Emin Ozgur Akgul

The effects of thyroxine replacement on the levels of serum asymmetric dimethylarginine (ADMA) and other biochemical cardiovascular risk markers in patients with subclinical hypothyroidism

Background  The relationship between subclinical hypothyroidism (SH) and cardiovascular disease (CVD) is still under debate. The purpose of the present study was to evaluate plasma total homocysteine (tHcy), high sensitive C‐reactive protein (hsCRP), small dense low‐density lipoprotein (sdLDL), l‐arginine and asymmetric dimethylarginine (ADMA) concentrations and their relationship to nitric oxide (NO) production, measured as plasma nitrite‐plus‐nitrate (NOx) concentration, in patients with SH before and after thyroxine replacement therapy and compared with control group values.

Comparison of the Efficacy of Melatonin and 1400W on Renal Ischemia/Reperfusion Injury: A Role for Inhibiting iNOS

Introduction. We investigated the roles of melatonin (a powerful antioxidant, iNOS inhibitor, and a scavenger of peroxynitrite) and 1400W (a strong and selective inhibitor of inducible nitric oxide) on renal dysfunction and injury induced by ischemia/reperfusion (I/R) of rat kidney, since oxidative and nitrosative injury are believed to be the major causes. Materials and methods. Thirty-two male Sprague-Dawley rats were divided into four groups of sham-operated, I/R, I/R + Melatonin and I/R + 1400W. Rats were given either melatonin (10 mg/kg) or 1400W (10 mg/kg) in the I/R + Melatonin and I/R + 1400W groups respectively at 6 h prior to ischemia and at the beginning of reperfusion via intraperitoneal route. I/R injury was induced by 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood were obtained for histopathologic and biochemical evaluation. Results. Melatonin and 1400W had an ameliorative effect on both oxidative and nitrosative stress in the kidneys against renal I/R injury in rats. In addition, melatonin significantly reduced elevated nitro-oxidative stress product, restored decreased antioxidant enzymes and attenuated histological alterations when compared with 1400W. Conclusions. Both Melatonin and 1400W were efficient in ameliorating experimental I/R injury of the kidneys. Moreover, melatonin was more effective than 1400W possibly through inhibiting iNOS as well as scavenging free oxygen radicals and peroxynitrite.

The role of preconditioning and N-acetylcysteine on oxidative stress resulting from tourniquet-induced ischemia-reperfusion in arthroscopic knee surgery.

BACKGROUND The aim of this study was to investigate the effects of ischemic preconditioning (IPC) and N-acetylcysteine (NAC) on oxidative stress resulting from tourniquet-induced ischemia-reperfusion (IR) period in arthroscopic knee surgery. METHODS Forty-five patients who had arthroscopic knee surgery for meniscal and chondral lesions and for pathologic medial plica were included in this study. They were assigned to the following treatment groups: control (group C; n=15), IPC (group P; n=15), and NAC (group N; n=15). Subjects in the control group underwent routine surgical procedures. Subjects in the preconditioning group were subjected to temporary ischemia, with tourniquet performed by three compression cycles of 5 minutes followed by 5 minutes of reperfusion just before the application of tourniquet inflation. Subjects in the NAC group received 10 mg/kg NAC dissolved in 100 mL 0.9% normal saline intravenously 30 minutes before tourniquet inflation. An hour before the tourniquet was applied (preischemia) and 2 hours after tourniquet was removed (reperfusion), blood samples (to test for metabolites) were obtained. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (TAC), and total oxidant status (TOS) were measured in all serum samples. Results were compared between preischemia and reperfusion in three groups. RESULTS MDA in the control group was found to be increased significantly compared with preischemia, whereas MDA in IPC and NAC groups did not change insignificantly. SOD and GSH activities in the control group were found to be increased significantly, whereas SOD and GSH activities in IPC and NAC groups did not change significantly after reperfusion. TAC in the control group was found to be decreased and TOS was found to be increased significantly, but TAC and TOS in IPC and NAC groups were not significantly different after reperfusion. Mean serum MDA, TOS, SOD, and GSH-Px levels were lower in group P than group C at reperfusion period (p<0.05). Mean serum SOD levels were lower in group P than group N at reperfusion period (p<0.05). CONCLUSIONS Tourniquet-induced IR period in routine arthroscopic knee surgery resulted in oxidative stress by increasing MDA, SOD, GSH-Px, TOS and decreasing TAC. NAC and IPC had protective effect on occurrence of oxidative stress resulting from IR period by preventing MDA, SOD, GSH-Px, TAC, and TOS changes in routine arthroscopic knee surgery.

