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It is currently not well known how necroptosis and necroptosis responses manifest in vivo. Here, we uncovered a molecular switch facilitating reprogramming between two alternative modes of necroptosis signaling in hepatocytes, fundamentally affecting immune responses and hepatocarcinogenesis. Concomitant necrosome and NF-κB activation in hepatocytes, which physiologically express low concentrations of receptor-interacting kinase 3 (RIPK3), did not lead to immediate cell death but forced them into a prolonged "sublethal" state with leaky membranes, functioning as secretory cells that released specific chemokines including CCL20 and MCP-1. This triggered hepatic cell proliferation as well as activation of procarcinogenic monocyte-derived macrophage cell clusters, contributing to hepatocarcinogenesis. In contrast, necrosome activation in hepatocytes with inactive NF-κB-signaling caused an accelerated execution of necroptosis, limiting alarmin release, and thereby preventing inflammation and hepatocarcinogenesis. Consistently, intratumoral NF-κB-necroptosis signatures were associated with poor prognosis in human hepatocarcinogenesis. Therefore, pharmacological reprogramming between these distinct forms of necroptosis may represent a promising strategy against hepatocellular carcinoma.
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Neoplasias Hepáticas , FN-kappa B , Humanos , FN-kappa B/metabolismo , Proteínas Quinasas/metabolismo , Necroptosis , Inflamación/patología , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , ApoptosisRESUMEN
Human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causative pathogen of the COVID-19 pandemic, exerts a massive health and socioeconomic crisis. The virus infects alveolar epithelial type 2 cells (AT2s), leading to lung injury and impaired gas exchange, but the mechanisms driving infection and pathology are unclear. We performed a quantitative phosphoproteomic survey of induced pluripotent stem cell-derived AT2s (iAT2s) infected with SARS-CoV-2 at air-liquid interface (ALI). Time course analysis revealed rapid remodeling of diverse host systems, including signaling, RNA processing, translation, metabolism, nuclear integrity, protein trafficking, and cytoskeletal-microtubule organization, leading to cell cycle arrest, genotoxic stress, and innate immunity. Comparison to analogous data from transformed cell lines revealed respiratory-specific processes hijacked by SARS-CoV-2, highlighting potential novel therapeutic avenues that were validated by a high hit rate in a targeted small molecule screen in our iAT2 ALI system.
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Células Epiteliales Alveolares/metabolismo , COVID-19/metabolismo , Fosfoproteínas/metabolismo , Proteoma/metabolismo , SARS-CoV-2/metabolismo , Células Epiteliales Alveolares/patología , Células Epiteliales Alveolares/virología , Animales , Antivirales , COVID-19/genética , COVID-19/patología , Chlorocebus aethiops , Efecto Citopatogénico Viral , Citoesqueleto , Evaluación Preclínica de Medicamentos , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Células Madre Pluripotentes Inducidas/virología , Fosfoproteínas/genética , Transporte de Proteínas , Proteoma/genética , SARS-CoV-2/genética , Transducción de Señal , Células Vero , Tratamiento Farmacológico de COVID-19RESUMEN
Emphysema and chronic obstructive pulmonary disease (COPD) most commonly result from the effects of environmental exposures in genetically susceptible individuals. Genome-wide association studies have implicated ADGRG6 in COPD and reduced lung function, and a limited number of studies have examined the role of ADGRG6 in cells representative of the airway. However, the ADGRG6 locus is also associated with DLCO/VA, an indicator of gas exchange efficiency and alveolar function. Here, we sought to evaluate the mechanistic contributions of ADGRG6 to homeostatic function and disease in type 2 alveolar epithelial cells. We applied an inducible CRISPR interference (CRISPRi) human induced pluripotent stem cell (iPSC) platform to explore ADGRG6 function in iPSC-derived AT2s (iAT2s). We demonstrate that ADGRG6 exerts pleiotropic effects on iAT2s including regulation of focal adhesions, cytoskeleton, tight junctions, and proliferation. Moreover, we find that ADGRG6 knockdown in cigarette smoke-exposed iAT2s alters cellular responses to injury, downregulating apical complexes in favor of proliferation. Our work functionally characterizes the COPD GWAS gene ADGRG6 in human alveolar epithelium.
