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1.
Pharmacol Res ; : 104872, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32360583

RESUMO

The rapidly progressing of coronavirus disease 2019 (COVID-19) pandemic has become a global concern. This meta-analysis aimed at evaluating the efficacy and safety of current option of therapies for severe acute respiratory syndrome (SARS), Middle Eastern respiratory syndrome (MERS) besides COVID-19, in an attempt to identify promising therapy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients. We searched PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and WANFANG DATA for randomized controlled trials (RCTs), prospective cohort, and retrospective cohort studies that evaluated therapies (hydroxychloroquine, lopinavir/ritonavir-based therapy, and ribavirin-based therapy, etc.) for SARS, MERS, and COVID-19. The primary outcomes were mortality, virological eradication and clinical improvement, and secondary outcomes were improvement of symptoms and chest radiography results, incidence of acute respiratory disease syndrome (ARDS), utilization of mechanical ventilation, and adverse events (AEs). Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effects models, and the quality of evidence was appraised using GRADEpro. Eighteen articles (5 RCTs, 2 prospective cohort studies, and 11 retrospective cohort studies) involving 4,941 patients were included. Compared with control treatment, anti-coronary virus interventions significantly reduced mortality (RR 0.65, 95% CI 0.44-0.96; I2 = 81.3%), remarkably ameliorate clinical improvement (RR 1.52, 95% CI 1.05-2.19) and radiographical improvement (RR 1.62, 95% CI 1.11-2.36, I2 = 11.0 %), without manifesting clear effect on virological eradication, incidence of ARDS, intubation, and AEs. Subgroup analyses demonstrated that the combination of ribavirin and corticosteroids remarkably decreased mortality (RR 0.43, 95% CI 0.27-0.68). The lopinavir/ritonavir-based combination showed superior virological eradication and radiographical improvement with reduced rate of ARDS. Likewise, hydroxychloroquine improved radiographical result. For safety, ribavirin could induce more bradycardia, anemia and transaminitis. Meanwhile, hydroxychloroquine could increase AEs rate especially diarrhea. Overall, the quality of evidence on most outcomes were very low. In conclusion, although we could not draw a clear conclusion for the recommendation of potential therapies for COVID-19 considering the very low quality of evidence and wide heterogeneity of interventions and indications, our results may help clinicians to comprehensively understand the advantages and drawbacks of each anti-coronavirus agents on efficacy and safety profiles. Lopinavir/ritonavir combinations might observe better virological eradication capability than other anti-coronavirus agents. Conversely, ribavirin might cause more safety concerns especially bradycardia. Thus, large RCTs objectively assessing the efficacy of antiviral therapies for SARS-CoV-2 infections should be conducted with high priority.

2.
Environ Monit Assess ; 192(6): 336, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382798

RESUMO

Estuary is an important route for the transport of terrestrial contaminants to the ocean. Its unique hydrodynamic properties may influence the fate and distribution of pollutants. Previous studies have shown that severe pollution because of antibiotics has occurred in many inland surface waterbodies; however, the behavior of antibiotic residuals remains poorly understood in estuarine environments. In this study, the occurrence and spatiotemporal distribution of seven selected antibiotics (i.e., sulfamethazine, sulfamethoxazole, trimethoprim, ofloxacin, ciprofloxacin, erythromycin, and roxithromycin) in a tidal river were investigated through one continuous and four synoptic sampling events. Results show that the concentrations of most antibiotics are in the nanogram per liter level, except for trimethoprim with the highest concentration up to 12,440 ng L-1 during the wet season. Except for sulfamethazine, the other six antibiotics showed high concentrations (i.e., > 100 ng L-1) in at least one sampling campaign. Different temporal distribution patterns of these antibiotics indicated that they were mainly controlled by source loading, flow condition, and discharge amounts. Spatial distribution indicated that the main pollution source of trimethoprim was located in lower reaches, while the other six antibiotics mainly came from the upstream sources. Based on the theoretical dilution line, erythromycin and roxithromycin degraded in the tidal river, whereas the other five types of antibiotics showed a conservative behavior. Tide has important effects on the spatial distribution of antibiotics, especially those with a wide concentration range, in estuarine environments. Furthermore, risk assessment based on the calculated risk quotients showed that five types of antibiotics pose high risks to aquatic organisms. These observations provided new insight into the distribution and transport of common antibiotics in estuarine environments.

