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1.
J Fluoresc ; 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38457078

RESUMO

The design and development of a fluorescence sensor aimed at detecting and quantifying trace amounts of toxic transition metal ions within environmental, biological, and aquatic samples has garnered significant attention from diagnostic and testing laboratories, driven by the imperative to mitigate the health risks associated with these contaminants. In this context, we present the utilization of a heterocyclic symmetrical Schiff Base derivative for the purpose of fluorogenic and chromogenic detection of Co2+, Cu2+ and Hg2+ ions. The characterization of the ligand involved a comprehensive array of techniques, including physical assessments, optical analyses, NMR, FT-IR, and mass spectrometric examinations. The mechanism of ligand-metal complexation was elucidated through the utilization of photophysical parameters and FT-IR spectroscopic analysis, both before and after the interaction between the ligand and the metal salt solution. The pronounced alterations observed in absorption and fluorescence spectra, along with the distinctive chromogenic changes, following treatment with Co2+, Cu2+ and Hg2+, affirm the successful formation of complexes between the ligands and the treated metal ions. Notably, the receptor's complexation response exhibited selectivity towards Co(II), Cu(II), and Hg(II), with no observed chromogenic changes, spectral variations, or band shifts for the various tested metal ions, including Na+, Ag+, Ni2+, Mn2+, Pd2+, Pb2+, Cd2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+ and Al3+. This absence of interaction between these metal ions and the ligand could be attributed to their compact or inadequately conducive conduction bands for complexation with the ligand's structural composition. To quantify the sensor's efficacy, fluorescence titration spectra were employed to determine the detection limits for Co2+, Cu2+ and Hg2+, yielding values of 2.92 × 10-8, 8.91 × 10-8, and 4.39 × 10-3 M, respectively. The Benesi-Hildebrand plots provided association constant values for the ligand-cobalt, ligand-copper, and ligand-mercury complexes as 0.74, 2.52, and 13.89 M-1, respectively.

2.
J Fluoresc ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38625572

RESUMO

This study was based on the development of surface-based photoluminescence sensor for metal detection, quantification, and sample purification employing the solid sensory chip having the capability of metal entrapment. The Co(II), Cu(II) and Hg(II) sensitive fluorescence sensor (TP) was first synthesized and characterized its sensing abilities towards tested metal ions by using fluorescence spectral investigation while the synthesis and complexation of the receptor was confirmed by the chromogenic, optical, spectroscopic and spectrometric analysis. Under optical investigation, the ligand solution exhibited substantial chromogenic changes as well as spectral variations upon reacting with copper, cobalt, and mercuric ions, while these behaviors were not seen for the rest of tested metallic ions i.e., Na+, Ag+, Ni2+, Mn2+, Pd2+, Pb2+, Cd2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+, and Al3+. These colorimetric alterations and spectral shifting could potentially be employed to detect and quantify these specific metal ions. After the establishment of the ligand's selective complexation ability towards selected metals, it was fabricated over the substituted porous silicon surface (FPS) keeping in view of the development of surface-based photoluminescence sensor (TP-FPS) for the selected metal sensation and entrapment to purify the sample just be putting off the metal entrapped sensory solid chip. Surface characterization and ligand fabrication was inspected by plan and cross sectional electron microscopic investigations, vibrational and electronic spectral analysis. The sensitivity of the ligand (TP) in the solution phase metal discrimination was determined by employing the fluorescence titration analysis of the ligand solution after progressive induction of Co2+, Cu2+, and Hg2+, which afford the detection limit values of 2.14 × 10- 8, 3.47 × 10- 8 and 3.13 × 10- 3, respectively. Concurrently, photoluminescence titration of the surface fabricated sensor (TP-FPS) revealed detection limit values of 3.14 × 10- 9, 7.43 × 10- 9, and 8.21 × 10- 4, respectively, for the selected metal ions.

3.
J Fluoresc ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913090

RESUMO

Fluorescent cytotoxic compounds with readout delivery are crucial in chemotherapy. The growing demands of these treatment strategies require the novel heterocyclic molecules with better selectivity alongside fluorescence marker potential. In this context, a series of nine isatin Schiff base derivatives 4a-i were synthesized, characterized and evaluated for UV-visible, fluorescence, thermal and bioanalysis in order to explore the effect of structure on their bioprofiles. The analogue 4d exhibited maximum cytotoxic activity on Hella cells with percentage inhibition of 83% at 50 µM and 100% at 150 µM concentrations while 4c showed minimum cytotoxic activity with the value of 19% at 50 µM and 22% at 150 µM concentrations. Meanwhile, 4g was found to exhibit maximum inhibition potential towards Vero Cells with the percentage inhibition values of 83 at 50 µM concentration. The overall SAR study showed that the para-fluoro-substituted isatin moieties exhibited the appreciable percentage inhibition while the least activity was delivered by the isatin derivatives with para-bromo substitution.

