Behavioural, physiological and molecular responses of the Antarctic fairy shrimp Branchinecta gaini (Daday, 1910) to polystyrene nanoplastics.

Plastic pollution represents an emerging environmental issue in terrestrial Antarctica, especially in the Antarctic Peninsula and Maritime Antarctica, which have been recently recognized as hot spots for plastic litter. In these regions, freshwater (FW) environments such as lakes host isolated ecosystems and species that can be severely affected by increasing environmental and anthropogenic stressors, which include plastics that are still overlooked. In this study, we investigated for the first time the impact of nanoplastics on adults of the fairy shrimp Branchinecta gaini (Order Anostraca) populating Antarctic FW ecosystems, using surface charged polystyrene nanoparticles (PS NPs) as a proxy. Short-term acute toxicity (48 h) was investigated by exposing adults to carboxyl (-COOH, 60 nm) and amino-modified (-NH2, 50 nm) PS NPs at 1 and 5 µg mL-1. Biodisposition of PS NPs and lethal and sub-lethal effects (i.e., swimming, moulting, histology, gene expression) were assessed. Behaviour of PS NPs in Antarctic FW media was monitored through 48 h of exposure showing that both PS NPs kept their nanoscale size in the Antarctic FW media. Survival of fairy shrimp adults over short-term exposure was not affected, on the other hand an increase in moulting rate and alterations in the gut epithelium were observed upon exposure to both PS NPs. Significant alterations at the behavioural (ventilation rate) and molecular (up-regulation of Hsp70mit, Hsp83, Sod, P450) levels were related to PS NP surface charge and associated with PS-NH2 exposure only. Nanoplastics could represent a threat for Antarctic FW biodiversity and the Antarctic fairy shrimp could be a valuable model for assessing their impact on such remote and pristine aquatic ecosystems.

Normal, dust-obscured galaxies in the epoch of reionization.

Over the past decades, rest-frame ultraviolet (UV) observations have provided large samples of UV luminous galaxies at redshift (z) greater than 6 (refs. 1-3), during the so-called epoch of reionization. While a few of these UV-identified galaxies revealed substantial dust reservoirs4-7, very heavily dust-obscured sources at these early times have remained elusive. They are limited to a rare population of extreme starburst galaxies8-12 and companions of rare quasars13,14. These studies conclude that the contribution of dust-obscured galaxies to the cosmic star formation rate density at z > 6 is sub-dominant. Recent ALMA and Spitzer observations have identified a more abundant, less extreme population of obscured galaxies at z = 3-6 (refs. 15,16). However, this population has not been confirmed in the reionization epoch so far. Here, we report the discovery of two dust-obscured star-forming galaxies at z = 6.6813 ± 0.0005 and z = 7.3521 ± 0.0005. These objects are not detected in existing rest-frame UV data and were discovered only through their far-infrared [C II] lines and dust continuum emission as companions to typical UV-luminous galaxies at the same redshift. The two galaxies exhibit lower infrared luminosities and star-formation rates than extreme starbursts, in line with typical star-forming galaxies at z ≈ 7. This population of heavily dust-obscured galaxies appears to contribute 10-25% to the z > 6 cosmic star formation rate density.

Eventos adversos supuestamente atribuibles a la vacunación e inmunización asociados a la vacuna anti-COVID-19 Sputnik V en el personbal del hospital Juan P. Garrahan / Adverse events allegedly attributable to vaccination and immunization with the anti-COVID-19 Sputnik V vaccine in the staff of the Hospital Juan P. Garrahan

