Is oxidative stress related to childhood urolithiasis?

Background

Urolithiasis is a common condition in pediatric populations in Turkey. The role of oxidative stress in renal stone formation in pediatric patients has not been reported to date. The aim of this study was to assess oxidative stress in childhood urolithiasis.

Methods

Seventy-four children diagnosed with urolithiasis and 72 healthy control subjects were enrolled in the study. Kidney stone formers were evaluated by analysis of metabolic conditions related to urolithiasis, such as hypercalciuria, hyperoxaluria, hypocitraturia and hyperuricosuria. Urine total antioxidant status (TAS), and total oxidant status (TOS) were measured, and oxidative stress index (OSI) was calculated as an indicator of the degree of oxidative stress.

Results

Among the stone formers, metabolic analyses revealed that 30 % had hypercalciuria, 45 % had hypocitraturia, 6 % had hyperoxaluria and 40 % had hyperuricosuria. Elevated levels of the renal tubular damage marker urinary N-acetyl- beta-d-glucosaminidase (NAG) was elevated in 25 % of the patient group, but microalbuminuria was not detected. Total oxidant status and total antioxidant status were significantly higher in stone formers than in the controls (p?=?0.023 and 0.004, respectively). In addition, urinary NAG was significantly correlated with TOS (r?=?0.427, p?=?0.019).

Conclusions

The results of this study show that oxidative stress may play an important role in the pathogenesis of pediatric stone formers.     

Renal parenchymal thickness in children with solitary functioning kidney

Background

Reduced renal parenchymal thickness (PT) is a parameter used by clinicians to assess the degree of hydronephrosis. In patients with a congenital hydronephrotic solitary functioning kidney (SFK), PT is difficult to determine as there is no comparison with the contralateral kidney. The aim of this study was to obtain ultrasound measurements of PT in children with normal SFK and to compare these data with PT measurements in children with two functioning kidneys.

Methods

This was a prospective multicenter study carried out between 2006 and 2011 in which 236 children aged 11 days to 18.96 years with healthy SFK were examined. The SFK etiologies were unilateral renal agenesis or a nonfunctioning contralateral kidney, mostly due to multicystic dysplasia. In addition to determining other parameters, we measured PT in the middle third of the kidney by ultrasound. Correlations between PT and age, height and weight were assessed.

Results

Correlation analysis showed a positive correlation with renal PT for all parameters. The correlation coefficients for age, height and weight were 0.863, 0.873 and 0.874, respectively. In most age categories, the renal parenchyma was significantly thicker in the SFK than in two functioning kidneys.

Conclusions

Based on our results, we suggest that PT in the SFK is correlated with height, weight and age of the patient. Consequently, measurements of PT may be used for monitoring the development of the healthy SFK and may contribute to a more accurate assessment of the severity of SFK anomalies.     

Urothelial Cancer in Patients with Endemic Balkan Nephropathy (EN) after Renal Transplantation

Goal. Analysis of the incidence of urothelial cancer and outcome of treatment in patients with Endemic Balkan Nephropathy (EN) after renal transplantation. Methods. From January 1985 until October 2006, 550 kidney transplantations (389 cadaveric) and 5 combined kidney and pancreas transplantations were performed in University Hospital Center Rijeka. In only 6 (1.1%) of 555 transplant recipients, EN was diagnosed as the original kidney disease, based on medical history, clinical findings, and laboratory results, but without pathohistologic verification. All patients with EN received the first renal transplant from a cadaver. Patients' mean age at transplantation was 50.3 ±15.9 yrs, five patients (83.3%) were male. The incidence of malignant tumors in all 555 transplant recipients was analyzed, with an emphasis on the incidence of urothelial cancer and outcome of treatment in the group of patients with EN. Results. During posttransplant follow-up period, malignancy was diagnosed in 27 (4.9%) out of 555 transplant recipients. Skin cancer was diagnosed in 7 patients (1.3%), followed by cancer of the urinary tract in 6 patients (1.1%) and breast cancer in 3 patients (0.5%). In 3 of 6 patients with EN, urothelial cancer was diagnosed, resulting in the death in two patients. In the third patient, urothelial cancer showed a high affinity for recurrence, and besides the strong reduction of immunosuppressive therapy, repeated surgical treatment was needed. Conclusions. Patients with EN show a high incidence of urothelial cancer after renal transplantation. A thorough nephro-urological evaluation is needed before transplantation, and a careful follow-up is required afterward to ensure an early diagnosis of malignancy. Preventive nephroureterectomy is recommended.     

创伤及内毒素对大鼠肠屏障功能的损害

目的　探讨创伤合并感染对机体肠屏障功能的损害作用。方法　随机、对照性实验。雄性成年SD大鼠 3 5只 ,分为对照组 (Con)及肠内营养 (EN)、静脉营养 (PN)和脓血症组 (Sep)。后三组做成静脉营养模型 ,施以不同损害刺激。结果　Sep组小肠黏膜损害最重 ,内毒素导致EN、Sep组血浆中一氧化氮升高 ,分别为 10 3 .3 9、113 .3 3 μmol/L ;Sep组小肠通透性和细菌易位率增加 ,分别为 4.0 0 %和 83 .3 3 %。EN组肠屏障损害显著减轻。结论　静脉营养 1周导致大鼠小肠黏膜萎缩 ,肠通透性增加 ;内毒素加重了创伤大鼠肠屏障功能损害 ,可能与体内一氧化氮产生增多有关 ;肠道喂养显著减轻了肠屏障功能损伤     

Comparison of early postoperative enteral nutrients versus chow on colonic anastomotic healing in normal animals

We aimed to clarify the effects of different enteral nutrients (normal chow, complete balanced nutrition, elemental nutrition enriched with glutamine, immune-enhancing diet and fiber) on colonic anastomotic healing in the stress-free metabolic state. The study was carried out with 50 male Balb-C mice in five groups of 10 animals each. After transverse colon anastomosis, animals were fed with early enteral nutrients using normal chow (group 1), Ensure((R)) (group 2), Alitraq((R)) (group 3), Impact((R)) (group 4), and Benefiber Resource((R)) orange juice drink (group 5) for 7 days. There were no significant differences among the groups in bursting pressure (p > 0.05). There was no statistical difference in terms of hydroxyproline level among groups 1-3. The hydroxyproline levels of groups 4 and 5 were statistically higher than that of the control group (p < 0.05 for both comparisons). Under normal conditions without stress, we could not demonstrate the superior effects of early enteral feeding with specialized enteral preparations over normal diets on colonic anastomoses when the bursting pressures were compared.     

Results of intravenous regional anaesthesia with distal forearm application

The aim of this study was to evaluate the clinical effectiveness of distal forearm intravenous regional anaesthesia (IVRA) with the tourniquet applied 3 cm above the wrist. One hundred and twenty patients undergoing out-patient hand surgery were operated for 13 different hand problems under distal forearm IVRA, using 10 ml of a solution containing 1.5 mg/kg prilocaine. Sensory block onset time was 4.5 minutes (3.5-6.5 min.). Mean tourniquet time was 17.6 minutes (range, 7-27.5 min). Mean tourniquet pressure was 240 mmHg (range, 220-270 mm Hg). The mean VAS score for tourniquet pain was 3.8 (range, 2-10). No local or systemic side effects related to the IVRA were observed. The study showed that distal forearm IVRA using 10 ml of a solution containing 1.5 mg/kg prilocaine provides safe, rapid and effective anaesthesia for patients undergoing outpatient hand surgery.     

Dipeptidyl peptidase IV in mammalian lungs

Endothelial cells of the pulmonary circulation are equipped with an ectoenzyme protease system on their luminal surface. The membrane-bound proteases act on the circulating polypeptides and cleave certain peptide bonds in their structure, thus modifying their biological properties. We studied the enzyme dipeptidyl peptidase IV (DP-IV) in mammalian lungs in order to elucidate its contribution to the aforementioned proteolytic processing. We have found that lungs of mammalian species posses DP-IV with different levels of specific activity. In rat lungs the specific activity of DP-IV progressively increased during development between the 18th fetal and the 70th postnatal days. Human embryonal and fetal lungs had significantly higher specific activity of DP-IV compared with the lungs of adult individuals. The enzyme in lungs was mainly membrane bound and was solubilized by some detergents, but not with papain and trypsin. The Triton X-100-solubilized DP-IV from rat lung lysosomal-microsomal membranes migrated during electrophoresis on continuous 4–30% gradient polyacrylamide gel at native apparent M_r values of 260 000 and 490 000. Using a histochemical technique we found the enzyme activity of DP-IV in the capillary bed of the lung alveolar septa only. Four aminoacyl-L-proline-4-nitroanilide substrates for DP-IV were cleaved rapidly during one passage through isolated perfused blood-free rat lungs. The perfusion profiles of cleavage of these substrates were largely coincident with that of Blue Dextran 2 000, a compound, which is unlikely to leave the intravascular space. Taken together, the data suggest that DP-IV operates in vivo as a membrane-bound ectoenzyme on the luminal surface of pulmonary endothelial cells and that it may cleave certain circulating polypeptides.