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1.
Eur J Dermatol ; 34(1): 40-50, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38557457

RESUMO

There is growing concern about the presence of endocrine disrupting chemicals (EDCs) in cosmetics. We aimed to identify the main cosmetic ingredients with suspected endocrine-disrupting properties, and analyse their presence in current marketed products. Particular attention was given to products intended for susceptible (due to physiological status) and vulnerable (due to specific pathologies) groups with a view to informing cosmetologists and related health professionals of the scientific basis and current status of any concerns. Suspected EDCs used as cosmetic ingredients, included in lists published by regulatory agencies, were documented and investigated by weight of evidence analysis based on endocrine-related toxicity studies. In total, 49 suspected EDCs were identified from a sample of over a thousand cosmetic products marketed in the European Union. Suspected EDCs were found in approximately one third of products, with a similar frequency in products intended for susceptible and vulnerable groups. Avobenzone (CAS number:70356-09-1), octisalate (CAS number: 118-60-5), and butylated hydroxytoluene (CAS number: 128-37-0) were mostly commonly identified. The presence of EDCs was particularly high for sun care cosmetic products. Our results highlight potentially significant exposure through cosmetics to substances currently studied by regulatory institutions as suspected endocrine disrupters. EDCs are not yet universally regulated, and informing health professionals and educating the population as a precaution are options to reduce individual exposure levels, especially in vulnerable and susceptible groups. Special recommendations are needed for products intended for oncological patients.


Assuntos
Cosméticos , Disruptores Endócrinos , Humanos , Disruptores Endócrinos/química , Disruptores Endócrinos/toxicidade , Cosméticos/efeitos adversos , Cosméticos/química , Hidroxitolueno Butilado
2.
Toxics ; 10(6)2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35736921

RESUMO

The risk assessment of pesticide residues in food is a key priority in the area of food safety. Most jurisdictions have implemented pre-marketing authorization processes, which are supported by prospective risk assessments. These prospective assessments estimate the expected residue levels in food combining results from residue trials, resembling the pesticide use patterns, with food consumption patterns, according to internationally agreed procedures. In addition, jurisdictions such as the European Union (EU) have implemented large monitoring programs, measuring actual pesticide residue levels in food, and are supporting large-scale human biomonitoring programs for confirming the actual exposure levels and potential risk for consumers. The organophosphate insecticide chlorpyrifos offers an interesting case study, as in the last decade, its acceptable daily intake (ADI) has been reduced several times following risk assessments by the European Food Safety Authority (EFSA). This process has been linked to significant reductions in the use authorized in the EU, reducing consumers' exposure progressively, until the final ban in 2020, accompanied by setting all EU maximum residue levels (MRL) in food at the default value of 0.01 mg/kg. We present a comparison of estimates of the consumer's internal exposure to chlorpyrifos based on the urinary marker 3,5,6-trichloro-2-pyridinol (TCPy), using two sources of monitoring data: monitoring of the food chain from the EU program and biomonitoring of European citizens from the HB4EU project, supported by a literature search. Both methods confirmed a drastic reduction in exposure levels from 2016 onwards. The margin of exposure approach is then used for conducting retrospective risk assessments at different time points, considering the evolution of our understanding of chlorpyrifos toxicity, as well as of exposure levels in EU consumers following the regulatory decisions. Concerns are presented using a color code, and have been identified for almost all studies, particularly for the highest exposed group, but at different levels, reaching the maximum level, red code, for children in Cyprus and Israel. The assessment uncertainties are highlighted and integrated in the identification of levels of concern.

3.
Arq Bras Cir Dig ; 34(4): e1628, 2022.
Artigo em Português, Inglês | MEDLINE | ID: mdl-35107490

RESUMO

OBJECTIVES: Ductal adenocarcinoma of the pancreas is the fourth most common cancer-associated cause of death in the Western world. The presence of circulating tumor cells (CTCs) can be considered a potential prognostic factor, as these cells represent tumor progression, allowing monitoring of therapeutic efficacy. The objectives of this study were to explore the morphological, molecular, and phenotypic characteristics of CTCs from the blood of patients with pancreatic carcinoma and to correlate the findings with response to treatment, progression-free survival, overall survival (OS), and deep vein thrombosis (DVT). METHODS: Peripheral blood (10 mL) was analyzed before the beginning of treatment after 60 and 120 days. CTCs were detected by using ISET® and characterized by immunocytochemistry. For microRNAs (miRNAs) analysis, peripheral leukocytes from the same patients and healthy individuals (controls) were collected in parallel at baseline. The expression of miRNAs was evaluated (in pool) using TaqMan® Array Human MicroRNA Cards v2.0. RESULTS: Only nine patients were included. The proteins, namely, matrix metalloproteinase-2 (MMP2) and TGFß-RI, were highly expressed (77.7%) in CTCs at baseline; at the first follow-up, MMP2 was predominant (80%) and, at the second follow-up, MMP2 and vimentin were predominant (50%). Circulating tumor microemboli (CTMs) were found in two patients and both presented DVT. The miR-203a-3p was highly expressed in CTCs. The miR-203a-3p is involved in the stimulation of epithelial-to-mesenchymal transition (EMT) and is related to worse OS in pancreatic cancer (TCGA data). CONCLUSION: Due to the low number of patients and short follow-up, we did not observe a correlation between CTCs and response to treatment. However, there was a correlation between CTM and DVT and also miR-203a-3p was highly expressed in CTCs, corroborating the findings of EMT proteins. This study opens the perspectives concerning the dynamic change in the pattern of proteins expressed along with treatment and the use of miRNAs as new targets in pancreatic carcinoma.


