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1.
Environ Res ; 231(Pt 2): 116031, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37156355

RESUMO

OBJECTIVE: Polychlorinated biphenyls (PCBs) have been reported to be a risk factor for premature death, while a high diet quality is thought to lower mortality risk. We aimed to examine whether PCBs were associated with higher all-cause and cause-specific mortality risk and whether such associations could be modified by the diet quality among US middle-aged and older adults. METHODS: Included were 1259 participants aged 40 years or older from the 1999-2004 National Health and Nutrition Examination surveys. Exposure to PCBs was assessed in non-fasting serum samples, and mortality status was ascertained through December 31, 2019 using the public-use, linked mortality files. Diet quality was assessed using the Healthy Eating Index-2015 based on 24-h dietary recalls. Cox proportional hazard regression was applied to assess the associations of different PCB congener groups with mortality and the modifying effect by the diet quality. RESULTS: During a median follow-up of 17.75 years, 419 deaths occurred, including 131 from cardiovascular disease (CVD) and 102 from cancer. Serum concentrations of dioxin-like PCBs and non-dioxin-like PCBs were significantly associated with all-cause mortality, with hazard ratios (HRs) of 1.84 (95% confidence interval [CI], 1.10, 2.99) and 1.82 (1.09, 3.03) for extreme-tertile comparisons. A significant interaction was noted between dioxin-like PCBs and diet quality (P for interaction: 0.012), with a substantially more pronounced association among participants with a low diet quality (HR, 3.47; 95% CI: 1.29, 9.32), compared to those with a high diet quality (HR, 0.98; 95% CI: 0.40, 2.43). A similar weaker association was observed for total PCBs in participants with a high diet quality (P for interaction: 0.032). However, effect modifications by diet quality were not noted for the associations between different PCB groups and CVD mortality. CONCLUSIONS: While our findings need to be validated in other populations and mechanistic studies, they may suggest that a high quality diet could potentially attenuate the harmful effects of chronic PCB exposure.


Assuntos
Doenças Cardiovasculares , Dioxinas , Bifenilos Policlorados , Pessoa de Meia-Idade , Humanos , Idoso , Bifenilos Policlorados/análise , Mortalidade Prematura , Dieta , Doenças Cardiovasculares/induzido quimicamente
2.
Acta Cardiol Sin ; 34(2): 144-151, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29643700

RESUMO

BACKGROUND: Remote cardiac rhythm monitoring and recording, using hand-carried electrocardiogram (ECG) device had been widely used in telemedicine. The feasibility and accuracy analysis on the data recorded by a new miniature ECG system-on-chip (SoC) system has not been explored before. METHODS: This study evaluated the accuracy of the ECG recordings captured by CardioChip - a single-channeled, low-powered, miniature ECG SoC designed for mobile applications; comparing against Philips Pagewriter Trim III - a Food and Drug Administration certified, widely-used standard 12-lead ECG recording device, within Mackay Memorial Hospital in Taiwan. RESULTS: Total of 111 participants, age ranging from 39 to 87years old [mean age: 61.2 ± 13.4, 57 male (51.3%)] were enrolled. Two experienced cardiologists rated and scored the ECG morphology to be the same between the two devices, while CardioChip ECG was more sensitive to baseline noise. R-peak amplitudes measured both devices using single lead information (CardioChip ECG vs. Lead 1 in standard 12-lead ECG) showed statistical consistency. Offline analysis of signal correlation coefficients and coherence showed good correlation with both over 0.94 in average (0.94 ± 0.04 and 0.95 ± 0.04, respectively), high agreement between raters (94% agreement) for detecting abnormal cardiac rhythm with excellent R-peak amplitude (r = 0.98, p < 0.001) and PR interval (r = 0.91, p < 0.001) correlations, indicating excellent correlation between ECG recordings derived from two different modalities. CONCLUSIONS: The results suggested that CardioChip ECG is comparable to medical industry standard ECG. The future implementation of wearable ECG device embedded with miniature ECG system-on-chip (SoC) system is ready for clinical use, which will potentially enhance efficacy on identifying subjects with suspected cardiac arrhythmias.

