1400 | Department of Pediatrics and Nephrology, Medical University of Bialystok, Białystok, Poland. Corresponding Author: Agata Korzeniecka-Kozerska, MD Department of Pediatrics and Nephrology, Medical University of Białystok, 15-274 Białystok, 17 Waszyngtona Street, Poland. Tel: +48 85 7450 663 Fax: +48 85 7421 838 E-mail: agatakozerska@poczta. onet.pl Received December 2012 Accepted December 2013 Purpose: Oxidative‎stress‎can‎cause‎tissue‎damage‎in‎many‎diseases.‎Oxidative‎status‎depends‎ on‎the‎balance‎between‎total‎oxygen‎radical‎absorbance‎capacity‎and‎antioxidants.‎Neurogenic‎ bladder‎(NB)‎is‎a‎special‎state‎where‎oxidative‎status‎can‎influence‎urinary‎tract‎function.‎We‎ decided‎to‎measure‎antioxidant‎(thiol)‎status‎in‎patients‎with‎NB‎and‎assess‎the‎effect‎of‎NB‎on‎ the‎urinary‎antioxidant‎status‎and‎to‎correlate‎it‎with‎urodynamic‎findings.‎‎ Materials and Methods:‎The‎investigation‎was‎conducted‎on‎two‎groups.‎The‎first‎group,‎ constituted‎of‎41‎children‎with‎NB.‎The‎second‎group,‎consisted‎of‎20‎healthy‎children‎with‎no‎ abnormality‎in‎urinary‎and‎nervous‎systems.‎The‎antioxidant‎status‎was‎assessed‎based‎on‎the‎ enzyme-linked‎immunosorbent‎assay‎of‎thiols. Results:‎The‎median‎value‎of‎urinary‎protein‎thiol‎level‎was‎significantly‎lower‎in‎NB‎patients‎ than‎in‎reference‎group‎[median‎48‎(0.0-633.33)‎and‎221.55‎(0.17-1293]‎µmoL/g‎protein,‎re- spectively‎(P‎<‎.01).‎We‎found‎out‎the‎statistically‎significant‎differences‎in‎urinary‎thiol‎level‎ between‎patients‎with‎and‎without‎overactivity‎(P‎=‎.017)‎and‎between‎catheterized‎and‎non- catheterized patients (P‎=‎.048). Conclusion:‎This‎study‎demonstrates‎that‎antioxidant‎status‎in‎patients‎with‎NB‎decreased‎and‎ the‎level‎of‎thiol‎status‎depends‎on‎the‎grade‎of‎bladder‎overactivity.‎Oxidative‎stress‎may‎be‎ involved‎in‎the‎pathophysiology‎of‎bladder‎dysfunction‎related‎to‎neurogenic‎damage. Keywords:‎urinary‎bladder,‎neurogenic,‎overactive;‎spinal‎dysraphism,‎complications;‎menin- gomyelocele;‎pyrroles. Agata Korzeniecka Kozerska, Bożena Okurowska Zawada, Joanna Michaluk Skutnik, Anna Wasilewska The Assessment of Thiol Status in Chil- dren with Neurogenic Bladder Caused by Meningomyelocele Pediatric Urology PEDIATRIC UROLOGY 1401Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L INTRODUCTION Oxidative‎ stress‎ can‎ cause‎ tissue‎ damage‎ in‎ many‎children‎and‎adults‎diseases.‎Hyperglycemia‎in‎dia-betic‎adult‎patients‎can‎increase‎the‎levels‎of‎free‎ radicals.(1)‎Other‎authors‎have‎described‎an‎increase‎in‎oxi- dative‎stress‎in‎pregnant‎woman,‎patients‎with‎rheumatoid‎ arthritis‎and‎bladder‎carcinoma‎and‎in‎children‎with‎cerebral‎ palsy.(2-5)‎Oxidative‎status‎depends‎on‎the‎balance‎between‎ total‎oxygen‎radical‎absorbance‎capacity‎and‎antioxidants‎as‎ a‎compensatory‎reaction‎of‎the‎body.‎Among‎many‎antioxi- dants,‎thiols‎(sulfhydryl‎groups)‎may‎play‎an‎important‎role.