Resumen Objetivo: Presentar los resultados de nuestra serie de nefrectomía laparoscópica en pielonefritis xantogranulomatosa (PXG). Método: Se realizó un estudio retrospectivo que incluyó 143 pacientes tratados con nefrectomía laparoscópica por exclusión renal, de los cuales 15 fueron por PXG, en el periodo comprendido de 2011 a 2019. Se recolectaron datos demográficos y clínicos, resultados transoperatorios, complicaciones y días de estancia hospitalaria. Resultados: Se realizó nefrectomía laparoscópica transperitoneal de forma exitosa en 15 pacientes con PXG, sin necesidad de conversión. El tiempo transoperatorio promedio fue de 124.4 minutos (rango: 70-240). El sangrado transoperatorio fue de 148.5 ml (rango: 30-550), sin requerimiento de transfusión sanguínea. No se reportaron complicaciones transoperatorias; se presentó una complicación en el posoperatorio (6.6%) clasificada como Clavien-Dindo I (infección de la herida quirúrgica). La estancia hospitalaria promedio fue de 2.85 días (rango: 2-7). Conclusiones: El manejo definitivo de la PXG es la nefrectomía, y el abordaje laparoscópico debe ser considerado como una modalidad de tratamiento a pesar de ser una patología que presenta un proceso inflamatorio grave y crónico, obteniéndose beneficios como disminución en el tiempo quirúrgico, menor sangrado, menor tasa de complicaciones y menos días de estancia hospitalaria cuando es realizado por un cirujano experimentado.

Abstract Objective: To present the results of our case series on laparoscopic nephrectomy in xanthogranulomatous pyelonephritis (XGP). Methods: A retrospective study was conducted that included 143 patients treated with laparoscopic nephrectomy for non-functioning kidney, of whom 15 had XGP, within the time frame of 2011 to 2019. The demographic and clinical data were collected, along with the intraoperative results, complications, and days of hospital stay. Results: Transperitoneal laparoscopic nephrectomy was successfully performed on 15 patients with XGP, with no need for conversion. Mean intraoperative time was 124.4 minutes (range 70-240) and intraoperative blood loss was 148.5 ml (range 30-550), with no blood transfusion required. No intraoperative complications occurred but there was one postoperative complication (6.6%), classified as Clavien-Dindo I (surgical wound infection). Mean hospital stay was 2.85 days (range 2-7). Conclusions: Nephrectomy is the definitive management for XGP, and the laparoscopic approach should be considered a treatment modality, despite the fact that the pathology involves a severe chronic inflammatory process. Its benefits are reduced surgery duration, less blood loss, a lower complication rate, and fewer days of hospital stay, when performed by a skilled and experienced surgeon.

Abstract Objective: To present the results of our series of patients with lower third ureteral pathology, who underwent laparoscopic ureteral reimplantation in a tertiary care hospital. Material and methods: A retrospective study that included 18 patients with lower third ureteral pathology, treated with laparoscopic ureteral reimplantation, between July 2014 and December 2020. Demographic and clinical data, intraoperative results, complications, and days of hospital stay were collected, as well as postoperative control. Results: Transperitoneal Lich-Gregoir laparoscopic ureteral reimplantation was performed in 18 patients with lower third ureteral pathology (6 men and 12 women, 8 cases with right laterality and 10 left). Etiology: (11) 61% postsurgical stenosis, (2) 11% ureterovaginal fistula; (3) 17% vesicoureteral reflux, and (2) 11% congenital stricture. All cases had preoperative imaging studies. The mean age was 38.7 years; transoperative time 152 minutes; intraoperative bleeding of 65 ml. There were no intraoperative complications; The average hospital stay was 2.5 days. In all cases, a double J ureteral catheter was placed, which was removed 4 to 6 weeks after surgery. Conclusions: The laparoscopic ureteral reimplantation is a safe procedure for the treatment of lower third ureteral pathology. This modality seems to improve the profile of perioperative complications compared to the open approach, maintaining long-term results. The laparoscopic approach shows a decrease in surgical time, less bleeding, and a lower rate of complications and hospital stay, however, laparoscopic skills and experience must be available to perform it.

