384 research outputs found

    AVALIAÇÃO DA COMPACTAÇÃO DO SOLO EM ÁREA DE CERRADO sensu stricto ATRAVÉS DO MAPEAMENTO DA RESISTÊNCIA À PENETRAÇÃO

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    Avaliou-se a compactação do solo em uma área de cerrado sensu stricto através da resistência do solo à penetração e da densidade do solo. Foram considerados dois tratamentos. O tratamento 1 referiu-se a área de Cerrado não submetido a qualquer tipo de distúrbio antrópico e o tratamento 2, a Cerrado submetido a corte com lâmina e retirada da lenha. O experimento foi realizado em delineamento em blocos casualizados constituído por dois tratamentos e três blocos, sendo demarcadas em campo, seis parcelas de 20 x 50 m. Foram coletadas amostras de solo na área de estudo para a caracterização física e classificação. Os dados de densidade foram obtidos pelo método do anel volumétrico e os dados de resistência do solo á penetração porum penetrômetro de impacto. O solo da área de estudo apresentou comportamento argiloso laterítico,altamente plástico. As camadas de solo de 20 até 40 cm de profundidade apresentaram os maiores valores deresistência á penetração do solo para os dois tratamentos, com valor máximo próximo de 4,5 MPa (camadade 30 cm, tratamento sem perturbação), Não houve discrepância acentuada entre os valores de densidade do solo (0,71 até 0,77 g/cm³). O teste F mostrou haver diferenças estatísticas entre os tratamentos, tanto para a resistência à penetração quanto para a densidade do solo, a depender da profundidade do solo analisada e do tratamento. O tratamento 1, sem perturbação, proporcionou maior nível de compactação em todas as profundidades

    The gut microbiota plays a protective role in the host defence against pneumococcal pneumonia

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    Objective Pneumonia accounts for more deaths than any other infectious disease worldwide. The intestinal microbiota supports local mucosal immunity and is increasingly recognised as an important modulator of the systemic immune system. The precise role of the gut microbiota in bacterial pneumonia, however, is unknown. Here, we investigate the function of the gut microbiota in the host defence against Streptococcus pneumoniae infections. Design We depleted the gut microbiota in C57BL/6 mice and subsequently infected them intranasally with S. pneumoniae. We then performed survival and faecal microbiota transplantation (FMT) experiments and measured parameters of inflammation and alveolar macrophage whole-genome responses. Results We found that the gut microbiota protects the host during pneumococcal pneumonia, as reflected by increased bacterial dissemination, inflammation, organ damage and mortality in microbiota-depleted mice compared with controls. FMT in gut microbiota-depleted mice led to a normalisation of pulmonary bacterial counts and tumour necrosis factor-alpha and interleukin-10 levels 6 h after pneumococcal infection. Whole-genome mapping of alveolar macrophages showed upregulation of metabolic pathways in the absence of a healthy gut microbiota. This upregulation correlated with an altered cellular responsiveness, reflected by a reduced responsiveness to lipopolysaccharide and lipoteichoic acid. Compared with controls, alveolar macrophages derived from gut microbiota-depleted mice showed a diminished capacity to phagocytose S. pneumoniae. Conclusions This study identifies the intestinal microbiota as a protective mediator during pneumococcal pneumonia. The gut microbiota enhances primary alveolar macrophage function. Novel therapeutic strategies could exploit the gut-lung axis in bacterial infections.Peer reviewe

    Microenvironmental IL1 1 β promotes metastatic colonisation of breast cancer cells in the bone via activation of Wnt-dependent cancer stem cell activity

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    Dissemination of tumour cells to the bone marrow is an early event in breast cancer, however cells may lie dormant for many years before bone metastases develop. Treatment for bone metastases is not curative, therefore new adjuvant therapies which prevent the colonisation of disseminated cells into metastatic lesions are required. There is evidence that cancer stem cells (CSCs) within breast tumours are capable of metastasis, but the mechanism by which these colonise bone is unknown. Here, we establish that bone marrow-derived IL1β stimulates breast cancer cell colonisation in the bone by inducing intracellular NFkB and CREB signalling in breast cancer cells, leading to autocrine Wnt signalling and CSC colony formation. Importantly, we show that inhibition of this pathway prevents both CSC colony formation in the bone environment, and bone metastasis. These findings establish that targeting IL1β-NFKB/CREB-Wnt signalling should be considered for adjuvant therapy to prevent breast cancer bone metastasis

