2,490 research outputs found
New tools to prevent cancer growth and spread: a 'Clever' approach
Clever-1 (also known as Stabilin-1 and FEEL-1) is a scavenger receptor expressed on lymphatic endothelial cells, sinusoidal endothelial cells and immunosuppressive monocytes and macrophages. Its role in cancer growth and spread first became evident inStab1(-/-)knockout mice, which have smaller primary tumours and metastases. Subsequent studies in mice and humans have shown that immunotherapeutic blockade of Clever-1 can activate T-cell responses, and that this response is mainly mediated by a phenotypic change in macrophages and monocytes from immunosuppressive to pro-inflammatory following Clever-1 inhibition. Analyses of human cancer cohorts have revealed marked associations between the number of Clever-1-positive macrophages and patient outcome. As hardly any reports to date have addressed the role of Clever-1 in immunotherapy resistance and T-cell dysfunction, we performed data mining using several published cancer cohorts, and observed a remarkable correlation between Clever-1 positivity and resistance to immune checkpoint therapies. This result provides impetus and potential for the ongoing clinical trial targeting Clever-1 in solid tumours, which has so far shown a shift towards immune activation when a particular epitope of Clever-1 is blocked
Epigenetic control of CD1D expression as a mechanism of resistance to immune checkpoint therapy in poorly immunogenic melanomas
Immune Checkpoint Therapies (ICT) have revolutionized the treatment of metastatic melanoma. However, only a subset of patients reaches complete responses. Deficient β2-microglobulin (β2M) expression impacts antigen presentation to T cells, leading to ICT resistance. Here, we investigate alternative β2M-correlated biomarkers that associate with ICT resistance. We shortlisted immune biomarkers interacting with human β2M using the STRING database. Next, we profiled the transcriptomic expression of these biomarkers in association with clinical and survival outcomes in the melanoma GDC-TCGA-SKCM dataset and a collection of publicly available metastatic melanoma cohorts treated with ICT (anti-PD1). Epigenetic control of identified biomarkers was interrogated using the Illumina Human Methylation 450 dataset from the melanoma GDC-TCGA-SKCM study. We show that β2M associates with CD1d, CD1b, and FCGRT at the protein level. Co-expression and correlation profile of B2M with CD1D, CD1B, and FCGRT dissociates in melanoma patients following B2M expression loss. Lower CD1D expression is typically found in patients with poor survival outcomes from the GDC-TCGA-SKCM dataset, in patients not responding to anti-PD1 immunotherapies, and in a resistant anti-PD1 pre-clinical model. Immune cell abundance study reveals that B2M and CD1D are both enriched in tumor cells and dendritic cells from patients responding to anti-PD1 immunotherapies. These patients also show increased levels of natural killer T (NKT) cell signatures in the tumor microenvironment (TME). Methylation reactions in the TME of melanoma impact the expression of B2M and SPI1, which controls CD1D expression. These findings suggest that epigenetic changes in the TME of melanoma may impact β2M and CD1d-mediated functions, such as antigen presentation for T cells and NKT cells. Our hypothesis is grounded in comprehensive bioinformatic analyses of a large transcriptomic dataset from four clinical cohorts and mouse models. It will benefit from further development using well-established functional immune assays to support understanding the molecular processes leading to epigenetic control of β2M and CD1d. This research line may lead to the rational development of new combinatorial treatments for metastatic melanoma patients that poorly respond to ICT
Application of an Ionic Liquid in the Microwave Assisted Extraction of Cytotoxic Metabolites from Fruits of Schinus terebinthifolius Raddi (Anacardiaceae)