Introducción: Debido a la emergencia provocada por la pandemia por el virus SARS-CoV-2 se ha producido una crisis sanitaria global. Una vez disponibles las vacunas, se espera que jueguen un rol decisivo para el control de la enfermedad. Dichas vacunas fueron desarrolladas en tiempo récord por lo que es esencial monitorear su seguridad. Durante la Campaña de Vacunación contra COVID-19, todos los Eventos supuestamente atribuibles a vacunación e inmunización (ESAVI) debieron ser notificados al Ministerio de Salud de la Nación a través del Sistema Integrado de Información Sanitaria de Argentina (SIISA). Materiales y métodos: Se realizó un estudio observacional prospectivo desde el 04/01/2021 al 05/05/2021 en el personal del Hospital Garrahan. Se utilizaron dos métodos de vigilancia de ESAVI. La vigilancia pasiva incluyó las notificaciones voluntarias recibidas de forma telefónica y a través de un cuestionario publicado en intranet. La vigilancia activa se realizó sobre los primeros 947 trabajadores inmunizados, enviando el mismo cuestionario por WhatsApp. Resultados: Hasta el día 05/05/2021 fueron inmunizados 5056 agentes, 4865 con las dos dosis. Se notificaron 473 ESAVI. De ellos, 304 correspondían a la primera dosis y 169 a la segunda. La cantidad de notificaciones según su origen fue de 136 para la vigilancia pasiva, y 333 para la vigilancia activa. Se registraron 5 ESAVI graves; tres anafilaxias, un escotoma secundario a la hipertermia generada por la vacuna y una reacción alérgica grave. Los síntomas locales más frecuentes fueron: dolor, enrojecimiento, hinchazón e induración. Los síntomas sistémicos más frecuentes fueron: fiebre, febrícula, astenia, cefalea, mialgia, artralgia y síntomas gastrointestinales. Como tratamiento en la mayoría de los casos se utilizó paracetamol. Discusión: El presente trabajo logró recolectar un número significativo de notificaciones, brindando información útil al tratarse de una vacuna recientemente aprobada en nuestro país y el mundo. (AU)

Introduction: Due to the SARS-CoV-2 pandemic emergency, a global health crisis has occurred. Once vaccines become available, they are expected to play a decisive role in controlling the disease. These vaccines were developed in record time, and therefore it is essential to monitor their safety. During the COVID-19 Vaccination Campaign, all Events Suspected to be Attributable to Vaccination and Immunization (ESAVI) had to be notified to the National Ministry of Health through the Integrated Health Information System of Argentina (SIISA). Material and methods: A prospective observational study was conducted from 04/01/2021 to 05/05/2021 in the staff of Garrahan Hospital. Two methods of ESAVI surveillance were used. Passive surveillance included voluntary notifications received by telephone and through a questionnaire posted on intranet. Active surveillance was conducted on the first 947 immunized workers, sending the same questionnaire by WhatsApp. Results: Up to 05/05/2021, 5056 workers were immunized, of whom 4865 with two doses. A total of 473 ESAVI were reported. Of these, 304 corresponded to the first dose and 169 to the second. The number of notifications was 136 for passive surveillance and 333 for active surveillance. Five severe ESAVIs were recorded; three anaphylaxis, one scotoma secondary to vaccine-generated hyperthermia, and one severe allergic reaction. The most frequent local symptoms were: pain, redness, swelling, and induration. The most frequent systemic symptoms were: mild fever or fever, asthenia, headache, myalgia, arthralgia, and gastrointestinal symptoms. Paracetamol was used as treatment in most cases. Discussion: In the present study a significant number of notifications was collected, providing useful information on a vaccine recently approved in our country and in the world (AU)

Rehabilitación respiratoria para pacientes con distrofia muscular de Duchenne en etapas de pérdida de la marcha / Respiratory rehabilitation for patients with Duchenne muscular dystrophy in stages of loss of gait

Duchenne muscular dystrophy (DMD) is one of the most common neuromuscular diseases. Its evolution with well-defined stages related to motor and functional alterations, allows easily establishing relationships with respiratory function through a simple laboratory assessment including vital capacity (VC) measurements as well as peak cough flows. Without any treatment with respiratory rehabilitation, the main cause of morbidity and mortality is ventilatory failure, secondary to respiratory pump muscles weakness and inefficient cough. The VC plateau is reached during the non-ambulatory stages, generally after 13 years old. Respiratory rehabilitation protocols, including air stacking techniques, manual and mechanical assisted coughing and non-invasive ventilatory support, can effectively addressed the VC decline as well as the decrease in peak cough flows, despite advancing to stages with practically non-existent lung capacity. Non-invasive ventilatory support may be applied after 19 years old, initially at night and then extending it during the day. In this way, survival is prolonged, with good quality of life, avoiding ventilatory failure, endotracheal intubation and tracheostomy. This article proposes staggered interventions for respiratory rehabilitation based on the functional stages expected in the patient with DMD who has lost ambulation.

