Carcinoma sebáceo, 6 años de experiencia en el Instituto Nacional del Cáncer

Objetivo: El carcinoma sebáceo (CS) es una neoplasia infrecuente, de la cual no existen reportes nacionales, ni guías de manejo en Chile. El Instituto Nacional del Cáncer (INC) es un centro de referencia nacional en el manejo de patologías oncológicas; el objetivo de este trabajo es describir la experiencia y tratamiento del carcinoma sebáceo en nuestro centro. Material y Método: Se realizó una revisión retrospectiva, descriptiva, de fichas clínicas entre marzo de 2016 y marzo de 2022 en el INC, en las cuales la biopsia definitiva fuese confirmatoria de CS. Resultados: Se reclutaron 10 pacientes, 6 hombres (60%) y 4 mujeres. Edad promedio fue de 62,9 años ± 18,7 DS. En el 80% de los casos el tumor se encontró en cabeza y cuello y solo 2 casos fueron CS ocular (20%). 4 pacientes tenían asociación al Síndrome de Muir-Torre (SMT) (40%), en el 100% de la muestra se realizó tratamiento quirúrgico con resección oncológica y control de márgenes intraoperatorio, utilizándose en solo 3 casos la técnica Cirugía Micrográfica de Mohs (MMS). En 4 pacientes (40%) se realizó biopsia de linfonodo centinela (BLNC), de los cuales ninguno resulto positivo para metástasis. Ningún paciente presento recidiva local, después de la cirugía y no hubo casos de mortalidad a causa de CS. Ningún paciente recibió radioterapia, quimioterapia o inmunoterapia adyuvante, solo 1 paciente recibió braquiterapia (BT) adyuvante. Conclusión: El CS es una patología compleja e infrecuente, que requiere un tratamiento multidisciplinario y cuyo pilar es la cirugía.

Objective: Sebaceous carcinoma (SC) is an infrequent neoplasm, without national reports nor management guidelines in Chile. National Cancer Institute (NCI) is a reference center for this kind of disease. The aim of this research is to describe the experience and treatment of the sebaceous carcinoma in our center. Methods: A retrospective, descriptive review of clinical records was performed, between March 2016 and March 2022 at the INC, in which the definitive biopsy was confirmatory of CS. Results: A total of 10 patients were enrolled; 6 male (60%) and 4 women. The mean age was 62.9 years ± 18.7 (SD). 80% of the cases were located at the head or the cervical area and only 2 cases were found in the ocular region (20%). Association with SMT (40%) was found in 4 patients. Surgical treatment with oncological resection and intraoperative assessment of margins was performed in 100% of the cases, using MMS technique. Sentinel lymph node biopsy (BLNC) was performed in 4 patients (40%), of which none had metastasis. No patient presented local recurrence after surgery and there were no cases of mortality due to CS. No patient received radiotherapy, chemotherapy or adjuvant immunotherapy. Just 1 received adjuvant brachytherapy. Conclusion: SC is a complex and infrequent disease, which requires multidisciplinary treatment mainly with surgery.

Use of Receiver Operating Curve Analysis and Machine Learning With an Independent Dose Calculation System Reduces the Number of Physical Dose Measurements Required for Patient-Specific Quality Assurance.

PURPOSE: Our purpose was to assess the use of machine learning methods and Mobius 3D (M3D) dose calculation software to reduce the number of physical ion chamber (IC) dose measurements required for patient-specific quality assurance during corona virus disease 2019. METHODS AND MATERIALS: In this study, 1464 inversely planned treatments using Pinnacle or Raystation treatment planning software (TPS) were delivered using Elekta Versa HD and Varian Truebeam and Truebeam STx linear accelerators between June 2018 and November 2019. For each plan, an independent dose calculation was performed using M3D, and an absolute dose measurement was taken using a Pinpoint IC inside the Mobius phantom. The point dose differences between the TPS and M3D calculation and between TPS and IC measurements were calculated. Agreement between the TPS and IC was used to define the ground truth plan failure. To reduce the on-site personnel during the pandemic, 2 methods of receiver operating characteristic analysis (n = 1464) and machine learning (n = 603) were used to identify patient plans that would require physical dose measurements. RESULTS: In the receiver operating characteristic analysis, a predelivery M3D difference threshold of 3% identified plans that failed an IC measurement at a 4% threshold with 100% sensitivity and 76.3% specificity. This indicates that fewer than 25% of plans required a physical dose measurement. A threshold of 1% on a machine learning model was able to identify plans that failed an IC measurement at a 3% threshold with 100% sensitivity and 54.3% specificity, leading to fewer than 50% of plans that required a physical dose measurement. CONCLUSIONS: It is possible to identify plans that are more likely to fail IC patient-specific quality assurance measurements before delivery. This possibly allows for a reduction of physical measurements taken, freeing up significant clinical resources and reducing the required amount of on-site personnel while maintaining patient safety.

