Trace elements in nasal polyps.

The aim of our study is to evaluate the status of selenium and zinc in nasal polyp tissues and to investigate the possible role of trace elements and antioxidants including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in nasal polyps. In this study, the antioxidant enzyme and trace element levels measured in polyp tissues of 37 patients were compared with the levels measured in conchal mucosa of 27 control cases. The antioxidant enzyme and trace element levels in tissues were measured with graphite and flame spectrophotometry methods using Shimatsu UV.1601 spectrophotometer and Perkin Elmer atomic spectrometer. The mean tissue zinc and selenium levels were, respectively, 2.55 µg/g and 30.03 pg/g in patient group, 4.37 µg/g and 44.95 pg/g in control group. The mean tissue SOD and GSH-Px levels were, respectively, 4.27 and 0.69 U/mg protein in patient group, 7.09 and 0.77 U/mg protein in control group. When the measured levels in patients and control cases were compared, there were statistically significant differences between zinc, selenium, and SOD levels (P = 0.001). There was no significant difference between GSH-Px levels (P = 0.465). In conclusion, it has been revealed that the levels of zinc, selenium, and SOD in nasal polyps were significantly lower, and it may be concluded that this may have a role in the development of nasal polyps.

Protective effects of zinc, pentoxifylline, and N-acetylcysteine in an animal model of laparoscopy-induced ischemia/reperfusion injury of the small intestine.

BACKGROUND: Pneumoperitoneum induced to facilitate laparoscopy is associated with splanchnic hypoperfusion, ischemia/reperfusion (I/R) injury, and oxidative stress. AIM: This study investigated the effects of pre- and postlaparoscopic conditioning, zinc, pentoxifylline, and N-acetylcysteine on markers of I/R injury of the small intestine in an animal model. METHODS: Male Sprague-Dawley rats (n=56) were randomized to 1 of 7 treatment groups. Except for group 7 (control group that underwent sham surgery without pneumoperitoneum), pneumoperitoneum was induced in all by use of carbondioxide insufflation under a pressure of 15 mmHg. Group 1 (laparoscopic I/R) was subjected to 60 minutes of pneumoperitoneum. Group 2 (laparoscopic preconditioning plus laparoscopy) was subjected to 5 minutes of insufflation and 5 minutes of desufflation followed by 60 minutes of pneumoperitoneum. Group 3 (laparoscopy plus laparoscopic postconditioning) was subjected to 60 minutes of pneumoperitoneum and 60 minutes of desufflation followed by 5 minutes of insufflation and 5 minutes of desufflation. Group 4 (zinc), group 5 (pentoxifylline), and group 6 (N-acetylcysteine) received a single intraperitoneal injection of zinc (50 mg/kg), pentoxifylline (50 mg/kg), or N-acetylcysteine (150 mg/kg), respectively, 5 minutes before the desufflation period. Animals were killed at the end of the experiments, and small intestine samples were tested for malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD). RESULTS: There was no significant difference for MDA levels between each other in the groups 1, 2, and 3. But MDA levels were higher significantly in groups 1, 2, and 3 than those of groups 4, 5, 6, and 7. SOD and GPX levels of group 3 were significantly higher than those of groups 1, 2, 4 through 7. According to the SOD levels, there was no significant difference between each other in those of groups 1, 2, 4 through 7. GPX levels of group 3 were significantly higher than those of groups 1, 2, 4 through 7. GPX levels of group 1 were significantly lower than those of groups 5 and 7. The mean CAT level of groups 1 and 2 was significantly lower than that of groups 3, 6, and 7. The mean CAT level of group 3 was significantly higher than that of groups 1, 2, 4 through 7. CONCLUSIONS: In this animal model of small intestine I/R injury, laparoscopy caused small intestine ischemia as evidenced by elevated markers of tissue I/R injury. This effect was significantly attenuated by zinc, pentoxifylline, and N-acetylcysteine, but not by prelaparoscopy conditioning and postlaparoscopy conditioning.

Beneficial effects of nebivolol treatment on oxidative stress parameters in patients with slow coronary flow.

OBJECTIVES: Imbalance between oxidative stress and antioxidant defense has been demonstrated in patients with slow coronary flow (SCF). The aim of this study was to investigate the effect of nebivolol treatment on oxidative stress parameters in SCF patients. STUDY DESIGN: The study included 32 patients (10 females, 22 males; mean age 53.3 ± 5.2 years) with SCF and 32 control subjects (14 females, 18 males; mean age 50.6 ± 5.2 years) with normal coronary arteries on angiography. Coronary slow flow was determined by the TIMI frame count method. Patients with SCF received nebivolol treatment (5 mg/day) for six months. Blood samples were analyzed for malondialdehyde (MDA) and serum nitric oxide (NO) levels, and erythrocyte catalase (CAT) and erythrocyte superoxide dismutase (SOD) activities in the control group and, in SCF patients, at baseline and after six months of nebivolol treatment. RESULTS: The two groups were similar with respect to age, body mass index, blood pressure, heart rate, and lipid profile. Smoking was more frequent in the SCF group compared to the controls. TIMI frame counts measured from the left anterior descending, circumflex, and right coronary arteries were significantly higher in the SCF group (p < 0.0001). Baseline MDA and NO levels, and SOD and CAT activities were significantly different between the two groups, with significantly increased MDA (p < 0.0001), and significantly decreased SOD (p < 0.0001), CAT (p < 0.001), and NO (p < 0.001) in the SCF group. After six months of nebivolol treatment, all oxidative stress parameters showed significant improvements compared to the baseline values (p < 0.0001 for MDA, SOD, CAT, and NO) and approximated to the values of the control group. CONCLUSION: Our results show that nebivolol treatment may be beneficial to improve oxidative stress parameters in patients with SCF, which are considered to be an early stage of atherosclerosis.

Serum reference levels of selenium, zinc and copper in healthy pregnant women at a prenatal screening program in southeastern Mediterranean region of Turkey.

PROJECT: The aim of the study was to investigate the serum reference range for Selenium (Se), Zinc (Zn) and Copper (Cu) levels in women of 10-14 (group I) and 16-20 (group II) weeks of gestation and compare them with those in non-pregnant healthy women and healthy men. PROCEDURE: This cross-sectional study was performed in 351 pregnant women [group I (n: 177) and group II (n: 174)], 30 non-pregnant women and 30 men as controls. The levels of Se, Zn and Cu levels were determined on flame and furnace atomic absorption spectrophotometer using Zeeman background correction. RESULTS: In the 10-14 weeks of gestation Se, Zn and Cu serum levels were 44.85+/-9.23, 81.30+/-31.94 and 132.33+/-38.24 microg/dl, in 16-20 weeks of gestation were 47.18+/-10.92, 74.25+/-22.47 and 164.86+/-39.69 microg/dl, in non-pregnant women were 55.38+/-8.81, 121.41+/-29.22 and 104.75+/-39.14 microg/dl also in men 72.24+/-9.28, 134.85+/-15.95 and 78.29+/-20.90 microg/dl, respectively. CONCLUSION: A significant low level of serum Se, Zn and a high level of Cu in the pregnant women in the 10-14 and 16-20 weeks of gestation were detected when compared with that of non-pregnant women and men.

Ischemia-reperfusion injury in skeletal muscle: comparison of the effects of subanesthetic doses of ketamine, propofol, and etomidate.

BACKGROUND: Interest in the effects of anesthetics in skeletal ischemia-reperfusion injury (IRI) has recently emerged. Thus, the objective was to compare the effects of subanesthetic doses of ketamine, propofol, and etomidate in a skeletal IRI model. METHODS: IRI was applied to rats by tourniquet method. Under thiopental anesthesia, five experimental groups were established as follows: (1) sham-control, (2) IRI, (3) IRI+Ketamine, (4) IRI+Propofol, and (5) IRI+Etomidate. Malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase were measured in skeletal muscle via a spectrophotometer. Zinc, iron, copper, and selenium were evaluated by atomic absorption spectrophotometer. RESULTS: While the values of malondialdehyde and glutathione peroxidase were higher and lower, respectively, those of superoxide dismutase and catalase were identical in IRI group in comparison with sham-control. Zinc displayed a decrease in IRI group; however, no differences in iron and copper levels were determined. In rats treated with subanesthetic doses of ketamine, elevated malondialdehyde levels in IRI group were reversed to control levels by each dose. While each dose of ketamine decreased superoxide dismutase activities in comparison with IRI group, a reduction in catalase activity was only seen in 3mg/kg ketamine-treated rats. The attenuated glutathione peroxidase activity seen in IRI was greatly reversed by ketamine administration in all doses. No differences in zinc, copper, and iron levels were detected between IRI and ketamine-treated groups. Similar results were obtained either by the administration of propofol or etomidate. CONCLUSIONS: Subanesthetic doses of ketamine, propofol and etomidate displayed beneficial effects in IRI.

The protective effect of erythropoietin on the acute phase of corrosive esophageal burns in a rat model.

INTRODUCTION: An experimental study was conducted to investigate the effects of erythropoietin on the acute phase of esophageal burn damage induced by sodium hydroxide. MATERIALS AND METHODS: A standard esophageal alkaline burn was produced by the application of 10% sodium hydroxide to the distal esophagus in an in vivo rat model. Fifty-six female rats were allocated into three groups: Group BC (baseline control, n = 8) rats were uninjured and untreated, Group PC (positive control, n = 24) rats were injured but untreated and Group EPO (erythropoietin-treated, n = 24) rats were injured and given subcutaneous erythropoietin (1,000 IU/kg per day), 15 min, 24, and 48 h after administration of the NaOH solution. Six animals from Group PC and six from Group EPO were killed at 4, 24, 48, and 72 h after application of NaOH to the esophagus. All of animals in Group BC were killed 4 h after exposure to 0.9% NaCl. Oxidative damage was assessed by measuring levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD) and catalase (CAT) in homogenized samples of esophageal tissue. Histologic damage to esophageal tissue was scored by a single pathologist blind to groups. RESULTS: MDA levels in the BC and EPO groups were significantly lower than those in the PC group (p < 0.05). CAT and SOD activities, and NO levels in the BC and EPO groups were significantly higher than in the PC group (p < 0.05). Esophageal tissue damage measured at 4, 24, 48, and 72 h after NaOH application was significantly less in the EPO group than in the PC group (p < 0.05). CONCLUSIONS: When administered early after an esophageal burn induced by 10% sodium hydroxide in this rat model, erythropoietin significantly attenuated oxidative damage, as measured by biochemical markers and histologic scoring.

Intraperitoneal Alpha-Lipoic Acid to prevent neural damage after crush injury to the rat sciatic nerve.

OBJECTIVE: Crush injury to the sciatic nerve causes oxidative stress. Alfa Lipoic acid (a-LA) is a neuroprotective metabolic antioxidant. This study was designed to investigate the antioxidant effects of pretreatment with a-LA on the crush injury of rat sciatic nerve. METHODS: Forty rats were randomized into four groups. Group I and Group II received saline (2 ml, intraperitoneally) and a-LA (100 mg/kg, 2 ml, intraperitoneally) in the groups III and IV at the 24 and 1 hour prior to the crush injury. In groups II, III and IV, the left sciatic nerve was exposed and compressed for 60 seconds with a jeweler's forceps. In Group I (n = 10), the sciatic nerve was explored but not crushed. In all groups of rats, superoxide dismutase (SOD) and catalase (CAT) activities, as well as malondialdehyde (MDA) levels were measured in samples of sciatic nerve tissue. RESULTS: Compared to Group I, Group II had significantly decreased tissue SOD and CAT activities and elevated MDA levels indicating crush injury (p < 0.05). In the a-LA treatment groups (groups III and IV), tissue CAT and SOD activities were significantly increased and MDA levels significantly decreased at the first hour (p < 0.05) and on the 3rd day (p < 0.05). There was no significant difference between a-LA treatment groups (p > 0.05). CONCLUSION: A-LA administered before crush injury of the sciatic nerve showed significant protective effects against crush injury by decreasing the oxidative stress. A-LA should be considered in the treatment of peripheral nerve injuries, but further studies are needed to explain the mechanism of its neuroprotective effects.

Protective effect of erythropoietin on torsion/detorsion injury in rat model.

PURPOSE: The aim of the study is to investigate the effects of erythropoietin on torsion/detorsion injury in rats. METHODS: Forty rats were divided randomly into 5 groups: group I (sham, S), sham operation; group II (torsion/detorsion 1, T/D(1)), 3 hours ischemia and 1 hour reperfusion; group III (torsion/detorsion 2, T/D(2)), 3 hours ischemia and 48 hours reperfusion; group IV (erythropoietin 1, EPO(1)), 3 hours ischemia, 1 hour reperfusion, and a single dose of EPO; and group V (erythropoietin 2, EPO(2)), 3 hours ischemia, 48 hours reperfusion, and 2 doses of EPO. Malondialdehyde (MDA) and nitric oxide (NO) levels and activities of superoxide dismutase and catalase were measured. Tissue damage to ovarian tissue was scored by histologic examination. Data were compared among groups with parametric tests. RESULTS: The MDA levels in the S and EPO groups were significantly lower than the T/D groups (P < .001). Catalase and superoxide dismutase activities, and NO levels in the S and EPO groups were significantly higher than in the T/D groups (P < .05). Ovarian tissue damage in the S and EPO groups was significantly less than in the T/D groups (P < .05). Levels of all biochemical markers and ovarian tissue damage scores were similar among the S, EPO(1), and EPO(2) groups (P > .05). CONCLUSION: Erythropoietin attenuates ischemia-reperfusion injury when given during the acute phase of ovarian torsion-detorsion in a rat model.

Resveratrol, a natural antioxidant, attenuates intestinal ischemia/reperfusion injury in rats.

The intestine is highly susceptible to ischemia/reperfusion (I/R) injury. Splanchnic ischemia is the initial event that releases injurious factors, leading to systemic disorders with high morbidity and mortality. Oxidative stress mediators are believed to contribute to the intestinal I/R injury. Resveratrol, a polyphenol found in grapes, is shown to be a strong antioxidant in various tissues, with a property of an estrogen-receptor agonist. Therefore, we investigated the effects of resveratrol on oxidative injury in the intestine. Female Wistar rats were randomly allocated into four groups (n = 8, each). The sham group was only subjected to surgical procedures, while other animals were subjected to intestinal ischemia (60 min) and subsequent reperfusion (60 min). One group received resveratrol (15 mg/kg, 0.3 ml/day intraperitoneally) for both 5 days before surgery and 15 min before ischemia, while the other was treated intraperitoneally with 0.5% ethyl alcohol as vehicle (0.3 ml/day). In the I/R rat intestines, we detected severe tissue injuries (p < 0.001), the significant increases in the tissue levels of malondialdehyde (MDA), nitric oxide (NO), and myeloperoxidase (MPO) (p < 0.001), and the decrease in superoxide dismutase (SOD) activity (p < 0.001), compared to the sham control. Resveratrol significantly ameliorated the intestinal injury, decreased MDA, NO and MPO levels to the sham control levels, and decreased bacterial translocation in mesentery lymph nodes, liver and spleen (p < 0.001). Resveratrol also restored the SOD activity. These results suggest that resveratrol could protect intestinal tissue against I/R injury with its potent antioxidant properties.

Effects of intravenous anesthetics on renal ischemia/reperfusion injury.

BACKGROUND: Renal ischemia/reperfusion (I/R)-induced tubular epithelial cell injury, called ischemic acute renal failure, is associated with high mortality in humans. Protecting the kidney against I/R injury is very important during complicated renal operations, transplantation surgery, and anesthesia. Aim. The purpose of this study was to investigate and compare the efficiency of ketamine, thiopental, propofol, etomidate, and intralipid in reducing the injury induced by free radicals in a rat model of renal I/R. METHOD: Forty-two Wistar rats were divided into seven groups in our study. Rats in the sham group underwent laparotomy and waited for 120 minutes (min) without ischemia. Rats in the control group were given nothing with ischemia-reperfusion. Rats in the I/R groups were given ketamine (20 mg/kg), thiopental (20 mg/kg) propofol (25 mg/kg), etomidate (10 mg/kg) and 10% intralipid (250 mg/kg) intraperitoneally 15 min prior to the ischemia for 60 min, followed by reperfusion for 60 min. The blood samples and kidney tissues of the rats were obtained under anesthesia at the end of the reperfusion period. Biochemical malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), blood urea nitrogen (BUN), creatine (Cr), aspartate aminotransferase (AST) were determined, and histopathological analysis was performed with these samples. RESULTS: MDA level was increased significantly in the control group (p < 0.05). Histopathological findings of the control group confirmed that there was renal impairment by tubular cell swelling, interstitial edema, medullary congestion, and tubular dilatation. MDA levels were lower in the ketamine, thiopental, and propofol groups compared to the control group (p < 0.05). In the thiopental and propofol groups, the levels of histopathological scores were significantly lower than control and etomidate groups in ischemia-reperfusion. CONCLUSION: Our results demonstrated that I/R injury was significantly reduced in the presence of propofol and thiopental. The protective effects of these drugs may belong to their antioxidant properties. These results may indicate that propofol and thiopental anesthesia protects against functional, biochemical, and morphological damage better than control in renal I/R injury.

Re-protective effects of pre- and post-laparoscopy conditioning, zinc, pentoxifylline, and N-acetylcysteine in an animal model of laparoscopy-induced ischemia/reperfusion injury of the kidney.

