Primary central nervous system tumors survival in children in ten Colombian cities: a VIGICANCER report.

Purpose: Primary central nervous system (CNS) tumors are the second most common cancer in children and adolescents, leading to premature death and disability. Population-based survival estimates aid decision-making in cancer control, however data on survival for primary CNS tumors in Latin America is lacking. We describe survival rates for children with primary CNS tumors treated in ten Colombian cities. Methods: We analyzed data from children and adolescents newly diagnosed with cancer between 2012 and 2021, participating in the Childhood Cancer Clinical Outcomes Surveillance System (VIGICANCER) in ten cities in Colombia. VIGICANCER collects information on clinical outcomes from twenty-seven pediatric oncology units and conducts active follow-up every three months. VIGICANCER does not register craniopharyngiomas; we excluded intracranial germ cell tumors for this report. We used the Kaplan-Meier method to estimate the overall survival probability, stratified by sociodemographic variables, topography, WHO grading, receipt of radiation therapy, and type of surgical resection. We analyzed the prognostic capacity of variables using multivariate proportional Cox's regression, stratified by city and year of diagnosis. Results: During the study period, VIGICANCER included 989 primary CNS tumors in 879 children and 110 adolescents. The cohort median age was 9 years; 53% of patients were males, and 8% were Afro-descendants. Most common tumors were supratentorial astrocytomas (47%), astrocytic tumors (35%), medulloblastomas (20%), ependymomas (11%), and mixed and unspecified gliomas (10%). Five-year overall survival of the entire cohort was 54% (95% CI, 51-58); for supratentorial gliomas, WHO grade I was 77%, II was 62%, III-IV was 27%, respectively, and for medulloblastoma was 61%. The adjusted hazard rate ratio for patients with WHO grade III and IV, for those with subtotal resection, for brainstem location, and for those not receiving radiation therapy was 7.4 (95% CI, 4.7-11.8), 6.4 (95% CI, 4.2-9.8), 2.8 (95% 2.1-3.8), 2.0 (95% CI, 1.3-2.8) and 2.3 (95% CI, 1.7-3.0), respectively. Conclusion: We found that half of Colombia's children and adolescents with primary CNS tumors survive five years, compared to 70% to 80% in high-income countries. In addition to tumor biology and location, gross total resection was crucial for improved survival in this cohort. Systematic monitoring of survival and its determinants provides empirical data for guiding cancer control policies.

Guía de práctica clínica basada en la evidencia para el manejo de trombocitopenia inmune primaria en población pediátrica / Evidence-based clinical practice guideline for the management of primary immune thrombocytopenia (ITP) in pediatric population

Primary immune thrombocytopenia (ITP) is the most common cause of thrombocytopenia in children, with a reported incidence of 1.1-12.5 cases per 100 000 children. However, currently, there are several definitions of ITP, as well as diagnostic and therapeutic approaches. To develop an evidence-based clinical practice guideline (CPG) to standardize the definition of ITP and, in this way, reduce the variability of its diagnosis, and to provide indications for the treatment of acute, persistent, and chronic ITP in patients under 18 years of age. The CPG was prepared by a multidisciplinary group that followed the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) guidelines for developing CPGs, formulated PICO clinical questions, and conducted systematic reviews. GRADE evidence profiles were created and recommendations, with their corresponding level of evidence and strength, were made after a panel of experts assessed the benefit-risk balance, the quality of evidence, the patients' values and preferences, and the context in which they should be implemented. A total of 23 recommendations were made to pediatricians, hematologists, and health professionals working in emergency services for treating acute, persistent, and chronic ITP. Overall, the CPG has low quality of evidence, and the recommendations were made in order to improve the success rate of ITP treatment and the prognosis of children with this condition. Although ITP is the main cause of thrombocytopenia in pediatrics, to date there is not enough high-quality evidence that supports the recommendations presented here for its proper classification and treatment in children. Thus, further studies providing high-quality evidence on this issue are required.

