Validação de um método para análise de metais em peixe por técnicas com plasma indutivamente acoplado

Mestrado em QuímicaA alimentação deve ser equilibrada e variada, oferecendo todos os nutrientes necessários para colmatar as necessidades humanas e garantir uma vida saudável. Para garantir que os alimentos sejam seguros, estes devem estar isentos de contaminantes, pelo menos em quantidades tóxicas. É então importante monitorizar a qualidade e segurança dos alimentos a fim de avaliar os riscos e benefícios do seu consumo. A quantificação da componente inorgânica em alimentos, i.e., dos elementos essenciais e dos potencialmente tóxicos, tem merecido poucos estudos apesar de ter um impacto relevante na saúde humana. Em Portugal são poucos os serviços acreditados prestados nesta área, e na literatura não há um consenso sobre a utilização de métodos de preparação de amostras. O objetivo deste estágio consistiu em validar uma metodologia para a análise elementar de amostras de peixe, no Laboratório Central de Análises (LCA) da Universidade de Aveiro (UA), recorrendo a técnicas de análise multi-elementares tais como emissão ótica e espectrometria de massa associadas a plasma indutivamente acoplado (ICP-OES e ICP-MS). A validação destas metodologias teve como objetivo a sua posterior acreditação. A matriz alimentícia escolhida para a realização deste trabalho foi o peixe. A escolha de apenas um tipo de matriz para a realização deste trabalho deveu-se a vários fatores, de entre os quais se destaca a necessidade de adotar diferentes estratégias de preparação de amostra e posterior análise, consoante a matriz alimentícia em questão, devido essencialmente à diferente composição que os alimentos possuem, o que introduz diferentes abordagens durante o processo de validação do método. Na validação foram tidos em consideração diferentes parâmetros de desempenho, nomeadamente a seletividade, o limite de deteção, o limite de quantificação, a gama de trabalho, a sensibilidade analítica, a justeza, a precisão e a incerteza. Os resultados obtidos na análise de soluções padrão, materiais de referência e amostras de peixe cumpriram os requisitos de desempenho definidos no LCA. Foram validadas as metodologias de quantificação de Mn e Sr por ICP-MS e de quantificação de Cu, Fe e Zn por ICP-OES, para a matriz peixe. A futura acreditação destas metodologias ficou condicionada pela participação com êxito num ensaio de comparação interlaboratorial.Food must be balanced and varied, providing all the necessary nutrients to bridge human needs and ensure a healthy life. To ensure that food is safe, it should be free of contaminants, at least in toxic amounts. It is therefore important to monitor the quality and safety of food in order to assess the risks and benefits of its consumption. The quantification of inorganic component in food, i.e. of essential and potentially toxic elements, has received few studies despite having a significant impact on human health. In Portugal there are few accredited services in this area, and in the literature there is no consensus on the use of sample preparation methods. The aim of this Internship was to validate a method for elemental analysis in fish, in Laboratório Central de Análises (LCA) of University of Aveiro (UA), using multi-elementar analysis techniques such as Inductively Coupled Plasma Optical Emission Spectrometry and Inductively Coupled Plasma Mass Spectrometry (ICP-OES and ICP-MS). The validation of these methodologies aimed their subsequent accreditation. The chosen food matrix for the achievement of this work was the fish. The choice of only one type of matrix for the achievement of this work was due to several factors among which highlights the need to adopt different sample preparation strategies and subsequent analysis, depending on the food matrix in question, essentially due to the different composition that they have, which introduces differences in the process of method validation. In validation process it was evaluated different performance parameters, namely selectivity, the detection limit, the quantification limit, the work range, the analytical sensibility, trueness, precision and uncertainty. The results of the analysis of standards solutions, reference materials and fish samples met the performance requirements defined in the LCA. In this work it was validated the methods of quantification of Mn and Sr by ICP-MS and quantification of Cu, Fe and Zn by ICP-OES for fish matrix. The future accreditation of these methodologies it is conditioned by successful participation in a interlaboratory comparison test

Alkalinity, inorganic carbon and CO2 flux variability during extreme rainfall years (2010-2011) in two polluted tropical estuaries NE Brazil

