Ee-Kyung Kim

Seoul National University Hospital, Sŏul, Seoul, South Korea

Are you Ee-Kyung Kim?

Claim your profile

Publications (66)79.59 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Increased pro-inflammatory cytokines are suggested in the pathogenesis of necrotizing enterocolitis (NEC). The transcription factor, nuclear factor-ĸB (NF-ĸB), is a central regulator of inflammatory and immune responses, and recent rodent NEC models have shown that NF-ĸB may have a critical role in the disease processes that underlie NEC. Heat shock proteins have important functions in response to stress-related events in a variety of systems, including digestive organs. Objectives: We investigated whether heat shock pretreatment protects intestinal epithelial damage in the early NEC rat model. Methods: We generated human NEC-like lesions in neonatal rat ileum by administering oral endotoxin (10 mg/kg), intermittent 8% hypoxia, and hypertonic formula. Heat shock was administered by raising the chamber temperature to 42°C for 20 min, 3 h prior to endotoxin ingestion. Results: Heat shock pretreatment increased the expression of HSP70 in the ileal tissue and attenuated histological severity of early experimental NEC. NF-ĸB was activated in the ileal tissue of the NEC group and this activation was attenuated by heat shock pretreatment, which was determined by electrophoretic mobility shift assay and Western blot analysis of p50 in subcellular fractionated samples. Conclusions: Heat shock pretreatment reduced the incidence and severity of early experimental NEC in rats. A possible mechanism underlying this protective effect includes inhibition of NF-ĸB activation through increased HSP70 expression.
    Neonatology 08/2012; 103(1):1-6. DOI:10.1159/000339179 · 2.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A nationwide survey was conducted to determine the incidence of bronchopulmonary dysplasia (BPD) in Korea and the intercenter differences in survival and BPD rates among preterm infants. Questionnaires were sent to all registered neonatal intensive care units (NICUs). The questionnaires inquired about the survival and BPD rates of very low birth weight (VLBW, < 1,500 g) infants who had been admitted to each NICU from 2007 to 2008. BPD was defined as requiring oxygen at 36 weeks' postmenstrual age. Almost all level III NICUs replied. During the study period, 3,841 VLBW infants were born in the NICUs that responded to the survey. The survival rate was 81% and the BPD rate was 18%. Combined outcome of BPD or death rate was 37%. The BPD rate and combined outcome of BPD or death rate varied considerably from 5% to 50% and 11% to 73%, respectively across the centers. There was no significant correlation between the survival rate and the BPD rate across the centers. In conclusion, the incidence of BPD among VLBW infants in Korea during the study period was 18%, and a considerable intercenter difference in BPD rates was noted.
    Journal of Korean medical science 08/2012; 27(8):914-21. DOI:10.3346/jkms.2012.27.8.914 · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine whether neurally adjusted ventilatory assist (NAVA), a new method of mechanical ventilation that delivers pressure assistance that is proportional to the electrical activity of the diaphragm (EAdi), could lower the inspiratory pressure and respiratory muscle load in preterm infants supported with ventilators. Twenty-six mechanically ventilated preterm infants were randomized to crossover ventilation with NAVA and synchronized intermittent mandatory ventilation (SIMV) with pressure support (PS) for 4 hours each in a randomized order. A 1-hour interval for washout was provided between the 2 modes of ventilation. The ventilator settings were adjusted to maintain similar levels of end-tidal partial pressure of CO(2). The ventilator parameters, vital signs, and gas exchange effects under the 2 ventilatory modes were compared. Nineteen infants completed the 9-hour crossover comparison protocol. Peak inspiratory pressure (PIP), work of breathing, and peak EAdi with NAVA were lower than those in SIMV with PS. Calculated tidal volume to peak EAdi ratio and PIP to peak EAdi ratio were higher with NAVA. There were no significant differences in mean airway pressure, inspiratory oxygen fraction, and blood gas values. The measurements of vital signs did not differ significantly between the 2 modes. NAVA lowered PIP and reduced respiratory muscle load in preterm infants at equivalent inspiratory oxygen fraction and partial pressure of CO(2) of capillary blood in comparison with SIMV with PS.
