• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.68-74
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• 2005

Purpose : There is growing use of continuous renal replacement therapy(CRRT) for pediatric patients, but reports about the use and outcome of CRRT in children is rare in Korea. We report our experiences of CRRT in critically ill pediatric patients. Methods : We reviewed the medical records of 23 pediatric patients who underwent CRRT at Asan Medical Center between May 2001 and May 2004. We evaluated underlying diseases, clinical features, treatment courses, CRRT modalities and outcomes. Results : Ages ranged from three days to 16 years with a median of five years. Patients weighed 2.4 to 63.9 kg(median 23.0 kg; 10 patients ${\leq}20kg$). The underlying diseases were malignancy(nine cases), multiple organ dysfunction syndrome(five cases), hyperammonemia(four cases), acute renal failure associated with liver failure(three cases), dilated cardiomyopathy(one case) and congenital nephrotic syndrome(one case). Pediatric Risk of Mortality(PRISM) III score was $17.6{\pm}7.6$ and the mean number of failing organs was $3.0{\pm}1.7$. Duration of CRRT was one to 27 days(median : nine days). Eleven patients(47.8%) survived. Chronic renal failure developed in two cases, intracranial hemorrhage in one case, and chylothorax in one case among the survivors. PRISM III score and the number of vasopressor before the start of CRRT was significantly lower in the survivors($12.7{\pm}4.2$ and $0.9{\pm}1.1$) compared with nonsurvivors($22.1{\pm}7.8$ and $2.4{\pm}1.4$)(P<0.05). Conclusion : CRRT driven in venovenous mode is an effective and safe method of renal support for critically-ill infants and children to control fluid balance and metabolic derangement. Survival is affected by PRISM III score and the number of vasopressors at the initiation of CRRT.

• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.785-790
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• 2009

Purpose : Febrile convulsions are a common pediatric neurological disease, and it is important to prevent such a disease by controlling the risk factors that may recur. A recent report states that influenza virus infections have a high probability of a relationship with febrile convulsions; therefore, it is necessary to identify the clinical properties of febrile convulsions in relation to domestic influenza virus infections. Methods : Between November 2005 and February 2008, children hospitalized because of febrile convulsions and subsequently confirmed to have influenza infections were enrolled as subjects (patient group, n=11). The control subjects were those admitted with influenza virus infections but no febrile convulsions (control group 1, n=46) and those who developed febrile convulsions without influenza virus infection (control group 2, n=53). Results : The patient group showed a higher maximum body temperature ($39.3{\pm}0.5^{\circ}C$), more histories of past febrile convulsions (72.7%), and a shorter total duration of fever ($2.9{\pm}1.2$ days) than control group 1. When multivariate analysis was performed, the probability of febrile convulsions was found to be as high as 225.9 times in patients who had influenza virus infections with a past history of febrile convulsions (OR=225.9, 95% CI: 1.7-4780.0, P<0.05). When patients with febrile convulsions were compared based on the symptoms of influenza virus infections, the patient group showed a shorter duration of fever ($0.9{\pm}0.7$ days) before convulsion than control group 2; these convulsions were mostly a recurrence of febrile convulsions. When multivariate analysis was performed, the cases with a past history of febrile convulsions showed 5.5 times (OR=5.5, 95% CI: 1.2-25.1, P=0.03) the probability of convulsions when infected with the influenza virus, and this probability decreased by 0.3 times over one-day increments of the febrile period until febrile convulsions (95% CI: 0.1-0.9, P=0.02). Maximum body temperature, total duration of fever, family history of febrile convulsions, and complex febrile convulsions did not show a statistical significance. Conclusion : In cases of pediatric influenza virus infection, the past history of febrile convulsions could be identified within the risk factor of recurrent febrile convulsions. Therefore, influenza vaccination of children having a past history of febrile convulsions will be helpful to avoid the recurrence of these convulsions.

• Clinical and Experimental Pediatrics
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• v.52 no.8
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• pp.938-943
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• 2009

