Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.024
Filtrar
1.
J Nanosci Nanotechnol ; 20(6): 3512-3518, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748045

RESUMO

Highly efficient and effective porous ZnO nanorod arrays were fabricated by annealing ZnO nanorod arrays grown on a substrate using a simple hydrothermal method. The annealing had a positive effect on the nanorod morphology, structure and optical properties. The porosity was closely related to the annealing temperature. After heating at 450 °C, pores appeared on the nanorods. It was demonstrated that the porosity could be exploited to improve the visible light absorption of ZnO and reduce the bandgap from 3.11 eV to 2.99 eV. A combination of improved charge separation and transport of the heat-treated ZnO thus led to an increase in the photoelectrochemical properties. At an irradiation intensity of 100 mW/cm-2, the photocurrent density of the porous nanorod array was approximately 1.3 mA cm-2 at 1.2 V versus Ag/AgCl, which was five times higher than that of the ZnO nanorods. These results revealed the synthesis of promising porous ZnO nanorods for photoelectrochemical applications.

2.
Mater Sci Eng C Mater Biol Appl ; 107: 110312, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761174

RESUMO

The versatile properties of graphene-based materials are enabling various tissue regeneration, towards meeting an ever increasing demand for replacement tissues due to injury through trauma and disease. In particular, an innate ability for graphene to promote osteogenic differentiation of stem cells, combined with the potential to enhance the biological activity of cells through electrical stimulation (ES) using graphene, supports its use for osteoinduction or reconstruction. In this paper, we describe a miniaturized graphene-cellulose (G-C) scaffold-based device that incorporates electroactive G-C 'paper' within a polystyrene chamber for concomitant cell culture and ES. The G-C electrodes possessed lower impedance and higher charge injection capacity than gold (Au) electrodes, with high stability. By coupling ES with previously reported properties of the G-C scaffolds, we have advanced the platform for improved adipose derived stem cell (ADSC) support and osteogenic differentiation. We anticipate using the G-C scaffold-based ES device for in vitro modelling of osteogenic induction, bone tissue engineering and in vivo bone regeneration towards new therapeutic strategies for bone injury and disease. Furthermore, the device could reasonably be used for ES and culture of other cell types and engineering other tissues.

3.
Arch Oral Biol ; 109: 104588, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31669922

RESUMO

OBJECTIVE: Dental occlusion are frequently changed in clinic. Molecular responses in jaw muscles to aberrant dental occlusion are changes are attractive, yet remain are obscure. DESIGN: Unilateral anterior crossbite (UAC) prostheses were applied to Sprague-Dawley rats and then ceased after two weeks to detect the reactions of the masseter, a representative jaw elevator, and the lateral pterygoid muscle (LPM), a representative jaw depressor. RESULTS: Two weeks of UAC elicited mild injury of the two muscles. Myogenesis and protective reactions were detected as increases in αB-crystallin expression in the masseter after 3 days and in the LPM after 2 weeks, and increases in desmin expression in both muscles after 2 weeks. A switch in fibre types from IIb to IIx occurred in the LPM but not in the masseter. Inflammatory responses, shown by the infiltration of inflammatory cells and increases in TNF-α mRNA expression, and fibrosis responses, shown by increased mRNA expression of Type I and III collagens, appeared very mild in the two muscles. These responses were partially recovered by the cessation of UAC. During the whole process, no obvious changes were observed in mitochondrial function, as indicated by the levels of proliferator-activated receptor γ coactivator 1α, mitofusin-2 and voltage-dependent anion channel. CONCLUSIONS: UAC causes injury and very limited inflammatory and fibrosis adaption in the masseter and LPM. Both muscles respond with myogenesis and protective activity. The LPM responds also with muscle fibre isoform alternations. These alterations were partially recovered by the cessation of dental stimulation at an early stage.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31669280

