Ozone therapy as an adjunct to vancomycin enhances bacterial elimination in methicillin resistant Staphylococcus aureus mediastinitis.

BACKGROUND: We aimed to investigate the influence of intraperitoneal ozone therapy on bacterial elimination and mediastinal inflammation in experimental Staphylococcus aureus mediastinitis. MATERIALS AND METHODS: Forty Wistar-Albino rats were randomized into five groups (eight per group) as follows: uncontaminated group, untreated contaminated group, ozone group, vancomycin group, and vancomycin + ozone group. Uncontaminated group underwent upper median sternotomy. The remaining four groups were inoculated with 0.5 mL 10(8) colony-forming units/mL methicillin-resistant Staphylococcus aureus in the mediastinal and sternal layers. Untreated contaminated group had no treatment. Rats in the vancomycin group received intramuscular vancomycin (40 mg/kg/d), and ozone was administered intraperitoneally (70 µg/mL, 1 mg/kg/d) in the ozone group for the treatment of mediastinitis. Vancomycin + ozone group rats were treated by the combination of both methods. At the end of 10 d, quantitative bacterial cultures and sternal tissue samples were obtained for determination of bacterial counts and histologic degree of inflammation. RESULTS: Both the vancomycin and the ozone treatments caused significant reduction of bacterial counts in quantitative bacterial cultures. Combination of vancomycin and ozone treatments resulted in further reduction of bacterial counts in mediastinum and sternum. Histologic examination of tissue samples revealed significant reduction in severity of mediastinitis related inflammation in vancomycin and vancomycin + ozone groups compared with untreated contaminated group. CONCLUSIONS: Ozone therapy as an adjunct to vancomycin leads to enhanced bacterial elimination in infected sternal and mediastinal tissues in experimental methicillin-resistant Staphylococcus aureus mediastinitis. The benefit of adjuvant ozone therapy is suggested to be related to its bactericidal effect.

The protective effect of adrenomedullin on renal injury, in a model of abdominal aorta cross-clamping.

Renal injury induced by aortic ischemia-reperfusion (IR) is an important factor in the development of postoperative acute renal failure following abdominal aortic surgery. The aim of this study was to examine the effect of adrenomedullin (AM) on kidney injury induced by infrarenal abdominal aortic IR in rats. Thirty-two Wistar Albino rats were randomized into four groups (eight per group) as follows: Control group, IR group (120-minute ischemia and 120-minute reperfusion), IR + AM group (a bolus intravenously of 0.05 µg/kg/min AM), and control + AM group. At the end of the experiment, blood and kidney tissue specimens were obtained for biochemical analysis. Immunohistological evaluation of the rat kidney tissues was also done. IR significantly increased (p < 0.05 vs control group) and AM significantly decreased (p < 0.05 vs. IR group) all of the biochemical parameters. Immunohistological evaluation showed that AM attenuated morphological changes as apoptosis associated with kidney injury. The results of this study indicate that AM attenuates both biochemically and immunohistopathologically kidney injury induced by aortic IR in rats.

ß-Glucan protects against lung injury induced by abdominal aortic ischemia-reperfusion in rats.

BACKGROUND: Aortic ischemia-reperfusion (IR) is an important factor in the development of postoperative acute lung injury following abdominal aortic surgery. The aim of our study was to examine the effect of ß-glucan on lung injury induced by abdominal aortic IR in rats. MATERIAL AND METHODS: Thirty-two Wistar-albino rats were randomized into four groups (eight per group) as follows: the control group (sham laparotomy), aortic IR (120 min ischemia and 120 min reperfusion), aortic IR + ß-glucan (ß-glucan 50 mg/kg/d for 10 d was administered orally before IR), and control + ß-glucan. Lung tissue samples were obtained for biochemical analysis. Protein concentrations in bronchoalveolar lavage fluid and lung wet/dry weight ratios were measured. Histologic evaluation of the rat lung tissues was also performed. RESULTS: Aortic IR significantly increased the levels of MDA, superoxide dismutase, catalase, and myeloperoxidase (P < 0.05 versus control).Whereas, ß-glucan significantly decreased the lung tissue levels of MDA, superoxide dismutase, catalase, myeloperoxidase, (P < 0.05 versus aortic IR), and protein concentration in bronchoalveolar lavage fluid as well as wet/dry lung weight ratio. Histologic evaluation showed that ß-glucan attenuated the morphological changes associated with lung injury. CONCLUSIONS: The results of this study indicate that ß-glucan attenuates lung injury induced by aortic IR in rats. We propose that this protective effect of ß-glucan is due to (1) reduced systemic inflammatory response, (2) reduced oxidative stress and lipid peroxidation in the lung tissue, (3) reduced pulmonary microvascular leakage, and (4) inhibition of leukocyte infiltration into the lung tissue.

Tezosentan reduces the renal injury induced by abdominal aortic ischemia-reperfusion in rats.

BACKGROUND: Renal injury induced by aortic ischemia-reperfusion (IR) is an important factor in the development of postoperative acute renal failure following abdominal aortic surgery. Endothelin (ET) is involved in the development of renal injury induced by aortic IR and tezosentan (R0 61-0612) is a specific ET receptor antagonist. The aim of this study was to examine the effect of tezosentan on renal injury induced by abdominal aortic IR in rats. MATERIAL AND METHODS: Twenty-four Wistar-Albino rats were randomized into three groups (eight per group). Control group underwent laparotomy and dissection of the infrarenal abdominal aorta (IAA) without occlusion. The aortic IR group underwent laparotomy and clamping of the IAA for 120 min followed by 120 min of reperfusion. Aortic IR + tezosentan group underwent same aortic IR periods, and received a bolus intravenous injection of 10 mg/kg tezosentan before ischemia plus continuous intravenous infusion of 1 mg/kg/h tezosentan during 120 min ischemia and 120 min reperfusion. At the end of the experiment, blood and kidney tissue specimens were obtained for biochemical analysis. Histological evaluation of the rat kidney tissues was also done. RESULTS: Biochemical analysis showed that aortic IR significantly increased (P < 0.05 versus control) while tezosentan significantly decreased (P < 0.05 versus aortic IR) the tissue levels of malondialdehyde, superoxide dismutase, catalase and myeloperoxidase. Histological analyses showed that aortic IR significantly increased (P < 0.05 versus control) while tezosentan significantly decreased (P < 0.05 versus aortic IR) focal glomerular necrosis, dilatation of Bowman's capsule, degeneration of tubular epithelium, necrosis in tubular epithelium and tubular dilatation in the renal tissue samples. CONCLUSION: The results of this study indicate that tezosentan reduces renal injury induced by aortic IR in rats. We think that tezosentan exerted this beneficial effect via reducing oxidative stress and lipid peroxidation, inhibition of leukocyte infiltration into renal tissue and acting cytoprotective on renal tubular cells after aortic IR.

Endothelin receptor antagonism by tezosentan attenuates lung injury induced by aortic ischemia-reperfusion.

Tezosentan is a novel dual endothelin receptor antagonist. The purpose of this study was to examine the effect of tezosentan on lung injury induced by abdominal aortic ischemia-reperfusion (IR) in rats. Thirty-two Wistar-albino rats were randomized into four groups (eight per group) as follows: control group (sham laparotomy), aortic IR group (120 min ischemia and 120 min reperfusion), aortic IR + tezosentan group (a bolus intravenous injection of 10 mg/kg tezosentan before ischemia plus continuous intravenous infusion of 1 mg/kg/hr tezosentan during 120 min ischemia and 120 min reperfusion), and control + tezosentan. Blood and lung tissue samples were obtained for biochemical analysis. Protein concentrations in bronchoalveolar lavage fluid and lung wet/dry weight ratios were measured. A histological evaluation was also done. Aortic IR significantly increased (p < 0.05 vs. control group) and tezosentan significantly decreased (p < 0.05 vs. aortic IR group) the plasma level of tumor necrosis factor-alpha; lung tissue levels of malondialdehyde, catalase, and myleperoxidase; and protein concentration in bronchoalveolar lavage fluid and lung wet/dry weight ratio. Histological evaluation showed that tezosentan attenuated the morphological changes associated with lung injury. The results of this study indicate that tezosentan attenuates lung injury induced by aortic IR in rats. We propose that this protective effect of tezosentan is due to (1) reduced systemic inflammatory response, (2) reduced oxidative stress and lipid peroxidation in lung tissue, (3) reduced pulmonary microvascular leakage, and (4) inhibition of leukocyte infiltration into lung tissue.