La distrofia muscular de Duchenne (DMD) es una de las enfermedades neuromusculares más frecuentes. Su curso evolutivo con etapas de declinación en la funcionalidad motora bien definidas, permite fácilmente establecer relaciones con la función respiratoria a través de un laboratorio de evaluación sencilla, básicamente de la capacidad vital (CV) y la capacidad tusígena. Sin intervenciones en rehabilitación respiratoria, la principal causa de morbimortalidad es la insuficiencia ventilatoria secundaria a debilidad de músculos de la bomba respiratoria e ineficiencia de la tos. En las etapas no ambulantes, se alcanza la meseta de la CV, generalmente después de los 13 años, su declinación junto con la disminución de la capacidad tusígena puede ser enfrentada efectivamente con la utilización de protocolos de rehabilitación respiratoria. Estos deben considerar la restitución de la CV con técnicas de insuflación activa o apilamiento de aire, tos asistida manual y mecánica, más soporte ventilatorio no invasivo, inicialmente nocturno después de los 19 años y luego diurno, pese a avanzar a etapas con capacidad pulmonar prácticamente inexistente. De esta manera, se prolonga la sobrevida, con buena calidad de vida, evitando el fallo ventilatorio, eventos de intubación endotraqueal y traqueostomía. Este artículo, hace propuestas escalonadas de intervención en rehabilitación respiratoria basadas en las etapas funcionales esperables en el paciente con DMD que ha perdido la capacidad de marcha.

Cuidados respiratorios de los pacientes con atrofia muscular espinal / Respiratory care approach for patients with spinal muscular atrophy

Spinal Muscular Atrophy (SMA) is a disease of the anterior horn of the spinal cord, which causes muscle weakness that leads to a progressive decrease in vital capacity and diminished cough flows. Respiratory morbidity and mortality are a function of the degree of respiratory and bulbar-innervated muscle. The former can be quantitated by the sequential evaluation of vital capacity to determine the lifetime maximum (plateau) and its subsequent rate of decline, progressing to ventilatory failure. SMA types 1 and 2 benefit from non-invasive respiratory care in early childhood and school age, improving quality and life expectancy. This document synthesizes these recommendations with special reference to interventions guided by stages that include air stacking, assisted cough protocols, preparation for spinal arthrodesis and non-invasive ventilatory support, even in those patients with loss of respiratory autonomy, minimizing the risk tracheostomy. Failure to consider these recommendations in the regular assessment of patients reduces the offer of timely treatments.

La Atrofia Muscular Espinal (AME) es una enfermedad genética del asta anterior de la medula espinal, que cursa con debilidad muscular progresiva. La intensidad y precocidad de la debilidad muscular presenta diferentes grados de afectación de los grupos musculares respiratorios, determinando la meseta en la capacidad vital y progresión a la insuficiencia ventilatoria, como también el compromiso de los músculos inervados bulbares. Los AME tipo 1 y 2, se benefician con cuidados respiratorios no invasivos en la infancia temprana y edad escolar, mejorando la calidad y esperanza de vida. Este documento sintetiza dichas recomendaciones, con especial referencia a intervenciones guiadas por etapas, que incluyan apilamiento de aire, protocolos de tos asistida, preparación para la artrodesis de columna y soporte ventilatorio no invasivo, incluso en aquellos pacientes con pérdida de la autonomía respiratoria, minimizando el riesgo de traqueostomía. La no consideración de estas recomendaciones en la valoración regular de los pacientes resta la oferta de tratamientos oportunos.

The multiple merger assembly of a hyperluminous obscured quasar at redshift 4.6.

Galaxy mergers and gas accretion from the cosmic web drove the growth of galaxies and their central black holes at early epochs. We report spectroscopic imaging of a multiple merger event in the most luminous known galaxy, WISE J224607.56-052634.9 (W2246-0526), a dust-obscured quasar at redshift 4.6, 1.3 billion years after the Big Bang. Far-infrared dust continuum observations show three galaxy companions around W2246-0526 with disturbed morphologies, connected by streams of dust likely produced by the dynamical interaction. The detection of tidal dusty bridges shows that W2246-0526 is accreting its neighbors, suggesting that merger activity may be a dominant mechanism through which the most luminous galaxies simultaneously obscure and feed their central supermassive black holes.