La púrpura trombocitopénica inmunológica (PTI) es la causa más frecuente de trombocitopenia en población pediátrica, con una incidencia de 1.1 a 12.5 casos por cada 100 000 niños. Sin embargo, en la actualidad hay diferentes definiciones de PTI, así como enfoques diagnósticos y terapéuticos. Desarrollar una guía de práctica clínica (GPC) basada en la evidencia para unificar las definiciones de PTI, y de esta forma reducir la variabilidad de su diagnóstico, y para proporcionar indicaciones para el tratamiento de la PTI aguda, persistente y crónica en pacientes menores de 18 años. La GPC fue desarrollada por un grupo multidisciplinario, el cual siguió las guías GRADE para la realización de GPC, formuló preguntas clínicas PICO y realizó revisiones sistemáticas. Se crearon perfiles de evidencia GRADE y se realizaron las recomendaciones, con su respectivo nivel de evidencia y fortaleza, luego de que un panel de expertos evaluara el equilibrio beneficio-riesgo, la calidad de la evidencia, las preferencias y valoraciones de los pacientes y el contexto en el que debieran implementarse. Se formularon 23 recomendaciones para el tratamiento de la PTI aguda, persistente y crónica dirigidas a pediatras, hematólogos y profesionales de la salud que trabajan en servicios de urgencias. En general, la evidencia de la guía es de baja calidad y las recomendaciones fueron formuladas para mejorar la tasa de éxito del tratamiento de la PTI y el pronóstico de estos pacientes. A pesar de que la PTI es la principal causa de trombocitopenia en población pediátrica, actualmente no hay suficiente evidencia de alta calidad que respalde las recomendaciones aquí presentadas para su adecuada clasificación y tratamiento en niños. Por lo anterior, se requiere realizar nuevos estudios que brinden evidencia de alta calidad en el tema.

Results of the implementation of the PETHEMA LPA 99 protocol for treating children with acute promyelocytic leukemia in Bogotá, Colombia / Resultados de la implementación del protocolo PETHEMA LPA 99 en el tratamiento de niños con leucemia promielocítica aguda en Bogotá, Colombia

Abstract Introduction: In the United States, between 4 and 8% of children with acute myeloid leukemia have acute promyelocytic leukemia (APL), but a higher incidence of this malignancy has been reported in Latin America (20%-28%). The implementation of the PETHEMA LPA 99 protocol, designed for the treatment of APL in adults, has shown an overall survival (OS) >80%. Objective: To describe the results obtained after the implementation of the PETHEMA LPA 99 protocol to treat children with APL at the Fundación Hospital Pediátrico La Misericordia in Bogotá, D.C., Colombia. Materials and methods: Descriptive and retrospective cohort study. The medical records of 30 pediatric patients (<18 years) with APL, who were treated using the PETHEMA LPA 99 protocol between January 2005 and December 2012, were reviewed. Data on the following variables were obtained: early death, death during induction therapy, OS, event-free survival (EFS), and relapse. Results: The male sex was predominant (60%) among the 30 patients included in the study. Regarding risk classification, 13 (43%) were classified as high-risk patients, 12 (40%) as medium-risk, and 5 (17%) as low-risk. Seven individuals died: 2 before receiving cancer treatment, 2 during induction therapy, and 3 after relapse. Relapse was reported in 5 patients. There were no deaths during the consolidation or maintenance phases. OS was 75.4% (95%CI: 55.1-87.5) and EFS was 64.3% (95%CI: 40-80.5). Moreover, OS at 11 years was 80%, 91.7%, and 59.2% for low-risk, intermediate-risk, and high-risk patients, respectively. The median follow-up time was 6.35 years (0-11.43 years). Conclusions: In general, the implementation of the PETHEMA LPA 99 protocol to treat APL in the study population showed very satisfactory results. Therefore, its use in pediatric population is recommended, taking into account the adjustments described in the protocol regarding the characteristics of this age group.

