[Translated article] Mechanical resistance of polylactic acid bone matrices developed by 3D printing for the reconstruction of bone defects.

INTRODUCTION: Bone defects are one of the main limitations in orthopaedic surgery and traumatology. For this reason, multiple bone replacement systems have been developed, either by prosthetic implant or by substitution with osteoforming substances, whose limitations are their survival and lack of structurality, respectively. The objective of this work is the generation of a new material for the creation of biologically active structures that have sufficient tensile strength to maintain the structure during remodelling. MATERIAL AND METHODS: A new filament based on the fusion of natural polylactide acid (PLA) powder was designed for the generation of pieces by means of fused deposition modelling (FDM) on which to carry out tensile mechanical tests of osteosynthesis material. A total of 13 groups with different cortical thickness, filling and layer height were carried out, with 10 tensile tests in each group, defining the tensile breaking limit for each group. The regression lines for each group and their mechanical resistance to traction on the filament used were determined. RESULTS: The filament ratio per contact surface unit with the osteosynthesis used was the main determinant of the mechanical resistance to traction, either at the expense of the increase in cortical thickness or by the increase in the percentage of cancellous bone filling. Layer height had a minor effect on tensile strength. The regression value was high for cortical thickness and cancellous filling, being elements with a predictable biomechanical behaviour. CONCLUSIONS: The new methodology allows the creation of personalised neutral and implantable PLA bone matrices for the reconstruction of large bone defects by means of 3D printing by FDM with a mechanical resistance to traction greater than that of current biological support structures.

Efectividad y seguridad de los nuevos anticuerpos monoclonales en la profilaxis de la migraña / Effectiveness and safety of new monoclonal antibodies in migraine prophylaxis

Objetivos: Analizar la efectividad y seguridad en vida real de los nuevos anticuerpos monoclonales subcutáneos para la profilaxis de la migraña. Métodos: Estudio observacional retrospectivo llevado a cabo desde enero de 2020 hasta abril de 2021 con pacientes diagnosticados de migraña crónica o episódica. Las variables de interés se analizaron por el personal facultativo farmacéutico en una base de datos anonimizada. Esta base se completa como práctica clínica habitual durante la entrevista clínica en la consulta de pacientes externos. Resultados: Se analizaron 53 pacientes. Se observó una reducción del número de crisis respecto al valor basal a los 3, a los 6 y a los 12 meses de tratamiento, así como de otros fármacos para el tratamiento de la migraña. La mayoría de reacciones adversas descritas fueron de tipo leve, obligando a la suspensión del tratamiento de solo uno de los pacientes. Se describió un aumento de la tensión arterial en varios pacientes, así como una incidencia de estreñimiento superior a los ensayos pivotales. Conclusiones: Este estudio muestra una disminución del número de crisis de migraña y del uso de otros fármacos antimigrañosos tras el uso de anticuerpos monoclonales. Los tratamientos se pueden considerar seguros, observándose una baja incidencia de reacciones adversas graves. La mayoría de pacientes fueron tratados con erenumab. Se dispone de menos datos a medida que avanza del tiempo de estudio, por lo que resulta necesario recopilar más información para conocer el perfil de efectividad y seguridad de estos fármacos a largo plazo.(AU)

Objectives: To analyse the effectiveness and safety in real life of new subcutaneous monoclonal antibodies for the prophylaxis of migraine. Methods: Retrospective observational study conducted from January 2020 to April 2021 with patients diagnosed with chronic or episodic migraine. The variables of interest were collected by the pharmacist in an anonymised database during the clinical interview in the outpatient clinic. This databased is completed as standard clinical practice during the clinical interview in the outpatient clinic. Results: 53 patients were analysed. A reduction in the number of attacks from baseline was observed at 3, 6 and 12 months of treatment, as well as for other migraine treatment drugs. Most of the adverse reactions described were mild, leading to discontinuation of treatment in only one patient. An increase in blood pressure was reported in several patients, as well as a higher incidence of constipation than in pivotal trials. Conclusions: This study shows a decrease in the number of migraine attacks and in the use of other anti-migraine drugs after the use of monoclonal antibodies. The treatments can be considered safe, with a low incidence of serious adverse reactions. Most patients were treated with erenumab. Less information is available as the study time progresses, so more information needs to be collected to understand the long-term effectiveness and safety profile of these drugs.(AU)

Antimicrobial evaluation of silver nanoparticles using extracts of Crescentia cujete L.

