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The mean number of micronuclei in buccal mucosa cells of the nonsmokers was significantly lower than that of the smokers. However, the mean number of micronucleus of buccal mucosa cells in smokers who smoked more than 10 years was higher than smokers who smoked less than 10 years. Increasing the smoking duration could heighten the frequency of micronucleus; however, the difference was not significant.

Background and objective: Gingival bleeding reduction in smokers has been associated with decreased blood vessel density. The mechanism of suppressive effect of cigarette smoking on blood vessel density is not precisely defined. The aim of this study was to evaluate the impact of smoking on angiogenesis by assessing mast cells density and VEGF expression in chronic periodontitis. Materials& Methods: 52 paraffin embedded block of gingiva tissues with periodontitis obtained from 30 nonsmokers and 22 smokers undergoing flap surgery were examined immunohistochemically for VEGF expression. Mast cell counts was completed on toluidine blue stained slides. Exposure to cigarette smoking was calculated by the number of packs × year. Patients were classified into 4 groups based on the number of smoked cigarettes. The correlation between VEGF expression and mast cell counts was evaluated and compared in nonsmokers and smokers. Results: The mean number of mast cells (p=0.004) and average value of VEGF expression (p = 0.000) in nonsmokers was significantly higher than smokers. No correlation was noted between VEGF expression / mast cell counts and number of smoked cigarettes in four groups of smokers (p=0.29,0.12 , 0.20 and 0.11, respectively). Conclusion: Mast cells and VEGF expression may account for suppressive effect of cigarette smoking on blood vessels in periodontitis.

Background: Despite the available data on demographic information of oral squamous cell carcinoma (OSCC), the changing trend of histopathologic pattern of OSCC has not conducted yet, in Iran. The aim was to investigate the pattern of histopathologic features of OSCC in Iran by analyzing the patients referred to Cancer Institute, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran, during 2006-2015. Materials and Methods: The study was a retrospective institutional study. The pathology records with the diagnosis of OSCC were retrieved from Iran National Tumor Bank, Cancer Biology Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran, during 2006-2015. The demographic characteristics and histopathologic features were recorded and analyzed for possible trend. Descriptive analysis was used for statistical interpretation. Results: The data showed an increasing number of moderately and poorly differentiated OSCC. Accordingly, higher increasing rate in tumor size and vascular, perineural invasion was detected. Conclusion: On the basis of histopathologic features, moderately differentiated OSCC with increasing rate of tumor size and vascular, perineural invasion was indicated in recent decade. Based on the findings, lower differentiation potentially is compatible with worsen prognosis.

Background & Objective: The role of synchronized expression pattern of cytokeratin (CK) 7 and CK20 in the prognosis of colon adenocarcinoma is unclear. The current study aimed at determining the relationship between the expression of cytokeratins 7 and 20 and prognostic factors in colon adenocarcinoma. Methods: In the current cross sectional Study, 52 archival samples of colon adenocarcinoma with different histopathologic differentiation were examined immunohistochemically to analyze the expression of Ck7 and Ck20. The relationship between cytokeratin expression and prognostic factors, such as histopathologic differentiation, lymph node involvement, and depth of invasion, were assessed. Results: CK7-/CK20+ was the most prevalent pattern in the current study. The difference among histopathologic grade, lymph node involvement, and depth of invasion in different CK7/CK20 expression patterns was insignificant (P=0.26, P=0.46, and P=0.22, respectively). Conclusion: No relationship was observed between CK7/CK20 expression and prognostic factors in colon adenocarcinoma, in the current study.

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Background: The effect of cigarette smoking duration on salivary pH and its relation to the rate of dental caries is unknown. Our aim was to comparatively investigate the salivary pH and DMFT index in cigarette smokers and non-smokers based on the quantitative rate of smoking. Methods: This case-control study was conducted using simple random sampling. Three ml samples of not stimulated whole saliva were collected from 92 smokers and 37 nonsmokers. DMFT indices were recorded. The rate of smoking was calculated by pack-year index. Salivary pH was measured by pH meter (744 Metrohm). The data were analyzed by analysis of variance (ANOVA) and Pearson correlation coefficient was used to compare the status of pH and DMFT between smokers and non-smokers. The correlation of pH level and DMFT index with the amount of smoking was also investigated in smokers. Results:The mean salivary pH level in smokers and non-smokers was 6.57±0.06 and 7.04±0.06, respectively. The mean DMFT in smokers and nonsmokers was 7.60±0.5 and 4.80±0.5, respectively. Salivary pH decreased significantly with the increase of pack-year index (P = 0.01). The relationship between DMFT and the amount of smoking was not significant. DMFT index was significantly higher in smokers with over 300 pack-years than in other smokers (P = 0.01). Conclusions: Cigarette smoking was associated with lower salivary pH and higher DMFT index. The increased number of smoked cigarettes was associated with increased number of decayed teeth.

Background:The evidences on cytotoxic effect of cigarette and waterpipe smoking are very rare and controversial. The aim was to compare the cytotoxic effect of cigarette and waterpipe smoking on human buccal mucosa cells.Methods:The study was case–control. Feulgen-stained samples of exfoliated buccal mucosa cells were evaluated. The cytology slides of 25 cigarette smoker, 25 waterpipe smoker, and 25 individuals in the never smoked were examined. The number of pyknosis, karyorrhexis, and karyolysis in 1000 cells/subject were counted. Exposing to cigarette and waterpipe smoke was considered by the number of pack × years.Results:There were significant differences among the groups in terms of karyolysis and pyknosis while there was no significant difference among the cigarette smokers group and waterpipe smokers group in terms of karyorrhexis (P ≤ 0. 01). The cytotoxicity effect of cigarette smoking was not significantly correlated to time exposure (r = 0.099, P = 0.637). The cytotoxicity effect of waterpipe smoking was significantly correlated to time exposure (r = −370, P = 0.044).Conclusions:The cytotoxic effect of cigarette and waterpipe smoking on buccal mucosa cells was significantly higher than nonsmokers. The effect of cigarette smoking on cellular death was higher than waterpipe. The cytotoxic effect of waterpipe smoking was dose dependent.