Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.535
Filtrar
1.
Chemosphere ; 239: 124705, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31479913

RESUMO

Tamoxifen is a clinical drug for estrogen receptor (ER)-positive breast cancer. Recently, it has been detected in aquatic environment. The residual drugs will produce certain biological activity and create a risk to aquatic organism when they enter the water environment. Therefore, it has great significance to study the ecotoxicity of tamoxifen. In the study, we used zebrafish as a model of aquatic to investigate the ecotoxic mechanism of tamoxifen to aquatic. We found that tamoxifen induced liver lipid accumulation in zebrafish, which showed a significant hepatotoxicity with smaller liver area and bigger yolk area. Though biochemical and pathologic measurement, tamoxifen treated group showed higher transaminase and lipid content. The elevated liver lipid synthesis might due to the increase of lipid metabolism related gene Srebf1, Srebf2 and Fasn. Moreover, inflammatory cytokine Tnf-α, Il-1ß And Il-6 were increased. This result confirmed the toxicity of tamoxifen to aquatic, suggested liver injury was the main characteristic of its ecotoxicity. This study indicated it is important to avoid tamoxifen discharging into the aquatic ecology and provided a theoretical basis of prevention tamoxifen-induced ecotoxicity to aquatic.

2.
Chemosphere ; 240: 124744, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31557643

RESUMO

The heterogeneous reactions of α-Al2O3 particles with a mixture of ozone (∼50 ppm) and isoprene (∼50 ppm) were studied as a function of relative humidities (RHs). The reactions were monitored in real time through the microscopic Fourier transform infrared (micro-FTIR) spectrometer. The results show that the presence of ozone leads to the rapid conversion of isoprene to carboxylate (COO-) ions on the surfaces of α-Al2O3 particles in the initial stage. The water significantly suppresses the formation of the carboxylate ions. For the isoprene ozonolysis reaction on the α-Al2O3 particles, the reactive uptake coefficient is strongly suppressed by over a factor of 8 when the RH increases from 8% to 89%. The negative correlation between RH with the secondary organic aerosol (SOA) produced by isoprene ozonolysis plays a key role in the actual atmospheric environment under high humidity. Our results may provide insight into the ozonolysis process of biogenic alkenes over mineral aerosol surfaces with the influence of RHs.

3.
J Pharm Biomed Anal ; 177: 112876, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31525575

RESUMO

Flavonoids-enriched extract from Scutellaria baicalensis roots (FESR) ameliorated influenza A virus (IAV) induced acute lung injury (ALI) in mice by inhibiting the excessive activation of complement system in vivo. However, FESR had no anti-complementary activity in vitro. In order to reveal the effective materials of FESR for the treatment of IAV-induced ALI, the present research explored the metabolic process of FESR both in nomal and IAV infected mice by the method of UHPLC-ESI-LTQ/MS, as well as the metabolic activating mechanism. The results showed that the inactive flavonoid glycosides of FESR were partly metabolized into anti-complementary aglycones in vivo, mainly including 5,7,4'-trihydroxy-8-methoxy-flavone, norwogonin, baicalein, wogonin, oroxylin A and chrysin. Moreover, compared with the normal mice, IAV-induced ALI mice exhibited more efficient on producing and absorbing these active metabolites, with AUC0-t and Cmax in plasma and concentrations in lungs and intestines markedly elevated in the IAV treated groups (P <  0.05). Interestingly, the intestinal bacteria from IAV-induced ALI mice showed stronger ß-glucuronidase activity and also had higher efficiency on transforming FESR to the flavonoid aglycones. These findings suggested that the anti-complementary aglycones produced by metabolic activation in vivo should be the potential effective materials of FESR against IAV infections, and intestinal bacteria might play an important role on the higher bioavailability of FESR in IAV infected mice. Additionally, the animals under the pathological state are more suitable for the metabolic study of traditional Chinese medicine.