Fast molecular outflow from a dusty star-forming galaxy in the early Universe.

Galaxies grow inefficiently, with only a small percentage of the available gas converted into stars each free-fall time. Feedback processes, such as outflowing winds driven by radiation pressure, supernovae, or supermassive black hole accretion, can act to halt star formation if they heat or expel the gas supply. We report a molecular outflow launched from a dust-rich star-forming galaxy at redshift 5.3, 1 billion years after the Big Bang. The outflow reaches velocities up to 800 kilometers per second relative to the galaxy, is resolved into multiple clumps, and carries mass at a rate within a factor of 2 of the star formation rate. Our results show that molecular outflows can remove a large fraction of the gas available for star formation from galaxies at high redshift.

Author Correction: A massive core for a cluster of galaxies at a redshift of 4.3.

Change history: In this Letter, the Acknowledgements section should have included the following sentence: "The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.". This omission has been corrected online.

A massive core for a cluster of galaxies at a redshift of 4.3.

Massive galaxy clusters have been found that date to times as early as three billion years after the Big Bang, containing stars that formed at even earlier epochs1-3. The high-redshift progenitors of these galaxy clusters-termed 'protoclusters'-can be identified in cosmological simulations that have the highest overdensities (greater-than-average densities) of dark matter4-6. Protoclusters are expected to contain extremely massive galaxies that can be observed as luminous starbursts 7 . However, recent detections of possible protoclusters hosting such starbursts8-11 do not support the kind of rapid cluster-core formation expected from simulations 12 : the structures observed contain only a handful of starbursting galaxies spread throughout a broad region, with poor evidence for eventual collapse into a protocluster. Here we report observations of carbon monoxide and ionized carbon emission from the source SPT2349-56. We find that this source consists of at least 14 gas-rich galaxies, all lying at redshifts of 4.31. We demonstrate that each of these galaxies is forming stars between 50 and 1,000 times more quickly than our own Milky Way, and that all are located within a projected region that is only around 130 kiloparsecs in diameter. This galaxy surface density is more than ten times the average blank-field value (integrated over all redshifts), and more than 1,000 times the average field volume density. The velocity dispersion (approximately 410 kilometres per second) of these galaxies and the enormous gas and star-formation densities suggest that this system represents the core of a cluster of galaxies that was already at an advanced stage of formation when the Universe was only 1.4 billion years old. A comparison with other known protoclusters at high redshifts shows that SPT2349-56 could be building one of the most massive structures in the Universe today.

Galaxy growth in a massive halo in the first billion years of cosmic history.

According to the current understanding of cosmic structure formation, the precursors of the most massive structures in the Universe began to form shortly after the Big Bang, in regions corresponding to the largest fluctuations in the cosmic density field. Observing these structures during their period of active growth and assembly-the first few hundred million years of the Universe-is challenging because it requires surveys that are sensitive enough to detect the distant galaxies that act as signposts for these structures and wide enough to capture the rarest objects. As a result, very few such objects have been detected so far. Here we report observations of a far-infrared-luminous object at redshift 6.900 (less than 800 million years after the Big Bang) that was discovered in a wide-field survey. High-resolution imaging shows it to be a pair of extremely massive star-forming galaxies. The larger is forming stars at a rate of 2,900 solar masses per year, contains 270 billion solar masses of gas and 2.5 billion solar masses of dust, and is more massive than any other known object at a redshift of more than 6. Its rapid star formation is probably triggered by its companion galaxy at a projected separation of 8 kiloparsecs. This merging companion hosts 35 billion solar masses of stars and has a star-formation rate of 540 solar masses per year, but has an order of magnitude less gas and dust than its neighbour and physical conditions akin to those observed in lower-metallicity galaxies in the nearby Universe. These objects suggest the presence of a dark-matter halo with a mass of more than 100 billion solar masses, making it among the rarest dark-matter haloes that should exist in the Universe at this epoch.

