In Situ Accumulation of CaOx Crystals in C. quitensis Leaves and Its Relationship with Anatomy and Gas Exchange.

The accumulation of crystal calcium oxalate (CaOx) in plants is linked to a type of stress-induced photosynthesis termed 'alarm photosynthesis', serving as a carbon reservoir when carbon dioxide (CO2) exchange is constrained. Colobanthus quitensis is an extremophyte found from southern Mexico to Antarctica, which thrives in high-altitude Andean regions. Growing under common garden conditions, C. quitensis from different latitudinal provenances display significant variations in CaOx crystal accumulation. This raises the following questions: are these differences maintained under natural conditions? And is the CaOx accumulation related to mesophyll conductance (gm) and net photosynthesis (AN) performed in situ? It is hypothesized that in provenances with lower gm, C. quitensis will exhibit an increase in the use of CaOx crystals, resulting in reduced crystal leaf abundance. Plants from Central Chile (33°), Patagonia (51°), and Antarctica (62°) were measured in situ and sampled to determine gas exchange and CaOx crystal accumulation, respectively. Both AN and gm decrease towards higher latitudes, correlating with increases in leaf mass area and leaf density. The crystal accumulation decreases at higher latitudes, correlating positively with AN and gm. Thus, in provenances where environmental conditions induce more xeric traits, the CO2 availability for photosynthesis decreases, making the activation of alarm photosynthesis feasible as an internal source of CO2.

Ecophysiology of Antarctic Vascular Plants: An Update on the Extreme Environment Resistance Mechanisms and Their Importance in Facing Climate Change.

Antarctic flowering plants have become enigmatic because of their unique capability to colonize Antarctica. It has been shown that there is not a single trait that makes Colobanthus quitensis and Deschampsia antarctica so special, but rather a set of morphophysiological traits that coordinately confer resistance to one of the harshest environments on the Earth. However, both their capacity to inhabit Antarctica and their uniqueness remain not fully explained from a biological point of view. These aspects have become more relevant due to the climatic changes already impacting Antarctica. This review aims to compile and update the recent advances in the ecophysiology of Antarctic vascular plants, deepen understanding of the mechanisms behind their notable resistance to abiotic stresses, and contribute to understanding their potential responses to environmental changes. The uniqueness of Antarctic plants has prompted research that emphasizes the role of leaf anatomical traits and cell wall properties in controlling water loss and CO2 exchange, the role of Rubisco kinetics traits in facilitating efficient carbon assimilation, and the relevance of metabolomic pathways in elucidating key processes such as gas exchange, nutrient uptake, and photoprotection. Climate change is anticipated to have significant and contrasting effects on the morphophysiological processes of Antarctic species. However, more studies in different locations outside Antarctica and using the latitudinal gradient as a natural laboratory to predict the effects of climate change are needed. Finally, we raise several questions that should be addressed, both to unravel the uniqueness of Antarctic vascular species and to understand their potential responses to climate change.

Leaf hydraulic properties of Antarctic plants: effects of growth temperature and its coordination with photosynthesis.

One of the well-documented effects of regional warming in Antarctica is the impact on flora. Warmer conditions modify several leaf anatomical traits of Antarctic vascular plants, increasing photosynthesis and growth. Given that CO2 and water vapor partially share their diffusion pathways through the leaf, changes in leaf anatomy could also affect the hydraulic traits of Antarctic plants. We evaluated the effects of growth temperature on several anatomical and hydraulic parameters of Antarctic plants and assessed the trait co-variation between these parameters and photosynthetic performance. Warmer conditions promoted an increase in leaf and whole plant hydraulic conductivity, correlating with adjustments in carbon assimilation. These adjustments were consistent with changes in leaf vasculature, where Antarctic species displayed different strategies. At higher temperature, Colobanthus quitensis decreased the number of leaf xylem vessels, but increased their diameter. In contrast, in Deschampsia antarctica the diameter did not change, but the number of vessels increased. Despite this contrasting behavior, some traits such as a small leaf diameter of vessels and a high cell wall rigidity were maintained in both species, suggesting a water-conservation response associated with the ability of Antarctic plants to cope with harsh environments.