This work reports the application of an ionic liquid (1-butyl-3-methylimidazolium bromide, BMImBr) in the microwave assisted extraction (MAE) of metabolites from fruits of Schinus terebinthifolius. Dried fruits were individually extracted using BMImBr: H2O 1: 1, v/v (experiment 1) and pure H2O (experiment 2) by MAE (10 min at 60 degrees C). After partition using EtOAc, the yield to experiment 1 was about 23% while to experiment 2 was 0.1%. The EtOAc fraction obtained from experiment 1 was purified by chromatographic methods to afford 3-oxotirucalla-7,24Z-dien27- oic acid, 3a-hydroxytirucalla-7,24Z-dien-27-oic acid, 3 alpha-acetoxytirucalla-7,24Z-dien-27-oic acid, gallic acid, and ethyl gallate, being the first occurrence of the third compound as natural product. Cytotoxic activity was evaluated in vitro against cancer cell lines (A2058, HeLa, SiHa, HCT, SKBR-3, U87, and B16F2Nex2), being 3 alpha-acetoxytirucalla-7,24Z-dien-27-oic acid the more active metabolite with IC50 ranging from 10.9 +/- 1.3 to 17.3 +/- 1.4 mu g mL(-1), lower than that determined to positive control cisplatin.FAPESPCAPESCNPqInstituto de Ciências Ambientais, QuÃmicas e Farmacêuticas, Universidade Federal de São Paulo (UNIFESP), 09972-270 Diadema-SP, BrazilDepartamento de Micro, Imuno e Parasitologia, Universidade Federal de São Paulo (UNIFESP), 04023-062 São Paulo-SP, BrazilInstituto de Ciências Ambientais, QuÃmicas e Farmacêuticas, Universidade Federal de São Paulo (UNIFESP), 09972-270 Diadema-SP, BrazilDepartamento de Micro, Imuno e Parasitologia, Universidade Federal de São Paulo (UNIFESP), 04023-062 São Paulo-SP, BrazilFAPESP: BIOTA 2011/51739-6FAPESP: 2015/11936-2Web of Scienc
Molecular, Biological and Structural Features of VL CDR-1 Rb44 Peptide, Which Targets the Microtubule Network in Melanoma Cells
Microtubules are important drug targets in tumor cells, owing to their role in supporting and determining the cell shape, organelle movement and cell division. The complementarity-determining regions (CDRs) of immunoglobulins have been reported to be a source of anti-tumor peptide sequences, independently of the original antibody specificity for a given antigen. We found that, the anti-Lewis B mAb light-chain CDR1 synthetic peptide Rb44, interacted with microtubules and induced depolymerization, with subsequent degradation of actin filaments, leading to depolarization of mitochondrial membrane-potential, increase of ROS, cell cycle arrest at G2/M, cleavage of caspase-9, caspase-3 and PARP, upregulation of Bax and downregulation of Bcl-2, altogether resulting in intrinsic apoptosis of melanoma cells. The in vitro inhibition of angiogenesis was also an Rb44 effect. Peritumoral injection of Rb44L1 delayed growth of subcutaneously grafted melanoma cells in a syngeneic mouse model. L1-CDRs from immunoglobulins and their interactions with tubulin-dimers were explored to interpret effects on microtubule stability. The opening motion of tubulin monomers allowed for efficient L1-CDR docking, impairment of dimer formation and microtubule dissociation. We conclude that Rb44 VL-CDR1 is a novel peptide that acts on melanoma microtubule network causing cell apoptosis in vitro and melanoma growth inhibition in vivo
Cytotoxic and Antimicrobial Constituents from the Essential Oil of Lippia alba (Verbenaceae).
Backgroud:Lippia alba (Verbenaceae) is a plant widely used in folk medicine to treat various diseases. The present work deals with the chemical composition of the crude essential oil extracted from leaves of L. alba and evaluation of its antimicrobial and cytotoxic activities. Methods: Leaves of L. alba were extracted by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) as well as by nuclear magnetic resonance (NMR) spectroscopy. Cytotoxic and antimicrobial activities of crude essential oil were evaluated in vitro using MTT and broth microdilution assays, respectively. Results: Chemical analysis afforded the identification of 39 substances corresponding to 99.45% of the total oil composition. Concerning the main compounds, monoterpenes nerol/geraniol and citral correspond to approximately 50% of crude oil. The cytotoxic activity of obtained essential oil against several tumor cell lines showed IC50 values ranging from 45 to 64 µg/mL for B16F10Nex2 (murine melanoma) and A549 (human lung adenocarcinoma). In the antimicrobial assay, was observed that all tested yeast strains, except C. albicans, were sensitive to crude essential oil. MIC values were two to four-folds lower than those determined to bacterial strains. Conclusion: Analysis of chemical composition of essential oils from leaves of L. alba suggested a new chemotype nerol/geraniol and citral. Based in biological evidences, a possible application for studied oil as an antifungal in medicine, as well as in agriculture, is described
Chemical Composition and In Vitro Cytotoxic and Antimicrobial Activities of the Essential Oil from Leaves of Zanthoxylum monogynum St. Hill (Rutaceae).