‎ There‎are‎some‎notifications‎about‎plasma‎or‎urinary‎thiol‎ status‎in‎pediatric‎nephrological‎problems.‎An‎impaired‎an- tioxidative‎system‎has‎also‎been‎observed‎in‎patients‎with‎ nephrotic‎syndrome,‎primary‎glomerular‎disease,‎and‎in‎pa- tients‎with‎proteinuria‎or‎renal‎failure.(6-10)‎ Neurogenic‎bladder‎(NB)‎is‎an‎exceptional,‎incurable‎state,‎ depended‎on‎the‎range‎of‎nervous‎system‎damage.‎To‎assess‎ the‎bladder‎function,‎the‎urodynamic‎study‎should‎be‎per- formed.‎In‎this‎procedure‎we‎can‎measure‎intravesical‎pres- sure‎during‎storage‎and‎voiding‎phase.‎Most‎of‎the‎patients‎ with‎NB‎have‎dysfunctional‎voiding‎so‎our‎measurement‎is‎ based‎only‎on‎storage‎phase.‎The‎time‎of‎observation‎in‎this‎ procedure‎is‎quite‎short‎and‎the‎outcomes‎cannot‎be‎accurate.‎ We‎don’t‎know‎what‎is‎going‎on‎with‎bladder‎function‎dur- ing‎whole‎day‎and/or‎night‎time?‎There‎are‎many‎factors‎in- volved‎in‎the‎control‎of‎bladder‎function.‎In‎healthy‎children,‎ firstly‎it‎stayed‎under‎central‎nervous‎system‎(CNS)‎control.‎ Each‎levels‎of‎CNS‎(brain,‎spinal‎cords,‎and‎peripheral‎gan- glia)‎are‎involved‎in‎this‎control.‎There‎are‎some‎suggestions‎ demonstrating‎that‎oxidative‎status‎influences‎urinary‎tract‎ function.‎ Most‎ of‎ them‎ demonstrate‎ destroyed‎ balance‎ in‎ plasma‎reactive‎oxygen‎species‎(ROS)‎and‎antioxidants‎(e.g.‎ ascorbic‎acid,‎α-tocopherol,‎uric‎acid‎and‎bilirubin)‎which‎ may‎minimize‎tissue‎damage‎mostly‎in‎adults‎and‎mainly‎in‎ an‎experimental‎data.(11-15) Patients‎with‎NB‎are‎still‎significant‎group‎among‎dialyzed‎ patients.‎There‎is‎a‎need‎to‎look‎for‎the‎reliable‎examinations‎ for‎early‎detection‎of‎lower‎urinary‎tract‎deterioration.‎We‎ have‎no‎doubts‎that‎early‎identification‎of‎the‎risk‎factors‎of‎ chronic‎renal‎failure‎development‎should‎have‎priority,‎from‎ the‎healthy‎and‎the‎economical‎point‎of‎view‎too.‎ Till‎now,‎there‎were‎only‎a‎few‎studies‎which‎examined‎uri- nary‎antioxidant‎status‎in‎patients‎with‎NB.‎Most‎of‎them‎ were concentrated on the adult patients.(16,17)‎None‎of‎them‎ assessed‎the‎thiol‎status.‎Hence,‎we‎decided‎to‎measure‎anti- oxidant‎status‎in‎the‎urine‎of‎children‎with‎NB‎based‎on‎the‎ assessment‎of‎urinary‎thiol‎status‎and‎compare‎it‎with‎healthy‎ subjects.‎The‎aim‎of‎our‎study‎was‎to‎investigate‎the‎urinary‎ antioxidant‎status‎in‎patients‎with‎NB‎due‎to‎meningomye- locele‎(MMC)‎and‎to‎correlate‎it‎with‎bladder‎function. MATERIAL AND METHODS The‎study‎was‎carried‎out‎in‎the‎department‎of‎pediatrics‎and‎ nephrology,‎medical‎university‎of‎Bialystok,‎Poland.‎Patients‎ with‎urodynamically‎confirmed‎diagnosis‎of‎NB‎were‎includ- ed‎in‎the‎study.‎Finally,‎41‎NB‎patients‎aged‎median‎9.0‎(0.7- 17.5)‎years‎old‎were‎enrolled‎in‎the‎study‎(group‎1).‎Twenty‎ healthy‎individuals‎aged‎median‎9.5‎(3-17)‎years‎old‎without‎ any‎nephrological‎and‎CNS‎diseases‎history‎were‎enrolled‎as‎ a‎reference‎group‎(group‎2).