3.
BMC Bioinformatics ; 17(1): 379, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27634291

RESUMO

BACKGROUND: Pathogen metadata includes information about where and when a pathogen was collected and the type of environment it came from. Along with genomic nucleotide sequence data, this metadata is growing rapidly and becoming a valuable resource not only for research but for biosurveillance and public health. However, current freely available tools for analyzing this data are geared towards bioinformaticians and/or do not provide summaries and visualizations needed to readily interpret results. RESULTS: We designed a platform to easily access and summarize data about pathogen samples. The software includes a PostgreSQL database that captures metadata useful for disease outbreak investigations, and scripts for downloading and parsing data from NCBI BioSample and BioProject into the database. The software provides a user interface to query metadata and obtain standardized results in an exportable, tab-delimited format. To visually summarize results, the user interface provides a 2D histogram for user-selected metadata types and mapping of geolocated entries. The software is built on the LabKey data platform, an open-source data management platform, which enables developers to add functionalities. We demonstrate the use of the software in querying for a pathogen serovar and for genome sequence identifiers. CONCLUSIONS: This software enables users to create a local database for pathogen metadata, populate it with data from NCBI, easily query the data, and obtain visual summaries. Some of the components, such as the database, are modular and can be incorporated into other data platforms. The source code is freely available for download at https://github.com/wchangmitre/bioattribution .


Assuntos
Surtos de Doenças , Genoma Microbiano , Metadados , Software , Bases de Dados Factuais , Genômica , Humanos
4.
Nutrients ; 15(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37447305

RESUMO

(1) Background: it is unclear whether serum vitamin B12 and circulating methylmalonic acid (MMA) are related with a poor prognosis among individuals with chronic kidney disease (CKD); (2) Methods: this prospective cohort study included 2589 individuals with CKD who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004, and from 2011 to 2014, respectively. Hazard ratios (HRs) and 95% Cis for the associations of MMA and vitamin B12 levels with the risk of all-cause and cardiovascular disease (CVD) mortality were calculated using multivariable Cox proportional hazards regression models. Restricted cubic spline analyses were used to examine the non-linear association of MMA levels with all-cause and CVD mortality. (3) Results: among the 2589 participants, we identified 1192 all-cause deaths and 446 CVD deaths, respectively, with a median follow-up of 7.7 years. Compared with participants with MMA < 123 nmol/L, those with MMA ≥ 240 nmol/L had an increased all-cause and CVD mortality in the multivariable-adjusted model [HR (95% CI), 2.01 (1.54-2.62) and 1.76 (1.18-2.63), respectively]; (4) Conclusions: higher circulating MMA levels were found to be strongly associated with an elevated all-cause and CVD mortality among individuals with CKD, while serum vitamin B12 levels were not associated.


Assuntos
Doenças Cardiovasculares , Insuficiência Renal Crônica , Humanos , Ácido Metilmalônico , Inquéritos Nutricionais , Estudos Prospectivos , Vitamina B 12 , Vitaminas
5.
Am J Trop Med Hyg ; 108(4): 684-692, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-36878209

RESUMO

Early prevention of liver injury by controlling risk factors deserves concern because of the heavy liver disease burden. Helicobacter pylori (HP) infection affects half of the world's population and the relationship between it and early liver damage is unclear. This study focuses on assessing the correlation between them in the general population to provide clues to prevent liver disease. A total of 12,931 individuals underwent liver function and imaging tests as well as 13C/14C-urea breath tests. Results showed that the detection rate of HP was 35.9%, and the HP-positive group had a higher rate of liver injury (47.0% versus 44.5%, P = 0.007). Specifically, Fibrosis-4 (FIB-4) and alpha-fetoprotein levels in the HP-positive group were higher whereas the serum albumin level was lower. HP infection would raise the percentage of elevated aspartate aminotransferase (AST; 2.5% versus 1.7%, P = 0.006), elevated FIB-4 (20.2% versus 17.9%, P = 0.002), and abnormal liver imaging (31.0% versus 29.3%, P = 0.048). Most of these results remained stable after covariate adjustment but, for liver injury and liver imaging, the conclusions only held in young people (ORliver injury, odds ratio of liver injury, 1.127, P = 0.040; ORAST, 1.33, P = 0.034; ORFIB-4, 1.145, P = 0.032; ORimaging, 1.149, P = 0.043). Overall, HP infection might be associated with early liver injury, particularly in youth, suggesting that people with early liver injury should pay more attention to HP infection to prevent the occurrence of severe liver diseases.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Hepatopatias , Adolescente , Humanos , Estudos Transversais , Infecções por Helicobacter/complicações , Testes Respiratórios
6.
Anal Chim Acta ; 1206: 339729, 2022 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-35473878