3.
Curr Med Res Opin ; : 1-7, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32329364

RESUMO

Objective: Human participants play an important role in medical care advances. Recruiting enough participants is perhaps the most significant procedure that determines the success of medical research, and high participation rate brings about many benefits. Therefore, acquiring enough participants is important for medical researchers. To understand how to improve participation rate, we need to clarify factors affecting the public's attitude toward medical research. Through this review, we aim to examine which factors affect the attitude of human participants toward medical research.Methods: The relevant data were searched by using the keywords "Public," "Participants," "Medical" and "Research" in PubMed (MEDLINE), International Pharmaceutical Abstracts, Web of Science, Science Direct, CINAHL Plus, EMBASE, and China Knowledge Resource Integrated databases. A manual search was done to acquire peer-reviewed articles and reports about participation in medical research.Results: Sixty-three studies were identified for inclusion after full text screening. The included studies were of variable quality. Some factors affecting people's attitude toward participating in medical research have been identified and discussed in our review.Conclusion: This review demonstrated that willingness of participants to take part in medical research was influenced by a variety of factors. These factors may be used to predict the public's willingness to take part in medical research and may potentially be used in developing strategies aimed at improving participation rate.

4.
Int J Antimicrob Agents ; : 105961, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32234464

RESUMO

The impact of communicable diseases (infectious diseases) on human health is obvious. The sudden outbreak of COVID-19 (Corona Virus Disease 2019) has made people realise the threat of communicable diseases to mankind. As a city of many migrants, Zhuhai Special Economic Zone experienced great challenges brought about by the COVID-19 epidemic. Experience has been acquired from all aspects of this. A highly reactive, multifunctional and efficient emergency management system should be established, and the significance of information communication should be fully understood for the future.

5.
Viruses ; 12(4)2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32268591

RESUMO

Rabies, caused by rabies virus (RABV), is a fatal neurological disease that still causes more than 59,000 human deaths each year. Type III interferon IFN-λs are cytokines with type I IFN-like antiviral activities. Although IFN-λ can restrict the infection for some viruses, especially intestinal viruses, the inhibitory effect against RABV infection remains undefined. In this study, the function of type III IFN against RABV infection was investigated. Initially, we found that IFN-λ2 and IFN-λ3 could inhibit RABV replication in cells. To characterize the role of IFN-λ in RABV infection in a mouse model, recombinant RABVs expressing murine IFN-λ2 or IFN-λ3, termed as rB2c-IFNλ2 or rB2c-IFNλ3, respectively, were constructed and rescued. It was found that expression of IFN-λ could reduce the pathogenicity of RABV and limit viral spread in the brains by different infection routes. Furthermore, expression of IFN-λ could induce the activation of the JAK-STAT pathway, resulting in the production of interferon-stimulated genes (ISGs). It was also found that rRABVs expressing IFN-λ could reduce the production of inflammatory cytokines in primary astrocytes and microgila cells, restrict the opening of the blood-brain barrier (BBB), and prevent excessive infiltration of inflammatory cells into the brain, which could be responsible for the neuronal damage caused by RABV. Consistently, IFN-λ was found to maintain the integrity of tight junction (TJ) protein ZO-1 of BBB to alleviate neuroinflammation in a transwell model. Our study underscores the role of IFN-λ in inhibiting RABV infection, which potentiates IFN-λ as a possible therapeutic agent for the treatment of RABV infection.

