59 results on '"Phan, Tuan-Nghia"'
Search Results
52. Purification and Characterization of a DNA Helicase from Pea Chloroplast that Translocates in the 3'-to-5' Direction
- Author
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Tuteja, Narendra, primary, Phan, Tuan-Nghia, additional, and Tewari, Krishna K., additional
- Published
- 1996
- Full Text
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53. Killed Bacillus subtilis spores expressing streptavidin: a novel carrier of drugs to target cancer cells.
- Author
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Nguyen, Van Anh Thi, Huynh, Hong Anh, Hoang, Tong Van, Ninh, Ngoc Thi, Pham, An Thi Hong, Nguyen, Hoa Anh, Phan, Tuan-Nghia, and Cutting, Simon M.
- Subjects
DRUG carriers ,CANCER treatment ,DRUG side effects ,BACILLUS subtilis ,STREPTAVIDIN ,CANCER cells - Abstract
Carriers of drugs in cancer therapy are required to reduce side-effects of the drugs to normal cells. Here we constructed killed recombinant Bacillus subtilis spores (SA1) that expressed streptavidin as a chimeric fusion to the spore coat protein CotB and used the spores as bioparticle carrier. When bound with biotinylated cetuximab these spores could specifically target to the epidermal growth factor receptor on HT 29 colon cancer cells, thereby delivered paclitaxel to the cells with 4-fold higher efficiency, as indicated by fluorescent intensity of paclitaxel Oregon Green 488 bound to HT29 cells. Based on real-time monitoring of cell index, the IC
50 of growth of HT29 cells by paclitaxel-SA1-cetuximab was estimated to be 2.9 nM approximately 5-fold lower than water-soluble paclitaxel (14.5 nM). Instability of DNA content was observed when cells were treated with 16 nM paclitaxel-SA1-cetuximab, resulting in a 2-fold enhancement in polyploidy cells. Thus, by targeting the release of paclitaxel to HT29 cells, spore-associated cetuximab augmented the inhibitory effect of paclitaxel on cell division and proliferation. The SA1 could be used as a 'universal' drug carrier to target specific biomarkers on cancer cells by conjugating with suitable biotinylated antibodies. [ABSTRACT FROM AUTHOR]- Published
- 2013
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54. Synthesis of Silica-Coated Magnetic Nanoparticles and Application in the Detection of Pathogenic Viruses.
- Author
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Dao Van Quy, Nguyen Minh Hieu, Pham Thi Tra, Nguyen Hoang Nam, Nguyen Hoang Hai, Nguyen Thai Son, Phan Tuan Nghia, Nguyen Thi Van Anh, Tran Thi Hong, and Nguyen Hoang Luong
- Subjects
CHEMICAL synthesis ,SILICA ,MAGNETIC nanoparticles ,VIRUSES ,PATHOGENIC microorganisms ,DIAGNOSTIC microbiology ,METAL coating - Abstract
Magnetic Fe
3 O4 nanoparticles were prepared by coprecipitation and then coated with silica. These Fe3 O4 /SiO2 nanoparticles consisted of a 10-15 nm magnetic core and a silica shell of 2-5 nm thickness. The superparamagnetic property of the Fe3 O4 /SiO2 particles with the magnetization of 42.5 emu/g was confirmed by vibrating sample magnetometer (VSM). We further optimized buffers with these Fe3 O4 /SiO2 nanoparticles to isolate genomic DNA of hepatitis virus type B (HBV) and of Epstein-Barr virus (EBV) for detection of the viruses based on polymerase chain reaction (PCR) amplification of a 434 bp fragment of S gene specific for HBV and 250 bp fragment of nuclear antigen encoding gene specific for EBV. The purification efficiency of DNA of both HBV and EBV using obtained Fe3 O4 /SiO2 nanoparticles was superior to that obtained with commercialized Fe3 O4 /SiO2 microparticles, as indicated by (i) brighter PCR-amplified bands for both HBV and EBV and (ii) higher sensitivity in PCR-based detection of EBV load (copies/mL). The time required for DNA isolation using Fe3 O4 /SiO2 nanoparticles was significantly reduced as the particles were attracted to magnets more quickly (15-20 s) than the commercialized microparticles (2-3 min). [ABSTRACT FROM AUTHOR]- Published
- 2013
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55. Influence of phytochemicals in piper betle linn leaf extract on wound healing
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Phan Tuan Nghia, Do Minh Ha, Le Thi Lien, Pham Luong Hang, Nguyen Dinh Thang, and Nguyen Thi Tho
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Chronic wound ,medicine.medical_specialty ,Angiogenesis ,Fibroblast (NIH3T3) ,Biomedical Engineering ,Wound healing ,Dermatology ,Critical Care and Intensive Care Medicine ,chemistry.chemical_compound ,Leaf extract ,In vivo ,Immunology and Allergy ,Medicine ,Fibroblast ,Piper ,biology ,Traditional medicine ,integumentary system ,Piper betle Linn ,business.industry ,Granulation tissue ,biology.organism_classification ,Malondialdehyde ,Surgery ,medicine.anatomical_structure ,chemistry ,Malondialdehyde (MDA) ,Emergency Medicine ,medicine.symptom ,business ,Research Article - Abstract
Background Wound healing has being extensively investigated over the world. Healing impairment is caused by many reasons including increasing of free-radicals-mediated damage, delaying in granulation tissue formation, reducing in angiogenesis and decreasing in collagen reorganization. These facts consequently lead to chronic wound healing. Piper betle Linn (Betle) leaves have been folklore used as an ingredient of drugs for cutaneous wound treatment. However, the effect of betle leaf on wound healing is not yet well elucidated. In this study, we aimed to investigate the healing efficacy of methanol leaf extract of Piper betle Linn on proliferation of fibroblast NIH3T3 cells as well as full-thickness burn and excision wounds in swiss mice. Methods Scratch wound healing assays were conducted to examine the effects of betle leaf extract on healing activity of fibroblast cells. Burn and excision wounds on swiss mouse skins were created for investigating the wound healing progress caused by the betle leaf extract. Malondialdehyde (MDA) was also evaluated to examine the products of lipid hydroperoxide (LPO) under conditions of with or without betle leaf extract treatment. Results The results of this study showed that Piper betle Linn leaf extract in methanol increased proliferation of NIH3T3 cells and promoted wound healing in vitro and in vivo with both burn wound and excision wound models. In addition, this extract significant decreased level of malondialdehyde (MDA) in liver of treated-mice compared with that in non-treated mice. Conclusions Our results suggest that Piper betle Linn can be used as an ingredient in developing natural origin drugs for treatment of cutaneous wounds.
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56. A New Saponin with Anti-HIV-1 Protease Activity from Acacia pennata
- Author
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Nguyen, Van-Dung, Nguyen, Hong-Loan Thi, Do, Linh-Chi, Van Tuan, Vu, Thuong, Phuong Thien, and Phan, Tuan-Nghia
- Abstract
We investigated the phytochemicals from an ethanol extract of Acacia pennata(L.) Willd stems, a Vietnam medicinal plant, which led to the isolation of a new saponin termed 21β-O-[(2E)-6-hydroxyl-2,6-dimethyl-2,7-octadienoyl] pitheduloside G (1), as well as pitheduloside G (2), a known saponin. The structures of compounds 1and 2were elucidated via spectroscopy and compared with those reported in the literature. The isolates (1and 2) were tested for their inhibitory effects on human immunodeficiency virus type 1 (HIV-1) protease (PR). We found that the new compound, 21β-O-[(2E)-6-hydroxyl-2,6-dimethyl-2,7-octadienoyl] pitheduloside G (1), possessed potent anti-HIV-1 PR activity, with a half-maximum inhibitory concentration (IC50) value of 2.0 ± 0.2 μM. In contrast, pitheduloside G (2) exhibited much less inhibition, with an IC50value of 18 ± 0.5 μM. Both compounds were nontoxic in human embryonic kidney 293T cells at concentrations effective against HIV-1 PR. This is the first report regarding the isolation of an anti-HIV-1 PR compound (1) from an Acaciaplant species.
- Published
- 2018
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57. Identification and characterization of a stress-inducible gene OsNLI-IF enhancing drought tolerance in transgenic tobacco.
