Gürbüz Polat

Decreased Serum Total Antioxidant Status and Erythrocyte-Reduced Glutathione Levels Are Associated with Increased Serum Malondialdehyde in Atherosclerotic Patients

BACKGROUND Coronary artery disease is the significant cause of morbidity and mortality today. The treatment of coronary artery disease is improving, but its prevalence is increasing. Both primary and secondary prevention measures are of vital importance. METHODS In this study, vitamin C, total antioxidant status, malondialdehyde in serum and erythrocyte-reduced glutathione levels were investigated in patients with atherosclerosis and compared with those of controls. Levels of serum MDA, vitamin C, total antioxidant status, and erythrocyte-reduced glutathione were determined according to the methods of Yagi, Bauer et al., Miller et al., and Beutler, respectively. RESULTS Erythrocyte-reduced glutathione, serum vitamin C, total antioxidant status, and malondialdehyde values of both patients with atherosclerosis and controls were as follows: 2.80 +/- 0.76, 5.82 +/- 0.67 micromol GSH/g Hb; 1.00 +/- 0.19, 1.62 +/- 0.30 mg/dL; 0.86 +/- 0.14, 1.43 +/- 0.16 mmol/L, and 4.26 +/- 0.9, 1.02 +/- 0.80 nmol/mL, respectively. There was a decrease in the levels of serum vitamin C, erythrocyte-reduced glutathione, and total antioxidant status (p <0.001), and increase in the levels of serum malondialdehyde (p <0.001) in patients with atherosclerosis when compared with those of controls. CONCLUSIONS Because treatment of atherosclerosis is improving, our results suggest that antioxidant agents may have preventive roles in the formation of atherosclerosis.

Dexamethasone Down-Regulates Endothelial Expression of Intercellular Adhesion Molecule and Impairs the Healing of Bowel Anastomoses

OBJECTIVE To find out the role of endothelial expression of intercellular adhesion molecule-1 (ICAM-1) in the healing of intestinal anastomoses in rats, and to establish the effects of peroperative treatment with corticosteroids. DESIGN Experimental animal study. SETTING University hospital, Turkey. MATERIAL 78 Male Wistar rats. INTERVENTIONS Rats were divided into four groups: Group I, colonic anastomosis only (=18); Group II, colonic anastomosis plus caecal ligation and puncture (=18); Group III, colonic anastomosis plus dexamethasone (=18); and Group IV, colonic anastomosis, plus caecal ligation and puncture, plus dexamethasone (=18). Six animals served as the sham group. The animals underwent bowel transsection and primary anastomosis Infection was produced by caecal ligation and puncture Preoperatively, dexamethasone was given intramuscularly in a dose of 2 mg/kg/day. MAIN OUTCOME MEASURES After 1, 3 and 5 days, anastomotic healing and endothelial expression of ICAM-1 were measured microscopically. RESULTS Anastomotic healing was significantly impaired in dexamethasone-treated animals, and endothelial expression of ICAM-1 was reduced. Endothelial expression of ICAM-1 was no higher in the infected group than in controls. Maximum expression of ICAM-1 on endothelial cells was seen on the first day in each group, and declined on the following days, although the sebsequent reduction in expression was not significant. CONCLUSION Dexamethasone down-regulated expression of ICAM-1, which is important in migration of leucocytes from the circulation to the wound site, and significantly impaired the healing of intestinal anastomoses in rats.

Ischemic preconditioning reduces intestinal epithelial apoptosis in rats.

Recent experimental studies have described protective effect of ischemic preconditioning (IPC) on ischemia–reperfusion (I/R) injury of the intestine. We hypothesize that to reach a new point of view on the effect of IPC in intestinal barrier function, the relationship between I/R-induced mucosal injury and apoptosis must first be clarified. The present study was undertaken to investigate the role of IPC on intestinal apoptosis and probable contributions of bcl-2 expression to this process. We also investigated the effect of intestinal IPC on ileal malondyaldihyde levels. Forty-four male Wistar rats were randomized into four groups each consisting of 11 rats: sham-operated control, I/R group (30 min of superior mesenteric artery occlusion), IPC-I/R group (10 min of temporary artery occlusion prior before an ischemic insult of 30 min), and IPC alone group (10 min of preconditioning). Twenty-four hours later, ileum samples were obtained. Ileal malondyaldihyde levels were increased in the I/R group (31.9 ± 18.8 vs. 106.8 ± 39.8) but not in the IPC alone and IPC-I/R groups (38.1 ± 13.6 and 44.7 ± 12.7;P < 0.01). The number of apoptotic cells was significantly lower in IPC-I/R group than that of I/R group, and these findings were further supported by DNA laddering and M30 findings. Diminished bcl-2 expression observed in the ileal specimens of I/R group was prevented by IPC. Our results indicate that IPC may provide a protective effect on ileal epithelium and that this effect is probably the result of a significant increase in the expression of bcl-2 after the insult. The reversal of apoptosis by IPC might help preserving the vitality of intestinal structures that have a critical function, cessation of which often leads to multiorgan dysfunction syndrome.