6.
Acta Trop ; 207: 105485, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32277927

RESUMO

Carbapenems are traditionally recognized to be the last resort drugs to treat infections due to MDR organisms such as E. coli. As such, the emergence of New Delhi metallo-ß-lactamase-producing E. coli strains have become a challenging threat to the public health. In this regard, we examined the molecular characteristics of carbapenem-resistant E. coli (CRE) isolated from waterfowls in China's tropical island, Hainan. A total of 311 single E. coli strains were obtained from 20 various farms of healthy ducks and geese in 2 districts of Hainan island. The CRE strains were initially identified via phenotypic resistance and modified Hodge test. PCR assay and subsequent nucleotide sequencing were used to detect different types of carbapenemase encoding genes (blaNDM, blaVIM, blaIMP, blaOXA and blaKPC). In addition, MLST and PFGE analyses were also performed. Among the 311 E. coli strains, 8 strains were detected to produce a single type of carbapenemase i.e. NDM-1 (2.6%). A total of 5 sequence types (STs) were observed, of which ST10 was the most prevalent accounting for 37.5% (3/8). Moreover, these 8 isolates yielded 6 different PFGE clusters but showed approximately related PFGE types, suggesting the propagation of similar clone between the farms. This is the first report on the identification of NDM-1-producing E. coli from waterfowls in Hainan island, China. Our results emphasize the need for better efforts to control the further spread of NDM-1-producing E. coli strains in this tropical island.

7.
Int Immunopharmacol ; 81: 106227, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32078941

RESUMO

Small molecule inhibitors have proven useful in the treatment of a variety of tumors, but they are often limited by unsustainable benefits and confer resistance quickly. Immunotherapy can result in durable clinical responses, but activity only occurs in a minority of patients. The unfavorable tumor microenvironment (TME) is an important factor limiting immunotherapy. An appropriate understanding of how small molecule inhibitors modulate the TME may optimize the combination of targeted treatment and immunotherapy in managing tumors. In this study, we found that transient treatment with sunitinib malate inhibited the disorganized extension of tumor vessels, pericytes and collagen IV but increased the relative ratio of pericyte-wrapping blood vessels with alleviated hypoxia in tumors, which resulted from tumor vascular normalization. Sunitinib malate increased infiltration of CD8+ T cells and decreased regulatory T cells (Tregs), accompanied by inhibited expression of TGF-ß1 and IL-10 and increased CCL-28, IFN-γ and IL-12, but no significant inhibition of myeloid-derived suppressor cells (MDSCs) was observed. In addition, sunitinib malate increased the levels of PD-1 and PD-L1 in TME, combined with anti-PD-1 therapy showed a significant reduction in tumor burden compared with either monotherapy, suggesting that anti-PD-1 therapy is reasonable after sunitinib malate treatment.

8.
Bull Environ Contam Toxicol ; 104(4): 489-496, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32047949

RESUMO

Biochar was prepared by mixing sewage sludge with sawdust via a co-pyrolysis with different mixture ratios and temperatures. The results showed that the sawdust addition resulted in a lower yield of biochar with higher C content. The total concentrations of Pb and Cd in biochar were reduced. Besides, pyrolysis can transform the potentially toxic Pb and Cd to stable fractions. However the sawdust addition had slight influence on the chemical forms of Pb and Cd in the biochar. The biochar with 50% sawdust at 600°C exhibited a remarkable reduction of the leachable metal concentrations. The possible transformation mechanisms of Pb and Cd were inferred as the formation of aluminum and silicon-containing minerals. These results provide insights into the influence of sawdust addition on the characteristics of biochar and the possible Pb and Cd immobilization mechanisms during co-pyrolysis process.