The susceptibility of coastal environments to shifts in the biogeochemical cycles of carbon and nutrients driven by anthropogenic pressure and climate change is a real challenge for the scientific community. This paper evaluated the effects of an extreme rainfall event over the nutrients and carbonate parameters in two polluted tropical estuaries. Surface water samples were taken seasonally along a salinity gradient in the Capibaribe and Barra de Jangadas estuaries in order to investigate the spatial and seasonal variability of dissolved nutrients, chlorophyll-a, dissolved oxygen, total alkalinity, inorganic carbon, partial pressure of CO2 (pCO2) and CO2 fluxes. The increased riverine influence caused by the fluvial flooding during the extremely rainy season augmented the nitrogen concentrations in the plumes, which also presented reduced salinity, alkalinity and dissolved oxygen values. In the Capibaribe plume it has also shifted the mean CO2 flux value of - 4.01 mmolC m-2 d-1 during the dry season, to a positive mean flux of + 5.7 mmolC m-2 d-1 during the rainy season. Within the estuaries the BOD5,20 and dissolved phosphorus values were higher during the dry season (pA suscetibilidade dos ambientes costeiros às mudanças nos ciclos biogeoquímicos do carbono e nutrientes impulsionados pela pressão antrópica e mudanças climáticas é um verdadeiro desafio para a comunidade científica. Este artigo avaliou os efeitos de um evento de precipitação extrema sobre os parâmetros de oxigênio, nutrientes e do sistema carbonato em dois estuários tropicais poluídos. As amostras de água superficial foram retiradas sazonalmente ao longo de um gradiente de salinidade nos estuários do Capibaribe e Barra de Jangadas, a fim de investigar a variabilidade espacial e sazonal dos nutrientes dissolvidos, clorofila-a, oxigênio dissolvido, alcalinidade total, carbono inorgânico, pressão parcial de CO2 (pCO2) e fluxos de CO2. O aumento da influência ribeirinha causada pelas inundações fluviais durante a estação de precipitação extrema aumentou as concentrações de nitrogênio nas plumas dos estuários, que também apresentaram valores reduzidos de salinidade, alcalinidade e oxigênio dissolvido. Na pluma do Capibaribe o valor médio de fluxo de CO2 também mudou, passou de - 4,01 mmolC m-2 d-1 durante a estação seca, para um fluxo médio positivo de + 5,7 mmolC m-2 d-1 durante a estação chuvosa. Dentro dos estuários, os valores de BOD5,20 e fosfato dissolvido foram maiores durante a estação seca (

Regional accuracy of ZTE-based attenuation correction in static and dynamic brain PET/MR

Accurate MR-based attenuation correction (MRAC) is essential for quantitative PET/MR imaging of the brain. In this study, we analyze the regional bias caused by MRAC based on Zero-Echo-Time MR images (ZTEAC) compared to CT-based AC (CTAC) in static and dynamic PET imaging. In addition the results are compared to the performance of the current default Atlas-based AC (AtlasAC) implemented in the GE SIGNA PET/MR. Methods: Thirty static [18F]FDG and 11 dynamic [18}F]PE2I acquisitions from a GE SIGNA PET/MR were reconstructed using ZTEAC (using a research tool, GE Healthcare), single-subject AtlasAC (the current default AC in GE's SIGNA PET/MR) and CTAC (from a PET/CT acquisition of the same day). In the 30 static [18F]FDG reconstructions, the bias caused by ZTEAC and AtlasAC in the mean uptake of 85 anatomical volumes of interest (VOIs) of the Hammers' atlas was analyzed in PMOD. For the 11 dynamic [18}F]PE2I reconstructions, the bias caused by ZTEAC and AtlasAC in the non displaceable binding potential BPnd in the striatum was calculated with cerebellum as the reference region and a simplified reference tissue model. Results: The regional bias caused by ZTEAC in the static [18F]FDG reconstructions ranged from -8.0% to +7.7% (mean 0.1%, SD 2.0%). For AtlasAC this bias ranged from -31.6% to +16.6% (mean -0.4%, SD 4.3%). The bias caused by AtlasAC showed a clear gradient in the cranio-caudal direction (-4.2% in the cerebellum, +6.6% in the left superior frontal gyrus). The bias in the striatal BPnd for the [18F]PE2I reconstructions ranged from -0.8% to +4.8% (mean 1.5%, SD 1.4%) using ZTEAC and from -0.6% to +9.4% using AtlasAC (mean 4.2%, SD 2.6%). Conclusion: ZTEAC provides excellent quantitative accuracy for static and dynamic brain PET/MR, comparable to CTAC, and is clearly superior to the default AtlasAC currently implemented in the GE SIGNA PET/MR.Comment: 23 pages in total, 7 figures, 1 table, 3 supplementary figures, 5 supplementary table