OBJETIVOS: O adenocarcinoma ductal do pâncreas é a quarta causa de morte associada ao câncer mais comum no mundo ocidental. A presença de células tumorais circulantes (CTCs) pode ser considerada um potencial fator prognóstico, visto que essas células representam a progressão tumoral, permitindo o monitoramento da eficácia terapêutica. explorar as características morfológicas, moleculares e fenotípicas das células tumorais circulantes (CTCs) do sangue de pacientes com carcinoma pancreático e correlacionar os achados com a resposta ao tratamento, sobrevida livre de progressão, sobrevida global (SG) e trombose venosa profunda (TVP). MÉTODOS: o sangue periférico (10mL) foi analisado antes do início do tratamento e após 60 e 120 dias. As CTCs foram detectadas pelo ISET® e caracterizadas por imunocitoquímica. Para análise de miRNAs, leucócitos periféricos dos mesmos pacientes e indivíduos saudáveis foram coletados em paralelo no início do estudo. A expressão de miRNAs foi avaliada usando TaqMan T Array Human MicroRNA Cards v2.0. RESULTADOS: foram incluídos 9 pacientes. As proteínas MMP2 e TGFß-RI foram altamente expressas (77,7%) nas CTCs no início do estudo. No primeiro acompanhamento, MMP2 era predominante (80%) e no segundo acompanhamento, MMP2 e vimentina eram predominantes (50%). Microêmbolos tumorais circulantes (MTC) foram encontrados em dois pacientes e ambos apresentavam TVP. O miR-203a-3p foi altamente expresso em CTCs. miR-203a-3p está envolvido na estimulação da transição epitelio-mesenquima (TEM) e relacionado a pior SG no câncer pancreático (dados TCGA). CONCLUSÃO: Devido ao baixo número de pacientes e curto seguimento, não observamos correlação entre CTCs e resposta ao tratamento. No entanto, houve uma correlação entre MTC e TVP. Além disso, miR-203a-3p foi altamente expresso em CTCs, corroborando os achados de proteínas EMT. Este estudo abre perspectivas sobre a mudança dinâmica no padrão de proteínas expressas ao longo do tratamento e a utilização de miRNAs como novos alvos no carcinoma pancreático.


Assuntos
Metaloproteinase 2 da Matriz/genética , MicroRNAs , Células Neoplásicas Circulantes , Neoplasias Pancreáticas , Humanos , MicroRNAs/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas
4.
EFSA J ; 19(8): e06768, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34377190

RESUMO

The EFSA has updated the Guidance on risk assessment of the application of nanoscience and nanotechnologies in the food and feed chain, human and animal health. It covers the application areas within EFSA's remit, including novel foods, food contact materials, food/feed additives and pesticides. The updated guidance, now Scientific Committee Guidance on nano risk assessment (SC Guidance on Nano-RA), has taken account of relevant scientific studies that provide insights to physico-chemical properties, exposure assessment and hazard characterisation of nanomaterials and areas of applicability. Together with the accompanying Guidance on Technical requirements for regulated food and feed product applications to establish the presence of small particles including nanoparticles (Guidance on Particle-TR), the SC Guidance on Nano-RA specifically elaborates on physico-chemical characterisation, key parameters that should be measured, methods and techniques that can be used for characterisation of nanomaterials and their determination in complex matrices. The SC Guidance on Nano-RA also details aspects relating to exposure assessment and hazard identification and characterisation. In particular, nanospecific considerations relating to in vitro/in vivo toxicological studies are discussed and a tiered framework for toxicological testing is outlined. Furthermore, in vitro degradation, toxicokinetics, genotoxicity, local and systemic toxicity as well as general issues relating to testing of nanomaterials are described. Depending on the initial tier results, additional studies may be needed to investigate reproductive and developmental toxicity, chronic toxicity and carcinogenicity, immunotoxicity and allergenicity, neurotoxicity, effects on gut microbiome and endocrine activity. The possible use of read-across to fill data gaps as well as the potential use of integrated testing strategies and the knowledge of modes or mechanisms of action are also discussed. The Guidance proposes approaches to risk characterisation and uncertainty analysis.

