Base de dados : MEDLINE
Pesquisa : D01.524.500.040 [Categoria DeCS]
Referências encontradas : 271 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 28 ir para página                         

  1 / 271 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27705550
[Au] Autor:Levin JL; Rouk A; Shepherd S; Hurst GA; McLarty JW
[Ad] Endereço:a Department of Occupational Health Sciences , University of Texas Health Science Center at Tyler , Tyler , Texas , USA.
[Ti] Título:Tyler asbestos workers: A mortality update in a cohort exposed to amosite.
[So] Source:J Toxicol Environ Health B Crit Rev;19(5-6):190-200, 2016.
[Is] ISSN:1521-6950
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The Tyler asbestos plant produced pipe insulation from 1954 to 1972 and exclusively used amosite asbestos. There were 1130 former workers of this plant during the period of operation. A death certificate mortality analysis was published regarding this plant in 1998 for the period through 1993. This study represents an update of the mortality analysis with additional certificates collected for deaths occurring through 2011.Searches of the National Death Index database were conducted in 2004 and again in 2013. At the time of the latter search, only deaths occurring through 2011 were available. In total, 265 distinct additional death certificates were secured and added to 304 available from the original study. After the new certificates were coded (ICD-9), data were analyzed using the Centers for Disease Control and Prevention Life Table Analysis System (LTAS) and standard mortality ratios (SMR) generated with 95% confidence limits (CL). LTAS constructs cause-specific mortality rates by age, gender, race, and person-time at risk, and compares observed rates with a referent population in order to derive SMR. A significant excess number of deaths due to nonmalignant respiratory disease (asbestosis) and from select malignant neoplasms were identified. There were in total 23 mesothelioma deaths (4% of deaths), with 16 pleural and 7 peritoneal. The SMR for malignant neoplasms of the trachea, bronchus, and lung was 244 (with 95% CL 196, 300), suggesting that exposed workers from this cohort were nearly 2.5-fold (244 %) more likely to die from this cause as the general referent population. The analysis also showed that exposures of short duration (<6 mo) produced significantly elevated SMR for all respiratory cancers, lung cancer, and pleural mesothelioma. There was a significant difference in median duration of exposure for mesothelioma types, confirming association of peritoneal mesothelioma with longer duration of exposure. Deaths due to intestinal cancer (predominantly colon; not including rectum) were also found in excess. The mortality experience of the Tyler cohort continues to be followed with great interest, given the exclusivity of exposure to amosite. Data confirm the inherent pathogenicity of this fiber type for nonmalignant disease as well as select cancers, particularly relevant given the importance of this amphibole's use in the United States.
[Mh] Termos MeSH primário: Amianto Amosita/toxicidade
Asbestose/mortalidade
Doenças Profissionais/mortalidade
Exposição Ocupacional
[Mh] Termos MeSH secundário: Asbestose/etiologia
Estudos de Coortes
Feminino
Seres Humanos
Masculino
Doenças Profissionais/induzido quimicamente
Texas/epidemiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
12172-73-5 (Asbestos, Amosite)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170526
[Lr] Data última revisão:
170526
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161006
[St] Status:MEDLINE


  2 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27224852
[Au] Autor:Martin J; Beauparlant M; Sauvé S; L'Espérance G
[Ad] Endereço:a Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) Montréal , Québec , Canada.
[Ti] Título:On the threshold conditions for electron beam damage of asbestos amosite fibers in the transmission electron microscope (TEM).
[So] Source:J Occup Environ Hyg;13(12):924-935, 2016 12.
