Mesothelioma and environmental exposure

Our plain-English summary of Mesothelioma and environmental exposure, by C. Varga, K. Szendi (Annals of the New York Academy of Sciences, 2008).

The study

• Authors: C. Varga, K. Szendi
• Journal: Annals of the New York Academy of Sciences
• Published: 2008;1138:73-6
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

A novel animal model was developed to study the direct exposure of mesothelial cells to crocidolite and chrysotile asbestos fibers. Chemically pure and pretreated Union Internationale Centre le Cancer (UICC) samples were implanted into a peritoneal envelope (Kertai's fold) of Wistar rats. Following the 12-month exposure, lack of mesothelioma induction was detected in all groups. Results suggest that the mechanism of mesothelioma formation is not a consequence of peritoneal physical exposure to the fibers.

In plain English

This short report described an animal experiment from the University of Pecs, Hungary. The authors developed a new rat model to expose mesothelial cells directly to asbestos. They used standard UICC samples of crocidolite and Rhodesian chrysotile asbestos. These were either chemically pure or pretreated overnight with 1-nitropyrene, a cancer-causing chemical, as a model of environmental exposure. Gelatin capsules holding 10 mg of fibers were surgically implanted into Kertai's fold, a pocket of abdominal lining (peritoneum) attached to the liver. Five groups of six inbred Wistar rats were used, and zinc oxide served as a negative control. The rats were autopsied after 12 months. Clumps of fibers were found in the abdominal cavity, and the stomach wall was thickened. Under the microscope, liver tissue was unchanged, and there was a foreign-body type granulomatous reaction with multinucleated giant cells. No signs of mesothelioma were seen in either the exposed or the control groups. The authors called this completely unexpected. They suggested that mesothelioma formation may not depend on physical contact between fibers and mesothelial cells.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: animal experiment (in vivo rat model, surgical implantation of fibers)
• Who was studied: Five groups of six inbred Wistar rats (approximate body weight 400 g); Department of Environmental Health, University of Pecs, Hungary
• Exposure: 10 mg of UICC crocidolite or Rhodesian chrysotile asbestos, chemically pure or pretreated overnight in saturated aqueous 1-nitropyrene, in hard gelatin capsules implanted into Kertai's fold (a peritoneal envelope lined with mesothelial cells); zinc oxide as negative control; 12 months until autopsy
• Main results:
  • At autopsy, gray/blue clumps of asbestos fibers were found in the peritoneal cavity (in Kertai's fold and on nearby organs), and thickening of the gastric wall was observed
  • Histology showed unchanged liver tissue and a granulomatous reaction of foreign body type with multinucleated giant cells
  • No signs of mesothelioma were detected, macroscopically or microscopically, in either the exposed or the control groups after 12 months
• The authors' conclusion: The authors found the result completely unexpected, especially for the pretreated fibers. They suggested that mesothelioma formation may be independent of physical contact between fibers and mesothelial cells, and that a remote effect should be looked for.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Environmental Exposure, Mesothelial Cells, Crocidolite, Chrysotile, UICC.

Related studies

• The use of wild animal models to detect evidence of environmental contamination by asbestos-like substance — R. Puleio, M.R. Schiavo, et al. (2013)
• Gene expression changes after exposure to six-mix in a mouse model — E.A. Putnam, A. Smartt, et al. (2008)
• Environmental toxicants--induced epigenetic alterations and their reversers — M. Kim, M. Bae, et al. (2012)
• A review of carcinogenicity studies of asbestos and non-asbestos tremolite and other amphiboles — J. Addison, E.E. McConnell (2008)
• Local recurrence model of malignant pleural mesothelioma for investigation of intrapleural treatment — I. Opitz, D. Lardinois, et al. (2007)
• Giant cell formation after intraperitoneal application of crocidolite asbestos fibres in rats — S. Sethi, E.G. Beck, et al. (1974)

Browse more research in Annals of the New York Academy of Sciences, or return to medical research.