Traqueostomía en pacientes con COVID-19: recomendaciones actuales / Traqueostomy in COVID-19 patients: current recomendations

Resumen El nuevo coronavirus (SARS-CoV-2), causante de la enfermedad COVID-19, es una pandemia con alta morbimortalidad mundial. Uno de los factores más importantes es su alta tasa de transmisibilidad por gotitas, aerosoles y fómites. La tendencia actual es el aumento progresivo de pacientes contagiados en nuestro país y, por consiguiente, de mayor cantidad de enfermos en unidades de cuidados intensivos (UCI) con uso de ventilación mecánica invasiva (VMI). La traqueostomía (TQT) se utiliza en pacientes críticos para facilitar la VMI a largo plazo y el destete de la ventilación. Una TQT temprana, definida como la realizada en los primeros 7 días después de la intubación orotraqueal (IOT), se asocia a una reducción en el tiempo de la VMI, mortalidad y permanencia en UCI. La TQT es una técnica quirúrgica con alta generación de aerosoles la cual implica medidas especiales frente a la realización de ésta en pacientes con COVID-19. Para limitar el contagio del SARS-CoV-2 en los trabajadores de salud es necesario el uso de elementos de protección personal (EPP) adecuados según la intervención a realizar. Es por esta razón que en el presente artículo se propone utilizar el acrónimo C-O-RO-NA para no olvidar elementos y pasos fundamentales al momento de realizar esta técnica, minimizando de esta manera el contagio en los trabajadores de salud.

The new coronavirus (SARS-CoV-2), which causes COVID-19 disease, is a high mortality pandemic illness. One of the most important factors is its high rate of transmissibility by respiratory droplets, aerosols and fomites. The reigning trend of this disease is progressively increasing infected patients in our country, therefore, more patients in intensive care units (ICU) with invasive mechanical ventilation (IMV). Tracheostomy (TQT) is used in critical patients to facilitate long-term IMV and ventilation weaning. An early TQT, defined as performed in the first 7 days after orotracheal intubation (IOT) is associated with a reduction IMV duration, mortality rate and length of stay in ICU. TQT is a surgical procedure which generates a huge amount of aerosols that need special measures to perform in COVID-19 patients. It is necessary to use appropriate personal protection elements (PPE) according to the intervention, limiting the spread of SARS-CoV-2 in health workers. It is for this reason that this article proposes to use the acronym C-O-RO-NA to remember fundamental elements and steps when performing this technique in order to minimize health workers infection.

Carcinoma basocelular metastásico / Metastatic basal cell carcinoma

El carcinoma basocelular es la neoplasia con mayor incidencia a nivel mundial. Es de crecimiento lento y localmente agresiva pero posee un potencial metastásico extremadamente bajo, que se estima entre 0,0028% y 0,5%. El objetivo de este trabajo es mostrar la experiencia de una institución con el manejo de esta enfermedad metastásica. Estudio descriptivo retrospectivo de los pacientes con carcinoma basocelular metastásico tratados en el Instituto Nacional del Cáncer, entre julio 2004 y julio 2015. Se realizó una revisión de la literatura. Se evidenciaron 3 casos con esta enfermedad poco habitual en un plazo de 11 años. Un paciente falleció a los 42 meses de seguimiento. Hay 2 pacientes aún en control, uno de ellos lleva 29 meses de seguimiento y actualmente tiene enfermedad metastásica pulmonar, y el último paciente lleva 92 meses de seguimiento libre de enfermedad. El carcinoma basocelular metastásico, es una entidad poco frecuente por lo que todos los que nos vemos involucrado en su manejo debemos mantenernos alerta para una pesquisa oportuna. La cirugía asociada a la radioterapia siguen siendo los pilares del tratamiento. Esta patología debiera manejarse en centros de referencia a nivel nacional.

Basal cell carcinoma is the most frequent neoplasm worldwide. It's a slow growing and locally aggressive tumor, but it has a metastatic potential estimated between 0,0028 and 0,5%. The purpose of this study is to show the experience of a center in the management of this metastatic disease. Descriptive retrospective study of patients with metastatic basal cell carcinoma treated at the Instituto nacional del cancer from July2004 to July 2015. A revision of the literature was also made. 3 cases with this unusual disease during an 11 years period. The first one died at 42 months of follow up. There are 2 patients on follow up, 1 of them has lung metastatic disease after 29 months of follow up, and the last one is free of disease with 92 months of follow up. Metastatic basal cell carcinoma is an unusual entity, thus everyone that is involved in it's treatment, must be aware of this in order to do an early diagnosis. Surgery associated to radiotherapy are the mainstays of treatment. This disease should be managed on national referral centers.

