic phase it is recommended to use indirect techniques; generally, immunoassay techniques (ELISA) that detect IgG antibodies directed against T. cruzi antigens are performed. As false positive results are possible, a positive or undetermined result must be confirmed by at least another technique (indirect immunofluorescence or indirect hemmaglutination). In Chile, confirmation of infection is performed by the Instituto de Salud Pública National Reference Laboratory or at surrogate centers. Molecular methods may be used to make the diagnosis in acute or chronic phase of infection, with more accuracy in the acute phase, and it is mainly recommended to diagnose vertical transmission of T. cruzi as early diagnosis of congenital infection increases the possibility to cure the sibling and besides it is a good marker to evaluate the effectiveness of treatment.

Guías clínicas de la enfermedad de Chagas 2006: parte VI: tratamiento antiparasitario de la enfermedad de Chagas / Guidelines for the Chagas disease: part VI: antiparasitic treatment for Chagas disease

As expert consensus has been arisen about universal antiparasitic treatment for all patients infected with Trypanosoma cruzi, most important drugs licensed for Chagas disease treatment are reviewed: nifurtimox and benznidazol, their mechanisms of action, doses, treatment schedules, adverse effects and contraindications. Two other drugs used for Chagas disease treatment, for which a Chilean experience may be exhibited, are allopurinol and itraconazole. Indications for treatment of Chagas disease in immunocompetent patients and inmunocompromised hosts are detailed. This chapter refers besides to the evaluation and monitoring of antiparasitic therapy in inmunocompromised patients, the availability of drugs and includes various forms facsímiles suggested to perform clinical and laboratory follow up of patients that undergo treatment, indicating the prescribed drug, adverse effects and time of follow up.

Con el consenso de expertos de que todo paciente infectado con Trypanosoma cruzi debiera recibir tratamiento anti-parasitario, se revisan los principales medicamentos aprobados para la enfermedad de Chagas: nifurtimox y benznidazol, sus mecanismos de acción, dosis, duración del tratamiento, efectos adversos y contraindicaciones. Se mencionan otros dos medicamentos utilizados en el tratamiento, en el que existe alguna experiencia nacional, como son allopurinol e itraconazol. Se revisan las indicaciones de tratamiento de la enfermedad de Chagas en personas inmuno-competentes y las indicaciones de tratamiento en hospederos inmunodeprimidos. Este capítulo finaliza abordando la evaluación y monitorización de la terapia antiparasitaria en inmunodeprimidos, la disponibilidad de medicamentos e incluye facsímiles de formularios sugeridos para realizar el seguimiento clínico y de laboratorio de los pacientes que son sometidos a tratamiento, indicando el fármaco utilizado, los efectos adversos y el tiempo de seguimiento.

Guías clínicas de la enfermedad de Chagas 2006: parte V: diagnóstico de laboratorio / Guidelines for the Chagas disease: part V: laboratory diagnosis of Chagas disease

In this fifth part of Guidelines for Chagas disease, diagnostic techniques for Trypanosoma cruzi infection in humans are reviewed, the interpretation of laboratory results and an algorithm for laboratory diagnosis in immunocompetent hosts are presented. Chagas disease may be diagnosed by three kinds of techniques: direct, which allow detect the presence of the parasite in different kind of samples; indirect, based on the search of immune specific response against T. cruzi antigens and molecular, which detect parasite genetic material. Direct techniques are utilized mamly in acute phase of disease, as the parasite is present in blood of infected host. These techniques do not require be confirmed by other methods. For chronic undetermined phase and for symptomatic phase it is recommended to use indirect techniques; generally, immunoassay techniques (ELISA) that detect IgG antibodies directed against T. cruzi antigens are performed. As false positive results are possible, a positive or undetermined result must be confirmed by at least another technique (indirect immunofluorescence or indirect hemmaglutination). In Chile, confirmation of infection is performed by the Instituto de Salud Pública National Reference Laboratory or at surrogate centers. Molecular methods may be used to make the diagnosis in acute or chronic phase of infection, with more accuracy in the acute phase, and it is mainly recommended to diagnose vertical transmission of T. cruzi as early diagnosis of congenital infection increases the possibility to cure the sibling and besides it is a good marker to evalúate the effectiveness of treatment.