Resumen Introducción. En Estados Unidos de América, entre 4 y 8% de niños con leucemias mieloides agudas tienen leucemia promielocítica aguda (LPA), mientras que en Latinoamérica se ha descrito una mayor incidencia de esta neoplasia (20-28%). La implementación del protocolo PETHEMA LPA 99, diseñado para el tratamiento de LPA en adultos, ha mostrado una supervivencia global (SG) >80%. Objetivo. Describir los resultados de la aplicación del protocolo PETHEMA LPA 99 en el tratamiento de niños con LPA en la Fundación Hospital Pediátrico la Misericordia, en Bogotá D.C., Colombia. Materiales y métodos. Estudio de cohorte descriptivo y retrospectivo. Se revisaron las historias clínicas de 30 pacientes pediátricos (<18 años) con LPA que recibieron tratamiento mediante el protocolo PETHEMA LPA 99 entre enero de 2005 y diciembre de 2012. Se obtuvieron datos sobre las siguientes variables: muerte temprana, muerte en terapia de inducción, SG, supervivencia libre de evento (SLE) y recaída. Resultados. De los 30 pacientes, la mayoría eran de sexo masculino (60%). Respecto a la clasificación de riesgo, 13 (43%) fueron clasificados como pacientes de riesgo alto; 12 (40%), de riesgo intermedio, y 5 (17%), de riesgo bajo. 7 individuos murieron: 2 antes del tratamiento oncológico, 2 durante la terapia de inducción y 3 luego de presentar recaída. Se reportó recaída en 5 pacientes. No hubo muertes durante las fases de consolidación o de mantenimiento. La SG fue de 75.4% (IC95%: 55.1-87.5) y la SLE fue de 64.3% (IC95%: 40-80.5). La SG a 11 años fue de 80%, 91.7% y 59.2% para los pacientes de riesgo bajo, riesgo intermedio y riesgo alto, respectivamente. La mediana de seguimiento fue 6.35 años (0-11.43 años). Conclusiones. En general, la implementación del protocolo PETHEMA LPA 99 en el tratamiento de la LPA en la población de estudio mostró resultados muy satisfactorios, por lo que se recomienda su uso en población pediátrica, teniendo en cuenta los ajustes recomendados por el protocolo en relación con las características de este grupo etario.

Reactivation of Chagas disease after autologous hematopoietic stem cell transplantation

Abstract Chagas disease (CD) is a protozoan zoonosis caused by Trypanosoma cruzi. Reactivation of CD occurs via drug-induced immunosuppression before and during transplantation. Here, we report the case of a 62-year-old man diagnosed with classic Hodgkin lymphoma who received highly aggressive conditioning chemotherapy before undergoing stem cell transplantation (SCT). The patient tested positive for CD in pre-transplantation evaluation. The patient exhibited persistent fever and elevated C-reactive protein levels before and after SCT, and was treated with antibiotics. Micro-Strout test showed evidence of trypomastigotes and he was treated with benznidazole until tested negative. Post-transplantation seropositive patients should be screened for possible reactivation.

Reactivation of Chagas disease after autologous hematopoietic stem cell transplantation.

Chagas disease (CD) is a protozoan zoonosis caused by Trypanosoma cruzi. Reactivation of CD occurs via drug-induced immunosuppression before and during transplantation. Here, we report the case of a 62-year-old man diagnosed with classic Hodgkin lymphoma who received highly aggressive conditioning chemotherapy before undergoing stem cell transplantation (SCT). The patient tested positive for CD in pre-transplantation evaluation. The patient exhibited persistent fever and elevated C-reactive protein levels before and after SCT, and was treated with antibiotics. Micro-Strout test showed evidence of trypomastigotes and he was treated with benznidazole until tested negative. Post-transplantation seropositive patients should be screened for possible reactivation.

Hidroxicloroquina para manejo de infección por SARS-CoV-2 Una revisión exploratoria / Hydroxychloroquine for treatment of SARS-CoV-2 infection An exploratory review