- Author
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Nguyen Duy Phuong, Tuteja, Narendra, Phan Tuan Nghia, and Pham Xuan Hoi
- Subjects
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GENETIC engineering of tobacco , *DROUGHT tolerance , *TRANSGENIC plants , *NUCLEOTIDE sequence , *CROP development - Abstract
Plants respond to the adverse environment by activating a series of stress-inducible genes, including genes encoding transcription factors. The expression of these genes is regulated by a core DNA sequence contained in their promoter region called cis-acting element. The promoter region of several stress-responsive genes contains several stress-regulated cis-acting elements such as dehydration-responsive element, Crepeat, low-temperature-responsive element, NAC recognition sequence and ZFHD recognition sequence. In this study we isolated a cDNA for a transcription factor named nuclear LIM interactor-interacting factor from rice cDNA library by yeast one-hybrid screening using two target sequences of 50 nucleotides derived from two stress-inducible promoters, JRC0528 and JRC0332, of cold-inducible genes OsZF1 and OsNAC6 respectively, as baits. The NLI-IF protein showed both DNA-binding and transcriptional activities in yeast experiments. Expression of OsNLI-IF was found to be induced by cold, heat, salt and drought stresses. The OsNLI-IF gene overexpressing transgenic tobacco plants showed improvement in drought tolerance. The present study emphasizes that OsNLI-IF could be useful for development of drought-tolerant transgenic crop plants. [ABSTRACT FROM AUTHOR]
- Published
- 2015
58. Screening of common point-mutations and discovery of new T14727C change in mitochondrial genome of Vietnamese encephalomyopathy patients.
- Author
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Truong HT, Nguyen VA, Nguyen LV, Pham VA, and Phan TN
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- Asian People, DNA, Mitochondrial, Female, Humans, Leigh Disease pathology, Male, Mitochondrial Encephalomyopathies pathology, Polymorphism, Genetic, Genome, Mitochondrial genetics, Leigh Disease genetics, Mitochondrial Encephalomyopathies genetics, Point Mutation genetics
- Abstract
Vietnamese patients (106) tentatively diagnosed with encephalomyopathy were screened for the presence of 15 common point mutations in mitochondria using PCR-RFLP. The screened mutations include A3243G, T3271C and T3291C for Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like episodes (MELAS); A8344G and T8356C for Myoclonus Epilepsy and Rag-Red Fibers (MERRF); G11778A, G3460A and T14484C for Leber's Hereditary Optic Neuropathy (LHON); T8993G/C and T9176G for Leigh syndrome; A1555G for deafness syndrome; G4298A, T10010C, T14728C and T14709C for neuromuscular syndrome. As a result, 6 cases of A3243G (5.7%) and 2 cases of T14727C (3.9%) were found. The 6 cases of A3243G mutation were heteroplasmic at different levels (4.23-80.85%). The T14727C change was discovered for the first time in the MTTE gene encoding for tRNA(Glu) and showed homoplasmy. The T14727C change was probably a mutation because it was further confirmed as vertically inherited from the mother and not the result of isolated polymorphism.
- Published
- 2016
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59. A novel nuclear DNA helicase with high specific activity from Pisum sativum catalytically translocates in the 3'-->5' direction.
- Author
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Phan TN, Ehtesham NZ, Tuteja R, and Tuteja N
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- Base Sequence, Cations, Divalent pharmacology, DNA Helicases antagonists & inhibitors, DNA Helicases isolation & purification, Dactinomycin pharmacology, Daunorubicin pharmacology, Dimerization, Ethidium pharmacology, Kinetics, Molecular Weight, Nogalamycin pharmacology, Plant Leaves enzymology, Substrate Specificity, Cell Nucleus enzymology, DNA Helicases metabolism, Dactinomycin analogs & derivatives, Pisum sativum enzymology
- Abstract
A novel ATP-dependent nuclear DNA unwinding enzyme from pea has been purified to apparent homogeneity and characterized. This enzyme is present at extremely low abundance and has the highest specific activity among plant helicases. It is a heterodimer of 54 and 66 kDa polypeptides as determined by SDS/PAGE. On gel filtration chromatography and glycerol gradient centrifugation it gives a native molecular mass of 120 kDa and is named as pea DNA helicase 120 (PDH120). The enzyme can unwind 17-bp partial duplex substrates with equal efficiency whether or not they contain a fork. It translocates unidirectionally along the bound strand in the 3'-->5' direction. The enzyme also exhibits intrinsic single-stranded DNA- and Mg2+-dependent ATPase activity. ATP is the most favoured cofactor but other NTPs and dNTPs can also support the helicase activity with lower efficiency (ATP > GTP = dCTP > UTP > dTTP > CTP > dATP > dGTP) for which divalent cation (Mg2+ > Mn2+) is required. The DNA intercalating agents actinomycin C1, ethidium bromide, daunorubicin and nogalamycin inhibit the DNA unwinding activity of PDH120 with Ki values of 5.6, 5.2, 4.0 and 0.71 micro Ms, respectively. This inhibition might be due to the intercalation of the inhibitors into duplex DNA, which results in the formation of DNA-inhibitor complexes that impede the translocation of PDH120. Isolation of this new DNA helicase should make an important contribution to our better understanding of DNA transaction in plants.
- Published
- 2003
- Full Text
- View/download PDF
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