9.
Mater Sci Eng C Mater Biol Appl ; 108: 110214, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923933

RESUMO

In this work, PdNPs@ZnO-Co3O4 was synthesized via the facile oxidation treatment of bimetallic ZnCo-zeolitic-imidazolate-framework (ZnCo-ZIF) followed by in situ chemical reduction of PdNPs on the surface of the nanocrystals. After combined with MWCNTs, the PdNPs@ZnO-Co3O4-MWCNTs nanocomposites were formed, which were then exploited as novel electrode materials to construct the non-enzyme electrochemical sensors for high-sensitivity detection of tanshinol. Due to the high catalytic activity of multi-metallic PdNPs@ZnO-Co3O4, and the excellent charge transfer property between imidazole groups of the ligands in MOFs and MWCNTs, the obtained sensor exhibited high sensitivity for tanshinol detection under optimum experimental conditions. The sensor shows two well linear relationship between the current and tanshinol concentration in the range of 0.002-0.69 mM (R2 = 0.989) and 0.69-3.75 mM (R2 = 0.994) with the corresponding sensitivity of 59.16 µA mM-1 and 19.08 µA mM-1. And the limit of detection (LOD) was calculated to be 0.019 µM (S/N = 3). Furthermore, with the advantages of good repeatability, stability and selectivity, the fabricated sensor can be successfully applied to measurement of tanshinol in real medicinal liquids samples. Our results would accelerate the applications of MOFs in electrochemical field and provide insights into design of multifunctional non-enzyme sensing materials for various applications in biocatalysis, bioanalysis and drug testing.

10.
Nanotechnology ; 31(15): 155503, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-31891922

RESUMO

Flexible tactile sensor array has drawn great attention due to its ability to mimic human skin for sensing weak pressure and distinguishing pressure distribution, but the deficiency of sensitivity, the low resolution, and the complex and costly fabrication process seriously limit its development. Hence, it is urgent to explore a fully flexible sensor array with high sensitivity and high resolution as an electronic-skin. Here, the flexible piezoelectric tactile sensor array based on the composite film of PZT nanowires and polydimethylsiloxane (PDMS) was fabricated by the simple fabrication process (electrospinning process and mixture process). The electrospun PZT nanofibers have high aspect ratio and could enhance the generation and accumulation of the piezoelectric charges in the two electrodes of the composite film. By virtue of the inherently high piezoelectric coefficient of PZT material and high aspect ratio of PZT nanofibers, the composite film (75 wt% PZT nanofibers) presents high force-electric conversion capability and high sensitivity. Owing to the bottom electrode sheet shared by all sensor units and the supporting layer with relatively high elastic modulus, the sensor array shows high resolution to qualitatively sense the distribution and size of the impact in real time. Moreover, the sensor array also shows great durability, repeatability, and large working range. Based on these excellent characteristics, the sensor array has wide potential applications in the field of bionics science, robotics science and human-machine interaction.

11.
Environ Technol ; : 1-9, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31810427

RESUMO

In this study, biochars were produced by co-pyrolysis of rice husk and sewage sludge, the environmental risk of heavy metal (Pd and Cd) in the biochars was assessed. Co-pyrolysis resulted in a lower yield but a higher C content compared with sewage sludge pyrolysis alone, the relative contents of Pb and Cd in biochars were declined. Co-pyrolysis process transformed the bioavailable heavy metals into stable speciation. The environmental risk assessment codes of Pb and Cd were reduced by 1-2 grades. The co-pyrolysis technology provides a feasible method for the safe disposal of heavy metal-contaminated sewage sludge.

12.
Mol Biol Rep ; 47(2): 1393-1398, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31786766

RESUMO

Peroxynitrite is an ion acting as a powerful oxidant and nucleophile, which plays a key role in the inflammation and aging process by nitrating tyrosine or tryptophan residues of the proteins. Nitration of a target protein is considered to be a proper method to study the behavioral change of the proteins being nitrated. The commonly used methods for peroxynitrite preparation in vitro usually contain high concentration of sodium hydroxide, which easily induces hydrolysis of target proteins. Accordingly, the method for peroxynitrite preparation was optimized in vitro by changing the sequence of hydrochloric acid and sodium hydroxide added. After different amount of hydrochloric acid added to the system following sodium nitrite, peroxynitrite can be yielded in a concentration up to 60 mM with sodium hydroxide as low as 17 mM. More importantly, biological activity of the target protein was well maintained after protein nitration since low sodium hydroxide was used.

13.
Bioresour Technol ; 297: 122420, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31784248

RESUMO

The feasibility of mixed dye wastewater treatment was evaluated with a novel integrated bioprocess that consisted of a hybrid anaerobic reactor (HAR) with a built-in bioelectrochemical system, an aerobic biofilm reactor (ABFR) and a denitrification reactor (DR). The position of the DR significantly affected chemical oxygen demand (COD) and colority in effluent, and placing the DR after the ABFR improved effluent quality probably due to minimization of the undesired autoxidation of aromatic amine in dye wastewater. The optimal integrated process of HAR + ABFR + DR efficiently treated mixed dye wastewater, and concentrations of COD and TN were decreased down to 75 ± 18 mg/L and 12.91 ± 0.31 mg/L, respectively, along with colority 48 ± 4 times. Total phosphorus reduced to below 0.5 mg/L with coagulation using poly aluminum chloride, and the effluent quality fully met the discharge standard. This comprehensive study suggests the feasibility of the BES based process for practical application to mixed dye wastewater treatment.


Assuntos
Eliminação de Resíduos Líquidos , Águas Residuárias , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Nitrogênio , Fósforo
14.
ACS Appl Mater Interfaces ; 12(1): 1877-1884, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31816239

RESUMO

Serum-soluble folate binding protein (FBP) is an important tumor marker, and the development of a simple biosensing method is highly needed. In this work, a photoelectrochemical (PEC) biosensor for the detection of FBP was proposed based on the construction of an antifouling interface and the unique ligand-protein recognition. The PEC sensing platform was prepared by the biomimetic polydopamine (PDA) coating on TiO2 nanotubes arrays (NTAs). A significant PEC enhancement effect was obtained due to the macroporous structures. Excellent antifouling performance was achieved by conjugation of amino-group-terminated 8-arm poly(ethylene glycol) (PEG). The incorporation of folic acid (FA) retains the antifouling property and shows recognition abilities toward FBP. The fabricated PEC biosensor shows good analytical performance. The combination of ligand-protein recognition and a PEC antifouling interface provides a good consideration for the development of FBP biosensors.

15.
Colloids Surf B Biointerfaces ; 186: 110706, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31838270

RESUMO

m-Aminobenzoic acid (ABA) is one popular derivative of highly conductive monomer of aniline, which contains a carboxyl (COOH) group in its skeleton that is beneficial to various bio-interface and bio-analysis. Hence, Poly(m -aminobenzoic acid) (PABA) membrane was firstly electrochemical deposited onto bare electrode surface using a straightforward cyclic voltammetry (CV) method. PABA membrane exhibited excellent electrochemical stability and apparent wrinkle morphology that could effectively enhance response signal and immensely increase specific surface area of electrode. Next, PABA membrane was decorated with well-designed hairpin aptamer and preferred antifouling peptide in sequence to construct a two-layer architectural bio-interface that could present both sensitive target recognition capability and excellent antifouling ability. Benefiting from the electrodeposited PABA membrane to enhance electrochemical response signal, the developed biosensor performed excellent sensitivity toward target protein, meanwhile, associated with good selectivity and reproducibility attributing to the favored peptide that was able to decline nonspecific protein adsorption and improve target recognition.

16.
J Hazard Mater ; 382: 121046, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31450205

RESUMO

Understanding the electrode configuration is vital for the successful application of bioelectrochemical system (BES) in recalcitrant wastewater treatment. Especially in those traditional anaerobic processes that integrate with BES to construct effective hybrid bioreactors. Hybrid bioreactors employed granular graphite as electrode material achieved 86.62 ±â€¯1.83% decolorization efficiency of azo dye acid orange 7 (AO7) at influent AO7 loading rate of 800 g/(m3∙d) and it was about 6% higher than that with carbon fiber brush electrodes. Such electrodes were positioned above the anaerobic sludge layer and higher efficiency (8%) than the reactors with electrodes placed beneath the sludge layer was observed. Tracer experiments and modeling of residence time distribution indicated that the fluid pattern in hybrid bioreactors was modified to plug flow pattern and had a better consummate mixing ability compared to the conventional anaerobic reactor. Simulation using computational fluid dynamics technique showcased favorable mass transfer near electrode modules. The hydrodynamics of simulation and experimental results were connected by simplifying electrode module as a porous media model. This study thus proved that hybrid bioreactors can effectively enhance wastewater treatment comprehensively through the analysis of decolorization performance and hydrodynamics.

17.
Chemosphere ; 239: 124787, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31526987

RESUMO

Herein, the mutual effect between azo dye and the performance of electrochemically active bacteria (EAB) is investigated in detail, which is crucial to understand and control the bio-electrochemical systems (BESs) operation for azo dye containing wastewater treatment. EAB is enriched at controlled potential of -0.2 V vs Ag/AgCl in single-chamber BESs. Over 95% azo dye (alizarin yellow R (AYR)) was decolorized regardless of the initial AYR concentration ranging from 30 to 120 mg/L within 24 h. The fastest decolorization rate was obtained at AYR initial concentration of 70 mg/L, which was 4.25 times greater in the closed circuit BESs than that in the open circuit one. 16S rRNA gene based microbial community analysis showed that Geobacter was dominant in EAB with relative abundance increased from 77.98% (0 mg/L AYR) to 92.22% (70 mg/L AYR), indicating that azo dye selectively boosts the growth of exoelectrogens in electrode biofilm communities. Under electricity stimulation, extracellular process can be mutually conducted by azo dye compounds, which is favorable for accelerating reaction rate and avoiding of significant toxic effect on EAB.


Assuntos
Compostos Azo/química , Bactérias/química , Corantes/química , Eliminação de Resíduos Líquidos/métodos , Compostos Azo/metabolismo , Bactérias/genética , Bactérias/metabolismo , Biofilmes , Cor , Corantes/metabolismo , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos/microbiologia , Geobacter/genética , Geobacter/metabolismo , Microbiota/genética , RNA Ribossômico 16S , Águas Residuárias/química
18.
Pharm Biol ; 58(1): 8-15, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31847682

RESUMO

Context: Resveratrol is a natural polyphenol compound. It exhibits antitumor, immunostimulatory, and antiviral activities. However, poor water solubility and structural instability limit its administration and storage.Objective: A resveratrol dry suspension (RDS) was prepared and immunomodulatory effect in immunosuppressive mice induced by cyclophosphamide and anti-inflammatory activities in mice were evaluated.Materials and methods: The preparation of RDS was optimized by the orthogonal design method. To evaluate the immunomodulatory effects, SPF Kunming mice were divided into seven groups comprising of nine males and nine females for each group. The RDS supplemented group was administrated doses of 3.33, 1.67, and 0.83 g/kg/d. Then visceral index, lymphocyte proliferation, the ratio of CD3+ CD4+/CD3+ CD8+, and the contents of cytokines in serum were tested. To ameliorate effects of acetic acid induced capillary permeability, xylene-based ear oedema, and cotton pellet granuloma, RDS as anti-inflammatory agent was administered at doses of 1, 0.33, and 0.1 g/kg/d as compared to indomethacin (IM) provided as a positive control at 10 mg/kg.Results: RDS inhibited the degradation of resveratrol and enhanced the CD3+ CD4+/CD3+ CD8+ ratio, spleen index, IL-2 level, and splenic lymphocytes in immunosuppressive mice. RDS (0.1 g/kg/d) significantly inhibited the acetic acid-induced capillary permeability, and at doses of 0.33 and 1 g/kg/d repressed the ear swelling and granuloma formation in immunocompromised mice.Discussion and Conclusion: RDS is a stable, cheaper, and suitable preparation with potent immunoregulatory and anti-inflammatory activities. Keeping in view these remarkable properties, RDS could be an appropriate preparation for clinic use of resveratrol.

19.
Viruses ; 11(12)2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31847269

RESUMO

The QX-type avian infectious bronchitis virus (IBV) is still a prevalent genotype in Southwestern China. To analyze the antigenicity and pathogenicity characteristics of the dominant genotype strains (QX-type), S1 gene sequence analysis, virus cross-neutralization tests, and pathogenicity test of eight QX-type IBV isolates were conducted. Sequence analysis showed that the nucleotide homology between the eight strains was high, but distantly related to H120 and 4/91 vaccine strains. Cross-neutralization tests showed that all eight strains isolated from 2015 and 2017 belonged to the same serotype, but exhibited antigenic variations over time. The pathogenicity test of the five QX-type IBV isolates showed that only three strains, CK/CH/SC/DYW/16, CK/CH/SC/MS/17, and CK/CH/SC/GH/15, had a high mortality rate with strong respiratory and renal pathogenicity, whereas CK/CH/SC/PZ/17 and CK/CH/SC/DYYJ/17 caused only mild clinical symptoms and tissue lesions. Our results indicate that the prevalent QX-type IBVs displayed antigenic variations and pathogenicity difference. These findings may provide reference for research on the evolution of IBV and vaccine preparation of infectious bronchitis (IB).

20.
J Bone Miner Res ; 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31725940

RESUMO

We analyzed the skeletal phenotypes of heterozygous null Cyp27b1 (Cyp27b1+/- ) mice and their wild-type (WT) littermates to determine whether haploinsufficiency of Cyp27b1 accelerated bone loss, and to examine potential mechanisms of such loss. We found that serum 1,25-dihydroxyvitamin D [1,25(OH)2 D] levels were significantly decreased in aging Cyp27b1+/- mice, which displayed an osteoporotic phenotype. This was accompanied by a reduction of expression of the B lymphoma Moloney murine leukemia virus (Mo-MLV) insertion region 1 (Bmi1) at both gene and protein levels. Using chromatin immunoprecipitation (ChIP)-PCR, electrophoretic mobility shift assay (EMSA) and a luciferase reporter assay, we then showed that 1,25(OH)2 D3 upregulated Bmi1 expression at a transcriptional level via the vitamin D receptor (VDR). To determine whether Bmi1 overexpression in mesenchymal stem cells (MSCs) could correct bone loss induced by 1,25(OH)2 D deficiency, we overexpressed Bmi1 in MSCs using Prx1-driven Bmi1 transgenic mice (Bmi1Tg ) mice. We then compared the bone phenotypes of Bmi1Tg mice on a Cyp27b1+/- background, with those of Cyp27b1+/- mice and with those of WT mice, all at 8 months of age. We found that overexpression of Bmi1 in MSCs corrected the bone phenotype of Cyp27b1+/- mice by increasing osteoblastic bone formation, reducing osteoclastic bone resorption, increasing bone volume, and increasing bone mineral density. Bmi1 overexpression in MSCs also corrected 1,25(OH)2 D deficiency-induced oxidative stress and DNA damage, and cellular senescence of Cyp27b1+/- mice by reducing levels of reactive oxygen species (ROS), elevating serum total superoxide dismutase levels, reducing the percentage of γH2 A.X, p16, IL-1ß, and TNF-α-positive cells and decreasing γH2A.X, p16, p19, p53, p21, IL-1ß, and IL-6 expression levels. Furthermore, 1,25(OH)2 D stimulated the osteogenic differentiation of MSCs, both ex vivo and in vitro, from WT mice but not from Bmi1-/- mice and 1,25(OH)2 D administration in vivo increased osteoblastic bone formation in WT, but not in Bmi1 -/- mice. Our results indicate that Bmi1, a key downstream target of 1,25(OH)2 D, plays a crucial role in preventing bone loss induced by 1,25(OH)2 D deficiency. © 2019 American Society for Bone and Mineral Research.

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