Satisfacción personal y percepción de éxito en mujeres en traumatología: factores determinantes en la elección de la especialidad y desarrollo profesional / Personal satisfaction and perception of success among female orntthopedic surgeons: key factors in the choice of specialty and professional development

Históricamente, las médicas han sido asociadas a especialidades determinadas. En los últimos años, estos estereotipos han sido lentamente revertidos con mayor participación de la mujer en especialidades quirúrgicas. En el proceso de aprendizaje se sabe la importancia que tienen los modelos y mentores. Buscamos evaluar el grado de satisfacción y el éxito profesional de las mujeres en Traumatología, y qué factores cumplieron un rol positivo en la decisión de optar por ella.Se encuestó a 108 mujeres dedicadas a la Traumatología, y se evaluaron las influencias positivas y los mentores como modelo en la toma de decisión por la especialidad y los grados de satisfacción personal y profesional.Pese a una mayor percepción de dificultades en lograr el objetivo, destacan los altos grados de satisfacción profesional y personal de las mujeres en Traumatología: 95% refirió haber elegido la especialidad correcta, 100% afirmó que las dificultades se compensan con los resultados obtenidos, y 96% volvería a elegir la misma especialidad. En relación con la percepción de éxito, 73% se considera exitosa en su vida profesional, y en la vida personal, 85%.Muy relevante en la toma de decisión por la especialidad es el rol que cumplen docentes, mentores, y el gusto por la cirugía y los deportes. Un 84% recibió alguna influencia positiva, 61% tuvo como modelo en su formación una traumatóloga, y un 98% recomendaría a otras mujeres en período de formación que se dedicaran a la Traumatología.Las estrategias de incremento de la participación femenina en la especialidad pudiesen orientarse a fomentar modelos femeninos durante el aprendizaje.

Historically, female doctors have been associated with certain specialties. In recent years, these stereotypes have been slowly reversed with an increased participation of women in surgical specialties. The importance of models and mentors in the learning process is known. We seek to evaluate the level of professional satisfaction and success of women in Traumatology, as well as the factors that may have played a positive role in the decision to pursue this specialty. We surveyed 108 women working in Traumatology and evaluated the positive influences and mentors as models in the decision-making regarding the specialty and the degrees of personal and professional satisfaction. Despite a greater perception of difficulties in achieving the purpose, the high degrees of professional and personal satisfaction of women in Traumatology stands out: 95% reported having chosen the correct specialty, 100% stated that the difficulties are offset by the results obtained, and 96% would choose the same specialty again. Regarding the perception of success, 73% consider themselves successful in their occupation, and 85% consider themselves successful in their personal lives. The role played by teachers, mentors, as well as an interest in surgery and sports are very relevant in choosing the specialty. In total, 84% of the sample received some positive influence 61% had a female traumatologist as a model during their training, and 98% would recommend other women in training to dedicate themselves to Traumatology. The strategies to increase female participation in the specialty could be aimed at promoting female role models during learning.

¿Cómo ha afectado el COVID-19 a traumatólogos y residentes de traumatología en Chile? / How has covid-19 affected orthopedic surgeons and residents in chile?

