Evaluation of the Suitability of Establishing Biological Exposure Indices of Styrene

Choi, Ah-rum,Im, Sung-guk,Lee, Mi-young,Lee, Se-Hoon Occupational Safety and Health Research Institute 2019 Safety and health at work Vol.10 No.1

Background: This study was designed to provide logical backgrounds for the revision of biological exposure indices (BEIs) for styrene exposure in Korea. In order to investigate the correlation between airborne styrene and biological exposure indices, we measured urinary mandelic acid (MA) and phenylglyoxylic acid (PGA) in workers exposed to styrene occupationally, as well as airborne styrene at workplaces. Methods: Surveys were conducted for 56 subjects. The concentrations of airborne styrene and urinary metabolites of styrene were measured in 36 workers who were occupationally exposed to styrene, and in 20 controls. Air samples were collected using personal air samplers and analyzed by gas chromatography. Urine samples were collected at the end of the shift and analyzed by high performance liquid chromatography. Results: The geometric mean concentration of airborne styrene was 9.6 ppm. The concentrations of urinary MA, PGA, and MA+PGA in the exposure group were 267.7, 143.3, and 416.8 mg/g creatinine, respectively. The correlation coefficients for correlation between airborne styrene and MA, PGA, and MA+PGA were 0.714, 0.604, and 0.769, respectively. The sum of urinary MA and PGA corresponding to an exposure of 20 ppm styrene was 603 mg/g creatinine. Conclusion: The correlation of the sum of urinary MA and PGA with airborne styrene was better than the correlation of each individual urinary determinant. It is considered appropriate to amend the concentration of urinary MA+PGA to 600 mg/g creatinine as a BEI, which corresponds to an airborne styrene concentration of 20 ppm in Korea.

수요자 중심의 산업안전보건교육 과정 개발을 위한 요구분석 -관리감독자 정기안전보건교육을 중심으로-

최아름 ( Ah Rum Choi ),황정호 ( Jung Ho Hwang ),김진아 ( Jina Kim ) 한국산업보건학회 (구 한국산업위생학회) 2020 한국산업보건학회지 Vol.30 No.4

Objectives: The purpose of this study is to suggest a direction for consumer-oriented curriculum development by analyzing the priorities of subjects and their preference for educational methods. Methods: The participants included 773 management supervisors and education practitioners in the workplace, and a survey was conducted from April 17 to August 30, 2019. Frequency analysis, t-test, Borich’s Needs Analysis, and Locus for Focus Model analysis were performed using Microsoft Excel 2019 and IBM SPSS 21.0. Results: The highest perceived priorities for education subjects were as follows: ① ‘CPR and First Aid Practice’ and ‘Occupational Disaster Prevention and First Aid Basics’ in the manufacturing industry; and ② ‘Emotional Labor and Job Stress Prevention’, ‘Occupational Disaster Prevention and First Aid basics, and ‘Musculoskeletal Disorder Prevention’ in the service industry. ‘Collective education’ was the most preferred method of education. ‘School-type’ was preferred for the seating arrangement, and the proper number of trainees was considered to be about 30. Respondents said the contents of the education was a top priority when they applied for education, and curriculum and appropriate textbooks should be considered in calculating the cost of education. Conclusions: Practical subjects and subjects related to major hazards by industry were required for management supervisor education. It was proposed in this study that the contents and operating methods of education be changed so that workers can easily comprehend essential subjects such as the Occupational Safety and Health Act. In conclusion, it is necessary to design the curriculum and apply educational methods suitable for each subject’s characteristics in consideration of the priorities for subjects reflected in the needs of trainees.