Resumen Objetivo: Presentar los resultados de nuestra serie de pacientes con patología ureteral de tercio inferior que se les realizó reimplante ureteral laparoscópico en un hospital de tercer nivel. Material y métodos: Estudio retrospectivo que incluyó 18 pacientes, con patología ureteral de tercio inferior tratados con reimplante ureteral laparoscópico, en un periodo comprendido de Julio 2014 a diciembre 2020. Se recolectaron datos demográficos, clínicos, resultados transoperatorios, complicaciones, días de estancia hospitalaria y control posoperatorio. Resultados: Se realizó reimplante ureteral laparoscópico Lich-Gregoir transperitoneal en 18 pacientes con patología ureteral de tercio inferior (6 hombres y 12 mujeres, 8 casos con lateralidad derecha y 10 izquierdos). La etiología: (11) 61 % estenosis posquirúrgica, (2) 11% fístula uretero-vaginal; (3) 17% reflujo vesicoureteral y (2) 11 % estenosis congénita. Todos los casos contaban con estudios de imagen preoperatorios. La media de edad fue 38.7 años; el tiempo transoperatorio 152 minutos; sangrado transoperatorio de 65 ml. No hubo complicaciones transoperatorias; La estancia hospitalaria promedio fueron 2.5 días. En todos los casos se colocó catéter ureteral doble j, el cual fue retirado a los 4 a 6 semanas posquirúrgicas. Conclusiones: El reimplante ureteral laparoscópico es un procedimiento seguro para el tratamiento de patología ureteral de tercio inferior. Dicha modalidad parece mejorar el perfil de complicaciones perioperatorias comparadas con el abordaje abierto, manteniendo los resultados a largo plazo. El abordaje laparoscópico demuestra una disminución del tiempo quirúrgico, menor sangrado, menor tasa de complicaciones y de estancia hospitalaria, sin embargo, se debe contar con las habilidades en laparoscopia y experiencia para realizarlo.

Resumen Antecedentes: Pentafecta es el estándar en la evaluación integral de los pacientes sometidos a prostatectomía radical. El objetivo de este estudio es evaluar y describir los desenlaces oncológicos y funcionales en pacientes con cáncer de próstata de alto riesgo sometidos a prostatectomía radical asistida por robot. Método: Estudio descriptivo, retrospectivo, de 20 pacientes con diagnóstico de cáncer de próstata de alto riesgo. El grupo de alto riesgo se compone por pacientes con antígeno prostático específico mayo o igual a 20 ng/ml, reporte histopatológico con Gleason mayor o igual a 8 y/o estadios clínicos T2/T3 tratados con abordaje robótico. Resultados: El control bioquímico se alcanzó a partir de las primeras 6 semanas posterior al evento quirúrgico. El 75% (n = 15) presentaron márgenes quirúrgicos negativos. El 100% de los pacientes (n = 20) presentaron continencia urinaria inmediatamente después del retiro de la sonda vesical. La función eréctil se conservó a 3, 6 y 12 meses en el 100% de los pacientes a los que se realizó neuropreservación, pero con uso de inhibidor de la fosfodiesterasa (n = 5). Se reportaron complicaciones en el 10% de los casos (Clavien-Dindo I-II). Conclusiones: La prostatectomía radical asistida por robot en pacientes con cáncer de próstata de alto riesgo se considera una opción de tratamiento adecuada en casos seleccionados. Se necesita un diseño experimental distinto para definir las ventajas o desventajas de este abordaje, así como determinar su papel y aplicación en la práctica clínica.

Abstract Background: Pentafecta is currently the standard in the comprehensive evaluation of patients undergoing radical prostatectomy, the objective of this study is the evaluation of oncological and functional outcomes in patients with prostate cancer of high risk undergoing robot-assisted radical prostatectomy. Method: Descriptive, retrospective study of 20 cases with a diagnosis of high-risk prostate cancer. The high-risk group is composed of a prostate-specific antigen equal or greater than 20 ng/mL, Gleason score equal or greater than 8, or clinical stages T2/T3 treated with robotic approach. Results: Biochemical control was achieved from the first six weeks after the surgical event. 75% (n = 15) had negative surgical margins. 100% of the patients (n = 20) presented urinary continence immediately after removal of the urinary catheter. Erectile function was preserved at 3, 6 and 12 months in 100% of the patients who underwent neuropreservation but with use of an PDE inhibitor. (n = 5). Complications were reported in 10% (Clavien-Dindo I-II). Conclusions: Robot-assisted radical prostatectomy in patients with high-risk prostate cancer is considered an appropriate treatment option in selected patients. A different experimental design is needed to define the advantages or disadvantages of this approach, as well as to determine its role and application in clinical practice.