El proceso pedagógico de posgrado en la especialización médica. Sus esencialidades y fines / The pedagogical process of postgraduate in medical specialization. Its essentialities and purposes

En este trabajo se ofrecen reflexiones relacionadas con el proceso pedagógico de posgrado en la especialización médica, hechas por los autores después de haber leído los planteamientos esenciales realizados en el artículo "Algunas reflexiones relacionadas con el trabajo de terminación de las especialidades" publicado en la revista Medisur. Un análisis profundo del mencionado trabajo suscitó la necesidad de exponer, de manera sintética, algunas consideraciones particulares acerca del tema, no con ánimo de réplica, sino con el propósito de esclarecer algunos puntos invariantes correspondientes al objeto de estudio en el cual se inscribe, en este caso el proceso pedagógico de posgrado en la especialización, sus fines y sus características esenciales, de acuerdo con lo más avanzado de los estudios teóricos sobre el tema, de lo cual se derivan algunas respuestas a las preguntas realizadas por el autor de la citada publicación.

In this paper reflections related to the pedagogical process of postgraduate in the medical specialization, made by the authors after having read the essential statements in the article ¨ "Reflections on the Final Paper of the Specializations", published by Medisur. A deep analysis of the above-mentioned work raised the need to expose, in a synthetic way, some particular considerations about the topic, not aimed at replying, but with the purpose of clarifying some invariant issues corresponding to the object of study in which it is inscribed, in this case the pedagogical process of postgraduate in specialization, its purposes and essential characteristics according with the most updated theoretical studies about the theme, from which some answers to the questions made by the author of the cited publication are derived.

A mathematical framework for virtual IMRT QA using machine learning.

PURPOSE: It is common practice to perform patient-specific pretreatment verifications to the clinical delivery of IMRT. This process can be time-consuming and not altogether instructive due to the myriad sources that may produce a failing result. The purpose of this study was to develop an algorithm capable of predicting IMRT QA passing rates a priori. METHODS: From all treatment, 498 IMRT plans sites were planned in eclipse version 11 and delivered using a dynamic sliding window technique on Clinac iX or TrueBeam Linacs. 3%/3 mm local dose/distance-to-agreement (DTA) was recorded using a commercial 2D diode array. Each plan was characterized by 78 metrics that describe different aspects of their complexity that could lead to disagreements between the calculated and measured dose. A Poisson regression with Lasso regularization was trained to learn the relation between the plan characteristics and each passing rate. RESULTS: Passing rates 3%/3 mm local dose/DTA can be predicted with an error smaller than 3% for all plans analyzed. The most important metrics to describe the passing rates were determined to be the MU factor (MU per Gy), small aperture score, irregularity factor, and fraction of the plan delivered at the corners of a 40 × 40 cm field. The higher the value of these metrics, the worse the passing rates. CONCLUSIONS: The Virtual QA process predicts IMRT passing rates with a high likelihood, allows the detection of failures due to setup errors, and it is sensitive enough to detect small differences between matched Linacs.

El trabajo interdisciplinario en la carrera de medicina: consideraciones teóricas y metodológicas / Interdisciplinary Work in Medical Education: Theoretical and Methodological Considerations

La interdisciplinariedad constituye una necesidad en el mundo actual dado el carácter complejo de la realidad que implica un abordaje multidimensional no realizable desde disciplinas aisladas y con fragmentación del conocimiento. En las Universidades de Ciencias Médicas el trabajo para lograr la interdisciplinariedad desde el currículo es vital, partiendo del trabajo docente metodológico en los diferentes claustros de la carrera. Desde la teoría existe una serie de conceptualizaciones invariantes imprescindibles para el establecimiento de relaciones interdisciplinarias, sustento teórico que respalda todo el manejo metodológico dirigido a estos fines. El trabajo que se presenta tiene el objetivo de realizar una sistematización de los principales aspectos teóricos y metodológicos del tema y determinar sus implicaciones en la gestión de la didáctica desde el trabajo docente metodológico en la educación médica explicitando la aproximación a la interdisciplinariedad realizada en la cátedra clínica en el primer semestre del tercer año de la carrera de medicina mediante la interrelación y vinculación de aspectos cognitivos, procedimentales y axiológicos de nodos interdisciplinarios entre propedéutica clínica y psicología médica.

