The role of insulin-like growth factor I-II receptor on development of pleomorphic adenoma.

Pleomorphic adenoma is a slow-growing salivary gland tumor frequently arising from the parotid gland. In this study, we investigated the role of the insulin-like growth factor I-II receptor (IGFI-IIR) levels on the development of parotid gland pleomorphic adenomas. The study included 20 males and 20 females who had superficial parotidectomy with a histopathological diagnosis of pleomorphic adenoma in Firat University Otorhinolaryngology Clinic between 2000 and 2011. The ages of the patients ranged between 20 and 50 years. The control tissues were obtained unilaterally from the parotid glands of five female and five male cadavers during autopsy, and consisted of 0.5 × 0.5 cm sized normal parotid gland tissues. The expression of IGFI-IIR were measured in both tumor and tumor-free normal parotid tissue in the study group while only the normal parotid tissues were studied in the cadavers. Primary polyclonal antibodies against IGFI-IIR were used with "Streptavidin-Biotin Complex" method for immunohistochemical staining of both the study and the control groups' tissue sections. In this study, the IGFI-IIR levels were found significantly higher in the pleomorphic adenoma tissue (p < 0.05). In addition, IGFI-IIR expression was greater in normal parotid tissues of the study group when compared to the normal parotid tissues of the cadavers. However, the difference was not statistically significant (p > 0.017). Greater expression for IGFI-IIR in pleomorphic adenoma when compared to normal parotid tissues of the patients and the cadavers suggests that IGFI-II may be important factors in the development of pleomorphic adenoma.

Dietary arginine silicate inositol complex inhibits periodontal tissue loss in rats with ligature-induced periodontitis.

The purpose of this study was to induce experimental periodontitis in rats previously fed diets containing arginine silicate inositol (ASI) complex and examine the biochemical, immunological, and radiological effects. Fifty two 8-week-old female Sprague Dawley rats were equally divided into four groups. The control group included those fed a standard rat diet with no operation performed during the experiment. The periodontitis, ASI I, and ASI II groups were subjected to experimental periodontitis induction for 11 days after being fed a standard rat diet alone, a diet containing 1.81 g/kg ASI complex, or a diet containing 3.62 g/kg ASI complex, respectively, for 8 weeks. Throughout the 11-day duration of periodontitis induction, all rats were fed standard feed. The rats were euthanized on the eleventh day, and their tissue and blood samples were collected. In the periodontitis group, elevated tissue destruction parameters and reduced tissue formation parameters were found, as compared to the ASI groups. Levels of enzymes, cytokines, and mediators associated with periodontal tissue destruction were lower in rats fed a diet containing ASI complex after experimental periodontitis. These results indicate that ASI complex could be an alternative agent for host modulation.

Systemic and local zoledronic acid treatment with hydroxyapatite bone graft: A histological and histomorphometric experimental study.

In this study, the aim was to compare the relative efficacy of systemic and local zoledronic acid (ZA) on a hydroxyapatite (HA) bone graft in a rat critical-size calvarial bone defect. In total, 84 female rats were divided into four groups: Empty control (EC) group with no treatment applied; HA group, in which only HA bone graft material was used in the calvarium; and HA plus local ZA (HA+LZA) and HA plus systemic ZA (HA+SZA) groups, in which animals received ZA locally or systemically, respectively, with HA bone graft material in the calvarium. A 5-mm standardised critical-size calvarial bone defect was created with a standard trephine drill and the respective treatment was applied. Rats were sacrificed 7, 14 and 28 days later. The numbers of osteoclasts and osteoblasts, and degree of bone formation were evaluated histopathologically and histomorphometrically. Statistically significant differences were detected between the HA, HA+LZA and HA+SZA groups and the EC group for new bone formation (P<0.05). Osteoblast numbers in the HA+LZA and HA+SZA groups were significantly higher compared with those in the EC and HA groups (P<0.05). No statistically significant difference was detected between the HA+LZA and HA+SZA groups in new bone formation or osteoblast number (P>0.05). Bone formation was significantly higher in the HA group than in the EC group (P<0.05). The numbers of osteoclasts in the HA+LZA and HA+SZA groups were significantly higher than those in the groups EC and HA (P<0.05); however, there was no significant difference between groups HA+LZA and HA+SZA (P>0.05). Within the limitations of this study, systemic or local administration of ZA enhanced new bone formation with a HA bone graft in a rat critical-size calvarial defect model.

