Halil Tugtepe

The protective effect of oxytocin on renal ischemia/reperfusion injury in rats

AIM Oxytocin was previously shown to have anti-inflammatory effects in different inflammation models. The major objective of the present study was to evaluate the protective role of oxytocin (OT) in protecting the kidney against ischemia/reperfusion (I/R) injury. MATERIALS AND METHODS Male Wistar albino rats (250-300 g) were unilaterally nephrectomized, and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. OT (1 mg/kg, ip) or vehicle was administered 15 min prior to ischemia and was repeated immediately before the reperfusion period. At the end of the reperfusion period, rats were decapitated and kidney samples were taken for histological examination or determination of malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Creatinine and urea concentrations in blood were measured for the evaluation of renal function, while TNF-alpha and lactate dehydrogenase (LDH) levels were determined to evaluate generalized tissue damage. Formation of reactive oxygen species in renal tissue samples was monitored by chemiluminescence technique using luminol and lucigenin probes. RESULTS The results revealed that I/R injury increased (p<0.01-0.001) serum urea, creatinine, TNF-alpha and LDH levels, as well as MDA, MPO and reactive oxygen radical levels in the renal tissue, while decreasing renal GSH content. However, alterations in these biochemical and histopathological indices due to I/R injury were attenuated by OT treatment (p<0.05-0.001). CONCLUSIONS Since OT administration improved renal function and microscopic damage, along with the alleviation of oxidant tissue responses, it appears that oxytocin protects renal tissue against I/R-induced oxidative damage.

Foreign body aspiration in children: The value of diagnostic criteria

OBJECTIVE Foreign body aspiration (FBA) is a serious problem in children. While bronchoscopy should be performed in all patients with aspiration; patients without aspiration should be carefully excluded to avoid an unnecessary bronchoscopy. In this study we analyzed the details of our series, complication rates and compared the diagnostic findings between patients with an aspirated FB and those without. We also calculated the sensitivities, specificities, positive predictive values and negative predictive values of clinical history, symptoms, physical examination findings and radiological findings in patients with suspected FBA (sFBA). Finally, we evaluated the validity of our bronchoscopy indications in these patients. METHODS We reviewed the data of 207 patients who underwent rigid bronchoscopy for sFBA. We used clinical history, symptoms, physical examination and radiological findings as diagnostic findings. Complication rates in addition to these four diagnostic criteria constitute our indications for performing a rigid bronchoscopy. RESULTS After excluding 15 patients with radiopaque FB or previous fiberoptic bronchoscopy, 138 of 192 patients had an aspirated foreign body. The sensitivity and specificity of clinical history, symptoms, physical examination findings and radiological findings were 90.5% and 24.1%, 97.8% and 7.4%, 96.4% and 46.3, and 71.7% and 74.1% respectively. There was only one major complication which caused moderate neurological sequelae. There was no mortality and no thoracotomy or tracheotomy requirement in this group. CONCLUSIONS While symptoms, physical examination findings and clinical history had high sensitivities, radiological findings had the highest specificity. Low specificities of clinical history, symptoms and physical examination findings were due to our expanded bronchoscopy indication, which aimed to include all patients with foreign body aspiration. Our low complication rate facilitated the expansion of bronchoscopy indications, even for patients with slight clinical suspicion.

Oxytocin alleviates oxidative renal injury in pyelonephritic rats via a neutrophil-dependent mechanism

BACKGROUND Urinary tract infection (UTI) may cause inflammation of the renal parenchyma and may lead to impairment in renal function and scar formation. Oxidant injury and reactive oxygen species (ROS) have been found responsible in the pathogenesis of UTI. The neurohypophyseal hormone oxytocin (OT) facilitates wound healing and is involved in the modulation of immune and inflammatory processes. We investigated the possible therapeutic effects of OT against Escherichia coli induced pyelonephritis in rats both in the acute and chronic setting. METHODS Twenty-four Wistar rats were injected 0.1 ml solution containing E. coli ATCC 25922 10(10) colony forming units/ml into left renal medullae. Six rats were designed as sham group and were given 0.1 ml 0.9% NaCl. Pyelonephritic rats were treated with either saline or OT immediately after surgery and at daily intervals. Half of the pyelonephritic rats were decapitated at the 24th hour of E. coli infection, and the rest were followed for 7 days. Renal function tests (urea, creatinine), systemic inflammation markers [lactate dehydrogenase (LDH) and tumor necrosis factor alpha (TNF-alpha)] and renal tissue malondialdehyde (MDA) as an end product of lipid peroxidation, glutathione (GSH) as an antioxidant parameter and myeloperoxidase (MPO) as an indirect index of neutrophil infiltration were studied. RESULTS Blood urea, creatinine, and TNF-alpha levels were increased, renal tissue MDA and MPO levels were elevated and GSH levels were decreased in both of the pyelonephritic (acute and chronic) rats. All of these parameters and elevation of LDH at the late phase were all reversed to normal levels by OT treatment. CONCLUSION OT alleviates oxidant renal injury in pyelonephritic rats by its anti-oxidant actions and by preventing free radical damaging cascades that involves excessive infiltration of neutrophils.

Melatonin prevents neutrophil‐mediated oxidative injury in Escherichia coli‐induced pyelonephritis in rats

Abstract:  Regarding the mechanisms of renal scarring in pyelonephritis, several hypotheses have been put forward, among which oxidative stress is prominent. The present study investigated the possible protective effect of melatonin treatment against Escherichia coli‐induced oxidative injury and scarring in renal tissue. For this purpose, 0.1 mL E. coli (ATCC 25922; 1010 colony‐forming units/mL) or saline was injected directly into the renal parenchyma of Wistar rats. Pyelonephritic rats were treated with either saline or melatonin (10 mg/kg) intraperitoneally. Twenty‐four hours or 1 wk after E. Coli injection, rats were decapitated and trunk blood samples were collected for BUN, creatinine, tumor necrosis factor‐α (TNF‐α) and lactate dehydrogenase (LDH) determination. In kidney samples, histological analysis was performed, and malondialdehyde (MDA), glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents were measured. Formation of reactive oxygen species was monitored using a chemiluminescence (CL) technique. Escherichia Coli inoculation caused a significant reduction in renal GSH levels, which was accompanied by significant increases in MDA levels, MPO activity, CL levels and collagen content of the renal tissues (P < 0.05–0.001). Similarly, serum TNF‐α and, LDH, BUN and creatinine levels were elevated in the pyelonephritic rats when compared with control animals. Melatonin treatment reversed all these biochemical indices, as well as histopathological alterations induced by acute pyelonephritis. The protective effects of melatonin can be ascribed to its ability to inhibit neutrophil infiltration, to balance the oxidant–antioxidant status, and to regulate the generation of inflammatory mediators, suggesting a future role for melatonin in the treatment of acute pyelonephritis.

Contradictory supranormal function in hydronephrotic kidneys: fact or artifact on pediatric MAG-3 renal scans?

Objectives: Contradictory supranormal renal function (SRF) in unilateral hydronephrosis is a debatable subject resulting from the methodology of nuclear renography or the characteristics of the patient. In this study, we aimed to investigate the frequency and comparison of SRF with MAG-3 scans by 8 different technical analyses in pediatric hydronephrosis. Methods: We reviewed Tc-99m MAG-3 scans in 82 children with unilateral hydronephrosis (52 male, 30 female, mean age: 47.7 ± 64.5 months). Of 82, 34 also had Tc-99m DMSA scans. Data were reprocessed with 4 different regions of background activity (subrenal, perirenal C-type, perirenal ring, and lateral) at 2 different time intervals (1–2 and 2–3 minute), and 8 different estimates of MAG-3 differential renal function (DRF) were obtained in 67 patients. SRF was defined as DRF greater than 55% in the hydronephrotic kidney. Results: The routine processing protocol showed only 3 renal units with SRF, and all were on the right side (3.6%). After reprocessing, a total of 10 dilated kidneys had SRF in 1 or more of DRF estimates (5.2% of all estimations). These cases were significantly younger (8.1 ± 6.7 vs. 42.5 ± 52.5, P < 0.05) and had a larger renal area ratio (1.25 ± .24 vs. 1.07 ± .21, P < 0.05). There was no SRF with DMSA. In comparison between MAG-3 and DMSA DRF in 20 children who underwent both tests within 3 months, the best correlation was obtained when C-type correction was used for both agents at 2 time intervals (r: .86 and .84 for early and late time intervals, P < 0.00001, respectively). Conclusions: SRF in unilateral hydronephrosis is, at least, in part, technical in origin in this particular pediatric patient population with tubular immaturity (ie, physiological high background activity) and asymmetric kidney size.

False positivity of FDG-PET/CT in a child with Hodgkin disease

Role of Positron Emission Tomography (PET) with F‐18‐2‐fluoro‐2‐deoxy‐D‐glucose (FDG) in staging of Hodgkin disease is well established despite several controversies. We report a Stage III Hodgkin lymphoma patient with false positive FDG‐PET/CT results. Seven‐year‐old male with Hodgkin lymphoma was in remission at end of chemotherapy. At third and fourth month of postchemotherapy follow‐up, increased Gallium uptake and positive FDG‐PET/CT in right lower quadrant of abdomen was observed. Open biopsy revealed lymphoid hyperplasia. He has been followed for 21 months without any evidence of disease. Despite its documented benefit, we believe that results of FDG‐PET/CT should be interpreted with great caution in order to avoid unnecessary interventions. Pediatr Blood Cancer 2008;50:881–883.

