101
|
Nguyen PH, Kim SS, Nguyen TT, Tran LM, Hajeebhoy N, Frongillo EA, Ruel MT, Rawat R, Menon P. Supply- and Demand-Side Factors Influencing Utilization of Infant and Young Child Feeding Counselling Services in Viet Nam. PLoS One 2016; 11:e0151358. [PMID: 26962856 PMCID: PMC4786102 DOI: 10.1371/journal.pone.0151358] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/26/2016] [Indexed: 11/17/2022] Open
Abstract
Adequate utilization of services is critical to maximize the impact of counselling on infant and young child feeding (IYCF), but little is known about factors affecting utilization. Our study examined supply- and demand-side factors associated with the utilization of IYCF counselling services in Viet Nam. We used survey data from mothers with children <2y (n = 1,008) and health staff (n = 60) from the evaluation of a program that embedded IYCF counseling into the existing government health system. The frequency of never users, one-time users, repeat users, and achievers of the recommended minimum number of visits at health facilities were 45.1%, 13.0%, 28.4% and 13.5%, respectively. Poisson regression showed that demand-generation strategies, especially invitation cards, were the key factors determining one-time use (Prevalence ratio, PR 3.0, 95% CI: 2.2-4.2), repeated use (PR 3.2, 95% CI: 2.4-4.2), and achievement of minimum visits (PR 5.5, 95% CI: 3.6-8.4). Higher maternal education was associated with higher utilization both for one-time and repeated use. Being a farmer, belonging to an ethnic minority, and having a wasted child were associated with greater likelihood of achieving the minimum recommended number of visits, whereas child stunting or illness were not. Distance to health center was a barrier to repeated visits. Among supply-side factors, good counselling skills (PR: 1.3-1.8) was the most important factor associated with any service use, whereas longer employment duration and greater work pressure of health center staff were associated with lower utilization. Population attributable risk estimations showed that an additional 25% of the population would have achieved the minimum number of visits if exposed to three demand-generation strategies, and further increased to 49% if the health staff had good counseling skills and low work pressure. Our study provides evidence that demand-generation strategies are essential to increase utilization of facility-based IYCF counselling services in Viet Nam, and may be relevant for increasing and sustaining use of nutrition services in similar contexts.
Collapse
Affiliation(s)
- Phuong H Nguyen
- Poverty, Health, and Nutrition Division, International Food Policy Research Institute, Washington, DC, United States of America
| | - Sunny S Kim
- Poverty, Health, and Nutrition Division, International Food Policy Research Institute, Washington, DC, United States of America
| | | | | | | | - Edward A Frongillo
- Department of Health Promotion, Education, and Behavior, University of South Carolina, Columbia, SC, United States of America
| | - Marie T Ruel
- Poverty, Health, and Nutrition Division, International Food Policy Research Institute, Washington, DC, United States of America
| | - Rahul Rawat
- Poverty, Health, and Nutrition Division, International Food Policy Research Institute, Washington, DC, United States of America
| | - Purnima Menon
- Poverty, Health, and Nutrition Division, International Food Policy Research Institute, Washington, DC, United States of America
| |
Collapse
|
102
|
Kouza M, Co NT, Nguyen PH, Kolinski A, Li MS. Preformed template fluctuations promote fibril formation: insights from lattice and all-atom models. J Chem Phys 2016; 142:145104. [PMID: 25877597 DOI: 10.1063/1.4917073] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Fibril formation resulting from protein misfolding and aggregation is a hallmark of several neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Despite the fact that the fibril formation process is very slow and thus poses a significant challenge for theoretical and experimental studies, a number of alternative pictures of molecular mechanisms of amyloid fibril formation have been recently proposed. What seems to be common for the majority of the proposed models is that fibril elongation involves the formation of pre-nucleus seeds prior to the creation of a critical nucleus. Once the size of the pre-nucleus seed reaches the critical nucleus size, its thermal fluctuations are expected to be small and the resulting nucleus provides a template for sequential (one-by-one) accommodation of added monomers. The effect of template fluctuations on fibril formation rates has not been explored either experimentally or theoretically so far. In this paper, we make the first attempt at solving this problem by two sets of simulations. To mimic small template fluctuations, in one set, monomers of the preformed template are kept fixed, while in the other set they are allowed to fluctuate. The kinetics of addition of a new peptide onto the template is explored using all-atom simulations with explicit water and the GROMOS96 43a1 force field and simple lattice models. Our result demonstrates that preformed template fluctuations can modulate protein aggregation rates and pathways. The association of a nascent monomer with the template obeys the kinetics partitioning mechanism where the intermediate state occurs in a fraction of routes to the protofibril. It was shown that template immobility greatly increases the time of incorporating a new peptide into the preformed template compared to the fluctuating template case. This observation has also been confirmed by simulation using lattice models and may be invoked to understand the role of template fluctuations in slowing down fibril elongation in vivo.
Collapse
Affiliation(s)
- Maksim Kouza
- Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warszaw, Poland
| | - Nguyen Truong Co
- Department of Physics, Institute of Technology, National University of HCM City, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam
| | - Phuong H Nguyen
- Laboratoire de Biochimie Theorique, UPR 9080 CNRS, IBPC, Universite Paris 7, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Andrzej Kolinski
- Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warszaw, Poland
| | - Mai Suan Li
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| |
Collapse
|
103
|
Tran TT, Nguyen PH, Derreumaux P. Alzheimer's Disease: Insights into Amyloid Fibril Formation from Lattice Monte Carlo Simulations. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
104
|
Hoang Man V, Van-Oanh NT, Derreumaux P, Li MS, Roland C, Sagui C, Nguyen PH. Picosecond infrared laser-induced all-atom nonequilibrium molecular dynamics simulation of dissociation of viruses. Phys Chem Chem Phys 2016; 18:11951-8. [DOI: 10.1039/c5cp07711g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Laser-induced all-atom nonequilibrium molecular dynamics simulation of virus dissociation.
Collapse
Affiliation(s)
- Viet Hoang Man
- Department of Physics
- North Carolina State University
- Raleigh
- USA
| | - Nguyen-Thi Van-Oanh
- Laboratoire de Chimie Physique
- Université Paris-Sud XI
- F91405 Orsay Cedex
- France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Theorique
- UPR 9080 CNRS
- IBPC
- Universite Denis Diderot
- Paris
| | - Mai Suan Li
- Institute of Physics
- Polish Academy of Sciences
- 02-668 Warsaw
- Poland
- Institute for Computational Science and Technology
| | | | - Celeste Sagui
- Department of Physics
- North Carolina State University
- Raleigh
- USA
| | | |
Collapse
|
105
|
Nguyen PH, Hoang MV, Hajeebhoy N, Tran LM, Le CH, Menon P, Rawat R. Maternal willingness to pay for infant and young child nutrition counseling services in Vietnam. Glob Health Action 2015; 8:28001. [PMID: 26328947 PMCID: PMC4557091 DOI: 10.3402/gha.v8.28001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/18/2015] [Accepted: 07/22/2015] [Indexed: 11/14/2022] Open
Abstract
Background Alive & Thrive Vietnam, a 6-year initiative (2009–2014), has developed and incorporated elements of social franchising into government health services to provide high-quality nutrition counseling services to improve infant and young child feeding practices. One element of franchising that has not yet been implemented is fee for service, which is a potential financing mechanism for sustaining services in the long run. Objective This research aims to estimate maternal willingness to pay (WTP) for nutrition counseling services and to examine potential factors associated with their WTP. Design and methods Data were drawn from an impact evaluation survey of 2,511 women with a child <2 years old from four provinces in Vietnam. An iterative bidding technique was employed to explore individual WTP. The first bid was defined as VND 20,000 (~US$ 1), which was approximately the level of the actual service cost. Depending on the participant response, the bid increased or decreased. Finally, the respondents were asked about the highest price they would be willing to pay for the service. Results Overall, 92.6% of clients reported a need for nutrition counseling services for children <2 years. The WTP rates at bid levels of VND 5,000, 10,000, 20,000, 40,000, and 100,000 were 95.2, 94.4, 90.7, 68.9, and 33.4%, respectively. The mean and median of the maximum WTP were VND 58,500 and 50,000, respectively. In multiple regression models, WTP rates were higher among younger women, the Kinh majority group, and better educated and wealthier women. Conclusion A high demand for nutrition counseling coupled with a WTP by almost all segments of society would potentially cover costs of delivery for nutrition counseling services in Vietnam.
Collapse
Affiliation(s)
- Phuong H Nguyen
- International Food Policy Research Institute, Washington, DC, USA;
| | - Minh V Hoang
- Center for Health System Research, Hanoi Medical University, Hanoi, Vietnam
| | | | | | - Chung H Le
- Center for Health System Research, Hanoi Medical University, Hanoi, Vietnam
| | - Purnima Menon
- International Food Policy Research Institute, Washington, DC, USA
| | - Rahul Rawat
- International Food Policy Research Institute, Washington, DC, USA
| |
Collapse
|
106
|
Tarus B, Tran TT, Nasica-Labouze J, Sterpone F, Nguyen PH, Derreumaux P. Structures of the Alzheimer's Wild-Type Aβ1-40 Dimer from Atomistic Simulations. J Phys Chem B 2015; 119:10478-87. [PMID: 26228450 DOI: 10.1021/acs.jpcb.5b05593] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have studied the dimer of amyloid beta peptide Aβ of 40 residues by means of all-atom replica exchange molecular dynamics. The Aβ-dimers have been found to be the smallest toxic species in Alzheimer's disease, but their inherent flexibilities have precluded structural characterization by experimental methods. Though the 24-μs-scale simulation reveals a mean secondary structure of 18% β-strand and 10% α helix, we find transient configurations with an unstructured N-terminus and multiple β-hairpins spanning residues 17-21 and 30-36, but the antiparallel and perpendicular peptide orientations are preferred over the parallel organization. Short-lived conformational states also consist of all α topologies, and one compact peptide with β-sheet structure stabilized by a rather extended peptide with α-helical content. Overall, this first all-atom study provides insights into the equilibrium structure of the Aβ1-40 dimer in aqueous solution, opening a new avenue for a comprehensive understanding of the impact of pathogenic and protective mutations in early-stage Alzheimer's disease on a molecular level.
