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Anaesthesia for Caesarean section in the presence of aortic coarctation
(Lippincott Williams & Wilkins, 2002) Togal, T; Durmus, M; Koroglu, A; Demirbilek, S; Karaaslan, K; Ersoy, O
[Abstract Not Available]
Antioxidant properties of propofol and erythropoietin after closed head injury in rats
(Pergamon-Elsevier Science Ltd, 2005) Ozturk, E; Demirbilek, S; But, AK; Saricicek, V; Gulec, M; Akyol, O; Ersoy, MO
Reactive oxygen species play a role during brain injury due to closed head trauma. Enzymatic or nonenzymatic antioxidants may protect brain tissue against oxidative damage. The present study was performed to assess the changes of endogenous indices of oxidative stress in serum from rats subjected to head trauma and whether treatment with propofol and/or erythropoietin (EPO) modifies the levels of endogenous indices of oxidative stress. For these purposes, female Wistar Albino rats were divided into five groups: nontraumatic sham group, trauma performed control, trauma with propofol (i.p.), trauma with EPO (i.p.) and trauma with propofol and EPO performed study groups. At the end of the experimental procedure, blood was taken by cardiac puncture to determine superoxide dismutase (SOD) and xanthine oxidase (XO) activities as well as malondialdehyde (MDA) and nitric oxide (NO) levels in serum. Serum NIDA level of control traumatic brain injury (TBI) group was significantly higher than sham operation group (p < 0.012). Serum NIDA levels in propofol, EPO and propofol+EPO groups were found to be decreased in comparison with control group (p < 0.039, p < 0.030 and p < 0.018, respectively). Serum NO level was found to be increased in TBI group, but difference was not statistically significant when compared to sham-operated group (p=0.092). Propofol, EPO and propofol+EPO administration efficiently reduced serum NO levels to reach sham-operated group (p < 0.002, p < 0.001 and p < 0.015, respectively). These results suggested that acute administration of both propofol and EPO altered the indices of oxidative stress similarly against brain injury due to trauma. (c) 2005 Elsevier Inc. All rights reserved.
Comparison of propofol-alfentanil and propofol-remifentanil anaesthesia in percutaneous nephrolithotripsy
(Cambridge Univ Press, 2005) Cicek, M; Koroglu, A; Demirbilek, S; Teksan, H; Ersoy, MO
Background and objective: Percutaneous nephrolithotripsy (PCNL) is used for the fragmentation and removal of stones from the renal pelvis and renal calyceal systems. We compared the effects of propofol-alfentanil or propofol-remifentanil anaesthesia on haemodynamics, recovery characteristics and postoperative analgesic requirements during percutaneous nephrolithotripsy. Methods: Thirty non-premedicated patients were randomly allocated to receive either propofol-alfentanil (Group A) or propofol-remifentanil (Group R). The loading dose of the study drug was administered over 60 s (alfentanil 10 mu g kg(-1) or remifentanil 1 mu g kg(-1)) followed by a continuous infusion (alfentanil 15 mu g kg(-1) h(-1) or remifentanil 0.15 mu g kg(-1) min(-1)). Propofol was administered until loss of consciousness and maintained with a continuous infusion of 75 mu g kg(-1) min(-1) in both groups. Atracuriurn was given for endotracheal intubation at a dose of 0.5 mg kg(-1) and maintained with a continuous infusion of 0.4 mg kg(-1) h(-1) Mean arterial pressure heart rate, the total amount of propofol, time of recovery of spontaneous ventilation, extubation and eye opening in response to verbal stimulus and analgesic requirement were recorded. Results: In Group A, mean arterial pressure was higher at the first minute in the prone position, and during skin incision and lithotripsy, and heart rate was higher during skin incision and lithotripsy when compared with Group R (P < 0.05). The total amount of propofol did not differ between groups. Time of recovery of spontaneous ventilation, extubation and eye opening were significantly shorter in Group R than Group A (P < 0.05). Conclusions: Both propofol-remifentanil and propofol-alfentanil anaesthesia provided stable haemodynamics during percutaneous nephrolithotripsy, whereas propofol-remifentanil allowed earlier extubation.
