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1.
Water Res ; 168: 115160, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31614233

RESUMO

Aquatic ecosystems have been increasingly threatened by anthropogenic activities, e.g., wastewater discharge and farm operation. Several methods are adopted to evaluate the effects of anthropogenic activities on biological risk in the environment, such as qPCR and amplicon next-generation sequencing. However, these methods fall short of providing genomic information of target species, which is vital for risk assessment from genomic aspect. Here, we developed a novel approach integrating metagenomic analysis and flow cytometry to identify and quantify potential pathogenic antibiotic resistant bacteria (PARB; carrying both antibiotic resistance genes (ARGs) and virulence factor genes (VFGs)) in the environment, which are of particular concern due to their infection ability and antibiotic resistance. Based on the abundance/density of PARB, we evaluated microbiological risk in a river impacted by both municipal drainage and agriculture runoff. We collected samples upstream (mountainous area) as the control. Results showed that 81.8% of dominant PARB (33) recovered using our approach were related to known pathogenic taxa. In addition, intragenomic ARGs-VFGs coexistence patterns in the dominant Pseudomonas genomes (20 out of 71 PARB) showed high similarity with the most closely related Pseudomonas genomes from the NCBI RefSeq database. These results reflect acceptable reliability of the approach for (potential) pathogen identification in environmental samples. According to the PARB density, microbiological risk in samples from the agricultural area was significantly higher than in samples from the urban area. We speculated that this was due to the higher antibiotic usage in agriculture as well as intragenomic ARGs-VFGs co-evolution under antibiotic selective pressure. This study provides an alternative approach for the identification and quantification of PARB in aquatic environments, which can be applied for microbiological risk assessment.


Assuntos
Antibacterianos , Ecossistema , Resistência Microbiana a Medicamentos , Genes Bacterianos , Genoma Bacteriano , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Virulência
2.
Anal Chim Acta ; 1094: 70-79, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31761049

RESUMO

To explore how hypochlorous acid (HClO) affects human health, a highly sensitive, selective, and trace detection method for hypochlorite (ClO-) is crucial for determining its non-negligible function in both environment and living systems. Herein, a dicyanoisophorone-phenylboronic acid-based novel ratiometric near-infrared fluorescent probe (Probe 1) was designed for the rapid and specific detection of ClO- based on the intramolecular charge transfer (ICT) mechanism. Excess addition of HClO to the Probe 1 solution, 186-times ratio (I652/I582) augment were gained. And this probe provided a colorimetric and ratiometric fluorescence response to ClO- with a high selectivity, a rapid response (within 30 s), and had an extremely low detection limit (15.7 nM). In addition, owing to the good sensing properties and low cytotoxicity of Probe 1, it can be used to expediently visualize exogenous ClO- in HepG2 cells and endogenous ClO- in RAW264.7 macrophage cells. Furthermore, the probe was successfully used for the bioimaging of zebrafish with an acute inflammation. Thus, Probe 1 is a promising vehicle to identify the level of HClO in animals with associated diseases.

3.
ACS Sens ; 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31793289

RESUMO

The analysis of exhaled human breath has great significance for early noninvasive diagnosis. A poor selectivity and strong humidity influence are two bottlenecks for the application of gas sensors to exhaled breath analysis. In this work, we utilized the adsorption, dissolution, ionization and migration processes of ammonia in wet nonconjugated hydrophilic polymers to realize an effective ammonia detection. The indispensable high-humidity atmosphere of exhaled breath was turned into a favorable condition for ammonia sensing. Nonconjugated polymer sensors can distinguish ammonia from most other gases because of its extremely high solubility and good ionization ability. A sensor based on polyvinyl pyrrolidone (PVP) could detect 0.5 ppm ammonia with an extremely high selectivity. The ammonia sensing mechanism was thoroughly investigated by complex impedance plots (CIPs) and a quartz crystal microbalance (QCM) measurement. Finally, the potential of the PVP sensor for ammonia detection in exhaled breath was evaluated in simulated environments.