Collapse
Affiliation(s)
- Bogdan Tarus
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Thanh T Tran
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Jessica Nasica-Labouze
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Fabio Sterpone
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Phuong H Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| |
Collapse
|
107
|
Berthoumieu O, Nguyen PH, Castillo-Frias MPD, Ferre S, Tarus B, Nasica-Labouze J, Noël S, Saurel O, Rampon C, Doig AJ, Derreumaux P, Faller P. Combined experimental and simulation studies suggest a revised mode of action of the anti-Alzheimer disease drug NQ-Trp. Chemistry 2015; 21:12657-66. [PMID: 26179053 DOI: 10.1002/chem.201500888] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Indexed: 11/09/2022]
Abstract
Inhibition of the aggregation of the monomeric peptide β-amyloid (Aβ) into oligomers is a widely studied therapeutic approach in Alzheimer's disease (AD). Many small molecules have been reported to work in this way, including 1,4-naphthoquinon-2-yl-L-tryptophan (NQ-Trp). NQ-Trp has been reported to inhibit aggregation, to rescue cells from Aβ toxicity, and showed complete phenotypic recovery in an in vivo AD model. In this work we investigated its molecular mechanism by using a combined approach of experimental and theoretical studies, and obtained converging results. NQ-Trp is a relatively weak inhibitor and the fluorescence data obtained by employing the fluorophore widely used to monitor aggregation into fibrils can be misinterpreted due to the inner filter effect. Simulations and NMR experiments showed that NQ-Trp has no specific "binding site"-type interaction with mono- and dimeric Aβ, which could explain its low inhibitory efficiency. This suggests that the reported anti-AD activity of NQ-Trp-type molecules in in vivo models has to involve another mechanism. This study has revealed the potential pitfalls in the development of aggregation inhibitors for amyloidogenic peptides, which are of general interest for all the molecules studied in the context of inhibiting the formation of toxic aggregates.
Collapse
Affiliation(s)
- Olivia Berthoumieu
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) and Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4 (France)
| | - Phuong H Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France)
| | - Maria P Del Castillo-Frias
- Manchester Institute of Biotechnology, Faculty of Life Sciences, The University of Manchester, 131 Princess Street, Manchester M1 7DN (UK)
| | - Sabrina Ferre
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) and Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4 (France)
| | - Bogdan Tarus
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France)
| | - Jessica Nasica-Labouze
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France)
| | - Sabrina Noël
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) and Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4 (France)
| | - Olivier Saurel
- IPBS Institute of Pharmacology and Structural Biology, Université de Toulouse, UPS, 205 route de Narbonne, 31077 Toulouse (France).,IPBS, UMR 5089, CNRS, 205 route de Narbonne, BP 64182, 31077 Toulouse (France)
| | - Claire Rampon
- Université de Toulouse, UPS, CNRS, Centre de Recherches sur la Cognition, Animale, 118 route de Narbonne, 31062 Toulouse Cedex 4 (France)
| | - Andrew J Doig
- Manchester Institute of Biotechnology, Faculty of Life Sciences, The University of Manchester, 131 Princess Street, Manchester M1 7DN (UK).
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France). .,Institut Universitaire de France, IUF, 103 Boulevard Saint-Michel, 75005 Paris (France).
| | - Peter Faller
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4 (France) and Université de Toulouse, UPS, INPT, 31077 Toulouse Cedex 4 (France).
| |
Collapse
|
108
|
Lapping K, Frongillo EA, Nguyen PH, Coates J, Webb P, Menon P. Organizational factors, planning capacity, and integration challenges constrain provincial planning processes for nutrition in decentralizing Vietnam. Food Nutr Bull 2015; 35:382-91. [PMID: 25902597 DOI: 10.1177/156482651403500310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Translating national policies and guidelines into effective action at the subnational level (e.g., province or region) is a prerequisite for ensuring an impact on nutrition. In several countries, including Vietnam, the focus of this paper, this process is affected by the quality of the decentralized process of planning and action. OBJECTIVE This study examined how provincial planning processes for nutrition occurred in Vietnam during 2009 and 2010. Key goals were to understand variability in processes across provinces, identify factors that influenced the process, and assess the usefulness of the process for individuals involved in planning and action. METHODS A qualitative case-study methodology was used. Data were drawn from interviews with 51 government officials in eight provinces. RESULTS The study found little variability in the planning process among these eight provinces, probably due to a planning process that was predominantly a fiscal exercise within the confines of a largely centralized structure. Respondents were almost unanimous about the main barriers: a top-down approach to planning, limited human capacity for effective planning at subnational levels, and difficulty in integrating actions from multiple sectors. Provincial-level actors were deeply dissatisfied with the nature of their role in the process. CONCLUSIONS Despite the rhetoric to the contrary, too much power is probably still retained at the central level. A strategic multiyear approach is needed to strengthen the provincial planning process and address many of the key barriers identified in this study.
Collapse
|
109
|
Abstract
Following a previous report on a coarse-grained protein model in implicit solvent, we applied simulated tempering (ST) with on-the-fly Helmholtz free energy (weight factors) determination to the folding or aggregation of seven proteins with the CHARMM, OPLS, and AMBER protein, and the SPC and TIP3P water force fields. For efficiency and reliability, we also performed replica exchange molecular dynamics (REMD) simulations on the alanine di- and deca-peptide, and the dimer of the Aβ16-22 Alzheimer's fragment, and used experimental data and previous simulation results on the chignolin, beta3s, Trp-cage, and WW domain peptides of 10-37 amino acids. The sampling with ST is found to be more efficient than with REMD for a much lower CPU cost. Starting from unfolded or extended conformations, the WW domain and the Trp-cage peptide fold to their NMR structures with a backbone RMSD of 2.0 and 1 Å. Remarkably, the ST simulation explores transient non-native topologies for Trp-cage that have been rarely discussed by other simulations. Our ST simulations also show that the CHARMM22* force field has limitations in describing accurately the beta3s peptide. Taken together, these results open the door to the study of the configurations of single proteins, protein aggregates, and any molecular systems at atomic details in explicit solvent using a single normal CPU. They also demonstrate that our ST scheme can be used with any force field ranging from quantum mechanics to coarse-grain and atomistic.
Collapse
Affiliation(s)
- Tong Zhang
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.,‡School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Phuong H Nguyen
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Jessica Nasica-Labouze
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.,§International School of Advanced Studies (SISSA), Via Bonomea, 265, 34126 Trieste, Italy
| | - Yuguang Mu
- ‡School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Philippe Derreumaux
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.,∥Institut Universitaire de France, 103 Boulevard Saint-Michel, 75005 Paris, France
| |
Collapse
|
110
|
Nguyen PH, Popova AM, Hideg K, Qin PZ. A nucleotide-independent cyclic nitroxide label for monitoring segmental motions in nucleic acids. BMC Biophys 2015; 8:6. [PMID: 25897395 PMCID: PMC4404236 DOI: 10.1186/s13628-015-0019-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/16/2015] [Indexed: 01/07/2023]
Abstract
Background Spin labels, which are chemically stable radicals attached at specific sites of a bio-molecule, enable investigations on structure and dynamics of proteins and nucleic acids using techniques such as site-directed spin labeling and paramagnetic NMR. Among spin labels developed, the class of rigid labels have limited or no independent motions between the radical bearing moiety and the target, and afford a number of advantages in measuring distances and monitoring local dynamics within the parent bio-molecule. However, a general method for attaching a rigid label to nucleic acids in a nucleotide-independent manner has not been reported. Results We developed an approach for installing a nearly rigid nitroxide spin label, designated as R5c, at a specific site of the nucleic acid backbone in a nucleotide-independent manner. The method uses a post-synthesis approach to covalently attach the nitroxide moiety in a cyclic fashion to phosphorothioate groups introduced at two consecutive nucleotides of the target strand. R5c-labeled nucleic acids are capable of pairing with their respective complementary strands, and the cyclic nature of R5c attachment significantly reduced independence motions of the label with respect to the parent duplex, although it may cause distortion of the local environment at the site of labeling. R5c yields enhanced sensitivity to the collective motions of the duplex, as demonstrated by its capability to reveal changes in collective motions of the substrate recognition duplex of the 120-kDa Tetrahymena group I ribozyme, which elude detection by a flexible label. Conclusions The cyclic R5c nitroxide can be efficiently attached to a target nucleic acid site using a post-synthetic coupling approach conducted under mild biochemical conditions, and serves as a viable label for experimental investigation of segmental motions in nucleic acids, including large folded RNAs. Electronic supplementary material The online version of this article (doi:10.1186/s13628-015-0019-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Phuong H Nguyen
- Department of Chemistry, University of Southern California, 840 Downey Way, Los Angeles, CA 90089-0744 USA ; Current Address: Bachem Americas, Torrance, CA 90505 USA
| | - Anna M Popova
- Department of Chemistry, University of Southern California, 840 Downey Way, Los Angeles, CA 90089-0744 USA ; Current Address: Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037 USA
| | - Kálmán Hideg
- Institute of Organic and Medicinal Chemistry, University of Pécs, Szigetic Strasse 12, Pécs, Hungary
| | - Peter Z Qin
- Department of Chemistry, University of Southern California, 840 Downey Way, Los Angeles, CA 90089-0744 USA
| |
Collapse
|
111
|
Nasica-Labouze J, Nguyen PH, Sterpone F, Berthoumieu O, Buchete NV, Coté S, De Simone A, Doig AJ, Faller P, Garcia A, Laio A, Li MS, Melchionna S, Mousseau N, Mu Y, Paravastu A, Pasquali S, Rosenman DJ, Strodel B, Tarus B, Viles JH, Zhang T, Wang C, Derreumaux P. Amyloid β Protein and Alzheimer's Disease: When Computer Simulations Complement Experimental Studies. Chem Rev 2015; 115:3518-63. [PMID: 25789869 DOI: 10.1021/cr500638n] [Citation(s) in RCA: 469] [Impact Index Per Article: 52.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jessica Nasica-Labouze
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Phuong H Nguyen
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Fabio Sterpone
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Olivia Berthoumieu
- ‡LCC (Laboratoire de Chimie de Coordination), CNRS, Université de Toulouse, Université Paul Sabatier (UPS), Institut National Polytechnique de Toulouse (INPT), 205 route de Narbonne, BP 44099, Toulouse F-31077 Cedex 4, France
| | | | - Sébastien Coté
- ∥Département de Physique and Groupe de recherche sur les protéines membranaires (GEPROM), Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3T5, Canada
| | - Alfonso De Simone
- ⊥Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Andrew J Doig
- #Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Peter Faller
- ‡LCC (Laboratoire de Chimie de Coordination), CNRS, Université de Toulouse, Université Paul Sabatier (UPS), Institut National Polytechnique de Toulouse (INPT), 205 route de Narbonne, BP 44099, Toulouse F-31077 Cedex 4, France
| | | | - Alessandro Laio
- ○The International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Mai Suan Li
- ◆Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland.,¶Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam
| | - Simone Melchionna
- ⬠Instituto Processi Chimico-Fisici, CNR-IPCF, Consiglio Nazionale delle Ricerche, 00185 Roma, Italy
| | | | - Yuguang Mu
- ▲School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
| | - Anant Paravastu
- ⊕National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Samuela Pasquali
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | | | - Birgit Strodel
- △Institute of Complex Systems: Structural Biochemistry (ICS-6), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Bogdan Tarus
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - John H Viles
- ▼School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Tong Zhang
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France.,▲School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
| | | | - Philippe Derreumaux
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France.,□Institut Universitaire de France, 75005 Paris, France
| |
Collapse
|
112
|
Hoang Viet M, Truong PM, Derreumaux P, Li MS, Roland C, Sagui C, Nguyen PH. Picosecond melting of peptide nanotubes using an infrared laser: a nonequilibrium simulation study. Phys Chem Chem Phys 2015; 17:27275-80. [DOI: 10.1039/c5cp04401d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Resonance between carboxylate bond vibrations and laser frequency results in melting of nanotube.
