Cem Sezer

Effects of topical vitamin E on keratocyte apoptosis after traditional photorefractive keratectomy.

Purpose: To evaluate the keratocyte apoptosis and effects of topical vitamin E on keratocyte apoptosis after photorefractive surgery. Methods: Rabbits were divided into 7 groups, and all groups were compared with controls after epithelial scraping, epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK), transepithelial PRK, production of a corneal flap with microkeratome and laser-assisted in situ keratomileusis (LASIK). The effects of topical Vitamin E treatment were investigated in the traditional PRK group. The terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy have been used to detect apoptosis in rabbit cornea. Results: Transepithelial PRK induced minimal keratocyte apoptosis, less than in all other refractive surgical procedures. The greatest amount of keratocyte apoptosis was observed after traditional PRK (p = 0.001), therefore we tested the effects of topical vitamin E in this group. The number of apoptotic keratocytes significantly reduced after vitamin E therapy (p < 0.005). Conclusion: Keratocytes undergo apoptosis after refractive surgery in response to mechanical epithelial removal, preparing of corneal flap and excimer laser stromal photoablation. The topical application of vitamin E immediately after surgery can prevent keratocyte apoptosis, and this result suggests that free radicals may be partly responsible for keratocyte apoptosis after excimer laser keratectomy.

Keratocyte apoptosis and corneal antioxidant enzyme activities after refractive corneal surgery.

Purpose Refractive corneal surgery induces keratocyte apoptosis and generates reactive oxygen radicals (ROS) in the cornea. The purpose of the present study is to evaluate the correlation between keratocyte apoptosis and corneal antioxidant enzyme activities after different refractive surgical procedures in rabbits.Methods Rabbits were divided into six groups. All groups were compared with the control group (Group 1), after epithelial scraping (Group 2), epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK: Group 3), transepithelial PRK (Group 4), creation of a corneal flap with microkeratome (Group 5) and laser-assisted in situ keratomileusis (LASIK, Group 6). Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy were used to detect apoptosis in rabbit eyes. Glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities of the corneal tissues were measured with spectrophotometric methods.Results Corneal Gpx and SOD activities decreased significantly in all groups when compared with the control group (P<0.05) and groups 2, 3 and 6 showed a significantly higher amount of keratocyte apoptosis (P<0.05). Not only a negative correlation was observed between corneal SOD activity and keratocyte apoptosis (cc: −0.3648) but Gpx activity also showed negative correlation with keratocyte apoptosis (cc: −0.3587).Conclusion The present study illustrates the negative correlation between keratocyte apoptosis and corneal antioxidant enzyme activities. This finding suggests that ROS may be partly responsible for keratocyte apoptosis after refractive surgery.

Expression of Bcl-2 and c-ErbB-2 in colorectal neoplasia.

Several studies have been demonstrated the value of c-ErbB-2 and Bcl-2 in predicting the biological behaviour of tumors. The aim of this study was to investigate Bcl-2 and c-ErbB-2 expression in colorectal carcinomas and the correlation between their presence and other clinicopathologic parameters. Eighty-six colorectal carcinomas and 17 adenomas were stained with Bcl-2 and c-ErbB-2 immunohistochemically. Staining patterns were assessed semiquantitatively and correlated with tumor size, Duke’s classification, tumor differentiation, mucinous characteristic and anatomic locations. We detected Bcl-2 expression in 10 of 17 adenomas (58.8 %) and 31 of 86 carcinomas (36.04 %). Positive staining in normal mucosa was observed only in the compartment of cryptic cells. However neither the difference in the rates of Bcl-2 positivity in adenoma and carcinoma groups, nor the correlation with other mentioned clinicopathological parameters, were found statistically significant. Bcl-2 expression was found to be significantly high in mucinous carcinomas. Expression of c-ErbB-2 was observed in 12 of 86 (13.95 %) carcinomas. It was not detected in adenomas and normal mucosa. Although the incidence of c-ErbB-2 in nonmucinous carcinoma was higher than that of mucinous carcinoma, this was not significant. In addition we were unable to show any significant relation between c-ErbB-2 expression and other clinicopathologic features. Our result suggest that c-ErbB-2 protein expression in colorectal carcinomas, is not very frequent event. There is no correlation between c-ErbB-2 expression and malignant potential of colorectal carcinomas. Higher expressions of Bcl-2 in adenomas than carcinomas suggest us a possible role of Bcl-2 in early carcinogenesis of colon. However since we were unable to find any significant correlation between Bcl-2 expression and other parameters the impact of this gene on biological behavior is still unclear for us.

