60 research outputs found
Fertilidade do solo e estoques de carbono e nitrogênio sob sistemas agroflorestais no Cerrado mineiro
Agroforestry systems are used to diversify food production, provide an increase in the biodiversity of fauna and flora as well as the conservation of carbon and nutrients in the soil. Thus, the objective of this study was to evaluate the fertility and carbon (C) and nitrogen (N) stocks of the soil after ten years of agroforestry system (SAFs) implantation in the Cerrado biome of Minas Gerais state, Brazil. The study was carried out in the American Agroextractivist Settlement, located in the municipality of Grão Mogol, northern mesoregion of the state of Minas Gerais. Three SAFs and two adjacent native vegetation areas (VNs) were used as reference for the study, which were grouped according to the soil class: Red-Yellow Latosol and Haplic Cambisol. The soil sampling was carried out in March 2013, ten years after the implementation of the SAFs, where composite samples were removed from the 0-5 and 0-20 cm soil depth layers for the evaluation of nutrient contents and apparent density, and in the first layer the soil C and N stocks. SAFs that were deployed with management based on prune trees and maintenance of floristic diversity contributed with the improvement of the soil quality and the maintenance of fertility and C stocks at levels like in native vegetation. On the other hand, the SAF that was implanted with the previous suppression of the native vegetation reduced the tree diversity and, consequently, the C stocks over time. However, management with annual crops and the use of legumes contributed to the improvement of soil fertility and to the increase of N contents and stocks.Os sistemas agroflorestais são utilizados para diversificar a produção de alimentos, proporcionar aumento na biodiversidade da fauna e da flora e conservação do carbono e nutrientes no solo. Sendo assim, o objetivo deste estudo foi avaliar a fertilidade e os estoques de carbono (C) e nitrogênio (N) do solo após dez anos de implantação de sistemas agroflorestais (SAFs) no Cerrado mineiro. O estudo foi realizado no Assentamento Agroextrativista Americana, localizado no município de Grão Mogol, mesorregião norte do Estado de Minas Gerais. Foram selecionados três SAFSs e duas áreas de vegetação nativa (VN) adjacentes, utilizadas como referência para o estudo, as quais foram agrupados em função da classe de solo: Latossolo Vermelho Amarelo e Cambissolo Háplico. A amostragem do solo foi realizada em março de 2013, dez anos após a implantação dos SAFs, em que amostras compostas foram retiradas das camadas 0-5 e 0-20 cm de profundidade para avaliação dos teores de nutrientes e densidade aparente, e na primeira camada os estoques de C e N do solo. Os SAFs que foram implantados com manejo baseado em desrama e manutenção da diversidade florística contribuíram com e melhoria da qualidade do solo e manutenção da fertilidade e estoques de C em níveis semelhantes à vegetação nativa. Já o SAF que foi implantado com a prévia supressão da vegetação nativa reduziu a diversidade arbórea e, consequentemente, os estoques de C ao longo do tempo. Porém, o manejo com culturas anuais e uso de leguminosas contribuiu para a melhoria da fertilidade do solo e incremento dos teores e estoques de N
Stage at diagnosis and stage-specific survival of breast cancer in Latin America and the Caribbean : a systematic review and meta-analysis
Background: Female breast cancer is the most common cancer in Latin American and Caribbean (LAC) countries and is the leading cause of cancer deaths. The high mortality-to-incidence ratio in the regions is associated with mainly the high proportion of advanced stage diagnosis, and also to inadequate access to health care. In this study we aimed to systematically review the proportion of advanced stage (III-IV) at diagnosis (pas) and the five-year stage-specific survival estimates of breast cancer in LAC countries. Methods: We searched MEDLINE, Embase, and LILACS (Latin American and Caribbean Health Science Literature) to identify studies, in any language, indexed before Nov 5, 2018. We also conducted manual search by reviewing citations of papers found. pas was summarized by random effects model meta-analysis, and meta-regression analysis to identify sources of variation. Stage-specific survival