4.
Bioorg Chem ; : 103413, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31791679

RESUMO

A series of new ferulic acid derivatives were designed, synthesized and evaluated as multi-target inhibitors against Alzheimer's disease. In vitro studies indicated that most compounds showed significant potency to inhibit self-induced ß-amyloid (Aß) aggregation and acetylcholinesterase (AChE), and had good antioxidant activity. Specifically, compound 4g exhibited the potent ability to inhibit cholinesterase (ChE) (IC50, 19.7 nM for hAChE and 0.66 µM for hBuChE) and the good Aß aggregation inhibition (49.2% at 20 µM), and it was also a good antioxidant (1.26 trolox equivalents). Kinetic and molecular modeling studies showed that compound 4g was a mixed-type inhibitor, which could interact simultaneously with the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, compound 4g could remarkably increase PC12 cells viability in hydrogen peroxide-induced oxidative cell damage and Aß-induced cell damage. Finally, compound 4g had good ability to cross the BBB using the PAMPA-BBB assay. These results suggested that compound 4g was a promising multifunctional ChE inhibitor for the further investigation.

5.
Sci Rep ; 9(1): 18293, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31797960

RESUMO

The standardization of apiceutical products like as propolis extracts has been widely debated worldwide and variations in the propolis chemical composition are still very relevant topics for use-standardized of different propolis-type as medication by much of the world's population. The present manuscript discuss important issues related to the climate effect and variations in propolis metabolite-profiling changes, antioxidant capacity and variations of the antibacterial activity of the Brazilian red propolis metabolites using comprehensive multivariate correlations. It was observed the increasing of guttiferones concentrations during the intense drought period and drastic decreasing in rainy period. The climate variation induced the high concentration of flavonoids in rainy period with pronounced dropped in some rainy months. The Pearson´s analysis demonstrated correlation between IC50 from DPPH and guttiferones and flavonoids concentrations. The PCA-X and Hotelling T2 test showed outliers during the months with lowest concentrations of formononetin and isoliquiritigenin was observed in antibacterial tests. The PLS-DA, OPLS-DA and VIP analysis demonstrate guttiferone E, guttiferone B, liquiritigenin, naringenin are considered important substances responsible by anti-staphylococcal activity in red propolis composition during the rainy season and drought period, but a synergistic effect with other flavonoids and isoflavonoids are not ruled out.

6.
Plant Dis ; : PDIS05191047RE, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31801036

RESUMO

Rice orange leaf disease (ROLD), caused by rice orange leaf phytoplasma (ROLP), is transmitted by leafhopper vectors Recilia dorsalis and Nephotettix cinticeps. ROLD severely devastates rice production in Asia. Accurate detection of the pathogen is important for disease management. Current nested polymerase chain reaction (nested PCR) method using phytoplasma universal primers is widely used to detect phytoplasmas; however, it has shortcoming of inconvenience and inaccuracy, for it needs two round of PCR reactions and could produce false positive results due to nontarget amplification. In this study, we developed a PCR assay using a set of primers designed based on the ROLP genome sequence to amplify house-keeping gene FtsH-1 in rice and leafhopper vector samples. This method is simple and rapid, and its sensitivity up to 10 pg/µl of total ROLP DNA. It also minimizes the false positive problem produced by nested PCR. This method was used to survey the geographic distribution of ROLD in southern China from 2016 to 2018. The results showed that the distribution areas and vector carrying rate of ROLD had gradually increased.