    The Journal of pediatrics 06/2012; 161(5):808-813.e2. DOI:10.1016/j.jpeds.2012.04.040 · 3.74 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of our study was to investigate the differential effects of dexamethasone (DXM) and hydrocortisone (HCS) on somatic growth and postnatal lung development in a rat model of bronchopulmonary dysplasia (BPD). A rat model of BPD was induced by administering intra-amniotic lipopolysaccharide (LPS) and postnatal hyperoxia. The rats were treated with a 6-day (D1-D6) tapering course of DXM (starting dose 0.5 mg/kg/day), HCS (starting dose 2 mg/kg/day), or an equivalent volume of normal saline. DXM treatment in a rat model of BPD induced by LPS and hyperoxia was also associated with a more profound weight loss compared to control and LPS + O(2) groups not exposed to corticosteroid, whereas HCS treatment affected body weight only slightly. Examination of lung morphology showed worse mean cord length in both LPS + O(2) + DXM and LPS + O(2) + HCS groups as compared to the LPS + O(2) alone group, and the LPS + O(2) + DXM group had thicker alveolar walls than the LPS + O(2) group at day 14. The HCS treatment was not significantly associated with aberrant alveolar wall thickening and retarded somatic growth. The use of postnatal DXM or HCS in a rat model of BPD induced by intra-amniotic LPS and postnatal hyperoxia appeared detrimental to lung growth, but there was less effect in the case of HCS. These findings suggest that effect of HCS on somatic growth and pulmonary outcome may be better tolerated in neonates for preventing and/or treating BPD.
    Journal of Korean medical science 04/2012; 27(4):395-401. DOI:10.3346/jkms.2012.27.4.395 · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Granulocyte colony-stimulating factor (G-CSF) is known to mobilize endothelial progenitor cells (EPCs) from bone marrow. EPCs reportedly promote neovascularization and participate in the repair of lung structure in adult animals. We tested the hypothesis that G-CSF contributes to alveolar growth by increasing the production of angiogenic growth factor in the lungs of hyperoxia-exposed neonatal mice. Neonatal mice were exposed to hyperoxia (80%) or room air (RA) for 7 days and treated with G-CSF (50 μg/kg/day) or vehicle for 5 days. Blood was subjected to flow cytometry to gate for CD45(dim/-)/Sca-1(+)/CD133(+)/vascular endothelial growth factor (VEGF) receptor-2 (VEGFR2) to define the EPC population at day 7. The percentage of EPCs in the peripheral blood and VEGF and VEGFR2 levels in the lungs of neonatal mice exposed to hyperoxia were significantly reduced compared to those of mice kept in RA. G-CSF significantly increased EPCs in the peripheral blood, and VEGF and VEGFR2 levels in the lungs of both mice exposed to hyperoxia and mice kept in RA. G-CSF restored alveolarization inhibited by hyperoxia without altering normal alveolarization under RA. G-CSF restored alveolarization inhibited by hyperoxia in the developing lungs and this alveolarization-enhancing effect of G-CSF is associated with mobilization of EPCs and upregulation of VEGF signaling.
    Neonatology 01/2012; 101(4):278-84. DOI:10.1159/000335285 · 2.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study was aimed to evaluate the neonatal mortality and morbidity of infants affected by twin-twin transfusion syndrome (TTTS) compared to the control twins matched for gestational age. Also the perinatal outcomes of donor parts of TTTS twins with their counterpart recipients were compared.
    01/2012; 19(1):32. DOI:10.5385/jksn.2012.19.1.32
  • [Show abstract] [Hide abstract]
    ABSTRACT: Brain magnetic resonance imaging (MRI) scans have become increasingly popular as a predictive tool for neurodevelopmental outcome in preterm infants, while serial brain ultrasonograms remain as a standard evaluation modality for neonatal brain. The aim of this study was to determine whether brain MRI taken at term-equivalent age could give us further information over serial brain ultrasonograms taken during admission.
    01/2012; 19(1):41. DOI:10.5385/jksn.2012.19.1.41
  • [Show abstract] [Hide abstract]
    ABSTRACT: To report the follow-up status and neurodevelopmental outcomes of extremely low birth weight (ELBW) survivors at 18 months' corrected age (CA).
    01/2012; 19(1):17. DOI:10.5385/jksn.2012.19.1.17
  • [Show abstract] [Hide abstract]
    ABSTRACT: Neonatal morbidity is strongly related to birth weight, and low birth weight (LBW) is known to be associated with childhood and even adult outcomes. This study aimed to investigate the associations of parental socio-economic status (SES) on the risks of low birth weight in the Republic of Korea.
    01/2012; 19(4):262. DOI:10.5385/jksn.2012.19.4.262
  • [Show abstract] [Hide abstract]
    ABSTRACT: Peroxiredoxins (Prdx), a family of antioxidant proteins, have important defensive roles in the degenerative brain diseases and neuronal cell death in adult subjects. However, little is known in the neonatal brain. Here, we studied the developmental expression of Prdxs and their response to dexamethasone in the perinatal rat brain. Prdx 1 expression increased during late gestations and peaked at postnatal-day 1, when its expression gradually decreased. Prdx 2 expression remained largely unchanged. Prdx 6 expression continually increased as growing. Using immunohistochemistry, each Prdx showed a strong expression in the cerebral cortex and hippocampus. Prdx 1 was strongly expressed in the corpus callosum. The dexamethasone injection increased the expression of Prdx 6. In conclusion, we reveal for the first time that Prdx 1, 2 and 6 are found in abundance in the perinatal rat brain and are differentially expressed during development. The expression of Prdx 6 was affected by dexamethasone treatment.
    Free Radical Research 12/2011; 46(3):231-9. DOI:10.3109/10715762.2011.649749 · 2.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Meconium obstruction (MO) of prematurity can result in increased morbidity or mortality and prolonged hospitalization if not diagnosed and treated appropriately. The aims of our study were to identify the incidence and risk factors associated with MO and to review the treatment outcomes. A retrospective analysis was undertaken of 101 extremely low birth weight infants (ELBWIs) who were born between January 1, 2007, and April 1, 2009, at Seoul National University Hospital. Prenatal and neonatal factors were compared between the MO and control groups. The treatment outcomes were also reviewed. Twenty-two (22%) patients were diagnosed as having MO. Eighteen of these patients (82%) had prenatal risk factors for MO. Respiratory distress syndrome was more prevalent in the MO group than in the control group (p = 0.001). Overall, 17 of the 22 patients (77%) were relieved with medical treatment and the rest underwent ileostomy. The times to full enteral feeding did not differ between the medically treated group and the control group. However, the surgically treated group required more time to achieve full enteral feeding, and some patients had persistent gastrointestinal problems. MO is not a rare condition in ELBWIs, and the majority of ELBWIs have prenatal risk factors. Medical management was effective, and medically manageable cases had good prognoses for subsequent feeding, whereas some surgically managed cases had persistent gastrointestinal problems.
    Neonatology 10/2011; 101(3):172-8. DOI:10.1159/000330850 · 2.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Despite the potential importance of pulmonary artery hypertension (PAH) in preterm infants with bronchopulmonary dysplasia (BPD), little is known about the risk factors for PAH. To investigate the risk factors for PAH in preterm infants with BPD. Infants diagnosed with BPD were assigned to the PAH group or non-PAH group except for infants with mild BPD who had no PAH. PAH was diagnosed on the basis of echocardiograms demonstrating elevated right ventricle pressure beyond the postnatal age of 2 months. Logistic regression analysis was done for the multivariate assessment of the risk factors for PAH in preterm infants with moderate or severe BPD. A total of 98 infants among 145 infants with BPD were divided into a PAH group (n = 25) or non-PAH group (n = 73), while the remaining 47 infants had mild BPD with no PAH. Among the study patients, survival rate of the PAH group was significantly lower than that of the non-PAH group. Infants with PAH had more severe cases of BPD and underwent longer durations of oxygen therapy, conventional or high-frequency ventilation, and hospitalization compared to those without PAH. Low 5-min Apgar scores (≤6; relative risk (RR) 6.2; 95% confidence interval (CI) 1.4-28.0; p = 0.017) and oligohydramnios (RR 7.7; 95% CI 2.0-29.6; p = 0.030) were found to be significant risk factors for PAH according to multivariate analysis. The present study shows that oligohydramnios is a specific risk factor for PAH in preterm infants with moderate or severe BPD.
