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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117418, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31362186

RESUMO

A series of luminescent lanthanide compounds with 2, 3, 5, 6-tetrafluoro-1, 4-benzenedicarboxylate (H2BDC-F4) acting as the organic ligand have been synthesized by solvothermal reaction. The terbium compound (C1: Tb-BDC-F4) and europium compound (C7: Eu-BDC-F4) exhibit intense green and red luminescence respectively upon excitation of the ligand at room temperature, which suggests that H2BDC-F4 ligand can sensitize Tb3+ and Eu3+ ions effectively. The emitting color of the mixed lanthanide compounds is tunable from green to red in the mixed lanthanide compounds TbxEu1-x-BDC-F4 (x = 0.3%, 0.5%, 0.7%, 1%, and 2%), which is caused by energy transfer from Tb3+ to Eu3+. The self-reference ratiometric optical thermometry was realized by fluorescence intensity ratio between Tb3+ green emission (∼544 nm) and Eu3+red emission (∼ 619 nm). The maximum relative sensitivity SR,max is 0.76%K-1@50 K. Furthermore, the emitting color of C5: Eu0.01Tb0.99-BDC-F4 could be tuned from green to orange by temperature in the range of 50 to 300 K. It allows the mixed Eu/Tb-BDC-F4 compounds to be potentially used as sensitive luminescent materials to directly imagine the temperature distribution.

2.
J Nanosci Nanotechnol ; 20(3): 1983-1988, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492371

RESUMO

The current study was conducted to investigate the potential of three circulating miRNAs (miR-21, miR-16 and miR-100) as HCC diagnostic marker in the population living in Guangdong province, China. First, the Fe3O4 and Fe3O4@SiO2 magnetic microsphere were prepared. Fe3O4@SiO2 microspheres were further used for total RNA purification from serum. After that, the real-time qPCR was conducted for the detecting the miRNA in the serum of HCC patients and healthy volunteers. Scanning electron microscope and transmission electron microscope images showed that monodisperse Fe3O4 and Fe3O4@SiO2 microspheres were successfully synthesized with a mean diameter of about 500 nm and 600 nm, respectively. The microsphere was spherical in shape with good state of dispersion. The characteristic peak at 1088.8 cm-1 in FTIR spectra belonged to the asymmetry stretching vibration of Si-O-Si, which confirmed the SiO2 coating on Fe3O4 microspheres. The successful amplification of miRNAs in qPCR verified that the total RNA extracted using the Fe3O4@SiO2 microspheres retained high quality. The real time PCR results showed that miR-21 was differentially expressed in the serum of HCC patients and healthy volunteers. miR-21 and alpha-fetoprotein (AFP) together could be potentially used as HCC diagnostic marker in Guangdong province population in China.

3.
J Nanosci Nanotechnol ; 20(5): 3195-3200, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31635664

RESUMO

Surface-enhanced fluorescence detection has large potential for detecting many chemical and biological trace analytes. This paper presents a novel method for preparing silver nanomaterials in microfluidic chip channels for the surface-enhanced fluorescence detection of fluorescent dye (SYBR Green I) molecules. Microfluidic chip channels were fabricated by a 248-nm excimer laser. Silver nanoparticles (Ag-NPs) were prepared inside the microfluidic chip channels by directly heating the silver precursor solution. The influence of different temperatures on the sizes of the silver nanoparticles was studied. Then, the surface-enhanced fluorescence technology based on the microfluidic system was used to detect the fluorescent dye molecules. As a result, the fluorescence signal of the fluorescent dye molecules was significantly enhanced by the silver nanoparticles. In addition, the effect of particle size on the fluorescence signal was studied. This simple and fast method is suitable for a fluorescent PCR (polymerase chain reaction) system and has good application prospects for detecting harmful microorganisms in a spacecraft.

