Effects of epigallocatechin gallate on CoCl_(2)-induced apoptosis in PC12 cells

Yang, Kyu-Ho,Mo, Hyun-Chul,Choi, Nam-Ki,Kim, Seon-Mi,Kim,Won-Jae 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.1

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride (CoCl_(2)) has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG). a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by CoCl_(2) and effects of EGCG on CoCl_(2)-induced apoptosis in PC12 cells. Administration of CoCl_(2) decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with 100 µM EGCG for 30 min before PC12 cells were exposed to 150 µM CoCl_(2), being resulted in the cell viability and DNA fragmentation being rescued. CoCl_(2) caused morphologic changes such as cell swelling and condensed nuclei, whereas EGCG attenuated morphologic changes by CoCl_(2). EGCG suppressed the apoptotic peak and a loss of Δψ_(m) induced by CoCl_(2). CoCl_(2) decreased Bcl-2 expression but Bax expression was not changed in CoCl_(2)-treated cells. EGCG attenuated the Bcl-2 underexpression by CoCl_(2). CoCl_(2) augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity, a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by CoCl_(2). NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated CoCl_(2)-induced apoptosis in consistent with those of EGCG. These results suggest, that CoCl_(2) induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against CoCl_(2)-induced apoptosis in PC12 cells. 신경세포자멸사는 저산소 및 허혈환경에서 일어나며 이러한 세포죽은 reactive oxidant species (ROS) 생성을 동반함이 알려져있다. 그러나, 저산소 및 허혈환경에서 일어나는 세포자멸사의 기전 및 그 치료방법은 아직 정립되어 있지 않다. CoCl_(2)는 ROS를 생성하는 등 저산소환경과 유사한 조건을 초래하는 것으로 알려져 있다. Epigallocatechin gallate (EGCG)는 녹차의 polyphenol 성분으로서 세포성장과 죽음에 다양한 약리학적 효과를 나타냄이 알려져 있다. 본 연구는 PC12 세포에서 CoCl_(2)에 의한 세포자멸사기전을 밝히고 이에 미치는 EGCG의 효과를 조사하는데 목적이 있다. Cell viability는 MTT 측정으로 조사되었고, DNA fragmentation은 DNA laddering으로 조사되었다. Bcl-2와 Bax발현 정도는 RT-PCR로, caspase-3와 -9의 활성은 spectrophotometer, caspase-8의 활성은 flow cytometry에 의해 측정되었다. 미토콘드리아에서 세포질로 분비된 cytochrome c는 western blot으로, 분해된 DNA 양과 미토콘드리아 세포막전위 (Δψ_(m))는 FACScan으로 조사되었다. CoCl_(2)투여로 PC12 세포수는 용량 및 시간 의존형태로 감소하였고, genomic DNA fragmentation이 발생하였다. CoCl_(2)투여로 야기된 cell viability의 감소와 DNA fragmentation은 EGCG 전처치에 의해 억제되었다. CoCl_(2)은 세포용적팽창과 condensed nuclei 같은 형태적 변화를 일으켰으며, apoptotic peak, Δψ_(m)감소 및 cytochrome c 유리를 야기하였다. EGCG는 CoCl_(2)에 의한 세포형태변화, apoptotic peak, Δψ_(m)소실 및 cytochrome c 유리를 억제시켰다. CoCl_(2)는 Bcl-2 발현을 감소시켰지만, Bax 발현에는 영향을 미치지 않았다. EGCG는 CoCl_(2)에 의해 야기된 Bcl-2 발현 감소를 억제시켰다. CoCl_(2)는 caspase-3, -8, 그리고 -9의 활성을 증가시켰으며, EGCG는 CoCl_(2)에 의한 세포자멸사를 억제시켰다. 본 실험결과는 PC12 세포에서 CoCl_(2)가 미토콘드리아 의존 및 death receptor의존 기전으로 세포자멸사를 일으키며, EGCG는 세포자멸사기전을 억세지킴으로 신경보호기능을 가짐을 시사하였다.

수종의 밴드 접착 시멘트의 물성에 대한 비교 연구

양규호,김기백,김선미,최남기 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

본 연구의 목적은 시중에 유통되고 있는 밴드 시멘트들을 종류별로 이용하여 교정용 밴드의 결합강도를 비교하고, 각 시멘트의 파절 양상을 비교하여 교정용 밴드에 대한 사용지침을 마련하는데 도움이 되고자 하였다. 100개의 발거된 인간의 제 3대구치를 이용해 실험군은 총 5개의 군으로 하였으며, 각 군당 시편수가 20개가 되도록 임의적으로 분류하였다. 실험에 사용한 밴드 시멘트는 다음과 같다; Ormco gold, Ultra Band-Lo™, Fuji Ortho™ LC, 3M Unitek™ Multi-Cure Glass Ionomer, Ketac-Cem™. Universal testing machine(Instron Corp., Canton, MA, USA)를 사용하여 최대하중값을 측정하였고, 전단결합강도 값을 계산하였다. 밴드가 탈락한 후, 탈락부위를 평가하여 법랑질과 시멘트, 시멘트와 밴드 사이로 구분하였다. 밴드의 전단강도는 One-way ANOVA를 이용하여 통계처리 하였으며 Tukey test를 이용하여 검정하였다. 또한 탈락 부위는 Chi-squre analysis를 이용하여 통계 처리하였고, Fisher's exact test로 군간 유의성을 검정하였다. 실험 결과 평균 파절 강도는 Ormco군이 가장 높았고(2.44±0.57), Fuji Ortho™군(2.24±0.50), Ketac-Cem™군(2.10±0.57), 3M Unitek™군(1.82±0.43), Band-Lok™군(1.73±0.28) 순이었으며, Ormco군은 Band-Lok™군과 3M Unitek™군, Fuji Ortho™군은 Band Lok™군과만 통계적으로 유의할만한 차이를 보였다(p<0.05). 파절 양상에서 Ormco군과 Band-Lok™군은 서로뿐만 아니라 다른 군과 유의할만한 차이를 보였으며, Fuji Ortho™, 3M Unitek™, Ketac-Cem™군 간에는 유의한 차이가 없었다. The aim of this study was to compare the shear-peel strength and the fracture site of 5 commercially available orthodontic band cements. One hundred molar bands were cemented to extracted human 3rd molars. The specimens were prepared in accordance with the manufacturer's instructions for each cement. After storage in a humidor at 37℃ for 24 hours. the shear debonding force was assessed for each specimen using an universal testing machine with crosshead speed of 2 mm/minute. Maximal failure stress was converted to mean shear-peel strength. MPa. The predominant site of band failure was recorded visually for all specimens as either at the band/cement or cement/enamel interface. Mean shear-peel strength of Ormco was the highest(2.44±0.57). followed by Fuji Ortho™(2.24±0.50), Ketac-Cem™(2.10±0.57). 3M Unitek™(1.82±0.43). Band-Lok™(1.73±0.28). There were statistically significant differences between Ormco and Band-Lok™. Ormco and 3M Unitek™. and Fuji Ortho™ and Band-Lok™(p<0.05). The predominant site of bonding failure for bands cemented with the Ormco was at the band/cement interface. whereas bands cemented with Ultra Band-Lok™ failed predominantly at the enamel/cement interface. There was no significant difference among the other cements(Fuji Ortho™. 3M Unitek™. Ketac-Cem™).

