Protective Effects of N-acetylcystenine and Selenium against Doxorubicin Toxicity in Rats

Yeo-sung Yoon,Sun-don Kim,Min-hye Lee,Heung-shik S.Lee,In-se Lee,Je-kyung Sung,Eun-sung Park 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.2

Effects of N-acetylcysteine and Selenium against Doxorubicin Toxicity in RatsEun-sung Park, Sun-don Kim1, Min-hye Lee, Heung-shik S. Lee, In-se Lee, Je-kyung Sung and Yeo-sung Yoon*

금속가공유 사용 근로자에서 발생한 과민성폐장염 1예

이선웅,고동희,진구원,박동욱,이정탁,송윤희,이상윤 大韓産業醫學會 2008 대한직업환경의학회지 Vol.20 No.1

서론: 과민성폐장염의 원인물질로 금속가공유는 외국의 경우 작업장의 집단발병 사례들을 중심으로 많은 보고가 되어 왔으나 우리나라에서는 아직 보고되지 않았으며,저 자들은 금속가공유에 1년간 노출된 근로자에서 발생한 과민성폐장염 1예를 발견하였기에 작업환경측정을 시행한 후 작업관련성을 평가하여 보고하는 바이다. 증례: 64세 남자 환자가 1년간 강관을 절단하는 작업을 한 후 호흡곤란을 주소로 내원하였다 노출력,임상적 소견 및 방사선학적 소견을 토대로 과민성폐장염으로 진단되었다. 작업환경 측정결과 공기 중 금속가공유,엔도 톡신,총 세균 및 곰팡이는 각각 0.531 mg/m³, 6.33 EU/m³ 100 CFU/m³ 및 75 CFU/m³이었고,금속가 공유 내 엔도톡신,총세균 및 곰팡이는 각각 1.5x10⁴EU/mL,4.6x10^(5) CFU/mL 및 1.8×10^(5) CFU/mL이었다. 고찰: 금속가공유 내의 원인항원에 대한 침강항체를 검사하지 못했으나,작업환경 측정결과 금속가공유가 일반적인 허용가능 수준 이상으로 오염되었으며,기존의 과민성폐장염 발생 사례들과 비슷한 수준 또는 그 이상으로 오염되어 있었다. 공기 중 금속가공유 농도 역사 NIOSH의 REL과 ACGIH의 NIC를 초과하고,기존의 사례들에 비해서도 대체적으로 높은 수준 이었다. 금속가공유 이외의 다른 원인에 대한 감별과 기존의 발생사례들과의 노출수준 비교를 통하여,저자들은 환자가 금속가공유에 의한 미생물 항원에 노출되어 과민성폐장염이 발생한 것으로 판단하였다. Introduction: There have been no reports of hypersensitivity pneumonitis caused by metal working fluids in Korea, despite their existence in other countries. Here, we report the first such case, along with an assessment of work-relatedness through exposure assessment. Case report: A 64-year old male patient visited the hospital with dyspnea after metal pipe cutting for about a year. He was diagnosed with hypersensitivity pneumonitis from the evidence of specific exposure history, clinical symptoms, and radiologic findings. The air exposure levels of the oil mist, endotoxin, total bacteria and fungus in the work environment was TWA(8-hr) 0.531 mg/m³, 6.33 EU/m³, 100 CFU/m₃ and 75 CFU/m³, respectively. The concentrations of the endotoxin, total bacteria and fungus within the metal working fluid was 1.5 X 10⁴EU/mL, 4.6 X 10^(5) CFU/mL and 1.8 X 10^(5) CFU/mL, respectively. Discussion: Although the patient did not receive a specific precipitating antibody test, the microbial concentration within the metal working fluid was higher than normal and similar to previous case reports, The oil mist level in the air exceeded the NIOSH REL and ACGIH NIC, and were similar or higher than previous cases. By excluding other causes of hypersensitivity pneumonitis, we concluded that the disease developed from exposure to microbial antigens in the metal working fluid.

정수처리공정에서 소독부산물인 트리할로메탄의 생성모델

이성식,성낙창,이종팔,박현석,정미은,이상준,윤태경 한국환경과학회 2004 한국환경과학회지 Vol.13 No.3

We have been proposed model equation which is able to predict the trihalomethane producing concentration formation, that is one of byproduct, in the water treatment processes. In proposed model, the effects of trihalomethane factors like chlorine contact time, pH, temperature, TOC and UV-254 are considered. The concentration of the trihalomethane produced is proportion to the contact with chlorine, pH of water, temperature of water TOC and UV-254, respectively. This proposed model could be predicted the formed concentration of trihalomethanes by trihalomethane factors.

흰쥐 성장기간에 따른 Xylene의 독성에 관한 연구

이혜자,이상희,전태원,이상일,윤종국 대한의생명과학회 2000 Journal of biomedical laboratory sciences Vol.6 No.3

실험동물에 있어서 연령 차이에 따라서 xylene 독성이 어떠한 차이가 있는지를 검토하는 일환으로 5주령 및 12주령 흰쥐에 50% m-xylene을 체중 100 g 당 0.25 ml씩 1회 투여한 다음 24시간 후에 처치하여 다음과 같은 결과를 얻었다. Xylene 투여로 인한 요 중 methylhippuric acid 함량은 5주령군이 12주령군에 비해 현저하게 높게 나타났다. 그리고 간조직 중 cytochroms P-450 함량은 대조군에 있어서 5주령군이 12주령군 보다 약 50% 정도 낮게 나타났으나 xylene 투여로 인한 cytochrome P-450 함량 증가율은 12주령군 보다 5주령군에서 높게 나타났다. 간 alcohol dehydrogenase 활성치도 대조군에 있어서는 5주령군이 12주령 보다 약 35% 정도 낮게 나타났으나 xylene 투여로 인한 본 효소의 활성 증가율은 5주령군에서 오히려 높게 나타났다. 그러나 간 aldehyde dehydrogenase 활성치는 대조군 및 xylene 투여군 모두 5주령과 12주령간에 유의한 차이를 나타내지 않았다. 한편 xylene 투여시 체중 당 간무게, 간조직 malondialdehyde 함량 및 혈청 ALT 활성 변동을 통하여 간손상 정도를 상호 비교 관찰하였을 때, 12주령군이 5주령 실험동물 보다 간손상이 다소 심하게 나타남을 알 수가 있었다. 이상 실험결과는 연령에 따라 xylene에 의한 간손상의 차이는 이물질의 생체내 대사율이 달리 나타나기 때문일 것으로 생각된다. To evaluate an effect of aging on the xylene toxicity, 50% m-xylene in olive oil (0.25 ml/100 g body wt.) was administered to 5 week and 12 week-old rats one times intraperitoneally and sacrificed at 24 hrs afterwards. The increasing rate of urinary H-methylhippuric acid concentration was higher in 12 week-old rats than 5 week-old rats by the treatment of m-xylene. On the liver function findings, i.e., liver weight/body weight (%), serum levels of ALT activity and hepatic malondialdehyde content, 12 week-old rats showed more severe liver injury than 5 weeks those in xylene-treated rats. And the hepatic cytochrome P-450 contents was higher in 12 weeks rats than those of in 5 week-old rats, but the increasing rate of that was lower in 12 week-old rats. Hepatic alcohol dehydrogenase activity was also higher in 12 week-old rats than in 5 week-old rats whereas the increasing rate of that was higher in 5 week-old than those in 12 week-old rats by the xylene treatment. Furthermore, the hepatic aldehyde dehydrogenase activities were no differences between the 5 and 12 week-old rats both in the control and xylene-treated group, In conclusion, age may influences upon the hepatotoxicity with xylene and it may be responsible for xylene metabolism in rats.

Apoptosis and necroptosis‑inducing effects of arctigenin on nasal septum carcinoma RPMI‑2650 cells in 2D and 3D culture

Yoon‑Jin Lee,Kwan‑Sik Park,Byoung Joon Baek,Kyong‑Ae Lee,Sang‑Han Lee 대한독성 유전단백체 학회 2020 Molecular & cellular toxicology Vol.16 No.1

Backgrounds Arctigenin derived from the seeds of Arctium lappa Linnaeus is known as an anticancer drug candidate by targeting various pathways involved in anticancer therapy. Methods Using 2D monolayer and 3D spheroid culture systems in nasal septum carcinoma RPMI-2650 cells, the effects of arctigenin and dexamethasone on cell viability, ROS levels, ATP level, mitochondrial function, apoptosis and necroptosis were examined. Results The combination treatment of both compounds induced strong cytotoxicity, accompanied by increases of sub-G0/ G1 peak, annexin V-PE-positive cells, and ROS levels, loss of mitochondrial membrane potential, and decrease of cellular ATP content. These changes were observed as simultaneous induction of DNA damage, apoptosis, and necroptosis. A series of changes by arctigenin and dexamethasone were efficiently restored by decreasing ROS levels or supplementing ATP. Treatment of 3D spheroids with arctigenin and dexamethasone decreased cell viability in the spheroids, but it was slightly resistant than cells under 2D conditions. In addition, this phenomenon was accompanied by an increase in mediators for both apoptosis and necroptosis. Conclusion Results of this study suggest that the apoptosis and necroptosis-inducing effects of arctigenin are associated with ATP depletion due to oxidative mitochondrial dysfunction.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

연작업자들의 신기능 평가에서 요중 δ-aminolevulinic acid 측정의 의의

이병국,이숙,김용배,리갑수,김화성,황규윤,장봉기,이성수,안규동 순천향대학교 산업의학연구소 1999 순천향산업의학 Vol.5 No.1

To clarify the effect of occupational lead exposure on renal function 241 lead workers working and 56 non lead workers were studied in 5 lead acid battery industries. Study variables for renal effect were urinary N-acetyl-β-D-glucosaminidase(NAG), urinary total protein(U-TP), blood urea nitrogen(BUN), serum creatinine(S-Cr), and serum uric acid(S-Ua). On the other hand, blood lead(PbB), zinc protoporphyrin in whole blood(ZPP), and delta-aminolevulinic acid in urine(δ-ALA) were selected for the variables of lead exposure. Information on age, work duration, smoking and drinking history were also obtained. The results obtained were as follows. While the mean values of lead exposure indicators of lead workers were significantly different from non-exposed ones, the mean values of BUN, U-TP and S-Cr of renal function indicators of exposed were also different from non-exposed. BUN, U-TP and NAG showed statistically significant correlation with PbB and ZPP, and NAG revealed also statistically strongly significant correlation with δ-ALA. On multiple regression using renal fuction indicators as a dependent variable and δ-ALA, age, work duration,lead exposure,smoking and drinking as independent variables, only δ-ALA contributed to NAG.

업종에 따른 연 취급 사업장의 기중 연 농도 및 연 노출 수준 평가

이병국,김용배,리갑수,안현철,김화성,이용진,황규윤,장봉기,이성수,안규동 순천향대학교 산업의학연구소 1999 순천향산업의학 Vol.5 No.1

In order to obtain an useful information for health management and biological monitoring of lead exposed workers, Authors tried to investigate air lead level and the lead exposed level of workers in lead industry according to occupational category. The subjects in our study were 2074 workers in 7 lead-using industries, and study subjects were divided into 4 occupational categories such as storage battery industry (type 1), primary smelting industry (type 2), secondary smelting industry (type 3) and litharge making industry (type 4). Blood zincprotoporphyrin concentration (ZPP), blood lead concentration (PbB) and urinary δ -aminolevulinic acid (ALAU), hemoglobin (Hb), hematocrit (Hct) were selected as the indices of lead exposure. Personal variables such as age, work duration were also collected. The results were as follows. 1. The geometric mean air lead in 9 lead-using industry was 0.1133±4.3120 ㎎/㎥, and that in type 1, 2, 3 and 4 was 0.1038±3.4952 ㎎/㎥, 0.0429±3.4329 ㎎/㎥, 0.1877±2.5123 ㎎/㎥ and 0.9961±5.2910 ㎎/㎥, respectively. 2. The mean ZPP in 9 lead-using industry was 53.1±28.0 ㎍/㎗, and that in type 1, 2, 3 and 4 was 52.0±24.8 ㎍/㎗, 48.0±16.4 ㎍/㎗, 109.8±85.6 ㎍/㎗ and 74.3±37.8 ㎍/㎗, respectively. There was significant difference in ZPP according to occupational category (P<0.01). The percents of lead workers whose ZPP were above 100 ㎍/㎗ in type 1, 2, 3 and 4 were 4.0%, 1.7%, 34.3% and 21.6%, respectively. 3. The mean PbB in lead-using industry was 26.0±11.2 ㎍/㎗, and that in type 1, 2, 3 and 4 was 25.3±11.1 ㎍/㎗, 26.7±8.8 ㎍/㎗, 50.3±15.2 ㎍/㎗ and 36.4±11.0 ㎍/㎗, respectively. There was significant difference in PbB according to occupational category (P<0.01). The percents of lead workers whose PbB were above 40 ㎍/㎗ in type 1, 2, 3 and 4 were 10.4%, 7.7% 71.9% and 43.2%, respectively. 4. While the correlation of Hb corrected PbB with ZPP was higher than non corrected PbB, the correlation of log-transformed ZPP with PbB was higher than non corrected ZPP. 5. Simple linear regressions of PbB and corrected PbB as independent variable with ZPP, log-transformed ZPP and ALAU as dependent variable were statistically significant (P0.01). Coefficient of determination of corrected PbB with other variables was higher than non corrected PbB. As the result of this study, it was suggested that reconsideration of environmental and biological monitoring program was highly recommended for secondary smelting and litharge making industry.

모 연취급장 근로자들의 연폭로지표들과 혈압과의 관련성

임상복,김용배,이용진,리갑수,김화성,황규윤,장봉기,이성수,안규동,이병국 순천향대학교 산업의학연구소 1998 순천향산업의학 Vol.4 No.1

In order to investigate the relationship between blood lead with other lead exposure indices and blood pressure in occupationally lead exposed male workers, 629 workers(515 lead exposed workers and 114 non lead exposed workers) in a storage battery factory were studied. Blood lead(PbB), zinc protoporphyrin(ZPP) and urinary δ-aminolevulinic acid(ALAU) were selected as an index of lead exposure. Height and weight were also meaured with calibrated automatic height-weight machine to produce fatness index directly. Personal information on smoking and drinking history were also collected. Blood pressure was mearured by trained nurses with automatic sphingomanometer. All workers took at least 30 minute rest before their measurement of blood pressure. The results obtained were as follows: 1. The prevalence rate of hypertension of lead exposed and non-exposed workers were 3.5% in both group without any difference. 2. There were no differences of systolic and diastolic pressure between groups divided by lead exposure, smoking habit, drinking habit. but the increase of age group made the difference of diastolic pressure, and only differenct of systolic pressure observed in age group of less than 20 and that of more than 40. 3. In pearson's correlation analysis, PbB was correlated with systolic pressure significantly, but not with diastolic pressure. PbB was also correlated with pressure difference(systolic pressure-diastolic pressure). 4. There were no significant increase of systolic, diastolic pressure and pressure difference by the increase of PbB and ZPP grouping. 5. Stepwise multiple regression analysis using systolic pressure as dependent variable and PbB, ZPP, ALAU, age, work duration, smoking habit, drinking habit and fatness (weight*0.9/height-100) as independent variables, revealed that PbB, age, drinking habit and fatness in order were significantly contributed to the dependent variable. 6. Stepwise multiple regression analysis using diastolic pressure as dependent variable and PbB, ZPP, ALAU, age, work duration, smoking habit, drinking habit and fatness (weight*0.9/height-100) as independent variables, revealed that ALAU, age and fatness in order were significantly contributed to the dependent variable. 7. Stepwise multiple regression analysis using pressure difference as dependent variable and PbB, ZPP, ALAU, age, work duration, smoking habit, drinking habit and fatness(weight*0.9/height-100) as independent variables, revealed that PbB, age and fatness in order were significantly contributed to the dependent variable. 8. Logistic analysis of hypertensive conditions with categorized blood lead and other selected categorized independent variables indicated that only age(40> and 40≤) and fatness(1.0> and 1.0≤) were significantly contributed to dependent variable with 95% significant odd ratio confidence interval. With above results, lead exposure in terms of blood lead seemed to be minimally contributed to the raise of blood pressure, and the effect of blood lead was found to be more prominent on the pressure difference than the systolic and diastolic pressure themselves.

A Multi-Center Educational Research Regarding Breastfeeding for Pediatrics Residents in Korea

Yong Sung Choi,정성훈,김은선,Eun Sun Kim,Eunhee Lee,Euiseok Jung,So-Yeon Lee,이우령,Hye Sun Yoon,Yong Joo Kim,Ji Kyoung Park,Son Moon Shin,Ellen Ai-Rhan Kim 대한신생아학회 2022 Neonatal medicine Vol.29 No.1

Purpose: Pediatricians have a significant responsibility to educate mothers about the importance of breastfeeding. However, there have been minimal efforts in the courses of resident training in Korea. The purpose of this study is to evaluate the change in knowledge and attitude before and after a 4-week breastfeeding educational intervention among multicenter residents. Methods: Prospective interventional educational research was designed for residents at eight training hospitals in Korea. Institutional reviews were obtained in each hospital. The education curriculum consisted of 14 courses regarding breastfeeding theory and practice. These materials were used to teach pediatric residents for 4 weeks. Knowledge-based tests were administered before the course, and re-tests were administered after the course using different test items of similar levels. Test scores and survey responses were compared before and after the intervention. Results: A total of 73 residents (1st year 20, 2nd year 23, 3rd year 16, and 4th year residents 14) from eight training hospitals completed the intervention. Their average age was 30.3±2.9 years, 17 (23.3%) were male, 22 (30.1%) were married, and eight had more than one child of their own. The mean pre-test score was 61.8±13.4 and the mean post-test score was 78.3±7.5 (P<0.001). The inter-grade difference in the score was significant in the pre-test (P=0.005), but not significant in the post-test (P=0.155). There were more responses of obtaining confidence after the intervention (P<0.001). Conclusion: In our study, pediatric residents showed improvement in their knowledge and confidence level after 4 weeks of the breastfeeding curriculum. This will provide a basis for future policymaking in the training of pediatric residents regarding breastfeedReceived: 6 January 2022 Revised: 15 February 2022 Accepted: 15 February 2022 Correspondence to: Ellen Ai-Rhan Kim, MD Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea Tel: +82-2-3010-3390 Fax: +82-2-3010-6978 E-mail: arkim@amc.seoul.kr A Multi-Center Educational Research Regarding Breastfeeding for Pediatrics Residents in Korea Yong-Sung Choi, MD,PhD1, Sung-Hoon Chung, MD, PhD2, Eun Sun Kim, MD, PhD3, Eun Hee Lee, MD4, Euiseok Jung, MD5, So Yeon Lee, MD, PhD5, Wooryoung Lee, MD6, Hye Sun Yoon, MD, PhD7, Yong Joo Kim, MD, PhD8, Ji Kyoung Park, MD, PhD9, Son Moon Shin, MD, PhD9, and Ellen Ai-Rhan Kim, MD, PhD5 1Department of Pediatrics, Kyung Hee University Hospital, Seoul, Korea 2Department of Pediatrics, Kyung Hee University Hospital at Gangdong, Seoul, Korea 3Department of Pediatrics, Kangwon National University Hospital, Chuncheon, Korea 4Department of Pediatrics, Korea University Anam Hospital, Seoul, Korea 5Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea 6Department of Pediatrics, Soonchunhyang University Seoul Hospital, Seoul, Korea 7Department of Pediatrics, Nowon Eulji Medical Center, Eulji University, Seoul, Korea 8Department of Pediatrics, Hanyang University Seoul Hospital, Seoul, Korea 9Department of Pediatrics, Inje University Busan Paik Hospital, Busan, Korea Neonatal Med 2022 February;29(1):28-35 https://doi.org/10.5385/nm.2022.29.1.28 pISSN 2287-9412 . eISSN 2287-9803 Copyright(c) 2022 By Korean Society of Neonatology This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/4.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Original Article 29 Neonatal Med 2022 February;29(1):28-35 https://doi.org/10.5385/nm.2022.29.1.28 ing in Korea.