4.
Carbohydr Polym ; 227: 115332, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590887

RESUMO

Advanced oxidation processes (AOPs) based on activated persulfate have received extensive attention for sludge pretreatment. Persulfate (PS) is a persistent oxidant and the excess persulfate in the sludge affects the carbohydrate analysis using the traditional phenol-sulfuric acid method. In this study, an improved phenol-sulfuric acid method was developed for the determination of carbohydrates in the presence of persulfate, and a critical procedure was introduced before the conventional determination with the assistance of the chemical pretreatments. The best reagent was screened from four reductants (i.e. Na2S, KI, Na2SO3 and Na2S2O3) and two free-radical scavengers (i.e. phenol and benzoic), and the optimal conditions were determined based on the monosaccharides (i.e. glucose, galactose and mannose) and the polysaccharides in different EPS fractions from two activated sludges. The results showed that Na2SO3 was the best reagent for chemical pretreatment due to redox reaction, high selectivity and colorless oxidation product, and the others were not suitable as pretreatment reagents mainly since the reaction products affect the final spectral analysis. Besides, the optimal Na2SO3 concentration for eliminating the impact of PS was 150 mmol/L, and the relative deviation of measurement is less than 5% if the PS concentration was on more than 100 mmol/L, regardless of the kinds of carbohydrates. Compared with the anthrone-sulfuric acid method and the sulfuric method, the improved phenol-sulfuric acid method has a great advantage for determining the carbohydrate concentration in the presence of PS.

5.
Food Chem Toxicol ; : 110932, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31682935

RESUMO

Immunomodulatory peptides with the sequences TSeMMM and SeMDPGQQ from selenium (Se)-enriched rice protein hydrolysates (SPHs) were identified in our previous study. We synthesized these two peptides to study whether they have neuroprotective effects on Pb2+-induced oxidative stress in mouse hippocampal HT22 cells, SPHs and a purified SPH fraction (SPHs-2) were used to compare the effects. Peptides pretreatments significantly suppressed Pb2+-induced cytotoxicity by increasing cell viability and decreasing cell apoptosis. TSeMMM and SeMDPGQQ reduced nitric oxide (NO) levels by 37.47% and 14.72% of Pb2+ group, as well as lactate dehydrogenase (LDH) release by 12.98% and 6.32% of Pb2+ group. TSeMMM and SeMDPGQQ could increase the activities of antioxidant enzymes; for example, the activity of superoxide dismutase (SOD) increased by 47.79% and 13.93%, respectively, and that of glutathione peroxidase (GSH-Px) increased by 94.7% and 78.73% of Pb2+ group. Additionally, nuclear factor erythroid 2-related factor (Nrf2) nuclear translocation and heme oxygenase 1 (HO-1) expression were triggered. These results suggest that TSeMMM and SeMDPGQQ can suppress oxidative damage caused by Pb2+; moreover, TSeMMM showed better neuroprotective potential than SeMDPGQQ.

6.
Opt Express ; 27(21): 30639-30652, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684308

RESUMO

In order to break through the inherent limitation of channel capacity, we employ a correlated multiple input multiple output (MIMO) framework over non-line-of-sight (NLOS) ultraviolet (UV) turbulent channels. Subsequently, a method of segmented correlation is proposed to define the spatial correlation of UV MIMO structures. Furthermore, the correlation and channel capacity are studied with varying elevation angle, turbulence intensity, signal-to-noise ratio (SNR) and number of transceiver in pairs (NTPs). The results show that this correlated MIMO framework can obtain higher channel capacity by reducing the elevation angle of the transceivers or increasing turbulence intensity or NTPs. Moreover, channel capacity increases with the SNR. But at low SNR, a larger gain of channel capacity can be provided. Therefore, this paper develops the capacity of UV turbulent channels and provides a guide for optimal parameter configuration of correlated UV MIMO.

7.
Opt Express ; 27(22): 31407-31417, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31684375

RESUMO

The electromagnetic field theory for a step-index fiber geometry is developed to sense a surrounding chiral drug via long-period fiber gratings (LPFGs). This theory employs Debye potentials and electromagnetic fields for cladding modes in the LPFGs by introducing constitutive relations for a chiral drug. The fields in the chiral drug are transformed and decomposed into right- and left-hand circularly polarized components to account for the magnetoelectric coupling due to the chirality. The solving process for complex propagation constants is given. Numerical results show that responses of the LPFGs to refractive index and chirality changes are different. The two minimum transmissions of a coated LPFG are very sensitive to the variation of the complex chirality. On the other hand, the two resonance wavelengths keep invariant as real and imaginary parts of the comparatively small chirality change. This work enriches the electromagnetic field theory for better design of LPFGs against the highly sensitive chirality detection.