probabilities were described as provided by study authors, as it was not possible to conduct meta-analysis. PROSPERO CRD42017052493. Results: For pas we included 63 studies, 13 of which population-based, from 22 countries comprising 221,255 women diagnosed from 1966 to 2017. The distribution of patients by stage varied greatly in LAC (pas 40.8%, 95%CI 37.0% to 44.6%; I2=99%; p<0.0001). The heterogeneity was not explained by any variable included in the meta-regression. There was no difference in pas among the Caribbean (pas 43.0%, 95%CI 33.1% to 53.6%), Central America (pas 47.0%, 95%CI 40.4% to 53.8%) and South America (pas 37.7%, 95%CI 33.1% to 42.5%) regions. For 5-year stage-specific survival we included 37 studies, comprising 28,988 women from ten countries. Seven of these studies were included also for pas. Since we were unable to adjust for age, comparability between countries and regions was hampered, and as expected, the results varied widely from study to study. Conclusions: LAC countries should look to address concerns with early detection and diagnosis of breast cancer, and wherever viable implement screening programs and to provide timely treatment
Comparative Effectiveness and Safety of Monoclonal Antibodies (Bevacizumab, Cetuximab, and Panitumumab) in Combination with Chemotherapy for Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis
Background: The last decade has seen the increasing use of biological medicines in combination with chemotherapy containing 5- Fluorouracil/oxaliplatin or irinotecan for the treatment of metastatic colorectal cancer (mCRC). These combinations have resulted in increased progression-free survival (PFS) in patients with mCRC; however, there are remaining concerns over the extent of their effect on overall survival (OS). Published studies to date suggest no major differences between the three currently available monoclonal antibodies (MoAbs); however, there are differences in costs. In addition, there is rising litigation in Brazil in order to access these medicines as they are currently not reimbursed. Objective: To compare the effectiveness and safety of three MoAbs (bevacizumab, cetuximab and panitumumab) associated with fluoropyrimidine-based chemotherapy regimens or compared to fluoropyrimidine-based chemotherapy alone in patients with mCRC through an updated systematic review and meta-analysis with concurrent or non concurrent observational cohort studies to guide the authorities and judiciary. Method: A systematic review and meta-analysis was performed based on cohort studies published in databases up to November 2017. Effectiveness measures include OS, PFS, post-progression survival (PPS), RECIST (Response Evaluation Criteria In Solid Tumors), response rate, metastasectomy and safety. The methodological quality of the studies was also evaluated. Results: 21 observational cohort studies were included. There were statistically significant and clinically relevant benefits in patients treated with bevacizumab versus no bevacizumab mainly around OS, PFS, PPS and the metastasectomy rate, but not for the disease control rates. However, there was an increase in treatment-related toxicities, and concerns with the heterogeneity of the studies. Conclusion: The results pointed to an advantage in favor of bevacizumab for OS, PFS, PPS, and metastasectomy. Although this advantage may be considered clinically modest, bevacizumab represents a hope for increased survival and a chance of metastasectomy for patients with mCRC. However, there are serious adverse events associated with its use, especially severe hypertension and gastrointestinal perforation that need to be considered
Connexin43 promotes exocytosis of damaged lysosomes through actin remodelling
A robust and efficient cellular response to lysosomal membrane damage prevents leakage from the lysosome lumen into the cytoplasm. This response is understood to happen through either lysosomal membrane repair or lysophagy. Here we report exocytosis as a third response mechanism to lysosomal damage, which is further potentiated when membrane repair or lysosomal degradation mechanisms are impaired. We show that Connexin43 (Cx43), a protein canonically associated with gap junctions, is recruited from the plasma membrane to damaged lysosomes, promoting their secretion and accelerating cell recovery. The effects of Cx43 on lysosome exocytosis are mediated by a reorganization of the actin cytoskeleton that increases plasma membrane fluidity and decreases cell stiffness. Furthermore, we demonstrate that Cx43 interacts with the actin nucleator Arp2, the activity of which was shown to be necessary for Cx43-mediated actin rearrangement and lysosomal exocytosis following damage. These results define a novel mechanism of lysosomal quality control whereby Cx43-mediated actin remodelling potentiates the secretion of damaged lysosomes