RESUMO

In this work, we proposed a rapid and easy check of the drinking water pollution level due to bacteria growth by semiconductor gas sensor. Highly sensitive vertical channel organic ammonia gas sensor was used to detect the gases emitted from the polluted water, and then determined effective ammonia concentration according to its response. Residues from meat of fish, shrimp, and fruits were mashed and added to the clean water. The water samples were stored at 35 °C for natural decay. Initially the bacteria concentration was below 100 colony forming unit per ml (cfu/ml), then it increased to103 cfu/ml in 2 h and 105 cfu/ml in 4 h, which was beyond the drinking safety standard, 500 cfu/ml. At this gas level no bad odor can be sensed by human yet, however, the effective ammonia concentration of those samples rises to 300-500 ppb in 2 h. The amine gas sensor can therefore be used as a rapid check if the bacteria level inside the water is far over the safety standard.


Assuntos
Água Potável , Amônia , Bactérias , Água Potável/microbiologia , Gases , Semicondutores , Microbiologia da Água
7.
Biophys J ; 100(8): 2024-32, 2011 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-21504739

RESUMO

Experimental and epidemiological studies have shown that the nonsteroidal antiinflammatory drug naproxen may be useful in the treatment of Alzheimer's disease. To investigate the interactions of naproxen with Aß dimers, which are the smallest cytotoxic aggregated Aß peptide species, we use united atom implicit solvent model and exhaustive replica exchange molecular dynamics. We show that naproxen ligands bind to Aß dimer and penetrate its volume interfering with the interpeptide interactions. As a result naproxen induces a destabilizing effect on Aß dimer. By comparing the free-energy landscapes of naproxen interactions with Aß dimers and fibrils, we conclude that this ligand has stronger antiaggregation potential against Aß fibrils rather than against dimers. The analysis of naproxen binding energetics shows that the location of ligand binding sites in Aß dimer is dictated by the Aß amino acid sequence. Comparison of the in silico findings with experimental observations reveals potential limitations of naproxen as an effective therapeutic agent in the treatment of Alzheimer's disease.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/química , Anti-Inflamatórios/farmacologia , Naproxeno/farmacologia , Fragmentos de Peptídeos/química , Multimerização Proteica/efeitos dos fármacos , Sequência de Aminoácidos , Peptídeos beta-Amiloides/metabolismo , Anti-Inflamatórios/metabolismo , Ligantes , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Naproxeno/metabolismo , Fragmentos de Peptídeos/metabolismo , Estabilidade Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína , Solventes/química , Termodinâmica
8.
BMC Bioinformatics ; 12: 109, 2011 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-21507258

