Maintenance of joint reduction and allograft incorporation in treating tibial plateau fractures. Retrospective case series using cortico-cancellous, non-irradiated, bone allograft.

Background: Restoring joint congruence and maintaining reduction until healing is imperative in treating tibial plateau fractures (TPF). The main objective of this study was to evaluate the feasibility of augmentation with impacted bone allograft (IBA) to prevent loss of reduction in tibial plateau fractures during healing and to evaluate its incorporation. Methods: We retrospectively analyzed all patients with an acute, closed tibial plateau fracture (Schatzker II, III, IV) treated between 2010 and 2019 with open reduction and internal fixation (ORIF) and impacted bone allograft (IBA), with a minimum follow-up of 24 months. We evaluated the postoperative radiographs by drawing a line along the tibial axis and another perpendicular to the healthy plateau to measure the reduction and subsequent behavior. The incorporation of the allograft was evaluated by radiological analysis assessing its integration, non-union, resorption, or sclerosis. We used the clinical-radiological Rasmussen system and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to objectify the outcomes. Results: 78 TPFs were included, with a median age of 51.5 (40.7-62.2) years and a median follow-up of 66 (24-89) months. Two (2.5 %) patients presented loss of joint reduction (subsidence) during the follow-up regarding the achieved in the surgery. Seventy-six (94.7 %) patients presented integration, two (2.5 %) resorption, and one (1.3 %) sclerosis. Seventy-two (92.3 %) patients presented excellent and good results in the Rasmussen radiological score, and 72 (92.3 %) patients presented excellent or good clinical scores. The mean WOMAC at two years postoperatively was 15 ± 6.5. Conclusion: Our results demonstrate that allograft is an adjuvant in maintaining a reduction in type II, III, and IV Schatzker's tibial plateau fractures. Low rates of loss of reduction during follow-up can be expected with its use.

Therapeutic potential of oleic acid supplementation in myotonic dystrophy muscle cell models.

BACKGROUND: We recently reported that upregulation of Musashi 2 (MSI2) protein in the rare neuromuscular disease myotonic dystrophy type 1 contributes to the hyperactivation of the muscle catabolic processes autophagy and UPS through a reduction in miR-7 levels. Because oleic acid (OA) is a known allosteric regulator of MSI2 activity in the biogenesis of miR-7, here we sought to evaluate endogenous levels of this fatty acid and its therapeutic potential in rescuing cell differentiation phenotypes in vitro. In this work, four muscle cell lines derived from DM1 patients were treated with OA for 24 h, and autophagy and muscle differentiation parameters were analyzed. RESULTS: We demonstrate a reduction of OA levels in different cell models of the disease. OA supplementation rescued disease-related phenotypes such as fusion index, myotube diameter, and repressed autophagy. This involved inhibiting MSI2 regulation of direct molecular target miR-7 since OA isoschizomer, elaidic acid (EA) could not cause the same rescues. Reduction of OA levels seems to stem from impaired biogenesis since levels of the enzyme stearoyl-CoA desaturase 1 (SCD1), responsible for converting stearic acid to oleic acid, are decreased in DM1 and correlate with OA amounts. CONCLUSIONS: For the first time in DM1, we describe a fatty acid metabolism impairment that originated, at least in part, from a decrease in SCD1. Because OA allosterically inhibits MSI2 binding to molecular targets, reduced OA levels synergize with the overexpression of MSI2 and contribute to the MSI2 > miR-7 > autophagy axis that we proposed to explain the muscle atrophy phenotype.

Importance of three physiological models for teaching the carbohydrates metabolism.

In this work extensive misconceptions of university students' -from nutrition area- about the metabolism of carbohydrates (CHM) in the human organism have been documented. The results lead to consider their difficulties concerning the learning of a complex set of imbricated biochemical models involved. Pursuant to these considerations, three physiological models are proposed as conceptual axes around which CHM in the human organism could be taught, in order to avoid fragmentation in students' knowledge and to give simple physiological contexts where to integrate those biochemical models. These contexts are: (a) a physiological model of the carbon cycle, (b) a physiological model of blood glucose uptake and homeostasis, and (c) a physiological model of the availability of small metabolites.

Therapeutic potential of oleic acid supplementation in myotonic dystrophy muscle cell models

Background We recently reported that upregulation of Musashi 2 (MSI2) protein in the rare neuromuscular disease myotonic dystrophy type 1 contributes to the hyperactivation of the muscle catabolic processes autophagy and UPS through a reduction in miR-7 levels. Because oleic acid (OA) is a known allosteric regulator of MSI2 activity in the biogenesis of miR-7, here we sought to evaluate endogenous levels of this fatty acid and its therapeutic potential in rescuing cell differentiation phenotypes in vitro. In this work, four muscle cell lines derived from DM1 patients were treated with OA for 24 h, and autophagy and muscle differentiation parameters were analyzed. Results We demonstrate a reduction of OA levels in different cell models of the disease. OA supplementation rescued disease-related phenotypes such as fusion index, myotube diameter, and repressed autophagy. This involved inhibiting MSI2 regulation of direct molecular target miR-7 since OA isoschizomer, elaidic acid (EA) could not cause the same rescues. Reduction of OA levels seems to stem from impaired biogenesis since levels of the enzyme stearoyl-CoA desaturase 1 (SCD1), responsible for converting stearic acid to oleic acid, are decreased in DM1 and correlate with OA amounts. Conclusions For the first time in DM1, we describe a fatty acid metabolism impairment that originated, at least in part, from a decrease in SCD1. Because OA allosterically inhibits MSI2 binding to molecular targets, reduced OA levels synergize with the overexpression of MSI2 and contribute to the MSI2 > miR-7 > autophagy axis that we proposed to explain the muscle atrophy phenotype.

Scanning Electron Microscopy and EDX Spectroscopy of Commercial Swabs Used for COVID-19 Lateral Flow Testing.

The chemical composition of COVID test swabs has not been examined beyond the manufacturer's datasheets. The unprecedented demand for swabs to conduct rapid lateral flow tests and nucleic acid amplification tests led to mass production, including 3D printing platforms. Manufacturing impurities could be present in the swabs and, if so, could pose a risk to human health. We used scanning electron microscopy and energy dispersive X-ray (EDX) spectroscopy to examine the ultrastructure of seven assorted brands of COVID test swabs and to identify and quantify their chemical elements. We detected eight unexpected elements, including transition metals, such as titanium and zirconium, the metalloid silicon, as well as post-transition metals aluminium and gallium, and the non-metal elements sulphur and fluorine. Some of the elements were detected as trace amounts, but for others, the amount was close to reported toxicological thresholds for inhalation routes. Experimental studies have shown that the detrimental effects of unexpected chemical elements include moderate to severe inflammatory states in the exposed epithelium as well as proliferative changes. Given the massive testing still being used in the context of the COVID pandemic, we urge caution in continuing to recommend repeated and frequent testing, particularly of healthy, non-symptomatic, individuals.

Complicaciones tempranas de la artroplastia total de cadera por vía anterolateral transglútea directa: estudio comparativo / Early complications in direct transgluteal anterolateral total hip arthroplasty. A comparative study

Introducción: En los últimos años, la introducción de diversas técnicas, el instrumental quirúrgico y las competencias del cirujano han contribuido a disminuir las complicaciones tempranas que pueden sobrevenir luego de una artroplastia de cadera. Las complicaciones más frecuentes son: el aflojamiento femoral, la trombosis venosa profunda y la luxación. Objetivos: Evaluar la tasa de complicaciones intraoperatorias y durante los primeros 12 meses luego de una artroplastia de cadera por vía anterolateral directa; y comparar los resultados con la serie publicada en 2007. Materiales y métodos: Estudio de cohorte retrospectivo que incluyó a pacientes operados por artrosis primaria de cadera en 2 instituciones, divididos en: grupo I (468 pacientes operados entre junio de 1999 y junio de 2003) y grupo II (344 pacientes operados entre enero de 2018 y enero de 2020). Resultados:La tasa global de complicaciones en la nueva serie fue del 4,7%. La trombosis venosa profunda fue la complicación que más se repitió, no hubo episodios de luxación. El empleo de cabezas de 22 mm de diámetro se asoció con un riesgo de luxación más alto que con cabezas más grandes (OR = 6,7; IC95% 1,2-78,2). Conclusiones: La artroplastia total de cadera con abordaje anterolateral transglúteo directo causó una baja tasa global de complicaciones dentro del primer año de la cirugía. Las complicaciones se redujeron casi a la mitad en las cirugías realizadas entre 2018 y 2020, con respecto a la serie anterior, fundamentalmente a expensas de la luxación. Nivel de Evidencia: IV

Introduction: In recent years, the advent of new procedures, surgical instruments, and surgeon skills has contributed to a reduction in the number of early complications that can arise after hip arthroplasty. Among the most frequent are femoral loosening, deep vein thrombosis, and dislocation. Objective: To evaluate the rate of intraoperative complications and complications within the first 12 months after a hip arthroplasty performed utilizing the direct anterolateral approach; and to compare the results to a series published in 2007. materials and methods: Retrospective cohort study, which included patients who underwent surgery for primary hip osteoarthritis at two institutions, divided into: group I (468 patients who were operated between June 1999 and June 2003) and group II (344 patients who were operated between January 2018 and January 2020). Results: The global rate of complications in group II was 4.7%. Deep vein thrombosis was the most frequent event, and there were no episodes of dislocation. The use of 22 mm diameter heads was associated with a higher risk of dislocation compared to surgeries in which larger heads were used (OR= 6.7 - 95% CI 1.2 - 78.2). Conclusions: Total hip replacement through a direct transgluteal anterolateral approach had a low global rate of complications within the first postoperative year. Complications were reduced by almost half in surgeries performed between 2018 and 2020, compared to the previous series, mainly in regards to dislocation. Level of Evidence: IV

Resultados iniciales del uso de cotilos de doble movilidad en pacientes >65 años con fractura de cadera. Análisis retrospectivo de 102 casos / Preliminary outcomes with dual mobility cups in patients older than 65 with hip fractures. A retrospective analysis of 102 patients

Objetivo: El objetivo de este estudio retrospectivo fue evaluar los resultados funcionales y la tasa de luxación en pacientes >65 años con fractura de cadera operados con prótesis de doble movilidad. materiales y métodos: Se analizó a los pacientes tratados por una fractura de cadera entre 2017 y 2021. Se incluyó a pacientes >65 años, tratados con copas de doble movilidad y un seguimiento mínimo de 24 meses. Se analizaron los datos demográficos, las comorbilidades, los resultados funcionales (Parker y puntaje de Harris), las complicaciones (infección, luxación, aflojamiento), las reoperaciones y revisiones. Resultados: Se trataron 102 fracturas de cadera (75 mediales y 27 intertrocantéricas) en 102 pacientes. El 72,5% eran mujeres (media de la edad 80.59 ± 6.92 años), el Índice de Comorbilidad de Charlson promedio fue de 4,71 y el puntaje ASA, 2,47. El 93,1% comenzó a caminar al segundo día de la cirugía. Según el puntaje de Harris, los resultados fueron excelentes o muy buenos en el 94,1%; los puntajes de Parker preoperatorio y posoperatorio no difirieron significativamente (p <0,05). El seguimiento promedio fue de 30 meses. Hubo 8 (7,84%) complicaciones: 2 (1,9%) casos de trombosis venosa profunda, 4 (3,9%) de tromboembolismo pulmonar, tres infecciones (2,9%) y una (0,9%) luxación. La tasa de reoperaciones fue del 2,9%. Conclusiones: Con el empleo de copas de doble movilidad se obtuvieron resultados funcionales aceptables y una tasa de luxación relativamente baja (0,9%). Esto sugiere que estos implantes representan una opción en el tratamiento de estas lesiones. Nivel de Evidencia: IV

Objective: This retrospective study aimed to assess the functional outcomes and dislocation rate in the treatment with dual mobility prostheses in patients older than 65 with hip fractures. materials and methods: We analyzed all patients treated between 2017 and 2021 for hip fractures in our service. We included patients older than 65 years, treated with dual mobility cups, and a minimum follow-up of 24 months. We analyzed demographic data, comorbidities, functional outcomes (Parker score and Harris Hip Score, HHS), complications (infection, dislocation, loosening), reoperations, and revisions. Results: We included 102 hip fractures (75 medial and 27 intertrochanteric) in 102 patients. Seventy-four (72.5%) were women, the mean age was 80.59 ± 6.92 years, the mean Charlson index was 4.71 (range 3-10), and ASA was 2.47 (1-4). 93.1% started walking on the second postoperative day. 94.1% presented excellent or very good outcomes according to the HHS, the postoperative Parker index did not show significant differences in comparison to the preoperative one (p < 0.05). The average follow-up was 30 months (range 24-60). There were 8 (7.84%) complications: 2 (1.9%) deep vein thrombosis, 4 (3.9%) pulmonary thromboembolism, 3 infections (2.9%), and 1 (0.9%) dislocation. The reoperation rate was 2.9%. Conclusions: We obtained acceptable functional outcomes using dual mobility cups with a relatively low dislocation rate (0.9%). This suggests that these implants are an option to consider in treating these lesions. Level of Evidence: IV

Parenteral succinate reduces levels of reactive oxygen species without changing serum caspase-3 levels in septic rats.

INTRODUCTION: Sepsis is a syndrome of physiological, pathological, and biochemical disorders with several processes co-occurring; reactive oxygen species (ROS) production and apoptosis are 2 of them. Succinate is a Krebs cycle intermediate that is oxydized in complex II of the mitochondria. This study aims to investigate the influence of succinate infusion on these processes. MATERIAL AND METHODS: Sepsis was induced with caecal ligation and puncture in 200 gr Sprague Dawley rats. Four groups were formed with 10 animals (1 - control, 2 - succinate, 3 - sepsis, and 4 - sepsis + succinate). 5 mmol kg-1 of intraperitoneal succinate were administered twice in groups 2 and 4. ROS and caspase-3 levels were measured. RESULTS: Overall, ROS levels (P = 0.017), but not caspase-3 levels (P = 0.89) differed significantly between the groups. The succinate administration reduced serum ROS levels (group 4 vs. 3) in a statistically significant way [0.0623 units (95% CI: 0.0547-0.0699) vs. 0.0835 (0.06-0.106), P = 0.017)], but it did not reduce serum caspase-3 levels (P = 0.39). There was no correlation between serum ROS levels and serum caspase-3 levels. CONCLUSIONS: In this model, ROS levels were reduced with succinate infusion, but caspase-3 levels were not. In addition, ROS levels and apoptosis levels are not correlated, which suggests that those processes occur at different times.

Serum reactive oxygen species and apoptosis markers in septic patients.

INTRODUCTION: Oxidative stress is one of the pathophysiological processes that occur during sepsis. Reactive oxygen species (ROS) production causes lipid peroxidation and protein and DNA damage. ROS and DNA damage triggers apoptosis. Several studies have shown that organ failure in sepsis is mediated by apoptosis. The aim of this study is to investigate the levels of serum ROS and serum caspase-3 in septic patients and healthy volunteers, and their correlation. MATERIAL AND METHODS: Serum samples were taken within the first 12 hours of ICU stay. The dichlorofluorescein technique was used to determine serum ROS levels, and the ELISA technique was used to quantify serum caspase-3 in septic patients and healthy volunteers. RESULTS: There was no difference in serum ROS levels between healthy volunteers and septic patients (P = 0.26), and there was a significant difference in serum caspase-3 levels between healthy volunteers and septic patients (P < 0.001). There was no difference between patients who lived and died in the intensive care unit (ICU) in serum ROS (P = 0.089) and serum caspase-3 (P = 0.18). There was no correlation between both markers (R = -0.0013, P = 0.98). CONCLUSIONS: We conclude that there is no correlation between serum ROS and caspase-3; therefore, both processes might not be associated during the first hours of ICU stay.

Parenteral Succinate Reduces Systemic ROS Production in Septic Rats, but It Does Not Reduce Creatinine Levels.

In sepsis, reactive oxygen species (ROS) production is increased. This process takes place mainly within the electron transport chain. ROS production is part of the pathophysiology of multiple organ failure in sepsis. Succinate yields Dihydroflavine-Adenine Dinucleotide (FADH2), which enters the chain through complex II, avoiding complex I, through which electrons are lost. The aim of this work is to determine if parenteral succinate reduces systemic ROS production and improves kidney function. Rats with cecal ligation and puncture were used as model of sepsis, and 4 groups were made: Control group; Succinate group, which only received parenteral succinate; Sepsis group; and Sepsis which received parenteral succinate. Systemic ROS are measured 24 hours after the procedure. Rats subjected to cecal puncture treated with succinate had less systemic ROS than Septic untreated rats (p = 0.007), while there were no differences in creatinine levels (p = 0.07). There was no correlation between creatinine and systemic ROS levels (p = 0.3). We concluded that parenteral succinate reduces ROS levels, but it does not reduce creatinine levels. Since there is no correlation between both levels, the processes would not be related.

Teaching nutritional biochemistry: an experimental approach using yeast.

In this report, we present a practical approach to teaching several topics in nutrition to science students at the high school and college freshmen levels. This approach uses baker's yeast (Saccharomyces cerevisiae) as a biological system model. The diameters of yeast colonies, which vary according to the nutrients present in the medium, can be observed, compared, and used to teach metabolic requirements. The experiments described in this report show simple macroscopic evidence of submicroscopic nutritional events. This can serve as a useful base for an analogy of heterotrophic human cell nutrition.

Idebenone treatment mediates the effect of menadione oxidative stress damage in Saccharomyces cerevisiae.

We investigated the damage caused by oxidative stress using the yeast Saccharomyces cerevisiae as a model biological system. After inducing oxidative stress with menadione, we were able to evaluate the extent of cellular oxidative stress by utilizing 2',7'-dichlorofluorescein diacetate (DCFH-DA) as a marker of the presence of reactive oxygen species. Cells were grown on different carbon sources in order to compare fermentative and oxidative metabolism. Under these conditions we evaluated the effectiveness of idebenone (2,3-dimethoxy-5-methyl-6-(10- hydroxydecyl)-1,4-benzoquinone) as a molecule that could relieve menadione-induced growth inhibition in Saccharomyces cerevisiae.

Student assessment in large-enrollment biology classes.

Enrollments into first-year university biology courses may be very large, and therefore evaluating student learning can represent quite a challenge. In this article, we present our experience in assessing students by means of an assessment instrument called "Understand Before Choosing" (UBC). It has been used for six semesters, and its performance has been compared with two other common means of assessment, the use of multiple-choice questions and the use of open-ended questions. UBC consists of a text (100 lines, nearly 700 words) on the subject being tested, and a set of carefully worded questions that require the selection of one of five crafted options to be answered. To choose the best option, a student needs to understand the concepts embedded in the text.

Teaching lactose metabolism: A Complex Challenge Faced with a Simple Kit.

We developed an experimental didactic proposal to teach both carbohydrate metabolism and lactose intolerance as the disease related to that metabolism. Therefore, we implemented an empirical strategy consisting of inexpensive and nontoxic components for which students do not need to know any of the laboratory techniques. The fact that students were able to discuss their own results obtained from the experiments performed in their classroom gave them an additional motivation to learn the subject.

Brefeldin A decreases the activity of the general amino acid permease (GAP1) and the more specific systems for L-leucine uptake in Saccharomyces cerevisiae.

Brefeldin A is a commonly used antifungal agent that reversibly blocks protein transport from the endoplasmic reticulum to the Golgi complex. In this study, we aimed to characterize L-leucine uptake in Saccharomyces cerevisiae in the presence of brefeldin A. For this purpose, we used a synthetic medium, containing L-proline and the detergent SDS, which allows the agent to permeate into the yeast cell. The results obtained with a wild type strain and a gap1 mutant indicate that BFA causes either direct or indirect modification of the transport and/or processing of L-leucine permeases. The presence of BFA affects the kinetic parameter values for L-leucine uptake and decreases not only the uptake mediated by the general system (GAP1), but also that through the specific BAP2 (S1) and/or S2 systems.

Estudio comparativo entre las técnicas de homogeneización con ditiotreitol y toma y frotis en fresco, en citologías de expectoración para el diagnóstico de cáncer del pulmón / Comparative trial between techniques of homogeneization by dithiothreitol and pick and smear in citology of sputum for diagnosis of lung cancer

El cáncer de pulmón es uno de los problemas de salud más importantes a nivel mundial. En estados Unidos conforma la primera causa de muerte en varones. La situación en nuestro país no es muy diferente. La citología del esputo es la técnica convencional no invasiva más útil para hacer el diagnóstico, pero no es un método muy sensible (se acerca al 50 por ciento). Pensamos que un método no invasivo que facilite la detección en etapas más tempranas da mayores posibilidades de tratamiento con mejores resultados. Este estudio se realizó en el Hospital Central Militar y en el Instituto Nacional de Enfermedades Respiratorias con 23 pacientes mayores de 35 años, de octubre de 1997 a abril de 1998, que presentaban algunos criterios clínicos y radiológicos como tabaquismo, tos, nódulo solitario y derrame pleural. Se obtuvo una muestra de expectoración para frotis, se diluyó en 20 ml de carbowax al 3 por ciento, se centrifugó, se obtuvo una muestra y se tiñó. El resto se diluyó en ditiotreitol DTT al 0.2 por ciento, etanol al 60 por ciento y carbowax al 3 por ciento, centrifugando y reposando durante 3 días. Se obtuvo una muestra y se tiñó (método de homogeneización con DTT). Se observaron y compararon ambas muestras. En 15 pacientes se encontró cáncer, de los cuales 6 fueron de tipo bronquial y 9 de tipo parenquimatoso, detectando 5 bronquiales con ambos métodos, por lo que la sensibilidad de ambas técnicas es estadísticamente significativa para detectar cáncer bronquial (83 por ciento de los casos), mientras que los métodos descritos no son útiles para diagnosticar el cáncer del pulmón en parénquima

Síndrome de Potter: caso clínico / Potter's syndrome: a clinical case

Se presenta un caso de Síndrome de Potter, cuyo diagnóstico prenatal se consideró, basado en los hallazgos clínicos, confirmándose mediante estudio ecotomográfico fetal. La existencia de un oligohidroamnios severo al examen físico de ingreso fue el principal signo para plantear la posible existencia de este síndrome, el cual es confirmado por el examen ultrasonográfico que mostró acentuada disminución del líquido amniótico, además de ausencia de imagen renal bilateral

Análisis de 1 611 pacientes atendidos en la unidad de Terapia Intensiva / Analysis of 1 611 patients assisted at the intensive care unit

se estudian 1 611 pacientes atendidos en la Unidad de Terapia Intensiva del Hospital Infantil Docente "Pedro Borrás". Se indican las causas del ingreso, el sexo, el grupo etario y otros factores importantes. Se analiza el movimiento hospitalario y el índice ocupacional de camas

Análisis de 1 611 pacientes atendidos en la unidad de Terapia Intensiva / Analysis of 1 611 patients assisted at the intensive care unit

se estudian 1 611 pacientes atendidos en la Unidad de Terapia Intensiva del Hospital Infantil Docente "Pedro Borrás". Se indican las causas del ingreso, el sexo, el grupo etario y otros factores importantes. Se analiza el movimiento hospitalario y el índice ocupacional de camas