Abstract Clinical case description: A 64-year-old woman with an unremarkable past medical history was evaluated due to lower urinary tract symptoms and hematuria of 1-month progression. A magnetic resonance imaging scan revealed a lesion consistent with urethral tumor. During urethrocystoscopy, a tumor was found inside a urethral diverticulum. Transurethral resection was carried out, followed by the later performance of anterior pelvic exenteration. The histopathologic result was clear cell adenocarcinoma inside a proximal urethral diverticulum. The patient did not undergo adjuvant therapy, remaining in follow-up and surveillance, and is presently recurrence-free. Relevance: Urethral carcinoma is an uncommon tumor and its appearance in a diverticulum is rare. Those types of tumor are highly invasive and require aggressive treatment to offer the possibility of cure. Clinical implications: No standardized treatment is in place. Surgical treatment through radical urethrectomy or anterior pelvic exenteration, with or without adjuvant therapy, is the most widely accepted therapeutic option. Conclusions: Clear cell adenocarcinoma arising in a urethral diverticulum is uncommon and usually has a locally advanced presentation. There is no standardized treatment or follow-up for the disease.

Resumen Descripción caso clínico: Femenino de 64 años, sin antecedentes de importancia, valorada por síntomas urinarios bajos y hematuria de 1 mes de evolución. En los estudios radiológicos se encuentra una imagen compatible con una tumoración uretral en la resonancia magnética. Se realiza uretrocistoscopía encontrando una tumoración dentro de un divertículo de uretra, se le realiza resección transuretral y posteriormente exenteración pélvica anterior. Histopatológicamente se reportó un adenocarcinoma de células claras dentro de un divertículo uretral proximal. No se realizó adyuvancia, permanece en seguimiento y vigilancia, actualmente libre de recidiva. Relevancia: Los carcinomas de uretra son neoplasias poco comunes y que estos se originen en un divertículo son raros. Estos tipos de tumores son de comportamiento agresivo y se requiere de un tratamiento agresivo para poder ofrecer la mayor probabilidad de curación. Implicaciones clínicas: No existe un tratamiento estandarizado, el tratamiento quirúrgico mediante una uretrectomía radical o una exenteración pélvica anterior con o sin adyuvancia sería la opción terapeútica más aceptada. Conclusiones: El adenocarcinoma de células claras que se origina de un divertículo de uretra es una enfermedad poco común, usualmente se presentan de forma localmente avanzada; para lo cual no se cuenta con un tratamiento o seguimiento estandarizado.

Abstract Introduction: The creation of 3D printed silicone models has several purposes, one of which is to provide augmented reality (AR), thanks to the imaging and visualization methods that serve as aids in “surgical planning”. They enable precise analysis of the anatomy at the site to be treated and can influence surgical strategy change or decision-making. Materials and methods: The present case report describes the surgical planning carried out with a 3D printed model, in a 40-year-old patient incidentally diagnosed with a T2aN0M0 CS I left kidney tumor, measuring 20 mm, that was slightly exophytic, with a RENAL Score of 4a. Results: Total surgery duration was 180 min, with a console time of 120 min, blood loss of 50cc, and warm ischemia time of 12 min. No drain was placed, hospital stay was 2 days, and there were no complications. Discussion: Visualizing the anatomic characteristics on the model enabled surgical programming to be carried out, along with guided dissection and selective clamping that did not involve the entire renal hilum. Three-dimensional models are based on multi-slice digital tomography images that are converted to real scale and then printed with different materials, achieving an anatomic representation of the organ to be treated. Conclusions: That type of planning favors better understanding of the surgical anatomy of the tumor and improved decision-making. Case series on different anatomic variations, as well as other organs, should be carried out.

Resumen Introducción: La creación de modelos impresos en silicón 3-D tiene varios objetivos, uno de ellos es el resultado de la realidad aumentada (AR), gracias a los métodos de imagen y de visualización como auxiliares en la planificación quirúrgica, ya que permiten un análisis preciso de la anatomía del sitio a tratar y pueden ser un punto de cambio de estrategia quirúrgica o incluso de toma de decisiones. Material y métodos: Reporte de caso de impresión de modelo 3D y realización de planeación quirúrgica en paciente de 40 años con diagnóstico de Tumor Renal Izquierdo T2aN0M0 EC I. Incidentaloma de 20 mm, discretamente exofítica con un RENAL Score de 4a. Resultados: Tiempo quirúrgico Total de 180 min; tiempo de consola de 120 min; sangrado de 50cc; tiempo de Isquemia Caliente 12 min; no se colocó drenaje; días de estancia hospitalaria 2; no se presentaron complicaciones. Discusión: La visualización de las características anatómicas en el modelo permiten programar y disecar de manera guiada y hacer un clamping selectivo y no de la totalidad del hilio renal. Los modelos tridimensionales están basados en imágenes multicorte de tomografía de los que la extracción digital es llevada a una representación de escala real y posteriormente es impresa en diferentes materiales, de tal manera que contamos con una representación anatómica del órgano que deseamos tratar. Conclusiones: Contar con este tipo de planeación favorece un mejor entendimiento de la anatomía quirúrgica del tumor y la toma de decisiones. Es necesario realizar series de casos para las diferentes variaciones tanto anatómicas como de otros órganos.