RESUMO

BACKGROUND: OmniLog™ phenotype microarrays (PMs) have the capability to measure and compare the growth responses of biological samples upon exposure to hundreds of growth conditions such as different metabolites and antibiotics over a time course of hours to days. In order to manage the large amount of data produced from the OmniLog™ instrument, PheMaDB (Phenotype Microarray DataBase), a web-based relational database, was designed. PheMaDB enables efficient storage, retrieval and rapid analysis of the OmniLog™ PM data. DESCRIPTION: PheMaDB allows the user to quickly identify records of interest for data analysis by filtering with a hierarchical ordering of Project, Strain, Phenotype, Replicate, and Temperature. PheMaDB then provides various statistical analysis options to identify specific growth pattern characteristics of the experimental strains, such as: outlier analysis, negative controls analysis (signal/background calibration), bar plots, pearson's correlation matrix, growth curve profile search, k-means clustering, and a heat map plot. This web-based database management system allows for both easy data sharing among multiple users and robust tools to phenotype organisms of interest. CONCLUSIONS: PheMaDB is an open source system standardized for OmniLog™ PM data. PheMaDB could facilitate the banking and sharing of phenotype data. The source code is available for download at http://phemadb.sourceforge.net.


Assuntos
Bases de Dados Factuais , Armazenamento e Recuperação da Informação/métodos , Fenótipo , Bacillus anthracis/classificação , Bacillus anthracis/crescimento & desenvolvimento , Bacillus anthracis/metabolismo , Internet , Análise em Microsséries , Software
9.
Biophys J ; 98(11): 2662-70, 2010 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-20513411

RESUMO

Using implicit solvent molecular dynamics and replica exchange simulations, we study the impact of ibuprofen on the growth of wild-type Abeta fibrils. We show that binding of ibuprofen to Abeta destabilizes the interactions between incoming peptides and the fibril. As a result, ibuprofen interference modifies the free energy landscape of fibril growth and reduces the free energy gain of Abeta peptide binding to the fibril by approximately 2.5 RT at 360 K. Furthermore, ibuprofen interactions shift the thermodynamic equilibrium from fibril-like locked states to disordered docked states. Ibuprofen's anti-aggregation effect is explained by its competition with incoming Abeta peptides for the same binding site located on the fibril edge. Although ibuprofen impedes fibril growth, it does not significantly change the mechanism of fibril elongation or the structure of Abeta peptides bound to the fibril.


Assuntos
Peptídeos beta-Amiloides/química , Amiloide/química , Ibuprofeno/química , Simulação de Dinâmica Molecular , Fragmentos de Peptídeos/química , Multimerização Proteica/efeitos dos fármacos , Estrutura Quaternária de Proteína , Temperatura , Termodinâmica , Água/química
10.
Proteins ; 78(13): 2849-60, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20635343

RESUMO

Nonsteroidal anti-inflammatory drugs are considered as potential therapeutic agents against Alzheimer's disease. Using replica exchange molecular dynamics and atomistic implicit solvent model, we studied the mechanisms of binding of naproxen and ibuprofen to the Abeta fibril derived from solid-state NMR measurements. The binding temperature of naproxen is found to be almost 40 K higher than of ibuprofen implicating higher binding affinity of naproxen. The key factor, which enhances naproxen binding, is strong interactions between ligands bound to the surface of the fibril. The naphthalene ring in naproxen appears to provide a dominant contribution to ligand-ligand interactions. In contrast, ligand-fibril interactions cannot explain differences in the binding affinities of naproxen and ibuprofen. The concave fibril edge with the groove is identified as the primary binding location for both ligands. We show that confinement of the ligands to the groove facilitates ligand-ligand interactions that lowers the energy of the ligands bound to the concave edge compared with those bound to the convex edge. Our simulations appear to provide microscopic rationale for the differing binding affinities of naproxen and ibuprofen observed experimentally.


Assuntos
Peptídeos beta-Amiloides/química , Ibuprofeno/química , Modelos Moleculares , Naproxeno/química , Sequência de Aminoácidos , Peptídeos beta-Amiloides/metabolismo , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/metabolismo , Sítios de Ligação , Ligação Competitiva , Simulação por Computador , Humanos , Ibuprofeno/metabolismo , Cinética , Dados de Sequência Molecular , Estrutura Molecular , Naproxeno/metabolismo , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Temperatura
11.
J Nat Prod ; 71(11): 1930-3, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18986201