8.
Medicine (Baltimore) ; 98(44): e17554, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31689759

RESUMO

INTRODUCTION: Solid pseudopapillary tumors (SPT) account for 1% to 3% of all pancreatic tumors. They have low malignant potential with a favorable prognosis, and predominantly occur in young women. The pathogenesis and clinical behavior of SPT are still uncertain. In addition, most ruptures of SPT were associated with blunt abdominal trauma, while spontaneous ruptures seemed to be quite rare. Up to now, there have been only 3 spontaneous ruptured SPT cases reported worldwide. PATIENT CONCERNS: Here, we reported a 22-year-old female patient with left lower abdominal pain. Computed tomography (CT) showed that a hemorrhagic complex solid cystic mass located in the lesser omentum sac. DIAGNOSIS: According to pathological findings of tumor specimen, the diagnosis of solid pseudopapillary tumor (SPT) of the pancreas was made. INTERVENTIONS: Distal pancreatectomy and splenectomy was carried out. OUTCOMES: The patient recovered to normal status within 10 days after surgery. CONCLUSION: Besides, we reviewed about 50 cases in literatures to find out the clinical characteristics and differential diagnostic strategies of SPT.

9.
Bioorg Med Chem Lett ; : 126769, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31699607

RESUMO

A series of novel alkoxy-piperidine derivatives were synthesized and evaluated for their serotonin reuptake inhibitory and binding affinities for 5-HT1A/5-HT7 receptors. In vivo antidepressant activities of the selective compounds were explored using the forced swimming test (FST) and tail suspension test (TST) in mice. The results showed that compounds 7a (reuptake inhibition (RUI), IC50 = 177 nM; 5-HT1A, Ki = 12 nM; 5-HT7, Ki = 25 nM) and 15g (RUI, IC50 = 85 nM; 5-HT1A, Ki = 17 nM; 5-HT7, Ki = 35 nM) were potential antidepressant agents in animal behavioral models with high 5-HT1A/5-HT7 receptor affinities and moderate serotonin reuptake inhibition, and good metabolic stability in vitro.

10.
Orphanet J Rare Dis ; 14(1): 237, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666091

RESUMO

BACKGROUND: Hirschsprung disease (HSCR) is an inherited congenital disorder characterized by the absence of enteric ganglia in the distal part of the gut. RET is the major causative gene and contains > 80% of all known disease-causing mutations. RESULTS: To determine the incidence of RET pathogenic variants, be they Mendelian inherited, mosaic in parents or true de novo variants (DNVs) in 117 Chinese families, we used high-coverage NGS and droplet digital polymerase chain reaction (ddPCR) to identify 15 (12.8%) unique RET coding variants (7 are novel); one was inherited from a heterozygous unaffected mother, 11 were DNVs (73.3%), and 3 full heterozygotes were inherited from parental mosaicism (2 paternal, 1 maternal): two clinically unaffected parents were identified by NGS and confirmed by ddPCR, with mutant allele frequency (13-27%) that was the highest in hair, lowest in urine and similar in blood and saliva. An extremely low-level paternal mosaicism (0.03%) was detected by ddPCR in blood. Six positive-controls were examined to compare the mosaicism detection limit and sensitivity of NGS, amplicon-based deep sequencing and ddPCR. CONCLUSION: Our findings expand the clinical and molecular spectrum of RET variants in HSCR and reveal a high frequency of RET DNVs in the Chinese population.

11.
Math Biosci Eng ; 16(6): 6454-6466, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31698572

RESUMO

Pediatricians and pediatric endocrinologists utilize Bone Age Assessment (BAA) for in-vestigations pertaining to genetic disorders, hormonal complications and abnormalities in the skeletal system maturity of children. Conventional methods dating back to 1950 were often tedious and suscep-tible to inter-observer variability, and preceding attempts to improve these traditional techniques have inadequately addressed the human expert inter-observer variability so as to significantly refine bone age evaluations. In this paper, an automated and efficient approach with regression convolutional neu-ral network is proposed. This approach automatically exploits the carpal bones as the region of interest (ROI) and performs boundary extraction of carpal bones, then based on the regression convolutional neural network it evaluates the skeletal age from the left hand wrist radiograph of young children. Experiments show that the proposed method achieves an average discrepancy of 2.75 months between clinical and automatic bone age evaluations, and achieves 90.15% accuracy within 6 months from the ground truth for male. Further experimental results with test radiographs assigned an accuracy within 1 year achieved 99.43% accuracy.

