40 results on '"Vu, Hoan"'
Search Results
2. Effectiveness of Bach Nien Kien Health Supplement in the Treatment of Patients With Symptomatic Knee Osteoarthritis.
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VU, HOAN M., TRAN, HAU D., NGUYEN, ANH K., BO HAN, and HOANG, BA X.
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KNEE osteoarthritis ,ELECTROACUPUNCTURE ,GLUCOSAMINE ,DRUG efficacy ,HERBAL medicine - Abstract
Background/Aim: Knee osteoarthritis (KOA) is the most common disease in adults. We conducted a clinical study to evaluate the efficacy and safety of Bach Nien Kien (BNK) in supportive therapy for patients with symptomatic KOA. Patients and Methods: An open interventional study was performed on 60 patients aged 38 to 70 with the diagnosis of symptomatic KOA. The patients were assigned to a study group (SG) with 30 subjects and a control group (CG) with 30 subjects using a matching method. The patients in SG were treated with electroacupuncture, glucosamine supplement, and BNK, while the patients in CG received the same treatment without BNK. Results: At the end of the 30-day treatment (d30), the SG had a reduction in VAS score compared to a pre-treatment level of 3.03±0.96 points, which was more than the CG of 2.5±0.90 points. The excellent result in the SG was 10%, and the CG had no excellent result. The good result in the SG was 56.7%, and the CG group was only 26.7%. The moderate and poor results in the CG were high, 63.3%, and 10%, respectively; in the SG, only 26.7% and 6.7%. The difference in overall treatment results between the SG and CG was statistically significant (p<0.05). During the 30-day treatment period in both groups, no patient reported any undesirable effects. Conclusion: Bach Nien Kien health supplement is effective and safe for controlling KOA symptoms and improving joint motion and quality of life for patients with symptomatic KOA. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Bioaffinity Mass Spectrometry Screening
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Yang, Ben, Feng, Yun Jiang, Vu, Hoan, McCormick, Brendan, Rowley, Jessica, Pedro, Liliana, Crowther, Gregory J., Van Voorhis, Wesley C., Forster, Paul I., and Quinn, Ronald J.
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- 2016
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4. Opuntia ficus-indica (L.): An Overview of the Recent Application and Opportunities in Food.
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Ha, Quynh T. T., Nguyen, Khanh K., Le, Anh N., Vu, Hoan T., and Nguyen, Tuan N.
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OPUNTIA ficus-indica ,PRICKLY pears ,HYPOGLYCEMIA ,POLYPHENOLS ,ANTIOXIDANTS - Abstract
Opuntia ficus-indica (OFI, prickly pears, nopal cactus) has been used as a food, in beverages, besides prickly pears's natural betalain pigment serves as a food colorant. The abundant biological components of nopal cactus, including polyphenols, flavonoids, and other related compounds that exhibit therapeutic like, hypoglycemia management, anti-infection, anti-inflammatory, and antioxidation. Its versatility is remarkable, finding applications in pharmaceuticals, cosmetics, human and livestock nutrition, alternative fuels, construction, erosion control, and animal care. Recent studies highlight its potential to inhibit the growth of cervical, ovarian, and bladder cancer cells in vitro. In vivo tests on mice demonstrated decreased tumor growth in the ovarian cancer model. However, more meticulously designed clinical trials are required, utilizing phytochemically characterized preparations. Opuntia ficus-indica recast an exceptional safety and tolerability profile, underscoring its potential as a versatile and health-promoting resource. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Bifunctional copper(II) chelators from the coupling of the encapsulating ligand 1-methyl-8-amino-3,13,16-trithia-6,10,19-triazabicyclo[6.6.6]icosane (AMN3S3sar) with carboxylic acids; applications of the coupling agent DMT-MM
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Lee, Hui Hui, Lim, Peiying Alinia, Vu, Hoan, Poulsen, Sally-Ann, and Gahan, Lawrence R.
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- 2015
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6. Adapting grain crop seed threshing equipment for processing sesame for streamlining the mechanisation of post-harvest operations.
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Narayanan, Ramadas, Bhattarai, Surya, Tram, Vu Hoan, and Hunter, Lewis
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- 2023
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7. Near Field Investigation of a Plasmonic Lüneburg Lens
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Ehlermann, Jens, Vu, Hoan, and Mendach, Stefan
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- 2015
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8. Efficacy and Tolerability of Ich Nieu Khang Dietary Supplement for Overactive Bladder.
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Vu, Hoan M., Tran, Van T. H., Hoang, Huy Q., Han, Bo, and Hoang, Ba X.
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DRUG efficacy , *SLEEP quality , *DRUG tolerance , *URINATION disorders , *OVERACTIVE bladder , *PHYTOCHEMICALS , *DIETARY supplements , *SEVERITY of illness index , *DESCRIPTIVE statistics , *URINARY incontinence , *RESEARCH funding , *EVALUATION - Abstract
This study aims to assess the effectiveness and safety of plant-derived food supplement Ich Nieu Khang (INK) as a dietary supplement for overactive bladder (OAB) symptoms. A total of 50 patients 18–80 years of age with the diagnosis and symptoms of the OAB were enrolled in the study and followed up for 30 days. The INK treatment efficacy, in terms of changes in nocturnal and day-time urination frequency, urination incontinence episodes, level of OAB symptoms according to Homma's OABSS scale, sleep quality according to Pittsburg Sleep Quality Index (PSQI), and possible side effects of the INK phytotherapy, was evaluated. INK significantly improved all OAB symptoms scores with a reduction of average nocturia from 4.06 ± 1.53 to 1.14 ± 0.94, the daily average urination urgency from 7.67 ± 5.00 to 5. 82 ± 3.70, the daily average frequency of urination from 9.96 ± 4.04 to 8.00 ± 3.70, weekly average incontinence of urination from 0.92 ± 1.56 to 0.60 ± 1.02, and OABSS Homma's score decreased from 9.31 ± 1.44 to 6.8 ± 2.21. INK phytotherapy also resulted in sleep quality improvement by PSQI score decreasing from 13.11 ± 1.33 to 10.54 ± 2.21. There were no adverse effects and abnormalities in paraclinical parameters with INK therapy. The results of our study suggest that INK dietary supplement is effective and safe phytotherapy for patients with primary OAB symptoms within 30 days of treatment. Larger control clinical trials are warranted to confirm our findings and promote wider use of INK for OAB and possible other age-related urination disorders. [ABSTRACT FROM AUTHOR]
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- 2023
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9. Direct Screening of Natural Product Extracts Using Mass Spectrometry
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Vu, Hoan, Pham, Ngoc B., and Quinn, Ronald J.
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- 2008
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10. Fragment-Based Screening of a Natural Product Library against 62 Potential Malaria Drug Targets Employing Native Mass Spectrometry
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Vu, Hoan, Pedro, Liliana, Mak, Tin, McCormick, Brendan, Rowley, Jessica, Liu, Miaomiao, Di Capua, Angela, Williams-Noonan, Billy, Pham, Ngoc B., Pouwer, Rebecca, Nguyen, Bao, Andrews, Katherine T., Skinner-Adams, Tina, Kim, Jessica, Hol, Wim G. J., Hui, Raymond, Crowther, Gregory J., Van Voorhis, Wesley C., and Quinn, Ronald J.