RESUMO

Three new ent-kaurane type diterpenes, broussonetones A-C (1-3), were isolated from leaves of Broussonetia papyrifera, together with seven known compounds, and their structures determined by 1D and 2D NMR and MS methods. Compounds 1-3 were marginal inhibitors of tyrosinase. Antioxidant assays showed them also to be inhibitors of xanthine oxidase. The mild inhibition of tyrosinase and significant inhibition of xanthine oxidase suggests that 1-3 could be useful ingredients in the development of skin-protecting cosmetics.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Broussonetia/química , Diterpenos do Tipo Caurano/isolamento & purificação , Diterpenos do Tipo Caurano/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Plantas Medicinais/química , Antineoplásicos Fitogênicos/química , Antioxidantes/química , Compostos de Bifenilo/farmacologia , Diterpenos do Tipo Caurano/química , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Picratos/farmacologia , Folhas de Planta/química , Taiwan , Xantina Oxidase/antagonistas & inibidores
12.
Artigo em Inglês | MEDLINE | ID: mdl-29857461

RESUMO

Electronic health record (EHR) systems have been used widely in research. However, most of the EHRs are highly dimensional and it is challenging to analyze such large data set. Bioinformatics is an interdisciplinary science with a focus on data management and interpretation for complex biological phenomena. We investigated biomarkers of nutrition from 3001 patients. Multivariate-adjusted hazard ratios of mortality were calculated according to both albumin and sodium levels. We explore the association of aging predicted by all-cause mortality in future.


Assuntos
Biomarcadores , Serviços de Assistência Domiciliar , Mortalidade , Registros Eletrônicos de Saúde , Previsões , Humanos , Modelos de Riscos Proporcionais
13.
Am Surg ; 73(1): 62-6, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17249459

RESUMO

This study prospectively examined the care of trauma patients in extremis on presentation to a tertiary medical center between January 2000 and August 31, 2002. There were 144 patients who presented without a pulse or spontaneous respiration and required cardiopulmonary resuscitation (mean age, 41.5+/-2.3 years; male-to-female ratio, 105:39). Successfully resuscitated patients, who were either admitted to the surgical intensive care unit (SICU) or who were taken to the operating room for surgical exploration, had significantly shorter duration of cardiopulmonary resuscitation (14.55+/-1.64 minutes vs. 33.32+/-1.23 minutes; P < 0.001) and received less amounts of epinephrine than those who died in the emergency room (P < 0.05). One hundred sixteen patients died in the emergency room. Nineteen admitted patients died within 24 hours of presentation. Nine patients survived beyond 24 hours and all of them were admitted directly to the SICU for the management of brain injury. Six patients were taken to the operating room for surgical exploration to control the bleeding; all of them died in the operating room or shortly thereafter in the SICU. No patient in this study survived to be discharged. The financial cost of successfully resuscitated patients was significantly higher than that of patients who died in the emergency room (P < 0.001). Instead of insisting on aggressive measures to resuscitate trauma patients in extremis on presentation, the authors suggest we should redirect that fervor toward efforts made to promote trauma awareness and injury prevention programs.


Assuntos
Apneia/terapia , Reanimação Cardiopulmonar/métodos , Parada Cardíaca/terapia , Ferimentos e Lesões/complicações , Adolescente , Adulto , Idoso , Apneia/etiologia , Apneia/mortalidade , Reanimação Cardiopulmonar/mortalidade , Criança , Pré-Escolar , Feminino , Seguimentos , Parada Cardíaca/etiologia , Parada Cardíaca/mortalidade , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taxa de Sobrevida/tendências , Taiwan/epidemiologia , Índices de Gravidade do Trauma , Resultado do Tratamento , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/terapia
14.
BMC Microbiol ; 6: 48, 2006 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-16737533