Oxidant and antioxidant activities of different anesthetic techniques. Propofol versus desflurane.

OBJECTIVE: To investigate the correlation between propofol and desflurane in terms of lipid peroxidation and antioxidant activity and to search the possible antioxidant anesthesia technique. METHODS: The study was performed in the Department of Anesthesia and Reanimation, Medical Faculty, Suleyman Demirel University, Isparta, Turkey, between January 2006 and July 2006. Thirty, ASA I-II patients, with an age range of 19-55 years, undergoing elective surgery under general anesthesia were randomized to receive either propofol infusion (Group P) or desflurane inhalation (Group D) following standard induction. Malondialdehyde (MDA), glutathione peroxidase (GSH), super oxide dismutase (SOD) and alpha-tocopherol (Vitamin E) were measured preoperatively, at peroperatively first hour and postoperatively 12-hour. RESULTS: Malondialdehyde was found lower peroperatively in Group P compared to Group D (p<0.05). In Group D, Vitamin E levels were decreased significantly peroperatively compared to preoperative period (p=0.001). CONCLUSION: We observed a systemic oxidative stress increment with desflurane by terms of MDA; a lipid peroxidation product and endogenous antioxidant activity suppression by terms of Vitamin E at only peroperative period. This study may be defined to support the fact that free oxygen radicals were released more by desflurane than propofol.

Comparison of Sharp Dissection, Electrocautery, and Ultrasonic Activated Scalpel with Regard to Endothelial Damage, Preparation Time, and Postoperative Bleeding During Radial Artery Harvesting.

OBJECTIVE: To examine the effects of classical technique, electrocautery, and ultrasonic dissection on endothelial integrity, function, and preparation time for harvesting the radial artery (RA) during coronary artery bypass grafting (CABG). METHODS: Forty-five patients who underwent isolated CABG and whose RA was suitable for use were studied and divided into three groups: Group 1, classical method (using sharp dissection); Group 2, electrocautery; and Group 3, ultrasonic cautery. Levels of prostacyclin and nitric oxide derivatives were examined biochemically; vascular cell adhesion molecule 1 (VCAM-1) and endothelial nitric oxide synthetase (eNOS) values were assessed using immunohistochemical staining. RA preparation time, RA length/harvesting time ratio, and drainage amounts at the site of RA removal were compared. RESULTS: Differences in RA preparation time (Group 1: 25±6 min, Group 2: 18±3 min, Group 3: 16±3 min, P<0.001) and length/harvesting time ratio (Group 1: 0.76±0.19 cm/min, Group 2: 0.98±0.16 cm/min, Group 3: 1.13±0.09 cm/min, P<0.001) were statistically significant among the groups. Levels of prostacyclin and nitric oxide derivatives were not statistically significant different, VCAM-1 and eNOS expressions were observed to be similar among the groups, and endothelial damage was detected in only one patient per group. CONCLUSION: Use of ultrasonic cautery during RA preparation considerably reduces the preparation time and postoperative drainage amount. However, the superiority of one method over the others could not be demonstrated when the presence of endothelial damage with both biochemical and histopathological evaluations was considered.

Does continuous insulin therapy reduce postoperative supraventricular tachycardia incidence after coronary artery bypass operations in diabetic patients?

OBJECTIVE: To compare continuous insulin infusion (CII) and intermittent subcutaneous insulin therapy for preventing supraventricular tachycardia. The authors propose that continuous insulin therapy is more effective to reduce supraventricular tachycardias. DESIGN: A prospective randomized study. SETTING: This study was performed in 2 different centers between April 2005 and February 2007: Gülhane Military Medical Academy and University of Süleyman Demirel. PARTICIPANTS: Two hundred diabetic patients were included in this prospective randomized study. Patients were divided into 2 groups according to their insulin therapy in 2 different centers. INTERVENTIONS: Group 1 included 100 diabetes mellitus (DM) patients, and CIIs were administrated. These patients received a CII infusion titrated per protocol in the perioperative period (Portland protocol). Group 2 also included 100 DM patients, and subcutaneous insulin was injected every 4 hours in a directed attempt to maintain blood glucose levels below 200 mg/dL. Sliding scale dosage of insulin was titrated to each patient's glycemic response during the prior 4 hours. MEASUREMENTS AND MAIN RESULTS: There were 5 hospital mortalities in the intermittent insulin group. The causes of death were pump failure in 3 patients and ventricular fibrillation in 2 patients. There were 2 hospital mortalities in the CII group (p = 0.044). Thirty-six patients in the intermittent insulin group and 21 patients in the CII group required positive inotropic drugs after cardiopulmonary bypass (p = 0.028). Low cardiac output developed in 28 and 16 patients in the intermittent and CII groups, respectively (p = 0.045). Univariate analysis identified positive inotropic drug requirement (p = 0.011, odds ratio [OR] = 3.41), ejection fraction (EF) (p = 0.001, OR = 0.92), cross-clamp time (p = 0.046, OR = 0.97), left internal mammary artery (p = 0.023, OR = 0.49), chronic obstructive pulmonary disease (COPD) (forced expiratory volume in 1 second <75% of predicted value (p = 0.009, OR = 2.02), intra-aortic balloon pump (p = 0.045, OR = 1.23), body mass index (p = 0.035 OR = 5.60), and CII (p < 0.001, OR = 0.36) as predictors of SVT. Stepwise multivariate analysis confirmed the significance of some of the previously mentioned variables as predictors of SVT. The value of -2 log likelihood of multivariate analyses was 421.504. These were EF (p < 0.001, OR = 0.91), positive inotropic drug requirement (p < 0.001, OR = 3.94), COPD (p = 0.036, OR = 2.11), and CII (p < 0.001, OR = 0.19). CONCLUSION: Continuous insulin therapy in the perioperative period reduces infectious complications, such as sternal wound infection and mediastinitis, cardiac mortality caused by pump failure, and the risk of development of supraventricular tachycardias.

Endothelin receptor blockade with tezosentan ameliorates myocardial injury induced by abdominal aortic ischemia-reperfusion.

Endothelin is both a potent vasoconstrictor and an important mediator of ischemia-reperfusion (IR) injury. Therefore, the role of endothelin receptor antagonism in IR-induced-tissue injury carries great interest. Here, we examined the effect of tezosentan, a nonselective antagonist for endothelin receptors, on myocardial injury induced by abdominal aortic IR, which represents a model of the IR injury in distant organs frequently occurred after vascular surgery. Thirty-two Wistar rats were randomized into four groups (n = 8) as follows: control (sham laparotomy), aortic IR (120 min ischemia and 120 min reperfusion), aortic IR + tezosentan (10 mg/kg intravenous injection before ischemia plus continuous intravenous infusion of 1 mg/kg/hr during the IR injury), and control + tezosentan. Biochemical analysis showed that aortic IR significantly increased (p < 0.05 vs control) the plasma levels of troponin-I, interleukin-6 and tumor necrosis factor-alpha, and the myocardial tissue levels of malondialdehyde, superoxide dismutase and catalase, whereas tezosentan significantly decreased these same factors (p < 0.05 vs aortic IR). Histological evaluation also showed that aortic IR significantly increased (p < 0.05 vs control) myocardial disorganization, myofiber swelling and myofiber eosinophilia in myocardial tissue samples, whereas tezosentan significantly decreased these factors (p < 0.05 vs aortic IR). These results indicate that tezosentan has protective effects against myocardial injury induced by abdominal aortic IR in rats. We propose that the mechanisms underlying this protective effect of tezosentan involves the reduction of oxidative stress and subsequent lipid peroxidation, the inhibition of systemic inflammatory response, and acting cytoprotective on myocytes after aortic IR.

The effect of ozone treatment on remote organ myocardial injury in an aortic ischemia-reperfusion model.

BACKGROUND: This study aims to investigate the effect of ozone on myocardial ischemia-reperfusion injury occurring after occlusion - reperfusion of infrarenal abdominal aorta in rats. METHODS: Thirty-two Wistar albino rats (weighing 200-250 g) were randomized into four equal groups. The control (sham) group underwent laparotomy and dissection of the infrarenal abdominal aorta without occlusion. Intraperitoneal ozone was applied for 10 days 1 mg/kg/day in the control+ozone group. Afterwards, control+ozone group underwent laparotomy and dissection of the infrarenal abdominal aorta without occlusion. Aortic ischemia-reperfusion and aortic ischemia-reperfusion+ozone groups underwent dissection of the infrarenal abdominal aorta, followed by achieving ischemia and reperfusion by cross-clamping the infrarenal abdominal aorta for 60 minutes and removing the cross-clamp for 60 minutes, respectively. The tissue levels of malondialdehyde and activity levels of superoxide dismutase, catalase, and myeloperoxidase were measured in the myocardial specimens. The tumor necrosis factor, interleukin-6 and troponin-I levels were measured in the plasma. A histopathological examination of the myocardial specimens was undertaken. RESULTS: Biochemical analysis showed that aortic ischemia-reperfusion significantly increased (p<0.05 vs. control) while ozone significantly decreased (p<0.05 vs. aortic ischemia-reperfusion) the myocardial tissue levels of superoxide dismutase and catalase and level of plasma troponin-I. Histologically, in the aortic ischemia-reperfusion group, myocardial disorganization, myofiber swelling and myofiber eosinophilia in the myocardial tissue samples were significantly increased compared to the control group (p<0.05 vs. control). However, histopathological changes in the aortic ischemia-reperfusion+ozone group decreased compared to the aortic ischemia-reperfusion group. CONCLUSION: The results of this experimental study indicate that ozone attenuates myocardial injury and oxidative stress that develop after infrarenal aortic ischemia-reperfusion through three markers; (i) decreased tissue superoxide dismutase and catalase levels, (ii) d ecreased p lasma t roponin-I l evels, a nd (iii) reduced histopathological changes, albeit not statistically significant.

Frequency of development of aspirin resistance in the early postoperative period and inadequate inhibition of thromboxane A2 production after coronary artery bypass surgery.

BACKGROUND: This study aims to investigate the frequency of the development of aspirin resistance, whether or not this resistance was reversible, and to evaluate the efficiency of the mechanism of incomplete inhibition of thromboxane A2 in development of aspirin resistance in the early postoperative period in patients who had undergone coronary artery bypass grafting. METHODS: Eighty patients (55 males, 25 females; mean age 63.1±9.2 years; range 51 to 75 years) who underwent coronary artery bypass grafting between February 2009 and March 2010 at our clinic were prospectively evaluated. Venous blood samples were collected from all patients and evaluated by a platelet function analyzer in the preoperative period and on postoperative days 7 and 15. Aspirin resistance diagnosis was defined as collagen-epinephrine closure time less than 186 seconds. The urine levels of 11-dehidro thromboxane B2 were also measured on postoperative day one. RESULTS: Aspirin resistance was found in 23 patients (28.75%) in the preoperative period, in 31 patients (38.75%) on the postoperative seventh day and in 25 patients (31.25%) on the postoperative 15th day. The urine levels of 11-dehidro thromboxane B2 in patients with aspirin resistance on the postoperative seventh day were significantly higher than those in patients without aspirin resistance (p<0.001). The mean aortic cross-clamping time (p=0.003) and cardiopulmonary bypass time (p=0.029) in the patients with aspirin resistance on the postoperative seventh day were significantly higher than those in patients without aspirin resistance. CONCLUSION: The results of this study suggest that aspirin resistance develops within the first seven days after coronary artery bypass grafting and is highly reversible, and that the mechanism of inadequate inhibition of thromboxane A2 by aspirin has a role in the development of aspirin resistance in the early postoperative period.