‎This‎group‎was‎recruited‎from‎ healthy‎elementary,‎middle‎and‎secondary‎school‎pupils,‎ob- tained‎from‎2007‎to‎2009‎in‎the‎OLAF‎study:‎“Elaboration‎of‎ reference‎blood‎pressure‎ranges‎for‎Polish‎children‎and‎ado- lescents”‎PL0080‎OLAF.‎The‎material‎from‎the‎younger‎con- trol‎subjects‎(aged‎3-6‎years‎old)‎was‎obtained‎from‎healthy‎ children‎attending‎to‎day‎care‎or‎nursery‎school.‎The‎healthy‎ subjects‎were‎on‎normal‎diet‎without‎any‎vitamins,‎drugs‎or‎ diet‎supplements.‎ The‎eligible‎cases‎(group‎1)‎were‎male‎and‎female‎patients‎ aged‎1-18‎years‎old‎with‎NB‎due‎to‎MMC‎and‎with‎voiding‎ dysfunction‎for‎at‎least‎one‎year‎prior‎to‎screening.‎Patients‎ in‎MMC‎group‎underwent‎cystometry‎and‎patients‎in‎non- catheterized‎group‎underwent‎uroflowmetry.‎All‎of‎them‎had‎ normal‎renal‎function‎[glomerular‎filtration‎rate‎(GFR)‎of‎>‎ 90‎mL/min/1.73m2]‎and‎normal‎serum‎creatinine‎levels.‎Ac- cording‎to‎the‎findings‎of‎urodynamic‎study‎oxybutynin‎was‎ administered‎if‎necessary.‎ Patients‎with‎urinary‎tract‎infection‎(UTI)‎in‎the‎past‎4‎weeks‎ or‎other‎infections‎were‎excluded‎from‎the‎study.‎The‎non- catheterized‎patients‎with‎NB‎and‎children‎from‎the‎control‎ group‎all‎underwent‎uroflowmetry‎study‎3‎times‎and‎to‎in- crease‎ precision,‎ the‎ results‎ were‎ averaged‎ and‎ compared‎ with the urinary thiols concentrations. Most‎of‎NB‎patients‎cannot‎empty‎their‎bladders‎by‎them- selves‎so‎we‎were‎terminating‎the‎infusion‎during‎cystometry‎ when‎the‎volume‎of‎solution‎was‎the‎same‎as‎obtain‎from‎ everyday‎clean‎intermittent‎catheterization‎(CIC).‎It‎was‎our‎ intention‎to‎imitate‎bladder‎function‎as‎in‎natural‎environ- ment.‎ NB‎ children‎ received‎ medications‎ according‎ to‎ the‎ urodynamic‎study‎results.‎The‎urodynamic‎work-up‎included‎ Thiol Status in Children with Neurogenic Bladder | Kozerska et al 1402 | the‎measurements‎of‎following‎parameters:‎detrusor‎pressure‎ at‎ overactivity‎ (Pdet‎ overact),‎ detrusor‎ pressure‎ at‎ maxi- mum‎cystometric‎capacity‎(Pdet‎CC),‎bladder‎wall‎compli- ance,‎and‎electromyography‎(EMG)‎of‎sphincter‎at‎begin- ning‎(EMG‎1)‎and‎at‎the‎end‎(EMG‎2)‎of‎the‎filling‎phase.‎ Anticholinergic‎drugs‎were‎administered‎if‎the‎patient‎had‎ detrusor‎overactivity.‎Informed‎consent‎was‎obtained‎from‎ all‎subjects‎and‎their‎parents‎for‎all‎procedures‎connected‎to‎ obtaining‎biological‎material. The‎ first‎ daytime‎ urine‎ samples‎ were‎ collected‎ from‎ all‎ examined‎patients‎and‎urinary‎total‎protein,‎creatinine,‎mi- croalbumin‎and‎osmolality‎were‎determined.‎Urinary‎thiol‎ (sulfhydryl)‎status‎was‎measured‎by‎enzyme-linked‎immuno- sorbent‎assay‎(ELISA)‎according‎to‎manual‎instruction,‎(Im- mundiagnostik‎AG‎Stubenwald-Allee‎8a,‎64625‎Bensheim,‎ Germany).‎Urinary‎protein‎and‎creatinine‎levels‎were‎also‎ measured‎in‎24-hour‎urine‎samples‎by‎an‎automated‎clinical‎ analyzer.‎Urinary‎thiol‎levels‎were‎calculated‎from‎the‎total‎ thiol‎levels‎adjusted‎for‎protein‎concentration‎in‎urine‎and‎ expressed‎in‎µmol/g‎protein.‎Serum‎proteins,‎albumin‎and‎ creatinine‎concentrations‎were‎determined‎in‎both‎groups.