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Antimalarials ,Biological Products ,natural products ,native mass spectrometry ,target identification ,fragments ,Plasmodium falciparum ,malaria ,Drug Evaluation, Preclinical ,Protozoan Proteins ,Featured Article ,Mass Spectrometry ,Protein Binding - Abstract
Natural products are well known for their biological relevance, high degree of three-dimensionality, and access to areas of largely unexplored chemical space. To shape our understanding of the interaction between natural products and protein targets in the postgenomic era, we have used native mass spectrometry to investigate 62 potential protein targets for malaria using a natural-product-based fragment library. We reveal here 96 low-molecular-weight natural products identified as binding partners of 32 of the putative malarial targets. Seventy-nine (79) fragments have direct growth inhibition on Plasmodium falciparum at concentrations that are promising for the development of fragment hits against these protein targets. This adds a fragment library to the published HTS active libraries in the public domain.
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- 2018
11. On a final value problem for a biparabolic equation with statistical discrete data.
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Tuan, Nguyen Huy, Thach, Tran Ngoc, Cam Vu, Hoan Luu, and Can, Nguyen Huu
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STATISTICS ,EQUATIONS - Abstract
This article is devoted to the study of final value problems for biparabolic equation with discrete data in two cases as the linear source and the nonlinear source, respectively. In each of the cases, we show the instability of the solutions and then establish approximate solutions by applying some regularization methods. In addition, the convergence estimates and numerical experiments showing the flexibility of those methods are given. [ABSTRACT FROM AUTHOR]
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- 2021
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12. Achyrodimer F, a tyrosyl-DNA phosphodiesterase I inhibitor from an Australian fungus of the family Cortinariaceae
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Tian, Li-Wen, Feng, Yunjiang, Tran, Trong D., Shimizu, Yoko, Pfeifer, Tom, Vu, Hoan T., and Quinn, Ronald J.
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- 2017
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13. Risk factors of Pancreatic Cancer in Vietnam: A Matched Case-Control Hospital-Based Study.
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Van Tran, Thuan, Van Dao, Tu, Nguyen, Khac-Dung, van TA, To, Vu, Khanh Truong, Trinh, Son Hong, Nguyen, Hoang Cong, Bui, Oanh Thi, Nguyen, Quang Tien, Vu, Hoan Duc, Nguyen, Hiep Le, and Tran, Huong Thanh
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- 2021
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14. Coupling of quantum-well emission to waveguide–plasmon polaritons in rolled-up microtubes.
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Vu, Hoan, Siebels, Jan, Sonnenberg, David, Mendach, Stefan, and Kipp, Tobias
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POLARITONS ,PHOTOLUMINESCENCE measurement ,WAVEGUIDES ,QUANTUM wells ,AUDITING standards - Abstract
We study the coupling of GaAs quantum wells to waveguide–plasmon polaritons supported by a thin InAlGaAs-based slab waveguide and a Ag grating. The hybrid photon–plasmon modes are excited in a freestanding emitter–waveguide–plasmon structure realized by rolling-up strained InAlGaAs-based layers and nanopatterned Ag structures. By varying the grating's bar width, we tune the plasmonic resonance of the system. We observe by means of spatially, spectrally, and temporally resolved photoluminescence measurements, a coupling of the quantum-well emission to the waveguide–plasmon system for a specific grating's bar width. Supported by finite-element simulations, we can assign the coupling to the excitation of a waveguide–plasmon polariton. [ABSTRACT FROM AUTHOR]
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- 2020
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15. Laparoscopic Ladd's procedure in neonates: A simple landmark detorsion technique.
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Pham, Hien Duy, Okata, Yuichi, Vu, Hoan Manh, Xuan, Nam Tran, and Duc, Tam Tran
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SMALL intestine surgery ,ISCHEMIA diagnosis ,DISEASE relapse ,DIGESTIVE organ surgery ,BOWEL obstructions ,LAPAROSCOPIC surgery ,MEDICAL records ,POSTOPERATIVE period ,REOPERATION ,RISK assessment ,SURGICAL therapeutics ,VOLVULUS ,TREATMENT effectiveness ,RETROSPECTIVE studies ,TREATMENT duration ,ACQUISITION of data methodology ,CHILDREN - Abstract
Background: The aim of this study was to assess the efficacy of our simple landmark technique for laparoscopic detorsion and the Ladd's procedure (lap‐Ladd) for malrotation with midgut volvulus in neonates and to identify the risk factors for reoperation after the lap‐Ladd. Methods: We conducted a retrospective chart review of 42 patients after lap‐Ladd for malrotation between April 2017 and June 2019. Information regarding patient status and intraoperative and postoperative data were analyzed. Results: Thirty‐one patients had volvulus (73.8 %), while 11 patients did not (26.2%). The median age and weight between the two groups at operation were 9 days (range, 3–28 days), 3.2 kg (range, 2–8 kg) and 6 days (range, 2–11), 2.9 kg (range, 2–3.8 kg), respectively. The operative time was significantly shorter in patients with volvulus compared to those without (60 vs 105 min, P = 0.002). Two cases were converted to open surgery because of ischemic changes of the total small intestine during surgery. Reoperation was required in two patients with volvulus (due to adhesive small bowel obstruction and recurrent volvulus). There was no significant predictive factor for reoperation after the lap‐Ladd procedure. Conclusion: Our simple landmark lap‐Ladd procedure demonstrated feasibility and good short‐term outcomes in neonates with malrotation, regardless of the presence or absence of volvulus. [ABSTRACT FROM AUTHOR]
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- 2020
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16. Cystic duct anomaly and pancreaticobiliary maljunction mimicking choledochal cyst
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Pham, Hien Duy, Okata, Yuichi, M.D., Ph.D., Duc, Tam Tran, Vu, Hoan Manh, and Xuan, Nam Tran
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- 2020
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17. Open Source Drug Discovery with the Malaria Box Compound Collection for Neglected Diseases and Beyond
