[Show abstract][Hide abstract] ABSTRACT: Introduction: To report our experience in fetuses prenatally diagnosed with common arterial trunk (CAT) and to evaluate the postnatal outcomes. Material and Methods: This was a retrospective study conducted at Asan Medical Center, Seoul, Korea, between 2003 and 2012. Maternal medical and fetal echocardiographic records regarding fetuses were prenatally diagnosed with CAT were reviewed. Postnatal outcomes of survivors were also assessed during the mean follow-up of 36 months. Results: Of the 17 fetuses that were prenatally diagnosed with CAT and had a final diagnosis by postnatal echocardiography or autopsy, 12 were confirmed to have CAT and 5 were incorrectly diagnosed with CAT. Of the latter, 3 had pulmonary atresia and 2 had aortic atresia. The diagnostic accuracy was 71%. The median gestational age at prenatal diagnosis of confirmed CAT was 24.4 weeks (range 21.1-34.3). The truncal valve was prenatally thickened in 8 fetuses. All but 1 of the 12 confirmed CAT cases had associated heart and/or extracardiac anomalies. Of the 8 liveborn cases of postnatally confirmed CAT, 2 died before or after surgery respectively. The remaining 6 remained alive after successful corrective surgery. Conclusion: Prenatal diagnosis of CAT can be difficult in some cases and other diseases should be excluded before diagnosing CAT. Isolated CAT can be repaired by postnatal corrective surgery with a good outcome.
Fetal Diagnosis and Therapy 09/2013; · 1.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aims of this study were to investigate whether early arterial blood gas analysis (ABGA) could define the severity of disease in infants with congenital diaphragmatic hernia (CDH). We conducted a retrospective study over a 21-yr period of infants diagnosed with CDH. Outcomes were defined as death before discharge, and extracorporeal membrane oxygenation requirements (ECMO) or death. A total 114 infants were included in this study. We investigated whether simplified prediction formula [PO2-PCO2] values at 0, 4, 8, and 12 hr after birth were associated with mortality, and ECMO or death. The area under curve (AUC) of receiver operating characteristic curve was used to determine the optimum ABGA values for predicting outcomes. The value of [PO2-PCO2] at birth was the best predictor of mortality (AUC 0.803, P < 0.001) and at 4 hr after birth was the most reliable predictor of ECMO or death (AUC 0.777, P < 0.001). The value of [PO2-PCO2] from ABGA early period after birth can reliably predict outcomes in infants with CDH.
Journal of Korean medical science 06/2013; 28(6):924-8. · 0.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ebstein's anomaly is frequently detected before birth, with prenatal detection accounting for the majority of cases in the current population. This study aimed to identify the outcome variables among these infants. The medical records of 59 patients with neonatal Ebstein's anomaly managed at the Asan Medical Center between January, 2001 and June, 2012 were investigated retrospectively. In 46 cases, the diagnosis was made prenatally. Surgical/interventional procedures were performed for 27 of the analyzed patients. Biventricular repair was successful for 12 patients but not for 9 patients with pulmonary atresia. The median follow-up period was 1.96 years (range 0.0-10.4 years). The overall mortality rate was 23.7 % (14/59). Of the 14 deaths, 5 occurred within several hours after birth. The 1- and 5-year survival rates were 78.6 and 76.3 %, respectively. Univariate analysis identified several variables related to the time to death: fetal distress (p = 0.002), prematurity (p = 0.036), low birth weight (p = 0.003), diameter of the atrial septal defect (p = 0.022), and pulmonary stenosis/atresia (p = 0.001). Neither the Carpentier classification (p = 0.175) nor the Celermajer index (p = 0.958) was a significant variable. According to the multivariate analysis, fetal distress (p = 0.004) and pulmonary atresia/stenosis (p < 0.001) were significant determinants of outcome. In conclusion, fetal distress and pulmonary atresia/stenosis are significant predictors of mortality in the current population of patients with neonatal Ebstein's anomaly. A close cooperation of associated clinicians is required for an improvement in outcome. To establish a better surgical strategy for patients with Ebstein's anomaly and pulmonary atresia, studies of larger populations are required.
