• Clinical and Experimental Pediatrics
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• v.52 no.12
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• pp.1364-1369
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• 2009

Purpose : To analyze abnormal ventricular activation in childhood congenital heart disease induced by postoperative changes in ventricular volume and pressure and ventricular scar formation using signal-averaged electrocardiography (SAECG). Methods : Fifty-two patients who had undergone open heart surgery (OHS) were enrolled. Patients were divided into the following 3 groups: right ventricular volume overload (atrial septal defect, group1), left ventricular volume overload (ventricular septal defect, group2), and right ventricular pressure overload (tetralogy of Fallot, group 3). The patients were monitored by standard 12-lead ECG and SAECG before and 2 months after the operation. QRS duration, QT and QTc intervals, filtered QRS (f-QRS), high frequency low amplitude potential (HFLA), and root mean square (RMS) voltage in the terminal 40 ms of SAECG were determined. Results : In the preoperative period, group1 showed significant increase in QRS (P=0.011) compared to those of the other 2 groups. In the postoperative period, group3 showed significant increase in the QTc interval (P=0.004) compared to those in the other 2 groups. SAECG parameters showed no significant differences among the groups in the pre- or postoperative period. Of the 52 patients, 12 (23%) in the preoperative period and 21 (40%) in the postoperative period had at least 1 SAECG abnormality. The prevalence of SAECG abnormalities was significantly higher in the postoperative group 2 and group 3 (preoperative: 20% versus postoperative: 28%, P<0.001, preoperative: 14% versus postoperative: 64%, P<0.001, respectively). Conclusion : Abnormal SAECG patterns may be attributed to postoperative scars, OHS itself, and/or ventricular overload.

• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.818-823
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• 2009

Purpose : We aimed to evaluate the frequency and characteristics of minor clinical manifestations of atopic dermatitis (AD) in Korean children to aid the diagnosis and treatment of AD. Methods : From April 2007 to December 2007, we enrolled 106 children (aged 1 month [infants] to 15 years) diagnosed with AD at the Pediatric Allergy Respiratory Center in Soonchunhyang University Hospital. Clinical manifestations were examined and laboratory findings (total and specific immunoglobulin E [IgE] levels and peripheral blood eosinophil count) were analyzed and compared. Results : Minor symptoms, in order of frequency, included xerosis (78.3%), aggravation due to environmental or emotional stress (43.4%), lichenification (35.8%), orbital darkening (34.0%), periauricular eczema (33.0%), and cutaneous infection (31.1%). Older children (${\geq}2$ years) showed more orbital darkening (P=0.01), horizontal crease (P=0.01), and lichenification (P=0.001) than infants. Patients with severe AD (scoring atopic dermatitis [SCORAD] score, ${\geq}40$) showed higher frequencies of xerosis (P= 0.04), cutaneous infection (P=0.03), ichthyosis (P=0.18), keratosis pilaris (P=0.02), pityriasis alba (P=0.07), recurrent conjunctivitis (P=0.02), orbital darkening (P=0.001), aggravation due to environmental or emotional stress (P=0.05), facial eczema (P=0.001), lichenification (P=0.001), and hand/foot eczema (P=0.04) than those with mild-to-moderate AD. Children with atopic eczema showed more facial eczema (P=0.01) and lichenification (P=0.04) than those with non-atopic eczema. Conclusion : The clinical manifestations of AD were similar to those established by Hanifin and Rajka. However, we need to develop our own diagnostic criteria for AD, because the frequencies shown by our subjects differed from those observed in other countries.

• 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.1247-1251
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• 2007

Purpose : Pathologically, Kawasaki disease (KD) is associated with widespread vascular endothelial damage in the acute phase. The vasculitis induced endothelial injury leads to coagulation abnormalities. Abnormalities of endothelial function, platelet activation, and fibrinolysis are present during acute phase and long after the onset of KD. The aim of study is to evaluate the change of hemostatic markers in the clinical stages of KD and to assess the hemostatic markers to be a useful indicator of the development of coronary artery lesion (CAL). Methods : Seventy four KD patients diagnosed in Chungnam National University Hospital from November 2004 to June 2007. Eleven febrile control and eleven healthy children were selected for healthy control. All blood samples were collected before and after Intravenous gammaglobulin (IVGG), $2^{nd}$ week, and $4^{th}-8^{th}$ week of illness of KD. Results : Initial D-dimer level of Kawasaki disease showed meaningful difference compared to control group (P<0.05). D-dimer and fibrinogen degradation products (FDP) before IVGG increased compared with normal control group and decreased after IVGG administration. It is normalized until 2 weeks later, and continue to decreasing. D-dimer and FDP were significantly different according to the CAL before IVGG. Conclusion : The hemostatic markers may change to the clinical stage of KD, which may suggest the degree of endothelial injury. Increased some hemostatic markers may be the predictors for development of CAL.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.610-615
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• 2008