Delayed gastric emptying in gastroesophageal reflux disease
(Springer, 2005) Demirbilek, S; Karaman, A; Gürünlüoglu, K; Akin, M; Tas, E; Aksoy, RT; Kekilli, E
The association between gastroesophageal reflux (GER) and intestinal malrotation (IM) has been well described. Delayed or impaired gastric emptying in IM is thought to be a contributing factor in the development of gastroesophageal reflux disease (GERD). The current study assessed the role of malrotation in delayed gastric emptying in children with GERD. We also evaluated the interactions between GERD, malrotation, gastric pH abnormalities, and gastric dysmotility. Sixty-seven patients between 1 and 5 years of age ( mean 3.08 +/- 1.2) and with symptoms of GER, such as emesis, reactive or recurrent lung disease, and/or growth retardation, were studied in 2001 - 2005. Upper and lower gastrointestinal contrast studies were performed for the diagnosis of malrotation. Gastric motility was evaluated with a liquid gastric emptying protocol. GER was documented by upper gastrointestinal studies, scintigraphy, and/or 24- h pH monitoring. In our series of 44 children with GERD, there was an unexpectedly high incidence of IM: 54.5% (24/44). IM has previously been known to occur in 25% of patients with GERD. GERD was found in 24 (82.7%) of 29 patients with IM. Mean nuclear gastric emptying (MNGE) was 51.6 +/- 8.04 min in patients with isolated GERD and 96.6 +/- 20.5 min in children with IM and GERD. There was a statistically significant difference in MNGE time ( p< 0.05) between children with primary GERD and in those with GERD and IM. Esophageal pH monitoring showed that mean fraction time below pH 4 was 7.06 +/- 1.1% in patients with isolated GERD and 14.7 +/- 4.1% in patients with IM and GERD. GERD is common in children between 1 and 5 years old. Using gastric emptying studies and esophageal pH monitoring, we have shown that gastric dysmotility and esophageal pH abnormalities are highly prevalent, especially in children with malrotation compared with children with isolated GERD. These findings suggest that malrotation is an important factor responsible for delayed gastric emptying in GERD. Hence, we recommend that all infants and children with GERD and delayed gastric emptying undergo careful evaluation for malrotation.
Does pneumoperitoneum always require laparotomy?: Report of six cases and review of the literature
(Springer, 2005) Karaman, A; Demirbilek, S; Akin, M; Gürünlüoglu, K; Irsi, C
The presence of intraperitoneal free air signals perforation of a hollow viscus in over 90% of the patients. Rarely, however, the presence of pneumoperitoneum may not indicate an intra-abdominal perforation and thus may not require laparotomy. This condition, which poses a dilemma to the surgeon faced with this problem, is termed nonsurgical, spontaneous or idiopathic pneumoperitoneum. Six cases of nonsurgical pneumoperitoneum admitted over a 2-year period to our institution are reported, and the etiological mechanisms and the pathophysiology of the appearance of intra-abdominal free gas are reviewed. Two of the six children with nonsurgical pneumoperitoneum underwent exploratory laparotomy when clinical examination suggested an acute abdomen; no intra-abdominal pathology was documented in one of these patients. In the other children, malrotation was found. Four patients, on ventilatory support, were managed conservatively after performing a diagnostic peritoneal lavage and/or contrast studies those were negative. An appreciation of the condition and its likely etiological factors should improve awareness and possibly reduce the imperative to perform emergency laparotomy on an otherwise well patient with an unexplained pneumoperitoneum.
Effects of fentanyl on the incidence of emergence agitation in children receiving desflurane or sevoflurane anaesthesia
(Greenwich Medical Media Ltd, 2004) Demirbilek, S; Togal, T; Cicek, M; Aslan, U; Sizanli, E; Ersoy, MO
Background and objective: In children, emergence agitation frequently complicates sevoflurane and desflurane anaesthesia. The effect of intravenous fentanyl 2.5 mug kg(-1) was examined on the incidence of emergence agitation in children who received desflurane or sevoflurane after midazolam premedication and intravenous thiopental induction. Methods: One hundred and twenty children (2-7 yr) undergoing adenoidectomy or tonsillectomy, or both, were studied. All children were premedicated orally with midazolam 0.5 mg kg(-1). After intravenous induction with thiopental and atracurium to facilitate endotracheal intubation, patients were randomly assigned to one of four groups: Patients in Groups I and 3 received physiological saline solution, whereas patients in Groups 2 and 4 received intravenous fentanyl 2.5 mug kg(-1) during induction. Anaesthesia was maintained with sevoflurane in Groups I and 2 and with desflurane in Groups 3 and 4. After discontinuation of the volatile anaesthetic, the times to tracheal extubation and response to verbal stimuli (emergence time), and emergence behaviours were recorded. Results: The time to tracheal extubation was significantly shorter in Groups 3 (5.2 +/- 1.7 min) and 4 (6.4 +/- 2.1 min) than in Groups 1 (8.1 +/- 2.1 min) (P = 0.0001 and 0.006, respectively) and 2 (8.8 +/- 1.9 min) (P = 0.0001). The emergence time was significantly shorter in Group 3 (10.0 +/- 3.9 min) than in Groups 1 (13.8 +/- 4.9 min) (P = 0.017) and 2 (14.9 +/- 4.1 min) (P = 0.003). The incidence rate of severe agitation was 13% in Groups 1 and 3, and 7 and 10% in Groups 2 and 4, respectively (P > 0.05). Conclusions: After midazolam premedication and intravenous induction of anaesthesia with thiopental, administration of intravenous fentanyl 2.5 mug kg(-1) did not provide any clinically significant benefit on emergence agitation in children who receive sevoflurane or desflurane anaesthesia.
The effects of methylene blue on lung injury in septic rats
(Karger, 2006) Demirbilek, S; Sizanli, E; Karadag, N; Karaman, A; Bayraktar, N; Turkmen, E; Ersoy, MO
Purpose: We aimed to investigate the effects of methylene blue (MB) on NO production, myeloperoxidase (MPO) activity, antioxidant status and lipid peroxidation in lung injury during different stages of sepsis in rats. Material and Methods: Rats were randomly divided into 4 groups (n = 20): group C, sham operated; group CMB, sham operated and receiving MB (25 mg/kg, i.p.); group S, sepsis; group SMB, sepsis and receiving MB (25 mg/ kg, i.p.). Sepsis was induced by cecal ligation and puncture (CLP). The MB dose was administered after CLP. Each group was subdivided into two subgroups (n = 10) which were sacrificed at 9 or 18 h after the surgical procedure. The levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX) and MPO activity, total nitrite/nitrate and malondialdehyde (MDA) in the lung tissue were measured. Lung injury was graded from 1 (injury to 25% of the field) to 4 (diffuse injury) by the pathologist. Results: In group SMB, while SOD and CAT increased in both early and late sepsis periods, GSH-PX increased significantly only in the early sepsis period when compared with group S. Increase in lung MPO activity after CLP-induced sepsis was prevented by MB administration. MB significantly decreased to nitrite/nitrate and MDA levels both in early and late sepsis periods when compared with group S (p < 0.05). Group S showed a marked increase in neutrophil infiltration into the interstitial space and thickening of the alveolar septa, whereas the alveolar damage score was lower in the SMB group (p < 0.05). Conclusion: MB reduced the MPO activity and lipid peroxidation by both decreasing oxidative stress and NO overproduction in the lungs, which resulted in the attenuation of lung injury after CLP-induced sepsis in rats. Copyright (c) 2006 S. Karger AG, Basel.
Effects of polyenylphosphatidylcholine on cytokines, nitrite/nitrate levels, antioxidant activity and lipid peroxidation in rats with sepsis
(Springer, 2004) Demirbilek, S; Ersoy, MÖ; Demirbilek, S; Karaman, A; Bayraktar, M; Bayraktar, N
Objectives: To determine the effect of pretreatment with polyenylphosphatidylcholine ( lecithin, PPC) on plasma levels of tumor necrosis factor ( TNF)-alpha, interleukin (IL)-6, IL-10, total nitrite/nitrate (NOx), and tissue levels of superoxide dismutase ( SOD) and malondialdehyde (MDA) in septic rats. Design: Prospective, randomized, controlled animal study. Setting: University laboratory. Subjects: Forty-five Spraque-Dawley rats were divided into three groups: group C, sham-operated; group S, sepsis; and group P, sepsis pretreated with PPC. Interventions: Rats were made septic by cecal ligation and puncture (CLP). Group P rats were treated with PPC ( 100 mg/day orally) for 10 days before sepsis. Twenty-four hours later CLP, plasma concentrations of TNFalpha, IL-6 and IL-10 and plasma levels of NOx were measured. SOD and MDA were determined in liver, lung and heart homogenates. Measurements and main results: All rats in group P survived during the 24-h observation time after CLP, whereas survival rate in group S was 66.7% (10/15; P< 0.05). PPC significantly reduced plasma levels of TNF-alpha (P= 0.006), IL-6 ( P= 0.007), IL-10 ( P= 0.016), NOx ( P< 0.001), and tissue levels of MDA ( P< 0.001) in group P with respect to in group S. Tissue levels of SOD significantly increased in group P when compared with group S ( P< 0.001). Conclusions: These results show that PPC pretreatment exerts cumulative effects in decreasing the levels of cytokines, NOx, and tissue MDA concentrations, with a concomitant increase in survival in septic rats. Lecithin therapy may be a useful adjuvant therapy in controlling of the excessive production of the inflammatory cytokines in patients with severe sepsis. Descriptor: SIRS/sepsis, experimental studies.
The effects of remifentanil and alfentanil-based total intravenous anesthesia (TIVA) on the endocrine response to abdominal hysterectomy
(Elsevier Science Inc, 2004) Demirbilek, S; Ganidagli, S; Aksoy, N; Becerik, C; Baysal, Z
Study Objective: To compare the effects of remifentanil with alfentanil as a part of total intravenous anesthesia (TIVA) on plasma concentrations of cortisol, insulin, and glucose, and hemodynamic responses in patients undergoing abdominal hysterectomy. Design: Randomized, double-blind study. Setting: University hospital. Patients: 24 ASA physical status I female patients scheduled for abdominal hysterectomy. Interventions: Premedicated patients were randomly allocated to receive either remifentanil-propofol (Group R) or a (alfentanil-propofol (Group A). The loading dose of the study drug was administered over 60 seconds (remifentanil l mug kg(-l) or alfentanil 10 mug kg(-l)) followed by a continuous infusion (remifentanil 0.2 mug kg(-l) min(-l) or a fentanil 0.5 mug kg(-l) min). In both groups, propofol was administered until loss of consciousness and maintained with a propofol infusion rate of 100 mug kg(-l) min(-l). After induction of anesthesia, all patients were manually ventilated by mask with O-2-air mixture for 20 minutes. Then rocuronium 0.6 mg kg(-l) was given for tracheal intubation. Measurements: Mean arterial pressure (MAP) and heart rate (HR) were recorded. Plasma concentrations of cortisol, insulin, and glucose were measured during anesthesia and in the recovery room. Main Results: In Group R, MAP and HR were lower after tracheal intubation and skin incision than in Group A (p < 0.05). Plasma cortisol concentrations decreased from baseline values at 20 minutes after induction, after tracheal intubation, and skin incision in Group R (p < 0.001). Plasma concentrations of cortisol and glucose increased from baseline values at 30 minutes after skin incision and continued to increase in both groups (p = 0.001). Plasma concentrations of cortisol, insulin, and glucose did not differ between groups at all sampling times. Conclusion: Remifentanil provided better hemodynamic stability than alfentanil during anesthesia and surgery. However, both remifentanil and alfentanil had similar effects on the stress endocrine response to abdominal hysterectomy. (C) 2004 by Elsevier Inc.
Effects of S(+) ketamine added to bupivacaine for spinal anaesthesia for prostate surgery in elderly patients
(Greenwich Medical Media Ltd, 2004) Togal, T; Demirbilek, S; Koroglu, A; Yapici, E; Ersoy, O
Background and objective: Intrathecal ketamine as the sole anaesthetic agent has demonstrated a lack of cardiovascular depression that should be of advantage in an elderly population. S(+) ketamine has three-times the analgesic potency of R(-) ketamine and its antinociceptive effects after intrathecal administration in rats are known. We decided to evaluate the effects of intrathecal S(+) ketamine added to a small dose of spinal bupivacaine in elderly patients undergoing transurethral prostate surgery. Methods: Forty males over 60 yr old, scheduled for transurethral prostate resection under spinal anaesthesia, were studied in a prospective, double-blinded, randomized way. Patients were allocated to receive either bupivacaine 10 mg or bupivacaine 7.5 mg combined with S(+) ketamine 0.1 mg kg(-1). Spinal block onset time, maximum sensory level, duration of blockade, haemodynamic variables, postoperative analgesic requirements and adverse events were recorded. Results: Onset times of motor and sensory block were shorter in the bupivacaine plus S(+) ketamine group. Incomplete motor block of the lower extremities was seen in 80% of the patients in bupivacaine plus S(+) ketamine group. Duration of complete motor block and spinal analgesia was shorter in the bupivacaine plus S(+) ketamine group. There was no significant difference in arterial pressure. Heart rate decreased after spinal anaesthesia in the bupivacaine plus S(+) ketamine group and was significantly lower until the end of anaesthesia. The incidence of adverse effects was not different between groups. Conclusions: Intrathecal S(+) ketamine administered with a low dose of bupivacaine provides shorter motor and sensory block onset time, shorter duration of action and less motor blockade in elderly males.
Glial cell line-derived neurotrophic factor and synaptophysin expression in pelviureteral junction obstruction
(Elsevier Science Inc, 2006) Demirbilek, S; Edali, MN; Gürünlüoglu, K; Türkmen, E; Tas, E; Karaman, A; Akin, M
Objectives. To examine the expression of neuronal markers in congenital pelviureteral junction (PUJ) obstruction as a causative factor. The findings from some investigations have suggested that defective neuronal innervation may play an important role in the pathogenesis of PUJ obstruction. Methods. Using specific antibodies, we studied the neuronal markers of specimens from 12 cases of PUJ obstruction and 10 normal PUJs by immunohistochemistry using glial cell line-derived neurotrophic factor (GDNF), synaptophysin, S-100, and neurofilament. Results. In the PUJ obstruction specimens, staining with hematoxylin-eosin and Masson's trichrome revealed muscular hypertrophy and an increase in collagen tissue and fibrosis in the lamina propria and tunica muscularis. The most striking finding on immunohistochemistry was the marked nuclear staining of cells with synaptophysin in all layers of the PUJ obstruction specimens that was totally absent in the normal PUJ specimens. In addition, significantly less intense staining for GDNF was found in the PUJ obstruction specimens compared with the normal PUJ specimens. The underexpression of GDNF in PUJ obstruction specimens was localized in the muscular layer especially. Immunohistochemical staining for S-100 and neurofilament showed no differences in the expression level of these neuronal markers in normal and PUJ obstruction specimens. Conclusions. Because GDNF is a survival factor for central and peripheral neurons, defective expression of GDNF could play an important role in the defective neuronal innervation of PUJ obstruction. Intense nuclear expression of synaptophysin in all layers of obstructed PUJ specimens suggested that obstructed PUJs have a serious structural abnormality.
Hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia in coronary artery bypass surgery
(W B Saunders Co-Elsevier Inc, 2005) But, AK; Durmus, M; Toprak, HI; Ozturk, E; Demirbilek, S; Ersoy, MO
Objective: The purpose of this study was to compare the hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia during coronary artery bypass surgery. Design: Prospective study. Setting: University hospital. Participants: Sixty patients undergoing elective coronary artery bypass grafting surgery with ejection fraction more than 45%. Interventions: Anesthesia was induced with etomidate, 0.2 mg/kg, and fentanyl, 5 mu g/kg, in group D (n = 30) and with midazolam, 0.1 to 0.3 mg/kg, and fentanyl, 5 mu g/kg, in group M (n = 30). Anesthesia was maintained with desflurane, 2% to 6%, and fentanyl, 15 to 25 mu g/kg, in group D and midazolam infusion, 0.1 to 0.5 mg/kg/h, and fentanyl, 15 to 25 mu g/kg, in group M. Measurements and Main Results: Hemodynamic monitoring included a 5-lead electrocardiogram, a radial artery catheter, and a pulmonary artery catheter. Data were obtained before induction of anesthesia (t(0)), after induction of anesthesia (t(1)), after intubation (t(2)), after surgical incision (t(3)), after sternotomy (t(4)), before cardiopulmonary bypass (t(5)), after protamine infusion (t(6)), and at the end of the surgery (t(7)). Blood samples were obtained to measure total bilirubin, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase, alkaline phosphatase, creatinine, and blood urea nitrogen just before induction of anesthesia and at the first, fourth, and 14th days postoperatively. Conclusions: Intraoperative hemodynamic responses were similar in both groups, and transient hepatic and renal dysfunctions were observed in the postoperative period in both groups. The extubation and intensive care unit discharge times were found to be shorter in the desflurane-fentanyl group. (c) 2005 Elsevier Inc. All rights reserved.
Polyenylphosphatidylcholine pretreatment protects rat liver from ischemia/reperfusion injury
(Elsevier Ireland Ltd, 2006) Demirbilek, S; Karaman, A; Gürünlüoglu, K; Tas, E; Akin, M; Aksoy, RT; Türkinen, E
Background: Hepatic injury induced by ischemia/reperfusion following surgery, transplantation, or circulatory shock combined with resuscitation is a major clinical problem. Polyenylphosphatidylcholine (PPC) has strong antioxidant, cytoprotective and anti-inflammatory effects. Aim: In this study, the influence of PPC pretreatment on ischemia-reperfusion (I/R) injury of the liver was examined in rats. Methods: The animals were divided into three groups: control (n = 10), I/R (n = 15) and IIR + PPC (n = 15). PPC was given 100 mg/day for 7 days before experiment. Several parameters of hepatic damage, oxidative stress, neutrophil infiltration and nuclear factor kappa beta (NF-kappa B) expression were measured as well as microscopic examination. Results: We observed that a significant reduction in AST and ALT values in the PPC treated group when compared with the ischemic group. The increases in hepatic total NO2 + NO3 and MDA, and decreases in SOD and GSH levels after reperfusion were partially, but significantly, inhibited by PPC pretreatment. I/R induced increase in hepatic myeloperoxidase content and NF-kappa B expression were also lowered by PPC pretreatment. Animals pretreated with PPC presented minimal hemorrhage and reduced signs of liver injury. Conclusion: PPC pretretament provided significant protection againts I/R injury to the liver. This treatment could be therapeutic in liver transplantation and other conditions associated with I/R injury. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
Protective effect of polyunsaturated phosphatidylcholine on liver damage induced by biliary obstruction in rats
(W B Saunders Co-Elsevier Inc, 2003) Karaman, A; Demirbilek, S; Sezgin, N; Gürbüz, N; Gürses, I
Background/Purpose: Persistent inflammatory response secondary to congenital or acquired biliary choleastasis plays an important role in the pathophysiology of hepatic tissue damage. The polyunsaturated fatty acids (PUFA) have been shown to suppress the inflammatory reactions in vivo and in vitro. PUFA has been shown also to protect againts various types of experimental liver damage in animal models and isolated hepatocytes. Therefore, the aim of this study was to investigate the protective effect of PUFA administration on liver damage using the rat chronic biliary obstruction model. Methods: Swiss albino rats of either sex were divided into 4 groups as follows: control group (group 1, 10 rats); rats with sham operation and treated with saline group 2, 10 rats); rats with biliary obstruction (group 3, 15 rats); and polyunsaturated phophatidylcholine (PPC)-treated rats with biliary obstruction (Group 4, 15 rats). Biliary obstruction was induced by double ligation and division of the common bile duct. PUFA treatment was started 2 weeks later from biliary obstruction in doses of 50 mg/d per rat and continued for 2 weeks. All animals were killed after 4 weeks of common bile duct ligation or sham operation. Liver damage and cholestasis were determined by biochemical and histologic examinations. Results: The data showed a decrease in plasma bilirubin level (both conjugated and unconjugated) and liver enzyme levels (AST, ALT, AP, GGT, 5'-NT) in group 4, when compared with group 3 (P < .05). Tissue levels of malondialdehyde (MDA) in group 4 was 20.00 +/- 2.93 compared with that in group 3, 27.12 +/- 2.96 (P < .05). Administration of PUFA to the biliary obstructed rats resulted in inhibition of collagen accumulation (P < .05) and ductal proliferation (P < .05). Conclusions: PUFA reduced liver damage, ductular proliferation, and fibrosis in biliary obstructed rats. These effects suggest that it might be a useful agent to preserve liver function in patients with biliary obstruction such as biliary atresia. (C) 2003 Elsevier Inc. All rights reserved.
Protective effect of polyunsaturated phosphatidylcholine pretreatment on stress ulcer formation in rats
(W B Saunders Co-Elsevier Inc, 2004) Demirbilek, S; Gürses, I; Sezgin, N; Karaman, A; Gürbüz, N
Purpose: The aim of this study was to investigate whether polyunsaturated phosphatidylcholine. (PPC) pretreatment has any protective effect on gastric mucosal damage induced by cold-restraint stress (CRS) in rats. Methods: Forty swiss albino rats were divided into 3 groups. Group 1 (n = 10) was control, group 2 (n = 15) was stress ulcer, and group 3 (n = 15) was PPC-treated rats with stress ulcer. Stress ulcer was induced by the cold-restraint method for 4 hours at 4degreesC after a starvation period of 72 hours. In the group 3 rats, PPC treatment was started 10 days before stress at a dose of 100 mg/d by oral route. Rats were terminated, stomachs were excised. Macroscopic ulcer index (UI), gastric tissue malondialdehyde (MDA) and superoxide dismutase (SOD) activities, plasma total nitrite, and erythrocyte catalase (CAT) concentrations were assayed. Results: Histopathologic examination showed a stress ulcer index of 0.12 +/- 0.19 mm in the treatment group and 23.6 +/- 8.97 mm in the stress ulcer group (P < .001). Tissue MDA and SOD concentrations were higher in the stress ulcer group than in the treatment group, the differences were statistically significant (P < .001). Plasma NO3- + NO2- levels were higher (P < .005) and CAT levels were lower (P < .001) in the nontreatment group. There were no significant differences with respect to UI, MDA, and SOD levels among the control and treatment groups (P > .05). Conclusions: These results suggest that pretreating rats with PPC inhibits cold-restraint stress-induced gastric mucosal injury and might be useful in preventing stress-induced stomach ulcers. (C) 2004 Elsevier Inc. All rights reserved.
Sedative, haemodynamic and respiratory effects of dexmedetomidine in children undergoing magnetic resonance imaging examination: preliminary results
(Elsevier Sci Ltd, 2005) Koroglu, A; Demirbilek, S; Teksan, H; Sagir, O; But, AK; Ersoy, MO
Background. We evaluated the sedative, haemodynamic and respiratory effects of dexmedetomidine and compared them with those of midazolam in children undergoing magnetic resonance imaging (MRI) procedures. Methods. Eighty children aged between 1 and 7 yr were randomly allocated to receive sedation with either dexmedetomidine (group D, n=40) or midazolam (group M, n=40). The loading dose of the study drugs was administered for 10 min (dexmedetomidine 1 mu g kg(-1) or midazolam 0.2 mg kg(-1)) followed by continuous infusion (dexmedetomidine 0.5 mu g kg(-1) h(-1) or midazolam 6 mu g kg(-1) min(-1)). Inadequate sedation was defined as difficulty in completing the procedure because of the child's movement during MRI. The children who were inadequately sedated were given a single dose of rescue midazolam and/or propofol intravenously. Mean arterial pressure (MAP), heart rate (HR), peripheral oxygen saturation (Sp(o2)) and ventilatory frequency (VF) were monitored and recorded during the study. Results. The quality of MRI was significantly better and the rate of adequate sedation was higher in group D than in group M (P < 0.001). In group D, the requirement for rescue drugs was lower and the onset of sedation time was shorter than in group M (P < 0.001). MAP, HR and VF decreased from baseline during sedation in both groups (P < 0.001). Conclusions. Dexmedetomidine provided adequate sedation in most of the children aged 1-7 yr without haemodynamic or respiratory effects during MRI procedures.
Small-dose capsaicin reduces systemic inflammatory responses in septic rats
(Lippincott Williams & Wilkins, 2004) Demirbilek, S; Ersoy, MO; Demirbilek, S; Karaman, A; Gürbüz, N; Bayraktar, N; Bayraktar, M
We investigated the influence of small- and large-dose capsaicin in modulating systemic inflammatory responses during different stages of sepsis in rats. Rats were divided into six groups: group C, control; group S, sepsis; group CLC, small dose of capsaicin (1 mg/kg subcutaneously); group SLC, small dose of capsaicin plus sepsis; group CHC, large dose of capsaicin (150 mg/kg subcutaneously); group SHC, large dose of capsaicin plus sepsis. Rats were made septic by cecal ligation and puncture (CLP). Each group was subdivided into two subgroups. The animals were killed at 9 or 18 h after CLP. Plasma concentrations of calcitonin gene-related peptide (CGRP), tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-10, and total nitrite/nitrate (NOx) were measured. Superoxide dismutase and malondialdehyde (MDA) were determined in liver, lung, and heart tissues. CGRP was increased in groups S, CLC, and SLC when compared with the other groups. In the SLC group, plasma concentrations of TNF-alpha, IL-6, NOx, and tissue MDA levels were reduced and IL-10 level was increased when compared with groups S and SHC 18 h after CLP (P < 0.05). Small-dose capsaicin treatment increased antiinflammatory IL-10 levels and attenuated the increases in proinflammatory cytokines, NOx, and tissue MDA in septic rats.
The use of magnesium to prevent laryngospasm after tonsillectomy and adenoidectomy: a preliminary study
(Blackwell Publishing Ltd, 2003) Gulhas, N; Durmus, M; Demirbilek, S; Togal, T; Ozturk, E; Ersoy, MO
Background : Laryngospasm is the most common cause of upper airway obstruction after tracheal extubation. Magnesium has a central nervous system depressant property, which contributes to the depth of anaesthesia. It also has calcium antagonist properties, which provide muscle relaxation. In this study, we aimed to determine the effect of magnesium on preventing laryngospasm. Methods : After approval of the Ethics Committee and informed parental consent, 40 patients, ASA I-II, aged 3-12 years, who were scheduled for tonsillectomy or/and adenoidectomy, were randomly divided into two groups. Anaesthesia was induced with sevoflurane, lidocaine 1 mg.kg(-1) , alfentanil 10 mug.kg(-1) , vecuronium 0.1 mg.kg(-1) and maintained with sevoflurane 2% and 60% nitrous oxide in oxygen. After intubation, patients in group I received 15 mg.kg(-1) magnesium in 30 ml 0.9% NaCl over 20 min. Patients in group II received 0.9% NaCl alone in the same volume. After reversal of neuromuscular blockade, all patients were extubated at a very deep plane of anaesthesia. The incidence of laryngospasm was determined until the time of discharge from the postanaesthesia care unit. Results : Although laryngospasm was not observed in group I, it was observed in five patients in group II (25%). The incidence of laryngospasm in group II was significantly higher than group I. The plasma magnesium concentrations were significantly higher in group I than group II. Conclusions : We found a significant decrease in the incidence of laryngospasm in paediatric patients receiving magnesium. It is suggested that the use of intravenous magnesium intraoperatively may prevent laryngospasm.
The use of silver nitrate for chemical de-epithelialization and urothelialization of intestine in a rabbit model of augmentation cystoplasty
(Springer, 2003) Demirbilek, S; Uguralp, S; Gürbüz, N; Sezgin, N; Kirimlioglu, H
Urinary tract reconstruction using bowel segments can result in complications such as electrolyte abnormalities, infections, stones and cancer. Intestinal mucosa is the primary site responsible for these complications. De-epithelialization of the mucosa and subsequent urothelialization might alleviate these problems. We recently reported our success in de-epithelialization and subsequent uroepithelialization of intestinal segments using 10 g/100 ml AgNO3 solution in a rat model of augmentation. In this study, chemical de-epithelialization of a colonic segment was attempted using 10 g/100 ml AgNO3 solution in a rabbit model of augmentation. Sigmoid cystoplasty was performed in 20 male New Zealand rabbits using a 6 cm patch of sigmoid colon. There were two groups, including one group of five rabbits (control, group 1) that underwent augmentation alone, while another group (15 rabbits, treatment group or group 2) was treated with 10g/100 ml AgNO3 solution before augmentation. Control rabbits were killed at the week 8 of experimentation. Treatment rabbits were killed at 2-, 4-, 6- and 8-week intervals. Immediately before augmentation and at the end of the 8 week experimental period each rabbit underwent cystometry. De-epithelialization of the bowel epithelium without urothelialization was apparent in the treatment rabbits killed at 2 and 4 weeks. Histological analysis revealed almost complete urothelialization of the augmented sections treated with 10 g/100 ml AgNO3 solution at the end of the 6 and 8 week of experimental periods. The preoperative and postoperative bladder capacities increased substantially in all groups. There was no obvious histologic difference in the amount of collagen present in the augmented tissues in any of the experimental groups. The present study confirmed that the treatment of intestinal segments with 10g/100 ml AgNO3 solution led to chemical de-epithelialization and urothelialization of the augmented segments. This procedure could, theoretically, have applications to human surgery.
Using porcine small intestinal submucosa in intestinal regeneration
(Springer, 2003) Demirbilek, S; Kanmaz, T; Özardali, I; Edali, MN; Yücesan, S
Small intestinal submucosa (SIS) is an unusual tissue that promotes constructive tissue remodeling when applied as a xenogeneic material. The aim of our experimental study was to assess its effectiveness in intestinal regeneration. Twenty white New Zealand rabbits were anesthetized and underwent celiotomy. A 6-cm antimesenteric incision was created at the jejunal segment. An elliptical SIS graft measuring 6 cm long and 2 cm wide was sutured to the jejunal defect as a patch graft. Thirteen living rabbits were divided into groups of three and the grafts were harvested at postoperative weeks 2, 4, and 6. The obtained specimens were evaluated for gross and histologic appearance. In morphometric examination, in the 2, 4, and 6 weeks groups, the diameters of grafted intestines were larger than preoperatively by 50%, 25%, and 25% respectively; also the grafts had contracted to 0%, 25%, and 50% of their original sizes respectively. At the end of 2 weeks, the grafts were intact without evidence of epithelial regeneration. By 4 weeks, intestinal tissue regeneration was started, and epithelial coverage of the grafts was detected. The grafts were covered with a complete intestinal mucosa at 6 weeks. Remarkable regeneration marked fibroplasia, angiogenesis, and mild mononuclear cell infiltration had also occurred throughout the grafts at 6 weeks. Porcine SIS appeared an effective biodegradable scaffold, facilitating regeneration of intestinal tissue. These results suggest that SIS may be useful to increase the mucosal surface of intestine and may provide a new substance for short gut syndrome in the future.

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