Evaluation of Effects of Topical Melatonin Application on Osseointegration of Dental Implant: An Experimental Study.

The aim of the present study was to evaluate the effect of local melatonin application during surgery on bone implant connection (BIC) in rabbit tibiae. Six 0.8- to 1-year-old male New Zealand rabbits were divided into 3 groups: (1) a control group (CG) in which rabbits were not treated with additive materials and only implant integration was executed; (2) a melatonin dose 1 (MLT D-1) group in which rabbits were treated with 1.2 mg of melatonin locally before implant placement into the rabbits' tibiae; and (3) a melatonin dose 2 (MLT D-2) group in which rabbits were treated with 3 mg melatonin locally before implant placement into the rabbits' tibiae. Four weeks after the procedure, the rabbits were euthanized; their tibiae were dissected from muscles and soft tissues, fixed with formaldehyde, and later embedded in methacrylate. Histologic and histomorphometric analyses were then performed under light microscopy. Following this, BIC was detected histomorphometrically, and P < .05 was considered statistically significant. Results showed that the highest BIC percentage was detected in MLT D-2, with a mean value of 39.46% ± 0.78, as compared with a mean value of 33.89% ± 0.92 in group MLT D-1 and 27.42% ± 0.89 in CG. Similarly, the mean BIC percentage of the MLT D-2 group was the highest among the three, with the mean BIC percentage of the MLT D-1 still registering as higher than CG. Within the limitations of this rabbit study, it appears that local melatonin application during implant surgery may improve BIC.

Protective effects of melatonin and vitamin E in brain damage due to gamma radiation: an experimental study.

Gamma radiation is known to cause serious damage in the brain, and many agents have been used for neuroprotection. In this study, lipid peroxidation levels and histopathological changes in brain tissues of whole-body irradiated rats with likely radiation injury were compared to those with melatonin and vitamin E protection. Forty rats in four equal groups were used. The control group received neither radiation nor medication. The remaining groups received doses of 720 cGy in two equal fractions 12 h apart. The second group received radiation but no medication, the third received radiation plus 100 mg/kg per day of vitamin E i.p., and the fourth received radiation plus 100 mg/kg per day of melatonin i.p. over 5 days. On the 10th postoperative day, all the rats were decapitated and specimens from parietal cortices were analyzed for tissue malondialdehyde (MDA) levels and histopathological changes. Increases in MDA were relatively well prevented by melatonin treatment but less so with vitamin E therapy. On histopathological examination, melatonin significantly reduced the rates of edema, necrosis, and neuronal degeneration, whereas vitamin E reduced only necrosis. Neither substance was capable of preventing vasodilatation. In conclusion, melatonin may be useful in preventing the pathological changes of secondary brain damage as a result of free oxygen radicals generated by irradiation.

[The effect of vitamin E on histopathologic healing and lipid peroxidation levels in experimentally induced traumatic tympanic membrane perforations]. / Travmatik timpanik membran perforasyonlarinda E vitamininin histopatolojik iyilesme ve lipid peroksidasyon düzeyleri üzerine etkileri: Deneysel çalisma.

OBJECTIVES: To examine the favorable effects of vitamin E on tympanic membrane perforations induced mechanically in guinea pigs. STUDY DESIGN: Bilateral tympanic membrane perforations of 1.8 mm were induced in 40 guinea pigs. The animals were randomly divided into two groups equal in number. One group remained untreated, while the other was administered vitamin E (100 mg/kg/day) through intramuscular injections. On days 1, 3, 5, and 7, five animals in each group were randomly sacrificed. Histopathologic changes in the tympanic membranes were evaluated and malondialdehyde levels were determined. RESULTS: Significant increases were observed in epithelial thickness, fibroblastic proliferation, and neovascularization in the study group (p<0.05). Epithelial thickness was found to be increased in both groups beginning from the first day; however, this increase was more rapid in the study group. Although malondialdehyde levels showed significant increases on days 3 and 5 in both groups (p<0.05), they returned to the first day values in vitamin E-treated animals on day 7, whereas controls still maintained high malondialdehyde levels. CONCLUSION: Vitamin E hastens the healing process of traumatic tympanic membrane perforations.