| 1. |
|
|
| 2. |
- Ibrahim, S O, et al.
(författare)
-
Immunohistochemical detection of p53 in non-malignant and malignant oral lesions associated with snuff dipping in the Sudan and Sweden
- 1996
-
Ingår i: International Journal of Cancer. - 0020-7136 .- 1097-0215. ; 68:6, s. 749-753
-
Tidskriftsartikel (refereegranskat)abstract
- Immunohistochemistry was used to examine the expression of p53 in pre-malignant oral lesions and oral squamous-cell carcinomas (SCCs) from Swedish and Sudanese snuff-dippers, as well as in pre-malignant oral lesions and oral SCCs from non-snuff-dippers from the Sudan, Sweden and Norway. Of the 14 SCCs from Sudanese snuff-dippers, 21% (3/14) expressed p53. Of the 14, 60 and 41 SCCs from non-snuff-dippers from the Sudan, Sweden and Norway, 64% (9/14), 65% (39/60) and 68% (28/41) expressed p53, respectively. A statistically significant difference in expression of p53 was found in SCCs from Sudanese snuff-dippers compared to those from non-snuff-dippers from all/or any of the 3 countries. None of the suspected pre-malignant oral lesions from Sudanese snuff dippers or non-snuff-dippers expressed p53. Only 2 out of the 15 oral fibro-epithelial hyperplastic lesions from Swedish snuff-dippers expressed p53. Some of the oral epithelial dysplastic lesions, as well as the carcinoma in situ lesions from Norwegian non-snuff-dippers, expressed p53, while the oral fibro-epithelial hyperplastic lesions did not. The low relative frequency of p53 expression found in oral SCCs from snuff-dippers compared to those from non-snuff-dippers might suggest differences in mechanisms of oncogenic action induced by snuff. Alternatively, the pathogenesis of malignant oral lesions from snuff-dippers may follow a p53-independent pathway. In view of the unusually high levels of the tobacco-specific nitrosamines (TSNA) found in the type of snuff used in the Sudan, investigations of p53 mutations or oncogenes are needed.
|
|
| 3. |
- Idris, AM, et al.
(författare)
-
The Swedish snus and the Sudanese toombak : are they different?
- 1998
-
Ingår i: Oral Oncology. - 1368-8375 .- 1879-0593. ; 34:6, s. 558-566
-
Tidskriftsartikel (refereegranskat)abstract
- In Sweden, snuff (locally known as snus), was introduced since the year 1637. Presently, Sweden has the highest per capita consumption and sale figures of snuff in the world, and the habit is becoming increasingly popular. Snus is manufactured into a dry form used in the nasal cavity and a moist form used in the oral cavity. Snus manufactured for oral use is a moist ground tobacco of Dark Kentucky or Virginia species mixed with an aqueous solution of water and other blending ingredients. This form of snuff is found in two types: (1) loose and (2) portion-bag-packed. These are the most widely used. The loose moist form (1–2 g a quid) is the most popular type consumed by 73% of the males, followed by the portion-bag-packed form (0.5–1 g a quid), consumed by 13% of the males, while 14% of the males are mixed users. The majority of snus users place the quid in the vestibular area of the upper lip, and the prevalence among persons 15 years of age or older is 15.9% among males and 0.2% among females. The pH of snus has declined from a previous range of 8–9 to a range of 7.8–8.5, moisture content ranges 35–60% and nicotine content is in the order of 5–11 mg/g dry wt tobacco-specific N-nitrosamines (TSNAs) in micrograms (N′-nitrosonornicotine: NNN 5–9; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone: NNK 1–2; N′-nitrosoanatabine: NAT 2–5). In the Sudan, snuff, locally known as toombak, was introduced approximately 400 years ago. It is always processed into a loose moist form, and its use is widespread in the country. Tobacco used for manufacture of toombak is of the species Nicotiana rustica, and the fermented ground powder is mixed with an aqueous solution of sodium bicarbonate. The resultant product is moist, with a strong aroma, highly addictive and its use is widespread particularly among males. Its pH range is 8–11, moisture content ranges 6–60% and nicotine content is from 8 to 102 mg/g dry wt, and TSNAs contents in micrograms (NNN 420–1 550; NNK 620–7 870; NAT 20–290). Snus and toombak dippers develop a clinically and histologically characteristic lesion at the site of dipping. Probably due to control of the TSNAs in snus, this type of snuff is associated with a lower risk of cancer of the oral cavity (relative risk: RR 5–6-fold), whereas the risk for cancer of the oral cavity among toombak users was high (RR 7.3–73.0-fold). In conclusion, the two snuff products significantly differ in many aspects. Most notable differences are tobacco species, fermentation and ageing, nicotine and TSNAs content, pH, expression of the p53 tumour supressor gene, and keratin types 13, 14, and 19. It was, therefore, the object of the present study to highlight the oral health hazards of toombak, and to compare it with snus regarding the aforementioned differences.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Ibrahim, Anwaar M
(författare)
-
Endothelium-derived Vasoactive Factors and Leukocyte-derived Inflammatory Mediators. Studies in subjects with or at risk for vascular disease
- 1999
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study was undertaken to evaluate relationships between endothelial function (assessed as mediators of endothelium-derived vasoactive factors such as nitric oxide [NO], prostacyclin [PGI2] and endothelin [ET-1] ), and risk factors for atherosclerosis, as well as to study possible relationships between endothelial function and leukocyte activation (indicated by measurements of leukocyte-derived inflammatory mediators) in subjects with or at risk for atherosclerosis. In subjects with asymptomatic atherosclerosis we found inverse relationships between cyclic guanosine monophosphate (cGMP) in platelets (mediator of NO activity) and both serum total cholesterol and plasma ET-1 suggesting that NO-mediated vasodilation may be impaired in hypercholesterolemia and that maintenance of vascular tone is achieved by a balance between NO and ET-1. Another high risk group for atherosclerosis, NIDDM patients, showed higher plasma levels of ET-1 than healthy control subjects indicating a relationship between ET-1 and diabetic endothelial damage. NIDDM patients also showed higher intraplatelet cGMP levels than control subjects indicating enhanced NO activity in NIDDM. In this study we also demonstrated in vivo relationships between activated leukocytes and platelet antiaggregation during the atherosclerotic process, and chronic endothelial and leukocyte activation during follow up of patients after acute cerebral ischemia. No evidence for monocyte activation was demonstrated in NIDDM patients, however. The onset of menopause carries increased risk for atherosclerosis in women. This study suggests that the antiatherogenic properties of hormone replacement therapy (HRT) might occur through improvement of endothelial function; increased NO activity and reduced ET-1 levels, whereas we found no evidence for effects of HRT upon monocyte activation.
|
|
| 8. |
|
|
| 9. |
|
|