Purpose : We performed this study in order to investigate the effect of direct renin inhibition on an experimental animal model with nephrotoxic serum nephritis and tried to give useful information for clinical research and renin inhibitor treatment. Methods : Thirty BALB/c 6-week-old male mice were divided into 4 groups: control group (CO, n=5), control-treatment group with aliskiren (CT, n=5), disease group (DO, n=10), and disease treatment group with aliskiren (DT, n=10). Nephritis was induced by an intravenous injection of 0.25 mg/g weight of rabbit anti-GBM immunoglobulin G. Model 2002 Alzet mini-osmotic pumps (Durect Corp.) for aliskiren infusion were implanted into CT and DT. Each group strain was sacrificed serially one at a time on day 14. We estimated the protein-creatinine ratio in 12-hour-collected urine (UP/Cr) and measured the mesangial matrix score in the PAS-stained kidney of each strain. Results : One strain at CT and DT died on day 6 and 7, respectively. Each group strain was sacrificed serially at a time on day 10 because DO were seriously ill. The UP/Cr of each group is as follows: CO, $31.24{\pm}6.54mg/mg$, CT, $23.38{\pm}13.60mg/mg$, DO, $112.72{\pm}10.97mg/mg$, DT $114.07{\pm}32.30mg/mg$. There was no significant difference between DO and DT. The mesangial matrix score of each group was CO, $0.23{\pm}0.10$; CT, $0.13{\pm}0.03$; DO, $1.90{\pm}0.48$; and DT, $1.28{\pm}0.41$, respectively, and there was a significant difference between DO and DT in the extent of mesangial matrix expansion (P=0.008). Conclusion : We found that renin inhibition was able to suppress the mesangial matrix expansion in experimental mice with acute nephritis, although there were no significant differences in UP/Cr.

• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1241-1246
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• 2007

Purpose : Recently, there has been several studies to clarify the pathogenesis of Kawasaki disease (KD) and the relations of VEGF and endostatin that act on vascular endothelial cells to the coronary artery complications. In this report, we measured serum levels of VEGF and endostatin in acute and subacute phases of KD to assess the change of these levels and the relations to the development of coronary artery lesions (CAL). Methods : Twenty six patients were diagnosed and treated for KD between January, 2001 and July, 2005 at Kangnam St. Mary's Hospital, the Catholic University of Korea. They were divided into those with and without CAL. Serum levels of VEGF and endostatin were measured during acute and subacute phases and compared to those measured in healthy and disease control groups. Results : Serum levels of VEGF were increased in KD but no differences were noted in KD with and without CAL. Serum levels of endostatin were decreased in the acute phase of KD, however they were recovered in the subacute phase of KD, regardless of CAL. The VEGF/endostatin ratio was increased in KD. KD without CAL showed a relative decrease in this ratio during the subacute phase. Significant positive correlations were found between serum VEGF and WBC count, VEGF and ESR, VEGF/endostatin ratio and ESR in the acute phase of KD. Conclusion : Analysis of factors influencing the vascular endothelium such as VEGF and endostatin will help to clarify the etiology of KD and the pathogenesis of CAL.

• Progress in Medical Physics
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• v.9 no.3
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• pp.137-141
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• 1998

The purposes of this report are to evaluate whether lead ball and steel ball could be used as protective material of radiation and to acquire physical data of them for protecting 4-10 MV X-ray beams. Lead balls of diameter 2.0～2.5mm or steel balls of diameter 1.5～2.0 mm were filled in an acrylic box of uniform width. An MV radiograph of metal balls in a box were taken to ascertain uniformity of ball distribution in the box. Average density of metal ball and linear attenuation coefficient of metal balls for 4～10 MV X -rays were measured. At the time of measurement of linear attenuation coefficient, Farmer ionization chamber was used and to minimize the scatter effect, distance between the ball and the ionization chamber was 70 cm and field size was 5.5cm${\times}$5.5cm. For comparison, same parameters of lead and steel plates were measured. The distribution of metal balls was uniform in the box. The density of a mixture of lead-air was 6.93g/cm$^3$, 0.611 times density of lead, and the density of a mixture of steel-air was 4.75g/cm$^3$, 0.604 times density of steel. Half-value layers of a mixture of lead-air were 1.89 cm for 4 MV X-ray, 2.07 cm for 6 MV X-ray and 2.16 cm for 10 MV X-ray, and approximately 1.64 times of HVL of lead plate. Half-value layers of a mixture of steel-air were 3.24 cm for 4 MV X-ray, 3.70 cm for 6 MV X-ray and 4.15 cm for 10 MV X-ray, and approximately 1.65 times of HVL of lead plate. Metal balls can be used because they could be distributed evenly. Average densities of mixtures of lead-air and steel-air were 6.93g/cm$^3$, 4.75g/cm$^3$ respectively and approximately 1.65 times of densities of lead and steel. Product of density and HVL for a mixture of metal-air are same as the metal.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.119-124
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• 1997