Background: The Zanthoxylum monogynum species belongs to the family Rutaceae and is found in Southeast, Midwest, and Northeast Brazil. For this genus several biological activities have been described. Methods: The essential oil (EO) was obtained from the leaves of Zanthoxylum monogynum by hydro-distillation and was analyzed by gas chromatograph and gas chromatograph/mass spectrometry (GC and GC/MS). Also the EO of Z. monogynum was evaluated for in vitro cytotoxic activity against six tumor cell lines and for antimicrobial activity, performing disk diffusion and MIC assays with yeast and bacterial strains. Results: The chemical analysis afforded the identification of 18 components (99.0% of the EO). The major components were found to be citronellol (43.0%) and farnesol (32.0%). The in vitro cytotoxic activity against tumor cell lines, resulted in IC50 values ranging from 11-65 µg/mL against all tested cell lines. Antimicrobial activity of the essential oil was also tested and oil was effective, especially against Cryptococcus sp. yeast. All the tested yeast strains showed at least 90% growth inhibition. Conclusions: the essential oil from leaves of Z. monogynum has a different qualitative and quantitative composition when compared to the composition previously described. Also this EO has significant cytotoxic activity and moderate activity against Cryptococcus sp. and Saccharomyces cereviseae yeasts
ResÃduos de serviços de saúde (RSS) e seus impactos ambientais: desafios para a gestão e gerenciamento no Brasil/ Health services waste (RSS) and its environmental impacts: challenges for management and management in Brazil
 A adequação da gestão e gerenciamento dos RSS à s legislações ambientais atuais caracterizam-se como um grande desafio para os gestores. Nesse sentido, objetiva-se realizar um estudo de revisão bibliográfica para analisar o gerenciamento dos RSS a partir das legislações pertinentes para verificar como os estados brasileiros tem se comprometido com o gerenciamento desses resÃduos. Realizou-se abordagem qualitativa e exploratória das informações, em 21 artigos pesquisados nas bases de dados: Scientific Electronic Library Online (SCIELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Medical Literature Analysis and Retrieval System On-Line (MEDLINE), com descritores: gerenciamento dos serviços de saúde; resÃduos dos serviços de saúde; resÃduos hospitalares; e saúde e meio ambiente. Os resultados obtidos diagnosticaram que a situação do gerenciamento e o manejo dos RSS nas Instituições de saúde apresentam deficiências, o que potencializa o risco à saúde pública e ao meio ambiente, sendo necessário à ênfase ao cumprimento das determinações legais e o investimento na Educação Ambiental (EA) como ferramenta de gestão.
VARICOSE VEINS SURGERY OF LOWER LIMBS CAN WE PRESERVE GREAT SAPHENOUS VEIN?
Introdução: A avaliação por eco-Doppler mostrou a grande veia safena como uma veia interfascial e não superficial. O Eco-Doppler mostrou também veias varicosas com junção safeno femoral competente, bem como veias varicosas que envolvem somente veias colaterais ou veias colaterais mais segmentos da grande veia safena. Consequentemente foram definidos dois padrões principais de refluxo venoso: o refluxo axial com envolvimento contÃnuo da grande veia safena, desde a junção safenofemoral ao maléolo e o refluxo segmentar com envolvimento de segmentos da grande veia safena e/ou veias colaterais, mas sem continuidade entre si. O padrão de refluxo segmentar divide-se em 3 subtipos: no subtipo 1 estão apenas envolvidos ramos superficiais, no subtipo 2 estão envolvidos ramos superficiais mais segmentos da grande veia safena e no subtipo 3 verifica-se refluxo ao nÃvel da junção safenofemoral e de veias colaterais da coxa.Objetivo: Podemos preservar a grande veia safena tratando veias varicosas com um padrão de refluxo segmentar?Metodologia: Foram operados 54 doentes com padrão de refluxo segmentar com preservação da grande veia safena. O seguimento clÃnico considerou o alÃvio sintomático e cosmético e a não recorrência de varizes, avaliando a cirurgia como satisfatória. O seguimento por Eco-Doppler classificou o refluxo em: ausência de refluxo, persistência de refluxo ou progressão de refluxo. O tempo médio de seguimento foi de 12,1 meses.Resultados. Resultados clÃnicos: 98.5% avaliou a cirurgia como satisfatória. Resultados do Eco-Doppler: 58% com ausência de refluxo, 42% com persistência de refluxo e 1 caso com progressão do refluxo.Conclusão: Os resultados do nosso estudo, clÃnicos e avaliação por Eco-Doppler, sustentam a preservação da grande veia safena.A resposta à nossa questão se podemos preservar a grande veia safena é um sim terminante.Os nossos achados sustentam também o conceito de que as veias varicosas são um processo local e multifocal com inÃcio em qualquer segmento de veia e não um processo descendente com inÃcio na junção safenofemoral. Os ramos varicosos superficiais aparentam ter um papel principal neste processo e não o tronco da veia safena, como considerado previamente
- …