Abstract Background: Genitourinary cancer is a great health problem worldwide, and mortality rates are higher in less developed countries. Mexico’s geographic distribution is complex, making it difficult to provide health services to rural communities. In the present study, we present the experience in providing medical services to remote communities through telemedicine, mainly in relation to the diagnosis of urologic neoplasias. By sharing our experience, we hope the program, as well as the process of primary care diagnosis of urologic neoplasias, can be improved, enhancing opportune patient referral. Materials and Methods: A retrospective, descriptive analysis of the urology consultations carried out by the urology service personnel through telemedicine, within the time frame of January 2009 to May 2017, was conducted. The case records of patients suspected of urologic neoplasia were examined and the data of patients in whom the diagnosis was confirmed were analyzed. Results: A total of 1,265 consultations were given by the urology service through telemedicine during the study period. Of those, 696 were first-time consultations and the rest were subsequent appointments. Fifty-nine patients were suspected of having genitourinary cancer (8% of the first-time consultations) and the disease was confirmed in 17 patients (2% of the first-time consultations). The most prevalent neoplasia was prostate cancer, presenting in 6 patients (35%), and the remaining cases corresponded to bladder cancer (29%), penile cancer (12%), testicular cancer (12%), kidney cancer (6%), and urothelial cancer of the upper urinary tract (6%). Mean patient age was 65.7 years, with a predominance of men (n = 15). The majority of cases were diagnosed in clinically advanced stages. Conclusion: In our experience, the role of telemedicine was limited, regarding the opportune diagnosis of genitourinary cancer, given that the majority of cases analyzed were diagnosed in advanced stages.

Resumen Antecedentes: El cáncer genitourinario es un gran problema de salud global, los índices de mortalidad son mayores en países con menor desarrollo. México tiene una distribución geográfica compleja, haciendo difícil proveer servicios de salud en las comunidades rurales. En este estudio presentamos la experiencia obtenida tras brindar servicios médicos a través de telemedicina a comunidades alejadas, principalmente en el diagnóstico de neoplasias urológicas. Se espera que, al compartir nuestra experiencia, se desarrollen mejoras en el programa y en el proceso de diagnóstico de neoplasias urológicas en consulta de primer nivel, esto para mejorar la referencia oportuna de los pacientes. Material y Métodos: Análisis descriptivo retrospectivo de las consultas urológicas otorgadas por el personal del servicio de urología a través de telemedicina de enero 2009 a mayo del 2017. Se examinaron los expedientes de los pacientes captados con sospecha de neoplasia urológica y se analizaron los datos de los pacientes en quienes el diagnóstico fue confirmado. Resultados: Un total de 1,265 consultas fueron otorgadas por el servicio de urología a través de telemedicina en este periodo de tiempo. De estas, 696 fueron consultas de primera vez, y el resto subsecuentes. 59 pacientes tuvieron sospecha de cáncer genitourinario (8% de las consultas de primera vez), y se confirmó la enfermedad en 17 pacientes (2% de las consultas de primera vez). La neoplasia más prevalente fue cáncer de próstata con 6 casos (35%), el resto de los casos corresponden a cáncer vesical (29%), cáncer de pene (12%), cáncer testicular (12%), cáncer renal (6%) y cáncer urotelial del tracto urinario superior (6%). La edad promedio de los pacientes fue 65.7 años y el predominio de los casos fue representado por el sexo masculino con 15 casos. La mayoría de los casos fueron diagnosticados en estadios clínicos avanzados. Conclusión: En nuestra experiencia, la telemedicina tiene un papel limitado en el diagnóstico oportuno de cáncer genitourinario, ya que la mayoría de los casos presentados fueron diagnosticados en estadios avanzados.

Abstract On March 11, 2020, coronavirus disease 2019 (COVID-19) was declared a pandemic and has created an impact like no other on health systems worldwide. A restructuring in the priority of patient care has currently taken place that is based on the patient’s underlying pathology. Urology services are no exception, postponing all the elective surgeries that can be delayed without putting the patient at risk. A surgical protocol has been adopted during the pandemic that attempts to reduce the amount of time the operating room is in use, as well as the risk for postoperative complications, so that hospital stay can be reduced. In such a setting, minimally invasive surgery, such as laparoscopic and robotic-assisted surgery, can play a beneficial role in treating oncologic pathologies that cannot be deferred. Based on the best evidence that has currently been published and the guidelines of international associations, this paper summarizes the recommendations regarding urologic laparoscopic and robotic-assisted surgery in times of COVID-19.