En esta quinta parte de las Guías Clínicas de enfermedad de Chagas, se revisa el diagnóstico de la infección por Trypanosona cruzi en humanos, la interpretación de los resultados y un algoritmo de diagnóstico de laboratorio en inmunocompetentes. La enfermedad de Chagas se puede diagnosticar por medio de tres tipos de técnicas: directas, que permiten evidenciar la presencia del parásito en diferentes tipos de muestras; indirectas, que corresponden a la búsqueda de anticuerpos específicos contra antígenos de T. cruzi y moleculares, basadas en la detección del material genético del parásito. Las técnicas directas se emplean, de preferencia, en la fase aguda de la enfermedad, donde es posible detectar al parásito circulando en el torrente sanguíneo de la persona infectada. Estas técnicas no requieren ser confirmadas por otros métodos. Para la fase crónica indeterminada y para la fase sintomática es recomendado el uso de las técnicas indirectas; generalmente se emplean técnicas de inmuno ensayo (ELISA) que detectan anticuerpos de tipo IgG contra antígenos de T. cruzi. Por la posibilidad de reacciones falsas positivas, la recomendación es que los resultados positivos o indeterminados sean confirmados con, a lo menos, otra técnica diferente (inmunofluorescencia indirecta o hemaglutinación indirecta). En Chile la confirmación es realizada por el Laboratorio Nacional de Referencia del Instituto de Salud Pública y los centros autorizados por éste. Los métodos moleculares pueden ser empleados para el diagnóstico en fase aguda o crónica, teniendo mayor rendimiento en la primera, y su uso es recomendado principalmente como apoyo para la pesquisa de hijos de madres infectadas en la transmisión transplacentaria de la infección donde el diagnóstico precoz aumenta las posibilidades de cura del niño y es un buen marcador para evaluar el éxito del tratamiento.

[Guidelines for Chagas disease: Part III. Chagas disease in donors to blood banks]. / Guías clínicas de la enfermedad de Chagas: Parte III. Enfermedad de Chagas en donantes de banco de sangre.

In this chapter it is emphasized the importance to guarantee safety and high quality blood transfusions. Besides, the following topics are analyzed: the importance of Trypanosoma cruzi infection acquired by blood transfusions, the obligatory screening implemented in Chilean blood banks and serological diagnostic techniques used that for, the seroprevalence observed, the importance to confirm results and methods recommended in this purpose and, to notify the donor once the infection is confirmed. In addition a facsímil of a letter used to notify the positive donor is included as guidelines to make advice after, attaching a pro-forma of clinical-epidemiological registration to refer the donor to medical evaluation and treatment.

[Guidelines for chagas disease: Part IV. Chagas disease in immune compromised patients]. / Guías clínicas de la enfermedad de Chagas: Parte IV. Enfermedad de Chagas en pacientes inmunocomprometidos.

A summary of different kind of immune suppressed hosts and the importance of Trypanosoma cruzi infection in this group of patients is presented. Then, most relevant aspects of immune compromised host-parasite interaction are analyzed such as the moment of acquiring the infection, immune compromise level, mechanisms of acquisition the infection and geographic region. Clinical features of primary infection and reactivation of infection in chronic Chagasic patients are described making special emphasis in solid organ transplant and BMT. Chagas disease in AIDS patients is discussed including its treatment, follow up, monitoring the immune compromise level and prophylaxis.

Guías clínicas de la enfermedad de Chagas: Parte III. Enfermedad de Chagas en donantes de banco de sangre / Guidelines for chagas disease: Part III. Chagas disease in donors to blood banks

In this chapter it is emphasized the importance to guarantee safety and high quality blood transfusions. Besides, the following topics are analyzed: the importance of Trypcmosoma cruzi infection acquired by blood transfusions, the obligatory screening implemented in Chilean blood banks and serological diagnostic techniques used that for, the seroprevalence observed, the importance to confirm results and methods recommended in this purpose and, to notify the donor once the infection is confirmed. In addition a facsímil of a letter used to notify the positive donor is included as guidelines to make advice after, attaching a pro-forma of clinical-epidemiological registration to refer the donor to medical evaluation and treatment.