INTRODUCCIÓN Desde marzo del 2020, Chile se ha visto afectado por la pandemia por coronavirus 2019 (coronavirus disease 2019, COVID-19, en inglés), que ha provocado alteraciones en todo el mundo, causando un gran impacto en los servicios de salud y el personal sanitario. OBJETIVO Describir características demográficas y laborales relacionadas al contagio de COVID-19 en traumatólogos y residentes de traumatología en Chile. MÉTODOS Realizamos una encuesta on-line, solicitando información demográfica, datos laborales, exposición y contagio de COVID-19, sintomatología y medidas de protección. RESULTADOS En total, 567 médicos contestaron. De ellos, 37 (6,4%) tuvieron COVID-19, sin diferencia significativa respecto a género. Se observó mayor contagio entre residentes, 9 de 73 (12,3%), que entre traumatólogos, 28 de 494 (5,7%), así como mayor contagio entre quienes trabajaron más de 60 horas (p <0,05). De los contagiados, 31 (83,8%) eran de la Región Metropolitana (RM), cuyo contagio es significativamente mayor que en el resto de las regiones (p < 0,05). Sólo 8 (21,6%) de los contagiados presentaban antecedentes médicos. Requirieron hospitalización 3 (5,4%), 1 de los cuales en Unidad de Cuidados Intensivos (UCI), y el resto fue manejado en forma domiciliaria. El sitio de contagio más frecuente fue el trabajo, siendo las áreas comunes las más sospechadas, seguidas de la atención ambulatoria y las áreas de hospitalización traumatológica. Un 40.5% (15) reportó haber contagiado a alguien más. Hubo además un impacto en los ingresos de los traumatólogos: un 14,8% (84) refirió una disminución menor al 20%, y un 45%, disminución mayor al 50%. Esta fue mayor en los traumatólogos que en los residentes, y en aquellos de la RM que en otras regiones (p < 0,05). CONCLUSIÓN Aunque la actividad traumatológica se ha visto disminuida por la pandemia, los traumatólogos se han visto expuestos al riesgo de contagio por COVID-19. El trabajo parece ser el lugar de mayor riesgo, sobre todo las áreas comunes.

BACKGROUND Since March 2020, Chile has been affected by the coronavirus disease 2019 (COVID-19) pandemic, which has caused disruptions throughout the world, greatly impacting health services and healthcare workers. OBJETIVE To describe the demographic characteristics related to the COVID-19 pandemic in orthopedic surgeons and orthopedic surgery residents in Chile. METHODS We conducted an on-line survey requesting data on demographics, work, exposure to and infection by COVID-19, symptoms, and protection practices. RESULTS A total of 567 surgeons answered the survey; 37 (6.4%) had had COVID-19, without gender differences. There was a higher rate of infection among residents, 9 from 73 (12.3%), than among surgeons, 28 from 494 (5.7%), as well as higher rates of infection among those working more than 60 hours (p < 0.05). Among those infected, 31 (83.8%) were from the Metropolitan Region (MR), where the rate of infection was significantly higher compared with other regions (p < 0.05). Only 8 (21.6%) of those infected had medical history. Hospitalization was required by 3 (5.4%), 1 of them in the Intensive care Unit (ICU), and the remaining were handled at home. The most frequent location of infection was the workplace, with the common areas being the main suspected sites, followed by outpatient clinics and orthopedic surgery wards. In total, 40.5% (15) of the sample reported having infected other individuals. There was also an impact in the surgeon's income: 14.8% (84) reported a decrease lower than 20%, and 45% (256), a decrease higher than 50%. This decrease was higher among surgeons than among residents, and higher among those from the MR compared to other regions (p < 0.05). CONCLUSION Even though orthopedic surgery practice has been reduced by the pandemic, orthopedic surgeons have been exposed to the risk of infection by COVID-19. The workplace seems to be the site that poses the greatest risk, especially the common areas.

Anatomical and biochemical evolutionary ancient traits of Araucaria araucana (Molina) K. Koch and their effects on carbon assimilation.

The study of ancient species provides valuable information concerning the evolution of specific adaptations to past and current environmental conditions. Araucaria araucana (Molina) K. Koch belongs to one of the oldest families of conifers in the world, but despite this, there are few studies focused on its physiology and responses to changes in environmental conditions. We used an integrated approach aimed at comprehensively characterizing the ecophysiology of this poorly known species, focusing in its stomatal, mesophyll and biochemical traits, hypothesizing that these traits govern the carbon assimilation of A. araucana under past and present levels of atmospheric CO2. Results indicated that A. araucana presents the typical traits of an ancient species, such as large stomata and low stomatal density, which trigger low stomatal conductance and slow stomatal responsiveness to changing environmental conditions. Interestingly, the quantitative analysis showed that photosynthetic rates were equally limited by both diffusive and biochemical components. The Rubisco catalytic properties proved to have a low Rubisco affinity for CO2 and O2, similar to other ancient species. This affinity for CO2, together with the low carboxylation turnover rate, are responsible for the low Rubisco catalytic efficiency of carboxylation. These traits could be the result of the diverse environmental selective pressures that A. araucana was exposed during its diversification. The increase in measured temperatures induced an increase in stomatal and biochemical limitations, which together with a lower Rubisco affinity for CO2 could explain the low photosynthetic capacity of A. araucana in warmer conditions.