Resumen El 11 de Marzo del 2020, se declaró como pandemia la enfermedad de coronavirus (COVID-19), la cual ha generado un impacto como ninguno antes en los sistemas de salud de todo el mundo. Actualmente se ha realizado una reestructuración en la prioridad de atención de pacientes de acuerdo con su patología de base. Los servicios de urología no son la excepción interrumpiendo todas cirugías electivas que se puedan retrasar sin generar riesgos para el paciente. Durante la pandemia se ha adoptado un protocolo quirúrgico en el que se busca disminuir el tiempo de uso de quirófano y el riesgo de complicaciones postoperatorias para disminuir estancias hospitalarias. Es en este escenario donde la cirugía mínimamente invasiva como cirugía laparoscópica y robótica puede tener un rol benéfico sobre todo para el tratamiento de patología oncológica que no puede ser diferida. Basándonos en la mejor evidencia actual publicada y en los lineamientos de asociaciones internacionales, este trabajo resume las recomendaciones y precauciones para realizar procedimientos urológicos con abordaje laparoscópico o robótico en tiempos de COVID-19.

Abstract Objective: Purple urine bag syndrome is a rare condition. Neither the underlying disease nor the microbiology of those patients has been adequately reported or studied due to the small number of patients and the types of studies published. The aim of the present work was to describe the clinical characteristics of patients with purple urine bag syndrome seen over a one-year period. Material and methods: A descriptive study was conducted, within the time frame of March 1, 2016 to February 28, 2017. The clinical characteristics and urine culture results of patients that came to the outpatient consultation of the urology service presenting with purple urine bag syndrome, were analyzed. Results: Twenty-three patients were studied. Nineteen percent of the patients were men and the mean patient age was 71.3 years. Five (21.7%) of the patients presented with diabetes mellitus and 4 (17.3%) with high blood pressure. Only 3 (13%) patients presented with a symptom associated with urinary infection. The most prevalent pathogen in the urine cultures was Klebsiella pneumoniae in 7 (30.4%) of the patients, followed by Escherichia coli. Two patients presented with recurrence, but they had no symptoms or comorbidities. Limitations: Study limitations were its retrospective design and the descriptive statistical analysis. Conclusion: Based on the study population and findings, we believe purple urine bag syndrome is a clinical finding that presents in patients of both sexes that are chronic users of urinary catheters, and is most likely benign, given that a low percentage of patients present with symptoms. However, as stated in the literature, it is recommendable to change the catheter and bag, as well as to perform urine cultures and administer empiric antibiotic therapy in the patients that present with symptoms, to prevent later complications.

Resumen Objetivo: El síndrome de bolsa de orina púrpura es una condición poco frecuente: No se han documentado y estudiado adecuadamente las enfermedades de base ni la microbiologia de los pacientes por falta de número de pacientes y los tipos de estudios publicados. El objetivo de este trabajo es describir las características clínicas de los pacientes vistos durante un año con síndrome de bolsa de orina púrpura. Material y Métodos: Estudio descriptivo, realizado del 1 de marzo 2016 al 28 de febrero 2017, analizando las características clínicas y el resultado de cultivo urinario de pacientes que acudían a consulta externa del servicio de urología presentando síndrome de bolsa de orina púrpura. Resultados: El número de pacientes estudiados fue 23, de los cuales 91% fueron de sexo masculino y la edad promedio fue de 71.3 años. Pocos casos con comorbilidades como diabetes mellitus en 5 (21.7%) e hipertensión arterial en 4 (17.3%) . Solo 3 pacientes (13%) presentaron algún síntoma asociado a infección urinaria. El patógeno mas prevalente en cultivos urinarios fue Klebsiella pneumoniae en 7 de los pacientes (30.4%), siguiendo en frecuencia Escherichia coli. Se presentó recidiva en 2 pacientes, de los cuales ninguno presentaba síntomas o comorbilidades. Limitaciones: El estudio se limita a la naturalidad retrospectiva del mismo, además que estadísticamente se trata de un estudio descriptivo. Conclusión: En base a la población estudiada y los hallazgos encontrados, consideramos que es un hallazgo clínico que se presenta en pacientes portadores crónicos de catéteres urinarios de ambos sexos, de curso probablemente benigno, ya que un bajo porcentaje de los pacientes presentan síntomas. Sin embargo, como menciona la literatura es recomendado el cambio del catéter y de la bolsa, además de realizar cultivos urinarios y dar antibioticoterapia empírica en quienes presenten síntomas para evitar complicaciones ulteriores.

