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Resumen: Introducción: estudios recientes han reportado fenómenos trombóticos o coagulopatía en pacientes con COVID-19. Hay posiciones divergentes en cuanto a la prevención, el diagnóstico y el tratamiento de estos fenómenos, y la práctica clínica actual está basada únicamente en deducciones por extensión a partir de estudios retrospectivos, series de casos, estudios observacionales y guías internacionales desarrolladas previas a la pandemia. Objetivo: establecer una serie de recomendaciones sobre prevención, diagnóstico y manejo de las complicaciones trombóticas asociadas a COVID-19. Métodos: se desarrolló una guía rápida en la que se aplicó el marco de la evidencia a la decisión (EtD) de GRADE y un sistema de participación iterativo, con análisis estadísticos y cualitativos de sus resultados. Resultados: se generaron 31 recomendaciones clínicas enfocadas a: a) Pruebas de coagulación en adultos sintomáticos con sospecha de infección o infección confirmada por SARS-CoV-2; b) Tromboprofilaxis en personas adultas con diagnóstico de COVID-19 (escalas de riesgo, tromboprofilaxis de manejo ambulatorio, intrahospitalario y duración de tromboprofilaxis después del egreso de hospitalización), c) Diagnóstico y tratamiento de las complicaciones trombóticas y d) Manejo de personas con indicación previa a usar agentes anticoagulantes. Conclusiones: las recomendaciones clínicas de este consenso orientan la toma de decisiones clínicas respecto a prevención, diagnóstico y tratamiento de fenómenos trombóticos en pacientes con COVID-19, y representan un acuerdo que ayudará a disminuir la dispersión en las prácticas clínicas acorde con el desafío que impone la pandemia. Abstract: Introduction: recent studies have reported the occurrence of thrombotic phenomena or coagulopathy in patients with COVID-19. There are divergent positions regarding the prevention, diagnosis, and treatment of these phenomena, and current clinical practice is based solely on deductions by extension from retrospective studies, case series, observational studies, and international guidelines developed prior to the pandemic. Objective: to generate a group of recommendations on the prevention, diagnosis and management of thrombotic complications associated with COVID-19. Methods: a rapid guidance was carried out applying the GRADE Evidence to Decision (EtD) frameworks and an iterative participation system, with statistical and qualitative analysis. Results: 31 clinical recommendations were generated focused on: a) Coagulation tests in symptomatic adults with suspected infection or confirmed SARS CoV-2 infection; b) Thromboprophylaxis in adults diagnosed with COVID-19 (Risk scales, thromboprophylaxis for outpatient, in-hospital management, and duration of thromboprophylaxis after discharge from hospitalization), c) Diagnosis and treatment of thrombotic complications, and d) Management of people with previous indication of anticoagulant agents. Conclusions: recommendations of this consensus guide clinical decision-making regarding the prevention, diagnosis, and treatment of thrombotic phenomena in patients with COVID-19, and represent an agreement that will help decrease the dispersion in clinical practices according to the challenge imposed by the pandemic.

PurposeThe COVID-19 pandemic has spread worldwide, and almost 396 million people have been infected around the globe. Latin American countries have been deeply affected, and there is a lack of data in this regard. This study aims to identify the clinical characteristics, in-hospital outcomes, and factors associated with ICU admission due to COVID-19. Furthermore, to describe the functional status of patients at hospital discharge after the acute episode of COVID-19.Material and methodsThis was a prospective, multicenter, multinational observational cohort study of subjects admitted to 22 hospitals within Latin America. Data were collected prospectively. Descriptive statistics were used to characterize patients, and multivariate regression was carried out to identify factors associated with severe COVID-19.ResultsA total of 3008 patients were included in the study. A total of 64.3% of patients had severe COVID-19 and were admitted to the ICU. Patients admitted to the ICU had a higher mean (SD) 4C score (10 [3] vs. 7 [3)], pConclusionsThis study confirms that patients with SARS CoV-2 in the Latin American population had a lower mortality rate than previously reported. Systemic complications are frequent in patients admitted to the ICU due to COVID-19, as previously described in high-income countries.

Presentamos una visión del panorama estructuralista alrededor de 1900 para apreciar que en la presentación axiomática de los reales por Hilbert, su noción de completez estaba fuertemente influenciada por la obra de Dedekind y el pensamiento filosófico de la época, el cual lo representamos en Husserl. Para caracterizar desde una perspectiva formal esta completez, haremos una lectura desde la teoría de categorías para la axiomática de los números reales de Hilbert. Para tal efecto, formaremos la categoría de todos los cuerpos arquimedianos totalmente ordenados y probaremos que los números reales son el objeto final de dicha categoría y así tendremos inmediatamente los teoremas de categoricidad e inmersión de los números reales. Esperamos dar una amplia sustentación para validar nuestra presentación que contrasta con las habituales lecturas conjuntistas, y proporciona una aproximación a los inicios del estructuralismo en las matemáticas en las cercanías de 1900.

Introducción. Actualmente no se cuenta con muchos datos disponibles sobre la sepsis en los países en desarrollo y especialmente en América Latina. Objetivo. Este estudio tuvo como objetivo determinar la frecuencia, las características clínicas y epidemiológicas y las consecuencias de la sepsis en una población de pacientes que requirieron ingreso en algunas unidades colombianas de cuidados intensivos. Materiales y métodos. Este fue un análisis secundario de un estudio prospectivo realizado en un período de seis meses contados a partir del 1° de septiembre de 2007 hasta el 28 de febrero del 2008 en diez unidades médico-quirúrgicas de cuidados intensivos de cuatro ciudades de Colombia. Los pacientes se consideraron elegibles si tenían un diagnóstico probable o confirmado de infección según los registros médicos. Se registraron las características demográficas, los diagnósticos de primer ingreso y las enfermedades concomitantes, el estado clínico y la sepsis, sepsis grave o choque séptico. Resultados. Durante el período de estudio, 826 pacientes fueron ingresados en las unidades de cuidados intensivos seleccionadas para el estudio. De estos pacientes, 421 (51 %) desarrollaron sepsis en la comunidad, 361 (44 %) en la unidad de cuidados intensivos y 44 (5 %) durante la hospitalización en la sala general; 253 pacientes (30,6 %) presentaron afectación de un órgano del sistema: 20 % tuvo problemas respiratorios, seguido por problemas en los riñones y el sistema nervioso central con 3,4 % y 2,7 %, respectivamente. Conclusiones. En la muestra de pacientes sépticos, la prevalencia de la sepsis, así como de la mortalidad global, en los pacientes tratados en la unidad de cuidados intensivos fue similar a la reportada en otros estudios.

Parasitic protozoa are among the most important pathogens worldwide. Diseases such as malaria, leishmaniasis, amoebiasis, giardiasis, trichomoniasis, and trypanosomiasis affect millions of people. Humans are constantly threatened by infections caused by these pathogens. Parasites engage a plethora of surface and secreted molecules to attach to and enter mammalian cells. The secretion of lytic enzymes by parasites into host organs mediates critical interactions because of the invasion and destruction of interstitial tissues, enabling parasite migration to other sites within the hosts. Extracellular matrix is a complex, cross-linked structure that holds cells together in an organized assembly and that forms the basement membrane lining (basal lamina). The extracellular matrix represents a major barrier to parasites. Therefore, the evolution of mechanisms for connective-tissue degradation may be of great importance for parasite survival. Recent advances have been achieved in our understanding of the biochemistry and molecular biology of proteases from parasitic protozoa. The focus of this paper is to discuss the role of protozoan parasitic proteases in the degradation of host ECM proteins and the participation of these molecules as virulence factors. We divide the paper into two sections, extracellular and intracellular protozoa.

Abstract The distinct conjugation machineries encoded by plasmids pNP40 and pUC11B represent the most prevalent plasmid transfer systems among lactococcal strains. In the current study, we identified genetic determinants that underpin pNP40‐ and pUC11B‐mediated, high‐frequency mobilisation of other, non‐conjugative plasmids. The mobilisation frequencies of the smaller, non‐conjugative plasmids and the minimal sequences required for their mobilisation were determined, owing to the determination of the oriT sequences of both pNP40 and pUC11B, which allowed the identification of similar sequences in some of the non‐conjugative plasmids that were shown to promote their mobilisation. Furthermore, the auxiliary gene mobC, two distinct functional homologues of which are present in several plasmids harboured by the pNP40‐ and pUC11B‐carrying host strains, was observed to confer a high‐frequency mobilisation phenotype. These findings provide mechanistic insights into how lactococcal conjugative plasmids achieve conjugation and promote mobilisation of non‐conjugative plasmids. Ultimately, these insights would be harnessed to optimise conjugation and mobilisation strategies for the rapid and predictable development of robust and technologically improved strains.

Plasmids pNP40 and pUC11B encode two prevalent yet divergent conjugation systems, which have been characterized in detail recently. Here, we report the elucidation of the putative adhesins of the pNP40 and pUC11B conjugation systems, encoded by traAd and trsAd, respectively. Despite their significant sequence divergence, TraAd and TrsAd represent the most conserved component between the pNP40- and the pUC11B-encoded conjugation systems and share similar peptidoglycan-hydrolase domains. Protein structure prediction using AlphaFold2 highlighted the structural similarities between their predicted domains, as well as the potential homo-dimeric state of both proteins. Expression of the putative surface adhesins resulted in a cell clumping phenotype not only among cells expressing these surface adhesins but also between adhesin-expressing and non-producing cells. Furthermore, mutant derivatives of plasmids pNP40 or pUC11B carrying a mutation in traAd or trsAd, respectively, were shown to act as efficient donors provided the corresponding recipient expresses either traAd or trsAd, thus demonstrating in trans reciprocal complementarity of these proteins in conjugation systems.

Lactococcal conjugative plasmids are poorly characterized compared to those harbored by numerous other Gram-positive bacteria, despite their significance in dairy fermentations and starter culture development. Furthermore, the transcriptional landscape of these lactococcal conjugation systems and their regulation have not been studied in any detail. Lactococcal plasmids pNP40 and pUC11B possess two genetically distinct and prevalent conjugation systems. Here, we describe the detailed transcriptional analysis of the pNP40 and pUC11B conjugation-associated gene clusters, revealing three and five promoters, respectively, for which the corresponding transcriptional start sites were identified. Regulation of several of these promoters, and therefore conjugation, is shown to involve the individual or concerted activities of the corresponding relaxase and transcriptional repressor(s) encoded by each conjugative plasmid. This work highlights how the conjugative potential of these systems may be unlocked, with significant implications for the starter culture and food fermentation industry.

Abstract Plasmid pUC11B is a 49.3‐kb plasmid harboured by the fermented meat isolate Lactococcus lactis subsp. lactis UC11. Among other features, pUC11B encodes a pMRC01‐like conjugation system and tetracycline‐resistance. In this study, we demonstrate that this plasmid can be conjugated at high frequencies to recipient strains. Mutational analysis of the 22 genes encompassing the presumed pUC11B conjugation cluster revealed the presence of several genes with essential conjugation functions, as well as a gene, trsR, encoding a putative transcriptional repressor of this conjugation cluster. Furthermore, plasmid pUC11B encodes an anti‐restriction protein, TrsAR, which facilitates higher conjugation frequencies when pUC11B is transferred into recipient strains containing Type II or Type III RM systems. These findings demonstrate how RM mechanisms can be circumvented when they act as a biological barrier for conjugation events.

Introduction: The objective of this study was to compare the continuous infusion of cefepime with the intermittent infusion in patients with sepsis caused by Gram-negative bacilli (GNB). Methods: Randomized 1:1 multicenter double-blinded placebo-controlled study with allocation concealment; multicenter study in the intensive care units of Colombia. Patients with sepsis, severe sepsis or septic shock, and GNB-suspected bacteremia. Cefepime was administered for 7 to 14 days over 30 m intermittently every 8 h over 24 h plus continuous saline solution (0.9%) (G1) or 3 g administered continuously plus saline solution every 8 h (0.9%) (G2). The percentage of clinical response at 3, 7, and 14 days, relapse at 28 days, and mortality at discharge were measured. Results: The recruitment was stopped at the suggestion of the Institutional Review Board (IRB) following an FDA alert about cefepime. Thirty-two patients were randomized; 25 received the intervention, and GNB bacteremia was confirmed in 16 (9 G1 and 7 G2). Favorable clinical response in days 3, 7, and 14 was 88.8%, 88.8%, and 77.8% (G1) and was similar for G2 (85.7%). There were no relapses or deaths in G2, while in G1, one relapse and two deaths were observed. Conclusions: The results of this study support the use of cefepime for the treatment of Gram-negative infections in critically ill patients, but we could not demonstrate differences between continuous or intermittent administration because of the small sample size, given the early suspension of the study.

Abstract Identify risk factors associated with mortality in HIV patients admitted to an ICU in the city of Bogotá. Retrospective cohort study of patients treated in an ICU during the years 2017–2019. The analysis included descriptive statistics, association tests, and a logistic regression model. A predictive model of mortality at the time of admission to the ICU was developed. 110 HIV patients were identified. Association was found between a Charlson index ≥ 6 and mortality (OR = 2.3, 95% CI 1.0–5.1) and an increase in mortality in the first 21 days of ICU stay (OR = 2.2, 95% CI 1.0–4.9). In the logistic regression analysis, the absence of highly active antiretroviral therapy (HAART) upon admission to the ICU (OR = 2.5 95% CI 1.0–6.1) and the first 21 days of ICU stay (OR = 2.3 95% CI 1.0–5.4) were associated with an increase in mortality. The predictive mortality model established that mortality was higher in patients admitted to the ICU without having previously received HAART than in those who did receive therapy at the time of admission to the ICU. In patients with HIV admitted to the ICU, the absence of HAART will negatively impact mortality during their hospital stay.

Introduction and Objectives: Alcohol-associated hepatitis (AH) is a severe entity associated with high mortality. Corticosteroids might be used in cases with severe disease and several dynamic models can predict mortality and response to corticosteroids in AH patients. However, there is no consensus on the best of them. This study aimed to evaluate dynamic models to predict response to corticosteroid treatment based on short-term mortality in patients with severe AH based on a worldwide cohort. Materials and Methods: A retrospective cohort study of patients with severe AH (between 2009 – 2019). We included patients who received corticosteroid treatment and calculated the Lille model of day 4 (Lille-4), day 7 (Lille-7) (cut-off value ≥0.45), and the Trajectory of Serum Bilirubin (TSB)(cut-off value ≥0.8 of the ratio between bilirubin at admission and day 7) to predict mortality. We estimated up to 30-day survival using Kaplan-Meier curves, and we performed multivariable analyzes using Cox regression. Specifically, we constructed two models to compare Lille-4 vs. TSB and Lille-7 vs. TSB, adjusting by well-known clinical variables associated with higher mortality in AH (age, sex, and creatinine at admission). Results: 1,066 patients were included (30 centers, 10 countries), age 47.7 ± 10.9 years, 30% women. The MELD score on admission was 25 [21-30]. Responders were considered by Lille-4 49.1%, Lille-7 46.6%, and TSB 55.4%. In the first Cox regression, we observed that Lille-4 and TSB predicted 30-day mortality (HR 3.0, 95%CI: 1.7-5.1; p

Breast cancer (BC) is a heterogeneous disease, and establishing biomarkers is essential to patient management. We previously described that extracellular vesicle–derived miRNAs (EV-miRNAs) miR-142-5p, miR-150-5p, miR-320a, and miR-4433b-5p in serum discriminated BC from control samples, either alone or combined in a panel. Using these previously described markers, we intend to evaluate whether the same markers identified in EVs are also potential biomarkers in tissue and serum. Expression analysis using RT-qPCR was performed using serum of 67 breast cancer patients (BC-S), 19 serum controls (CT), 83 fresh tumor tissues (BC-T), and 29 adjacent nontumor tissue samples (NT). In addition, analysis from The Cancer Genome Atlas (TCGA) data (832 BC-T and 136 NT) was performed. In all comparisons, we found concordant high expression levels of miR-320a and miR-4433b-5p in BC-S compared to CT in both EVs and cell-free miRNAs (cf-miRNAs). Although miR-150-5p and miR-142-5p were not found to be differentially expressed in serum, panels including these miRNAs improved sensitivity and specificity, supporting our previous findings in EVs. Fresh tissue and data from the TCGA database had, in most comparisons, an opposite behavior when compared to serum and EVs: lower levels of all miRNAs in BC-T than those in NT samples. TCGA analyses revealed reduced expression levels of miR-150-5p and miR-320a-3p in BC-T than those in NT samples and the overexpression of miR-142-5p in BC-T, unlike our RT-qPCR results from tissue in the Brazilian cohort. The fresh tissue analysis showed that all miRNAs individually could discriminate between BC-T and NT in the Brazilian cohort, with high sensitivity and sensibility. Furthermore, combining panels showed higher AUC values and improved sensitivity and specificity. In addition, lower levels of miR-320a-3p in serum were associated with poor overall survival in BC Brazilian patients. In summary, we observed that miR-320a and miR-4433b-5p distinguished BC from controls with high specificity and sensibility, regardless of the sample source. In addition, lower levels of miR-150-5p and higher levels of miR-142-5p were statistically significant biomarkers in tissue, according to TCGA. When combined in panels, all combinations could distinguish BC patients from controls. These results highlight a potential application of these miRNAs as BC biomarkers.

Plasmid pNP40, which was first identified nearly 40 years ago in Lactococcus lactis subsp. lactis biovar diacetylactis DRC3, encodes functions such as heavy metal-, bacteriophage-, and nisin-resistance, as well as plasmid transfer ability by conjugation. Here, we report an optimized conjugation protocol for this plasmid, yielding a transfer frequency that is approximately 4,000-fold higher than those previously reported in literature, while we also observed high-frequency plasmid co-mobilization. Individual mutations in 18 genes that encompass the presumed conjugation cluster of pNP40 were generated using ssDNA recombineering to evaluate the role of each gene in the conjugation process. A possible transcriptional repressor of this conjugation cluster, the product of the traR gene, was identified in this manner. This mutational analysis, paired with bioinformatic predictions as based on sequence and structural similarities, allowed us to generate a preliminary model of the pNP40 conjugation machinery.

Los gases arteriales son claves para la evaluación o seguimiento del estado de un paciente. Existen muchas formas de realizar una lectura e interpretación, pero ninguna es totalmente aceptada. Proponemos utilizar un enfoque basado en “TRES EJES”, que sintetiza de forma organizada y sistemática las teorías con mayor evidencia actualmente, teniendo en cuenta el sitio de la atención. El primer eje es la oxigenación-ventilación que representa el compromiso pulmonar o lo descarta, basado en todos los índices que la evidencia recomienda y definiendo, si se requiere, apoyo con oxígeno o ventilación. El segundo eje es el equilibrio ácido-base, tomando las teorías clásicas y fisicoquímicas para un abordaje más completo del paciente, teniendo en cuenta el sitio y recursos. Finalmente, el eje de la perfusión, que muestra el estado cardiovascular y perfusión tisular, y es un apoyo sobre todo en cuidado intensivo. Además, recopilamos las etiologías de la mayoría de trastornos y se tuvo en cuenta la influencia de la altura.

Abstract A new kind of nanodevice that acts like tweezers through remote actuation by an external magnetic field is designed. Such device is meant to mechanically grab micrometric objects. The nanotweezers are built by using a top-down approach and are made of two parallelepipedic microelements, at least one of them being magnetic, bound by a flexible nanohinge. The presence of an external magnetic field induces a torque on the magnetic elements that competes with the elastic torque provided by the nanohinge. A model is established in order to evaluate the values of the balanced torques as a function of the tweezers opening angles. The results of the calculations are confronted to the expected values and validate the overall working principle of the magnetic nanotweezers.

El labio y paladar hendido, son malformaciones congénitas de origen multifactorial de tipo facial y bucal que ocurren durante la 6ta y 8va semana del desarrollo embrionario. Sus etiologías son: factores genéticos y ambientales, alterando la fusión de los procesos labiales y palatinos durante el desarrollo embrionario, lo que origina desórdenes de la alimentación, respiración, lenguaje, masticación, deglución, fonación, estética y autoestima. Por lo anterior, es importante realizar una rehabilitación ortopédica para lograr un adecuado desarrollo y crecimiento del aparato estomatognático. Objetivo: Evaluar el efecto que produce la aparatología ortopédica pre-quirúrgica de Hotz, desde su colocación, hasta el primer tiempo quirúrgico en un paciente con Labio y Paladar Hendido (LPH). Reporte del caso: Paciente masculino, de dos semanas de edad, con LPH, acude a Clínica de Atención Integral para el Paciente de la Escuela Nacional de Estudios Superiores, Unidad León. Antecedentes patológicos: labio y paladar hendido completo unilateral izquierdo. Tratamiento: Colocación de ortopedia prequirúrgica. Resultados: El uso de la aparatología ortopédica previa a la intervención quirúrgica funcionó como contención en el sector anterior, ayudando al arco dental en la cirugía primaria al momento de la labioplastía, obteniendo uniones mucoperiósticas menos agresivas, conservando el tamaño entre los procesos alveolares y el de la brecha de la hendidura en la zona anterior, mientras que en la zona posterior, aumentó favoreciendo positivamente al paciente para una succión nutricia más eficaz y funcional. Conclusiones: La placa pre-quirúrgica y la cirugía, pueden ser significativamente eficaces para un mejor desarrollo maxilofacial, mejorando la forma de la arcada y alineación pasiva del maxilar en paciente con LPH, siendo de gran ayuda para la alimentación en los pacientes postnatales.

Recientemente, la especificación de un problema en ciencias de la computación –un paso intermedio entre el problema dado y su aplicación como un sistema de software que garantiza su solución– utiliza el álgebra universal y la teoría de coálgebras para su descripción. Esta etapa incluye componentes sintácticas y semánticas, que tienen como resultado un sistema lógico. En [3], se propone la lógica ecuacional multitipada para la especificación de problemas. Dualmente, en [9] se estudia una lógica de comportamiento abstracto, la cual modela procesos y comportamiento de sistemas coalgebraicos. En ambas lógicas los componentes sintáctico y semántico son conectados por medio de una relación de satisfacción, caracterizada por el siguiente principio: la verdad se preserva bajo transformaciones del lenguaje. En un marco general y moderno, hoy contamos con las instituciones en la especificación algebraica y coinstituciones en la especificación coalgebraica. El propósito del presente artículo es estudiar un caso particular de la lógica de comportamiento abstracto presentada en [9], en donde las coálgebras las restringimos a funtores polinomiales. Identificamos la respectiva coinstitución coalgebraica, detallando sus componentes y explícitamente presentaremos la relación de satisfacción como un resultado final. Abstract. Recently, the specification of a problem in computer sciences –an intermediate step between the given problem and its implementation as a software system that guarantees its solution– uses universal algebra and coalgebra theories for its description. This stage includes a syntactic and a semantic component, having a logic system as result. In [3], the case of many-sorted equational logic is studied for the purpose of specification problems. Dually, in [9] an abstract behavioral logic, which models processes and coalgebraic systems behavior is studied. In both logics, the syntactic and semantic components are connected via a satisfaction relation, characterized by the following principle: the truth of formulas is invariant under language translations. In a general and modern framework, we use the institutions in algebraic specification and coinstitutions in coalgebraic specification. We research a particular case of behavioral abstract logic presented in [9], in which coalgebras are restricted to polinomial functors. We identify the respective algebraic coinstitution, detail all its components, and explicitly present the satisfaction relation as the final result.

Using ellipsometry, the film structure is characterized by optical indices n, k (visible region, 450 nm <  < 580 nm) and the thickness (15 < d < 35 nm). The optical indices change with the quantity of silver deposited, obtaining effective indices of 1.0 < n < 1.8 and 1.6 < k < 2.6 to the smaller deposits that belong to a volumetric fraction between 0.35 and 0.5 of silver in the air. An effective optical thickness film decrease is observed when the silver volumetric fraction increases, and a thickness increase with close indices to solid silver when the deposited silver increases. Optical and effective medium theory indices are compared.

Uti lizando elipsometría , se caracteriza l a estructura de la película mediante los índices ópticos n, k (región visible, 450 nm <  < 580 nm) y el espesor ( 15 < d < 35 nm). Los índices ópticos varían con la cantidad de plata depositada obteniéndose para los menores depósitos índices efectivos 1.0 < n < 1.8 y 1.6 < k < 2.6 que corresponden, de acuerdo a los modelos utilizados, a una fracción volumétrica entre 0.35 y 0.5 d e plata en aire. Al aumentar la fracción volumétrica de plata se observa primeramente una disminución del espesor óptico efectivo de la película y para mayor cantidad de plata depositada se observa un aumento del espe sor con índices que tienden a valores má s p róximos a los de la plata maciza . Se comparan los índices ópticos obtenidos con los que se obtienen mediante las teorías de medio efectivo.

