Ugur Uyeturk

Does the Hounsfield Unit Value Determined by Computed Tomography Predict the Outcome of Percutaneous Nephrolithotomy

PURPOSE We aimed to evaluate whether the Hounsfield unit (HU) value predicts outcome in percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS One hundred and seventy-nine patients who had undergone PCNL in our clinics in the last 4 years were included. Demographic and clinical data of the patients and complications, if any, were recorded. The mean age of the patients was 45.3 ± 14.3 years (range 5-82 y), and 111 of them were males (62%). The mean stone size and HU values were found to be 693.1 ± 628.0 (95-4200) mm(2) and 706.3 ± 245.0 (214-1325), respectively. RESULTS In logistic regression analysis, the size of the stone, the opacity of the stone, and the HU values were found to be independent predictors of the failure of the procedure (P<0.05). A cutoff value of 677.5 was used for the HU in the receiver operating characteristics analysis. Having a HU value under the cutoff value increased the likelihood of procedure failure by 2.65 times, whereas stones residing in the staghorn localization increased failure by 5.68. It was also observed that if the stones size was 485 mm(2) or more, the chance of failure increased by 1.9, whereas when the stone was nonopaque, failure increased by 6.04 times (P<0.05). There was a positive correlation between hematocrit decrease and a decrease in HU values (P<0.05), but no correlation was observed between the HU values and duration of surgery or fluoroscopy (P>0.05). CONCLUSION In addition to the size and location of the stones, the HU value determined in the unenhanced CT scan may be one of the parameters affecting PCNL outcomes. PCNL is a more efficient method in stones with higher HU values. Therefore, the HU values may be a useful tool for the selection of the treatment modality in patients with renal stones.

Usefulness of hounsfield unit and density in the assessment and treatment of urinary stones

Computed tomography (CT) is widely used to examine stones in the urinary system. In addition to the size and location of the stone and the overall health of the kidney, CT can also assess the density of the stone in Hounsfield units (HU). The HU, or Hounsfield density, measured by CT, is related to the density of the tissue or stone. A number of studies have assessed the use of HU in urology. HUs have been used to predict the type and opacity of stones during diagnosis, and the efficacy has been assessed using methods including extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), ureterorenoscopic ureterolithotripsy (URSL), and medical expulsive treatment (MET). Previous studies have focused on the success rate of HU for predicting the type of stone and of ESWL treatment. Understanding the composition of the stone plays a key role in determining the most appropriate treatment modality. The most recent reports have suggested that the HU value and its variants facilitate prediction of stone composition. However, the inclusion of data regarding urine, such as pH and presence of crystals, increases the predictive accuracy. HUs, which now form part of the clinical guidelines, allow us to predict the success of ESWL; therefore, they should be taken into account when ESWL is considered as a treatment option. However, there are currently insufficient data available regarding the value of HU for assessing the efficacy of PCNL, URSL, and MET. Studies performed to date suggest that these values would make a significant contribution to the diagnosis and treatment of urinary system stones. However, more data are required to assess this further.

Does the kidney injury molecule-1 predict cisplatin-induced kidney injury in early stage?

Background It is not possible to diagnose acute kidney injury (AKI) in early stages with traditional biomarkers. Kidney injury molecule-1 (KIM-1) is a novel biomarker promising the diagnosis of AKI in early stages. We studied whether urinary and serum KIM-1 (KIM-1 U and KIM-1 S ) concentrations were useful in predicting cisplatin-induced AKI in early stages. Methods We prospectively analysed 22 patients on cisplatin treatment. KIM-1 S and KIM-1 U concentrations were assessed in the samples of the patients on four different time periods (before treatment [BT], first [AT1], third [AT3] and fifth [AT5] day after treatment). Results KIM-1 U concentrations on the first day after cisplatin treatment in patients with AKI were significantly increased compared to both KIM-1 U concentrations of the same patients BT (P = 0.009) and to AT1-KIM-1 U concentrations of the patients without AKI (P = 0.008). A receiver operating characteristic analysis revealed that AT1-KIM-1 U concentrations may predict AKI with an 87.5% sensitivity and 93.3% specificity (area under the curve = 0.94). KIM-1 S concentrations were not significantly changed between BT and AT periods. Conclusions KIM-1 U concentrations may predict cisplatin-induced AKI in early stages with high sensitivity and specificity.

