Hemorragia del tracto digestivo superior, enfoque para el médico general / Upper digestive tract bleeding, approach for the general Practitioner / Hemorragia do trato digestivo superior, enfoque para o médico geral

La hemorragia del tracto digestivo superior (HTDS) es el sangrado originado por encima del ángulo de Treitz. A pesar del aumento en las estrategias de prevención, del incremento en los tratamientos con Inhibidor de bomba de protones (IBP) y de la intervención endoscópica temprana, esta patología sigue siendo una causa frecuente de consulta a urgencias, con una morbimortalidad no despreciable y alta carga para el sistema de salud. Esta revisión se enfoca en la HTDS de causa diferente a las varices. La principal causante de esta entidad es la enfermedad ácido-péptica, que es consecuencia del gran consumo de antiinflamatorios no esteroideos (AINES) y de la infección por Helicobacter Pylori. Otras causas son el síndrome de Mallory Weiss, la esofagitis erosiva, las malformaciones arteriovenosas y la malignidad.

Upper gastrointestinal bleeding (UGIB) refers to any bleeding originating above the angle of Treitz. Despite an increase in prevention strategies, proton pump inhibitor (PPI) therapy and early endoscopic intervention, this pathology continues to be an important cause of admission to the emergency department for gastrointestinal causes, having a pretty high morbidity and mortality in addition to a high burden on the health system. This review focuses on non-variceal UGIB. The main cause of this entity being peptic acid disease, due to great consumption of NSAIDs and Helicobacter Pylori infection. Other causes are Mallory Weiss syndrome, erosive esophagitis, arteriovenous malformations, and malignancy.

A hemorragia do trato digestivo superior (HTDS) é o sangrado originado acima do ângulo de Treitz. Apesar do aumento nas estratégias de prevenção, do incremento nos tratamentos com Inibidor da bomba de prótons (IBP) e da intervenção endoscópica precoce, esta patologia segue sendo uma causa frequente de consulta a urgências, com uma morbimortalidade não depreciável e alta carga para o sistema de saúde. Esta revisão se enfoca na HTDS de causa diferente às varizes. A principal causante desta entidade é a doença ácido-péptica, que é consequência do grande consumo de anti-inflamatórios não esteróideos (AINES) e da infecção por HelicobacterPylori. Outras causas são a síndrome de Mallory Weiss, a esofagites erosiva, as malformações arteriovenosas e a malignidade. Palavras-chave: hemorragia gastrointestinal; úlcera péptica; endoscopia gastrointestinal; inibidores da bomba de prótons; medicina geral.

100% peer review in radiation oncology: is it feasible?

PURPOSE: Peer review has been proposed as a strategy to ensure patient safety and plan quality in radiation oncology. Despite its potential benefits, barriers commonly exist to its optimal implementation in daily clinical routine. Our purpose is to analyze peer-review process at our institution. METHODS AND MATERIALS: Based on our group peer-review process, we quantified the rate of plan changes, time and resources needed for this process. Prospectively, data on cases presented at our institutional peer-review conference attended by physicians, resident physicians and physicists were collected. Items such as time to present per case, type of patient (adult or pediatric), treatment intent, dose, aimed technique, disease location and receipt of previous radiation were gathered. Cases were then analyzed to determine the rate of major change, minor change and plan rejection after presentation as well as the median time per session. RESULTS: Over a period of 4 weeks, 148 cases were reviewed. Median of attendants was six physicians, three in-training-physicians and one physicist. Median time per session was 38 (4-72) minutes. 59.5% of cases presented in 1-4 min, 32.4% in 5-9 min and 8.1% in ≥ 10 min. 79.1% of cases were accepted without changes, 11.5% with minor changes, 6% with major changes and 3.4% were rejected with indication of new presentation. Most frequent reason of change was contouring corrections (53.8%) followed by dose or fractionation (26.9%). CONCLUSION: Everyday group consensus peer review is an efficient manner to recollect clinical and technical data of cases presented to ensure quality radiation care before initiation of treatment as well as ensuring department quality in a feedback team environment. This model is feasible within the normal operation of every radiation oncology Department.