Exosomes secreted by cardiomyocytes subjected to ischaemia promote cardiac angiogenesis
Funding Information: This work was supported by European Regional Development Fund (FEDER) through the Operational Program for Competitiveness Factors (COMPETE) [HealthyAging2020 CENTRO-01-0145-FEDER-000012-N2323, POCI-01-0145-FEDER-016385, POCI-01-0145-FEDER-007440 to CNC.IBILI, POCI-01-0145-FEDER-007274 to i3S/INEB and NORTE-01-0145-FEDER-000012 to T.L.L.]; national funds through the Portuguese Foundation for Science and Technology (FCT) [PTDC/SAU-ORG/119296/2010, PTDC/ NEU-OSD/0312/2012, PESTC/ SAU/UI3282/2013-2014, MITP-TB/ECE/0013/ 2013, FCT-UID/NEU/04539/2013], PD/BD/52294/2013 to T.M.R.R., SFRH/ BD/85556/2012 (co-financed by QREN) to V.C.S]; Lisboa Portugal Regional Operational Programme (LISBOA 2020) and Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement; and by INFARMED Autoridade Nacional do Medicamento e Produtos de Saúde, I.P. [FIS-FIS-2015-01_CCV_20150630-157]. Publisher Copyright: © 2017 The Author.Aims Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide and results from an obstruction in the blood supply to a region of the heart. In an attempt to replenish oxygen and nutrients to the deprived area, affected cells release signals to promote the development of new vessels and confer protection against MI. However, the mechanisms underlying the growth of new vessels in an ischaemic scenario remain poorly understood. Here, we show that cardiomyocytes subjected to ischaemia release exosomes that elicit an angiogenic response of endothelial cells (ECs). Methods and results Exosomes secreted by H9c2 myocardial cells and primary cardiomyocytes, cultured either in control or ischaemic conditions were isolated and added to ECs. We show that ischaemic exosomes, in comparison with control exosomes, confer protection against oxidative-induced lesion, promote proliferation, and sprouting of ECs, stimulate the formation of capillary-like structures and strengthen adhesion complexes and barrier properties. Moreover, ischaemic exosomes display higher levels of metalloproteases (MMP) and promote the secretion of MMP by ECs. We demonstrate that miR-222 and miR-143, the relatively most abundant miRs in ischaemic exosomes, partially recapitulate the angiogenic effect of exosomes. Additionally, we show that ischaemic exosomes stimulate the formation of new functional vessels in vivo using in ovo and Matrigel plug assays. Finally, we demonstrate that intramyocardial delivery of ischaemic exosomes improves neovascularization following MI. Conclusions This study establishes that exosomes secreted by cardiomyocytes under ischaemic conditions promote heart angiogenesis, which may pave the way towards the development of add-on therapies to enhance myocardial blood supply.publishersversionpublishe
Comparative effectiveness and safety of monoclonal antibodies for mCRC
Introduction: Biological medicines are increasingly used in combination with chemotherapy for patients with metastatic colorectal cancer (mCRC), resulting in increased progression-free survival (PFS). However, concerns remain over the extent of their effect on overall survival (OS) given the high costs of these monoclonal antibodies (MoAbs) (bevacizumab, cetuximab and panitumumab) and their safety. Published studies suggest no major differences in effectiveness and safety between the MoAbs; however, differences in costs with cetuximab more expensive than bevacizumab by 127% in Brazil and more expensive than panitumumab by 112%, with panitumumab more expensive than bevacizumab by 6%. Since there is rising litigation in Brazil in order to access these 3 MoAbs as they are not currently reimbursed, we wanted to compare their effectiveness and safety associated with chemotherapy or chemotherapy alone in patients with mCRC to provide