Omentum prevents intestinal adhesions to mesh graft in abdominal infections and serosal defects

BackgroundMany studies have evaluated the use of grafts in the reconstruction of abdominal wall defects. In this study, the effects resulting from the presence or absence of the omentum were evaluated in the setting of infection or serosal defects in the formation of adhesions in abdominal closures using mesh grafts.MethodsFor this study, 60 Wistar albino rats were divided into six groups. A circular 3.79-cm2 fascioperitoneal defect was created. After group-specific procedures, defects were reconstructed using polypropylene mesh grafts. In group C (control group), only a mesh graft recontruction was performed, whereas group O (O for omentectomy) underwent an omentectomy plus mesh closure. In group SD (serosal defect group), the cecum was abrased with a brush before mesh closure. Group SDO underwent cecal abrasion plus an omentectomy. In group I (infection group), the intraabdominal space was filled with 1 ml of solution containing 100,000 colony-forming units (CFUs) of Escherichia coli per milliliter. Group IO received the same same amount of E. coli solution plus an omentectomy before mesh closure. After 28 days, the groups were evaluated by intraabdominal and blood cultures, grading of intraabdominal adhesions, graft–organ adhesions, proportion of adhesions to graft size, and histopathologic studies. The results were statistically evaluated using one-way variant analysis and Scheffe’s and Fisher’s definite chi-square tests.ResultsFor the groups in which the greater omentum was preserved, intestinal adhesions to the graft surface were less frequently observed, especially in cases with intraabdominal infections and serosal defects (p < 0.05).ConclusionsPreservation of the greater omentum reduces the formation of intestinal adhesions, especially in cases with underlying infections and serosal defects in abdominal closures using mesh grafts. This could be beneficial in related clinical situations in lowering the rate of intestinal fistulas, erosions, and obstructions that can be attributed to the formation of adhesions.

Pleomorphic adenoma of an unusual size in the deep lobe of the parotid gland

Tumors of the salivary glands in children are not as common as in adults and they are mostly benign. The most common benign epithelial neoplasm seen in children is pleomorphic adenoma. As is usually the case in the adult population, it is usually found in the superficial lobe of the parotid gland. Its localization in the deep lobe is rare. Pleomorphic adenomas of the deep lobe present with a neck mass and when it is large, it may have an intraoral extension as well. It may also assume a dumb-bell shape as it enlarges and may be observed on CT or MRI scans as a prestyloid mass. The choice of treatment depends on the localization and the size of the tumor. The method can be transoral, cervical, transmandibular, transparotid, retromandibular fossa or a combination of these. A child with an unusually large pleomorphic adenoma of the deep lobe of the parotid gland is presented in this study. The deep lobe tumor was totally removed using a combination of cervical and transmandibular approaches.

Magnetic resonance imaging and morphometric histologic analysis of prostate tissue composition in predicting the clinical outcome of terazosin therapy in benign prostatic hyperplasia

Abstract Purpose: To determine whether magnetic resonance imaging (MRI) or quantitative color‐imaged morphometric analysis (MA) of the prostate gland are related to the clinical response to terazosin.

Effect of mechanical vs dilute ethanol epithelial removal on keratocyte apoptosis and polymorphonuclear leukocyte migration

Purpose To investigate keratocyte apoptosis and polymorphonuclear (PMN) cell infiltration to the corneal stroma after mechanical epithelial scraping and chemical de-epithelialization with 18% ethanol solution.Methods Twelve New Zealand Albino rabbits (24 eyes) were randomly divided into three groups. Group A was the control group with no epithelial removal. Group B underwent a 7.5-mm mechanical epithelial removal with a blunt spatula. Group C underwent 7.5-mm chemical de-epithelialization with 18% ethanol-balanced salt solution. Corneas were stained with terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay after 24 h. Only nuclear staining in keratocytes was counted. Polymorphonuclear (PMN) leukocyte densities were also assessed by light microscopy.Results Mechanical de-epithelialization (group B) and chemical de-epithelialization with 18% ethanol (group C) showed no difference in keratocyte apoptosis compared with the control group. There was also no difference between groups B and C. Group B showed no difference in PMN leukocyte counts compared with the control group. But the number of PMN leukocytes observed in group C was significantly higher than those encountered in the corneas of the control group (P < 0.05) and group B (P < 0.05).Conclusions Dilute alcohol induces more PMN cell infiltration when compared with mechanical de-epithelialization although there is no difference in the apoptosis rates.

Immunohistochemical Analysis of E-Cadherin, p53 and Inhibin-α Expression in Hydatidiform Mole and Hydropic Abortion

The purpose of this study was to investigate the role of E-cadherin, p53, and inhibin-α immunostaining in the differential diagnosis of hydropic abortion (HA), partial hydatidiform mole (PHM), and complete hydatidiform mole (CHM). E-cadherin, p53, and inhibin-α protein expression patterns were investigated immunohistochemically using paraffin -embedded tissue sections from histologically diagnosed cases of HA (n = 23), PHM (n = 24), and CHM (n = 23). Expression patterns of these markers were scored semi-quantitatively according to the staining intensity, percentage of positive cells, and immunoreactivity score. Classification of cases was established on histologic criteria and supported by the molecular genotyping. Immunostaining allowed the identification of specific cell types with E-cadherin, p53, and inhibin-α expression in all cases. E-cadherin expression was detected on the cell surface of villous cytotrophoblasts. We observed a marked decline in the expression of E-cadherin from HAs to PHMs to CHMs. The p53-positive reaction was restricted to the nucleus of villous cytotrophoblasts. Significantly increased p53 expression was observed in CHMs, compared with HAs and PHMs. The expression of inhibin-α was localised in the cytoplasm of villous syncytiotrophoblasts, and the expression of this marker was significantly higher in PHMs and CHMs than HAs. In conclusion, immunohistochemical analysis of E-cadherin, p53, and inhibin-α expression could serve as a useful adjunct to conventional methods in the differential diagnosis of HA, PHM, and CHM.