New natural reducing agents with a lower negative impact on the environment and with a high antimicrobial potential are required for the process of obtaining silver nanoparticles through the chemical reduction method. The use of plant extracts can be a fast track in the formation of nanoparticles. In this case, organic compounds such as terpenes, flavonoids, enzymes, proteins, and cofactors present in plants act as reducing agents for nanomaterials. This research evaluated the antimicrobial property of silver nanoparticles from extracts of Crescentia cujete L. The presence of quercetin (flavonoid) was determined by high-performance liquid chromatography (HPLC); the production of silver nanoparticles (AgNPs) was established by green synthesis; the size and morphology of the nanomaterials were evaluated by scanning electron microscope (SEM). The antimicrobial capacity was studied by two analysis methods: modified culture medium and surface seeding. The presence of quercetin (26.55 mg L-1) in the crude extract of Crescentia cujete L., identified by HPLC, was evidenced. Nanoparticle formation was spherical, with an average size of 250 ± 3 and 460 ± 6 nm. Microbiological cultures with treatment showed 94% microbial inhibition. It was concluded that the Crescentia cujete L., leaves shoed an acceptable concentration of quercetin to be used as a useful adjuvant to enhance the reduction of NPs synthesis. The nanoparticles produced by green synthesis proved to have a positive effect to combat pathogenic microorganisms.

Synthesis of bis-furyl-pyrrolo[3,4-b]pyridin-5-ones via Ugi-Zhu reaction and in vitro activity assays against human SARS-CoV-2 and in silico studies on its main proteins.

An Ugi-Zhu three-component reaction (UZ-3CR) coupled in one pot manner to a cascade process (N-acylation/aza Diels-Alder cycloaddition/decarboxylation/dehydration) was performed to synthesize a series of bis-furyl-pyrrolo[3,4-b]pyridin-5-ones in 45 to 82% overall yields using ytterbium triflate as a catalyst, toluene as a solvent, and microwaves as a heat source. The synthesized molecules were evaluated in vitro against human SARS-CoV-2 through a time-of-addition approach, finding that compound 1e, at a concentration of 10.0 µM, exhibited a significant reduction at the initial infection stages, thus showing prophylactic potential. On the other hand, it was found that compound 1d, at the same concentration, was significantly active when applied post-infection, thus exhibiting a therapeutic profile. Moreover, compound 1f showed both, prophylactic and therapeutic activity. Then, to understand interactions between synthesized compounds and the main proteins related to the virus, docking studies were performed on spike-glycoprotein, main-protease, and Nsp3 protein, finding moderate to strong binding energies, matching accurately with the in vitro results. Additionally, a pharmacophore model was computed behind further rational drug design.

Mechanical resistance of polylactic acid bone matrices developed by 3D printing for the reconstruction of bone defects. / Resistencia mecánica de matrices óseas de ácido poliláctico desarrolladas por impresión 3D para la reconstrucción de defectos óseos.

INTRODUCTION: Bone defects are one of the main limitations in orthopedic surgery and traumatology. For this reason, multiple bone replacement systems have been developed, either by prosthetic implant or by substitution with osteoforming substances, whose limitations are their survival and lack of structurality, respectively. The objective of this work is the generation of a new material for the creation of biologically active structures that have sufficient tensile strength to maintain the structure during remodeling. MATERIAL AND METHODS: A new filament based on the fusion of natural polylactide acid (PLA) powder was designed for the generation of pieces by means of fused deposition modeling (FDM) on which to carry out tensile mechanical tests of osteosynthesis material. A total of 13 groups with different cortical thickness, filling and layer height were carried out, with 10 tensile tests in each group, defining the tensile breaking limit for each group. The regression lines for each group and their mechanical resistance to traction on the filament used were determined. RESULTS: The filament ratio per contact surface unit with the osteosynthesis used was the main determinant of the mechanical resistance to traction, either at the expense of the increase in cortical thickness or by the increase in the percentage of cancellous bone filling. Layer height had a minor effect on tensile strength. The regression value was high for cortical thickness and cancellous filling, being elements with a predictable biomechanical behavior. CONCLUSIONS: The new methodology allows the creation of personalized neutral and implantable PLA bone matrices for the reconstruction of large bone defects by means of 3D printing by FDM with a mechanical resistance to traction greater than that of current biological support structures.

Use of a recombinant positive control in the diagnostic of canine Ehrlichiosis from 16sRNA gen of Ehrlichia canis in Mexico City.