Effects of temperature and water availability on light energy utilization in photosynthetic processes of Deschampsia antarctica.

Regional climate change in Antarctica would favor the carbon assimilation of Antarctic vascular plants, since rising temperatures are approaching their photosynthetic optimum (10-19°C). This could be detrimental for photoprotection mechanisms, mainly those associated with thermal dissipation, making plants more susceptible to eventual drought predicted by climate change models. With the purpose to study the effect of temperature and water availability on light energy utilization and putative adjustments in photoprotective mechanisms of Deschampsia antarctica Desv., plants were collected from two Antarctic provenances: King George Island and Lagotellerie Island. Plants were cultivated at 5, 10 and 16°C under well-watered (WW) and water-deficit (WD, at 35% of the field capacity) conditions. Chlorophyll fluorescence, pigment content and de-epoxidation state were evaluated. Regardless of provenances, D. antarctica showed similar morphological, biochemical and functional responses to growth temperature. Higher temperature triggered an increase in photochemical activity (i.e. electron transport rate and photochemical quenching), and a decrease in thermal dissipation capacity (i.e. lower xanthophyll pool, Chl a/b and ß carotene/neoxanthin ratios). Leaf mass per unit area was reduced at higher temperature, and was only affected in plants exposed to WD at 16°C and exhibiting lower electron transport rate and amount of chlorophylls. D. antarctica is adapted to frequent freezing events, which may induce a form of physiological water stress. Photoprotective responses observed under WD contribute to maintain a stable photochemical activity. Thus, it is possible that short-term temperature increases could favor the photochemical activity of this species. However, long-term effects will depend on the magnitude of changes and the plant's ability to adjust to new growth temperature.

In situ warming in the Antarctic: effects on growth and photosynthesis in Antarctic vascular plants.

The Antarctic Peninsula has experienced a rapid warming in the last decades. Although recent climatic evidence supports a new tendency towards stabilization of temperatures, the impacts on the biosphere, and specifically on Antarctic plant species, remain unclear. We evaluated the in situ warming effects on photosynthesis, including the underlying diffusive, biochemical and anatomical determinants, and the relative growth of two Antarctic vascular species, Colobanthus quitensis and Deschampsia antarctica, using open top chambers (OTCs) and gas exchange measurements in the field. In C. quitensis, the photosynthetic response to warming relied on specific adjustments in the anatomical determinants of the leaf CO2 transfer, which enhanced mesophyll conductance and photosynthetic assimilation, thereby promoting higher leaf carbon gain and plant growth. These changes were accompanied by alterations in the leaf chemical composition. By contrast, D. antarctica showed no response to warming, with a lack of significant differences between plants grown inside OTCs and plants grown in the open field. Overall, the present results are the first reporting a contrasting effect of in situ warming on photosynthesis and its underlying determinants, of the two unique Antarctic vascular plant species, which could have direct consequences on their ecological success under future climate conditions.