RESUMO

NK-lysins, a type of broad-spectrum antimicrobial peptide (AMP), act as an essential effector of innate defense against microbial attack in higher vertebrates and so in fish. The present study delineates the structural and functional characterization of NK-lysin from yellow catfish (Pelteobagrus fulvidrac) (Pelteobagrus fulvidraco). PfNK-lysin encodes a 153-residue peptide, which displays the hallmark features of other known NK-lysins with the ordered array of six well-conserved cysteine residues and five-exon/four-intron structure. It was found to be ubiquitous in tissues, being detected most abundantly in gill and head kidney. In vivo exposure to stimuli (LPS, PolyI:C, and Edwardsiella ictaluri) induced PfNK-lysin expression in head kidney and spleen. Synthetic PfNK-lysin-derived peptide exhibited in vitro bactericidal potency against both Gram-positive and Gram-negative bacteria, with the highest inhibitory effect on pathogen Edwardsiella ictaluri. Fluorescence microscopy and scanning electron microscopy further confirmed its capacity to cause damage to the bacterial plasma membrane. Taken together, these data suggest that PfNK-lysin might participate in antimicrobial defense of yellow catfish by membrane-disruptive action.

5.
Asian J Androl ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31670279

RESUMO

The aim of this study was to investigate the role of seminal plasma miR-210-3p in the impairment of semen quality caused by varicocele. This study included 102 patients whose semen quality was normal when they were diagnosed with varicocele. A 2-year follow-up for included patients was performed, and they were divided into Group A (semen quality became abnormal) and Group B (semen quality remained normal) according to the results of semen analysis during the follow-up. Semen parameters and seminal plasma miR-210-3p expression were investigated by semen analysis and quantitative real-time polymerase chain reaction, respectively. In vitro experiments with GC-2 cells were performed to explore the role of miR-210-3p in spermatogenic cells. The results of quantitative real-time polymerase chain reaction showed that the level of seminal plasma miR-210-3p in Group A was higher than that in Group B both after 2-year follow-up and when they were diagnosed with varicocele (both P < 0.01). Apoptosis and proliferation assays showed that miR-210-3p induces apoptosis of spermatogenic cells by promoting caspase-3 activation. In conclusion, our study indicated that seminal plasma miR-210-3p induces spermatogenic cell apoptosis by activating caspase-3 in patients with varicocele. Seminal plasma miR-210-3p may be a potential biomarker for predicting impaired semen quality caused by varicocele.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 227: 117565, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31670041

RESUMO

Retinal is a flexible natural chromophore and widely present in organisms. The slender conjugated polyene structure retinal is conducive to entering protein structure. In this work, a novel turn-on fluorescent probe for Cu2+ based on retinal and phenylenediamine was designed and synthesized. The probe achieved recognition of copper ions in human serum complex protein environment. Furthermore, the high sensitivity, selectivity for Cu2+ and the sensing mechanism was also investigated.

7.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 31(10): 1299-1301, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31771734

RESUMO

OBJECTIVE: Autophagy is a process of degrading the damaged organelles and macromolecules by lysosomes in cells, which belongs to the programmed cell death. Cerebral ischemia is one of the important reasons for activation of autophagy. Studies have showed that autophagy plays a protective role in neuronal death induced by ischemia. However, it has also been found that excessive activation of autophagy could aggravate cerebral ischemia injury. In recent years, more and more Chinese medicine has been proved to regulate the autophagy level of brain neurons and reduce cerebral ischemia injury. In this paper, the main molecular mechanism of autophagy in the process of cerebral ischemic injury and the intervention effects of Chinese herbs on autophagy arereviewed in order to explore the basic principle of regulating autophagy by Chinese herbs and to play a better role in the clinical treatment of cerebral ischemic diseases.

8.
Exp Ther Med ; 18(6): 4528, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31772639

RESUMO

[This retracts the article DOI: 10.3892/etm.2017.4342.].

