The Effect of ncsA (Apoprotein) from Streptomyces carzinostaticus ATCC15944 on Neocarzinostatin Production

Hang VU THI THU,Tae-Jin OH,Jae Kyung SOHNG 한국생물공학회 2009 한국생물공학회 학술대회 Vol.2009 No.10

SCN1A Gene Mutation and Adaptive Functioning in 18 Vietnamese Children with Dravet Syndrome

Thi Thu Hang Do,Diem My Vu,Thi Thuy Kieu Huynh,Thi Khanh Van Le,손은화,Thieu Mai Thao Le,Huu Hao Ha,Chi Bao Bui 대한신경과학회 2017 Journal of Clinical Neurology Vol.13 No.1

Background and Purpose Dravet syndrome is a rare and severe type of epilepsy in infants. The heterogeneity in the overall intellectual disability that these patients suffer from has been attributed to differences in genetic background and epilepsy severity. Methods Eighteen Vietnamese children diagnosed with Dravet syndrome were included in this study. SCN1A variants were screened by direct sequencing and multiplex ligation-dependent probe amplification. Adaptive functioning was assessed in all patients using the Vietnamese version of the Vineland Adaptive Behavior Scales, and the results were analyzed relative to the SCN1A variants and epilepsy severity. Results We identified 13 pathogenic or likely pathogenic variants, including 6 that have not been reported previously. We found no correlations between the presence or type of SCN1A variants and the level of adaptive functioning impairment or severity of epilepsy. Only two of nine patients aged at least 5 years had an adaptive functioning score higher than 50. Both of these patients had a low frequency of convulsive seizures and no history of status epilepticus or prolonged seizures. The remaining seven had very low adaptive functioning scores (39 or less) despite the variability in the severity of their epilepsy confirming the involvement of factors other than the severity of epilepsy in determining the developmental outcome. Conclusions Our study expands the spectrum of known SCN1A variants and confirms the current understanding of the role of the genetic background and epilepsy severity in determining the developmental outcome of Dravet syndrome patients.

Influence of Apoproteins for Enediyne Production

Vu Thi Thu Hang,김태수,오태진,송재경 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.3

Kedarcidin and neocarzinostatin belong to the chromoprotein family of endiyene antibiotics and have potent antitumor activity. Their structures consist of an apoprotein and a nonpeptide chromophore. Apoprotein has been known to be essential to stabilize and regulate the availability of a labile chromophore. Here, we have identified the complete kedarcidin apoprotein gene (kedA) from Streptoalloteichus sp. ATCC 53650 (Actinomycete L585-6). KedA was characterized by a comparative study with neocarzinostatin apoprotein (NcsA). Overexpression of kedA resulted in a ~ 2-fold enhanced production of kedarcidin in Streptoalloteichus sp., whereas overexpression of ncsA resulted in a ~ 1.6-fold enhanced production of neocarzinostatin in Streptomyces carzinostaticus ATCC 15944. Moreover, the apoprotein-overexpressed strain showed a high growth rate, which demonstrates that the apoprotein not only protects the labile chromophore, but also tolerates the toxicity of endiyene antibiotics in the host strain.

In vivo characterization of NcsB3 to establish the complete biosynthesis of the naphthoic acid moiety of the neocarzinostatin chromophore : In vivo characterization of NcsB3

Hang, Vu Thi Thu,Oh, Tae Jin,Yamaguchi, Tokutaro,Sohng, Jae Kyung Oxford University Press 2010 FEMS microbiology letters Vol.311 No.2

<P>Neocarzinostatin (NCS) is an enediyne antibiotic produced by Streptomyces carzinostaticus. The NCS chromophore consists of an enediyne core, a sugar moiety, and a naphthoic acid (NA) moiety. The latter plays a key role in binding the NCS chromophore to its apoprotein to protect and stabilize the bioactive NCS chromophore. In this study, we expressed three genes: ncsB (naphthoic acid synthase), ncsB3 (P450 hydroxylase), and ncsB1 (O-methyltransferase), in Streptomyces lividans TK24. The three genes were sufficient to produce 2-hydroxy-7-methoxy-5-methyl-1-naphthoic acid. Production was analyzed and confirmed by LC-MS and nuclear magnetic resonance. Here, we report the functional characterization of ncsB3 and thereby elucidate the complete biosynthetic pathway of NA moiety of the NCS chromophore.</P>

Cloning, High-Level Expression, Purification, and Properties of a Novel Endo-β-1,4-Mannanase from Bacillus subtilis G1 in Pichia pastoris

( Vu Thi Thu Hang ),( Dinh Thi Quyen ),( Thi Tuyet Dao ),( Sy Le Thanh Nguyen ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.3

A novel gene coding for an endo-β-1,4-mannanase (manA) from Bacillus subtilis strain G1 was cloned and overexpressed in P. pastoris GS115, and the enzyme was purified and characterized. The manA gene consisted of an open reading frame of 1,092 nucleotides, encoding a 364-aa protein, with a predicted molecular mass of 41 kDa. The β-mannanase showed an identity of 90.2-92.9% (≤95%) with the corresponding amino acid sequences from B. subtilis strains deposited in GenBank. The purified β- mannanase was a monomeric protein on SDS-PAGE with a specific activity of 2,718 U/mg and identified by MALDITOF mass spectrometry. The recombinant β-mannanase had an optimum temperature of 45oC and optimum pH of 6.5. The enzyme was stable at temperatures up to 50oC (for 8 h) and in the pH range of 5-9. EDTA and most tested metal ions showed a slightly to an obviously inhibitory effect on enzyme activity, whereas metal ions (Hg2+, Pb2+, and Co2+) substantially inhibited the recombinant β-mannanase. The chemical additives including detergents (Triton X- 100, Tween 20, and SDS) and organic solvents (methanol, ethanol, n-butanol, and acetone) decreased the enzyme activity, and especially no enzyme activity was observed by addition of SDS at the concentrations of 0.25-1.0% (w/v) or n-butanol at the concentrations of 20-30% (v/v). These results suggested that the β-mannanase expressed in P. pastoris could potentially be used as an additive in the feed for monogastric animals.

Genetic variations of PEDV of field isolates from Vietnam and plaque selected viruses after 20 serial passages in Vero cells

( Thi Thu Hang Vu ),( Minjoo Yeom ),( Woonsung Na ),( Van Phan Le ),( Daesub Song ) 대한인수공통전염병학회 2019 창립총회 및 학술대회 초록집 Vol.2019 No.1

Introduction: The antigenic diversity makes porcine epidemic diarrhea (PED) as a challenge for the pig industry in all over the world. The emergence of PED virus (PEDV) causes significantly economic loss in pig farms annually. In this research, as an initial step, full-length of spike (S) gene of 8 PEDV-positive samples collected from the farms and 16 clones of 20th passage- PEDV2 strain were sequenced and analyzed to identify the genetic variation of PEDV in the field as well as in the cell adapted condition. Methods: 8 positive PEDV samples were collected from outbreaks in Vietnam during 2018. While PEDV2 strain after 20 serial passages in Vero cell was plaque purified, 16 clones were selected and propagated by transferring from the plaque assay plate into the new plates and then to the T25 tissue culture flasks. RNA of all viral samples were purified and used as the template of RT-PCR with S gene specific primers for sequencing. BioEdit and MEGA 6.0 program were used for sequence analysis. Results: 8 PEDV strains circulating in Vietnam during 2018 belong to three different clades as Asian non-S INDEL, new S INDEL and classical S INDEL. Otherwise 16 PEDV clones from 20^th passage- PEDV2 strain were also divided into three groups with different deletion inside S gene sequence compared with original strain. Conclusion: PED virus strains have variable ability in various environmental conditions, in the field as well as in cell culture. From this result, in each outbreak, samples should be classified independently so that a proper vaccine solution can be developed. Further studies need to be done to clarify the relationship between genetic variants and pathogenicity of PED virus strains.

Electrochemical Detection of TNT by Differential Pulse Adsorptive Stripping Voltammetry at Carbon Paste Electrode Modified by 1-Butyl-3-methylimidazolium Tetrafluoroborate

Ha Thi Thu Vu,Hanh Thi Vinh Le,Yen Thi Hai Pham,Hung Quoc Le,Phong Hong Pham 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.3

Different kinds of materials for electrodes based on glassy carbon, carbon fibers, and modified by an ionic liquid (BMIMBF4) were used to determine 2,4,6-trinitrotoluene (TNT) in water environment by differential pulse adsorptive stripping voltammetry. The modified electrode based on BMIMBF4 showed a better performance than those based on the microelectrode and glassy carbon electrode (GCE) in term of sensitivity. The best performance was obtained with the ionic liquid-modified electrode with 80:10:10 (w/w/w) of the graphite powder/paraffin oil/BMIMBF4 composition in PBS, pH 8. The TNT concentration was linear in the range 1.5 to ~30 ppm for all studied electrodes (r = 0.9978) with a detection limit of 88.6 ppb using IL-CPE (ionic liquid-modified carbon paste electrode). This latter electrode was used to measure real samples taken from Red River, Vietnam. The recovery study for TNT in natural samples gave values from 99.7% to 103.3%. IL-CPE demonstrated long-term stability and reproducibility, with a relative standard deviation of 1.67%.