Interdisciplinarity is a necessity in today’s world given the complex nature of reality that requires a multidimensional approach unachievable through isolated disciplines and fragmentation of knowledge. At medical universities, the work to attain interdisciplinarity is vital, starting from the methodological and teaching work in different faculty meetings. There are a number of essential invariant conceptualizations for establishing interdisciplinary relationships, which constitute the theoretical foundation that supports all methodological efforts to achieve this purpose. The present paper aims to conduct a systematization of the main theoretical and methodological aspects of this topic and to determine their implications for didactics considering the methodological and teaching work in medical education. The approach to interdisciplinarity conducted by the clinical sciences department during the first semester of the third year of the medical program is presented. This was achieved by interrelating and linking cognitive, procedural and axiological aspects of interdisciplinary nodes between clinical propedeutics and medical psychology.

Cirugía trans-oral robótica para manejo de cáncer de orofaringe / Trans-oral robotic surgery for tongue cancer

Background: The traditional treatment of oropharyngeal cancer was based mainly in radio and chemotherapy, aiming to avoid organ excisions. However, the adverse effects of these therapies prompted the development of new therapies. Among these, trans-oral robotic surgery (TORS) has promising results. Case reports: We report two patients operated using this technique. An 82 years old woman treated for a tumor in the base of the tongue six years ago with radiotherapy. A new lesion in the tongue was found and excised by TORS uneventfully. The pathology report confirmed the complete excision of the malignant lesion. A 57 years old male with a history of palate cancer treated with radiotherapy in 1990. In 2013 a submandibular mass was biopsied confirming the presence of a squamous carcinoma metastasis. During a bilateral suprahyoid dissection, a tumor in the base of the tongue was found. In a second intervention the tumor was excised by TORS. The pathology reports tumor free borders but near the lesion. Postoperative radiotherapy was recommended.

Introducción: El cáncer de orofaringe representa una importante causa de morbimortalidad en la esfera de las patologías de cabeza y cuello en la actualidad. Su tratamiento tradicional por mucho tiempo consideró la conservación de órganos, utilizando mayoritariamente la radio y quimioterapia como herramientas terapéuticas. Los efectos no deseados tanto de las terapias médicas como las quirúrgicas han obligado a desarrollar técnicas nuevas para el manejo de estas enfermedades. Es así que a partir del año 2006 se ha ido desarrollando a nivel mundial la técnica de cirugía robótica transoral (TORS). La morbilidad y resultados oncológicos de este procedimiento hasta ahora se ven alentadores, por lo que se está transformando en una alternativa terapéutica que debemos manejar. Casos clínicos: Se presentan los dos primeros casos a nivel país realizados en esta institución de cánceres de orofaringe tratados con la técnica tradicional y después de largo tiempo recidivados. Se les realizó cirugía resectiva de sus tumores a través de TORS; se describen los resultados de estos procedimientos.

Nuevo método de inclusión en resina poliéster P-4 para cortes anatómicos / New method for P-4 polyester resin inclusion for anatomical slices

La resina poliéster (P-4) se ha utilizado en varias técnicas anatómicas, gracias a su bajo costo, fácil manejo y obtención. Entre ellas la inclusión, que se realiza en capas dejando muestras relativamente opacas y de un grosor que no permite ver claramente las estructuras. También encontramos la plastinación de cortes anatómicos, técnica más sofisticada, compleja y de un alto costo económico. El objetivo fue idear un método de inclusión para cortes anatómicos, que mejore la calidad de la técnica clásica. Se utilizaron cortes anatómicos de segmento distal de miembro inferior humano y de un grosor promedio de 0,5 cm fijados con acetona y cortes de encéfalo de vacuno de igual grosor, fijados con formalina acuosa al 10%. La totalidad de las muestras son deshidratadas en acetona a -17 °C. Posteriormente se impregnan e incluyen en resina poliéster (P-4) a temperatura ambiente. Se obtuvieron muestras con una buena transparencia y solidez que permite ver en detalle muchas estructuras, similar a la obtenida con la técnica de plastinación en resina. Mediante un método relativamente fácil de realizar es posible obtener piezas anatómicas de muy buena calidad.

The polyester resin (P-4) has been used in several anatomical techniques, due to its low cost, easy handling and elicit. Among them, the inclusion, which is performed on samples leaving relatively opaque layers and an important thickness which does not allow a clear vision of the structures. There is also the plastination of anatomical slices with this polymer which although, technically sophisticated and complex has a high economic cost. The objective is to develop a method for anatomical section inclusion, improving the quality of classic technique. Distal segment of human lower limb anatomical slices were used with an average thickness of 0.5 cm fixed with acetone and bovine brain slices equal thickness, fixed with 10% aqueous formalin. All the samples are dried in acetone at -17 °C. Subsequently, they are impregnated and included on polyester resin (P-4) at room temperature. Samples were obtained with good transparency and solidity that allows observation of details of many structures, similar to that obtained with the resin plastination technique. Using this relatively easy method we can get very good quality anatomical samples.

