세로머, 세라믹 및 복합레진의 기계적 성질의 비교에 관한 연구

백정화,박일윤,황호길 大韓齒科保存學會 1999 Restorative Dentistry & Endodontics Vol.24 No.1

Soft Agar Assay를 이용한 배양골조직과 골세포의 Transforming Growth Factor-β유리에 관한 연구

백정화,김관식,정동균 대한구강생물학회 1991 International Journal of Oral Biology Vol.15 No.2

To study the effect of PTH, osteotropic hormone, on the TGF-β activity in conditioned medium prepared from bone explants, fetal rat ulnae and radii were removed at 19-day of gestation and organ cultured for 24 hours. Then media were changed with fresh BGJb media for control group or PTH-supplemented media (50 or 200 ng/㎖) for experimental group respectively and conditioned media were prepared by 2-day culture of explants. To study the cellular orgin of matrix-associatied TGF-β and the effect of PTH on the TGF-β activity in conditioned media prepared from bone cells, five bone cell populations were prepared from fetal rat calvaria by sequential enzyme digestion. After primary culture, each bone cell population was collected and resuspended as Ⅰ-Ⅱ, Ⅲ and Ⅳ-Ⅴ groups. After 24 hours, media were changed with fresh minimum essential medium(MEM) or 600 ng/㎖ PTH-supplemented media and conditioned media were prepared by 2-day culture. For activation of latent TGF-β activity in bone cell-conditioned media, media were acidified and then neutralized. TGF-β activities of conditioned media were measured by anchorage-independent growth of NRK fibroblasts using modified Todaro soft agar assay method(1987) and the number of colonies ≥ 50 ㎛ was counted. The observed results were as follows. 1. TGF-β, without 2 ng/㎖ EGF, did not induce colony formation in soft agar suspensions. 2. With 2 ng/㎖ EGF, TGF-β induced NRK cells to form large colonies in soft agar suspensions and colony numbers increased proportionally to TGF-β concentrations from 50 pg/㎖ to 1600 pg/㎖. 3. When ulnae and radii were incubated with 50 ng/㎖ PTH, TGF-β activity in conditioned media was not significantly different from control conditioned media. In contrast, TGF-β activity in conditioned media prepared from culture with supplementation of 200 ng/㎖ PTH, was significantly increased(p < 0.01). 4. TGF-β activity was detectable in all bone cell populations and the amount was not significantly different between cell populations. 5. When bone cell populations were incubated with 600 ng/㎖ PTH. TGF-β activity in conditioned media from each population was not significantly different from control conditioned media. These results suggest that all cell populations isolated from calvaria synthesize TGF-β and PTH has no apparent effects on the TGF-β production of bone cell populations. In addition, increased TGF-β activity in bone explant conditioned media by 200 ng/㎖ PTH appears to be due to the enhanced release of TGF-β from bone matrix secondary to bone resorptive process.

집쥐에 의한 슴새 번식성공률 감소

남기백,유승화,김동원,유정칠 경희대학교 한국조류연구소 2002 연구보고 Vol.8 No.1

본 조사는 2001년 6월 25일부터 30일, 8월 12일부터 17일, 10월 20~25일까지 제주도 북제주군 추자면에 위치한 사수도에서 집단 번식하는 슴새의 번식성공률을 조사하였다. 현재 사수도에는 약 4000쌍 정도의 슴새가 번식을 하는 것으로 조사되었다. 총 110개의 둥지를 관찰한 결과, 부화률은 약 15%로 나타났으며, 전체 번식성공률은 약 3%로 나타났다. 전체 번식실패률은 96.4%로 나타났으며, 번식실패 요인으로 집쥐에 의한 포식이 92.5%로 가장 높게 나타났다. 또한 포란기와 부화기에 포식률이 각각 42%, 36%로 육추기의 포식률(11%)보다 높게 나타났다. The rate of breeding success of Streaked Shearwaters (Calonectris leucomelas) was studied at Sasu-islet, in chuja-do, cheju island during 25-30 June, 12-17 August, 20-25 October 2001. The breeding population of Streaked Shearwaters at Sasu-islet is estimated to be about 4,000 pairs. This study was based on detailed observations of 110 nests dispersed over a wide range of nest habitats within colony. Hatching success was 15% (n=17), breeding success was 3% (n=3) and breeding failure was 96% (n=106). Norway Rat(Rattus norvegicus) were responsible for failure of at least 89% of all the breeding failure. The predation rates of both incubation and hatiching periods was higher than that of rearing period.

