Low-intensity ultrasound increased colony forming unit-fibroblasts of mesenchymal stem cells during primary culture.

Choi, Woo Hee,Choi, Byung Hyune,Min, Byoung-Hyun,Park, So Ra Mary Ann Liebert, Inc 2011 Tissue engineering. Part C, Methods Vol.17 No.5

<P>Mesenchymal stem cells (MSCs) from bone marrow (BM) are an attractive cell source for stem cell-based therapeutic applications, but they exist at low-end ratios, which further decreases along with increased donor age. Thus, for clinical applications, there is a high demand for large numbers of active MSCs. This study investigated if low-intensity ultrasound (LIUS), a special type of mechanical stimulation, could increase the yield of MSCs during primary culture from the BM. Cultures were treated with LIUS for 10 min/day during the first 6 days after initial plating of BM mononuclear cells. After 12 days, the colony-forming unit-fibroblasts assay was performed, and the colonies were culture-expanded for further analyses. The LIUS stimulation showed a significant increase in the number of MSCs colonies when compared with that of the control group. The LIUS-stimulated MSCs showed no difference compared with the untreated control MSCs in terms of their proliferation rate, expression of MSCs-enriched surface antigens, and multi-lineage differentiation ability. The LIUS stimulation also showed an increase in the expression of integrins, fibronectin, and paxillin, and induced the formation of focal adhesions in MSCs, all of which involved in the cell adhesion process. These results demonstrated that LIUS stimulation could activate the cell adhesion process and increase the colony-forming ability of MSCs during the early stage of primary culture, without affecting their phenotypes and multi-potency. The results of this study suggest that LIUS could be a useful tool to obtain a large amount of MSCs for various therapeutic applications.</P>

Comparison of Dual Probe Bipolar Mode with Monopolar and Single Probe Bipolar Modes : Comparison of Dual Probe Bipolar Mode with Monopolar and Single Probe Bipolar Modes

Lee, Jeong Min,Han, Joon Koo,Kim,Se Hyung,Lee, Jae Young,Kim, Dae Jin,Lee, Min Woo,Cho, Gyung goo,Han, Chang Jin,Choi, Byung Ihn Korean Radiological Society 2004 Korean Journal of Radiology Vol.5 No.2

A Comparative Experimental Study of the, In-vitro Efficiency of Hypertonic, Saline-Enhanced Hepatic Bipolar and, Monopolar Radiofrequency Ablation

Lee, Jeong Min,Han, Joon Koo,Kim, Se Hyung,Sohn, Kyu Li,Lee, Kyoung Ho,Ah, Su Kyung,Choi, Byung Ihn Korean Radiological Society 2003 Korean Journal of Radiology Vol.4 No.3

Streptococcus salivarius의 요소분해효소 활성에 관한 연구

정상백,최호영,민병순,박상진,이진용,최기운 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.1

Dental caries is induced by organic acids produced by oral bacteria. In order to prevent dental caries, therefore, it is essential to maintain neutral pH in the oral cavity. Urea plays a major role in oral pH homeostasis. Urea is hydrolyzed by bacterial ureases to ammonia, causing a pH elevation, Streptococcus salivarius has been shown to be a major contribution to oral ureolysis. Synthesis of urease by S. salivarius appears to be constituitive, but can be greatly enhanced by low pH. It is, therefore, conceivable that ureolytic activity of S. salivarius from a carious lesion is greater than that of the bacterium from a healthy tooth. In the present study, urease activity of S. salivarius isolates from dental plaque of carious lesions was compared with that of the isolates from plaques of the teeth and the dorsum of the tongue; 45 S. salivarius strains were isolated from carious lesions(>C2) of 21 individuals with dental caries and 30 strains from 10 individuals without dental caries. The results were as follows: 1. All the 21 individuals with dental caries harbored ureolytic S. salivarius whereas 3 of 13 individuals without dental caries harbored non-ureolytic strains of S. salivarius. 2. All the 45 S. salivarius isolates from carious lesions showed urease activity. In contrast, of 30 isolates from individuals without dental caries, 17 isolates(56.7%) did not demonstrate urease activity, or if any, very little(<5μmol/min/mg). 3. Urease activity of the isolates from carious lesions was greater than that of the isolates from individuals without dental caries:the urease activity ranged from 42 to 381μmol/min/mg and from 0 to 208μmol/min/mg, respectively. 4. At acid pH(5.5), the isolates which showed intermediate urease activity at pH 7.0 demonstrated even higher activity whereas the isolate with no or lower urease activity did not show any significant difference in their activity. However, the isolates with the greatest urease activity from both individuals with and without dental caries, exhibited a rather much lower urease activity at pH 5.5. The overall results suggest that isolates may have their own urease activity but the isolates exposed to chronic acidic environment of the carious lesion might elevate urease activity of S. salivarius, which in turn, might influence on survival of S. salivarius itself and other bacteria establishing a new oral bacterial ecosystem.

The effects of secondary task on the control of vehicle under driving simulator: a study among 50s taxi drivers

Han Soo Kim,Jin Seung Choi,Dong Won Kang,Hong Won Yeon,Mi Hyun Choi,Doo Hwan Ji,Byung Chan Min,Soon Cheol Chung,Gye Rae Tack 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

Objective: The aim of this study is to quantitatively evaluate the effects of the secondary task during simulated driving using the variable indicating control of vehicle. Background: There are so many researches for simulated driving and performance. For instance, some researches show that the effects of cell phone conversations on simulated driving. Cell phone conversations impaired explicit recognition memory. Method: Participants included 50s taxi drivers; 15 males and 15 females. All subjects were instructed to keep a distance (30m) from the car ahead and a constant speed (80km/hr or 100km/hr). Sending text message (STM) and Searching navigation (SN) were selected as the secondary task. Experiment consisted of rest for 3min., driving alone for 1min. and driving with secondary task for 1 min.. We were analyzed anterior-posterior coefficient of variation (APCV) and medial-lateral coefficient of variation (MLCV). Results: APCV was increased by 175.4% in STM and 223.8% in SN at 80km/hr. MLCV was increased by 242.3% in STM and 323.4% in SN at 100km/hr. There was no significant difference between genders. Conclusion: Consequently, performing secondary task during driving impaired the control of vehicle.

저산소성 허혈성 뇌손상을 유발시킨 어린 백서에서 Myeloperoxidase 측정 검사

양혜정(Hae Joung Yang),피대훈(Dae Hun Pee),임지혜(Ji Hye Lim),최병민(Byung Min Choi),이기형(Kee Hyoung Lee),은백린(Baik-Lin Eun) 대한소아신경학회 2002 대한소아신경학회지 Vol.10 No.2