7.
Nat Commun ; 10(1): 5132, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31723129

RESUMO

The Arabidopsis EH proteins (AtEH1/Pan1 and AtEH2/Pan1) are components of the endocytic TPLATE complex (TPC) which is essential for endocytosis. Both proteins are homologues of the yeast ARP2/3 complex activator, Pan1p. Here, we show that these proteins are also involved in actin cytoskeleton regulated autophagy. Both AtEH/Pan1 proteins localise to the plasma membrane and autophagosomes. Upon induction of autophagy, AtEH/Pan1 proteins recruit TPC and AP-2 subunits, clathrin, actin and ARP2/3 proteins to autophagosomes. Increased expression of AtEH/Pan1 proteins boosts autophagosome formation, suggesting independent and redundant pathways for actin-mediated autophagy in plants. Moreover, AtEHs/Pan1-regulated autophagosomes associate with ER-PM contact sites (EPCS) where AtEH1/Pan1 interacts with VAP27-1. Knock-down expression of either AtEH1/Pan1 or VAP27-1 makes plants more susceptible to nutrient depleted conditions, indicating that the autophagy pathway is perturbed. In conclusion, we identify the existence of an autophagy-dependent pathway in plants to degrade endocytic components, starting at the EPCS through the interaction among AtEH/Pan1, actin cytoskeleton and the EPCS resident protein VAP27-1.

8.
Macromol Rapid Commun ; : e1900493, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31709698

RESUMO

In this work, the authors report a novel single-step, one-pot process for the synthesis of self-assembled nanoparticles using a polymerization-induced self-assembly (PISA) mechanism. In contrast to conventional approaches employing a pre-formed macromolecular stabilizer, the disparate reactivities between two monomers, oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and diacetone acrylamide (DAAm), are exploited instead to synthesize a gradient copolymer directly in aqueous solution. Due to the hydrophobicity of poly(DAAm), these gradient copolymers can self-assemble in situ to form spheres and worms stabilized by the OEGMA residues. A surprisingly broad range of parameters are identified in which the worm morphology can be stabilized, which is highlighted by significant gelation of the reaction mixture in situ. This single-step gradient copolymerization approach to PISA is more efficient than conventional two-step syntheses. These results demonstrate improved reproducibility owing to the production of self-assembled nanoparticles directly in a one-pot and single-step synthesis.

9.
Molecules ; 24(21)2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31694349

RESUMO

Based upon the intramolecular charge transfer (ICT) mechanism, a novel ratiometric fluorescent probe EB was developed to detect SO32-/HSO3-. The probe displayed both colorimetric and ratiometric responses toward SO32-/HSO3-. It displayed a quick response (within 60 s), good selectivity and high sensitivity (a detection limit of 28 nM) towards SO32-/HSO3-. The SO32-/HSO3- sensing mechanism was confirmed as the Michael addition reaction by ESI-MS. Moreover, the probe could be applied to measure the level of sulfite in real samples, like sugar and chrysanthemum, and it could also be used to detect SO32-/HSO3- in HepG2 cells through confocal fluorescence microscopy, which proved its practical application in clinical diagnosis.

10.
Clin Exp Rheumatol ; 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31694744

RESUMO

OBJECTIVES: Although articular cartilage contributes to smooth joint motion, once damaged this functionality cannot be recovered. Activation of the IL-6/STAT3 signalling pathway contributes to chondrogenic differentiation of mesenchymal stem cells (MSCs), indicating a role for soluble IL-6R (sIL-6R) during chondrogenesis in vitro. The aim of this study is to develop a novel therapeutic tool for regenerative medicine of articular cartilage. METHODS: Human bone marrow-derived MSCs were pre-treated with sIL-6R to direct their differentiation into chondrocytes, then seeded on a poly-lactic-co-glycolic acid (PLGA) sheet to enhance the localised residence of MSCs. The material was implanted into knee joint spaces of antigen-induced arthritis (AIA) rats, an animal model of rheumatoid arthritis (RA). After 8 weeks, the effects of the implantation on articular cartilage repair were assessed by x-ray image and staining with safranin O (S-O), aggrecan and human leukocyte antigen (HLA). RESULTS: Swelling of knees in AIA rats, but not sham-treated rats, was observed. AIA rats implanted with PLGA and sIL-6R-treated MSCs showed similar knee joint imaging to sham rats using x-ray; however, those with PLGA alone, or with PLGA with MSCs, did not. Rats implanted with PLGA and sIL-6R-treated MSCs, but not PLGA alone or PLGA with MSCs, showed positive imaging by S-O staining as well as human aggrecan. HLA was not detected in the knees of any of the rats. CONCLUSIONS: PLGA and sIL-6R-treated MSCs help to repair articular cartilage with high efficacy. Thus, the application of this promising strategy to regenerative medicine for articular cartilage in patients with RA is anticipated.