Routine Flexible Nephroscopy for Percutaneous Nephrolithotomy for Renal Stones with Low Density: A Prospective, Randomized Study

PURPOSE We evaluated the usefulness of routine flexible nephroscopy during percutaneous nephrolithotomy. MATERIALS AND METHODS Patients diagnosed with kidney stones who were scheduled to undergo percutaneous nephrolithotomy between March 2011 and July 2012 were randomized into 2 groups. Group 1 underwent standard percutaneous nephrolithotomy using rigid nephroscopy. Group 2 underwent flexible nephroscopy, in addition to standard percutaneous nephrolithotomy and laser lithotripsy or basket catheter stone extraction, as needed. Surgery was performed subcostally and with minimal percutaneous access in group 2 to use the advantages of flexible nephroscopy. We compared the 2 groups in terms of preoperative stone characteristics and postoperative success criteria, including the stone-free rate, bleeding, number of access sites, etc. RESULTS The study included 61 males (76.3%) and 19 females (23.8%) with a mean ± SD age of 43.75 ± 12.4 years (range 19 to 74). There was no significant difference in stone size, HU density or stone location between the 2 groups. Comparison of perioperative and postoperative parameters revealed a higher stone-free rate (92.5% vs 70%), fewer access sites and a lower hematocrit decrease in group 2. The stone-free rate was higher in patients with stones with a density of less than 677.5 HU (100% in group 2 vs 64.7% in group 1). CONCLUSIONS Routine flexible nephroscopy during percutaneous nephrolithotomy was associated with a higher stone-free rate, fewer interventions and less bleeding, especially in patients with low HU density stones.

Neutrophil-lymphocyte ratio as a predictor of recurrence and progression in patients with high-grade pT1 bladder cancer.

INTRODUCTION We investigated the value of the preoperative neutrophil-lymphocyte ratio (NLR) in predicting recurrence and progression of high-grade pT1 non-muscle-invasive tumour in patients with bladder cancer during a 5-year follow-up period. METHODS We retrospectively reviewed data of 1100 patients with bladder cancer; these patients underwent transurethral resection and were monitored at multiple centres from 2008 to 2013. In total, 166 consecutive and newly diagnosed patients with high-grade pT1 tumours were included in this study. The NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. RESULTS Of the 166 patients, 152 were male. The patients were evaluated as two separate groups in terms of recurrence and progression. The mean follow-up period was 24.2 months (interquartile range 13.8-36.6 months). A statistically significant difference was found between recurrence and tumour size (p = 0.001), number of tumours (p < 0.001), NLR (p < 0.001), and smoking (p = 0.007). No statistically significant correlation was found between NLR and progression. According to receiver operating characteristic (ROC) analysis, the optimum cut-off value for the NLR was ≥2.43 (74% sensitivity, 60% specificity, p < 0.001; area under the curve [AUC] 0.687, 95% confidence interval [CI] 0.607-0.767). Multivariate logistic regression analysis determined that the following factors were independent predictors of recurrence in patients with high-grade pT1 non-muscle-invasive bladder cancer: tumour number (OR 5.32, 95% CI 2.10-12.90), NLR of ≥2.43 (OR 2.587; 95% CI 1.156-5.789), and smoking (OR 4.17, 95% CI 1.31-13.21). CONCLUSION A high preoperative NLR may play an important role in predicting recurrence of superficial transitional cell type high-grade pT1 bladder tumours. Prospective studies are required to validate the role of NLR as a prognostic marker in high-grade pT1 bladder tumours.

Protective Effects of N-Acetylcysteine on Experimentally Undescended Testis

PURPOSE We evaluated the efficacy of N-acetylcysteine for testicular damage induced by undescended testes in rats. MATERIALS AND METHODS Flutamide was injected in the abdomen of pregnant rats daily from days 14 to 20 of gestation. Male offspring with cryptorchidism were randomly divided into 2 groups. Healthy male rats without undescended testes comprised the control group (group 1). Group 2 (undescended testes without N-acetylcysteine) received no treatment. Group 3 (undescended testes plus N-acetylcysteine) received intraperitoneal N-acetylcysteine daily. At 70 days after experiment initiation the testes were removed for histopathological and biochemical analysis. RESULTS Mean malonyl dialdehyde values were lowest in group 1 and highest in group 2. In group 3 malonyl dialdehyde levels were significantly lower than in group 2 (p <0.001). Conversely, mean glutathione peroxidase was highest in group 1 and lowest in group 2. Glutathione peroxidase levels in group 3 were significantly higher than in group 2 (p <0.001). Histopathological differences between groups 1 and 3 in the modified Johnsen score were not significant (p = 0.041). However, the differences between these groups and group 2 were significant (p <0.001). The median apoptotic cell count did not differ between groups 1 and 3 but it was significantly higher in group 2 than in the other groups (p = 0.03 and <0.001, respectively). CONCLUSIONS N-acetylcysteine may alleviate undescended testis induced damage to testes through its antioxidant effects. The underlying mechanism of these effects merits further investigation. Long-term studies are also needed as well as comparative animal and human studies.

Protective Effects of Rosmarinic Acid on Doxorubicin-Induced Testicular Damage

Background: We investigated the protective effects of rosmarinic acid (RA) on testicular damage induced by doxorubicin (DXR) in rats. Methods: In total, 21 rats were divided into 3 groups: the control group that received no treatment, the DXR group that received intraperitoneal (i.p.) DXR on day 7 and the DXR + RA group that received intragastric RA for 10 days with i.p. DXR on day 7. The rats were sacrificed on day 11 for histological and biochemical analyses. To assess oxidative damage, glutathione peroxidase (GPx) and malondialdehyde (MDA) levels were measured. Results: The median modified Johnsen score of the DXR + RA group was higher than that of the DXR group (p = 0.002). The rats with the narrowest seminiferous tubules were in the DXR group (0.17 ± 0.03), and the difference between the DXR + RA and DXR groups was statistically significant (p = 0.002). The number of apoptotic cells in the DXR group was significantly higher than that in the control group, and there were significantly fewer apoptotic cells in the DXR + RA group than in the DXR group (p = 0.002). The MDA level was lowest in the control group and highest in the DXR group, and the level observed in the DXR + RA group significantly lower than that in the DXR group (p = 0.002). The GPx level was highest in the control group, with the level observed in the DXR + RA group significantly higher than that in the DXR group (p = 0.002). The testosterone level was lowest in the DXR group and highest in the control group, and that observed in the DXR + RA group was significantly higher than that in the DXR group (p = 0.018). Conclusions: RA can correct DXR-induced testicular damage through its antioxidant properties. However, the mechanism underlying the effects of RA requires further investigation, and long-term and comparative human studies are also needed.

The role of the uncertainty of measurement of serum creatinine concentrations in the diagnosis of acute kidney injury.

Abstract Uncertainty of measurement is the numeric expression of the errors associated with all measurements taken in clinical laboratories. Serum creatinine concentration is the most common diagnostic marker for acute kidney injury. The goal of this study was to determine the effect of the uncertainty of measurement of serum creatinine concentrations on the diagnosis of acute kidney injury. We calculated the uncertainty of measurement of serum creatinine according to the Nordtest Guide. Retrospectively, we identified 289 patients who were evaluated for acute kidney injury. Of the total patient pool, 233 were diagnosed with acute kidney injury using the AKIN classification scheme and then were compared using statistical analysis. We determined nine probabilities of the uncertainty of measurement of serum creatinine concentrations. There was a statistically significant difference in the number of patients diagnosed with acute kidney injury when uncertainty of measurement was taken into consideration (first probability compared to the fifth p = 0.023 and first probability compared to the ninth p = 0.012). We found that the uncertainty of measurement for serum creatinine concentrations was an important factor for correctly diagnosing acute kidney injury. In addition, based on the AKIN classification scheme, minimizing the total allowable error levels for serum creatinine concentrations is necessary for the accurate diagnosis of acute kidney injury by clinicians.

An experimental study on effects of pyrrolidine dithiocarbamate on ischemia-reperfusion injury in testis

INTRODUCTION The aim of this experimental study was to investigate the histopathological and biochemical effects of pyrrolidine dithiocarbamate, an antioxidant and inhibitor of NF-kβ, on ischemiareperfusion injury in rats. METHODS A total of 21 male Wistar-Albino rats were randomly distributed into three groups as sham group (Group 1), ischemia-reperfusion (I/R) group (Group 2) and I/R with pyrrolidine dithiocarbamate (PDTC) group (Group 3). Left testicles of rats in Groups 2 and 3 underwent testicular torsion of 720° for four hours and 100 mg/kg of PDTC was administered intraperitoneally prior to detorsion in Group 3. An hour after detorsion process, left orchiectomies were performed and 5 ml of intracardiac blood samples were drawn from rats in all three groups. Histopathological examination of testis tissues performed and measurement of superoxide dismutase (SOD) and malondialdehyde (MDA) levels in blood samples were taken. RESULTS Elevated levels of MDA and decreased SOD activity, together with decreased Johnson tubular biopsy scores consistent with I/R injury were observed in Group 2 (p<0.05). Group 1 and Group 3 were similar in terms of MDA levels, SOD activity, and Johnson scores (p>0.05). CONCLUSIONS Our results indicated that PDTC may have beneficial effects for alleviation of I/R injury in testicular tissue in rats. Understanding the underlying mechanisms and exploration of its diagnostic and therapeutic potential requires further randomized, controlled trials on a larger scale.

Alleviation of kidney damage induced by unilateral ureter obstruction in rats by Rhodiola rosea.

PURPOSE To evaluate the efficacy of Rhodiola rosea extract in terms of alleviating the renal damage induced by unilateral ureter obstruction (UUO) in rats. MATERIAL AND METHODS Thirty Wistar albino male rats were divided into five groups: (I) Control, (II) UUO 7 days, (III) UUO 7 days+extract,(IV) UUO 14 days, and (V) UUO 14 days+extract. Seven or 14 days after the initiation of the experimental procedure, the left kidneys of rats in all five groups were removed for histological examination, and their blood was drawn for biochemical measurements. RESULT Median malondialdehyde (MDA) and glutathione peroxidase (GPx) levels were, respectively, 39.4 (5.04) nmol/mL and 25.8 (8.01) nmol/minute/mL in group I, 77.9 (12.38) nmol/mL and 5.8 (1.95) nmol/minute/mL in group II, 48.7 (12.1) nmol/mL and 9.1 (2.3) nmol/minute/mL in group III, 58.5 (23.83) nmol/mL and 8.4 (2.1) nmol/minute/mL in group IV, and 44.8 (4.97) nmol/mL and 13.8 (3.73) nmol/minute/mL in group V. There was a statistically significant difference among the groups in terms of MDA and GPx levels (p<0.05 for both). The median numbers of apoptotic cells were 1 (1), 8 (2.25), 3 (1.25), 23.5 (9), and 7 (I) in groups I, II, III, IV, and V, respectively. There was a statistically siginificant difference among the groups in terms of apoptotic cell number (p<0.05). CONCLUSION R. rosea extract was shown to alleviate the renal damage induced by UUO through its antioxidant effects. The mechanism by which R. rosea extract causes these effects merits further investigation.