4.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1130-1131: 121831, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669630

RESUMO

A novel nano-titania modified covalent organic frameworks (NTM-COFs) has been synthesized and characterized by transmission electron microscopy (TEM) and scanning electron micrographs (SEM). Besides, NTM-COFs, as efficient sorbent, has also been evaluated in the on-line pass-through cleanup procedure prior to the analysis of local anesthetic drugs (lidocaine, bupivacaine and tetracaine) in human plasma by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). Under optimum conditions, the level of matrix effects can be dramatically reduced by the NTM-COFs based on-line pass-through cleanup procedure, with acceptable recoveries ranging from 88.8% to 103%. Satisfactory trueness and precision of the proposed method were also obtained, with the within- and between-run RSDs less than 7.0% and relative error (REs) less than 12%. The limits of detections (LODs) of lidocaine, bupivacaine and tetracaine were 0.029 µg·L-1, 0.027 µg·L-1 and 0.016 µg·L-1, respectively. The analytical method has been successfully applied for the determination of the plasma concentrations of bupivacaine in five parturients who received an epidural administration of bupivacaine hydrochloride during vaginal delivery. Results demonstrate the applicability of the developed NTM-COFs on-line pass-through cleanup procedure coupled with LC-MS/MS method to clinical studies.

5.
Blood Press ; : 1-10, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31718311

RESUMO

Purposes: Many studies have indicated that orthostatic hypotension (OH) may be a risk factor for dementia and stroke, but the results have been inconsistent. To further ascertain the links between OH and cognition or stroke, a meta-analysis was performed.Methods: The Chinese Biomedical Database, PubMed, Web of Science, and the Cochrane Library database were searched (up to March 2019) to identify prospective cohort studies that examined the associations between OH and the risks of stroke and dementia among adult populations. Subgroup analyses and meta-regression analyses were conducted to identify sources of heterogeneity. We also performed Begg's test and Egger's test to assess publication bias.Results: A total of 3490 articles were identified, and 18 prospective observational cohort studies were ultimately included. Among these studies, eight prospective studies were about stroke, nine studies were about cognition and one study reported data about both stroke and dementia. Meta-analysis revealed an association between OH and worse cognition (hazard ratio (HR): 1.18, 95% confidence interval (CI): 1.03-1.35, I2 = 69.5%). For dementia, the pooled HR was 1.30, with 95% CI: 1.14-1.48, I2 = 31.0%. In addition, we found that OH was associated with a higher risk of stroke (HR: 1.36, 95% CI = 1.17-1.57, I2 = 67.3%). No publication bias was detected.Conclusion: This meta-analysis provides evidence that OH was associated with worse cognition. OH accounted for a 30% increase in the risk of dementia and a 36% increase in the risk of stroke.

6.
J Biomol Struct Dyn ; : 1-21, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31684825

RESUMO

We prepared extracts of Alisma orientalis from Sichuan and Fujian Province, China. Based on the ratio of alisol B 23-acetate (23B) to alisol A 24-acetate (24A) in two Alisma orientalis extracts, we prepared two mixtures of 24A and 23B (24A:23B = 1:3 or 1:10). The antitumor molecular mechanism of the monomers 24A and 23B, the two mixtures and the effective components of Alisma orientalis from different habitats were studied. The MTT assay suggested that the difference in the antitumor activity of Alisma orientalis from different habitats was correlated to the ratio of 24A to 23B. The multi-spectroscopic analysis suggested that the effective components, the monomers and mixtures interacted with c-myc DNA in a partial intercalation manner. The binding strength of the alisol acetates to c-myc DNA was consistent with the anticancer activity, indicating that c-myc DNA was the anticancer target. The molecular simulation indicated that the mixtures were all directly bound to different base pairs of c-myc DNA for a superimposed effect, which led to the binding strength of the mixtures to c-myc DNA was stronger than that of the monomers. The molecules in the 1:3 mixture were all bound to different base pairs of c-myc DNA. However, for the 1:10 mixture, seven molecules of 23B bound to the side chain of 24A, resulting in the mixture with a long chain structure which increased the steric hindrance of 24A. As a result, affinity between 24A and c-myc DNA in the 1:10 mixture was weaker than that in the 1:3 mixture.The antitumor molecular mechanism of the alisol monomers 24A and 23B, the mixtures with different proportions and the effective components of Alisma orientalis from different habitats were studied. The order of the antitumor activity was as follows: Sichuan > Fujian, 24A-23B (1:3) > 24A-23B (1:10) > 23B > 24A. The antitumor activity of Alisma orientalis from different habitats was consistent with the mixtures which were designed according to the contents of the active ingredients of the medicinal materials, indicating that the antitumor activity of Alisma orientalis from Sichuan is better than that from Fujian which is related to the contents of 24A and 23B and the proportion of 1:3 is better than 1:10. The binding strength of the mixtures to c-myc DNA was consistent with the anticancer activity. The mixtures were all directly bound to different base pairs of c-myc DNA for a superimposed effect, which led to the strength of the interaction of the mixtures to c-myc DNA was stronger than that of the monomers. For the 24A-23B (1:3) mixture, the four small molecules bound to c-myc DNA directly and interacted with different base pairs of c-myc DNA. While for the 24A-23B (1:10) mixture, 24A and three 23B molecules interacted with c-myc DNA, the remaining seven 23B molecules bound to the side chain of 24A, which increased the steric hindrance. The binding of the mixture to c-myc DNA was decreased.

