• Journal of Chest Surgery
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• 제46권3호
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• pp.178-184
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• 2013

Background: Treatment for patent ductus arteriosus (PDA) in premature infants can consist of medical or surgical approaches. The appropriate therapeutic regimen remains contentious. This study evaluated the role of surgery in improving the survival of premature neonates weighing less than 1,500 g with PDA. Materials and Methods: From January 2008 to June 2011, 68 patients weighing less than 1,500 g with PDA were enrolled. The patients were divided into three groups: a group managed only by medical treatment (group I), a group requiring surgery after medical treatment (group II), and a group requiring primary surgical treatment (group III). Results: The rate of conversion to surgical methods due to failed medical treatment was 67.6% (25/37) in the patients with large PDA (${\geq}2$ mm in diameter). The number of patients who could be managed with medical treatment was nine which was only 20.5% (9/44) of the patients with large PDA. There was no surgery-related mortality. Group III displayed a statistically significantly low rate of development of bronchopulmonary dysplasia (BPD) (p=0.008). The mechanical ventilation time was significantly longer in group II (p=0.002). Conclusion: Medical treatment has a high failure rate in infants weighing less than 1,500 g with PDA exceeding 2.0 mm. Surgical closure following medical treatment requires a longer mechanical ventilation time and increases the incidence of BPD. Primary surgical closure of PDA exceeding 2.0 mm in the infants weighing less than 1,500 g should be considered to reduce mortality and long-term morbidity events including BPD.

• Clinical and Experimental Pediatrics
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• 제58권9호
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• pp.347-353
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• 2015

Purpose: The purpose of this study was to evaluate the efficacy and safety of Montelukast sodium in the prevention of bronchopulmonarydysplasia (BPD). Methods: The Interventional study was designed as a multicenter, prospective, and randomized trial, with open labeled and parallel-experimental groups, 66 infants were enrolled and allocated to either the case group (n=30) or the control group (n=36) based on gestational age (GA). Infants in the case group were given Montelukast sodium (Singulair) based on their body weight (BW). Zero week was defined as the start time of the study. Results: The incidence of moderate to severe BPD was not different between the groups (case group: 13 of 30 [43.3%] vs. control group: 19 of 36 [52.8%], P=0.912). Additionally, secondary outcomes such as ventilation index, mean airway pressure and resort to systemic steroids were not significantly different. There were no serious adverse drug reactions in either group, and furthermore the rate of occurrence of mild drug related-events were not significantly different (case group: 10 of 42 [23.8%] vs. control group: 6 of 48 (15.8%), P=0.414). Conclusion: Montelukast was not effective in reducing moderate or severe BPD. There were no significant adverse drug events associated with Montelukast treatment.

• Journal of Periodontal and Implant Science
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• 제26권2호
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• pp.491-510
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• 1996

This study was performed to evaluate the effects of platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) on the characteristics of beagle dog's periodontal ligament (BPD) cells and bone marrow (BBM) cells which have the important role on the early stage of periodontal tissue regeneration in vitro. In control group, the cells ($1.5{\times}10^5$cells/ml) were cultured alone with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum, $50{\mu]g/ml$ ascorbic acid, and 10mM/ml ${\beta}-glycerophosphate$. In experimental groups, growth factors, PDGF or EGF(10ng/ml), were added into the above culture condition. And then each group was characterized by examining the cell proliferation rate, amount of total protein synthesis, alkaline phosphatase activity at 1, 5, 9, 13, 17th day after seeding of cells into the culture wells. The results were as follows: 1. Both BPD and BBM cells in PDGF-treated group proliferated more rapidly than non-treated cells. This finding also was observed in EGF-treated group but it was not as prominent as that of PDGF-treated group. The proliferation rates of both cells showed the time-dependent pattern during experimental periods in all three groups. 2. Amount of total protein synthesis was more increased in PDGF-treated group than in control group. But no significant difference between EGF-treated group and control group was observed throughout experimental periods even though the tendency of amount of protein synthesis was time-dependent pattern. 3. Alkaline phosphatase activity also more increased in PDGF-treated group than control group. But slight decrease tendency was seen in both cells of EGF-treated group. From the above results, PDGF appeared to enhance the proliferation and cellular activities including amount of total protein synthesis and alkaline phosphatase activity of BPD and BBM cell, but EGF did not show notable effects. The optimal application of these growth factors was thought to be useful as the adjunctive means in periodontal regeneration procedures.

