척추경 나사못 시스템의 극한 단면 하중

송권욱,차승환,정일섭 嶺南大學校 工業技術硏究所 2002 工業技術硏究所論文集 Vol.30 No.2

Simplified modeling technique was applied to generate finite element models for lumbar spine and instrumented pedicle screw systems. Three consecutive vertebrae were included in a model, and two level instrumentaion was analyzed. In these simplified models, spring elements and multi-point constraints were used to represent the stiffness of functional spine units. Instrumented screws were modeled by using beam elements constrained to adjacent cancellous bone nodes. External loads on lumbar were estimated from intact models, based on the experimentally noted normal range of motion for flexion, extension, lateral bending and torsion. Compression load was determined by overload assumption based on the weight of human body. These estimated loads were regarded as external loads and applied to instrumented models, and section loads in implanted pedicle screw system were computed. The conditions, magnitudes and locations of critical section loads were sought for and summarized. From the computed internal loads, critical load cases were identified. The effective stresses for the critical cases were evaluated and found to be well below the static strength of titanium alloy.

감마선조사 닭고기의 미생물학적 및 유전독성학적 안전성 평가

곽희진,정차권,강일준 한국조리과학회 2001 한국식품조리과학회지 Vol.17 No.6

Gamma irradiation (1-10 kGy) was applied to chicken for the evaluation of their microbiological safety and possible genotoxicity. In 3 kGy-irradiated sample, the growth of psychrophile was inhibited about 1.5 log cycles and no cells were recovered in total microbial counts. All kinds of contaminated microorganism were sterilized by 7 kGy-irradiation. Also, irradiation followed by freeze-storage at the same time was very effective in inhibiting bacterial growth. The genotoxicity of 10 kGy-irradiated chicken was evaluated by Salmonella Typhimurium reversion assay and in vivo micronucleus assay using mouse bone marrow cells. The results were negative in the bacterial reversion assay with S. Typhimurium TA98, TA100, TA1535, and TA1539. Clastogenic effects were not shown in vivo mouse micronucleus assay at 10 kGy-dose tested.

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).

Effects of Biotin - rich Functional Food (Whalgichan) on Hair Growth and Biological Stimulation in Rat and Human

Cha-Kwon Chung 한국식품영양과학회 2000 Preventive Nutrition and Food Science Vol.5 No.1

For the development of functional food for hair-growth stimulation, this study has tried an in vivo and clinical test. As an in vivo test male Sprague Dawley rats and as a clinical test 27 baldheaded or loosehaired men were recruited. Before the experiment, the total hair count in 6 ㎟ of the designated area was 46.5. In four weeks and eight weeks of the functional food feeding it increased to 61.8 and 75.3, respectively. Hence the net increase was totaled at 62% in eight weeks. Also, depilation was decreased by 28%. Before the experiment, average hair loss was 65.7. In four weeks and eight weeks of the functional food feeding it decreased to 55.2 and 47.3, respectively. LDL and phospholipids were decreased by 42% and 36%, respectively during that period. However, HDL was increased by 21%. Forty percent of the subjects responded that itching of head skin was reduced and 34% responded to have reduced dandruff. No side-effects among the subjects were examined and no other blood parameters were significantly affected by the diet. The results in this study suggest that biotin-rich functional food may stimulate cholesterol and lipid metabolism and blood flow leading to the growth of new hair and prevention of hair loss.

Effect of Dietary Minerals and Ca - Regulating Hormones on Bone Enzyme, Alkaline Phosphatase Activity

Cha-Kwon Chung,Kyung-Sun Ha,Jeong-In Sohn 한국식품영양과학회 1996 Preventive Nutrition and Food Science Vol.1 No.1

Parathyroid hormone(PTH) is known to stimulate bone resorption and to inhibit bone collagen synthesis. In contrast, as the evidence of stimulation of bone formation by PTH has recently been observed, the study on the role of PTH involved in osteoporosis draws remarkable attention. This study has dealt with the role of alkaline phosphatase(AP), a marker enzyme for bone formation and osteoblast action. Animals(BALB/c mice) were divided into three dietary groups(high and medium Ca and Ca-free) and hormones including PTH, calcitonin(CT), cholecalciferol(vitamin D) were i.p. injected. AP in the serum and liver was measured using Sigma 221 alkaline buffer solutions containing 9mM of p-nitrophenyl phosphate. Enzyme was reacted at 37℃ for 10 minutes and the reaction was stopped by 1.8ml of 0.1N NaOH and measured at 410㎚. We found that serum and liver AP activity was increased by low dietary Ca. Compared to the control, and serum AP activity was enhanced by PTH and vitamin D regardless of the levels of dietary Ca. On the other hand, liver AP activity was inhibited by PTH and vitamin D at all levels of dietary Ca. CT inhibited the action of PTH and vitamin D in the serum. But, the inhibition of PTH and vitamin D action by CT was not observed in the liver, unlike in the case of serum.