Resumen Introducción: la hidroxicloroquina se ha venido postulando en estos tiempos de pandemia como posible tratamiento eficaz frente a COVID-19. Esto ya que se ha demostrado por expertos chinos su capacidad para inhibir la replicación viral usando distintos mecanismos. En este momento es de vital importancia tener conocimiento acerca de las últimas investigaciones y ensayos clínicos en lo que respecta a un esquema de tratamiento efectivo que ayude a un mejor manejo de pacientes con infección por SARS-CoV-2. Objetivo: presentar la información disponible sobre el uso de hidroxicloroquina como opción de manejo para pacientes infectados por SARS-CoV-2. Material y métodos: se realizó una revisión siguiendo el marco metodológico sugerido por Arksey y O'Malley. Las bases de datos utilizadas fueron: PubMed, MedLine, Lilacs, Scopus, Clinical Trials, Cochrane y CNKI. Se incluyeron únicamente textos en español e inglés, finalmente se realizó una caracterización y resumen de los estudios pertinentes para esta revisión. Resultados: se incluyeron en la revisión 87 artículos académicos incluyendo estudios experimentales y no experimentales; todos con evidencia sobre el uso de hidroxicloroquina en COVID-19. Conclusiones: A la fecha no hay información científica disponible que sustente y tenga la suficiente evidencia para soportar el uso de la hidroxicloroquina como tratamiento farmacológico en la pandemia actual. Dos ensayos clínicos aleatorizados se contradicen en cuanto a la efectividad de la hidroxicloroquina; sin embargo, ambos comparten errores metodológicos y tamaños de muestra limitados; y un único ensayo no aleatorizado con los mismos errores demuestra efectividad de la hidroxicloroquina. En cuanto al perfil de seguridad se cuenta con información que evidencia una menor tasa de efectos adversos de la hidroxicloroquina frente a la cloroquina por lo que se preferiría su uso en caso de demostrar efectividad frente a COVID-19. Existen varios ensayos clínicos aleatorizados en curso que se espera esclarezcan las dudas que surgen al revisar la literatura.(Acta Med Colomb 2020; 45. DOI:https://doi.org/10.36104/amc.2020.1880).

Abstract Introduction: hydroxychloroquine has been recommended in this pandemic as a possible effective treatment for COVID-19. This is because Chinese experts have demonstrated its ability to inhibit viral replication through various mechanisms. At this juncture, it is vitally important to understand the latest research and clinical trials regarding an effective treatment regimen which would help improve the treatment of patients with SARS-CoV-2 infection. Objective: to present the available information regarding the use of hydroxychloroquine as a treatment option for patients infected with SARS-CoV-2. Material and methods: a review was carried out following the methodological framework proposed by Arksey and O'Malley. The data bases used were: PubMed, MedLine, Lilacs, Scopus, Clinical Trials, Cochrane and CNKI. Only texts in Spanish and English were included. Finally, the pertinent studies for this review were described and summarized. Results: a total of 87 academic articles were included in the review, including experimental and non-experimental studies, all containing evidence regarding the use of hydroxychloroquine in COVID-19. Conclusions: To date, there is no available substantiating scientific data with enough evidence to support the use of hydroxychloroquine as a pharmacological treatment for the current pandemic. Two randomized clinical trials contradict each other regarding the efficacy of hydroxychloroquine. However, they both share methodological errors and have small sample sizes. A single nonrandomized trial with the same errors shows efficacy of hydroxychloroquine. As far as the safety profile, there is data showing a lower rate of adverse effects for hydroxychloroquine compared with chloroquine, so its use would be preferred if it were to be proven effective against COVID-19. There are several randomized clinical trials underway which, it is hoped, will answer the questions raised by the literature review.(Acta Med Colomb 2020; 45. DOI:https://doi.org/10.36104/amc.2020.1880).

Loss surface of XOR artificial neural networks.

Training an artificial neural network involves an optimization process over the landscape defined by the cost (loss) as a function of the network parameters. We explore these landscapes using optimization tools developed for potential energy landscapes in molecular science. The number of local minima and transition states (saddle points of index one), as well as the ratio of transition states to minima, grow rapidly with the number of nodes in the network. There is also a strong dependence on the regularization parameter, with the landscape becoming more convex (fewer minima) as the regularization term increases. We demonstrate that in our formulation, stationary points for networks with N_{h} hidden nodes, including the minimal network required to fit the XOR data, are also stationary points for networks with N_{h}+1 hidden nodes when all the weights involving the additional node are zero. Hence, smaller networks trained on XOR data are embedded in the landscapes of larger networks. Our results clarify certain aspects of the classification and sensitivity (to perturbations in the input data) of minima and saddle points for this system, and may provide insight into dropout and network compression.