4.
Emerg Infect Dis ; 29(2): 393-396, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36692447

RESUMO

Spillovers of Nipah virus (NiV) from Pteropus bats to humans occurs frequently in Bangladesh, but the risk for spillover into other animals is poorly understood. We detected NiV antibodies in cattle, dogs, and cats from 6 sites where spillover human NiV infection cases occurred during 2013-2015.


Assuntos
Quirópteros , Infecções por Henipavirus , Vírus Nipah , Humanos , Animais , Cães , Bovinos , Bangladesh/epidemiologia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/veterinária , Surtos de Doenças
5.
Proc Natl Acad Sci U S A ; 117(46): 29190-29201, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33139552

RESUMO

Nipah virus (NiV) is an emerging bat-borne zoonotic virus that causes near-annual outbreaks of fatal encephalitis in South Asia-one of the most populous regions on Earth. In Bangladesh, infection occurs when people drink date-palm sap contaminated with bat excreta. Outbreaks are sporadic, and the influence of viral dynamics in bats on their temporal and spatial distribution is poorly understood. We analyzed data on host ecology, molecular epidemiology, serological dynamics, and viral genetics to characterize spatiotemporal patterns of NiV dynamics in its wildlife reservoir, Pteropus medius bats, in Bangladesh. We found that NiV transmission occurred throughout the country and throughout the year. Model results indicated that local transmission dynamics were modulated by density-dependent transmission, acquired immunity that is lost over time, and recrudescence. Increased transmission followed multiyear periods of declining seroprevalence due to bat-population turnover and individual loss of humoral immunity. Individual bats had smaller host ranges than other Pteropus species (spp.), although movement data and the discovery of a Malaysia-clade NiV strain in eastern Bangladesh suggest connectivity with bats east of Bangladesh. These data suggest that discrete multiannual local epizootics in bat populations contribute to the sporadic nature of NiV outbreaks in South Asia. At the same time, the broad spatial and temporal extent of NiV transmission, including the recent outbreak in Kerala, India, highlights the continued risk of spillover to humans wherever they may interact with pteropid bats and the importance of limiting opportunities for spillover throughout Pteropus's range.


Assuntos
Quirópteros/virologia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/transmissão , Infecções por Henipavirus/veterinária , Infecções por Henipavirus/virologia , Vírus Nipah/classificação , Vírus Nipah/genética , Animais , Ásia , Bangladesh/epidemiologia , Surtos de Doenças , Feminino , Especificidade de Hospedeiro , Humanos , Imunidade , Masculino , Modelos Biológicos , Epidemiologia Molecular , Vírus Nipah/imunologia , Filogenia , Zoonoses/epidemiologia , Zoonoses/imunologia , Zoonoses/transmissão , Zoonoses/virologia
6.
Emerg Infect Dis ; 28(7): 1384-1392, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35731130

RESUMO

Knowledge of the dynamics and genetic diversity of Nipah virus circulating in bats and at the human-animal interface is limited by current sampling efforts, which produce few detections of viral RNA. We report a series of investigations at Pteropus medius bat roosts identified near the locations of human Nipah cases in Bangladesh during 2012-2019. Pooled bat urine was collected from 23 roosts; 7 roosts (30%) had >1 sample in which Nipah RNA was detected from the first visit. In subsequent visits to these 7 roosts, RNA was detected in bat urine up to 52 days after the presumed exposure of the human case-patient, although the probability of detection declined rapidly with time. These results suggest that rapidly deployed investigations of Nipah virus shedding from bat roosts near human cases could increase the success of viral sequencing compared with background surveillance and could enhance understanding of Nipah virus ecology and evolution.


Assuntos
Quirópteros , Infecções por Henipavirus , Vírus Nipah , Animais , Bangladesh/epidemiologia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/veterinária , Humanos , Vírus Nipah/genética , RNA Viral/genética
7.
Molecules ; 27(18)2022 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-36144642

RESUMO

Organic solar cells are famous for their cheap solution processing. Their industrialization needs fast designing of efficient materials. For this purpose, testing of large number of materials is necessary. Machine learning is a better option due to cheaper prediction of power conversion efficiencies. In the present work, machine learning was used to predict power conversion efficiencies. Experimental data were collected from the literature to feed the machine learning models. A detailed data visualization analysis was performed to study the trends of the dataset. The relationship between descriptors and power conversion efficiency was quantitatively determined by Pearson correlations. The importance of features was also determined using feature importance analysis. More than 10 machine learning models were tried to find better models. Only the two best models (random forest regressor and bagging regressor) were selected for further analysis. The prediction ability of these models was high. The coefficient of determination (R2) values for the random forest regressor and bagging regressor models were 0.892 and 0.887, respectively. The Shapley additive explanation (SHAP) method was used to identify the impact of descriptors on the output of models.


Assuntos
Visualização de Dados , Aprendizado de Máquina , Projetos de Pesquisa
8.
J Vet Pharmacol Ther ; 44(3): 298-312, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33438767

RESUMO

Microencapsulation is a process where very minute droplets or particles of solid or liquid or gas are trapped with a polymer to isolate the internal core material from external environmental hazards. Microencapsulation is applied mostly for flavor masking, fortification, and sustained and control release. It improves palatability, absorption, and bioavailability of drugs with good conformity. Microencapsulation has been widely studied in numerous drug delivery systems for human health. The application of microcapsules in the veterinary pharmaceutical sciences is increasing day by day. The treatment systems for humans and animals are likely to be similar, but more complex in the veterinary field due to the diversity of the species, breeds, body size, biotransformation rate, and other factors associated with animal physiology. Commercially viable, economically profitable, and therapeutically effective microencapsulated vaccine, anthelmintic, antibacterial, and other therapeutics have a great demand for livestock and poultry production. Nowadays, researchers emphasize the controlled and sustained-release dosage form of drugs in the veterinary field. This paper has highlighted the microencapsulation materials, preparation techniques, characteristics, roles, and the application of microcapsules in veterinary medicine.


Assuntos
Polímeros , Animais , Disponibilidade Biológica , Cápsulas
9.
J Environ Manage ; 287: 112257, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33690013

RESUMO

The economic developments around the globe resulted in the increased demand of energy, which overburdened the supply chain sources of energy. Fossil fuel reserves are exploited to meet the high demand of energy and their combustion is becoming the main source of environmental pollution. So there is dire need to find safe, renewable and sustainable energy resources. Waste to energy (WtE) may be viewed as a possible alternate source of energy, which is economically and environmentally sustainable. Municipal solid waste (MSW) is a major contributor to the development of renewable energy and sustainable environment. At present the scarcity of renewable energy resources and disposal of MSW is a challenging problem for the developing countries, which has generated a wide ranging socioeconomic and environmental problems. This situation stimulates the researchers to develop alternatives for converting WtE under a variety of scenarios. Herein, the present scenario in developing the WtE technologies such as, thermal conversion methods (Incineration, Gasification, Pyrolysis, Torrefaction), Plasma technology, Biochemical methods, Chemical and Mechanical methods, Bio-electrochemical process, Mechanical biological treatment (MBT), Photo-biological processes for efficacious energy recovery and the challenges confronted by developing and developed countries. In this review, a framework for the evaluation of WtE technologies has been presented for the ease of researchers working in the field. Furthermore, this review concluded that WtE is a potential renewable energy source that will partially satisfy the demand for energy and ensure an efficient MSW management to overcome the environmental pollution.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Biomassa , Incineração , Resíduos Sólidos , Tecnologia
10.
Langmuir ; 36(27): 7908-7915, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32551692