Effect of Dietary Minerals and Ca-Regulating Hormones on Bone Enzyme Alkaline Phosphatase Activity

Chung, Cha-Kwon,Ha, Kyung-Sun,Sohn, Jeong-In The Korean Society of Food Science and Nutrition 1996 Preventive Nutrition and Food Science Vol.1 No.1

Parathyroid hormone(PTH) is known to stimulate bone resorption and to inhibit bone collagen synthesis. In contrast, as the evidence of stimulation of bone formation by PTH has recently been observed, the study on the role of PTH involved in osteoporosis draws remarkable attention. This study has dealt with the role of alkaline phoshatase(AP), a marker enzyme for bone formation and osteoblast action, Animals(BALS/cmice) were divided into three dietary groups(high and medium Ca and Ca-free) and hormones including PTH, calcitonin(CT), cholecalciferol(citamin D) were i.p. injected. AP in the serum and liver was measured using Sigma 221 alkaline buffer solutions containing 9mM of p-nitrophenyl phoshate. Enzume was reacted at 37$^{\circ}C$ for 10 minutes and the reaction was stopped by 1.8ml of 0.1N NaOH and measured at 410nm. We found that serum and liver AP activity was increased by low dietary Ac. Compared to the control, and serum Ap activity was enhanced by PTH and vitamin D regardless of the dietary Ca. On the other hand, liver AP activity was inhibited by OTH and vitamin D at all levels of dietary Ca. CT inhibited the action of PTH and vitamin D in the serum. But, the inhibition of PTH and vitamin D action by CT was not observed in the liver, unlike in the case of serum.

Effects of γ-Irradiated Pork Diet on Cytochrome P-450 System, Microsome Glucose 6-Phosphatase Activity and Antioxidative Defense Systems in Rat Hepatocarcinogenesis

Cha-Kwon Chung,강일준,Jung-Hee Kim 한국식품영양과학회 2003 Preventive Nutrition and Food Science Vol.8 No.2

This study investigated the effects of a γ-irradiated pork (0-30 kGy) diet on lipid peroxidation, cytochrome P-450 content, microsomal glucose 6-phosphatase (G-6-Pase) activity and antioxidative defense systems in diethylnitrosamine (DEN)-induced rat hepatocarcinogenesis. The body weight of rats fed irradiated diets did not change significantly. Liver weight was significantly increased by the administration of DEN, but not by irradiated diets at any dose level. There were no significant effects of gamma irradiation on the content of microsomal malondialdehyde (MDA), cytochrome P-450, or on the activity of G-6-Pase. However, with DEN treatment, cytochrome P-450 content was significantly increased while microsomal G-6-Pase activity was significantly decreased. The γ-irradiated diet supplement did not affect serum retinol or α-tocopherol concentrations. However, it did cause a significant decrease in hepatic retinol at 30 kGy. With DEN treatment, hepatic retinol content was even more significantly (p<0.05) decreased compared to the non-irradiated control. The enzyme activities related to antioxidative defense systems, including glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rx) and glutathione S-transferase (GST) were not affected by gamma irradiation. These results suggest that an irradiated pork diet up to 30 kGy may not cause a health hazard in experimental animals.

위암 조직과 정상 조직에서의 표피성장인자 수용체와 변환성장인자의 규명

정차권(Cha-Kwon Chung) 한국식품영양과학회 1994 한국식품영양과학회지 Vol.23 No.2

원발성 위암환자로 확진받은 환자들의 암조직과 암 조직 주위의 정상점막 조직을 대조군으로 사용하여, TGF-α와 이에 대한 결합력을 갖고있는 EGF-Receptor에 대한 mRNA를 면역세포화학적 방법과 in situ hybridization방법을 결합하여 규명하였다. 성장한 세포에서 발견되지 않는 TGF-α가 위암환자의 조직학적으로는 정상적으로 간주되는 위점막 조직에서 발견된 점으로 미루어 TGF-α가 암의 분화에 적극적으로 개업하고 있다는 증거가 된다. EMB-11 항체를 사용한 면역세포 화학적 방법에 의해 macrophage를 발견하였고, macro-phage cell에서 TGF-α와 EGF-R mRNA가 발현됨을 규명할 수 있었다. 또한 단클론 항체를 이용해 EGF-R에 해당하는 단백질을 발견하였다. CEA를 이용한 면역세포화학 실험에서 정상으로 간주되는 위점막 조직에서 암 세포를 규명하였다. 특히, macrophage cell의 활동이 암의 증식과 더불어 증가하고 있다는 점을 관찰할 수 있었다. 위암의 검사 방법으로서 본 실험에서 사용된 면역세포화학적 기법과 in situ hybridization방법을 사용하여 생검을 통한 조직을 대상으로 성장인자에 대한 검사를 함으로써 정확한 위암의 발생과 진행에 대한 판단을 내리는데 이용할 수 있고 실용성이 있다고 사료된다. The specimens used in this study were obtained from patients with primary gastric carcinoma and adjacent non-malignant mucosa from the same patients. Using the techniques of immunocytochemistry and in situ hybridization, transforming growth factor-α(TGF-α) and epiderimal growth factor receptor(EGF-R) mRNAs were identified. TGF-α was observed in macrophages and dividing tumor cells but, not in normal cells. EGF-R was observed both in malignant and non-malignant gastric tissues. Although normally, TGF-α is not seen in normal gastric tissues, TGF-α was discovered in the adjacent non-malignant tissue of histologically normal, which strongly suggest that TGF-α is involved in the differentiation of cancer cells. Immunocytochemistry using EMB-11 antibody identified the existence of macrophages which express TGF-α and EGF-R mRNA. Protein products of EGF-R was identified using monoclonal antibody. Cancer cells were also identified in the non-malignant normal tissues by the method of immunocytochemistry using carcino embryonic antigen(CEA) antibody. It is considered that the activity of TGF-α increased as tumor cell proliferates. Immunocytochemistry and in situ hybridization techniques can be used to diagnose gastric cancer along with the use of α-feto protein and CEA.

위암을 유도시킨 흰쥐에서 한국 전통 식품이 위암발생에 미치는 영향

정차권 (Chung Cha Kwon),강일준 (Kang Il Jun),김현숙 (Kim Hyun Sook),남상명 (Nam Sang Myung),김동준 (Kim Dong Joon),이민철 (Lee Min Chul) 韓國營養學會 1996 Journal of Nutrition and Health Vol.29 No.7

고지방 식이에 따른 어성초 추출물 투여가 혈청지질 및 항산화 효소 활성에 미치는 영향

정차권(Cha-Kwon Chung),함승시(Sung-Shi Ham),이상영(Sang-Young Lee),오덕환(Duck-Hwan Oh),최수영(Soo-Yong Choi),강일준(Il-Jun Kang),남상명(Sang-Myung Nam) 한국식품영양과학회 1999 한국식품영양과학회지 Vol.28 No.1

어성초는 해독 및 이뇨효과가 있으며 백일해, 기관지염, 간염 등의 증상을 완화한다고 알려져 있다. 본 연구는 어성초 에탄올 추출물을 투여하였을 때 혈청내 지질대사와 생체내 항산화 효소의 활성을 조사하였다. 강원도에서 자생하는 어성초 에탄올 추출물을 4주간 SD rat에 경구투여하였고 동시에 실험식이를 6주 동안 공급하였으며 고지방식이로서 10%의 lard와 1% cholesterol 및 0.25%의 sodium cholate를 공급하였다. 정상식이(C) 및 어성초추출물(CE)을 투여한 결과 총 콜레스테롤 함량이 감소되었다. HDL cholesterol은 정상식이군에 비해 증가되었으며 동맥경화 지수는 54%의 감소를 보였다. 또한 HTR은 어성초 추출물 투여군에서 유의적으로 증가하여 HDL cholesterol의 비율이 증가하였다(p<0.01). 고지방식이군(CL)의 콜레스테롤 함량은 정상식이군에 비해 유의적으로 증가하였으며(p<0.01), 동맥경화지수는 4배나 증가되었다. 어성초 추출물을 투여함으로써 동맥경화지수는 통계적으로 유의적인 감소를 나타내었고(p<0.01). HDL-cholesterol 함량은 고지방식이군(CL)에 비해 53% 증가하였다. 고지방식이 및 어성초 추출물투여군(CLE)은 고지방식이군(CL)에 비해 중성지질 함량이 51% 감소하여 통계적 유의성을 나타냈다(p<0.01). 인지질 또한 어성초 추출물 투여시 대조군에 비해 감소하였다(p<0.01). 어성초 추출물(CLE)을 투여함으로써 GOT, GPT 및 ALP활성은 감소하였고 GST활성과 catalase활성은 정상식이군에 비해 증가하였다. 고지방식이 및 어성초 추출물(CLE)을 투여했을 때 GST활성과 catalase활성은 고지방식이군(CL)에 비해 유의적으로 증가하였고 Cu,Zn-SOD는 어성초 추출물군(CLE)에서 감소하였다(p<0.01). Effects of Houttuynia cordata ethanol extracts on lipid metabolism and antioxidant enzymes in Sprague Dawley male rats were investigated. High fat used in the diet mixture included 10% of lard, 1% of cholesterol and 0.25% of sodium cholate. Total serum cholesterol contents of the rats fed Houttuynia cordata extracts were decreased compared to the control. On the other hand, HDL-cholesterol contents were increased along with the decrease of athrogenic index. When high fat diet was fed, total serum cholesterol contents were significantly increased(p<0.01) with the athrogenic index increase of four times of the control. With the administration of Houttuynia cordata extract HDL-cholesterol was increased by 53% in the high fat diet group. Antioxidant enzymes including GST and catalase activities were increased comparing the control. On the otherhand, the extracts lowered phospholipid(p<0.01), GOT, GPT, Cu,Zn-SOD and alkaline phosphatase enzyme activities in the serum which are related to the liver functions. Therefore, the above results suggest that Houttuynia cordata ethanol extracts can help to maintain normal liver functions and help to protect from peroxidative damages caused by excess dietary fat intake.