• IMMUNE NETWORK
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• 제2권2호
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• pp.79-85
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• 2002

Background: In contrast to evidences of Ig H chain receptor editing in transformed cell lines and transgenic mouse models, there has been no direct evidence that this phenomenon occurs in human developing B cells. Methods: $V_HDJ_H$ rearrangements were obtained from genomic DNA of individual $IgM^-$ B cells from liver and $IgM^+B$ cells from bone marrow of 18 wk of gestation human fetus by PCR amplification and direct sequencing. Results: We found three examples of H chain receptor editing from $IgM^+$ and $IgM^-human$ fetal B cells. Two types of $V_H$ replacements were identified. The first involved $V_H$ hybrid formation, in which part of a $V_H$ gene from the initial VDJ rearrangement is replaced by part of an upstream $V_H$ gene at the site of cryptic RSS. The second involved a gene conversion like replacement of CDR2, in which another $V_H$ gene donated a portion of its CDR2 sequence to the initial VDJ rearrangement. Conclusion: These data provide evidence of receptor editing at the H chain loci in developing human B cells, and also the first evidence of a gene conversion event in human Ig genes.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1377-1383
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• 2005

In a cDNA microarray experiment using Cy3 and Cy5 as labeling agents, particularly for the direct design, cDNAs from some genes incorporate one dye more efficiently than the other, which is referred to as the gene-specific dye bias. Dye-swaps, in which two dyes are switched on replicate arrays, are commonly used to control the gene-specific dye bias. We developed a simple procedure to extract the gene-specific dye bias information from a partial dye swap experiment. We detected gene-specific dye bias by identifying outliers in an X-Y plane, where the X axis represents the average log-ratio from two sets of dye swap pairs and the Y axis exhibits the average log ratio of four forward labeled arrays. We used this information for detecting differentially expressed genes, of which the additionally detected genes were validated by real-time RT-PCR.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.114-114
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• 2003

Ginseng is a medicinal herb widely used in Asian countries, and its pharmacological effects has been demonstrated in various systems such as cardiovascular, central nervous, and endocrine systems. Its effects are mainly attributed to the ginsenosides. We hypothesize that a component of Panax ginseng, ginsenoside-Rbl, acts by binding to estrogen receptor. We have investigated the estrogenic activity of ginsenoside-Rbl in a transient transfection system using estrogen receptors ${\alpha}$ or ${\beta}$ with estrogen -responsive luciferase plasmids in COS monkey kidney cells. Ginsenoside-Rbl activated both estrogen receptors ${\alpha}$ and ${\beta}$ in a dose-dependent manner (0.5 -100 M ). Activation was inhibited by the specific estrogen receptor antagonist ICI 182,780, indicating that the estrogenic effect of ginsenoside-Rbl is estrogen receptor dependent. Next, we evaluated the ability of ginsenoside-Rbl to induce estrogen-responsive progesterone receptor gene by semi-quantitative RT-PCR assays. MCF-7 cells treated with l7${\beta}$-estradiol or ginsenoside- Rb1 exhibited an increased expression of progesterone receptor mRNA. However, ginsenoside-Rbl failed to displace the specific binding of ［3H］17${\beta}$-estradiol to estrogen receptor in MCF-7 cells as examined by whole cell ligand binding assays, suggesting that there is no direct interaction of ginsenoside-Rbl with estrogen receptor. Our results indicate that estrogen-like activity of ginsenoside-Rbl is independent of direct estrogen receptor association.

• Childhood Kidney Diseases
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• 제3권2호
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• pp.209-216
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• 1999

목적 : 신성 요붕증(Nephrogenic diabetes insipidus, NDI)은 바소프레신(arginine vasoporessin, AVP)에 대한 신세뇨관의 저항성으로 인하여 요농축의 장애를 특징으로 하는 드문 유전성 질환이다. 반성유전형 신성 요붕증은 바소프레신 V2수용체(AVPR2)의 장애에 기인하며, NDI 환자에서 지금까지 다양한 AVPR2의 돌연변이가 보고되었다. 저자들은 임상적으로 반성 유전형 신성 요붕증으로 진단된 가계에서 AVPR2 유전자의 돌연변이를 발견하기 위하여 분자유전학적 검사를 실시하였다. 방법 : 대상환자의 백혈구에서 추출한 DNA로 AVPR2유전자를 polymerase chain reaction-single strand conformational polymorphism(PCR-SSCP)분석하여 이상이 발견된 부분은 클론닝하여 염기서열을 분석하였다. 같은 PCR 산물을 Hae III로 처리하여 PCR-RFLP(restriction fragement length polymorphism) 분석을 하였다. 결과 : AVPR2 유전자를 PCR-SSCP 분석하였을 때 PCR 산물의 정상인과 이동거리의 차이가 발견되어 환아에서 돌연변이가 있고 환아의 어머니는 보인자임을 예측하였고, 염기서열을 분석하여 675번째 염기 A가 G로 치환됨으로 tryptophan이 cysteine으로 바뀌는 R202C 점돌연변이를 발견하였다. 같은 PCR 산물을 PCR-RFLP 분석을 하였을 때 돌연변이로 인한 Hae III의 인지부위의 상실을 확인하였고 환아의 어머니가 이종접합보유자 (heterozygote)임을 확인하였다. 결론 : 저자들은 임상적으로 신성 요붕증으로 확인된 환아와 어머니의 V2 수용체 유전자를 분석하여 R202C 돌연변이를 확인하였다. 신성 요붕증은 진단이 지연되면 성장장애, 정신박약과 사망을 초래할 수 있는 심각한 질환이나, 태생기 또는 신생아기에 진단하면 후유증을 예방할 수 있으므로 조기진단 및 보인자 발견에 분자유전학적 진단 방법을 적극 활용하여야 하겠다.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.144-151
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• 2014

Increasing the gene copy number has been commonly used to enhance the protein expression level in the yeast Pichia pastoris. However, this method has been shown to be effective up to a certain gene copy number, and a further increase of gene dosage can result in a decrease of expression level. Evidences indicate the gene dosage effect is product-dependent, which needs to be determined when expressing a new protein. Here, we describe a direct detection of the gene dosage effect on protein secretion through expressing the enhanced green fluorescent protein (EGFP) gene under the direction of the ${\alpha}$-factor preprosequence in a panel of yeast clones carrying increasing copies of the EGFP gene (from one to six copies). Directly examined under fluorescence microscopy, we found relatively lower levels of EGFP were secreted into the culture medium at one copy and two copies, substantial improvement of secretion appeared at three copies, plateau happened at four and five copies, and an apparent decrease of secretion happened at six copies. The secretion of EGFP being limiting at four and five copies was due to abundant intracellular accumulation of proteins, observed from the fluorescence image of yeast and confirmed by western blotting, which significantly activated the unfolded protein response indicated by the up-regulation of the BiP (the KAR2 gene product) and the protein disulfide isomerase. This study implies that tagging a reporter like GFP to a specific protein would facilitate a direct and rapid determination of the optimal gene copy number for high-yield expression.

• Asian Pacific Journal of Cancer Prevention
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• 제16권13호
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• pp.5371-5376
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• 2015

Berberine (B1), isolated from stems of Coscinium fenestratum (Goetgh.) Colebr, was used as a principle structure to synthesize three phenolic derivatives: berberrubine (B2) with a single phenolic group, berberrubine chloride (B3) as a chloride counter ion derivative, and 2,3,9,10-tetra-hydroxyberberine chloride (B4) with four phenolic groups, to investigate their direct and indirect antioxidant activities. For DPPH assay, compounds B4, B3, and B2 showed good direct antioxidant activity ($IC_{50}$ values=$10.7{\pm}1.76$, $55.2{\pm}2.24$, and $87.4{\pm}6.65{\mu}M$, respectively) whereas the $IC_{50}$ value of berberine was higher than $500{\mu}M$. Moreover, compound B4 exhibited a better DPPH scavenging activity than BHT as a standard antioxidant ($IC_{50}=72.7{\pm}7.22{\mu}M$) due to the ortho position of hydroxyl groups and its capacity to undergo intramolecular hydrogen bonding. For cytotoxicity assay against human fibrosarcoma cells (HT1080) using MTT reagent, the sequence of $IC_{50}$ value at 7-day treatment stated that B1 < B4 < B2 ($0.44{\pm}0.03$, $2.88{\pm}0.23$, and $6.05{\pm}0.64{\mu}M$, respectively). Berberine derivatives, B2 and B4, showed approximately the same level of CAT expression and significant up-regulation of SOD expression in a dose-dependent manner compared to berberine treatment for 7-day exposure using reverse transcription-polymerase chain reaction (RT-PCR) assays. Our findings show a better direct-antioxidant activity of the derivatives containing phenolic groups than berberine in a cell-free system. For cell-based system, berberine was able to exert better cytotoxic activity than its derivatives. Berberine derivatives containing a single and four phenolic groups showed improved up-regulation of SOD gene expression. Cytotoxic action might not be the main effect of berberine derivatives. Other pharmacological targets of these derivatives should be further investigated to confirm the medical benefit of phenolic groups introduced into the berberine molecule.

• 한국가축번식학회지
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• 제27권1호
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• pp.25-34
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• 2003

인체 트롬보포이에틴(hTPO)은 megakaryopoiesis 과정에 주요한 역할을 하는 사이토카인이다. 따라서 이러한 트롬보포이에틴을 유선조직에서 직접적으로 발현시키기 위하여 소 베타 카제인 프로모터, 인체 트롬보포이에틴 cDNA 및 네오유전자로 구성된 발현벡터를 구축하였다. 소 귀조직 세포로부터 유도된 섬유아세포에 lipoffctamine을 이용하여 발현벡터(pBT-L n대)의 삽입을 유도하였다. G4l8 저항성을 지닌 세포의 콜로니 형성을 유도하기 위하여 2주 이상 배양을 실시하였다. 형질전환 콜로니는 PCR에 의해 동정하였으며, 이들 콜로니를 핵치환 전까지 계속적으로 증식을 유도하였다. 형질전환 세포에 의해 재구성된 난자는 전기적인 융합과 calcium ionophore와 6-DMAP를 이용한 활성화를 실시하였으며, 체외에서 7일간 배양을 실시하였다. 총 35개의 콜로니를 PCR에 의해 분석한 결과, 이 중 29(82.9%)개가 형질전환된 콜로니였다. 형질전환된 세포로 재구성된 난자의 난할율 및 배반포로의 발달율은 65.1%와 23.8%로 나타났다. 형질전환된 세포로 재구성된 난자로부터 발달한 29개의 배반포 중 27개가 형질전환으로 확인되었다. 따라서 이러한 결과들은 형질전환 소 수정란을 형질전환된 세포를 이용한 체세포 복제 기법을 통해 효과적으로 생산할 수 있다는 것을 제시하고있다.

• 동아시아식생활학회지
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• 제19권2호
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• pp.295-300
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• 2009

본 연구에서는 육류 식품 시료에서 단시간 내에 살모넬라를 검출하기 위하여 PCR을 이용한 검출용 프라이머들의 특이성과 민감성을 평가하였다. 실험에 사용된 프라이머들은 Salmonella Typhimurium의 mdh와 invA 유전자의 염기서열에 기초하여 제작되었다. 각각의 primer들의 검출 감도를 평가하여 최종적으로 broad spectrum primer SLM1과 S. Typhimurium specific primer SLT4를 선발하였다. 또한, 시료에 오염된 병원균의 최소 검출량이 어느 정도인지를 확인하기 위하여 살모넬라 균수를 reaction tube당 $10^0{\sim}10^3$ cell까지 다양하게 하여 검출 감도를 측정한 결과, 최소 1 cell에서도 PCR 산물을 나타내어 검출 감도가 매우 우수한 것으로 나타났다. 살모넬라 균주를 혼합한 소고기와 돼지고기 시료에서 각각 프라이머들의 검출 감도를 평가한 결과, 증균하지 않은 시료 자체와 세균학적 방법으로 증균 배양한 시료 그리고 증균 배양된 시료로부터 세균의 DNA를 추출한 시료 간에 큰 차이를 나타내지 않았다. 이에 육류 식품에서 살모넬라 혹은 S. Typhimurium의 검출을 위한 프라이머로서 효율적으로 사용이 가능할 것으로 판단된다.

• 한국가금학회지
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• 제35권1호
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• pp.9-13
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• 2008

양계 산업에서 살모넬라에 의한 질병들 중 가장 중요한 원인체는 S. Gallinarum, S. Purollum, S. Enteritidis로 간주된다. 생화학적 검사에 의한 직접적인 균 분리.동정과 같은 이들 질병에 대한 종래의 진단법은 많은 시간이 소요되며, 특이성 또한 낮다. 본 연구는 3종의 살모넬라균에 의해 야기되는 이들 질병에 대한 빠르고 정확한 진단을 위한 효율적인 진단법에 초점을 두었다. 먼저 종래의 생화학적 검사를 대신하여 새로 고안된 ITSF/ITSR PCR primer를 이용하여 살모넬라균임을 확인하였으며, 증폭된 phase 1 flagellin (fliC) 유전자를 BpmI 또는 BfaI 제한 효소로 처리하여 S. Gallinarum, S. Purollum, S. Enteritidis를 상호 용이하게 감별하였다. 이상의 결과는 3종의 살모넬라균을 효율적으로 진단하기 위해 신속하게 검출하고 감별할 수 있는 유용한 진단법임을 알 수 있었다.

• Journal of Microbiology
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• 제44권4호
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• pp.423-431
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• 2006

Among 53 Acinetobacter baumannii isolates collected in 2004, nine imipenem-resistant isolates were obtained from clinical specimens taken from patients hospitalized in Busan, Korea. Nine carbapenemase-producing isolates were further investigated in order to determine the mechanisms underlying resistance. These isolates were then analyzed via antibiotic susceptibility testing, microbiological tests of carbapenemase activity, pI determination, transconjugation test, enterobacterial repetitive consensus (ERIC)-PCR, and DNA sequencing. One outbreak involved seven cases of infection by A. baumannii producing OXA-23 ${\beta}-lactamase$, and was found to have been caused by a single ERIC-PCR clone. During the study period, the other outbreak involved two cases of infection by A. baumannii producing IMP-1 ${\beta}-lactamase$. The two clones, one from each of the outbreaks, were characterized via a modified cloverleaf synergy test and an EDTA-disk synergy test. The isoelectric focusing of the crude bacterial extracts detected nitrocefin-positive bands with pI values of 6.65 (OXA-23) and 9.0 (IMP-1). The PCR amplification and characterization of the amplicons via direct sequencing showed that the clonal isolates harbored $bla_{IMP-1}$ or $bla_{oxA-23}$ determinants. The two clones were characterized by a multidrug resistance phenotype that remained unaltered throughout the outbreak. This resistance encompassed penicillins, extended-spectrum cephalosporins, carbapenems, monobactams, and aminoglycosides. These results appear to show that the imipenem resistance observed among nine Korean A. baumannii isolates could be attributed to the spread of an IMP-lor OXA-23-producing clone. Our microbiological test of carbapenemase activity is a simple method for the screening of clinical isolates producing class D carbapenemase and/or class B $metallo-{\beta}-lactamase$, in order both to determine their clinical impact and to prevent further spread.