12.
Exp Neurol ; 323: 113077, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31678140

RESUMO

HIV-associated neurocognitive disorders (HAND) continue to persist despite effective control of viral replication. Although the mechanisms underlying HAND are poorly understood, recent attention has focused on altered neuronal population activity as a correlate of impaired cognition. However, while alterations in neuronal population activity in the gamma frequency range are noted in the setting of HAND, the underlying mechanisms for these changes is unclear. Perineuronal nets (PNNs) are a specialized extracellular matrix that surrounds a subset of inhibitory neurons important to the expression of neuronal oscillatory activity. In the present study, we observe that levels of PNN-degrading matrix metalloproteinases (MMPs) are elevated in HIV-infected post-mortem human brain tissue. Furthermore, analysis of two PNN components, aggrecan and brevican, reveals increased proteolysis in HIV-infected brains. In addition, local field potential recordings from ex vivo mouse hippocampal slices demonstrate that the power of carbachol-induced gamma activity is increased following PNN degradation. Together, these results provide a possible mechanism whereby increased MMP proteolysis of PNNs may stimulate altered neuronal oscillatory activity and contribute to HAND symptoms.

13.
Ophthalmic Physiol Opt ; 39(6): 451-458, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31696541

RESUMO

PURPOSE: To determine the differences in mean ocular dimensions between urban and rural children and identify possible influencing factors. METHODS: This work uses previously published data from the Shandong Children Eye Study, which was based on a random cluster sampling applied to a cross-sectional school-based study design in the rural Guanxian County and Weihai city. All children underwent auto-refractometry and biometry under cycloplegia. RESULTS: The study included 3290 children (aged 9.35 ± 2.93 years), consisting of 888 pairs of boys and 757 pairs of girls matched by sex, age and refractive error (each pair matching one child from urban cohort with one from the rural cohort). Overall urban children were significantly taller and heavier than rural children (t-test; p < 0.001), which was confirmed for all age groups for weight. Urban ocular axial lengths were significantly longer by 0.23 mm compared to the rural population (t-test; p < 0.001), mostly in younger children and boys. Meanwhile, corneal curvatures were flatter in the urban cohort by 0.08 mm (p < 0.001). This association of axial length with urban vs rural region was reduced in magnitude by 69.7% after accounting for height. CONCLUSIONS: For the same, matched refractive error, children from urban regions had significantly longer eyes and flatter corneal curvature than rural children. Since corneal curvature is defined during the first 2 years of life, early environmental factors may be the source of these differences in ocular dimensions.

14.
Se Pu ; 37(10): 1036-1041, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642280

RESUMO

A method combining QuEChERS with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of higenamine in Chinese herbal medicine, condiments, and topical medicine. The sample was subjected to extraction using a formic acid-ethanol mixture, followed by purification of the QuEChERS sorbents; then, the extraction solution was introduced into the LC-MS/MS system for detection in multiple reaction monitoring (MRM) mode. Under the optimal conditions, the detection limit of the developed method was 0.03 ng/g, and the linear range was 0.10-100 ng/g with a relative standard deviation (RSD) of 4.33% (0.5 ng/g, n=7). The method was then applied to the determination of higenamine in 13 kinds of Chinese herbal medicine, four kinds of condiments, and a topical medicine. Higenamine was detected in dried lotus leaf, dried lotus seed, Chinese yam, Yuzhu, Yam, Sichuan pepper, Cassia, and the topical medicine at 9667.6, 1183.8, 21.5, 8.2, 8.5, 148.6, 21.3, and 173.3 µg/kg, respectively. The recoveries of higenamine in Sichuan pepper and cassia was 92.6%-109.8%. In conclusion, the method is fast, simple, reliable, and suitable for use in batch operation.


Assuntos
Alcaloides/análise , Condimentos/análise , Medicamentos de Ervas Chinesas/análise , Tetra-Hidroisoquinolinas/análise , Cromatografia Líquida , Espectrometria de Massas em Tandem
15.
Molecules ; 24(20)2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31652602