12.
Artigo em Inglês | MEDLINE | ID: mdl-31766855

RESUMO

HIV has remarkable genetic diversity among populations. The diversity has critical impacts on transmission, immune escape, pathogenesis, and clinical management. HIV-1 diversity originates from frequent mutation and recombination during reverse transcription. This work focuses on the quasispecies genetic dynamics within individuals with primary infections. 11 MSMs from the Beijing PRIMO Clinical Cohort were identified as primary infection and had their 3 or 4 series of anticoagulant blood samples collected. Viral RNA was extracted and amplified using single-genome amplification. Products of the gp120 gene that met single-genome amplification requirements were sequenced. Subtype assortment of all collected sequences was performed using both jpHMM and REGA. Quasispecies diversity at each time was estimated using Mega 6. Intra-patient recombination was analyzed using RDP4. According to the Fiebig classification system, YA-81 belongs to stage III and YA-113 belongs to the stage IV. The other samples are all associated with the infection stage of V/VI. YA113 had a dual infection with subtype B and a new URF involving CRF01_AE and C. Other 8 were infected with CRF01_AE, 1 was infected with B/C recombinant and the last one with B. Of the 10 single infections, 8 were caused by one founder virus. They all displayed a sharp increase of quasispecies diversity during the sampling times. 2 were caused by at least 2 founder viruses. The diversity of these strains starts at a significantly high level and is followed by a relatively steady trend. Critically, the separate subtypes YA113-B and YA113-CRF01_AE/C both showed a similar trend to those infected by a single founder virus. Recombination analysis revealed that 5 of 11 cases underwent detectable intrapatient recombination. These findings indicate that tracing the dynamics of HIV-1 quasisipecies during early infection may be relevant and valuable for understanding pathways of viral diversification and immune escape.

13.
J Pharm Biomed Anal ; : 112997, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31767226

RESUMO

Swertiamarin, a typical compound of secoiridiod glycosides with various pharmacological effects which is the major iridoid glicoside of Swertia. In this study, we have established a fast and sensitive LC-MS/MS method. The aim was to conduct pharmacokinetic studies of swertiamarin in vivo of rats. Gentiopicroside was used as internal standard and a C18 column was employed for the separation of analytes. The selected reaction monitoring transitions were m/z 375→177, 357.1→195 for swertiamarin and the internal standard, respectively, in a positive ion mode. The results showed that swertiamarin had a good linearity in the range of 2-8000 ng/mL (r > 0.997) and its limit of detection (LLOD) was 0.5 ng/mL. The developed method subsequently successfully used in the pharmacokinetic study of swertiamarin in rats after oral administration (50, 100, and 150 mg/kg). We obtained a series of pharmacokinetic parameters, and the half-time of swertiamarin was 1 h, while the oral bioavailability was between 5.6-7.6%. Six metabolites of swertiamarin were identified based on accurate mass measurements of protonated molecules and their MS/MS spectrum by ultra-high-performance chromatography/tandem quadrupole time-of-flight mass spectrometry. Furthermore, metabolites were classified into three groups and the metabolic pathway of swertiamarin was proposed. The finding may help for the understanding of effectiveness and safety of swertiamarin.