Abstract The influence of the frecuency content of seismic excitations on the behavior of an optimal tuned mass damper (TMD) is studied in the context of a system with explicit consideration of soil-structure interaction. A stochastic analysis is made in the time domain for two random processes, one considering a broad bandwidth process (BBP) and other considering a narrow bandwidth process (NBP). A structure built over three different types of soil (soft, medium and hard) is considered. For the optimization of the TMD, the minimization of the ratio between the standard deviation of the displacement of the main structure with TMD with respect to a structure without TMD, is used as the target function. It is found that for seismic excitations with high frecuency content, the ratio of the TMD frequencies compared to the fixed base frequency of the structure approaches to 1 as the soil becomes more rigid. It is also observed that the TMD become tuned with the flexible base frequency for all soil types, producing perfect tuning for small mass ratios and detuning gradually for higher mass ratios. On the other hand, the TMD optimal damping ratio increases as the TMD mass ratio is higher, independently of the soil type. The TMD is more efficient for higher values of the TMD mass ratios, especially on soft soil. In structures built over flexible base, that are subjected to low frequency content excitations, the optimal TMD is tuned with the flexible base, independently of the type of soil and the fixed base period of the main structure. The TMD optimal damping is not sensitive to the flexible period for small mass ratios, and reaches its minimum value when it matches with the predominant period of the seismic event. On the other hand, the TMD reaches its maximum efficiency when it is tuned with the flexible period of the soil-structure system, and coincides with the predominant period of the seismic exitation and is higher on soft soil. A deterministic analysis is made using two seismic records, an artificial earthquake compatible with the Chilean code NCh2745 characterized by high frequencies content and other similar to the event in 1985 in Mexico, characterized by low frequencies content. It is seen that the optimal TMD is efficient controlling the response of the structure in all types of soil analyzed.

El cultivo del tabaco se ha convertido en uno de los más importantes en Colombia, generando empleo a mano de obra calificada y no calificada. En la poscosecha del tabaco se han detectado varias problemáticas a resolver, una de ellas la concerniente al alto costo del combustible empleado en los hornos de curado. Por ello, se realizó una evaluación al intercambiador de calor tradicional tipo hornilla para determinar la eficiencia en el uso del combustible. La información obtenida deja en evidencia la gran dificultad que se tiene con este sistema de transferencia de calor por convección natural para mantener temperaturas estables al interior del horno, generando condiciones ambientales que se alejan considerablemente de las previstas para este proceso, dependiendo estas variaciones, en gran medida, de la frecuencia de cargue de la hornilla, encontrándose además, que la eficiencia en el aprovechamiento de la energía entregada por el carbón es menor del 10 %.

Tobacco has become one of the most important crops in Colombia, generating employment for both skilled and unskilled workers. In the post-harvesting of tobacco were found several problems to be solved, one of them concerning the high cost of the fuel used in the curing ovens. Therefore, an evaluation to the traditional heat exchanger, burner type, to determine the efficiency of the fuel used, was performed. The information obtained shows clearly the great difficulty that we have with this system of heat transfer by natural convection to maintain stable temperatures inside the oven, creating environmental conditions that deviate significantly from those required for this process, depending these variations largely on the frequency of loading of the burner, we also found that the use efficiency of the energy delivered by coal is less than 10 %.

O cultivo de tabaco tornou-se um dos mais importantes na Colômbia, criando postos de trabalho para mão de obra qualificada e não qualificada. Em pós-colheita do tabaco se tem identificaram vários problemas a serem resolvidos, um delas ao relativo ao elevado custo do combustível utilizado nos fornos. Portanto, realizou se uma avaliação tradicional ao intercambiador de calor tradicional tipo hormilla para determinar a eficiência do tipo de combustível A informação obtida mostra claramente a grande dificuldade que temos com este sistema de transferência de calor por convecção natural para manter as temperaturas estáveis no interior do forno, a criação de condições ambientais que se desviam significativamente daquelas exigidas para este processo, dependendo destas variações em em grande medida, a frequência da carga do queimador também descobriu que a eficiência na utilização da energia fornecida pelo carvão é inferior a 10 %.

Se diseñó, implementó y evaluó un sistema de humidificación por nebulización para la hoja de tabaco, que cuenta con un sistema para el control y el registro de las condiciones ambientales del recinto, lo que permite generar un ambiente con humedad relativa más homogénea, logrando un mejor uso del agua y mayor control en la humedad relativa y en el manejo del contenido de humedad de la hoja de tabaco curada, con la consiguiente mejora en la calidad del producto a comercializar. Se obtuvieron rangos de trabajo de humedad relativa entre el 55 y el 75%, y tiempos de 4 a 6 horas para alcanzar la rehumidificación de la hoja hasta el 16%, en base húmeda. Con base en los resultados obtenidos y las observaciones hechas en campo, en cuanto al manejo operativo de este recinto, se propusieron dos nuevos diseños para el sistema de humidificación que permitirían un mejor manejo de la hoja reduciendo las pérdidas por manipulación y sobrehumedecimiento. Este trabajo fortalece el proceso de investigación en el área de la poscosecha de tabaco, al complementar otros proyectos de investigación al respecto, que se han realizado en Colombia.

A tobacco leaf humidifying system involving nebulisation was designned, implemented and evaluated; it had a system for monitoring and recording environmental conditions thereby producing an environment having more homogeneous relative humidity, ensuring better water use, better control of relative humidity and better control in managing cured tobacco leaf moisture content, thereby leading to a consequent improvement in final product quality. 55% to 75% relative humidity and 4 to 6 hour working ranges were obtained to ensure leaf humidification reached 16% humidity on a wet basis. Two new designs are proposed for the conditioning stage regarding this conditioning chamber’s operational management, based on the results and field observations, which would allow better leaf management, thereby avoiding the risk of losses due to manipulation and over-humidification. This work strengthens research in the field of tobacco postharvest technology, complementing other research projects which have been carried out in Colombia.

Teniendo como base la infraestructura existente de un horno tradicional de curado de tabaco, se rediseño e implementó en él un sistema de intercambio de calor por convección forzada que funciona con cisco de café como combustible. Este horno de curado de tabaco por convección forzada USCO-MADR fue evaluado durante el periodo de cosecha, lográndose un manejo controlado de las variables de temperatura y humedad relativa dentro de él durante las tres etapas del curado de la hoja de tabaco; el equipo utilizado tuvo un excelente desempeño al emplear cisco de café como combustible con los siguientes consumos durante el proceso de curado: en la fase de “amarillamiento”, 8,92 kilogramos por hora; en la de “secado de paño y fijación de color”, 17,75 kilogramos por hora; y en la de “secado de vena”, 19,29 kilogramos por hora; el análisis comparativo de los costos operativos del horno evaluado, con los ajustes propuestos a éste, permiten presentarlo a la cadena de tabaco como una alternativa promisoria.

A traditional oven for curing tobacco leaves was redesigned (based on existing infrastructure); a forced-convection heat exchanger system was implemented in it which worked with coffee hulls as fuel. This oven (called a forced-convection tobacco leaf curing oven) was evaluated during the harvesting season. It was found that temperature and relative humidity inside the furnace could be controlled with this assembly during the three stages involved in curing tobacco leaves. The equipment used performed excellently when using coffee hulls as fuel, having the following approximate consumption during curing: 8.92 kilograms per hour during the yellowing stage, 17.75 kilograms per hour during the leaf drying and color fixation phase and 19.29 kilograms per hour during the stem drying stage. Comparative analysis of the oven´s operating costs along with the proposed adjustments to be made to it would allow its implementation as a promising alternative in the existing tobacco chain.

Foi estudada a distribuição da distrofina na membrana plasmática das fibras musculares em 22 crianças com distrofia muscular congênita, através de técnicas de imuno-histoquímica. A distrofina foi identificada nas biópsias musculares processadas a fresco, por técnicas de imunofluorescência utilizando anticorpos policlonais. Todos os casos tinham interrupções da imunofluorescência na membrana plasmática. Em 17 elas eram grandes, em 12 eram pequenas e em 7 eram de ambos os tipos. Fibras com interrupções pequenas e constantes, como um rosário, foram vistas em 15 casos. Essas anormalidades estavam presentes em todas as fibras em 5 casos, eram frequentes em 8, ocasionais em 5 e raras em 4. Cinco casos mostraram fibras sem distrofina. Esses dados sugerem que a expressão da distrofina é anormal nesse grupo de crianças. Essas anormalidades podem também ser encontradas em casos precoces de distrofia muscular de Becker e distrofia autossômica recessiva da infância. Portanto, isoladamente a imuno-histoquímica não permite a diferenciação.