7.
Genes (Basel) ; 10(11)2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31689985

RESUMO

The reverse transcription quantitative polymerase chain reaction (RT-qPCR) has been widely used to determine gene functions in Laodelphax striatellus (Fallén) (small brown planthopper). Selection of suitable reference gene(s) for normalizations of RT-qPCR data is critical for reliable results. To date, reports on identification of suitable L. striatellus reference genes are still very limited. L. striatellus is a destructive rice pest and it can transmit multiple viruses, including Rice black-streaked dwarf virus (RBSDV), Rice stripe virus (RSV), and Maize rough dwarf virus (MRDV), to many important cereal crops worldwide. In this study, we examined the stablity of seven selected candidate reference genes in L. striatellus at different developmental stages, in different tissues, in RBSDV- or RSV-infected L. striatellus or in RBSDV-infected and Lssynaptojanin 1 (LsSYNJ1)-silenced L. striatellus. The RT-qPCR data representing individual candidate genes were analyzed using five different methods: the delta Ct method, geNorm, NormFinder, BestKeeper, and the RefFinder algorithm, respectively. The most stable reference gene for the specific condition was selected according to a comprehensive analysis using the RefFinder method. Ribosomal protein L5 (LsRPL5) and LsRPL8 are the most stably expressed genes in L. striatellus at different developmental stages. Alpha-1-tubulin (Lsα-TUB) is the most stably expressed reference gene in different tissues of RBSDV viruliferous (RBSDV-V) or non-viruliferous (RBSDV-NV) L. striatellus. LsRPL8 is the most stably expressed reference gene in RBSDV-V or RSV viruliferous (RSV-V) L. striatellus, while beta-tubulin (Lsß-TUB) is the most stably expressed reference gene in RBSDV-V and LsSYNJ1-silenced L. striatellus. The selected reference genes were further investigated during analyses of RBSDV P5-1 and P10 gene expression in different tissues from RBSDV-V or RBSDV-NV L. striatellus. The stably expressed reference genes identified in this study will benefit future gene function studies using L. striatellus.

8.
Hypertens Res ; 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31700166

RESUMO

Atrial fibrillation (AF) is the most common human arrhythmia in clinical practice and may be promoted by atrial inflammation and fibrosis. Ubiquitination is an important posttranslational modification process that is reversed by deubiquitinating enzymes (DUBs). DUBs play critical roles in modulating the degradation, activity, trafficking, and recycling of substrates. However, less research has focused on the role of DUBs in AF. Here, we investigated the effect of ubiquitin C-terminal hydrolase 1 (UCHL1), an important DUB, on the development of AF induced by angiotensin II (Ang II). Male wild-type mice were treated with the UCHL1 inhibitor LDN57444 (LDN) at a dose of 40 µg/kg and infused with Ang II (2000 ng/kg/min) for 3 weeks. Our results showed that Ang II-infused wild-type (WT) mice had higher systolic blood pressure and an increased incidence and duration of AF. Conversely, this effect was attenuated in LDN-treated mice. Moreover, the administration of LDN significantly reduced Ang II-induced left atrial dilation, fibrosis, inflammatory cell infiltration, and reactive oxygen species (ROS) production. Mechanistically, LDN treatment inhibited the activation of multiple signaling pathways (the AKT, ERK1/2, HIF-1α, and TGF-ß/smad2/3 pathways) and the expression of CX43 protein in atrial tissues compared with that in vehicle-treated control mice. Overall, our study identified UCHL1 as a novel regulator that contributes to Ang II-induced AF and suggests that the administration of LDN may represent a potential therapeutic approach for treating hypertensive AF.

9.
Small ; : e1903057, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31701640

RESUMO

Electroless deposition via a spontaneous redox reaction between the metal precursor and support is believed to be a promising approach for the syntheses of supported metal nanoparticles (SMNPs). However, its widespread applications are significantly prohibited by the low reductivity and high cost of support. To overcome these shortcomings, a porous carbon (PC) is herein developed as a promising matrix for the electroless deposition of metal NPs. Benefiting from abundant oxygen-based surface functional groups, the PC shows stronger reducibility (low redox potential) than conventional carbon substrate such as carbon nanotubes or graphene oxide, enabling a facile electroless deposition of Ir, Rh, and Ru NPs on its surface. These SMNPs exhibit an impressive electrocatalytic activity for the hydrogen evolution reaction (HER) or hydrogen oxidation reaction (HOR). For example, the Rh NP/PC can deliver an HER current density of 10 mA cm-2 with a small overpotential of 21 mV in 0.5 m H2 SO4 , while the Ru NP/PC exhibits excellent HOR activity in 0.1 m KOH in terms of high mass and surface specific exchange current density of 263 A g-1 Ru and 0.227 mA cm-2 Ru . The present strategy may open up opportunities for mass production of efficient supported NPs for diverse applications.

10.
J Control Release ; 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31672622

RESUMO

With the in-depth research of organelles, the microenvironment characteristics of their own, such as the acid environment of lysosomes and the high temperature environment of mitochondria, could be used as a natural and powerful condition for tumor therapy. Based on this, we constructed a two-step precise targeting nanoplatform which can realize the drug release and drug action triggered by the microenvironment of lysosomes (endosomes) and mitochondria, respectively. To begin with, the mesoporous silica nanoparticles (MSNs) were modified with triphenylphosphonium (TPP) and loaded with 2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH). Then, folic acid (FA) targeted pH-sensitive liposomes containing docetaxel (Lipo/DTX-FA) were prepared by thin-film dispersion method, and the core-shell AIPH/MSN-TPP@Lipo/DTX-FA nanoparticles were constructed by self-assembly during the hydration of the liposomes. When this nanoplatform entered into the tumor cells through FA receptor-mediated endocytosis, the pH-sensitive liposomes were destabilized in the lysosomes, resulting in the release of DTX and AIPH/MSN-TPP nanoparticles. After that, AIPH was delivered to mitochondria by AIPH/MSN-TPP, and the alkyl radicals produced by AIPH under the high temperature environment can cause oxidative damage to mitochondria. Not only that, the DTX could enhance the anti-tumor effect of AIPH by downregulating the expression of anti-apoptotic Bcl-2 protein. The in vitro and in vivo results demonstrate that this delivery system could induce apoptosis based on organelles' s own microenvironment, which provides a new approach for tumor therapy.

11.
J Cell Mol Med ; 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31755222

RESUMO

Increased immature neovessels contribute to plaque growth and instability. Here, we investigated a method to establish functional and stable neovessel networks to increase plaque stability. Rabbits underwent aortic balloon injury and were divided into six groups: sham, vector and lentiviral transfection with vascular endothelial growth factor-A (VEGF)-A, fibroblast growth factor (FGF)-2, platelet-derived growth factor (PDGF)-BB and FGF-2 + PDGF-BB. Lentivirus was percutaneously injected into the media-adventitia of the abdominal aorta by intravascular ultrasound guidance, and plaque-rupture rate, plaque-vulnerability index and plaque neovessel density at the injection site were evaluated. Confocal microscopy, Prussian Blue assay, Evans Blue, immunofluorescence and transmission electron microscopy were used to assess neovessel function and pericyte coverage. To evaluate the effect of FGF-2/PDGF-BB on pericyte migration, we used the mesenchymal progenitor cell line 10T1/2 as an in vitro model. VEGF-A- and FGF-2-overexpression increased the number of immature neovessels, which caused intraplaque haemorrhage and inflammatory cell infiltration, eventually resulting in the plaque vulnerability; however, FGF-2/PDGF-BB induced mature and functional neovessels, through increased neovessel pericyte coverage. Additionally, in vitro analysis of 10T1/2 cells revealed that FGF-2/PDGF-BB induced epsin-2 expression and enhanced the VEGF receptor-2 degradation, which negatively regulated pericyte function consistent with the in vivo data. These results showed that the combination of FGF-2 and PDGF-BB promoted the function and maturation of plaque neovessels, thereby representing a novel potential treatment strategy for vulnerable plaques.

