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1.
Cell ; 151(5): 1068-82, 2012 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-23142051

RESUMEN

Through in vivo selection of human cancer cell populations, we uncover a convergent and cooperative miRNA network that drives melanoma metastasis. We identify miR-1908, miR-199a-5p, and miR-199a-3p as endogenous promoters of metastatic invasion, angiogenesis, and colonization in melanoma. These miRNAs convergently target apolipoprotein E (ApoE) and the heat shock factor DNAJA4. Cancer-secreted ApoE suppresses invasion and metastatic endothelial recruitment (MER) by engaging melanoma cell LRP1 and endothelial cell LRP8 receptors, respectively, while DNAJA4 promotes ApoE expression. Expression levels of these miRNAs and ApoE correlate with human metastatic progression outcomes. Treatment of cells with locked nucleic acids (LNAs) targeting these miRNAs inhibits metastasis to multiple organs, and therapeutic delivery of these LNAs strongly suppresses melanoma metastasis. We thus identify miRNAs with dual cell-intrinsic/cell-extrinsic roles in cancer, reveal convergent cooperativity in a metastatic miRNA network, identify ApoE as an anti-angiogenic and metastasis-suppressive factor, and uncover multiple prognostic miRNAs with synergistic combinatorial therapeutic potential in melanoma.


Asunto(s)
Apolipoproteínas E/metabolismo , Melanoma/genética , MicroARNs/metabolismo , Metástasis de la Neoplasia/genética , Neovascularización Patológica/metabolismo , Animales , Línea Celular Tumoral , Células Cultivadas , Modelos Animales de Enfermedad , Células Endoteliales/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas del Choque Térmico HSP40/metabolismo , Humanos , Proteínas Relacionadas con Receptor de LDL/metabolismo , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/patología , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , MicroARNs/antagonistas & inhibidores , Metástasis de la Neoplasia/tratamiento farmacológico , Metástasis de la Neoplasia/patología , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/genética , Oligonucleótidos/farmacología
2.
Genes Dev ; 30(4): 386-98, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26883358

RESUMEN

Post-transcriptional deregulation is a defining feature of metastatic cancer. While many microRNAs have been implicated as regulators of metastatic progression, less is known about the roles and mechanisms of RNA-binding proteins in this process. We identified muscleblind-like 1 (MBNL1), a gene implicated in myotonic dystrophy, as a robust suppressor of multiorgan breast cancer metastasis. MBNL1 binds the 3' untranslated regions (UTRs) of DBNL (drebrin-like protein) and TACC1 (transforming acidic coiled-coil containing protein 1)-two genes that we implicate as metastasis suppressors. By enhancing the stability of these genes' transcripts, MBNL1 suppresses cell invasiveness. Consistent with these findings, elevated MBNL1 expression in human breast tumors is associated with reduced metastatic relapse likelihood. Our findings delineate a post-transcriptional network that governs breast cancer metastasis through RNA-binding protein-mediated transcript stabilization.


Asunto(s)
Neoplasias de la Mama/fisiopatología , Regulación Neoplásica de la Expresión Génica , Proteínas de Unión al ARN/metabolismo , Animales , Neoplasias de la Mama/genética , Línea Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Células HEK293 , Humanos , Proteínas de Microfilamentos/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Invasividad Neoplásica/genética , Metástasis de la Neoplasia , Unión Proteica , Estabilidad Proteica , Proteínas de Unión al ARN/genética , Recurrencia , Migración Transendotelial y Transepitelial/genética
3.
Radiology ; 308(1): e230970, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37489981

RESUMEN

Background Radiological imaging guidelines are crucial for accurate diagnosis and optimal patient care as they result in standardized decisions and thus reduce inappropriate imaging studies. Purpose In the present study, we investigated the potential to support clinical decision-making using an interactive chatbot designed to provide personalized imaging recommendations from American College of Radiology (ACR) appropriateness criteria documents using semantic similarity processing. Methods We utilized 209 ACR appropriateness criteria documents as specialized knowledge base and employed LlamaIndex, a framework that allows to connect large language models with external data, and the ChatGPT 3.5-Turbo to create an appropriateness criteria contexted chatbot (accGPT). Fifty clinical case files were used to compare the accGPT's performance against general radiologists at varying experience levels and to generic ChatGPT 3.5 and 4.0. Results All chatbots reached at least human performance level. For the 50 case files, the accGPT performed best in providing correct recommendations that were "usually appropriate" according to the ACR criteria and also did provide the highest proportion of consistently correct answers in comparison with generic chatbots and radiologists. Further, the chatbots provided substantial time and cost savings, with an average decision time of 5 minutes and a cost of 0.19 € for all cases, compared to 50 minutes and 29.99 € for radiologists (both p < 0.01). Conclusion ChatGPT-based algorithms have the potential to substantially improve the decision-making for clinical imaging studies in accordance with ACR guidelines. Specifically, a context-based algorithm performed superior to its generic counterpart, demonstrating the value of tailoring AI solutions to specific healthcare applications.


Asunto(s)
Algoritmos , Programas Informáticos , Humanos , Toma de Decisiones Clínicas , Ahorro de Costo , Radiólogos
4.
Biol Pharm Bull ; 46(8): 1057-1064, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37532557

RESUMEN

Glinus oppositifolius is an endemic herbaceous plant found in tropical Asian countries and is native in Vietnam. It is used in traditional folk medicine because of its flavor and antiseptic and laxative effects. In the current research, the effects of Tox-off, Biovip, and the purified compounds isolated from G. oppositifolius in the previous study were evaluated on the activation of adenosine 5'-monophosphate-activated protein kinase (AMPK)-activated protein kinase (AMPK) and acetyl-coenzyme A carboxylase (ACC) in C2C12 myoblasts. In addition, the most potent active compounds, traphanoside-GO1 (TRA-GO1) and TRA-GO5 have validated the reduction of fatty acid synthase (FAS) and sterol regulatory element binding protein (SREBP)-1c in HepG2 cells. We found that Tox-off and Biovip significantly increased the phosphorylation of AMPK and ACC in C2C12 myoblasts. Furthermore, TRA-GO1 and TRA-GO5 significantly increased the AMPK activation and phosphorylation of its downstream substrate ACC in a concentration-dependent way compared to the dimethyl sulfoxide (DMSO) control. Besides, the protein level of FAS and SREBP-1c decreased by TRA-GO1 and TRA-GO5 in a concentration-dependent manner. Taken together, our results showed that the increased AMPK and ACC phosphorylation by active components of G. oppositifolius may activate the AMPK signaling pathways, which are useful for the anti-obesity and its related metabolic disorders.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Molluginaceae , Humanos , Células Hep G2 , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Metabolismo de los Lípidos , Ácido Graso Sintasas/metabolismo , Acetil-CoA Carboxilasa/metabolismo
5.
Int J Health Plann Manage ; 38(2): 473-493, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36447363

RESUMEN

Primary healthcare is critical in addressing the main health problems of communities. In Vietnam, the increasing healthcare demands cause major challenges, especially overcrowding. This study identified public preferences regarding the selection of healthcare facilities for first visit. A discrete choice online survey was generated from five attributes including visit duration, travel time, personal connection with medical staff, doctors' experience, and health insurance. A Dz -efficient design constructed 36 choice sets, divided into three blocks of 12 choice sets. Each block formed one version of the questionnaire, which was randomly distributed to the participants. Heterogeneity in participant preferences was analysed by a latent class model with socio demographic characteristics and experiences of the last visit. 822 participants valued doctors' experience for both minor and severe symptoms. Preference heterogeneity for minor symptoms was quick service provision, highly experienced doctors, and payment through health insurance for the first (44.18%), second (32.17%), and third classes (23.66%), respectively. Regarding severe symptoms, they favoured all five attributes, quick health service, and reduced travel time for the first, second, and third classes, respectively (heterogeneities of 58.16%, 27.79%, and 14.05%, respectively). Predictions of choice from the worst to optimal healthcare facility scenario were 8.91%-61.91% and 10.16%-69.83% for minor and severe symptoms, respectively. Knowledge regarding public preference heterogeneity supports policymakers increase public acceptance in choosing primary healthcare facilities. Visit duration and doctors' experience should be considered a priority in decision making.


Asunto(s)
Conducta de Elección , Prioridad del Paciente , Humanos , Vietnam , Atención a la Salud , Instituciones de Salud
6.
Environ Monit Assess ; 194(Suppl 2): 765, 2022 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-36255568

RESUMEN

Can Tho city in the Mekong Delta is in the top ten areas affected by climate change. Therefore, assessing climate change impacts, social and economic activities require proposed solutions to respond to climate change. This study aims to (i) apply the MIKE 11 model (Hydrodynamic module and Advection-Dispersion module) to simulate the impacts of climate change scenarios on water resources in Can Tho city; (ii) calculate water balance in Can Tho city; and (iii) suggest climate change adaptation plan for sustainable social-economic activities of the city. The results show that when the rainfall changes due to climate change, the flow rate tends to decrease at high tide and increase at low tide. When the sea level rises due to climate change, the flow rate tends to increase at high tide and decrease at low tide. For 2030, the flow will decrease up to 15.6% and 14.3% at the low tide period for RCP 2.6 and RCP 8.5 compared to the present, respectively. The flow will increase up to 63.5% and 58.9% at the high tide period for RCP 2.6 and RCP 8.5 compared to the present, respectively. The water demand evaluation shows that the water resource reserve in Can Tho city meets water demands in current and future scenarios under climate change. While rainwater and groundwater can provide enough water in the rainy season, the city has to use surface water during the dry season due to a lack of rainwater. Of these, agriculture contributes the most water demands (85%). Eight adaptation measures to climate change for Can Tho city are developed from 2021 to 2050.


Asunto(s)
Cambio Climático , Recursos Hídricos , Vietnam , Monitoreo del Ambiente , Agua
7.
PLoS Med ; 17(11): e1003393, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33211712

RESUMEN

BACKGROUND: There is a high risk of Plasmodium vivax parasitaemia following treatment of falciparum malaria. Our study aimed to quantify this risk and the associated determinants using an individual patient data meta-analysis in order to identify populations in which a policy of universal radical cure, combining artemisinin-based combination therapy (ACT) with a hypnozoitocidal antimalarial drug, would be beneficial. METHODS AND FINDINGS: A systematic review of Medline, Embase, Web of Science, and the Cochrane Database of Systematic Reviews identified efficacy studies of uncomplicated falciparum malaria treated with ACT that were undertaken in regions coendemic for P. vivax between 1 January 1960 and 5 January 2018. Data from eligible studies were pooled using standardised methodology. The risk of P. vivax parasitaemia at days 42 and 63 and associated risk factors were investigated by multivariable Cox regression analyses. Study quality was assessed using a tool developed by the Joanna Briggs Institute. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42018097400). In total, 42 studies enrolling 15,341 patients were included in the analysis, including 30 randomised controlled trials and 12 cohort studies. Overall, 14,146 (92.2%) patients had P. falciparum monoinfection and 1,195 (7.8%) mixed infection with P. falciparum and P. vivax. The median age was 17.0 years (interquartile range [IQR] = 9.0-29.0 years; range = 0-80 years), with 1,584 (10.3%) patients younger than 5 years. 2,711 (17.7%) patients were treated with artemether-lumefantrine (AL, 13 studies), 651 (4.2%) with artesunate-amodiaquine (AA, 6 studies), 7,340 (47.8%) with artesunate-mefloquine (AM, 25 studies), and 4,639 (30.2%) with dihydroartemisinin-piperaquine (DP, 16 studies). 14,537 patients (94.8%) were enrolled from the Asia-Pacific region, 684 (4.5%) from the Americas, and 120 (0.8%) from Africa. At day 42, the cumulative risk of vivax parasitaemia following treatment of P. falciparum was 31.1% (95% CI 28.9-33.4) after AL, 14.1% (95% CI 10.8-18.3) after AA, 7.4% (95% CI 6.7-8.1) after AM, and 4.5% (95% CI 3.9-5.3) after DP. By day 63, the risks had risen to 39.9% (95% CI 36.6-43.3), 42.4% (95% CI 34.7-51.2), 22.8% (95% CI 21.2-24.4), and 12.8% (95% CI 11.4-14.5), respectively. In multivariable analyses, the highest rate of P. vivax parasitaemia over 42 days of follow-up was in patients residing in areas of short relapse periodicity (adjusted hazard ratio [AHR] = 6.2, 95% CI 2.0-19.5; p = 0.002); patients treated with AL (AHR = 6.2, 95% CI 4.6-8.5; p < 0.001), AA (AHR = 2.3, 95% CI 1.4-3.7; p = 0.001), or AM (AHR = 1.4, 95% CI 1.0-1.9; p = 0.028) compared with DP; and patients who did not clear their initial parasitaemia within 2 days (AHR = 1.8, 95% CI 1.4-2.3; p < 0.001). The analysis was limited by heterogeneity between study populations and lack of data from very low transmission settings. Study quality was high. CONCLUSIONS: In this meta-analysis, we found a high risk of P. vivax parasitaemia after treatment of P. falciparum malaria that varied significantly between studies. These P. vivax infections are likely attributable to relapses that could be prevented with radical cure including a hypnozoitocidal agent; however, the benefits of such a novel strategy will vary considerably between geographical areas.


Asunto(s)
Antimaláricos/uso terapéutico , Combinación Arteméter y Lumefantrina/uso terapéutico , Malaria Vivax/tratamiento farmacológico , Plasmodium vivax/patogenicidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Artemisininas/uso terapéutico , Niño , Preescolar , Femenino , Humanos , Lactante , Malaria/tratamiento farmacológico , Malaria Falciparum/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Parasitemia/tratamiento farmacológico , Plasmodium vivax/efectos de los fármacos , Adulto Joven
8.
Biol Cybern ; 113(1-2): 149-159, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30377766

RESUMEN

This paper presents an optimal control approach to modeling effects of cardiovascular regulation during head-up tilt (HUT). Many patients who suffer from dizziness or light-headedness are administered a head-up tilt test to explore potential deficits within the autonomic control system, which maintains the cardiovascular system at homeostasis. This system is complex and difficult to study in vivo, and thus we propose to use mathematical modeling to achieve a better understanding of cardiovascular regulation during HUT. In particular, we show the feasibility of using optimal control theory to compute physiological control variables, vascular resistance and cardiac contractility, quantities that cannot be measured directly, but which are useful to assess the state of the cardiovascular system. A non-pulsatile lumped parameter model together with pseudo- and clinical data are utilized in the optimal control problem formulation. Results show that the optimal control approach can predict time-varying quantities regulated by the cardiovascular control system. Our results compare favorable to our previous study using a piecewise linear spline approach, less a priori knowledge is needed, and results were obtained at a significantly lower computational cost.


Asunto(s)
Presión Sanguínea/fisiología , Modelos Cardiovasculares , Dinámicas no Lineales , Postura/fisiología , Pruebas de Mesa Inclinada , Gasto Cardíaco/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Extremidad Inferior/fisiología , Resistencia Vascular
9.
J Math Biol ; 79(3): 987-1014, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31152210

RESUMEN

This study develops non-pulsatile and pulsatile models for the prediction of blood flow and pressure during head-up tilt. This test is used to diagnose potential pathologies within the autonomic control system, which acts to keep the cardiovascular system at homeostasis. We show that mathematical modeling can be used to predict changes in cardiac contractility, vascular resistance, and arterial compliance, quantities that cannot be measured but are useful to assess the system's state. These quantities are predicted as time-varying parameters modeled using piecewise linear splines. Having models with various levels of complexity formulated with a common set of parameters, allows us to combine long-term non-pulsatile simulations with pulsatile simulations on a shorter time-scale. We illustrate results for a representative subject tilted head-up from a supine position to a [Formula: see text] angle. The tilt is maintained for 5 min before the subject is tilted back down. Results show that if volume data is available for all vascular compartments three parameters can be identified, cardiovascular resistance, vascular compliance, and ventricular contractility, whereas if model predictions are made against arterial pressure and cardiac output data alone, only two parameters can be estimated either resistance and contractility or resistance and compliance.


Asunto(s)
Presión Sanguínea , Gasto Cardíaco/fisiología , Hemodinámica , Modelos Cardiovasculares , Flujo Pulsátil , Posición Supina , Resistencia Vascular/fisiología , Adulto , Frecuencia Cardíaca , Humanos , Masculino , Pruebas de Mesa Inclinada
10.
Clin Transplant ; 31(12)2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28925558

RESUMEN

BACKGROUND: Non-HLA antibodies against human endothelial progenitor cells (EPC) in pre-transplant recipient serum can have a deleterious influence on the graft. EPC enriched from peripheral blood have been commonly used for EPC cross-matching. In the present study, we describe cross-matches using EPC enriched from fresh or frozen-thawed spleen cell preparations, thereby widening the sample source for deceased-donor cross-matching and retrospective studies. METHODS: EPC cross-matches were performed retrospectively using spleen cells and the flow cytometric XM-ONE cross-match test kit. RESULTS: Healthy controls (n = 28) showed no IgG antibodies against EPC. When sera of 11 random dialysis patients were studied, 2 patients (18%) exhibited IgG EPC antibodies. When pre-transplant sera of 20 kidney graft recipients with good long-term graft outcome (serum creatinine 1.0 ± 0.2 mg/dL measured 2463 ± 324 days post-transplant) were investigated using frozen-thawed and then separated Tie-2-enriched spleen cells of the original transplant donor, 3 patients (15%) had pre-transplant IgG EPC antibodies. When pre-transplant sera of 5 patients with intra-operative graft loss were studied employing the original donor spleen cells, 4 (80%) patients showed IgG EPC antibodies. CONCLUSIONS: Cross-matches with spleen cell-derived EPC using the XM-ONE assay are technically possible. Our very preliminary experience suggests clinical relevance.


Asunto(s)
Células Progenitoras Endoteliales/inmunología , Prueba de Histocompatibilidad , Isoanticuerpos/sangre , Fallo Renal Crónico/cirugía , Trasplante de Riñón , Receptor TIE-2/metabolismo , Bazo/inmunología , Adulto , Anciano , Estudios de Casos y Controles , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto , Supervivencia de Injerto , Humanos , Isoanticuerpos/inmunología , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Bazo/citología , Bazo/metabolismo , Donantes de Tejidos , Receptores de Trasplantes
11.
J Appl Toxicol ; 37(12): 1448-1454, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28585774

RESUMEN

Despite the plethora of studies discussing the benefits of vitamin D on physiological functioning, few mathematical models of vitamin D predict the response of the body on low-concentration supplementation of vitamin D under sunlight-restricted conditions. This study developed a physiologically based pharmacokinetic (PBPK) model utilizing published human data on the metabolic cascade of orally derived, low-concentration (placebo, 5 µg and 10 µg) supplementation of vitamin D over the course of 28 days in the absence of sunlight. Vitamin D and its metabolites are highly lipophilic and binding assays of these compounds in serum may not account for binding by lipids and additional proteins. To compensate for the additional bound amounts, this study allowed the effective adipose-plasma partition coefficient to vary dynamically with the concentration of each compound in serum utilizing the Hill equation for binding. Through incorporating the optimized parameters with the adipose partition coefficient adaptation to the PBPK model, this study was able to fit serum concentration data for circulating vitamin D at all three supplementation concentrations within confidence intervals of the data. Copyright © 2017 John Wiley & Sons, Ltd.


Asunto(s)
Colecalciferol/farmacocinética , Modelos Biológicos , Distribución Tisular/fisiología , Tejido Adiposo/metabolismo , Administración Oral , Calcifediol/sangre , Calcifediol/metabolismo , Colecalciferol/administración & dosificación , Colecalciferol/sangre , Relación Dosis-Respuesta a Droga , Humanos , Estaciones del Año , Luz Solar
12.
Chaos ; 27(7): 073106, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28764411

RESUMEN

The identification of network connectivity from noisy time series is of great interest in the study of network dynamics. This connectivity estimation problem becomes more complicated when we consider the possibility of hidden nodes within the network. These hidden nodes act as unknown drivers on our network and their presence can lead to the identification of false connections, resulting in incorrect network inference. Detecting the parts of the network they are acting on is thus critical. Here, we propose a novel method for hidden node detection based on an adaptive filtering framework with specific application to neuronal networks. We consider the hidden node as a problem of missing variables when model fitting and show that the estimated system noise covariance provided by the adaptive filter can be used to localize the influence of the hidden nodes and distinguish the effects of different hidden nodes. Additionally, we show that the sequential nature of our algorithm allows for tracking changes in the hidden node influence over time.

13.
PLoS Med ; 13(3): e1001977, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27011229

RESUMEN

BACKGROUND: The global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden. In this analysis, we use surveillance data to provide an estimate of influenza-associated hospitalizations among children worldwide. METHODS AND FINDINGS: We aggregated data from a systematic review (n = 108) and surveillance platforms (n = 37) to calculate a pooled estimate of the proportion of samples collected from children hospitalized with respiratory illnesses and positive for influenza by age group (<6 mo, <1 y, <2 y, <5 y, 5-17 y, and <18 y). We applied this proportion to global estimates of acute lower respiratory infection hospitalizations among children aged <1 y and <5 y, to obtain the number and per capita rate of influenza-associated hospitalizations by geographic region and socio-economic status. Influenza was associated with 10% (95% CI 8%-11%) of respiratory hospitalizations in children <18 y worldwide, ranging from 5% (95% CI 3%-7%) among children <6 mo to 16% (95% CI 14%-20%) among children 5-17 y. On average, we estimated that influenza results in approximately 374,000 (95% CI 264,000 to 539,000) hospitalizations in children <1 y-of which 228,000 (95% CI 150,000 to 344,000) occur in children <6 mo-and 870,000 (95% CI 610,000 to 1,237,000) hospitalizations in children <5 y annually. Influenza-associated hospitalization rates were more than three times higher in developing countries than in industrialized countries (150/100,000 children/year versus 48/100,000). However, differences in hospitalization practices between settings are an important limitation in interpreting these findings. CONCLUSIONS: Influenza is an important contributor to respiratory hospitalizations among young children worldwide. Increasing influenza vaccination coverage among young children and pregnant women could reduce this burden and protect infants <6 mo.


Asunto(s)
Hospitalización/estadística & datos numéricos , Gripe Humana/epidemiología , Enfermedades Respiratorias/epidemiología , Adolescente , Niño , Preescolar , Monitoreo Epidemiológico , Femenino , Salud Global , Humanos , Lactante , Masculino , Enfermedades Respiratorias/virología
14.
PLoS Pathog ; 10(8): e1004310, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25144780

RESUMEN

To guide control policies, it is important that the determinants of influenza transmission are fully characterized. Such assessment is complex because the risk of influenza infection is multifaceted and depends both on immunity acquired naturally or via vaccination and on the individual level of exposure to influenza in the community or in the household. Here, we analyse a large household cohort study conducted in 2007-2010 in Vietnam using innovative statistical methods to ascertain in an integrative framework the relative contribution of variables that influence the transmission of seasonal (H1N1, H3N2, B) and pandemic H1N1pdm09 influenza. Influenza infection was diagnosed by haemagglutination-inhibition (HI) antibody assay of paired serum samples. We used a Bayesian data augmentation Markov chain Monte Carlo strategy based on digraphs to reconstruct unobserved chains of transmission in households and estimate transmission parameters. The probability of transmission from an infected individual to another household member was 8% (95% CI, 6%, 10%) on average, and varied with pre-season titers, age and household size. Within households of size 3, the probability of transmission from an infected member to a child with low pre-season HI antibody titers was 27% (95% CI 21%-35%). High pre-season HI titers were protective against infection, with a reduction in the hazard of infection of 59% (95% CI, 44%-71%) and 87% (95% CI, 70%-96%) for intermediate (1∶20-1∶40) and high (≥1∶80) HI titers, respectively. Even after correcting for pre-season HI titers, adults had half the infection risk of children. Twenty six percent (95% CI: 21%, 30%) of infections may be attributed to household transmission. Our results highlight the importance of integrated analysis by influenza sub-type, age and pre-season HI titers in order to infer influenza transmission risks in and outside of the household.


Asunto(s)
Gripe Humana/epidemiología , Gripe Humana/transmisión , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Composición Familiar , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Vietnam/epidemiología , Adulto Joven
15.
Clin Transplant ; 30(2): 124-30, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26537026

RESUMEN

BACKGROUND: Literature reports suggest that non-HLA-antibodies against human endothelial progenitor cells (EPC) can be detected in pre-transplant recipient serum and that EPC antibodies can have a deleterious influence on the graft. METHODS: We investigated 71 renal transplant recipients from living donors for a possible influence of pre-transplant donor-specific IgG and/or IgM recipient antibodies against EPC of the donor using the flow cytometric XM-ONE cross-match. RESULTS: Eight of the 71 patients developed acute biopsy-proven rejection. Two of these patients showed IgM antibodies against EPC prior to transplantation while the other six patients had neither IgG nor IgM EPC antibodies. Conversely, pre-transplant IgG or IgM antibodies against EPC were detected in 19 patients without acute rejection (3 × both IgG and IgM, 1 × IgG and 15 × IgM). The remaining 44 patients had neither EPC antibodies nor experienced rejection. Comparing serum creatinine levels at one month and one yr post-transplant within and among the three patient groups revealed that serum creatinine levels were similar in patients with or without EPC antibodies (p > 0.05). CONCLUSION: In this series of 71 recipients with living donor kidneys, pre-transplant EPC antibodies detected with the XM-ONE test kit were neither associated with acute rejection nor with graft function at one month or one yr.


Asunto(s)
Células Progenitoras Endoteliales/inmunología , Rechazo de Injerto/diagnóstico , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Isoanticuerpos/sangre , Trasplante de Riñón , Donadores Vivos , Adulto , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/epidemiología , Rechazo de Injerto/etiología , Supervivencia de Injerto , Prueba de Histocompatibilidad , Humanos , Isoanticuerpos/inmunología , Fallo Renal Crónico/cirugía , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Pronóstico , Factores de Riesgo , Receptores de Trasplantes
16.
J Pharmacokinet Pharmacodyn ; 43(1): 85-98, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26585899

RESUMEN

In nonlinear mixed effect (NLME) modeling, the intra-individual variability is a collection of errors due to assay sensitivity, dosing, sampling, as well as model misspecification. Utilizing stochastic differential equations (SDE) within the NLME framework allows the decoupling of the measurement errors from the model misspecification. This leads the SDE approach to be a novel tool for model refinement. Using Metformin clinical pharmacokinetic (PK) data, the process of model development through the use of SDEs in population PK modeling was done to study the dynamics of absorption rate. A base model was constructed and then refined by using the system noise terms of the SDEs to track model parameters and model misspecification. This provides the unique advantage of making no underlying assumptions about the structural model for the absorption process while quantifying insufficiencies in the current model. This article focuses on implementing the extended Kalman filter and unscented Kalman filter in an NLME framework for parameter estimation and model development, comparing the methodologies, and illustrating their challenges and utility. The Kalman filter algorithms were successfully implemented in NLME models using MATLAB with run time differences between the ODE and SDE methods comparable to the differences found by Kakhi for their stochastic deconvolution.


Asunto(s)
Hipoglucemiantes/farmacocinética , Metformina/farmacocinética , Algoritmos , Simulación por Computador , Estudios Cruzados , Preparaciones de Acción Retardada , Humanos , Hipoglucemiantes/administración & dosificación , Metformina/administración & dosificación , Dinámicas no Lineales , Ensayos Clínicos Controlados Aleatorios como Asunto , Procesos Estocásticos
17.
Clin Infect Dis ; 61(4): 563-71, 2015 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-25940354

RESUMEN

BACKGROUND: The pandemic potential of avian influenza viruses A(H5N1) and A(H7N9) remains an unresolved but critically important question. METHODS: We compared the characteristics of sporadic and clustered cases of human H5N1 and H7N9 infection, estimated the relative risk of infection in blood-related contacts, and the reproduction number (R). RESULTS: We assembled and analyzed data on 720 H5N1 cases and 460 H7N9 cases up to 2 November 2014. The severity and average age of sporadic/index cases of H7N9 was greater than secondary cases (71% requiring intensive care unit admission vs 33%, P = .007; median age 59 years vs 31, P < .001). We observed no significant differences in the age and severity between sporadic/index and secondary H5N1 cases. The upper limit of the 95% confidence interval (CI) for R was 0.12 for H5N1 and 0.27 for H7N9. A higher proportion of H5N1 infections occurred in clusters (20%) compared to H7N9 (8%). The relative risk of infection in blood-related contacts of cases compared to unrelated contacts was 8.96 for H5N1 (95% CI, 1.30, 61.86) and 0.80 for H7N9 (95% CI, .32, 1.97). CONCLUSIONS: The results are consistent with an ascertainment bias towards severe and older cases for sporadic H7N9 but not for H5N1. The lack of evidence for ascertainment bias in sporadic H5N1 cases, the more pronounced clustering of cases, and the higher risk of infection in blood-related contacts, support the hypothesis that susceptibility to H5N1 may be limited and familial. This analysis suggests the potential pandemic risk may be greater for H7N9 than H5N1.


Asunto(s)
Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H7N9 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/virología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Animales , Número Básico de Reproducción , Niño , Preescolar , Salud de la Familia , Femenino , Humanos , Lactante , Gripe Humana/patología , Masculino , Persona de Mediana Edad , Medición de Riesgo , Índice de Severidad de la Enfermedad , Adulto Joven
18.
J Water Health ; 13(3): 726-36, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26322758

RESUMEN

Because of the recognition that arsenic (As) at low concentrations in drinking water causes severe health effects, the technologies of As removal have become increasingly important. In this study, a simplified and effective method was used to immobilize iron oxyhydroxide onto a pretreated naturally occurring rice straw (RS). The modified RS adsorbent was characterized, using scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analyzer, and surface area analyzer. Experimental batch data of As(V) adsorption were modeled by the isotherms and kinetics models. Although all isotherms, the Langmuir model fitted the equilibrium data better than Freundlich and Dubinin-Radushkevich models and confirmed the surface homogeneity of adsorbent. The iron oxyhydroxide-coated rice straw (IOC-RS) was found to be effective for the removal of As(V) with 98.5% sorption efficiency at a concentration of <50 mg/L of As(V) solution, and thus maximum uptake capacity is ∼22 and 20 mg As(V)/g of IOC-RS at pH 4 and 6, respectively. The present study might provide new avenues to achieve the As concentrations required for drinking water recommended by the World Health Organization.


Asunto(s)
Arsénico/aislamiento & purificación , Compuestos Férricos/química , Oryza/química , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Arsénico/química , Concentración de Iones de Hidrógeno , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
19.
BMC Public Health ; 15: 940, 2015 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-26395076

RESUMEN

BACKGROUND: A dengue outbreak in an ecotourism destination spot in Vietnam, from September to November 2013, impacted a floating village of fishermen on the coastal island of Cat Ba. The outbreak raises questions about how tourism may impact disease spread in rural areas. METHODS: Epidemiological data were obtained from the Hai Phong Preventive Medical Center (PMC), including case histories and residential location from all notified dengue cases from this outbreak. All household addresses were geo-located. Knox test, a spatio-temporal analysis that enables inference dengue clustering constrained by space and time, was performed on the geocoded locations. From the plasma available from two patients, positive for Dengue serotype 3 virus (DENV3), the Envelope (E) gene was sequenced, and their genetic relationships compared to other E sequences in the region. RESULTS: Of 192 dengue cases, the odds ratio of contracting dengue infections for people living in the floating villages compared to those living on the island was 4.9 (95 % CI: 3.6-6.7). The space-time analyses on 111 geocoded dengue residences found the risk of dengue infection to be the highest within 4 days and a radius of 20 m of a given case. Of the total of ten detected clusters with an excess risk greater than 2, the cluster with the highest number of cases was in the floating village area (24 patients for a total duration of 31 days). Phylogenetic analysis revealed a high homology of the two DENV3 strains (genotype III) from Cat Ba with DENV3 viruses circulating in Hanoi in the same year (99.1 %). CONCLUSIONS: Our study showed that dengue transmission is unlikely to be sustained on Cat Ba Island and that the 2013 epidemic likely originated through introduction of viruses from the mainland, potentially Hanoi. These findings suggest that prevention efforts should be focused on mainland rather than on the island.


Asunto(s)
Dengue/epidemiología , Brotes de Enfermedades/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Análisis por Conglomerados , Virus del Dengue , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Filogenia , Población Rural/estadística & datos numéricos , Análisis Espacio-Temporal , Vietnam/epidemiología , Adulto Joven
20.
J Infect Dis ; 207(9): 1442-50, 2013 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-22807519

RESUMEN

BACKGROUND: Dengue is the most common arboviral infection of humans. There are currently no specific treatments for dengue. Balapiravir is a prodrug of a nucleoside analogue (called R1479) and an inhibitor of hepatitis C virus replication in vivo. METHODS: We conducted in vitro experiments to determine the potency of balapiravir against dengue viruses and then an exploratory, dose-escalating, randomized placebo-controlled trial in adult male patients with dengue with <48 hours of fever. RESULTS: The clinical and laboratory adverse event profile in patients receiving balapiravir at doses of 1500 mg (n = 10) or 3000 mg (n = 22) orally for 5 days was similar to that of patients receiving placebo (n = 32), indicating balapiravir was well tolerated. However, twice daily assessment of viremia and daily assessment of NS1 antigenemia indicated balapiravir did not measurably alter the kinetics of these virological markers, nor did it reduce the fever clearance time. The kinetics of plasma cytokine concentrations and the whole blood transcriptional profile were also not attenuated by balapiravir treatment. CONCLUSIONS: Although this trial, the first of its kind in dengue, does not support balapiravir as a candidate drug, it does establish a framework for antiviral treatment trials in dengue and provides the field with a clinically evaluated benchmark molecule. CLINICAL TRIALS REGISTRATION: NCT01096576.


Asunto(s)
Antivirales/administración & dosificación , Dengue/tratamiento farmacológico , Nucleósidos/administración & dosificación , Administración Oral , Adulto , Antígenos Virales/sangre , Antivirales/efectos adversos , Dengue/patología , Dengue/virología , Virus del Dengue/aislamiento & purificación , Método Doble Ciego , Fiebre/tratamiento farmacológico , Humanos , Masculino , Nucleósidos/efectos adversos , Placebos/administración & dosificación , Resultado del Tratamiento , Carga Viral , Viremia/tratamiento farmacológico , Adulto Joven
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