Collapse
Affiliation(s)
- Man Hoang Viet
- Department of Physics
- North Carolina State University
- Raleigh
- USA
| | - Phan Minh Truong
- Institute for Computational Science and Technology
- Quang Trung Software City
- Tan Chanh Hiep Ward
- Ho Chi Minh City
- Vietnam
| | - Philippe Derreumaux
- Laboratoire de Biochimie Theorique
- UPR 9080 CNRS
- IBPC
- Universite Denis Diderot
- Paris
| | - Mai Suan Li
- Institute for Computational Science and Technology
- Quang Trung Software City
- Tan Chanh Hiep Ward
- Ho Chi Minh City
- Vietnam
| | | | - Celeste Sagui
- Department of Physics
- North Carolina State University
- Raleigh
- USA
| | | |
Collapse
|
113
|
Tuan NT, Nguyen PH, Hajeebhoy N, Frongillo EA. Gaps between breastfeeding awareness and practices in Vietnamese mothers result from inadequate support in health facilities and social norms. J Nutr 2014; 144:1811-7. [PMID: 25332480 DOI: 10.3945/jn.114.198226] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Although gaps between breastfeeding awareness and practices have been described, determinants of the gaps have not been well investigated. OBJECTIVE The aim of this study was to examine determinants of the gap between breastfeeding awareness and practices in Vietnam. METHODS We interviewed 10,834 mothers with children aged 0-23 mo in 11 of 63 Vietnam provinces about breastfeeding practices, awareness, barriers, and support. A gap between awareness and practice was defined when a mother was aware of the benefit but did not perform the corresponding practice. Logistic regression models were used to examine determinants associated with the gaps. RESULTS The percentages of mothers with an awareness-practice gap for early initiation of breastfeeding, exclusive breastfeeding (EBF), continued breastfeeding at 1 y, and continued breastfeeding at 2 y were 34%, 66%, 19%, and 49%, respectively. Mothers had a lower awareness-practice gap in early initiation of breastfeeding if they received breastfeeding support from a health worker during pregnancy (OR: 0.79; 95% CI: 0.69, 0.92) or at birth (OR: 0.73; 95% CI: 0.60, 0.88). This gap was more likely to occur among those with a natural birth in the hospital (OR: 1.92; 95% CI: 1.50, 2.45), cesarean delivery (OR: 28.95; 95% CI: 20.1, 44.7), and breastfeeding difficulties (OR: 1.52; 95% CI: 1.21, 1.90). For EBF, the gap was lower among mothers with a higher social norm (OR: 0.20; 95% CI: 0.15, 0.27) or when they received breastfeeding support at birth by a health worker (OR: 0.82; 95% CI: 0.70, 0.95). In addition, intention of feeding infant formula at birth and having breastfeeding difficulties were associated with an increased gap in EBF [ORs (95% CIs): 1.28 (1.08, 1.51) and 1.29 (1.06, 1.57), respectively]. For continued breastfeeding at 1 y, social norms were associated with a lower gap (OR: 0.61; 95% CI: 0.41, 0.91), whereas breastfeeding difficulties were associated with an increased gap (OR: 1.70; 95% CI: 1.12, 2.57). CONCLUSION Reducing breastfeeding awareness-practice gaps requires strengthening breastfeeding support in health facilities and the sociocultural environment to make desired practices normative.
Collapse
Affiliation(s)
- Nguyen T Tuan
- Alive & Thrive Project, Family Health International 360, Hanoi, Vietnam;
| | - Phuong H Nguyen
- International Food Policy Research Institute, Hanoi, Vietnam; and
| | - Nemat Hajeebhoy
- Alive & Thrive Project, Family Health International 360, Hanoi, Vietnam
| | - Edward A Frongillo
- Arnold School of Public Health, University of South Carolina, Columbia, SC
| |
Collapse
|
114
|
Nguyen PH, Menon P, Keithly SC, Kim SS, Hajeebhoy N, Tran LM, Ruel MT, Rawat R. Program impact pathway analysis of a social franchise model shows potential to improve infant and young child feeding practices in Vietnam. J Nutr 2014; 144:1627-36. [PMID: 25143372 DOI: 10.3945/jn.114.194464] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
By mapping the mechanisms through which interventions are expected to achieve impact, program impact pathway (PIP) analysis lays out the theoretical causal links between program activities, outcomes, and impacts. This study examines the pathways through which the Alive & Thrive (A&T) social franchise model is intended to improve infant and young child feeding (IYCF) practices in Vietnam. Mixed methods were used, including qualitative interviews with franchise management board members (n = 12), surveys with health providers (n = 120), counseling observations (n = 160), and household surveys (n = 2045). Six PIP components were assessed: 1) franchise management, 2) training and IYCF knowledge of health providers, 3) service delivery, 4) program exposure and utilization, 5) maternal behavioral determinants (knowledge, beliefs, and intentions) toward optimal IYCF practices, and 6) IYCF practices. Data were collected from A&T-intensive areas (A&T-I; mass media + social franchise) and A&T-nonintensive areas (A&T-NI; mass media only) by using a cluster-randomized controlled trial design. Data from 2013 were compared with baseline where similar measures were available. Results indicate that mechanisms are in place for effective management of the franchise system, despite challenges to routine monitoring. A&T training was associated with increased capacity of providers, resulting in higher-quality IYCF counseling (greater technical knowledge and communication skills during counseling) in A&T-I areas. Franchise utilization increased from 10% in 2012 to 45% in 2013 but fell below the expected frequency of 9-15 contacts per mother-child dyad. Improvements in breastfeeding knowledge, beliefs, intentions, and practices were greater among mothers in A&T-I areas than among those in A&T-NI areas. In conclusion, there are many positive changes along the impact pathway of the franchise services, but challenges in utilization and demand creation should be addressed to achieve the full intended impact.
Collapse
Affiliation(s)
- Phuong H Nguyen
- International Food Policy Research Institute (IFPRI), Hanoi, Vietnam
| | | | | | | | | | | | | | | |
Collapse
|
115
|
Nishikawa N, Nguyen PH, Derreumaux P, Okamoto Y. Replica-exchange molecular dynamics simulation for understanding the initial process of amyloid peptide aggregation. Molecular Simulation 2014. [DOI: 10.1080/08927022.2014.938445] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
116
|
Viet MH, Nguyen PH, Derreumaux P, Li MS. Effect of the English familial disease mutation (H6R) on the monomers and dimers of Aβ40 and Aβ42. ACS Chem Neurosci 2014; 5:646-57. [PMID: 24949887 DOI: 10.1021/cn500007j] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The self-assembly of the amyloid beta (Aβ) peptides into senile plaques is the hallmark of Alzheimer's disease. Recent experiments have shown that the English familial disease mutation (H6R) speeds up the fibril formation process of alloforms Aβ40 and Aβ42 peptides altering their toxicity to cells. We used all-atom molecular dynamics simulations at microsecond time scales with the OPLS-AA force field and TIP4P explicit water model to study the structural dynamics of the monomer and dimer of H6R sequences of both peptides. The reason behind the self-assembly acceleration is common that upon mutation the net charge is reduced leading to the weaker repulsive interaction between chains that facilitates the peptide association. In addition, our estimation of the solvation free energy shows that the mutation enhances the hydrophobicity of both peptides speeding up their aggregation. However, we can show that the acceleration mechanisms are different for different peptides: the rate of fibril formation of Aβ42 increases due to increased β-structure at the C-terminal in both monomer and dimer and enhanced stability of salt bridge Asp23-Lys28 in monomer, while the enhancement of turn at residues 25-29 and reduction of coil in regions 10-13, 26-19, and 30-34 would play the key role for Aβ40. Overall, our study provides a detailed atomistic picture of the H6R-mediated conformational changes that are consistent with the experimental findings and highlights the important role of the N-terminal in Aβ peptide aggregation.