[Is] ISSN:1545-9632
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Asbestos amosite fibers were investigated to evaluate the damage caused by a transmission electron microscope (TEM) electron beam. Since elemental x-ray intensity ratios obtained by energy dispersive x-ray spectroscopy (EDS) are commonly used for asbestos identification, the impact of beam damage on these ratios was evaluated. It was determined that the magnesium/silicon ratio best represented the damage caused to the fiber. Various tests showed that most fibers have a current density threshold above which the chemical composition of the fiber is modified. The value of this threshold current density varied depending on the fiber, regardless of fiber diameter, and in some cases could not be determined. The existence of a threshold electron dose was also demonstrated. This value was dependent on the current density used and can be increased by providing a recovery period between exposures to the electron beam. This study also established that the electron beam current is directly related to the damage rate above a current density of 165 A/cm . The large number of different results obtained suggest, that in order to ensure that the amosite fibers are not damaged, analysis should be conducted below a current density of 100 A/cm .
[Mh] Termos MeSH primário: Amianto Amosita/química
Amianto Amosita/efeitos da radiação
Microscopia Eletrônica de Transmissão/métodos
[Mh] Termos MeSH secundário: Magnésio
Silício/química
Espectrometria por Raios X/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
12172-73-5 (Asbestos, Amosite); I38ZP9992A (Magnesium); Z4152N8IUI (Silicon)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171120
[Lr] Data última revisão:
171120
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160526
[St] Status:MEDLINE


  3 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:27083413
[Au] Autor:Gavett SH; Parkinson CU; Willson GA; Wood CE; Jarabek AM; Roberts KC; Kodavanti UP; Dodd DE
[Ad] Endereço:National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA. Gavett.Stephen@epa.gov.
[Ti] Título:Persistent effects of Libby amphibole and amosite asbestos following subchronic inhalation in rats.
[So] Source:Part Fibre Toxicol;13:17, 2016 Apr 15.
[Is] ISSN:1743-8977
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Human exposure to Libby amphibole (LA) asbestos increases risk of lung cancer, mesothelioma, and non-malignant respiratory disease. This study evaluated potency and time-course effects of LA and positive control amosite (AM) asbestos fibers in male F344 rats following nose-only inhalation exposure. METHODS: Rats were exposed to air, LA (0.5, 3.5, or 25.0 mg/m(3) targets), or AM (3.5 mg/m(3) target) for 10 days and assessed for markers of lung inflammation, injury, and cell proliferation. Short-term results guided concentration levels for a stop-exposure study in which rats were exposed to air, LA (1.0, 3.3, or 10.0 mg/m(3)), or AM (3.3 mg/m(3)) 6 h/day, 5 days/week for 13 weeks, and assessed 1 day, 1, 3, and 18 months post-exposure. Fibers were relatively short; for 10 mg/m(3) LA, mean length of all structures was 3.7 µm and 1% were longer than 20 µm. RESULTS: Ten days exposure to 25.0 mg/m(3) LA resulted in significantly increased lung inflammation, fibrosis, bronchiolar epithelial cell proliferation and hyperplasia, and inflammatory cytokine gene expression compared to air. Exposure to 3.5 mg/m(3) LA resulted in modestly higher markers of acute lung injury and inflammation compared to AM. Following 13 weeks exposure, lung fiber burdens correlated with exposure mass concentrations, declining gradually over 18 months. LA (3.3 and 10.0 mg/m(3)) and AM produced significantly higher bronchoalveolar lavage markers of inflammation and lung tissue cytokines, Akt, and MAPK/ERK pathway components compared to air control from 1 day to 3 months post-exposure. Histopathology showed alveolar inflammation and interstitial fibrosis in all fiber-exposed groups up to 18 months post-exposure. Positive dose trends for incidence of alveolar epithelial hyperplasia and bronchiolar/alveolar adenoma or carcinoma were observed among LA groups. CONCLUSIONS: Inhalation of relatively short LA fibers produced inflammatory, fibrogenic, and tumorigenic effects in rats which replicate essential attributes of asbestos-related disease in exposed humans. Fiber burden, inflammation, and activation of growth factor pathways may persist and contribute to lung tumorigenesis long after initial LA exposure. Fiber burden data are being used to develop a dosimetry model for LA fibers, which may provide insights on mode of action for hazard assessment.
