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- Hirsch, Jan M, et al.
(författare)
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A clinical, histomorphological and histochemical study on snuff-induced lesions of varying severity
- 1982
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Ingår i: Journal of Oral Pathology & Medicine. - : Wiley. - 0904-2512 .- 1600-0714. ; 11:5, s. 387-398
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Tidskriftsartikel (refereegranskat)abstract
- The oral lesions in 50 habitual snuff-dippers were graded on a four-point scale. The patients' tobacco and drinking habits were studied by means of a questionnaire. From each patient a biopsy was taken for histomorphological and histochemical analysis. A correlation between snuff habits and the clinical degrees was found, as well as between the snuff habits and certain superficial and deeply located cell changes. The incidence of keratinized lesions, sialadenitis and slight dysplasia (based on subjective evaluation under a light microscope) was higher than previously reported. Presence of dysplastic changes could not be predicted by means of the parameters which characterise the snuff habit or from the clinical grade. The histomorphological and histochemical results were interpreted as showing that the mucosa react to snuff inducing hyperplasia in the basal cell layers. In the surface layer indications of lethal damage were found. The overall stromal reaction to snuff was weak. However, the salivary glands and excretory ducts exhibited degenerative changes which were found to be more severe than the pathological changes in the surface epithelium.
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| 4. |
- Hirsch, Jan M, et al.
(författare)
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Effect of long-term application of snuff on the oral mucosa : an experimental study in the rat
- 1983
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Ingår i: Journal of Oral Pathology & Medicine. - : Wiley. - 0904-2512 .- 1600-0714. ; 12:3, s. 187-198
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Tidskriftsartikel (refereegranskat)abstract
- The long-term effect of snuff exposure was studied in Sprague-Dawley rats using a surgically-created test canal in the lower lip to retain snuff. The rats received standard snuff (n = 42) and highly alkaline snuff (n = 10) for 9-22 months, whereupon they were killed. Untreated rats with identical test canals (n = 15) served as controls. A complete post-mortem examination was performed. One rat exposed to standard snuff for 9 months developed a squamous cell carcinoma of the oral cavity. However, exposure to standard snuff usually resulted in a mild to moderate hyperplasia of the epithelium, hyperorthokeratosis and acanthosis. Rats exposed to snuff for 18-22 months showed vacuolated cells penetrating deeper into the epithelium with hyperplastic and atrophic lesions. In a few rats, severe dysplastic changes developed in the crevicular epithelium. Rats exposed to alkaline snuff differed little from the first group except that there was focally atrophic and ulcerated epithelium and less fibrosis. Pathological findings outside the oral cavity were rare. Squamous cell hyperplasia of the forestomach was found in rats exposed to snuff for 18-22 months, possibly caused by ingested snuff. In conclusion, this study has shown that exposure of rats to snuff for 10-16 hours per day 5 days a week for most of their life-span resulted in lesions mainly restricted to the epithelium and the underlying connective tissue of the surgically created test canal.
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| 5. |
- Hirsch, Jan M, et al.
(författare)
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Inhibition of herpes simplex virus replication by tobacco extracts
- 1984
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 44:5, s. 1991-1997
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 (HSV-1) has been associated with the genesis of leukoplakias, epithelial atypia, and oral cancer. Tobacco habits, such as snuff dipping, are also definitely correlated with this type of lesion. The normal cytolytic HSV-1 infection can, after in vitro inactivation, transform cells. Extracts of snuff were prepared and assayed for their ability to inhibit HSV-1 replication. Plaque formation assays of HSV-1 in the presence of snuff extract showed that a reduced number of plaques was formed. Different batches of one brand of snuff were tested for inhibition of herpes simplex virus (HSV) production. More than 99% inhibition of 24-hr HSV production was obtained with undiluted batches. The 1:5 dilutions of snuff had an inhibitory effect of 85% and 1:25 dilutions, 39%. In agreement, the attachment of the virus to the host cell and penetration of the virus to the cell nuclei were found to be inhibited as was the synthesis of viral DNA. Nicotine had an inhibitory effect, while aromatic additions to snuff were found to have no major inhibitory effect on HSV replication. Snuff extracts were prepared from different brands of snuff reported to contain high and low quantities of tobacco-specific N-nitrosamines. Brands with reported high levels of tobacco-specific N-nitrosamines had significantly greater ability to inhibit HSV replication. In conclusion, this study has shown that extracts of snuff have inhibitory effects on the production of cytolytic HSV-1 infections. A chronic snuff dipper keeps tobacco in the mouth for the major part of the day. Thus, virus shed in the oral cavity in connection with a reactivated latent HSV-1 infection has great possibilities of being affected by snuff or derivatives of snuff. It is suggested that an interaction between tobacco products and HSV-1 might be involved in the development of dysplastic lesions in the oral cavity.
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| 6. |
- Hirsch, Jan M, et al.
(författare)
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Snuff-induced lesions of the oral mucosa : an experimental model in the rat
- 1981
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Ingår i: Journal of oral pathology. - 0300-9777. ; 10:5, s. 342-353
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Tidskriftsartikel (refereegranskat)abstract
- An experimental model in the white rat has been developed in order to study the influence of snuff on oral mucosa. A test canal in the lower lip, with one orifice buccally to the incisors and one on the lip side, was created by surgical means. The connection between the canal and the oral cavity was made to ensure the presence of saliva in the canal so that physiological conditions resembling those of the oral cavity were obtained. The canal was filled with snuff morning and night 5 days a week. The mean value for the maximal retention time of the snuff was 6 h. The animals tolerated the dose and time of exposure without signs of severe toxic symptoms. Histological examination of the canals after 9 months of exposure to snuff showed a mildly to moderately hyperplastic epithelium with hyperorthokeratosis. Locally deep proliferations of epithelium with acanthotic rete pegs could be seen. In the stratum basale hyperplasia with disturbed polarity and hyperchromatic nuclei and single mitosis were noted.
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- Kjellstrand, Per, et al.
(författare)
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Effects of long-term exposure to trichloroethylene on the behavior of mongolian gerbils (Meriones Unguiculatus)
- 1981
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Ingår i: Journal of Toxicology and Environmental Health. - : Informa UK Limited. - 0098-4108. ; 8:5-6, s. 787-793
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Tidskriftsartikel (refereegranskat)abstract
- Two groups of Mongolian gerbils (Meriones unguiculatus) were continuously exposed to 150 ppm trichloroethylene (TCE) for 77 and 106 d, respectively. The behavior of the animals was tested in a symmetrical maze baited with sunflower seeds during a period of 23 d, beginning at the end of exposure. One additional group was exposed for 150 d and then allowed 40 d free from exposure before the start of the maze test Comparisons between the TCE‐ and air‐exposed animals showed differences in the number of correct choices and the number of seeds consumed in the maze, both after 71 and 106 d of exposure and at the end of the 40‐d rehabilitation period that followed the 150‐d exposure. The results were interpreted in terms of the “emotionality” of the animals.
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- Kjellstrand, Per, et al.
(författare)
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Sensitivity of mongolian gerbils to trichloroethylene exposure during neonatal growth
- 1982
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Ingår i: Toxicology Letters. - : Elsevier BV. - 1879-3169 .- 0378-4274. ; 14:1-2, s. 97-101
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Tidskriftsartikel (refereegranskat)abstract
- Continuous exposure of young mongolian gerbils to trichloroethylene (230 ppm) was started at different times during the first month of life. The onset of exposure was accompanied by an increased number of deaths among the pups and by an immediate reduction in growth rate. The proportion of dead pups was greatest when exposure was started at birth, and decreased rapidly with increasing age at onset of exposure. Growth rate was partially restored approx. 1 week after the onset of exposure. After weaning the effect of the exposure on growth decreased, and the variation in the effect among different litters was considerably reduced. The enhanced sensitivity of the pups to trichloroethylene (TCE) exposure is believed to be due to a disturbance in the mother-offspring relationship.
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| 10. |
- Kjellstrand, Per, et al.
(författare)
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Trichloroethylene: Effects on body and organ weights in mice, rats and gerbils
- 1981
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Ingår i: Toxicology. - 0300-483X. ; 21:2, s. 105-115
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Tidskriftsartikel (refereegranskat)abstract
- The influence of continuous inhalation of 150 ppm trichloroethylene (TCE) on body, liver, spleen, and kidney weights in rats, mice, and mongolian gerbils was tested. An age dependent decrease in body weight gain was observed in female rats exposed to TCE. All 3 spcies showed liver enlargement caused by the exposure. The effect was much more pronounced in mice, in which the increase was 60–80%, than in rats and gerbils where it was only 20–30%. After the end of the TCE-exposure the liver weights of the mice decreased rapidly. After 5 days of rehabilitation to the weight was only 10–20% higher than that of the controls. This difference persisted for at least 25 days. The spleen weight appeared unaffected or somewhat smaller in TCE-exposed animals of all species. An increased kidney weight (15%) was observed in TCE-exposed gerbils. This effect was less pronounced in mice and rats. Effects on the liver have earlier been seen only after exposure to concentrations much higher than that used in the present study. This difference is results in proposed to be due to the different schedules used for the exposure.
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