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Células Madre Pluripotentes Inducidas , Enfermedad Pulmonar Obstructiva Crónica , Receptores Acoplados a Proteínas G , Humanos , Células Epiteliales Alveolares/metabolismo , Células Epiteliales/metabolismo , Estudio de Asociación del Genoma Completo , Células Madre Pluripotentes Inducidas/metabolismo , Pulmón/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/genética , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Receptores Acoplados a Proteínas G/genéticaRESUMEN
The molecular factors and genetic adaptations that contributed to the emergence of Mycobacterium tuberculosis (MTB) from an environmental Mycobacterium canettii-like ancestor, remain poorly investigated. In MTB, the PhoPR two-component regulatory system controls production and secretion of proteins and lipid virulence effectors. Here, we describe that several mutations, present in phoR of M. canettii relative to MTB, impact the expression of the PhoP regulon and the pathogenicity of the strains. First, we establish a molecular model of PhoR and show that some substitutions found in PhoR of M. canettii are likely to impact the structure and activity of this protein. Second, we show that STB-K, the most attenuated available M. canettii strain, displays lower expression of PhoP-induced genes than MTB. Third, we demonstrate that genetic swapping of the phoPR allele from STB-K with the ortholog from MTB H37Rv enhances expression of PhoP-controlled functions and the capacities of the recombinant strain to colonize human macrophages, the MTB target cells, as well as to cause disease in several mouse infection models. Fourth, we extended these observations to other M. canettii strains and confirm that PhoP-controlled functions are expressed at lower levels in most M. canettii strains than in M. tuberculosis. Our findings suggest that distinct PhoR variants have been selected during the evolution of tuberculosis bacilli, contributing to higher pathogenicity and persistence of MTB in the mammalian host.
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Mycobacterium tuberculosis , Tuberculosis , Animales , Ratones , Humanos , Virulencia/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Mutación , Tuberculosis/microbiología , MamíferosRESUMEN
We investigated the role of ligand clustering and density in the activation of natural killer (NK) cells. To that end, we designed reductionist arrays of nanopatterned ligands arranged with different cluster geometries and densities and probed their effects on NK cell activation. We used these arrays as an artificial microenvironment for the stimulation of NK cells and studied the effect of the array geometry on the NK cell immune response. We found that ligand density significantly regulated NK cell activation while ligand clustering had an impact only at a specific density threshold. We also rationalized these findings by introducing a theoretical membrane fluctuation model that considers biomechanical feedback between ligand-receptor bonds and the cell membrane. These findings provide important insight into NK cell mechanobiology, which is fundamentally important and essential for designing immunotherapeutic strategies targeting cancer.
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Membrana Celular , Células Asesinas Naturales , Células Asesinas Naturales/inmunología , Membrana Celular/química , Membrana Celular/metabolismo , Humanos , Ligandos , Activación de Linfocitos , Fenómenos Biomecánicos , Modelos BiológicosRESUMEN
Cancer testis antigens (CTAs) are an extensive gene family with a unique expression pattern restricted to germ cells, but aberrantly reactivated in cancer tissues. Studies indicate that the expression (or re-expression) of CTAs within the MAGE-A family is common in hepatocellular carcinoma (HCC). However, no systematic characterization has yet been reported. The aim of this study is to perform a comprehensive profile of CTA de-regulation in HCC and experimentally evaluate the role of MAGEA3 as a driver of HCC progression. The transcriptomic analysis of 44 multi-regionally sampled HCCs from 12 patients identified high intra-tumor heterogeneity of CTAs. In addition, a subset of CTAs was significantly overexpressed in histologically poorly differentiated regions. Further analysis of CTAs in larger patient cohorts revealed high CTA expression related to worse overall survival and several other markers of poor prognosis. Functional analysis of MAGEA3 was performed in human HCC cell lines by gene silencing and in a genetic mouse model by overexpression of MAGEA3 in the liver. Knockdown of MAGEA3 decreased cell proliferation, colony formation and increased apoptosis. MAGEA3 overexpression was associated with more aggressive tumors in vivo. In conclusion MAGEA3 enhances tumor progression and should be considered as a novel therapeutic target in HCC.