12.
Microb Pathog ; : 103871, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31733278

RESUMO

Antimicrobial peptides have recently attracted much attention due to their broad-spectrum antimicrobial activity, rapid microbial effects, and minimal tendency toward resistance development. In this study, a series of new C-C terminals and C-N terminals dimer peptides were designed and synthesized by intermolecular dimerization of the partial d-amino acid substitution analogues of Anoplin, and the effects of different dimerization positions on biological activity were researched. The antimicrobial activity and stability of the new C-C terminals and C-N terminals dimer peptides were significantly improved compared with their parent peptide Anoplin. They displayed no obvious hemolytic activity and lower cytotoxicity, with a higher therapeutic index. Furthermore, the new dimer peptides not only enabled to rapidly disrupt bacterial membrane and damage its integrity which was different from conventional antibiotics but also penetrated bacterial membrane into binding to intracellular genomic DNA. More importantly, the new dimer peptides showed excellent antimicrobial activity against multidrug-resistant strains isolated from clinics in contrast to conventional antibiotics with low tendency to develop the bacterial resistance, besides they exhibited better anti-biofilm activity than antibiotic Rifampicin. Interestingly, the C-N terminals dimer peptides were superior to C-C terminals ones in antimicrobial and anti-biofilm activity, therapeutic index, outer membrane permeability, and DNA binding ability, whereas there were no noteworthy effects in different dimerization positions on stability. Thus, these data suggested that dimerization in different positions represented a potent strategy to develop novel antimicrobial agents for fighting against increasing bacterial resistance.

13.
Anal Chem ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31687801

RESUMO

This work initially reports the use of a quite familiar optical phenomenon of colloidal solutions, namely, the Tyndall Effect (TE) as signal readout for highly sensitive colorimetric chemical and biological analysis. Taking gold nanoparticles (GNPs) as a model colloid, the TE-inspired assay (TEA) is developed based on the conversion of a specific recognition event (e.g., the aptamer-analyte binding) into the aggregation of GNPs, leading to a significant TE enhancement. In the TEA, a cheap laser pointer pen is used as a hand-held light source, while a smartphone serves as a portable quantitative reader. The results show that the TE signaling strategy achieves a ∼1000-fold sensitivity improvement compared with the most common surface plasmon resonance signaling method using GNPs. The utility of the TEA is well demonstrated with the inexpensive, rapid, and portable detection of trace levels of analytes ranging from an important small-molecule drug (cocaine, ∼1.5 pM detection limit) to a protein biomarker (interferon-γ, ∼2.2 fM detection limit) and a toxic metal ion (Ag+, ∼1.4 nM detection limit). In addition, as the TE enhancement simply stems from the aggregation of either bare (unmodified) or modified GNPs, the TEA is universally applicable to almost all of the existing GNP-based liquid-phase colorimetric assays. The TEA method developed herein lights a new way for equipment-free point-of-care analysis in various fields including medical diagnosis, food safety evaluation, and environmental monitoring, especially in the resource-poor areas of the world.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31734084

RESUMO

BACKGROUND: Elderly patients with major depression have a poorer prognosis, are less responsive to treatment, and show greater functional decline compared with younger patients, highlighting the need for effective treatment. METHODS: This phase 3 double-blind study randomized patients with treatment-resistant depression (TRD) ≥65 years (1:1) to flexibly dosed esketamine nasal spray and new oral antidepressant (esketamine/antidepressant) or new oral antidepressant and placebo nasal spray (antidepressant/placebo). The primary endpoint was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to day 28. Analyses included a preplanned analysis by age (65-74 versus ≥75 years) and post-hoc analyses including age at depression onset. RESULTS: For the primary endpoint, the median-unbiased estimate of the treatment difference (95% CI) was -3.6 (-7.20, 0.07); weighted combination test using MMRM analyses z = 1.89, two-sided p = 0.059. Adjusted mean (95% CI) difference for change in MADRS score between treatment groups was -4.9 (-8.96, -0.89; t = -2.4, df = 127; two-sided nominal p = 0.017) for patients 65 to 74 years versus -0.4 (-10.38, 9.50; t = -0.09, two-sided nominal p = 0.930) for those ≥75 years, and -6.1 (-10.33, -1.81; t = -2.8, df = 127; two-sided nominal p = 0.006) for patients with depression onset <55 years and 3.1 (-4.51, 10.80; t = 0.8, two-sided nominal p = 0.407) for those ≥55 years. Patients who rolled over into the long-term open-label study showed continued improvement with esketamine following 4 additional treatment weeks. CONCLUSIONS: Esketamine/antidepressant did not achieve statistical significance for the primary endpoint. Greater differences between treatment arms were seen for younger patients (65-74 years) and patients with earlier onset of depression (<55 years).

