Bahadır Çalışkan

Erdosteine and Ebselen As Useful Agents in Intestinal Ischemia/ Reperfusion Injury

BACKGROUND Reactive oxygen and nitrogen species generated during reperfusion of the tissue are characteristic of ischemia/reperfusion (I/R) injury. The purpose of the present study was to investigate whether erdosteine and ebselen, molecules with antioxidant properties and peroxynitrite scavenging capability, respectively, can reduce oxidative stress and histological damage in the rat small bowel subjected to mesenteric I/R injury. MATERIALS AND METHODS Forty Sprague-Dawley rats were divided into five groups equally: sham, I/R, I/R plus erdosteine, I/R plus ebselen, and I/R plus erdosteine and ebselen. Intestinal ischemia for 45 min and reperfusion for 3 d were carried out. Ileal specimens were obtained to determine the tissue levels of malondialdehide (MDA), protein carbonyl content (PCC), superoxide dismutase (SOD), glutathione peroxidase (GPx), nitrite/nitrate (NO(x)) level and histological changes. RESULTS Intestinal I/R resulted in increased tissue MDA, PCC, and NO(x) levels and decreased SOD and GPx activities. Both erdosteine and ebselen alone significantly decreased MDA, PCC, and NO(x) levels and increased antioxidant enzymes activities, but all values were different from control. These changes almost returned to control values in the group treated with erdostein and ebselen. Histopathologically, the intestinal injury in rats treated with erdosteine and ebselen as well as combination were less than I/R group. CONCLUSIONS Both erdosteine and ebselen were able to attenuate I/R injury of the intestine via inhibition of lipid peroxidation and protein oxidation, maintenance of antioxidant, and free radical scavenger properties. Nevertheless, combination treatment showed more promising results, suggesting that scavenging peroxynitrite nearby antioxidant activity is important in preventing intestinal I/R injury.

Pediatric abdominal masses: diagnostic accuracy of diffusion weighted MRI.

PURPOSE To retrospectively identify apparent diffusion coefficient (ADC) values of pediatric abdominal mass lesions, to determine whether measured ADC of the lesions and signal intensity on diffusion-weighted (DW) images allow discrimination between benign and malignant mass lesions. MATERIALS AND METHODS Approval for this retrospective study was obtained from the institutional review board. Children with abdominal mass lesions, who were examined by DW magnetic resonance imaging (MRI) were included in this study. DW MR images were obtained in the axial plane by using a non breath-hold single-shot spin-echo sequence on a 1.5-T MR scanner. ADCs were calculated for each lesion. ADC values were compared with Mann-Whitney U test. Receiver operating characteristic curve analysis was performed to determine cut-off values for ADC. The results of visual assessment on b800 images and ADC map images were compared with chi-square test. RESULTS Thirty-one abdominal mass lesions (16 benign, 15 malignant) in 26 patients (15 girls, 11 boys, ranging from 2 days to 17 years with 6.9 years mean) underwent MRI. Benign lesions had significantly higher ADC values than malignant ones (P < .001). The mean ADCs of malignant lesions were 0.84 +/- 1.7x10(-3) mm2/s, while the mean ADCs of the benign ones were 2.28 +/- 1.00x10(-3) mm2/s. With respect to cutoff values of ADC: 1.11x10(-3) mm2/s, sensitivity and negative predictive values were 100%, specificity was 78.6% and positive predictive value was 83.3%. For b800 and ADC map images, there were statistically significant differences on visual assessment. All malignant lesions had variable degrees of high signal intensity whereas eight of the 16 benign ones had low signal intensities on b800 images (P < .001). On ADC map images, all malignant lesions were hypointense and most of the benign ones (n=11, 68.7%) were hyperintense (P < .001). CONCLUSION DW imaging can be used for reliable discrimination of benign and malignant pediatric abdominal mass lesions based on considerable differences in the ADC values and signal intensity changes.

Ozone therapy prevents renal inflammation and fibrosis in a rat model of acute pyelonephritis

Abstract Introduction. Not only bacterial characteristics but also oxidative/nitrosative stress could play a significant role in renal parenchymal inflammatory processes in acute pyelonephritis (APN). This study was conducted to evaluate the effect of ozone therapy (OT), as an immunomodulator and antioxidant, on the renal function, morphology and biochemical parameters of oxidative stress in an experimental model of APN in rats. Materials and methods. Forty rats were divided equally into five groups as control, APN, APN + Antibiotic, APN + OT, and APN + Antibiotic + OT. APN was induced by 0.1 ml of freshly prepared Escherichia coli (ATCC 25922) solution containing 1010 colony-forming unit/ml into the kidney. A control group was administered 0.1 ml of 0.9 % NaCl solution. Treatment was begun 72 h after bacterial inoculation. Control and APN groups were given 0.9% NaCl solution, APN + Antibiotic and APN + OT were given either antibiotic (ciprofloxacine 150 mg/kg intramuscular/twice daily) or OT. APN + Antibiotic + OT group was given both antibiotic and OT for five consecutive days. At the end of the seventh day, animals were killed via decapitation and trunk blood was collected. Both kidneys were harvested and one half of each kidney were immediately stored for antioxidant enzyme activity, tissue lipid peroxidation and protein carbonyl content. The remainder was fixed for histopathologic examination. Results. E. coli-induced APN increased the renal glomerular and tubular dysfunction, oxidative stress parameters and antioxidant enzyme activities. Either antibiotherapy or OT markedly ameliorated renal dysfunction, the antioxidant status of the kidneys and histopathological injuries subjected to E. coli-induced APN. Interestingly, the combination of antibiotherapy and OT was much more effective than either of the treatment modalities alone. Conclusion. The combination of antibiotherapy and OT markedly ameliorated renal dysfunction and improved antioxidant status and histopathologic modalities in rats subjected to E. coli-induced APN than either antibiotherapy or OT treatment alone. Therefore, OT may be considered as an adjuvant therapy to classical antibiotherapy to prevent renal inflammation and fibrosis in APN.

Mercaptoethylguanidine attenuates caustic esophageal injury in rats: a role for scavenging of peroxynitrite

INTRODUCTION After ingestion of caustic material, tissue damage is caused by reactive oxygen species and reactive nitrogen species such as peroxynitrite. Mercaptoethylguanidine (MEG) is a well-known scavenger of peroxynitrite. This study was designed to determine whether MEG has a beneficial effect on caustic esophageal injury. MATERIALS AND METHODS Forty-five rats were allocated into 3 groups: sham-operated, untreated, and treated groups. Caustic esophageal burn was created by instilling 15% NaOH in the distal esophagus. The rats were left untreated or treated with 10 mg/kg per day MEG intraperitoneally for 5 days. All rats were killed at 28 days. Efficacy of the treatment was assessed both histopathologically and biochemically. RESULTS Of 15 rats, 6 (40%) died in the untreated group, and only 1 (7%) rat died in the treated group. The stenosis index (SI) and the histopathologic damage score were significantly lower in the MEG treatment group than the untreated group, which showed a correlation with tissue hydroxyproline level. In the untreated group, tissue oxidative stress parameters (malondialdehyde and protein carbonyl content) were significantly higher; and antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase) were significantly lower. Administration of MEG ameliorated oxidative stress parameters and antioxidant enzyme activities. Urinary nitrate and nitrite levels increased in the treated and untreated groups in the first 3 days, suggesting increased nitrosative stress; but at the fourth day, nitrate and nitrite level reached control values in the treated group. CONCLUSION Peroxynitrites play an important role in the healing process of caustic esophagitis. As a peroxynitrites scavenger, MEG potentially might be a useful adjuvant agent in the treatment of esophageal caustic burn by modulating the antioxidant defense mechanism.

Henoch-Schönlein purpura presenting with symptoms mimicking balanoposthitis

Henoch-Schönlein purpura is a leukocytoclastic vasculitis, characterized with palpable purpuric rush and collection of immunglobuline A (Ig A) around small vessels. Onset of purpuric rush at gluteus and lower extremities is the main symptom of the disease, however it presents with a wide variety of signs and symptoms. Here, we present a two-year-old boy who had presented with penile swelling and color change. Then, purpuric rush was occurred and it was seen spontenous resolution on second day without treatment.

Bladder dysfunction in infants with primary vesicoureteric reflux.

There is growing evidence that bladder dysfunction is a negative prognostic factor for spontaneous resolution of vesicoureteric reflux (VUR). This study evaluated the prevalence of urodynamic abnormalities in infants with primary VUR who were referred over a 4-year period. The urodynamic evaluations and medical records of 54 infants with primary VUR (79 ureters with reflux) were reviewed prospectively. Urodynamic dysfunction was observed in 46.3% (n = 25) of infants with primary VUR; 35.2% (n = 19) had a low bladder capacity and 11.1% (n = 6) had a large bladder capacity. All infants with large bladder capacities also had high grade (IV-V) VUR. In conclusion, there was a close relationship between bladder dysfunction and primary VUR. For that reason, urodynamic testing of infants with primary VUR should be performed as part of routine clinical evaluations.

Small intestinal lactoferrin and calprotectin levels in different stages of necrotizing enterocolitis in a rat model

PURPOSE Necrotizing enterocolitis (NEC) is a severe disease of mostly premature infants with high morbidity and mortality rates. There is no reliable biomarker for detecting newborns at risk for NEC development. We aimed to investigate small intestinal lactoferrin (LF) and calprotectin (CAL) levels as predictors and indicators of disease severity in an experimental newborn rat model. MATERIALS AND METHODS Newborn pups were randomly divided into two groups, NEC and control. The NEC group pups were decapitated on the second, third and fourth days of the experiment for an assessment of the different stages of NEC. In the study group, hypoxia-reoxygenation model used to induce NEC. As biochemical parameters, small intestinal LF and CAL levels were measured with an enzyme-linked immunosorbent assay technique and intestinal injury scoring was evaluated as a pathologic parameter. RESULTS Small intestinal levels of both LF and CAL increased in the second and the third day groups, but began to decrease by the fourth day. The first, second and third day levels of LF and CAL were higher than controls. The intestinal injury scores of all NEC groups were significantly higher than the control group. CONCLUSION Small intestinal lactoferrin and calprotectin were good markers for demonstrating NEC. However, instead of spot testing, monitoring the levels of these markers may be more informative.