765 research outputs found

    Exosomes and immune response in cancer: Friends or foes?

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    Exosomes are a type of extracellular vesicle whose study has grown exponentially in recent years. This led to the understanding that these structures, far from being inert waste by-products of cellular functioning, are active players in intercellular communication mechanisms, including in the interactions between cancer cells and the immune system. The deep comprehension of the crosstalk between tumors and the immune systems of their hosts has gained more and more importance, as immunotherapeutic techniques have emerged as viable options for several types of cancer. In this review, we present a comprehensive, updated, and elucidative review of the current knowledge on the functions played by the exosomes in this crosstalk. The roles of these vesicles in tumor antigen presentation, immune activation, and immunosuppression are approached as the relevant interactions between exosomes and the complement system. The last section of this review is reserved for the exploration of the results from the first phase I to II clinical trials of exosomes-based cell-free cancer vaccines.The laboratory is supported by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by FCT— Fundacao para a Ciencia e a Tecnologia/Ministerio da Ciencia, Tecnologia e Inovacao in the framework of the projects “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274), (PTDC/BIM-ONC/2754/2014), and (PTDC/BIM-MEC/2834/2014); and by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), in the framework of the project NORTE- 01-0145-FEDER-000029. SM is supported by FCT (IF/00543/2013)

    Echocardiographic evaluation including tissue Doppler imaging in New Zealand white rabbits sedated with ketamine and midazolam

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    Limited data are available on the use of more recent echocardiographic parameters in the rabbit. Echocardiographic examination, including conventional echocardiography and tissue Doppler imaging (TDI), was performed on 26 male New Zealand white rabbits under ketamine-midazolam sedation. Particular emphasis was placed on the more recent systolic and diastolic parameters, such as myocardial performance index (Tei index) and mitral annular motion (from septal and lateral sides of the left ventricle) obtained using pulsed TDI. Parameters that assessed systolic and diastolic function (fractional shortening, Tei index, and maximal mitral E- and A-wave velocities) were comparable to those reported in the literature for rabbits in the awake state. The less cardiodepressive anaesthetic protocol could offer a good alternative in performing echocardiographic evaluation whenever such caution is necessary. TDI is feasible in healthy rabbits and potentially suitable for the investigation of left ventricle systolic and diastolic function

    Gastric microbial community profiling reveals a dysbiotic cancer-associated microbiota

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    Objective Gastric carcinoma development is triggered by Helicobacter pylori. Chronic H. pylori infection leads to reduced acid secretion, which may allow the growth of a different gastric bacterial community. This change in the microbiome may increase aggression to the gastric mucosa and contribute to malignancy. Our aim was to evaluate the composition of the gastric microbiota in chronic gastritis and in gastric carcinoma. Design The gastric microbiota was retrospectively investigated in 54 patients with gastric carcinoma and 81 patients with chronic gastritis by 16S rRNA gene profiling, using next-generation sequencing. Differences in microbial composition of the two patient groups were assessed using linear discriminant analysis effect size. Associations between the most relevant taxa and clinical diagnosis were validated by real-time quantitative PCR. Predictive functional profiling of microbial communities was obtained with PICRUSt. Results The gastric carcinoma microbiota was characterised by reduced microbial diversity, by decreased abundance of Helicobacter and by the enrichment of other bacterial genera, mostly represented by intestinal commensals. The combination of these taxa into a microbial dysbiosis index revealed that dysbiosis has excellent capacity to discriminate between gastritis and gastric carcinoma. Analysis of the functional features of the microbiota was compatible with the presence of a nitrosating microbial community in carcinoma. The major observations were confirmed in validation cohorts from different geographic origins. Conclusions Detailed analysis of the gastric microbiota revealed for the first time that patients with gastric carcinoma exhibit a dysbiotic microbial community with genotoxic potential, which is distinct from that of patients with chronic gastritis.This research was supported by a Worldwide Cancer Research grant to CF and JCM (Reference 16-1352). RMF, JPM and IPR have fellowships from Fundacao para a Ciencia e a Tecnologia (FCT; SFRH/BPD/84084/2012, PD/BD/114014/2015 and SFRH/BD/110803/2015, respectively) through Programa Operacional Capital Humano (POCH) and the European Union. JPM's fellowship is in the framework of FCT's PhD Programme BiotechHealth (Ref PD/0016/2012). i3S-Instituto de Investigacao e Inovacao em Saude is funded by Fundo Europeu de Desenvolvimento Regional (FEDER) funds through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through Fundacao para a Ciencia e a Tecnologia (FCT)/Ministerio da Ciencia, Tecnologia e Inovacao (POCI-01-0145-FEDER-007274)