    The consensus molecular subtypes of colorectal cancer

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    Colorectal cancer (CRC) is a frequently lethal disease with heterogeneous outcomes and drug responses. To resolve inconsistencies among the reported gene expression-based CRC classifications and facilitate clinical translation, we formed an international consortium dedicated to large-scale data sharing and analytics across expert groups. We show marked interconnectivity between six independent classification systems coalescing into four consensus molecular subtypes (CMSs) with distinguishing features: CMS1 (microsatellite instability immune, 14%), hypermutated, microsatellite unstable and strong immune activation; CMS2 (canonical, 37%), epithelial, marked WNT and MYC signaling activation; CMS3 (metabolic, 13%), epithelial and evident metabolic dysregulation; and CMS4 (mesenchymal, 23%), prominent transforming growth factor-beta activation, stromal invasion and angiogenesis. Samples with mixed features (13%) possibly represent a transition phenotype or intratumoral heterogeneity. We consider the CMS groups the most robust classification system currently available for CRC-with clear biological interpretability-and the basis for future clinical stratification and subtype-based targeted interventions

    Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation

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    <p>Abstract</p> <p>Background</p> <p><it>Leishmania (Viannia) shawi </it>parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from <it>L. (V.) shawi </it>promastigotes were demonstrated using BALB/c mice, the susceptibility model for this parasite. In order to identify protective fractions, SLA was fractionated by reverse phase HPLC and five antigenic fractions were obtained.</p> <p>Methods</p> <p>F1 fraction was purified from L. (V.) shawi parasite extract by reverse phase HPLC. BALB/c mice were immunized once a week for two consecutive weeks by subcutaneous routes in the rump, using 25 μg of F1. After 1 and 16 weeks of last immunization, groups were challenged in the footpad with L. (V.) shawi promastigotes. After 2 months, those same mice were sacrificed and parasite burden, cellular and humoral immune responses were evaluated.</p> <p>Results</p> <p>The F1 fraction induced a high degree of protection associated with an increase in IFN-γ, a decrease in IL-4, increased cell proliferation and activation of CD8<sup>+</sup>T lymphocytes. Long-term protection was acquired in F1-immunized mice, associated with increased CD4<sup>+ </sup>central memory T lymphocytes and activation of both CD4<sup>+ </sup>and CD8<sup>+ </sup>T cells. In addition, F1-immunized groups showed an increase in IgG2a levels.</p> <p>Conclusions</p> <p>The inductor capability of antigens to generate memory lymphocytes that can proliferate and secrete beneficial cytokines upon infection could be an important factor in the development of vaccine candidates against American Tegumentary Leishmaniasis.</p