RESUMO

Nanostructures play an important role in targeting sparingly water-soluble drugs to specific sites. Because of the structural flexibility and stability, the use of template microemulsions (µEs) can produce functional nanopharmaceuticals of different sizes, shapes, and chemical properties. In this article, we report a new volatile oil-in-water (o/w) µE formulation comprising ethyl acetate/ethanol/brij-35/water to obtain the highly water-dispersible nanoparticles of an antihyperlipidemic agent, ezetimibe (EZM-NPs), to enhance its dissolution profile. A pseudoternary phase diagram was delineated in a specified brij-35/ethanol ratio (1:1) to describe the transparent, optically isotropic domain of the as-formulated µE. The water-dilutable µE formulation, comprising an optimum composition of ethyl acetate (18.0%), ethanol (25.0%), brij-35 (25.0%), and water (32.0%), showed a good dissolvability of EZM around 4.8 wt % at pH 5.2. Electron micrographs showed a fine monomodal collection of EZM-loaded µE droplets (∼45 nm) that did not coalesce even after lyophilization, forming small spherical EZM-NPs (∼60 nm). However, the maturity of nanodrug droplets observed through dynamic light scattering suggests the affinity of EZM to the nonpolar microenvironment, which was further supported through peak-to-peak correlation of infrared analysis and fluorescence measurements. Moreover, the release profile of the as-obtained EZM-nanopowder increased significantly >98% in 30 min, which indicates that a reduced drug concentration will be needed for capsules or tablets in the future and can be simply incorporated into the multidosage formulation of EZM.


Assuntos
Hipolipemiantes , Água , Emulsões , Ezetimiba , Solubilidade
11.
Proc Natl Acad Sci U S A ; 114(43): E9135-E9144, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29073110

RESUMO

Alzheimer's disease (AD) comprises multifactorial ailments for which current therapeutic strategies remain insufficient to broadly address the underlying pathophysiology. Epigenetic gene regulation relies upon multifactorial processes that regulate multiple gene and protein pathways, including those involved in AD. We therefore took an epigenetic approach where a single drug would simultaneously affect the expression of a number of defined AD-related targets. We show that the small-molecule histone deacetylase inhibitor M344 reduces beta-amyloid (Aß), reduces tau Ser396 phosphorylation, and decreases both ß-secretase (BACE) and APOEε4 gene expression. M344 increases the expression of AD-relevant genes: BDNF, α-secretase (ADAM10), MINT2, FE65, REST, SIRT1, BIN1, and ABCA7, among others. M344 increases sAPPα and CTFα APP metabolite production, both cleavage products of ADAM10, concordant with increased ADAM10 gene expression. M344 also increases levels of immature APP, supporting an effect on APP trafficking, concurrent with the observed increase in MINT2 and FE65, both shown to increase immature APP in the early secretory pathway. Chronic i.p. treatment of the triple transgenic (APPsw/PS1M146V/TauP301L) mice with M344, at doses as low as 3 mg/kg, significantly prevented cognitive decline evaluated by Y-maze spontaneous alternation, novel object recognition, and Barnes maze spatial memory tests. M344 displays short brain exposure, indicating that brief pulses of daily drug treatment may be sufficient for long-term efficacy. Together, these data show that M344 normalizes several disparate pathogenic pathways related to AD. M344 therefore serves as an example of how a multitargeting compound could be used to address the polygenic nature of multifactorial diseases.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Memória/efeitos dos fármacos , Proteína ADAM10/genética , Proteína ADAM10/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Aprendizagem em Labirinto/efeitos dos fármacos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Memória/fisiologia , Camundongos Transgênicos , Fragmentos de Peptídeos/metabolismo , Proteínas Repressoras/genética , Vorinostat
12.
Cell Mol Life Sci ; 75(7): 1163-1178, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29080090

RESUMO

Many pathogenic bacteria require flagella-mediated motility to colonise and persist in their hosts. Helicobacter pylori and Campylobacter jejuni are flagellated epsilonproteobacteria associated with several human pathologies, including gastritis, acute diarrhea, gastric carcinoma and neurological disorders. In both species, glycosylation of flagellin with an unusual sugar pseudaminic acid (Pse) plays a crucial role in the biosynthesis of functional flagella, and thereby in bacterial motility and pathogenesis. Pse is found only in pathogenic bacteria. Its biosynthesis via six consecutive enzymatic steps has been extensively studied in H. pylori and C. jejuni. This review highlights the importance of flagella glycosylation and details structural insights into the enzymes in the Pse pathway obtained via a combination of biochemical, crystallographic, and mutagenesis studies of the enzyme-substrate and -inhibitor complexes. It is anticipated that understanding the underlying structural and molecular basis of the catalytic mechanisms of the Pse-synthesising enzymes will pave the way for the development of novel antimicrobials.