Influence of Spectroscopic Techniques on the Estimation of the Degree of Conversion of Bulk-fill Composites.

OBJECTIVES: To compare the degree of conversion (DC) of different flowable and sculptable bulk-fill composites (BFC), at 0- and 4-mm depths from the surface, by Fourier transform infrared (FTIR), attenuated total reflection FTIR (ATR-FTIR), and FT-Raman spectroscopic techniques. METHODS AND MATERIALS: Six BFC were investigated, including three sculptable composites (Admira Fusion [Voco], Aura Bulk Fill [SDI], and X-tra Fill [Voco]) and three flowable composites (Venus Bulk Fill [Heraeus], Filtek [3M], and X-tra Base [Voco]). Three molds of each composite were light cured as specified by the manufacturer. For each mold, slices corresponding to 0-mm (surface) and 4-mm depth were analyzed by spectroscopic techniques: ATR-FTIR, FTIR, and FT-Raman. The spectra of uncured composite material were used as an analytical control for background subtraction of the treated composite. The area and amplitude of the reference peaks (1607 and 1637 cm-1) were obtained to calculate the DC percentage at 0- and 4-mm depth. A Kruskal-Wallis nonparametric test was used for materials, and paired comparisons were made using Mann-Whitney nonparametric test. Wilcoxon's rank test was used for comparison between spectroscopic methods and between 0- and 4-mm depth in each composite. Significance was accepted at p<0.05. RESULTS: FTIR showed significantly lower DC values, both in areas and amplitudes of the peaks, when compared with the results reported by different BFC. Differences between the surface and 4-mm depth were detected more precisely by FT-Raman. ATR-FTIR obtained DC values significantly higher than those obtained by FTIR. CONCLUSIONS: The vibrational spectroscopy method significantly influenced DC measurements of the flowable and sculptable BFC explored.

[Psychomotor development from 0 to 4 years in indigenous children. A sistematic literature search]. / Desarrollo psicomotor de 0 a 4 años en infancia indígena. Revisión sistemática de la literatura.

INTRODUCTION: The objective of this study was to evaluate published articles regarding the development of indigenous children aged 0 to four years. SUBJECTS AND METHOD: Systematic literature search. Parti cipants: Primary studies with populations of indigenous children aged 0 to four years. Type of studies: Primary studies with qualitative or quantitative methodologies published in the last ten years until November 2015. Databases: MEDLINE, Digital Library of the University of Girona: CERCADOR, EMBASE, Scielo. SEARCH STRATEGY: sensitive and specific. Free terms, MeSH, and Boolean. RESULTS: Nine articles remain for analysis. There are six central subjects related to intracultural patterns of expected development in indigenous childhood: 1) physical, 2) language, 3) socio-cognitive, 4) emo tional, 5) teaching-learning, 6) psychosocial, which reveal the existence of categories of sociocultural and spiritual contents. There is no defined period of time associated with the education. Learning is through observation and participation. Development is understood as a whole, intertwining the social, cultural, natural and spiritual. CONCLUSION: Spirituality and nature are at the center. Time as a goal to gain skills does not have a cultural function to demonstrate the acquisition of the inherent va lues to the culture. To base the assessment of development exclusively on psychomotor development as monitoring guide is insufficient to assess the integrality and complexity of the advances, abilities, and skills of indigenous children.