[Mh] Termos MeSH primário: Adenocarcinoma Bronquíolo-Alveolar/induzido quimicamente
Adenoma/induzido quimicamente
Amianto Amosita/toxicidade
Amiantos Anfibólicos/toxicidade
Exposição por Inalação
Neoplasias Pulmonares/induzido quimicamente
Pulmão/efeitos dos fármacos
Pneumonia/induzido quimicamente
Fibrose Pulmonar/induzido quimicamente
[Mh] Termos MeSH secundário: Adenocarcinoma Bronquíolo-Alveolar/genética
Adenocarcinoma Bronquíolo-Alveolar/metabolismo
Adenocarcinoma Bronquíolo-Alveolar/patologia
Adenoma/metabolismo
Adenoma/patologia
Animais
Apoptose/efeitos dos fármacos
Proliferação Celular/efeitos dos fármacos
Transformação Celular Neoplásica/induzido quimicamente
Citocinas/genética
Citocinas/metabolismo
Relação Dose-Resposta a Droga
Células Epiteliais/efeitos dos fármacos
Células Epiteliais/metabolismo
Células Epiteliais/patologia
Hiperplasia
Mediadores da Inflamação/metabolismo
Pulmão/metabolismo
Pulmão/patologia
Neoplasias Pulmonares/genética
Neoplasias Pulmonares/metabolismo
Neoplasias Pulmonares/patologia
Masculino
Pneumonia/genética
Pneumonia/metabolismo
Pneumonia/patologia
Fibrose Pulmonar/genética
Fibrose Pulmonar/metabolismo
Fibrose Pulmonar/patologia
Ratos Endogâmicos F344
Medição de Risco
Transdução de Sinais/efeitos dos fármacos
Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Asbestos, Amphibole); 0 (Cytokines); 0 (Inflammation Mediators); 12172-73-5 (Asbestos, Amosite)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160417
[St] Status:MEDLINE
[do] DOI:10.1186/s12989-016-0130-z


  4 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:26822244
[Au] Autor:Miscetti G; Bodo P; Lumare A; Abbritti EP; Garofani P; Burani V
[Ad] Endereço:AZIENDA UNITA' SANTARIA REGIONE UMBRIA N.1 Perugia. miscetti@libero.it.
[Ti] Título:[Asbestos exposure assessment in the first case of intrasplenic mesothelioma].
[Ti] Título:Accertamento dell'esposizione ad amianto nel primo caso di mesothelioma splenico..
[So] Source:Med Lav;107(1):29-36, 2016 Jan 20.
[Is] ISSN:0025-7818
[Cp] País de publicação:Italy
[La] Idioma:ita
[Ab] Resumo:BACKGROUND: In 2013 the International Journal of Surgical Pathology published a case report of intrasplenic malignant mesothelioma (MM) in a 48-year-old man: it was the first report in literature describing a case of primitive intra-splenic MM, described without  a history of asbestos exposure. OBJECTIVE: To verify the possible past exposure to asbestos, ignored by the patient himself, by studying in depth his environmental and occupational history. METHODS: Information about the occupational and non-occupational history of the subject was collected by Experts of the Operational Unit of Occupational Health and Safety Control (UOC PSAL) of the Local Health Unit Umbria 1 - Perugia, using the Italian National Mesothelioma Register (ReNaM) questionnaire and guide lines; an inspection was  carried out at the past canning industry where the patient worked in the period 1982-1990 and material was taken to be analysed by MOCF and SEM. RESULTS: Samples showed the presence of asbestos  fibres belonging to the amphibole class (amosite and crocidolite) and to the serpentine class (chrysotile). CONCLUSIONS: The survey described the past occupational exposure to asbestos in a canning industry, where  the subject worked in the period 1982-1990,  unknown to the patient himself. The authors strongly confirm the  usefulness of standardized methods, such as the ReNaM Questionnaire, and the importance of technical expertise of the investigator to find and analyse the suspect materials and to demonstrate  possible past occupational exposure to asbestos.