10.
Mol Immunol ; 117: 122-130, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31765841

RESUMO

The acute phase reactant C-reactive protein (CRP) binds with high affinity to fibronectin (FN), but this binding occurs only at pH 6.5 or lower, and the binding is inhibited by calcium ions at physiological pH. Since CRP in the circulating blood exists in a calcium-binding form, the interaction between CRP and FN in vivo has been uncertain. CRP can undergo a conformational rearrangement in the absence of calcium or in the local microenvironment (e.g., acidic pH) of inflamed tissue to dissociate into monomeric CRP (mCRP). Therefore, we tested whether these discrepancies can be explained by the different isoforms and locations of CRP. Surface plasmon resonance and ELISA assays showed that mCRP binds with high affinity to FN, and the binding of mCRP to FN was unaffected by calcium or pH. Peptide competition assay, deletion mutant binding assay and protein docking analyse verified that the binding site of mCRP to FN is residues a.a.35-47. Furthermore, mCRP can significantly enhance the adhesion of monocytes to FN as well as upregulate the adhesion molecules expression on endothelial cell. Colocalization of mCRP with FN was observed in mice with DSS-induced colitis, whereas there was very little signal orcolocalization of CRP. These results provide in vitro and in vivo evidence that mCRP formed by local dissociation from circulating CRP is the major isoform that interacts with FN and regulates FN-mediated monocyte adhesion, which is involved in the pro-inflammatory process.

11.
Medicine (Baltimore) ; 98(48): e18178, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31770269

RESUMO

RATIONALE: Occasionally, tubulointerstitial lesions can be found in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). However, significantly isolated tubulointerstitial nephritis (TIN) with germinal centers is rare. PATIENT CONCERNS: A 17-year-old Chinese Han patient showed rapidly progressive glomerulonephritis, anuria, and serum creatinine of 19.4 mg/dL. DIAGNOSIS: He had positive ANCA targeting myeloperoxidase (55.0 RU/mL). The renal biopsy showed crescent formation in 100% of glomeruli. Of special note, the glomerular crescents were surrounded by granulomatous inflammation, extensive tubular destruction or disappearance, and massive interstitial infiltration. A diagnosis of AAV was thus made with the involved organ restricted to the kidney. INTERVENTIONS: The patient underwent 7 rounds of plasmapheresis, 3 pulses of methylprednisolone therapy (500 mg per pulse), and oral prednisolone (50 mg/d). Rituximab (500 mg) was used after the plasma exchange treatment. OUTCOMES: ANCA was negative, while anti-modified C-reactive protein (anti-mCRP) antibodies remained positive. The patient was dependent on hemodialysis. We found anti-mCRP antibody in the serum of the patient, with the major epitope on amino acids 35 to 47 of mCRP. LESSONS: We proposed that the anti-mCRP antibody might play an important role in this case of acute TIN in AAV.

12.
Artigo em Inglês | MEDLINE | ID: mdl-31770317

RESUMO

STUDY DESIGN: Basic science. OBJECTIVE: The aim of this study was to examine the effect of vascular endothelial growth factor (VEGF)-transfected bone marrow mesenchymal stem cells (BMSCs) on the recovery of motor and sensory functions of rats with spinal cord injury (SCI). SUMMARY OF BACKGROUND DATA: There is no effective treatment to protect against SCI. BMSCs have been widely applied to the treatment of nervous system damage due to the function of prompt neurite growth and inhibition of demyelination following injury. METHODS: VEGF-transfected BMSCs were injected to rats with SCI and the recovery of motor and sensory functions was observed. The Basso, Beattie, and Bresnahan, mechanical withdrawal threshold and thermal withdraw latency grading was conducted to assess the recovery status of motor and sensory functions of the SCI rats. The expression of VEGF, CD31, and NF200 was detected by immunofluorescence. RESULTS: The recovery of the rat motor and sensory functions in the VEGF-transfected BMSC (BMSC-VEGF) group was higher than those of the other groups with the exception of the Sham group (P < 0.05). The expression of the CD31 and NF200 proteins in the rat SCI regions was the highest in the BMSC-VEGF group, whereas the survival of BMSC in the BMSC-VEGF group was increased compared with that in the BMSC-Ad group. In addition, the injection of VEGF-transfected BMSCs can improve the angiogenesis of the injured area and retain the survival of injected cells and neurons. CONCLUSION: The injection of BMSC-VEGF improved the recovery of motor function in SCI rats. LEVEL OF EVIDENCE: N/A.