[Show abstract][Hide abstract] ABSTRACT: Non-immune hydrops fetalis is the most severe presenting feature of lysosomal storage disorders. However, it is difficult to identify the underlying condition because the different lysosomal storage diseases share many clinical features. A neonate with hydrops fetalis is described here. A lysosomal storage disorder was first suspected when the placental biopsy showed the presence of macrophages containing numerous cytoplasmic vacuoles. Subsequent comprehensive diagnostic processes and biochemical and molecular genetics characterization revealed a rare genetic cause, namely sialidosis type 2. Liquid chromatography-mass spectrometry revealed increased amounts of bound sialic acid in the urine. Pathogenic NEU1 mutations were detected. This is the first case with sialidosis type 2 ever known in the Korean population, exhibiting its most severe manifestation.
[Show abstract][Hide abstract] ABSTRACT: Abstract Background: Thyroid dysfunction is very common and is associated with neurodevelopmental impairments in preterm infants. Objectives: This study was conducted to determine the incidence and natural course of various thyroid dysfunctions and their impacts on neurodevelopmental outcomes among premature infants. Methods: A total of 177 infants were enrolled who were born at <34 weeks or whose birth weight was <1500 g and who underwent repeat thyroid function tests. We analyzed how various thyroid dysfunctions affected neurodevelopmental outcomes at 18 months of corrected age. Results: Thyroid dysfunction was noted in 88 infants. Hypothyroxinemia was observed in 23 infants, and their thyroid function was influenced by variable clinical factors. Free T4 levels were all normalized without thyroxine medication, and neurodevelopmental outcomes were not affected. In contrast, hyperthyrotropinemia was not associated with other clinical factors. Among 58 subjects who had hyperthyrotropinemia, only 31 infants showed normal thyroid-stimulating hormone (TSH) levels at follow-up tests. The remaining 27 infants had persistently high TSH levels, which significantly and poorly influenced the neurodevelopmental outcomes. Conclusions: Thyroid dysfunction is common among preterm infants. With the exception of persistent hyperthyrotropinemia, it generally does not affect neurodevelopmental outcomes. However, the beneficial effects of thyroid hormone therapy in patients with persistent hyperthyrotropinemia merits further study.
[Show abstract][Hide abstract] ABSTRACT: For evaluating the immunogenicity of an influenza vaccine, the microneutralization (MN) test has a higher sensitivity and specificity as compared to the hemagglutination inhibition (HI) test. However, the MN test is more time consuming and is difficult to standardize. We performed the MN test to determine its usefulness as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines.
We compared the MN test with the HI test using 50 paired samples taken from a previous clinical study (2008-2009) in Korean children under 18 years of age.
The linear correlation coefficients of the 2 tests for H3N2, H1N1, and influenza B were 0.69, 0.70, and 0.66, respectively. We identified a high index of coincidence between the 2 tests. For an influenza vaccine, the postvaccination seroprotection rates and seroconversion rates determined by the MN test were 78.0% and 96.0%, 90% and 42.0%, and 42.0% and 48.0% for H3N2, H1N1, and influenza B, respectively. Geometric mean titer fold increases of H3N2, H1N1, and influenza B were 2.89, 5.04, and 4.29, respectively, and were 2.5-fold higher. We obtained good results in the evaluation of the immunogenicity of the 2008-2009 seasonal influenza vaccines.
We found that the MN test was as effective as the HI test. Therefore, we suggest that the MN test can be used as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines.
Korean Journal of Pediatrics 12/2012; 55(12):474-80.
[Show abstract][Hide abstract] ABSTRACT: Type 1 citrullinemia (CTLN1) often presents as a hyperammonemic encephalopathy in the neonatal period, but it can also develop in the late-infantile period and in adults. In addition, some patients can be identified in the presymptomatic period by neonatal or family member screening. In this study, twenty Korean patients with CTLN1 (19 families) were examined; fourteen patients with neonatal-onset, three with late-onset, and three that were identified presymptomatically. The 13 patients with hyperammonemic encephalopathy received continuous venovenous hemofiltration (CVVH) or peritoneal dialysis (PD). Although the hyperammonemia was relieved more effectively in the six patients on CVVH than the seven on PD, most of these patients suffered from severe neurologic deficits. Recurrent hyperammonemic episodes (7 pts, 35%), recurrent and reversible acute hepatic dysfunction (5 pts, 25%), and focal cerebral infarction (2 pts, 10%) were noted. The neonates with hyperammonemic encephalopathy had extensive brain injuries at the onset of hyperammonemia, followed by encephalomalacia and brain atrophy at quite an early age. Genetic testing for the ASS1 gene revealed a different mutation spectrum from those of other ethnicities; Three common mutations, c.421-2A>G (37.8%), c.1128-6_1188dup67 (18.9%), and p.Gly324Ser (16.2%), accounted for 73% of the mutations. The poor outcome was expected in patients with the peak ammonia level at onset over 600μmol/L, whose proportion was higher in the neonatal presentation group than in the presymptomatic/late presentation group. Our findings add to the current understanding of the ethnic diversity of CTLN1 from both clinical and genetic perspectives.
Molecular Genetics and Metabolism 11/2012; · 2.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The goal of this study was to evaluate the effect of 2 different strategies for parenteral amino acid (AA) supplementation in the range of standard doses (>1.0-1.5 g/kg/d) on growth outcomes in very low birth weight (VLBW) infants. Materials and METHODS: The unit policy of AA doses on the first day of life changed from 1.5 g/kg/d (n = 56; standard protein group, SP, in 2008) to 3.0 g/kg/d (n = 53; high protein group, HP, in 2009) with a daily advance to a target dose of 3.5-4.0 g/kg/d. Daily nutritive and laboratory profiles were collected for the initial 14 days, and patient weight, height, and head circumference on postnatal day 14 and again at 36 weeks, 6 months, and 12 months of corrected age were evaluated. RESULTS: During the first 14 days, AA intake was greater in the HP group than in the SP group (2.9 ± 0.4 vs 2.6 ± 0.4 g/kg/d, P < .001). The HP group demonstrated a lower peak plasma glucose level during the first 3 days (116 ± 24 vs 137 ± 39 mg/dL) and a higher serum urea nitrogen level for the first 14 postnatal days than the SP group (19.2 ± 7.0 vs 14.8 ± 6.7 mg/dL) (both P < .01). From birth to postnatal 14 days and to 36 weeks, 6 months, and 12 months of corrected age, the z score changes in all growth parameters did not differ between the 2 groups. Conclusion: In the range of the standard AA protocol, there was no dose-response relationship between the early AA doses and the growth outcomes in VLBW infants. (JPEN J Parenter Enteral Nutr. XXXX;xx:xx-xx).
Journal of Parenteral and Enteral Nutrition 08/2012; · 2.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gaucher's disease is caused by a deficiency of glucocerebrosidase (GBA) and results in the accumulation of glucocerebroside within macrophages. We report on a 33(+2) gestational week premature infant whose family history was significant for a previously undiagnosed premature sibling with similar clinical features, including severe hydrops fetalis, hepatosplenomegaly, skin lesions at birth followed by death. The diagnosis of Gaucher's disease type 2 in the present case was based on postmortem pathological findings and a subsequent gene analysis that indicated a heterozygous condition for the novel deletion mutation at GBA cDNA nucleotide position 630 resulting in the frameshift (Pro171fsX21) in exon 6 and a G→A transition mutation at GBA cDNA nucleotide position 887 (Arg257Gln) in exon 7.
[Show abstract][Hide abstract] ABSTRACT: Nonketotic hyperglycinemia, also known as glycine encephalopathy, is an autosomal recessive disorder of an inborn error of the glycine metabolism, caused by deficiency in the mitochondrial glycine cleavage enzyme. The majority of cases are caused by mutations in P-protein, one of the four components of the glycine cleavage enzyme, glycine decarboxylase. We describe a male neonate with hypotonia, hiccups, and persistent apnea, but without seizures. The patient's glycine level in cerebrospinal fluid and plasma was 328.3 nmol/mL (reference value, 2.2-14.2 nmol/mL) and 1439 nmol/mL (reference value, 232-740 nmol/mL), respectively. The cerebrospinal fluid/plasma ratio of 0.228 represented an increase (normal range, <0.04). Two novel heterozygous missense mutations (c.1130C>T (p.A377V) and c.2081_2088del (p.A694DfsX11) in exons 8 and 18) in the glycine decarboxylase gene confirmed the diagnosis of nonketotic hyperglycinemia.