RESUMO

The dried roots of Euphorbia kansui S.L.Liou ex S.B.Ho have long been used to treat edema in China. However, the severe toxicity caused by Euphorbia kansui (EK) has seriously restricted its clinical application. Although EK was processed with vinegar to reduce its toxicity, the detailed mechanisms of attenuation in toxicity of EK stir-fried with vinegar (VEK) have not been well delineated. Diterpenoids are the main toxic ingredients of EK, and changes in these after processing may be the underlying mechanism of toxicity attenuation of VEK. 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol (3-O-EZ) is one of the diterpenoids derived from EK, and the content of 3-O-EZ was significantly reduced after processing. This study aims to explore the underlying mechanisms of toxicity reduction of VEK based on the change of 3-O-EZ after processing with vinegar. Based on the chemical structure of 3-O-EZ and the method of processing with vinegar, simulation experiments were carried out to confirm the presence of the product both in EK and VEK and to enrich the product. Then, the difference of peak area of 3-O-EZ and its hydrolysate in EK and VEK were detected by ultra-high-performance liquid chromatography (UPLC). Furthermore, the toxicity effect of 3-O-EZ and its hydrolysate, as well as the underlying mechanism, on zebrafish embryos were investigated. The findings showed that the diterpenoids (3-O-EZ) in EK can convert into less toxic ingenol in VEK after processing with vinegar; meanwhile, the content of ingenol in VEK was higher than that of EK. More interestingly, the ingenol exhibited less toxicity (acute toxicity, developmental toxicity and organic toxicity) than that of 3-O-EZ, and 3-O-EZ could increase malondialdehyde (MDA) content and reduce glutathione (GSH) content; cause embryo oxidative damage by inhibition of the succinate dehydrogenase (SDH) and superoxide dismutase (SOD) activity; and induce inflammation and apoptosis by elevation of IL-2 and IL-8 contents and activation of the caspase-3 and caspase-9 activity. Thus, this study contributes to our understanding of the mechanism of attenuation in toxicity of VEK, and provides the possibility of safe and rational use of EK in clinics.

16.
BMC Psychiatry ; 19(1): 323, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31660909

RESUMO

BACKGROUND: Numerous studies have reported contradicting results on the relationship between cancer mortality and schizophrenia. Our aim is to quantify the mortality rate of common site-specific cancers among patients with schizophrenia and to synthesize the available research evidence. METHODS: We performed a systemic search of the PubMed, EMBASE and Web of Science databases. Studies reporting the mortality rate of different cancer in patients with schizophrenia were included. A random-effects model was applied to calculate the pooled relative risks (RRs) with 95% confidence intervals (95%CIs). RESULTS: Seven studies consisting of 1,162,971 participants with schizophrenia were included in this meta-analysis. Data regarding mortality risk of breast, colon, lung and prostate cancer among schizophrenia patients were subjected to quantitative analysis. Pooled results showed significant increases in mortality risk of breast cancer (RR = 1.97, 95%CI 1.38-2.83), lung cancer (RR = 1.93, 95%CI 1.46-2.54) and colon cancer (RR = 1.69, 95%CI 1.60-1.80) in patients with schizophrenia compared with those in the general population or control group. The mortality risk of prostate cancer increased in male patients, although no significant difference was detected (RR = 1.58, 95% CI 0.79-3.15). Increased risks of mortality from lung and colon cancer were observed in female patients (RR = 2.49, 95%CI 2.40-2.59 and RR = 2.42, 95%CI 1.39-4.22, respectively) and elevated risks of mortality from lung and colon cancer in male patients (RR = 2.40, 95%CI 2.30-2.50 and RR = 1.90, 95%CI 1.71-2.11, respectively) were detected. CONCLUSIONS: Individuals with schizophrenia have a significantly high risk of mortality from breast, colon, and lung cancer.

17.
Brain Res ; : 146518, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31647899

RESUMO

Chloroquine, a prototype anti-malaria drug, has been reported to possess anti-inflammatory effects. Moreover, chloroquine pretreatment could improve DNA damage repair. It is therefore reasonable to hypothesize that chloroquine pretreatment could attenuate ischemia/reperfusion injury in the brain. Considering the fact that chloroquine could also improve glucose metabolism, we speculated that the potential effects of chloroquine on ischemia/reperfusion injury might be particularly pronounced in diabetic mice. In this study, chloroquine pretreatment protected neurons from Oxygen Glucose Deprivation (OGD) induced cytotoxicity and apoptosis. In vivo, Ob/ob mice and wildtype (WT) mice were pretreated with chloroquine for 3 weeks. Then, ischemic stroke was induced by 60 min Middle Cerebral Artery Occlusion (MCAO). We found that chloroquine pretreatment normalized blood glucose in diabetic ob/ob mice, and reduced cerebral damage after ischemic stroke especially for diabetic mice. In addition, chloroquine pretreatment reduced High-mobility group box 1 (HMGB1) content in the cerebrospinal fluid (CSF) and serum and lowered myeloperoxidase (MPO) activity and inflammatory cytokines gene expression both in the ob/ob diabetic mice and WT mice. Moreover, harmful DNA damage-signaling responses, including PARP activation and p53 activation, were also attenuated by chloroquine pretreatment in these two kinds of mice. In conclusion, chloroquine pretreatment could reduce cerebral damage after ischemic stroke especially in diabetic mice through multiple mechanisms, which include reducing neural cell DNA injury, restoring euglycemia and anti-inflammatory effects. The findings may provide potential for the development of chloroquine in the prevention and treatment of stroke in diabetic high-risk patients.