Ehrlichia canis has gained importance over the years as a zoonotic bacterium, nevertheless in Mexico is unknown the extent of the problem in animals and public health. The country had a few studies carried out locally using serology and molecular tests as diagnostic methods. Ehrlichiosis is not considered endemic in the central valley of Mexico, because the climatic conditions in the region have not allowed the vector (Rhipicephalus sanguineus) to establish itself adequately, therefore, diagnosis is not used in clinical practice in this area. A nested PCR (nPCR) offers rapid results with high sensitivity and specificity regardless of cost. The use of a recombinant positive control provides the advantage of timely diagnosis, follow-up treatment and allows the clinician to decide. In this work, the nPCR reported by Wen et al. (J Clin Microbiol 35(7):1852-2185, 1997) was used for the diagnosis of E. canis by modifying the reaction conditions to improve the detection of the test. We constructed a recombinant positive control to nPCR as diagnostic technique for E. canis, also we modified the reaction conditions to improve detection of the test which allowed the diagnosis of E. canis in dogs in the Mexican Republic using 53 samples from dogs with positive serological diagnosis of Ehrlichiosis, some of them from the valley of Mexico. Currently, this nPCR is offered to public at the Faculty of Veterinary Medicine and Zootechnics of the National Autonomous University of Mexico at an accessible cost and allows to begin to generate epidemiological information to know distribution of the bacterium.

Satisfacción laboral de los profesionales de enfermería en un hospital de segundo nivel, en la Ciudad de México / Job satisfaction of nursing professionals in a second level hospital, in Mexico City

Objetivo: Analizar la satisfacción laboral de los profesionales de enfermería en un hospital de segundo nivel de la Ciudad de México. Marco teórico: La satisfacción laboral es un estado emocional positivo basado en la percepción subjetiva del propio trabajo, de acuerdo con la actitud frente al mismo, así como con las creencias y valores de la persona. Material y métodos: Estudio de carácter cuantitativo, no experimental, transversal, prolectivo, descriptivo y diagnóstico. La variable estudiada fue la satisfacción laboral. El universo se conformó por 530 profesionales de enfermería y la muestra por 200 de ellos. Resultados: 52.50% del personal de enfermería está satisfecho con su trabajo, 63.50% consideran que el trabajo que realizan es de mucho valor y 40% piensan que ocasionalmente carecen del tiempo necesario para realizar sus actividades. Discusión: 52.50% del personal de enfermería está satisfecho con su trabajo, lo que contrasta con la investigación de Pérez Fonseca y cols., en la cual se reporta 83.10% del personal de enfermería insatisfecho. Conclusiones: Los profesionales de enfermería del hospital de segundo nivel están satisfechos con el trabajo que realizan. Sin embargo, conviene monitorear de forma continua las áreas que causan insatisfacción para corregirlas en favor del personal de enfermería y de los pacientes

Objective: To analyze job satisfaction in nursing professionals at a second level hospital in Mexico City. Theoretical Framework: Job satisfaction is a positive emotional state based on the subjective perception of one's own work, according to the attitude toward it, as well as the person's beliefs and values. Material and methods: Quantitative, experimental, transversal, prolective, descriptive and diagnostic study. The variable was job satisfaction. The universe was confirmed by 530 nursing professionals, and the sample by 200 nursing professionals. Results: 52.50% of the nursing staff were satisfied with their work, 63.50% considered that the work they do is of great value, and 40% believed that occasionally they lack the necessary time to carry out their activities. Discussion: 52.50% of the nursing staff were satisfied with their work, which differs from the research by Pérez Ma. y Cols. that report 83.10% of dissatisfied staff. Conclusions: Nursing professionals at a second level hospital were satisfied with the work they do. However, it would be advisable to continuously monitor the areas that cause dissatisfaction in order to improve them in favor of the nursing staff and patient.