The effect of L-carnitine on the prevention of experimentally induced myringosclerosis in rats

The objective of this study was to investigate the possible effect of L-carnitine on the prevention of experimentally induced myringosclerosis. Twenty Sprague-Dawley rats were bilaterally myringotomized. The rats were divided into two groups randomly: group 1 which were intraperitoneally administered saline and group 2 which were intraperitoneally administered L-carnitine. Blood samples were collected for biochemical evaluation and the tympanic membranes were harvested after 28 days. Histopathological and immunohistochemical evaluation were done under light microscopy. The mean malondialdehyde levels were 3.9+/-0.9 in group 2, and 7.9+/-1.1 in group 1 (P<0.001), nitric oxide levels were 25.6+/-6.4 in group 2 and 30.8+/-8.2 in group 1 (P=0.14) and acetylcholinesterase was 1035+/-60 in group 2 and 678+/-35 in group 1 (P=0.001). Myringosclerosis was more frequent and severe in group 1 than group 2 (P<0.007). Immunoreactivity was seen in 16 of 20 tympanic membranes in group 2 and six of 20 tympanic membranes in group 1 (P=0.005). We conclude that L-carnitine diminishes the occurrence of myringosclerosis in rats after myringotomy possibly by antioxidant activity and decreasing the formation of reactive oxygen species.

THE EFFECTS OF DEXAMETHASONE ON LIPID PEROXIDATION AND NITRIC OXIDE LEVELS ON THE HEALING OF TRACHEAL ANASTOMOSES: AN EXPERIMENTAL STUDY IN RATS

Corticosteroids are shown to have deleterious effects on wound healing for various tissues. Arginine metabolism and nitric oxide (NO) synthesis play an important role in many aspects of inflammation and wound healing. The study was designed to evaluate the relationship of dexamethasone impaired healing of tracheal anastomoses to NO metabolism and lipid peroxidation. Forty-two adult Wistar rats were randomly divided into five groups. The animals underwent tracheal transection and primary anastomoses. The groups were assigned as follows: Group I (GI) (sham, N = 6); Group II (GII) (control, N = 6); Group III (GIII), dexamethasone, 0.1 mg kg(-1) per day, intramuscularly for a week (N = 10); Group IV (GIV), dexamethasone, 1 mg kg(-1) per day, intramuscularly for a week (N = 10); Group V (GV), dexamethasone, 6 mg kg(-1) intramuscularly as a single dose (N = 10). After 7 days, bursting pressure was used to evaluate anastomotic healing. Serum nitrite/nitrate and malondialdehyde (MDA) levels were measured as an index of NO synthesis and lipid peroxidation, respectively. The bursting pressure significantly decreased in GIII and GIV when compared to the control group. The difference between GIII and GIV was also statistically significant. Nitrite/nitrate and MDA levels of GIII were found to be significantly higher than the control group. Also, the difference was found to be statistically significant between GIII and GIV in regard to nitrite/nitrate levels. The present study demonstrates that daily administration of dexamethasone for a week inhibits NO synthesis in a dose-dependent manner on tracheal anastomotic healing. Besides the generally accepted evaluation parameters including bursting pressure and hydoxyproline content; NO and MDA levels may be helpful in the assessment of wound healing especially for the investigation of impairment mechanism.

The effects of carnitine on distally-burned dorsal skin flap: an experimental study in rats