5.
EFSA J ; 19(5): e06585, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33976718

RESUMO

The present opinion deals with an updated safety assessment of the food additive titanium dioxide (E 171) based on new relevant scientific evidence considered by the Panel to be reliable, including data obtained with TiO2 nanoparticles (NPs) and data from an extended one-generation reproductive toxicity (EOGRT) study. Less than 50% of constituent particles by number in E 171 have a minimum external dimension < 100 nm. In addition, the Panel noted that constituent particles < 30 nm amounted to less than 1% of particles by number. The Panel therefore considered that studies with TiO2 NPs < 30 nm were of limited relevance to the safety assessment of E 171. The Panel concluded that although gastrointestinal absorption of TiO2 particles is low, they may accumulate in the body. Studies on general and organ toxicity did not indicate adverse effects with either E 171 up to a dose of 1,000 mg/kg body weight (bw) per day or with TiO2 NPs (> 30 nm) up to the highest dose tested of 100 mg/kg bw per day. No effects on reproductive and developmental toxicity were observed up to a dose of 1,000 mg E 171/kg bw per day, the highest dose tested in the EOGRT study. However, observations of potential immunotoxicity and inflammation with E 171 and potential neurotoxicity with TiO2 NPs, together with the potential induction of aberrant crypt foci with E 171, may indicate adverse effects. With respect to genotoxicity, the Panel concluded that TiO2 particles have the potential to induce DNA strand breaks and chromosomal damage, but not gene mutations. No clear correlation was observed between the physico-chemical properties of TiO2 particles and the outcome of either in vitro or in vivo genotoxicity assays. A concern for genotoxicity of TiO2 particles that may be present in E 171 could therefore not be ruled out. Several modes of action for the genotoxicity may operate in parallel and the relative contributions of different molecular mechanisms elicited by TiO2 particles are not known. There was uncertainty as to whether a threshold mode of action could be assumed. In addition, a cut-off value for TiO2 particle size with respect to genotoxicity could not be identified. No appropriately designed study was available to investigate the potential carcinogenic effects of TiO2 NPs. Based on all the evidence available, a concern for genotoxicity could not be ruled out, and given the many uncertainties, the Panel concluded that E 171 can no longer be considered as safe when used as a food additive.

6.
Transl Oncol ; 14(1): 100932, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33157516

RESUMO

Colorectal cancer is a common and often deadly cancer. Circulating tumor cells (CTCs) have been implicated as a potentially valuable prognosis factor. The detection of circulating tumor microemboli (CTM) and of simple blood component parameters that reflect inflammatory status, such as the platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR), may provide information about tumor progression. The aim of this study was to explore the importance of CTCs, CTM, PLR, and NLR prospectively in non-metastatic colon cancer progression. CTCs were enriched using ISETⓇ (Isolation by SizE of Tumor cells) and identified by immunocytochemical exclusion of leukocytes. We evaluated CTCs and blood cell parameters in a cohort of 69 stage I-III colon cancer patients (52.2% men; median age, 61 years; age range, 19-87 years) at a baseline timepoint prior to resection surgery. The median of CTC levels at baseline was 20 cells/8 mL (0-94) and higher levels were associated with CTM presence (p = 0.02). CTM were found in 18 (26.1%) patients. Of 18 stage I patients, 33.3% had CTM and of 51 stages II or III patients, 13.7% had CTM (p = 0.08). Patients with a high PLR (>124) were mostly (75.6%) diagnosed with high-risk stages II/III cancer (stages I/low-risk II, 24.4%; p = 0.014). All 8 patients that had disease recurrence during follow-up had a high PLR (p = 0.02 vs. low PLR). NLR was not significantly associated with disease stage or recurrence. The present results indicate that CTCs and PLR analyses may be clinically useful for colon cancer management and risk stratification.

7.
ABCD (São Paulo, Impr.) ; 34(4): e1628, 2021. tab, graf
Artigo em Inglês, Português | LILACS | ID: biblio-1360014

RESUMO

RESUMO -RACIONAL: O adenocarcinoma ductal do pâncreas é a quarta causa de morte associada ao câncer mais comum no mundo ocidental. A presença de células tumorais circulantes (CTCs) pode ser considerada um potencial fator prognóstico, visto que essas células representam a progressão tumoral, permitindo o monitoramento da eficácia terapêutica. OBJETIVOS: explorar as características morfológicas, moleculares e fenotípicas das células tumorais circulantes (CTCs) do sangue de pacientes com carcinoma pancreático e correlacionar os achados com a resposta ao tratamento, sobrevida livre de progressão, sobrevida global (SG) e trombose venosa profunda (TVP). MÉTODOS: o sangue periférico (10mL) foi analisado antes do início do tratamento e após 60 e 120 dias. As CTCs foram detectadas pelo ISET® e caracterizadas por imunocitoquímica. Para análise de miRNAs, leucócitos periféricos dos mesmos pacientes e indivíduos saudáveis foram coletados em paralelo no início do estudo. A expressão de miRNAs foi avaliada usando TaqMan T Array Human MicroRNA Cards v2.0. RESULTADOS: foram incluídos 9 pacientes. As proteínas MMP2 e TGFß-RI foram altamente expressas (77,7%) nas CTCs no início do estudo. No primeiro acompanhamento, MMP2 era predominante (80%) e no segundo acompanhamento, MMP2 e vimentina eram predominantes (50%). Microêmbolos tumorais circulantes (MTC) foram encontrados em dois pacientes e ambos apresentavam TVP. O miR-203a-3p foi altamente expresso em CTCs. miR-203a-3p está envolvido na estimulação da transição epitelio-mesenquima (TEM) e relacionado a pior SG no câncer pancreático (dados TCGA). CONCLUSÃO: Devido ao baixo número de pacientes e curto seguimento, não observamos correlação entre CTCs e resposta ao tratamento. No entanto, houve uma correlação entre MTC e TVP. Além disso, miR-203a-3p foi altamente expresso em CTCs, corroborando os achados de proteínas EMT. Este estudo abre perspectivas sobre a mudança dinâmica no padrão de proteínas expressas ao longo do tratamento e a utilização de miRNAs como novos alvos no carcinoma pancreático.


