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Kwang-Sun Lee

Publications and source records attributed to Kwang-Sun Lee.

15 recordsLinked to original sources
PubMed2006

Clinical manifestations and risk factors of children receiving triple ventilating tube insertions for treatment of recurrent otitis media with effusion.

OBJECTIVE: Our goal was to determine risk factors for children receiving additional ventilating tube insertions after initial tube insertion and to determine the changes of clinical manifestations in children who have undergone 3 ventilating tube insertion procedures. STUDY DESIGN: We retrospectively analyzed medical and operation records of 423 young patients who had ventilating tube insertion because of chronic otitis media with effusion from January 1993 to December 1998. The single-operation group included patients who had 1 ventilating tube insertion only, and the triple-operation group included patients who received ventilating tube insertion 3 times because of recurring chronic otitis media with effusion. RESULTS: At the first operation, there were significant differences between the single- and triple-operation groups in mean age, the proportion who received a concurrent adenoidectomy, the mean indwelling period of the first ventilating tube, the proportion who developed postoperative otorrhea within 1 month, and the proportion who had early extrusion of the ventilating tube within 3 months of surgery. In the triple-operation group, the accumulated number of adenoidectomies, the indwelling period of the ventilating tube, and the time interval before subsequent ventilating tube insertion after ventilating tube extrusion significantly increased as ventilating tube insertion procedures were performed repeatedly. Although there was no difference when compared with the single-operation group, the proportion of glue-like effusion significantly decreased as ventilating tube insertion procedures were performed repeatedly. There were no significant differences between the single- and triple-operation groups in male/female ratio, site of ventilating tube insertion, and the proportion of patients with glue-like effusion at the first ventilating tube insertion. CONCLUSIONS: The probability of receiving additional ventilating tube insertion because of recurrent otitis media with effusion significantly increased in younger patients at the time of first ventilating tube insertion. The concurrent adenoidectomy, duration of the ventilating tube, postoperative otorrhea within 1 month, and early extrusion of the ventilating tube also influenced the probability of additional ventilating tube insertion.

Child, Preschool↗
PubMed2006

Inner ear anomalies in cochlear implantees: importance of radiologic measurements in the classification.

OBJECTIVE: To classify the inner ear anomalies of cochlear implantees with profound sensorineural hearing loss. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: For the normative data of the inner ear structures, the temporal bone computed tomography of 60 patients (120 ears) with normal bone-conduction threshold (< 15 dB) were used, and the data were applied to 570 ears of 285 cochlear implantees. INTERVENTIONS: Predesignated inner ear structures were measured in temporal bone computed tomography images from the normal and cochlear implantation groups using a computer-based caliper that formed part of a picture archiving and communication system. MAIN OUTCOME MEASURES: The inner ear anomalies were defined when the structures presented visually obvious malformations or the measurements deviated 2 standard deviations from the means in the normative data. RESULTS: The application of normative data to 570 profound SNHL ears resulted in the identification of 293 individual anomalies in 127 anomalous ears. An enlarged vestibular aqueduct was the most common individual anomaly (49 cases), followed by vestibular enlargement (38 cases) and other semicircular canal dysplasia (37 cases). When the individual anomalies were reaccounted according to the more prominent anomaly where multiple anomalies were present in each ear, incomplete partition type II was the most common (34 ears), followed by cochlear hypoplasia (22 ears) and incomplete partition type I (20 ears). CONCLUSION: We suggested a measurement technique for the inner ear structures using computed tomography and derived normative measurements helpful for diagnosing inner ear anomalies. Using these normative data, we classified the inner ear anomalies of profound SNHL ears in cochlear implantees.

Adolescent↗
PubMed2005

Special relationships between fetal inflammatory response syndrome and bronchopulmonary dysplasia in neonates.

OBJECTIVE: To confirm previous known relationships between Fetal Inflammatory Response Syndrome (FIRS) and neonatal bronchopulmonary dysplasia (BPD) and to present information on previously unknown special relationships between inflammatory variables and BPD. STUDY DESIGN: At delivery, we obtained biological specimens including umbilical cord venous blood for plasma interleukin-6 levels, as well as placental histology and bacteriology. Among other neonatal outcomes, we collected prospective information on BPD. RESULTS: Of 141 newborns in the study, 16 had BPD; 79% of these had antecedent FIRS, 27% of those without FIRS had BPD. By multivariable regression, only very low birth weight (adjusted [adj] odds ratio [OR] 32.0, 95% Confidence Interval [CI] 5.0 to positive infinity) and FIRS (adj OR 5.7, 95% CI 1.1 to 42.3) remained significant risk factors. Escherichia coli, perhaps due to its pyogenic nature (strongly elicits inflammatory responses), may have had a special relationship with BPD. CONCLUSIONS: In our data, FIRS and neonatal BPD are highly associated. It is possible that certain pyogenic bacteria in the chorioamnion space may be implicated more often than others. CONDENSATION: Neonates having Fetal Inflammatory Response Syndrome at delivery may later develop BPD. Pyogenic bacteria, such as Escherichia coli, may be implicated more frequently.