13.
Nat Commun ; 10(1): 5332, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31767846

RESUMO

Dynamic mRNA modification in the form of N6-methyladenosine (m6A) adds considerable richness and sophistication to gene regulation. The m6A mark is asymmetrically distributed along mature mRNAs, with approximately 35% of m6A residues located within the coding region (CDS). It has been suggested that methylation in CDS slows down translation elongation. However, neither the decoding feature of endogenous mRNAs nor the physiological significance of CDS m6A has been clearly defined. Here, we found that CDS m6A leads to ribosome pausing in a codon-specific manner. Unexpectedly, removing CDS m6A from these transcripts results in a further decrease of translation. A systemic analysis of RNA structural datasets revealed that CDS m6A positively regulates translation by resolving mRNA secondary structures. We further demonstrate that the elongation-promoting effect of CDS methylation requires the RNA helicase-containing m6A reader YTHDC2. Our findings established the physiological significance of CDS methylation and uncovered non-overlapping function of m6A reader proteins.

14.
Front Immunol ; 10: 2532, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31736959

RESUMO

Interleukin (IL)-36 is a member of the IL-1 superfamily and includes three agonists (IL-36α, IL-36ß, and IL-36γ) and an antagonist (IL-36Ra). IL-36 agonists bind to heterodimeric receptor complexes. Then, the heterotrimer complexes signal via intracellular functional domains, binding to downstream signaling proteins and inducing inflammatory responses. In this review, we summarized the current knowledge about the biological role of IL-36 and its correlation with systemic inflammatory diseases. The information collected will help to increase the understanding of the potential of IL-36 and may give clues for developing novel therapeutic strategies.

15.
Comput Math Methods Med ; 2019: 5297284, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31737085

RESUMO

Evidence from clinical data suggests that the stenotic side branch (SB) is one of the key predictors for SB occlusion-based adverse events. In this study, we hypothesized that coronary bifurcations with stenotic SB might lead to severe concentration polarization of atherogenic lipids, such as the low-density lipoproteins (LDL), motivating the adverse events in the clinic. To confirm this hypothesis, this work numerically investigated the transport of LDL in different bifurcation lesions based on the Medina classification with various location and stenosis severities. The results showed that the coronary bifurcations with stenotic SB might be suffering more serious concentration polarization of LDL on the luminal surface of the SB due to higher level of LDL concentrations. Moreover, compared to the other bifurcation lesion types, the type (1,0,1) had the highest luminal surface LDL concentration along the SB and the highest degree of risk to enhance the process of atherosclerosis. In addition, this study also showed that the luminal surface LDL concentration increased with elevated stenosis severity. The type (1,0,1) with the severe stenosis (75% diameter reduction) had the highest concentration at the SB. In conclusion, these results suggested that both location of lesions and stenosis severities had great influence on the distribution of LDL on the luminal surface of the SB. Therefore, the estimation of disease severity and the interventional therapy should be carried out not only according to the stenosis severities in clinic. Moreover, compared to the other bifurcation lesion types, the type (1,0,1), rather than the type (1,1,1) as usually considered, had the highest luminal surface LDL concentration along the SB and the highest degree of risk to enhance the process of atherosclerosis.