BACKGROUND: Pneumoperitoneum (P) created to facilitate laparoscopy (L) is associated with splanchnic hypoperfusion, ischemia/reperfusion (I/R) injury, and oxidative stress. AIM: This study investigated the effects of pre- and post-laparoscopic conditioning, zinc, pentoxifylline (PTX), and N-acetylcysteine (NAC) on markers of I/R injury in an animal model. METHODS: Sprague-Dawley male rats (n = 56, weight range 300-350 g) were randomly placed in one of seven treatment groups. Except for group C (control group who underwent a sham operation without pneumoperitoneum), pneumoperitoneum was created in all using CO(2) insufflation under a pressure of 15 mmHg. Group L (laparoscopy) was subjected to 60 min of pneumoperitoneum. Group Lpre (laparoscopic preconditioning plus laparoscopy) was subjected to 5 min of insufflation and 5 min of desufflation followed by 60 min of pneumoperitoneum. Group Lpost (laparoscopy plus laparoscopic post-conditioning) was subjected to 60 min of pneumoperitoneum and 60 min of desufflation followed by 5 min of insufflation and 5 min of desufflation. The laparoscopy plus zinc (LZ), PTX (LP), and NAC (LNAC) groups received a single intraperitoneal injection of zinc (50 mg/kg), pentoxifylline (50 mg/kg), or N-acetylcysteine (150 mg/kg) 5 min before the desufflation period. Animals were sacrificed at the end of the experiments, and kidney samples were tested for malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD). RESULTS: MDA levels, as an indicator of oxidative stress in kidney tissue samples, were significantly higher in all pneumoperitoneum groups compared to Group C, except for Group Lpre. The pattern of change in tissue levels of SOD, GPX, and catalase was variable in the different treatment groups. CONCLUSIONS: In this animal model of renal ischemia/reperfusion injury, laparoscopy caused renal ischemia as evidenced by elevated markers of tissue ischemia-reperfusion injury. This effect was significantly attenuated by post-laparoscopy conditioning, zinc, pentoxifylline, and N-acetylcysteine, but not by pre-laparoscopy conditioning.

Administration of honey to prevent peritoneal adhesions in a rat peritonitis model.

AIM: We investigated the effects of intraperitoneal honey on the development of postoperative intra-abdominal adhesions and oxidative stress in a model of bacterial peritonitis. METHODS: Bacterial peritonitis was induced in 18 rats by cecal ligation and puncture. The rats were randomly assigned to three groups. Group 1 (n=6) received honey intraperitoneally, group 2 (n=6) received 5% dextrose intraperitoneally, and the third group received no fluid or medicine intraperitoneally one day after cecal ligation and puncture procedure. All animals were killed 14 days later so we could assess the adhesion score. Tissue antioxidant levels were measured in 1-g tissue samples taken from the abdominal wall. RESULTS: Adhesion scores of honey treated group were significantly lower according to the control group (P<0.05) and statistically significant. Adhesion scores of honey were lower from 5% dextrose but not statistically significant (P>0.05). Malondialdehyde values of honey group were significantly lower from the control group (P<0.05) and levels in 5% dextrose group was higher than the honey group. Catalase levels were high in control and 5% dextrose groups. Superoxide dismutase levels were higher in the control group than the honey group (statistically significant). CONCLUSIONS: Intraperitoneal honey decreased the formation of postoperative intra-abdominal adhesions without compromising wound healing in this bacterial peritonitis rat model. Honey also decreased the oxidative stress during peritonitis.

Intraperitoneal EMLA (lidocaine/prilocaine) to prevent abdominal adhesion formation in a rat peritonitis model.

OBJECTIVE: The accelerative effect of EMLA (eutectic mixture of lidocaine 2.5% and prilocaine 2.5%) in the wound healing process is known. We hypothesised that post-operative peritoneal adhesions may be reduced with intra-peritoneal EMLA administration in a model of bacterial peritonitis. STUDY DESIGN: Bacterial peritonitis was induced in 24 rats by cecal ligation and puncture. The rats were randomly assigned to one of four groups. Group 1 (n=6)) received EMLA intraperitoneally, group 2 (n=6) received 2% lidocaine hcl solution intraperitoneally, the third group received one dose (100 mg/kg) of ceftriaxone sodium (Rocephin, Roche, 1 g) intraperitoneally one day after cecal ligation and puncture procedure, and in control group (group 4, n=6), no fluid or medicine was introduced into the abdomens of the rats. All animals were killed 14 days later in order to assess the adhesion score. Tissue antioxidant levels were measured in 1 g tissue samples taken from the abdominal wall. RESULTS: The adhesion score was significantly lower in the EMLA group than in the lidocaine and control groups. The catalase levels were higher in the lidocaine and control groups than in EMLA group. CONCLUSIONS: Intraperitoneal EMLA inhibited the formation of postoperative intra-abdominal adhesions without compromising the wound healing in this bacterial peritonitis rat model. EMLA also decreased the oxidative stress during peritonitis (Tab. 1, Fig. 7, Ref. 27). Full Text (Free, PDF) www.bmj.sk.