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Phillips, Margaret A., Van Voorhis, Wesley C., Adams, John H., Adelfio, Roberto, Ahyong, Vida, Akabas, Myles H., Alano, Pietro, Alday, Aintzane, Alsibaee, Aishah, Alzualde, Ainhoa, Andrews, Katherine T., Avery, Simon V., Avery, Vicky M., Ayong, Lawrence, Baker, Mark, Baker, Stephen, Ben Mamoun, Choukri, Bhatia, Sangeeta, Bickle, Quentin, Bounaadja, Lotfi, Bowling, Tana, Boucher, Lauren E., Boyom, Fabrice F., Brea, Jose, Brennan, Marian, Burton, Audrey, Caffrey, Conor R., Camarda, Grazia, Carrasquilla, Manuela, Carter, Dee, Belen Cassera, Maria, Chih-Chien Cheng, Ken, Chindaudomsate, Worathad, Chubb, Anthony, Colon, Beatrice L., Corbett, Yolanda, Crowther, Gregory J., Cowan, Noemi, Le Dang, Na, Delves, Michael, DeRisi, Joseph L., Du, Alan Y., Duffy, Sandra, Abd El-Salam El-Sayed, Shimaa, Ferdig, Michael T., Fidock, David A., Florent, Isabelle, Fokou, Patrick V. T., Galstian, Ani, Gamo, Francisco Javier, Gokool, Suzanne, Gold, Ben, Golub, Todd, Goldgof, Gregory M., Guha, Rajarshi, Guiguemde, W. Armand, Gural, Nil, Guy, R. Kiplin, Hansen, Michael A. E., Hanson, Kirsten K., Hemphill, Andrew, Hooft van Huijsduijnen, Rob, Horii, Takaaki, Horrocks, Paul, Hughes, Tyler B., Huston, Christopher, Igarashi, Ikuo, Ingram-Sieber, Katrin, Itoe, Maurice A., Jadhav, Ajit, Naranuntarat Jensen, Amornrat, Jensen, Laran T., Jiang, Rays H.Y., Kaiser, Annette, Keiser, Jennifer, Ketas, Thomas, Kicka, Sebastien, Kim, Sunyoung, Kirk, Kiaran, Kumar, Vidya P., Kyle, Dennis E., Lafuente, Maria Jose, Landfear, Scott, Lee, Nathan, Lee, Sukjun, Lehane, Adele M., Li, Fengwu, Little, David, Liu, Liqiong, Loza, Maria I., Lubar, Aristea, Lucantoni, Leonardo, Lucet, Isabelle, Maes, Louis, Mancama, Dalu, Mansour, Nuha R., March, Sandra, McGowan, Sheena, Medina Vera, Iset, Meister, Stephan, Mercer, Luke, Mestres, Jordi, Mfopa, Alvine N., Misra, Raj N., Moon, Seunghyun, Moore, John P., Morais Rodrigues da Costa, Francielly, Muriana, Arantza, Nakazawa Hewitt, Stephen, Nare, Bakela, Nathan, Carl, Narraidoo, Nathalie, Nawaratna, Sujeevi, Ojo, Kayode K., Ortiz, Diana, Panic, Gordana, Papadatos, George, Parapini, Silvia, Patra, Kailash, Pham, Ngoc, Prats, Sarah, Plouffe, David M., Poulsen, Sally-Ann, Pradhan, Anupam, Quevedo, Celia, Quinn, Ronald J., Rice, Christopher A., Abdo Rizk, Mohamed, Ruecker, Andrea, St. Onge, Robert, Salgado Ferreira, Rafaela, Samra, Jasmeet, Robinett, Natalie G., Schlecht, Ulrich, Schmitt, Marjorie, Silva Villela, Filipe, Silvestrini, Francesco, Sinden, Robert, Smith, Dennis A., Soldati, Thierry, Stamm, Serge Maximilian, Sullivan, David J., Sullivan, William, Suresh, Sundari, Suzuki, Brian M., Suzuki, Yo, Swamidass, S. Joshua, Taramelli, Donatella, Tchokouaha, Lauve R.Y., Theron, Anjo, Thomas, David, Tonissen, Kathryn F., Townson, Simon, Tripathi, Abhai K., Trofimov, Valentin, Udenze, Kenneth O., Ullah, Imran, Vallieres, Cindy, Vigil, Edgar, Vinetz, Joseph M., Voong Vinh, Phat, Vu, Hoan, Watanabe, Nao-aki, Weatherby, Kate, White, Pamela M., Wilks, Andrew F., Winzeler, Elizabeth A., Wojcik, Edward, Wree, Melanie, Wu, Wesley, Yokoyama, Naoaki, Zollo, Paul H. A., Abla, Nada, Blasco, Benjamin, Burrows, Jeremy, Leroy, Didier, Spangenberg, Thomas, Wells, Timothy, and Willis, Paul A.
- Abstract
A major cause of the paucity of new starting points for drug discovery is the lack of interaction between academia and industry. Much of the global resource in biology is present in universities, whereas the focus of medicinal chemistry is still largely within industry. Open source drug discovery, with sharing of information, is clearly a first step towards overcoming this gap. But the interface could especially be bridged through a scale-up of open sharing of physical compounds, which would accelerate the finding of new starting points for drug discovery. The Medicines for Malaria Venture Malaria Box is a collection of over 400 compounds representing families of structures identified in phenotypic screens of pharmaceutical and academic libraries against the Plasmodium falciparum malaria parasite. The set has now been distributed to almost 200 research groups globally in the last two years, with the only stipulation that information from the screens is deposited in the public domain. This paper reports for the first time on 236 screens that have been carried out against the Malaria Box and compares these results with 55 assays that were previously published, in a format that allows a meta-analysis of the combined dataset. The combined biochemical and cellular assays presented here suggest mechanisms of action for 135 (34%) of the compounds active in killing multiple life-cycle stages of the malaria parasite, including asexual blood, liver, gametocyte, gametes and insect ookinete stages. In addition, many compounds demonstrated activity against other pathogens, showing hits in assays with 16 protozoa, 7 helminths, 9 bacterial and mycobacterial species, the dengue fever mosquito vector, and the NCI60 human cancer cell line panel of 60 human tumor cell lines. Toxicological, pharmacokinetic and metabolic properties were collected on all the compounds, assisting in the selection of the most promising candidates for murine proof-of-concept experiments and medicinal chemistry programs. The data for all of these assays are presented and analyzed to show how outstanding leads for many indications can be selected. These results reveal the immense potential for translating the dispersed expertise in biological assays involving human pathogens into drug discovery starting points, by providing open access to new families of molecules, and emphasize how a small additional investment made to help acquire and distribute compounds, and sharing the data, can catalyze drug discovery for dozens of different indications. Another lesson is that when multiple screens from different groups are run on the same library, results can be integrated quickly to select the most valuable starting points for subsequent medicinal chemistry efforts.
- Published
- 2016
18. Non-zinc mediated inhibition of carbonic anhydrases: coumarins are a new class of suicide inhibitors
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Maresca, Alfonso, Temperini, Claudia, Vu, Hoan, Pham, Ngoc B., Quinn, Ronald J., and Supuran, Claudiu T.
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Coumarins -- Chemical properties ,Coumarins -- Structure ,Hydrolysis -- Analysis ,Organometallic compounds -- Structure ,Organometallic compounds -- Chemical properties ,X-ray crystallography -- Usage ,Zinc -- Chemical properties ,Chemistry - Abstract
The X-ray crystal structure of the adduct between the zinc metalloenzyme carbonic anhydrase II (CA) with the natural product coumarin derivative 6-(1S-hydroxy-3-methylbutyl)-7-methoxy-2H-chromen-2-one has shown the coumarin hydrolysis product bound within the enzyme active site. Several structurally simple coumarin scaffolds are shown to inhibit all 13 catalytically active mammalian CA isoforms, where inhibition is time dependent.
