Article Reviews
Mesothelioma Cancer Research Study #1:
“Specificity of asbestos-induced chromosomal aberrations in short-term cultured human mesothelial cells”
Cancer Genetics and Cytogenetics Volume 41, Issue 1, August 1989, Pages 33-39
by Kenth Olofssona and Joachim Mark, a Department of Pathology and Cytogenetics, Central Hospital, Skövde, Sweden.
Abstract – Short-term cultured normal human mesothelial cells were exposed for 48 hours to three different asbestos compounds, crocidiolite, chrysotile, and amosite. In the concentration used (0.01 mg/ml) all three asbestiform minerals caused, within a few days, a significant increase of cells showing numerical and/or structural abnormalities. The abnormalities were analyzed in detail using banding techniques. The results were compared with the cytogenetic observations in 52 published cases of mesotheliomas.
This comparison revealed only a few similarities as regards numerical deviations. The structural rearrangements in asbestos-exposed cultures, however, in many instances involved chromosome types and chromosome regions preferentially affected in mesotheliomas.”
Mesothelioma Cancer Research Study #2:
“Recovery of ingested asbestos fibers from the gastrointestinal lymph in rats”
Environmental Research Volume 22, Issue 1, June 1980, Pages 201-216
by P. Sebastien, c, R. Masse†, d and J. Bignon.
Abstract – Using the transmission electron microscope, asbestos fibers have been assessed in lymph fluid collected from the thoracic lymph duct in five groups of rats previously exposed to asbestos fibers (by ingestion). Ten rats were gavaged a single dose weighing approximately 20 mg. Five were given pure UICC chrysotile A while another group of five had pure UICC crocidolite.
All the rats of the chrysotile group were positive animals with recovery rate values ranging from 6.9 × 10−7 to 3 × 10−5 (90% of the fibers being recovered during the first 16 hr following the gavage). The crocidolite group had only three positive animals and lower recovery rate values of 5.7 × 10−8 to 5.6 × 10−7. A third group was fed a synthetic diet containing 1%, by weight, chrysotile with a majority of short fibers (90% below 4 μm). Of the 15 rats comprising this group, 13 were positive with maximum daily recovery rates ranging from 2.1 × 10−7 to 2.1 × 10−6. A group of eight rats fed the same kind of diet but containing a higher proportion of long fibers, showed only four positive animals, however, they had higher daily recovery rates ranging from 1.9 × 10−5 to 2.1 × 10−4. No fibers were encountered in the samples of the two control rats. This study demonstrates the passage of chrysotile and crocidolite fibers across the gastrointestinal wall, with the passage rate being higher for long fibers than short ones.”
Mesothelioma Cancer Research Study #3:
“Penetration of cells by asbestos fibers”
Environ Health Perspect. 1974 December; 9: 255–260
by J. M. G. Davis, R. E. Bolton, and J. Garrett
Abstract – Studies on the behavior of asbestos fibers within tissues have shown that the only cells that regularly contain asbestos are macrophages and their derivatives. However, these cells actively incorporate the asbestos fibers by the process of phagocytosis, and there is little evidence of direct penetration. Examination of the gut lining after prolonged asbestos ingestion has shown no evidence of dust penetration either through or between the epithelial cells. The structure and arrangement of these cells is discussed, and it is suggested that they are exceptionally well adapted to prevent penetration by any solid material.
Mesothelioma Cancer Research Study #4:
“Static electrification of airborne asbestos: A study of its causes, assessment and effects on deposition in the lungs of rats”
American Industrial Hygiene Association Journal, Volume 42, Issue 10 October 1981, pages 711 – 721
by J. H. Vincent; W. B. Johnston; A. D. Jones; A. M. Johnston
Abstract – The paper describes a series of experiments carried out in the laboratory to investigate how asbestos fibres might become electrostatically charged during the process of being made airborne, the magnitude and polarity of the charge per fibre, and the effect on lung deposition in rats. Measurements of the penetration of fibres through an electrostatic elutriator enabled the magnitude and distribution of charge in a cloud of fibres to be quantitatively assessed. Thus it was found that a typical fibre of UICC amosite, as dispersed in a typical animal exposure chamber, carried a net charge of magnitude equivalent to about 60 electrons. The distribution of charge was bimodal, suggesting that two charging mechanisms were taking place, the main one producing net negative charge and the lesser one producing net positive charge. These were attributed to materials in the dust dispenser used and with which the fibres came into contact during dispersal. It was found that the magnitude of charge on a typical fibre could be significantly reduced by the introduction of equal numbers of positive and negative gaseous ions from an a.c. corona discharge ioniser. Finally it was found that enhancement by up to 40% of the dust deposited into the slowest clearing part of the respiratory tract of experimental rats was brought about by the electrostatic charge on the airborne fibres. The implications of this finding in the field of occupational hygiene are briefly discussed.