27 results on '"Duc HN"'
Search Results
2. Role of regulatory capacity in the animal and human health systems in driving response to zoonotic disease outbreaks in the the Mekong region
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McPake, B, Gilbert, K, Vong, S, Ros, B, Has, P, Anh, TK, Pham-Duc, P, Quoc, CH, Duc, HN, Siengsounthone, L, Luangphaxay, C, Annear, P, McKinley, J, McPake, B, Gilbert, K, Vong, S, Ros, B, Has, P, Anh, TK, Pham-Duc, P, Quoc, CH, Duc, HN, Siengsounthone, L, Luangphaxay, C, Annear, P, and McKinley, J
- Abstract
We conducted a policy situation analysis in three Mekong region countries, focused on how the animal and human health systems interact to control avian influenza (AI). The study used scoping literature reviews aimed at establishing existing knowledge concerning the regulatory context. We then conducted a series of key informant interviews with national and sub-national government officials and representatives of producers and poultry farmers to understand their realities in managing the complex interface of the two sectors to control AI. We found signs of formal progress in establishing the policy and legislative frameworks needed to enable cooperation of the two sectors but a series of constraints that impede their effective operation. These included the competitive relationships involved, especially with budgetary allocations and mandates that can conflict with each other. Many local actors also view development partners (e.g., bilateral and multilateral donors) as having a dominant role in establishing these collaborations, limiting the extent to which there is local ownership of the agenda. The animal and human health sectors are not equally resourced, with the animal health sector disadvantaged in terms of surveillance and laboratory systems, human resources and financial allocations. Contrasting strategies for achieving objectives have also characterised the two sectors in recent decades, seeing a major shift towards the use of incentive-based approaches in the human health sector but very little parallel development in the animal health sector, largely dependent on command and control approaches. Successful future collaborations between the two sectors are likely to depend on better resourcing in the animal health sector, increasing local ownership of the agenda, and ensuring that both sectors can use the full range of regulatory strategies available to achieve objectives.
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- 2022
3. Urban air pollution estimation using unscented Kalman filtered inverse modeling with scaled monitoring data
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Metia, S, Ha, QP, Duc, HN, and Scorgie, Y
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© 2019 The increasing rate of urbanization requires effective and reliable techniques for air quality monitoring and control. For this, the Air Pollution Model and Chemical Transport Model (TAPM-CTM) has been developed and used in Australia with emissions inventory data, synoptic data and terrain data used as its input parameters. Since large uncertainties exist in the emissions inventory (EI), further refinements and improvements are required for accurate air quality prediction. This study evaluates the performance of urban air quality forecasting, using TAPM-CTM, and improves accuracy of air pollution estimation by using a two-stage optimization technique to upgrade EI with validation from monitoring data. The first stage is based on statistical analysis for EI correction and the second stage is based on the unscented Kalman filter (UKF) to take into account the spatio-temporal distributions of air pollutant levels utilizing a Matérn covariance function. The predicted nitrogen monoxide (NO) and nitrogen dioxide (NO2) concentrations with a priori emissions are first compared with observations at monitoring stations in the New South Wales (NSW). Ozone (O3) is also considered since at the ground level it represents a major air pollutant affecting human health and the environment. In the second stage, with the improved EI, TAPM-CTM model errors are reduced further by using the UKF to calibrate EI. Results obtained show effectiveness of the proposed technique, which is promising for air quality inverse modeling, an important aspect of air pollution control in smart cities to achieve environmental sustainability.
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- 2020
4. Evaluation of Regional Air Quality Models over Sydney, Australia: Part 2, Comparison of PM2.5 and Ozone
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Guerette, E-A, Chang, LT-C, Cope, ME, Duc, HN, Emmerson, KM, Monk, K, Rayner, PJ, Scorgie, Y, Silver, JD, Simmons, J, Trieu, T, Utembe, SR, Zhang, Y, Paton-Walsh, C, Guerette, E-A, Chang, LT-C, Cope, ME, Duc, HN, Emmerson, KM, Monk, K, Rayner, PJ, Scorgie, Y, Silver, JD, Simmons, J, Trieu, T, Utembe, SR, Zhang, Y, and Paton-Walsh, C
- Abstract
Accurate air quality modelling is an essential tool, both for strategic assessment (regulation development for emission controls) and for short-term forecasting (enabling warnings to be issued to protect vulnerable members of society when the pollution levels are predicted to be high). Model intercomparison studies are a valuable support to this work, being useful for identifying any issues with air quality models, and benchmarking their performance against international standards, thereby increasing confidence in their predictions. This paper presents the results of a comparison study of six chemical transport models which have been used to simulate short-term hourly to 24 hourly concentrations of fine particulate matter less than and equal to 2.5 µm in diameter (PM2.5) and ozone (O3) for Sydney, Australia. Model performance was evaluated by comparison to air quality measurements made at 16 locations for O3 and 5 locations for PM2.5, during three time periods that coincided with major atmospheric composition measurement campaigns in the region. These major campaigns included daytime measurements of PM2.5 composition, and so model performance for particulate sulfate (SO42−), nitrate (NO3−), ammonium (NH4+) and elemental carbon (EC) was evaluated at one site per modelling period. Domain-wide performance of the models for hourly O3 was good, with models meeting benchmark criteria and reproducing the observed O3 production regime (based on the O3/NOx indicator) at 80% or more of the sites. Nevertheless, model performance was worse at high (and low) O3 percentiles. Domain-wide model performance for 24 h average PM2.5 was more variable, with a general tendency for the models to under-predict PM2.5 concentrations during the summer and over-predict PM2.5 concentrations in the autumn. The modelling intercomparison exercise has led to improvements in the implementation of these models for Sydney and has increased confidence in their skill at reproducing observed atmospheric
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- 2020
5. Estimation of Power Plant Emissions with Unscented Kalman Filter
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Metia, S, Ha, QP, Duc, HN, and Azzi, M
- Abstract
© 2008-2012 IEEE. Emissions from power plants constitute a major part of air pollution and should be adequately estimated. In this paper, we consider the problem of estimating nitrogen dioxide (NO-X ) emission of power plants by developing an inverse method to integrate satellite observations of atmospheric pollutant column concentrations with species concentrations and direct sensitivities predicted by a regional air quality model, in order to discern biases in the emissions of the pollutant precursors. Using this method, the emission fields are analyzed using a 'bottom-up' approach, with an inversion performed by an unscented Kalman filter (UKF) to improve estimation profiles from emissions inventories data for the Sydney metropolitan area. The idea is to integrate information from the original inventories with tropospheric nitrogen dioxide (NO-2) emissions estimated during one month from the air pollution model-chemical transport model, and then, for validation, to compare the resulting model with satellite retrievals from the ozone monitoring instrument (OMI) above the region. The UKF-based estimation of NO-2 emissions shows better agreement with OMI observations, implying a significant improvement in accuracy as compared with the original inventories. Therefore, the proposed method is a promising tool for estimation of air emissions in urban areas.
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- 2018
6. Inverse Air-Pollutant Emission and Prediction Using Extended Fractional Kalman Filtering
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Metia, S, Oduro, SD, Duc, HN, and Ha, Q
- Abstract
© 2016 IEEE. It is essential to maintain air-quality standards and to take necessary measures when air-pollutant concentrations exceed permissible limits. Pollutants such as ground-level ozone (O3), nitrogen oxides (NOX), and volatile organic compounds (VOCs) emitted from various sources can be estimated at a particular location through integration of observation data obtained from measurement sites and effective air-quality models, using emission inventory data as input. However, there are always uncertainties associated with the emission inventory data as well as uncertainties generated by a meteorological model. This paper addresses the problem of improving the inverse air pollution emission and prediction over the urban and suburban areas using the air-pollution model with chemical transport model (TAPM-CTM) coupled with the extended fractional Kalman filter (EFKF) based on a Matérn covariance function. Here, nitrogen oxide (NO), nitrogen dioxide (NO2), and O3 concentrations are predicted by TAPM-CTM in the airshed of Sydney and surrounding areas. For improvement of the emission inventory, and hence the air-quality prediction, the fractional order of the EFKF is tuned using a genetic algorithm (GA). The proposed methodology is verified with measurements at monitoring stations and is then applied to obtain a better spatial distribution of O3 over the region.
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- 2016
7. An ecological economic comparison between integrated rice-fish farming and rice monocultures with low and high dikes in the Mekong Delta, Vietnam.
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Berg H, Lan THP, Tam NT, Trang DH, Van PHT, Duc HN, and Da CT
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- Animals, Ecosystem, Vietnam, Agriculture, Fishes, Crops, Agricultural, Oryza, Pesticides
- Abstract
This study makes an ecological economic comparison between three different rice farming strategies in the Mekong Delta. Interviews were made with 30 farmers with two crops of rice and low dikes (2RLd), 30 farmers with three crops of rice and high dikes (3RHd) and 18 farmers with two crops of rice and one crop of fish (2RF). 2RF farmers had the highest annual net income and benefit cost ratio, because of low production costs and high yields of rice and fish. 2RLd farmers had the lowest annual net income. 3RHd had the highest annual rice yield, but also used the highest amount of rice seeds and agrochemicals, generating the lowest benefit cost ratio. Most farmers (70%) preferred two crops because of a higher production efficiency. High dikes and frequent use of pesticides and fertilizers were seen to decrease the water and rice quality, connectivity and biodiversity in farms with three crops. It is concluded that rice farming with two crops, and especially if integrated with fish and applying IPM, provides a sustainable alternative to rice farming with three crops and high dikes, because it makes use of the high connectivity within the rice-field ecosystem for an efficient production of healthy food through increased recycling of nutrients and natural pest control mechanisms., (© 2023. The Author(s).)
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- 2023
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8. Selective thrombolysis trans-catheter for safe and effective subacute stent graft occlusion treatment.
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Duc HN, Hoai LT, Tuan LN, Duc MT, and Cong LD
- Abstract
A 74-year-old man developed a subacute thrombosis with a stent graft occlusion, 4 months after an endovascular aneurysm repair. He presented with lateral lower limb ischemia and presented intermittent claudication. Using an intra-arterial thrombolysis transcatheter infusion and angioplasty. We report successful endovascular and medical treatment. The patient recovered without complications and was discharged., (© 2023 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)
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- 2023
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9. Cell differentiation modifies the p53 transcriptional program through a combination of gene silencing and constitutive transactivation.
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Tatavosian R, Donovan MG, Galbraith MD, Duc HN, Szwarc MM, Joshi MU, Frieman A, Bilousova G, Cao Y, Smith KP, Song K, Rachubinski AL, Andrysik Z, and Espinosa JM
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- Mice, Animals, Humans, Transcriptional Activation genetics, Transcription Factors metabolism, Cell Differentiation genetics, Gene Silencing, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism, Neoplasms genetics
- Abstract
The p53 transcription factor is a master regulator of cellular responses to stress that is commonly inactivated in diverse cancer types. Despite decades of research, the mechanisms by which p53 impedes tumorigenesis across vastly different cellular contexts requires further investigation. The bulk of research has been completed using in vitro studies of cancer cell lines or in vivo studies in mouse models, but much less is known about p53 action in diverse non-transformed human tissues. Here, we investigated how different cellular states modify the p53 transcriptional program in human cells through a combination of computational analyses of publicly available large-scale datasets and in vitro studies using an isogenic system consisting of induced pluripotent stem cells (iPSCs) and two derived lineages. Analysis of publicly available mRNA expression and genetic dependency data demonstrated wide variation in terms of expression and function of a core p53 transcriptional program across various tissues and lineages. To monitor the impact of cell differentiation on the p53 transcriptome within an isogenic cell culture system, we activated p53 by pharmacological inhibition of its negative regulator MDM2. Using cell phenotyping assays and genome wide transcriptome analyses, we demonstrated that cell differentiation confines and modifies the p53 transcriptional network in a lineage-specific fashion. Although hundreds of p53 target genes are transactivated in iPSCs, only a small fraction is transactivated in each of the differentiated lineages. Mechanistic studies using small molecule inhibitors and genetic knockdowns revealed the presence of two major regulatory mechanisms contributing to this massive heterogeneity across cellular states: gene silencing by epigenetic regulatory complexes and constitutive transactivation by lineage-specific transcription factors. Altogether, these results illuminate the impact of cell differentiation on the p53 program, thus advancing our understanding of how this tumor suppressor functions in different contexts., (© 2023. The Author(s).)
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- 2023
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10. FAM193A is a positive regulator of p53 activity.
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Szwarc MM, Guarnieri AL, Joshi M, Duc HN, Laird MC, Pandey A, Khanal S, Dohm E, Bui AK, Sullivan KD, Galbraith MD, Andrysik Z, and Espinosa JM
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- Humans, Apoptosis, Cell Cycle Proteins metabolism, Cell Line, Tumor, Proto-Oncogene Proteins metabolism, Proto-Oncogene Proteins c-mdm2 metabolism, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism, Antineoplastic Agents pharmacology, Neoplasms pathology
- Abstract
Inactivation of the p53 tumor suppressor, either by mutations or through hyperactivation of repressors such as MDM2 and MDM4, is a hallmark of cancer. Although many inhibitors of the p53-MDM2/4 interaction have been developed, such as Nutlin, their therapeutic value is limited by highly heterogeneous cellular responses. We report here a multi-omics investigation of the cellular response to MDM2/4 inhibitors, leading to identification of FAM193A as a widespread regulator of p53 function. CRISPR screening identified FAM193A as necessary for the response to Nutlin. FAM193A expression correlates with Nutlin sensitivity across hundreds of cell lines. Furthermore, genetic codependency data highlight FAM193A as a component of the p53 pathway across diverse tumor types. Mechanistically, FAM193A interacts with MDM4, and FAM193A depletion stabilizes MDM4 and inhibits the p53 transcriptional program. Last, FAM193A expression is associated with better prognosis in multiple malignancies. Altogether, these results identify FAM193A as a positive regulator of p53., Competing Interests: Declaration of interests J.M.E. has provided consulting services for Elli Lily and Co. and Gilead Sciences Inc. and serves on the advisory board of Perha Pharmaceuticals and on the editorial board of Cell Reports., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2023
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11. The Effect of Mixture of Heavy Metals on Obesity in Individuals ≥50 Years of Age.
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Duc HN, Oh H, and Kim MS
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- Bayes Theorem, Humans, Middle Aged, Obesity epidemiology, Obesity, Abdominal, Mercury, Metals, Heavy
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Little is known about the association between a mixture of heavy metals and obesity among individuals ≥50 years of age with comorbidities. Thus, we identified the associations of serum cadmium (Cd), lead (Pb), and mercury (Hg) with obesity using linear regression models; weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) were conducted as secondary analyses. Of the 6434 subjects included in the analysis, 13.8% had obesity and 44.6% had abdominal obesity. In the logistic regression model, serum Hg was associated with obesity and abdominal obesity, and significant trends were observed for these heavy metal tertiles (p < 0.001). Serum Hg levels were also associated with body mass index (BMI) and waist circumference (WC). The WQS index was significantly associated with both obesity (OR = 1.43, 95% CI: 1.40-1.46) and abdominal obesity (β = 1.51, 95% CI: 1.48-1.54). The qgcomp index also found a significant association between heavy metals and both obesity (OR = 1.35, 95% CI: 1.12-1.63) and abdominal obesity (OR = 1.34, 95% CI: 1.12-1.60). Serum Hg was the most heavily weighed heavy metal in these models. In BKMR analysis, the overall effect of the mixture was significantly associated with obesity, BMI, and WC. Serum Hg showed positive trends and was observed as the most important factor associated with obesity, BMI, and WC. Our findings were largely robust to secondary analyses that used three novel mixture modeling approaches: WQS, qpcomp, and BKMR. Given increasing exposure to heavy metals, well-characterized cohorts of individuals aged ≥50 years are required to determine the mixed effects of heavy metals on obesity and related diseases., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2022
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12. Trisomy 21 increases microtubules and disrupts centriolar satellite localization.
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McCurdy BL, Jewett CE, Stemm-Wolf AJ, Duc HN, Joshi M, Espinosa JM, Prekeris R, and Pearson CG
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- Antigens, Neoplasm metabolism, Cell Cycle Proteins metabolism, Centrioles metabolism, Centrosome metabolism, Cilia metabolism, Cytoskeletal Proteins metabolism, Humans, Microtubules metabolism, Down Syndrome metabolism
- Abstract
Trisomy 21, the source of Down syndrome, causes a 0.5-fold protein increase of the chromosome 21-resident gene Pericentrin (PCNT) and reduces primary cilia formation and signaling. We investigate how PCNT imbalances disrupt cilia. Using isogenic RPE-1 cells with increased chromosome 21 dosage, we find PCNT accumulates around the centrosome as a cluster of enlarged cytoplasmic puncta that localize along microtubules (MTs) and at MT ends. Cytoplasmic PCNT puncta impact the density, stability, and localization of the MT trafficking network required for primary cilia. The PCNT puncta appear to sequester cargo peripheral to centrosomes in what we call pericentrosomal crowding. The centriolar satellite proteins PCM1, CEP131, and CEP290, important for ciliogenesis, accumulate at enlarged PCNT puncta in trisomy 21 cells. Reducing PCNT when chromosome 21 ploidy is elevated is sufficient to decrease PCNT puncta and pericentrosomal crowding, reestablish a normal density of MTs around the centrosome, and restore ciliogenesis to wild-type levels. A transient reduction in MTs also decreases pericentrosomal crowding and partially rescues ciliogenesis in trisomy 21 cells, indicating that increased PCNT leads to defects in the MT network deleterious to normal centriolar satellite distribution. We propose that chromosome 21 aneuploidy disrupts MT-dependent intracellular trafficking required for primary cilia.
