Effects of length and chemical modification on the activation of vascular endothelial cells induced by multi walled carbon nanotubes / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effects of multi-walled carbon nanotubes (MWCNTs) with different length or chemical modification on endothelial cell activation and to explore the role of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome.@*METHODS@#MWCNTs were characterized by dynamic light scattering (DLS) after being suspended in culture medium. The immortalized mouse cerebral microvascular endothelial cell line b.End3 was treated with short MWCNTs (S-MWCNT, 0.5 to 2 μm), long MWCNTs (L-MWCNT, 10 to 30 μm) and the above long MWCNTs functionalized by carboxyl-(L-MWCNT-COOH), amino-(L-MWCNT-NH2) or hydroxyl-(L-MWCNT-OH) modification. Cytotoxicity of MWCNTs in b.End3 cells was determined by cell counting kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) release assay, and non-toxic low dose was selected for subsequent experiments. Effects of all types of MWCNTs on the endothelial activation of b.End3 were determined by the measurement of vascular cell adhesion molecule-1 (VCAM-1) concentration in cell supernatant and adhesion assay of human monocytic cell line THP-1 to b.End3.To further elucidate the mechanism involved, the protein expressions of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3(NLRP3) in cells treated with S-MWCNT, L-MWCNT and L-MWCNT-COOH were measured by Western blot.@*RESULTS@#At a higher concentration (125 μg/cm2) and treated for 24 h, all types of MWCNTs significantly inhibited viability of b.End3 cells. At a sub-toxic concentration (6.25 μg/cm2), all types of MWCNTs treated for 12 h significantly induced the activation of b.End3 cells, as evidenced by the elevated VCAM-1 release and THP-1 adhesion. Compared with S-MWCNT, L-MWCNT significantly promoted endothelial cell activation. L-MWCNT and L-MWCNT-COOH activated b.End3 cells to a similar extent. Furthermore, treatment with S-MWCNT, L-MWCNT and L-MWCNT-COOH increased NLRP3 expression in a time-dependent manner at 6.25 μg/cm2. Compared with S-MWCNT, cells treated with L-MWCNT for 4 h and 12 h exhibited significantly increased protein expressions of NLRP3. However, no significant differences were detected in the level of NLRP3 protein in cells treated with L-MWCNT and L-MWCNT-COOH.@*CONCLUSION@#Compared with the surface chemical modification, length changes of MWCNTs exerted more influence on endothelial cell activation, which may be related to the activation of NLRP3 inflammasome. Our study contributes further understanding of the impact of MWCNTs on endothelial cells, which may have implications for the improvement of safety evaluation of MWCNTs.

Cuidado em saúde em adultos com hipertensão arterial autorreferida no Brasil segundo dados da Pesquisa Nacional de Saúde, 2013 / Health care in adults with self-reported hypertension in Brazil according to the National Health Survey, 2013

RESUMO: Objetivo: Descrever indicadores de cuidado em saúde em adultos com hipertensão arterial autorreferida no Brasil, segundo características sociodemográficas. Métodos: Foram utilizados dados da Pesquisa Nacional de Saúde 2013, estudo transversal de base populacional, referentes ao cuidado em saúde com a hipertensão arterial autorreferida quanto ao uso de serviços de saúde. As prevalências e seus intervalos de confiança de 95% (IC95%) foram calculados segundo sexo, idade, raça/cor e escolaridade, representativos para Brasil e grandes regiões. Resultados: A hipertensão arterial foi referida por 21,4% (IC95% 20,8 - 22,0) dos entrevistados, sendo maior em mulheres e em pessoas sem instrução e com ensino fundamental incompleto. Dentre estes, 45,9% (IC95% 44,0 - 47,7) referiram ter recebido assistência médica pela última vez em uma Unidade Básica de Saúde; 81,4% (IC95% 80,1 - 82,7) referiram tomar medicamentos para a hipertensão; e 92,0% (IC95% 91,2 - 92,8) referiram ter realizado todos os exames complementares que foram solicitados. Conclusão: É importante conhecer a cobertura e o acesso aos serviços de saúde para o cuidado aos indivíduos com hipertensão arterial, de modo a avançar na qualidade da assistência prestada e reduzir as desigualdades identificadas.

ABSTRACT: Objective: To describe health care indicators in adults with self-reported hypertension in Brazil, according to socio-demographic characteristics. Methods: Data from the National Health Survey 2013, a cross-sectional population-based study, about health care of self-reported hypertension and health services were used. Prevalence and 95% confidence intervals (95%CI) were calculated for sex, age, race/color skin and schooling levels, representing Brazil and major regions. Results: Hypertension was reported by 21.4% (95%CI 20.8 - 22.0) of respondents, being higher in women and in people without instruction and incomplete middle school. Among these, 45.9% (95%CI 44.0 - 47.7) reported having received medical care for the last time in a basic health unit; 81.4% (95%CI 80.1 - 82.7) reported taking medication for high blood pressure; and 92.0% (95%CI 91.2 - 92.8) reported having taken all requested complementary examinations. Conclusion: It is important to know the coverage and access to health services for the care of patients with hypertension, in order to improve care quality and reduce identified inequalities.

Reviewing the environmental and human health knowledge base of carbon nanotubes / Revisão sobre a base de conhecimento de saúde ambiental e humana dos nanotubos de carbono

Carbon nanotubes (CNTs) are one of the most promising materials in nanotechnology. The various synthesis, purification and postprocessing methods produce CNTs with diverse physical characteristics, appliable in many fields. Their extensive projected use makes it important to understand their potential harmful effects. Besides showing a notable range of results of some toxicology studies, this review concluded that: a) there are different types of CNTs; thus, they cannot be considered a uniform group of substances; and b) in environmental compartments, CNTs can be bioavailable to organisms. Their properties suggest a possible accumulation along the food chain and high persistence. In organisms, CNT absorption, distribution, metabolism, excretion and toxicity depend on the inherent physical and chemical characteristics (e.g., functionalization, coating, length and agglomeration state), influenced by external environmental conditions during CNT production, use, and disposal. Thus, characterized exposure scenarios could be useful in toxicology studies. However, upon reaching the lungs in enough quantity, CNTs produce a toxic response (time and dose-dependent). The risks to human health and environment should be identified for a successful introduction of CNTs in future applications.

Os nanotubos de carbono(CNT)são um dos materiais mais promissores da nanotecnologia. Os métodos de síntese, purificação e pós-processamento produzem CNT com diversas características físicas e uso em várias áreas. A projeção de uso abrangente do CNT urge a compreensão de seus possíveis efeitos nocivos. Essa revisão mostra um leque de resultados de estudos toxicológicos e concluiu que: a) há diferentes tipos de CNT; portanto, não pode ser considerado um grupo uniforme de substâncias; e b) em compartimentos ambientais,o CNT pode ser biodisponível aos organismos. Suas propriedades sugerem possível acúmulo na cadeia alimentar e alta persistência. Em organismos, sua absorção, distribuição, metabolismo, excreção e toxicidade do dependem de características físicas e químicas inerentes (e.g., funcionalização, revestimento, comprimento e estado de aglomeração), influenciadas por condições ambientais externas durante a produção, uso e eliminação de CNT. Portanto, os cenários de exposição caracterizados podem ser úteis em estudos toxicológicos. Contudo, quando chega aos pulmões em quantidade suficiente, o CNT produz uma resposta tóxica (tempo e dose dependente). Os riscos à saúde humana e meio ambiente devem ser identificados para que o CNT possa ser usado com sucesso em futuras aplicações.

Nanoparticles-A Thoracic Toxicology Perspective

A substantial literature demonstrates that the main ultrafine particles found in ambient urban air are combustion-derived nanoparticles (CDNP) which originate from a number of sources and pose a hazard to the lungs. For CDNP, three properties appear important-surface area, organics and metals. All of these can generate free radicals and so induce oxidative stress and inflammation. Inflammation is a process involved in the diseases exhibited by the individuals susceptible to the effects of PM- development and exacerbations of airways disease and cardiovascular disease. It is therefore possible to implicate CDNP in the common adverse effects of increased PM. The adverse effects of increases in PM on the cardiovascular system are well-documented in the epidemiological literature and, as argued above, these effects are likely to be driven by the combustion-derived NP. The epidemiological findings can be explained in a number of hypotheses regarding the action of NP:-1) Inflammation in the lungs caused by NP causes atheromatous plaque development and destabilization; 2) The inflammation in the lungs causes alteration in the clotting status or fibrinolytic balance favouring thrombogenesis; 3) The NP themselves or metals/organics released by the particles enter the circulation and have direct effects on the endothelium, plaques, the clotting system or the autonomic nervous system/ heart rhythm. Environmental nanoparticles are accidentally produced but they provide a toxicological model for a new class of purposely 'engineered' NP arising from the nanotechnology industry, whose effects are much less understood. Bridging our toxicological knowledge between the environmental nanoparticles and the new engineered nanoparticles is a considerable challenge.