• Neonatal Medicine
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• 제15권1호
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• pp.22-31
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• 2008

목 적 : 기관지폐이형성증은 미숙한 폐에서의 혈관과 폐포발달의 저해로 특징 질 수 있다. 폐 발달의 결과를 고려하면 줄기세포의 투여로 자가 회복기전을 이용한 폐 발달의 촉진의 가능성은 유망하고 이로 폐 기관지이 형성의 유병률과 합병증을 줄일 수 있다. 강화된 Green fluorescent protein (EGFP)를 표기인자로 표시한 줄기세포를 비 EGFP 마우스에 주사하여 생착 여부를 보고자 하였다. 방 법 : VEGFR2 억제제인 SU1498을 생후 3일된 마우스에 주사하여 폐포발달이 저해된 모형을 만들었다. 생후 4일에 $1{\times}10^6$ EGFP 양성 줄기세포를 복강 내로 주입하였다. 줄기세포를 투여한 폐의 형태학적인 분석과 면역염색을 시행 하였고, 주입된 줄기 세포의 생착을 확인하기 위해서 동일초점 현미경으로 분석하였다. 결 과 : SU1498을 주사한 신생마우스에서 폐포 표면적과 평균 폐포 용적이 감소되었다. 폐 발달이 억제된 마우스 모형에서 주입한 EGFP 양성 줄기세포가 발견 되었고, 내피세포와 외피세포로 분화함을 공초점 현미경으로 확인하였다. 결 론 : 주입된 EGFP 양성 줄기세포가 혈관생성억제제를 이용하여 만든 마우스의 폐 발달 저해 모형에서 생착 하여 내피세포와 외피세포로 분화함을 확인하였다.

• Journal of Chest Surgery
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• 제56권3호
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• pp.155-161
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• 2023

Background: Surgical closure of an atrial septal defect (ASD) is infrequently indicated during infancy. We evaluated the clinical characteristics and outcomes of patients who underwent surgical ASD closure during infancy. Methods: A single-center retrospective review was performed for 39 patients (19 males) who underwent surgical ASD closure during infancy between 1993 and 2020. The median body weight percentile at the time of operation was 9.3. Results: During a median follow-up of 60.9 months, 4 late deaths occurred due to chronic respiratory failure. A preoperative history of bronchopulmonary dysplasia (BPD) was the only risk factor for late mortality identified in Cox regression (hazard ratio, 3.54; 95% confidence interval [CI], 1.75-163.04; p=0.015). The 5-year survival rate was significantly lower in patients with preoperative history of BPD (97.0% vs. 50.0%, p<0.001) and preoperative ventilatory support (97.1% vs. 40.4%, p<0.001). There were significant postoperative increases in left ventricular end-diastolic (p=0.017), end-systolic (p=0.014), and stroke volume (p=0.013) indices. A generalized estimated equation model showed significantly better postoperative improvement in body weight percentiles in patients with lower weight percentiles at the time of operation (<10th percentile, p=0.01) and larger indexed ASD diameter (≥45 mm/m², p=0.025). Conclusion: Patients with ASD necessitating surgical closure during infancy are extremely small preoperatively and remain small even after surgical closure. However, postoperative somatic growth was more prominent in smaller patients with larger defects, which may be attributable to an increase in postoperative cardiac output due to changes in ventricular septal configuration. The benefits of ASD closure in patients with BPD are undetermined.

• Neonatal Medicine
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• 제25권1호
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• pp.7-15
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• 2018

We need to understand the outcomes into adulthood for survivors born either extremely low birthweight (ELBW; <1,000 g) or extremely preterm (EP; <28 weeks' gestational age), particularly their blood pressure and cardiovascular metabolic status,respiratory function, growth, psychological and mental health performance, and functional outcomes. Blood pressure is higher in late adolescence and early adulthood in ELBW/EP survivors compared with controls. In some studies, expreterm survivors have higher insulin and blood lipid concentrations than controls, which may also increase their risk for later cardiovascular disease. ELBW/EP survivors have more expiratory airflow obstruction than do controls. Those who had bronchopulmonary dysplasia (BPD) in the newborn period have even worse lung function than those who did not have BPD. As a group, they are unlikely to achieve their full lung growth potential, which means that more of them are likely to develop chronic obstructive airway disease in later life. Although they are smaller than term born controls, their weight gradually rises and ultimately reaches a mean z-score close to zero in late adolescence, and they ultimately attain a height z-score close to their mid-parental height z-score. On average, ex-preterm survivors have intelligence quotient (IQ) scores and performance on tests of academic achievement approximately 2/3 SD lower than do controls, and they also perform less well on tests of attention and executive function. They have similar high rates of anxiety and depression symptoms in late adolescence as do controls. They are, however, over-represented in population registries for rarer disorders such as schizophrenia and Autism Spectrum Disorder. In cohort studies, ex-preterm survivors mostly report good quality of life and participation in daily activities, and they report good levels of self-esteem. In population studies, they require higher levels of economic assistance, such as disability pensions, they do not achieve education levels as high as controls, fewer are married, and their rates of reproduction are lower, at least in early adulthood. Survivors born ELBW/EP will present more and more to health carers in adulthood, as they survive in larger numbers.

• Clinical and Experimental Pediatrics
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• 제55권11호
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• pp.414-419
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• 2012

Purpose: This study aimed to assess early development in very low birth weight (VLBW) infants with mild intraventricular hemorrhage (IVH) or those without IVH and to identify the perinatal morbidities affecting early neurodevelopmental outcome. Methods: Bayley Scales of Infant Development-II was used for assessing neurological development in 49 infants with a birth weight <1,500 g and with low grade IVH (${\leq}$grade II) or those without IVH at a corrected age of 12 months. Results: Among the 49 infants, 19 infants (38.8%) showed normal development and 14 (28.6%) showed abnormal mental and psychomotor development. Infants with abnormal mental development (n=14) were mostly male and had a longer hospitalization, a higher prevalence of patent ductus arteriosus (PDA) and bronchopulmonary dysplasia (BPD), and were under more frequent postnatal systemic steroid treatment compared with infants with normal mental development (n=35, P<0.05). Infants with abnormal psychomotor development (n=29) had a longer hospitalization and more associated PDA compared to infants with normal psychomotor development (n=20, P<0.05). Infants with abnormal mental and psychomotor development were mostly male and had a longer hospitalization and a higher prevalence of PDA and BPD compared to infants with normal mental and psychomotor development (n=19, P<0.05). Using multiple logistic regression analysis, a longer duration of hospitalization and male gender were found to be significant risk factors. Conclusion: Approximately 62% of VLBW infants with low grade IVH or those without IVH had impaired early development.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제23권4호
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• pp.377-387
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• 2020

Purpose: To compare between sodium acetate (SA) and sodium chloride (SC) in parenteral nutrition (PN) with associated metabolic acidosis and neonatal morbidities in preterm infants. Methods: Preterm infants below 33 weeks gestational age, and with a birth weight under 1,301 g were enrolled and further stratified into two groups: i) <1,000 g, or ii) ≥1,000 g in birth weight. The subjects were randomized to receive PN containing SA or SC within the first day of life. The results of routine blood investigations for the first 6 days of PN were collated, and the neonatal outcomes were recorded upon discharge or demise. Results: Fifty-two infants entered the study, with 26 in each group: 29 infants had extremely low birth weight (ELBW). There were no significant differences in birth weight, gestation, sex, exposure to chorioamnionitis and antenatal steroids, surfactant doses and duration of mechanical ventilation between groups. The SA group had significantly higher mean pH and base excess (BE) from days 4 to 6 than the SC (mean pH, 7.36 vs. 7.34; mean BE -1.6 vs. -3.5 [p<0.01]), with a two-fold increase in the mean BE among ELBW infants. Significantly fewer on SA required additional bicarbonate (n=4 vs. 13, p=0.01). The rate of bronchopulmonary dysplasia (BPD) was approximately four-fold lower in SA than SC (n=3 vs. 11, p<0.01). No significant differences were observed in necrotizing enterocolitis, patent ductus arteriosus, retinopathy of prematurity, cholestatic jaundice, and mortality between groups. Conclusion: The use of SA in PN was associated with reduced metabolic acidosis and fewer BPD.

• 한국음향학회지
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• 제36권4호
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• pp.285-291
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• 2017

두 개 수신기에 들어오는 신호 간의 시간 지연 값을 추정하기 위한 방법들이 연구되고 있다. 그중에서 채널 추정 기법을 기반으로 한 방법의 경우는 두 수신기의 입력 신호간의 상대적인 지연을 채널의 임펄스 응답처럼 추정하는 방법이다. 이 경우에는 해당 채널의 특성이 희소 채널의 특성을 가지고 있다. 기존의 방법들은 채널의 희소성을 이용하지 못하고 있는 방법이 대부분이다. 본 논문에서는 채널의 희소성을 이용하기 위하여 희소 신호 최적화 방법의 하나인 BPD(Basis Pursuit Denoising) 최적화 기법을 사용한 시간 지연 추정 방법을 제안한다. 제안한 방법을 기존의 일반 상호 상관(Generalized Cross Correlation, GCC) 방법과 적응 소유치 분해법 및 희소 신호 추정법의 일종인 RZA-LMS(Reweighted Zero-Attracting Least Mean Square)들과 비교하여, 백색 가우시안 신호원과 유색 신호원 및 해양 포유류 신호원에 대해서 비교 실험을 하였다. 그 결과 갑자기 추정성능이 열화되는 문턱 현상이 늦게 나타나거나 훨씬 줄어드는 것을 보였다.

• 한국지형학회지
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• 제26권3호
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• pp.53-67
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• 2019

The purpose of this study is to identify the quality of landslide susceptibility in a landslide-prone area (Jinbu-myeon, Gangwon-do, South Korea) by spatial prediction modeling approach and compare the results obtained. For this goal, a landslide inventory map was prepared mainly based on past historical information and aerial photographs analysis (Daum Map, 2008), as well as some field observation. Altogether, 550 landslides were counted at the whole study area. Among them, 182 landslides are debris flow and each group of landslides was constructed in the inventory map separately. Then, the landslide inventory was randomly selected through Excel; 50% landslide was used for model analysis and the remaining 50% was used for validation purpose. Total 12 contributing factors, such as slope, aspect, curvature, topographic wetness index (TWI), elevation, forest type, forest timber diameter, forest crown density, geology, landuse, soil depth, and soil drainage were used in the analysis. Moreover, to find out the co-relation between landslide causative factors and incidents landslide, pixels were divided into several classes and frequency ratio for individual class was extracted. Eventually, six landslide susceptibility maps were constructed using the Bayesian Predictive Discriminant (BPD), Empirical Likelihood Ratio (ELR), and Linear Regression Method (LRM) models based on different category dada. Finally, in the cross validation process, landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract success rate curve. The result showed that Bayesian, likelihood and linear models were of 85.52%, 85.23%, and 83.49% accuracy respectively for total data. Subsequently, in the category of debris flow landslide, results are little better compare with total data and its contained 86.33%, 85.53% and 84.17% accuracy. It means all three models were reasonable methods for landslide susceptibility analysis. The models have proved to produce reliable predictions for regional spatial planning or land-use planning.