Rabdomiosarcoma de oído: Experiencia en la Fundación Hospital de la Misericordia / Ear rhabdomyosarcoma: Fundacion Hospital de la Misericordia Experience

Los rabdomiosarcomas son el tercer tumor sólido extracraneal más frecuente durante la niñez y el sarcoma más frecuente durante este periodo. 1/3 de estos tumores compromete las áreas en cabeza y cuello y solo un 4% compromete el oído medio como su sitio primario. La Fundación Hospital de La Misericordia (HOMI) en un centro hospitalario de cuarto nivel comprometido con la atención integral de la población pediátrica y es un centro de remisión nacional para el manejo de patologías de alta complejidad. Se realiza una revisión de casos de rabdomiosarcoma de oído de esta institución y una revisión de la literatura de esta patología para socializar los síntomas y pronóstico de esta patología en Colombia.

The rhabdomiosarcoma is the third most frequent extracraneal solid tumor in childhood and is the most frequent sarcoma in this age group. 1/3 of these comprise the head and neck area, and only 4% are present in the middle ear as its primary site. The Fundación Hospital de La Misericordia (HOMI) is a 4th level hospital committed with the attention of pediatric population and it is a national referral center for the management of high complexity pathologies. We will make a revision of ear rhabdomiosarcoma at our institution and a review of the literature to socialize symptoms and pronostic factors in Colombia.

Bacteriemia asociada a catéter por Cupriavidus pauculus / Cupriavidus pauculus catheter related bacteremia

Cupriavidus pauculus es un bacilo Gram negativo con metabolismo oxidativo, que se ha aislado de muestras de agua y suelo, pero raramente de personas como entidad clínica. En la literatura científica existen menos de veinte artículos de reportes de caso de este microorganismo. La mayoría han sido pacientes con algún tipo de inmunosupresión, sometidos a procedimientos invasivos, especialmente de tipo vascular, y que han requerido múltiple manejo antibiótico. Cupriavidus pauculus ha mostrado baja virulencia y sensibilidad antibiótica, principalmente a trimetoprim-sulfametoxazol, betalactámicos de amplio espectro y quinolonas. Se presenta el caso de una paciente de 55 años con antecedentes de trasplante renal, que ingresó con infección de tejidos blandos y a quien se le diagnosticó bacteriemia asociada a catéter por C. pauculus durante la hospitalización.

Cupriavidus pauculus it’s a gram-negative bacillus with an oxidative metabolism that has been isolated in water and soil samples, but rarely in people clinical entities. There are less than 20 articles case-reported about this microorganism. Most of which have been patients with some type of immune impairment, mostly subjects with invasive vascular procedures, who had required multiples antibiotic management. Cupriavidus pauculus has mainly shown a low virulence and antibiotic sensibility to trimethoprim-sulfametoxazol, broad spectrum betalactamics and quinolones. As presented in the case of a 55 year old patient with renal transplantation history admitted with a soft tissue infection and diagnosed with a catheter associated bacteremia by C. pauculus, during hospitalization.

Crecimiento de plantas de papa (Solanum tuberosum L.) Cv. Alpha, inducido por diversas soluciones salinas. / Growth of potato plants (Solanum tuberosum L.) Cv. Alpha induced by diverse salinity solutions. / Crecimiento de plantas de batata (Solanum tuberosum L.) Cv. Alpha, inducido por diversas soluções salinas

Se estudió en macetas el crecimiento de plantas de papa (Solanum tuberosum L.) cv. Alpha, en condiciones de estrés inducido por sales (NaCl, NaHCO3, Na2SO4, CaCl2·2H2O, MgCl2·6H2O y MgSO4·7H2O) y por las salinidades sulfático-clorhídrica, clorhídrico-sulfática y sulfático-sódica, a concentraciones de 0,00 a 9,60g·l-1. Cada sal y tipo de salinidad produjo un retardo diferencial de la emergencia de brotes, en íntima relación con su porcentaje de brotación analizado en la fase experimental anterior. Dicho retraso obedece a 1) el efecto osmótico de NaCl, Na2SO4, CaCl2·2H2O, salinidades clorhídrico-sulfática y sulfático-clorhídrica, y 2) al efecto tóxico de MgCl2·6H2O, MgSO4·7H2O, NaHCO3 y salinidad sulfático-sódica. Ambos efectos incrementan el periodo de quiescencia de los tubérculos, siendo más agudo el efecto tóxico de las sales sódico-alcalinas. El estrés salino prolongó la duración de las etapas de crecimiento vegetativo y retrasó la iniciación de tubérculos. El escaso desarrollo foliar al momento de la iniciación de los tubérculos originó una lenta tasa de crecimiento de los mismos, produciendo papa pequeña. El fenómeno fue más pronunciado en las plantas sometidas a salinidad sulfático-sódica y NaHCO3, a concentraciones superiores a 3,84g·l-1, donde se formaron plantas con enanismo y ausencia de tubérculos.

The growth of potato plants (Solanum tuberosum L.) cv. Alpha was studied in stress conditions induced by salts (NaCl, NaHCO3, Na2SO4, CaCl2·2H2O, MgCl2·6H2O and MgSO4·7H2O) and by sulphatic-chlorhidric, chlorhidric-sulphatic and sulphatic-sodic salinities, in concentrations ranging from 0.00 to 9.60gl-1. Each salt and salinity produced a differential retardation in sprouts emergence, closely related with the sprouting percentage analyzed in a previous experiment. This retardation is due to 1) the osmotic effect of NaCl, Na2SO4, CaCl2·2H2O, sulphatic-chlorhidric salinity and chlorhidric-sulphatic salinity, and 2) the toxic effect of MgCl2·6H2O, MgSO4·7H2O, NaHCO3 and sulphatic-sodic salinity. Both effects increase the dormancy period of the tubers, and generally the toxic effect of alkaline-sodic salts is more intense. The saline effect extended the phase of vegetative growth and retarded tuber initiation. The poor development of leaves in the tubers initiation period caused a slow rate of growth of the potato tubers and small potatoes were produced. The phenomenon was more pronounced in plants subjected to sulphatic-sodic salinity and NaHCO3 in concentrations higher than 3.84g·l-1, when dwarf plants and plants without tubers were produced.

Foi estudado, em vasos experimentais, o crecimiento de plantas de batata (Solanum tuberosum L.) cv. Alpha, en condições de estresse inducido por sais de NaCl, NaHCO3, Na2SO4, CaCl2·2H2O, MgCl2·6H2O e MgSO4·7H2O e salinidades sulfático-clorhídrica, clorhídrico-sulfática y sulfático-sódica, em concentrações de 0.00 a 9.60 g L-1. Cada sal e tipo de salinidade produciu uma demora diferencial da emergência de rebentos ou brotos, em íntima relaçao com a sua percentagem de brotação, analisada na primeira fase experimental (Sánchez et al., 2003). Dita demora obedece a: 1) o efeito osmótico das sais NaCl, Na2SO4, CaCl2·2H2O, salinidades clorhídrico-sulfática e sulfático-clorhídrica, e 2) ao efeito tóxico das sais MgCl2·6H2O, MgSO4·7H2O, NaHCO3 e á salinidade sulfático-sódica; ambos efeitos vão incrementar o periodo de quiesencia dos tubérculos, tornando mais agudo o efeito tóxico das sais sódico-alcalinas. O estresse salino prolongou a duração das etapas de crescimento vegetativo, a de iniciación de tubérculos. O escaso desenvolvimiento foliar no momento da iniciação dos tubérculos, deu origem a uma lenta tasa de crecimiento dos mesmos, producindo batata pequena; o fenómeno foi mais pronunciado nas plantas sometidas a salinidade sulfático-sódica e NaHCO3, em concentrações superiores a 3,84g·l-1. aonde se formaram plantas con nanismo e ausênicia de tubérculos.

Antenas de baja temperatura de ruido

Contenido: Cap.1 Introduccion Cap.2 Reduccion de la temperatura de ruido en las antenas Cap.3 Diseño del modador CAp.4 Optimizacion de la antena aoplada con modador Cap.5 Aplicacion a las microondas. Conclusiones.