ABSTRACT - BACKGROUND: Ductal adenocarcinoma of the pancreas is the fourth most common cancer-associated cause of death in the Western world. The presence of circulating tumor cells (CTCs) can be considered a potential prognostic factor, as these cells represent tumor progression, allowing monitoring of therapeutic efficacy. OBJECTIVES: The objectives of this study were to explore the morphological, molecular, and phenotypic characteristics of CTCs from the blood of patients with pancreatic carcinoma and to correlate the findings with response to treatment, progression-free survival, overall survival (OS), and deep vein thrombosis (DVT). METHODS: Peripheral blood (10 mL) was analyzed before the beginning of treatment after 60 and 120 days. CTCs were detected by using ISET® and characterized by immunocytochemistry. For microRNAs (miRNAs) analysis, peripheral leukocytes from the same patients and healthy individuals (controls) were collected in parallel at baseline. The expression of miRNAs was evaluated (in pool) using TaqMan® Array Human MicroRNA Cards v2.0. RESULTS: Only nine patients were included. The proteins, namely, matrix metalloproteinase-2 (MMP2) and TGFβ-RI, were highly expressed (77.7%) in CTCs at baseline; at the first follow-up, MMP2 was predominant (80%) and, at the second follow-up, MMP2 and vimentin were predominant (50%). Circulating tumor microemboli (CTMs) were found in two patients and both presented DVT. The miR-203a-3p was highly expressed in CTCs. The miR-203a-3p is involved in the stimulation of epithelial-to-mesenchymal transition (EMT) and is related to worse OS in pancreatic cancer (TCGA data). CONCLUSION: Due to the low number of patients and short follow-up, we did not observe a correlation between CTCs and response to treatment. However, there was a correlation between CTM and DVT and also miR-203a-3p was highly expressed in CTCs, corroborating the findings of EMT proteins. This study opens the perspectives concerning the dynamic change in the pattern of proteins expressed along with treatment and the use of miRNAs as new targets in pancreatic carcinoma.


Assuntos
Humanos , Neoplasias Pancreáticas/genética , Metaloproteinase 2 da Matriz/genética , MicroRNAs/genética , Células Neoplásicas Circulantes
8.
São Paulo; s.n; 2020. 120 p. figuras, tabelas, quadros.
Tese em Português | Inca | ID: biblio-1099762

RESUMO

O adenocarcinoma ductal do pâncreas é a quarta causa associada a câncer mais comum de morte no mundo ocidental. A presença de células tumorais circulantes (CTCs) no sangue pode ser considerada como um potencial fator prognóstico. Assim, o estudo de componentes que contribuem para sua formação de metástases tem se mostrado promissor. CTCs representam, em tempo real, a progressão tumoral, permitindo o monitoramento da eficácia terapêutica. O presente projeto teve por objetivo detectar CTCs presentes no sangue periférico de pacientes com adenocarcinoma ductal de pâncreas, avaliar a expressão de proteínas relacionadas à transição epitélio-mesênquima (TEM) tais como a mesotelina, vimentina, Metaloproteinase de Matriz 2 (MMP2) e o Receptor Beta do Fator de Crescimento Transformador I (TGFß-RI) e correlacionar com a resposta ao tratamento e sobrevida livre de progressão. Ainda, tentamos correlacionar os níveis de CTCs e expressão dos miRNAs destas células com sobrevidas livre de progressão (SLP) e global (SG). Foram analisadas amostras de sangue de 9 pacientes com adenocarcinoma de pâncreas (10 ml de sangue periférico) antes do início do tratamento e após 60 e 120 dias. As CTCs foram detectadas pelo sistema ISET (Rarecells, France) e depois caracterizadas por imunocitoquímica . Para análise de miRNAS das CTCs, foram colhidos em paralelo, leucócitos periféricos dos mesmos pacientes e de indivíduos saudáveis, como controle. Para essa análise, utilizamos apenas o material da coleta baseline. A extração do material foi realizada com um kit comercial (Qiagen) e a avaliação da expressão dos microRNAs com TaqMan Low Density Array (TLDA) em pool. As análises das proteínas envolvidas na TEM na coleta baseline, indicam que as CTCs expressavam predominantemente MMP2 (77,77%), seguida de TGFß-RI (44,44%), vimentina (33,33%) e mesotelina (22,22%). No primeiro grupo de acompanhamento de 5 pacientes, as CTCs expressaram MMP2 e vimentina (80%), TGFß-RI (60%) e mesotelina (20%). Comparadas ao grupo de 8 pacientes do segundo seguimento, as CTCs expressaram MMP2 (50%), vimentina (25%) e TGF-RI (12,5%). Constatamos que 3/9 pacientes no presente estudo progrediram (33,33%). Em dois pacientes, foram encontrados microêmbolos tumorais circulantes (MTC) e ambos apresentaram Trombose Venosa Periférica (TVP), mostrando que talvez haja uma correlação entre MTC e TVP. Encontramos dois microRNAs altamente expressos nas CTCs dos pacientes aqui avaliados, ambos envolvidos na estimulação do processo de TEM: hsa-miR-203a-3p e hsa-324-5p. Não houve diferença estatisticamente significante no número de casos com presença de proteína ou correlação com outros fatores, embora a MMP2 tenha sido altamente expressa nas três coletas, seguida por TGFß-RI e vimentina. Também não encontramos qualquer correlação entre as variáveis analisadas e SLP e SG. Neste trabalho foi possível encontrar CTCs em todos os 9 pacientes com câncer de pâncreas. Devido ao baixo número de pacientes incluídos e curto tempo de follow-up, não conseguimos ver correlação entre níveis de CTCs e expressão de proteínas e SLPe SG, mas continuaremos acompanhando o pacientes. Encontramos correlação entre presença de MTC e TEP. E conforme esperávamos, encontramos microRNAs relacionados à TEM altamente expressos em CTCs de pacientes com câncer de pâncreas (AU)


Ductal adenocarcinoma of the pancreas is the fourth most common cancer-associated cause of death in the Western world. The presence of circulating tumor cells (CTCs) in the blood can be considered as a potential prognostic factor. Thus, the study of components that contribute to metastases formation has shown to be promising. CTCs represent, in real time, tumor progression, allowing monitoring of therapeutic efficacy. The aim of this project was to detect CTCs present in the peripheral blood of patients with pancreatic ductal adenocarcinoma, to evaluate the expression of proteins related to the epithelial-mesenchymal transition (TEM) such as mesothelin, vimentin, Matrix Metalloproteinase 2 (MMP2) and Transforming Growth Factor Beta Receptor I (TGFß-RI) and correlate with response to treatment, progression-free survival (PFS) and overall survival (OS). Still, we tried to correlate the levels of CTCs and expression of miRNAs of these cells with progression-free and global survival. Blood samples from 9 patients with pancreatic adenocarcinoma (10 ml of peripheral blood) were analyzed before the start of treatment and after 60 and 120 days. CTCs were detected by the ISET system (Rarecells, France) and then characterized by immunocytochemistry. For analysis of the CTCs miRNAs, peripheral leukocytes from the same patients and healthy individuals were collected in parallel as a control. For this analysis, we used only the material from the baseline collection. The extraction of the material was made with a commercial kit (Qiagen) and the evaluation of the expression of the microRNAs with TaqMan Low Density Array (TLDA) in pool. The analysis of proteins involved in TEM in the baseline collection, indicates that CTCs expressed predominantly MMP2 (77.77%), TGFß-RI (44.44%), vimentin (33.33%) and mesothelin (22.22%). In the first follow-up group of 5 patients, CTCs expressed MMP2 in (80%), vimentin and TGFß-RI in (60%) and mesothelin (20%). Compared to the group of 8 patients in the second follow-up, CTCs expressed MMP2 in (50%), vimentin (25%) and TGF-RI in (12.5%). We found that 3/9 patients in the present study progressed (33.33%). In two patients, circulating tumor microemboli (CTM) were found and both had Peripheral Venous Thrombosis (PVT), showing that there may be a correlation between CTM and PVT. We found two microRNAs highly expressed in the CTCs of the patients evaluated here, both involved in the stimulation of the TEM process: hsa-miR-203a-3p and hsa-324-5p. There was no statistically significant difference in the number of cases with protein or correlation with other factors, although MMP2 was highly expressed in the three collections, followed by TGFß-R1 and vimentin. We also found no correlation between the variables analyzed and PFS and OS. In this work, it was possible to find CTCs in all 9 pancreatic cancer patients. Due to the low number of patients included and short follow-up time, we were unable to see a correlation between CTC levels and protein expression and PFS and OS, but we will continue to monitor the patients. Here, we found a correlation between the presence of CTM and PVT. As we expected, we found TEM-related microRNAs highly expressed in CTCs of patients with pancreatic cancer (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Neoplasias Pancreáticas , Biomarcadores Tumorais , MicroRNAs , Transição Epitelial-Mesenquimal , Biópsia Líquida , Células Neoplásicas Circulantes
9.
EFSA J ; 16(5): e05262, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-32625899

RESUMO

In compliance with Article 43 of Regulation (EC) No 396/2005, EFSA received from the European Commission a mandate to provide its reasoned opinion on the existing maximum residue levels (MRLs) for acetamiprid which might lead to consumers intake concerns on the basis of the new toxicological reference values agreed upon by Member States (MSs) in October 2017. In order to identify the MRLs of potential concern that require a more detailed assessment, EFSA performed a preliminary risk assessment, identifying a risk for consumers for 12 commodities. Measures for reduction of the consumer exposure were assessed by EFSA and should be considered by risk managers. Furthermore, in accordance with Article 6 of Regulation (EC) No 396/2005, ADAMA Makhteshim Ltd submitted two requests to modify the existing MRL for acetamiprid in table olives, olives for oil production, barley and oats. The data submitted in support of the requests were found to be sufficient to derive MRL proposals for all crops under assessment. Based on the risk assessment results, EFSA concluded that the short-term and long-term intake of residues resulting from the use of acetamiprid according to the intended agricultural practices on table olives, olives for oil production, barley and oats is unlikely to present a risk to consumer health.

11.
Arch Toxicol ; 91(8): 2723-2743, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28374158

RESUMO

Glyphosate is the most widely used herbicide worldwide. It is a broad spectrum herbicide and its agricultural uses increased considerably after the development of glyphosate-resistant genetically modified (GM) varieties. Since glyphosate was introduced in 1974, all regulatory assessments have established that glyphosate has low hazard potential to mammals, however, the International Agency for Research on Cancer (IARC) concluded in March 2015 that it is probably carcinogenic. The IARC conclusion was not confirmed by the EU assessment or the recent joint WHO/FAO evaluation, both using additional evidence. Glyphosate is not the first topic of disagreement between IARC and regulatory evaluations, but has received greater attention. This review presents the scientific basis of the glyphosate health assessment conducted within the European Union (EU) renewal process, and explains the differences in the carcinogenicity assessment with IARC. Use of different data sets, particularly on long-term toxicity/carcinogenicity in rodents, could partially explain the divergent views; but methodological differences in the evaluation of the available evidence have been identified. The EU assessment did not identify a carcinogenicity hazard, revised the toxicological profile proposing new toxicological reference values, and conducted a risk assessment for some representatives uses. Two complementary exposure assessments, human-biomonitoring and food-residues-monitoring, suggests that actual exposure levels are below these reference values and do not represent a public concern.


Assuntos
Carcinógenos/toxicidade , Glicina/análogos & derivados , Herbicidas/toxicidade , Animais , Monitoramento Ambiental/métodos , União Europeia , Glicina/toxicidade , Humanos , Agências Internacionais , Valores de Referência , Medição de Risco/métodos , Roedores , Fatores de Tempo , Testes de Toxicidade/métodos , Glifosato
12.
Appl Opt ; 51(7): B108-14, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22410907

RESUMO

A predictive model to determine the concentration of nickel and vanadium in vacuum residues of Colombian crude oils using laser-induced breakdown spectroscopy (LIBS) and artificial neural networks (ANNs) with nodes distributed in multiple layers (multilayer perceptron) is presented. ANN inputs are intensity values in the vicinity of the emission lines 300.248, 301.200 and 305.081 nm of the Ni(I), and 309.310, 310.229, and 311.070 nm of the V(II). The effects of varying number of nodes and the initial weights and biases in the ANNs were systematically explored. Average relative error of calibration/prediction (REC/REP) and average relative standard deviation (RSD) metrics were used to evaluate the performance of the ANN in the prediction of concentrations of two elements studied here.


Assuntos
Lasers , Modelos Teóricos , Redes Neurais de Computação , Níquel/análise , Análise Espectral/métodos , Vanádio/análise , Destilação , Petróleo/análise
13.
Environ Pollut ; 160(1): 28-33, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22035922

RESUMO

The exposure to benzo[a]pyrene (B[a]P) results in an alteration of immune function in mammals and fish, and the analysis of cytokine mRNA levels has been suggested for predicting the immunomodulatory potential of chemicals. To obtain evidence of the innate immune responses to B[a]P in Xenopus laevis, the present study monitored the mRNA expression of interleukin 1-ß (IL-1ß), tumor necrosis factor α (TNF-α) and heat shock protein 70 (HSP70) in a laboratorial exposure. Tadpoles exposed to 8.36, 14.64, 89.06 and 309.47 µg/L of B[a]P,were used for detecting hsp70, IL-1ß and TNF-α mRNA induction. A dose-response increase in the expression of hsp70 and IL-1ß mRNA was found. The results of this study confirmed the use of hsp70 and IL-1ß, but not TNF-α, as sensitive indicators of immunotoxic effect of B[a]P in X. laevis. Further research would be required for the validation of these endpoints.