부정교합에 따른 설위치 및 설압에 대한 연구

양규호,김선미 大韓小兒齒科學會 1995 大韓小兒齒科學會誌 Vol.22 No.1

This study was to investigate the effect of posture and force of tongue on the malocclusion by Angle's Classification. Fifty eight subjects who had no congenital orofacial defects- 19 of ClassⅠ, 19 of Class Ⅱ and 20 of Class Ⅲ- were selected. The posture of tongue and hyoid bone was measured by lateral cephalogram taken at rest. Also pressures of tongue in swallowing, phonetics and maximum thrust were measured with physiograph and analysed for each group. And lateral cephalogram was taken form the same subject at centric occlusion and the posture and force of tongue were compared with craniogacial variables. Results of the present investigation led to the following results : 1. Tongue tips of Class Ⅱ and Ⅲ were located at lower and more posterior positon than that of ClassⅠ and the tongue dorsum was located at the lowest position in Class Ⅲ. There was no difference in position of hyoid bone among Class Ⅰ, Ⅱ and Ⅲ. 2. There was no difference of tongue pressure exerted to maxillary incisor among ClassⅠ,Ⅱ and Ⅲ, but there was the highest tongue pressure of Class Ⅲ during speech exerted to mandibular incisors. 3. The ratio of upper pressure to lower pressure of the tongue during speech is the highest in ClassⅠ followed by Class Ⅱ and Ⅲ. 4. Horizontal position of tongue tip at rest position was correlated with ANB, AB plane angle, Posterior facial height of craniofacial measurement in ClassⅠ, Y axis to FH plane, FMA in Class Ⅱ, and SNA, Overjet in Class Ⅲ. 5. There wee correlation between upper and lower pressures of tongue and craniofacial measurements at centric occlusion in each Class. 6. The lower level of tongue tip and tongue base, the higher pressure of tongue exerted to lower incisors.

교정치료환자의 구강위생

양규호,김선미 大韓小兒齒科學會 1994 大韓小兒齒科學會誌 Vol.21 No.1

We must do an evaluation of individual dental caries and gingivitis risk to solve the problem of dental caries and periodontal disease increasing with removable and fixed ortho-dontic tx. We did oral hygiene education with young patients from a position of pedodontist, so continuous effect will be accomplished not only during orthodontic treatment peroid but also thereafter. The results were as follows: 1. Essential preventive method are proper oral hygiene instruction with the usage of toothpaste containing fluoride, interdental brush, floss silk, ?? and fluoride gargling agent and diet control. 2. Supportive preventive methods are plague removal by Chlorhexidine and Sanguinarin medication. 3. Oral prophylaxis and the recall system of reeducation should be done by professional personnel.

骨格型 III級 不正咬合과 正常咬合 兒童의 一部 咀爵筋 및 口輪筋 活性度 分析

梁圭鎬,金善姬 大韓小兒齒科學會 1989 大韓小兒齒科學會誌 Vol.16 No.1

This study was performed to investigate the relationship between the EMG activity of the orofacial muscles and facial skeletal form in skeletal class III malocclusion and normal occlusion. The subjects consisted of 23boys with skeletal class III malocclusion and 30 boys with normal occlusion, aged from 10 to 13 years. The measurements from cast model, cephalometrics, and EMG recordings from the anterior temporal, masseter and orbicularis were analyzed at rest position, during maximal biting in centric occlusion, and during mastication and swallowing of peanuts. the following results were obtained; 1. At rest position, the activity of the anterior temporal muscle was the highest of all the muscles examined both in the boys with normal occlusion and skeletal class III malocclusion. The orbicularis oris muscle activity of skeletal class III subjects was higher than that of normal subjects, while the activities of anterior temporal and masseter muscles were not significantly different brtween the two groups. 2. During mastication or maximal biting in centric occlusion, the activities of anterior temporal and masseter muscles in skeletal class III subjects were singificantly lower than that of normal subjects. 3. During swallowing the orbicularis oris muscle activity of skeletal class III subjects was higher than that of normal subjects. 4. The activities of anterior temporal and masseter muscles during mastication or maximal biting in centric occlusion were inversely correlated with the mandibular prognathism and with reversed overjet. 5. No significant correlation was noted between the activities of masticatory muscles and the total number of erupted teeth or occluded ones.

정상교하 아동의 두개안면부 성장에 관한 종적 연구

양규호,박창헌,손정수,김낙현,최남기,김선미,김기백,신혜성 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

혼합치열기 정상교합 아동 24명(남:14명 여:10명 초진 시 평균 나이 9±1.3세, 평균 관찰 기간: 13±1.3개월)에 대한 성장량을 측정하여 기능적 교정장치의 순수 치료효과를 평가하는데 도움이 되기 위해 3회(5~8개월 간격) 촬영한 측모 두부 방사선 규격 사진에 대한 분석 결과 다음과 같은 결론을 얻었다. 1. 남아는 상악골은 전하방, 하악골은 전방성장하였고, 여아는 상하악골이 전하방 성장하였다(p<0.05). 2. 상하악골의 남녀간 차이에서 수평적 성장상태는 여아가 컸고(A point 여아: 2.39mm, 남아: 1.26mm, p<0.05), 수직적 성장상태는 유의한 차이가 없었다. 3. 상악 전치의 치축은 두개저에 대해서 순측 경사하였고(p<0.01) 하악 전치의 치축은 큰 변화가 없었다. The purpose of this study was to provide the reference data evaluating the treatment effect of orthopedic appliances. The skeletal and dental growth increments were measured in 24 normal mixed dentition children(boys: 14, girls: 10) by three serial lateral cephalograms: initial mean age: 9±1.3 years, mean observation period: 13±1.3 months, Cephalometric changes were analysed. The results were as follows: 1. In boys, the maxilla showed forward and downward growth pattern and the mandible showed forward growth pattern(p<0.05). In girls, the maxilla and mandible showed forward and downward growth pattern(p<0.05). 2. Horizontal growth of both maxilla and mandible in girls was superior to those in boys(A point: girls: 2.39mm, boys: 1.26mm, with p<0.05), whereas vertical growth of both maxilla and mandible in boys was similar to those in girls. 3. The change in tooth axis showed labioversion of upper incisor(p<0.01) and comparatively stable lower incisor position.

유치열의 이중치 및 결손치의 발생빈도와 영구치열과의 상호관계

양규호,임혜정,최남기,김선미 대한소아치과학회 2007 大韓小兒齒科學會誌 Vol.34 No.3

Berlin reactivator에 의한 Angle씨 2급 1류 부정교합의 치험예

양규호,김선희,김용남 大韓小兒齒科學會 1988 大韓小兒齒科學會誌 Vol.15 No.1

The patient, 8 years 9 months old male, complained of protrusion of upper anterior teeth. As a result of clinical examination and cephalometric analysis. It was revealed forward relationship in maxilla, but normal in mandible. This patient was treated with berlin reactivator combined with extraoral headgear. After 9 months, the following results were obtained: 1. Canine and molar relationship was improved. 2. The overjet was somewhat improved. 3. Forward maxillary growth was inhibited. 4. Relations of the upper and lower jaws (ANB difference) were improved.

치면열구전색제와 유동성 복합 레진의 미세 경도 및 표면 조도의 비교

양규호,최남기,김선미,최지은 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

본 연구는 예방적 레진 수복술에 전통적으로 사용되던 소와열구 전색제를 대신하여, 유동성 복합 레진이 사용될 경우의 타당성을 검토하기 위해 시행되었다. 비커스 미세경도를 측정하기 위해 직경 10 mm, 높이 3 mm인 11개의 시편을 제작하여 비커스 미세경도 측정기(FM-7, FUTURE-TEC Inc., Japan)를 이용하여 압입하중 50 gf, 유지시간 15초의 조건 하에서 측정하여 각 군의 평균값을 산출하였다. 표면조도를 측정하기 위해 칫솔마모시험기(Toothbrush abrasive machine K236, Tokyo Machine Co., Japan)로 4개의 시편 표면에 200 rpm의 속도로 4000회의 칫솔질을 시행한 뒤 표면조도형상측정기(Form Tahrsurf series 2, Rank Taylor Hobson Co., England)를 이용해 표면조도를 측정하였다. α=0.05의 유의 수준에서 Kruskal-Wallis rank test와 Mann-Whitney U test를 사용하였다. 또한 주사전자현미경으로 관찰하여 각 군의 마모 양상을 비교하여 다음과 같은 결론을 얻었다. 1. 비커스 미세경도 측정 결과 Filtek Z350 flowable(3M ESPE, U.S.A), Palfique Estelite LV(Tokuyama Dental, Japan), Ultraseal XT plus(Ultradent, U.S.A) 순으로 높게 나타났으며 모든 군 간에 통계적으로 유의한 차이가 있었다(p<0.0001). 2. 표면 조도 측정 결과, Ultraseal^(R), Estelite^(R), Z350^(R) 순으로 높게 나타났으나 통계적으로 유의한 차이는 없었다(p=0.116). 3. 마모되지 않은 표면과 마모가 일어난 표면을 주사전자현미경으로 관찰한 결과, 전색제인 Ultraseal XT plus와 유동성 복합레진인 Palfique Estelite LV, 나노필러를 함유한 유동성 복합레진인 Filtek Z350 flowable이 서로 다른 마모 양상이 나타나는 것을 볼 수 있었다. 이상의 결과를 토대로 할 때, 유동성 복합 레진이 전색제에 비해 물성적 측면에서 더 우수한 것으로 나타났다. This study was performed to compare the wear resistance of sealant and flowable resins for analyzing the effect of flowable resin as a sealant in preventive resin restorations. Specimens were made and Vicker's hardness number and surface roughness were measured. SEM observations of the polished and abraded surfaces were established. Kruskal-Wallis rank test and Mann-Whitney U test at the significant level of α=0.05 were used. The following results were obtained: 1. The microhardness was decreased among groups in following order: Z350(3M ESPE, U.S.A), Estelite(Tokuyama Dental, Japan) and Ultraseal(Ultradent, U.S.A). There were significant differences in all groups(p<0.0001). 2. The surface roughness was decreased among groups in following order: Ultraseal XT plus, Palfique Estelite LV and Filtek Z350 flowable, However, there is no statistically significant differences in roughness among Estellite, Z350 and Ultraseal at the significance level of α=0,05, with p=0.116 3. SEM observation of the unworn and worn surfaces revealed the qualitative differences in the wear appearance among groups. The results in this study indicate that flowable resin is better than sealant in aspect of physical properties.

한국성인에서의 Tweed Triangle과 Soft-Tissue에 관한 연구

양규호,김선희 大韓小兒齒科學會 1995 大韓小兒齒科學會誌 Vol.22 No.1

In this study, an effort was made to measure the Tweed triangle in assessing hard tissue, at the same time, to use the Z angle and Ricketts' E line in assessing facial esthetics. The cephalometric radiograms were taken from the Korean adult subjects, 21 to 27 years old, that consist of 30 males and 30 females with normal occlusion and harmonious profile, 8 items were statistically analysed. The results of this study were as follows : 1. In this study, standard values measured with 6 items in Korean were FMA 24.13˚, IMPA 94.42˚, FMIA 61.14˚, Z angle 73.95˚, Total chin 14.91mm, Upper lip thickness 12.73mm, UL to E line -1.56mm and LL to E line 0.28mm. 2. The mean of the Twed triangle in Korean males was FMA 23.95˚, IMPA 92.13˚ and FMIA 63.90˚. In females, FMA 24.32˚, IMPA 96.70˚ and FMIA 58.98˚. 3. The mean of measurements of the soft tissre in Korean males was Z angle 74.87˚, Total chin 15.05mm, Upper lip thickness 12.98mm, UL to E line -1.67mm and LL to E line 0.17mm. In females, Z angle 73.-3˚, Total chin 14.76mm and Upper lip thickness 12.48mm, UL to E line -1.45mm and LL to E line 0.40mm. 4. As compared 8 items by sex, there is no significant difference except the FMIA and IMPA among the 8 items(p<0.05). 5. As verified the correlation of the IMPA, FNIA, Z angle, UL to E line and LL to E line, there are correlations between FMIA and IMPA, FMIA and Z angle, FMIA and LL to E line, Z angle and UL to E line, Z angle and LL to E line(p<0.05). 6. As compared with the present study, Japanese and Caucasian, the mandibular incisor of Korean was proclined more than that of Caucasian, the FMA was smaller than in Japanese. The Z angle and Total chin of Korean was larger than those of Japanese, but the upper lip thickness of Korean was smaller than that of Japanese. The position of the upper lip and lower lip to Ricketts' E line in Korean adults was protruded more than those of Caucasian.