Ultrasoft platelet-like particles stop bleeding in rodent and porcine models of trauma.

Uncontrolled bleeding after trauma represents a substantial clinical problem. The current standard of care to treat bleeding after trauma is transfusion of blood products including platelets; however, donated platelets have a short shelf life, are in limited supply, and carry immunogenicity and contamination risks. Consequently, there is a critical need to develop hemostatic platelet alternatives. To this end, we developed synthetic platelet-like particles (PLPs), formulated by functionalizing highly deformable microgel particles composed of ultralow cross-linked poly (N-isopropylacrylamide) with fibrin-binding ligands. The fibrin-binding ligand was designed to target to wound sites, and the cross-linking of fibrin polymers was designed to enhance clot formation. The ultralow cross-linking of the microgels allows the particles to undergo large shape changes that mimic platelet shape change after activation; when coupled to fibrin-binding ligands, this shape change facilitates clot retraction, which in turn can enhance clot stability and contribute to healing. Given these features, we hypothesized that synthetic PLPs could enhance clotting in trauma models and promote healing after clotting. We first assessed PLP activity in vitro and found that PLPs selectively bound fibrin and enhanced clot formation. In murine and porcine models of traumatic injury, PLPs reduced bleeding and facilitated healing of injured tissue in both prophylactic and immediate treatment settings. We determined through biodistribution experiments that PLPs were renally cleared, possibly enabled by ultrasoft particle properties. The performance of synthetic PLPs in the preclinical studies shown here supports future translational investigation of these hemostatic therapeutics in a trauma setting.

The interplay of fibroblasts, the extracellular matrix, and inflammation in scar formation.

Various forms of fibrosis, comprising tissue thickening and scarring, are involved in 40% of deaths across the world. Since the discovery of scarless functional healing in fetuses prior to a certain stage of development, scientists have attempted to replicate scarless wound healing in adults with little success. While the extracellular matrix (ECM), fibroblasts, and inflammatory mediators have been historically investigated as separate branches of biology, it has become increasingly necessary to consider them as parts of a complex and tightly regulated system that becomes dysregulated in fibrosis. With this new paradigm, revisiting fetal scarless wound healing provides a unique opportunity to better understand how this highly regulated system operates mechanistically. In the following review, we navigate the four stages of wound healing (hemostasis, inflammation, repair, and remodeling) against the backdrop of adult versus fetal wound healing, while also exploring the relationships between the ECM, effector cells, and signaling molecules. We conclude by singling out recent findings that offer promising leads to alter the dynamics between the ECM, fibroblasts, and inflammation to promote scarless healing. One factor that promises to be significant is fibroblast heterogeneity and how certain fibroblast subpopulations might be predisposed to scarless healing. Altogether, reconsidering fetal wound healing by examining the interplay of the various factors contributing to fibrosis provides new research directions that will hopefully help us better understand and address fibroproliferative diseases, such as idiopathic pulmonary fibrosis, liver cirrhosis, systemic sclerosis, progressive kidney disease, and cardiovascular fibrosis.

The Combined Influence of Viscoelastic and Adhesive Cues on Fibroblast Spreading and Focal Adhesion Organization.

INTRODUCTION: Tissue fibrosis is characterized by progressive extracellular matrix (ECM) stiffening and loss of viscoelasticity that ultimately impairs organ functionality. Cells bind to the ECM through integrins, where αv integrin engagement in particular has been correlated with fibroblast activation into contractile myofibroblasts that drive fibrosis progression. There is a significant unmet need for in vitro hydrogel systems that deconstruct the complexity of native tissues to better understand the individual and combined effects of stiffness, viscoelasticity, and integrin engagement on fibroblast behavior. METHODS: We developed hyaluronic acid hydrogels with independently tunable cell-instructive properties (stiffness, viscoelasticity, ligand presentation) to address this challenge. Hydrogels with mechanics matching normal or fibrotic lung tissue were synthesized using a combination of covalent crosslinks and supramolecular interactions to tune viscoelasticity. Cell adhesion was mediated through incorporation of either RGD peptide or engineered fibronectin fragments promoting preferential integrin engagement via αvß3 or α5ß1. RESULTS: On fibrosis-mimicking stiff elastic hydrogels, preferential αvß3 engagement promoted increased spreading, actin stress fiber organization, and focal adhesion maturation as indicated by paxillin organization in human lung fibroblasts. In contrast, preferential α5ß1 binding suppressed these metrics. Viscoelasticity, mimicking the mechanics of healthy tissue, largely curtailed fibroblast spreading and focal adhesion organization independent of adhesive ligand type, highlighting its role in reducing fibroblast-activating behaviors. CONCLUSIONS: Together, these results provide new insights into how mechanical and adhesive cues collectively guide disease-relevant cell behaviors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12195-021-00672-1.