Pronación: Tecnología de enfermería que produce bienestar en el cuidado de los pacientes COVID-19, en el Hospital General Dr. Manuel Gea González en la Ciudad de México / Pronation: A nursing technology that promotes wellbeing among COVID-19 patients at General Hospital Dr. Manuel Gea Gonzalez in México City

Introduction: pronation is a procedure used at the Intensive Care Unit with patients presenting Acute Respiratory Distress Syndrome (ARDS) with severe hypoxemia. Bibliographical references clearly support the application of this procedure due to the improvement it produces in oxygenation and the increased survival rate in patients. The main foundation behind this technology is that Ventral Decubitus (VD) promotes an improved redistribution of ventilation toward the dorsal regions of the lung, which are mainly collapsed during Dorsal Decubitus. Nursing staff have used this procedure because VD has proven to be a strategy with a useful and accessible impact over respiratory physiology. Objective: to analyze Pronation as a nursing technology and its promotion of COVID-19 patients' wellbeing at the General Hospital Dr. Manuel Gea González, in Mexico City. Material and methods: a nonexperimental, quantitative, cross-sectional, prolective, descriptive study to analyze pronation, as a nursing technology that promotes wellbeing in the care of COVID-19 patients at General Hospital Dr. Manuel Gea González, in Mexico City. Pronation as a nursing technology was the variable being measured. The universe was 530 nursing professionals working at the Hospital. The population and sample were 52 nursing specialists working with COVID-19 patients, representing 9.81% of the Universe. Results: as for training and experience with Pronation, 50% of the staff consider they have received sufficient training in regards to the SARS-CoV-2 virus, but they are still under training. Additionally, 84.62 % consider that Pronation promotes a remarkable recovery in the patients, with oxygen saturations between 80 to 100 %; 71.16 % believe that patients do show hemodynamic instability due to the position shift, but not in every case; and 80.77 % consider they make sure their patients do not develop pressure ulcers, given that 65.39 % practice patient hygiene and movement to prevent such ulcers. Discussion: from the interviewed staff, 50.01 % consider they have received sufficient training regarding COVID and the pronation of patients. This is consistent with Hernandez et al., who describe the need of a team trained specifically on the procedure, preferably comprised of Nurses specialized in Intensive Care. Likewise, 84.62% of staff members believe Pronation improves oxygen saturation in patients from 80% to 100%, this is contrasted with Barrantes and Vargas, who indicate that if Pronation does not result in 5% improvement in oxygen saturation, the patient must be returned to dorsal decubitus. Conclusion: ventilation in prone position is a pulmonary protective action used for over 30 years that produces an evident and continuous improvement in blood oxygenation and the respiratory physiology. Therefore, nursing specialists caring for COVID-19 patients recommend its use.

Introducción: la pronación es una maniobra utilizada en las unidades de cuidados intensivos, en pacientes que presentan síndrome de distrés respiratorio agudo (SDRA), cuando la hipoxemia es severa. Apoyada por una sólida evidencia científica, tiene impacto en la forma en que se ventila a los pacientes como parámetro de seguridad, esto aumenta la supervivencia. Objetivo: analizar la pronación, como tecnología de enfermería, que produce bienestar en el cuidado de los pacientes COVID-19, en el Hospital General Dr. Manuel Gea González, en la Ciudad de México. Material y métodos: estudio de carácter cuantitativo, no experimental, transversal, prospectivo, descriptivo. Variable medida: la pronación, como tecnología de enfermería. El universo 530 profesionales de enfermería que trabajan en el hospital, muestra: 52 especialistas de enfermería que trabajan con pacientes COVID-19. Resultados: en relación a la capacitación y experiencia en pronación, el 50% del personal manifiestan que sí recibieron suficiente capacitación sobre el virus SARS-CoV-2, aunque siguen capacitándose en ésta área; el 84.62 % consideran que en la pronación, los pacientes mejoran bastante, saturando entre el 80 y 100 % de oxígeno y el 80.77 % siempre cuidan que los pacientes no tengan úlceras por presión.Discusión: el 50.01 % del personal entrevistado manifiesta que sí recibió suficiente capacitación sobre la COVID-19 para pronar a los pacientes, lo que es semejante a la investigación de Hernández GD., et al.¹ Conclusión: la ventilación en posición prono es una medida de protección pulmonar utilizada hace más de 30 años que produce una mejoría evidente y sostenida de la oxigenación de la sangre y en la fisiología respiratoria, por lo que los especialistas de enfermería que atiende pacientes COVID-19 recomiendan su aplicación, pues está asociada al aumento de probabilidad de supervivencia.

Coexistence of genetically modified seed production and organic farming in Chile.

The seed industry in Chile has thrived since the implementation of a stringent, voluntarily self-imposed coexistence strategy between genetically modified organisms (GMOs) and non-GMO seed activities. GMO varieties of maize, soybean, and canola represent the vast majority of biotech seeds produced in Chile. Chile's exports of genetically modified (GM) seeds and organically grown food products (which excludes GM seeds and materials) continue to expand. Organic Chilean farmers predominantly produce and export fruits such as blueberries, wine grapes, and apples. Under normal agricultural conditions, the inadvertent presence of GMOs in non-GMO or organic crops cannot be ruled out. Producers of organic foods are required to implement stringent measures to minimize contact with any non-organic crop, regardless of whether these crops are GM. Only very small amounts of organic maize, soybean, and canola - if any - have been produced in Chile in recent years. Given the characteristics and nature of Chile's agriculture, the direct impact of the GM seed industry on organic farming in Chile is likely to be negligible. The Chilean experience with coexistence between GM seed and organic industries may inform other countries interested in providing its farmers with alternative agricultural production systems.

Soft matter dynamics: A versatile microgravity platform to study dynamics in soft matter.

We describe an experiment container with light scattering and imaging diagnostics for experiments on soft matter aboard the International Space Station (ISS). The suite of measurement capabilities can be used to study different materials in exchangeable sample cell units. The currently available sample cell units and future possibilities for foams, granular media, and emulsions are presented in addition to an overview of the design and the diagnostics of the experiment container. First results from measurements performed on ground and during the commissioning aboard the ISS highlight the capabilities of the experiment container to study the different materials.

Implementation of a Postfracture Care Program in a Private Hospital in Colombia.

PURPOSE: To describe the implementation of a postfracture care program in a private hospital in Colombia, the results achieved after the program's first year, and the challenges encountered. METHODS: A cross-sectional descriptive study of the first year's outcomes. The program was implemented following best practices described in the "Capture the Fracture" framework. We assessed the management of fractures before the launch of the program. A multidisciplinary group was established to collaborate on the diagnosis and treatment of patients with osteoporotic fractures. A full-time program coordinator was appointed. We analyzed the program's clinical outcomes and limitations. RESULTS: One-hundred and ninety patients were included in the study, with an average age of 76.7. Hip fracture was the most frequent one (33.6%). After the first year of implementing the program, 39.4% of patients received osteoporosis treatment, with an adherence rate of 73%. The incidence of subsequent falls was 5.8% and 1% for new fractures. CONCLUSIONS: The implementation of a program for patients' care with fragility fractures is challenging for healthcare institutions. The role of a full-time coordinator is critical for the proper operation of such programs.

Chile as a key enabler country for global plant breeding, agricultural innovation, and biotechnology.

Chile has become one of the main global players in seed production for counter-season markets and research purposes. Chile has a key role contributing to the reduction in seed production shortages in the Northern Hemisphere by speeding up the development of new hybrids, cultivars, and genetically modified (GM) organisms. The seeds that Chile produces for export include a considerable amount of GM seeds. Between 2009 and 2018, 1,081 different seed-planting events were undertaken for seed multiplication and/or research purposes. Every single event that had commodity cultivation status in 2018 in at least one country underwent field activities in Chile at least once over the last 10 y. Chile just adopted a regulatory approach for new plant breeding techniques. This type of regulatory approach should contribute to maintaining the status of Chile as a hot spot for future innovation in plant breeding-based biotechnology.

Surgical treatment of periprosthetic humerus fractures and algorithm. / Tratamiento quirúrgico de las fracturas periprotésicas de húmero y algoritmo de actuación.

INTRODUCTION: Periprosthetic humerus fractures are infrequent and sometimes difficult to treat. There is limited literature and no consensus on the handling of these fractures. The objective of this study was to compare our results with those published in the literature, in order to improve our care and propose a management algorithm. MATERIAL AND METHOD: Observational study of 10cases of periprosthetic humerus fractures with a mean follow-up of the patients of 23months. An analysis of sociodemographic, radiological and surgical variables was performed. They were reviewed clinically and by telephone using the UCLA Shoulder Score and Quick-DASH scales. A systematic search was made in Pubmed for periprosthetic humerus fractures, for a literature review with which to compare our series. RESULTS: We analysed 10patients with an average age of 69.4years (37-91). Of the patients, 90% underwent surgery through open reduction and internal fixation. Nine of the ten patients consolidated in a mean time of 6.2months (range 5-12), the remaining suffered a new fracture 5months after the intervention, who were reoperated and a new osteosynthesis performed with bone allograft. In the UCLA scale there was a decrease of 10.66points, and an increase of 27.3points in the Quick-DASH, at the end of the follow-up. CONCLUSIONS: In our series of cases we found similarities in the literature, in relation to demographic aspects and obtaining good radiographic results, which do not correspond to the functional outcome of patients.