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Antígenos de Neoplasias/genética , Antígenos de Neoplasias/inmunología , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Proteínas de Neoplasias/genética , Testículo/inmunología , Transcriptoma , Apoptosis/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/inmunología , Proliferación Celular/genética , Progresión de la Enfermedad , Perfilación de la Expresión Génica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/inmunología , Masculino , Pronóstico , Regulación hacia ArribaRESUMEN
PURPOSE: To examine the link between tremor and sex chromosome abnormalities, emphasizing the necessity of comprehensive physical examination. CASE DESCRIPTION: An 18-year-old man exhibited an isolated action tremor in both hands. Despite having no familial history of tremors and no identifiable secondary causes, his tall stature and learning difficulties suggested a genetic origin. His karyotype confirmed the diagnosis of Jacob's syndrome (XYY syndrome). Therapies with primidone and propranolol were ineffective for his tremor. CONCLUSIONS: Tremor can be caused by various conditions, and aneuploidies might often be overlooked as a cause. They should be considered in young patients with concrete phenotypes and negative familiar history of tremors. Karyotyping is a cost-effective diagnostic tool crucial for genetic counselling. Common treatments for tremors often yield unsatisfactory results in these cases.
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Intensive home treatment (IHT) has shown to be a feasible alternative to hospitalization for the management of acute psychiatric episodes, but there are no real-world studies assessing if patients with a first IHT use it again for the management of their recurrences. The objectives of this retrospective cohort study were to map the use ofacute treatment resources after the implementation of IHT in our territory through the establishment of trajectories of management, and to disentangle if there are profiles of patients who fit better each trajectory. We included the first 1000 episodes admitted to IHT, of which we selected those that corresponded to the first IHT of a patient (index admission). Trajectories after the index admission were: (T-A) absence of use of acute resources, (T-B) only IHT, and (T-C) at least one hospitalization. Follow-up ranged from 6 months to 6 years. We calculated the frequency of each trajectory and performed univariate analyses searching for associations between trajectory and clinical factors. Among those patients with psychiatric history (N = 659), 66.2% followedT-A, 11.2% T-B, and 22.6% T-C. The probability of following T-C was higher for patients with a psychotic disorder (pBonf = 0.018) and with previous hospitalizations (pBonf < 0.0001). Among those patients without psychiatric history (N = 168), 82.7% followed T-A, 6.6% T-B, and 10.7% T-C. The probability of following T-B was higher for those with a higher severity at the index admission (pBonf = 0.028). This study shows that some -or even all- recurrences of some subjects were successfully managed with IHT, providing real-world evidence for its use in acute psychiatric conditions.
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Servicios de Atención de Salud a Domicilio , Humanos , Estudios Retrospectivos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Servicios de Atención de Salud a Domicilio/estadística & datos numéricos , Trastornos Mentales/terapia , Hospitalización/estadística & datos numéricos , Enfermedad AgudaRESUMEN
Water is becoming an increasingly scarce resource due to growing multi-sector demand and the effects of climate change. During droughts, the proportional rule is the most widespread water allocation method applied in irrigation systems. However, this method fails to guarantee efficient water allocation or to provide a fair method of water allocation. This paper aims to verify whether by replacing the water allocation methods based on a proportional rule with methods based on a priority rule could improve the allocation of water resources and minimize the negative economic impacts of water shortages. The ultimate objective of this research is to design a water pricing scheme capable of guaranteeing efficient water reallocation during drought conditions. Therefore, an experiment was carried out for the largest irrigated area in southern Italy, covered by the Capitanata Reclamation and Irrigation board (CBC). A positive mathematical programming model was implemented in order to simulate the effects of the proposed mechanism. The findings show that priority mechanisms have the potential to improve overall economic efficiency in the event of water shortages. However, results also point to the need for optimal design of a differentiated water pricing scheme.
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Abastecimiento de Agua , Agua , Sequías , Recursos Hídricos , Costos y Análisis de CostoRESUMEN
BACKGROUND: Developmental Dysplasia of the Hip (DDH) is a condition affecting hip joint development in children, presenting multiple manifestations. Immobilization methods to ensure hip concentricity, such as the human position and modified Lange position, vary in effectiveness and risks, especially avascular necrosis. The purpose of this study was to identify whether closed reduction (CR), with two different immobilization techniques, is effective in avoiding complications such as residual hip dysplasia (RHD), re-dislocation, and Avascular Necrosis (AVN). METHODS: A total of 66 patients with DDH (84 hips) were treated with two different techniques of immobilization (groups A and B); the mean age at the time of reduction was 8 (6-13) months. The rates of RHD, Re-dislocation, and AVN were determined with a minimum follow-up of 48 months in both techniques. RESULTS: The Chi-square analysis conducted across the study groups unveiled that patients in Group B demonstrated a protective effect against AVN compared to those in Group A (OR: 0.248, 95% CI: 0.072-0.847, p = 0.026). However, no statistically significant differences were found between the groups concerning RHD (p = 0.563) and re-dislocation (p = 0.909). CONCLUSIONS: After the initial Human Position immobilization, the second cast with the modified Lange "second position" demonstrated a protective effect compared with maintaining the Human Position immobilization throughout the immobilization period, reducing the likelihood of AVN development in patients undergoing closed reduction for developmental dysplasia of the hip.