Comparison of sharp dissection, electrocautery, and ultrasonic activated scalpel with regard to endothelial damage, preparation time, and postoperative bleeding during radial artery harvesting

Abstract Objective: To examine the effects of classical technique, electrocautery, and ultrasonic dissection on endothelial integrity, function, and preparation time for harvesting the radial artery (RA) during coronary artery bypass grafting (CABG). Methods: Forty-five patients who underwent isolated CABG and whose RA was suitable for use were studied and divided into three groups: Group 1, classical method (using sharp dissection); Group 2, electrocautery; and Group 3, ultrasonic cautery. Levels of prostacyclin and nitric oxide derivatives were examined biochemically; vascular cell adhesion molecule 1 (VCAM-1) and endothelial nitric oxide synthetase (eNOS) values were assessed using immunohistochemical staining. RA preparation time, RA length/harvesting time ratio, and drainage amounts at the site of RA removal were compared. Results: Differences in RA preparation time (Group 1: 25±6 min, Group 2: 18±3 min, Group 3: 16±3 min, P<0.001) and length/harvesting time ratio (Group 1: 0.76±0.19 cm/min, Group 2: 0.98±0.16 cm/min, Group 3: 1.13±0.09 cm/min, P<0.001) were statistically significant among the groups. Levels of prostacyclin and nitric oxide derivatives were not statistically significant different, VCAM-1 and eNOS expressions were observed to be similar among the groups, and endothelial damage was detected in only one patient per group. Conclusion: Use of ultrasonic cautery during RA preparation considerably reduces the preparation time and postoperative drainage amount. However, the superiority of one method over the others could not be demonstrated when the presence of endothelial damage with both biochemical and histopathological evaluations was considered.

Adrenomedullin attenuates aortic cross-clamping-induced myocardial injury in rats.

BACKGROUND: In this study we investigate the effects of adrenomedullin on myocardial injury after ischemia-reperfusion (I/R) after abdominal aortic surgery. METHODS: Thirty-two Wistar rats were randomized into 4 groups (n = 8) as follows: control group (sham laparotomy), the aortic I/R group, aortic I/R plus adrenomedullin group (underwent aortic I/R periods, and received a bolus intravenous injection of .05 µg/kg/min adrenomedullin), and the control plus adrenomedullin group. RESULTS: Biochemical analysis showed that aortic I/R significantly increased (P < .05) the plasma levels of troponin-I and tumor necrosis factor-α, and the myocardial tissue levels of malondialdehyde, superoxide dismutase, catalase, and angiotensin II, whereas aortic I/R plus adrenomedullin significantly decreased these same factors (P < .05). Aortic I/R significantly increased (P < .05) myocardial tissue levels of nitric oxide whereas aortic I/R plus adrenomedullin significantly increased the same factor (P < .05). CONCLUSIONS: These results indicate that adrenomedullin has protective effects against myocardial injury induced by abdominal aortic I/R in rats.

Management of concomitant coronary and bilateral carotid artery disease: a case report.

Patients with severe coexistent coronary and carotid artery stenosis represent a difficult and high-risk population. Herein we describe management of a patient with concomitant coronary artery and bilateral carotid artery disease. Firstly, left carotid artery stenting was done using a self-expandable monorail stent and a neurological protective device. Post-stent angiogram revealed satisfactory dilatation in the left carotid artery. Later, coronary artery bypass grafting to the four coronary arteries was done. Then right carotid endarterectomy was done. He had no neurological complication during or after any of the operation and he remains in good health since his last operation. We think the staged treatment, consisting of carotid artery stenting plus coronary artery bypass grafting plus carotid endarterectomy, in a patient with concomitant severe coronary artery and bilateral carotid artery disease is feasible, safe, and may be an alternative to combined coronary artery bypass grafting plus carotid endarterectomy.