RESUMO

BACKGROUND: The lack of detailed understanding of the mechanism of action of many biowarfare agents poses an immediate challenge to biodefense efforts. Many potential bioweapons have been shown to affect the cellular pathways controlling apoptosis 1234. For example, pathogen-produced exotoxins such as Staphylococcal Enterotoxin B (SEB) and Anthrax Lethal Factor (LF) have been shown to disrupt the Fas-mediated apoptotic pathway 24. To evaluate how these agents affect these pathways it is first necessary to understand the dynamics of a normally functioning apoptosis network. This can then serve as a baseline against which a pathogen perturbed system can be compared. Such comparisons can expose both the proteins most susceptible to alteration by the agent as well as the most critical reaction rates to better instill control on a biological network. RESULTS: We explore this through the modeling and simulation of the Fas-mediated apoptotic pathway under normal and SEB influenced conditions. We stimulated human Jurkat cells with an anti-Fas antibody in the presence and absence of SEB and determined the relative levels of seven proteins involved in the core pathway at five time points following exposure. These levels were used to impute relative rate constants and build a quantitative model consisting of a series of ordinary differential equations (ODEs) that simulate the network under both normal and pathogen-influenced conditions. Experimental results show that cells exposed to SEB exhibit an increase in the rate of executioner caspase expression (and subsequently apoptosis) of 1 hour 43 minutes (+/- 14 minutes), as compared to cells undergoing normal cell death. CONCLUSION: Our model accurately reflects these results and reveals intervention points that can be altered to restore SEB-influenced system dynamics back to levels within the range of normal conditions.


Assuntos
Apoptose/efeitos dos fármacos , Simulação por Computador , Enterotoxinas/toxicidade , Modelos Biológicos , Receptores do Fator de Necrose Tumoral/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Murinos , Apoptose/imunologia , Apoptose/fisiologia , Western Blotting , Caspase 3 , Caspase 8 , Caspases/biossíntese , Caspases/genética , Enterotoxinas/imunologia , Citometria de Fluxo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células Jurkat , Método de Monte Carlo , Estatística como Assunto , Fatores de Tempo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/biossíntese , Receptor fas
15.
Am J Cancer Res ; 6(9): 1922-1934, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27725899

RESUMO

Interactions between infiltrating macrophages in the tumor microenvironment (TME) and tumor cells contribute to tumor progression. The potential impacts of recruited macrophages to the upper urinary tract urothelial cell carcinomas (UUTUCs) progression remain unclear. Here we found human UUTUCs might recruit more macrophages than surrounding normal urothelial cells in human clinical specimens and in in vitro co-culture experiments with UUTUC cells and macrophages. The consequences of recruiting more macrophages to UUTUCs might then enhance UUTUC cell growth, migration and invasion. Further investigation found that the androgen receptor (AR) not only enhanced UUTUC cells capacity to recruit more macrophages, it could also promote the macrophages-enhanced UUTUC cells growth, migration and invasion. Downstream AR target cytokine search found AR might function through modulating CCL5 expression to influence UTTUC progression. Interruption of CCL5 partially reversed the AR-regulated macrophage-enhanced UUTUC progression. AR in UUTUC cells also increased tumor formation in vivo. Taken together, these results suggest that macrophages recruitment may enhance UUTUC progression, modulated by AR-CCL5 signal through alterations in chromatin state to establish a tumor microenvironment with recruited macrophages and cytokines to facilitate cell growth, migration and invasion.

16.
Brain Res ; 1025(1-2): 10-20, 2004 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-15464739

RESUMO

Acute social defeat in mice activates the hypothalamic-pituitary-adrenal axis (HPA) and induces long-term behavioral changes, including exaggerated fear responses and inhibition of territorial behavior. Stress-induced hormonal and neurotransmitter release may contribute to disruption of expression of genes important for cell survival, neuronal plasticity, and neuronal remodeling. Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor associated with structural cellular changes that occur during nervous system development and contributes to neural plasticity in the adult brain. In rats, acute (1-2 h) restraint stress transiently reduces BDNF mRNA expression in the hippocampus, a region important in the memory and in HPA regulation; restraint stress also decreases BDNF expression in the basolateral amygdala (BLA), a region important for fear consolidation and emotional memory. We hypothesized that a brief (10 min) exposure to intense social stress, a more naturalistic stressor than restraint stress, would also reduce BDNF mRNA in the hippocampus and BLA of mice. In the present study, we examined the time course of expression of BDNF mRNA expression in the hippocampus and amygdala, as well as other subcortical and cortical brain regions, following acute social stress. In situ hybridization analysis for BDNF mRNA expression showed that there was a significant decrease in BDNF mRNA expression in all regions studied in mice 24 h after social defeat when compared to control (naive) mice (P<0.05). These findings support our hypothesis that BDNF mRNA levels are reduced by social stress, and may have implications for brain plasticity and behavioral changes following social stress.


Assuntos
Córtex Cerebral/metabolismo , Fatores de Crescimento Neural/biossíntese , Comportamento Social , Estresse Psicológico/metabolismo , Animais , Regulação da Expressão Gênica/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
17.
Toxicol Sci ; 126(2): 497-505, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22240983

RESUMO

The highly toxic organophosphorus compound VX [O-ethyl S-[2-(diisopropylamino)ethyl]methylphosphonate] is an irreversible inhibitor of the enzyme acetylcholinesterase (AChE). Prolonged inhibition of AChE increases endogenous levels of acetylcholine and is toxic at nerve synapses and neuromuscular junctions. We hypothesized that repeated exposure to sublethal doses of VX would affect genes associated with cell survival, neuronal plasticity, and neuronal remodeling, including brain-derived neurotrophic factor (BDNF). We examined the time course of BDNF expression in C57BL/6 mouse brain following repeated exposure (1/day × 5 days/week × 2 weeks) to sublethal doses of VX (0.2 LD(50) and 0.4 LD(50)). BDNF messenger RNA expression was significantly (p < 0.05) elevated in multiple brain regions, including the dentate gyrus, CA3, and CA1 regions of the hippocampal formation, as well as the piriform cortex, hypothalamus, amygdala, and thalamus, 72 h after the last 0.4 LD(50) VX exposure. BDNF protein expression, however, was only increased in the CA3 region of the hippocampus. Whether increased BDNF in response to sublethal doses of VX exposure is an adaptive response to prevent cellular damage or a precursor to impending brain damage remains to be determined. If elevated BDNF is an adaptive response, exogenous BDNF may be a potential therapeutic target to reduce the toxic effects of nerve agent exposure.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Substâncias para a Guerra Química/toxicidade , Compostos Organotiofosforados/toxicidade , Animais , Encéfalo/metabolismo , Hibridização In Situ , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Compostos Organotiofosforados/administração & dosagem
18.
PLoS One ; 6(5): e20335, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21655255

RESUMO

Human Serum paraoxonase 1 (HuPON1) is an enzyme that has been shown to hydrolyze a variety of chemicals including the nerve agent VX. While wildtype HuPON1 does not exhibit sufficient activity against VX to be used as an in vivo countermeasure, it has been suggested that increasing HuPON1's organophosphorous hydrolase activity by one or two orders of magnitude would make the enzyme suitable for this purpose. The binding interaction between HuPON1 and VX has recently been modeled, but the mechanism for VX hydrolysis is still unknown. In this study, we created a transition state model for VX hydrolysis (VX(ts)) in water using quantum mechanical/molecular mechanical simulations, and docked the transition state model to 22 experimentally characterized HuPON1 variants using AutoDock Vina. The HuPON1-VX(ts) complexes were grouped by reaction mechanism using a novel clustering procedure. The average Vina interaction energies for different clusters were compared to the experimentally determined activities of HuPON1 variants to determine which computational procedures best predict how well HuPON1 variants will hydrolyze VX. The analysis showed that only conformations which have the attacking hydroxyl group of VX(ts) coordinated by the sidechain oxygen of D269 have a significant correlation with experimental results. The results from this study can be used for further characterization of how HuPON1 hydrolyzes VX and design of HuPON1 variants with increased activity against VX.


Assuntos
Arildialquilfosfatase/metabolismo , Compostos Organotiofosforados/química , Compostos Organotiofosforados/metabolismo , Arildialquilfosfatase/genética , Humanos , Hidrólise , Modelos Moleculares
19.
J Mol Model ; 17(1): 97-109, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20379755

RESUMO

Human serum paraoxonase 1 (HuPON1) is an enzyme that can hydrolyze various chemical warfare nerve agents including VX. A previous study has suggested that increasing HuPON1's VX hydrolysis activity one to two orders of magnitude would make the enzyme an effective countermeasure for in vivo use against VX. This study helps facilitate further engineering of HuPON1 for enhanced VX-hydrolase activity by computationally characterizing HuPON1's tertiary structure and how HuPON1 binds VX. HuPON1's structure is first predicted through two homology modeling procedures. Docking is then performed using four separate methods, and the stability of each bound conformation is analyzed through molecular dynamics and solvated interaction energy calculations. The results show that VX's lone oxygen atom has a strong preference for forming a direct electrostatic interaction with HuPON1's active site calcium ion. Various HuPON1 residues are also detected that are in close proximity to VX and are therefore potential targets for future mutagenesis studies. These include E53, H115, N168, F222, N224, L240, D269, I291, F292, and V346. Additionally, D183 was found to have a predicted pKa near physiological pH. Given D183's location in HuPON1's active site, this residue could potentially act as a proton donor or accepter during hydrolysis. The results from the binding simulations also indicate that steered molecular dynamics can potentially be used to obtain accurate binding predictions even when starting with a closed conformation of a protein's binding or active site.


Assuntos
Arildialquilfosfatase/química , Arildialquilfosfatase/metabolismo , Substâncias para a Guerra Química/química , Biologia Computacional , Compostos Organotiofosforados/química , Domínio Catalítico/fisiologia , Substâncias para a Guerra Química/metabolismo , Humanos , Hidrólise , Modelos Moleculares , Simulação de Dinâmica Molecular , Compostos Organotiofosforados/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Especificidade por Substrato
20.
PLoS One ; 6(3): e17836, 2011 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-21464989

RESUMO

BACKGROUND: Despite the decades-long use of Bacillus atrophaeus var. globigii (BG) as a simulant for biological warfare (BW) agents, knowledge of its genome composition is limited. Furthermore, the ability to differentiate signatures of deliberate adaptation and selection from natural variation is lacking for most bacterial agents. We characterized a lineage of BGwith a long history of use as a simulant for BW operations, focusing on classical bacteriological markers, metabolic profiling and whole-genome shotgun sequencing (WGS). RESULTS: Archival strains and two "present day" type strains were compared to simulant strains on different laboratory media. Several of the samples produced multiple colony morphotypes that differed from that of an archival isolate. To trace the microevolutionary history of these isolates, we obtained WGS data for several archival and present-day strains and morphotypes. Bacillus-wide phylogenetic analysis identified B. subtilis as the nearest neighbor to B. atrophaeus. The genome of B. atrophaeus is, on average, 86% identical to B. subtilis on the nucleotide level. WGS of variants revealed that several strains were mixed but highly related populations and uncovered a progressive accumulation of mutations among the "military" isolates. Metabolic profiling and microscopic examination of bacterial cultures revealed enhanced growth of "military" isolates on lactate-containing media, and showed that the "military" strains exhibited a hypersporulating phenotype. CONCLUSIONS: Our analysis revealed the genomic and phenotypic signatures of strain adaptation and deliberate selection for traits that were desirable in a simulant organism. Together, these results demonstrate the power of whole-genome and modern systems-level approaches to characterize microbial lineages to develop and validate forensic markers for strain discrimination and reveal signatures of deliberate adaptation.


Assuntos
Bacillus/genética , Armas Biológicas , Engenharia Genética/métodos , Genoma Bacteriano/genética , Alelos , Bacillus/citologia , Bacillus/enzimologia , Bacillus/isolamento & purificação , Pareamento de Bases/genética , Catalase/metabolismo , Contagem de Colônia Microbiana , Biologia Computacional , Análise Mutacional de DNA , Evolução Molecular , Genótipo , Mutação INDEL/genética , Metaboloma/genética , Fenótipo , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNA , Deleção de Sequência , Esporos Bacterianos/genética
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