Collapse
Affiliation(s)
- Man Hoang Viet
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Phuong H. Nguyen
- Laboratoire
de Biochimie Theorique, UPR 9080 CNRS, IBPC, Universite Paris 7, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Derreumaux
- Laboratoire
de Biochimie Theorique, UPR 9080 CNRS, IBPC, Universite Denis Diderot, Paris Sorbonne Cité 13 rue Pierre et Marie Curie, 75005 Paris, France
- Institut Universitaire de France, Bvd Saint Michel, 75005 Paris, France
| | - Mai Suan Li
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
- Institute for Computational Science and Technology, Quang Trung Software City, Tan Chanh Hiep Ward,
District 12, Ho Chi Minh City, Vietnam
| |
Collapse
|
117
|
Hajeebhoy N, Nguyen PH, Mannava P, Nguyen TT, Mai LT. Suboptimal breastfeeding practices are associated with infant illness in Vietnam. Int Breastfeed J 2014; 9:12. [PMID: 25097662 PMCID: PMC4121620 DOI: 10.1186/1746-4358-9-12] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 07/24/2014] [Indexed: 11/24/2022] Open
Abstract
Background Despite evidence supporting the importance of breastfeeding to child health, breastfeeding practices remain suboptimal in Vietnam. There is currently little evidence on the importance of breastfeeding in the prevention of morbidity during infancy in Vietnam. In order to provide country specific data for policy makers to support breastfeeding friendly policies and programs, analysis was undertaken on a cross-sectional dataset to investigate the association between breastfeeding practices and prevalence of diarrhea and acute respiratory infection (ARI) among infants aged 0–5 months. Methods Data on socio-demographic characteristics, infant feeding practices and prevalence of diarrhea and ARI were obtained from 6,068 mother-child dyads in 11 provinces of Vietnam in 2011. Multivariate logistic regression was used to examine the associations between breastfeeding practices and child illnesses. Results On average, the prevalence of diarrhea and ARI among infants 0–5 months was 5.3% and 24.5%, respectively. Though half of all infants were breastfed within one hour of birth, 73.3% were given prelacteal foods in the first three days after birth. Only 20.2% of children 0–5 months old were exclusively breastfed, while 32.4% were predominantly breastfed and 47.4% partially breastfed. After adjusting for confounders, early initiation of breastfeeding was associated with lower prevalence of diarrhea [adjusted odds ratio (AOR) = 0.74 (95% CI 0.58, 0.93)], while prelacteal feeding was associated with higher prevalence [AOR = 1.53 (95% CI 1.15, 2.03)]. Compared to infants who were exclusively breastfed, infants who were predominantly [AOR = 1.52 (95% CI 1.05, 2.21)] or partially breastfed [AOR = 1.55 (95% CI 1.07, 2.24)] were more likely to have diarrhea. Prelacteal feeding [AOR = 1.16 (95% CI 1.01, 1.33)] and partial breastfeeding [AOR relative to exclusive breastfeeding = 1.24 (95% CI 1.03, 1.48)] were associated with higher prevalence of ARI. While the protective effects of exclusive breastfeeding against diarrhea declined with child age, this effect for ARI appears to have remained constant. Conclusions Early initiation and exclusive breastfeeding protects against diarrhea and ARI. Results confirm that interventions to improve early and exclusive breastfeeding would contribute to improving child health and nutrition in Vietnam.
Collapse
Affiliation(s)
| | - Phuong H Nguyen
- International Food Policy Research Institute (IFPRI), Hanoi, Vietnam
| | - Priya Mannava
- Independent Public Health Consultant, Hanoi, Vietnam
| | - Tuan T Nguyen
- Family Health International (FHI 360), Hanoi, Vietnam
| | - Lan Tran Mai
- International Food Policy Research Institute (IFPRI), Hanoi, Vietnam
| |
Collapse
|
118
|
Truong PM, Viet MH, Nguyen PH, Hu CK, Li MS. Effect of Taiwan Mutation (D7H) on Structures of Amyloid-β Peptides: Replica Exchange Molecular Dynamics Study. J Phys Chem B 2014; 118:8972-81. [DOI: 10.1021/jp503652s] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Phan Minh Truong
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh
Hiep Ward, District 12, Ho Chi Minh City, Vietnam
| | - Man Hoang Viet
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Phuong H. Nguyen
- Laboratoire
de Biochimie Theorique, UPR 9080 CNRS, IBPC, Universite Paris 7, 13
rue Pierre et Marie Curie, 75005, Paris, France
| | - Chin-Kun Hu
- Institute
of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Mai Suan Li
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| |
Collapse
|
119
|
Tarus B, Nguyen PH, Berthoumieu O, Faller P, Doig AJ, Derreumaux P. Molecular structure of the NQTrp inhibitor with the Alzheimer Aβ1-28 monomer. Eur J Med Chem 2014; 91:43-50. [PMID: 25011560 DOI: 10.1016/j.ejmech.2014.07.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/19/2014] [Accepted: 07/01/2014] [Indexed: 01/28/2023]
Abstract
The self-assembly of the amyloid-β (Aβ) peptide of various amino acid lengths into senile plaques is one hallmark of Alzheimer's disease pathology. In the past decade, many small molecules, including NQTrp, have been identified to reduce aggregation and toxicity. However, due to the heterogeneity of the conformational ensemble of Aβ with drugs, we lack detailed structures of the transient complexes. Following our previous simulation of the monomer of Aβ1-28, here we characterize the equilibrium ensemble of the Aβ1-28 monomer with NQTrp by means of extensive atomistic replica exchange molecular dynamics simulations using a force field known to fold diverse proteins correctly. While the secondary structure content and the intrinsic disorder of the whole peptides are very similar and the lifetimes of the salt-bridges remain constant, the population of β-hairpin is reduced by a factor of 1.5 and the population of α-helix in the region 17-24 is increased by a factor of two upon NQTrp binding. These two factors, which impact the free energy barrier for nucleation, provide a first explanation for the reported reduced Aβ1-40/1-42 aggregation kinetics in the presence of NQTrp. Backbone and side-chain interactions of Aβ with NQTrp may also inhibit Aβ-Aβ contacts. The fraction of free Aβ1-28 monomer is, however, on the order of 20-25% at 17.5 mM, and this shows that the affinity of NQTrp is low and hence its inhibitory activity is not very strong. This inhibitor can be improved to reduce the formation of dimer, a critical step in aggregation and toxicity.
Collapse
Affiliation(s)
- Bogdan Tarus
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Phuong H Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Olivia Berthoumieu
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 Route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France; Université de Toulouse, UPS, INPT, F-31077 Toulouse Cedex 4, France
| | - Peter Faller
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 Route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France; Université de Toulouse, UPS, INPT, F-31077 Toulouse Cedex 4, France
| | - Andrew J Doig
- Manchester Institute of Biotechnology, Faculty of Life Sciences, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France; Institut Universitaire de France, IUF, 103 Boulevard Saint-Michel, 75005 Paris, France.
| |
Collapse
|
120
|
Nguyen PH, Saha KK, Ali D, Menon P, Manohar S, Mai LT, Rawat R, Ruel MT. Maternal mental health is associated with child undernutrition and illness in Bangladesh, Vietnam and Ethiopia. Public Health Nutr 2014; 17:1318-27. [PMID: 23642497 PMCID: PMC10282455 DOI: 10.1017/s1368980013001043] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 03/07/2013] [Accepted: 03/12/2013] [Indexed: 11/05/2022]
Abstract
OBJECTIVE We assessed associations of maternal common mental disorders (CMD) with undernutrition and two common illnesses in children aged 0-5 years. DESIGN Cross-sectional survey. Maternal CMD was measured using the WHO Self-Reporting Questionnaire-20. Child undernutrition was defined as stunting, underweight or wasting. Child illnesses included diarrhoea and acute respiratory infections (ARI). Multivariate logistic regression was used to test these associations adjusting for confounders at child, maternal and household levels. SETTING Bangladesh, Vietnam and Ethiopia. SUBJECTS Mothers with children aged 0-5 years from 4400 households in Bangladesh, 4029 households in Vietnam and 3000 households in Ethiopia. RESULTS The prevalence of maternal CMD was high, ranging from 31 % in Vietnam to 49 % in Bangladesh. Child undernutrition was more prevalent in Bangladesh and Ethiopia than in Vietnam. Symptoms of ARI and diarrhoea were also prevalent. In multivariate analysis, maternal CMD was associated with child stunting in Bangladesh (OR = 1·21; 95 % CI 1·03, 1·41) and with child underweight in Vietnam (OR = 1·27; 95 % CI 1·01, 1·61); no association was found with wasting. Maternal CMD was strongly associated with diarrhoea and ARI in all three countries. CONCLUSIONS Maternal CMD, which affected nearly half of women in Bangladesh and one-third in Vietnam, was an important determinant of child stunting and underweight, respectively. No such association was found in Ethiopia, although CMD affected 39 % of women. Maternal CMD was strongly associated with childhood illnesses in all three countries. Interventions to support maternal mental health are important for women's own well-being and could make important contributions to improving child health and nutrition.
Collapse
Affiliation(s)
- Phuong H Nguyen
- International Food Policy Research Institute (IFPRI), Alive & Thrive, Room 203–204, E4B, Trung Tu Diplomatic Compound, No. 6, Dang Van Ngu, Hanoi, Vietnam
| | | | | | | | - Swetha Manohar
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Lan Tran Mai
- International Food Policy Research Institute (IFPRI), Alive & Thrive, Room 203–204, E4B, Trung Tu Diplomatic Compound, No. 6, Dang Van Ngu, Hanoi, Vietnam
| | | | | |
Collapse
|
121
|
Nguyen PH, Li MS, Derreumaux P. Amyloid oligomer structure characterization from simulations: A general method. J Chem Phys 2014; 140:094105. [DOI: 10.1063/1.4866902] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
122
|
Nguyen PH, Nguyen H, Gonzalez-Casanova I, Copeland E, Strizich G, Lowe A, Pham H, Truong TV, Nguyen S, Martorell R, Ramakrishnan U. Micronutrient intakes among women of reproductive age in Vietnam. PLoS One 2014; 9:e89504. [PMID: 24586831 PMCID: PMC3931833 DOI: 10.1371/journal.pone.0089504] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 01/21/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Micronutrient deficiencies are a public health concern worldwide negatively affecting maternal and child health outcomes. The primary underlying causes of micronutrient deficiencies are insufficient intake and poor bioavailability of micronutrients. However, reliable data on micronutrient intakes are sparse. The objectives of this study were to identify the key local food sources providing the majority of micronutrients and assess the adequacy and determinants of micronutrient intakes. METHODS The study used data from a survey of 4,983 rural women of reproductive age (WRA) participating in a preconception micronutrient supplementation trial in Vietnam. Micronutrient intakes were assessed using a validated 107-item semi-quantitative food-frequency questionnaire. Multivariate linear and logistic regression analyses were used to examine the association between socioeconomic status and micronutrient intakes. RESULTS Starchy staples were the main source of iron and zinc (37% and 54%, respectively) with only a small proportion from meat (10% and 18%, respectively). The primary source of folate and vitamin A were vegetables; vitamin B12 came from meat and eggs. The proportion of the population with intakes below the estimated average requirement was 25% for iron, 16% for zinc, 54% for folate, 64% for vitamin B12 and 27% for vitamin A. Socioeconomic status was the main determinant of micronutrient intakes. WRA in the highest quintile consumed 26% more iron, 19% more zinc, 36% more folate, 82% more vitamin B12 and 47% more vitamin A compared to those in the lowest quintile. Women in the upper quintiles of SES were more likely to obtain nutrients from more nutritious and higher bioavailable foods than those in the lowest quintile. CONCLUSIONS Underprivileged women were at increased risk for insufficient micronutrient intakes due to poor diet quality. Targeted efforts to promote the consumption of local nutrient rich foods along with educational programs and social development are needed.