High serum levels of neopterin in patients with Crimean–Congo hemorrhagic fever and its relation with mortality

Summary Objective Neopterin is generated and released in increased amounts by macrophages upon activation by interferon-gamma during cellular immune response. In this study, we aimed to investigate serum neopterin levels in patients with Crimean–Congo hemorrhagic fever (CCHF) and its clinical significance as a predictor factor of mortality. Methods Neopterin concentrations on the first day of hospitalization were measured in serum samples from 51 CCHF patients. Serum neopterin levels and other clinical–laboratory parameters for fatal and nonfatal CCHF patients were compared. Results Serum neopterin levels (73.22±54.30nmol/L) were highly elevated in all CCHF patients (p <0.0001) with higher levels in fatal group (153.66±81.34nmol/L, p =0.0001) compared to nonfatal disease (55.99±24.09nmol/L). In univariate analysis, the level of neopterin on the first day of hospitalization, bleeding, platelet count, aspartate transferase and lactate dehydrogenase were associated with mortality. In multivariate analysis, only the serum level of neopterin was associated with mortality. As a mortality risk factor, area under the curve was 0.939 (p =0.0001, 95% confidence interval: 0.85–1.00). Conclusions In this first study of serum neopterin levels for CCHF, elevated serum neopterin level showing strong activation of monocytes/macrophages was a risk factor for CCHF.

Comparison of the effect of topical and systemic melatonin administration on delayed wound healing in rats that underwent pinealectomy

Abstract Objectives. Melatonin is a hormone which has many systemic effects in addition to its strong antioxidant properties. The aim of the present study was to investigate the difference between sytemic and topical administration of melatonin by forming a chronic wound model in rats whose release of basal melatonin was supressed by pinealectomy. Material and methods. Experimental animals used in the study were divided into four equal groups: (i) a group of normal animals with wound formation (control), (ii) a group of animals who underwent pinelaectomy and wound formation (PINx), (iii) a group that underwent PINx + systemic melatonin administration, and (iv) a group that underwent PINx + topical melatonin administration. Fifteen days after pinealectomy, a bipediculed flap was formed on the back of the rats under anesthesia and then six excisional skin wounds were produced in all groups. Following the treatment that lasted 7 days, on day 8 the wound surface areas were measured and wound tissues were removed under anesthesia. In these tissues the levels of malondialdehit (MDA) and hydroxyproline (OH-proline) and the activities of superoxide dismutase(SOD) and glutathion peroxidase (GSH-Px) were measured. Results. In the PINx group, OH-prolin levels decreased significantly compared to the control group and wound surface areas increased. MDA levels increased compared to the control group, and SOD and GSH-Px decreased accordingly. Conversely, in two melatonin groups in which melatonin was administered systemically or topically MDA decreased while SOD ve GSH-Px enzymes increased. Conclusion. In conclusion, in the present study it was shown that wound healing was prolonged in experimental animals deprived of melatonin through pinealectomy. Melatonin exerts positive effects on wound healing, whether it is administered topically or systemically.

Simultaneous determination of cyclosporine A, tacrolimus, sirolimus, and everolimus in whole-blood samples by LC-MS/MS.