Purpose : Idiopathic thrombocytopenic purpura (ITP) is a relatively common hematological disease in children. It generally occurs after exposure to a common viral infection episode; however, it may occasionally follow immunization with measles, measles-mumps-rubella (MMR), hepatitis B (HBV), influenza, diphtheria-tetanus-pertussis (DTP), or chickenpox vaccines. In this study, the incidence, clinical characteristics, and treatment outcome of vaccination-associated ITP were investigated and compared with non-vaccination-associated ITP. Methods : The admission records of 105 pediatric ITP patients between 0-14 years of age admitted to Department of Pediatrics, Wonkwang University Hospital from January 1994 to July 2007 were retrospecitively reviewed. Patients were grouped into a vaccination-associated group and a non-vaccination-associated group according to vaccination history within the previous 1 month, and various clinical features between the two groups were statistically analyzed. Results : Thirteen patients (12%) had a preceding vaccination. Eight had received DTP vaccination, 2 had received hepatitis B, and 1 each had received influenza, MMR, and Japanese B encephalitis vaccination. However, none of the patients had a recurrent thrombocytopenia after subsequent vaccinations. In the vaccination-associated group, the age was significantly lower, anemia was more common, and the risk period with blood platelet count $<20{\times}10^9/L$ was significantly shorter than for the in non-vaccination-associated group. Also, wet purpura was less prominent and the remission within 1month was more frequently achieved in the vaccination-associated ITP group. Conclusion : Vaccination-associated ITP patients showed mild symptoms with a more benign and shorter lasting course than non-vaccination-associated ITP patients. Moreover, platelet count assessment at the time of the next immunization may not be necessary.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.729-735
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• 2008

Purpose : Chlamydia trachomatis is one of the most common sexually transmitted diseases and is also a cause of pneumonia in infants. Respiratory infections by respiratory viruses are also common for infants. The objectives of this study were to identify the clinical manifestations and to determine the prevalence of C. trachomatis respiratory infections and coinfections by respiratory viruses in infants younger than 6 months of age. Methods : For this study, we enrolled 6 months or younger infants who were admitted to the Dankook University Hospital between January 2002 and July 2007, with respiratory symptoms. Nasopharyngeal aspirates or throat swabs were collected within s d of hospitalization and C. trachomatis was detected using polymerase chain reaction (PCR). Patients who tested positive underwent multiplex PCR for respiratory viruses. Results : A total of 690 patients underwent chlamydial PCR testing and 36 (5.2%) had positive results. Of the 36, 28 (78%) were male; 30 were vaginally delivered. From the 36 patients positive for C. trachomatis, 26 underwent multiplex respiratory viral PCR; 12 were coinfected with viruses. Respiratory syncytial virus (RSV) was the most frequent pathogen that was detected in 6 patients. Increased C-reactive protein and fever were significant in patients coinfected with respiratory viruses. Conclusion : C. trachomatis can infected in infants delivered by cesarean section as well as in 6 months old or younger infants. Infant with C. trachomatis respiratory infections can also be coinfected with respiratory infection also coinfected with respiratory viruses. Further studies are needed to better understand the prevalence rates of the this infection and its coinfection rate with respiratory viruses.

• Progress in Medical Physics
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• v.21 no.1
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• pp.86-92
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• 2010

The purpose of this study was to measure curvature contour skin dose using radiochromic film and TLD for a conventional open field. We also attempted to quantify the degradation of skin sparing associated with use of immobilization devices for high energy photon beams and to calculate the skin dose with a help of Monte Carlo (MC) simulation. To simulate head-and-neck and shoulder treatment, a cylindrical solid water phantom 11 cm in diameter was irradiated with 6 MV x-rays using $40{\times}40\;cm^2$ field at 100 cm source axis distance (SAD) to the center of the phantom. Aquaplastic mesh mask was placed on the surface of the cylindrical phantom that mimicked relevant clinical situations. The skin dose profile was obtained by taking measurements from $0^{\circ}$ to $360^{\circ}$ around the circumference of the cylindrical phantom. The skin doses obtained from radiochromic film were found to be 47% of the maximum dose of $D_{max}$ at the $0^{\circ}$ beam entry position and 61% at the $90^{\circ}$ oblique beam position without the mask. Using the mask (1.5 mm), the skin dose received was 59% at $0^{\circ}$ incidence and 78% at $80^{\circ}$ incidence. Skin dose results were also gathered using thin thermoluminescent dosimeters (TLD). With the mask, the skin dose was 66% at $0^{\circ}$ incidence and 80% at $80^{\circ}$ incidence. This method with the mask revealed the similar pattern as film measurement. For the treatments of the head-and-neck and shoulder regions in which immobilization mask was used, skin doses at around tangential angle were nearly the same as the prescription dose. When a sloping skin contour is encountered, skin doses may be abated using thinner and more perforated immoblization devices which should still maintain immoblization.

• Progress in Medical Physics
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• v.21 no.1
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• pp.1-8
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• 2010

In this study, we evaluated the dose response of MAGAT (Methacrylic Acid Gelatin gel and THPC) normoxic polymer gel dosimeters based on the X-ray CT scanner. To perform this study, we determined the proper ratio of the gel composition and acquired X-ray scan parameters. MAGAT gel dosimeters were manufactured using MAA (MethacrylicAcid) and gelatin of various concentration, irradiated up to 20 Gy. We obtained the 20 CT images from the irradiated gel dosimeters by using on a Phillips Brilliance Big Bore CT scanner with the various scan parameters. This CT images were used to determine the $N_{CT}$-dose response, dose sensitivity and dose resolution As an amount of MAA and gelatin were increase, the slope and intercept were increase in each MAGAT gel dosimeter with various concentration of the $N_{CT}$-dose response curve. The dose sensitivity was $0.38{\pm}0.08$ to $0.859{\pm}0.1$ and increased were amount of the MAA was increased or the gelatin was decreased. However, the change of gelatin concentration was very small compare to MAA. The Dose resolution ($D_{\Delta}^{95%}$) varies considerably from 2.6 to 6 Gy, dependent on dose resolution and CT image noise. The slope and dose sensitivity was almost ident verywith the variation of the tube voltage, tube current and slice thickness in the dose response curve, but the noise (standard deviation of averamalg CT number) was decreased when the tube voltage, tube current and slice thickness are increase. The optimal MAGAT polymer gel dosimeter based on the CT were evaluated to determine the CT imaging scan parameters of the maximum tube voltage, tube current and slice thickness (commonly used in clinical) using the composition ratio of a 9% MAA, 8% gelatin and 83% water. This study could get proper composition ratio and scan parameter evaluating dose response of MAGAT normoxic polymer gel dosimeter using CT scanner.

• Pediatric Infection and Vaccine
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• v.10 no.1
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• pp.81-86
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• 2003

Purpose : Streptococcus pneumoniae remains a leading cause of meningitis, sepsis, pneumonia, and otitis media in children worldwide. Emergence of drug-resistant organism has substantially complicated the therapy of these infections. This study was conducted to determine the clinical features and changing patterns of antibiotic-resistant rates of Streptococcus pneumoniae. Methods : We have retrospectively examined 306 cases of culture proven patients who were admitted to the Department of Pediatrics, Severance hospital, from the year 1991 to year 2000. The type of culture specimen used, presence of penicillin resistance, characteristics according to various presenting diseases and their prevailing year were also examined. Results : The mean age of cases was 7.9 year and the ratio of male to female was 1.6 : 1. The main age group of pneumococcal infection was under 2 years(42%). Systemic infections associated with pneumococci were sepsis(19.3%) and meningitis(9.5%), while local infections presented as pneumonia(29.2%), otitis media(19.3%), exudative tonsillitis(13.3%), and sinusitis(9.2%) in the order of frequency. Seasonal variation was seen in the incidence of pneumococcal infection: high incidence of infection was seen in Spring(Mar.~Apr; 32%), while the incidence was low during summer(Aug.~Sep.; 6%). Penicillin-resistant rate of pneumococci was steadily on the increase since the year 1991(65%) to year 2000(84%). Conclusion : Antibiotic-resistant pneumococci increased during the past decade. For effective prevention of pneumococcal infections, national survey of pneumococcal infections and expanded use of pneumococcal vaccination would be needed.

• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.55-62
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• 2015

Purpose: Varicella Zoster Immune Globulin (VZIG) is available in Korea for post-exposure prophylaxis of the Varicella-zoster virus (VZV) in high-risk patients. In July 2013, the United States Centers for Disease Control and Prevention (US CDC) recommended extending the time for administration of VariZIG$^{(R)}$ from within 96 hours up to 10 days after VZV exposure. This study was performed to analyze the effectiveness of VZIG prophylaxis between the two groups of patients who received VZIG within 96 hours and more than 96 hours of exposure to varicella. Methods: A retrospective chart review was performed in pediatric patients who received VZIG at Samsung Medical Center, Seoul, Korea from January 2001 to December 2012. Results: A total of 91 patients were identified. Fifty-seven patients were male (62.6%) and the median age was 5.91 years. Thirty-nine patients (42.9%) were exposed to VZV in the hospital. Underlying diseases were solid tumors (41.8%), hematologic malignancies (40.7%), and others (17.5%). Forty-five patients (49.5%) were hematopoietic cell transplant recipients. Seventy-four patients (81.3%) received VZIG within 96 hours after VZV exposure. There was no significant difference in the development of chickenpox between the two groups (2.7% vs. 5.9%, P=0.4664). In 22 seronegative patients, we also observed no significant difference between the groups in terms of the development of chickenpox (6.6% vs. 0%, P=0.667). Conclusions: This study showed that the effectiveness of VZIG for the prevention of chickenpox was comparable between patients who received VZIG within 96 hours and those who received VZIG more than 96 hours after exposure to VZV.