Epidemiología del melanoma en la región de O'Higgins durante los años 2012 y 2015 / Epidemiology of melanoma in the O'Higgins region during the years 2012 and 2015

Introducción: La incidencia y mortalidad del melanoma maligno (MM) ha aumentado a nivel internacional durante las últimas décadas. En Chile existen escasos registros locales y regionales de cáncer de piel. El objetivo de este trabajo es describir los casos de MM en el Hospital Regional de Rancagua (HRR). Métodos: Se evaluaron todas las biopsias con diagnóstico de MM del HRR entre los años 2012-2015. Se registraron variables demográficas, clínicas e histológicas. Se excluyeron segundas biopsias y metástasis. Resultados: Se identificaron 48 biopsias de MM, 54% fueron hombres. la mediana de edad al diagnóstico fue de 61,5 años. La distribución de la localización fue: 34% extremidades inferiores (EEII), 25% dorso, 25% cara-cuello y 15% extremidades superiores (EESS). La localización más frecuente en hombres fue caracuello (35%) y en las mujeres EEII (38%). El subtipo histológico más frecuente fue: extensión superficial (48%), seguido de nodular (30%), in-situ (20%) y acral lentiginoso (2%). En hombres predominó extensión superficial y nodular (42%) mientras que in-situ sólo se observó en el 16%. En mujeres el 55% fue extensión superficial, seguido de in-situ con 23%. El Breslow de los MM infiltrantes fue: 34% <1mm, 26% 1- 2mm, 17% 2-4mm y 23% >4mm. En hombres 26% fue <1mm mientras que en las mujeres el 44%. Conclusión: Esta es una primera aproximación para evaluar la epidemiología del MM en la sexta región. Los pocos casos encontrados hacen suponer un subdiagnóstico. Se debe continuar trabajando para mejorar el registro y generar estrategias para prevención y diagnóstico precoz.

Introduction: The incidence and mortality of malignant melanoma (MM) has increased over the last decades worldwide. In Chile there are few local and regional registries of skin cancer. In the O'Higgins region, the epidemiology of MM is unknown. The aim of this study is to describe the cases of MM in Rancagua Regional Hospital (RRH). Methods: All MM biopsies from RRH were evaluated between 2012-2015. Demographic, clinical and histological characteristics were recorded. Second biopsies and metastases were excluded. Results: Forty-eight biopsies were evaluated, 54% were from male patients. The mean age at diagnosis was 62.1 years. The most frequent location of MM was 34% in lower extremities, 25% in the back, 25% in face and neck and 15% upper extremities. The most frequent site in men was face and neck (35%) and in women lower extremities (38%). The most frequent histological subtype was superficial extension (48%), followed by nodular (30%), in-situ (20%) and acral lentiginous (2%). In men, superficial extension and nodular (42%) were the most frequent and In-situ was present only in 16%, in women predominated superficial extension(55%) followed by in-situ (23%). The Breslow of the invasive MM was: 34% <1mm, 26% 1-2mm, 17% 2-4mm and 23% >4mm. In men 26% was <1mm and in women 44%. Conclusion: This is a first approximation to describe the epidemiology of MM in the O'Higgins region. The few cases found make us suspect underdiagnosis. An improvement in MM registry will serve to generate strategies for prevention and early diagnosis.

Queratosis pilar simil asociado a uso de nilotinib / Keratosis pilaris associated with nilotinib use

Nilotinib es un inhibidor altamente selectivo de BCR-ABL tirosina kinasa usado para el tratamiento de Leucemia mieloide crónica. Las reacciones cutáneas fueron uno de los efectos adversos no hematológicos más frecuentemente reportados en relación al uso de esta droga. El presente artículo documenta el caso una paciente femenina de 17 años de edad diagnosticada con Leucemia mieloide crónica que había estado en tratamiento con Nilotinib por 5 meses desarrollando una reacción tipo queratosis pilar. La paciente fue tratada con medidas generales, Urea 15% y antihistamínicos, con cese del prurito. Es importante reconocer las reacciones cutáneas asociadas al uso de Nilotinib para así otorgar alivio oportuno de los síntomas con el fin de lograr una mejor adherencia al tratamiento de la Leucemia mieloide crónica y mejorar la calidad de vida del paciente.