Bronchopulmonary Dysplasia↗
PubMed2004

Maternal education modifies the age-related increase in the birth prevalence of Down syndrome.

OBJECTIVE: To test the hypothesis that the age-related increase in the birth prevalence of Down syndrome is less for women with higher levels of education due to their more frequent use of prenatal diagnosis. METHODS: We compared the effects of maternal age on the odds of Down syndrome at birth, and on amniocentesis use, in women with <12 years of education with those who had >or=12 years of education. We used a national data set and analyzed the effects of education separately for African Americans (N = 1643054), and non-Hispanic whites (N = 6676885) in the US birth cohorts of 1989-1991. Analyses included Mantel-Haenszel and logistic regression models with the likelihood ratio test to assess interactions between education and age effects. RESULTS: For both African Americans and non-Hispanic whites, the age-related increase in the odds of Down syndrome was substantially less for women with higher levels of education (p < 0.001). For both ethnic groups, women with higher levels of education were more likely to use amniocentesis (p < 0.001). CONCLUSIONS: Our results suggest that women with higher levels of education are more likely to use prenatal diagnosis. Moreover, this effect of education on prenatal diagnosis use, translates into a lower rate of age-related increase in the birth prevalence of Down syndrome.

Adult↗
PubMed2004

Facial nerve schwannomas: different manifestations and outcomes.

BACKGROUND: The purpose of this study was to provide data on the different clinical presentations of facial nerve schwannoma, the appropriate planning for the management of schwannoma of various origins, and the predictive outcomes of surgical management. METHODS: A retrospective study was conducted in a tertiary referral hospital. We reviewed 8 consecutive cases of facial nerve schwannoma diagnosed and managed between 1993 and 2001. RESULTS: Facial nerve schwannomas originated in the internal auditory canal (IAC) (2 cases), parotid gland (2 cases), intratemporal portion (3 cases), and stylomastoid foramen (1 case). Tumor of the stylomastoid foramen presented as an intra- and extratemporal mass. The initial presenting symptom of the 8 patients was facial nerve paralysis in 4 patients, hearing loss in 2, facial numbness in 1, and an infra-auricular mass in 1. Facial palsy occurred in 7 patients during the course of the disease. One patient with a mass in the parotid gland did not show facial palsy up to 1 year after presentation of the initial symptom (facial numbness). Facial nerve paralysis was most severe in intratemporal tumors and less severe in parotid tumors. The patients with IAC suffered from hearing loss and intermittent vertigo and showed decreased vestibular function. The patients with intratemporal tumors also complained of hearing loss. The tumors were completely removed by superficial parotidectomy for parotid tumors; the translabyrinthine approach for 1 IAC tumor and 1 intratemporal tumor; the middle fossa approach for the other IAC tumor; the transmastoid approach for mastoid tumors; and the infratemporal fossa approach for intratemporal and extratemporal tumors. End-to-end cable grafts for the facial nerve were performed in 5 out of 8 cases. In 2 cases, the facial nerve was preserved after the resection of the mass. One case showed complete loss of the peripheral branch of the facial nerve. CONCLUSIONS: Facial nerve schwannoma can present in various ways. By examining the site of origin and the presenting symptoms and signs, we were able to diagnose facial nerve schwannoma preoperatively. According to the operative management of the facial nerve, the postoperative outcome of facial function could be estimated. Our finding could be pivotal in the management of the facial nerve schwannoma.

Adult↗
PubMed2004

Association between lenticulostriate vasculopathy (LSV) and neonatal intraventricular hemorrhage (IVH).

OBJECTIVES: To determine whether there is an unconfounded association between neonatal intraventricular hemorrhage (IVH) and lenticulostriate vasculopathy (LSV (also known as thalamostriate or mineralizing vasculopathy)). STUDY DESIGN: During the conduct of the Magnesium and Neurologic Endpoints Trial (MagNET), a randomized controlled trial involving maternal, hence fetal, exposure to antenatal magnesium sulfate in the context of preterm labor, head ultrasounds were obtained for each of the surviving neonates. Because of our previous experience in the diagnosis of LSV, when ascertaining the presence of IVH, as called for by the research protocol of our study, the presence or absence of LSV was also determined. RESULTS: We found LSV to be relatively prevalent (10% (14 of 140) among surviving babies). More importantly, it was significantly associated with the occurrence of neonatal IVH, even when controlled for possible confounding (adjusted OR 9.8, 95% confidence interval 1.3 to 73.1; p=0.03). CONCLUSION: Given the known relationships between IVH and neonatal morbidity and mortality, the finding of a statistically significant association between neonatal IVH and LSV may suggest more substantial implications for the latter than previously believed.

Basal Ganglia Cerebrovascular Disease↗
PubMed2003

Racial disparity in meconium-stained amniotic fluid and meconium aspiration syndrome in the United States, 1989-2000.

OBJECTIVE: To estimate the prevalence of meconium-stained amniotic fluid and meconium aspiration syndrome, as well as the differences in case fatality from meconium aspiration syndrome, between non-Hispanic black and non-Hispanic white infants. METHODS: We studied non-Hispanic black and non-Hispanic white live births with weights greater than 2.5 kg and gestational ages greater than 35 weeks, using the linked US birth and infant death cohorts for three periods: 1989-1991, 1995-1997, and 1998-2000. We used logistic regression to estimate the risks of meconium-stained amniotic fluid and meconium aspiration syndrome and to estimate the case fatality of meconium aspiration syndrome by maternal race, birth weight, period, and pregnancy complications. RESULTS: Risk of meconium-stained amniotic fluid was 80% higher in non-Hispanic blacks when compared with non-Hispanic whites (birth weight-adjusted odds ratio [OR], 1.81, 95% confidence interval [CI] 1.80, 1.82). The prevalence of pregnancy complications did not explain this racial disparity. Risk of meconium aspiration syndrome in non-Hispanic blacks was 67% higher when compared with non-Hispanic whites (birth weight-adjusted OR 1.67, 95% CI 1.64, 1.70). The case fatality rate of meconium aspiration syndrome was similar between non-Hispanic blacks and non-Hispanic whites in the three periods, with rates of 15.5, 15.2, and 11.2 per 1000 in non-Hispanic blacks and 13.5, 11.2, and 10.1 per 1000 in non-Hispanic whites in 1989-1991, 1995-1997, and 1998-2000, respectively. CONCLUSION: Our results suggest that when compared with non-Hispanic whites, non-Hispanic blacks are at significantly greater risk for meconium-stained amniotic fluid and meconium aspiration syndrome but not for meconium aspiration syndrome case fatality.

Amniotic Fluid↗
PubMed2002

The magpie trial.

Explore the source record for details and available documents.

Anticonvulsants↗
PubMed2002

Effect of medium milieu on sperm penetration and pronuclear formation of bovine oocytes matured in vitro.

The purpose of the present study was to investigate the optimal concentration of osmolarity, calcium and bicarbonate for sperm penetration and formation of pronuclei (PN), and to investigate the time required for capacitation, penetration across the zona pellucida and formation of PN in bovine cumulus-free oocytes matured in vitro. Bovine follicular oocytes collected at slaughter were matured and fertilized in vitro. Bovine sperm penetrated the zona pellucida in medium containing 240 to 440 mOsm, whereas PN formation was observed in a narrow range of osmolarities, from 280 to 360 mOsm. Maximal penetration by spermatozoa and PN formation was obtained in the medium with 2.5 mM calcium. High rates of spermatozoa penetration were observed in the medium with 37 to 49 mM NaHCO3. However, PN were formed regardless of the concentration of NaHCO3. The times required for sperm capacitation and penetration through the zona pellucida were 260 and 50 min, respectively. The first development of PN was recorded at 120 min after sperm penetration. Therefore, our study suggests that fertilization ability of spermatozoa in vitro appears to be more stable in high concentrations of NaCI. Oocytes are more sensitive to osmotic stress than spermatozoa. Calcium is required for both sperm penetration and PN formation in cumulus-free oocytes, but bicarbonate may be needed mainly for the penetration of spermatozoa.

Animals↗
PubMed2002

Retinoic acid 4-hydroxylase-mediated catabolism of all-trans retinoic acid and the cell proliferation in head and neck squamous cell carcinoma.

All-trans retinoic acid (RA) can be catabolized to polar metabolites by microsomal P450s (P450). The aim of this study was to confirm if retinoic acid 4-hydroxylase (CYP26) is a P450 induced by RA and to investigate the role of cellular RA binding proteins (CRABPs), using a slow catabolizer, AMC-HN-4, and a rapid catabolizer, AMC-HN-6. Also, we analyzed the effect of RA catabolism on cell proliferation of head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. Both cell lines weakly expressed CYP26 and CRABPs, but RA induced CYP26 only in AMC-HN-6. The sensitivity to RA was variable by the amount of CYP26, and the rapid catabolism by CYP26 made AMC-HN-6 resistant to RA in vitro. In addition, The RA had a stronger effect on the inhibition of tumor growth of AMC-HN-4 than that of AMC-HN-6 in vivo. Conclusively, the CYP26 activity might be one essential factor for the RA sensitivity, but in cells showing induction of CYP26, the RA sensitivity is inversely related to the rate of RA catabolism.

Animals↗
PubMed2002

Association between the use of antenatal magnesium sulfate in preterm labor and adverse health outcomes in infants.

OBJECTIVE: The purpose of this study was to determine whether the use of antenatal magnesium sulfate prevents adverse outcomes (neonatal intraventricular hemorrhage, periventricular leucomalacia, death, and cerebral palsy). STUDY DESIGN: In a controlled trial, we randomized mothers in preterm labor to magnesium sulfate, "other" tocolytic, or placebo. At delivery, umbilical cord blood was collected for the later determination of serum ionized magnesium levels. Neonatal cranial ultrasound scans were obtained periodically for the diagnosis of intraventricular hemorrhage and periventricular leucomalacia. Among survivors, the diagnosis of cerebral palsy was made at age 18 months. RESULTS: Children with adverse outcomes had higher umbilical cord magnesium levels at delivery. In regression models that controlled for confounders, which included very low birth weight, magnesium remained a significant risk factor (adjusted odds ratio, 3.7; 95% CI, 1.1-11.9; P =.03). CONCLUSION: Contrary to original hypotheses, this randomized trial found that the use of antenatal magnesium sulfate was associated with worse, not better, perinatal outcome in a dose-response fashion.

Adult↗
PubMed2002

Association between maternal serum ionized magnesium levels at delivery and neonatal intraventricular hemorrhage.

OBJECTIVES: To determine whether magnesium sulfate (MgSO(4)) exposure is associated with a reduced risk for neonatal intraventricular hemorrhage (IVH). STUDY DESIGN: In a randomized, controlled trial, women in preterm labor were randomly assigned to receive MgSO(4), "other" tocolytic, or saline control. At delivery, we collected maternal antecubital and umbilical cord blood for determination of serum ionized magnesium levels. Neonatal IVH was diagnosed by cranial ultrasonogram. RESULTS: Among 144 infants, 24 were diagnosed with IVH. Using crude intention-to-treat analysis, we found that 18% (13/74) of survivors exposed after birth to MgSO(4) had IVH compared with 16% (11/70) of babies who were not exposed. Infants who had IVH were more likely to have been delivered by mothers with higher serum ionized magnesium (Mg) levels (0.75 vs 0.56 mmol/L) (P =.01). Using multivariable logistic regression, we confirmed that higher Mg levels are a significant predictor of neonatal IVH (adjusted odds ratio, 15.8; 95% CI, 1.4-175.0) even when adjusted for birth weight, gestational age, antenatal hemorrhage, and neonatal glucocorticoid exposure. CONCLUSIONS: In mothers with preterm labor, our data indicate that antenatal MgSO(4) exposure may be associated with an increased risk for IVH among their newborns.

Adult↗
PubMed2002

Relationship between hypermagnesaemia in preterm labour and adverse health outcomes in babies.

The Magnesium and Neurologic Endpoints Trial (the so-called MagNET Trial) was a randomized clinical trial that was undertaken to establish whether the antenatal usage of magnesium sulphate could protect neonates from having adverse neurologic outcomes. Unfortunately, the trial was suspended after 15 months of enrolment because of excess total paediatric mortality among those exposed to magnesium sulphate. Following our original report and contrary to the original hypotheses, additional analyses of our data have actually shown a statistically significant increase in the risk of neonatal intraventricular hemorrhage, as well as total adverse paediatric outcomes, among those with higher levels of ionized magnesium at delivery. Nonetheless, it has been postulated, but not established, that anions of magnesium other than sulphate could have a more benign, or even beneficial, effect on health outcomes in the neonate.

Adult↗