• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권1호
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• pp.39-45
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• 2005

Stem cell therapy using mesenchymal stem cells(MSCs) transplantation have been paid attention because of their powerful proliferation and pluripotent differentiating ability. Although umbilical cord blood (UCB) is well known to be a rich source of hematopoietic stem cells with practical and ethical advantages, the presence of mesenchymal stem cells (MSCs) in UCB has been controversial and it remains to be validated. In this study, we examine the presence of MSCs in UCB harvests and the prevalence of them is compared to that of endothelial progenitor cells. For this, CD34+ and CD34- cells were isolated and cultured under the endothelial cell growth medium and mesenchymal stem cell growth medium respectively. The present study showed that ESC-like cells could be isolated and expanded from preterm UCBs but were not acquired efficiently from full-terms. They expressed CD14-, CD34-, CD45-, CD29+, CD44+, CD105+ cell surface marker and could differentiate into adipogenic and osteogenic lineages. Our results suggest that MSCs are fewer in full-term UCB compared to endothelial progenitor cells.

• Archives of Pharmacal Research
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• 제29권8호
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• pp.651-656
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• 2006

This study examined the chemopreventive effect of saponins that were isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), against the tobacco-specific carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), -on lung tumorigenesis in A/J mice. The mice were treated with a single NNK dose (100 mg/kg b.w., i.p.). CKS (0.5, 1, 4 mg/kg body wt.) was administered orally daily for 3 days/week beginning 1 day after the NNK treatment and was maintained throughout the experiment. The administration of CKS suppressed the NNK-induced increase in the level of proliferating cell nuclear antigen, which are a marker of cell proliferation, in the lungs of the mice 4 weeks after the NNK injection. Twenty-five weeks after the NNK treatment, the mice were sacrificed and the number of surface lung tumors was measured. CKS significantly reduced the number of lung tumors induced by NNK in a dose dependent manner. These results suggest that CKS suppresses the development of lung tumors and has a chemopreventive effect against NNK-induced mouse lung tumorigenesis.

• Journal of Oral Medicine and Pain
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• 제7권1호
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• pp.66-70
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• 1982

Medical personnek are one of several groups that have been reported to have a high incidence of hepatiris B. It is also thought that the occurrence rate of hepatitis B surface antigen(HBsAg), aserologic marker for hepatitis B virus(HBV), is expected to be high in the dental personnel who are frequently exposed to the blood and saliva of the patients. Although many studies have been done to determine the HBsAg status of virus groups, limited investigations have been performed on dental personnel, especially in this country. The main purpose of this study was to identify HBsAg positivity among dental students, interns, and residents who would be expected to be a high risk group of hepatitis B infection. Screening test for HBsAg of a dental school population was performed by indirect hemagglutination(IHA)in 1982. The results were as follows : 1. Thirty four out of a total 362 persons(9.4%)tested in the study had positive response for HBsAg in their serum samples. 2. Twenty seven out of 320 dental students(8.4%)had positive for HBsAg, and in Senior class 12 out of 82 dental students (14.6%)had positive response that was the highest incidence among dental students group. 3. Seven out of 42 interns and residents(16.7%)had positive for HBsAg, and it was the highest incidence in this dental school population.

• Bulletin of the Korean Chemical Society
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• 제18권7호
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• pp.761-766
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• 1997

Phospholipase C from Clostridium perfringens is known to catalyze the hydrolysis of phospholipids in biological membranes. In this study, a simple and sensitive method for assaying phospholipase C was developed by using liposomes entrapping calcein as a fluorescent marker. Phospholipase C-induced lysis of liposomes was determined by measuring the fluorescence intensity of calcein released out from liposomes, Various liposomes with different compositions were prepared by reverse-phase evaporation method to investigate the effect of liposomal composition on the lytic activity of phospholipase C. The calcein-entrapping efficiency of liposomes was affected by the chain length of fatty acid in phosphatidylcholine constituting liposomes. The lytic activity of phospholipase C was the highest against liposomes prepared with eggPC. The lytic activity decreased with increasing chain length of fatty acid in phosphatidylcholine. Incorporation of cholesterol more than 20% into the liposomal bilayer inhibited the phospholipase C-induced lysis. The lysis of liposomes was more greatly increased by the addition of 10 mM of calcium. The lytic activity of phospholipase C was also affected by the surface charge of liposomes. Taken together, it was concluded that reverse-phase evaporation vesicles composed of dipalmitoylphosphatidylcholine and cholesterol in the molar ratio of 9 : 1 allowed to detect the lowest concentration of phospholipase C (0.10 μg/assay volume). This study suggested that the use of liposomes can provide a simple, sensitive and inexpensive method for assaying phospholipase C.

• 대한조선학회논문집
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• 제37권4호
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• pp.48-55
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• 2000

선박의 저항을 줄이기 위하여 발생시킨 기포의 거동을 알기 위해, 선체주위의 기포거동에 과한 기초적 연구를 수행하였다. 본 연구에서는 선체주위에 발생된 기포의 거동에 대하여, 기포의 크기와 발생위치를 변화시켜가며 수치계산 및 실험을 수행하여, 선체주위의 기포거동에 관한 특성을 연구하고자 하였다. 기포의 거동방정식은 기포의 부력을 고려한 Kawakita의 것을 사용하였다. 수치계산은 MAC(Marker And Cell)법을 기초로 한 유한차분법(Finite Difference Method)을 사용하였으며, 실험은 Series 60선형에 대하여 회류수조에서 수행되었다. 실험과 계산은 서로 비교하여 보았다.

• 대한수의학회지
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• 제61권3호
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• pp.22.1-22.7
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• 2021

Fenbendazole (FBZ) is a commonly used anthelmintics in veterinary medicine that has recently been found to have anticancer effects in humans. On the other hand, few studies have examined the anti-inflammatory effects of FBZ, and its mechanism is unknown. In this study, mouse bone marrow cells (BMs) were treated with lipopolysaccharide (LPS), a representative inflammation-inducing substance, to generate a situation similar to osteomyelitis in vitro. The effect of FBZ on inflammatory BMs was examined by measuring the metabolic activity, surface marker expression, cell nuclear morphology, and mitochondrial membrane potential (MMP) of BMs. FBZ decreased the metabolic activity and MMP of LPS-treated BMs. Annexin V-fluorescein isothiocyanate/propidium iodide staining and Hoechst 33342 staining showed that FBZ reduced the number of viable cells and induced the cell death of inflammatory BMs. In addition, FBZ reduced the proportion of granulocytes more than B lymphocytes in LPS-treated BMs. Overall, FBZ induces cell death by destabilizing the MMP of LPS-induced inflammatory BMs. In addition to anthelmintic and anticancer agent, FBZ can play a role as an anti-inflammatory agent.

• Journal of Veterinary Science
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• 제22권6호
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• pp.74.1-74.13
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• 2021

Tissue engineering has been extensively investigated and proffered to be a potential platform for novel tissue regeneration. The utilization of mesenchymal stem cells (MSCs) from various sources has been widely explored and compared. In this regard, MSCs derived from bone marrow have been proposed and described as a promising cell resource due to their high yield of isolated cells with colony-forming potential, self-renewal capacity, MSC surface marker expression, and multi-lineage differentiation capacities in vitro. However, there is evidence for bone marrow MSCs (BM-MSCs) both in vitro and in vivo from different species presenting identical and distinct potential stemness characteristics. In this review, the fundamental knowledge of the growth kinetics and stemness properties of BM-MSCs in different animal species and humans are compared and summarized. Finally, to provide a full perspective, this review will procure results of current information studies focusing on the use of BM-MSCs in clinical practice.

• 대한수의학회지
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• 제62권3호
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• pp.20.1-20.8
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• 2022

5-Fluorouracil, doxorubicin, and vincristine are chemotherapy agents used to treat various cancers, such as breast cancer and lymphoma for decades, and their effects on cancer have been proven. On the other hand, these anti-cancer drugs cause fatal side effects, including immunosuppression. This study investigated whether sonicated Bordetella bronchiseptica bacterin (B. bronchiseptica) can attenuate the immunosuppression of spleen cells induced by these chemotherapy agents and which subsets of spleen cells were affected. B. bronchiseptica increased the metabolic activity of spleen cells treated with 3 anti-cancer drugs. Cell death analysis using Annexin V/propidium iodide showed that B. bronchiseptica markedly decreased the death of spleen cells. The subsets of spleen cells were analyzed by flow cytometry using a surface marker-specific antibody. B. bronchiseptica increased nitric oxide production in the spleen cells treated with anti-cancer drugs (p < 0.0001). Despite the pharmacological effects of anti-cancer drugs, many patients suffer from the fatal side effects of immunosuppression. This study provides valuable information on how to overcome chemotherapy-induced immunosuppression.

• Clinical and Experimental Reproductive Medicine
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• 제33권3호
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• pp.171-178
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• 2006

목 적: 인간 배아줄기세포는 재생 의학이나 조직공학에 있어서 큰 잠재적인 능력을 가지고 있는 것으로 알려져 있다. 이들은 다양한 growth factors 처리나 유전자 발현을 변화시켜 특정 세포로 유도 분화 및 분리가 가능하지만 그 효율성은 아직까지 낮은 상태이다. 본 연구에서는 인간 배아줄기세포로부터 비특이적으로 분화된 세포들을 특정 세포 표면 항체를 이용한 magnetic cell sorting (MACS) 방법으로 분리, 배양하여 그들의 특성을 살펴보았다. 연구방법: 미분화 배아줄기세포주(Miz-hESC4)를 물리적인 방법으로 계대 배양하였으며, 부유 배양법으로 배아체 형성을 유도하였다. 배아체의 자발적인 분화를 위해 DMEM에 10% FBS를 첨가하여 2주 동안 배양하였다. 이렇게 분화된 세포들을 CD34, human epithelial antigen (HEA), human fibroblast (HFB)에 대한 항체를 이용한 MACS system으로 각각의 항체에 대한 양성 또는 음성 세포를 분리하였다. 이러한 MACS 분리 세포를 4주 동안 배양하면서 형태적인 변화를 관찰하고 특이 유전자의 발현 양상을 분석하였다. 결 과: 분리 배양한 CD34 양성 세포들은 배양 초기에는 둥근 형태를 나타내다가 배양 후기에는 작은 다각형의 형태로 관찰되었으며, HEA 양성 세포들은 큰 다각형의 형태를 나타내었고, HFB 양성 세포들은 전형적인 방추체 형태로 관찰되었다. 특이 유전자에 대한 RT-PCR 결과에서, CD34 양성 세포들과 HFB양성 세포들에서는 내배엽과 중배엽 관련 유전자의 발현하는 것을 확인할 수 있었고, HEA 양성 세포들에서는 외배엽 관련 유전자인 NESTIN과 NF68KD의 발현을 관찰할 수 있었다. 배양기간이 경과함에 따라 CD34 양성 세포의 특이 유전자 발현 양상이 변화되었다. 결 론: 이상의 결과는 비특이적으로 분화된 인간 배아줄기세포로부터 특이 세포를 MACS 방법을 이용하여 성공적으로 분리할 수 있음을 보여주었다. 따라서, MACS 방법과 특이 세포에 대한 항체는 인간 배아줄기세포의 유도 분화와 특이 세포의 분리에 매우 유용할 것으로 생각된다.

• Journal of Yeungnam Medical Science
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• 제13권2호
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• pp.272-278
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• 1996

B형 간염 표면항원(HBsAg)의 4가지 주요 아형 조사를 통해 HBsAg과 B형 간염표면항체가 모두 양성인 환자에서 항원과 항체의 아형이 다름을 밝힘으로 항원-항체 공존을 이해하게 되었으며, 감염경로를 추적하는 역학적 조사, 인구이동양상의 지표에 유용하게 사용될 수 있다. 현재까지 우리나라의 HBV 아형에 관한 연구는 전체적인 빈도의 조사나 HBsAg과 anti-HBs가 공존하는 경우에서 아형이 가지는 의미에 대한 것이 전부였다. 본 연구에서는 영남대학교 의과대학 부속병원에서 만성 간질환으로 진단받고 경과추적중인 HBsAg 양성인 환자 214명을 대상으로 혈청에 존재하는 HBsAg 아형을 단세포군 항체를 이용한 혈청학적 방법으로 조사하였다. 214명의 검체중 206명(93.9%)에서 adr, 6명(2.8%)에서 adw, 2명(0.9%)에서 ayr, 2명(0.9%)에서 ar, 3명(1.4%)에서 adwr로 나타났으며 ayw는 한 례에서도 발견되지 않았다. 아형과 질환의 중증도 사이에는 유의한 연관성은 발견되지 않았다. 결론적으로 만성 간질환 환자에서 adr이 가장 많고 질환의 중증도와 아형간에 유의한 연관성은 발견되지 않았지만, 아형이 만성 B형 바이러스 간염의 간경변증이나 간세포암으로의 진행과 예후에 영향을 미치는지 밝히기 위해서는 좀 더 연구를 진행하여야 할 것이다.