    COMPLICAÇÕES DA DERIVAÇÃO VENTRÍCULO-PERITONEAL EM PACIENTES PEDIÁTRICOS: UMA REVISÃO INTEGRATIVA

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    Introduction: Hydrocephalus is characterized by the accumulation of cerebrospinal fluid (CSF) in the cerebral ventricular system, leading to increased intracranial pressure and dilatation of the ventricles. In children, it is manifested by irritability, accelerated growth of the head circumference, and signs of intracranial hypertension. Ventriculoperitoneal shunt (PVD) is a common surgical technique for CSF drainage. Objective: To analyze the complications associated with PVD in pediatric patients, identifying risk factors, patterns of occurrence, and clinical outcomes, to improve care and clinical outcomes. Methodology: An integrative review was carried out in consultation with PubMed and SciELO. Descriptors such as "ventriculoperitoneal shunt," "complications," "hydrocephalus," "infection," and "malfunction" were used. Articles from the last five years, in Portuguese and English, addressing complications of PVD were included. Out-of-scope, full-text, and duplicate studies were excluded. A total of 11 articles were selected for analysis. Results: We included 11 articles that highlighted complications such as infections, device malfunctions, obstructions, and abdominal complications. Shunt infections occur in up to 15% of pediatric cases, often within the first 6 to 12 months postoperatively. Distal catheter malfunction is common and requires frequent surgical revisions. Rare complications include abdominal pseudocysts, distal catheter extrusion, and gram-negative bacterial infections, with high rates in the first few days after shunt insertion. Frequent revisions increase the risk of complications. Conclusions: PVD, although effective, has several complications that impact the quality of life of pediatric patients. Infections and system malfunctions are the most common complications. Multidisciplinary management and preventive strategies are essential to optimize clinical outcomes and quality of life for patients.Introducción: La hidrocefalia se caracteriza por la acumulación de líquido cefalorraquídeo (LCR) en el sistema ventricular cerebral, lo que conduce a un aumento de la presión intracraneal y a la dilatación de los ventrículos. En los niños, se manifiesta por irritabilidad, crecimiento acelerado de la circunferencia cefálica y signos de hipertensión intracraneal. La derivación ventriculoperitoneal (PVD, por sus siglas en inglés) es una técnica quirúrgica común para el drenaje del LCR. Objetivo: Analizar las complicaciones asociadas a la EVP en pacientes pediátricos, identificando factores de riesgo, patrones de ocurrencia y resultados clínicos, para mejorar la atención y los resultados clínicos. Metodología: Se realizó una revisión integradora en consulta con PubMed y SciELO. Se utilizaron descriptores como "derivación ventriculoperitoneal", "complicaciones", "hidrocefalia", "infección" y "disfunción". Se incluyeron artículos de los últimos cinco años, en portugués e inglés, que abordaron las complicaciones de la EVP. Se excluyeron los estudios fuera de alcance, de texto completo y duplicados. Se seleccionaron un total de 11 artículos para el análisis. Resultados: Se incluyeron 11 artículos que destacaron complicaciones como infecciones, mal funcionamiento del dispositivo, obstrucciones y complicaciones abdominales. Las infecciones por derivación ocurren hasta en el 15% de los casos pediátricos, a menudo dentro de los primeros 6 a 12 meses después de la operación. El mal funcionamiento del catéter distal es común y requiere revisiones quirúrgicas frecuentes. Las complicaciones raras incluyen pseudoquistes abdominales, extrusión de catéter distal e infecciones bacterianas gramnegativas, con tasas altas en los primeros días después de la inserción de la derivación. Las revisiones frecuentes aumentan el riesgo de complicaciones. Conclusiones: La EVP, aunque efectiva, tiene varias complicaciones que impactan en la calidad de vida de los pacientes pediátricos. Las infecciones y el mal funcionamiento del sistema son las complicaciones más comunes. El manejo multidisciplinario y las estrategias preventivas son esenciales para optimizar los resultados clínicos y la calidad de vida de los pacientes.Introdução: A hidrocefalia é caracterizada pelo acúmulo de líquido cefalorraquidiano (LCR) no sistema ventricular cerebral, levando ao aumento da pressão intracraniana e dilatação dos ventrículos. Em crianças, manifesta-se por irritabilidade, crescimento acelerado do perímetro cefálico e sinais de hipertensão intracraniana. A derivação ventrículo-peritoneal (DVP) é uma técnica cirúrgica comum para drenagem do LCR. Objetivo: Analisar as complicações associadas à DVP em pacientes pediátricos, identificando fatores de risco, padrões de ocorrência e desfechos clínicos, para melhorar os cuidados e resultados clínicos. Metodologia: Realizou-se uma revisão integrativa consultando PubMed e SciELO. Utilizaram-se descritores como "ventriculoperitoneal shunt," "complications," "hydrocephalus," "infection," e "malfunction". Foram incluídos artigos dos últimos cinco anos, em português e inglês, abordando complicações da DVP. Excluíram-se estudos fora do escopo, não disponíveis em texto completo e duplicados. Selecionaram-se 11 artigos para análise. Resultados: Foram integrados 11 artigos que destacaram complicações como infecções, mau funcionamento do dispositivo, obstruções e complicações abdominais. Infecções de shunt ocorrem em até 15% dos casos pediátricos, frequentemente nos primeiros 6 a 12 meses pós-cirurgia. O mau funcionamento do cateter distal é comum e requer revisões cirúrgicas frequentes. Complicações raras incluem pseudocistos abdominais, extrusão distal do cateter e infecções bacterianas gram-negativas, com altas taxas nos primeiros dias após a inserção do shunt. Revisões frequentes aumentam o risco de complicações. Conclusões: A DVP, embora eficaz, apresenta várias complicações que impactam a qualidade de vida dos pacientes pediátricos. Infecções e mau funcionamento do sistema são as complicações mais comuns. A gestão multidisciplinar e estratégias preventivas são essenciais para otimizar os resultados clínicos e a qualidade de vida dos pacientes

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
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