    Neonatology 07/2011; 101(1):40-6. DOI:10.1159/000327891 · 2.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Currently, bronchopulmonary dysplasia (BPD) occurs almost exclusively in pre-term infants. In addition to prematurity, other factors like oxygen toxicity and inflammation can contribute to the pathogenesis. This study aimed to compare urinary inflammatory and oxidative stress markers between the no/mild BPD group and moderate/severe BPD group and between BPD cases with significant early lung disease like respiratory distress syndrome (RDS) ('classic' BPD) and with minimal early lung disease ('atypical' BPD). A total of 60 patients who were a gestational age < 30 weeks or a birth weight < 1250 g were included. Urine samples were obtained on the 1(st), 3(rd) and 7(th) day of life and measured the levels of leukotriene E(4) (LTE(4)) and 8-hydroxydeoxyguanosine (8-OHdG). The 8-OHdG values on the 3(rd) day showed significant correlation to duration of mechanical ventilation. The 8-OHdG levels on the 7(th) day were the independent risk factor for developing moderate/severe BPD. In 'classic' BPD, the 8-OHdG values on the 3(rd) day were higher than those of 'atypical' BPD. In 'atypical' BPD, the LTE(4) values on the 7(th) day were higher than the values in 'classic' BPD. These results suggest that oxidative DNA damage could be the crucial mechanism in the pathogenesis of current BPD and the ongoing inflammatory process could be an important mechanism in 'atypical' BPD.
    Free Radical Research 06/2011; 45(9):1024-32. DOI:10.3109/10715762.2011.588229 · 2.99 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: McKusick-Kaufman syndrome (MKS) is an autosomal recessive multiple malformation syndrome characterized by hydrometrocolpos (HMC) and postaxial polydactyly (PAP). We report a case of a female child with MKS who was transferred to the neonatal intensive care unit of Seoul National University Children's Hospital on her 15th day of life for further evaluation and management of an abdominal cystic mass. She underwent abdominal sonography, magnetic resonance imaging, genitography and cystoscopy which confirmed HMC with a transverse vaginal septum. X-rays of the hand and foot showed bony fusion of the left third and fourth metacarpal bones, right fourth dysplastic metacarpal bone and phalanx, right PAP and hypoplastic left foot with left fourth and fifth dysplastic metatarsal bones. In addition, she had soft palate cleft, mild hydronephroses of both kidneys, hypoplastic right kidney with ectopic location and mild rotation, uterine didelphys with transverse vaginal septum and low-type imperforated anus. She was temporarily treated with ultrasound-guided transurethral aspiration of the HMC. Our patient with HMC and PAP was diagnosed with MKS because she has two typical abnormality of MKS and she has no definite complications of retinal disease, learning disability, obesity and renal failure that develop in Bardet-Biedl syndrome, but not in MKS until 33 months of age. Here, we describe a case of a Korean patient with MKS.
    Korean Journal of Pediatrics 05/2011; 54(5):219-23. DOI:10.3345/kjp.2011.54.5.219
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine if histologic chorioamnionitis (HC) in the presence of respiratory distress syndrome (RDS) augments adverse pulmonary outcomes in extremely low birth weight (ELBW) infants. We retrospectively identified 184 ELBW infants who were born at and admitted to the neonatal intensive care units between June 2005 and June 2009. The mean gestational age of the cases was 27 ± 2 weeks, and the mean birth weight was 791 ± 147 g. A total of 88% (161/184) of patients developed bronchopulmonary dysplasia (BPD). HC was observed in 71 of 238 infants (39%). When infants were divided on the basis of the presence or absence of HC and RDS, the incidence of moderate or severe BPD and duration of oxygen requirement were greater in the HC+RDS+ group than in the HC-RDS+ or HC+RDS- groups. The combination of prenatal (HC) and postnatal (RDS) injuries increased significantly the risk for BPD. In the multivariate analysis, the significant predictors of developing BPD were low gestational age (odds ratio (OR), 0.6; confidence interval (CI), 0.4 to 0.7) and exposure to both HC and RDS (OR, 4.7; CI, 1.1 to 20.2). The HC and RDS work synergistically to induce lung injury in ELBW infants. Chorioamnionitis may interact with RDS to further increase the risk of BPD, despite either HC or RDS could not show independent significant association with BPD.
    Journal of perinatology: official journal of the California Perinatal Association 03/2011; 31(3):166-70. DOI:10.1038/jp.2010.113 · 2.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There were many reports of longitudinal changes in the causative organisms of neonatal sepsis in Western countries but few in Asia. We aimed to study longitudinal trends in the epidemiology of neonatal sepsis at Seoul National University Children's Hospital (SNUCH), a tertiary center in Korea, and compared the results to previous studies of Western countries. The medical records of all of the neonates who were hospitalized at SNUCH from 1996 to 2005 with positive blood cultures were reviewed. We also compared the findings to previous 16-yr (1980-1995). One hundred and forty-nine organisms were identified in 147 episodes from 134 infants. In comparison with the previous 16-yr studies, there was a decrease in the number of Escherichia coli infections (16.2% vs 8.7%: odds ratio [OR] 0.495; 95% confidence interval [CI], 0.255-0.962; P = 0.035), but an increase in Staphylococcus aureus (16.6% vs 25.5%: OR 1.720; 95% CI, 1.043-2.839; P = 0.033) and fungal infections (3.3% vs 18.7%: OR 6.740; 95% CI, 2.981-15.239; P < 0.001), predominantly caused by Candida species. In conclusion, the incidence of sepsis caused by E. coli decreases, but S. aureus and fungal sepsis increases significantly. Compared with Western studies, the incidence of sepsis caused by S. aureus and fungus has remarkably increased.
    Journal of Korean medical science 02/2011; 26(2):284-9. DOI:10.3346/jkms.2011.26.2.284 · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the association between the occurrence and severity of retinopathy of prematurity (ROP) and postnatal weight gain.
    Journal of the Korean Ophthalmological Society 01/2011; 52(9):1071. DOI:10.3341/jkos.2011.52.9.1071
  • [Show abstract] [Hide abstract]
    ABSTRACT: Preterm infants with oligohydramnios after preterm premature rupture of membranes can present with severe respiratory distress immediately after birth, and the most common cause is pulmonary hypoplasia. Unlike infants with pulmonary hypoplasia, some cases have shown dramatic improvement with aggressive ventilatory support during the initial 1-2 days of distress; those patients have been defined as having dry lung syndrome. It is assumed that oligohydramnios leads to functional pulmonary hypoplasia by compression of the fetal lungs; some of the improvement in dry lung syndrome may thus have resulted from inflation of compressed lung tissue and increase of lung compliance. We report two incidences of dry lung syndrome that were treated successfully with high inflation pressure and inhaled nitric oxide (NO); these are the first dry lung syndrome cases to be reported in Korean infants.
    01/2011; 18(1):158. DOI:10.5385/jksn.2011.18.1.158
  • 01/2011; 18(1):111. DOI:10.5385/jksn.2011.18.1.111
  • [Show abstract] [Hide abstract]
    ABSTRACT: Late-onset hypotension in preterm infants is not a rare condition. Late circulatory collapse due to adrenal insufficiency (AI) is one of the major causes of late-onset hypotension. We assessed the incidence and causes of late-onset hypotension. We also compared the clinical findings according to the presence of AI.
    01/2011; 18(2):211. DOI:10.5385/jksn.2011.18.2.211