Infecciones fúngicas en pacientes hemato-oncológicos pediátricos / Fungal infections in pediatric hematology-oncology patients

Introducción: Las infecciones fúngicas invasivas (IFI) son una causa importante de morbimortalidad en pacientes inmunocomprometidos. En las últimas décadas se produjo un incremento, variaciones epidemiológicas y avances en los métodos de diagnóstico y tratamiento de las mismas. El objetivo de este estudio fue analizar las características epidemiológicas, clínicas y de evolución de IFI en pacientes hematooncológicos. Material y Métodos: Estudio de cohorte observacional retrospectivo y prospectivo. Se incluyeron pacientes con edades entre 1 mes y 18 años con diagnóstico de enfermedad hemato-oncológica admitidos en Hospital Juan P. Garrahan en el período 01/2010 - 04/2014 con diagnóstico de IFI según la EORTC. Resultados: Durante el período de estudio se incluyeron 124 pacientes con IFI. La incidencia fue de 2,65 casos /100 episodios febriles. Las enfermedades de base correspondieron a leucemias agudas en 66,1% (n:82) y a trasplante de médula ósea en 27,4%. Los períodos de mayor riesgo de aparición de IFI fueron las etapas de inducción (21,8%), recaída (16,9%) y re- inducción (12,9%). En general las IFI (n: 110; 88,7%) ocurrieron en el contexto de neutropenia febril. La documentación microbiológica demostró el predominio de Aspergillus spp. especies de Candida no albicans y baja prevalencia de mucorales. Se evidenció co-infección en 80 pacientes (64,5%). El tratamiento antifúngico empírico fue anfotericina liposomal en 48,8% de los pacientes, 46,3% recibió anfotericina desoxicolato y 4,9% voriconazol. Ingresaron a la UCI 30 pacientes (31,5%). La evolución de los pacientes con IFI fue favorable en 77,4%, de los casos; mientras que fallecieron 28 (22,6%). Del total de los pacientes fallecidos, 23 (82%) tuvieron una infección concomitante. Conclusiones: La incidencia de IFI documentada en nuestro estudio fue de 2,65 casos /100 episodios febriles, las leucemias agudas fueron las patologías de base más frecuentemente asociadas y la mayoría de las IFI se asoció a neutropenia febril. Aspergillus spp. fue el hongo más frecuentemente hallado. La mortalidad relacionada a IFI fue de 22,6% La presencia de co-infecciones se asoció con peor evolución (AU)

Introduction: Fungal invasive infections (FII) are an important cause of morbidity and mortality in immunocompromised patients. Over the past decades an increase in incidence, epidemiologic variations, diagnostic methods, and treatment has occurred. The aim of this study was to analyze epidemiological and clinical features and outcome of FII in hematology-oncology patients. Material and Methods: An observational retrospective and prospective cohort study. Patients aged between 1 month and 18 years with hematology-oncology disease admitted to Hospital Juan P. Garrahan from 01/2010 to 04/2014 diagnosed with FII according to the EORTC were included. Results: During the study period 124 patients with FII were included. Incidence was 2,65 cases /100 febrile episodes. Underlying diseases were acute leukemia in 66,1% (n:82) and bone marrow transplantation in 27,4%. The periods of increased risk of FII were the induction (21,8%), relapse (16,9%), and re-induction (12,9%) stages. FII occurred typically in the context of febrile neutropenia (n: 110; 88,7%). Microbiology predominantly showed Aspergillus spp, non-albicans Candida spp, and a lower prevalence of mucor sp. Co-infection was observed in 80 patients (64,5%). Empirical antifungal therapy was liposomal amphotericin in 48.8% of the patients, amphotericin B deoxycholate in 46.3%, and voriconazole in 4,9%. Thirty patients (31,5%) were admitted to the ICU. Outcome of patients with FII was favorable in 77,4% of the cases, while 28 (22,6%) died. Of all patients that died 23 (82%) had a concomitant infection. Conclusions: In our study, incidence of documented FII was 2,65 cases /100 febrile episodes. Acute leukemia was the most common underlying disease and the majority of FII were associated with febrile neutropenia. Aspergillus spp was the most commonly found fungus. FII-related mortality was 22,6%. The presence of coinfections was associated with worse outcome (AU)