Influencing Factors of the International Payment Service Quality at Joint Stock Commercial Bank for Investment and Development of Vietnam

TRAN, Thi-Thu,NGO, Thi Quynh-Anh,CUNG, Thi Ngoc-Anh,NGUYEN, Thi-Giang,VU, Dang-Duong,NGUYEN, Phi-Hung,TSAI, Jung-Fa Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.10

International payment is an essential part of the economy, which is beneficial to both commercial banks and trading enterprises. Moreover, service quality, which has been a key point of discussion for decades, relates to customer satisfaction. This study aims to investigate the factors influencing international payment service quality at the Join Stock Commercial Bank for Investment and Development of Vietnam (BIDV) from 2015 through 2019. This research deploys both quantitative and qualitative methods to discuss the effects of these components. Statistical data was examined through different tests, including reliability analysis, correlation, and regression analysis by SPSS 16.0. The authors obtain and analyze 157 valid responses from customer surveys, then by applying an integration SERVPERF and PSQM model, identify five main components: Reliability, Tangibles, Assurance, Convenience, and Responsiveness, which explain how the customer perceives the service quality of international payment activities at BIDV. The results show that these five factors have a positive relationship with service quality, in which, Reliability has the most significant impacts on service quality level. Besides, the findings not only contribute to the literature but also give some practical implications for BIDV to improve its international payment service quality and help them to obtain customer satisfaction in the fast-changing environment.

Numerical Analysis of Dielectrophoresis-Based Microfluidic Chip with a Facing-Electrode Design for Cell Separation

Nguyen Thu Hang,Nguyen Mai Chi,Nguyen Hoang Trung,Thi Y Van Tran,Vu Ngoc Trung,Thu Hang Bui,Duc Trinh Chu,Bui Tung Thanh,Jen Chun-Ping,Quang Loc Do 한국농업기계학회 2024 바이오시스템공학 Vol.49 No.1

Purpose Circulating tumor cell separation and analysis have played a critical role in cancer diagnosis, prognosis, and treatment. In this work, we aim to design and investigate a novel biochip that integrates dielectrophoresis, microfl uidic technology to separate circulating tumor cells from blood cells. To create a dielectrophoresis-induced non-uniform electric fi eld, a facing-electrode design was proposed and utilized, in which a slanted electrode array and a simple rectangular ground electrode are placed parallel on the top and bottom parts of the microfl uidic channel, respectively. This design can reduce the particle position dependence in the microchannel and the complexity of the microfabrication process. Methods The separation process, effi ciency, and optimization of the proposed device were numerically investigated using the fi nite element method. Parametric research was conducted to comprehensively examine the impact of various operating and design factors on the cell movement and trajectories in the microfl uidic device. Results The results indicated the potential of the proposed biochip to ensure cancer cell separation from blood cells with high effi ciency, high purity in a label-free, non-invasive, easy integration, and low-cost manner. Under the optimal conditions, the separation effi ciency reached 92%, 88%, and 96% for human colon cancer cells (HT-29), red blood cells, and white blood cells, respectively. Conclusions In this study, a novel DEP-based microfl uidic chip was proposed to separate HT-29 tumor cells from blood cells and numerically investigated to verify the performance of the biochip design. Our fi ndings could provide a foundation for further theoretical and practical investigations. The proposed system can separate cancer cells from red blood cells and white blood cells as well as off ers numerous advantages, such as compact size, low voltage, high effi ciency, non-invasiveness, and label-free nature. The tumor cell enrichment platform has the potential for application in cancer detection, analysis, and assessment.

Landscape Function and Tourism Industry: A Case Study of Moc Chau Plateau, Vietnam

LE, Hoa Thi Thu,TONG, Binh Thanh,VU, Ngoc Thi Minh,HO, Luu Si,PHAM, Thang Viet,TRINH, Hang Thi Thu Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

Tourism is not only a cultural service but also a resource consuming industry. Landscape function framework is a powerful tool to show the relationship between nature and people. This study collects 50 documents around the world to analyze the relationship between the 4 functional groups of the landscape (regulatory functions, production and supply functions, resident functions, information and entertainment functions) and the tourism industry. On that basis, we created an establishment for practical contact analysis of the goods and services of the landscape for tourism development in Moc Chau plateau, Vietnam. Research results show that tourism is an economic sector that benefits from the landscape and has a clear resource orientation. Moc Chau plateau has rich tourism resources and has the conditions to develop various types of tourism, especially cultural tourism based on community and resort tourism. The two cultural functions and the providing functions are the two most important functional groups for the tourism development of Moc Chau district, bringing the two most important tourism icons for Moc Chau, a green steppe, cool milk benevolent and also a district rich in national culture. From these conclusions, the authors give recommendations and notable points about landscapes in the tourism industry, especially in places with topography like Moc Chau.