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GENERAL PURPOSE: To review a practical and scientifically sound application of the wound bed preparation model for communities without ideal resources. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and registered nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant will:1. Summarize issues related to wound assessment.2. Identify a class of drugs for the treatment of type II diabetes mellitus that has been shown to improve glycemia, nephroprotection, and cardiovascular outcomes.3. Synthesize strategies for wound management, including treatment in resource-limited settings.4. Specify the target time for edge advancement in chronic, healable wounds.
Chronic wound management in low-resource settings deserves special attention. Rural or underresourced settings (ie, those with limited basic needs/healthcare supplies and inconsistent availability of interprofessional team members) may not have the capacity to apply or duplicate best practices from urban or abundantly-resourced settings. The authors linked world expertise to develop a practical and scientifically sound application of the wound bed preparation model for communities without ideal resources. A group of 41 wound experts from 15 countries reached a consensus on wound bed preparation in resource-limited settings. Each statement of 10 key concepts (32 substatements) reached more than 88% consensus. The consensus statements and rationales can guide clinical practice and research for practitioners in low-resource settings. These concepts should prompt ongoing innovation to improve patient outcomes and healthcare system efficiency for all persons with foot ulcers, especially persons with diabetes.
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Diabetes Mellitus Tipo 2 , Pie Diabético , Úlcera del Pie , Humanos , Técnica Delphi , Diabetes Mellitus Tipo 2/terapia , Pie Diabético/diagnóstico , Pie Diabético/terapia , Configuración de Recursos LimitadosRESUMEN
BACKGROUND: Antiphospholipid syndrome (APS) is the main cause of acquired thrombophilia where peripheral circulating cells such as monocytes have a key role. Currently, several studies have linked long non-coding RNAs (lncRNAs) in different inflammatory and autoimmune processes, including lupus. However, the role of lncRNAs in antiphospholipid syndrome is unknown, therefore, we aimed to select and measure expression levels of three lncRNAs based on its abundance in monocytes from APS patients. METHODS: Selection of lncRNAs candidates were carried out based on its abundance in monocytes and their relationship with Perez-Sanchez miRNA signature by using miRNet 2.0 bioinformatic tool, then lncRNAs expression levels was measured in monocytes by RT-qPCR. RESULTS: This is the first study to report that lncRNAs: FGD5-AS1, OIP5-AS1 and GAS5 are promising candidates for play a role on APS monocytes and they are expressed differently between patients and controls. CONCLUSIONS: OIP5-AS1, FGD5-AS1 and GAS5 are downregulated on monocytes from APS patients.
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Síndrome Antifosfolípido , MicroARNs , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Síndrome Antifosfolípido/genética , Monocitos/metabolismo , MicroARNs/genética , Biología ComputacionalRESUMEN
Fluorescent nucleobase analogues (FBAs) are established tools for studying oligonucleotide structure, dynamics and interactions, and have recently also emerged as an attractive option for labeling RNA-based therapeutics. A recognized drawback of FBAs, however, is that they typically require excitation in the UV region, which for imaging in biological samples may have disadvantages related to phototoxicity, tissue penetration, and out-of-focus photobleaching. Multiphoton excitation has the potential to alleviate these issues and therefore, in this work, we characterize the multiphoton absorption properties and detectability of the highly fluorescent quadracyclic adenine analogue 2CNqA as a ribonucleotide monomer as well as incorporated, at one or two positions, into a 16mer antisense oligonucleotide (ASO). We found that 2CNqA has a two-photon absorption cross section that, among FBAs, is exceptionally high, with values of σ2PA(700 nm) = 5.8 GM, 6.8 GM, and 13 GM for the monomer, single-, and double-labelled oligonucleotide, respectively. Using fluorescence correlation spectroscopy, we show that the 2CNqA has a high 2P brightness as the monomer and when incorporated into the ASO, comparing favorably to other FBAs. We furthermore demonstrate the usefulness of the 2P imaging mode for improving detectability of 2CNqA-labelled ASOs in live cells.