‎ The‎GFR‎was‎calculated‎using‎Schwartz‎formula.‎The‎study‎ was‎ approved‎ by‎ the‎ Ethics‎ Committee‎ of‎ Medical‎ Uni- versity‎of‎Bialystok‎in‎accordance‎with‎the‎Declaration‎of‎ Helsinki.‎The‎OLAF‎study‎was‎approved‎by‎The‎Children’s‎ Memorial‎Health‎Institute‎Ethics‎Committee. Statistical Analysis The‎demographic‎and‎biochemical‎data‎of‎NB‎patients‎was‎ statistically‎analyzed‎and‎expressed‎as‎median‎with‎minimum‎ and‎maximum‎range‎compared‎with‎reference‎group.‎Since‎ the‎antioxidant‎parameters‎were‎not‎as‎per‎the‎Gaussian‎dis- tribution, Mann-Whitney U‎test‎was‎used‎for‎the‎comparisons‎ between‎2‎groups.‎Spearman’s‎coefficient‎of‎correlations‎(r)‎ were‎calculated‎to‎look‎at‎the‎possible‎association‎between‎ thiol‎parameters‎and‎biochemical‎and‎urodynamic‎one.‎All‎sta- tistical‎analyses‎were‎performed‎using‎Statistica‎10.0‎(StatSoft‎ Inc.,‎Tulsa,‎OK,‎USA).‎A‎P‎value‎of‎less‎than‎.05‎was‎consid- ered‎statistically‎significant. RESULTS Characteristics‎ of‎ studied‎ subjects‎ are‎ shown‎ in‎ Table‎ 1.‎ There‎were‎no‎statistically‎significant‎differences‎in‎demo- graphic‎characteristics‎of‎studied‎groups‎such‎as‎age,‎gender‎ and‎body‎mass‎index.‎There‎were‎differences‎in‎the‎physical‎ development‎parameters‎resulted‎from‎the‎principal‎disease.‎ The‎children‎with‎MMC‎had‎lower‎muscular‎mass‎(due‎to‎ paralysis‎of‎the‎limbs)‎or‎excess‎body‎weight‎resulting‎from‎ the‎ lack‎of‎activity‎during‎the‎ lifespan‎(the‎children‎were‎ wheelchair‎ dependent).‎ Moreover,‎ the‎ differences‎ in‎ the‎ height‎are‎often‎caused‎by‎distortion‎and‎malformations‎of‎ the‎bone‎structure.‎The‎median‎time‎of‎follow‎up‎of‎the‎NB‎ patients‎was‎6‎(0.5-15)‎years.‎Nine‎from‎41‎patients‎were‎ non-catheterized.‎The‎catheterized‎subjects‎were‎emptying‎ their‎ bladder‎ with‎ median‎ urination‎ frequency‎ of‎ 4‎ (3-5)‎ times‎per‎day‎with‎night‎brake.‎ In‎present‎study‎we‎compared‎the‎parameters‎of‎the‎kidneys‎ Figure 1. The comparison of urine thiol levels between patients with neurogenic bladder (NB) and reference group. Figure 2. The data of median urine thiols in patients with neuro- genic bladder in various urodynamic conditions. Pediatric Urology 1403Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L function‎(urinary‎and‎serum‎creatinine,‎urinary‎excretion‎of‎ the‎protein,‎urine‎osmolality,‎GFR‎and‎microalbuminuria)‎ and‎serum‎albumin‎and‎protein‎levels.‎Laboratory‎findings‎ and‎comparisons‎are‎shown‎in‎Table‎1.‎We‎observed‎statisti- cally‎significant‎differences‎in‎the‎serum‎creatinine,‎GFR‎and‎ creatinine‎and‎protein‎excretion‎(in‎morning‎sample‎and‎24- hour‎urine‎collection).‎There‎were‎differences‎between‎study‎ groups‎in‎the‎serum‎albumin‎concentrations‎values‎but‎the‎ results‎were‎not‎statistically‎significant.‎We‎did‎not‎find‎dif- ferences‎in‎presence‎of‎microalbuminuria‎and‎serum‎protein‎ levels‎between‎study‎groups‎(P = .47 and P = .12, respec- tively). As‎it‎has‎been‎shown‎in‎Figure‎1,‎the‎urinary‎thiol‎level‎was‎ significantly‎decreased‎in‎NB‎patients‎compared‎to‎the‎con- trol‎group‎and‎the‎related‎numerical‎data‎were,‎median‎48‎ (0.0-633.33)‎and‎221.55‎(0.17-1293)‎µmol/g‎protein,‎respec- tively‎(P‎<‎.001).‎This‎reduction‎was‎not‎related‎to‎UTI‎in‎the‎ past,‎the‎follow-up‎duration‎and‎bladder‎wall‎thickness,‎or‎ the‎dose‎of‎administered‎treatment. Urodynamic‎ findings‎ are‎ shown‎ in‎ Table‎ 2.‎ We‎ revealed‎ statistically‎ significant‎ differences‎ in‎ most‎ uroflowmetry‎ parameters‎between‎study‎groups.‎Urinary‎thiol‎level‎corre- lated‎negatively‎with‎voided‎volume‎(r‎=‎-0.450,‎P‎<‎.05)‎ and‎positively‎with‎residual‎urine‎(r‎=‎0.25,‎P‎<‎.05).‎The‎ thiol‎status‎levels‎in‎various‎urodynamic‎conditions‎in‎NB‎ patients‎are‎shown‎in‎Figure‎2.‎We‎found‎statistically‎sig- nificant‎differences‎in‎urinary‎thiol‎levels‎between‎patients‎ with‎and‎without‎bladder‎overactivity‎(P =‎.017)‎and‎between‎ catheterized and non-catheterized patients (P‎ =‎ .048).‎We‎ also‎found‎differences‎between‎urinary‎thiols‎concentrations‎ between‎patients‎with‎normal‎and‎low‎bladder‎compliance‎ (P‎=‎.33)‎and‎between‎patients‎with‎low‎(<‎10‎cmH2O)‎and‎ high‎(>‎10‎cmH2O)‎detrusor‎pressure‎during‎filling‎phase‎(P =‎.48),‎but‎the‎differences‎were‎not‎statistically‎significant.‎ There‎were‎no‎correlations‎between‎urinary‎thiol‎and‎cys- tometric‎capacity,‎EMG‎activity‎at‎the‎beginning‎and‎at‎the‎ end‎of‎filling‎phase.‎Apart‎of‎outcomes‎mentioned‎above‎we‎ found‎positive‎correlation‎between‎urinary‎thiol‎status‎and‎ the‎age‎of‎NB‎patients‎(r‎=‎0.33,‎P‎<‎.05)‎and‎serum‎protein‎ concentration (r‎=‎.355,‎P‎<‎.05).‎ Table 1. The characteristics of study groups and comparison between patients with neurogenic bladder and reference group.* Variables Group 1 Group 2 P Age (years) 9.0 (0.7-17.5) 9.5 (3-17) .32 Gender Male 19 8 NA Female 22 12 NA Height (cm) 134 (70-170) 152 (89-176) .004 Weight (kg) 29 (6.2-92) 43 (16-70) .021 Body mass index (kg/m2) 17.01 (8.83-17) 18.13 (12-24) .75 Oxybutynin administration mg/day 3.75 (1.25-10) ----- NA mg/kg body weight 0.17 (0.1-0.42) ----- NA OAB treatment/none treatment 16/41 ----- NA Serum creatinine (mg/dL) 0.32 (0.19-0.77) 0.51 (0.2-083) .00 Urine creatinine (mg/dL) 53.17 (14.58-149) 100.17 (63-244) .000 GFR mL/min/1.73m2 body surface 233 (102-303) 162.91 (110-330) .017 Urine osmolality 715 (314-1177) 685 (391-1130) .85 Microalbuminuria 5.5 (0.1-386.9) 1.4 (0.3-51.8) .47 Serum protein (g/L) 7.08 (5.8-8.13) 7.55 (6.62-8.14) .12 Serum albumin (g/dL) 4.63 (3.61-5.47) 4.79 (4.41-5.23) .067 Urine protein (mg/dL) 10 (0-128) 0 (0-2) .000 Urine protein (mg/24-hour) 60 (0-560) 5.11 (1.06-10.05) .02 Keys: OAB, overactive bladder; GFR, glomerular filtration rate; NA, not applicable. * Data are presented as median (range). Thiol Status in Children with Neurogenic Bladder | Kozerska et al 1404 | DISCUSSION The‎purpose‎of‎this‎study‎was‎to‎evaluate‎the‎antioxidant‎sta- tus‎in‎urine‎of‎patients‎with‎MMC‎and‎to‎answer‎whether‎ oxidative‎ status‎ has‎ an‎ influence‎ on‎ the‎ bladder‎ function.‎ The‎results‎ demonstrated‎ that‎ the‎decreased‎concentration‎ of‎ sulfhydryl‎ groups‎ (-SH)‎ or‎ groups‎ existing‎ as‎ protein‎ bound‎thiols‎in‎the‎urine‎of‎patients‎with‎NB‎is‎caused‎by‎in- creased‎oxidation.‎Our‎findings‎are‎comparable‎to‎the‎data‎in‎ the‎literature‎in‎various‎pathological‎conditions‎in‎children.‎ Kazunari‎ and‎ colleagues(18)‎ assessed‎ urinary‎ 8-hydroxy- 2-deoxyguanosine‎(8-OhdG)‎in‎patients‎with‎idiopathic‎ne- phrotic‎syndrome‎and‎reported‎increased‎levels‎of‎ROS‎and‎ decreased‎levels‎of‎antioxidants‎in‎the‎active‎phase‎of‎the‎ diseases‎which‎were‎normalized‎in‎remission‎phase.‎These‎ findings‎are‎in‎agreement‎with‎Mishra‎and‎Schaefer’s‎study. (19)‎These‎findings‎suggest‎an‎important‎role‎of‎oxidative‎sta- tus‎in‎the‎pathogenesis‎of‎idiopathic‎nephrotic‎syndrome‎in‎ children.‎Chien‎and‎colleagues(20)‎in‎an‎experimental‎study‎ revealed‎that‎substance‎P‎influences‎NB‎function‎by‎its‎abil- ity‎to‎stimulate‎ROS‎generation.‎Other‎experimental‎studies‎ have‎demonstrated‎imbalance‎between‎ROS‎and‎antioxidant‎ ability‎ (as‎ a‎ positive‎ reaction‎ of‎ our‎ body)‎ in‎ neurogenic‎ damage.‎We‎did‎not‎find‎any‎study‎concerning‎with‎measur- ing‎of‎urinary‎thiol‎(sulfhydryl)‎groups‎in‎patients‎with‎NB.‎ Decreased‎urinary‎protein‎thiols‎in‎patients‎with‎overactive‎ bladder‎let‎us‎to‎suspect‎that‎oxidative‎stress‎is‎involved‎in‎ the‎disturbed‎bladder‎function.‎Thus,‎could‎we‎try‎to‎normal- ize‎function‎of‎the‎bladder‎by‎taking‎antioxidants?‎Could‎we‎ influence‎the‎detrusor‎pressure‎by‎antioxidants?‎Could‎we‎ change‎the‎muscarinic‎receptor‎function‎by‎decreased‎oxi- dative‎stress?(13)‎What‎could‎be‎the‎administration‎method?‎ Answer‎to‎this‎questions‎required‎further,‎very‎well-planned‎ and‎good-organized‎studies‎which‎we‎are‎planning.‎Till‎now,‎ the‎literature‎review‎shows‎that‎there‎are‎some‎therapeutic‎ interventions‎and‎numerous‎bioactive‎compounds‎that‎have‎ antioxidant‎status‎benefits‎but‎unfortunately‎still‎in‎clinical‎ trials‎or‎on‎animal‎models.(16)‎ Our‎results,‎focused‎on‎positive‎correlation‎between‎urinary‎ protein‎thiol‎level‎and‎serum‎protein‎concentration,‎raise‎an‎ interesting‎question‎whether‎higher‎serum‎protein‎concentra- tion‎can‎increase‎urinary‎protein‎excretion‎and‎in‎this‎way‎ affect‎the‎oxidative‎status‎in‎NB?‎ Summarizing,‎ received‎ from‎ uroflowmetry‎ results‎ let‎ us‎ speculate‎that,‎although‎the‎patients‎emptying‎their‎bladders‎ by‎themselves‎(urodynamic‎findings‎let‎them‎to‎do‎that),‎the‎ bladders‎do‎not‎work‎correctly.‎It‎confirms‎that‎non-catheter- ized‎NB‎patients‎require‎greater‎attention‎or‎verify‎recom- mendations. The‎kidney‎function‎deterioration‎is‎connected‎with‎the‎high- er‎frequency‎of‎detrusor‎overactivity‎diagnosed‎in‎childhood. (21)‎Thus,‎the‎meticulous‎estimation‎based‎on‎the‎urodynamic‎ findings‎in‎connection‎with‎the‎assessment‎of‎oxidative‎sta- tus‎in‎childhood‎can‎be‎a‎very‎important‎prediction‎to‎later‎ kidney‎impairment,‎it‎is‎the‎potential‎clinical‎application‎of‎ our‎ finding.‎This‎ condition‎ must‎ be‎ fulfilled‎ especially‎ in‎ such‎exceptional‎state‎as‎NB‎is,‎when‎the‎prognosis‎of‎blad- Table 2. Urodynamic findings and comparison between study groups.* CYSTOMETRY Pdet, cmH2O Pdet CC, cmH2O Bladder wall compliance, mL EMG 1, micro- volts EMG 2, microvolts NB patients (4-100) 25 (2-75) 14 (3-70) 10 4.5 (0-25) 7 (0-47) UROFLOWMETRY Time to max flow, s Delay time, s Flow time, s Voiding time, s Maximum flow rate, mL/s Average flow rate, mL/s Voided volume, mL Residual urine, mL NB patients 7 (7.0-23.4) 15.6 (3.4-280) 20 (2-129) 28 (3-427) 6.3 (1.4-15) 4.25 (0.5-13) 111.4 (5-275) 80 (5-117.5) Control group 7 (4-12) 2 (1-3) 17 (10-38) 19.5 (11-41) 22.9 (13.3-41) 18.1 (6-31) 219.5 (104-456) 0 (0-5) P .835 < .001 .340 .061 < .001 < .001 .004 < .001 Keys: Pdet, detrusor pressure at overactivity; Pdet CC, detrusor pressure at cystometric capacity; EMG 1- electromyography of sphincter at the beginning of filling phase; EMG 2, at the end of filling phase; NB, neurogenic bladder. * Data are presented as median (range). Pediatric Urology 1405Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L REFERENCES 1. Awanti S, Baruah PS, Prakash M. Serum and urine protein thiols in type 2 diabetes mellitus patients. Indian J Physiol Pharmacol. 2009;53:185-8. 2. Umeshchandra S, Umeshchandra DG, Awanti S. Serum protein thiol status in pregnant women with malaria. RJPBCS. 2012;3:114-9. 3. Pedersen-Lane JH, Zurier RB, Lawrence DA. Analysis of the thiol sta- tus of peripheral blood leukocytes in rheumatoid arthritis patients. J Leukoc Biol. 2007;81:934-41. 4. Badjatia N, Satyam A, Singh P, Seth A, Sharma A. Altered antioxi- dant status and lipid peroxydation in Indian patients with urothelial bladder carcinoma. Urol Oncol. 2010;28:360-7. 5. Kulak W, Sobaniec W, Solowej E, Sobaniec H. Antioxidant en- zymes and lipid peroxides in children with cerebral palsy. Life Sci. 200;77:3031-6. 6. Karthikeyan K, Sinha I, Prabhu K, Bhaskaranand N, Rao A. Plasma protein thiols and total antioxidant power in perdiatricnephrotic syndrome. Nephron Clin Pract. 2008;110: 10-4. 7. Markan S, Kohli HS, Sud K, et al. Oxidative stress in primary glomer- ular diseases: a comparative study. Mol Cell Biochem. 2008;311:105- 10. 8. Prakash M, Shetty JK, Dash S, et al. Urinary protein thiols in different grades of proteinuria. Indian J Clin Biochem. 2008;23:404-6. 9. Mallikarjunappa S, Prakash M. Urine protein thiols in chronic renal failure patients. Indian J Nephrol. 2007;17:7-9. 10. Nakai K, Yoneda K, Maeda R, et al. Urinary biomarker of oxidative stress in patients with psoriasis vulgaris and atopic dermatitis. J Eur Acad Dermatol Venereol. 2009;23:1405-8. 11. Goulart M, Batoréu MC, Rodrigues AS, Laires A, Rueff J. Lipoperoxi- dation products and thiol antioxidants in chromium exposed work- ers. Mutagenesis. 2005;20:311-5. 12. Masuda H, Kihara K, Saito K, et al. Reactive oxygen species medi- ate detrusor overactivity via sensitization of afferent pathway in the bladder of anesthetized rats. BJU Int. 2008;101:775-80. 13. de Jongh R, Haenen GR, van Koeveringe GA, Dambros M, De Mey JG, van Kerrebroeck PE. Oxidative stress reduces the muscarinic receptor function in the urinary bladder. Neurourol Urodyn. 2007;26:302-8. 14. Azadzoi KM, Yalla SV, Siroky MB. Oxidative stress and neurodegen- eration in the ischemic overactive bladder. J Urol. 2007;178:710-5. 15. Kawada N, Moriyama T, Ando A, et al. Increased oxidative stress in mouse kidneys with unilateral obstruction. Kidney Int. 1999;56:1004-13. 16. Jia Z, Zhu H, Li J, Wang X, Misra H, Li Y. Oxidative stress in spinal cord injury and antioxidant-based intervention. Spinal Cord. 2012;50:264-74. 17. Barrington JW, Jones A, James D, Smith S, Stephenson TP. Anti- oxidant deficiency following clam entrerocystoplasty. Br J Urol. 1997;80:238-42. 18. Kaneko K, Kimata T, Takahashi M, Shimo T, Tanaka S, Tsuji S. Change in urinary 8-hydroxydeoxyguanosine in idiopathic nephrotic syn- drome. Pediatr Nephrol. 2012;27:155-6. 19. Mishra OP1, Gupta AK, Prasad R, et al. Antioxidant status of children with idiopathic nephrotic syndrome. Pediatr Nephrol. 2011;26:251- 6. 20. Chien CT, Yu HJ, Lin TB, Lai MK, Hsu SM. Substance P via NK1 recep- tor facilitates hyperactive bladder afferent signaling. Am J Physiol Renal Physiol. 2003;283:840-51. 21. Thorup J, Biering-Sorensen F, Cortes D. Urological outcome after myelomeningocele: 20 years of follow-up. BJU Int. 2011;107:994-9. der‎function‎in‎NB‎children‎mostly‎remains‎unclear. Our‎study‎has‎some‎limitations.‎Most‎of‎the‎MMC‎patients‎ were‎treating‎with‎oxybutynin‎in‎different‎doses‎and‎there‎ was‎no‎possibility‎to‎interrupt‎therapy.‎The‎non-treated‎group‎ was‎too‎small‎and‎did‎not‎allow‎us‎to‎draw‎an‎unequivocal‎ conclusion.‎Another‎limitation‎of‎this‎study‎was‎a‎one-time‎ thiol‎status‎evaluation‎in‎specific‎patients,‎which‎may‎not‎ac- curately‎reflect‎NB‎function.‎Thus,‎further‎studies‎are‎neces- sary‎to‎better‎clarify‎correlations‎between‎bladder‎function‎ and‎oxidative‎status‎in‎MMC‎patients.‎ CONCLUSION We‎concluded‎that‎antioxidant‎status‎in‎patients‎with‎NB‎de- creased‎in‎patients‎with‎overactive‎bladder‎and‎the‎level‎of‎ thiol‎status‎depends‎on‎the‎grade‎of‎detrusor‎overactivity.‎In‎ addition,‎oxidative‎stress‎may‎be‎involved‎in‎the‎pathophysi- ology‎of‎bladder‎dysfunction‎related‎to‎neurogenic‎damage. ACKNOWLEDGEMENTS This‎study‎is‎supported‎by‎a‎grant‎from‎the‎Medical‎Univer- sity‎of‎Bialystok,‎Poland.‎Authors‎have‎no‎conflict‎of‎interest‎ to disclose. CONFLICT OF INTEREST None declared Thiol Status in Children with Neurogenic Bladder | Kozerska et al