14.
Environ Int ; 133(Pt B): 105270, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31683155

RESUMO

The spread of antibiotic resistance genes (ARGs) is a growing global problem. Activated sludge (AS) in wastewater treatment plants (WWTPs) has been proposed as a hotspot for ARGs. However, few studies have been conducted to uncover the temporal dynamics of the resistome of AS in WWTPs by long-term longitudinal sampling. In this study, we quantified ARGs and identified their host microbiome in a Hong Kong WWTP in 97 monthly AS samples spanning 9 years. Throughout this analysis, we demonstrated that both the abundance and structures of the resistome changed significantly every two to three years, implying that there was a successive selection of resistomes in the AS system over the study period. The detection of genes of antibiotic-resistant pathogens that are emerging major threats to public health in the AS samples, including mcr, CRE (carbapenem-resistant Enterobacteriaceae) and MRSA (methicillin-resistant Staphylococcus aureus)-related genes, highlight the role of WWTPs as reservoirs of ARGs. In addition, the core resistome (abundant and persistent genes) in AS were found to overlap with those in other ecosystems such as urban sewage, livestock feces, and fishpond sediments, revealing the broad dissemination of ARGs in WWTPs and other environments. Annual variation of resistomes were explained via structural equation modeling (SEM), which deciphered the structural linkages of determining factors such as the operational parameters, microbial community composition and horizontal gene transfer (HGT). Specifically, potentially relevant antibiotic resistance bacteria (ARBs) were explored and discussed based on assembly-based analyses and network correlations. Moreover, consistent with the clear relationship between resistomes and mobile genetic elements (MGEs), it was found that there was a relatively high potential for gene exchange in AS in comparison with soil genomes, which could be explained by the engineering features of WWTPs. Based on these findings, longitudinal monitoring of WWTPs is warranted for risk assessment to reveal emerging ARGs, resistome evolution, correlations with ARBs, and the potential for spread in downstream environments and concomitant exposure risks for humans.

15.
Virol J ; 16(1): 145, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31771593

RESUMO

BACKGROUND: Rice stripe mosaic virus (RSMV) is a tentative new Cytorhabdovirus species in family Rhabdoviridae transmitted by the leafhopper Recilia dorsalis. Although the virus was first detected in southern China in 2015, few studies have investigated rice symptoms and yield losses caused by RSMV infection. METHODS: In this study, we observed and systematically compared symptoms of three virally infected, representative varieties of indica, hybrid and japonica rice and determined the yield parameters of the artificially inoculated plants. RESULTS: The three RSMV-infected cultivated rice varieties exhibited slight dwarfing, striped mosaicism, stiff, crinkled or even twisted leaves, an increased number of tillers, delayed heading, cluster-shaped shortening of panicles and mostly unfilled grains. Slight differences in symptom occurrence time were observed under different environmental conditions. For example, mosaic symptoms appeared earlier and crinkling symptoms appeared later, with both symptoms later receding in some infected plants. Yield losses due to RSMV also differed among varieties. The most serious yield reduction was experienced by indica rice (cv. Meixiangzhan), followed by hybrid indica rice (cv. Wuyou 1179) and then japonica (cv. Nipponbare). Single panicle weight, seed setting rate and 1000-kernel weight were reduced in the three infected varieties compared with healthy plants-by 85.42, 94.85 and 31.56% in Meixiangzhan; 52.43, 53.06 and 25.65% in Wuyou 1179 and 25.53, 49.32 and 23.86% in Nipponbare, respectively. CONCLUSIONS: Our findings contribute basic data for field investigations, formulation of prevention and control strategies and further study of the pathogenesis of RSMV.