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- 2022
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13. Diversity of Fusarium associated banana wilt in northern Viet Nam.
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Thi LL, Mertens A, Vu DT, Vu TD, Minh PLA, Duc HN, de Backer S, Swennen R, Vandelook F, Panis B, Amalfi M, Decock C, Gomes SIF, Merckx VSFT, and Janssens SB
- Abstract
Fusarium is one of the most important fungal genera of plant pathogens that affect the cultivation of a wide range of crops. Agricultural losses caused by Fusariumoxysporumf.sp.cubense ( Foc ) directly affect the income, subsistence, and nourishment of thousands of farmers worldwide. For Viet Nam, predictions on the impact of Foc for the future are dramatic, with an estimated loss in the banana production area of 8% within the next five years and up to 71% within the next 25 years. In the current study, we applied a combined morphological-molecular approach to assess the taxonomic identity and phylogenetic position of the different Foc isolates collected in northern Viet Nam. In addition, we aimed to estimate the proportion of the different Fusarium races infecting bananas in northern Viet Nam. The morphology of the isolates was investigated by growing the collected Fusarium isolates on four distinct nutritious media (PDA, SNA, CLA, and OMA). Molecular phylogenetic relationships were inferred by sequencing partial rpb1 , rpb2 , and tef1a genes and adding the obtained sequences into a phylogenetic framework. Molecular characterization shows that c. 74% of the Fusarium isolates obtained from infected banana pseudostem tissue belong to F.tardichlamydosporum . Compared to F.tardichlamydosporum , F.odoratissimum accounts for c.10% of the Fusarium wilt in northern Viet Nam, demonstrating that Foc TR4 is not yet a dominant strain in the region. Fusariumcugenangense - considered to cause Race 2 infections among bananas - is only found in c. 10% of the tissue material that was obtained from infected Vietnamese bananas. Additionally, one of the isolates cultured from diseased bananas was phylogenetically not positioned within the F.oxysporum species complex (FOSC), but in contrast, fell within the Fusariumfujikuroi species complex (FFSC). As a result, a possible new pathogen for bananas may have been found. Besides being present on several ABB 'Tay banana', F.tardichlamydosporum was also derived from infected tissue of a wild Musalutea , showing the importance of wild bananas as a possible sink for Foc ., (Loan Le Thi, Arne Mertens, Dang Toan Vu, Tuong Dang Vu, Pham Le Anh Minh, Huy Nguyen Duc, Sander de Backer, Rony Swennen, Filip Vandelook, Bart Panis, Mario Amalfi, Cony Decock, Sofia I. F. Gomes, Vincent S. F. T. Merckx, Steven B. Janssens.)
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- 2022
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14. Impact of biomass burnings in Southeast Asia on air quality and pollutant transport during the end of the 2019 dry season.
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Duc HN, Bang HQ, Quan NH, and Quang NX
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- Aerosols analysis, Asia, Southeastern, Biomass, Environmental Monitoring, Particulate Matter analysis, Seasons, Air Pollutants analysis, Air Pollution analysis
- Abstract
At the end of the dry season, March and April in Southeast Asia (SEA), agricultural refuse burnings occur over the region, mainly in the countries of Myanmar, Thailand, Laos, Cambodia and Vietnam, in preparation for the wet rice plantation. In this study, the impact of biomass burnings at the height of the burning period in March 2019 in mainland SEA on air quality and pollutant transport is modelled using the Weather Research Forecast WRF-Chem air quality model with emission input from the National Center for Atmospheric Research (NCAR) Fire Emission Inventory from NCAR (FINN). FINN is derived from satellite remote sensing data and species emission factors. A simulation of the dispersion of pollutants from biomass burnings from 13 to 19 March 2019, when the burnings was most intense, was performed. Validation of the model prediction using observed meteorological and pollutant data such as AOD measurements on ground from AERONET (Aerosol Robotic Network) and data from MODIS and CALIPSO satellites is carried out at various sites in the region. The results show that impact on air quality was most pronounced in Thailand and Laos but the effect of biomass burnings in mainland SEA at the end of the dry season is widespread in terms of pollutant dispersion and population exposure over the whole region and beyond. It is also shown that the transport of pollutants from biomass burnings in SEA to southern China, Taiwan and beyond is facilitated by the Truong Son mountain range, when under westerly wind, acting as a launching pad to uplift the pollutant plumes to higher altitude which then can be dispersed widely and transported farther from the biomass burning sources in Thailand and Laos., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
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- 2021
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15. Effects of Antioxidant Vitamins, Curry Consumption, and Heavy Metal Levels on Metabolic Syndrome with Comorbidities: A Korean Community-Based Cross-Sectional Study.