LEM domain-containing protein 3 antagonizes TGFß-SMAD2/3 signaling in a stiffness-dependent manner in both the nucleus and cytosol.

Transforming growth factor-ß (TGFß) signaling through SMAD2/3 is an important driver of pathological fibrosis in multiple organ systems. TGFß signaling and extracellular matrix (ECM) stiffness form an unvirtuous pathological circuit in which matrix stiffness drives activation of latent TGFß, and TGFß signaling then drives cellular stress and ECM synthesis. Moreover, ECM stiffness also appears to sensitize cells to exogenously activated TGFß through unknown mechanisms. Here, using human fibroblasts, we explored the effect of ECM stiffness on a putative inner nuclear membrane protein, LEM domain-containing protein 3 (LEMD3), which is physically connected to the cell's actin cytoskeleton and inhibits TGFß signaling. We showed that LEMD3-SMAD2/3 interactions are inversely correlated with ECM stiffness and TGFß-driven luciferase activity and that LEMD3 expression is correlated with the mechanical response of the TGFß-driven luciferase reporter. We found that actin polymerization but not cellular stress or LEMD3-nuclear-cytoplasmic couplings were necessary for LEMD3-SMAD2/3 interactions. Intriguingly, LEMD3 and SMAD2/3 frequently interacted in the cytosol, and we discovered LEMD3 was proteolytically cleaved into protein fragments. We confirmed that a consensus C-terminal LEMD3 fragment binds SMAD2/3 in a stiffness-dependent manner throughout the cell and is sufficient for antagonizing SMAD2/3 signaling. Using human lung biopsies, we observed that these nuclear and cytosolic interactions are also present in tissue and found that fibrotic tissues exhibit locally diminished and cytoplasmically shifted LEMD3-SMAD2/3 interactions, as noted in vitro Our work reveals novel LEMD3 biology and stiffness-dependent regulation of TGFß by LEMD3, providing a novel target to antagonize pathological TGFß signaling.

Factores de riesgo para el fracaso de destete en una población de pacientes con EPOC en ventilación mecánica prolongada / Risk Factors for Weaning Failure in Patients with Chronic Obstructive Pulmonary Disease in Prolonged Mechanical Ventilation

Introducción: Los pacientes con EPOC experimentan episodios de falla respiratoria que requieren de asistencia ventilatoria mecánica (AVM). Debido al compromiso pulmonar, muscular y nutricional, experimentan dificultad en el destete. Hay escasa información de los factores que puedan predecir el fracaso del destete en pacientes con EPOC en VM prolongada (VMP). El objetivo de este trabajo es encontrar factores de riesgo para el fracaso del destete en pacientes con EPOC y evaluar mortalidad según éxito o fracaso en el destete. Materiales y Métodos: El estudio se realizó en un centro de weaning (CW) y se incluyeron pacientes internados en una unidad de terapia intensiva (UTI) por reagudización de su EPOC derivados a nuestro CW traqueostomizados con requerimiento de AVM. Resultados: Se recolectaron los datos de 40 pacientes, de los cuales 21 finalizaron AVM de manera exitosa y 19 fracasaron. El análisis univariado arrojó 4 variables asociadas al fracaso del destete: Pimax (p = 0.035), días de AVM en el CW (p = 0.005), pH (p = 0.039) y la PaCO2 (p = 0.002). Sin embargo, solo la PaCO2 a las 12hs de la prueba de respiración espontánea (PRE) fue predictor de fracaso de destete (p = 0.007). No se encontraron predictores de mortalidad. Conclusión: Encontrar factores de riesgo que permitan identificar el fracaso en la desvinculación de la VM puede contribuir en la decisión de insistir con el destete, o bien, plantear un programa de internación domiciliaria con la finalidad de mejorar la calidad de vida. La única variable asociada al fracaso de destete fue la PaCO2 a las 12hs de comenzada la PRE.