Grado de adherencia a la recomendación de actividad física, sedentarismo y riesgo cardiovascular en adolescentes de enseñanza media de Punta Arenas, Chile / Degree of adherence to physical activity recommendation, sedentary lifestyle and cardiovascular risk in teenagers from Punta Arenas, Chile

Objective: The aim of this study was to identify the degree of compliance to the global recommendations on physical activity and its association with cardiovascular risk, anthropometric and socio-demographic variables in teenagers from the district of Punta Arenas, Chile. Subjects and Methods: A random, stratified and proportional sample was obtained of322 students from private, private-subsidized and public local schools. Global physical activity questionnaire (GPAQv2), and anthropometric measurements of weight, height, waist circumference, and classification of nutritional status were applied according to the standards of the Chilean Ministry of Health. Results: 50.31% of the sample showed a normal nutritional status, 48.14% presented overweight status. We also found 666.8 min/day of average sedentary lifestyle between the means by gender. The female gender presents an OR: 1.9; 95% IC: 1.16 to 3.11 according to WHO recommendations. Discussion: It was found that most of the students resulted in the category "sufficiently active" as WHO recommended. An 82.30% showed no high cardiovascular risk. Conclusion: The level of physical activity would not be influenced by nutritional status, showing that the majority of students perform moderate physical activity on their free time.

Objetivo: El objetivo de este estudio fue identificar el grado de adherencia a las recomendaciones mundiales sobre actividad física, así como su asociación con riesgo cardiovascular, variables antropométricas y socio-demográficas en adolescentes de la comuna de Punta Arenas. Sujetos y métodos: Se obtuvo una muestra aleatoria, estratificada y proporcional de 322 estudiantes de establecimientos particular-pagados, particular-subvencionados y municipalizados. Se aplicó el cuestionario mundial sobre actividad física (GPAQv2), y mediciones antropométricas de peso, talla, perímetro de cintura, y clasificación del estado nutricional según normas MINSAL. Resultados: El 50,31% del total de la muestra tenía un estado nutricional normal y 48,14% presentó malnutrición por exceso. También, 666,8 min/día de sedentarismo promedio entre las medias por sexo. El sexo femenino presenta un OR: 1,9; 95%IC: 1,16-3,11 según recomendaciones de la OMS. Discusión: Se encontró a la mayoría de los estudiantes evaluados en la categoría "suficientemente activos" según las recomendaciones de la OMS. Se observó un alto porcentaje sin riesgo cardiovascular (82,30%). Conclusión: El nivel de actividad física no estaría condicionado por el estado nutricional, evidenciándose en la mayoría de los alumnos la realización de actividad física moderada en su tiempo libre.

Dusty starburst galaxies in the early Universe as revealed by gravitational lensing.

In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.

Carcinoma epidermoide oral y orofaríngeo: estudio clínico-patológico / Oral and oropharingeal squamous cells carcinoma: clinico-pathological study

Introduction: Oral cancer is a common disease in many parts of the world, in Chile only accounts for 1.6 percent of all cancers. The majority is squamous cell carcinoma with important clinical, epidemiological and pathological differences between lip, oral and orofaringeal locations. Objective: To analyze clinical and pathological characteristics of oral and oropharingeal squamous cell carcinoma in Temuco, Chile. Materials and Methods: A descriptive, retrospective study of all diagnosed cases in 15 years (1994 and 2008). The patients were analyzed according to gender, age; and the tumors were classified based on anatomic location, size, macroscopical findings and degree of differentiation. Results: We found 93 carcinomas, with male to female ratio of 5:1, average age 67 years. Patients under 50 years accounted for only 8 percent of cases. The most common sites were lower lip, tongue and gingiva, with an average size of 28 mm, which increased towards orofarinx and more than half were moderately differentiated. Conclusions: In our region, this carcinoma most often affects the seventh decade of life and male population and has similar characteristics to those in other countries which is predominantly. The size at diagnosis is significant. The detection of some differences in the group with mapuche surnames warrants a study with a larger number of cases.