Objectives. Cyclosporine A (CyA), tacrolimus (TRL), sirolimus (SIR), and everolimus (RAD) are immunosuppressive drugs frequently used in organ transplantation. Our aim was to confirm a robust sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of CyA, TRL, SIR, and RAD in whole-blood samples. Materials and Methods. We used an integrated online solid-phase extraction-LC-MS/MS system and atmospheric pressure ionization tandem mass spectrometry (API-MS/MS) in the multiple reaction monitoring (MRM) detection mode. CyA, TRL, SIR, and RAD were simultaneously analyzed in whole blood treated with precipitation reagent taken from transplant patients. Results. System performance parameters were suitable for using this method as a high-throughput technique in clinical practice. The high concentration of one analyte in the sample did not affect the concentration of other analytes. Total analytical time was 2.5 min, and retention times of all analytes were shorter than 2 minutes. Conclusion. This LC-MS/MS method can be preferable for therapeutic drug monitoring of these immunosuppressive drugs (CyA, TRL, SRL, and RAD) in whole blood. Sample preparation was too short and simple in this method, and it permits robust, rapid, sensitive, selective, and simultaneous determination of these drugs.

Comparison of hyperbaric oxygen and medical ozone therapies in a rat model of experimental distal colitis

Abstract Objectives. Previous studies have shown that hyperbaric oxygen (HBO) is effective in reducing the severity of acute distal colitis (ADC). Ozone therapy (OT) reduces inflammation in several pathological conditions. We aimed to compare the effects of HBO therapy and OT in an experimental ADC rat model. Materials and methods. Forty rats were randomly divided into four groups: Sham, ADC, ADC + HBO, and ADC + OT. Rats in the sham group were given isotonic saline. In the remaining groups, ADC was created by intracolonic administration of 4% acetic acid. No treatment was given to the ADC group. The rats in the ADC + HBO and ADC + OT groups were given HBO and ozone treatments, respectively. The administration of acetic acid caused an inflammatory response in all animals. Distal colons and blood samples were obtained. Results. The histopathological score was significantly higher in the ADC group compared to the other groups. The histopathological scores in the ADC + HBO and ADC + OT groups were significantly lower compared to the ADC group (both p < 0.001). The most pronounced therapeutic effect was observed in the ADC + OT group. Malondialdehyde and neopterin levels and superoxide dismutase and glutathione peroxidase activities in the ADC group were significantly higher compared to the other groups (p < 0.001). Conclusion. Our data showed that the therapeutic effect of OT is more pronounced than that of HBO therapy. Its possible effect is by means of decreasing inflammation, edema, and oxidative stress. These findings also suggest that it is possible to improve the outcome of ADC by using ozone therapy as an adjuvant therapy.

Elevated plasma asymmetric dimethylarginine level in acute myocardial infarction patients as a predictor of poor prognosis and angiographic impaired reperfusion

OBJECTIVES We aimed to investigate the effects of admission asymmetric dimethylarginine (ADMA) levels on myocardial perfusion and prognosis in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). BACKGROUND ADMA, an endogenous inhibitor of endothelial nitric oxide synthase, was found to be elevated in plasma of patients with cardiovascular risk factors. METHODS 168 consecutive patients undergoing primary PCI for STEMI <12 h after symptom onset and 75 healthy age and sex matched volunteer controls were enrolled in the study. Patients with STEMI were grouped into tertiles according to their admission plasma ADMA levels. Major adverse cardiac events during hospitalization or at one-year clinical follow-up were evaluated. Also angiographic impaired reperfusion was assessed by 3 different methods after PCI: angiographic thrombolysis in myocardial infarction (TIMI) flow, TIMI frame count and TIMI myocardial perfusion grade (TMPG). RESULTS Plasma level of L-arginine were lower in patients with STEMI than in the control group subjects, whereas plasma ADMA levels were increased in the STEMI patient group. The rate of impaired angiographic reperfusion increased across the tertile groups. Also one-year mortality rates showed a significant increase across the tertile groups (4% vs. 10% vs. 20%, p<0.01). Using multiple Cox regression analysis, only TIMI risk score, left ventricle ejection fraction (LVEF), abnormal TMPG, and increased ADMA values on admission emerged as independent predictors of one-year mortality. The ROC analysis indicated an optimal cut-point of ≥1.37 μmol/L, which detects one-year mortality with a negative predictive value of 96%. CONCLUSIONS In STEMI patients undergoing primary PCI, high admission ADMA levels were found to be associated with impaired myocardial perfusion and increased one-year mortality. Therefore admission ADMA level detection may be helpful in identifying the patients at a greater risk of impaired myocardial perfusion and poor prognosis.

Effect of Preconditioned Hyperbaric Oxygen and Ozone on Ischemia-Reperfusion Induced Tourniquet in Skeletal Bone of Rats

BACKGROUND The aim of the study was to investigate effect of I/R injury on bone tissue and protective role of hyperbaric oxygen precondition (HBO-PC) and ozone precondition (O(3)-PC) on I/R injury by using biochemical analysis. MATERIALS AND METHODS Thirty-two rats were included in study. The animals were divided into four equal groups: sham operation, I/R, I/R+HBO and I/R+O(3). One session of 60 min, 3 ATA, 3-4 L/min, 100% oxygenation was defined as one dose of HBO. First dose of HBO was administrated 72 h before ischemia. Subsequent, one-dose of HBO administrated per 12 hours until ischemia time (total seven doses); 0.7 mg/kg ozone/oxygen mixture intraperitoneally was defined as one dose of ozone. First dose of O(3) was administered 72 h before ischemia (total four doses). I/R model was induced in anesthetized rats by unilateral (right) femoral artery clipping for 2 h followed by 22 h of reperfusion. The right tibia and were harvested. Tissue was assayed for levels of malondialdehyde (MDA) and protein carbonyl (PCO), activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). RESULTS MDA and PCO levels were increased in I/R group. SOD activity was increased; GSH-Px activity was decreased in I/R group. MDA and PCO levels were decreased, SOD and GSH-Px activities were increased in both HBO+I/R and O(3)+I/R groups. CONCLUSION It has been shown that levels of MDA and PCO in bone were increased followed by 2 h of ischemia and 22 h of reperfusion period. Ozone-PC and HBO-PC has protective effect against skeletal bone I/R injury by decreasing levels of MDA and PCO, increasing activities of SOD and GSH-Px in rats.

The protective effects of ozone therapy in a rat model of acetaminophen-induced liver injury

OBJECTIVES Acetaminophen (APAP) overdose may cause acute liver injury. Ozone therapy (OT) is shown to reduce inflammation and necrosis in several entities. Thus, we have designed this study to evaluate the efficacy of OT in a rat model of APAP-induced liver injury. METHODS Twenty-seven Sprague-Dawley rats were divided into three groups: sham, APAP and APAP+OT groups. In the APAP and the APAP+OT groups, liver injury was induced by oral administration of 1 g/kg APAP. The APAP+OT group received a single dose ozone/oxygen mixture (0.7 mg/kg) intraperitoneally 1h after APAP administration. All animals were killed at 24 hour after APAP administration. Blood samples and liver tissues were harvested to determine liver injury and oxidative stress parameters. Liver tissues and blood samples were obtained for biochemical and histopathological analyses. RESULTS APAP administration caused necrosis in the liver after 24h. The degrees of liver necrosis of the APAP group were higher than the other groups (in both p<0.05, respectively). In the APAP+OT group, liver antioxidant enzymes activities were significantly higher than the APAP group (p<0.05), but were lower than the sham group (p<0.05). In the sham group, serum neopterin, a marker of cell-mediated immunity, concentrations (4.8±1.2 nmol/L) were lower than the APAP (14.7±1.4 nmol/L) and APAP+OT groups (7.5±2.4 nmol/L) (in both p<0.05, respectively). CONCLUSION Our results showed that OT prevented liver necrosis in rats and reduced neopterin levels. These findings suggest that the use of OT as an adjuvant therapy which might improve the outcome in APAP induced liver injury.