future guidance to the judiciary and the healthcare system. Method: A systematic review and meta-analysis based on cohort studies published in databases up to November 2017. Effectiveness measures include PFS, post-progression survival (PPS), RECIST (Response Evaluation Criteria In Solid Tumors), response rates, metastasectomy rates, OS and safety. We also evaluated the methodological quality of the studies. Results: Overall, 21 observational cohort studies were included in the review. There were statistically significant and clinically relevant benefits in patients treated with bevacizumab versus those not treated with bevacizumab (no bevacizumab arm) mainly around PFS, PPS, metastasectomy rates and OS, but not for disease control rates. However, bevacizumab increased toxicities and there were concerns with the heterogeneity of the studies. Conclusion: The results suggested an advantage in favour of bevacizumab for a number of outcome measures and costs in patients with mCRC. However, this advantage may be only clinically modest for bevacizumab. This though has to be weighed against the serious adverse events associated with bevacizumab, especially severe hypertension and gastrointestinal perforation
TÉCNICAS DE ANESTESIA PARA CIRURGIA DE CÂNCER DE CÓRNEA E PROCEDIMENTOS DE CIRURGIA GERAL
Anesthesia plays a crucial role in corneal cancer surgery and general surgery procedures, directly affecting patient safety and comfort during the procedure. Therefore, it is essential to investigate the most appropriate anesthetic techniques for these types of surgeries. Objective: This study aims to analyze the anesthesia techniques used in corneal cancer surgeries and general surgery procedures, aiming to identify the most effective and safe ones for patients. Methodology: An integrative literature review was conducted, encompassing studies selected between 2002 and 2023 from the SciELO, BVS, and Web of Science databases. The guiding question, defined by the PICO acronym, was: "What are the most effective and safe anesthesia techniques for corneal cancer surgeries and general surgery procedures?" Results: The review results showed a variety of anesthesia techniques used in these surgeries, with significant differences in effectiveness and safety. There was a need for individualized approach, taking into consideration the specific characteristics of each patient and procedure. Conclusion: It is concluded that the choice of anesthesia technique should be made carefully, considering factors such as type of surgery, patient's clinical condition, and anesthesiologist's experience. A multidisciplinary approach and the search for updated evidence are recommended to guide clinical practice.A anestesia desempenha um papel crucial na cirurgia de câncer de córnea e procedimentos de cirurgia geral, afetando diretamente a segurança e o conforto do paciente durante o procedimento. Portanto, é essencial investigar as técnicas anestésicas mais adequadas para esses tipos de cirurgias. Objetivo: Este estudo tem como objetivo analisar as técnicas de anestesia utilizadas em cirurgias de câncer de córnea e procedimentos de cirurgia geral, buscando identificar as mais eficazes e seguras para os pacientes. Metodologia: Foi realizada uma revisão integrativa da literatura, abrangendo estudos selecionados entre 2002 a 2023 nas bases de dados SciELO, BVS e Web of Science. A pergunta norteadora, definida pelo acrônimo PICO, foi: "Quais são as técnicas de anestesia mais eficazes e seguras para cirurgias de câncer de córnea e procedimentos de cirurgia geral?" Resultados: Os resultados da revisão mostraram uma variedade de técnicas anestésicas utilizadas nessas cirurgias, com diferenças significativas em eficácia e segurança. Foi observada uma necessidade de abordagem individualizada, levando em consideração as características específicas de cada paciente e procedimento. Conclusão: Conclui-se que a escolha da técnica de anestesia deve ser feita de forma criteriosa, considerando fatores como tipo de cirurgia, condição clínica do paciente e experiência do anestesiologista. Recomenda-se uma abordagem multidisciplinar e a busca por evidências atualizadas para orientar a prática clínica
Pervasive gaps in Amazonian ecological research
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
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