The dystrophin distribution in the plasma muscle membrane using immunohystochemistry was studied in 22 children with congenital muscular dystrophy. The dystrophin was detected by immunofluorescence in muscle biopsy through a polyclonal antibody. All the cases had patchy interruptions of the fluorescence in the plasma membrane. A large patchy interruption of the sarcolemma was found in 17 cases, small interruption in 12, and a combination of large and small patchy discontinuity in 7. Small gaps around the fiber like a rosary were found in 15 cases. The frequency of these abnormalities ranged cases from: all fibers in 5 cases, frequent in 8, occasional in 5, and rare in 4. Five cases had total absence of immunofluorescence. These results suggest that the dystrophin expression is abnormal in this group of children and that this type of abnormalities can not be differentiated from early Becker muscular dystrophy nor childhood autosomal recessive muscular dystrophy through immunohystochemistry alone.

Para determinar se imuno-histoquímica com distrofina poderia melhorar a detecção de portadoras de distrofia muscular de Duchenne (DMD) e de Becker (DMB), analisamos 14 biópsias musculares de 13 portadoras prováveis ou possíveis de DMD e de uma portadora provável de DMB. Todas as mulheres foram também avaliadas usando métodos convencionais, incluindo análise genética, avaliação clínica e neurológica, níveis séricos de CK, EMG e biópsia muscular com estudo histoquímico. Em 6 casos havia um mosaico de fibras musculares distrofina-positivas e distrofina-negativas, que permitia caracterizar um estado de portadora. Comparando imuno-histoquímica com distrofina e métodos tradicionais, notou-se que este método é menos sensível que medidas de CK, mas é mais sensível que EMG e biópsia muscular. O uso deste método associado a CK, EMG e biópsia muscular aumentou ta possibilidade de detecção de portadoras. Este método é também útil para distinguir portadoras manifestantes de DMD de pacientes com outras doenças neuromusculares como a distrofia cintura-membros e amiotrofia espinhal progressiva,

To ascertain whether dystrophin immunohistochemistry could improve DMD/ BMD carrier detection, we analyzed 14 muscle biopsies from 13 DMD and one BMD probable and possible carriers. All women were also evaluated using conventional methods, including genetic analysis, clinical and neurological evaluation, serum CK levels, KMG, and muscle biopsy. In 6 cases, there was a mosaic of dystrophin-positive and dystrophin-deficient fibers that allowed to make the diagnosis of a carrier state. Comparing dystrophin immunohistochemistry to the traditional methods, it was noted that this method is less sensitive than serum CK measuremens, but is more sensitive than EMG and muscle biopsy. The use of dystrophin immunohistochemistry in addition to CK, EMG and muscle biopsy improved the accuracy of carrier detection. This method is also helpful to distinguish manifesting DMD carriers from patients with other neuromuscular diseases like limb-girdle muscular dystrophy and spinal muscular atrophy.

Foram estudados 55 casos de distrofia muscular progressiva (34 Duchenne, 12 Duchenne com distrofina residual e 9 Becker), comparando idade, época de início e tempo de sintomas, graduação na escala de Vignos e Archibald, níveis de enzimas séricas e presença de distrofina nas biópsias musculares por imunofluorescência. A intensidade dos sintomas, gravidade do quadro clínico, proliferação de tecido ccnjuntivo endomisial e infiltração por tecido adiposo estão inversamente relacionadas à quantidade de distrofina presente nas biópsias e, diretamente, à presença de fibras hipertróficas e fibras angulares escuras atróficas. Nos comentários são abordados alguns aspectos sobre a diferenciação da distrofia muscular de Duchenne e Becker, a distrofina residual nos casos de Duchenne e a importância do teste para o diagnóstico adequado.

Study of 55 cases of progressive muscular dystrophies (34 Duchenne, 12 Duchenne with residual dystrophin and 9 Becker patients) comparing age, age at the initial symptoms, duration of symptoms, levels of serum enzymes, degree of disability measured by the Vignos and Archibald scale, and the type and amount of dystrophin found in the muscle biopsies by immunofluorescence. Statistical analysis showed a tendency of the symptoms and progression of disease to be related with the low quantity of dystrophin in the biopsies. There was no difference in the parameter analysed between the Duchenne patients with, and without residual dystrophin, as well as the Duchenne with residual dystrophin and Becker patients. There was an inverse relation with the amount of dystrophin and¹ the endomysial connective tissue and fatty infilration, and a direct relation with hypertrophic fibers and atrophic angulated fibers in the NADH-tetrazolium reductase. In the comments a discussion is made about the difficulties in differentiate Duchenne and Becker dystrophies, the cases with residual dystrophin and the importance of the correct diagnosis.