16.
Biomed Res Int ; 2019: 6407210, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31781632

RESUMO

Currently, gastric cancer treatment is mainly based on first-line intervention with oxaliplatin (OXA) after surgical resection, but the application of OXA has been limited due to the toxic side effects caused by the cumulative dose. The toxicity of OXA mainly includes hepatotoxicity, nephrotoxicity, and ototoxicity, and there is an urgent clinical need to find alternatives that are less toxic and more effective. Rutin (RT) is a natural flavonoid with many biological activities. Studies have found that RT inhibits tumor cell growth and enhances their sensitivity toward certain drugs. As the underlying impact of RT on gastric cancer and its molecular mechanism remain poorly understood, we performed a series of experiments to determine whether RT has the effect of treating gastric cancer, and whether it can cooperate with OXA to treat gastric cancer and its related mechanisms. In the present study, we founded that RT suppressed cell viability, inhibited cell proliferation by causing G0/G1 arrest, and induced apoptosis in SGC 7901 cells. And RT can play as an antitumor agent together with OXA. The mechanism of RT-induced apoptosis may be associated with the activation of the p38/Caspase signal pathway. These results demonstrated the potential of RT as a promising therapeutic compound to treat gastric cancer. At the same time, RT can synergize with OXA to reduce the dose of OXA and reduce the toxicity.

17.
Anal Chem ; 91(23): 14834-14837, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31726822

RESUMO

Cathepsin B (CTSB) is a lysosomal protease, and several human cancers are reported highly expressing CTSB. Many optical methods have been developed for CTSB detection but not a bioluminescence (BL) probe. Herein, a CTSB-specific bioluminescence probe Val-Cit-AL was rationally designed for selectively sensing CTSB activity in vitro with a 67-fold "Turn-On" of BL intensity and an excellent limit of detection. Inhibitory experiments indicated that Val-Cit-AL is capable of sensing CTSB activity in living cells and tumors. We anticipate that Val-Cit-AL might be applied to diagnose CTSB-related diseases in rodent models or evaluate CTSB roles in more biological processes in the near future.

18.
Environ Sci Technol ; 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31738526

RESUMO

The physicochemical properties of engineered nanomaterials can change drastically during aging in the environment. Understanding how these changes influence protein corona formation on nanomaterials is critical for accurately predicting the human exposure risks of aged nanomaterials. Here, we show that sulfidation, a prevalently occurring environmental aging process, of Ag and ZnO nanomaterials significantly affected the protein compositions of the hard corona formed in human saliva, sweat, and bronchoalveolar lavage fluid, corresponding to three most common exposure pathways, that is, ingestion, dermal contact, and inhalation. In particular, a diverse variety of proteins selectively associated with either sulfidized or pristine nanomaterials. Random forest classification of the proteomic data revealed that this selective protein adsorption process was mainly dictated by electrostatic interaction, hydrophobic interaction, and steric hindrance between proteins and nanomaterials, which were susceptible to the changes in surface charge, hydrophobicity, and aggregation status of nanomaterials induced by sulfidation. Furthermore, even for the proteins that do not exhibit distinct adsorption selectivity between sulfidized and pristine nanomaterials, sulfidation altered the extents of impact of nanomaterials on the conformation and likely functions of the adsorbed proteins. These findings unearth a previously neglected mechanism via which environmental sulfidation process mediates the biological effects of soft-metal-containing nanomaterials.

19.
J Colloid Interface Sci ; 560: 284-292, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31670101

RESUMO

In this work, the chitosan wrapped multiwalled carbon nanotubes (MWCNTs-CS) composited material was prepared by surface deposition and crosslinking method. This mild process can maintain the unique properties of the original carbon nanotubes intact. The morphological character of MWCNTs-CS was examined via Fourier transform infrared spectroscopy and field emission scanning electron microscopy. MWCNTs-CS was used as sensing film to fabricate quartz crystal microbalance (QCM) humidity sensors. The optimized sensor possesses high response sensitivity (46.7 Hz/% RH), negligible humidity hysteresis (around 1.1% RH), quick response and recovery time (75 s/34 s), and remarkable reversibility, repeatability, long-term stability and selectivity. Langmuir adsorption isotherm model was used to study the adsorption process of water molecules on MWCNTs-CS film, and the Gibbs free adsorption energy was calculated as -21.85 kJ/mol. By combining the good mechanic properties of MWCNTs and the high hydrophilia of chitosan, the MWCNTs-CS composites are promising for humidity sensing application.

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