• Molecules and Cells
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• 제24권1호
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• pp.125-131
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• 2007

von Willebrand factor (vWF) is a multimeric glycoprotein which functions within the coagulation system. It colocalizes with factor VIII (FVIII) by non-covalent interaction and alters its intracellular trafficking. vWF is also instrumental in maintaining the stability of secreted FVIII. The principal objective of this study was to generate a lentivirus-based vWF expression vector for gene therapy of hemophilia A. We inserted a vWF of 8.8 Kb into a lentiviral vector thereby producing VSV-G-pseudotyped vEx52. However, its titer was quite low, presumably because the length of vWF gene exceeds the size limit of the lentiviral vector. In order to overcome the low-titer, we concentrated the vEx52 and thus increased the efficiency of transduction approximately 6-fold with $1/100^{th}$ of the volume. However, as concentration requires an additional laborious step, we attempted to enhance the transduction efficiency by deleting exons 24-46 and 29-46 in pRex52 to construct pRex23 and pRex28, and in pvEx52, yielding pvEx23 and pvEx28, respectively. The transfected pRex52 had a profound effect on the activity of secreted FVIII, and this activity declined as domains of vWF were deleted. However, when the domain-deleted vWF-lentiviruses were transduced into K562 cells, the vEx28 increased the activity of the secreted FVIII compared to what was observed with vEx52. This result is probably due to higher efficiencies of transduction and expression while retaining the essential domains required for proper interaction with FVIII.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6073-6076
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• 2012

Discovery of anticancer drugs that kill or disable tumor cells in the presence of normal cells without undue toxicity is a potential challenge for therapeutic care. Several papers in the literature have emphasized the potential implications of marine products such as seaweeds which exhibit antitumor activity. Study attempts to screen the antitumor effect of Sargassum sp, against chosen cell lines such as MCF-7 (Breast cancer) and Hep-2 (Liver Cancer). Ethanol extract of Sargassum sp. was concentrated using a Soxhlet apparatus and dissolved in DMSO. In vitro cytotoxic activity of Sargassum sp at various concentrations ($100{\mu}g/ml-300{\mu}g/ml$) screened for antitumor effect against the chosen cell lines using MTT assay (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole). The study documented that the percentage of cell viability has been reduced with increased concentration, as evidenced by cell death. Sargassum sp extract shows potential cytotoxic activity ($P{\leq}0.05$) with $IC_{50}$ of $200{\mu}g/ml$ and $250{\mu}g/ml$ against Hep-2 and MCF-7 cell lines respectively. The ethanol fraction of Sargassum sp induced cell shrinkage, cell membrane blebbing and formation of apoptotic bodies with evidence of bioactive components as profound influencing factors for anti-tumor effects. Further research need to be explored for the successful application of Sargassum sp as a potent therapeutic tool against cancer.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.34-36
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• 2002

Epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) have been shown to stimulate proliferation and differentiation of various somatic cells, including placental trophoblasts and also to enhance fetal growth and development when maternally administered. Since an increase of the expression of placental EGF and IGF-I receptors in rat, mouse, and human with the gestation advanced, both EGF and IGF-I were considered to play pivotal roles on fetal growth by regulating some function of placental cells. Amino acids are crucial importance for both maternal and fetal requirements of energy source and essential constituent of fetal mass during pregnancy. Impaired fetal and placental uptake of amino acids has been observed in several models of growth retardation in the rat. Amino acid is concentrated in the fetal side through active transport by amino acid transporters and is one of the important metabolic fuels for the fatal growth. Therefore, at first plasma amino acid concentrations in mothers and fetuses were measured as an index of uphill transport across the placenta associated with EGF and IGF-1. The EGF administration at the concentration of 0, 0.1, or 0.2 $\mu\textrm{g}$/g to pregnant rats from day 18 to 21 of gestation apparently increased fetal/maternal ratio of serum proline concentration and also fatal growth in EGF dose-dependent manner. When IGF-I in doses of 0, 1, 2, and 4 $\mu\textrm{g}$/g were administrated, the ratio of leucine, isoleucine, tryptophan, phenylalanine, tyrosine and also fetal growth significantly increased with a dose-dependent manner. These results suggested that EGF and IGF-I enhanced fatal growth by, as one of its possible mechanisms, promoting placental activity to transfer some amino acid supplies from the mother to the fetus in late pregnancy.