18.
Inorg Chem ; 58(20): 13766-13770, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31599582

RESUMO

A zeolite-like gyroidal MOF (denoted as SCNU-1) constructed with Cu ions and 4-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol has a featured interpenetrating uninodal utc-c network which is for the first time found in the real structure. Moreover, SCNU-1 exhibits high thermal (>773 K), solvent, and acid/base stabilities; the largest CO2 affinity, 90 kJ/mol, among the MOFs functionalized with an aromatic hydroxyl group; and excellent CO2/N2 selectivity.

19.
Aging (Albany NY) ; 11(20): 8825-8844, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31652420

RESUMO

BACKGROUND: Hepatocellular carcinomas (HCC) constantly rank among the malignancies with the highest death tolls on the global scale. Moreover, HCC are associated with a limited set of therapeutic options. This is particularly true in the case of advanced stage cancers, where long-term survival is uncommon. For the inoperable, advanced HCC patients, chemotherapy is the main modality of treatment. Due to the lack of known molecular targets, the efficacy of the chemotherapy is limited. CONCLUSION: These findings clearly indicate that DNA methylation plays a key role in regulating ACADS expression and that it can be a potential therapeutic target for treating HCC. MATERIALS AND METHODS: A thorough comparative analysis of 282 cancer samples with 47 normal samples from GEO datasets resulted in the observation that that the level of ACADS was significantly downregulated in HCC. Loss-of-function analyses were then conducted to understand the biological function of ACADS in HCC. It was noted that ACADS was involved in the proliferation and metastasis of HCC. Experiments involving the knockdown of DMNT expression led to the discovery that the expression of ACADS in the HCC cells was significantly increased. The TCGA database was then employed to identify tumor tissue samples which showed higher methylation levels at cg01535453, cg08618068, and cg10174836 (which are the target sites of the ACADS CpG islands) as compared with normal liver tissue samples. All these findings indicated that ACADS might be a novel methylation biomarker associated with HCC.

20.
PLoS Pathog ; 15(10): e1008147, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31644572

RESUMO

Potato spindle tuber viroid (PSTVd) is a circular non-coding RNA of 359 nucleotides that replicates and spreads systemically in host plants, thus all functions required to establish an infection are mediated by sequence and structural elements in the genome. The PSTVd secondary structure contains 26 Watson-Crick base-paired stems and 27 loops. Most of the loops are believed to form three-dimensional (3D) structural motifs through non-Watson-Crick base pairing, base stacking, and other local interactions. Homology-based prediction using the JAR3D online program revealed that loop 27 (nucleotides 177-182) most likely forms a 3D structure similar to the loop of a conserved hairpin located in the 3' untranslated region of histone mRNAs in animal cells. This stem-loop, which is involved in 3'-end maturation, is not found in polyadenylated plant histone mRNAs. Mutagenesis showed that PSTVd genomes containing base substitutions in loop 27 predicted by JAR3D to disrupt the 3D structure were unable to replicate in Nicotiana benthamiana leaves following mechanical rub inoculation, with one exception: a U178G/U179G double mutant was replication-competent and able to spread within the upper epidermis of inoculated leaves, but was confined to this cell layer. Remarkably, direct delivery of the U178G/U179G mutant into the vascular system by needle puncture inoculation allowed it to spread systemically and enter mesophyll cells and epidermal cells of upper leaves. These findings highlight the importance of RNA 3D structure for PSTVd replication and intercellular trafficking and indicate that loop 27 is required for epidermal exit, but not epidermal entry or transit between other cell types. Thus, requirements for RNA trafficking between epidermal and underlying palisade mesophyll cells are unique and directional. Our findings further suggest that 3D structure and RNA-protein interactions constrain RNA sequence evolution, and validate JAR3D as a tool to predict RNA 3D structure.

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