Object To investigate the correlation of IGF-2 exon 9 CpG island methylation and the expression of IGF-2,and further explore the mechanism of Wilms tumor. Methods The IGF-2 exon 9 methylation status and IGF2 gene expression in 42 cases of Wilms tumor and corresponding normal tissues were detected by using methylation-sensitive restriction enzyme PCR and allele-specific IGF2 gene expression analysis.Results IGF-2 exon 9 methylation rate was 15% in W ilms tumor group, and 97% in normal tissue group. The difference was significant (P < 0.01), and the difference in pathological type was also significantly different (P < 0.01). Exon 9 unmethylated tissues showing biallelic expressions of IGF-2 were significantly higher than that of methylated tissues (P < 0.05). Conclusion IGF-2 exon 9 unmethylation may be the cause of biallelic expression of IGF, which contritues to tumorigenesis in Wilms tumor.

Objective To evaluate the diagnosis and treatment of pheochromocytoma in children. Methods Eighteen children with pheochromocytoma were diagnosed and treated from 1980 to 2000.The primary clinical manifestations included severe headache,blurring of vision,palpitation,excessive perspiration.Sustained hypertension occurred in 10 cases,sustained hypertension accompanied by episodic exacerbation in 7 and episodic hypertension in 1.The mean blood pressure was 185/130 mmHg(1 mmHg=0.133 kPa),with the highest up to 260/190 mmHg.VMA was increased in 89% (16/18) of the cases,and blood and urinary catecholamine was increased in 92% (12/13).Retroperitoneal pneumography was performed in 3 cases,CT in 14 cases and MRI in 2 cases,with all positive findings.B-ultrasonography showed positive in 94%(15/16). Results This series of 18 cases accounted for 11.6% of the pheochromocytoma cases admitted homochronously (18/155).All the 18 cases underwent surgery with the help of proper peir-operative management.The pheochromocytomas (comfired by pathology) were successfully extirpated with the tumor weight ranging from 40 to 150 g.All the cases were followed up for 1 to 20 years.Their blood pressure returned to normal in 94%(17/18).Only 1 case had relapse 2 years later with diagnosis of malignancy,and died in the following year. Conclusions Since the clinical manifestations of pheochromocytoma in children are atypical,endocrinological and imaging examinations are necessary to children with hypertension.Surgical excision is the best option,and oppropriate perioperative management is extremely important.The outcome of surgical management in children is better than that in the adults.

ObjectiveTo study the diagnosis and therapy of circumcaval ureter.MethodsFifteen cases of circumcaval ureter were studied retrospectively.The cardinal symptoms include discomfort over the back and loins,nephrocolic and bloody urine.The diagnosis mainly depends on IVU and retrograde urography.12 patients underwent ureteroureterostomy,2 ureteropyeloneostomy and 1 nephrectomy.ResultsAll the patients have been follewed up from 1 to 15 years by IVU and ultrasonography,and no nephrohydrosis or stenosis of the anastomosis site has been noted.All the patients have been free from any complaints.ConclusionsIVU and retrograde urography are the cardinal means for the diagnosis of circumcaval ureter,and operation is indicated in order to improve the renal function.It is important to choose a proper time and an adequate surgical technique.