목 적 : 예전에는 뇌경색 부위에서 발견되는 백혈구를 단지 뇌손상에 뒤따르는 생리적인 반응으로만 생각하였으나 최근 10년 사이 재관류 손상에서도 백혈구에 의한 염증 작용이 중요한 역할을 한다고 알려지면서 이들의 역할에 대한 연구가 새롭게 이루어지고 있다. PML의 존재는 세포질내 과립에서 분비되는 MPO를 생화학적으로 측정함으로서 증명할 수 있는데 저자들은 미성숙 뇌에서 저산소성 허혈증에 의한 뇌손상이 발생할 때 백혈구가 침윤되는 과정을 MPO 측정 검사를 통하여 관찰하였고, P와 L-selectin 억제제인 Fucoidin을 투여한 후 MPO의 변화를 확인하였다. 방 법 : 생후 7일된 어린 흰쥐를 사용하여 우측총 경동맥을 전기 응고시켜 자르고 8% 산소에 노출시켰다. 저산소 노출 후 회복 시간에 따라 동물을 희생시키고 뇌를 추출하여 뇌조직 1 g당 10mL의 20 mM potassium Phosphate buffer(pH 7.4)를 첨가하여 50초간 분쇄하였다. 각각의 균질회된 조직 샘플들은 4℃에서 20분 동안 원심 분리하여 상층액을 제거한 후, 침전물은 처음 조직량에 따라 조직 1 g당 10 mL의 0.5% cetylditrimethylethyl ammonium bromide(wt/vol)가 첨가된 50 mM potassium phosphate buffer(pH 6.0)를 첨가하였다. Vortex를 이용하여 buffer와 침전물을 잘 섞고 60℃수조에서 120분 동안 방치하였다. 그 후 각 조직 샘플들을 4 watts에서 음파처리하고 4℃에서 15분 동안 원심 분리를 시행하여 상층액을 새로운 tube에 옮겼다. MPO 측정검사를 위한 MPO reaction buffer는 50 mM potassium phosphate buffer(pH 6.0) 100 mL에 0.53 mM odianisidine edihydrochlorde와 0.0005% HO를 섞어 만들었다. MPO reaction solution 2.9 mL에 각각의 MPO sample 0.1 mL을 첨가하여 460 nm의 파장에서 5분 동안 MPO에 다른 흡광도 차이를 관찰하였다. 결 과 : 조직내 백혈구 침윤의 지표로 측정한 MPO 활성도는 대조군에서는 미미하였으나 총 경동백을 절단한 우측 대뇌군에서는 허혈 및 저산소증 유발 후 8시간째부터 현저히 증가되기 시작하여 24시간 경과 후 발현이 가장 높았으며, Fucoidin 50 mg/kg으로 전처치한 약물 실험군에서는 MPO 활성도가 현저히 감소하였다. 결 론 : 백혈구는 미성숙 뇌의 저산소성 허혈증에 의한 뇌손상에서 중요한 매개체 역할을 하며, 백혈구의 생화학적 활성도를 나타내는 MPO 활성도는 저산소성 허혈성 뇌손상의 정도를 측정하는 지표로 이용될 수 있다고 생각된다. Purpose : Neutrophils found around an infarcted area in the brain was once considered as only the physiologic response following the brain injury, but recent studies have shown that inflammatory responses by neutrophils play an important role in the reperfusion injury. The presence of ploymorphonuclear leukocytes(PML) is proven by biochemical assay of myeloperoxidase(MPO) Secreted in the cytoplasmic granules. We observed the process of PML infiltration on hypoxic-ischemic brain injury of immature rats by the assay of MPO activity and changes of the MPO activity after the administration of fucoidin, inhibitor of P- and L-selectin. Methods : We used a well characterized model of the brains of 7 day-old-rats, which had unilateral hypoxic and ischemic injuries(HI). Those injuries were induced by unilateral carotid artery ligation followed by timed exposure to hypoxic inspiratory gas mixture(8% O). MPO activity was measured in the brain tissue homogenates of HI rats(n=18) at 0, 2, 8, 24 and 48 hrs and in rats that received fucoidin immediately before and again after hypoxia(50 mg/kg, n=6) at 8 and 24 hrs. Controls(n=2) were rats with neither hypoxia nor ischemia. The brain samples were homogenized in 20 mM potassium phosphate buffer(pH 7.4) for 50 secs. The homogenate was centrifuged at 14,000 g at 4℃ for 15 mins and the supernatant was discarded. The tissue was pulverized, weighed, and suspended in 1 mL of 50 mM potassium phosphate buffer solution(pH 6.0) contatining 0.5% cetylditrimethylammonium bromide(wt/vol). The tissue was sonicated and centrifuged at 10,000 g for 15 mins. 200 µL of the supernatant was mixed with 1 mL of 50 mM potassium phosphate buffer solution(pH 6.0) containing 10 μL of 1.325 mM o-dianisidine hydrochloride and 170 µL of 3% hydrogen peroxide(vol/vol). Changes in absorbance at 460 nm were measured for 5 mins by using microplate reader. One unit of MPO activity was defined as that degrading 1 µmol peroxide/min at 25℃, and the result was expressed as units of MPO/100 gm tissue. Results : In HI rats, MPO activity increased at 2 hrs after HI and peaked at 24 hrs in the right hemisphere. In rats with fucoidin treatment immediately before and again after hypoxia, the MPO activity significantly decreased in both hemispheres compared with HI rats(P<0.05). MPO activity in the tissue of control rats was insignificant. Conclusion : The dynamic changes of the MPO activity suggest the important role of PMN on hypoxic-ischemic brain injuries in immature rats. MPO activity could be used as an index of the severity of injuries of hypoxic-ischemic brains.

Sustained-release praziquantel tablet : pharmacokinetics and the treatment of clonorchiasis in beagle dogs

Hong, Sung-Tae,Lee, Sang Hyup,Lee, Seung-Jin,Kho, Weon-Gyu,Lee, Mejeong,Li, Shunyu,Chung, Byung-Suk,Seo, Min,Choi, Min-Ho 梨花女子大學校 藥學硏究所 2003 藥學硏究論文集 Vol.- No.12

Praziquantel is rapidly absorbed and secreted; and thus fractional doses are recommended for the treatment of cestode and trematode infections. In the present study, we developed a new praziquantel tablet formula allowing sustained-release (SRP). In vitro dissolution of SRP tablets showed that praziquantel at 300 ㎎/tablet combined with hydroxypropyl methylcellulose dissolved completely at a constant rate over 10 h, whereas the conventional praziquantel tablet (PZQ) was only 40% dissolved. Pharmacokinetic studies in dogs confirmed that SRP was absorbed more slowly than PZQ. The mean value of the area under the concentration/time curve from 0 h to the final observation time, the maximum concentration in serum, and the time of maximum concentration in serum for SRP were 3.471.500 ng/min for 0.25 ㎖, 10,300 ng for 0.25 ㎖, and 192 min. while the values for PZQ were 688,600 ng/min for 0.25㎖, 2,500 ng for 0.25㎖, and 135 min. The cure rate in dogs with a heavy infection (500 metacercariae) treated with a single dose of SRP (150 ㎎/tablet) at 50 ㎎/㎏ was 80%, while in dogs treated with a single dose of SRP (300 ㎎/tablet) at 30 mg/kg it was 60%, and the cure rate with PZQ was 20%. In each case. the egg reduction rate was similar (over 90%). No abnormal liver functions or hepatic or renal pathologies were observed in dogs administered with SRP at 30 ㎎/㎏. The SRP tablet showed sustained release and slow absorption; and it had an improved anthelmintic efficacy against Clonorchis sinensis in experimental dogs. compared with conventional praziquantel.

치아우식증 수복용 복합레진의 개발과 치아 적합성에 관한 연구 제 3 편 : 각종 용액내에서의 표면경도 변화와 세포독성에 관한 연구

최유진,조한국,민병순 大韓齒科器材學會 1992 대한치과재료학회지 Vol.19 No.2

This studies were planned to evaluate the cytotoxicity of cured experimental composite resin using a cell culture method, and the hardness changes of it stored in various aqueous acids and ethanol with considerations that solubility of resin surfaces will occure the decrease of hardness should be related with toxicity occured by elucited components. Cytotoxicity of experimental resins were tested by agar overlay methods, and some solutions in which disc type resin specimens will be stored were prepared by dilution of ethanol or acids into distilled water. The microhardness of experimental and commercial dental restorative composite materials exposed to various chemicals were measured with micro Vicker's hardness tester. Following conclusions were drawn : 1. KCR-22, experimental composite resins prepared in this study exhibited the same degree of cytotoxicity with commercial products. 2. The intensity of cytotoxicity decreased after incorporation of filler to BIS-GMA based resins. 3. The hardness numbers decreased dramatically once the composite had been immersed in ethanol solutions, however any of acidic solutions did not show the decrease of VHN. 4. The incorporation of fillers to BIS-GMA based resins which showed the double increased VHN than unfilled resins. 5. Surface hardness were increased rapidly in saline compared to it in air.

鐵骨桂脚部의 베이스플레이트 두께 변화에 다른 支壓强度에 관한 實驗的 硏究

최문식,민병렬 단국대학교 1998 論文集 Vol.32 No.-

Steel structure, steel reinforced concrete and composite structure has been increasingly used to cover the increased structural load due to the construction of high-rise buildings. Thus when designing the steel structure, it is generally considered difficult to evaluate the appropriate bearing strength of the steel base, upon which large axial load is applied. The impact of steel base to the bearing strength may be various such as to the loaded areas, strength of concrete, shape of base, and steel reinforcing bars. Entire strength of the building is transferred to the reinforced concrete footing through the baseplate. However, in the case of utilizing the baseplate with low bending strength or thin baseplate, it will be hard to estimate the accurate bearing strength upon the concrete footing due to the problem of bending occurrence by which loaded area becomes smaller than baseplate. Therefore, in the reported research, the variation of the bearing strength was analyzed by altering the thickness of steel baseplate and the appropriate estimation method of bearing strength was suggested comparing with the results of other researches.

슬관절에 히야루론산 주입후 발생한 활막성 연골종증 : 증례 보고

최의성,김용민,김동수,손현철,박경진,조병기,배승환 충북대학교 의과대학 충북대학교 의학연구소 2009 忠北醫大學術誌 Vol.18 No.2

활막성 연골종증은 비교적 드문 양성 종양으로 관절내 활액막 결체조직의 양성 반응성 이형성에 의해 여러 개의 연골성 결절을 형성하고 이것이 관절내로 유리되어 유리체를 형성하는 질환으로 주로 슬관절에 발생한다. 활막성 연골종증의 정확한 발생 기전은 아직 밝혀지지 않았으나 외상, 감염 등이 원인으로 제시되고 있다. 저자들은 슬관절 내 히야루론산 주입후 발생한 슬관절내 활막성 연골종증을 1 례 경험하였으며, 관절경적 제거술을 통해 만족스런 결과를 얻었다. As a relatively rare benign tumor, synovial chondromatosis forms several cartilaginous nodules by the benign reactive metaplasia of synovial connective tissues within joints, which are loosed into the joints and cause a disease forming loose body mainly in knee joint. Accurate mechanism of synovial chondromatosis has not been clarified yet; however, trauma, infections and others have been suggested as its possible causes. The authors of this study experienced an example of a patient with synovial chondromatosis in knee joint occurred after the injection of hyaluronic acid in the joints and had a satisfactory outcome through the arthroscopic resection.