Purpose: To assess the utility of magnetic resonance(MR) cerebral blood volume (CBV) map in the evaluation of brain tumors. Materials and Methods: We performed perfusion MR imaing preoperatively in the consecutive IS patients with intracranial masses(3 meningiomas, 2 glioblastoma multiformes, 3 low grade gliomas, 1 lymphoma, 1 germinoma, 1 neurocytoma, 1 metastasis, 2 abscesses, 1 radionecrosis). The average age of the patients was 42 years (22yr -68yr), composed of 10 males and S females. All MR images were obtained at l.ST imager(Signa, CE Medical Systems, Milwaukee, Wisconsin). The regional CBV map was obtained on the theoretical basis of susceptibility difference induced by first pass circulation of contrast media. (contrast media: IScc of gadopentate dimeglumine, about 2ml/sec by hand, starting at 10 second after first baseline scan). For each patient, a total of 480 images (6 slices, 80 images/slice in 160 sec) were obtained by using gradient echo(CE) single shot echo-planar image(EPI) sequence (TR 2000ms, TE SOms, flip angle $90^{\circ}$, FOV $240{\times}240mm,{\;}matrix{\;}128{\times}128$, slice-thick/gap S/2.S). After data collection, the raw data were transferred to CE workstation and rCBV maps were generated from the numerical integration of ${\Delta}R2^{*} on a voxel by voxel basis, with home made software (${\Delta}R2^{*}=-ln (S/SO)/TE). For easy visual interpretation, relative RCB color coding with reference to the normal white matter was applied and color rCBV maps were obtained. The findings of perfusion MR image were retrospectively correlated with Cd-enhanced images with focus on the degree and extent of perfusion and contrast enhancement. Results: Two cases of glioblastoma multiforme with rim enhancement on Cd-enhanced Tl weighted image showed increased perfusion in the peripheral rim and decreased perfusion in the central necrosis portion. The low grade gliomas appeared as a low perfusion area with poorly defined margin. In 2 cases of brain abscess, the degree of perfusion was similar to that of the normal white matter in the peripheral enhancing rim and was low in the central portion. All meningiomas showed diffuse homogeneous increased perfusion of moderate or high degree. One each of lymphoma and germinoma showed homogenously decreased perfusion with well defined margin. The central neurocytoma showed multifocal increased perfusion areas of moderate or high degree. A few nodules of the multiple metastasis showed increased perfusion of moderate degree. One radionecrosis revealed multiple foci of increased perfusion within the area of decreased perfusion. Conclusion: The rCBV map appears to correlate well with the perfusion state of brain tumor, and may be helpful in discrimination between low grade and high grade gliomas. The further study is needed to clarify the role of perfusion MR image in the evaluation of brain tumor.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.24-31
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• 2004

Purpose : To know the differences of proton MR spectroscopic features between recurrent rectal cancer and fibrosis in post-operative period, and to evaluate the possibility to discriminate recurrent rectal cancer from post-operative fibrosis by analysis of proton MR spectra. Materials and Methods : We evaluated the proton MR spectra from 25 soft tissue masses in perirectal area that developed in post-operative period after operation for the resection of rectal cancer. Our series included 11 cases of recurrent rectal cancer and 14 of fibrotic mass. All cases of recurrent rectal cancer and post-operative fibrosis were confirmed by biopsy. We evaluated the spectra with an attention to the differences of pattern of the curves between recurrent rectal cancer and post-operative fibrosis. The ratio of peak area of all peaks at 1.6-4.1ppm to lipid (0.9-1.6ppm) [P (1.6-4.1ppm/P (0.9-1.6ppm)] was calculated in recurrent rectal cancer and post-operative fibrosis groups, and compared the results between these groups. We also evaluated the sensitivity and specificity for discriminating recurrent rectal cancer from post-operative fibrosis by analysis of $^1H-MRS$. Results : Proton MR spectra of post-operative fibrosis showed significantly diminished amount of lipids compared with that of recurrent rectal cancer. The ratio of P (1.6-4.1ppm)/P (0.9-1.6ppm) in post-operative fibrosis was much higher than that of recurrent rectal cancer with statistical significance (p < .05) due to decreased peak area of lipids. Mean (standard deviations of P (1.6-4.1ppm)/P (0.9-1.6ppm) in post-operative fibrosis and recurrent rectal cancer group were $2.71{\pm}1.48\;and\;0.29{\pm}0.11$, respectively. With a cut-off value of 0.6 for discriminating recurrent rectal cancer from post-operative fibrosis, both the sensitivity and specificity were $100\%$ (11/11, and 14/14). Conclusion : Recurrent rectal cancer and post-operative fibrosis can be distinguished from each other by analysis of proton MR spectroscopic features, and $^1H-MRS$ can be a new method for differential diagnosis between recurrent rectal cancer and post-operative fibrosis.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.1
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• pp.28-35
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• 2008