Introduction: Patients suffering from chronic obstructive pulmonary disease (COPD) have an airflow limitation and require mechanical ventilation (MV). Because of deteriorated lung function, respiratory muscles weakness and malnutrition, patients also present difficulties in the weaning process. Information on the factors that can predict weaning failure in patients with COPD after prolonged MV is scarce. To identify risk factors for weaning failure in patients with COPD and evaluate the mortality depending on weaning success or failure. Materials and Methods: This study was carried out at a weaning center in Buenos Aires, Argentina. We evaluated patients admitted to an intensive care unit (ICU) and referred to the weaning center as a result of COPD exacerbation, after tracheostomy and in need of mechanical ventilation. Results: Data from 40 patients were collected; 21 were successfully weaned from MV and 19 failed the weaning process. Univariate analysis showed 4 variables associated with weaning failure: maximum inspiratory pressure (MIP) (p = 0.035), length of MV at weaning center (p = 0.005), pH (p = 0.039) and PaCO2 (p = 0.002). However, only PaCO2 twelve hours after the spontaneous breathing trial (SBT) was a predictor of weaning failure (p=0.007). Mortality predictors were not found. Conclusion: The only predictive variable associated with weaning failure was PaCO2 twelve hours after SBT. Finding risk factors for failure in discontinuing MV may provide information to decide whether to insist in the weaning process or choose home MV to improve life quality.

Factores de riesgo para el fracaso de destete en una población de pacientes con EPOC en ventilación mecánica prolongada

Introducción: Los pacientes con EPOC experimentan episodios de falla respiratoria que requieren de asistencia ventilatoria mecánica (AVM). Debido al compromiso pulmonar, muscular y nutricional, experimentan dificultad en el destete. Hay escasa información de los factores que puedan predecir el fracaso del destete en pacientes con EPOC en VM prolongada (VMP). El objetivo de este trabajo es encontrar factores de riesgo para el fracaso del destete en pacientes con EPOC y evaluar mortalidad según éxito o fracaso en el destete. Materiales y Métodos: El estudio se realizó en un centro de weaning (CW) y se incluyeron pacientes internados en una unidad de terapia intensiva (UTI) por reagudización de su EPOC derivados a nuestro CW traqueostomizados con requerimiento de AVM. Resultados: Se recolectaron los datos de 40 pacientes, de los cuales 21 finalizaron AVM de manera exitosa y 19 fracasaron. El análisis univariado arrojó 4 variables asociadas al fracaso del destete: Pimax (p = 0.035), días de AVM en el CW (p = 0.005), pH (p = 0.039) y la PaCO2 (p = 0.002). Sin embargo, solo la PaCO2 a las 12hs de la prueba de respiración espontánea (PRE) fue predictor de fracaso de destete (p = 0.007). No se encontraron predictores de mortalidad. Conclusión: Encontrar factores de riesgo que permitan identificar el fracaso en la desvinculación de la VM puede contribuir en la decisión de insistir con el destete, o bien, plantear un programa de internación domiciliaria con la finalidad de mejorar la calidad de vida. La única variable asociada al fracaso de destete fue la PaCO2 a las 12hs de comenzada la PRE.(AU)

Introduction: Patients suffering from chronic obstructive pulmonary disease (COPD) have an airflow limitation and require mechanical ventilation (MV). Because of deteriorated lung function, respiratory muscles weakness and malnutrition, patients also present difficulties in the weaning process. Information on the factors that can predict weaning failure in patients with COPD after prolonged MV is scarce. To identify risk factors for weaning failure in patients with COPD and evaluate the mortality depending on weaning success or failure. Materials and Methods: This study was carried out at a weaning center in Buenos Aires, Argentina. We evaluated patients admitted to an intensive care unit (ICU) and referred to the weaning center as a result of COPD exacerbation, after tracheostomy and in need of mechanical ventilation. Results: Data from 40 patients were collected; 21 were successfully weaned from MV and 19 failed the weaning process. Univariate analysis showed 4 variables associated with weaning failure: maximum inspiratory pressure (MIP) (p = 0.035), length of MV at weaning center (p = 0.005), pH (p = 0.039) and PaCO2 (p = 0.002). However, only PaCO2 twelve hours after the spontaneous breathing trial (SBT) was a predictor of weaning failure (p=0.007). Mortality predictors were not found. Conclusion: The only predictive variable associated with weaning failure was PaCO2 twelve hours after SBT. Finding risk factors for failure in discontinuing MV may provide information to decide whether to insist in the weaning process or choose home MV to improve life quality.(AU)

Decanulación después de la estadía en UCI: Análisis de 181 pacientes traqueotomizados / Decannulation after the ICU Stay. Analysis of 181 Tracheostomized Patients