Introducción: El cáncer oral es una enfermedad frecuente en muchas partes del mundo, en Chile corresponde al 1,6 por ciento del total de cánceres. La gran mayoría corresponde a carcinoma epidermoide, con importantes diferencias clínicas, epidemiológicas y patológicas entre las localizaciones labial, intraoral y orofaríngea. Objetivo: Analizar las características clínicas y patológicas del carcinoma epidermoide oral y orofaríngeo en Temuco, Chile. Material y Método: Estudio descriptivo, retrospectivo de todos los casos diagnosticados en 15 años (1994 y 2008), en el Hospital Regional de Temuco. Los pacientes fueron analizados de acuerdo a género, edad, y los tumores fueron clasificados basados en su localización anatómica, tamaño, características macroscópicas y grado de diferenciación. Resultados: Se encontraron 93 carcinomas, con relación hombre:mujer de 5:1, edad promedio 67 años. Pacientes menores a 50 años correspondían sólo al 8 por ciento de los casos. Las localizaciones más frecuentes fueron labio inferior, lengua y encía, con un tamaño promedio de 28 mm, el que aumentó hacia la orofarinx, más de la mitad eran moderadamente diferenciados. Conclusiones: En nuestra región, este carcinoma afecta con mayor frecuencia a la séptima década de la vida y a población masculina y posee características similares a las descritas en otros países donde predomina la raza blanca. El tamaño al diagnóstico es considerable. La detección de algunas diferencias en el grupo con apellidos mapuches amerita un estudio con un mayor número de casos.

Retiro de ventilación mecánica prolongada: experiencia de seis años con la aplicación de protocolo especializado / Weaning of prolonged mechanical ventilation: specialized protocol

La Ventilación Mecánica Prolongada (VMP) ha sido definida como aquella mayor de 21 días por al menos 6 horas diarias. Este fenómeno es un creciente problema para las Unidades de Cuidados Intensivos (UCI) en todo el mundo. Los consensos internacionales señalan que los pacientes con VMP deben ser tratados en unidades diferentes a las UCI, con protocolos especializados multiprofesionales dedicados a intentar el retiro del respirador. En nuestro Centro hemos recibido desde el año 2002 a 31 pacientes con VMP y les hemos aplicado un Protocolo de Rehabilitación Respiratoria Integral para ese objetivo. Las patologías predominantes fueron neuromusculares. El protocolo tiene 4 etapas progresivas, las 2 primeras comprenden la evaluación general y el inicio de terapias multiprofesionales. Las 2 siguientes consisten en retiro progresivo del respirador y continuación de terapias. Se midió la presión inspiratoria, presión espiratoria espiratoria máximas (PImáx y PEmáx) y la presión inspiratoria máxima sostenida (PIms), también se evaluó la actividad muscular de cuello, tronco y extremidades, así como el estado general y nutritivo, el nivel de conciencia y la calidad del apoyo familiar. Se entra a etapa 3 cuando los valores de PImáx y PEmáx son 60 y 50 cmH2O, respectivamente. Fueron excluidos de llegar a las últimas 2 etapas 7 pacientes, quienes no lograron este nivel de presiones. Resultados: 19pacientes (61 por ciento) con promedio de edad de 44 años (16-77), fueron retirados del respirador, 5 están aún en etapas 2 y 3; el promedio de VMP fue de 238 días y de 74 días a contar desde el ingreso a etapa 3. El promedio de mejoría de PImax fue de 59 por ciento, la PEmáx 60 por ciento y la PIms 61 por ciento, todos valores con significación estadística (p <0,001). El control cefálico y de tronco mejoró con las terapias. También el daño cognitivo, la depresión y la alteración de la función deglutoria...