    Intramural Vesical Leiomyoma in a Patient with a Pelvic Fibrous Tumour - Case Report

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    Introdução: O leiomioma vesical é um tumor benigno raro que representa,aproximadamente, 0,5% do total de neoplasias da bexiga. É frequentemente um achado imagiológico, sendo a sua localização e dimensões determinantes no desenvolvimento de sintomatologia e no tipo de procedimento a efectuar. Caso Clínico: Reporta-se o caso de um doente com queixas urinárias de disúria, polaquiúria e esforço miccional, inicialmente interpretadas como HBP. A investigação diagnóstica culminou com a enucleação de uma volumosa massa intramural da bexiga, com diagnóstico histológico de leiomioma, num doente com antecedentes de doença de Madelung e excisão prévia de um tumor fibroso paravesical. Discussão: O leiomioma vesical, embora apresentando características imagiológicas típicas, deve ser sempre biopsado para confirmação histológica da sua etiologia. O tumor fibroso pélvico apresenta sempre indicação cirúrgica pois, numa minoria de casos, pode apresentar comportamento agressivo com infiltração dos órgãos adjacentes

    Broadening Risk Factor or Disease Definition as a Driver for Overdiagnosis: A Narrative Review

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    Medical overuse-defined as the provision of health services for which potential harms exceed potential benefits-constitutes a paradigm of low-value care and is seen as a threat to the quality of care. Value in healthcare implies a precise definition of disease. However, defining a disease may not be straightforward since clinical data do not show discrete boundaries, calling for some clinical judgment. And, if in time a redefinition of disease is needed, it is important to recognize that it can induce overdiagnosis, the identification of medical conditions that would, otherwise, never cause any significant symptoms or lead to clinical harm. A classic example is the impact of recommendations from professional societies in the late 1990s, lowering the threshold for abnormal total cholesterol from 240 mg/dl to 200 mg/dl. Due to these changes in risk factor definition, literally overnight there were 42 million new cases eligible for treatment in the United States. The same happened with hypertension-using either the 2019 NICE guidelines or the 2018 ESC/ECC guidelines criteria for arterial hypertension, the proportion of people overdiagnosed with hypertension was calculated to be between 14% and 33%. In this review, we will start by discussing resource overuse. We then present the basis for disease definition and its conceptual problems. Finally, we will discuss the impact of changing risk factor/disease definitions in the prevalence of disease and its consequences in overdiagnosis and overtreatment (a problem particularly relevant when definitions are widened to include earlier or milder disease).info:eu-repo/semantics/publishedVersio

    Broadening Risk Factor or Disease Definition as a Driver for Overdiagnosis: A Narrative Review

    Get PDF
    Medical overuse-defined as the provision of health services for which potential harms exceed potential benefits-constitutes a paradigm of low-value care and is seen as a threat to the quality of care. Value in healthcare implies a precise definition of disease. However, defining a disease may not be straightforward since clinical data do not show discrete boundaries, calling for some clinical judgment. And, if in time a redefinition of disease is needed, it is important to recognize that it can induce overdiagnosis, the identification of medical conditions that would, otherwise, never cause any significant symptoms or lead to clinical harm. A classic example is the impact of recommendations from professional societies in the late 1990s, lowering the threshold for abnormal total cholesterol from 240 mg/dl to 200 mg/dl. Due to these changes in risk factor definition, literally overnight there were 42 million new cases eligible for treatment in the United States. The same happened with hypertension-using either the 2019 NICE guidelines or the 2018 ESC/ECC guidelines criteria for arterial hypertension, the proportion of people overdiagnosed with hypertension was calculated to be between 14% and 33%. In this review, we will start by discussing resource overuse. We then present the basis for disease definition and its conceptual problems. Finally, we will discuss the impact of changing risk factor/disease definitions in the prevalence of disease and its consequences in overdiagnosis and overtreatment (a problem particularly relevant when definitions are widened to include earlier or milder disease).info:eu-repo/semantics/publishedVersio

    Klebsiella pneumoniae bacteraemia complicating rotavirus gastroenteritis in two infants with glucocorticoid deficiency