Collapse
Affiliation(s)
- Phuong H. Nguyen
- Thai Nguyen University of Pharmacy and Medicine, Thai Nguyen, Vietnam
- International Food Policy Research Institute, Hanoi, Vietnam
- * E-mail:
| | - Hieu Nguyen
- Thai Nguyen University of Pharmacy and Medicine, Thai Nguyen, Vietnam
| | - Ines Gonzalez-Casanova
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Erika Copeland
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Garrett Strizich
- Mailman School of Public Health, Columbia University, New York, New York, United States of America
| | - Alyssa Lowe
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Hoa Pham
- Thai Nguyen University of Pharmacy and Medicine, Thai Nguyen, Vietnam
| | - Truong V. Truong
- Thai Nguyen University of Pharmacy and Medicine, Thai Nguyen, Vietnam
| | - Son Nguyen
- Thai Nguyen University of Pharmacy and Medicine, Thai Nguyen, Vietnam
| | - Reynaldo Martorell
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Usha Ramakrishnan
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| |
Collapse
|
123
|
Nguyen PH, Tarus B, Derreumaux P. Familial Alzheimer A2 V Mutation Reduces the Intrinsic Disorder and Completely Changes the Free Energy Landscape of the Aβ1–28 Monomer. J Phys Chem B 2014; 118:501-10. [DOI: 10.1021/jp4115404] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Phuong H. Nguyen
- Laboratoire
de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Bogdan Tarus
- Laboratoire
de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Derreumaux
- Laboratoire
de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
- Institut Universitaire de France, IUF, 103 Boulevard Saint-Michel, 75005 Paris, France
| |
Collapse
|
124
|
Rawat R, Nguyen PH, Ali D, Saha K, Alayon S, Kim SS, Ruel M, Menon P. Learning how programs achieve their impact: embedding theory-driven process evaluation and other program learning mechanisms in alive & thrive. Food Nutr Bull 2013; 34:S212-25. [PMID: 24261078 DOI: 10.1177/15648265130343s207] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Traditionally, impact evaluations have focused primarily on answering what impact programs or interventions have, with less attention to how or why impacts are achieved, or not achieved. The Alive & Thrive initiative, a 6-year program that aims to improve infant and young child feeding (IYCF) practices and reduce stunting in Bangladesh, Ethiopia, and Vietnam, has a specific objective to generate learning on how to achieve and replicate Alive & Thrive's impact. OBJECTIVE In Alive & Thrive, theory-driven process evaluation methods are the primary mechanism through which data are generated to address this objective. This paper focuses on the different methodological approaches that are being utilized, to answer the critical "how" questions, and to generate information on the many processes and pathways to program impact. METHODS We identify four key principles in our methodological approach that guides all process evaluation activities: (1) developing detailed program impact pathway (PIP) models, (2) linking data collection to PIPs utilizing mixed methods and multiple data sources, (3) linking evaluation activities with program implementation timelines, and (4) engaging with the program implementation and management teams. RESULTS Beginning with the launch of the program, we outline the steps that have been taken in the design and implementation of the process evaluations of Alive & Thrive, and provide examples of how these steps have been operationalized in different country contexts. CONCLUSIONS This theory-driven and country- and component-specific approach, centered on careful analysis of PIPs, is intended to generate information on implementation and utilization pathways of Alive & Thrive's interventions, thereby answering the questions of how impacts are achieved, or why not. This evaluation approach is not without challenges, and we highlight some of these key challenges.
Collapse
Affiliation(s)
- Rahul Rawat
- International Food Policy Research Institute, 2033 K Street, NW, Washington, DC 20006, USA.
| | | | | | | | | | | | | | | |
Collapse
|
125
|
Ali D, Saha KK, Nguyen PH, Diressie MT, Ruel MT, Menon P, Rawat R. Household food insecurity is associated with higher child undernutrition in Bangladesh, Ethiopia, and Vietnam, but the effect is not mediated by child dietary diversity. J Nutr 2013; 143:2015-21. [PMID: 24089419 DOI: 10.3945/jn.113.175182] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Household food insecurity (HFI) is a recognized underlying determinant of child undernutrition, but evidence of associations between HFI and child undernutrition is mixed. The purpose of this study was to investigate if HFI is associated with undernutrition in children aged 6-59.9 mo in Bangladesh (n = 2356), Ethiopia (n = 3422), and Vietnam (n = 3075) and if child dietary diversity (DD) mediated this effect. We used baseline survey data from the Alive & Thrive project. Logistic regression, adjusting for potential confounding factors, was used to determine the magnitude and significance of the association of HFI with stunting, underweight, and wasting. The mediating effect of child DD was tested by using a Sobel-Goodman mediation test. The prevalences of HFI were 66%, 40%, and 32% in Ethiopia, Vietnam, and Bangladesh, respectively. The prevalences of stunting, underweight, and wasting were higher in Bangladesh (47.1%, 43.7%, and 19.1%, respectively) and Ethiopia (50.7%, 27.5%, and 5.9%, respectively) than in Vietnam (20.7%, 15.8%, and 5%, respectively). In the adjusted models, the odds of being stunted or underweight were significantly higher for children in severely food-insecure households in Bangladesh (stunting OR: 1.36; 95% CI: 1.05, 1.76; underweight OR: 1.28; 95% CI: 0.99, 1.65) and Ethiopia (stunting OR: 1.48; 95% CI: 1.09, 2.00; underweight OR: 1.68; 95% CI: 1.22, 2.30) and in moderately food-insecure households in Vietnam (stunting OR: 1.39; 95% CI: 1.16, 1.65; underweight OR: 1.69; 95% CI: 1.28, 2.23). HFI was significantly associated with wasting in Bangladesh where close to 1 in 5 children demonstrated wasting. Child DD did not mediate the relation between HFI and undernutrition in any of the countries. Further research is recommended to investigate potential mediators in this pathway.
Collapse
Affiliation(s)
- Disha Ali
- International Food Policy Research Institute (IFPRI), Addis Ababa, Ethiopia
| | | | | | | | | | | | | |
Collapse
|
126
|
Viet MH, Nguyen PH, Ngo ST, Li MS, Derreumaux P. Effect of the Tottori familial disease mutation (D7N) on the monomers and dimers of Aβ40 and Aβ42. ACS Chem Neurosci 2013; 4:1446-57. [PMID: 24041307 DOI: 10.1021/cn400110d] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Recent experiments have shown that the mutation Tottori (D7N) alters the toxicity, assembly and rate of fibril formation of the wild type (WT) amyloid beta (Aβ) Aβ40 and Aβ42 peptides. We used all-atom molecular dynamics simulations in explicit solvent of the monomer and dimer of both alloforms with their WT and D7N sequences. The monomer simulations starting from a random coil and totaling 3 μs show that the D7N mutation changes the fold and the network of salt bridges in both alloforms. The dimer simulations starting from the amyloid fibrillar states and totaling 4.4 μs also reveal noticeable changes in terms of secondary structure, salt bridge, and topology. Overall, this study provides physical insights into the enhanced rate of fibril formation upon D7N mutation and an atomic picture of the D7N-mediated conformational change on Aβ40 and Aβ42 peptides.
Collapse
Affiliation(s)
- Man Hoang Viet
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow
32/46, 02-668 Warsaw, Poland
| | - Phuong H. Nguyen
- Laboratoire de Biochimie Theorique, UPR 9080 CNRS, IBPC, Universite Paris 7, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Son Tung Ngo
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow
32/46, 02-668 Warsaw, Poland
- Institute for Computational Science and Technology, 6 Quarter, Linh Trung Ward, Thu Duc
District, Ho Chi Minh City, Vietnam
| | - Mai Suan Li
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow
32/46, 02-668 Warsaw, Poland
| | - Philippe Derreumaux
- Laboratoire de Biochimie Theorique, UPR
9080 CNRS, IBPC, Universite Denis Diderot, Paris Sorbonne Cité 13 rue Pierre et Marie Curie, 75005, Paris, France
- Institut Universitaire de France, Bvd
Saint Michel, 75005, Paris, France
| |
Collapse
|
127
|
Nguyen PH, Kim SS, Keithly SC, Hajeebhoy N, Tran LM, Ruel MT, Rawat R, Menon P. Incorporating elements of social franchising in government health services improves the quality of infant and young child feeding counselling services at commune health centres in Vietnam. Health Policy Plan 2013; 29:1008-20. [PMID: 24234074 DOI: 10.1093/heapol/czt083] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Although social franchising has been shown to enhance the quality of reproductive health services in developing countries, its effect on nutrition services remains unexamined. This study assessed the effects of incorporating elements of social franchising on shaping the quality of infant and young child feeding (IYCF) counselling facilities and services in Vietnam. METHODS Process-related data collected 12 months after the launch of the first franchises were used to compare randomly assigned Alive & Thrive-supported health facilities (AT-F, n = 20) with standard facilities (SF, n = 12) across three dimensions of service quality: 'structure', 'process' and 'outcome' that capture the quality of facilities, service delivery, and client perceptions and use, respectively. Data collection included facility assessments (n = 32), staff surveys (n = 96), counselling observations (n = 137), client exit interviews (n = 137) and in-depth interviews with mothers (n = 48). RESULTS Structure: AT-F were more likely to have an unshared, well-equipped room for nutrition counselling than SF (65.0% vs 10.0%). PROCESS Compared with SF providers, AT-F staff had better IYCF knowledge (mean score 9.9 vs 8.8, range 0-11 for breastfeeding; mean score 3.6 vs 3.2, range 0-4 for complementary feeding). AT-F providers also demonstrated significantly better interpersonal communication skills (score 9.6 vs 5.1, range 0-13) and offered more comprehensive counselling sessions. OUTCOME Overall utilization of franchises was low (10%). A higher proportion of pregnant women utilized franchise services (48.9%), compared with mothers with children 6-23.9 months (1.4%). There was no quantitative difference in client satisfaction with counselling services between AT-F and SF, but franchise users praised the AT-F for problem solving related to child feeding. CONCLUSIONS Incorporating elements of social franchising significantly enhances the quality of IYCF counselling services within government primary healthcare facilities, particularly their structural and process attributes. Provided that service utilization is improved through demand generation, this model has the potential to impact IYCF practices and child nutrition.
