Re: Induction of mesothelioma in p53+/- mouse by intraperitoneal application of multi-wall carbon nanotube

Our plain-English summary of Re: Induction of mesothelioma in p53+/- mouse by intraperitoneal application of multi-wall carbon nanotube, by G. Ichihara, V. Castranova, A. Tanioka, et al (The Journal of Toxicological Sciences, 2008).

The study

• Authors: G. Ichihara, V. Castranova, A. Tanioka, K. Miyazawa
• Journal: The Journal of Toxicological Sciences
• Published: 2008;33(3):381-2; author reply 382-4
• Type of article: Comment, Letter
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This item is not a research study. It is an exchange of letters about a 2008 mouse experiment by Takagi and colleagues, in which multi-wall carbon nanotubes (MWCNT) were injected into the abdomens of mice and compared with asbestos. The letter's authors (Ichihara and colleagues) raised five concerns. First, the 3 mg dose per mouse was unrealistically large. Second, the number of nanotube fibers was underestimated because the sample was clumped. Third, no photographs showed typical mesotheliomas after MWCNT. Fourth, deaths may have come from intestinal blockage caused by abdominal adhesions rather than from mesothelioma. Fifth, poor description of the material compromised interpretation of the results. In reply, the original authors said the high dose was chosen to avoid missing a hazard. They reported that early visual findings in dying animals in a follow-up study at lower doses indicated mesotheliomas in all dose groups. They stated that their tumor classification did not exaggerate lethal tumors and that MWCNT was as potent as crocidolite. They also stated that the hazard of the nano-sized particles in the sample was not assessed and remains unknown.

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: Letter to the editor criticizing a published animal experiment, with the original authors' reply (correspondence, not a study)
• Who was studied: Mice in the criticized study by Takagi et al. (2008). The letters give no group sizes.
• Exposure: Multi-wall carbon nanotubes (MWCNT), 3 mg per mouse, injected into the abdominal cavity, compared with asbestos (crocidolite)
• Main results:
  • The letter's authors stated that the MWCNT sample was heavily clumped, so the number of fibers given was underestimated.
  • The letter's authors noted that the original paper reported intestinal blockage (ileus) from severe peritoneal adhesions as a major cause of death in MWCNT-exposed mice. They suggested the higher death rate might not reflect mesothelioma.
  • As their fifth concern, the letter's authors stated that poor material characterization severely compromised interpretation of the results.
  • The original authors defended the high dose as a way to avoid false-negative results in a first hazard-identification study.
  • The original authors reported that preliminary visual findings from dying animals in a follow-up study at lower doses indicated mesotheliomas in all dose groups. This included a low-dose group without severe peritoneal adhesion.
  • The original authors said Fig. 6 showed a typical early mesothelial lesion induced by MWCNT.
  • The original authors stated that their tumor classification did not exaggerate lethal tumor yield. They said that, whether counted by context or as total tumor yield, MWCNT was as potent as crocidolite.
  • The original authors stated that heating to 480 degrees was applied only to samples prepared for electron microscopy.
• The authors' conclusion: The letter's authors concluded that the study was flawed in both its exposure doses and its sample characterization. The original authors concluded that the study assessed micrometer-sized rod- or fiber-shaped particles in the MWCNT sample 'as is', and that the hazard of the nano-sized particles remains unknown.
• Limitations the authors state:
  • The original authors acknowledged that the dose was at the high end of the range.
  • The original authors acknowledged that the medium used to disperse the MWCNT could not separate all of it into individual fibers.
  • The original authors stated that the hazard of the nano-sized particles in the sample was not assessed.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma.

Related studies

• Induction of mesothelioma in p53+/- mouse by intraperitoneal application of multi-wall carbon nanotube — A. Takagi, A. Hirose, et al. (2008)
• Dose-dependent mesothelioma induction by intraperitoneal administration of multi-wall carbon nanotubes in p53 heterozygous mice — A. Takagi, A. Hirose, et al. (2012)
• Aspect ratio has no effect on genotoxicity of multi-wall carbon nanotubes — J.S. Kim, K. Lee, et al. (2011)
• Effects of sustained stimulation with multi-wall carbon nanotubes on immune and inflammatory responses in mice — A. Yamaguchi, T. Fujitani, et al. (2012)
• Single- and multi-wall carbon nanotubes versus asbestos: are the carbon nanotubes a new health risk to humans? — M. Pacurari, V. Castranova, et al. (2010)
• High-temperature calcined fullerene nanowhiskers as well as long needle-like multi-wall carbon nanotubes have abilities to induce NLRP3-mediated IL-1β secretion — H. Cui, W. Wu, et al. (2014)

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