En este capítulo se establece la importancia de otorgar seguridad desde el punto de vista biológico y garantizar transfusiones de calidad y sin agentes infectantes detectables. Se analiza la importancia de la infección por Trypanosoma cruzi a través de transfusión sanguínea, el tamizaje obligatorio que se efectúa en Chile y las técnicas serológicas empleadas, la seroprevalencia encontrada en los bancos de sangre, la importancia de la confirmación y las técnicas empleadas y, la notificación al donante una vez confirmada la infección. Se acompaña de una carta tipo de notificación al donante positivo y una interesante guía para efectuar la consejería que debe seguir a la notificación, adjuntándose un formato de una ficha clínico-epidemiológica para su derivación a médico para estudio y tratamiento.

Guías clínicas de la enfermedad de Chagas: Parte IV. Enfermedad de Chagas en pacientes inmunocomprometidos / Guidelines for chagas disease: Part IV. Chagas disease in immune compromissed patients

A summary of different kind of immune supressed hosts and the importance of Tryponosoma cruzi infection in this group of patients is presented. Then, most relevant aspects of immune compromised host-parasite interaction are analyzed such as the moment of acquiring the infection, immune compromise level, mechanisms of acquisition the infection and geographic region. Clinical features of primary infection and reactivation of infection in chronic Chagasic patients are described making especial emphasis in solid organ transplant and BMT. Chagas disease in AIDS patients is discussed including its treatment, follow up, monitoring the immune compromise level and prophylaxis.

Se revisa someramente los diferentes tipos de inmu-osupresión y la importancia de la infección por Trypa-nosoma cruzi en este tipo de pacientes. Se analizan los aspectos más relevantes de la relación hospedero inmunocomprometido-r. cruzi, tales como el momento de la infección, grado de inmunocompromiso, mecanismos de adquisición de la infección y área geográfica. Se presenta el cuadro clínico en el caso de primoinfección, como así también en la reactivación de la infección en pacientes chagásicos crónicos, haciéndose hincapié en el trasplante de órganos sólidos y precursores hematopoyéticos. Mención especial se hace de la enfermedad de Chagas en pacientes con SIDA, destacando el cuadro clínico y enfatizando en su tratamiento, seguimiento, monitorización del nivel de su compromiso inmunológico y profilaxis.

Guías clínicas de la enfermedad de Chagas: Parte I. Introducción y epidemiología / Guidelines for the Chagas disease: Part I. Introduction and epidemiology

La existencia natural de esta zoonosis vectorial y el desarrollo de iniciativas en la Región de las Americas desde 1991 para controlar la Enfermedad de Chagas, hicieron necesario la elaboración de este documento para actualizar los conocimientos sobre esta materia y de este modo presentar una guía para el equipo de salud en Chile, puesto que es un problema de Salud Pública que debe ser abordado de forma integral. Se presenta la definición de Enfermedad de Chagas y su clasificación de acuerdo a la clasificación internacional de enfermedades (CIÉ 10). Se comenta en forma concisa y breve su importancia general, la importancia como carga de enfermedad, se analiza la distribución del vector, la magnitud del problema en Chile, su reservorio, las características del parásito y, sus mecanismos de transmisión. Se establece la definición de caso sospechoso agudo y confirmado para Chile, la situación epidemiológica en el país y un breve análisis costo beneficio del problema.

The natural existence of this vectorial zoonosis and the development since 1991 of initiatives in the American Region in order to control Chagas Disease, did necessary to prepare this document to update the knowledge about the disease and to exhibit guidelines for healthcare workers in Chile, as Chagas disease is a public health problem that needs to be attended in an integral way. A definition for Chagas disease and its classification according to the international classification of diseases (ICD 10) are presented. The general importance and disease load are concise and briefly commented, while the vector geographic distribution, the magnitude in Chile, its reservoir, the parasite main characteristics and its transmission mechanisms are reviewed. A definition for acute suspected and confirmed cases is given, and the epidemiological situation in Chile and a brief cost-benefit analysis of Chagas disease are presented.

