소아의 단순성 비만증에 의한 지방간의 진단: ALT치와 복부 전산화단층촬영 및 간생검 소견간의 상관관계

이성희,김화중,오재철,한혜정,김희섭,차한,박호진,신미경,이민진,이상천,Lee, Seong-Hee,Kim, Hwa-Jung,Oh, Jae-Cheol,Han, Hae-Jeong,Kim, Hee-Sup,Tchah, Hann,Park, Ho-Jin,Shin, Mi-Keong,Lee, Min-Jin,Lee, Sang-Chun 대한소아소화기영양학회 1999 Pediatric gastroenterology, hepatology & nutrition Vol.2 No.2

목 적: 소아비만의 중요한 합병증 중 하나인 지방간을 진단함에 있어 ALT치와 CT 및 간생검 소견간의 상관관계를 살펴봄으로써, 선별검사로서 ALT치의 유용성과 확진검사로서 CT 및 간생검의 필요성을 알아보고자 한다. 대상 및 방법: 1990년 3월부터 1997년 12월까지 서울적십자병원 소아과에 내원하여 단순비만으로 진단 받은 78명 중 지방간 진단을 위해 CT를 실시한 26명을 대상으로 하였으며, 생화학검사 중 지방간의 선별검사로서 보다 특이성이 높은 ALT치가 지나치게 높거나 비만도가 심한 비만아들 중 15례에서 간생검을 실시하였다. 이들을 ALT치에 따라 3개 군으로 분류하고 각 군별로 신체계측지수, CT 및 간생검상 지방침착도 간의 상관관계를 비교 분석하였다. 결 과: 1) ALT치와 신체계측지수간의 상관관계: 대상 비만아 26례 중 ALT치는 17례(63.4%)에서 이상 상승(>30 IU/L)되었으나, ALT치의 상승과 신체계측지수들(비만도, RI, BMI, 체지방률) 간에는 유의한 상관관계가 없었다(p>0.05) 2) CT상 지방침착도와 ALT치 및 신체계측지수 간의 상관관계: 26례 중 13례(50%)에서 CT상 정상이었고, 나머지 13례는 정도의 차이는 있으나 모두 간음영이 증가된 지방간 소견을 보였다. CT상 지방간의 정도와 ALT치의 상승간에는 유의한 상관관계가 있었으나(p=0.01), 신체계측지수와는 유의한 상관관계가 없었다(p>0.05). 3) 간 생검상 지방간의 정도와 비만도, ALT치와의 상관관계: 26례 중 15례에서 간 생검을 실시한 결과, 1례에서 정상이었고 나머지 14례에서 모두 지방간 소견을 보였다. 그러나 간 생검상 정상인 1례는 고도비만이었으나 ALT치는 정상치였고, 중등도의 지방간 소견 보인 3례 중 1례는 고도비만이었음에도 ALT치는 정상이었으며 2례는 ALT치가 정상이거나 약간 증가하였으며, 심한 지방간 소견 보인 9례 중 1례는 경한 비만이었으나 ALT는 158 IU/L로 심한 상승을 보였다. 간 생검상 지방간인 14례를 지방침착도에 따라 3개 군으로 분류하여 비만도와 ALT치를 비교분석한 결과 비만도와 간 생검 소견간에는 유의한 차이가 없었으나(p>0.05), ALT치와 간 생검상 지방간의 정도간에는 유의한 차이가 있었다(p=0.01). 4) CT와 간 생검 소견간의 상관관계: 26례 중 15례에서 CT와 간 생검 모두를 시행한 결과, CT상 6례는 정상이었고, CT상 지방간 소견 보인 9례에서는 간의 지방침착도에 따른 음영의 변화를 기준으로 한 CT소견과 간 생검상 지방침착도간에 유의한 상관관계를 보였다(r=0.6094). 결 론: 최근 소아비만이 급증 추세에 있고 그에 따른 여러 가지 합병증들은 물론 성인비만으로 이행될 수 있으므로 학교보건 등을 통해 경각심을 높이도록 해야 하며, 특히 비만에 따른 지방간을 진단하기 위한 선별검사인 ALT치 등 생화학적인 간 기능 검사로는 간 손상 정도를 평가할 수 없기 때문에 보다 저비용이며 비침습적인 초음파검사를 적극 활용토록 하고 선별검사 등으로 선정된 고위험군에 대해서는 간 생검을 통해 간 손상 정도를 정확히 평가하고 지속적으로 추적 관리해야 할 것이다. Purpose: The purpose of our study is to provide useful information for diagnostic methods of fatty liver by childhood simple obesity and to provide correlation between serum alanine aminotransferase (ALT) for screening test and abdominal computerized tomography (CT) and liver biopsy for confirmative diagnostic methods of fatty liver. Methods: Among 78 obese childrens who visited our hospital, CT was carried out in 26 childrens. Of these, liver biopsy was carried out in 15 childrens who had high obesity index or severe elevated ALT. Based on the level of serum ALT, 26 cases were classified into 3 groups, and compared with physical measurements and degree of fatty infiltration on CT and liver biopsy. Results: 1) Correlation between ALT and physical measurements: Of 26 obese children, ALT was abnormally elevated (>30 IU/L) in 17 cases (67.4%) but there was no significant correlation between ALT and physical measurements (p>0.05). 2) Correlation between degree of fatty infiltration on CT and ALT: Of 26 cases, 13 cases (50%) revealed fatty liver on CT. The degree of fatty liver on CT had significant correlation with elevation of ALT (p<0.05). 3) Correlation between the degree of fatty infiltration on liver biopsy and ALT: Liver biopsy was performed in 15 cases of which 14 cases revealed fatty liver. But one case had normal hepatic histology with severe obesity and normal ALT. Fourteen fatty liver cases on liver biopsy were classified into 3 groups by the degree of fatty infiltration and analysed with obesity index and ALT. The histologic hepatic steatosis had no significant correlation with obesity index (p>0.05), but significant correlation with ALT (p<0.05). 4) Correlation between CT and liver biopsy finding: Both CT and liver biopsy were performed in 15 cases of which 6 cases revealed normal finding on CT and 9 cases manifested fatty liver. There was significant correlation between CT and liver biopsy findings (r=0.6094). Conclusion: The results of our study suggest that abdominal CT and liver biopsy are useful and accurate methods of estimating fatty liver in the childhood obesity. But biochemical abnormalities of routine liver function tests dot not correlate well with severity of the fatty liver and liver injury.

기계적합금화에 의한 $Fe/Al_2O_3$ 및 $Fe/TiO_2$계 나노복합분말의 제조

이성희,이충효,Lee, Seong-Hee,Lee, Chung-Hyo 한국결정성장학회 2009 韓國結晶成長學會誌 Vol.19 No.4

Nanocomposite formation of metal-metal oxide systems by mechanical alloying (MA) has been investigated at room temperature. The systems we chose are the $Fe_3O_4$-M (M = AI, Ti), where pure metals are used as reducing agent. It is found that $Fe/Al_2O_3$ and $Fe/TiO_2$ nanocomposite powders in which $Al_2O_3$ and $TiO_2$ are dispersed in ${\alpha}$-Fe matrix with nano-sized grains are obtained by MA of $Fe_3O_4$ with Al and Ti for 25 and 75 hours, respectively. It is suggested that the shorter MA time for the nanocomposite formation in $Fe/Al_2O_3$ is due to a large negative heat associated with the chemical reduction of magnetite by aluminum. X-ray diffraction results show that the average grain size of ${\alpha}$-Fe in $Fe/TiO_2$ nanocomposite powders is in the range of 30 nm. The change in magnetic properties also reflects the details of the solid-state reduction of magnetite by pure metals during MA. 본 연구에서는 $Fe/Al_2O_3$ 및 $Fe/TiO_2$계 나노복합분말을 제조하기 위하여 실온 기계적 합금화법(MA)을 적용하였다. $Fe_3O_4-M$(M= AI, Ti)이고 여기서 순금속 Al 및 Ti은 고상반응 시 환원제로서 선택하였다. $Fe_3O_4$-순금속의 각각 25시간 및 75시간 MA 처리한 결과 $Fe/Al_2O_3$ 및 $Fe/TiO_2$ 나노복합분발이 얻어졌으며, 이것은 나노결정립의 ${\alpha}$-Fe 기지에 $Al_2O_3$ 및 $TiO_2$가 각각 미세하게 분산된 나노복합분말임을 알 수 있었다. 또한 Fe$_3$O$_4$-AI계에서 보다 짧은 반응 시간에 복합분말이 생성되는 것은 $Fe_3O_4$의 Al에 의한 환원반응 시 큰 반응열에 기인하는 것으로 사료된다. MA법으로 제조된 $Fe/TiO_2$ 복합분말의 X선 회절분석으로부터 ${\alpha}$-Fe 결정립 크기는 30 nm 임을 알 수 있었다. 또한 MA 과정 중 시료의 자기 측정으로부터 $Fe_3O_4$의 순금속 Al 및 Ti 에 의한 고상환원반응 과정을 자세히 관찰할 수 있었다.

분말피복압연법에 의해 제조된 Al 분말성형체의 반복겹침접합압연

이성희,Lee, Seong-Hee 한국분말야금학회 2005 한국분말재료학회지 (KPMI) Vol.12 No.1

An aluminum powder compact consolidated by a powder-in sheath rolling (PSR) method was severely deformed by accumulative roll-bonding (ARB) process. The ARB process was performed up to 8 cycles at ambient temperature without lubrication. Optical microscope and transmission electron microscope observations revealed that microstructure of the ARB-processed Al powder compact is inhomogeneous in the thickness direction. The ultra-fine subgrains often reported in the ARB-processed bulky materials were also developed near surface of the Al powder compacts in this study. Tensile strength of the ARB-processed Al powder compact increased at the 1st cycle, but from the 2nd cycle it rather decreased slightly.

ARB가공된 인탈산동의 어닐링에 따른 미세조직 및 기계적 특성 변화

이성희,김춘수,김상식,한승전,임차용,Lee, Seong-Hee,Kim, Chun-Su,Kim, Sang-Shik,Han, Seung-Zeon,Lim, Cha-Yong 한국재료학회 2007 한국재료학회지 Vol.17 No.7

A deoxidized low-phosphorous copper processed by eight cycles of accumulative roll-bonding (ARB) was annealed at various temperatures ranging from 100 to $400^{\circ}C$. The annealed copper was characterized by transmission electron microscopy (TEM) and tensile & hardness test. TEM observation revealed that the ultrafine grains developed by the ARB still remained up to $350^{\circ}C$, however above $400^{\circ}C$ they were replaced by equiaxed and coarse grains due to an occurrence of the static recrystallization. The hardness of the copper decreased slightly with the annealing temperature up to $350^{\circ}C$, however they dropped largely above $400^{\circ}C$. Annealing characteristics of the copper were compared with those of an oxygen free copper processed by ARB and subsequently annealed.

ARB법에 의해 강소성가공된 무산소동의 어닐링 특성

이성희,조준,이충효,한승전,임차용,Lee Seong-Hee,Cho Jun,Lee Chung-Hyo,Han Seung-Zun,Lim Cha-Yong 한국재료학회 2005 한국재료학회지 Vol.15 No.9

An oxygen free copper severely-deformed by eight cycles (an equivalent strain of $\~6.4$) of accumulative roll-bonding (ARB) was annealed at various temperatures ranging from 100 to $300^{\circ}C$. The annealed copper was characterized by transmission electron microscopy (TEM) and tensile & hardness test. TEM observation revealed that the ultrafine grains developed by the ARB still remained up to $150^{\circ}C$, however above $200^{\circ}C$ they were replaced by equiaxed and coarse grains due to an occurrence of the static recrystallization. Tensile strength and hardness of the copper decreased slightly with the annealing temperature up to $150^{\circ}C$, however they dropped largely above $200^{\circ}C$. Annealing characteristics of the copper were compared with those of a commercially pure aluminum processed by ARB and subsequently annealed.

ARB법에 의해 강소성가공된 Al/SiC_p 입자분산복합재료의 미세조직 및 기계적 특성

이성희,김형욱,Lee Seong-Hee,Kim Hyoung-Wook 한국분말야금학회 2006 한국분말재료학회지 (KPMI) Vol.13 No.1

The $Al/SiC_p$ particle reinforced composite fabricated by a powder-in sheath rolling (PSR) method was severely. deformed by the accumulative roll-bonding (ARB) process. The ARB process was performed up to 8 cycles at ambient temperature without lubricant. The ARBed composite exhibited an ulbricant. grained structure similar to the other ARBed bulky materials. Tensile strength of the composite increased gradually with the number of ARB cycles, but from the 6th cycle it rather decreased slightly. These characteristics of the composite were somewhat different from those of Al powder compact fabricated by the same procedures. The difference in microstructure and mechanical properties between Al powder compact and the composite was discussed.

ARB법에 의한 Cu-Fe-P합금의 초미세결정립 형성

이성희,한승전,김형욱,임차용,Lee, Seong-Hee,Han, Seung-Zeon,Kim, Hyoung-Wook,Lim, Cha-Yong 한국재료학회 2009 한국재료학회지 Vol.19 No.8

A Cu-Fe-P copper alloy was processed by accumulative roll-bonding (ARB) for ultra grain refinement and high strengthening. Two 1mm thick copper sheets, 30 mm wide and 300 mm long, were first degreased and wire-brushed for sound bonding. The sheets were then stacked on top of each other and roll-bonded by about 50% reduction rolling without lubrication at ambient temperature. The bonded sheet was then cut into two pieces of the same dimensions and the same procedure was repeated for the sheets up to eight cycles. Microstructural evolution of the copper alloy with the number of the ARB cycles was investigated by optical microscopy (OM), transmission electron microscopy(TEM), and electron back scatter diffraction(EBSD). The grain size decreased gradually with the number of ARB cycles, and was reduced to 290 nm after eight cycles. The boundaries above 60% of ultrafine grains formed exhibited high angle boundaries above 15 degrees. In addition, the average misorientation angle of ultrafine grains was 30 degrees.

이속압연된 Cu-3.0Ni-0.7Si 합금의 어닐링에 따른 두께방향으로의 미세조직 및 기계적 특성 변화

이성희,Lee, Seong-Hee 한국재료학회 2018 한국재료학회지 Vol.28 No.5

Effects of annealing temperature on the microstructure and mechanical properties through thickness of a Cu-3.0Ni-0.7Si alloy processed by differential speed rolling are investigated in detail. The copper alloy with a thickness of 3 mm is rolled to a 50 % reduction at ambient temperature without lubricant and subsequently annealed for 0.5 h at $200-900^{\circ}C$. The microstructure of the copper alloy after annealing is different in the thickness direction depending on the amount of the shear and compressive strain introduced by the rolling; the recrystallization occurs first in the upper roll side and center regions which are largely shear-deformed. The complete recrystallization occurs at an annealing temperature of $800^{\circ}C$. The grain size after the complete recrystallization is finer than that of the conventional rolling. The hardness distribution of the specimens annealed at $500-700^{\circ}C$ is not uniform in the thickness direction due to partial recrystallization. This ununiformity of hardness corresponds well to the amount of shear strain in the thickness direction. The average hardness and ultimate tensile strength has the maximum values of 250 Hv and 450 Mpa, respectively, in the specimen annealed at $400^{\circ}C$. It is considered that the complex mode of strain introduced by rolling directly affects the microstructure and the mechanical properties of the annealed specimens.

저변형률속도에서 ARB가공된 무산소동의 미세조직 및 기계적 성질

이성희,한승전,임차용,Lee, Seong-Hee,Han, Seung-Zeon,Lim, Cha-Yong 한국재료학회 2007 한국재료학회지 Vol.17 No.10

The microstructure and mechanical properties of an oxygen free copper processed by accumulative roll bonding(ARB) at low strain rate were studied. The copper sheets were highly strained up to an equivalent strain of ${\sim}6.4$ by ARB process at ambient temperature. The strain rate of the copper during the ARB was $2.6sec^{-1}$. The microstructure and mechanical properties of the ARB-processed copper were compared to those of the specimens processed by ARB at relatively high strain rate ($37sec^{-1}$). The microstructure and mechanical properties of the copper with ARB process was very similar to each other despite of some differences in recovery.

동속압연과 이속압연이 동합금판재의 조직 및 기계적 성질에 미치는 영향

이성희,임정윤,윤대진,어광준,한승전,Lee, Seong-Hee,Lim, Jung-Youn,Yoon, Dae-Jin,Euh, Kwang-Jun,Han, Seung-Zeon 한국재료학회 2011 한국재료학회지 Vol.21 No.1

The effects of conventional rolling (CR) and differential speed rolling (DSR) on the microstructure and mechanical properties of a copper alloy sheet were investigated in detail. A copper alloy with thickness of 3 mm was rolled to a 50% reduction at ambient temperature without lubrication with a differential speed ratio of 2:1; sample was then annealed for 0.5h at various temperatures from 100 to $800^{\circ}C$. Conventional rolling, in which the rolling speed of the upper and lower rolls is identical, was performed under the same rolling conditions. The shear strain introduced by the CR showed positive values at positions on the upper roll side and negative values at positions on the lower roll side. However, the shear strain showed a zero or positive value at all positions for the samples rolled by the DSR. The microstrucure and mechanical properties of the as-rolled copper alloy did not show very significant differences between the CR and DSR for the microstructure and mechanical properties. However, those properties showed very significant differences in the case of the annealed samples. The effects of rolling method on the microstructure and mechanical properties of the as-rolled and subsequently annealed materials are discussed in terms of the shear strain.