Background: Bone tissue engineering is a widely growing field that requires the combination of cells, scaffolds and signaling molecules. Adipose derived stem cells (ADSCs) are an accessible and abundant source of mesenchymal stem cells with high plasticity. Polycaprolactone/alginate (PCL/Alg) composite scaffolds have been used in bone regeneration and nano-hydroxyapatite (n-HA) is used as a reinforcing, osteoconductive component in scaffold fabrication. This study was conducted to assess the ability of three different PCL/Alg based scaffolds to induce osteogenic differentiation of ADSCs and to compare between them. Methods:The study comprised 5 groups; negative control group with ADSCs cultured in complete culture media, positive control group with ADSCs cultured in osteogenic differentiation media, and 3 experimental groups with ADSCs seeded onto 3 scaffolds: S1 (PCL/Alg), S2 (PCL/Alg/Ca) and S3 (PCL/Alg/Ca/n-HA) respectively and cultured in osteogenic media. Mineralization and gene expression were assessed by Alizarin red S (ARS) staining and real time quantitative polymerase chain reaction (RT-qPCR). Evaluation was done at 7, 14 and 21 days.Results: ARS staining reflected a time dependent increase through days 7, 14 and 21, with S3 (PCL/Alg/ Ca/n-HA) group showing the highest mineralization levels. RT-qPCR detected upregulation of ALP gene expression at day 7 and decline thereafter. S2 (PCL/Alg/Ca) and S3 (PCL/Alg/Ca/n-HA) groups showed significantly higher gene expression levels than S1 (PCL/Alg).Conclusions: ADSCs and PCL/Alg-based scaffolds compose a good tissue engineering complex for bone regeneration. Addition of n-HA to PCL/Alg scaffolds and crosslinking with CaCl2 efficiently improve the osteogenic potential of ADSCs.

Background: Taste disturbance among tramadol abusers has been reported in the last few years. Aim: To assess the toxic effects of tramadol abuse on tongue structure including taste buds and reversibility of these changes on withdrawal. In addition, assess the effect of tramadol on Ki-67 as general marker for cellular proliferation. Methods: Forty-two adult male Sprague Dawley rats were divided into six groups: group I received normal saline, groups II and III received tramadol hydrochloride 40mg/kg for 20 and 30 days respectively orally, groups IV, V and VI received tramadol hydrochloride 40mg/kg for 30 days orally then received normal saline only for 10, 20, 30 days respectively. Rats were sacrificed and their tongues were dissected out. Results: On histological examination, the covering epithelium, fungiform and filiform papillae, taste buds and muscle layer were distorted in group II. In group III more damage occurred with complete disappearance of taste buds. On tramadol stoppage, gradual restoration of epithelium, papillae, taste buds and muscle fibers structure began in groups IV and V. In group VI, most histological features were restored but did not return to normal. Regarding Ki-67 immunostaining, the reaction area in tongue tissue increased with tramadol administration then began to decrease on its cessation but did not return to normal up to 30 days after withdrawal. Conclusion: Tramadol can disrupt the histological structure of the tongue tissue, destroy taste buds, and these changes are reversible on withdrawal. In addition, these toxic effects are not dependent on Ki-67 pathway.

Background: Electronic cigarette is a substitute to traditional nicotine smoke invented since 2004. There is no enough data about its safety with its the widespread usage. Aim of the study: The present study was designed to verify the impact of E-liquid of electronic cigarette on taste buds of fungiform papillae in albino rats. Materials and methods: 22 young adult male albino rats were divided into 3 groups. Group I: (control group), injected i.p by normal saline daily. Group II: (E-cigarette group): animals were injected i.p by E-cigarette refill liquid (ECRL) containing 0.5 mg of nicotine/kg for 6 days then continue to be administered the same dose day after day for 4 weeks. Group III (E-cigarette + vitamin C treated group): animals had been i.p injected by (ECRL) containing 0.5 mg of nicotine/ kg. One hour from i.p injection of the liquid, the animals were received vitamin C 300 mg/ kg through oro-gastric gavage for 6 days. Then animals were receive the regimen day after day till the end of 4 weeks. Rats of groups sacrificed 24 hs from last injection. After processing the tissue samples, they were stained using Haematoxylin & Eosin and Cytokeratin 7 & TNF α. The results were analyzed statistically using one way ANOVA test. Results: Evaluation of the sections revealed significant differences between all groups with marked improvement in group III. p value was less than 0.05. Conclusion: E-cigarette smoking has a harmful effect on taste buds of fungiform papilla histologically and immunohistochemically. Vitamin C has a protective effect on taste bud against E-cigarette refill liquid.

Introduction: Cadmium is a toxic, heavy industrial metal that causes serious environmental health hazards. Cadmium containing compounds have been classified as known human carcinogens and epidemiological data show causal associations to different types of cancers. This study designed to assess the carcinogenic effects of Cadmium on the gingival tissue of rats.Material and methods: Sixteen male albino Rats (age: 8 to 10 weeks and about 150 to 180 g body weight) from Animal Center of Faculty of Medicine, Mansoura University. The animals were divided into two equal groups, group I (control) and group II (cadmium chloride) rats were given 2 ml dose of a solution containing 10 mg/kg body weight of monohydrated cadmium chloride orally by gavage needle for 24 days. By the end of experiments, gingival epithelium around the teeth were carefully dissected, processed and stained using Haematoxyline & Eosin and immunohistochemical evaluation by iNOS. Statistical analysis was done to observe the statistical significant differences between the Cd group and control group in relation to dysplastic changes and iNOS immunoreaction. Results:The gingival tissue of Cd group revealed several dysplastic changes as, drop shape rete pegs, loss of polarity of basal cells, nuclear hyperchromatism, pleomorphism and increased mitotic pattern. Mild dysplasic changes were observed in 4 cases (50%), moderate dysplasic changes in 2 cases (25%), however no dysplastic changes in 2 cases (25%). a statistical significant difference regarding iNOS immunoreaction was found between control group and Cd group. Conclusion:This study showed that Cadmium chloride at low concentration and longtime of exposure can cause dysplastic changes in gingival tissue of rats.