17.
J Nat Prod ; 82(11): 3089-3095, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31702148

RESUMO

The Arctic fungus Eutypella sp. D-1, previously found to produce a variety of cytotoxic cyclopropyl-fused and cyclobutyl-fused pimarane diterpenoids when grown in the defined medium, was induced to produce unusual metabolites by growing on solid rice medium. A chemical investigation on the rice medium extract led to the isolation of four new meroterpenoids, eutypellacytosporins A-D (1-4), along with the known biogenetically related compound cytosporin D (5). The structures of the new compounds were elucidated by their detailed spectroscopic analysis and modified Mosher's method. Compounds 1-4 may be formed by the 12,32-ester linkage of two moieties, cytosporin D (5) and decipienolide A or B. All isolated compounds, except 5, showed weak cytotoxicity against DU145, SW1990, Huh7, and PANC-1 cell lines with IC50 values ranging from 4.9 to 17.1 µM.

18.
BMC Genomics ; 20(1): 851, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31726970

RESUMO

BACKGROUND: Endogenous α-synuclein (α-Syn) is involved in many pathophysiological processes in the secondary injury stage after acute spinal cord injury (SCI), and the mechanism governing these functions has not been thoroughly elucidated to date. This research aims to characterize the effect of α-Syn knockdown on transcriptional levels after SCI and to determine the mechanisms underlying α-Syn activity based on RNA-seq. RESULT: The establishment of a rat model of lentiviral vector-mediated knockdown of α-Syn in Sprague-Dawley rats with T3 spinal cord contusion (LV_SCI group). The results of the RNA-seq analysis showed that there were 337 differentially expressed genes (DEGs) between the SCI group and the LV_SCI group, and 153 DEGs specific to LV_SCI between the (SCI vs LV_SCI) and (SCI vs CON) comparisons. The top 20 biological transition terms were identified by Gene ontology (GO) analysis. The Kyoto Gene and Genomic Encyclopedia (KEGG) analysis showed that the LV_SCI group significantly upregulated the cholinergic synaptic & nicotine addiction and the neuroactive ligand receptor interaction signaling pathway. Enriched chord analysis analyzes key genes. Further cluster analysis, gene and protein interaction network analysis and RT-qPCR results showed that Chrm2 and Chrnb2 together significantly in both pathways. The proliferation of muscarinic cholinergic receptor subtype 2 (Chrm2) and nicotinic cholinergic receptor subtype ß2 (Chrnb2), and the neurogenesis were elevated in the injury site of LV_SCI group by immunofluorescence. Further by subcellular localization, the LV_SCI group enhanced the expression of Chrnb2 at the cell membrane. CONCLUSION: Knockdown of α-Syn after SCI enhance motor function and promote neurogenesis probably through enhancing cholinergic signaling pathways and neuroreceptor interactions. This study not only further clarifies the understanding of the mechanism of knockdown of α-Syn on SCI but also helps to guide the treatment strategy for SCI.

19.
Sci Rep ; 9(1): 17296, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31754202

RESUMO

Nephrolithiasis is a common disease affecting almost all populations, with an increasing prevalence over the past decades. Previous studies revealed several functional polymorphisms associated with the pathogenesis of nephrolithiasis. However, data on Asian populations are limited. In this study, three candidate polymorphisms were selected from previous studies to investigate the correlations with nephrolithiasis in a Taiwanese population. In total, 454 nephrolithiasis patients were recruited from Kaohsiung Medical University Hospital, with SNP frequency for 1513 subjects of general population from the Taiwan Biobank (TWB) as a genotypic reference. Results revealed that subjects with minor TT genotype at rs1256328 (alkaline phosphatase, liver/bone/kidney (ALPL)) have higher susceptibility to nephrolithiasis (odds ratio (OR) = 2.03, p = 0.0013). In addition, subjects carrying the minor AA genotype at rs12654812 (regulator of G protein signaling 14 (RGS14)) have higher susceptibility to nephrolithiasis (OR = 1.91, p = 0.0017). Among nephrolithiasis patients, subjects with GG at rs7627468 (calcium-sensing receptor (CASR)) have lower pH level in urine (p = 0.0088). Importantly, rs7627468 is associated with the expressions of IQCB1 and EAF2. rs12654812 could influence the expression of RGS14 itself, MXD3, and FGFR4. In summary, this study successfully validated the genetic roles of rs1256328 and rs12654812 in human nephrolithiasis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA