Aim: It was directed to evaluate rosmarinic acid (RA) effect as a chemopreventive modality on experimentally induced hamster buccal pouch (HBP) carcinogenesis. Material and methods: Forty Syrian male hamsters five weeks old, weighing 120-80g, were divided into four groups of ten hamsters in each as follows, GI: Only topical application of liquid paraffin (3 times a week for 14 weeks), GII: Topical application of 12 ,7 dimethyl benz[a]anthracene (DMBA) alone (%0.5 in liquid paraffin, 3 times a week for 14 weeks), GIII: Topical application of DMBA (%0.5 in liquid paraffin, 3 times a week for 14 weeks) associated by oral administration of RA (100mg/kg b.w in 1ml distilled water by oral gavage, 3 times a week for 14 weeks on opposite days of DMBA application), GIV : Oral administration of RA alone (100mg/kg b.w in 1ml distilled water by oral gavage, 3 times a week for 14 weeks). Results: Gross observation and histopathological findings revealed a-GI: normal stratified squamous epithelium b-GII: well and moderately differentiated SCC c-: GIII: revealed considerably reversed tumor incidence d: GIV: normal similar to GI. Immunohistochemical results revealed, oral administration of RA to DMBA treated hamsters restored the normal expression of bcl2-and Bax indicating that RA may have chemopreventive mechanism and/or pro-apoptotic effects. Conclusion: RA may act through different mechanisms, such as applying anti-inflammatory, antioxidant results as well as impede cell proliferation, migration, and selectively convince cancer cells apoptosis.

No abstract

Objectives:The aim of the present study is to evaluate CD44 expression to detect cancer stem cell activity along with analyzing the DNA ploidy, to predict the activity of oral carcinogenesis. Materials and method:Forty formalin fixed paraffin embedded tissues of oral lesions were used and divided equally into 4 groups; different premalignant white lesions, well, moderate, and poorly differentiated squamous cell carcinomas. All specimens were immunostained using CD44 antibodies. Moreover, the same paraffin blocks for each case used to prove the differentiation in DNA ploidy between groups using flow cytometer. Results:The CD44 immunoexpression showed a marked statistical significant difference between premalignant white lesions and poorly differentiated squamous cell carcinomas. Flow cytometric analysis of DNA parameters between the tested groups revealed a powerful difference of DNA ploidy between the premalignant group and other malignant groups. The S-phase fraction showed significant difference between poorly differentiated OSCC and premalignant lesions with no effective differences between the malignant lesions. Conclusions:The findings of the present study suggest that the CD44 immunoexpression collaborates with the DNA content analysis presented a real indicator in prediction the behavior of oral premalignant and malignant lesions.

Aim: Zeolites induce the proliferation and differentiation of cells of the osteoblast lineage. Application of zeolite in pulpotomized young permenat teeth had not been investigated. The objective of this study was to investigate histologicaly the capability of zeolite to induce dentin bridge formation and compare it with calcium hydroxide. Subjects and methods: Four dogs aged 12-24 month were included in the present study. In each dog, pulpotomy procedures were carried out in four premolars teeth in each quadrant and restored with one of the experimental materials in a way that teeth in each quadrant restored with one material differ from that of the contralateral quadrant.Specimens were harvested on the sixth week after operation and twelfth week after operative procedures, prepared and examined histologically by H&E (haematoxylin and eosin) stain, there were wide histological differences between the groups of this study along the different intervals of the study. Results: The result of the present study revealed inflammatory response of pulp tissue to both tested materials with various degrees that were subsided by time only in calcium hydroxide group. Calcium hydroxide has a powerful agent for regenerative effect on pulp tissue with dentin bridge formation.On the contrary; pulp degeneration and necrosis were the end results of pulpotomy with zeolite material. Conclusion: Calcium hydroxide could induce dentin bridge formation while zeolite failed.

No abstract