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Duc HN, Oh H, and Kim MS
- Abstract
The burden of metabolic syndrome (MetS) has increased worldwide, especially during the COVID-19 pandemic, and this phenomenon is related to environmental, dietary, and lifestyle risk factors. We aimed to determine the association between the levels of serum heavy metals, hs-CRP, vitamins, and curry intake and to predict risks of MetS based on marginal effects. A data set of 60,256 Koreans aged ≥ 15 years between 2009 and 2017 was used to obtain information on sociodemographic, lifestyle, family history characteristics, MetS, food intake survey, and serum heavy metals. Daily intake of vitamins was measured by a one-day 24 h recall, and curry consumption was calculated using a food frequency questionnaire. Serum heavy metal levels were quantified by graphite furnace atomic absorption spectrometry and using a mercury analyzer. We found that vitamin B1, B2, B3, C, and A intakes were significantly lower in subjects with than without MetS. In contrast, serum levels of Pb, Hg, Cd, vitamin A, E, and hs-CRP were significantly higher in subjects with MetS. The risk of MetS was significantly lower for high curry consumers than low curry consumers (adjusted odds ratio 0.85, 95%CI 0.74-0.98). The risks of MetS were reduced by 12% and 1%, when vitamin B1 and C intakes increased by one mg, respectively, but were increased by 14%, 3%, and 9%, when serum levels of Pb, Hg, and hs-CRP increased by one unit. These results show that the potential health benefits resulting from vitamin and curry intakes could protect the public against the dual burden of communicable and non-communicable diseases. Further studies are required to reduce risk factors associated with serum heavy metal levels and to determine whether interactions between vitamin and curry consumption influence the presence of MetS.
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- 2021
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16. Association between levels of thiamine intake, diabetes, cardiovascular diseases and depression in Korea: a national cross-sectional study.
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Duc HN, Oh H, Yoon IM, and Kim MS
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- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Cross-Sectional Studies, Depression epidemiology, Dyslipidemias epidemiology, Female, Humans, Hypertension epidemiology, Infant, Male, Middle Aged, Republic of Korea epidemiology, Young Adult, Cardiovascular Diseases epidemiology, Diabetes Mellitus, Type 2 epidemiology, Diet, Thiamine administration & dosage
- Abstract
The present study aimed to determine thiamine intake levels and the association between thiamine intake, diabetes, cardiovascular diseases and mental health. Participants were interviewed to obtain data on socio-demographic characteristics, lifestyle, current medications, medical and family history. The daily intake of thiamine was assessed by a 24-h recall. The mean age of the 34 700 study subjects was 42⋅9 years (sd 22⋅8, min-max: 1-80) and 19 342 (55⋅7 %) were women. The levels of thiamine intake were 1⋅126 mg (2016), 1⋅115 mg (2017) and 1⋅087 mg (2018) for women, which were equal to or only slightly above the recommended intake of 1⋅10 mg/d for women. The levels of thiamine intake from 2014-15 and 2016-18 significantly decreased. The estimated percentage of insufficient thiamine intake was 37⋅8 % (95 % CI 37⋅3, 38⋅4). Multivariable regression analysis adjusted for potential confounders showed that thiamine intake was critically associated with lower risks of hypertension, MI or angina, type 2 diabetes, depression and dyslipidemia. The daily thiamine intake from food can reversal the risks of hypertension (OR 0⋅95; 95 % CI 0⋅90, 0⋅99), MI or angina (OR 0⋅84; 95 % CI 0⋅74, 0⋅95), type 2 diabetes (OR 0⋅86; 95 % CI 0⋅81, 0⋅93), depression (OR 0⋅90; 95 % CI 0⋅83, 0⋅97) and dyslipidemia (OR 0⋅90; 95 % CI 0⋅86, 0⋅95), respectively. Further works are needed to identify the effects of thiamine and non-communicable diseases (NCDs) and mental health. A preventive thiamine supplementation strategy should be adopted to target NCDs and mental health and risk factors associated with thiamine deficiency. The optimisation of NCD control and mental health protection is also a vital integral part of Korea's public health system., (© The Author(s) 2021.)
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- 2021
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17. Nuclear condensates of the Polycomb protein chromobox 2 (CBX2) assemble through phase separation.
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Tatavosian R, Kent S, Brown K, Yao T, Duc HN, Huynh TN, Zhen CY, Ma B, Wang H, and Ren X
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- Animals, Cell Cycle Proteins genetics, Cell Nucleus genetics, Cells, Cultured, Chromatin Assembly and Disassembly, DNA genetics, Embryonic Stem Cells cytology, Embryonic Stem Cells metabolism, Histones genetics, Mice, Mice, Knockout, Nucleosomes genetics, Polycomb Repressive Complex 1 genetics, Protein Binding, Cell Cycle Proteins metabolism, Cell Nucleus metabolism, DNA metabolism, Heterochromatin metabolism, Histones metabolism, Nucleosomes metabolism, Polycomb Repressive Complex 1 metabolism
- Abstract
Polycomb group (PcG) proteins repress master regulators of development and differentiation through organization of chromatin structure. Mutation and dysregulation of PcG genes cause developmental defects and cancer. PcG proteins form condensates in the cell nucleus, and these condensates are the physical sites of PcG-targeted gene silencing via formation of facultative heterochromatin. However, the physiochemical principles underlying the formation of PcG condensates remain unknown, and their determination could shed light on how these condensates compact chromatin. Using fluorescence live-cell imaging, we observed that the Polycomb repressive complex 1 (PRC1) protein chromobox 2 (CBX2), a member of the CBX protein family, undergoes phase separation to form condensates and that the CBX2 condensates exhibit liquid-like properties. Using site-directed mutagenesis, we demonstrated that the conserved residues of CBX2 within the intrinsically disordered region (IDR), which is the region for compaction of chromatin in vitro , promote the condensate formation both in vitro and in vivo We showed that the CBX2 condensates concentrate DNA and nucleosomes. Using genetic engineering, we report that trimethylation of Lys-27 at histone H3 (H3K27me3), a marker of heterochromatin formation produced by PRC2, had minimal effects on the CBX2 condensate formation. We further demonstrated that the CBX2 condensate formation does not require CBX2-PRC1 subunits; however, the condensate formation of CBX2-PRC1 subunits depends on CBX2, suggesting a mechanism underlying the assembly of CBX2-PRC1 condensates. In summary, our results reveal that PcG condensates assemble through liquid-liquid phase separation (LLPS) and suggest that phase-separated condensates can organize PcG-bound chromatin., (© 2019 Tatavosian et al.)
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- 2019
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18. Smoke aerosols dispersion and transport from the 2013 New South Wales (Australia) bushfires.
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Duc HN, Chang LT, Azzi M, and Jiang N
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- Fires, Meteorology, New South Wales, Aerosols analysis, Air Pollutants analysis, Air Pollution analysis, Environmental Monitoring, Smoke analysis
- Abstract
Environmental monitoring and modelling, especially in the regional context, has seen significant progress with the widely usage of satellite measurement in conjunction with local meteorological and air quality monitoring to understand the atmospheric dispersion and transport of air pollutants. This paper studies the application of these data and modelling tools to understand the environment effects of a major bushfire period in the state of New South Wales (NSW), Australia, in 2013. The bushfires have caused high pollution episodes at many sites in the greater Sydney metropolitan areas. The potential long-range transport of aerosols produced by bushfires to other region and states has been seen by regulators as a major concern. Using data and images collected from satellites, in addition to the results obtained from different simulations carried out using HYSPLIT trajectory model and a regional meteorological model called Conformal Cubic Atmospheric Model (CCAM), we were able to identify at least 2 days on which the smoke aerosols from bush fires in NSW has been transported at high altitude to the northern state of Queensland and the Coral Sea. As a result, widespread high particle concentration in South East Queensland including the Brisbane area, as measured by nearly all the air quality monitoring stations in this region, occurred on the day when the smoke aerosols intruded to lower altitude as indicated by the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) Lidar measurements on the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) satellite. The use of meteorological or air quality modelling to connect the ground-based measurements with satellite observations as shown in this study is useful to understand the pollutant transport due to bushfires and its impact on regional air quality.
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- 2018
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19. Live-cell single-molecule dynamics of PcG proteins imposed by the DIPG H3.3K27M mutation.
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Tatavosian R, Duc HN, Huynh TN, Fang D, Schmitt B, Shi X, Deng Y, Phiel C, Yao T, Zhang Z, Wang H, and Ren X
- Subjects
- Animals, Brain Stem Neoplasms genetics, Chromatin genetics, Chromatin metabolism, Epigenesis, Genetic, Gene Expression Regulation, Neoplastic, Glioma genetics, HEK293 Cells, Histones metabolism, Humans, Intravital Microscopy, Mice, Mutation, Polycomb Repressive Complex 1 genetics, Polycomb Repressive Complex 2 genetics, Primary Cell Culture, Single Molecule Imaging, Tumor Cells, Cultured, Brain Stem Neoplasms pathology, Glioma pathology, Histones genetics, Polycomb Repressive Complex 1 metabolism, Polycomb Repressive Complex 2 metabolism
- Abstract
Over 80% of diffuse intrinsic pontine gliomas (DIPGs) harbor a point mutation in histone H3.3 where lysine 27 is substituted with methionine (H3.3K27M); however, how the mutation affects kinetics and function of PcG proteins remains elusive. We demonstrate that H3.3K27M prolongs the residence time and search time of Ezh2, but has no effect on its fraction bound to chromatin. In contrast, H3.3K27M has no effect on the residence time of Cbx7, but prolongs its search time and decreases its fraction bound to chromatin. We show that increasing expression of Cbx7 inhibits the proliferation of DIPG cells and prolongs its residence time. Our results highlight that the residence time of PcG proteins directly correlates with their functions and the search time of PcG proteins is critical for regulating their genomic occupancy. Together, our data provide mechanisms in which the cancer-causing histone mutation alters the binding and search dynamics of epigenetic complexes.
- Published
- 2018
- Full Text
- View/download PDF
20. Labelling HaloTag Fusion Proteins with HaloTag Ligand in Living Cells.
- Author
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Duc HN and Ren X
- Abstract
HaloTag has been widely used to label proteins in vitro and in vivo (Los et al ., 2008). In this protocol, we describe labelling HaloTag-Cbx fusion proteins by HaloTag ligands for live-cell single-molecule imaging (Zhen et al ., 2016).
- Published
- 2017
- Full Text
- View/download PDF
21. Live-cell single-molecule tracking reveals co-recognition of H3K27me3 and DNA targets polycomb Cbx7-PRC1 to chromatin.
- Author
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Zhen CY, Tatavosian R, Huynh TN, Duc HN, Das R, Kokotovic M, Grimm JB, Lavis LD, Lee J, Mejia FJ, Li Y, Yao T, and Ren X
- Subjects
- Animals, Cells, Cultured, Mice, Models, Biological, Mouse Embryonic Stem Cells, Protein Binding, Single Molecule Imaging, Chromatin metabolism, DNA metabolism, Histones metabolism, Polycomb Repressive Complex 1 metabolism
- Abstract
The Polycomb PRC1 plays essential roles in development and disease pathogenesis. Targeting of PRC1 to chromatin is thought to be mediated by the Cbx family proteins (Cbx2/4/6/7/8) binding to histone H3 with a K27me3 modification (H3K27me3). Despite this prevailing view, the molecular mechanisms of targeting remain poorly understood. Here, by combining live-cell single-molecule tracking (SMT) and genetic engineering, we reveal that H3K27me3 contributes significantly to the targeting of Cbx7 and Cbx8 to chromatin, but less to Cbx2, Cbx4, and Cbx6. Genetic disruption of the complex formation of PRC1 facilitates the targeting of Cbx7 to chromatin. Biochemical analyses uncover that the CD and AT-hook-like (ATL) motif of Cbx7 constitute a functional DNA-binding unit. Live-cell SMT of Cbx7 mutants demonstrates that Cbx7 is targeted to chromatin by co-recognizing of H3K27me3 and DNA. Our data suggest a novel hierarchical cooperation mechanism by which histone modifications and DNA coordinate to target chromatin regulatory complexes., Competing Interests: JBG: Filed patent application on the Janelia Fluor (JF) dyes (PCT/US2015/023953). LDL: Filed patent application on the Janelia Fluor (JF) dyes (PCT/US2015/023953). The other authors declare that no competing interests exist.
- Published
- 2016
- Full Text
- View/download PDF
22. Modelling and prediction of air pollutant transport during the 2014 biomass burning and forest fires in peninsular Southeast Asia.
- Author
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Duc HN, Bang HQ, and Quang NX
- Subjects
- Aerosols analysis, Asia, Southeastern, Biomass, Hazardous Substances, Particulate Matter analysis, Seasons, Smoke, Air Pollutants analysis, Air Pollution statistics & numerical data, Environmental Monitoring methods, Fires, Forests, Models, Chemical
- Abstract
During the dry season, from November to April, agricultural biomass burning and forest fires especially from March to late April in mainland Southeast Asian countries of Myanmar, Thailand, Laos and Vietnam frequently cause severe particulate pollution not only in the local areas but also across the whole region and beyond due to the prevailing meteorological conditions. Recently, the BASE-ASIA (Biomass-burning Aerosols in South East Asia: Smoke Impact Assessment) and 7-SEAS (7-South-East Asian Studies) studies have provided detailed analysis and important understandings of the transport of pollutants, in particular, the aerosols and their characteristics across the region due to biomass burning in Southeast Asia (SEA). Following these studies, in this paper, we study the transport of particulate air pollution across the peninsular region of SEA and beyond during the March 2014 burning period using meteorological modelling approach and available ground-based and satellite measurements to ascertain the extent of the aerosol pollution and transport in the region of this particular event. The results show that the air pollutants from SEA biomass burning in March 2014 were transported at high altitude to southern China, Hong Kong, Taiwan and beyond as has been highlighted in the BASE-ASIA and 7-SEAS studies. There are strong evidences that the biomass burning in SEA especially in mid-March 2014 has not only caused widespread high particle pollution in Thailand (especially the northern region where most of the fires occurred) but also impacted on the air quality in Hong Kong as measured at the ground-based stations and in LulinC (Taiwan) where a remote background monitoring station is located.
- Published
- 2016
- Full Text
- View/download PDF
23. Distinct Cellular Assembly Stoichiometry of Polycomb Complexes on Chromatin Revealed by Single-molecule Chromatin Immunoprecipitation Imaging.
- Author
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Tatavosian R, Zhen CY, Duc HN, Balas MM, Johnson AM, and Ren X
- Subjects
- Animals, Cell Line, Chromatin Immunoprecipitation, Epigenesis, Genetic, Humans, Mice, Chromatin metabolism, Polycomb-Group Proteins metabolism
- Abstract
Epigenetic complexes play an essential role in regulating chromatin structure, but information about their assembly stoichiometry on chromatin within cells is poorly understood. The cellular assembly stoichiometry is critical for appreciating the initiation, propagation, and maintenance of epigenetic inheritance during normal development and in cancer. By combining genetic engineering, chromatin biochemistry, and single-molecule fluorescence imaging, we developed a novel and sensitive approach termed single-molecule chromatin immunoprecipitation imaging (Sm-ChIPi) to enable investigation of the cellular assembly stoichiometry of epigenetic complexes on chromatin. Sm-ChIPi was validated by using chromatin complexes with known stoichiometry. The stoichiometry of subunits within a polycomb complex and the assembly stoichiometry of polycomb complexes on chromatin have been extensively studied but reached divergent views. Moreover, the cellular assembly stoichiometry of polycomb complexes on chromatin remains unexplored. Using Sm-ChIPi, we demonstrated that within mouse embryonic stem cells, one polycomb repressive complex (PRC) 1 associates with multiple nucleosomes, whereas two PRC2s can bind to a single nucleosome. Furthermore, we obtained direct physical evidence that the nucleoplasmic PRC1 is monomeric, whereas PRC2 can dimerize in the nucleoplasm. We showed that ES cell differentiation induces selective alteration of the assembly stoichiometry of Cbx2 on chromatin but not other PRC1 components. We additionally showed that the PRC2-mediated trimethylation of H3K27 is not required for the assembly stoichiometry of PRC1 on chromatin. Thus, these findings uncover that PRC1 and PRC2 employ distinct mechanisms to assemble on chromatin, and the novel Sm-ChIPi technique could provide single-molecule insight into other epigenetic complexes., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2015
- Full Text
- View/download PDF
24. Cbx2 stably associates with mitotic chromosomes via a PRC2- or PRC1-independent mechanism and is needed for recruiting PRC1 complex to mitotic chromosomes.
- Author
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Zhen CY, Duc HN, Kokotovic M, Phiel CJ, and Ren X
- Subjects
- Animals, Chromatin genetics, Chromosomes genetics, Embryonic Stem Cells cytology, Embryonic Stem Cells metabolism, Mice, Mitosis genetics, Polycomb Repressive Complex 1 metabolism, Polycomb-Group Proteins genetics, Ubiquitin-Protein Ligases genetics, Epigenesis, Genetic genetics, Polycomb Repressive Complex 1 genetics
- Abstract
Polycomb group (PcG) proteins are epigenetic transcriptional factors that repress key developmental regulators and maintain cellular identity through mitosis via a poorly understood mechanism. Using quantitative live-cell imaging in mouse ES cells and tumor cells, we demonstrate that, although Polycomb repressive complex (PRC) 1 proteins (Cbx-family proteins, Ring1b, Mel18, and Phc1) exhibit variable capacities of association with mitotic chromosomes, Cbx2 overwhelmingly binds to mitotic chromosomes. The recruitment of Cbx2 to mitotic chromosomes is independent of PRC1 or PRC2, and Cbx2 is needed to recruit PRC1 complex to mitotic chromosomes. Quantitative fluorescence recovery after photobleaching analysis indicates that PRC1 proteins rapidly exchange at interphasic chromatin. On entry into mitosis, Cbx2, Ring1b, Mel18, and Phc1 proteins become immobilized at mitotic chromosomes, whereas other Cbx-family proteins dynamically bind to mitotic chromosomes. Depletion of PRC1 or PRC2 protein has no effect on the immobilization of Cbx2 on mitotic chromosomes. We find that the N-terminus of Cbx2 is needed for its recruitment to mitotic chromosomes, whereas the C-terminus is required for its immobilization. Thus these results provide fundamental insights into the molecular mechanisms of epigenetic inheritance., (© 2014 Zhen et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).)
- Published
- 2014
- Full Text
- View/download PDF
25. Clinical utility of hyperglycosylated hCG in serum taken before hydatidiform mole evacuation to predict persistent trophoblastic disease.
- Author
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Duc HN, van Trommel NE, Sweep FC, Massuger LF, and Thomas CM
- Subjects
- Biomarkers blood, Chorionic Gonadotropin, beta Subunit, Human blood, Female, Glycosylation, Humans, Hydatidiform Mole blood, Hydatidiform Mole surgery, Pregnancy, Retrospective Studies, Sensitivity and Specificity, Chorionic Gonadotropin blood, Hydatidiform Mole diagnosis, Trophoblastic Neoplasms diagnosis
- Abstract
Objective: Human chorionic gonadotropin (hCG) is widely used in the management of hydatidiform mole and persistent trophoblastic disease (PTD). Studies on hyperglycosylated human chorionic gonadotropin (invasive trophoblast antigen, ITA) in PTD are limited. In serum samples taken before evacuation of molar pregnancies we measured the concentrations of free hCG beta-subunit (free hCGbeta), "total" hCG (hCG+hCGbeta) and ITA, and determined whether ITA, the two other hCG analytes, or the calculated ratios of hCGbeta/hCG+hCGbeta, hCGbeta/ITA and hCG+hCGbeta/ITA could predict the later development of PTD., Design: A retrospective study based on blood specimens collected in the Dutch Central Registry for Hydatidiform Moles. The study group comprised 97 patients with hydatidiform moles who did not develop PTD after mole evacuation and 33 patients who did develop PTD., Methods: Serum samples from 130 patients with hydatidiform mole with or without PTD were assayed using specific (radio)immunoassays for free hCGbeta, total hCG, and ITA. From these analytes we also calculated the ratios hCGbeta/hCG+hCGbeta, hCGbeta/ITA, and hCG+hCGbeta/ITA. To predict the development of PTD from these analytes and parameters we performed receiver-operating characteristic (ROC) curve analysis, resulting in areas under the curve (AUCs) that represented the diagnostic accuracy which was rated in a range from excellent (AUC >0.9 or <0.1) to poor (AUC 0.4-0.6)., Results: The diagnostic accuracy of ITA was moderate (0.618) and not different from that of free hCGbeta (0.610) and hCG+hCGbeta (0.622)., Conclusions: ITA as well as the other analytes and parameters in serum taken prior to evacuation from patients with molar pregnancies cannot be used to predict the subsequent development of persistent trophoblastic disease.
- Published
- 2006
26. [Aorto-coronary dysplasia and pseudoxanthoma elastica].
- Author
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Heno P, Fourcade L, Duc HN, Bonello R, Roux O, Van de Walle JP, Mafart B, and Touze JE
- Subjects
- Aortic Valve Insufficiency diagnosis, Aortic Valve Insufficiency surgery, Coronary Aneurysm diagnosis, Coronary Aneurysm surgery, Coronary Angiography, Coronary Artery Bypass, Heart Valve Prosthesis, Humans, Male, Middle Aged, Aortic Valve Insufficiency complications, Coronary Aneurysm complications, Pseudoxanthoma Elasticum complications
- Abstract
The authors report the case of a 50 year old man with pseudowanthoma elastica with a history of myocardial infarction and severe aortic regurgitation. Angiography showed multiple coronary artery aneurysms and aneurysmal dilatation of the aortic annulus. The outcome after triple coronary bypass surgery with aortic valve replacement in a valved Bentall conduit was favourable. Pseudoxanthoma elastica is a rare condition in which the prognosis depends on the degree of vascular involvement. In this context, coronary artery aneurysms and aneurysmal dilatation of the aorta are rare complications.
- Published
- 1998
27. Multicompartment models of cancer chemotherapy incorporating resistant cell populations.
- Author
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Duc HN and Nickolls PM
- Subjects
- Animals, Biological Availability, Carmustine therapeutic use, Cytarabine therapeutic use, Drug Resistance, Kinetics, Leukemia L1210 pathology, Mice, Models, Biological, Antineoplastic Agents therapeutic use, Leukemia L1210 drug therapy
- Abstract
The pharmacokinetics of antineoplastic drugs based on compartmental models are combined with deterministic exponential growth models of tumors containing drug-resistant and sensitive cells. Model predictions for single-drug therapy are compared with in vivo data obtained by other investigators for L1210 t-cell leukemia in mice treated with BCNU and Ara-C and for in vitro treatment of L1210 with Ara-C. The model and data compare favorably in terms of rate of tumor growth and duration of drug action for both constant infusion and bolus delivery of the drugs.
- Published
- 1987
- Full Text
- View/download PDF
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