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- 2009
19. Bioaffinity Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Direct Screening of Natural Product Extracts
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Vu, Hoan
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Natural product extracts ,Biological activities ,Electrospray ionization mass spectrometry ,Fourier transform spectroscopy - Abstract
The search for new drugs in natural products involves the screening of natural product extracts on therapeutic targets for the presence of active compounds and subsequent investigation of their biological activities. Towards this end, a rapid and effective strategy to identify the noncovalent interactions between active ligands from natural product extracts with therapeutic protein targets without false positive or negative results is critical. The current thesis presents the outcomes of research exploring a novel approach of biological screening of natural product extracts using bioaffinity ESI-FTICR-MS as a detection means. A research plan containing three major steps has been undertaken in this study. Step one examines the current challenges in identifying protein complexes by ESI-MS and developing optimized conditions for ESI-FTICR-MS. Step two involves the development of methods for identifying complexes of targets with various molecular mass values (600 – 66,000 Da) in the setting of crude extracts. Step three uses these methods to screen natural product extracts and identify active natural product compound – protein complexes, obtaining accurate molecular mass of active compounds and their mass fingerprint. On this basis, a mass-directed purification experiment was performed to isolate the identified active compounds. The binding of the pure active compounds with the protein target was then confirmed by competition experiments with a specific inhibitor of the protein. The procedure to achieve the optimal ESI-MS condition for detecting protein - small molecule complex has been successfully developed using bCA II as the test target protein and fractional factorial design (FFD) approach. Key instrumental factors controlling the desolvation process, as well as the interactions between these factors, have been identified using FFD experiment. It has been found that flow rate, nebulizer gas pressure and drying gas flow rate are factors that greatly affect the sensitivity of the complex detection. Capillary exit voltage also has a great effect on the desolvation in vacuum and on the preservation of the complex. These factors have been found to interact with each other and contribute to the final response, and therefore, have been incorporated in a second FFD experiment which focuses on minimum moment aberration. It has been found that the best condition is achieved when the capillary exit voltage is at the highest setting, and the flow rate, drying gas flow rate and nebulizing gas are at medium settings. The development of ESI-FTICR-MS methods for identifying noncovalent complexes in the environment of crude extracts has been accomplished using targets with various molecular mass values. In particular, ESI-FTICR-MS has been used to successfully detect hemin (< 1 kDa) and its complex with artemisinin. Accurate mass for artemisinin has been deduced with high resolution (deviation from theoretical value of less than 5 ppm). Screening 50 plant and marine sponge biota with hemin returned four active extracts. One of the four active natural product compounds had the molecular mass very close to artemisinin (Δ = 0.002 Da). The artemisinin identity of the active component has been confirmed using the MS2 pattern of artemisinin and the suspect artemisinin active component. A flavonoid was also detected in one of the active extracts and the structure elucidation of this active flavonoid has been proposed by comparing its diagnostic fragmentation patterns in multiple stage MS with those of other flavonones and flavonols. The first MS3 fragment ions of these 4 flavones and 2 flavonols are also presented in this study. The third and fourth active compounds have been isolated based on their accurate mass information using mass-directed purification. Their structures have also been determined by NMR. They are diacarnoic acids and are epi-isomers at position 3. MS2 experiments have been performed and can discriminate between these two compounds. Methods have also been developed for proteins having higher molecular masses using three target proteins ranging from 13 to 66 kDa. Using these methods, ESI-FTICR-MS or SEC-FTICR-MS have successfully identified these proteins and their complexes in a clean matrix, as well as in a natural product extract matrix. The use of microdialysis and SEC has been found to be a suitable method for protein desalting and buffer exchange, and for natural product extract filtering. The results support the conclusion that the ability of FTICR-MS to give accurate molecular mass of the inhibitors represents a powerful means for screening natural product extracts in a drug discovery process of finding diversified small molecule inhibitors. The methods developed for both direct infusion and online SEC-FTICR-MS have been successfully employed to screen 85 raw methanolic plant extracts with bCA II. A noncovalent complex has been detected and the active compound which binds to bCA II is identified. The specificity of the binding has also been confirmed by competition experiments with a specific inhibitor of the target protein. The outcomes of this work have been reported in the Journal of Biomolecular Screening (first published online on March 18, 2008). One of the key advantages of using ESI-FTICR-MS and associated methods is that the screening of the crude extracts is carried out without any preparation work such as pre-chromatographed, or pre-purification steps, thus avoiding any contamination which may lead to false positive or negative results. Information on the exact mass of the active compound also provides insights into the chemical composition or structural class of the compounds, thus shortening the long process of lead identification and allowing rapid mass-directed purification to isolate the active compounds. The demonstration of a coupled SEC-ESI-FTICR-MS procedure is superior to a batch method assay, whereby crude extracts are fractionated and subsequently bio-assayed until the active compound is found. Furthermore, this approach yields molecular masses in real time allowing subsequent mass-directed purification.
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- 2009
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20. Towards an approach for trust negotiation
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Vu, Hoan, Jaillon, Philippe, Roelens, Marc, Serpaggi, Xavier, Six, Grégory, Département Réseaux, Information, Multimédia (RIM-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre G2I
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ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2007
21. Correction: COVID-19 Discourse on Twitter in Four Asian Countries: Case Study of Risk Communication
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Park, Sungkyu, Han, Sungwon, Kim, Jeongwook, Molaie, Mir Majid, Vu, Hoang Dieu, Singh, Karandeep, Han, Jiyoung, Lee, Wonjae, and Cha, Meeyoung
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Public aspects of medicine ,RA1-1270 - Published
- 2021
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22. HierarchicalZSM-5 Materials for an EnhancedFormation of Gasoline-Range Hydrocarbons and Light Olefins in CatalyticCracking of Triglyceride-Rich Biomass.
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Vu, Hoan X., Schneider, Matthias, Bentrup, Ursula, Dang, Tung T., Phan, Binh M. Q., Nguyen, Duc A., Armbruster, Udo, and Martin, Andreas
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GASOLINE , *HYDROCARBONS , *TRIGLYCERIDES , *CATALYTIC cracking , *ZEOLITES , *BIOMASS , *ALKENES , *POROSITY - Abstract
A hierarchical ZSM-5 material witha high fraction of mesoporositycoupled to well-preserved intrinsic zeolite characteristics has beensuccessfully prepared by postsynthesis modifications involving optimizationof base treatment and subsequent strong acid washing of commercialAl-rich ZSM-5 (parent ZSM-5). The resulting hierarchical ZSM-5 materialwas thoroughly characterized before being tested in the cracking oftriglyceride-rich biomass, i.e., model feedstock triolein and realfeedstock waste cooking oil under fluid catalytic cracking conditions.The results show that the introduction of intracrystalline mesoporosityenhances the utilization of zeolite acid sites by the enlarged externalsurface, leading to an increased conversion. At the same time, itpartially suppresses the undesired secondary reactions by shorteningmicropore diffusion path lengths. With such a hierarchical ZSM-5 material,higher selectivities toward the desired products, i.e., gasoline-rangehydrocarbons and light olefins, than with commercial ZSM-5 have beenachieved. [ABSTRACT FROM AUTHOR]
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- 2015
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23. Experimental Strategies for Functional Annotation and Metabolism Discovery: Targeted Screening of Solute Binding Proteins and Unbiased Panning of Metabolomes.
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Vetting, Matthew W., Ai-Obaidi, Nawar, Suwen Zhao, San Francisco, Brian, Kim, Jungwook, Wichelecki, Daniel J., Bouvier, Jason T., Solbiati, Jose O., Vu, Hoan, Xinshuai Zhang, Rodionov, Dmitry A., Love, James D., Hillerich, Brandan S., Seidel, Ronald D., Quinn, Ronald J., Osterman, Andrei L., Cronan, John E., Jacobson, Matthew P., Gerlt, John A., and Almo, Steven C.
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- 2015
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24. Optical Sensing of Axons in GaAs Ring Resonators
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Koitmäe, Aune, Bausch, Cornelius, Diedrich, Daniel, Stava, Eric, Vu, Hoan, and Blick, Robert H.
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- 2013
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25. Early and Intermediate Outcomes of Laparoscopic Surgery for Choledochal Cysts with 400 Patients.
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Liem, Nguyen Thanh, Pham, Hien Duy, Dung, Le Anh, Son, Tran Ngoc, and Vu, Hoan Manh
- Subjects
LAPAROSCOPIC surgery ,CYSTS (Pathology) ,SURGERY ,OPERATIVE surgery ,JEJUNOSTOMY ,STENOSIS ,BILIARY tract ,HEALTH outcome assessment - Abstract
Objective: The aim of this study is to report early and intermediate outcomes of laparoscopic surgery for choledochal cysts with 400 cases. Patients and Methods: The operation was performed using four ports. The cystic duct was identified and divided. The liver was suspended by two stay-sutures: one on the round ligament and the other on the distal cystic duct. The choledochal cyst was isolated and removed completely, and biliary-digestive continuity was reestablished by hepaticoduodenostomy (HD) or hepaticojejunostomy (HJ). Results: From January 2007 to June 2011, 400 patients were operated on. There were 305 girls and 95 boys. Ages ranged from 1 month to 16 years (mean, 47.5±2.1 months). Cystic excision and HD were performed in 238 patients and HJ in 162 patients. The mean operating time was 164.8±51 minutes for the HD group and 220±60 minutes for the HJ group. Conversion to open surgery was required in 2 patients. There were no perioperative deaths. Postoperative biliary leakage occurred in 8 patients (2%), resolving spontaneously in 7 and requiring a second operation in 1 patient. The mean postoperative hospital stay was 6.4±0.3 days for the HD group and 6.7±0.5 days for the HJ group. Follow-up between 5 months and 57 months postdischarge (mean, 24.2±2.7 months) was obtained in 342 patients (85.5%). Cholangitis occurred in 5 patients (1.5%) in the HD group and 1 patient (0.6%) in the HJ group. Gastritis due to bilious reflux was 3.8% in the HD group. Conclusions: Laparoscopic repair is a safe and effective procedure for choledochal cyst. The rate of cholangitis and anastomotic stenosis is low. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
26. Promiscuity of Carbonic Anhydrase II. Unexpected Ester Hydrolysis of Carbohydrate-Based Sulfamate Inhibitors.
- Author
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Lopez, Marie, Vu, Hoan, Wang, Conan K., Wolf, Maarten G., Groenhof, Gerrit, Innocenti, Alessio, Supuran, Claudiu T., and Poulsen, Sally-Ann
- Subjects
- *
CARBONIC anhydrase , *HYDROLYSIS , *ESTERS , *HYDROXYL group , *MONOSACCHARIDES , *CRYSTAL structure , *X-ray crystallography - Abstract
Carbonic anhydrases (CAs) are enzymes whose endogenous reaction is the reversible hydration of CO2 to give HCO3- and a proton. CA are also known to exhibit weak and promiscuous esterase activity toward activated esters. Here, we report a series of findings obtained with a set of CA inhibitors that showed quite unexpectedly that the compounds were both inhibitors of CO2 hydration and substrates for the esterase activity of CA. The compounds comprised a monosaccharide core with the C-6 primary hydroxyl group derivatized as a sulfamate (for CA recognition). The remaining four sugar hydroxyl groups were acylated. Using protein X-ray crystallography, the crystal structures of human CA II in complex with four of the sulfamate inhibitors were obtained. As expected, the four structures displayed the canonical CA protein-sulfamate interactions. Unexpectedly, a free hydroxyl group was observed at the anomeric center (C-1) rather than the parent C-1 acyl group. In addition, this hydroxyl group is observed axial to the carbohydrate ring while in the parent structure it is equatorial. A mechanism is proposed that accounts for this inversion of stereochemistry. For three of the inhibitors, the acyl groups at C-2 or at C-2 and C-3 were also absent with hydroxyl groups observed in their place and retention of stereochemistry. With the use of electrospray ionization-Fourier transform ion cyclotron resonance-mass spectrometry (ESI-FTICR-MS), we observed directly the sequential loss of all four acyl groups from one of the carbohydrate-based sulfamates. For this compound, the inhibitor and substrate binding mode were further analyzed using free energy calculations. These calculations suggested that the parent compound binds almost exclusively as a substrate. To conclude, we have demonstrated that acylated carbohydrate-based sulfamates are simultaneously inhibitor and substrate of human CA II. Our results suggest that, initially, the substrate binding mode dominates, but following hydrolysis, the ligand can also bind as a pure inhibitor thereby competing with the substrate binding mode. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
27. Is the Laparoscopic Operation as Safe as Open Operation for Choledochal Cyst in Children?
- Author
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Liem, Nguyen T., Pham, Hien D., and Vu, Hoan M.
- Subjects
LAPAROSCOPIC surgery complications ,CYSTS (Pathology) ,SURGERY ,BLOOD transfusion ,PEDIATRIC surgery ,LENGTH of stay in hospitals ,OPERATIVE surgery ,PEDIATRICS - Abstract
Aim: The aim of this study was to compare the safety of laparoscopic operation with open surgery for choledochal cyst in children. Methods: Early outcomes of open surgery from January 2001 to December 2006 were compared with early outcomes of laparoscopic operations from January 2007 to July 2010. The main outcome variables included intra- and early postoperative complications, operative time, rate of reintervention, and duration of postoperative stay. Results: There were 307 patients in the open operation group and 309 patients in the laparoscopic operation group. There was no significant difference in cyst diameter between the 2 groups. The operative time was longer in the laparoscopic operation group. The number of patients requiring blood transfusion was lower in the laparoscopic operation group. Intraoperative complications were low in both groups and not significantly different. The rate of postoperative complications was lower in the laparoscopic operation group but not significantly. The rate of reintervention was significantly lower in the laparoscopic operation group. The postoperative stay was significantly shorter in the laparoscopic operation group. Conclusion: Laparoscopic operation is as safe as open operation for choledochal cyst. The postoperative stay was significantly shorter in the laparoscopic operation group. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
28. Controlling the Spontaneous Emission Rate of Quantum Wells in Rolled-Up Hyperbolic Metamaterials.
- Author
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Schulz, K. Marvin, Vu, Hoan, Schwaiger, Stephan, Rottler, Andreas, Korn, Tobias, Sonnenberg, David, Kipp, Tobias, and Mendach, Stefan
- Subjects
- *
PHOTON emission , *QUANTUM wells , *METAMATERIALS - Abstract
We experimentally demonstrate the enhancement of the spontaneous emission rate of GaAs quantum wells embedded in rolled-up metamaterials. We fabricate microtubes whose walls consist of alternating Ag and (In)(Al)GaAs layers with incorporated active GaAs quantum-well structures. By variation of the layer thickness ratio of the Ag and (In)(Al)GaAs layers we control the effective permittivity tensor of the metamaterial according to an effective medium approach. Thereby, we can design samples with elliptic or hyperbolic dispersion. Time-resolved low temperature photoluminescence spectroscopy supported by finite-difference time-domain simulations reveal a decrease of the quantum well's spontaneous emission lifetime in our metamaterials as a signature of the crossover from elliptic to hyperbolic dispersion. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
29. Application of Organosilane Monolayer Template to Quantitative Evaluation of Cancer Cell Adhesive Ability.
- Author
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Tanii, Takashi, Sasaki, Kosuke, Ichisawa, Kota, Demura, Takanori, Beppu, Yuichi, Vu, Hoan Anh, Chi, Hoan Thanh, Yamamoto, Hideaki, and Sato, Yuko
- Abstract
The adhesive ability of two human pancreatic cancer cell lines was evaluated using organosilane monolayer templates (OMTs). Using the OMT, the spreading area of adhered cells can be limited, and this enables us to focus on the initial attachment process of adhesion. Moreover, it becomes possible to arrange the cells in an array and to quantitatively evaluate the number of attached cells. The adhesive ability of the cancer cells cultured on the OMT was controlled by adding (-)-epigallocatechin-3-gallate (EGCG), which blocks a receptor that mediates cell adhesion and is overexpressed in cancer cells. Measurement of the relative ability of the cancer cells to attach to the OMT revealed that the ability for attachment decreased with increasing EGCG concentration. The results agreed well with the western blot analysis, indicating that the OMT can potentially be employed to evaluate the adhesive ability of various cancer cells. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
30. Practical Synthesis of 1,4-Dihydropyridines on Heterogeneous Sulfonicmodified Silica (SBA-15-SO 3 H) Catalyst Under Mild Condition.