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    Rotavirus gastroenteritis was complicated by Klebsiella Pneumoniae bacteraemia in two infants with glucocorticoid deficient conditions who were treated with 'stress dose' hydrocortisone during their illness. Delayed healing in the context of glucocorticoid administration combined with damage from rotavirus infection may result in increased risk of mucosal invasion by gastrointestinal bacteria and subsequent enteric gram-negative bacteraemia

    Context acquisition in auditory emotional recognition studies

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    This paper describes an environment to assess auditory emotional recognition based on a mobile application. The primary aim of this work is to provide a valuable instrument that can be used both in research and clinical settings, responding to the strong need of validated measures of emotional processing, especially in Portugal. The secondary aim is to acquire and study the participants' interaction behavior with the technological device (e.g. touch patterns, touch intensity), in search for a relationship with medical conditions, cognitive impairments, auditory emotional recognition capacities or socio-demographic indicators. This will establish the basis for the prediction of such aspects as a function of an individual's interaction with technological devices, potentially providing new diagnostic tools.This work has been supported by FCT-Fundacao para a Ciencia e Tecnologia within the Project Scope UID/ CEC/00319/2013 and Grant PTDC/MHN-PCN/3606/2012. The work of Davide Carneiro is supported by a post-doctoral Grant by FCT (SFRH/BPD/109070/2015). The work of Ana P. Pinheiro is supported by FCT Investigator Grant IF/00334/2012 funded by Fundacao para a Ciencia e a Tecnologia (FCT, Portugal).info:eu-repo/semantics/publishedVersio

    The adaptive immune landscape of the colorectal adenoma–carcinoma sequence

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    Background. The tumor immune microenvironment exerts a pivotal influence in tumor initiation and progression. The aim of this study was to analyze the immune context of sporadic and familial adenomatous polyposis (FAP) lesions along the colorectal adenoma–carcinoma sequence (ACS). Methods. We analyzed immune cell counts (CD3+, CD4+, CD8+, Foxp3+, and CD57+), tumor mutation burden (TMB), MHC-I expression and PD-L1 expression of 59 FAP and 74 sporadic colorectal lesions, encompassing adenomas with low-grade dysplasia (LGD) (30 FAP; 30 sporadic), adenomas with high-grade dysplasia (22 FAP; 30 sporadic), and invasive adenocarcinomas (7 FAP; 14 sporadic). Results. The sporadic colorectal ACS was characterized by (1) a stepwise decrease in immune cell counts, (2) an increase in TMB and MHC-I expression, and (3) a lower PD-L1 expression. In FAP lesions, we observed the same patterns, except for an increase in TMB along the ACS. FAP LGD lesions harbored lower Foxp3+ T cell counts than sporadic LGD lesions. A decrease in PD-L1 expression occurred earlier in FAP lesions compared to sporadic ones. Conclusions. The colorectal ACS is characterized by a progressive loss of adaptive immune infiltrate and by the establishment of a progressively immune cold microenvironment. These changes do not appear to be related with the loss of immunogenicity of tumor cells, or to the onset of an immunosuppressive tumor microenvironment.This research was funded by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operational Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the projects “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274), and “O papel dos Tregs na resposta imune ao cancro” (PTDC/MED-PAT/32462/2017)

    The age patterns of severe malaria syndromes in sub-Saharan Africa across a range of transmission intensities and seasonality settings

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    BACKGROUND: A greater understanding of the relationship between transmission intensity, seasonality and the age-pattern of malaria is needed to guide appropriate targeting of malaria interventions in different epidemiological settings. METHODS: A systematic literature review identified studies which reported the age of paediatric hospital admissions with cerebral malaria (CM), severe malarial anaemia (SMA), or respiratory distress (RD). Study sites were categorized into a 3 × 2 matrix of Plasmodium falciparum transmission intensity and seasonality. Probability distributions were fitted by maximum likelihood methods, and best fitting models were used to estimate median ages and to represent graphically the age-pattern of each outcome for each transmission category in the matrix. RESULTS: A shift in the burden of CM towards younger age groups was seen with increasing intensity of transmission, but this was not the case for SMA or RD. Sites with 'no marked seasonality' showed more evidence of skewed age-patterns compared to areas of 'marked seasonality' for all three severe malaria syndromes. CONCLUSIONS: Although the peak age of CM will increase as transmission intensity decreases in Africa, more than 75% of all paediatric hospital admissions of severe malaria are likely to remain in under five year olds in most epidemiological settings
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