Nilotinib is a highly selective inhibitor of BCR-ABL tyrosine kinase. It is used as a treatment for chronic myelogenous leukemia (CML). Cutaneous reactions are one of the most common non-hematologic reported adverse effects. The present article documents the case of a 17-year-old female patient diagnosed with CML. She was treated with nilotinib for 5 months and developed a keratosis pilaris-like reaction. The patient was treated with general measures, topical 15%-urea and antihistamines with improvement and cessation of pruritus. It is imperative to recognize the cutaneous adverse effects associated with the use of new oncologic treatments such as nilotinib.

Acropigmentación reticulada de Dohi: revisión de genodermatosis con pigmentación reticular a partir de un caso clínico / Reticulated acropigmentation of Dohi: review of genodermatosis with reticular pigmentation

La acropigmentación reticulada de Dohi (ARD) o discromía simétrica hereditaria se encuentra dentro de los desórdenes con pigmentación reticular hereditaria. Es una rara entidad que se describió por primera vez en 1929 en Japón por Toyama. Presenta herencia autosómica dominante y el gen responsable se encuentra en el cromosoma 1q21 que codifica para una proteína ARN-adenosina desaminasa (ADAR1 o DSRAD). A pesar, que es un desorden benigno y no reviste complicaciones suele ser estéticamente desfigurante. A continuación, se presenta un caso clínico y se realizará una revisión de la literatura de los otras genodermatosis con pigmentación reticular.

Hereditary symmetric dyschromatosis, also known as reticulated acropigmentation of Dohi is included within a spectrum of reticulate pigment disorders of the skin. It’s a pigmentary disorder characterized by the presence of hypopigmented and hyperpigmented macules giving a reticular pattern in acral areas. It is a rare entity first described in 1929 by Toyama in Japan. It has autosomal dominant inheritance and the responsible gene codes for an RNA adenosine deaminase protein (ADAR1 or dsRAD) on chromosome 1q21. Although, it`s a benign disorder, it can be aesthetically disfiguring. We present a case report and review of the literature of genodermatosis with reticular pigmentation.

Pentoxifilina como tratamiento efectivo de la lipoidoproteinosis / Pentoxifylline as an effective treatment of lipoidoproteinosis

La lipoido proteinosis es una enfermedad rara, que ocurre por un defecto en el gen que codifica la proteína de la matriz extracelular 1 (ECM1). Estogenera un aumento del colágeno tipo IV, que resulta en depósitos de material hialino anómalo en la dermis y otros tejidos. Actualmente no hay terapias curativas y los múltiples tratamientos utilizados han tenido resultados variables y efectos adversos relevantes.La pentoxifilina es un fármaco que inhibe al factor de crecimiento transformante beta (TGF-beta) y así, regula la producción de colágeno por los fibroblastos. Se ha empleado con éxito en casos de fibrosis renal, hepática y pulmonar y luego de la radioterapia. Se presenta este caso que constituye la primera comunicación de lipoidoproteinosis tratada con pentoxifilina, en el que se evidenció una mejoría clínica, ecográfica y laringoscópica.

Lipoid proteinosisis a rare disease, causedby a defect in the gene encoding the extracellular matrix protein 1 (ECM1), that leads to an increased of collagen type IV, resulting in abnormal deposits of hyaline material in the dermis and other tissues. Currently, there are no curative therapies; several ones have been used with varied results and adverse effects. Pentoxifylline is a drug with inhibitory effect on TGF-beta, thus regulates collagen production by fibroblasts. It has been successfully used in renal, liver and lung transplant and after radiotherapy fibrosis. We present this case because it is the first report of lipoid proteinosis treated with pentoxifylline; with demonstrated clinical, sonographic and laryngoscopic improvement.

[Subcorneal pustular dermatosis: report of one case]. / Pustulosis subcórnea (enfermedad de Sneddon-Wilkinson). Caso clínico.

BACKGROUND: We report a 35-year-old female patient with a one year history of a pustular and painful erythematous dermatitis, located in great folds, pubis and abdomen. She was evaluated in primary health care, receiving antifungal treatment, antimicrobials, topical and systemic non-steroidal anti-inflammatory drugs, with no response. A skin biopsy was compatible with subcorneal pustular dermatosis. She was initially treated with prednisone (0.8 mg/kg), observing a partial response. Therefore clotrimoxazole was initiated, obtaining an excellent response after 30 days of treatment.