[Mh] Termos MeSH primário: Asbestos/efeitos adversos
Carcinógenos
Embalagem de Alimentos
Neoplasias Pulmonares/etiologia
Anamnese
Mesotelioma/etiologia
Neoplasias Esplênicas/etiologia
[Mh] Termos MeSH secundário: Amianto Amosita/efeitos adversos
Asbesto Crocidolita/efeitos adversos
Asbestos Serpentinas/efeitos adversos
Seres Humanos
Neoplasias Pulmonares/diagnóstico
Masculino
Mesotelioma/diagnóstico
Meia-Idade
Medição de Risco
Neoplasias Esplênicas/diagnóstico
[Pt] Tipo de publicação:CASE REPORTS; ENGLISH ABSTRACT; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Asbestos, Serpentine); 0 (Carcinogens); 12001-28-4 (Asbestos, Crocidolite); 12172-73-5 (Asbestos, Amosite); 1332-21-4 (Asbestos)
[Em] Mês de entrada:1607
[Cu] Atualização por classe:160129
[Lr] Data última revisão:
160129
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160130
[St] Status:MEDLINE


  5 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:26715106
[Au] Autor:Gilham C; Rake C; Burdett G; Nicholson AG; Davison L; Franchini A; Carpenter J; Hodgson J; Darnton A; Peto J
[Ad] Endereço:London School of Hygiene and Tropical Medicine, London, UK.
[Ti] Título:Pleural mesothelioma and lung cancer risks in relation to occupational history and asbestos lung burden.
[So] Source:Occup Environ Med;73(5):290-9, 2016 May.
[Is] ISSN:1470-7926
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: We have conducted a population-based study of pleural mesothelioma patients with occupational histories and measured asbestos lung burdens in occupationally exposed workers and in the general population. The relationship between lung burden and risk, particularly at environmental exposure levels, will enable future mesothelioma rates in people born after 1965 who never installed asbestos to be predicted from their asbestos lung burdens. METHODS: Following personal interview asbestos fibres longer than 5 µm were counted by transmission electron microscopy in lung samples obtained from 133 patients with mesothelioma and 262 patients with lung cancer. ORs for mesothelioma were converted to lifetime risks. RESULTS: Lifetime mesothelioma risk is approximately 0.02% per 1000 amphibole fibres per gram of dry lung tissue over a more than 100-fold range, from 1 to 4 in the most heavily exposed building workers to less than 1 in 500 in most of the population. The asbestos fibres counted were amosite (75%), crocidolite (18%), other amphiboles (5%) and chrysotile (2%). CONCLUSIONS: The approximate linearity of the dose-response together with lung burden measurements in younger people will provide reasonably reliable predictions of future mesothelioma rates in those born since 1965 whose risks cannot yet be seen in national rates. Burdens in those born more recently will indicate the continuing occupational and environmental hazards under current asbestos control regulations. Our results confirm the major contribution of amosite to UK mesothelioma incidence and the substantial contribution of non-occupational exposure, particularly in women.
[Mh] Termos MeSH primário: Amiantos Anfibólicos/efeitos adversos
Neoplasias Pulmonares/induzido quimicamente
Pulmão
Mesotelioma/induzido quimicamente
Doenças Profissionais/induzido quimicamente
Exposição Ocupacional/efeitos adversos
Neoplasias Pleurais/induzido quimicamente
[Mh] Termos MeSH secundário: Adulto
Idoso
Amianto Amosita/efeitos adversos
Amianto Amosita/análise
Amiantos Anfibólicos/análise
Asbesto Crocidolita/efeitos adversos
Asbesto Crocidolita/análise
Asbestos Serpentinas/efeitos adversos
Asbestos Serpentinas/análise
Asbestose/complicações
Emprego
Feminino
Seres Humanos
Pulmão/química
Pulmão/patologia
Neoplasias Pulmonares/patologia
Masculino
Mesotelioma/patologia
Meia-Idade
Fibras Minerais/efeitos adversos
Fibras Minerais/análise
Doenças Profissionais/patologia
Neoplasias Pleurais/patologia
Medição de Risco
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Asbestos, Amphibole); 0 (Asbestos, Serpentine); 0 (Mineral Fibers); 12001-28-4 (Asbestos, Crocidolite); 12172-73-5 (Asbestos, Amosite)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151231
[St] Status:MEDLINE
[do] DOI:10.1136/oemed-2015-103074


  6 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:26311718
[Au] Autor:Burdett GJ; Dewberry K; Staff J
[Ad] Endereço:Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire SK17 9JN, UK garry.burdett@hsl.gsi.gov.uk.
[Ti] Título:Airborne Asbestos Exposures from Warm Air Heating Systems in Schools.
[So] Source:Ann Occup Hyg;60(1):27-39, 2016 Jan.
[Is] ISSN:1475-3162
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The aim of this study was to investigate the concentrations of airborne asbestos that can be released into classrooms of schools that have amosite-containing asbestos insulation board (AIB) in the ceiling plenum or other spaces, particularly where there is forced recirculation of air as part of a warm air heating system. Air samples were collected in three or more classrooms at each of three schools, two of which were of CLASP (Consortium of Local Authorities Special Programme) system-built design, during periods when the schools were unoccupied. Two conditions were sampled: (i) the start-up and running of the heating systems with no disturbance (the background) and (ii) running of the heating systems during simulated disturbance. The simulated disturbance was designed to exceed the level of disturbance to the AIB that would routinely take place in an occupied classroom. A total of 60 or more direct impacts that vibrated and/or flexed the encapsulated or enclosed AIB materials were applied over the sampling period. The impacts were carried out at the start of the sampling and repeated at hourly intervals but did not break or damage the AIB. The target air volume for background samples was ~3000 l of air using a static sampler sited either below or ~1 m from the heater outlet. This would allow an analytical sensitivity (AS) of 0.0001 fibres per millilitre (f ml(-1)) to be achieved, which is 1000 times lower than the EU and UK workplace control limit of 0.1 f ml(-1). Samples with lower volumes of air were also collected in case of overloading and for the shorter disturbance sampling times used at one site. The sampler filters were analysed by phase contrast microscopy (PCM) to give a rapid determination of the overall concentration of visible fibres (all types) released and/or by analytical transmission electron microscopy (TEM) to determine the concentration of asbestos fibres. Due to the low number of fibres, results were reported in terms of both the calculated concentration and the statistically relevant limits of quantification (LOQ), which are routinely applied. The PCM fibre concentrations were all below the LOQ but analytical TEM showed that few of the fibres counted in the background samples were asbestos. The background TEM asbestos concentrations for the individual samples analysed from all three schools were at or below the AS, with a pooled average below the LOQ (<0.00005 f ml(-1)). At the two CLASP schools, there was no significant increase in the airborne amosite concentration in the classrooms during simulated disturbance conditions. At the third school, four of the five classrooms sampled gave measurable concentrations of amosite by TEM during simulated disturbance conditions. The highest concentration of amosite fibres countable by PCM was 0.0043 f ml(-1) with a pooled average of 0.0019 f ml(-1). The air sampling strategy was effective and worked well and the results provide further important evidence to inform the sampling and management of asbestos in schools.
[Mh] Termos MeSH primário: Poluentes Atmosféricos/análise
Amianto Amosita/análise
Calefação/instrumentação
Instituições Acadêmicas
[Mh] Termos MeSH secundário: Monitoramento Ambiental/métodos
Seres Humanos
Exposição por Inalação/análise
Microscopia Eletrônica de Transmissão
Microscopia de Contraste de Fase
Exposição Ocupacional
Medição de Risco
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Air Pollutants); 12172-73-5 (Asbestos, Amosite)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:151225
[Lr] Data última revisão:
151225
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150828
[St] Status:MEDLINE
[do] DOI:10.1093/annhyg/mev062


  7 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:26193738
[Au] Autor:Bellassai D; Spinazzola A; Silvestri S
[Ti] Título:[Estimation of the indoor diffusion of asbestos fibers with the diffusion model for the external environment of Pasquill and Gifford].
[Ti] Título:Stima della diffusione indoor di fibre di amianto con il modello diffusionale di Pasquill e Gifford per l'ambiente esterno..
[So] Source:G Ital Med Lav Ergon;37(1):26-31, 2015 Jan-Mar.
[Is] ISSN:1592-7830
[Cp] País de publicação:Italy
[La] Idioma:ita
[Ab] Resumo:In absence of results of environmental monitoring to proceed with the assessment of occupational exposure, it was developed a model that retraces the one of Pasquill and Gifford, currently used for the estimation of concentrations of pollutants at certain distances from the source in outdoor environment. Purpose of the study is the quantitative estimate of the diffusion of airborne asbestos fibers in function of the distance from the source in an factory where railway carriages were produced during the period when asbestos was sprayed as insulator of the body. The treatment was carried out in a large shed without separation from other operations. The application of the model, given the characteristics of the emitting source, has allowed us to estimate the diffusion of particles inside the shed with an expected decrease in concentration inversely proportional to the distance from the source. By appropriate calculations the concentration by weight has been converted into number offibers by volume, the unit of measure currently used for the definition of asbestos pollution.
[Mh] Termos MeSH primário: Poluição do Ar em Ambientes Fechados/análise
Amianto Amosita/análise
Carcinógenos/análise
Materiais de Construção/análise
Monitoramento Ambiental
Ferrovias
[Mh] Termos MeSH secundário: Poluição do Ar em Ambientes Fechados/efeitos adversos
Amianto Amosita/efeitos adversos
Asbestose/etiologia
Asbestose/prevenção & controle
Materiais de Construção/toxicidade
Monitoramento Ambiental/métodos
Seres Humanos
Itália
Computação Matemática
Modelos Teóricos
[Pt] Tipo de publicação:ENGLISH ABSTRACT; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carcinogens); 12172-73-5 (Asbestos, Amosite)
[Em] Mês de entrada:1508
[Cu] Atualização por classe:150721
[Lr] Data última revisão:
150721
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150722
[St] Status:MEDLINE


  8 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26086123
[Au] Autor:Boyles MS; Young L; Brown DM; MacCalman L; Cowie H; Moisala A; Smail F; Smith PJ; Proudfoot L; Windle AH; Stone V
[Ad] Endereço:Centre for Nano Safety, Edinburgh Napier University, UK. Electronic address: matboyles@yahoo.co.uk.
[Ti] Título:Multi-walled carbon nanotube induced frustrated phagocytosis, cytotoxicity and pro-inflammatory conditions in macrophages are length dependent and greater than that of asbestos.
[So] Source:Toxicol In Vitro;29(7):1513-28, 2015 Oct.
[Is] ISSN:1879-3177
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The potential toxicity of carbon nanotubes (CNTs) has been compared to pathogenic fibres such as asbestos. It is important to test this hypothesis to ascertain safe methods for CNT production, handling and disposal. In this study aspects reported to contribute to CNT toxicity were assessed: length, aspect ratio, iron content and crystallinity; with responses compared to industrially produced MWCNTs and toxicologically relevant materials such as asbestos. The impacts of these particles on a range of macrophage models in vitro were assessed due to the key role of macrophages in particle clearance and particle/fibre-induced disease. Industrially produced and long MWCNTs were cytotoxic to cells, and were potent in inducing pro-inflammatory and pro-fibrotic immune responses. Short CNTs did not induce any cytotoxicity. Frustrated phagocytosis was most evident in response to long CNTs, as was respiratory burst and reduction in phagocytic ability. Short CNTs, metal content and crystallinity had less or no influence on these endpoints, suggesting that many responses were fibre-length dependent. This study demonstrates that CNTs are potentially pathogenic, as they were routinely found to induce detrimental responses in macrophages greater than those induced by asbestos at the same mass-based dose.
[Mh] Termos MeSH primário: Macrófagos/efeitos dos fármacos
Nanotubos de Carbono/toxicidade
[Mh] Termos MeSH secundário: Animais
Amianto Amosita/toxicidade
Líquido da Lavagem Broncoalveolar/citologia
Linhagem Celular
Sobrevivência Celular/efeitos dos fármacos
Células Cultivadas
Quimiocina CCL2/metabolismo
Seres Humanos
Ferro/análise
Macrófagos/metabolismo
Macrófagos/fisiologia
Masculino
Camundongos
Nanotubos de Carbono/química
Tamanho da Partícula
Fagocitose/efeitos dos fármacos
Ratos Sprague-Dawley
Fuligem/toxicidade
Fator de Crescimento Transformador beta1/metabolismo
Fator de Necrose Tumoral alfa/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Chemokine CCL2); 0 (Nanotubes, Carbon); 0 (Soot); 0 (Transforming Growth Factor beta1); 0 (Tumor Necrosis Factor-alpha); 12172-73-5 (Asbestos, Amosite); E1UOL152H7 (Iron)
[Em] Mês de entrada:1606
[Cu] Atualização por classe:150828
[Lr] Data última revisão:
150828
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150619
[St] Status:MEDLINE


  9 / 271 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:25745069
[Au] Autor:Bernareggi A; Ren E; Borelli V; Vita F; Constanti A; Zabucchi G
[Ad] Endereço:*Department of Life Sciences; Centre for Neuroscience B.R.A.I.N., University of Trieste, 34127 Trieste, Italy; and Department of Pharmacology, UCL School of Pharmacy, London, UK WC1N 1AX *Department of Life Sciences; Centre for Neuroscience B.R.A.I.N., University of Trieste, 34127 Trieste, Italy; an
[Ti] Título:Xenopus laevis Oocytes as a Model System for Studying the Interaction Between Asbestos Fibres and Cell Membranes.
[So] Source:Toxicol Sci;145(2):263-72, 2015 Jun.
[Is] ISSN:1096-0929
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The mode of interaction of asbestos fibres with cell membranes is still debatable. One reason is the lack of a suitable and convenient cellular model to investigate the causes of asbestos toxicity. We studied the interaction of asbestos fibres with Xenopus laevis oocytes, using electrophysiological and morphological methods. Oocytes are large single cells, with a limited ability to endocytose molecular ligands; we therefore considered these cells to be a good model for investigating the nature of asbestos/membrane interactions. Electrophysiological recordings were performed to compare the passive electrical membrane properties, and those induced by applying positive or negative voltage steps, in untreated oocytes and those exposed to asbestos fibre suspensions. Ultrastructural analysis visualized in detail, any morphological changes of the surface membrane caused by the fibre treatment. Our results demonstrate that Amosite and Crocidolite-type asbestos fibres significantly modify the properties of the membrane, starting soon after exposure. Cells were routinely depolarized, their input resistance decreased, and the slow outward currents evoked by step depolarizations were dramatically enhanced. Reducing the availability of surface iron contained in the structure of the fibres with cation chelators, abolished these effects. Ultrastructural analysis of the fibre-exposed oocytes showed no evidence of phagocytic events. Our results demonstrate that asbestos fibres modify the oocyte membrane, and we propose that these cells represent a viable model for studying the asbestos/cell membrane interaction. Our findings also open the possibly for finding specific competitors capable of hindering the asbestos-cell membrane interaction as a means of tackling the long-standing asbestos toxicity problem.
[Mh] Termos MeSH primário: Amianto Amosita/toxicidade
Asbesto Crocidolita/toxicidade
Membrana Celular/efeitos dos fármacos
Oócitos/efeitos dos fármacos
Xenopus laevis
[Mh] Termos MeSH secundário: Animais
Membrana Celular/ultraestrutura
Relação Dose-Resposta a Droga
Impedância Elétrica
Feminino
Ferro/toxicidade
Quelantes de Ferro/farmacologia
Potenciais da Membrana
Microscopia Eletrônica de Varredura
Microscopia Eletrônica de Transmissão
Modelos Animais
Oócitos/ultraestrutura
Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Iron Chelating Agents); 12001-28-4 (Asbestos, Crocidolite); 12172-73-5 (Asbestos, Amosite); E1UOL152H7 (Iron)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:150526
[Lr] Data última revisão:
150526
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150307
[St] Status:MEDLINE
[do] DOI:10.1093/toxsci/kfv050


  10 / 271 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:25737333
[Au] Autor:Lee EG; Nelson JH; Kashon ML; Harper M
[Ad] Endereço:1. Exposure Assessment Branch, National Institute for Occupational Safety and Health, Health Effects Laboratory Division, 1095 Willowdale Road, Morgantown, WV 26505, USA dtq5@cdc.gov.
[Ti] Título:Evaluation of the dark-medium objective lens in counting asbestos fibers by phase-contrast microscopy.
[So] Source:Ann Occup Hyg;59(5):616-28, 2015 Jun.
[Is] ISSN:1475-3162
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A Japanese round-robin study revealed that analysts who used a dark-medium (DM) objective lens reported higher fiber counts from American Industrial Hygiene Association (AIHA) Proficiency Analytical Testing (PAT) chrysotile samples than those using a standard objective lens, but the cause of this difference was not investigated at that time. The purpose of this study is to determine any major source of this difference by performing two sets of round-robin studies. For the first round-robin study, 15 AIHA PAT samples (five each of chrysotile and amosite generated by water-suspended method, and five chrysotile generated by aerosolization method) were prepared with relocatable cover slips and examined by nine laboratories. A second round-robin study was then performed with six chrysotile field sample slides by six out of nine laboratories who participated in the first round-robin study. In addition, two phase-shift test slides to check analysts' visibility and an eight-form diatom test plate to compare resolution between the two objectives were examined. For the AIHA PAT chrysotile reference slides, use of the DM objective resulted in consistently higher fiber counts (1.45 times for all data) than the standard objective (P-value < 0.05), regardless of the filter generation (water-suspension or aerosol) method. For the AIHA PAT amosite reference and chrysotile field sample slides, the fiber counts between the two objectives were not significantly different. No statistically significant differences were observed in the visibility of blocks of the test slides between the two objectives. Also, the DM and standard objectives showed no pattern of differences in viewing the fine lines and/or dots of each species images on the eight-form diatom test plate. Among various potential factors that might affect the analysts' performance of fiber counts, this study supports the greater contrast caused by the different phase plate absorptions as the main cause of high counts for the AIHA PAT chrysotile slides using the DM objective. The comparison of fiber count ratios (DM/standard) between the AIHA PAT chrysotile samples and chrysotile field samples indicates that there is a fraction of fibers in the PAT samples approaching the theoretical limit of visibility of the phase-contrast microscope with 3-degree phase-shift. These fibers become more clearly visible through the greater contrast from the phase plate absorption of the DM objective. However, as such fibers are not present in field samples, no difference in counts between the two objectives was observed in this study. The DM objective, therefore, could be allowed for routine fiber counting as it will maintain continuity with risk assessments based on earlier phase-contrast microscopy fiber counts from field samples. Published standard methods would need to be modified to allow a higher aperture specification for the objective.
[Mh] Termos MeSH primário: Amianto Amosita/análise
Asbestos Serpentinas/análise
Microscopia de Contraste de Fase/instrumentação
Fibras Minerais/análise
[Mh] Termos MeSH secundário: Poluentes Atmosféricos/análise
Poluentes Atmosféricos/normas
Microscopia de Contraste de Fase/métodos
National Institute for Occupational Safety and Health (U.S.)/normas
Variações Dependentes do Observador
Exposição Ocupacional
Reprodutibilidade dos Testes
Estados Unidos
[Pt] Tipo de publicação:EVALUATION STUDIES; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Air Pollutants); 0 (Asbestos, Serpentine); 0 (Mineral Fibers); 12172-73-5 (Asbestos, Amosite)
[Em] Mês de entrada:1604
[Cu] Atualização por classe:161025
[Lr] Data última revisão:
161025
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150305
[St] Status:MEDLINE
[do] DOI:10.1093/annhyg/mev007



página 1 de 28 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde