Antimutagenic effect of p-aminobenzoic acid (PABA) and sodium bisulfite (NaHSO_3)on the mutagenicity of N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was detected by the mehod of human lymphocytes unscheduled DNA Sythesis (LIDS). The results showed that when the concentration of PABA and NaHSO_3 was varied in presence of a constant concentration of MNNG, 5 ?10~(-5) mol/L concentration of PABA, 3 ? 10~(-4) mol/L concentration of NaHSO_3 were the most effective, while the concentration of MNNG varied in the presence of a constant concentration of PABA and NaHSO_3, antimutagenicity was the most effective at high concentration of MNNG. The results indicated that the PABA and NaHSO_3 exhibited antimutagenic activity towards MNNG-induced mutagenicity in LIDS and the extents of antimutagenicity were related with the concentration of MNNG.

Objective To evaluate the use of Mitrofanoff principle in the field of pediatric urology. Methods From May. 1997 to Dec.1999,the Mirtofanoff principle has been used in 7 children to achieve CIC and urinary continence.The mean age of the patients at operation was 8 years (range 3～14 years).A catheterisable conduit was created using the appendix.Either the cecum,ascending colon or plus the terminal ileum were used instead of the bladder or for augmentation of the bladder after detubularization.7 children consisted of an 8 years old boy has lost his bladder,right ureter and bilateral testis due to traffic accident, 4 children with congenital complete urinary incontinence (urogenital sinus abnormality 1,extrophy of bladder after failed reconstruction 1 and shortened urethra 2),and neurogenic bladder 2. Results Immediate success has been achieved in 5 children (70%),who were completely continent and practiced successful CIC via the Mitrofanoff stoma. Conclusions Use of the Mitrofanoff principle is a valuable procedure for urinary diversion in childhood.

Objective To study the clinical features of adrenocortical carcinoma in children. Methods From 1983 to 1999, 9 cases of adrenocortical carcinoma were reviewed retrospectively. Results Six cases were surgically treated, complete tumor resection in four cases and palliative tumor resection in two.All were female. All the operated cases were followed up for an average of 2 years and 3 months.The 2 year survival is 4 out of 6. Conclusions Early diagnosis and complete tumor resection is the only means to achieve good survival in children with adrenocortical carcinoma.

Objective To present experience on the management of traumatic posterior urethral stricture or obliteration in boys. Methods Treatment included transurethral resection (TUR) in 112 cases,combined perineal-transpubic urethral repair in 44,via perineal approach for urethral repair in 32,perineal urethrostomy performed either transpubicaly or(and) via perineal approach or interposition of a segment of pediculated skin tube of scrotum in 20 cases,Mitrofanoff in one,urethra anastomotic repair through rectal and perineal approach in one. Results The whole series have been followed up for 6 months to 14 years.Normal urination was achieved in 187(89%),incomplete urinary incontinence in 17,still with perineal urethrostomy in 5,and intermittent catheterization needed in 1.Posterior urethral diverticulum with chronic epididymitis persisted in one. Conclusions Appropriate initial treatment is important for the management of traumatic posterior urethral injury.In fresh cases simple cystostomy was only carried out for incomplete urethral disruption,end to end anastomosis via suprapubic combined with perineal approach is indicated in complete urethral disruption.For old urethral injury,internal urethrotomy is good for the majority of simple stricture.Transpubic combined with perineal approach is indicated for the length of posterior urethral stricture or obliteration longer than 2 cm.If the proximal urethral end is long enough for exposure the urethra can be repaired via perineal approach alone. Perineal urethrostomy should be reserved for patients with long segment of urethral obliteration.

Objective To explore the imaging features of bone tumor of fibrous tissue origin.Methods 31 patients with bone tumor of fibrous tissue or igin confirmed by pathology were analyzed. All patients were examined by X-ray, of them, 6 by CT in the meantime.Results Non-ossifying fibroma(NOF n=14)occured commonly i n long bone,the imaging findings presented sacculated and expanded bone destruct ion which was encircled by sclerotic borders,bony septum could be observed iusid e the lesion.Ossifying fibroma(OF n=10)occured more in maxillofacial bone,there were circle or elliptical and expansive bone change,and most of them associated with local bone malformation.Depending on the ossified degree,the density of les ion,could be hyperdense,ground-glass opacity,cyst or mixed density,defined borde r,partly associated with sclerotic borders.Desmoplastic fibroma of bone(DF n=1) presented multiple patchy bony erosion at lateral of lower part of femur,and ext ending to articalar facies,ill-defined border,and soft tissue slightly swelling. Fibrosarcoma of bone(FS n=6) occured commonly in long bone,presened bitted-like or greater patchy osseous absorption with soft fissue mass,rarely periosteal rea ction and calcification.58.08% patients(18/31) were accurately diagnosed.The nat ure of 6 patients was undefined.Misdiagnosis was made in 7.Conclusion Most of NOF and OF are of specific imaging fin dings and can be accurately diagnosed before cperation.DF is of slight symptoms with invaded growth and is easily misdiagnosed.In the imaging features of FS are apparently different with various type and histological differentiation,it must be differentiated from other diseases.

Objective To establish a stable and repeatable experimental partial bladder outlet obstruction(p-BOO)rat model and to figure out the impaction of p-BOO on detrusor biomechanical properties.Methods P-BOO animal model was established by partialligation of the bladder neck of male Wistar rats,a urethra stricture by laying a trochar outside of bladder neck.The rats were divided into sham-operation group,P-BOO 6 weeks group(P-B006W)and P～BOO 12 weeks group(PBOO12W)by time.Cystomety was performed in P-BOO6W and the rats were divided into detrusor instability group(DI)and destrusor stability group(DS)on the basis of destrusor stability.The active contraction of detrusor muscle stripes to Carbachol was recorded with tensile foree transducer.The compliance and maximum volume of bladder,bladder leak point pressure were examined by filling cystometry.Results The bladders of P-BOO animal model demonstrated typical post obstruction alterations after P-BOO.The maximum volume increased significantly in DI group(10.8±3.0)ml,DS group(10.3±1.9)ml and P-B0012W group(9.5±2.3)ml as compared with that in sham-operation group(2.1±0.3)ml(P＜0.05).The bladder leak point pressures were significantly higher in DI group(39.4±7.1)cm H2O,DS group(35.9±6.2)cmH2O and P-B0012W group(48.6±9.5)cm H2O as compared with that in sham-operation group(16.2±2.1)cm H2O(P＜0.05).The bladder compliances were significantly higher in 13I group(0.27±0.08)ml/cm H2O,DS group(0.29±0.05)ml/cm H2O and P-BOO12W group(0.21±0.05)ml/cm H2O as compared with that in sham-operationgroup(0.13±0.03)ml/cm H20(P＜0.05).The detrusor contractile force of DI group was significantly lower than that in the sham-operation group and DS group(P＜0.05).No definite contraction wave was detected in the detrusor muscle of P-BOO12W group(amplitude＜0.05g).Conclusions There are 2 different types of the detrusor contraction after P-BOO:DI group with impaired contraction and conversely DS group with compensatory contraction.The contractility of detrusor muscle will be damaged and even irreversible contractile function incapacitation will occur if the obstruction is not removed.The effect of bladder stability tO bladder compliance is inconspicuous and there is close correlation between bladder compliance and bladder capacity.

Objective To evaluate the application of preserved urethral plate urethroplasty to treat urethral fistula after hypospadias repair. Methods Two hundred and twenty-four cases with u-rethral fistula after hypospadias repair were treated by preserved urethral plate urethroplasty from 2001 to 2006.Follow-up data were reviewed and analyzed.All of these cases had big(>1 cm)ure-thral fistula.One hundred and two failed hypospadias cases were repaired by tubularized incised plateurethroplasty(Snodgrass).The patients were 2-16 years old and mean age was 3.7 years old.In thesame time period,86 failed hypospadias cases were repaired by Duplay urethroplasty.The children were 2-14 years old and mean age was 3.5 years old.Twenty failed hypospadias cases were repaircd by Onlay island flap urethroplasty and another 1 6 failed hypospadias cases were repaired by Flip-Flap urethroplasty. Results Fistulas were successfully repaired in 86(84.3%)cases out of 102 tubular-ized incised plate urethroplasty procedure.There were 1 3 urethral fistulas and 3 urethral strictures.Seventy-five(87.2%)cases were successful out of 86 Duplay procedure.There were 9 urethral fistulas and 2 urethral strictures.There was no significant difference between these tWO groups of results(P>0.05).Nineteen cases were successful out of 20 Onlay urethroplasty procedures and there was only l urethral fistula.Fourteen cases were successful out of 1 6 Flip-Flap procedures and there was onlv 2 u-rethral fistulas. Conclusions Surgical procedure for urethral fistula repair should be chosen accord-ing to the condition of penis.Tubularized incised plate urethroplasty can get same satisfactory result comparing with Duplay method for failed hypospadias repair.More Snodgrass should be used to assure the cosmetic penis.

Objective To discuss the management of urethral duplication in children. Methods The clinical data of 1 8 children(all are males)with urethral duplication were retrospectivelv ana-lyzed. All the 18 patients were sagittal plane included epispadias in 6,hyposPadias in 4 and Y type in the remaining 8. In 6 cases with epispadias,3 patients underwent excision of the accessorv dorsal ure-thra,3 patients without operation.Urethroplasty was necessary in the patient with a duplicated hypo-spadiac urethra. Of 8 patients with Y-type urethral duplication,7 patients underwent 2 stage repair including displacement of the urethra from the anal canal to the perineum at stage 1 and subsequent urethral reconstruction at stage 2.The ventral urethra which was hypospadias had been excised in the other one. Results All the patients were followed-up. Good cosmetic and functional resuIts were a-chieved in the 3 boys who underwent excision of the accessory dorsal urethra.In the hypospadiac du-plication,2 patients could void spontaneously through a normally positioned granular meatus.One boy presented with urethral stenosis after operated. One boy had a vesicostomy for neuropathic bladder. In Y-type urethral duplications,only 1 patient was successful after 2-stage urethroplasty,3 patients de- veloped urethra stricture or fistula,3 boys need the 2-stage operation,the other 0ne who underwent excision of the ventral urethra could void spontaneously. Conclusions Urethral duplication is a rare congenital anomaly.The clinical presentation varies because of the different anatomical Datterns of this abnormality. Commonly the ventral urethra is most functional and maintained after surgical correc-tion.Surgical management should be individual and depend on the anatomical configuration of the du-plicated urethras.

Objective:To investigate the reversing effect of phosphatidylinositol 3-kinase (PI3K) inhibitors, LY294002(LY) and wortmannin (Wort), on the drug resistance of mitoxantrone (MIT)-resistant human breast cancer MCF-7/MIT cells. Methods:Drug-resistant MCF-7/MIT cells were treated with LY or Wort combined with MIT. Cell viability and proliferation were measured using the MTT assay and morphological changes were recorded by microscopy. Intracellular accumulation of MIT in MCF-7/MIT cells was detected by flow cytometry. Mitochondrial membrane potential was determined by rhodamine 123 staining. Cell cycle was examined by propidium iodide staining. Results:LY significantly enhanced the cytotoxicity of MIT to MCF-7/MIT cells. In LY and MIT cotreated cells, the percentage of cells arrested at S and G2/M phases and the mitochondrial membrane potential decreased significantly compared with single LY- or MIT-treated cells. The mechanism was related with increased accumulation of MIT in MCF-7/MIT cells induced by LY. While Wort, another PI3K inhibitor, did not significantly enhance the cytotoxic effects of MIT.Conclusion: The PI3K inhibitor significantly enhances the sensitivity of MCF-7/MIT cells to MIT.

Objective To discuss the unique biological,histological and clinical features of pediatric renal cell carcinoma (RCC).Methods A retrospective review and biological analysis of all RCC cases presenting to our hospital from January 1973 to March 2012 was undertaken.Results Twenty-nine RCC pediatric patients (16 boys,13 girls) with mean age of 9.6 (range 2.5-16.0) years were identified.The presentations included hematuria in 17 (58.6％) cases with 3 who developed hematuria after trauma,abdominal mass with hematuria in 3 (10.3％),abdominal mass in 3,abdominal pain in 2,abdominal pain with hematuria in 1,and incidentally finding in 3.The diameter of tumor was from 2.5 cm to 25.0 cm,mean 6.8 cm.According to TNM stage grouping system,16 cases were stage Ⅰ,10 stage Ⅲ,and 3 stage Ⅳ.Xp1 1.2 translocation RCC was identified in 21 patients,clear cell RCC 6,papillary RCC 2.Of the 29 cases,3 patients with the tumor less than 7-cm had nephron-sparing surgery.A 15-cm tumor was incompletely removed in 1 patient and another patient with a 25 cm× 18 cm×15 cm tumor had gross residual.Nephrectomy was performed for the affected kidney in the remaining 24 patients.Twenty-one patients (Xp1 1.2 translocation RCC 13 patients,clear cell RCC 6,papillary RCC only 2) were followed up from 1.5 to 34.0 years,18 were living well (T1N0M0 in 11 cases,T1N1M0 in 2,T2N1M0 in 3,T3N1M0 in 1 and T4N1M1 in 1) and 3 died of recurrence.Conclusions Although RCC is rare in children,pediatric RCC behaves in a distinct fashion compared with adult forms of RCC.Hematuria is the main symptom in pediatric RCC.Xp11.2 translocation RCC is the predominant form,associated with an advanced stage at diagnosis.Nephrectomy is the common treatment for RCC and nephron sparing surgery could be a reasonable option for patients with tumor smaller than 7 cm.For localized RCC (T1-2 N0-1 M0),simple kidney removal surgery is sufficient for treatment without lymph node dissection and postoperative adjuvant treatment.