Histochemical study of asbestos fibre coating in experimental carrageenin granulomas

Our plain-English summary of Histochemical study of asbestos fibre coating in experimental carrageenin granulomas, by M. Governa, C. Rosanda Vadalá (British Journal of Industrial Medicine, 1973).

The study

• Authors: M. Governa, C. Rosanda Vadalá
• Journal: British Journal of Industrial Medicine
• Published: 1973;30(3):248-52
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Governa, M., and Rosanda Vadalà, C. (1973).British Journal of Industrial Medicine,30, 248-252. Histochemical study of asbestos fibre coating in experimental carrageenin granulomas. To study the composition of asbestos body coating, asbestos particles present in experimental carrageenin granulomas were tested histochemically for mucopolysaccharides, ferric and ferrous iron, haemoglobin, and haematoidin. The stains were applied on microscopical sections both untreated and treated with iron-extracting solutions and/or enzymes. The results indicate that asbestos is rapidly coated with haematoidin, ferric iron, and hyaluronic acid.

In plain English

This animal experiment aimed to find out what makes up the coating that forms on asbestos fibres in tissue. Guinea-pigs were injected under the abdominal skin with carrageenin, which produces a granuloma (a lump of inflamed, healing tissue). On one side the injection also contained 10 mg of asbestos dust made of chrysotile fibres. The tissue was then stained for iron, haemoglobin, haematoidin (a pigment formed from broken-down blood) and mucopolysaccharides. Three days after injection, the asbestos did not stain for iron, haemoglobin or haematoidin. Later, in new healing tissue, some fibres took stains that the authors attributed to acid mucopolysaccharides (chiefly hyaluronic acid), ferric iron and haematoidin, sometimes on the same bundles. Stained fibres were always very few compared with unstained ones. By days 17 to 21, most fibres were surrounded by large macrophages. The authors suggested that the inner layer may be haematoidin. They noted that their tests did not settle how the iron and hyaluronic acid relate. The authors concluded that asbestos in tissue seems to be quickly coated with haematoidin and hyaluronic acid, with ferric iron particles lying close to the fibres.

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 (histochemical study): carrageenin was injected under the skin of guinea-pigs, on one side with 10 mg of asbestos added, and the resulting granulomas were stained and examined
• Who was studied: Guinea-pigs of both sexes weighing 600 to 800 g; three animals were killed every other day from day 3 to day 21 after injection (total number not stated)
• Exposure: Commercial asbestos dust P 600 (Società Amiantifera Balangero, Italy) containing chrysotile fibres 0.01 to 0.3 mm long and 0.001 to 0.02 mm in diameter; 10 mg suspended in 2 ml of 1% carrageenin, injected under the skin of the abdominal wall
• Main results:
  • Three days after injection, the asbestos bundles and fibres in the fluid exudate were negative on the iron stains (Turnbull, Perls), negative on the haemoglobin stains (Dunn-Thompson, Okajima) and unstained by both haematoidin techniques
  • From day 17 onward (days 17, 19 and 21), most asbestos fibres were surrounded by large macrophages with several nuclei, and many particles appeared to have been engulfed
  • Only a very small amount of the asbestos stained with any method, compared with the amount that did not react
  • In serial sections, the same asbestos bundles that stained with toluidine blue (metachromasia) also stained with the Perls iron stain
  • Asbestos fibres that were positive for haematoidin also showed toluidine blue metachromasia and were positive to the Perls stain
  • The authors interpreted the toluidine blue staining on some fibres as due to acid mucopolysaccharides, especially hyaluronic acid
  • The iron staining disappeared after treatment with sodium dithionite or oxalic acid, which the authors took to mean that the iron on the fibres was ferric iron
  • In sections treated with iron-extracting solutions and testicular hyaluronidase, more bundles and fibres were haematoidin-positive than in sections left untreated or given only one of the treatments
  • The authors suggested that the inner layer of the coating consists of haematoidin
• The authors' conclusion: The authors concluded that asbestos introduced into tissue seems to be quickly coated with haematoidin and hyaluronic acid, and that ferric iron particles were also seen closely apposed to the asbestos
• Limitations the authors state:
  • Fibres that did not react to the stains were harder to find, so the authors could only say that the stained asbestos was always a very small amount compared with the unreacted asbestos
  • The experiments did not resolve how the ferric iron relates to the hyaluronic acid on the fibres
  • The haematoidin stain can also detect bile pigments. The authors attributed the reaction to haematoidin because the fibres had contacted extensive bleeding areas

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Balangero mine, Balangero, about 20 km north of Turin, Piedmont

All asbestos mines

Topics

Medical terms in this study, explained in our Lexicon: Granuloma, Asbestos Body Formation, Hyaluronic Acid.

Related studies

• A histochemical study of the asbestos body coating — M. Governa, C. Rosanda (1972)
• Asbestos body formation and iron accumulation in mouse peritoneal granulomas after the introduction of crocidolite asbestos fibers — H.K. Koerten, J. Hazekamp, et al. (1990)
• The calcification of fibrous pleural lesions produced in guinea-pigs by the injection of chrysotile asbestos dust — J.M. Davis (1971)
• Epithelial outgrowths from lung tissue following intrapleural injection of asbestos dust in experimental animals — J.M. Davis (1971)
• A 3-dimensional in vitro model of epithelioid granulomas induced by high aspect ratio nanomaterials — V.C. Sanchez, P. Weston, et al. (2011)
• Morbidity and Mortality in Talc Granuloma: Report of a Fatal Case — A.J. Swingle (1948)

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