15.
Artigo em Inglês | MEDLINE | ID: mdl-31734720

RESUMO

PURPOSE: This meta-analysis was conducted to investigate whether usage of corticosteroids was associated with an increased risk of central serous chorioretinopathy by summarizing all available evidence. METHODS: PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for all relevant studies published from inception to April 2019. Studies investigating the association between corticosteroids and the risk of central serous chorioretinopathy were included. RESULTS: Six case-control studies were finally included for the meta-analysis after study selection. The results of the analysis showed that there was a significantly higher risk of central serous chorioretinopathy among patients who once used corticosteroids (N = 707) compared with individuals without the usage of corticosteroids (N = 1927) (OR 4.050, 95% CI 2.270 to 7.220, I2 = 59%, P < 0.001). Results were the same for taking corticosteroids orally (OR 1.650, 95% CI 1.510 to 1.810, I2 = 47%, P < 0.001), through injection (OR 1.660, 95% CI 1.440 to 1.910, I2 = 0%, P < 0.001), and through nasal spray (OR 1.910, 95% CI 1.500 to 2.420, I2 = 17%, P < 0.001), but not for inhaled usage (OR 1.340, 95% CI 0.900 to 1.990, I2 = 0%, P = 0.160). CONCLUSIONS: In conclusion, this meta-analysis demonstrated that patients with the usage of corticosteroids had an increased risk of central serous chorioretinopathy. Patients who were prescribed with corticosteroids need greater attention to their retina health. Also, all central serous chorioretinopathy (CSC) patients should avoid the use of corticosteroids as much as they possibly can.

16.
J Biomater Sci Polym Ed ; : 1-18, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31724490

RESUMO

Biological modifications of the silk fibroin (silk) material have broad applications in textiles, biomedical materials and other industrial materials. It is economical to incorporate nanoparticles to the biosynthesis of silk fibroin by adding them to silkworm larval diets. This strategy may result in the rapid stable production of modified silk. Glucose-coated silver nanoparticles (AgNPs) were used to improve the AgNPs' biocompatibility, and the AgNPs were efficiently incorporated into silk by feeding. Larvae fed with AgNPs produced silk with significantly improved antibacterial properties and altered silk secondary structures. Both positive and negative effects on the growth and synthesis of silk proteins were observed after different AgNPs doses. Larvae feeding with low concentration of 0.02% and medium 0.20% AgNPs have greater transfer efficiencies of AgNPs to silk compared with feeding high concentration of 2.00% AgNPs. In addition, the elongation and tensile strength of the produced silk fibers were also significantly increased, with greater mammalian cell compatibility. The appropriate AgNPs concentration in the diet of silkworms can promote the synthesis of silk proteins, enhance their mechanical properties, improve their antibacterial property and inhibit the presence of Gram-negative bacteria.

17.
Gene ; : 144196, 2019 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-31669648

RESUMO

Accumulating evidence has indicated the important roles of circular RNAs (circRNAs) in different tumors. However, their detailed regulatory mechanisms in glioma are not fully understood. In this study, the functional role of a novel circRNA, circ-EZH2, was investigated by cell counting kit-8 (CCK-8), colony formation, flow cytometry, and transwell experiments. The regulatory mechanism of circ-EZH2 was explored by bioinformatics analysis, quantitative real-time PCR (qRT-PCR), Western blot and dual-luciferase reporter assay. We identified that circ-EZH2 was overexpressed in glioma tissues and cell lines. Further studies revealed that ectopic expression of circ-EZH2 significantly promoted cell growth, migration and invasion but inhibited cell apoptosis. By contrast, silencing of circ-EZH2 induced the opposite effects. Additionally, we found circ-EZH2 served as a miRNA sponge for miR-1265 to release its suppression on DDAH1 and CBX3. Rescue assays further revealed that the oncogenic function of circ-EZH2 was partly dependent on its modulation of DDAH1 and CBX3. Our study unraveled a novel molecular pathway in glioma and may provide a new perspective for the treatment of glioma.