- Author
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Hung TQ, Phuc BV, Loan PTT, Lan Nhi DT, Nguyen H, Xuan Vu H, Do DV, and Dang TT
- Abstract
Aims: Synthesis of 1,4-Dihydropyridines (1,4-DHP) using heterogeneous catalyst under mild condition., Objective: Our objective is to explore new applications of non-metal heterogeneous catalysts in the synthesis of 1,4-DHP derivatives in a greener and more efficient approach., Methods: A greener and more efficient method for the synthesis of 1,4-DHPs and an asymmetric 1,4-DHP (Felodipine drug) was successfully developed in high yields using a heterogeneous SBA- 15-SO
3 H catalyst., Results: A series of symmetric 1,4-DHP and an asymmetric 1,4-DHP (Felodipine drug) were successfully prepared in high yields using a heterogeneous SBA-15-SO3 H catalyst., Conclusion: The catalyst, SBA-15-SO3 H, exhibited an efficient catalyst activity for the synthesis of 1,4-DHP derivatives in high yields from the aldehyde, β-ketoester, and NH4 OAc as a nitrogen source under mild conditions and short reaction time. Bronsted acid sites of this solid catalyst were figured out to play a key role in this transformation. Interestingly, our catalyst is air-stable and can be recycled at least 5 times without losing catalytic activity., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)- Published
- 2023
- Full Text
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31. Changes in Serum Immunoglobulin G Subclasses during the Treatment of Patients with Chronic Obstructive Pulmonary Disease with Infectious Exacerbations.
- Author
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Ba Ta T, Tran Viet T, Xuan Nguyen K, Hai Nguyen C, Ngoc Vu H, Dinh Le T, Tien Nguyen S, Khac Dong H, Kim Thi Pham N, and Ngoc Dao B
- Subjects
- Humans, Prospective Studies, Immunoglobulin G, Pulmonary Disease, Chronic Obstructive
- Abstract
Introduction: Despite the theoretical importance of serum immunoglobulin (Ig) in the outcome of COPD exacerbations, the existing evidence for this has not been enough. This study was performed to evaluate changes in serum Ig levels and their relationship with outcomes of acute infectious exacerbations in patients with COPD. Methods: The prospective study was conducted at Military Hospital 103 from August 2017 to April 2019. Group D patients with COPD with infectious exacerbation were selected for participation in the study. The control group consisted of 30 healthy people. The patients were provided clinical examination and laboratory service; simultaneously, we measured their serum Ig levels (total IgG, IgG1, IgG2, IgG3, IgG4) at two time points: at admission (T1) and the final health outcome (T2). Results: The median levels of total IgG in patients at times T1 and T2 were significantly lower compared with those in the healthy group (1119.3 mg/dL and 1150.6 mg/dL compared with 2032.2 mg/dL) (p < 0.001). Regarding changes among IgG subclasses, the IgG1, IgG3, and IgG4 levels measured at T1 and T2 were reduced significantly compared with the control group (p < 0.05); the IgG3 levels at T1 were significantly higher than those at T2. IgG3 levels in patients with life-threatening exacerbations were significantly lower than the remaining ones (24.6 (26.8−155.5) mg/dL and 25.6 (29.5−161.2) mg/dL, respectively, p = 0.023). Conclusions: In group D patients with COPD with infectious exacerbations, there was a decrease in the serum IgG, IgG1, IgG3, and IgG4 levels. IgG3 levels were associated with the severity of COPD exacerbation.
- Published
- 2022
- Full Text
- View/download PDF
32. Risk factors of Pancreatic Cancer in Vietnam: A Matched Case-Control Hospital-Based Study.
- Author
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Van Tran T, Van Dao T, Nguyen KD, van Ta T, Vu KT, Trinh SH, Nguyen HC, Bui OT, Nguyen QT, Vu HD, Nguyen HL, and Tran HT
- Subjects
- Adult, Aged, Aged, 80 and over, Alcohol Drinking adverse effects, Case-Control Studies, Developing Countries, Female, Humans, Male, Middle Aged, Pancreatic Neoplasms diagnosis, Pancreatic Neoplasms etiology, Risk Factors, Smoking adverse effects, Vietnam, Diabetes Complications, Pancreatic Neoplasms epidemiology
- Abstract
Background: Data about the risk factors and pancreatic cancer in developing countries remain limited. We investigated for the first time the role of a number of risk factors (family cancer history, smoking, alcohol consumption, diabetes, inflammation disease, HBV infection) associated with pancreatic cancer among Vietnamese patients., Methods: We included all patients hospitalized at 4 Northern Vietnamese hospitals (Vietnam National Cancer Hospital, Bach Mai, Viet Duc, Thai Nguyen) and diagnosed with pancreatic cancer during the period from 2017 to 2019. Risk factors of eligible patients were collected and assessed the associations using a matched control study and logistic regression model analysis., Results: We identified 196 patients with diagnosis of pancreatic cancer of which 114 males and 82 females. The average age of the patient at the time of diagnosis was 58.28 years (standard deviation of 12.94, ranging from 25 to 87). Most of patients were diagnosed at advanced stage (85%). Smoking, diabetes, inflammation disease significantly increased the cancer risks (OR and 95% CI were 2.42 (1.38-4.37), 3.09 (1.54-6.68), 2.21 (1.42-3.45), respectively). HBV infection demonstrated a significant link with pancreatic cancer in univariate model (OR = 2.94 (1.08-9.36)), but not in multivariate model. However, cancer family history and alcohol drinkers did not show any significantly increased risk related to pancreatic cancer., Conclusions: Our finding showed smoking, diabetes, inflammation disease significantly increased the risk of pancreatic cancer in Vietnam.
- Published
- 2021
- Full Text
- View/download PDF
33. Open Source Drug Discovery with the Malaria Box Compound Collection for Neglected Diseases and Beyond.
- Author
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Van Voorhis WC, Adams JH, Adelfio R, Ahyong V, Akabas MH, Alano P, Alday A, Alemán Resto Y, Alsibaee A, Alzualde A, Andrews KT, Avery SV, Avery VM, Ayong L, Baker M, Baker S, Ben Mamoun C, Bhatia S, Bickle Q, Bounaadja L, Bowling T, Bosch J, Boucher LE, Boyom FF, Brea J, Brennan M, Burton A, Caffrey CR, Camarda G, Carrasquilla M, Carter D, Belen Cassera M, Chih-Chien Cheng K, Chindaudomsate W, Chubb A, Colon BL, Colón-López DD, Corbett Y, Crowther GJ, Cowan N, D'Alessandro S, Le Dang N, Delves M, DeRisi JL, Du AY, Duffy S, Abd El-Salam El-Sayed S, Ferdig MT, Fernández Robledo JA, Fidock DA, Florent I, Fokou PV, Galstian A, Gamo FJ, Gokool S, Gold B, Golub T, Goldgof GM, Guha R, Guiguemde WA, Gural N, Guy RK, Hansen MA, Hanson KK, Hemphill A, Hooft van Huijsduijnen R, Horii T, Horrocks P, Hughes TB, Huston C, Igarashi I, Ingram-Sieber K, Itoe MA, Jadhav A, Naranuntarat Jensen A, Jensen LT, Jiang RH, Kaiser A, Keiser J, Ketas T, Kicka S, Kim S, Kirk K, Kumar VP, Kyle DE, Lafuente MJ, Landfear S, Lee N, Lee S, Lehane AM, Li F, Little D, Liu L, Llinás M, Loza MI, Lubar A, Lucantoni L, Lucet I, Maes L, Mancama D, Mansour NR, March S, McGowan S, Medina Vera I, Meister S, Mercer L, Mestres J, Mfopa AN, Misra RN, Moon S, Moore JP, Morais Rodrigues da Costa F, Müller J, Muriana A, Nakazawa Hewitt S, Nare B, Nathan C, Narraidoo N, Nawaratna S, Ojo KK, Ortiz D, Panic G, Papadatos G, Parapini S, Patra K, Pham N, Prats S, Plouffe DM, Poulsen SA, Pradhan A, Quevedo C, Quinn RJ, Rice CA, Abdo Rizk M, Ruecker A, St Onge R, Salgado Ferreira R, Samra J, Robinett NG, Schlecht U, Schmitt M, Silva Villela F, Silvestrini F, Sinden R, Smith DA, Soldati T, Spitzmüller A, Stamm SM, Sullivan DJ, Sullivan W, Suresh S, Suzuki BM, Suzuki Y, Swamidass SJ, Taramelli D, Tchokouaha LR, Theron A, Thomas D, Tonissen KF, Townson S, Tripathi AK, Trofimov V, Udenze KO, Ullah I, Vallieres C, Vigil E, Vinetz JM, Voong Vinh P, Vu H, Watanabe NA, Weatherby K, White PM, Wilks AF, Winzeler EA, Wojcik E, Wree M, Wu W, Yokoyama N, Zollo PH, Abla N, Blasco B, Burrows J, Laleu B, Leroy D, Spangenberg T, Wells T, and Willis PA
- Subjects
- Drug Evaluation, Preclinical, Humans, Small Molecule Libraries, Antimalarials therapeutic use, Datasets as Topic, Drug Discovery methods, Malaria drug therapy, Neglected Diseases drug therapy
- Abstract
A major cause of the paucity of new starting points for drug discovery is the lack of interaction between academia and industry. Much of the global resource in biology is present in universities, whereas the focus of medicinal chemistry is still largely within industry. Open source drug discovery, with sharing of information, is clearly a first step towards overcoming this gap. But the interface could especially be bridged through a scale-up of open sharing of physical compounds, which would accelerate the finding of new starting points for drug discovery. The Medicines for Malaria Venture Malaria Box is a collection of over 400 compounds representing families of structures identified in phenotypic screens of pharmaceutical and academic libraries against the Plasmodium falciparum malaria parasite. The set has now been distributed to almost 200 research groups globally in the last two years, with the only stipulation that information from the screens is deposited in the public domain. This paper reports for the first time on 236 screens that have been carried out against the Malaria Box and compares these results with 55 assays that were previously published, in a format that allows a meta-analysis of the combined dataset. The combined biochemical and cellular assays presented here suggest mechanisms of action for 135 (34%) of the compounds active in killing multiple life-cycle stages of the malaria parasite, including asexual blood, liver, gametocyte, gametes and insect ookinete stages. In addition, many compounds demonstrated activity against other pathogens, showing hits in assays with 16 protozoa, 7 helminths, 9 bacterial and mycobacterial species, the dengue fever mosquito vector, and the NCI60 human cancer cell line panel of 60 human tumor cell lines. Toxicological, pharmacokinetic and metabolic properties were collected on all the compounds, assisting in the selection of the most promising candidates for murine proof-of-concept experiments and medicinal chemistry programs. The data for all of these assays are presented and analyzed to show how outstanding leads for many indications can be selected. These results reveal the immense potential for translating the dispersed expertise in biological assays involving human pathogens into drug discovery starting points, by providing open access to new families of molecules, and emphasize how a small additional investment made to help acquire and distribute compounds, and sharing the data, can catalyze drug discovery for dozens of different indications. Another lesson is that when multiple screens from different groups are run on the same library, results can be integrated quickly to select the most valuable starting points for subsequent medicinal chemistry efforts.
- Published
- 2016
- Full Text
- View/download PDF
34. Plasmodium gametocyte inhibition identified from a natural-product-based fragment library.
- Author
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Vu H, Roullier C, Campitelli M, Trenholme KR, Gardiner DL, Andrews KT, Skinner-Adams T, Crowther GJ, Van Voorhis WC, and Quinn RJ
- Subjects
- Alkaloids chemistry, Alkaloids isolation & purification, Alkaloids pharmacology, Antimalarials chemistry, Antimalarials isolation & purification, Azepines chemistry, Azepines isolation & purification, Azepines pharmacology, Deoxyuracil Nucleotides antagonists & inhibitors, Deoxyuracil Nucleotides chemistry, Deoxyuracil Nucleotides metabolism, Dose-Response Relationship, Drug, Heterocyclic Compounds, Bridged-Ring chemistry, Heterocyclic Compounds, Bridged-Ring isolation & purification, Heterocyclic Compounds, Bridged-Ring pharmacology, Kinetics, Lactones chemistry, Lactones isolation & purification, Lactones pharmacology, Life Cycle Stages physiology, Piperidines chemistry, Piperidines isolation & purification, Piperidines pharmacology, Plasmodium falciparum enzymology, Plasmodium falciparum growth & development, Protozoan Proteins chemistry, Protozoan Proteins metabolism, Recombinant Fusion Proteins chemistry, Recombinant Fusion Proteins metabolism, Spectrometry, Mass, Electrospray Ionization, Structure-Activity Relationship, Antimalarials pharmacology, Biological Products chemistry, Life Cycle Stages drug effects, Plasmodium falciparum drug effects, Protozoan Proteins antagonists & inhibitors, Small Molecule Libraries chemistry
- Abstract
Fragment-based screening is commonly used to identify compounds with relatively weak but efficient localized binding to protein surfaces. We used mass spectrometry to study fragment-sized three-dimensional natural products. We identified seven securinine-related compounds binding to Plasmodium falciparum 2'-deoxyuridine 5'-triphosphate nucleotidohydrolase (PfdUTPase). Securinine bound allosterically to PfdUTPase, enhancing enzyme activity and inhibiting viability of both P. falciparum gametocyte (sexual) and blood (asexual) stage parasites. Our results provide a new insight into mechanisms that may be applicable to transmission-blocking agents.
- Published
- 2013
- Full Text
- View/download PDF
35. Brevifollis gellanilyticus gen. nov., sp. nov., a gellan-gum-degrading bacterium of the phylum Verrucomicrobia.
- Author
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Otsuka S, Suenaga T, Vu HT, Ueda H, Yokota A, and Senoo K
- Subjects
- Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Fatty Acids analysis, Molecular Sequence Data, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Verrucomicrobia genetics, Verrucomicrobia isolation & purification, Vitamin K 2 analogs & derivatives, Vitamin K 2 analysis, Phylogeny, Polysaccharides, Bacterial metabolism, Verrucomicrobia classification
- Abstract
The taxonomic properties of strain DC2c-G4(T), a Gram-staining-negative, ovoid, gellan-gum-degrading bacterial isolate, were examined. Phylogenetic analysis based on 16S rRNA gene sequences identified this isolate as a member of the phylum Verrucomicrobia and closest to the genus Prosthecobacter. The 16S rRNA gene sequence similarities between this isolate and any of the type strains of species of the genus Prosthecobacter were less than 95 %. In addition, the absence of a single prostheca and the predominant menaquinone MK-7(H2) supported the differentiation of this isolate from the genus Prosthecobacter. Here, we propose Brevifollis gellanilyticus gen. nov., sp. nov. to accommodate the isolate. The type strain of the type species is DC2c-G4(T) (= NBRC 108608(T) = CIP 110457(T)).
- Published
- 2013
- Full Text
- View/download PDF
36. Identification and phylogenetic characterization of cobalamin biosynthetic genes of Ensifer adhaerens.
- Author
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Thi Vu H, Itoh H, Ishii S, Senoo K, and Otsuka S
- Subjects
- Bacterial Proteins genetics, Molecular Sequence Data, RNA, Ribosomal, 16S genetics, Rhizobiaceae classification, Sequence Analysis, DNA, Bacterial Proteins metabolism, Genes, Bacterial, Genome, Bacterial, Phylogeny, Rhizobiaceae enzymology, Rhizobiaceae genetics, Vitamin B 12 biosynthesis
- Abstract
Ensifer adhaerens CSBa was screened as a cobalamin producer. The draft genome sequence revealed that the strain possesses 22 cobalamin biosynthetic genes (cob genes). The cob gene arrangement on the genome of E. adhaerens CSBa was similar to that of other Ensifer species, and most similar to that of Pseudomonas denitrificans SC510. The cobN sequence phylogeny was generally congruent with that of the 16S rRNA gene, and it is suggeted that E. adhaerens CSBa might have inherited the cob genes from common ancestors of the Ensifer species. It was also suggested that the cob genes can be laterally transferred.
- Published
- 2013
- Full Text
- View/download PDF
37. Cytotoxic cyclic depsipeptides from the Australian marine sponge Neamphius huxleyi.
- Author
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Tran TD, Pham NB, Fechner G, Zencak D, Vu HT, Hooper JN, and Quinn RJ
- Subjects
- Animals, Antineoplastic Agents chemistry, Australia, Depsipeptides chemistry, HeLa Cells, Humans, Marine Biology, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Antineoplastic Agents isolation & purification, Antineoplastic Agents pharmacology, Depsipeptides isolation & purification, Depsipeptides pharmacology, Porifera chemistry
- Abstract
Three new cyclic depsipeptides, neamphamides B (2), C (3), and D (4), were isolated from the Australian sponge Neamphius huxleyi. The planar structural characterization of these molecules was elucidated using 2D NMR experiments and ESI-FTICR-MS(n). Their configurations were determined by Marfey's method and J-based NMR analysis. These new metabolites inhibited the growth of human cell lines (A549, HeLa, LNCaP, PC3, and NFF) with IC(50) values ranging from 88 to 370 nM. However, neamphamide D causes A549 cell proliferation at subcytotoxic doses and should be treated cautiously as a cytotoxic compound.
- Published
- 2012
- Full Text
- View/download PDF
38. Cytotoxic evaluation of alkaloids and isoflavonoids from the Australian tree Erythrina vespertilio.
- Author
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Iranshahi M, Vu H, Pham N, Zencak D, Forster P, and Quinn RJ
- Subjects
- Alkaloids isolation & purification, Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic isolation & purification, Australia, Cell Adhesion drug effects, Cell Line, Tumor, Cell Proliferation drug effects, Cytotoxins chemistry, Dose-Response Relationship, Drug, Drug Screening Assays, Antitumor, Fibroblasts drug effects, Fibroblasts pathology, Flavonoids isolation & purification, Foreskin cytology, Fruit chemistry, Humans, Infant, Newborn, Inhibitory Concentration 50, Isoflavones chemistry, Isoflavones isolation & purification, Male, Plant Bark chemistry, Plant Stems chemistry, Pterocarpans chemistry, Pterocarpans isolation & purification, Seeds chemistry, Structure-Activity Relationship, Antineoplastic Agents, Phytogenic pharmacology, Cytotoxins isolation & purification, Erythrina chemistry, Isoflavones pharmacology, Prostatic Neoplasms drug therapy, Pterocarpans pharmacology
- Abstract
A new glucoalkaloid, vespertilioside, together with three known alkaloids, including 11- β-methoxyglucoerysovine, erysotrine, and hypaphorine, were isolated from the fruits of E. vespertilio Benth. In addition, three known isoflavonoids, including phaseollin, alpiniumisoflavone, and phaseollidin, were identified from the plant stems. The structures of compounds were determined by 1D/2D NMR and mass experiments. The cytotoxic activity of all compounds was evaluated against a metastatic prostate cancer cell line (PC3) and neonatal foreskin fibroblast (NFF) using a real-time label-free cell analyser. Among the tested compounds, phaseollidin showed cytotoxic activities against PC3 (IC (50) = 8.83 ± 1.87 µM) and NFF (0.64 ± 0.37 µM) cell lines., (© Georg Thieme Verlag KG Stuttgart · New York.)
- Published
- 2012
- Full Text
- View/download PDF
39. Cocultivated bacteria can increase or decrease the culture lifetime of Chlorella vulgaris.
- Author
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Thi Vu H, Otsuka S, Ueda H, and Senoo K
- Subjects
- Bacteria growth & development, Coculture Techniques, Species Specificity, Bacteria classification, Chlorella vulgaris physiology, Microbial Interactions
- Published
- 2010
- Full Text
- View/download PDF
40. Fragment-based screening by X-ray crystallography, MS and isothermal titration calorimetry to identify PNMT (phenylethanolamine N-methyltransferase) inhibitors.
- Author
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Drinkwater N, Vu H, Lovell KM, Criscione KR, Collins BM, Prisinzano TE, Poulsen SA, McLeish MJ, Grunewald GL, and Martin JL
- Subjects
- Benzimidazoles chemistry, Binding Sites, Calorimetry, Crystallography, X-Ray, Kinetics, Ligands, Mass Spectrometry, Models, Molecular, Phenylethanolamine N-Methyltransferase metabolism, Enzyme Inhibitors chemistry, Phenylethanolamine N-Methyltransferase antagonists & inhibitors, Phenylethanolamine N-Methyltransferase chemistry
- Abstract
CNS (central nervous system) adrenaline (epinephrine) is implicated in a wide range of physiological and pathological conditions. PNMT (phenylethanolamine N-methyltransferase) catalyses the final step in the biosynthesis of adrenaline, the conversion of noradrenaline (norepinephrine) to adrenaline by methylation. To help elucidate the role of CNS adrenaline, and to develop potential drug leads, potent, selective and CNS-active inhibitors are required. The fragment screening approach has advantages over other lead discovery methods including high hit rates, more efficient hits and the ability to sample chemical diversity more easily. In the present study we applied fragment-based screening approaches to the enzyme PNMT. We used crystallography as the primary screen and identified 12 hits from a small commercial library of 384 drug-like fragments. The hits include nine chemicals with two fused rings and three single-ring chemical systems. Eight of the hits come from three chemical classes: benzimidazoles (a known class of PNMT inhibitor), purines and quinolines. Nine of the hits have measurable binding affinities (~5-700 μM) as determined by isothermal titration calorimetry and all nine have ligand efficiencies of 0.39 kcal/mol per heavy atom or better (1 kcal≈4.184 kJ). We synthesized five elaborated benzimidazole compounds and characterized their binding to PNMT, showing for the first time how this class of inhibitors interact with the noradrenaline-binding site. Finally, we performed a pilot study with PNMT for fragment-based screening by MS showing that this approach could be used as a fast and efficient first-pass screening method prior to characterization of binding mode and affinity of hits.
- Published
- 2010
- Full Text
- View/download PDF
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