• Journal of Microbiology
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• 제34권2호
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• pp.144-150
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• 1996

During growth of the genetically engineered E. coli CU103 in different media, extracellular DNAs released from the cells were studied. The extracellular DNAs released in the medium were concentrated by an thanol precipitation method and then quantified by a fluorescence method using Hoechst 33258. The released extracellular DNAs were also examined by gel electrophoresis and identified by Southern hybridization for the cloned pcbCD genes. The chromosomal DNAs and recombinant plasmid containing the cloned genes were observed to be released in an exponential growth phase. In Luria-Bertani (LB) broth and MM2-GLUCOSE, 210 and 69 ng/ml of DNAs were detected, respectively, after 3-4 days incubation at $30^{\circ}C$ and at pH 7.0. But the released DNAs were measured to be about 10-15 ng/ml in filtered river water (FW) and Tris-EDTA (TE). The at both $15^{\circ}C$ and $4^{\circ}C$, but the released DNAs were more easily degraded at the higher temperature. The extracellular DNAs were produced about 2 times more at pH 7.0 than at both pH 5.0 and pH 9.0 in MM2-glucose medium at $30^{\circ}C$. Therefore, the extracellular DNAs were found to be released actively from the cells during growth in liquid media.

• Applied Microscopy
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• 제35권3호
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• pp.177-186
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• 2005

장수풍뎅이 (Allomyrina dichotoma; Dynastidae; Coleoptera)를 사육하여 종령 유충의 전장 상피를 구성하는 세포들에 대한 미세구조를 전자현미경으로 관찰하였다. 상피조직은 편상피 세포들이 단층의 점막상피를 이루었으며, 그 내면은 얇은 큐티클 층으로 덮여 있었다. 상피세포의 유리면 원형질막은 미세융모로 변형되었고, 기저 원형질막은 기저막주름이 잡혀 "canaliculi"를 만들며 크게 발달한 사립체와 접해 있었다. 핵은 크게 발달하였고 세포질 내에는 발달한 사립체가 산재해 있었으며, 지질 및 단백질 과립과 글리코겐 입자들이 많이 축적되었다. 상피의 기저막은 여러겹으로 된 기저초를 이루고 있으며, 기저막내 또는 섬유상 결합조직인 점막하조직내에는 기관지세포와 신경이 뻗어 있었다. 그리고 점막하 조직 바깥쪽에는 환상근과 종주근이 관찰되었다.

• 생명과학회지
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• 제9권3호
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• pp.289-292
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• 1999

1998년 부산지역에서 호흡기 환자의 인후 가검물로부터 분리된 influenza 바이러스 다음과 같은 양사을 볼 수 있었다. 1.분리된 바이러스는 influenza A/Sydney/05/97-like(H3N2)형과 influenza A/Beijing/262/95-like(H1N1)형으로 동정되었다.2.바이러스분리는 4월에서 9월까지를 제외한 모든 달에서 이루어 졌으며 특히 12월에는 집중적인 양상을 보였다.3.연령별로 본 바이러스의 분리는 1세에서 68세까지 전 연령층에서 나타났으며 10세 이하가 가장 높은 분리율을 나타내었다.4.바이러스 분리 비율은 남녀가 1:1.2의 비율로 나타났다.5.분리 바이러스는 MDCK 세포에서 세포병변이 관찰 되었다.6.influenza 바이러스를 Negative staining으로 염색하여 전자현미경으로 관찰한 결과 원형의 바이러스로 in-fluenza A/Sydney/05/97-like(H3N2)는 130 nm,influenza A/Beijing/262/95-like(H1N1) 형은 145nm의 크기로 나타났다.

• 한국수소및신에너지학회논문집
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• 제24권1호
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• pp.50-60
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• 2013

High temperature proton exchange membrane fuel cells (PEMFCs) using phosphoric acid (PA) doped polybenzimidazole (PBI) membranes have been concentrated as one of solutions to the limits with traditional low temperature PEMFCs. However, the amount of reported experimental data is not enough to catch the operational characteristics correlated with cell performance and durability. In this study, design of experiments (DOE) based operational optimization method for high temperature PEMFCs has been proposed. Response surface method (RSM) is very useful to effectively analyze target system's characteristics and to optimize operating conditions for a short time. Thus RSM using central composite design (CCD) as one of methodologies for design of experiments (DOE) was adopted. For this work, the statistic models which predict the performance and degradation rate with respect to the operating conditions have been developed. The developed performance and degradation models exhibit a good agreement with experimental data. Compared to the existing arbitrary operation, the expected cell lifetime and average cell performance during whole operation could be improved by optimizing operating conditions. Furthermore, the proposed optimization method could find different new optimal solutions for operating conditions if the target lifetime of the fuel cell system is changed. It is expected that the proposed method is very useful to find optimal operating conditions and enhance performance and durability for many other types of fuel cell systems.

• Parasites, Hosts and Diseases
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• 제29권1호
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• pp.31-42
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• 1991

폐흡충(Paragonimus westermani)에 감염된 숙주에 대해 항체 생성을 유도하는 물질이 분포하고 있는 부위를 화인하기 위하여 대조군의 IgG와 폐홉충에 감염된 실험 개의 특이 IgG를 폐흡충 유약성충 조직에 반응시키고 면역황금표식법을 이용하여 전자현미경으로 관찰하여 다음과 같은 결과를 얻었다. 대조군의 IgG를 반응시킨 유약성충 표피층은 표피세포에서 분비되는 물질이 포함된 표피 합포체로 구성되어 기저층과 분명하게 구별되었으며 근육층도 잘 발달되어 있었다. 난황세포는 크기가 다양한 분비과립 등을 포함하고 있었으며 특히 조면소포체가 발달되어 있었다. 맹관의 막구조물은 잘 발달되었으며 장상피 합포체도 잘 발달되어 있었다. 한펀, 폐흡충에 감염된 실험동물의 특이 항체로 반응시킨 유약성충 표피충의 표피 합포체와 표피세포의 세포질에 황금입자의 매우 특이적인 표식가 관찰되었고 난황세포에서는 분필과립에 황금 입자가 높은 밀도로 관찰되었다. 그리고 맹관 상피 합포체는 미약하게 황금 표지가 되었고 맹관 막구조물과 맹관 내강에도 특이하게 황금 표지가 관찰되었지만 표피 합포체와 표피세포보다 밀도가 낮게 관찰되었다. 이상의 결과로 폐홉충에 감염된 실험 개는 폐흡충의 표피 합포체와 표피세포에서 생성된 물질과 난황세포에서 생성된 물질에 의하여 면역항체가 형성되며 일부는 맹관 내용물에 의해 약간의 면역항체가 유도되는 것으로 생각되었다.

• Parasites, Hosts and Diseases
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• 제25권2호
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• pp.199-208
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• 1987

The chemotherapeutic efficacy of trimethoprim-sulfamethoxazole ($Bactrim^{\circledR}$) in mice experimentally infected with Toxoplasma gcndii was evaluated. The average survival days and survival rate of mice infected intraperitoneally with $1{\times}10^5$ trophozoites and treated with $Bactrim^{\circledR}$ were compared with those of untreated group. The hematologic findings of blood samples of experimental mice were observed for comparison of side elects between $Bactrim^{\circledR}$ and pyrimethamine ($Daraprim^{\circledR}$), the latter of which has been one of the favorable drugs for the treatment of toxoplasmosis. The results are summarized as follows: 1. $Bactrim^{\circledR}$ showed a strong evidence of potent anti-Toxoplasma activity. The survival rate of mice administered with 24 mg of $Bactrim^{\circledR}$ per mouse per day for 7 days, was 83.3%, and the rate was increased to 100% in mice administered with two-fold concentrated dose of the drug. 2. The average numbers of white blood cells (W.B.C.) in the mouse groups treated with $Bactrim^{\circledR}$ or $Daraprim^{\circledR}$ were more increased than those only infected with T. gondii. The mice treated with $Daraprim^{\circledR}$ however, showed remarkably decreased numbers of W.B.C. as compared with those treated with $Bactrim^{\circledR}$ . 3. The average numbers of red blood cells (R.B.C.) and platelets both in the drug-treated and untreated T. gondii-infected mice were decreased as compared with normal mice. The numbers of R. B. C. in $Daraprim^{\circledR}-treated$ mice, however, were more decreased than in $Bactrim^{\circledR}-treated$ mice. 4. The average levels of hemoglobin both in the drug.treated and untreated T. gondii-infected mice were decreased, compared with normal mice. But there was no difference in the levels of hemoglobin between $Bactrim^{\circledR}$ and $Daraprim^{\circledR}-treated$ groups. In conclusion, trimethoprim.sulfamethoxasole ($Bactrim^{\circledR}$) was proven to be effective and safe for the treatment of murine toxoplasmosis. The efficacy was comparable with pyrimethamine ($Daraprim^{\circledR}$), but bone marrow depression was less severe with $Bactrim^{\circledR}$ treatment.

• 생명과학회지
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• 제12권1호
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• pp.55-60
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• 2002

골격근 세포의 분화는 근육특이 유전자들의 전사적 활성과 근육아세포에서 근육소관으로의 형태적 분화로 특징지어진다. 본 연구에서는 TSA가 근육형성의 일련의 과정에서 NF-kB DNA 결합 활성과 융합에 미치는 영향을 조사하였다. 대조군과 비교해서 TSA가 처리된 C2C12 myoblast는 융합하여 근육소관을 형성할 수 없었으며 NF-kB DNA 결합 활성은 억제되었다. 이런 현상들이 TSA에 의한 직접적인 것인지 알아보기 위해서 TSA가 처리되지 않고 분화를 유도하기 위해서 사용된 배지를 농축하여 C2C12 myoblast에 TSA와 함께 동시에 처리하였다. 그 결과 세포는 융합하여 근육소관을 형성하였으며 NF-kB DNA 결합 활성이 회복되었다. 이러한 결과는 TSA가 아마도 여러 관련 인자들을 통해 myoblast의 융합과 NF-kB DNA 결합 활성을 억제함으로 근육형성과정에 영향을 미침을 시사한다.