Assuntos
Campylobacter jejuni/metabolismo , Flagelina/metabolismo , Helicobacter pylori/metabolismo , Açúcares Ácidos/metabolismo , Infecções Bacterianas/microbiologia , Fenômenos Fisiológicos Bacterianos , Campylobacter jejuni/patogenicidade , Flagelos/metabolismo , Flagelos/fisiologia , Glicosilação , Helicobacter pylori/patogenicidade , Interações Hospedeiro-Patógeno
13.
BMC Vet Res ; 14(1): 31, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-29382338

RESUMO

BACKGROUND: Infectious diseases in farmed animals have economic, social, and health consequences. Foreign animal diseases (FAD) of swine are of significant concern. Mathematical and simulation models are often used to simulate FAD outbreaks and best practices for control. However, simulation outcomes are sensitive to the population structure used. Within Canada, access to individual swine farm population data with which to parameterize models is a challenge because of privacy concerns. Our objective was to develop a methodology to model the farmed swine population in Ontario, Canada that could represent the existing population structure and improve the efficacy of simulation models. RESULTS: We developed a swine population model based on the factors such as facilities supporting farm infrastructure, land availability, zoning and local regulations, and natural geographic barriers that could affect swine farming in Ontario. Assigned farm locations were equal to the swine farm density described in the 2011 Canadian Census of Agriculture. Farms were then randomly assigned to farm types proportional to the existing swine herd types. We compared the swine population models with a known database of swine farm locations in Ontario and found that the modeled population was representative of farm locations with a high accuracy (AUC: 0.91, Standard deviation: 0.02) suggesting that our algorithm generated a reasonable approximation of farm locations in Ontario. CONCLUSION: In the absence of a readily accessible dataset providing details of the relative locations of swine farms in Ontario, development of a model livestock population that captures key characteristics of the true population structure while protecting privacy concerns is an important methodological advancement. This methodology will be useful for individuals interested in modeling the spread of pathogens between farms across a landscape and using these models to evaluate disease control strategies.


Assuntos
Fazendas/classificação , Modelos Teóricos , Suínos , Criação de Animais Domésticos/métodos , Animais , Bases de Dados Factuais , Geografia , Ontário
14.
Cell Mol Life Sci ; 74(18): 3293-3303, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28409190

RESUMO

Chemotaxis is the directed motility by means of which microbes sense chemical cues and relocate towards more favorable environments. Methyl-accepting chemotaxis proteins (MCPs) are the most common receptors in bacteria and archaea. They are arranged as trimers of dimers that, in turn, form hexagonal arrays in the cytoplasmic membrane or in the cytoplasm. Several different classes of MCPs have been identified according to their ligand binding region and membrane topology. MCPs have been further classified based on the length and sequence conservation of their cytoplasmic domains. Clusters of membrane-embedded MCPs often localize to the poles of the cell, whereas cytoplasmic MCPs can be targeted to the poles or distributed throughout the cell body. MCPs play an important role in cell survival, pathogenesis, and biodegradation. Bacterial adaptation to diverse environmental conditions promotes diversity among the MCPs. This review summarizes structure, classification, and structure-activity relationship of the known MCP receptors, with a brief overview of the signal transduction mechanisms in bacteria and archaea.


Assuntos
Archaea/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil/metabolismo , Células Procarióticas/metabolismo , Archaea/classificação , Quimiotaxia , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil/química , Células Procarióticas/classificação , Domínios Proteicos , Transdução de Sinais , Relação Estrutura-Atividade
15.
J Infect Dis ; 216(suppl_4): S520-S528, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28934459

RESUMO

Background: In March 2011, a multidisciplinary team investigated 2 human cases of highly pathogenic avian influenza A(H5N1) virus infection, detected through population-based active surveillance for influenza in Bangladesh, to assess transmission and contain further spread. Methods: We collected clinical and exposure history of the case patients and monitored persons coming within 1 m of a case patient during their infectious period. Nasopharyngeal wash specimens from case patients and contacts were tested with real-time reverse-transcription polymerase chain reaction, and virus culture and isolates were characterized. Serum samples were tested with microneutralization and hemagglutination inhibition assays. We tested poultry, wild bird, and environmental samples from case patient households and surrounding areas for influenza viruses. Results: Two previously healthy case patients, aged 13 and 31 months, had influenzalike illness and fully recovered. They had contact with poultry 7 and 10 days before illness onset, respectively. None of their 57 contacts were subsequently ill. Clade 2.2.2.1 highly pathogenic avian influenza H5N1 viruses were isolated from the case patients and from chicken fecal samples collected at the live bird markets near the patients' dwellings. Conclusion: Identification of H5N1 cases through population-based surveillance suggests possible additional undetected cases throughout Bangladesh and highlights the importance of surveillance for mild respiratory illness among populations frequently exposed to infected poultry.


Assuntos
Surtos de Doenças , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/epidemiologia , Infecções Respiratórias/epidemiologia , Animais , Animais Selvagens/virologia , Bangladesh/epidemiologia , Pré-Escolar , Fezes/virologia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Vigilância da População , Aves Domésticas/virologia , Infecções Respiratórias/virologia , Manejo de Espécimes , Inquéritos e Questionários
16.
Int J Mol Sci ; 17(7)2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-27367672

RESUMO

General control non-repressible 5 (GCN5)-related N-acetyltransferases (GNAT) catalyze the transfer of an acyl moiety from acyl coenzyme A (acyl-CoA) to a diverse group of substrates and are widely distributed in all domains of life. This review of the currently available data acquired on GNAT enzymes by a combination of structural, mutagenesis and kinetic methods summarizes the key similarities and differences between several distinctly different families within the GNAT superfamily, with an emphasis on the mechanistic insights obtained from the analysis of the complexes with substrates or inhibitors. It discusses the structural basis for the common acetyltransferase mechanism, outlines the factors important for the substrate recognition, and describes the mechanism of action of inhibitors of these enzymes. It is anticipated that understanding of the structural basis behind the reaction and substrate specificity of the enzymes from this superfamily can be exploited in the development of novel therapeutics to treat human diseases and combat emerging multidrug-resistant microbial infections.


Assuntos
Acetiltransferases/química , Acetiltransferases/metabolismo , Acetiltransferases/antagonistas & inibidores , Animais , Domínio Catalítico , Cristalografia por Raios X , Inibidores Enzimáticos/farmacologia , Histona Acetiltransferases/antagonistas & inibidores , Histona Acetiltransferases/química , Histona Acetiltransferases/metabolismo , Humanos , Modelos Moleculares , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Especificidade por Substrato
17.
J Infect Dis ; 212(4): 562-9, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25712969

RESUMO

INTRODUCTION: Given that influenza A(H9N2) is recognized as a pandemic threat, we evaluated the overall burden of influenza A(H9N2) infections among avian-exposed human populations. METHODS: We performed a systematic search of PubMed, AGRICOLA, and CAB Abstracts databases for literature published during 1997-2013. Studies reporting serological evidence of human influenza A(H9N2) infection among avian-exposed populations were included. We used a World Health Organization (WHO)-recommended case definition for serological evidence of infection based on results of hemagglutination inhibition (HI) and microneutralization (MN) assays. We calculated overall seroprevalence through a random effects meta-analysis model. RESULTS: Seroprevalence data reported by the studies ranged from 1% to 43% (median, 9%) by HI, which was not significantly different from the seroprevalence estimated through the WHO-recommended case definition (median, 1.3%; range, 0.5%-42.6%). Reported seroprevalence by MN ranged from 0.6% to 9% (median, 2.7%), which was greater than the seroprevalence estimated through the WHO-recommended case definition (median, 0.3%; range, 0.1%-1.4%). CONCLUSIONS: A small proportion of avian-exposed humans had evidence of influenza A(H9N2) infection. As the virus has a near global distribution in poultry, it seems likely that present surveillance efforts are missing mild or asymptomatic infections among avian-exposed persons. It seems prudent to closely monitor avian-exposed populations for influenza A(H9N2) infection to provide prepandemic warnings.


Assuntos
Vírus da Influenza A Subtipo H9N2/imunologia , Influenza Humana/epidemiologia , Animais , Anticorpos Antivirais/sangue , Humanos , Influenza Humana/imunologia , Influenza Humana/virologia , Estudos Soroepidemiológicos , Zoonoses
18.
Pak J Pharm Sci ; 29(2): 489-95, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27087094

RESUMO

The current study was designed to check the antioxidant and enzyme inhibition potential of various extracts/ fractions of three selected plants. The aerial parts of Conocarpus erectus (Combretaceae), Ficus variegata (Moraceae) and Ficus maclellandii (Moraceae) were extracted with ethanol (95%) and the resulting crude extracts were partitioned with n-hexane, chloroform and n-butanol successively. Folin-Ciocalteu reagent was used to calculate the total phenolic contents, flavonoids contents were calculated with aluminum chloride while antioxidant and enzyme studies were carried out through standard protocols. All extracts/fractions contained reasonable amount of phenolic compounds ranging from 0.58-58.23 mg CE/g of DW and 0.43-30.56 mg GAE/g of DW. Total flavonoids were determined using rutin and quercetin standards, ranging from 2.65-18.2 mg rutin equivalent/g of dry weight and 0.92-5.41 mg quercetin equivalent/g of dry weight. Antioxidant studies such as DPPH inhibition FRAP and total antioxidant capacity (TAC) was checked. The crude ethanolic extract of C. erectus showed maximum antiradical scavenging power (90.43%; IC50=7 µg) and ferric reducing antioxidant power (16.5 µM eq.FeSO4.7H2O), respectively while leave extract of F. variegata (chloroform) was the most active (0.6577) in TAC among other extracts of the selected medicinal plants. Butanolic leave extract of C. erectus exhibited maximum enzyme inhibition activity (91.62% with IC50 40 µg/ml) while other extracts showed significant activity. It was observed from results that all extracts/fractions of under consideration plants, exhibited significant bioactivities especially ethanolic and butanolic fractions, which may be the richest source of such type of activities.


Assuntos
Antioxidantes/farmacologia , Inibidores da Colinesterase/farmacologia , Combretaceae/química , Ficus/química , Extratos Vegetais/farmacologia , Acetilcolinesterase/metabolismo , Antioxidantes/isolamento & purificação , Compostos de Bifenilo/química , Inibidores da Colinesterase/isolamento & purificação , Relação Dose-Resposta a Droga , Compostos Férricos/química , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/metabolismo , Humanos , Fitoterapia , Picratos/química , Componentes Aéreos da Planta , Extratos Vegetais/isolamento & purificação , Plantas Medicinais , Solventes/química
19.
Emerg Infect Dis ; 21(4): 629-37, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25811942

RESUMO

The risk for influenza A(H5N1) virus infection is unclear among poultry workers in countries where the virus is endemic. To assess H5N1 seroprevalence and seroconversion among workers at live bird markets (LBMs) in Bangladesh, we followed a cohort of workers from 12 LBMs with existing avian influenza surveillance. Serum samples from workers were tested for H5N1 antibodies at the end of the study or when LBM samples first had H5N1 virus-positive test results. Of 404 workers, 9 (2%) were seropositive at baseline. Of 284 workers who completed the study and were seronegative at baseline, 6 (2%) seroconverted (7 cases/100 poultry worker-years). Workers who frequently fed poultry, cleaned feces from pens, cleaned food/water containers, and did not wash hands after touching sick poultry had a 7.6 times higher risk for infection compared with workers who infrequently performed these behaviors. Despite frequent exposure to H5N1 virus, LBM workers showed evidence of only sporadic infection.


Assuntos
Fazendeiros , Virus da Influenza A Subtipo H5N1/classificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Adolescente , Adulto , Bangladesh/epidemiologia , Feminino , História do Século XXI , Humanos , Incidência , Virus da Influenza A Subtipo H5N1/genética , Influenza Humana/história , Influenza Humana/transmissão , Masculino , Pessoa de Meia-Idade , Vigilância da População , Fatores de Risco , Estudos Soroepidemiológicos , Sorotipagem , Adulto Jovem
20.
J Clin Microbiol ; 52(5): 1762-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24599980

RESUMO

During 2012, we identified sampled dogs with elevated levels of antibodies (≥1:40) against A(H1N1)pdm09 virus by using a hemagglutination inhibition (HI) assay (seroprevalence, 24.7%) and a microneutralization (MN) assay (seroprevalence, 10.8%). These high seroprevalences of A(H1N1)pdm09 among dogs without clinical signs of influenza support the premise that dogs may play a role in the human influenza ecology in China.


Assuntos
Doenças do Cão/diagnóstico , Doenças do Cão/virologia , Vírus da Influenza A Subtipo H1N1/imunologia , Infecções por Orthomyxoviridae/diagnóstico , Infecções por Orthomyxoviridae/virologia , Animais , Anticorpos Antivirais/imunologia , China , Doenças do Cão/imunologia , Cães , Testes de Inibição da Hemaglutinação/métodos , Infecções por Orthomyxoviridae/imunologia , Estudos Soroepidemiológicos
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