18.
J Magn Reson Imaging ; 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31710413

RESUMO

BACKGROUND: It is difficult to prospectively differentiate between benign (World Health Organization [WHO] I) and nonbenign (WHO II and III) meningiomas. PURPOSE: To evaluate the feasibility of preoperative differentiation between benign and nonbenign meningiomas by using texture analysis from multiparametric MR data. STUDY TYPE: Retrospective. SUBJECTS: In all, 184 patients with meningioma (139 benign and 45 nonbenign) were included as the training cohort and 79 patients with meningioma (60 benign and 19 nonbenign) were included as the external validation cohort. FIELD STRENGTH/SEQUENCE: T1 -weighted, T2 -weighted, and contrast-enhanced T1 -weighted imaging were performed on 1.5 or 3.0T MR systems from two centers. ASSESSMENT: Tumor segmentation and radiological characteristic (RC) evaluation were performed by experienced radiologists. The texture features were extracted from preprocessed images and combined with RCs, and then the combined features were reduced by using a two-step feature selection. Three single-sequence models and a multiparametric MRI (the combination of single sequences) model were constructed and then evaluated with the external validation cohort. STATISTICAL TESTS: Area under receiver operating characteristic curve (AUC), accuracy (Acc), f1-score (F1), sensitivity (Sen), and specificity (Spec), were calculated to quantify the performance of the models. RESULTS: Among the four texture models, the multiparametric MRI model demonstrated the best performance for differentiating between benign and nonbenign meningiomas in both the training and external validation cohorts (AUC 0.91, Acc 89%, F1 0.88, Sen 0.93, and Spec 0.87 in the training cohort; AUC 0.83, Acc 80%, F1 0.77, Sen 0.84, and Spec 0.78 in the validation cohort). DATA CONCLUSION: Nonbenign meningiomas might be preoperatively differentiated from benign meningiomas by using texture analysis from multiparametric MR data. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019.

19.
Chem Commun (Camb) ; 55(92): 13880-13883, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31675031

RESUMO

Based on the unique property of preferential sequestration of guest molecules, coacervate microdroplets are proposed as enzyme active membrane-free protocells, in which uricase is loaded for efficient detoxification of uric acid in serum.


Assuntos
Urato Oxidase/metabolismo , Ácido Úrico/metabolismo , Células Artificiais/química , Dextranos/química , Corantes Fluorescentes/química , Humanos , Polietilenos/química , Estabilidade Proteica , Compostos de Amônio Quaternário/química , Solubilidade , Ácido Úrico/sangue
20.
J Clin Periodontol ; 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31697412

RESUMO

OBJECTIVE: To evaluate the association between periodontitis and the incidence and mortality of gastrointestinal cancer. METHOD: A comprehensive literature search was conducted to identify all relevant studies published prior to April 2019 according to the established inclusion criteria. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with a random-effects model. RESULTS: We identified 10 studies with 26 estimates of the relationship between periodontitis and gastrointestinal cancer. The HR for the incidence of gastrointestinal cancer in periodontitis was 1.23 (95% CI: 1.10-1.37). Subgroup analyses showed that periodontitis was associated with an increased risk of gastrointestinal cancers in prospective cohort studies and high-quality studies, North American individuals, and individuals 18 years or older, as well as when the dental status was self-reported and when the study was adjusted for smoking. A meta-analysis of nine reports demonstrated that periodontitis was associated with increased mortality from gastrointestinal cancer (HR = 1.59, 95% CI: 1.16-2.16). Additionally, periodontitis was associated with mortality from pancreatic cancer (HR = 2.20, 95% CI: 1.44-3.37); thus, periodontitis may be a risk factor for pancreatic cancer. CONCLUSION: Our meta-analysis demonstrated that periodontitis may be a risk factor for gastrointestinal cancers. Additional prospective cohort studies are warranted to confirm these findings.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA