노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

Fe-C-Cr-Mo-V계 공구강의 미세조직과 건식 긁힘 마멸 거동 (마모재 : Al₂O₃)

백응률,최상호 영남대학교 재료기술연구소 2000 재료기술연구 Vol.1 No.1

High carbon- high chromium tool steels display a number of advantages in abr asive wear applications. They contain moderat e amounts of chromium that produces massive chromium- rich carbides in an austenitic matrix of sufficient hardenability to be transformed to martensit e with relatively simple heat treatment . In this study the role of vanadium- rich carbides with high hardness as well as chromium- rich carbides in improving abrasive wear resistance was investigat ed using a series of Fe- C- Cr -Mo- V system alloys with varying carbide volume fr action. The abr asive wear resistance of the alloys against Al₂O₃ harder than chromium- rich carbides but softer than vanadium- rich carbides was measured with a dry abrasive rubber wheel abr asion test. The abr asive wear resist ance was affected by a volume fraction and variety of carbide because of a differance of hardness between carbide and abrasive. As a result, The specimen with the most volume fraction of vanadium- rich carbide harder than Al2O3 had the mot excellent abrasive wear resistance.

농구 선수의 만성 슬개건염

서경호,서경묵,김성원,김백곤,송인섭 大韓再活醫學會 1998 Annals of Rehabilitation Medicine Vol.22 No.6

M_(7)C₃형 크롬탄화물의 경도에 미치는 고용원소(V, Mo, Mn)의 영향

백응률,유국종,정재영,안상호 영남대학교 재료기술연구소 2000 재료기술연구 Vol.1 No.1

This study makes an investigation into the effect of dissolved alloy element (V,Mo,Mn) on hardness of the M_(7)C₃ type chromium carbide. Dis solved alloy element (V,Mo,Mn) content in M_(7)C₃ type chromium carbide was analyzed by EDS and micro- hardness of the M_(7)C₃ type chromium carbide was measured by micro- Vicker s hardness tester . Increasing to V, Mo content in specimen, result to increasing dissolved V, Mo content in M_(7)C₃ type chromium carbide. Also hardnes s of M_(7)C₃ type chromium carbide was increased. At this point , V added specimen was superior to Mo added specimen. According as Mn content in specimen increases , Mn cont ent in M_(7)C₃ type chromium carbide some increased but hardness in M_(7)C₃ type chromium carbide some decreased.

광탄성 프린지 위상이동법을 적용한 디스크의 등경 및 등색프린지 분리법에 관한 시뮬레이션

백태현,김명수,조성호 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.2

광탄성법은 전체적인 응력장 해석을 위하여 가장 많이 사용되는 방법중의 하나이다. 광탄성법에서 주응력의 차이와 방향은 등색선과 등경선으로 나타난다. 재래식 방법으로는 주응력 방향은 평면 편광기의 편광자와 검광자를 동시에 회전시켜 수작업으로 측정하며, 이를 타디보간법이라 한다. 이러한 방법은 전체적인 응력장 해석시 매우 번거로우며 많은 시간이 걸린다. 재래식 광탄성법에서는 광탄성 프린지로부터 등경선을 분리시킬 수 없다. 본 연구에서는 광탄성이론을 Jones행렬로 나타내고 4단계와 8단계의 위상이동법에 대해서 기술하였다. 컴퓨터시뮬레이션을 통하여 압축하중을 받는 원형디스크의 광탄성 프린지로부터 등경선과 등색선을 분리시킬 수 있는 시험을 하였다. 디스크의 프린지는 응력-광 법칙에 의하여 생성하였다. 8단계 위상이동법으로 얻은 등경선과 등색선의 크기를 이론으로 계산한 값과 비교하였다. 컴퓨터 시뮬레이션으로부터 광탄성 프린지로부터 등경선과 등색선을 분리시킬 수 있는 가능성ㅇ르 예시하였다. Photoelasticity is one of the most widely used methods for whole field stress analysis. In photoelasticity, the difference and the directions of the principal stresses are given isochromatic and isoclinic fringe patterns. Conventionally, principal stress directions are measured by rotating the polarizer and analyzer of a plane polariscope at the same time. This is known to be the Tardy compensation method. This measurement can be very tedious and time consuming in whold field analysis. It is not possible to separate isoclincs from photoelastic fringes by conventional photoelastic technique. In this study, photoelastic theory is represented by Jones matrices and 4-steps and 8-steps phase shifting methods are described. A feasibility study using computer simulation is done to separate isoclincs and isochomatics from photoelastic fringes of a circular disk under diametrical compression. Fringe patterns of the disk are generated using stress optic law. The magnitudes of isoclincs and isochromatics obtained from 8-step phase shifting method are compared with those of theories. From computer simulation, it is verified to separate isoclincs and isochmatics from photoelastic fringes.

조혈모세포이식 후 골성장인자의 변화 및 골대사에 미치는 영향 : Impact on Bone Mineral Metabolism

백기현,오은숙,오기원,이원영,김혜수,권순용,한제호,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.5

연구배경: 각종 장기이식의 시행이 많아지고 이식 후 생존율이 증가함에 따라 이식 후 합병증에 대한 관심 또한 높아지고 있다. 조혈모세포이식 후에도 다양한 내분비적 합병증이 발생할 수 있으며 골격에 대한 합병증도 문제점으로 대두되고 있다. 조혈모세포 이식 후 발생하는 골소실에는 이식 후 초기의 골형성 저하와 골흡수 증가가 중요한 역할을 담당하리라고 추측되는데 이러한 골재형성불일치(biochemical uncoupling)에 골 성장인자들이 미치는 영향에 대해서는 알려진 바가 없다. 본 연구에서는 조혈모세포이식 전, 후로 말초 혈액에서 IGF-I, FGF-2, M-CSF같은 성장인자의 변화를 알아보고, 이들 성장인자의 변화가 조혈모세포이식 후의 골형과 골흡수에 미치는 영향 및 이식 후 발생되는 골량 소실과의 연관성을 확인해 보고자 하였다. 방법: 여러 가지 혈액질환으로 인해 동종 골수이식을 시행 받은 환자들을 전향적으로 관찰하였으며 이식 전 및 이식 후 1주, 2주, 3주, 4주 및 3개월, 6개월 1년에 말초 혈액에서 골교체표지자를 측정하였다. 이식 전 및 이식1년 후에 요추골 및 대퇴골 골밀도를 측정할 수 있었던 36명의 환자들을 대상으로 냉동 보관되어 있던 혈청을 이용하여 IGF-I, FGF-2 및 M-CSF를 시기별로 측정하였으며 이들 성장인자와 골교체표지자의 변화 및 골밀도 변화 사이의 상관관계를 확인하였다. 결과: 골흡수 표지자인 혈청 ICTP는 이식 전에 비해 이식 후 4주까지 점차 의의 있게 증가하다가 이후 6개월까지 더욱 증가한 후 감소하였다. 골형성 표지자인 osteocalcin은 이식 후 3주까지는 점차 감소하다가 이후 증가하여 이식 후 3개월 및 6개월에 기저치보다 통계적으로 유의하게 증가한 후 감소하였다. 혈청 IGF-I과 FGF-2는 각각 이식 후 3주 및 1주까지 의미있게 감소하다가 이후 증가하였으며 혈청 M-CSF는 이식 후 1주째에 기저치에 비해 의미 있게 증가하였다가 이후 기저치로 회복되었다. 이식 1년 후 평균 요추부 골밀도는 5.2% 감소하였고 평균 근위대퇴골 골밀도는 11.6% 감소하였다. 이식 전 및 이식 후 3주에 측정한 IGF-I과 같은 시기에 측정한 오스테오칼신 사이에 유의한 상관관계가 관찰되었으며 이식 후 3주째의 M-CSF와 골흡수표지자인 M-CSF 사이에서 의미 있는 양의 상관관계를 관찰할 수 있었다. 이식 후 3주 및 3개월에 IGF-I이 낮은 환자일수록 이식 1년 후 근위대퇴골에서의 골소실이 많은 것으로 분석되었다. 결론: 조혈모세포이식 후 발생하는 골소실에는 기존에 알려진 기저질환의 영향, 성호르몬의 감소, 면역억제의 투여, 골수기질세포와 조골세포의 손상 및 이식초기 사이토카인의 변화이외에도 골성장인자가 관련이 있음을 확인하였고, 이는 이식 후 발생되는 골량소실에 중요한 역할을 할 것이라고 사료된다. Background: A loss of bone mass is usually detected after a bone marrow transplantation (BMT), especially during the early post-transplant period. We recently reported that enhanced bone resorption following a BMT was related to both the steroid dose and the increase in IL-6. We also suggested damage to the marrow stromal microenvironment, by myoablation, partly explains the impaired bone formation following a BMT. It is well known that some growth factor play important role in bone growth and osteogenesis. However, the pathogenetic role of bone growth factors in post-BMT bone loss is unknown and data on the changes in the growth factors, in accordance with bone turnover markers and bone mineral density (BMD) changes are scarce. We investigated changes in bone growth factors such as IGF-I (Insulin-like growth factor-I), fibroblast growth factor-2 (FGF-2) and Macrophage colony stimulating factor (M-CSF), during the post-BMT period, and assessed whether the growth factor changes influenced the bone turnover and post-BMT bone loss. The present study is the first prospective study to describe the changes in bone growth factors following a BMT. Methods: We prospectively investigated 110 patients undergoing a BMT, and analyzed 36 patients (32.4±1.3 years, 17 men and 19 women) whose BMDs were measured before, and 1 year after, the BMT. The serum biochemical markers of bone turnover were measured before, 1, 2, 3 and 4 weeks, 3 and 6 months, and 1 year, after the BMT. The serum, FGF-2, IGF-I and M-CSF levels were measured before and 1 and 3 weeks, and 3 months after the BMT. The correlation between the changes of growth factors and various bone parameters was analyzed. Results: The mean bone losses in the lumbar spine and total proximal femur, calculated as the percentage change from the baseline to the level at 1 year, were 5.2(p<0.05) and 11.6%(p<0.01), respectively. the serum type I carboxyterminal telopeptide(ICTP), a bone resorption marker, increased progressively until 6 months after the BMT, but thereafter decreased, to the base value after 1 year. Serum osteocalcin, a bone formation marker, decreased progressively, until 3 weeks after the BMT but then increased transiently, and finally returned to the base level at 1 year. The serum IGF-I and FGF-2 also decreased progressively until 3 weeks 1 week after the BMT, respectively, then increased to the base values at 3 months. The serum M-CSF increased briskly at 1 week post-BMT, then decreased to the base level. There were positive correlations between the percentage changes from the baseline proximal femur BMD and the IGF-I levels 3 weeks and 3 months (r=0.52, p<0.01, r=0.41, p<0.05) post BMT. A significant correlation was found between the IGF-I and osteocalcin levels pre-BMT, and 3 weeks after the BMT. Another positive correlation was found between the M-CSF and the ICTP levels at 3 weeks post BMT (r=0.54, p<0.05). Conclusion: In conclusion, there were significant changes in the serum IGF-I, FGF-2 and M-CSF levels in the immediate post-BMT period, which were related to a decrease in bone formation and loss in the proximal femoral BMD during the year following the BMT (J Kor Soc Endocrinol 17:664∼674, 2002).

學齡期 兒童의 營養과 學校給食의 重要性

백영호,이상봉,박지훈 釜山大學校 附設 體育科學硏究所 1993 體育科學硏究所 論文集 Vol.9 No.-

The results of Meta Analysis on the importance of nutrition of school-aged children and school-feeding are as follows: 1. The nutrition of school age children has direct connection with physical stamina and physique like stature and weight. Since nutritional intake has a great effect on acknowledgement and personality as well as on growth and development, it is very necessary for the children to adequately intake five indispensable nutrients, especially dairy products and the whole fish. 2. Children of school age should intake various kinds of food indiscriminately. Well-balanced dietary intake among all kinds of food and variety of menu are very necessary. A meal is advisable to consist of 3-5 kinds of food which are properly chosen among five food group: (1) food group includes meat, fish, egg, and beans; (2) group milk, dairy products and the whole fish; (3) group vegetables and fruits; (4) group cereals and potatos; (5) group oil and fat. More thant anything else, adequate intake of high-quality protein is required ; the lower grader is advised to intake 60g, and the upper grader 70g-85g. 3. Since overweight in childhood can be transferred even to the adulthood, it is very important to take necessary steps to prevent fatness from childhood. At home, parents should pay constant attention to their children's standard weights lest they should become too fat. At school, teachers should not only have enough education and observation of the fat children, but also should devise more effective feeding program to prevent overweight. 4. School feeding should be directed to provide the children with well-balanced nutrition, thus helping the children grow in good health. Moreover it should be guided to achieve better understanding of eating life, the fixation of desirable eating habits, correct table manners and the habitualization of sanitary eating. 5. School feeding program should be designed to be easily computerized, which can make it easier to input nutrition analysis, cooking purpose, food price and so on. Besides it should be creative and reasonable enough to record the individual caloric intake and to indicate the deficient nutrition to fill up.

상악 및 하악의 전방 분절 절골술을 이용한 안면 프로파일 성형술의 임상적 고찰

백세민,오갑성,윤은성,백롱민,임재호 大韓成形外科學會 1996 Archives of Plastic Surgery Vol.23 No.5

Mid and lower facial convexity is more common in Oriental people than in Caucasian and it is thought to be caused by a more anterior position of dental and skeletal structures rather than soft tissue structures, a more procumbent dentition, and a more acute interincisial angle. To improve their lower facial profile, we performed maxillary and mandibular anterior segmental osteotomies in 96 patients, by way of using palatal mucoperiosteal flap for vascular circulation of the antrior segment and plates and screws for rigid fixation. We also used wafer splint which had been made through model surgery which dental cast and tracing of cephaloghram had been needed. We could get the accurate diagnosis and know how much and which direction the anterior segment should move to get the satisfactory result or improved lower facial profile and corrected occlusal relationship with the teeth. No major complications occurred throughout the followup period except three of over0recessed lip and two of septal deviation, otherwise most of the patients were satisfied with the result.

광탄성프린지 위상이동법을 이용한 에지균열판의 응력 해석

백태현,김명수,조성호 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.3

광탄성법은 투명한 물체에 힘을 가하면 복굴절 현상이 나타나며, 편광기에 의해 등색 및 등경프린지가 나타난다. 등색프린지를 이용하여 주응력차이 또는 평면상 전단응력을 계산할 수 있으며, 등경프린지에 의해 주응력 방향을 결정할 수 있다. 재래식 광탄성법에서는 특정한 위치에서 프린지를 개별적으로 측정해야 되는 불편한 점이 있어, 디지털 영상처리에 의해 광탄성 프린지로부터 전체적인 응력장을 해석할 수 있도록 프린지이동에 의한 위상이동법이 개발되었다. 프린지 위상이동법은 원형편광기에서 검광자를 0˚, 45˚, 90˚ 및 135˚회전시켜 프린지가 이동된 4개의 영상을 얻고, 이들로부터 위상차리로 나타나는 프린지분포를 측정한다. 본 연구에서는 프린지 위상이동법에 관한 광학적인 이론을 이용하여 압축하중을 받는 원형디스크의 프린지분포를 위상이동법으로 측정한 후 이론 값과 비교하였다. 또한, 인장하중을 받는 에지균열판의 응력분포 해석에 프린지 위상이동법을 적용하였다. 실험결과, 프린지 위상이동법으로 측정한 결과는 유한요소 해석 결과와 잘 일치하였다. 광탄성에서 위상이동법은 등경선과 평행하거나 직교하는 선상에서 응력분포를 용이하게 측정할 수 있으나, 일반적인 프린지 해석시 프린지 위상이동법을 적용하면 오차가 포함될 수 있다. The method of photoelasticity allows one to obtain principal stress differences and principal stress directions in a photoelastic model. In the classical approach, the photoelastic parameters are measured manually point by point. The previous methods require much time and skill in the identification and measurement of photoelastic data. Fringe phase shifting method has been recently developed and widely used to measure and analyze fringe data in photo-mechanics. This paper presents the test results of photoelastic fringe phase shifting technique for the stress analysis of a circular disk under compression and an edge-cracked plate subjectes to tensile load. The technique used here requires four phase stepped photoelastic images obtained from a circular polariscope by rotating the analyzer at 0˚, 45˚, 90˚ and 135˚. Experimental results are compared with those of FEM. Good agreement between the results can be observed. However, some error may be included if the technique is used to general direction which is not parallel to isoclinic fringe.

콜레스테롤 대사와 동맥 경화증을 위한 식이요법과 운동처방

백영호,이상봉 釜山大學校 附設 體育科學硏究所 1993 體育科學硏究所 論文集 Vol.9 No.-

Researchers have reviewed the effects of dietary and exercise on cholesterol metabolism and arteriosclerosis by previous researches and have noted the following. Dietary factors effect significantly on the plasma cholesterol concentration. HDL-C is effected by running, smoking, and sex. Diet and exercise in the regulation of plasma lipids and lipoprotein in patients at risk of coronary disease. Consistent duration of exercise and repeated exercise make increase HDL-C. Aerobic endurance training causes reduction of plasma cholesterol. Arteriosclerosis is induced by risk factors which are high body fat %, High blood pressure, smoking ciagrette person, transmissible factors, sedentary habit, no physical active person, and social-psychological stress. But there are several risk factors(smoking, dietary, no physical activity, and habit) individual be able to control. Diets containing less than 30% fat and/or high in polyunsaturated fat may decrease total cholesterol, HDL-C and LDL-C, but do not seem to affect the HDL-C/total cholesterol or HDL-C/LDL-C ratios. A little bit of alcohol consumption increases HDL-C levels. To reduce cholesterol levels, it is recommended that reduces an animal fat and saturated fat and increases vegetable fat and unsaturated fat. Gymnastics, long distance run, cross country, and tennis increase HDL, as well as reduces fat and body fat %, finally exercise training effect on reduce the risk of adult disease. The risk of heart disease be able to reduced by with exercise training, significant low fat, and low cholesterol dietary. The better exercise prescription is endurance aerobic exercise such as walking, jogging, cycling at indoor and outdoor, running, play basketball, play tennis, and swimming, combination exercise is more effective than single exercise. The effective exercise 3 conditions are intensity (70%-85% of Max. capacity), 30-60min at each time, and frequency (3-6 times in a week), but player consider individual differences. To get more effect exercise, exercise consistent is very important.