Pustulosis subcórnea (enfermedad de Sneddon-Wilkinson): Caso clínico / Subcorneal pustular dermatosis: Report of one case

Background: We report a 35-year-old female patient with a one year history of a pustular and painful erythematous dermatitis, located in great folds, pubis and abdomen. She was evaluated in primary health care, receiving antifungal treatment, antimicrobials, topical and systemic non-steroidal anti-inflammatory drugs, with no response. A skin biopsy was compatible with subcorneal pustular dermatosis. She was initially treated with prednisone (0.8 mg/kg), observing a partial response. Therefore clotrimoxazole was initiated, obtaining an excellent response after 30 days of treatment.

Atresia de esófago y sus asociaciones preferenciales / Esophageal atresia and related malformations

Esophageal atresia is a congenital malformation incompatible with life. The incidence is quite variable in Chile and all over the world. Objective: To estimate the prevalence at birth of esophageal atresia, comparing with previously published data. Patients and Methods: All children with congenital anomalies born at the UniversityofChile Clinical Hospital from 1999 to 2009 were included. Results: 19.312 births during the study period were registered, 1710 of them had a congenital anomaly (8,9 percent). Fifteen of the malformed newborns had esophageal atresia (7.8 x 10.000): one stillbirth and 14 alive newborns. 78,6 percent of cases were discharge alive from the hospital, 3 (21,4 percent) died during the hospitalization. Only 1/15 was an isolated esophageal atresia, 6 cases were syndromic and 9 were classified as VACTERL association. Prenatal diagnosis was made in 73,3 percent of the cases. Newborns with esophageal atresia had significantly less birth weight, less gestational age and more malformed relatives, than control newborns. Metrorrhagia during pregnancy in mothers was more frequent in cases than controls. No difference in maternal age between groups was founded. Conclusion: The esophageal atresia prevalence at birth was higher than previously reported local data, and lower than the rest of ECLAMC data; this could be explained because the University of Chile Clinical Hospital is a reference Hospital for prenatal diagnosed cases.

Introducción: Atresia de esófago es una malformación congénita incompatible con la vida, que tiene una frecuencia variable en Chile y en el resto del mundo. Objetivos: Presentar la prevalencia actual y compararla con comunicaciones anteriores. Estudiar las asociaciones más frecuentes con otras malformaciones y la sobreviva al alta hospitalaria. Pacientes y Método: Ingresaron a este trabajo todos los niños que presentaban una o más malformaciones nacidos entre 1999 y 2009 nacidos en la maternidad del Hospital Clínico. Resultados: Durante el período ocurrieron 19.312 nacimientos. Se encontró 1. 710 recién nacidos malformados (8,9 por ciento). A 15 de ellos (7,8 por 10.000) se les diagnosticó Atresia de esófago. Catorce eran nacidos vivos. 78,6 por ciento fueron tratados y dados de alta vivos. Tres (21,4 por ciento) fallecieron. Sólo 1 caso fue catalogado como forma aislada, 6 como formas sindrómicas. Nueve casos fueron catalogados como Asociación VACTERL. En 73,3 por ciento de los casos se hizo el diagnóstico prenatal de la Atresia de esófago. Cuando se los comparó con los controles, los malformados tenían un significativo menor peso de nacimiento y edad gestacional. No se encontró diferencia significativa en edad materna entre casos y controles. Sí había diferencia significativa en "otros malformados en la familia" y "metrorragia del primer trimestre" que eran más frecuentes en casos. Conclusión: La tasa de prevalencia al nacimiento fue mayor que la encontrada anteriormente y menor que el promedio dado por ECLAMC para Latinoamérica, probablemente debido a que el Hospital Clínico es un hospital de referencia de casos diagnosticados prenatalmente.