Collapse
Affiliation(s)
- Phuong H Nguyen
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| | - Sunny S Kim
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| | - Sarah C Keithly
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| | - Nemat Hajeebhoy
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| | - Lan M Tran
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| | - Marie T Ruel
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| | - Rahul Rawat
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| | - Purnima Menon
- International Food Policy Research Institute, Hanoi, Vietnam, International Food Policy Research Institute, Washington, DC 20006, USA, Institute of Social and Medical Studies, Hanoi, Vietnam, FHI360, Hanoi, Vietnam and International Food Policy Research Institute, New Delhi 110012, India
| |
Collapse
|
128
|
Bessède E, Staedel C, Acuña Amador LA, Nguyen PH, Chambonnier L, Hatakeyama M, Belleannée G, Mégraud F, Varon C. Helicobacter pylori generates cells with cancer stem cell properties via epithelial-mesenchymal transition-like changes. Oncogene 2013; 33:4123-31. [PMID: 24096479 DOI: 10.1038/onc.2013.380] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 07/22/2013] [Accepted: 07/30/2013] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori infection is the major risk factor for gastric adenocarcinoma. The link with gastric adenocarcinoma is partly due to the H. pylori CagA oncoprotein. CagA is responsible for a particular cell phenotype in vitro, the 'hummingbird' phenotype, that corresponds to an elongation of the cells, mimicking an epithelial-mesenchymal transition (EMT). EMT participates in the carcinogenesis process, and is involved in the generation of cancer stem cells (CSCs). However, its involvement in gastric carcinogenesis has yet not been studied. Therefore, the aim of this study was to determine the role of H. pylori in EMT and in the emergence of gastric CSCs. For this purpose, gastric epithelial cells were cocultured with a cagA-positive H. pylori strain or its isogenic-deleted mutants or were transfected with CagA expression vectors. Study of the expression of epithelial and mesenchymal markers showed that H. pylori, via CagA, is responsible for an EMT phenotype associated with an increase in mesenchymal markers as well as CD44 expression, a known gastric CSC marker. Moreover, infection led to an increased ability to migrate, to invade and to form tumorspheres. Cell sorting experiments showed that only the CD44(high) cells induced by H. pylori infection displayed the mesenchymal phenotype and CSC properties in vitro, and had higher tumorigenic properties than CD44(low) cells in xenografted mice. Immunohistochemistry analyses on human and mouse gastric mucosa tissue samples confirmed a high expression of CD44 and mesenchymal markers in H. pylori-infected cases, and in gastric dysplasia and carcinoma. All of these data suggest that H. pylori, via CagA, unveils CSC-like properties by induction of EMT-like changes in gastric epithelial cells.
Collapse
Affiliation(s)
- E Bessède
- 1] Université de Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France
| | - C Staedel
- 1] 'RNA: Natural and Artificial Regulation' (ARNA) Laboratory, Université de Bordeaux, Bordeaux, France [2] INSERM, U869, Bordeaux, France
| | - L A Acuña Amador
- 1] Université de Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France
| | - P H Nguyen
- 1] Université de Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France
| | - L Chambonnier
- 1] Université de Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France
| | - M Hatakeyama
- Division of Microbiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - G Belleannée
- Pathology Department, Haut Leveque Hospital, University Hospital Center, Bordeaux, France
| | - F Mégraud
- 1] Université de Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France
| | - C Varon
- 1] Université de Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France
| |
Collapse
|
129
|
Nguyen PH, Keithly SC, Nguyen NT, Nguyen TT, Tran LM, Hajeebhoy N. Prelacteal feeding practices in Vietnam: challenges and associated factors. BMC Public Health 2013; 13:932. [PMID: 24099034 PMCID: PMC4126174 DOI: 10.1186/1471-2458-13-932] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Accepted: 10/04/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite the importance of early initiation of and exclusive breastfeeding, prelacteal feeds continue to pose a barrier to optimal breastfeeding practices in several countries, including Vietnam. This study examined the factors associated with prelacteal feeding among Vietnamese mothers. METHODS Data from 6068 mother-child (<6 m) dyads were obtained from a cross-sectional survey conducted in 11 provinces in Vietnam in 2011. Multivariate logistic regression analyses were used to examine factors associated with prelacteal feeding. RESULTS During the first three days after birth, 73.3% of the newborns were fed prelacteals, 53.5% were fed infants formula, and 44.1% were fed water. The odds of feeding prelacteals declined with increased breastfeeding knowledge, beliefs about social norms in favor of exclusive breastfeeding, and confidence in one's own breastfeeding behaviors. Women who harbored misconceptions about breastfeeding had twice the odds of feeding any prelacteals (OR: 2.09, 95% CI: 1.74-2.50). Health care factors increasing the odds of prelacteal feeding included delivery by caesarean section (OR: 2.94, 95% CI: 2.39-3.61) or episiotomy (OR: 1.36, 95% CI: 1.17-1.58) and experiencing breastfeeding problems (OR: 1.31, 95% CI: 1.04-1.66). Health staff support during pregnancy and after birth reduced the odds of feeding formula. However, family support after delivery increased the odds of feeding water to newborns. CONCLUSIONS The multiple factors contributing to the high prevalence of prelacteal feeding behaviors stress the need for early and appropriate breastfeeding interventions in Vietnam, particularly during routine healthcare contacts. Improving breastfeeding practices during the first days of an infant's life could be achieved by improving knowledge and confidence of mothers through appropriate perinatal counseling and support. Ensuring that health facilities integrate these practices into routine ante-natal care and post-delivery management is critical.
Collapse
Affiliation(s)
- Phuong H Nguyen
- International Food Policy Research Institute, Hanoi, Vietnam.
| | | | | | | | | | | |
Collapse
|
130
|
Nguyen PH, Strizich G, Lowe A, Nguyen H, Pham H, Truong TV, Nguyen S, Martorell R, Ramakrishnan U. Food consumption patterns and associated factors among Vietnamese women of reproductive age. Nutr J 2013; 12:126. [PMID: 24028650 PMCID: PMC3847174 DOI: 10.1186/1475-2891-12-126] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 06/10/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Adequate nutrient intakes among women of reproductive age (WRA) are important determinants of maternal, neonatal and child health outcomes. However, data on dietary intake for WRA in Vietnam are lacking. This paper aimed to examine the adequacy and determinants of energy and macronutrient intakes among WRA enrolled in a study of preconceptual micronutrient supplementation (PRECONCEPT) being conducted in 20 rural communes in Thai Nguyen province, Vietnam. METHODS Dietary intakes were determined for 4983 WRA who participated in the baseline survey using a previously validated 107-item (semi-quantitative) food-frequency questionnaire that was administered by trained field workers. Multivariate linear and logistic regression analyses were used to examine factors associated with energy and macronutrient intakes. RESULTS A disproportionate number of energy came from starches, primarily rice. Carbohydrate, fat and protein constituted 65.6%, 19.5% and 14.8% of total energy, respectively. Fat intake was below recommended levels in 56.5% of respondents, but carbohydrate intakes were above recommended level in 54.6%. Only 0.1% and 5.2% of WRA achieved adequate intake of n-3 and n-6 long-chain polyunsaturated fatty acids, respectively. Multivariate linear regression revealed that low education, low socioeconomic status, and food insecurity were significant predictors of reduced total energy intake, reduced energy from protein and fat, and greater energy from carbohydrates. Logistic regression confirmed that inadequate macronutrient intake was more common among the poor, food insecure, and less educated. CONCLUSIONS Imbalanced dietary intakes among underprivileged women reflect lack of dietary diversity. Nutrition programs should be linked with social development, poverty reduction, education programs and behavior change counseling in order to improve the nutritional status of WRA in Vietnam.
Collapse
Affiliation(s)
- Phuong H Nguyen
- Thai Nguyen University of Pharmacy and Medicine, Thai Nguyen, Vietnam.
| | | | | | | | | | | | | | | | | |
Collapse
|
131
|
Sterpone F, Nguyen PH, Kalimeri M, Derreumaux P. Importance of the ion-pair interactions in the OPEP coarse-grained force field: parametrization and validation. J Chem Theory Comput 2013; 9:4574-4584. [PMID: 25419192 DOI: 10.1021/ct4003493] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have derived new effective interactions that improve the description of ion-pairs in the OPEP coarse-grained force field without introducing explicit electrostatic terms. The iterative Boltzmann inversion method was used to extract these potentials from all atom simulations by targeting the radial distribution function of the distance between the center of mass of the side-chains. The new potentials have been tested on several systems that differ in structural properties, thermodynamic stabilities and number of ion-pairs. Our modeling, by refining the packing of the charged amino-acids, impacts the stability of secondary structure motifs and the population of intermediate states during temperature folding/unfolding; it also improves the aggregation propensity of peptides. The new version of the OPEP force field has the potentiality to describe more realistically a large spectrum of situations where salt-bridges are key interactions.
Collapse
Affiliation(s)
- Fabio Sterpone
- Laboratoire de Biochimie Théorique, IBPC, CNRS, UPR9080, Univ. Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Phuong H Nguyen
- Laboratoire de Biochimie Théorique, IBPC, CNRS, UPR9080, Univ. Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Maria Kalimeri
- Laboratoire de Biochimie Théorique, IBPC, CNRS, UPR9080, Univ. Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, IBPC, CNRS, UPR9080, Univ. Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005, Paris, France ; Institut Universitaire de France, Bvd St Michel, 75005, Paris, France
| |
Collapse
|
132
|
Nguyen PH, Avula R, Ruel MT, Saha KK, Ali D, Tran LM, Frongillo EA, Menon P, Rawat R. Maternal and child dietary diversity are associated in Bangladesh, Vietnam, and Ethiopia. J Nutr 2013; 143:1176-83. [PMID: 23658424 DOI: 10.3945/jn.112.172247] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Dietary diversity (DD) reflects micronutrient adequacy of the diet and is associated with better child growth. Emerging evidence suggests that maternal and child DD are associated. This could have measurement and programmatic implications. Data on mother-child (6-24 mo) dyads in Bangladesh, Vietnam, and Ethiopia were used to examine agreement and association between maternal and child DD and identify determinants of maternal and child DD. The DD scores were derived from a 24-h recall of intake of foods from 7 groups. Multivariable regression was used to examine for the association, adjusting for covariates at child, maternal, and household levels. There was mother/child agreement for staple foods across the 3 countries but disagreement for flesh foods, dairy, fruits, and vegetables. A strong positive association was seen between maternal and child DD; a difference of one food group in mother's consumption was associated with a difference of 0.29, 033, and 0.24 groups in child's consumption in Bangladesh, Vietnam, and Ethiopia, respectively. The odds of achieving minimum DD (≥4 groups) were higher among children whose mother consumed 4 groups compared with ≤3 food groups [Bangladesh: OR = 2.73 (95% CI: 1.76, 4.25); Vietnam: OR = 2.30 (95% CI: 1.45, 3.43); Ethiopia: OR = 5.11 (95% CI: 2.36, 11.04)]. Maternal education was associated with both maternal and child DD; food security and socioeconomic status were associated only with maternal DD. Given the disagreements in mother/child intake for nutrient-rich foods, both maternal and child DD should be measured in surveys. Behavior change communications should focus on promoting both mother and child DD and encouraging mothers to feed young children all family foods, not just a subset.