산전 진단에서 관찰된 8번과 22번 염색체 사이의 미세 전좌에 의한 8번 염색체 단완 위성체

오아름(Ah Rum Oh),이봄이(Bom Yee Lee),최은영(Ene Yuong Choi),류현미(Hyun Mee Ryu),이승재(Seung Jae Lee),정지예(Ji Ye Jung),박소연(So Yeon Park) 대한의학유전학회 2011 대한의학유전학회지 Vol.8 No.2

초산인 35세 산모가 고령 임신과 모체혈액선별검사 고위험군을 주소로 양수천자를 실시한 결과 8번 염색체의 단완에 위성체가 붙어 있는 것이 발견되었다. 부모 염색체 검사 결과 모두 정상으로 확인되어 태아에게서 관찰된 8ps현상은 de novo로 판단된다. FISH 검사로 좀 더 자세히 분석한 결과, 8번 염색체와 22번 염색체 사이에 미세한 전좌가 관찰되었다. 태아의 염색체 8번과 22번 사이의 de novo 전좌를 갖고 있었지만 절단 부위가 DNA의 단순 반복 부위이므로 표현형에 영향을 미칠 가능성은 높지 않을 것으로 추측되었고, 임신 기간 동안 초음파상 이상 소견은 관찰되지 않았다. 유전상담을 통해 8번 염색체 단완의 미세 결실 가능성이 설명되었고, 부모의 결정에 따라 추가실험 없이 임신은 유지되었다. 그리고 38주에 정상 표현형의 남아가 분만되었다. 본 증례는 산전 진단에서 세포유전학적 검사로 8번 염색체 단완의 위성체만이 발견되었으나, 추가의 분자세포유전학적 진단으로 8번과 22번 염색체 단완 사이의 미세한 전좌를 확인하였다. 이처럼 보다 정확하고 자세한 분자세포 유전학적 분석들이 산전 진단에서는 필요함을 시사한 사례였다. The authors of the present study report the prenatal detection of a chromosomal abnormality with additional satellites on the distal short arm of chromosome 8. A 35-year-old woman was referred for amniocentesis because of her advanced maternal age and positive result for maternal serum screening test. Cytogenetic analysis of cultured amniocytes showed a satellite 8p chromosome. The satellite 8p chromosome was positive for nucleolus organizer region (NOR) staining. The parents’ karyotypes were normal. Fluorescence in situ hybridization (FISH) study for metaphases of fetal amniocytes revealed a cryptic translocation of chromosomes 8p and 22p. The fetal karyotype was described as 46,XY,8ps.ish t(8;22)(p23.3;p11.2) (D8S504-;D8S504+)dn. The parents decided to continue the pregnancy and a phenotypically normal boy was born at 38 weeks of gestation. In case of de novo terminal NORs detected prenatally, more accurate cytogenetic and molecular analysis should be performed in order to rule out cryptic chromosomal rearrangement among other chromosomes.

FOCUS - ICOH 발표자료 2: 스티렌의 생물학적 노출기준 설정을 위한 적합성 평가

최아름,임성국,이미영,이세훈,Choi, Ah-rum,Im, Sung-guk,Lee, Mi-young,Lee, Se-Hoon 대한산업보건협회 2015 산업보건 Vol.326 No.-

무정자증 불임남성에서 관찰된 SRY 유전자의 중복을 동반한 일동원체성 derivative Y 염색체

최은영(Eun Young Choi),이봄이(Bom Yi Lee),박주연(Ju Yeon Park),이연우(Yeon Woo Lee),오아름(Ah Rum Oh),이신영(Shin Young Lee),김신영(Shin Young Kim),한유정(You Jung Han),이미범(Mee Bum Lee),류현미(Hyun Mee Ryu),서주태(Ju Tae Seo),박소연( 대한의학유전학회 2010 대한의학유전학회지 Vol.7 No.2

Y 염색체의 구조적 이상은 남성의 정상적인 고환의 분화와 정자생성과정에 영향을 미친다. 본 증례의 무정자증 남성의 혈액세포에서 관찰된 비정상 Y 염색체는 SRY를 포함한 부분적 단완 중복과 Yq12 이질염색질 결실로 재배열된 일동원체성 derivative Y 염색체이다. 이러한 형태의 Y 염색체에 대해서는 매우 드물게 보고되어 있다. 이는 분자세포유전학 및 분자유전학 검사를 통하여 46,X,der(Y)(pter→q11.23::p11.2→pter).ish der(Y)(DYZ3+,DYZ1-,SRY++) 의 결과를 얻었다. 증례의 남성은 비정상 Y 염색체를 가졌음에도 불구하고 정상적인 고환의 크기와 혈액내 성호르몬의 수치는 정상이었다. 하지만 양측성 정계정맥류와 고환생검결과 정자형성기능저하증의 소견을 보였다. 이러한 비정상 Y 염색체는 부계의 감수분열 또는 배발생 초기 단계에서 Y 염색체 자매염색분체의 재배열 또는 Y 염색체내 비대립동종재조합(Non-allelic homologous recombination) 현상 때문에 일어난 것으로 생각되며 환자의 생식세포 분열과정 중 X-Y 성염색체 PAR1 (pseudoautosomal region 1) 부위가 접합하는 2가염색체 (X-Y bivalent) 형성장애기전으로 정자생성 또는 정자성숙 단계에 문제가 생긴 것으로 생각된다. 또한 남성특이영역(male specific region of the Y chromosome, MSY)에서 불임과 관련된 유전자들의 결실과 변이 등의 원인도 배제할 수 없을 것이다. 본 증례는 무정자증 불임남성의 생식과 관련된 표현형이 다양한 원인으로 결정될 수 있음을 시사하며 아울러 불임남성에 대한 보다 정확하고 자세한 분자ㆍ세포 유전학적 분석들이 불임남성의 치료에도 도움이 될 것이라 생각한다. Structural abnormalities of the Y chromosome affect normal testicular differentiation and spermatogenesis. The present case showed a rare monocentric derivative Y chromosome with partial duplication of Yp including the SRY gene and deletion of Yq12 heterochromatin. The karyotype was 46,X,der(Y) (pter→q11.23::p11.2→pter).ish der(Y)(DYZ3+,DYZ1-,SRY++), confirmed through a FISH study. Even though the patient possessed an abnormal Y chromosome, testicular biopsy showed normal testicular volumes in the proband, with gonadal hormonal levels in the normal range but bilateral varicocele and hypospermatogenesis. We speculate that the abnormal Y chromosome arose from sister chromatids during Y chromosome recombination or intra chromosomal NAHR (non-allelic homologous recombination) during meiosis in the patient’s father or in the very early stages of embryogenesis. The derivative Y chromosome might interfere in the meiotic stage of spermatogenesis, leading to the developmental arrest of germ cells. The present case illustrates that the infertility phenotype can have various causes. Also, it emphasizes the importance of accurate and various genetic analyses and could aid in male infertility treatment.

현대건설의 구조조정과 부활 무상감자와 대출금 출자전환을 중심으로

최종학 ( Jong Hag Choi ),최아름 ( Ah Rum Choi ) 한국회계학회 2012 회계저널 Vol.21 No.5

Hyundai Engineering & Construction Co. , Ltd. (Hyundai E&C) is a successful case of corporate restructuring after falling into a liquidity crisis during the Asian Financial Crisis. When the original controlling shareholders, Chairman Jung and his family, failed to save the firm, creditors carried out two rounds of reverse stock splits and subsequent equity injections, including debt-equity swaps, to revive the firm. In the process, existing shareholders` ownership was diluted while creditor banks became majority shareholders. Reverse stock splits and subsequent equity injections strengthen the balance sheet of the firm by cancelling out the accumulated deficit and increasing shareholders` equity. Hyundai E&C also reduced production cost and its workforce as a part of restructuring, Eventually, Hyundai E&C overcame a crisis and successfully revived the firm. In 2011, creditors bank sold Hyundai E&C to Hyundai Motor Group. This case study examines the impact of reverse stock splits and equity injections - in the form of debt-equity swap and conversion of convertible bonds - on (1) financial statements, (2) stock price of the firm and (3) its existing shareholders and creditors. The case concludes with a brief analysis of the success factors of corporate restructuring and a description of the divesture of the firm in 2011 by the creditor banks. In the process, students also can learn the procedures for the corporate restructuring.

Duplication of intrachromosomal insertion segments $4q32{\rightarrow}q35$ confirmed by comparative genomic hybridization and fluorescent $in$ $situ$ hybridization

Kim, Jin-Woo,Park, Ju-Yeon,Oh, Ah-Rum,Choi, Eun-Young,Ryu, Hyun-Mee,Kang, Inn-Soo,Koong, Mi-Kyoung,Park, So-Yeon The Korean Society for Reproductive Medicine 2011 Clinical and Experimental Reproductive Medicine Vol.38 No.4

A 35-year-old man with infertility was referred for chromosomal analysis. In routine cytogenetic analysis, the patient was seen to have additional material of unknown origin on the terminal region of the short arm of chromosome 4. To determine the origin of the unknown material, we carried out high-resolution banding, comparative genomic hybridization (CGH), and FISH. CGH showed a gain of signal on the region of $4q32{\rightarrow}q35$. FISH using whole chromosome painting and subtelomeric region probes for chromosome 4 confirmed the aberrant chromosome as an intrachromosomal insertion duplication of $4q32{\rightarrow}q35$. Duplication often leads to some phenotypic abnormalities; however, our patient showed an almost normal phenotype except for congenital dysfunction in spermatogenesis.

Effects of Calcium Ion Concentration Starch Hydrolysis of Barley a-Amylase Isozymes

( Jeong Bin Yuk ),( Seung Ho Choi ),( Tae Hee Lee ),( Myoung Uoon Jang ),( Jung Mi Park ),( Ah Rum Yi ),( Birte Svensson ),( Tae Jip Kim ) 한국미생물 · 생명공학회 2008 Journal of microbiology and biotechnology Vol.18 No.4

FOCUS - ICOH 발표자료 1: 톨루엔에 노출된 근로자들에 대한 공기 중 톨루엔과 생물학적 노출기준에 대한 평가

임성국,최아름,이미영,이세훈,Im, Sung-guk,Choi, Ah-rum,Lee, Mi-young,Lee, Se-Hoon 대한산업보건협회 2015 산업보건 Vol.326 No.-

An unusual de novo duplication 10p/deletion 10q syndrome: The first case in Korea

Lee, Bom-Yi,Park, Ju-Yeon,Lee, Yeon-Woo,Oh, Ah-Rum,Lee, Shin-Young,Choi, Eun-Young,Kim, Moon-Young,Ryu, Hyun-Mee,Park, So-Yeon Korean Society of Medical Genetics and Genomics 2015 대한의학유전학회지 Vol.12 No.1

We herein report an analysis of a female baby with a de novo dup(10p)/del(10q) chromosomal aberration. A prenatal cytogenetic analysis was performed owing to abnormal ultrasound findings including a choroid plexus cyst, prominent cisterna magna, and a slightly medially displaced stomach. The fetal karyotype showed additional material attached to the terminal region of chromosome 10q. Parental karyotypes were both normal. At birth, the baby showed hypotonia, upslanting palpebral fissures, a nodular back mass, respiratory distress, neonatal jaundice and a suspicious polycystic kidney. We ascertained that the karyotype of the baby was 46,XX,der(10)($pter{\rightarrow}q26.3::p11.2{\rightarrow}pter$) by cytogenetic and molecular cytogenetic analyses including high resolution GTG-and RBG-banding, fluorescence in situ hybridization, comparative genomic hybridization, and short tandem repeat marker analyses. While almost all reported cases of 10p duplication originated from one of the parents with a pericentric inversion, our case is extraordinarily rare as the de novo dup(10p)/del(10q) presumably originated from a rearrangement at the premeiotic stage of the parental germ cell or from parental germline mosaicism.