Características clínicas y metabólicas de síndrome de ovario poliquístico en la ciudad de Temuco / Clinical and metabolic characteristics of polycystic ovary syndrome in the city of Temuco

Polycystic Ovarian Syndrome (PCOS) is the most common endocrine disorder, its etiologyis multifactorial. It is associated with multiple metabolic abnormalities. Objective: To evaluate statistical association between the clinical characteristics of patients diagnosed with PCOS. Patients and Methods: Descriptive study, 121 patients between 13 and 44 years with PCOS were included, and their clinical characteristics, blood glucose, insulin, lipid profile and calculated HOMA were evaluated. Data was analyzed with Chi2, considering p < 0.05 as statistically significant. Results: Mean age 25,5 years, 12,5 years menarche. 22 percent with a history of abortion. Mean BMI 31,4. Acanthosis nigricans was presented in 58,6 percent. Average Glucose 96,5 mg/dl. Insulin resistance (IR) was found in 79.3 percent. Average HOMA 4,5. 64 percent of patients with IR presented Acanthosis nigricans (p = 0.002).It showed direct relationship between BMI and RI (p 0.000). 38,8 percent had dysglycemia. RI was found in 78,7 percent of patients with dysglycemia (p 0.8). Lipid profile was measured in 78 patients, of whom 40 percent had total cholesterol above 200 mg/dl, 49 percent hypertriglyceridemia and high LDL in 13 percent of cases. Conclusions: The data reported are similar to those reported in the international literature. Ourpopulation has obesity and dyslipidemia figures higher than those reported in national studies. The menarche occurs at a younger age while the prevalence of dyslipidemia and RI is greater than the general population, forming a higher risk group...

Experiencia en plastinación con resina poliéster P-4 para cortes anatómicos / Plastination experience in polyester resin (P-4)

El Laboratorio de Plastinación de la Universidad de los Andes ha trabajado hasta hoy, exclusivamente la técnica en Silicona para preservar el material cadavérico mediante este tipo de conservación. Sin embargo, este método tiene algunas desventajas en cortes anatómicos finos. Se desarrolló un método de plastinación en resina poliéster, en base a la técnica ya protocolizada, adaptándolas a nuestro laboratorio, con el fin de obtener muestras con mayor resistencia y calidad, sin alterar las estructuras. Se utilizaron cortes anatómicos de segmentos distales de miembro inferior humano fijados en acetona a - 17 C y otros de encéfalo de vacuno fijados con formalina acuosa al 10 por ciento a 4 C, de un grosor que varía entre 0,4 y 0,8 cm. Se procedió a deshidratar las muestras en acetona a -17 C para luego seleccionar piezas que fueron impregnadas y plastinadas con resina P-4 sin catalizador y otras con catalizador en proporciones 2:1. El proceso de polimerización fue común para ambas con luz ultravioleta. Se obtienen muestras sólidas y rígidas, con cierta transparencia, especialmente en los cortes más finos. No se observaron alteraciones de forma y tamaño. Los mejores resultados en cuanto a transparencia, se obtuvieron con la Resina sin catalizador. Se logró estandarizar una técnica con Resina poliéster P-4, obteniendo cortes anatómicos de buena calidad y con una resistencia mucho mayor que la obtenida para este tipo de muestras en la plastinación con Silicona...

The plastination laboratory at Universidad de los Andes has always worked exclusively silicone as a technique to preserve cadaveric material. However, this method has disadvantages in thin anatomical pieces. A plastination method has been developed using polyester resin P-4, using an already protocolized technique and adapting it to our laboratory to obtain better quality and resistant pieces, without altering the anatomical structures. Anatomical pieces of human lower extremities were used, which were fixated in acetone at -17 C and bovine encephalous pieces, fixated with 10 percent aquoeus formalyn at 4 C, with a variable width of 0.4 to 0.8 cm. The pieces were then dehydrated in acetone at -17 C; among these pieces, some were selected, impregnated and plastinated with P-4 resin, using in some of them a catalyst in a ratio of 2:1. The polymerization process was the same for all pieces with ultraviolet light. Solid and rigid pieces were obtained, with a partial transparency, especially on the thinnest cuts. No alterations in size and shape were observed. The best results in transparency were obtained with the technique without the use of catalyst. An adapted standardized protocol for polyester resin P-4 technique was achieved, obtaining good quality anatomical pieces with a higher resistance compared to pieces plastinated using the silicone technique...

Descripción anatómica de la irrigación del colgajo sural a pedículo distal en piezas cadavéricas / Anatomical description of the blood supply of the distally based sural flap in eight lower limbs

Background: The distally based sural fasciomyocutaneous flap is widely used in the coverage of deep soft tissue defects on the distal third of lower limbs. Aim: To perform a morphometric description of the perforating arteries that supplies the flap. Material and Methods: We used eight lower limbs from amputations performed above the knee. The limbs were injected through the popliteal artery with red colored latex. After the injection, the limbs were dissected to obtain a distally based sural fasciomyocutaneous flap. Once the fasciomyocutaneous island was obtained, the flap was elevated dissecting its pedicle. Once the whole flap was dissected, a morphometric registry of the lateral and medial perforating arteries was performed. The pivot point for the flap was set 5 cm above the upper border of the lateral malleolus. The distance between the upper border of the lateral malleolus and the emergence of each perforating artery was measured. Results: The sural nerve was identified in all eight dissections. A perineural plexus was the source of the blood supply of the flap, in three of the eight dissections. In two dissections, three sural arteries were identified (medial, median and lateral). The lateral sural artery was identified in two dissections and the medial and lateral arteries in one. Three to six perforating arteries were identified in the medial part of the pedicle and four to five perforating arteries in the lateral part of the pedicle. Conclusions: The distribution of the sural artery along the flap's pedicle is very variable. The most common distribution in these dissections was in the form of a perineural plexus. Considering the distance from the lateral malleolus to the emergence of the perforating arteries, the pivot point of the flap, should be set approximately at 5.5 centimeters above the lateral malleolus.

El colgajo sural fasciomiocutáneo es ampliamente utilizado en la reparación de defectos profundos de tejidos blandos del miembro inferior distal. Este estudio describe su base anatómica mediante la morfometría de las arterias perforantes en una muestra de nuestra población chilena. Material y Método: Se utilizaron 8 miembros inferiores de amputaciones supracondileas. Previa repleción con látex coloreado vía poplítea, se procedió a disecar los miembros inferiores para así obtener un colgajo fasciomiocutáneo sural de pedículo distal. Una vez obtenida la isla, se procedió a elevar el colgajo y disecar su pedículo. Luego se realizó la mor-fometría de las arterias perforantes tanto por lateral como por medial al pedículo, desde el punto pívot definido a 5 cm cefálico al maléolo lateral, hasta la base de la isla fasciomiocutánea. Se describió la distribución de la irrigación y se realizó registro fotográfico de los hallazgos. Resultados: El paquete vasculonervioso sural con un nervio fue identificado en todas las disecciones. La morfología arterial predominante fue la distribución como plexo perineural. Se reconocen tres arterias surales (lateral, mediana y medial). Fueron identificadas 3 a 6 perforantes hacia medial y 4 a 5 hacia lateral del pedículo. Conclusiones: La distribución de la arteria sural es variable y en la mayoría de los casos se presenta como plexo perineural. Dados los hallazgos de las perforantes, consideramos que el punto de giro del colgajo se encuentra aproximadamente a 5,5 cm del maleolo lateral, lo cual coincide con el punto ideal para la viabilidad del colgajo informado en otras series.

OS059. Blockade of the bradykinin B2 receptor in early pregnancy reduces fetal growth and trophoblast invasion in guinea-pigs.

INTRODUCTION: Research in preeclampsia (PE) is hampered by the difficulty of sampling the placental bed in early pregnancies followed to delivery to be defined as normal or preeclamptic. Thus, animal models contribute to the understanding of its physiopathology. The guinea-pig shares with humans extensive vascular remodelling, a hemomonochorial placenta [1] and a vasodilator and angiogenic utero-placental repertoire [2]. In pregnancy it expresses bradykinin (BK) B1R and B2R receptors in cells related to invasion, angiogenesis and vasodilatation. In addition, in HTR-8/SVneo cells, BK induces a B2R-mediated increase in migration and invasion [3]. OBJECTIVES: To test whether blocking the B2R with a rodent-selective non-peptide antagonist Bradyzide (BDZ) from days 20 to 34 of an ≈65 day gestation - period of maximal trophoblast invasion and placental development - induces PE-like morphological and functional alterations. METHODS: Virgin Pirbright guinea-pigs (Cavia Porcellus) after mating and echographic confirmation of pregnancy, were allocated in gestational day 20 to to subcutaneous implantation of Alzet pumps that delivered for 14 days saline (Control; n=7), BDZ0,875mg/kg/day (BDZ0,87; n=6) and BDZ 1,2mg/kg/day (BDZ1,2; n=7). Systolic pressure was acquired in the right hindlimb with a Power Lab 8 SP and analyzed with Labchart at day 34. On that day dams were sacrificed, vesical urine was extracted for protein determination, the fetuses and corresponding placentas weighed and the cephalo-caudal length measured. The placentas were studied by HE and immunohistochemistry for cytokeratin to identify trophoblasts. Results are expressed as means±SE. Statistical analysis was performed with Graphpad Prism 5.1, using one-way ANOVA, the recommended post hoc tests and χ2 test. RESULTS: Maternal systolic pressure tended to increase in BDZ0,875 and BDZ1,2 versus controls (63±567±6 versus 56±2,mm Hg respectively; NS). Proteinuria was not observed in any group. The number of viable fetuses tended to be reduced in both BZD treated groups (NS). The fetal weight (% maternal weight) was reduced in animals treated with BDZ0,875 and BDZ1,2 (042±002 and 045±001 versus 054±0,04 in controls; p (P<0.01 and 0.05 respectively). The cephalo-caudal length was reduced in BDZ0,875 and BDZ1,2 (373±24 and 371±07 versus 422±21mm in controls; P<0.01). No differences were observed in placental weight. Spiral arteries surrounded by trophoblasts (%) were reduced in BDZ 0875 and BDZ1,2 versus controls (63 and 66.6 versus 100%, P=0.02). Invaded spiral arteries (%) were also reduced in the treated groups (80 and 43 versus 100%; P<0.002) No differences were observed in the depth of trophoblast decidual invasion. CONCLUSION: This study demonstrates that blocking the B2R in early pregnancy impairs fetal growth and transformation of the spiral arteries, and supports the role of the B2R in the local physiological adaptation. Further studies are needed to elucidate whether the early impairment translates to hypertension and proteinuria in the last third of pregnancy; if so, the guinea-pig would provide a model to understand the physiopathology of the syndrome. Study financed by Fondecyt 1080228.

Contribución de la dermatoscopia en el establecimiento de márgenes quirúrgicos mínimos para la resección de carcinoma basocelular de cara y cuero cabelludo / A desmoscopic contribution to the establishment of minimal surgical margins of resection in basal cell carcinoma on the face and scalp

La resección quirúrgica es el tratamiento de elección para el carcinoma basocelular (CBC). Sin embargo, cuando ésta (..) (AU)

Surgical resection is the best treatment for basal cell carcinoma (BCC). However, when (..) (AU)

Evaluación de una intervención en actividad física en niños con síndrome de Down / Evaluation of a physical activity intervention among children with Down's syndrome

Introduction: In Chile there are no studies regarding the effects of physical activity on nutritional status of children with Down Syndrome. Objective: To evaluate the impact of a 12 week physical education program on the nutritional status, aerobic capacity and muscle strength in children with Down Syndrome. Subjects and Methods: Between August and November of 2006, a group of 18 children (10 males and 8 females) with Down Syndrome, aged between 5-9 years, underwent to a physical activity program over a 12 week period. A diagnostic and final evaluation of muscle strength variables (dorsal, abdominal and quadriceps) and aerobic capacity was done. Nutritional status was assessed by P/E and T/E (Fundación Catalana), IMC, IP/T and percentage of body fat. Results: Significant differences in muscle strength, aerobic capacity, IP/T and waist circumference were observed between the pre-test and post-test (p < 0.05). At the beginning of the intervention, 53 percent were overweight according to IMC, 26 percent to P/E and 68 percent according to IP/T; with an average percentage of body fat of 22.6 percent. Conclusion: Although the period of intervention was brief, a significant improvement was noted in muscle strength, aerobic capacity, IP/T and waist circumference. According to our results, there is a high prevalence of overweight status and obesity in this population of children with DS in which intervention with adequate physical activity is vital.

Introducción: En Chile no existen estudios acerca del efecto de la actividad física sobre el estado nutricional en niños con síndrome de Down. Objetivo: Conocer el estado nutricional en niños con síndrome de Down y la capacidad aeróbica y resistencia al esfuerzo muscular antes y después de una intervención en actividad física. Material y Método: Entre agosto y noviembre del año 2006, en un grupo de 18 niños (10 hombres y 8 mujeres) con síndrome de Down, con edades comprendidas entre 5 - 9 años, se desarrolló un estudio de intervención en actividad física de 12 semanas, realizándose una evaluación diagnóstica y una evaluación final de resistencia muscular (dorsal, abdominal y cuadriceps) y capacidad aeróbica. Se evaluó el estado nutricional a través de P/E y T/E (Fundación Catalana), IMC, IP/T y porcentaje de masa grasa. Resultados: Se observaron diferencias significativas en resistencia muscular, capacidad aeróbica, IP/T y circunferencia de cintura entre el pre-test y post-test (p < 0,05). AlI inicio de la intervención un 53 por ciento presentaba exceso de peso según IMC, un 26 por ciento según P/E y un 68 por ciento según IP/T; con un porcentaje masa grasa fue de 22,6 por ciento. Conclusión: Aunque el tiempo de intervención fue breve, se observó una mejora significativa en la resistencia muscular, capacidad aeróbica, IP/T y circunferencia de cintura. De acuerdo a nuestros resultados, existe una alta prevalencia de malnutrición por exceso en esta población de niños con SD en la que se hace vital intervenir con una actividad física adecuada.

Review: The angiogenic and vasodilatory utero-placental network.

The objective of this review is to propose addition of the kallikrein-kinin system (KKS) to the conventional angiogenic repertoire of gestation. This proposal is based on the improved revascularization induced by transfecting the human kallikrein gene; on the angiogenic, chemoattractant, promigratory, antiapoptotic, and antiaggregating effects of bradykinin; and on suppression of these effects by blockade of the bradykinin B2 receptor. In addition, both bradykinin and vascular endothelial growth factor (VEGF) stimulate nitric oxide (NO), and the VEGF and bradykinin receptors have multiple interactions that converge in the endothelial NO synthase (eNOS)-NO pathway. The work of others, and of our group, have demonstrated that eNOS and matrix metalloproteinases, the components of the VEGF and kallikrein-kinin systems, colocalize in specific cell types at human and guinea-pig utero-placental interfaces. Expression of the endothelial angiogenic/vasodilatory repertoire in the syncytiotrophoblast, and in trophoblasts replacing endothelial cells of the spiral arteries, supports the concept that the intervillous space and the transformed uterine arteries represent genuine new vascular structures that should be included in the analysis of pregnancy-induced neovascularization. We believe that the evidence presented provides support for further studies to test the functional significance of the KKS in placental development.

Carcinoide gastrointestinal: experiencia de siete años en el Instituto Nacional del Cáncer (2000-2006) / Carcinoid tumors: retrospective review of 25 patients

Background: The incidence of carcinoid tumors (CT) has increased in the last five decades. These supposedly benign tumors may not always behave as such. The largest series of CT show that the most common primary tumor site (appendiceal) changed over the years. Aim: To evaluate the management of gastrointestinal CT at the National Cancer Institute from 2000 to 2006, describe their anatomic location and estimate disease specific survival. Material and Methods: Review of the database of the Cancer Committee, during a period of 7 years, looking for patients with a pathological diagnosis of CT, whose clinical records were analyzed. Results: The records of 25 patients with gastrointestinal CT, aged 18 to 79 years (19 females) were analyzed. Five years disease specific survival was 91.1 percent. The most common location was appendiceal in 56 percent of cases, with a 5 years disease specific survival of 100 percent. Right hemicolectomy was performed in seven patients with appendiceal carcinoid. Other seven patients only underwent appendectomy. Five years disease specific survival was 100 percent in both groups. Conclusions: The appendix is still the most common location of CT in this series and long term survival is acceptable.

Los tumores carcinoides (TC) gastrointestinales han aumentando su incidencia en las últimas 5 décadas. Inicialmente estos tumores eran considerados de comportamiento benigno, sin embargo, con el tiempo han mostrado ser capaces de diseminarse y tener una evolución más agresiva. En general se considera al apéndice cecal como la ubicación más frecuente de TC pero esto ha cambiado en el último tiempo según publicaciones internacionales. El objetivo de este trabajo es presentar nuestra experiencia en el manejo de los TC gastrointestinales en el período 2000-2006 en el Instituto Nacional del Cáncer (INC) reportando una serie de casos, describir su ubicación anatómica y estimar la sobrevida específica de enfermedad. Método: Estudio descriptivo. Se revisó la base de datos del Comité Oncológico del INC, durante un período de 7 años, incluyendo pacientes con diagnóstico anatomopatológico de TC. Se revisaron las fichas clínicas y se recolectaron registros de defunción. Resultados: 25 pacientes con diagnóstico de TC confirmado por patología, presentando una sobrevida específica de enfermedad a 5 años de 91,1 por ciento. La ubicación más frecuente de TC fue apéndice cecal (56 por ciento) y este grupo de pacientes presenta sobrevida específica de enfermedad de 100 por ciento a 5 años. De los TC apendiculares, en 7 pacientes se realizó una hemicolectomía derecha en un segundo tiempo, y en 7 pacientes sólo se realizó apendicectomía, con sobrevida específica de enfermedad de 100 por ciento en ambos grupos a 5 años (p = 0,475). Conclusiones: El apéndice cecal continúa siendo el lugar más frecuente de presentación del TC y la sobrevida alejada es adecuada en esta serie de pacientes.