Collapse
Affiliation(s)
- Phuong H Nguyen
- International Food Policy Research Institute (IFPRI), Hanoi, Vietnam.
| | | | | | | | | | | | | | | | | |
Collapse
|
133
|
Nguyen PH, Derreumaux P. Conformational ensemble and polymorphism of the all-atom Alzheimer's Aβ(37-42) amyloid peptide oligomers. J Phys Chem B 2013; 117:5831-40. [PMID: 23581814 DOI: 10.1021/jp401563n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although the Aβ(37-42) peptide has two opposite terminal charges, counterintuitively its current fibril amyloid structure reveals in register parallel β-strands, as formed by the full length Aβ peptide. In this study, we carried out a replica exchange molecular dynamics simulation of 16 all-atom Aβ(37-42) peptides in explicit water starting from randomized and dispersed chains. The extensive conformational sampling (48 replicas, 460 ns/replica) with a total simulation time of 23 μs allows us to obtain a full picture on the equilibrium conformational distribution of oligomers and β-sheet sizes and gain some insights into the oligomerization process at 300 K. At the peptide concentration of 12 mM, self-assembly is described by the condensation-polymerization mechanism with conversion from micelle-like to high β-sheet structures. At equilibrium, the oligomer distribution consists of large aggregates and free monomers, representing 70% and 25% of all species, respectively. Though the formation/dissociation of β-strand is high, the population of 4-5 fully parallel β-strands, consistent with the arrangement in the current fibril, is marginal and that of 4-5 fully antiparallel β-strands, consistent with amyloid polymorphism, is non-negligible. However, the system adopts essentially mixed parallel/antiparallel β-strands. This indicates that a system of 16 Aβ(37-42) chains in explicit solvent still does not form more stable species that will irreversibly grow to a fibril, independently of polymorphism. Our results also suggest that the Aβ(37-42) fibril may display packing polymorphism with antiparallel β-strands, in addition to the experimentally observed in register parallel β-strands.
Collapse
Affiliation(s)
- Phuong H Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080, CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | | |
Collapse
|
134
|
Nguyen PH, Strizich G, Lowe AL, Nguyen H, Pham H, Truong T, Nguyen S, Reinhart GA, Harding KB, Neufeld LM, Martorell R, Ramakrishnan U. Food consumption pattern and associated factors in Vietnam. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.844.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- P H Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
- International Food Policy Research Inst.HanoiVietnam
| | | | | | - H Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - H Pham
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - T Truong
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - S Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | | | | | | | | | | |
Collapse
|
135
|
Begum K, Dewey KG, Peerson J, Saha KK, Ali D, Nguyen PH, Rawat R, Menon P. Cesarean delivery and maternal knowledge are important predictors of early breastfeeding practices in Bangladesh, Ethiopia and Vietnam. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.844.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Kuntal K. Saha
- International Food Policy Research InstituteWashingtonDC
| | - Disha Ali
- International Food Policy Research InstituteWashingtonDC
| | | | - Rahul Rawat
- International Food Policy Research InstituteWashingtonDC
| | - Purnima Menon
- International Food Policy Research InstituteWashingtonDC
| |
Collapse
|
136
|
Nguyen PH, Katz B, Lowe AE, Nguyen H, Truong T, Pham H, Nguyen S, Reinhart GA, Harding KB, Neufeld LM, Martorell R, Ramakrishnan U. Anthropometric differences and body composition among ethnic minorities in northern Vietnam. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1055.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- P H Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
- International Food Policy Research Inst.HanoiVietnam
| | | | | | - H Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - T Truong
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - H Pham
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - S Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | | | | | | | | | | |
Collapse
|
137
|
Ramakrishnan U, Nguyen PH, Copeland E, Lowe AE, Strizich G, Nguyen H, Pham H, Truong T, Nguyen S, Reinhart GA, Harding KB, Neufeld LM, Martorell R. Vitamin and Micronutrient Intakes among Women of Reproductive Age in Vietnam. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.844.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - P H Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
- International Food Policy Research Inst.HanoiVietnam
| | | | | | | | - H Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - H Pham
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - T Truong
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | - S Nguyen
- Thai Nguyen Univ. of Pharmacy and MedicineThai NguyenVietnam
| | | | | | | | | |
Collapse
|
138
|
Nguyen PH, Avula R, Saha KK, Ali D, Tran LM, Frongillo EA, Rawat R, Ruel MT, Menon P. Do babies eat what mothers eat? The relationship between maternal and child dietary diversity in Bangladesh, Vietnam and Ethiopia. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.243.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Rasmi Avula
- International Food Policy Research InstituteWashingtonDC
| | - Kuntal K. Saha
- International Food Policy Research InstituteWashingtonDC
| | - Disha Ali
- International Food Policy Research InstituteWashingtonDC
| | - Lan M. Tran
- International Food Policy Research InstituteWashingtonDC
| | | | - Rahul Rawat
- International Food Policy Research InstituteWashingtonDC
| | - Marie T. Ruel
- International Food Policy Research InstituteWashingtonDC
| | - Purnima Menon
- International Food Policy Research InstituteWashingtonDC
| |
Collapse
|
139
|
Nguyen PH, Hoang LN, Frongillo EA, Hajeebhoy N, Menon P. Targeted technical assistance improves the quality of provincial nutrition plans in Vietnam between 2010 and 2012. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.620.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Lan N Hoang
- Health Promotion, Education, and BehaviorUniversity of South CarolinaColumbiaSC
| | - Edward A Frongillo
- Health Promotion, Education, and BehaviorUniversity of South CarolinaColumbiaSC
| | | | - Purnima Menon
- International Food Policy Research InstituteWashingtonDC
| |
Collapse
|
140
|
Nguyen PH, Menon P, Kim S, Hajeebhoy N, Tran LM, Ruel MT, Rawat R. A social franchising approach to strengthening infant and young child feeding (IYCF) counseling improves the quality of services at health facilities in Vietnam. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.617.13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Purnima Menon
- International Food Policy Research InstituteWashingtonDC
| | - Sunny Kim
- International Food Policy Research InstituteWashingtonDC
| | | | | | - Marie T. Ruel
- International Food Policy Research InstituteWashingtonDC
| | - Rahul Rawat
- International Food Policy Research InstituteWashingtonDC
| |
Collapse
|
141
|
Nguyen PH, Okamoto Y, Derreumaux P. Communication: Simulated tempering with fast on-the-fly weight determination. J Chem Phys 2013; 138:061102. [DOI: 10.1063/1.4792046] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
142
|
Abstract
Recently there has been increasing research interest in displaying graphs with curved edges to produce more readable visualizations. While there are several automatic techniques, little has been done to evaluate their effectiveness empirically. In this paper we present two experiments studying the impact of edge curvature on graph readability. The goal is to understand the advantages and disadvantages of using curved edges for common graph tasks compared to straight line segments, which are the conventional choice for showing edges in node-link diagrams. We included several edge variations: straight edges, edges with different curvature levels, and mixed straight and curved edges. During the experiments, participants were asked to complete network tasks including determination of connectivity, shortest path, node degree, and common neighbors. We also asked the participants to provide subjective ratings of the aesthetics of different edge types. The results show significant performance differences between the straight and curved edges and clear distinctions between variations of curved edges.
Collapse
|
143
|
Nguyen PH, Lowe AE, Martorell R, Nguyen H, Pham H, Nguyen S, Harding KB, Neufeld LM, Reinhart GA, Ramakrishnan U. Rationale, design, methodology and sample characteristics for the Vietnam pre-conceptual micronutrient supplementation trial (PRECONCEPT): a randomized controlled study. BMC Public Health 2012; 12:898. [PMID: 23092451 PMCID: PMC3533960 DOI: 10.1186/1471-2458-12-898] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 10/11/2012] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Low birth weight and maternal anemia remain intractable problems in many developing countries. The adequacy of the current strategy of providing iron-folic acid (IFA) supplements only during pregnancy has been questioned given many women enter pregnancy with poor iron stores, the substantial micronutrient demand by maternal and fetal tissues, and programmatic issues related to timing and coverage of prenatal care. Weekly IFA supplementation for women of reproductive age (WRA) improves iron status and reduces the burden of anemia in the short term, but few studies have evaluated subsequent pregnancy and birth outcomes.The Preconcept trial aims to determine whether pre-pregnancy weekly IFA or multiple micronutrient (MM) supplementation will improve birth outcomes and maternal and infant iron status compared to the current practice of prenatal IFA supplementation only. This paper provides an overview of study design, methodology and sample characteristics from baseline survey data and key lessons learned. METHODS/DESIGN We have recruited 5011 WRA in a double-blind stratified randomized controlled trial in rural Vietnam and randomly assigned them to receive weekly supplements containing either: 1) 2800 μg folic acid 2) 60 mg iron and 2800 μg folic acid or 3) MM. Women who become pregnant receive daily IFA, and are being followed through pregnancy, delivery, and up to three months post-partum. Study outcomes include birth outcomes and maternal and infant iron status. Data are being collected on household characteristics, maternal diet and mental health, anthropometry, infant feeding practices, morbidity and compliance. DISCUSSION The study is timely and responds to the WHO Global Expert Consultation which identified the need to evaluate the long term benefits of weekly IFA and MM supplementation in WRA. Findings will generate new information to help guide policy and programs designed to reduce the burden of anemia in women and children and improve maternal and child health outcomes in resource poor settings. TRIAL REGISTRATION NCT01665378.
Collapse
Affiliation(s)
- Phuong H Nguyen
- Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen, Vietnam
- Poverty, Health and Nutrition Division, International Food Policy Research Institute, Hanoi, Vietnam
| | - Alyssa E Lowe
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Reynaldo Martorell
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Hieu Nguyen
- Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen, Vietnam
| | - Hoa Pham
- Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen, Vietnam
| | - Son Nguyen
- Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen, Vietnam
| | | | | | - Gregory A Reinhart
- The Mathile Institute for the Advancement of Human Nutrition, Dayton, OH, USA
| | - Usha Ramakrishnan
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| |
Collapse
|
144
|
Abstract
In transient infrared (IR) experiments, a molecular system may be photoexcited in a nonstationary conformational state, whose time evolution is monitored via IR spectroscopy with high temporal and structural resolution. As a theoretical formulation of these experiments, this work derives explicit expressions for transient one- and two-dimensional IR spectra and discusses various levels of approximation and sampling strategies. Adopting a photoswitchable octapeptide in water as a representative example, nonequilibrium molecular dynamics simulations are performed and the photoinduced conformational dynamics and associated IR spectra are discussed in detail. Interestingly, it is found that the time scales of dynamics and spectra may differ from residue to residue by up to an order of magnitude. Considering merely the cumulative spectrum of all residues, the contributions of the individual residues largely compensate each other, which may explain the surprisingly small frequency shifts and short photoproduct rise times found in experiment. Even when a localized amide I mode is probed (e.g., via isotope labeling), the vibrational frequency shift is shown to depend in a complicated way on the conformation of the entire peptide as well as on the interaction with the solvent. In this context, various issues concerning the interpretation of transient IR spectra and conformational dynamics in terms of a few exponential time scales are discussed.
Collapse
Affiliation(s)
- Maja Kobus
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | | | | | | |
Collapse
|
145
|
Riccardi L, Nguyen PH, Stock G. Construction of the Free Energy Landscape of Peptide Aggregation from Molecular Dynamics Simulations. J Chem Theory Comput 2012; 8:1471-9. [PMID: 26596757 DOI: 10.1021/ct200911w] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To describe the structure and dynamics of oligomers during peptide aggregation, a method is proposed that considers both the intramolecular and intermolecular structures of the multimolecule system and correctly accounts for its degeneracy. The approach is based on the "by-parts" strategy, which partitions a complex molecular system into parts, determines the metastable conformational states of each part, and describes the overall conformational state of the system in terms of a product basis of the states of the parts. Starting from a molecular dynamics simulation of n molecules, the method consists of three steps: (i) characterization of the intramolecular structure, that is, of the conformational states of a single molecule in the presence of the other molecules (e.g., β-strand or random coil); (ii) characterization of the intermolecular structure through the identification of all occurring aggregate states of the peptides (dimers, trimers, etc.); and (iii) construction of the overall conformational states of the system in terms of a product basis of the n "single-molecule" states and the aggregate states. Considering the Alzheimer β-amyloid peptide fragment Aβ16-22 as a first application, about 700 overall conformational states of the trimer (Aβ16-22)3 were constructed from all-atom molecular dynamics simulation in explicit water. Based on these states, a transition network reflecting the free energy landscape of the aggregation process can be constructed that facilitates the identification of the aggregation pathways.
Collapse
Affiliation(s)
- Laura Riccardi
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University , 79104 Freiburg, Germany
| | - Phuong H Nguyen
- Laboratoire de Biochimie Theorique - UPR 9080, Institut de Biologie Physico-Chimique , 13, rue Pierre et Marie Curie, F-75005 Paris, France
| | - Gerhard Stock
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University , 79104 Freiburg, Germany
| |
Collapse
|
146
|
Chebaro Y, Jiang P, Zang T, Mu Y, Nguyen PH, Mousseau N, Derreumaux P. Structures of Aβ17-42 trimers in isolation and with five small-molecule drugs using a hierarchical computational procedure. J Phys Chem B 2012; 116:8412-22. [PMID: 22283547 DOI: 10.1021/jp2118778] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The amyloid-β protein (Aβ) oligomers are believed to be the main culprits in the cytoxicity of Alzheimer's disease (AD) and p3 peptides (Aβ17-42 fragments) are present in AD amyloid plaques. Many small-molecule or peptide-based inhibitors are known to slow down Aβ aggregation and reduce the toxicity in vitro, but their exact modes of action remain to be determined since there has been no atomic level of Aβ(p3)-drug oligomers. In this study, we have determined the structure of Aβ17-42 trimers both in aqueous solution and in the presence of five small-molecule inhibitors using a multiscale computational study. These inhibitors include 2002-H20, curcumin, EGCG, Nqtrp, and resveratrol. First, we used replica exchange molecular dynamics simulations coupled to the coarse-grained (CG) OPEP force field. These CG simulations reveal that the conformational ensemble of Aβ17-42 trimer can be described by 14 clusters with each peptide essentially adopting turn/random coil configurations, although the most populated cluster is characterized by one peptide with a β-hairpin at Phe19-Leu31. Second, these 14 dominant clusters and the less-frequent fibril-like state with parallel register of the peptides were subjected to atomistic Autodock simulations. Our analysis reveals that the drugs have multiple binding modes with different binding affinities for trimeric Aβ17-42 although they interact preferentially with the CHC region (residues 17-21). The compounds 2002-H20 and Nqtrp are found to be the worst and best binders, respectively, suggesting that the drugs may interfere at different stages of Aβ oligomerization. Finally, explicit solvent molecular dynamics of two predicted Nqtrp-Aβ17-42 conformations describe at atomic level some possible modes of action for Nqtrp.
Collapse
Affiliation(s)
- Yassmine Chebaro
- Laboratoire de Biochimie Théorique, UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | | | | | | | | | | | | |
Collapse
|
147
|
Nguyen PH, Derreumaux P. Configurational entropy: an improvement of the quasiharmonic approximation using configurational temperature. Phys Chem Chem Phys 2012; 14:877-86. [DOI: 10.1039/c1cp21779h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
148
|
Abstract
INTRODUCTION Composite mesh prostheses incorporate the properties of multiple materials for ventral hernia repair. This study evaluated a polypropylene/ePTFE composite mesh with a novel internal polydioxanone (PDO) absorbable ring. METHODS Composite mesh was placed intraperitoneally in 16 pigs through an open laparotomy and explanted at 2, 4, 8, and 12 weeks. Intraabdominal adhesions were measured laparoscopically. Host tissue in-growth was assessed histologically and tensiometrically. Degradation of the internal PDO ring component was also measured tensiometrically. Appropriate statistical tests were used, and P ≤.05 indicated significance. RESULTS No adhesions were formed in 50% of the grafts explanted at 8 weeks and 25% of grafts explanted at 12 weeks. There were significantly more vascular structures at 8 weeks, 73.5 ± 28, compared with 2 weeks, 6.75 ± 2 (P ≤.01). The T-peel force at the mesh-host tissue interface was not significantly different among time points. The absorbable PDO ring underwent complete degradation by 12 weeks. CONCLUSIONS This composite mesh was associated with minimal intraabdominal adhesions, progressive in-growth of host tissues, and complete degradation of a novel internal PDO ring that aided mesh positioning. This composite hernia mesh showed a favorable performance in a porcine model of open ventral hernia repair.
Collapse
Affiliation(s)
- Jim F Byrd
- Section of HepatoPancreaticoBiliary Surgery, Department of General Surgery, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, North Carolina 28203, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
149
|
Nguyen PH, Staudt H, Wachtveitl J, Stock G. Real Time Observation of Ultrafast Peptide Conformational Dynamics: Molecular Dynamics Simulation vs Infrared Experiment. J Phys Chem B 2011; 115:13084-92. [DOI: 10.1021/jp207945p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Phuong H. Nguyen
- Laboratoire de Biochimie Theorique - UPR 9080, Institut de Biologie Physico-Chimique, 13, rue Pierre et Marie Curie, F-75005 Paris, France
| | - Heike Staudt
- Institute of Physical and Theoretical Chemistry, Goethe University, 60438 Frankfurt, Germany
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry, Goethe University, 60438 Frankfurt, Germany
| | - Gerhard Stock
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| |
Collapse
|
150
|
Nguyen PH, Keller JE, Novitsky YW, Heniford BT, Kercher KW. Laparoscopic approach to adrenalectomy: review of perioperative outcomes in a single center. Am Surg 2011; 77:592-596. [PMID: 21679593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Laparoscopic expertise increases the volume of adrenalectomies at referral centers. We report our 10-year experience with laparoscopic adrenalectomy. All laparoscopic adrenalectomies at a single institution were prospectively recorded in a surgical outcomes database. Patient demographics, operative/perioperative outcomes, and adrenal pathology were reviewed retrospectively. From March 1999 through July 2009, 154 laparoscopic adrenalectomies were performed in 150 patients. Average patient age was 49.9 years (range 15-82); mean body mass index was 31.1 kg/m(2) (range 17-56). Pathologic diagnoses included hyperaldosteronism (n = 69), nonfunctional adenoma (n = 28), pheochromocytoma (n = 23), hypercortisolism (n = 14), malignancy (primary n = 3, metastasis n = 9), and cyst (n = 4). Seventy-three per cent (n = 110) occurred on the left, 23 per cent (n = 35) on the right, 2.6 per cent (n = 4) bilateral, and 0.6 per cent (n = 1) as extra-adrenal. The average tumor measured 3.6 cm (range 0.4-12). The average operative time was 156 minutes (range 62-409), the mean estimated blood loss was 60 mL (range 10-400), and mean American Society of Anesthesiologists score was 2.6 (range 1-4). Three operations (0.2%) were converted to open. Three patients (0.2%) experienced perioperative complications (respiratory failure, urinary tract infection, line sepsis, and readmission within 30 days). The average length of stay was 3.4 days (range 1-44) and mean follow-up was 96.9 days (5-2567). No wound-related complications or deaths occurred. Pathologic diagnosis was not associated with a particular side or development of a complication (P > 0.5). Patients with pheochromocytomas had the longest operative times, highest estimated blood loss, and highest American Society of Anesthesiologists scores (218.2 minutes, 128 mL, 3.0; P < 0.004). Laparoscopic adrenalectomy is safe and effective. Removal of pheochromocytomas is more challenging and may be more appropriate for referral to a specialized center for optimal outcomes.
Collapse
Affiliation(s)
- Phuong H Nguyen
- Division of Gastrointestinal and Minimally Invasive Surgery, Carolinas Medical Center, Charlotte, North Carolina 28204, USA
| | | | | | | | | |
Collapse
|