• Clinical and Experimental Pediatrics
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• v.45 no.2
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• pp.232-239
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• 2002

Purpose : Renal cystic diseases comprise a mixed group of heritable, developmental and acquired disorders. Recently the use of imaging modalities such as ultrasonography and radionuclide scanning has increased the detection rate of renal cystic diseases. We studied to review the clinical features and treatment of renal cystic diseases in children. Methods : This study was performed in 95 children with renal cystic diseases in the Department of Pediatrics, Asan Medical Center from October 1989 to June 2001. Results : In 95 patients, there were 55 cases(58.0%) with multicystic dysplastic kidney(MCDK), 19 cases(20.0%) with simple renal cysts, 13 cases(13.7%) with hereditary polycystic kidney diseases( 7 with autosomal recessive type, 5 with autosomal dominant type, 1 with undetermined), 6 cases(6.3%) with renal cysts in tuberous sclerosis and 1 case(1.0%) with medullary cystic disease. All MCDK patients had no renal dysfunction and hypertension during the follow-up period. Three out of 13 with polycystic kidney diseases had progressed to end-stage renal disease during the follow-up period. One case with a simple cyst underwent laparoscopic malsupialization for decompression. Conclusion : Renal cystic diseases have diverse clinicopathologic features and variable prognosis. We emphasize that routine follow-up should be performed to prevent and to detect early treatable complication in renal cystic diseases. Therefore, their natural history and treatment need further investigation and long term follow-up is required.

• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.193-201
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• 2007

We used $^6Li$ and $^7Li$ MAS NMR to investigate the fate and local environments of Li in the interlayer of clay minerals such as hectorite, Woming-montmorillonite, beidellite, and lepidollite at room and high ($250^{\circ}C$) temperature. Although $^6Li$ NMR spectra show narrower peaks than those of $^7Li$ NMR, S/N ratio is low and there are no obvious differences in chemical shifts suggesting that it is difficult to apply $^6Li$ NMR to have information on the local environments of Li in the clay interlayers. $^7Li$ NMR spectra, however, show changes in the peak width and quadrupole patterns providing information on the local environments of Li in the interlayer even though changes in the chemical shift are not observed. In montmorillonite, two different local environments of Li are observed; one has a narrow peak with typical quadrupole patterns whereas another has a broad peak without those of the patterns. Changes in the peak width is also observed from broad to narrow in the $^7Li$ NMR spectra for beidellite but not for hectorite at high temperature. Our results suggest that the peak width change in the broad peak is attributed to the coordination changes in the water molecules around Li which is tightly bonded on the basal oxygen of Si tetrahedra as inner-sphere complexes. The narrow peak in montmorillnoite can be assigned to the Li bended as outer-sphere complexes.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.178-187
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• 2002

Purpose : The detection of hydronephrosis(HN) with antenatal ultrasonography was first reported in the 1970s. Prenatal HN is diagnosed with an incidence of 1:100 to 1:500 on antenatal screening. Recently, the purpose of antenatal screening has changed from simple detection to selection for specific diagnosis-based management. this study is to evaluate the usefulness of antenatal sonography for HN and to investigate the differential causes of HN and their clinical outcomes. Patients and methods : 11,783 live neonates with prenatal ultrasonographic examination at Ajou University School of Medicine, from Sep. 1994 to Aug. 2001 were analyzed. Results and conclusion : Hydronephrosis (>10 mm) was detected in 119 (1.0%) cases antenatally and among these, 91 were proved to have HN postnatally Males were three times more affected than females. Additional imaging studies revealed that ureteropelvic junction obstruction was the most common postnatal diagnosis (47%), followed by multicystic dysplastic kidney, vesicoureteral junction obstruction and vesicoureteral reflux. During 20 months' follow-up(3 to 72 months), 58(48%) renal units showed spontaneous resolution and surgical interventions were necessary in 10 (7.4%) of postnatally confirmed hydronephrotic renal units.