Genotoxic impact of aluminum-containing nanomaterials in human intestinal and hepatic cells.

Exposure of consumers to aluminum-containing nanomaterials (Al NMs) is an area of concern for public health agencies. As the available data on the genotoxicity of Al2O3 and Al0 NMs are inconclusive or rare, the present study investigated their in vitro genotoxic potential in intestinal and liver cell models, and compared with the ionic form AlCl3. Intestinal Caco-2 and hepatic HepaRG cells were exposed to Al0 and Al2O3 NMs (0.03 to 80 µg/cm2). Cytotoxicity, oxidative stress and apoptosis were measured using High Content Analysis. Genotoxicity was investigated through γH2AX labelling, the alkaline comet and micronucleus assays. Moreover, oxidative DNA damage and carcinogenic properties were assessed using the Fpg-modified comet assay and the cell transforming assay in Bhas 42 cells respectively. The three forms of Al did not induce chromosomal damage. However, although no production of oxidative stress was detected, Al2O3 NMs induced oxidative DNA damage in Caco-2 cells but not likely related to ion release in the cell media. Considerable DNA damage was observed with Al0 NMs in both cell lines in the comet assay, likely due to interference with these NMs. No genotoxic effects were observed with AlCl3. None of the Al compounds induced cytotoxicity, apoptosis, γH2AX or cell transformation.

Predictive early gene signature during mouse Bhas 42 cell transformation induced by synthetic amorphous silica nanoparticles.

Synthetic amorphous silica nanoparticles (SAS) are used widely in industrial applications. These nanoparticles are not classified for their carcinogenicity in humans. However, some data still demonstrate a potential carcinogenic risk of these compounds in humans. The Bhas 42 cell line was developed to screen chemicals, as tumor-initiators or -promoters according to their ability to trigger cell-to-cell transformation, in a cell transformation assay. In the present study, we performed unsupervised transcriptomic analysis after exposure of Bhas 42 cells to NM-203 SAS as well as to positive (Min-U-Sil 5® crystalline silica microparticles, and 12-O-tetradecanoylphorbol-13-acetate) and negative (diatomaceous earth) control compounds. We identified a common gene signature for 21 genes involved in the early stage of the SAS- Min-U-Sil 5®- or TPA-induced cell transformation. These genes were related to cell proliferation (over expression) and cell adhesion (under expression). Among them, 12 were selected on the basis of their potential impact on cell transformation. RT-qPCR and western blotting were used to confirm the transcriptomic data. Moreover, similar gene alterations were found when Bhas 42 cells were treated with two other transforming SAS. In conclusion, the results obtained in the current study highlight a 12-gene signature that could be considered as a potential early "bio-marker" of cell transformation induced by SAS and perhaps other chemicals.

In vitro cell transformation induced by synthetic amorphous silica nanoparticles.

Synthetic amorphous silica nanoparticles (SAS) are among the most widely produced and used nanomaterials, but little is known about their carcinogenic potential. This study aims to evaluate the ability of four different SAS, two precipitated, NM-200 and NM-201, and two pyrogenic, NM-202 and NM-203, to induce the transformation process. For this, we used the recently developed in vitro Bhas 42 cell transformation assay (CTA). The genome of the transgenic Bhas 42 cells contains several copies of the v-Ha-ras gene, making them particularly sensitive to tumor-promoter agents. The Bhas 42 CTA, which includes an initiation assay and a promotion assay, was validated in our laboratory using known soluble carcinogenic substances. Its suitability for particle-type substances was verified by using quartz Min-U-Sil 5 (Min-U-Sil) and diatomaceous earth (DE) microparticles. As expected given their known transforming properties, Min-U-Sil responded positively in the Bhas 42 CTA and DE responded negatively. Transformation assays were performed with SAS at concentrations ranging from 2µg/cm2 to 80µg/cm2. Results showed that all SAS have the capacity to induce transformed foci, interestingly only in the promotion assay, suggesting a mode of action similar to tumor-promoter substances. NM-203 exhibited transforming activity at a lower concentration than the other SAS. In conclusion, this study showed for the first time the transforming potential of different SAS, which act as tumor-promoter substances in the Bhas 42 model of cell transformation.

Epigenetic changes in the early stage of silica-induced cell transformation.

The increasing use of nanomaterials in numerous domains has led to growing concern about their potential toxicological properties, and the potential risk to human health posed by silica nanoparticles remains under debate. Recent studies proposed that these particles could alter gene expression through the modulation of epigenetic marks, and the possible relationship between particle exposure and these mechanisms could represent a critical factor in carcinogenicity. In this study, using the Bhas 42 cell model, we compare the effects of exposure to two transforming particles, a pyrogenic amorphous silica nanoparticle NM-203 to those of the crystalline silica particle Min-U-Sil® 5. Short-term treatment by Min-U-Sil® 5 decreased global DNA methylation and increased the expression of the two de novo DNMTs, DNMT3a and DNMT3b. NM-203 treatment affected neither the expression of these enzymes nor DNA methylation. Moreover, modified global histone H4 acetylation status and HDAC protein levels were observed only in the Min-U-Sil® 5-treated cells. Finally, both types of particle treatment induced strong c-Myc expression in the early stage of cell transformation and this correlated with enrichment in RNA polymerase II as well as histone active marks on its promoter. Lastly, almost all parameters that were modulated in the early stage were restored in transformed cells suggesting their involvement mainly in the first steps of cell transformation.

In vitro comet and micronucleus assays do not predict morphological transforming effects of silica particles in Syrian Hamster Embryo cells.

Crystalline silica particles and asbestos have both been classified as carcinogenic by the International Agency for Research on Cancer (IARC). However, because of the limited data available, amorphous silica was not classifiable. In vitro, the carcinogenic potential of natural crystalline and amorphous silica particles has been revealed by the Syrian Hamster Embryo (SHE) cell transformation assay. On the other hand, the genotoxic potential of those substances has not been investigated in SHE cells. And yet, genotoxicity assays are commonly used for hazard evaluation and they are often used as in vitro assays of reference to predict a possible carcinogenic potential. The main objective of this study was to compare the genotoxic potential and the carcinogenic potential of different crystalline and amorphous silica particles in SHE cells. Three silica samples of different crystallinity were used: natural amorphous silica, partially crystallized silica and quartz silica particles. Their genotoxicity were tested through the in vitro micronucleus assay and the comet assay in SHE, and their carcinogenic potential through the SHE transformation assay. In addition, silica samples were also tested with the same genotoxicity assays in V79 hamster-lung cells, a common in vitro model for particle exposure. Results obtained in the micronucleus and the comet assays show that none of the silica was capable of inducing genotoxic effects in SHE cells and only the amorphous silica induced genotoxic effects in V79 cells. However in the SHE cell transformation assays, the partially crystallized and quartz silica were able to induce morphological cell transformation. Together, these data suggest that, in vitro, the short-term genotoxic assays alone are not sufficient to predict the hazard and the carcinogenic potential of this type of particles; SHE transformation assay appears a more reliable tool for this purpose and should be included in the "in vitro battery assays" for hazard assessment.

Genotoxicity of synthetic amorphous silica nanoparticles in rats following short-term exposure. Part 2: intratracheal instillation and intravenous injection.

Synthetic amorphous silica nanomaterials (SAS) are extensively used in food and tire industries. In many industrial processes, SAS may become aerosolized and lead to occupational exposure of workers through inhalation in particular. However, little is known about the in vivo genotoxicity of these particulate materials. To gain insight into the toxicological properties of four SAS (NM-200, NM-201, NM-202, and NM-203), rats are treated with three consecutive intratracheal instillations of 3, 6, or 12 mg/kg of SAS at 48, 24, and 3 hrs prior to tissue collection (cumulative doses of 9, 18, and 36 mg/kg). Deoxyribonucleic acid (DNA) damage was assessed using erythrocyte micronucleus test and the standard and Fpg-modified comet assays on cells from bronchoalveolar lavage fluid (BALF), lung, blood, spleen, liver, bone marrow, and kidney. Although all of the SAS caused increased dose-dependent changes in lung inflammation as demonstrated by BALF neutrophilia, they did not induce any significant DNA damage. As the amount of SAS reaching the blood stream and subsequently the internal organs is probably to be low following intratracheal instillation, an additional experiment was performed with NM-203. Rats received three consecutive intravenous injections of 5, 10, or 20 mg/kg of SAS at 48, 24, and 3 hrs prior to tissue collection. Despite the hepatotoxicity, thrombocytopenia, and even animal death induced by this nanomaterial, no significant increase in DNA damage or micronucleus frequency was observed in SAS-exposed animals. It was concluded that under experimental conditions, SAS induced obvious toxic effects but did cause any genotoxicity following intratracheal instillation and intravenous injection.

Adesão às medidas de um bundle para prevenção de pneumonia associada à ventilação mecânica / Adherence to the items in a bundle for the prevention of ventilator-associated pneumonia

Objetivo: Avaliar a adesão ao bundle de ventilação mecânica em uma unidade de terapia intensiva, bem como o impacto dessa adesão nas taxas de pneumonia associada à ventilação mecânica. Métodos: Foram avaliados 198 leitos em 60 dias por meio de uma lista de checagem, contendo os itens: elevação da cabeceira de 30 a 45º, posição do filtro umidificador, ausência de líquidos no circuito do ventilador, higiene oral, pressão do balonete e fisioterapia. Posteriormente, foi realizada uma palestra educativa e foram avaliados outros 235 leitos nos 60 dias posteriores à intervenção. Ainda foram coletados dados de incidência de pneumonia associada à ventilação mecânica. Resultados: O estudo demonstrou aumento da adesão dos seguintes itens do bundle de ventilação: elevação da cabeceira de 18,7% para 34,5%, ausência de líquidos no circuito do ventilador de 55,6% para 72,8%, higiene oral de 48,5% para 77,8%, e pressão do balonete de 29,8% para 51,5%. A incidência de pneumonia associada à ventilação mecânica foi estatisticamente semelhante em ambos os períodos (p=0,389). Conclusão: Esta intervenção educacional resultou em aumento da adesão ao bundle de ventilação, porém não foi possível detectar redução na incidência de pneumonia associada à ...

Objective: To assess adherence to a ventilator care bundle in an intensive care unit and to determine the impact of adherence on the rates of ventilatorassociated pneumonia. Methods: A total of 198 beds were assessed for 60 days using a checklist that consisted of the following items: bed head elevation to 30 to 45º; position of the humidifier filter; lack of fluid in the ventilator circuit; oral hygiene; cuff pressure; and physical therapy. Next, an educational lecture was delivered, and 235 beds were assessed for the following 60 days. Data were also collected on the incidence of ventilator-acquired pneumonia. Results: Adherence to the following ventilator care bundle items increased: bed head elevation from 18.7% to 34.5%; lack of fluid in the ventilator circuit from 55.6% to 72.8%; oral hygiene from 48.5% to 77.8%; and cuff pressure from 29.8% to 51.5%. The incidence of ventilator-associated pneumonia was statistically similar before and after intervention (p=0.389). Conclusion: The educational intervention performed in this study increased the adherence to the ventilator care bundle, but the incidence of ventilator-associated pneumonia did not decrease in the small sample that was assessed. .

Adherence to the items in a bundle for the prevention of ventilator-associated pneumonia.

OBJECTIVE: To assess adherence to a ventilator care bundle in an intensive care unit and to determine the impact of adherence on the rates of ventilator-associated pneumonia. METHODS: A total of 198 beds were assessed for 60 days using a checklist that consisted of the following items: bed head elevation to 30 to 45º; position of the humidifier filter; lack of fluid in the ventilator circuit; oral hygiene; cuff pressure; and physical therapy. Next, an educational lecture was delivered, and 235 beds were assessed for the following 60 days. Data were also collected on the incidence of ventilator-acquired pneumonia. RESULTS: Adherence to the following ventilator care bundle items increased: bed head elevation from 18.7% to 34.5%; lack of fluid in the ventilator circuit from 55.6% to 72.8%; oral hygiene from 48.5% to 77.8%; and cuff pressure from 29.8% to 51.5%. The incidence of ventilator-associated pneumonia was statistically similar before and after intervention (p=0.389). CONCLUSION: The educational intervention performed in this study increased the adherence to the ventilator care bundle, but the incidence of ventilator-associated pneumonia did not decrease in the small sample that was assessed.

Nível de conhecimento de idosos sobre Diabetes Mellitus e sua percepção em relação à qualidade de vida / Level of knowledge of elderly on Diabetes Mellitus and its perception in relation to quality of life

Buscou-se com este estudo identificar alguns aspectos dos níveis de conhecimento e de percepção da qualidade de vida de idosos sobre a Diabetes Mellitus (DM). A amostra foi composta por 78 indivíduos idosos, sendo que todos responderam à versão brasileira do Questionário-Escala de Conhecimento do Diabetes Mellitus, antes e após as orientações sobre a patologia. Os dados apresentados nesta pesquisa mostram a deficiência nos conhecimentos dos idosos referentes à prevenção da patologia, tanto quanto sobre o tratamento e manutenção da qualidade de vida dos já portadores...

We sought to identify with some aspects of this study the levels of knowledge and perception of quality of life of seniors on the DM. The sample consisted of 78 elderly subjects, all of which responded to the Brazilian version of the Knowledge Scale Questionnaire Diabetes Mellitus before and after guidelines on the pathology. The data presented in this study showed a deficiency in knowledge of the elderly on the prevention of disease as much about the treatment and maintenance of quality of life of existing carriers...

Molecular and clinical characterization of rotavirus from diarrheal infants admitted to pediatric emergency units in france.

BACKGROUND: rotaviruses are the major cause of acute gastroenteritis in young children worldwide, and require careful surveillance, especially in the context of vaccination programs. Prospective surveillance is required to monitor and characterize rotavirus infections, including viral and clinical data, and to detect the emergence of potentially epidemic strains. METHODS: between 2006 and 2009, stool samples and clinical records were collected from 2044 children with acute diarrhea admitted to the pediatric emergency units of 13 French university hospitals. Rotaviruses were detected in stools, then genotyped by reverse transcription-polymerase chain reaction with regard to their outer capsid proteins VP4 and VP7. RESULTS: the genotyping of 1947 rotaviruses showed that G1 (61.7%) and G9 (27.4%) strains were predominant and stable, followed by G2 (6.5%), G3 (4.0%), and G4 (2.5%) strains. Most strains were associated with P[8] (92.9%). Overall, 31 uncommon strains and possible zoonotic reassortants were detected including G12 and G8 strains, some being closely related to bovine strains. No difference in clinical presentation and severity was found among genotypes. CONCLUSIONS: the relative stability of rotavirus genotypes currently cocirculating in France may ensure vaccine effectiveness in the short and medium term. However, the likely emergence of G12 and G8 strains should be monitored during ongoing and future vaccination programs, especially as all genotypes can cause severe infections. Special attention should be paid to the emergence of new rotavirus reassortants not included in current rotavirus vaccines.