[Show abstract][Hide abstract] ABSTRACT: The aims of this study were to observe the respiratory syncytial virus (RSV) hospitalization rate and to identify the risk factors for hospitalization for RSV infection among infants in Korea born at <35 weeks of gestational age and who had not previously received palivizumab.
We conducted a study over a 2.5-year period (between April 2007 and September 2009) that included premature infants (<35 weeks of gestational age) who underwent follow-up during 1 year after discharge from the neonatal intensive care unit. Demographic information was collected for each subject at baseline, and the reasons for hospitalization were obtained during the 1-year follow-up period.
The study population included 1022 subjects who completed follow-up interviews. Eight hundred seventeen infants were included in analysis for RSV hospitalization. Excluded from the study were 167 subjects with chronic lung disease who had received palivizumab prophylaxis and 38 subjects who were not tested for RSV. The overall incidence of RSV hospitalization in the group that did not receive palivizumab was 4.5% (37 of 817 patients). Independent risk factors associated with RSV hospitalization were multiple gestation (P = 0.022) and longer duration of mechanical ventilation in the neonatal intensive care unit (P = 0.039).
This study showed the epidemiology and risk factors of RSV hospitalization in preterm infants in Korea. RSV infection was one of the main causes of hospitalization after discharge from the neonatal intensive care unit in patients born at <35 weeks of gestational age.
[Show abstract][Hide abstract] ABSTRACT: Samples of breast milk were collected at postpartum weeks 1, 2, 4, 6, 8, and 12 from 104 Korean mothers who had delivered infants at less than 34 weeks or weighing less than 1.8 kg to investigate changes in fatty acid (FAs). Full-term breast milk (FBM) collected at the end of first week postpartum from 26 Korean women delivering healthy, term infants was used for comparison. Stability in relative FA composition was maintained during the first 3 months of lactation in preterm breast milk (PBM), and the relative composition of polyunsaturated FAs (PUFA), monounsaturated FAs, and saturated FAs remained constant in PBM. However, the ω6/ω3 ratio was significantly higher as lactation progressed owing to lower ω3 PUFA in PBM. The proportions of docosahexaenoic acid (DHA) and arachidonic acid (AA) in PBM gradually decreased over time, but the DHA/AA ratio was kept constant at 1.13, higher than that of Western countries. At the end of the first week, relative proportions of FAs were similar in PBM and FBM, but absolute concentrations of FA were higher in PBM.
Journal of Human Lactation 08/2011; 27(3):279-85. · 1.64 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The authors reviewed the medical records of very low-birth-weight infants admitted from 1998 to 2007 and compared neurodevelopmental outcomes with their previously reported data from 1989 to 1997. The recent group included 824 infants, and the previous group included 471 infants. Neurodevelopmental outcomes were classified into cerebral palsy and non-cerebral palsy neurodevelopmental impairment. In the recent group, the survival rate was significantly higher (79.4% vs 66.2%), the rate of cerebral palsy was lower (7.9% vs 10.5%), and the rate of non-cerebral palsy neurodevelopmental impairment was higher (6.0% vs 4.5%) but not significant. The survival rate increased significantly over time, but there was no significant change in neurodevelopmental outcomes over time. Multivariate analysis indicated that abnormal neurosonographic findings, using assisted ventilation, vaginal delivery, and abnormal brainstem auditory evoked potential, were associated with increased risk for cerebral palsy.
Journal of child neurology 06/2011; 26(11):1405-10. · 1.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Campomelic dysplasia (CD; OMIM #114290), a rare form of congenital short-limbed dwarfism, is due to mutations in SOX9, a member of the SOX (SRY-related HMG box) gene family. Multiparous mother at 38 weeks' gestation delivered a 3,272 g baby boy with characteristic phenotypes including bowing of the lower limbs, a narrow thoracic cage, 11 pairs of ribs, hypoplastic scapulae, macrocephaly, flattened supraorbital ridges and nasal bridge, cleft palate, and micrognathia. He underwent a tracheostomy at the age of three months for severe laryngomalacia after a number of repeated hospitalizations due to respiratory problems and died at the age of four months from progressive respiratory failure. He was diagnosed as having CD based on a novel frameshift mutation (p.Gln458ArgfsX12) in the SOX9 gene, the mutation which has not yet been reported in Korea.
Journal of Korean medical science 01/2011; 26(1):143-5. · 0.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It is not known whether deeper or longer hypothermia (HT) can achieve better neuroprotection against hypoxic ischemic encephalopathy (HIE) in neonates. To compare the neuroprotective effects of different durations and temperatures of postischemic HT in neonatal rats with severe HIE, 7-d-old rats were subjected to the Rice-Vannucci model for 150 min hypoxia. Only the rats with identified brain lesions in diffusion-weighted MRI were assigned to normothermia (NT, 36° C/48 h) or four HT (HT-30° C/48 h; HT-30° C/24 h; HT-33° C/48 h; and HT-33° C/24 h) groups. H-magnetic resonance spectroscopy (H-MRS) and T2-weighted MRI were obtained serially, and functional studies were performed. HT groups showed significantly greater residual hemispheric volume and better rotarod and cylinder tests than did the NT group at 5 wk postischemia. HT groups also showed lower lactate-plus-lipid level in H-MRS than did the NT group at 7 d postischemia. All of these outcome variables, however, did not differ among the 4 HT subgroups, despite a trend toward greater residual brain volume in the 48-h HT versus 24-h HT subgroups. In conclusion, neither reducing the target temperature from 33 to 30° C nor prolonging the duration from 24 to 48 h produced further improvements in neurologic outcomes in neonatal rat with HIE.
Pediatric Research 10/2010; 68(4):303-8. · 2.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Furosemide is known to increase renal prostaglandin synthesis. However, its influence on ductal closure and renal toxicities of indomethacin in preterm infants has not been conclusive, especially during the early neonatal period.
To identify the effects of furosemide after indomethacin administration on the rate of patent ductus arteriosus (PDA) closure and renal function in preterm infants.
68 infants (gestational age <34 weeks and birth weight <2,000 g) receiving indomethacin therapy (one course: 0.2-0.1-0.1 mg/kg q 12 h, mostly started <48 h after birth) were randomly assigned to the furosemide (n = 35) or control (n = 33) group. Each indomethacin dose was followed by furosemide (1.0 mg/kg) or placebo. The primary (PDA closure) and secondary (acute renal failure (ARF) and others) outcomes were assessed. Renal parameters before and 0-12 and 24-36 h after the first course of indomethacin were also investigated.
In an intention-to-treat analysis, there were no differences in the PDA closure rate between the furosemide (29/34) and the control (27/29) group (p = 0.437). The incidence of ARF (serum creatinine >1.6 mg/dl) was greater in the furosemide group (20/34) than in the control group (3/29) (p < 0.001). Compared with the control group, serum creatinine and cystatin C levels and fractional excretion of sodium were significantly increased in the furosemide group for 24-36 h after indomethacin therapy (p < 0.01). There were no between-group differences in mortality and other neonatal morbidity rates.
Use of furosemide in combination with indomethacin increased the incidence of ARF but did not affect the PDA closure rate in preterm infants.
[Show abstract][Hide abstract] ABSTRACT: Increased levels of lactate are observed by (1)H magnetic resonance spectroscopy ((1)H-MRS) in rat brains after stroke. However, it is not known whether the changes in lactate levels are predictive of the degree of neuronal damage.
To investigate the correlation between changes in lactate and lipid levels measured by (1)H-MRS and neuronal cell damage in the rat brain.
A middle cerebral artery occlusion (MCAO) model was used to evaluate focal ischemia in rats (n=36). After MCAO for 90 min T2-weighted images (T2WIs), diffusion-weighted images (DWIs), and (1)H-MRS data were obtained from brains immediately, 6 hours, 9 hours, 12 hours, 18 hours, 24 hours, 3 days, and 7 days after reperfusion. Infarct volumes were measured in T2WIs obtained 4 weeks after reperfusion. The degree of neuronal damage was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining in three rats from each group at the same time as brain images were collected.
Creatine (Cr)-normalized lactate + lipid levels ([Lac+Lip]/Cr) were negatively correlated with Cr-normalized N-acetyl-L-aspartate levels (NAA/Cr) and positively correlated with TUNEL-positive cell numbers up to 24 hours after reperfusion. (Lac+Lip)/Cr at 6 hours and 9 hours was significantly correlated with NAA/Cr at 7 days, but there was no significant correlation between (Lac+Lip)/Cr during the first 24 hours and infarct volume at 4 weeks.
Up to 24 hours after reperfusion, (Lac+Lip)/Cr was strongly negatively correlated with NAA/Cr, and was a good predictor of neuronal damage at 7 days; however, it was not predictive of final infarct volume at 4 weeks.
[Show abstract][Hide abstract] ABSTRACT: Purpose: Feeding desaturation is a common problem among preterm infants which can result in prolonged hospital stays, long-term feeding difficulties and growth delay. The purpose of this study was to identify the characteristics of premature infants with feeding desaturation and to examine the effect of orocutaneous stimulation on oral feeding. Methods: During the first phase of this study, 125 extremely low birth weight infants were reviewed retrospectively. Characteris-tics between infants with feeding desaturation (n=34) and those without feeding desaturation (n=91) were examined. During the second phase, 29 infants recruited from March, 2009 to May, 2010 were subjected to orocutaneous stimulation. The results of orocutaneous stimulation were compared to a control group (n=81). Results: The first phase of the study revealed that extremely low birth weight infants with feeding desaturation were significantly lower in gestational ages at birth, and had lower 5 minute apgar scores, more gastroesophageal refluxes and bronchopulmonary dysplasia. Infants without feeding desaturation reached full enteral feeding significantly earlier and showed shorter duration of hos-pital stay. At the second phase, infants in the intervention group showed shorter days to achieve initiation of bottle feeding, shorter days in achievement of full bottle feeding, last episodes of feeding desaturation and length of hospital stay compared to the control group of similar characteristics. Conclusion: Orocutaneous stimulation among extremely low birth weight infants results in earlier achievement of full bottle feed-ings without episodes of feeding desaturation hence shortens the length of hospital stay.
Journal of the Korean Society of Neonatology. 01/2010; 17(2).
[Show abstract][Hide abstract] ABSTRACT: Congenital heart disease (CHD) is the most common developmental malformation and the leading cause of neonatal mortality and morbidity. The introduction of fetal echocardiography has made prenatal diagnosis of CHD possible.
This study was conducted to investigate the impact of fetal echocardiography on the changing disease patterns and outcomes of CHD.
A retrospective analysis of data from infants with CHD admitted to the neonatal intensive care unit (NICU) of the Asan Medical Center during the time periods was performed. Period I (1994-1996) was considered representative of a period before the introduction of fetal echocardiography, while period II (2004-2006) represented a period of more extensive application of fetal echocardiography.
A total of 164 patients were admitted to the NICU during period I and 320 during period II. The number of infants prenatally diagnosed with CHD was 5 of 164 (3.0%) in period I and 219 of 320 (68.4%) in period II (p < 0.05). The overall accuracy of fetal diagnosis was approximately 92%. Of the 3 CHD categories, there was a greater proportion of infants with 'significant' heart disease in period II than I (47 vs. 32%; p < 0.05). In contrast, there was a smaller proportion of infants with 'simple' heart defects in period II than I (22 vs. 40%; p < 0.05). The proportion of infants with 'complex' heart disease was similar in both periods (28% in period I and 31% in period II). The 1-year survival rate of patients with CHD has improved remarkably with time (70.1% in period I to 88.8% in period II). Multivariate analysis showed prenatal diagnosis and planned delivery in a tertiary NICU are factors affecting CHD outcomes, especially when defects are 'complex' (p < 0.01).
Fetal echocardiography has resulted in an increased frequency of prenatal CHD diagnosis, has altered the disease patterns observed in the NICU, and has resulted in better 1-year outcomes.