Assuntos
Benzo(a)pireno/toxicidade , Monitoramento Ambiental/métodos , Expressão Gênica/efeitos dos fármacos , Fatores Imunológicos/genética , Interleucina-1beta/genética , Fator de Necrose Tumoral alfa/genética , Proteínas de Xenopus/genética , Xenopus laevis/genética , Animais , Benzo(a)pireno/química , Relação Dose-Resposta a Droga , Monitoramento Ambiental/instrumentação , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/imunologia , Fatores Imunológicos/imunologia , Interleucina-1beta/imunologia , Estrutura Molecular , Fator de Necrose Tumoral alfa/imunologia , Proteínas de Xenopus/imunologia , Xenopus laevis/imunologia
14.
Ecotoxicol Environ Saf ; 72(4): 1038-44, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19237196

RESUMO

This paper presents an experimental design for quantifying the transfer of chemicals at low trophic levels of terrestrial ecosystems. The soil microcosms, MS.3(foodchain) (food chain multi-specie soil system) covered the transfer from soil to earthworms (Eisenia fetida) and from soil to plant (Triticum aestivum), then to phytophagus (Rhopalosiphum padi) and finally predator (Chrysoperla carnea) species. Cadmium was used as model pollutant. Cadmium accumulation in foliar invertebrates was related to the species biology. A significant transfer of this metal through the minimized food chain was found for all species, but not a biomagnification in the predator species. Results pointed out the relevance of foliar invertebrates and their trophic relationships as additional exposure routes for assessing secondary poisoning in predators. Hence, MS.3(foodchain), could be applied for terrestrial environmental risk assessment when potential bioaccumulation could be expected.


Assuntos
Cádmio/toxicidade , Poluentes do Solo/toxicidade , Solo , Animais , Afídeos/metabolismo , Cádmio/química , Cádmio/metabolismo , Interpretação Estatística de Dados , Cadeia Alimentar , Larva , Lepidópteros/metabolismo , Oligoquetos/metabolismo , Medição de Risco , Microbiologia do Solo , Poluentes do Solo/química , Poluentes do Solo/metabolismo , Triticum/química , Triticum/metabolismo
15.
Aquat Toxicol ; 87(4): 280-8, 2008 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-18405983

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are assumed to be the primary determinant of oil petroleum toxicity. Since the PAH content in Prestige oil was relatively high, we investigated the effects of different oil fractions (crude or weathered oil -0.05 to 50 g/L, and shaken or sonicated water accommodated fractions, WAFs, 25-100%, v/v) on the embryo-larval development of medaka (Oryzias latipes). Concentrations of summation operator16PAHs analyzed in the incubation medium were highest in the shaken WAF followed by the crude oil, the sonicated WAF and the weathered oil. Both oils (> or =0.25 g/L) induced developmental abnormalities whereas no significant effects were seen in the WAF exposures. In vivo morphometric analysis of the surface of the gallbladder during advanced embryo organogenesis (192 h post-fertilization, hpf) revealed significant dilation in both WAF exposures (>3 x 10(4) microm(2) at > or =25%, v/v, compared to <1.7 x 10(4) microm(2) at 0%, v/v) followed by the crude oil (>2.2 x 10(4) microm(2) at > or =0.05 g/L). Fluorescent aromatic compounds were observed in the gallbladder and the yolk sac of 168-hpf embryos exposed to all oil fractions. Results suggest the presence of components in both oils capable of penetrating the chorion and inducing a toxicity not observed in the WAFs. Hence, the hazard and risk assessment of Prestige oil should not be based solely on the presence of PAHs since proximity or direct contact may induce toxicity not associated exclusively to these compounds. This research offers a new hypothesis for explaining the reported biological observations, which could be correlated to direct oil exposure rather than the traditional mechanism of waterborne PAH exposure. Further research is needed to identify those oil components responsible for toxicity.


Assuntos
Oryzias/anormalidades , Petróleo/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/toxicidade , Acidentes , Animais , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Vesícula Biliar/anormalidades , Vesícula Biliar/efeitos dos fármacos , Zigoto/efeitos dos fármacos , Zigoto/crescimento & desenvolvimento
16.
Mar Environ Res ; 62 Suppl: S352-5, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16709428

RESUMO

The Prestige oil spill caused severe effects on the coastal fauna and flora due to direct contact of organisms with the fuel oil. However, the water soluble fraction (WSF) of the fuel oil can also provoke deleterious effects in the long term and even in regions not directly affected by the spill. Our objective was to determine the toxicity of the WSF using a battery of laboratory toxicity tests. To obtain a WSF in the laboratory, a sample of the spilled fuel was mixed with adequate medium, sonicated, agitated and filtered. No cytotoxic effects were detected in RTG-2 cells exposed to the WSF. In an algae growth inhibition test (OECD test guideline 201) the WSF did not affect the growth of Chlorella vulgaris. Furthermore, acute and reproductive toxicity tests (OECD test guideline 202) carried out using Daphnia magna did not indicate any deleterious effect of the WSF. In a bioassay designed in our laboratory, D. magna were fed with algae previously exposed to the fuel, but no toxic effects were detected. However, the WSF was able to induce a dose-dependent increase of ethoxyresorufin-O-deethylase activity in RTG-2 cells, indicating the presence of chemicals that could cause sub-lethal effects to organisms. After chemical analyses it was established that the final total quantity of polyaromatic hydrocarbons dissolved in medium was approximately 70 ng/ml. These low concentrations explain the observed lack of toxicity.


Assuntos
Chlorella vulgaris/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bioensaio , Linhagem Celular , Citocromo P-450 CYP1A1/análise , Citocromo P-450 CYP1A1/metabolismo , Desastres , Relação Dose-Resposta a Droga , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Navios , Testes de Toxicidade Aguda/métodos
17.
Environ Toxicol Chem ; 25(12): 3141-7, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17220082

RESUMO

It has been accepted that aryl hydrocarbon receptor (AhR) ligands are compounds with two or more aromatic rings in a coplanar conformation. Although general agreement exists that carbaryl is able to activate the AhR, it has been proposed that such activation could occur through alternative pathways without ligand binding. This idea was supported by studies showing a planar conformation of carbaryl as unlikely. The objective of the present work was to clarify the process of AhR activation by carbaryl. In rat H4IIE cells permanently transfected with a luciferase gene under the indirect control of AhR, incubation with carbaryl led to an increase of luminescence. Ligand binding to the AhR was studied by means of a cell-free in vitro system in which the activation of AhR can occur only by ligand binding. In this system, exposure to carbaryl also led to activation of AhR. These results were similar to those obtained with the AhR model ligand beta-naphthoflavone, although this compound exhibited higher potency than carbaryl in both assays. By means of computational modeling (molecular mechanics and quantum chemical calculations), the structural characteristics and electrostatic properties of carbaryl were described in detail, and it was observed that the substituent at C-1 and the naphthyl ring were not coplanar. Assuming that carbaryl would interact with the AhR through a hydrogen bond, this interaction was studied computationally using hydrogen fluoride as a model H-bond donor. Under this situation, the stabilization energy of the carbaryl molecule would permit it to adopt a planar conformation. These results are in accordance with the mechanism traditionally accepted for AhR activation: Binding of ligands in a planar conformation.


Assuntos
Carbaril/química , Carbaril/metabolismo , Receptores de Hidrocarboneto Arílico/química , Receptores de Hidrocarboneto Arílico/metabolismo , Animais , Linhagem Celular Tumoral , Simulação por Computador , Expressão Gênica , Genes Reporter/genética , Ácido Fluorídrico/química , Modelos Moleculares , Conformação Molecular , Ratos , Receptores de Hidrocarboneto Arílico/genética
18.
Rev. colomb. obstet. ginecol ; 56(2): 147-154, jun. 2005. tab
Artigo em Espanhol | LILACS | ID: lil-406342

RESUMO

El presente estudio es un ensayo reflexivo, argumentativo, cuya tesis de discusión es que el Aprendizaje Basado en Problemas (ABP) puede ser una mejor alternativa a las necesidades actuales de la formación médica. Para la argumentación, el autor se basó en las recomendaciones que sobre educación médica han emitido organismos tales como la AAMC (American Association of Medical College) y la Academia Nacional de Medicina de Colombia, entre otros. Se hizo una revisión de teorías de la psicología cognitiva (constructivismo y andragogía), que son el fundamento conceptual del ABP, y se revisaron artículos descriptivos, prospectivos y metanálisis sobre los resultados de las investigaciones realizadas a la fecha en escuelas de medicina de diferentes culturas, con la más larga experiencia en la aplicación de ABP. El autor concluye que vale la pena incursionar en la aplicación de la ABP en las escuelas de medicina, ya que se obtiene como mínimo una mejoría significativa en la satisfacción de profesores y alumnos, así como una mejoría en el caudal de conocimiento de los estudiantes dentro del proceso de enseñanza-aprendizaje.


Assuntos
Humanos , Educação Médica , Aprendizagem Baseada em Problemas , Colômbia
19.
Lect. nutr ; (6): 123-9, abr.-jun. 1994. graf
Artigo em Espanhol | LILACS | ID: lil-237623

RESUMO

Presentamos un caso de hiperemesis gravídica severa que requirió soporte nutricional por via parental durante la segunda mitad del embarazo hasta la culminación del mismo. Se revisan las indicaciones, alternativas y la necesidad de mantener un estado nutricional óptimo durante el embarazo.


Assuntos
Humanos , Feminino , Gravidez , Nutrição Parenteral Total/métodos , Nutrição Parenteral Total/normas , Nutrição Parenteral Total/tendências , Gravidez
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