OBJECTIVE In ischemia and burn injuries, there are major alterations threatening tissue survival. Increased energy flow requirements are among the major problems in these disorders. Carnitine is an endogenous cofactor, which has a regulatory action on the energy flow from different oxidative sources. The purpose of this study was to determine the effects of carnitine in an experimental flap model. Biochemically, nitric oxide (NO), malondialdehyde (MDA), and acetylcholinesterase levels, and histopathologically tissue examination under light microscope were studied. METHODS In the rat dorsal skin, a 10 cm x 3 cm flap was marked. The most distal 3 cm x 3 cm of the flap was burned to full-thickness. The dorsal flap was elevated, and sutured back to its original site. Sixteen rats were divided into two groups (a control (1) and a study group (2)), consisting of eight rats in each. While the animals in the control group were just followed, the animals in the study group were administrated carnitine with a dose of 100 mg/kg per day for 7 days. RESULTS At the end of the experiment: the mean surviving areas of the flaps were 15.22 cm(2) (50.73%) in group 1, 20.53 cm(2) (68.43%) in group 2, and the difference was statistically significant (P=0.008). In the analysis of blood samples; the mean levels of NO were 22.63 and 40.78 micromol/l; of MDA were 6.74 and 3.79 ng/ml; and of acetylcholinesterase were 136.14 and 222.85 U/l in groups 1 and 2, respectively. The differences in the levels of NO (P=0.001), MDA (0.027) and acetylcholinesterase (P=0.006) were statistically significant. Histopathological examination revealed a full-thickness muscle necrosis in addition to skin tissue in the control group, while healing tissue was present with marked cellularity including mixed inflammatory cells and fibroblast proliferation with an increased vascularity in the form of capillary budding in the study group. CONCLUSION Carnitine has a positive effect in such a model, particularly in preventing the progressive effect of burn, and limiting the necrosis in the full-thickness burned part.

Prognostic value of matrix metalloproteinases (MMP-2 and MMP-9) in Hodgkin's and non-Hodgkin's lymphoma

Matrix metalloproteinases (MMPs) are responsible for the degradation of extracellular matrix and have an important role in tumour metastases. We investigated the role of MMP‐2 and MMP‐9 in Hodgkins disease (HD) and non‐Hodgkins lymphoma (NHL).The serum samples of patients with HD (n = 12), NHL (n = 30) and healthy control (n = 22) were analysed for MMP‐2 and MMP‐9. An immunoassay method was used for the determination of MMP‐2 and MMP‐9 levels. No statistical significance was found between HD and NHL groups for levels of MMP‐2. There were no relation between MMP‐2, MMP‐9 levels and clinical characteristics of patients. The mean MMP‐9 levels were found to be 555.6 ± 140 ng/ml, 446.6 ± 53.6 ng/ml and 111.2 ± 10.3 ng/ml in HD, NHL and control groups, respectively. Our results suggest that MMP‐9 levels are substantially increased in HD and NHL when compared with controls and may probably be used for distinguishing the benign diseases from malign lymphomas.

Study of Axial Bone Mineral Density in Postmenopausal Women with Diffuse Idiopathic Skeletal Hyperostosis Related to Type 2 Diabetes Mellitus

OBJECTIVE The association of bone mineral density (BMD) with diffuse idiopathic skeletal hyperostosis (DISH) related to diabetes mellitus was studied. METHODS We measured BMD and elevated known determinants of BMD (bone markers) in 35 patients with DISH-related type 2 diabetes mellitus, 47 type 2 female diabetics, and 52 female controls with no systemic disease and no drug administration. All subjects were matched for age and body mass index (BMI). All subjects were in the postmenopausal period. RESULTS Among subjects, BMD values were significantly higher in DISH patients than in diabetics and controls (p < 0.05). In addition, the duration of diabetes mellitus was longer in DISH patients and significantly correlated with total hip BMD in DISH patients (p < 0.05). CONCLUSIONS Patients with DISH have higher BMD, and increased BMD probably results from hyperostosis of the axial skeleton, which may cause decreased fracture risk.

Effects of trapidil on the healing of colonic anastomoses in an experimental rat model.

Background:  Trapidil has various properties including vasodilatation, inhibition of lipid peroxidation and platelet aggregation as well as, and reduction of, the inflammatory response to injury. The aim of the present study was to investigate the effects of trapidil on dexamethasone‐impaired colonic anastomotic healing in an experimental rat model.

A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers

Abstract Background: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. Methods: Blood samples were collected nationwide in 28 laboratories from the seven regions (≥400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA). Results: By ANOVA, differences of reference values among seven regions were significant in none of the 25 analytes. Significant sex-related and age-related differences were observed for 10 and seven analytes, respectively. MRA revealed BMI-related changes in results for uric acid, glucose, triglycerides, high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase, and γ-glutamyltransferase. Their RIs were thus derived by applying stricter criteria excluding individuals with BMI >28 kg/m2. Ranges of RIs by non-parametric method were wider than those by parametric method especially for those analytes affected by BMI. Conclusions: With the lack of regional differences and the well-standardized status of test results, the RIs derived from this nationwide study can be used for the entire Turkish population.