Quoted from http://toxsci.oxfordjournals.org/content/early/2012/05/12/toxsci.kfs171.abstract?maxtoshow=&HITS=10&hits=2&RESULTFORMAT=&andorexacttitle=or&andorexacttitleabs=and&fulltext=asbestos&andorexactfulltext=and&searchid=1&usestrictdates=yes&resourcetype=HWCIT&ct

The threshold length for fibre-induced acute pleural inflammation: shedding light on the early events in asbestos-induced mesothelioma

• Received February 10, 2012.

Abstract

Suspicion has been raised that high aspect ratio nanoparticles or nanofibres might possess asbestos-like pathogenicity. The pleural space is a specific target for disease in individuals exposed to asbestos and, by implication nanofibres. Pleural effects of fibres depends on fibre length, but the key threshold length beyond which adverse effects occur has never been identified up to now since all asbestos and vitreous fibre samples are heterogeneously distributed in their length. Nanotechnology advantageously allows for highly defined length distribution of synthetically engineered fibres which enable for in depth investigation of this threshold length. We utilised the ability to prepare silver-nanofibres of five defined length classes to demonstrate a threshold fibre length for acute pleural inflammation. Nickel-nanofibres and carbon nanotubes were then used to strengthen the relationship between fibre length and pleural inflammation. A method of intrapleural injection of nanofibres in female C57Bl/6 strain mice was used to deliver the fibre dose and we then assessed the acute pleural inflammatory response. Chestwall sections were examined by light and by scanning electron microscopy to identify areas of lesion; furthermore cell-nanowires interaction on the mesothelial surface of the parietal pleura in vivo, were investigated. Our results showed a clear threshold effect demonstrating that fibres beyond 4 µm in length are pathogenic to the pleura. The identification of the threshold length for nanofibre induced pathogenicity in the pleura has important implications for understanding the structure-toxicity relationship for asbestos-induced mesothelioma and consequent risk assessment with the aim to contribute to the engineering of synthetic nanofibres by the adoption of a benign-by-design approach.

Quoted from http://chestjournal.chestpubs.org/content/early/2012/05/08/chest.11-3204.abstract

Post Mortem Findings of Malignant Pleural Mesothelioma: A Two-Centre Study of 318 patients

Abstract

Background: Malignant pleural mesothelioma (MPM) is an incurable cancer with a rising incidence. MPM is often perceived as a locally invasive cancer and the exact cause of death is poorly understood.

Aim: This two-centre study describes the anatomical features of patients with MPM at post-mortem.

Methods: The Mesothelioma Registry of Western Australia (WA) and the Avon region (UK) Coroner’s reports were interrogated for the post-mortem records of confirmed mesothelioma cases.

Results: Post-mortem records of 318 pleural mesothelioma patients (169 from WA and 149 from Avon) were identified. Most (91.5%) patients were male (mean age 68.4±11.5) and MPM was right sided in 55.3%. Extrapleural dissemination of tumor was found in 87.7% of cases and lymph node involvement in 53.3%. Tumor dissemination in extra-thoracic sites was common (55.4% of patients) and almost all organs were involved, including liver (31.9%), spleen (10.8%), thyroid (6.9%), and the brain (3.0%). Pulmonary emboli (PE) were found in 6% of cases and considered as directly contributing to death in 13 (4.1%) patients. The precise cause of death could only be determined in 63 (19.8%) cases even after post-mortem. The body mass index was significantly lower in cases which had no identifiable anatomical cause of death at post-mortem (18.8±4.3 vs. 21.0±4.7, p=0.034).

Conclusion: In this largest post-mortem series on MPM, extra-thoracic dissemination of mesothelioma was common and often under-recognized. No anatomical cause of death was identified in the majority of patients even at autopsy, raising the possibility of physiological and metabolic causes of death.

Quoted from http://highwire.stanford.edu/cgi/medline/pmid;22544163

Mesothelioma Associated With Commercial Use of Vermiculite Containing Libby Amphibole. KK Dunning, S Adjei, L Levin, AM Rohs, T Hilbert, E Borton, V Kapil, C Rice, GK Lemasters, and JE Lockey J Occup Environ Med, April 25, 2012; .
OBJECTIVES:: To describe asbestos-related mortality among manufacturing workers who expanded and processed Libby vermiculite that contained amphibole fiber. METHODS:: Standardized mortality ratio was calculated for 465 white male workers 31 years after last Libby vermiculite exposure. RESULTS:: Two workers died from mesothelioma, resulting in a significantly increased standardized mortality ratio of 10.5 (95% confidence interval, 1.3 to 38.0). These workers were in the upper 10th percentile of cumulative fiber exposure, that is, 43.80 and 47.23 fiber-years/cm, respectively. One additional worker with cumulative fiber exposure of 5.73 fiber-years/cm developed mesothelioma but is not deceased. There were no other significantly increased standardized mortality ratios. CONCLUSIONS:: Workers expanding and processing Libby vermiculite in a manufacturing setting demonstrated an increased risk for the development of mesothelioma following exposure to the amphibole fiber contained within this vermiculite ore source.

Quoted from http://www.staradvertiser.com/news/breaking/150386255.html

UH researcher leads breakthrough on a deadly cancer

By Star-Advertiser staff

POSTED: 07:46 p.m. HST, May 06, 2012

An international team led by University of Hawaii Cancer Center researcher Haining Yang has identified a protein known as HMGB1 as a critical link in the development of malignant mesothelioma, one of the deadliest forms of cancer.

The findings were published in the current issue of the online journal “Cancer Research.”

Mesothelioma has been linked to occupational and environmental exposure to asbestos and the naturally occurring mineral fiber erionite. The average survival for those diagnosed with the disease is less than one year, in part because the cancer is highly aggressive and resistant to current treatments, and partly because it is usually diagnoses it its late states.

[Article continues at original source]

Quoted from http://annhyg.oxfordjournals.org/content/early/2012/05/04/annhyg.mes017.abstract?maxtoshow=&HITS=10&hits=6&RESULTFORMAT=&andorexacttitle=or&andorexacttitleabs=and&fulltext=asbestos&andorexactfulltext=and&searchid=1&usestrictdates=yes&resourcetype=HWCIT&ct

Pulmonary Carcinoid Tumors and Asbestos Exposure

• Received November 10, 2011.
• Accepted February 14, 2012.

Abstract

Objectives: The hypothesis that asbestos exposure may have more specific associations with particular histological types of lung cancer remains controversial. The aim of this study was to analyze the relationships between asbestos exposure and pulmonary carcinoid tumors.

Methods: A retrospective case–control study was conducted in 28 cases undergoing surgery for pulmonary carcinoid tumors and aged >40 years and in 56 controls with lung cancer of a different histological type, matched for gender and age, from 1994 to 1999, recruited in two hospitals in the region of Paris. Asbestos exposure was assessed via expertise of a standardized occupational questionnaire and mineralogical analysis of lung tissue, with quantification of asbestos bodies (AB).

Results: Definite asbestos exposure was identified in 25% of cases and 14% of controls (ns). Cumulative asbestos exposure was significantly higher in cases than in controls (P < 0.05), and results of the quantification of AB tended to be higher in cases than in controls (24 and 9% had >1000 AB per gram dry lung tissue, respectively, P = 0.09). Mean cumulative smoking was lower in cases than in controls (P < 0.05).

Conclusions: This study argues in favor of a relationship between asbestos exposure and certain pulmonary carcinoid tumors.