Eritrocitos humanos como biomodelo farmacológico de citoprotección antioxidante para la evaluación de nuevas alternativas terapéuticas en pacientes con COVID-19 / Human erythrocytes as pharmacological biomodel of antioxidant cytoprotection for the evaluation of new therapeutic alternatives in patients with COVID-19

Introducción: El estrés oxidativo puede afectar las membranas biológicas de diferentes tipos celulares en el organismo, lo cual se ha evidenciado en los daños a los tejidos y órganos de pacientes con COVID-19, por lo cual las investigaciones recientes están relacionadas con la búsqueda de fármacos citoprotectores y antioxidantes que minimicen estos daños. Objetivo: Evaluar los eritrocitos humanos como biomodelo farmacológico de citoprotección antioxidante. Métodos: Se evaluó el modelo de citotoxicidad en eritrocitos inducido por peróxido de hidrógeno y se valoró el sistema de diagnóstico propuesto en un ensayo de citoprotección en eritrocitos, con el empleo del ácido ascórbico como sustancia de referencia. Resultados: Para la concentración de eritrocitos utilizada se logró un modelo de citotoxicidad a la concentración de 10 mM de peróxido a los 30 minutos de incubación. La sustancia de referencia empleada no mostró signos de citotoxicidad en el test de hemólisis. En el ensayo de citoprotección se evidenció un efecto farmacológico del referente, con un valor del índice de citoprotección de 12,71 µg/mL. El estudio de microscopía óptica mostró daños morfológicos severos en los eritrocitos tratados con peróxido de tipo esferocitos, equinocitos y esferoequinocitos, que disminuyeron significativamente en presencia de dicha sustancia de referencia. Conclusiones: El biomodelo farmacológico propuesto puede ser empleado en la evaluación de nuevas alternativas terapéuticas con propiedades citoprotectoras antioxidantes para el tratamiento de pacientes con COVID-19.

Introduction: The oxidative stress can affect the biological membranes of different cellular types in the organism, which has been evidenced in the damages to the tissues and organs of patients with COVID-19, reason why the recent investigations are related to the search of cytoprotector and antioxidant drugs that minimize these damages. Objective: To evaluate the human erythrocytes as pharmacological biomodel of antioxidant cytoprotection. Methods: The cytotoxicity pattern was evaluated in erythrocytes induced by peroxide of hydrogen and the system of diagnosis proposed was valued in a cytoprotection assay in erythrocytes, with the use of ascorbic acid as reference substance. Results: For the concentration of erythrocytes used a cytotoxicity model was achieved to the concentration of 10 mM of peroxide at 30 minutes of incubation. The substance of reference used didn't show cytotoxicity signs in the hemolysis test. In the cytoprotection assay a pharmacological effect of the referent was evidenced, with a value of the cytoprotection index of 12.71 µg/mL. The study of optic microscopy showed severe morphological damages in the erythrocytes treated with peroxide of spherocytes, echinocytes and spheroechinocytes type that significantly diminished in presence of this reference substance. Conclusions: The proposed pharmacological biomodel can be used in the evaluation of new therapeutic alternatives with antioxidant cytoprotector properties for the treatment of patients with COVID-19.

Clinical Applications of Additive Manufacturing Models in Neurosurgery: a Systematic Review

Introduction Three-dimensional (3D) printing technologies provide a practical and anatomical way to reproduce precise tailored-made models of the patients and of the diseases. Those models can allow surgical planning, besides training and surgical simulation in the treatment of neurosurgical diseases. Objective The aim of the present article is to review the scenario of the development of different types of available 3D printing technologies, the processes involved in the creation of biomodels, and the application of those advances in the neurosurgical field. Methods We searched for papers that addressed the clinical application of 3D printing in neurosurgery on the PubMed, Ebsco, Web of Science, Scopus, and Science Direct databases. All papers related to the use of any additivemanufacturing technique were included in the present study. Results Studies involving 3D printing in neurosurgery are concentrated on threemain areas: (1) creation of anatomical tailored-made models for planning and training; (2) development of devices and materials for the treatment of neurosurgical diseases, and (3) biological implants for tissues engineering. Biomodels are extremely useful in several branches of neurosurgery, and their use in spinal, cerebrovascular, endovascular, neuro-oncological, neuropediatric, and functional surgeries can be highlighted. Conclusions Three-dimensional printing technologies are an exclusive way for direct replication of specific pathologies of the patient. It can identify the anatomical variation and provide a way for rapid construction of training models, allowing the medical resident and the experienced neurosurgeon to practice the surgical steps before the operation.

Hallazgo necrópsico de nefroblastoma asociado a síndrome metabólico experimental / Necropsic finding of nephroblastoma associated to experimental metabolic syndrome

Introducción: El síndrome metabólico presenta entre sus manifestaciones la obesidad, la cual se encuentra relacionada con el desarrollo de cáncer. Sin embargo, no habíamos encontrado en cuatro años ningún caso de neoplasias malignas en animales con síndrome metabólico. Objetivo: Describir el desarrollo de un tumor maligno a nivel renal en modelo experimental de síndrome metabólico. Métodos: El biomodelo experimental se logró por la aplicación de una solución de sacarosa al 35 por ciento, durante 20 semanas a 50 ratas machos Wistar destetados. El diagnóstico de nefroblastoma se realizó mediante necropsia con observación morfológica de la lesión renal. Resultados: Confirmado el síndrome metabólico se detectó en un caso, una masa palpable en abdomen. En la inspección macroscópica se observó un tumor en el polo inferior del riñón derecho, color pardo grisáceo, con hemorragia y cambios quísticos. Histológicamente se observaron alteraciones propias de un nefroblastoma mixto con componentes del blastema, mesenquimal y epitelial. Conclusiones: Se describe por vez primera, en estudio anatomopatológico, la presencia de un caso de nefroblastoma en rata con síndrome metabólico experimental(AU)

Introduction: One of the manifestations of metabolic syndrome is obesity, which is in turn related to the development of cancer. However, in four years we had not found any case of malignant neoplasms in animals with metabolic syndrome. Objective: Describe the development of a malignant renal tumor in an experimental metabolic syndrome model. Methods: The experimental biomodel was made applying a 35 percent saccharose solution to 50 male weaned Wistar rats for 20 weeks. The diagnosis of nephroblastoma was achieved by necropsy with morphological observation of the renal lesion. Results: Upon metabolic syndrome confirmation, a palpable mass was detected in the abdomen of one of the cases. Macroscopic observation revealed a grayish brown tumor in the lower pole of the right kidney with hemorrhaging and cystic changes. Histological examination found alterations typical of mixed nephroblastoma with blastema, mesenchymal and epithelial components. Conclusions: This is the first time a description is provided in an anatomopathological study of a case of nephroblastoma in a rat with experimental metabolic syndrome(AU)

Volumetric computed tomography reconstruction, rapid prototyping and 3D printing of opossum head ( Didelphis albiventris ) / Reconstrucción volumétrica por tomografia computarizada, prototipado rápido e impresión 3D de cabeza de zarigüeya ( Didelphis albiventris )

Natural anatomical pieces of wild animals are rare and teachers seek alternatives in satisfactory quantity and quality to inform their students. This article aims to describe the use of multiplanar reconstructions and 3D volume rendering computed tomography (CT) images, rapid prototyping and 3D printing of opossum head to create a biomodel to veterinary education in descriptive anatomy of wild animals. A six-step method study was conducted to construct the biomodel: (1) selection of opossum head from museum; (2) CT scanning of bones structures in veterinary hospital; (3) DICOM visualization medical images in multiplanar reconstructions and 3D volume rendering; (4) .dicom file conversion to .stl; (5) 3D printing of opossum head by rapid prototyping; (6) comparison of 3D model printed with the original anatomical piece. The use of CT images with their different forms of reconstruction can provide a more comprehensive 3D view of opossum craniofacial region and allow a better understanding of head anatomy of this species. The 3D printed biomodel can be a viable alternative to original bone specimens when used in anatomy education. However, further studies must be continued to validate the method in Veterinary Medicine courses.

Las piezas anatómicas naturales de animales salvajes son raras y los profesores buscan alternativas satisfactorias, en cantidad y calidad, para enseñar a sus alumnos. Este artículo tuvo como objetivo describir el uso de la reconstrucción volumétrica por tomografía computarizada, la creación rápida de prototipos y la impresión 3D de la cabeza de zarigüeya para obtener un biomodelo en anatomía descriptiva de animales salvajes para educación veterinaria. Se realizó un estudio en seis pasos para construir el biomodelo: (1) selección de cabeza de zarigüeya del museo; (2) tomografía computarizada de estructuras óseas en hospital veterinario; (3) visualización de las imágenes médicas en DICOM por reconstrucciones multiplanares y renderización de volumen 3D; (4) conversión de archivos .dicom a .stl; (5) impresión 3D de cabeza de zarigüeya mediante prototipado rápido; (6) comparación del modelo 3D impreso con la pieza anatómica original. El uso de imágenes de tomografía computarizada, con sus diferentes formas de reconstrucción, puede proporcionar una vista 3D más completa de la región craneofacial de zarigüeya y permitir una mejor comprensión de la anatomía de la cabeza de esta especie. El biomodelo 3D impreso puede ser una alternativa viable a las muestras óseas originales cuando se utiliza en la educación de la anatomía. Sin embargo, se deben continuar los estudios para validar el método en los cursos de Medicina Veterinaria.

La leucemia linfoblástica aguda y modelos animales alternativos para su estudio en Colombia / Alternative animal models for acute lymphoblastic leukaemia studies in Colombia

Resumen El pez cebra es un modelo establecido para el estudio del desarrollo en vertebrados y es especialmente útil para la investigación del proceso de hematopoyesis y las enfermedades asociadas a esta. Los linajes principales, los genes y los procesos de desarrollo con los seres humanos son conservados. En los últimos años, el pez cebra se ha utilizado cada vez más como un modelo para estudiar enfermedades hematopoyéticas humanas, incluyendo la leucemia linfoblástica aguda. Esta revisión evidencia la importancia del estudio de esta enfermedad en Colombia debido a las diferencias de la etiología que presenta este tipo de leucemia en comparación con otros países. Además, describe la aplicación del pez cebra como una herramienta alternativa para investigaciones preclínicas de la leucemia linfoblástica aguda. Este modelo es asequible, facilita la experimentación, su manipulación es relativamente simple y tiene gran versatilidad para estudios moleculares y genéticos del cáncer y está disponible en Colombia.

Abstract The zebrafish is an established model for the study of vertebrate development, and it is specially useful for the research into haematopoiesis and diseases associated with this process. Major lineages, genes, and developmental processes are conserved between zebrafish and humans. Thus it has been increasingly used as a model for a number of haematopoietic human diseases, such as acute lymphoblastic leukaemia. This review highlights the importance of the study of this disease in Colombia, because of the differences in its aetiology compared to other countries. It also describes the application of the zebrafish as an alternative tool for pre-clinical research of acute lymphoblastic leukaemia. This model is affordable, facilitates experimentation and handling, and is extremely versatile for molecular and genetic studies into cancer, and it is now available in Colombia.

3D print of the maxillary sinus for morphological study / Impresión 3D del seno maxilar para su estudio morfológico

The maxillary sinus (MS) is described as a pyramid-shaped cavity of the maxilla. Knowledge of its morphology makes it possible to define normality and abnormality so that its three-dimensional analysis can be a valuable preoperative tool during surgery in this anatomical area. The aim of this study is to present a strategy of morphological analysis of the MS using 3D printing acquired through computed cone beam tomography (CBCT) images. A cross-sectional descriptive study was conducted, including 15 subjects (8 women and 7 men). The 3D virtual reconstruction and modeling was done on the MSs bilaterally, and 30 physical models were produced on a 3D printer. The results revealed that the MSs obtained exhibited various morphologies. An individual analysis of each MS allowed the tripod nature of the MS to be defined. We also were able to observe anatomical repairs such as the MS ostium, as well as complex areas affecting important surgical decisions. This method for creating 3D models of MSs provides a new approach to understanding the precise anatomical characteristics in these structures, which cannot be assessed in the same way on a 2D screen. It may be concluded that 3D printouts of the MS are a suitable method of preoperative analysis that can be useful in educating the patient, however, less time-consuming strategies should be explored.

El seno maxilar (SM) es una cavidad piramidal en maxila. El objetivo de este estudio es presentar una estrategia de análisis morfológico del SM utilizando impresión 3D a través de la adquisición de imágenes provenientes de tomografías computadorizadas cone beam (TCCB). Se realizó un estudio descriptivo transversal incluyendo 15 sujetos (8 mujeres y 7 hombres). Se realizó la reconstrucción y modelado virtual 3D de los SMs bilateralmente y se obtuvieron 30 modelos físicos generados en una impresora 3D. Los resultados arrojaron que los SMs obtenidos presentaban morfologías variadas, el análisis individual de cada SM permitió definir la condición tripoidal del SM, reparos anatómicos como el ostium del SM, mientras que zonas complejas relacionadas a decisiones quirúrgicas importantes pudieron ser observadas. Este método de creación de modelos 3D de SMs entrega un nuevo enfoque que permite apreciar características anatómicas precisas de estas estructuras, que no se pueden evaluar de la misma forma en una pantalla 2D. Se puede concluir que la impresión 3D de SM entrega un método de analisis prequirúrgico adecuado y que puede ser útil en la educación del paciente; otras estrategias con menor consumo de tiempo deben ser exploradas.

Manufacture of custom-made cranial implants from DICOM® images using 3D printing, CAD/CAM technology and incremental sheet forming

INTRODUCTION: This work aims to pre-operatively manufacture custom-made low-cost implants and physical models (‘biomodels’) of fractured skulls. The pre-DOI: operative manufacturing of biomodels and implants allows physicians to study and plan surgery with a greater possibility of achieving the expected result. Customization contributes to both the esthetic and functional outcome of the implant because it considers the anatomy of each patient, while the low cost allows a greater number of people to potentially benefit. METHODS: From CT images of a fractured skull, a CAD model of the skull (biomodel) and a restorative implant were constructed digitally. The biomodel was then physically constructed with 3D Printing, and Incremental Sheet Forming (ISF) was used to manufacture the implant from a sheet of pure grade 2 titanium. Before cutting the implant’s final shape from a pre-formed sheet, heat treatment was performed to avoid deformations caused by residual stresses generated during the ISF process. RESULTS: A comparison of the dimensions of the implant and its respective CAD biomodel revealed geometric discrepancies that can affect both functional and aesthetic efficiency. Nevertheless, the final shape preserved symmetry between the right and left sides of the skull. Electron microscopy analysis did not indicate the presence of elements other than pure titanium. CONCLUSION: Dimensional variability can be decreased with changes in the manufacturing process (i.e., forming and cutting) and the heating ramp. Despite biomedical characteristics, there was no contamination of the implant by harmful chemical elements. 3D Printing was effective in making the biomodel, enabling pre-operative planning and improving physician-patient communication. Current results indicate that ISF is a process that can be used to obtain custom-made implants.

Uso de guía de metil-metacrilato fabricados en biomodelo de poliuretano para el tratamiento tardío de fractura panfacial / The use of metil-metacrilate guide manufactured on biomodel of polyurethane for late treatment of panfacial fracture

El manejo de las secuelas faciales por fracturas no tratadas ha tenido un crecimiento importante debido al uso de los biomodelos. Estos permiten optimizar la cirugía, disminuir los tiempos quirúrgicos y mejorar los resultados. El presente articulo muestra un caso de secuela de fractura facial tratada con osteotomías con ayuda de guías quirúrgicos fabricados en base a un biomodelo operado; se presenta el resultado postoperatorio de 6 meses con una resolución adecuada.

The management of facial sequel by facial fractures non-treated nowadays presents an important expansion by the use of biomodels. This system can be used for reduce surgical time, optimize surgical protocol and improve outcomes. This paper presents a sequel case for facial fracture treated with bone osteotomy using surgical guide manufactured base on biomodels operated; is showing the postoperative 6 month follow-up with good results.