Metallosis is an uncommon but relevant phenomenon in total hip arthroplasty involving trunnionosis of the contact surfaces. It is understood as the release and deposition of metallic particles (chromium, cobalt and tungsten alloys) in the adjacent tissue, causing inflammation, chronic pain, osteolysis and even implant failure. This reaction brings about new arthroplasty revision surgeries that often present a challenge to the orthopaedic surgeon and an increase in morbimortality. In this report, we present the case of a 61-year-old female patient with a left sub-capital hip fracture who underwent total hip arthroplasty with continued post-operative pain and dysfunction. A revision arthroplasty was performed 16 months later showing abundant metallosis of the surrounding tissues in addition to dissociation of the polyethylene liner with no apparent cup damage, for which head and liner exchange was performed. Due to failure of symptom improvement, a new revision arthroplasty was performed 6 months later consisting of a dual mobility cup replacement and a ceramic-on-ceramic bearing couple. Although this complication rarely affects metal-on-polyethylene contact surfaces, it has been consistently demonstrated that it is not exclusive to metal-on-metal contact surfaces, highlighting the importance of a collaborative approach between surgeons and implant registries to guide operative treatment as well as understanding component design.

The objective was to analyze the relationship between socioeconomic status and age at menarche among indigenous and non-indigenous girls in the Araucanía Region of Chile, controlling for nutritional status and mother's age at menarche. A total of 8,624 randomly selected girls from 168 schools were screened, resulting in the selection of 207 indigenous and 200 non-indigenous girls who had recently experienced menarche. Age at menarche was 149.6±10.7 months in the indigenous group and 146.6±10.8 months in the non-indigenous group. Among the non-indigenous, the analysis showed no significant association between age at menarche and socioeconomic status. In the indigenous group, age at menarche among girls with low socioeconomic status was 5.4 months later than among those with higher socioeconomic status. There were no differences in nutritional status according to socioeconomic level. Obesity was associated with earlier menarche. Menarche occurred earlier than in previous generations. An inverse relationship between socioeconomic status and age at menarche was seen in the indigenous group only; low socioeconomic status was associated with delayed menarche, regardless of nutritional status or mother's age at menarche.El objetivo fue analizar la relación entre nivel socioeconómico y edad de menarquia en adolescentes indígenas y no indígenas de la Región de la Araucanía, Chile, controlando el efecto del estado nutricional, y la edad de menarquia de las madres. Se estudiaron 8.624 niñas de 168 escuelas elegidas aleatoriamente, seleccionando 207 indígenas y 200 no indígenas que habían tenido recientemente la menarquia. La edad de menarquia ocurrió a los 149,6±10,7 meses en indígenas y a los 146,6±10,8 meses en no indígenas. En el grupo no indígena, hubo una relación significativa entre edad de menarquia y nivel socioeconómico. En el grupo indígena, edad de menarquia del nivel socioeconómico bajo fue de 5,4 meses más tarde que el nivel socioeconómico más alto. No se observaron diferencias de estado nutricional por nivel socioeconómico. La obesidad adelantó la menarquia y la edad de menarquia ocurrió antes que la de sus madres. Existe una relación inversa entre nivel socioeconómico y edad de menarquia sólo en el grupo indígena; en los niveles socioeconómicos más bajos la edad de menarquia se retrasa independiente del estado nutricional y de la edad de menarquia de la madre.

Background/Aims. Acute kidney injury is a common problem for patients with cirrhosis and is associated with poor survival. We aimed to examine the association between type of acute kidney injury and 90-day mortality. Methods. Prospective cohort study at a major US liver transplant center. A nephrologist’s review of the urinary sediment was used in conjunction with the 2007 Ascites Club Criteria to stratify acute kidney injury into four groups: prerenal azotemia, hepatorenal syndrome, acute tubular necrosis, or other. Results. 120 participants with cirrhosis and acute kidney injury were analyzed. Ninety-day mortality was 14/40 (35%) with prerenal azotemia, 20/35 (57%) with hepatorenal syndrome, 21/36 (58%) with acute tubular necrosis, and 1/9 (11%) with other (p=0.04 overall). Mortality was the same in hepatorenal syndrome compared to acute tubular necrosis (p=0.99). Mortality was lower in prerenal azotemia compared to hepatorenal syndrome (p=0.05) and acute tubular necrosis (p=0.04). Ten participants (22%) were reclassified from hepatorenal syndrome to acute tubular necrosis because of granular casts on urinary sediment. Conclusions. Hepatorenal syndrome and acute tubular necrosis result in similar 90-day mortality. Review of urinary sediment may add important diagnostic information to this population. Multicenter studies are needed to validate these findings and better guide management.