Prolonged mechanical ventilation (PMV) is defined as greater than 21 days of mechanical ventilation for at least 6hours per day and is an increasing problem for the Intensive Care Units in all over the world. Many expert consensus groups recommend that long-term facilities may be a useful resource of care to implement integrated and specialized protocols for weaning from PMV. Since 2002 our center admitted 31 patients in PMV who were included on an Integral Respiratory Rehabilitation Protocol that was applied for our primary outcome of weaning success. Neuromuscular diseases were the main cause requiring PMV. The protocol applied consists of 4 successive stages, the first two oriented to evaluation and initiation of multiprofessional therapies, the next two are dedicated to progressive weaning and continuation of therapy. Peak inspiratory and expiratory pressures, and maximal sustained inspiratory pressure (PImax, PEmax and PIms) were measured, additionally muscular activity from neck, trunk and legs, general and nutritional condition, conscience level and family support were evaluated. Entry to stage 3 was defined when the PImax and PEmax were 60 and 50 cmH2O. Seven patients who failed to achieve this pressure levels were excluded. Results: 19 patients (61 percent) with a mean age of 44 years (16-77) had successful weaning and 5 patients are still in stage 2 or 3. Mean duration of PMV was 238 days. Mean Time on Mechanical Ventilation from the beginning of stage3 until the final weaning was 74 days. PImax, PEmax and PIms increased in 59, 60 and 61 percent each, all with statistical significance p <0.001, cephalic and trunk muscle control was increased with integrated therapies. The cognitive impairment, depression and swallowing disorders were professionally treated. Conclusion: A specialized, multiprofessional integrated protocol for PMV in our center permitted a successful weaning rate comparable to the best international series.

Phenazine 5,10-dioxide derivatives as hypoxic selective cytotoxins: Part II. Structure-activity relationship studies.

The synthesis and evaluation as hypoxic selective cytotoxins of new derivatives of 2-amino or 2-hydroxyphenazine 5,10-dioxide are described. The compounds were developed as structural analogs of other bioreductive compounds and its in vitro cytotoxicities on V79 cells under hypoxic and aerobic conditions were determined. To gain insight into its mechanism of action electrochemical behavior, interaction with DNA experiments and QSAR studies were performed.

Terapias emergentes en artritis reumatoide / Emergent therapies for rheumatoid arthritis

The use of biological agents such as etanercept, infliximab, adalimumab and anakinra has been recently approved for the treatment of rheumatoid arthritis. All are effective controlling signs and symptoms and inhibiting disease progression. To overcome the problems generated by their high costs and possible participation in reactivating latent infections, other therapeutic tools are being developed. Gene therapy using expression vectors carrying genes coding for specific proteins, may interfere in key points involved in the pathogenesis of the disease. Intra-articular administration of cDNA coding for soluble TNF receptors, IL-1, or IL-1Ra decreases signs of the disease in animal models. Vectors, expressing inhibitors of signal transduction pathways involving to NF-kB and JAK-STAT-3, are effective in modulating joint inflammation in mice. The use of antigen-pulsed antigen presenting cells or dendritic cells (DC) bound to apoptosis-inducing molecules, specifically eliminates autoreactive T cells. Other novel approach attempts the development of T regulatory-inducing tolerogenic DC-based vaccines that inhibit autoreactive T cells, through the secretion of suppressing cytokines or by other mechanisms to be elucidated. Oral tolerance induction to auto-antigens is also a successful experimental strategy under study. Current research aims to control peripheral tolerance in rheumatoid arthritis patients.

T-kininogen can either induce or inhibit proliferation in Balb/c 3T3 fibroblasts, depending on the route of administration.

T-kininogen (T-KG) is a precursor of T-kinin, the most abundant kinin in rat serum, and also acts as a strong and specific cysteine proteinase inhibitor. Its expression is strongly induced during aging in rats, and expression of T-KG in Balb/c 3T3 fibroblasts results in inhibition of cell proliferation. However, T-KG is a serum protein produced primarily in the liver, and thus, most cells are only exposed to the protein from the outside. To test the effect of T-KG on fibroblasts exposed to exogenous T-KG, we purified the protein from the serum of K-kininogen-deficient Katholiek rats. In contrast to the results obtained by transfection, exposure of Balb/c 3T3 fibroblasts to exogenously added T-KG leads to a dose-dependent increase in [3H]-thymidine incorporation. This response does not require kinin receptors, but it is clearly mediated by activation of the ERK pathway. As a control, we repeated the transfection experiments, using a different promoter. The results are consistent with our published data showing that, under these circumstances, T-KG inhibits cell proliferation. We conclude that T-KG exerts opposite effects on fibroblast proliferation, depending exclusively on the way that it is administered to the cells (transfection versus exogenous addition).