Purpose: The aim of this study is to report the efficacy of infliximab, a monoclonal antibody directed against tumor necrosis factor alpha which is used for both treatment of refractory pediatric Crohn disease (CD) and induction of remission. Methods: Among pediatric patients who were diagnosed with CD at Samsung Medical Center between March 2001 and August 2007, a total of 16 patients were given infliximab to treat conventional therapyresistant refractory CD and severe active CD for induction of remission. Patients needing maintenance therapy were treated with an infliximab infusion every 8 weeks, and fistulizing CD patients occasionally received the infusion upon the condition that a fistula developed. The efficacy of treatment was assessed by comparing the Pediatric Crohn Disease Activity Index (PCDAI), Hct, ESR, CRP, and serum albumin levels using paired t-test. Results: The male/female ratio was 13:3, and the median age was 13 years (range, 21 months~15 years). The patients included 7 cases of therapy-resistant refractory CD, 7 cases of severe active CD, and 2 cases of fistulizing CD. Mean PCDAI before infliximab therapy was 34.19${\pm}$14.96, and mean follow-up PCDAI within 2 to 4 weeks after the last infusion was significantly lower, at 6.88${\pm}$10.31 (p=0.000). Hematological markers such as ESR (p=0.000), serum albumin (p=0.016), and CRP (p=0.009) also improved significantly after infusion. Remission was achieved in 2 of 4 patients refractory to conventional therapy. Among 3 steroid-dependent patients, 2 were able to discontinue steroid therapy, and dose reduction was possible in 1 patient. Remission after top-down therapy without prior use of other immunomodulators was achieved in 6 weeks in all 7 of the patients who had severe CD. Nine of ten refractory fistulizing CD patients also showed improvement after infliximab therapy. Conclusion: Infliximab was effective in pediatric refractory CD for induction of remission and maintenance therapy, as well as in severe CD for top-down induction therapy. Furthermore, infliximab has contributed to steroid cessation and dose reduction. Long-term follow-up evaluation is needed to determine safety and efficacy of infliximab in the future.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.213-221
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• 2005

Purpose : Urachal anomalies are rare but are known to develop several complications, especially infection. Moreover, uniform guidelines for management have not been presented because of the variable clinical characteristics of these anomalies. The purpose of this report is to review our experience with urachal anomalies and attempt to determine the optimal management. Methods : We retrospectively reviewed the records of fourteen children with a variety of urachal anomalies who had been treated from January 1996 to June 2005 at Dong Kang General Hospital. Results : The age distribution of the patients(mean age; 3.8 years) was six neonates, one infant, five preschool-age and two school-age children. The male to female ratio was 1:1. Six cases of urachal cyst, four cases of patent urachus, two cases of urachal sinus and two cases of urachal diverticulum were found. Three patients with patent urachus and one with urachal cyst had hydronephrosis. Other associated anomalies included an inguinal hernia in one patient with urachal sinus and a vesicoureteral reflux in one patient with urachal diver ticulum. As a first-line diagnostic tool, high-resolution ultrasound examination was performed in thirteen cases and computed tomography in one case. Surgical excision was performed in nine patients with urachal anomaly. Five cases out of six neonatal cases experienced spontaneous improvement during a three-month follow up period. Due to frequent infection of the umbilicus, surgical excision was performed on one neonate with urachal sinus. Conclusion : All patients with urachal anomalies should undergo investigation for associated anomalies. The neonate with urachal anomalies, especially patent urachus, do not require surgical excision unless the patient has multiple episodes of recurrent infection. (J Korean Soc Pediatr Nephrol 2005;9:213-221)

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.161-169
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• 2009

Purpose : This study was performed to report the diagnosis and treatment of nephrotic syndrome manifesting in the first year of life. Methods : We retrospectively reviewed the clinical data with chart review in 7 patients who were diagnosed as nephrotic syndrome manifesting in the first year of life from 1996 to 2007. Results : Three patients had congenital nephrotic syndrome, the other 4 patients had infantile nephrotic syndrome. Their ages ranged from birth to 11 months and male to female ratio was 1 to 6. Renal biopsies were done in 6 patients. One patient had Finnish type congenital nephrotic syndrome, 2 patients had diffuse mesangial sclerosis, 2 patients had focal segmental glomerulosclerosis and 1 patient had minimal change disease. Genetic analyses of NPHS2, PLCE1, and WT1 were done in 4 patients and 2 of them had WT1 mutation. Among 3 patients with congenital nephrotic syndrome, 1 patient was diagnosed as congenital nephrotic syndrome of Finnish type and the other 2 patients were diagnosed as Denys-Drash syndrome. All of the patients with congenital nephrotic syndrome died due to sepsis. Among 4 patients with infantile nephrotic syndrome, 2 patients died and 1 had remission, another patient progressed to end stage renal disease. Conclusion : Most of nephrotic syndrome manifesting in the first year was hereditary renal disease. Patients with nephrotic syndrome manifesting in the 3 month of life had poorer prognosis and needed more aggressive management including early dialysis and renal transplantation might be considered compared with infantile nephrotic syndrome. Further genotype-phenotype correlation studies are needed.