Objetivo: Encontrar predictores de decanulación en pacientes traqueostomizados y desvinculados de la asistencia ventilatoria mecánica. Analizar la mortalidad en el centro de weaning y supervivencia al alta. Materiales y métodos: Estudio retrospectivo. Se revisaron historias clínicas de pacientes que ingresaron al centro de weaning entre enero de 2004 y junio de 2011. Se estudiaron diferentes variables como posibles predictores de decanulación. Se analizó la mortalidad y se realizó seguimiento al alta. Resultados: Se incluyeron 181 pacientes con una media de 62 años. Se logró decanular al 44.2% de los pacientes (mediana 20 días). El análisis univariado encontró 6 variables asociadas al fracaso de decanulación: sexo masculino, antecedentes respiratorios, antecedentes cardiovasculares, albúmina al ingreso al centro de weaning, días de internación en centro de weaning y días de internación en Unidad de Cuidados Intensivos + centro de weaning. La regresión logística encontró como predictores independientes: sexo masculino y antecedentes respiratorios. En el análisis de regresión logística la decanulación fue un factor protectivo con respecto a la mortalidad. El 80% de los pacientes decanulados y el 15,8% de los no decanulados obtuvieron alta médica. La mediana de supervivencia de los decanulados fue de 45.47 meses y los no decanulados de 10.87. Conclusiones: Los pacientes de sexo masculino y aquellos con antecedentes respiratorios se asocian con fracaso de decanulación. Los pacientes decanulados tienen menor riesgo de muerte durante la internación.

Objective: Find predictors of decannulation in tracheostomized patients and without mechanical ventilation. A secondary objective was the analysis of mortality in the weaning center and survival at discharge. Material and methods: We reviewed, retrospectively, the medical records of patients admitted to the weaning center with tracheostomy and without mechanical ventilation between January 2004 and June 2011. Different variables as possible predictors of decannulation were studied. Mortality at weaning center and outcomes during follow up after discharge were analyzed. Results: We included 181 patients with an average age of 62 years old. Decannulation was carried out in 44.2% of the patients. The decannulation process took 20 days. The univariate analysis found six variables associated with decannulation failure: male gender, respiratory or cardiovascular history, albumin at admission to the weaning center, days of hospitalization in the weaning center and admission to intensive care units plus the weaning center. Logistic regression analysis found that male sex and respiratory history were independent predictors. Regarding mortality during hospitalization, logistic regression analysis found that decannulation was a protective factor. Another finding was that 80% of patients decannulated were discharged; only 15.8% of the group was not decannulated. The average survival was 45.47 months among the decannulated patients and 10.87 months for the non decannulated patients. Conclusions: We found that male sex and a history of respiratory failure were factors associated with unsuccessful decannulation. Decannulated patients had lower risk of death during hospitalization.

Decanulación después de la estadía en UCI: Análisis de 181 pacientes traqueotomizados

Objetivo: Encontrar predictores de decanulación en pacientes traqueostomizados y desvinculados de la asistencia ventilatoria mecánica. Analizar la mortalidad en el centro de weaning y supervivencia al alta. Materiales y métodos: Estudio retrospectivo. Se revisaron historias clínicas de pacientes que ingresaron al centro de weaning entre enero de 2004 y junio de 2011. Se estudiaron diferentes variables como posibles predictores de decanulación. Se analizó la mortalidad y se realizó seguimiento al alta. Resultados: Se incluyeron 181 pacientes con una media de 62 años. Se logró decanular al 44.2% de los pacientes (mediana 20 días). El análisis univariado encontró 6 variables asociadas al fracaso de decanulación: sexo masculino, antecedentes respiratorios, antecedentes cardiovasculares, albúmina al ingreso al centro de weaning, días de internación en centro de weaning y días de internación en Unidad de Cuidados Intensivos + centro de weaning. La regresión logística encontró como predictores independientes: sexo masculino y antecedentes respiratorios. En el análisis de regresión logística la decanulación fue un factor protectivo con respecto a la mortalidad. El 80% de los pacientes decanulados y el 15,8% de los no decanulados obtuvieron alta médica. La mediana de supervivencia de los decanulados fue de 45.47 meses y los no decanulados de 10.87. Conclusiones: Los pacientes de sexo masculino y aquellos con antecedentes respiratorios se asocian con fracaso de decanulación. Los pacientes decanulados tienen menor riesgo de muerte durante la internación.(AU)

Objective: Find predictors of decannulation in tracheostomized patients and without mechanical ventilation. A secondary objective was the analysis of mortality in the weaning center and survival at discharge. Material and methods: We reviewed, retrospectively, the medical records of patients admitted to the weaning center with tracheostomy and without mechanical ventilation between January 2004 and June 2011. Different variables as possible predictors of decannulation were studied. Mortality at weaning center and outcomes during follow up after discharge were analyzed. Results: We included 181 patients with an average age of 62 years old. Decannulation was carried out in 44.2% of the patients. The decannulation process took 20 days. The univariate analysis found six variables associated with decannulation failure: male gender, respiratory or cardiovascular history, albumin at admission to the weaning center, days of hospitalization in the weaning center and admission to intensive care units plus the weaning center. Logistic regression analysis found that male sex and respiratory history were independent predictors. Regarding mortality during hospitalization, logistic regression analysis found that decannulation was a protective factor. Another finding was that 80% of patients decannulated were discharged; only 15.8% of the group was not decannulated. The average survival was 45.47 months among the decannulated patients and 10.87 months for the non decannulated patients. Conclusions: We found that male sex and a history of respiratory failure were factors associated with unsuccessful decannulation. Decannulated patients had lower risk of death during hospitalization.(AU)