태권도 도장 교육환경에 대한 학부모의 만족도 조사연구

윤상화,정백수 龍仁大學校 武道硏究所 2003 武道硏究所誌 Vol.14 No.1

The objective of the present study is to investigate parents' satisfaction with taekwondo halls with regard facilities, size, safety, cleanliness, the disposition of the coach (director), management and educational aspects, aiming at increasing the membership of taekwondo halls, improving the health of members, and ultimately developing taekwondo as a sound living sport contributing to education, cultivation of good personality and the improvement of school records. This study selected 8 taekwondo halls under the supervision of Gyeongsangbuk-do Taekwondo Association and run by graduates of Yongin University, all of which were in Pohang, Gyeongsangbuk-do, and sampled parents of higher grade (4^(th), 5^(th), 6^(th) year) elementary school students who were attending the taekwondo hall. The present researcher prepared the tool used in this study by modifying questionnaires used in previous researches, Evaluation of Taekwondo Halls in Seoul pun, Sang-hwa, 1998) and Comparative Analysis of the Image of Middle School Teachers Expected in Korea and Japan (Lee, Mu-sun, 1994), Current State of Educational Environment and Its Improvement &m, Ok-ju, 1997). The questionnaire consists of a total of 35 questions, 5 about background variables, 5 above size and facilities, 5 about safety and cleanliness, 10 about the disposition and specialty of the coach (director), and 15 about satisfaction with management and educational aspects. The present study was carried out for about 3 months from November 2002 to January 2003. The number of questionnaires recovered from the 8 halls was 424. Excluding insincere replies, 283 of them were used in data analysis, for which SPSS WIN 10.0 was used. Frequency analysis was performed for all items, cross analysis was for each question according to the background variables of parents' satisfaction with the educational environment of taekwondo halls, and chi-square test was for testing the significance among groups. The significance level for the analysis was 5%. From the research methods and processes presented above, this study drew the following conclusions. 1) Parents' satisfaction with size and facilities With regard to parents satisfaction with the size and facilities of taekwondo halls by the gender of trainees, 7.7% of the parents replied Not Satisfied , 42.7% Moderately Satisfied , and 51.4% Satisfied , so as a whole, parents were satisfied with the size of taekwondo halls. Parents' satisfaction with the floor condition of taekwondo halls by gender, age, academic qualification and the length of training was 32.9% as a whole, so it was urgently required to improve the facilities of taekwondo halls. 2) Parents' satisfaction with safety and cleanliness With regard to parents' satisfaction with the safety and the cleanliness of taekwondo halls by parents' age, 6.8% of parents replied Not Satisfied , 45.4% Moderately Satisfied , and 47.1% Satisfied , so as a whole, parents were satisfied with the safety and the cleanliness of taekwondo halls. Parents' satisfaction with the safety of hall bus operation by gender, age, academic qualification, and the length of training was 64.5% as a whole, so they were relatively satisfied with the safety of hall bus operation. However, with regard to parents' satisfaction with fire prevention facilities by gender, age, academic qualification, and the length of training, 62.5% of the parents replied Not satisfied , so fire prevention facilities in taekwondo halls appeared inadequate. With regard to parents satisfaction with the cleanliness of the inside of taekwondo halls by gender, age, academic qualification, and the length of training, 36.4% of the parents replied Not Satisfied , so they appeared not satisfied with the cleanliness of the indoor environment of taekwondo halls. 3) Parents' satisfaction with the disposition and specialty of coaches (directors) With regard to parents' satisfaction with the kindness of coaches by gender, age, academic qualification, and the length of training, 89% of the parents replied positively. In addition replies to questions about coaches fairness, ***, leadership, *** and service spirit showed that most parents appeared to be satisfied with the coaches of taekwondo halls in terms of these characters. 4) Parents' satisfaction with management and educational aspects According to parents' replies to the question, Are trainees' problems well managed by the hall?, by gender, age, academic qualification, and the length of training. 36.4% of the parents were not satisfied, so the level of satisfaction was somewhat low. With regard to parents' satisfaction concerning the question, Did you receive a phone call for confirmation when ***', 20.1% of the parents answered 'No', so their satisfaction appeared to be somewhat low. With regard to parents' satisfaction concerning the question, Are children properly given personality education during training?, by the length of training, 81.6% of parents answered positively. However, with regard to parents' satisfaction with health and hygienic management by academic qualification, 37.7% of the parents replied 'Unsatisfied'. These results suggest that taekwondo halls must improve their facilities, safety, cleanliness and management.

韓國産 擔子菌類의 抗菌成分에 관한 硏究 (III) : 10種의 擔子菌에 대한 抗菌成分 檢索

鄭敬壽,白貞花,柳柄泰,金炳珏 충남대학교 약학대학 의약품개발연구소 1987 藥學論文集 Vol.3 No.-

The ether, methanol, and physiological saline extracts of the dried carpophores of ten basidiomycetes, which were collected from several locations of Korea, were subjected to a screening test for antibiotic activity by disc-plate method using Sarcina lutea, Bacillus subtilis, Escherichia coli, and Serratia marcescens as target organisms. As the result, the methanol extract of five basidiomycetes-Amanita rebescens, Amanita solitaria, Lactarius vellereus, Latarius subzonarius and Scleroderma verrucosum-were found te have antibiotic activity. Among them, the methanol extracts of A. rubescens and L. vellereus exerted strong activity against both of the gram positive and negative bacteria. The ether extracts of A. rubescens and S. verrucosum also showed activity against S. lutea. The physiological saline extract, however, showed no activity at all.

흰쥐중심편도체핵에서 Neurotensin 면역양성세포의 다리옆핵으로의 투사

박인식,최정화,박봉수,백선용,김봉선,김재봉,김진정 대한해부학회 1996 Anatomy & Cell Biology Vol.29 No.2

cAMP 농도에 영향을 미치는 수종약물이 파골세포형성에 미치는 영향

소영,고성희,백정화,김관식,정동균 대한구강생물학회 1992 International Journal of Oral Biology Vol.16 No.2

To study the effect of cAMP on the generation of osteoclasts from their precursor cells, the bone marrow cells were isolated from 7 to 9 week-old male mice. The femur and tibia were dissected aseptically and the marrow cavity was flushed with 1 ㎖ of α-minimum essential medium by slow injection. Collected marrow cells were cultured at 1.5-2.0×10^6 cells/well in 24-well plate for 8 days. In experimental group, PGE_2(5×10^-6, 10^-5M), forskolin(10^-5M) or IBMX(10^-4, 10^-5M) were added singly or in combination from the 1st day culture. After cultures, staining for tartrate-resistant acid phosphatase(TRACP)-marker enzyme of osteoclast-was performed according to the modified method of Burstone. The TRACP-positive multinucleated cells(MNC), which have 3 or more nuclei, were counted. The observed results were as follows. 1. In control group. TRACP-positive mononuclear cells were present, but no TRACP-positive multinucleated cells appeared. 2. PGE_2(5×10^-6M) or forskolin(10^-5M) significantly stimulated the formation of TRACP-positive MNC. Moreover, forskolin potentiated the TRACP-positive MNC formation induced by PGE_2 when added simultaneously. 3. IBMX(10^-4, 10^-5M), when added alone, significantly stimulated the formation of TRACP-positive MNC. However, IBMX(10^-5M) added in combination of PGE_2(10^-5M) partially inhibited the TRACP-positive MNC formation induced by PGE_2.

Platelet-Derived Growth Factor가 백서두개관 세포군의 증식 및 교원합성에 미치는 영향

김기수,고성희,백정화,민병무,김관식,정동균 대한구강생물학회 1991 International Journal of Oral Biology Vol.15 No.2

To study the effect of platelet-derived growth factor(PDGF) on the replication and collagen synthesis of rat calvarial cells, five bone cell populations(I-V) were prepared from fetal rat calvaria by sequential enzyme digestion. After primary culture for 6-7 days, each bone cell population was collected and then population Ⅰ and Ⅱ, Ⅳ and Ⅴ were pooled together. And the cells were resuspended at 6-8×10^4 cells/㎝^2 and cultured for 2-3 days. The medium was changed to serum-free medium prior to addition of growth factor. The effect of PDGF on the cell proliferation was measured by the incorporation of [^3H]thymidine into DNA. Protein synthesis was determined by measurement of [^3H]proline incorporation into collagenase-digestible protein(CDP) and noncollagenous protein(NCP) according to the method of Peterkofsky and Die-gelmann(1971). The observed results were as follows. 1. PDGF at 10 ng/㎖ significantly increased the [^3H]thymidine incorporation into DNA in all bone cell populations. 2. PDGF at 30 ng/㎖ significantly increased the synthesis of NCP in population Ⅰ, Ⅱ and Ⅳ, Ⅴ. 3. PDGF had no effect on the synthesis of CDP but percent collagen synthesis was decreased significantly in population Ⅳ, Ⅴ. Taken together, the increase of protein synthesis by PDGF in rat calvarial cells was due to the incraese of NCP synthesis.

Tricho-dento-osseous Syndrome Mutant Dlx3 Shows Lower Transactivation Potential but Has Longer Half-life than Wild-type Dlx3

Cha, Ji Hun 대한구강생물학회 2007 International Journal of Oral Biology Vol.32 No.4

Dlx3 is a homeodomain protein and is known to play a rolein development and differentiation of many tissues. Deletionof four base pairs in DLX3 (NT3198) is causally related totricho-dento-osseous (TDO) syndrome (OMIM #190320), agenetic disorder manifested by taurodontism, hair abnor-malities, and increased bone density in the cranium. Themolecular mechanisms that explain the phenotypic charac-teristics of TDO syndrome have not been clearly determined.In this study, we examined phenotypic characteristics ofwild type DLX3 (wtDlx3) and 4-BP DEL DLX3 (TDO mtDlx3)in C2C12 cells. To investigate how wtDlx3 and TDO mtDlx3differentially regulate osteoblastic differentiation, reporterassays were performed by using luciferase reporters containingthe promoters of alkaline phosphatase, bone sialoprotein orosteocalcin. Both wtDlx3 and TDO mtDlx3 enhancedsignificantly all the reporter activities but the effect ofmtDlx3 was much weaker than that of wtDlx3. In spite ofthese differences in reporter activity, electrophoretic mobilityshift assay showed that both wtDlx3 and TDO mtDlx3formed similar amounts of DNA binding complexes withDlx3 binding consensus sequence or with ALP promoteroligonucleotide bearing the Dlx3 binding core sequence.TDO mtDlx3 exhibits a longer half-life than wtDlx3 and itcorresponds to PESTfind analysis result showing thatpotential PEST sequence was missed in carboxy terminal ofTDO mtDlx3. In addition, co-immunoprecipitation demonst-rated that TDO mtDlx3 binds to Msx2 more strongly thanwtDlx3. Taken together, though TDO mtDlx3 acted as aweaker transcriptional activator than wtDlx3 in osteoblastic cells, there is possibility that during in vivo osteoblastdifferentiation TDO mtDlx3 may antagonize transcriptionalrepressor activity of Msx2 more effectively and for longerperiod than wtDlx3, resulting in enhancement of osteoblastdifferentiation.

Modulating Effect of Estrogen on the Fluoride-stimulated Osteoblastic Activities

Baek, Jeong-Hwa Korean Academy of Oral Biology and the UCLA Dental 2002 International Journal of Oral Biology Vol.27 No.1

Combination therapy of fluoride (F) and estrogen in osteoporosis patients has been shown to induce greater increase in axial bone mass and decrease in vertebral fracture rate than fluoride or estrogen alone. Therefore, there is a possibility that when estrogen is combined with F for osteoporosis therapy, estrogen may have modulating effects on osteogenic action of F in addition to its bone resorption inhibitory effect. To test this hypothesis, the present study aimed to investigate whether estrogen enhance the effect of F on cell proliferation, differentiation, and mineralized nodule formation in fetal rat calvarial osteoblastic cells in vitro. In this study, estrogen (10^-10, 10^-8M) alone did not significantly affect osteoblastic cell proliferation, differentiation, and mineralized nodule formation, though it slightly increased alkaline phosphatase activity. F enhanced mineralized nodule formation in dose-dependent manner and augmented the expression of osteoblast differentiation marker genes such as type I collagen, alkaline phosphatase, osteopontin and osteocalcin. In addition, F also enhanced cell proliferation. Although F alone increased osteogenic activity, those effects were more conspicuous at higher concentration of F which is higher than therapeutically active serum concentration. While estrogen alone did not significantly affect osteoblast activity, simultaneous addition with F further enhanced all the osteogenic parameters examined and those enhancing effects were more remarkable in the presence of lower concentration of F (1, 10μM). Therefore these findings suggest that estrogen have modulating effects so that F is more osteogenic in vitro in the presence of estrogen.