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Colorantes Fluorescentes , Oligonucleótidos , Colorantes Fluorescentes/química , Espectrometría de Fluorescencia/métodos , Nucleósidos de Purina , Adenina/químicaRESUMEN
INTRODUCTION: A National Cancer Information System is planned for phased implementation in Irish cancer centres to enable electronic prescribing (ePrescribing) of systemic anti-cancer therapy. This study aimed to capture the opinions of healthcare professionals in a hospital setting relating to the current paper-based workflow for systemic anti-cancer therapy prescribing and their attitudes and expectations of the new ePrescribing system to develop recommendations, which assist in the planning and implementation of future ePrescribing systems. METHODS: A mixed methods study of concurrent design was conducted. Interviews with healthcare professionals primarily aimed to evaluate processes and identify areas requiring improvement within the current paper-based workflow for systemic anti-cancer therapy prescribing. An online questionnaire adapted from the Information Systems Expectations and Experiences tool primarily aimed to capture expectations of the new ePrescribing system and attitudes towards the transition. RESULTS: Twelve healthcare professionals were interviewed, and 50 healthcare professionals responded to the online questionnaire (response rate: 33.3%). Eight major themes emerged from interview transcripts relating to opinions on the paper-based workflow. Questionnaire respondents reported positive attitudes towards ePrescribing implementation and had high expectations for workflow improvements and functionalities of the new system. Seven recommendations for ePrescribing implementation were developed: (1) prioritise specific processes; (2) plan for changes in communication; (3) repeat research in the post-implementation setting; (4) ensure good information technology infrastructure and system support; (5) ensure optimum training; (6) outline limitations of clinical decision support; (7) provide clear instructions on local configurability. CONCLUSION: This study identifies potential challenges in transitioning to ePrescribing and provides recommendations, which assist stakeholders in ensuring safe and effective transitions, thus informing future ePrescribing systems' implementation in haematology/oncology settings.
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Arthrospira platensis biomass is a sustainable source of bioactive products for the food, cosmetic, and medicine industries. As well as primary metabolites, different secondary metabolites can be obtained via distinct enzymatic degradation of biomass. In this work, different hydrophilic extracts were obtained after treating the biomass with: (i) a serine endo-peptidase (Alcalase®), (ii) a mixture of amino-, dipeptidyl-, and endo-peptidases (Flavourzyme®), (iii) a mixture of endo-1,3(4)-ß-glucanase and an endo-1,4-xylanase, and ß-glucanase (Ultraflo®), and (iv) an exo-1,3-glucanase (Vinoflow®) (all the enzymes from Novozymes A/S (bagsvaerd, Denmark)); with subsequent extraction of the biocomponents with an isopropanol/hexane mixture. The composition of each aqueous phase extract (in terms of amino acids, peptides, oligo-elements, carbohydrates, and phenols) and their in vitro functional properties were compared. The conditions described in this work using the enzyme Alcalase® permits the extraction of eight distinctive peptides. This extract is 7.3 times more anti-hypertensive, 106 times more anti-hypertriglyceridemic, 26 times more hypocholesterolemic, has 4.4 times more antioxidant activities, and has 2.3 times more phenols, than the extract obtained without any prior enzyme biomass digestion. Alcalase® extract is an advantageous product with potential application in functional food, pharmaceutics, and cosmetics.
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Antioxidantes , Spirulina , Antioxidantes/química , Antihipertensivos/farmacología , Antihipertensivos/metabolismo , Proteolisis , Biomasa , Proteínas/metabolismo , Péptidos/química , Spirulina/química , Subtilisinas/metabolismo , Fenoles/metabolismoRESUMEN
OBJECTIVE: Dental caries is one of the most common chronic diseases affecting millions of people globally. Some studies revealed the presence of bidirectional relationship between allergic rhinitis (AR) and oral diseases, with each disease having a potential impact on the other. In this study we aimed to systematically review the literature and analyze the available evidence regarding whether AR contributes to the development of dental caries. METHODS: Three authors, members of the YO-IFOS rhinology study group, independently analyzed the data sources (Pubmed, the Cochrane Library, EMBASE, SciELO) for papers assessing the relationship between rhinitis and caries, in adult and pediatric patients. RESULTS: Eight studies met the inclusion criteria (87612 participants). Six studies were performed in children. A total of three studies found an association between AR and dental caries. Only two studies had adjusted the measure of effect for potentially confounding variables. Regarding the quality of the selected studies according to the NICE classification, the most observed methodological limitations detected were: (1) the cross-sectional design of the included studies which could have introduced a simultaneity bias, and (2) not clearly reporting the inclusion and exclusion criteria. CONCLUSION: This systematic review can neither confirm nor deny the presence of an association between AR and caries. Despite the evidence is very scarce to conclude a relationship between AR and caries, the option for examining patients with repetitive caries by an otolaryngologist and those with AR by odontologist should be considered, as these examinations do not possess any risk for the patient.