Desarrollo psicomotor de 0 a 4 años en infancia indígena: revisión sistemática de la literatura / Psychomotor development from 0 to 4 years in indigenous children: a sistematic literature search

INTRODUCCIÓN: El objetivo de este estudio fue evaluar artículos publicados respecto al desarrollo de niños/niñas de 0 a 4 años en el curso de la infancia indígena. SUJETOS Y MÉTODO: Búsqueda sistemática de la literatura. Participantes: Estudios primarios cuya población correspondiera a niños/as de 0 a 4 años en el curso de la infancia indígena. Tipos de estudios: Se incluyeron aquellos estudios cuyas metodologías fueran cualitativas o cuantitativas publicados en los últimos 10 años hasta noviembre de 2015. Bases de datos: MEDLINE, Biblioteca Digital de la Universidad de Girona: CERCADOR, EMBASE, Scielo. Estrategia de búsqueda: sensible y específica. Términos libres, MeSH, y Boolean. RESULTADOS: Quedan 9 artículos para el análisis. Se presentan 6 temas centrales que se relacionan con patrones intraculturales del desarrollo esperado en la infancia indígena: 1) lo físico; 2) el lenguaje; 3)lo socio-cognitivo; 4) lo emocional; 5) la enseñanza-aprendizaje; 6) lo psicosocial, que permi ten ver la existencia de categorías de contenidos socioculturales y espirituales. No se muestra una temporalidad definida asociada a la formación. El aprendizaje es por observación y participación. El desarrollo es comprendido como un todo, entrelaza lo social, cultural, natural y espiritual. CONCLUSIÓN: La espiritualidad y naturaleza están en el centro. La temporalidad como meta para dominar destrezas no ejerce función cultural para demostrar la adquisición de valores propios de la cultura. Basar la valoración del desarrollo centrándose exclusivamente en el Desarrollo Psicomotor como guía de vigilancia es insuficiente para valorar la integralidad y complejidad de los progresos, habilidades y destrezas de los niños/niñas indígenas.

INTRODUCTION: The objective of this study was to evaluate published articles regarding the development of indigenous children aged 0 to four years. SUBJECTS AND METHOD: Systematic literature search. Participants: Primary studies with populations of indigenous children aged 0 to four years. Type of studies: Primary studies with qualitative or quantitative methodologies published in the last ten years until November 2015. Databases: MEDLINE, Digital Library of the University of Girona: CERCADOR, EMBASE, Scielo. Search strategy: sensitive and specific. Free terms, MeSH, and Boolean. RESULTS: Nine articles remain for analysis. There are six central subjects related to intracultural patterns of expected development in indigenous childhood: 1) physical, 2) language, 3) socio-cognitive, 4) emo tional, 5) teaching-learning, 6) psychosocial, which reveal the existence of categories of sociocultural and spiritual contents. There is no defined period of time associated with the education. Learning is through observation and participation. Development is understood as a whole, intertwining the social, cultural, natural and spiritual. CONCLUSION: Spirituality and nature are at the center. Time as a goal to gain skills does not have a cultural function to demonstrate the acquisition of the inherent va lues to the culture. To base the assessment of development exclusively on psychomotor development as monitoring guide is insufficient to assess the integrality and complexity of the advances, abilities, and skills of indigenous children.

Enfermedad de Parkinson: fisiopatología, diagnóstico y tratamiento / Parkinson disease: pathophysiology, diagnosis and treatment

Resumen La enfermedad de Parkinson es la segunda causa de enfermedad neurodegenerativa crónica progresiva, tiene una alta prevalencia e incidencia, genera un alto impacto en la calidad de vida de los pacientes e importantes costos en su atención. La enfermedad de Parkinson se desarrolla por la degeneración de las neuronas dopaminérgicas en la sustancia nigra pars compacta, lo que se manifiesta en la aparición de síntomas motores como la bradicinesia, temblor de reposo, rigidez e inestabilidad postural; así como también de síntomas no motores como alteraciones gastrointestinales, del sueño, autonómicas, cognitivas, entre otras, que reflejan el compromiso de diferentes vías no dopaminérgicas. El diagnóstico se apoya en sus manifestaciones clínicas más características y excluye otras causas de parkinsonismo. El tratamiento farmacológico busca controlar los síntomas motores y no motores, los cuales empeoran por la historia natural de la enfermedad o se acompañan de complicaciones debidas a la terapia, haciendo necesarias otras intervenciones como la estimulación cerebral profunda.

Abstract Parkinson's disease is the second cause of progressive chronic neurodegenerative disease, it has a high prevalence and incidence, generates a high impact on the quality of life of patients and significant costs due to its healthcare. Parkinson's disease is developed due to the degeneration of dopaminergic neurons in the substance nigra pars compacta, which is manifested in the appearance of motor symptoms such as bradykinesia, rest tremor, rigidity and postural instability; as well as non-motor symptoms such as gastrointestinal, sleep, autonomic, cognitive alterations, among others, reflecting the impairment of different non-dopaminergic pathways. The diagnosis is based on its most frequent clinical manifestations and the exclusion of other causes of parkinsonism. The pharmacological treatment seeks to control motor and non-motor symptoms, which are worsened by the natural history of the disease or are accompanied by side effects induced by pharmacotherapy, making necessary other approaches such as deep brain stimulation.

Hiperplasia nodular linfoide asociada con colitis ulcerativa: descripción de un caso y revisión de la literatura / Lymphoid Nodular Hyperplasia Associated with Ulcerative Colitis: Case Study and Literature Review

La hiperplasia nodular linfoide es una patología del aparato gastrointestinal, poco frecuente en adultos. Se caracteriza por un crecimiento del tejido linfoide mucoso y submucoso como respuesta a diferentes tipos de estímulos nocivos. Se ha descrito asociada con otras patologías como infección por VIH/ Síndrome de Inmunodeficiencia Adquirida, giardiasis, infección por Helicobacter Pylori, enfermedad celíaca, y en pocos casos con enfermedad inflamatoria intestinal. No tiene una presentación clínica específica y su manejo aún no está claro

Lymphoid nodular hyperplasia is a pathology of the gastrointestinal tract that rarely occurs among adults. It is characterized by growth of submucosal lymphoid tissue and mucosal response to different types of noxious stimuli. It has been described in association with other diseases such as HIV/AIDS, giardiasis, Helicobacter pylori infections, celiac disease, and very rarely with inflammatory bowel disease. At present, there is no specific clinical presentation or treatment

Biodegradable polymer blends based on corn starch and thermoplastic chitosan processed by extrusion.

Blends of thermoplastic cornstarch (TPS) and chitosan (TPC) were obtained by melt extrusion. The effect of TPC incorporation in TPS matrix and polymer interaction on morphology and thermal and mechanical properties were investigated. Possible interactions between the starch molecules and thermoplastic chitosan were assessed by XRD and FTIR techniques. Scanning Electron Microscopy (SEM) analyses showed a homogeneous fracture surface without the presence of starch granules or chitosan aggregates. Although the incorporation of thermoplastic chitosan caused a decrease in both tensile strength and stiffness, films with better extensibility and thermal stability were produced.

Evaluation of lens absorbed dose with Cone Beam IGRT procedures.

The purpose of this work is to evaluate the absorbed dose to the eye lenses due to the cone beam computed tomography (CBCT) system used to accurately position the patient during head-and-neck image guided procedures. The on-board imaging (OBI) systems (v.1.5) of Clinac iX and TrueBeam (Varian) accelerators were used to evaluate the imparted dose to the eye lenses and some additional points of the head. All CBCT scans were acquired with the Standard-Dose Head protocol from Varian. Doses were measured using thermoluminescence dosimeters (TLDs) placed in an anthropomorphic phantom. TLDs were calibrated at the beam quality used to reduce their energy dependence. Average dose to the lens due to the OBI systems of the Clinac iX and the TrueBeam were 0.71 ± 0.07 mGy/CBCT and 0.70 ± 0.08 mGy/CBCT, respectively. The extra absorbed dose received by the eye lenses due to one CBCT acquisition with the studied protocol is far below the 500 mGy threshold established by ICRP for cataract formation (ICRP 2011 Statement on Tissue Reactions). However, the incremental effect of several CBCT acquisitions during the whole treatment should be taken into account.

Fetal dose measurements and shielding efficiency assessment in a custom setup of (192)Ir brachytherapy for a pregnant woman with breast cancer.

PURPOSE: To assess the radiation dose to the fetus of a pregnant patient undergoing high-dose-rate (HDR) (192)Ir interstitial breast brachytherapy, and to design a new patient setup and lead shielding technique that minimizes the fetal dose. METHODS: Radiochromic films were placed between the slices of an anthropomorphic phantom modeling the patient. The pregnant woman was seated in a chair with the breast over a table and inside a leaded box. Dose variation as a function of distance from the implant volume as well as dose homogeneity within a representative slice of the fetal position was evaluated without and with shielding. RESULTS: With shielding, the peripheral dose after a complete treatment ranged from 50 cGy at 5 cm from the caudal edge of the breast to <0.1 cGy at 30 cm. The shielding reduces absorbed dose by a factor of two near the breast and more than an order of magnitude beyond 20 cm. The dose is heterogeneous within a given axial plane, with variations from the central region within 50%. Interstitial HDR (192)Ir brachytherapy with breast shielding can be more advantageous than external-beam radiotherapy (EBRT) from a radiation protection point of view, as long as the distance to the uterine fundus is higher than about 10 cm. Furthermore, the weight of the shielding here proposed is notably lower than that needed in EBRT. CONCLUSIONS: Shielded breast brachytherapy may benefit pregnant patients needing localized radiotherapy, especially during the early gestational ages when the fetus is more sensitive to ionizing radiation.

Commissioning and initial experience with a commercial software for in vivo volumetric dosimetry.

INTRODUCTION AND PURPOSE: Dosimetry Check (DC) (Math Resolutions) is a commercial EPID-based dosimetry software, which allows performing pre-treatment and transit dosimetry. DC provides an independent verification of the treatment, being potentially of great interest due to the high benefits of the in vivo volumetric dosimetry, which guarantee the treatment delivery and anatomy constancy. The aim of this work is to study the differences in dose between DC and the Treatment Planning System (TPS) to establish an accuracy level of the system. MATERIAL AND METHODS: DC v.3.8 was used along with Varian Clinac iX accelerator equipped with EPID aS1000 and Eclipse v.10.0 with AAA and Acuros XB calculation algorithms. The DC evaluated version is based on a pencil beam calculation algorithm. Various plans were generated over several homogeneous and heterogeneous phantoms. Isocentre point doses and gamma analysis were evaluated. RESULTS: Total dose differences at the isocentre between DC and TPS for the studied plans are less than 2%, but single field contributions achieve greater values. In the presence of heterogeneities, the discrepancies can reach up to 15%. In transit mode, DC does not consider properly the couch attenuation, especially when there is an air gap between phantom and couch. CONCLUSIONS: The possibility of this in vivo evaluation and the potentiality of this new system have a very positive impact on improving patient QA. But improvements are required in both calculation algorithm and integration with the record and verify system.

Presentación ginecológica de un linfoma no Hodgkin / Gynecologic presentation of pelvis lymphoma

Los linfomas no Hodgkin son un grupo heterogéneo de tumores linfoproliferativos. Suponen el 90% de todos los linfomas malignos. Su incidencia ha aumentado en las últimas décadas. Los linfomas no Hodgkin primarios que aparecen en la cavidad pélvica son raros. Se presenta el caso de una paciente que presentaba una masa palpable a través de la vagina en la musculatura profunda del suelo pélvico, que histológicamente correspondió a un linfoma no Hodgkin B difuso de células grandes, que es el tipo histológico más frecuente (AU)

Non-Hodgkin's lymphomas are a heterogenous group of lymphoproliferative neoplastic diseases, representing 90% of all malignant lymphomas. The incidence of these malignancies has risen during the past few decades. Primary pelvic non-Hodgkin's lymphomas are uncommon. We report a patient with a palpable mass located in the pelvic floor musculature. Histologic examination revealed diffuse large B-cell non-Hodgkin's lymphoma, which is the most frequent histological subtype (AU)

Effect of CHX on the decalcifying effect of 10% citric acid, 20% citric acid, or 17% EDTA.

The objective of this study was to measure the demineralization capacity of 10% and 20% citric acid and 17% EDTA after three time periods and to determine whether it was modified by the addition of 1% of commercial chlorhexidine (CHX). Three slices of 2-mm thickness were cut from the cervical third of the root of ten bovine incisors and sectioned into two equal parts, obtaining six specimens per tooth. Specimens were assigned to one of six groups (n = 10) for immersion in 25 ml of the above mentioned solutions or 25 ml of these same solutions plus 1% CHX (Hibimax). At 3, 10, and 15 min of immersion, the concentration of Ca2+ was measured by atomic absorption spectrophometry. The demineralization effect of all solutions was time-dependent (F = 158,448; p < 0.001), without significant differences among them (p = 0.783). Addition of 1% CHX did not modify the demineralizing capacity of these solutions. In the first three minutes, significantly more [Ca2+] was obtained when 17% EDTA was used in comparison with the other solutions.

Análisis de la gestión integral de residuos sólidos en la zona sur del Área Metropolitana del valle del Aburrá (2004) / Analysis of the integrated management of solid residues in the south zone of Medellín Metropolitan Area in 2004

Objetivo: analizar la gestión integral de residuos sólidos en la zona sur del área metropolitana del valle del Aburrá durante el año 2004. Metodología: se realizó un estudio descriptivo en que se observaron las condiciones socioeconómicas, técnicas, ambientales e institucionales relacionadas con el manejo de los residuos sólidos municipales en sus diferentes etapas. Resultados: al examinar la información se evidenció que la prestación del servicio público de aseo se ha orientado principalmente hacia la recolección y transporte hasta el sitio de disposición final, restándole importancia a las demás fases previstas dentro de la gestión integral de residuos. Por medio de un diagnóstico se hallaron las deficiencias y necesidades que sirvieron de base para el estudio de las alternativas de solución y elaboración de estrategias, lo que facilitó la propuesta de programas y proyectos encaminados al mejoramiento de la administración de los residuos desde la generación hasta la disposición final. Conclusión: se pudo verificar la prioridad de implementar campañas permanentes de sensibilización y educación para el logro de un cambio de actitud de los actores que intervienen en el manejo de los residuos municipales; además, se proponen estrategias de solución, con el fin de que se apropien de la problemática local y de que participen en el mejoramiento continuo de dicha gestión.

Technical note: fitted dosimetric parameters of high dose-rate 192Ir sources according to the AAPM TG43 formalism.

Functional fits for the anisotrophy function and the radial dose function, have been studied, in a previous work, in order to characterize dose-rate distributions around some of the high-intensity 192Ir sources. The purpose of the present work is to complete the previous one in order to include all the existing HDR and PDR 192Ir sources. The sources addressed here are: the Buchler source from Amersham, the 12i and Plus PDR sources and the 12i and Plus HDR sources from GammaMed, and the new VariSource HDR source wire model VS2000 from Varian Oncology Systems.

Hematoma subdural crónico: una enfermedad del adulto mayor / Chronic subdural hematoma: a disease of elderly people

The lack of specificity and heterogeneity of the clinical picture of chronic subdural hematoma, hampers its diagnosis. Aim: To report the experience of a Neurosurgical Service in chronic subdural hematoma. Patients and methods: One hundred patients (77 male, mean age 77ñ13 years) with chronic subdural hematoma were analyzed. Results: The main clinical presentations were mental status changes (50 percent) and progressive focal neurological deficit (46 percent). Five cases presented as a transient neurological deficit. All patients were treated with burr hole drainage. Thirteen had recurrence of the hematoma and they were reoperated. The surgical mortality was 3 percent. Eighty seven patients were followed for a mean of 66 months. Eighty one of these had a complete recovery, 6 had permanent neurological deficit and 2 of these were unable to care for themselves. Bad prognosis was associated with the absence of a previous trauma to explain the hematoma and symptoms of dementia as the clinical presentation. Conclusions: Most patients with chronic subdural hematoma treated with burr hole drainage have a good outcome

The drug-crime nexus in a community sample of adults.

The authors tested several theories using prospective data to explain the associations between drug abuse and crime in a community sample of 470 adults. Polydrug problems in early adulthood predicted both criminal behavior and polydrug problems in adulthood. Consequences of drug problems as a young adult included arrests and convictions for drug-related offenses, property damage, and driving under the influence of other drugs. Predictors of later polydrug problems included thefts, driving under the influence of alcohol and other drugs, arrests and convictions for drug-related offenses, and a lack of support for drug problems. Theoretical implications of these findings are discussed.

Fitted dosimetric parameters of high dose-rate 192Ir sources according to the AAPM TG43 formalism.

The purpose of this study is to find fitted functional forms to the anisotropy function, F(r, theta), and the radial dose function, g(r), in order to characterize dose-rate distributions around all the high-intensity 192Ir sources currently in use. Dosimetry data are at present available as tables for: the microSelectron HDR ("classic" and "new" design models), the PDR source, and the VariSource HDR source, expressed in terms of the AAPM Task Group No. 43 recommendations. There is only one paper out which introduces a functional form to fit the anisotropy function, but only for symmetric sources with respect to the transverse axis. However, dosimetric data of the HDR and PDR sources mentioned above cannot be reproduced with these functional forms. In our study F(r,theta) and g(r) published data are fitted with functional forms in such a way that appropriate limits are reached for both functions and the maximum fit error approaches the data uncertainty. The average fit error is less than 1% in all cases. These functional forms make handling data easier within the treatment planning system, avoiding the use of tabulated data.

Dosimetric characteristics of backscattered electrons in lead.

In electron beam therapy, tissue overdose due to electrons backscattered from lead has been profusely studied. To quantify this dose enhancement effect, an electron backscatter factor (EBF) was defined as the ratio of dose at the tissue-inhomogeneity interface with and without the scatterer present. The dependence of the EBF on energy at the scatterer surface is not well known for energies lower than 3 MeV which is the most frequent clinical situation. In this work, we have done Monte Carlo calculations with the GEANT code to study EBF in lead at this energy range. The applicability of this code and the developed procedure for dose estimation has been experimentally verified. The dependence of the EBF on the beam energy incident on the scatterer has been studied for different nominal beam energies incident at the phantom's surface. The results show a trend of increase of EBF with the beam energy incident on the scatterer between 0.5 and 1.5 MeV, keeping practically constant above this energy up to 3 MeV. Backscattered electron energy spectra and depth dose curves in the 'up-stream' direction have been obtained at the various energies of the primary electron beam striking on the lead scatterer. The results of this work are compared with previously published data.

Trauma espinal penetrante por arma de fuego / Gunshot spinal cord injury

El traumatismo raquimedular (TRM) penetrante por arma de fuego es una patología cada vez más prevalente, relevante y de un alto costo social y económico, por el grado de invalidez que genera en población generalmente joven. El tratamiento óptimo ha sido debatido ampliamente, estando sólo parcialmente establecido el rol de los antibióticos, corticoides y cirugía. Se presenta un caso clínico, con lesión incompleta a nivel de cauda equina, en el cual se realizó tratamiento quirúrgico con resultado final satisfactorio y se revisa la bibliografía correspondiente