Histologic Changes in Eustachian Tube Mucosa of Rats After Exposure to Gastric Reflux

Objective: Reflux is thought to be a risk factor for middle ear disease, but the mechanism underlying this relationship is unclear. In this study, we evaluated the effects of reflux on the eustachian tube (ET) mucosa.

Collagen Ultrastructure and TGF-β1 Expression Preserved with Aminoguanidine During Wound Healing in Diabetic Rats

Advanced glycoxidation end products have been implicated in delayed diabetic wound healing. In this study, we evaluated the effects of aminoguanidine, which is an advanced glycation and nitric oxide (NO) synthase inhibitor, on extracellular matrix protein expression, collagen configuration, and nitrite/nitrate levels in wounds of diabetic rats. Sixteen Wistar male rats were made diabetic by streptozotocin. Of these, eight rats were given AG (aminoguanidine bicarbonate (AG) (group DAG) in their drinking water, and eight rats were followed as diabetic paired controls (group D). Eight healthy rats were followed as the healthy control group (group H). At the eighth week, a 2 × 2 cm area full-thickness skin defect was created. The degree of contraction of the open wounds was evaluated for 2 weeks duration. On the 15th postoperative day, wound surface areas were measured, and wound specimens and blood samples were collected. The shrinking percentage of the wounds was small in both groups H and DAG compared with group D (p < 0.05). Similar to healthy rats, the aminoguanidine-treated diabetic rats had very strong transforming growth factor (TGF)-β1 expression in granulation tissue and intact skin in comparison with diabetic controls. In the diabetic group, the intact skin demonstrated sparsely distributed regular collagen fibers in the granulation zone, and the regular pattern of collagen fibers was lost. In conclusion, aminoguanidine improves wound healing, restores growth factor TGF-β1 expression, and preserves collagen ultra structure, whereas it has no prominent effect on NO levels within wound tissue in diabetic rats.

The Effect of Untethering on Urologic Symptoms and Urodynamic Parameters in Children With Primary Tethered Cord Syndrome

OBJECTIVE To evaluate urinary system symptoms (USSs) and urodynamic parameters (UPs) before and after untethering in children with primary tethered cord syndrome (pTCS). METHODS USSs and UPs of patients undergoing untethering for pTCS during the period January 2008-July 2012 were evaluated preoperatively and at the postoperative third and 12th months. For analysis, patients were separated into 4 groups according to the presence of USSs: group 1, USSs preoperative positive and postoperative negative; group 2, USSs preoperative positive and postoperative positive; group 3, USSs preoperative negative and postoperative positive; group 4, USSs preoperative negative and postoperative negative. Preoperative and postoperative USSs and UPs were compared. RESULTS Forty patients (average age, 7.2 years, follow-up of 2.8 years) were included. There were 13 patients in group 1, 11 in group 2, 3 in group 3, and 13 in group 4. All patients showed improvement when preoperative and postoperative USSs and UPs were compared. There was no correlation between USSs and UPs, both preoperatively and postoperatively. USSs and UPs at the postoperative third and 12th months were similar. Patients with no USS showed the most significant improvement in UP after untethering. CONCLUSION Our study has demonstrated that untethering in patients with pTCS improves urologic symptoms and UPs. However, there is no correlation between improvement in symptoms and urodynamic findings. Urodynamic changes are similar at the postoperative third and 12th months. As the most significant improvement was seen in patients without USSs, it is important that these patients undergo urodynamic studies preoperatively and postoperatively.

The effect of dorsal dartos flaps on complication rates in hypospadias repair: A randomised prospective study

AIM This study prospectively analysed the effect of using a dartos flap on the complication rates of TIPU (tubularised incised plate urethroplasty) in hypospadias repair. MATERIAL AND METHODS Patients having TIPU repair for hypospadias at our university hospital between January 2010 and August 2013 were prospectively divided into two groups. Group 1 had TIPU repair with dorsal dartos flap, whereas group 2 had flapless repair. At the end of the follow-up period (mean 23.3 m, median 20.2), complication rates were compared between two groups. RESULTS There were 107 patients in each group. The overall complication rate was 9.3%. The complication rates were 12.1% in group 1 (6 glans dehiscence and 7 fistula) and 6.5% in group 2 (2 glans dehiscence and 5 fistula). The differences between complication rates and fistula were statistically insignificant (p = 0.2511 and p = 0.7710, respectively). CONCLUSION Our prospective and randomised study found that the use of dartos flaps in hypospadias offers no statistically significant advantage over flapless repair for complication rates.