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Caries Dental , Rinitis Alérgica , Adulto , Niño , Humanos , Estudios Transversales , Caries Dental/epidemiología , Rinitis Alérgica/epidemiologíaRESUMEN
OBJECTIVE: Adenoid hypertrophy may coexist, and often does, with rhinitis. Therefore, in some cases, adenoidectomy alone, despite the fact that it reduces nasal resistance, may be insufficient to restore nasal breathing. Juliusson et al. suggested using rhinomanometry with and without nasal decongestant as a method for selecting patients for adenoidectomy. In this study, we aim to assess whether the decongestant test, when using normative data, is useful to select children for adenoidectomy. METHODS: Children between 4 and 15 years old undergoing adenoidectomy were selected from two tertiary referral university hospitals. Participants underwent anterior active rhinomanometry with and without nasal decongestant before and after surgery. Parents fill in the sinus and nasal quality-of-life survey (SN5). RESULTS: 47 participants were included, and mean age 6.5 ± 2.15. 2 cohorts were defined according to the result of the nasal decongestant test (> 40% improvement in nasal resistance or not). There is a statistically significant difference between groups, with a higher improvement in nasal resistance and airflow after adenoidectomy in the group with less than 40% improvement in nasal resistance. CONCLUSIONS: In conclusion, this study supports the use of the decongestant test with rhinomanometry to select children for adenoidectomy; especially as it has proven to be a simple technique, harmless, fast, and easily performed on collaborative children.
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Tonsila Faríngea , Obstrucción Nasal , Humanos , Niño , Preescolar , Adolescente , Adenoidectomía , Rinomanometría , Descongestionantes Nasales/uso terapéutico , Estudios de Cohortes , Tonsila Faríngea/cirugía , Obstrucción Nasal/cirugía , Hipertrofia/cirugía , Hipertrofia/complicacionesRESUMEN
The uncoupling protein UCP2 is a mitochondrial carrier for which transport activity remains controversial. The physiological contexts in which UCP2 is expressed have led to the assumption that, like UCP1, it uncouples oxidative phosphorylation and thereby reduces the generation of reactive oxygen species. Other reports have involved UCP2 in the Warburg effect, and results showing that UCP2 catalyzes the export of matrix C4 metabolites to facilitate glutamine utilization suggest that the carrier could be involved in the metabolic adaptations required for cell proliferation. We have examined the role of UCP2 in the energy metabolism of the lung adenocarcinoma cell line A549 and show that UCP2 silencing decreased the basal rate of respiration, although this inhibition was not compensated by an increase in glycolysis. Silencing did not lead to either changes in proton leakage, as determined by the rate of respiration in the absence of ATP synthesis, or changes in the rate of formation of reactive oxygen species. The decrease in energy metabolism did not alter the cellular energy charge. The decreased cell proliferation observed in UCP2-silenced cells would explain the reduced cellular ATP demand. We conclude that UCP2 does not operate as an uncoupling protein, whereas our results are consistent with its activity as a C4-metabolite carrier involved in the metabolic adaptations of proliferating cells.
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Metabolismo Energético , Canales Iónicos , Neoplasias Pulmonares , Proteína Desacopladora 2 , Humanos , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Adenosina Trifosfato/metabolismo , Línea Celular , Canales Iónicos/genética , Canales Iónicos/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Proteínas Desacopladoras Mitocondriales/metabolismo , Neoplasias , Especies Reactivas de Oxígeno/metabolismo , Proteína Desacopladora 2/genética , Proteína Desacopladora 2/metabolismoRESUMEN
The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1low cells present a migratory and invasive phenotype, while EWSR1::FLI1high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.