Ismet Yilmaz

The effects of duration of CO2 insufflation and irrigation on peritoneal microcirculation assessed by free radical scavengers and total glutathion levels during operative laparoscopy.

STUDY OBJECTIVE To investigate the effects of peritoneal exposure to carbon dioxide (CO2) on peritoneal microcirculation and free radical scavenger (FRS) metabolism, and its role in potential adhesion formation after operative laparoscopy. DESIGN Randomized, controlled study (Canadian Task Force classification I). SETTING University-affiliated hospital. PATIENTS Twenty-eight women undergoing operative laparoscopy for adnexal masses. INTERVENTION For each patient, a 1 x 1-cm sidewall peritoneal flap was excised at the end of laparoscopy and numbered randomly. Similar flaps obtained from 24 women immediately after entering the abdomen during laparotomy served as controls. MEASUREMENTS AND MAIN RESULTS Changes in glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were studied in homogenized peritoneal tissues. The duration of CO2 exposure and amount of CO2 used were correlated with levels of free radical scavengers and compared with controls. Mean CO2 exposure, amount of CO2 used, and CO2 pressure (15 mm Hg) was similar between low irrigation and irrigated laparoscopy (118.3 +/- 25 and 39.2 +/- 8.81 min and 125 +/- 20 and 44.5 +/- 6.81 min, respectively). The change in FRS levels was significantly correlated with duration and amount of CO2 exposure (r = -0.92). Levels of GSH-Px, SOD, CAT, and GSH were significantly lower in the CO2 exposure group than in controls (0.57 micro mol, 1.8 ng, 48.5 micro mol, 1.5 nmol vs 0.8 micro mol, 2.6 +/- 0.4 ng, 79 micro mol, 3.6 nmol, respectively). CONCLUSION Exposure to CO2 has adverse effects on peritoneal microcirculation and cell-protective systems, which are proposed mechanisms in adhesion formation. Avoiding long CO2 exposure and copiously irrigating the abdominal cavity throughout surgery may lessen these effects. The potential role of the peritoneal FRS system on postoperative adhesion formation and its relation to estrogen status mandates further studies.

Protective role of caffeic acid phenethyl ester in the liver of rats exposed to cold stress

Cold exposure can induce a form of environmental stress. Cold stress (CS) alters homeostasis, results in the creation of reactive oxygen species and leads to alterations in the antioxidant defense system. The caffeic acid phenethyl ester (CAPE), an active component of propolis, has an antioxidant capacity. We investigated the effect of CS on oxidative stress and antioxidant defense system and the possible protective effect of CAPE in rat liver tissue. Twenty‐four female Wistar Albino rats were divided into four groups: Control, CAPE‐treated, CS, and CAPE‐treated CS (CS + CAPE) group. Catalase (CAT), glutathione peroxidase (GSH‐Px), superoxide dismutase (SOD) activities and total glutathione (GSH) and malondialdehyde (MDA) levels were measured. In addition, histological changes in liver tissue were examined by light microscopy. SOD, CAT and GSH‐Px activities and total GSH level were significantly declined in the CS group. In the CS + CAPE group, the activities of these three enzymes and GSH level significantly raised with regard to the CS group. MDA levels increased in the CS group and decreased in the CS + CAPE group. The tissues of the CS group showed some histopathological changes such as necrosis, hepatocyte degeneration, sinusoidal dilatation, hemorrhage and vascular congestion and dilatation. In the CS + CAPE group, the histopathological evidence of hepatic damage was markedly reduced. Histological parameters were consistent with biochemical parameters. In this study, CS increased oxidative stress in liver tissue. CAPE regulated antioxidant enzymes, inhibited lipid peroxidation and reduced hepatic damage.

Adhesion formation after microlaparoscopic and laparoscopic ovarian coagulation for polycystic ovary disease

STUDY OBJECTIVE To compare the effects of microlaparoscopy and decreased CO2 exposure on peritoneal microcirculation and potential adhesion formation after ovarian surgery with those of conventional operative laparoscopy. DESIGN Prospective, randomized study (Canadian Task Force classification I). SETTING Teaching hospital. PATIENTS Eighteen women with polycystic ovary disease. INTERVENTIONS Microlaparoscopic or laparoscopic ovarian coagulation of the ovaries. MEASUREMENTS AND MAIN RESULTS Approximately 10 to 12 coagulation points were applied to each ovary. Two to 3 weeks after the initial surgery second-look microlaparoscopy was performed to determine the extent of adhesions in both groups. The frequency of adhesion formation and changes in glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were studied in homogenized peritoneal tissues obtained during surgery in each group. RESULTS Clinical profiles were similar between groups. Mean exposure, amount, and pressure of CO2 were significantly less in the microlaparoscopy group (p <0.05). The laparoscopy group had significantly more adhesions than the microlaproscopy group (24% vs 48%, p <0.05). The GSH-Px, SOD, CAT, and GSH levels were significantly lower in the laparoscopy group (0. 425 micromol, 1.2 ng, 37.55 micromol, and 0.9 nmol vs 0.755 micromol, 2.l ng, 625 micromol, and 2.6 nmol, respectively). CONCLUSION Reduced exposure to and amount of CO2 during microlaparoscopy may result in decreased adhesion formation compared with conventional laparoscopy. This effect may possibly be due to lack of or minimal adverse effects on peritoneal microcirculation and cell-protective systems, which are proposed mechanisms for adhesion formation and closely related to peritoneal injury. In addition, microlaparoscopy may be a cost-effective alternative to conventional laparoscopy. (J Am Assoc Gynecol Laparosc 6(2):159-163, 1999)

Protective effect of apricot (Prunus armeniaca L.) on hepatic steatosis and damage induced by carbon tetrachloride in Wistar rats.

The present study was planned to investigate the protective effect of 10 % and 20 % apricot-containing feed on carbon tetrachloride (CCl4)-induced hepatic steatosis and damage. Adult male Wistar rats (n 42) were divided into six groups of seven each, as follows: control group; CCl4 group; CCl4+10 % apricot group; CCl4+20 % apricot group; 10 % apricot group; 20 % apricot group. All apricot groups were fed with 10 % or 20 % apricot-containing feed for 5 months. CCl4 injections were applied to the CCl4 groups at the dose of 1 mg/kg for 3 d at the end of 5 months. In the CCl4 group, vacuolated hepatocytes and hepatic necrosis were seen, especially in the centrilobular area. Hepatocytes showed an oedematous cytoplasmic matrix, large lipid globules and degenerated organelles. The area of liver injury was found significantly decreased with apricot feeding. Malondialdehyde and total glutathione levels and catalase, superoxide dismutase and glutathione peroxidase activities were significantly changed in the CCl4 group and indicated increased oxidative stress. Apricot feeding decreased this oxidative stress and ameliorated histological damage. We concluded that apricot feeding had beneficial effects on CCl4-induced liver steatosis and damage probably due to its antioxidant nutrient (beta-carotene and vitamin) contents and high radical-scavenging capacity. Dietary intake of apricot can reduce the risk of liver steatosis and damage caused by free radicals.

Ultrastructural Clues for the Protective Effect of Ascorbic Acid and N-Acetylcysteine against Oxidative Damage on Caerulein-Induced Pancreatitis

Background: Oxygen free radicals (OFR) have been implicated in the induction of acute pancreatitis (AP). Aims: The aim of this study was to determine the effect of ascorbic acid and N-acetylcysteine (NAC), potent antioxidants, against oxidative stress in AP. Methods: AP was induced by two i.p. injections of caerulein at 2-hour intervals (50 µg/kg BW). One group received additionally an antioxidant mixture composed of L(+)-ascorbic acid (14.3 mg/kg BW) and NAC (181 mg/kg BW) i.p. The rats were sacrificed 12 h after the last injection. Oxidative stress markers were evaluated. Light-microscopic and ultrastructural examination was performed. Results: Formation of vacuoles, mitochondrial damage, and dilatation of rough endoplasmic reticulum, margination and clumping of chromatin were major ultrastructural alterations in AP group. Ascorbic acid + NAC prevented these changes. Small vacuoles were present within the cytoplasm of some of the acinar cells. Pancreas damage was accompanied by an increase in tissue malondialdehyde (MDA) levels (p < 0.05), whereas a decrease was seen in catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activities and total glutathione (GSH) levels (p < 0.005). Ascorbic acid + NAC decreased MDA levels but increased CAT, SOD, GPx activities and GSH levels (p < 0.005). Conclusion: These results suggest that ascorbic acid + NAC is potentially capable of limiting pancreatic damage produced during AP via protecting fine structure of acinar cells and tissue antioxidant enzyme activities.

Pressurized liquid extraction of phenolic compounds from Anatolia propolis and their radical scavenging capacities.

Propolis samples from important honey producing locations of Anatolia namely; Bingol (BG), Rize (RZ), Tekirdag (TK) and Van (VN), were evaluated for their antiradical capacities, total phenolic contents and individual phenolic compounds which was recovered by means of pressurized liquid extraction (PLE). Several extraction parameters of PLE such as; temperature, pressure, solvent type, extraction time and cell size were investigated for their effects on the extraction performances. The results showed that, 40 °C, 1500 psi, Ethanol:water:HCl; (70:25:5, v/v/v) containing 0.1% tert-butylhydroquinone (tBHQ) as solvent, three extraction cycles within 15 min, and a cell size of 11 mL was the most favorable PLE operating conditions. Results of the tests performed to designate the success of the polyphenol analysis showed that the recovery was in the range of 97.2% and 99.7%. Major phenolic compounds in all samples were found to be gallocatechin (GCT), catechin (CT), epicatechin gallate (ECTG), caffeic acid (CA), chlorogenic acid (ChA), and myricetin (Myr). ChA level of BG propolis was 4.5, 3 and 23 times higher than that of RZ, TK and VN region, respectively. Antiradical tests showed that all propolis samples have superior antiradical capacities up to 500 mg Trolox equivalent activity per gram of extract.

The investigation of the antioxidative properties of the novel synthetic organoselenium compounds in some rat tissues.

DMBA (7,12-dimethylbenz[a]anthracene) is a polycyclic aromatic hydrocarbon (PAH) known to cause tumors in rats. Selenium is an essential element with physiological non-enzymatic antioxidant properties. Because of the health problems induced by many environmental pollutants, many efforts have been undertaken in evaluating the relative antioxidant potential of selenium and synthetic organoselenium compounds. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (1-isopropyl-3-methylbenzimidazole-2-selenone [SeI] and 1,3-di-p-methoxybenzylpyrimidine-2-selenone [SeII]) in the determined doses. The protective effects of novel synthetic organoselenium compounds (SeI and SeII) against DMBA-induced changes in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities and total glutathione (GSH) and malone-dialdehyde (MDA) levels of rat heart and brain were investigated. It was determined that SeI and SeII fully or partially restored enzyme activity. It was also found that lipid peroxidation was also decreased in SeI and SeII treated groups. Consequently, it was determined that novel synthetic organoselenium compounds (SeI and SeII) provided protection of antioxidant activity, and protection against lipid peroxidation measured as MDA in SeI and SeII treated groups was provided by novel synthesized organoselenium compounds. The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rats was rationalized.

Protective role of melatonin given either before ischemia or prior to reperfusion on intestinal ischemia-reperfusion damage

Abstract:  Tissue injury resulting from ischemia‐reperfusion is of fundamental importance. Experimental evidence suggests that the generation of reactive oxygen species is significantly responsible for this type of injury. In the present study, besides investigating the protective role of melatonin on tissue damage caused by intestinal ischemia‐reperfusion, the protective activity of this compound was also analyzed in both pre‐ and post ischemia melatonin‐treated rats. The activities of the main antioxidative enzymes, catalase, superoxide dismutase and glutathione peroxidase in the intestine showed significant (P < 0.05) increases in melatonin‐treated animals that were subjected to ischemia/reperfusion compared with those subjected only to ischemia/reperfusion. Also, results clearly indicate that the level of malondialdeyhde, an index of lipid peroxidation, decreased significantly (P < 0.05) when rats subjected to intestinal/reperfusion were given melatonin either before ischemia or before reperfusion.

Endometrial Na+, K+-ATPase pump function and vasopressin levels during hysteroscopic surgery in patients pretreated with GnRH agonist *

STUDY OBJECTIVE To investigate the effects of gonadotropin-releasing hormone (GnRH) analog pretreatment on endometrial Na+, K+-adenosine triphosphatase (ATPase) pump function and peripheral blood vasopressin levels, and their role in fluid absorption and mechanisms of hyponatremia in patients undergoing hysteroscopic endometrial ablation. DESIGN Prospective, randomized, placebo-controlled study (Canadian Task Force classification I). SETTING University-affiliated hospital. PATIENTS Seventeen women with dysfunctional uterine bleeding. INTERVENTION Nine women received a GnRH analog and eight received saline approximately 6 to 8 weeks before hysteroscopic ablation by electrosurgery. MEASUREMENTS AND MAIN RESULTS Both before randomization and immediately before surgery, endometrial biopsy samples were obtained and numbered consecutively without patient identification. Operative hysteroscopy was performed with glycine 1.5% mixed with 2% alcohol. The amount of irrigant and irrigant deficit; blood levels of albumin and ethanol; hematocrit and hemoglobin; changes in sodium levels; and central venous pressure were compared. The Na+, K+-ATPase pump activity was significantly increased in the GnRH analog group compared with the saline group and correlated with decreased estradiol levels (0.4 +/- 0.08 vs 0.26 +/- 0.06 micro mol/min/ml). Vasopressin levels were significantly lower in the GnRH group (3.2 +/- 0.9 vs 7.6 +/- 1.7 micro mol/L). Mean volume of irrigant used and operating time were similar in both groups. Volume deficit, decrease in protein, and hematocrit were less in GnRH than in the saline group. Blood ethanol levels, decrease in sodium, and irrigant deficit were significantly lower in GnRH group. CONCLUSION Pretreatment with GnRH analogs may prevent the adverse effects of estradiol on endometrial Na+, K+-ATPase and creates a protective mechanism against iatrogenic hyponatremia, which is more critical in women than men in case of absorption of irrigating fluid. Moreover, created hypoestrogenism may enhance Na+, K+-ATPase activity in brain as well as endometrium, thus decreasing womens susceptibility to hyponatremic complications and brain damage. Suppressed vasopressin levels may be protective against fluid absorption in GnRH analog-treated patients.

Antioxidative effects of novel synthetic organoselenium compound in rat lung and kidney

The effects of environmental chemicals, drugs, and physical agents on the developing lung and kidney are influenced by the state of development and maturation. Selenium is an essential element with physiological nonenzymatic antioxidant properties. Therefore, we undertook the present study to evaluate the antioxidant potential of the novel synthetic organoselenium compounds (Se I and Se II). In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds [1-isopropyl-3-methylbenzimidazole-2-selenone (Se I) and 1,3-di-p-methoxybenzylpyrimidine-2-selenone (Se II)] in the determined doses. The protective effects of novel synthetic organoselenium compounds (Se I and Se II) against DMBA-induced changes in levels of some [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities and total glutathione (GSH), malonedialdehyde (MDA)] parameters in rat lung and kidney were investigated. As a result, it was found that both Se I and Se II had provided the antioxidant effects against DMBA-induced oxidative stress in rat lung and kidney and lipid peroxidation had also been decreased by these organoselenium compounds.