Guías clínicas de la enfermedad de Chagas: Parte II. Enfermedad de Chagas en el adulto, la infancia y adolescencia / Guidelines for the Chagas disease: Part II. Chagas disease in adults, infancy and adolescence

Se describen las distintas etapas de la enfermedad en el adulto: aguda, indeterminada o latente y crónica. Se menciona cómo se realiza el diagnóstico etiológico y la indicación de tratamiento. En la etapa crónica, cuando existe compromiso cardíaco así como también digestivo (esófago o colon), se mencionan los síntomas y signos, la evolución, los exámenes de apoyo diagnóstico y el tratamiento. Se analiza la enfermedad de Chagas congénita desde su prevalencia en la embarazada, la etapa de la enfermedad en la madre, las repercusiones de la transmisión del parásito sobre el producto de la concepción, la frecuencia de la transmisión, cómo se produce la infección del feto, la situación en embarazos sucesivos, hasta las consecuencias sobre el recién nacido, incluyendo la sintomatología cuando éste nace enfermo. Se comenta la concomitancia con la infección por virus de inmunodeficiencia humana. Las formas de presentación no vertical en la infancia y adolescencia no difieren de la enfermedad de Chagas en el adulto. Se menciona el diagnóstico directo e indirecto de la infección y se presenta un algoritmo del diagnóstico y seguimiento de la infección vertical por Tripanosoma cruzi.

The different stages of Chagas disease in adults: acute, undetermined or latent and chronic phases are described. This document contains guidelines for etiological diagnosis of Chagas disease and its treatment. In chronic phase, as cardiac and digestive system (esophagus and colon) are affected, symptoms and signs, evolution of the disease, laboratory analysis and treatment are described. The following topics in congenital Chagas disease are boarded: its prevalence in pregnant women, the importance of mother phase of disease, repercussions of the parasite transmission to the fetus, the frequency of transmission, how the infection to the fetus is produced, the importance of chronic infection in consecutive pregnancies, and clinical consequences to the newborn infant including symptoms of congenital disease. Concomitance with human immunodeficiency virus is commented. No vertically transmitted Chagas disease in infancy and adolescents has similar clinical manifestations as in adults. Direct and indirect laboratory tests of infection are described and an algorithm for diagnosis and follow up of vertical transmission of Trypccnosoma cruzi is presented.

Online learning: An alternative for STD/HIV/AIDS knowledge update.

The experience of the e-learning diploma "Specialist in management for control and prevention of STD/HIV/AIDS" for Latin-American health professionals is presented. It was developed by eminent advisory Chilean experts using a web CT platform with the support of the, Global Development Learning Network (GDLN) of World Bank and certificated by the Austral University of Chile, Virtual University and REUNA. The design, development, results of learning, and the opinion of the quality of the course are described. The purpose of this research was to know the opinion of the participants about the quality of diploma on line, and to orient the decision making with respect to the optimization for future versions of this diploma. The universe and sample correspond to first cohort of the diploma during year 2005, was conformed by 33 students. The instrument of data collection used was a survey of opinion applied when finalizing of the diploma. The data were process in SPSS 13.0. The measured criteria of quality were classified like high quality when 80% or more of the participants answered that the evaluated aspect was excellent, medium quality (61 and 79%) and low quality at least of 60% thought that was excellent. The results emphasize that the quality of the contents of the diploma it considers a 95% of the participants excellent. A 100% consider the roll carried out by the tutor excellent and 91.3% excellent the roll of the academic secretary. The means of support to the student were evaluated like excellent by 58.3% of the users. The system of communication by means of internal mail of the diploma was considered excellent by 67% of the students the forums were evaluated like excellent by 84.8% of the people. In relation to the Web site 84.5% consider it excellent, the learning activities were considered as excellent by 75% and the system of evaluation of the diploma was considered adapted by 83.3% of the participants. The 100% would recommend the diploma to other professional of the health, having indicated that the diploma allowed them to extend its knowledge, those that are of much actually daily utility and to establish work networks. One concludes that the quality of the diploma is high as far as contents, roll of the professors; the pedagogical aspects; the most deficit aspects and than are due to correct is the tool as guide of study and calendar, and to optimize the tool of communication by means of the mail of the Web site. The results evidence that this methodology, is an excellent media of learning and promoting the interdisciplinary networking in relevant health issues such as STD/HIV/AIDS control and prevention, where coordinate action is crucial.