Is rare cancer care organized at national health system level? Multiple case study in six EU countries

Background: As a system of European Reference Networks (ERNs) emerges, we aimed to shed light on the processes through which reference centres (RCs) for rare cancers are embedded in national health systems, and to formulate hypotheses about which national care models favour equitable access for patients. Methods We used a multiple-case-study design based on the experiences of Czechia, Finland, France, Italy, Lithuania and Spain. Using sarcoma as an example of rare cancer, 52 semi-structured interviews were conducted during six on-site visits. Results The comparative analysis showed substantial heterogeneity in the processes for formalising RCs status and in their levels of integration in the different health systems, but two models, namely, the centre-based and the network-based, can be envisaged at national level. RCs for rare cancers were legally established only in France and Spain. Expert clinicians cooperate in a structured way, using network mechanisms, in France and Italy, and these countries, plus Finland and Lithuania, had a referral system to facilitate patients' access from non-expert centres to RCs. Comparative analysis of the cases enabled the identification of key healthcare planning principles in instituting RCs at the national level, among them the need to stipulate the involvement of expert professionals in steering the rare cancer care system

MGMT-independent temozolomide resistance in pediatric glioblastoma cells associated with a PI3-kinase-mediated HOX/stem cell gene signature

Sensitivity to temozolomide is restricted to a subset of glioblastoma patients, with the major determinant of resistance being a lack of promoter methylation of the gene encoding the repair protein DNA methyltransferase MGMT, although other mechanisms are thought to be active. There are, however, limited preclinical data in model systems derived from pediatric glioma patients. We screened a series of cell lines for temozolomide efficacy in vitro, and investigated the differential mechanisms of resistance involved. In the majority of cell lines, a lack of MGMT promoter methylation and subsequent protein overexpression were linked to temozolomide resistance. An exception was the pediatric glioblastoma line KNS42. Expression profiling data revealed a coordinated upregulation of HOX gene expression in resistant lines, especially KNS42, which was reversed by phosphoinositide 3-kinase pathway inhibition. High levels of HOXA9/HOXA10 gene expression were associated with a shorter survival in pediatric high-grade glioma patient samples. Combination treatment in vitro of pathway inhibition and temozolomide resulted in a highly synergistic interaction in KNS42 cells. The resistance gene signature further included contiguous genes within the 12q13-q14 amplicon, including the Akt enhancer PIKE, significantly overexpressed in the KNS42 line. These cells were also highly enriched for CD133 and other stem cell markers. We have thus shown an in vitro link between phosphoinositide 3-kinase-mediated HOXA9/HOXA10 expression, and a drug-resistant, progenitor cell phenotype in MGMT-independent pediatric glioblastoma.Cancer Research UK (C1178/A10294, C309/A2187, C309/A8274), the Oak Foundation (L. Marshall), and La Fondation de France (N. Gaspar). We acknowledge NHS funding to the NIHR Biomedical Research Centre. P. Workman is a Cancer Research UK Life Fello

A systematic review of recent phase-II trials in refractory or recurrent osteosarcoma: Can we inform future trial design?

Background/Objective: To analyze changes in recurrent/refractory osteosarcoma phase II trials over time to inform future trials in this population with poor prognosis.// Methods: A systematic review of trials registered on trial registries between 01/01/2017–14/02/2022. Comparison of 98 trials identified between 2003 and 2016. Publication search/analysis for both periods, last update on 01/12/2022.// Results: Between 2017 and 2022, 71 phase-II trials met our selection criteria (19 osteosarcoma-specific trials, 14 solid tumor trials with and 38 trials without an osteosarcoma-specific stratum). The trial number increased over time: 13.9 versus 7 trials/year (p = 0.06). Monotherapy remained the predominant treatment (62% vs. 62%, p = 1). Targeted therapies were increasingly evaluated (66% vs. 41%, P = 0.001). Heterogeneity persisted in the trial characteristics. The inclusion criteria were measurable disease (75%), evaluable disease (14%), and surgical remission (11%). 82% of the trials included pediatric or adolescent patients. Biomarker-driven trials accounted for 25% of the total trials. The survival endpoint use (rather than response) slightly increased (40% versus 31%), but the study H1/H0 hypotheses remained heterogeneous. Single-arm designs predominated over multiarm trials (n = 7). Available efficacy data on 1361 osteosarcoma patients in 58 trials remained disappointing, even though 21% of these trials were considered positive, predominantly those evaluating multi-targeted kinase inhibitors.// Conclusion: Despite observed changes in trial design and an increased number of trials investigating new therapies, high heterogeneity remained with respect to patient selection, study design, primary endpoints, and statistical hypotheses in recently registered phase II trials for osteosarcoma. Continued optimization of trial design informed by a deeper biological understanding should strengthen the development of new therapies

International randomised controlled trial for the treatment of newly diagnosed EWING sarcoma family of tumours - EURO EWING 2012 Protocol

[Background] Although there have been multiple randomised trials in newly diagnosed Ewing sarcoma family of tumours (ESFT) and these have been conducted over many years and involved many international cooperative groups, the outcomes for all stages of disease have plateaued. Internationally, the standard treatment of ESFT is not defined, and there is a need to add new agents other than conventional chemotherapy to improve outcomes. This trial will compare two different induction/consolidation chemotherapy regimens: (1) vincristine, ifosfamide, doxorubicin and etoposide (VIDE) induction and vincristine, actinomycin D, ifosfamide or cyclophosphamide, or busulfan and mephalan (VAI/VAC/BuMel) consolidation and (2) vincristine, doxorubicin, cyclophosphamide, ifosfamide and etoposide (VDC/IE) induction and ifosfamide and etoposide, vincristine and cyclophosphamide, vincristine, actinomycin D and ifosfamide, or busulfan and mephalan (IE/VC/VAI/BuMel) consolidation (randomisation 1, or R1). A second randomisation (R2) will determine whether the addition of zoledronic acid to consolidation chemotherapy, as assigned at R1, is associated with improved clinical outcome.[Methods] EURO EWING 2012 is an international, multicentre, phase III, open-label randomised controlled trial. There are two randomisations: R1 and R2. Patients are randomly assigned at two different time points: at entry to the trial (R1) and following local control therapy (R2). The primary outcome measure is event-free survival. The secondary outcome measures include overall survival, adverse events and toxicity, histological response of the primary tumour, response of the primary tumour, regional lymph nodes or metastases (or both), and achievement of local control at the end of treatment.[Discussion] This study will establish which is the “standard regimen” of chemotherapy, taking into account both clinical outcomes and toxicity. This will form the chemotherapy backbone for future interventional studies where we may want to add new targeted agents. It will also determine the role of zoledronic acid in conjunction with the separate EE2008 trial. Any trial in ESFT needs to take into account the rarity of the tumour and consider that international cooperation is needed to provide answers in a timely manner.[Trial registration] Registered with EudraCT number 2012-002107-17 on 26 February 2012. Registered with ISRCTN number 92192408 on 4 November 2013.This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement n°602856. The NCC in France, CLB, receives additional funding from SFCE and Ligue contre le cancer. The coordinating sponsor (the University of Birmingham, Birmingham, UK) is funded by Cancer Research UK (grant award reference C5952/A14745)

Report from the 4th European Bone Sarcoma Networking meeting: focus on osteosarcoma

Abstract This report summarizes the proceedings of the 4th European Bone Sarcoma Networking Meeting, held in London, England, on 21 June 2017. The meeting brought together scientific and clinical researchers and representatives from sarcoma charities from 19 countries representing five networks across Europe, to present and discuss new developments on bone sarcoma. In view of the challenges is poses, the meeting focussed primarily on osteosarcoma with presentations on developments in our understanding of osteosarcoma genetics and immunology as well as results from preclinical investigations and discussion of recent and ongoing clinical trials. These include studies examining the efficacy of multi-targeted tyrosine kinase inhibitors and checkpoint inhibitors, as well as those with molecular profiling to stratify patients for specific therapies. Discussion was centred on generation of new hypotheses for collaborative biological and clinical investigations, the ultimate goal being to improve therapy and outcome in patients with bone sarcomas

Molecular and phenotypic characterisation of paediatric glioma cell lines as models for preclinical drug development.

Although paediatric high grade gliomas resemble their adult counterparts in many ways, there appear to be distinct clinical and biological differences. One important factor hampering the development of new targeted therapies is the relative lack of cell lines derived from childhood glioma patients, as it is unclear whether the well-established adult lines commonly used are representative of the underlying molecular genetics of childhood tumours. We have carried out a detailed molecular and phenotypic characterisation of a series of paediatric high grade glioma cell lines in comparison to routinely used adult lines