Time series evaluation of traumatic lesions and airsacculitis at one poultry abattoir in the state of São Paulo, Brazil (1996-2005).

Ten year official condemnation records of one officially inspected poultry abattoir in state of São Paulo, Brazil, were analyzed. Seasonal and cyclical trends were analyzed in relation to traumatic lesions and airsacculitis, which were the most relevant official condemnation causes. Time series analysis of the records, seasonal indexes and moving averages was used to describe the adherence to the mathematical model and to offer preventive management strategies for the slaughterhouse industry. Although cause-effect relationships were not defined, some insight was given into the causal mechanisms that generated the series.

Toxoplasma gondii genotyping in a dog co-infected with distemper virus and ehrlichiosis rickettsia

This paper reports a toxoplasmosis, erhlichiosis and distemper co-infection in a dog with an exuberant neuropathological clinical picture. Primary involvement was discussed based on information collected in the analysis of the clinical case, such as neurological impairment, epidemiological data, poor immunoprophylactic scheme of the dog affected and the role of these diseases on immunosuppression. Canine distemper and ehrlichiosis were diagnosed based on epidemiologic data, clinical signs, hematological and cytological evaluation. Toxoplasma gondii was isolated and genetically characterized as Type I using restriction analysis (RFLP) with SAG-2 genes. Immunosuppression features of both dogs and human beings are discussed, as well as implications on animal and public health. This is the first report on toxoplasmosis, ehrlichiosis and distemper co-infection in a dog in Brazil, associated with genotyping determination of the T. gondii strain involved.

Este artigo relata a co-infecção tripla pelos agentes da cinomose, erliquiose e toxoplasmose em um cão com acentuado quadro clínico neuropático. Discute-se a doença primária baseando-se em dados clínicos, epidemiológicos, no protocolo imunoprofilático inadequado e no papel daquelas doenças na imunossupressão. A cinomose e a erliquiose foram diagnosticadas mediante a situação epidemiológica da região e sinais clínicos compatíveis, aliados aos achados de hemograma e citologia. Utilizando-se a análise de restrição (RFLP) com os genes SAG-2, caracterizou-se geneticamente a linhagem de Toxoplasma gondii isolada, como pertencente ao Tipo I. Discutem-se aspectos de imunossupressão, tanto em cães quanto em seres humanos, bem como suas implicações em saúde pública e animal. Este é o primeiro relato de infecção tripla pelos agentes da toxoplasmose, erliquiose e cinomose no Brasil, associado com a genotipificação da estirpe de T. gondii envolvida.

Toxoplasma gondii genotyping in a dog co-infected with distemper virus and ehrlichiosis rickettsia.

This paper reports a toxoplasmosis, ehrlichiosis and distemper co-infection in a dog with an exuberant neuropathological clinical picture. Primary involvement was discussed based on information collected in the analysis of the clinical case, such as neurological impairment, epidemiological data, poor immunoprophylactic scheme of the dog affected and the role of these diseases on immunosuppression. Canine distemper and ehrlichiosis were diagnosed based on epidemiologic data, clinical signs, hematological and cytological evaluation. Toxoplasma gondii was isolated and genetically characterized as Type I using restriction analysis (RFLP) with SAG-2 genes. Immunosuppression features of both dogs and human beings are discussed, as well as implications on animal and public health. This is the first report on toxoplasmosis, ehrlichiosis and distemper co-infection in a dog in Brazil, associated with genotyping determination of the T. gondii strain involved.

Genotyping of Toxoplasma gondii strains isolated from dogs with neurological signs.

From 111 dogs with neurological signs admitted in this research in a 22-month period, brain samples of 34 animals were inoculated in mice in order to isolate Toxoplasma gondii. From these 34 dogs, 9 strains of T. gondii were isolated and the genetic characterization performed by restriction analysis (RFLP) of the SAG-2 gene. RFLP analysis showed that four of them were classified as Type I, and five as Type III. The present report is the first description of genotyping of T. gondii isolated from brain samples of naturally infected dogs, in Brazil.