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1.
Oxid Med Cell Longev ; 2021: 8868361, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33532039

RESUMO

Osteoarthritis (OA) is an urgent public health problem; however, the underlying causal mechanisms remain unclear, especially in terms of inflammatory mediators in cartilage degradation and chondrocyte imbalance. P2X7 receptor (P2X7R) is a critical inflammation switch, but few studies have examined its function and mechanisms in OA-like pyroptotic inflammation of chondrocytes. In this study, Sprague-Dawley rats were injected in the knee with monosodium iodoacetate (MIA) to induce OA, followed by multiple intra-articular injections with P2X7R antagonist A740003, P2X7R agonist BzATP, NF-κB inhibitor Bay 11-7082, and NLRP3 inhibitor CY-09. Primary rat chondrocytes were harvested and treated similarly. We assessed cell viability, damage, and death via cell viability assay, lactate dehydrogenase (LDH) release, and flow cytometry. Concentrations of adenosine triphosphate (ATP) and interleukin- (IL-) 1ß in cell culture supernatant and joint cavity lavage fluid were analyzed by enzyme-linked immunosorbent assay. Changes in expression levels of P2X7 and inflammation-related indicators were analyzed by immunofluorescence, quantitative reverse-transcription polymerase chain reaction, and western blotting. Cell morphology changes and pyroptosis were observed using transmission electron microscopy. Histology, immunohistochemistry, and microcomputed tomography were used to analyze damage to bone and cartilage tissues and assess the severity of OA. Similar to MIA, BzATP reduced cell viability and collagen II expression in a dose-dependent manner. Conversely, A740003 ameliorated MIA-induced cartilage degradation and OA-like pyroptotic inflammation by rescuing P2X7, MMP13, NF-κB p65, NLRP3, caspase-1 (TUNEL-positive and active), and IL-1ß upregulation. Additionally, A740003 reduced the caspase-1/propidium iodide double-positive rate, LDH concentration, and reactive oxygen species production. These effects also occurred via coincubation with Bay 11-7082 and CY-09. In conclusion, activated P2X7 promoted extracellular matrix degradation and pyroptotic inflammation in OA chondrocytes through NF-κB/NLRP3 crosstalk, thus, aggravating the symptoms of OA. The study findings suggest P2X7 as a potential target for inflammation treatment, providing new avenues for OA research and therapy.

2.
Target Oncol ; 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33544337

RESUMO

BACKGROUND: In the global FLAURA study, first-line osimertinib, a third-generation irreversible tyrosine kinase inhibitor (TKI) of epidermal growth factor receptor (EGFR), significantly improved progression-free survival (PFS) and overall survival (OS) versus comparator EGFR TKIs in patients with EGFR mutation-positive (EGFRm) advanced non-small-cell lung cancer (NSCLC). OBJECTIVE: The FLAURA China study assessed first-line osimertinib in Chinese patients with EGFRm advanced NSCLC (NCT02296125). METHODS: FLAURA China was a double-blind, randomized, phase III study. Adults from mainland China with previously untreated EGFRm (Exon 19 deletion or L858R) advanced NSCLC were enrolled in the global study or a China-only study under the same protocol; 136 patients were randomized to osimertinib (80 mg once daily [od]; n = 71) or comparator EGFR TKI (gefitinib or erlotinib; all sites selected gefitinib 250 mg od; n = 65). Patients were randomized and allocated to treatment groups by a central computer system. Treatment continued until disease progression, unacceptable toxicity, or withdrawal of consent. The primary endpoint was investigator-assessed PFS; OS was a secondary endpoint. RESULTS: All 136 randomized patients were analyzed. Osimertinib extended median PFS by 8.0 months versus comparator EGFR TKI (17.8 vs. 9.8 months; hazard ratio [HR] 0.56; 95% confidence interval [CI] 0.37-0.85). Median OS was 33.1 months in the osimertinib group versus 25.7 months in the comparator group (HR 0.85; 95% CI 0.56-1.29). At 3 years, 20% of patients on osimertinib and 8% on the comparator remained on randomized treatment. Grade 3 or higher adverse events (AEs) were reported in 54 and 28% of patients in the osimertinib and comparator groups, respectively, driven by increased local reporting of laboratory- and disease-related AEs. No new safety signals were identified. CONCLUSIONS: First-line osimertinib treatment resulted in a clinically meaningful PFS and OS benefit versus comparator EGFR TKI in Chinese patients with EGFRm advanced NSCLC. Safety data were consistent with the known safety profile of osimertinib. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT02296125, registered 20 November 2014.

3.
Nat Commun ; 12(1): 1094, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33597547

RESUMO

Seahorses have a circum-global distribution in tropical to temperate coastal waters. Yet, seahorses show many adaptations for a sedentary, cryptic lifestyle: they require specific habitats, such as seagrass, kelp or coral reefs, lack pelvic and caudal fins, and give birth to directly developed offspring without pronounced pelagic larval stage, rendering long-range dispersal by conventional means inefficient. Here we investigate seahorses' worldwide dispersal and biogeographic patterns based on a de novo genome assembly of Hippocampus erectus as well as 358 re-sequenced genomes from 21 species. Seahorses evolved in the late Oligocene and subsequent circum-global colonization routes are identified and linked to changing dynamics in ocean currents and paleo-temporal seaway openings. Furthermore, the genetic basis of the recurring "bony spines" adaptive phenotype is linked to independent substitutions in a key developmental gene. Analyses thus suggest that rafting via ocean currents compensates for poor dispersal and rapid adaptation facilitates colonizing new habitats.

4.
Plant Physiol ; 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33576790

RESUMO

Protein phosphorylation is a common post-translational modification that frequently occurs during plant-virus interaction. Host protein kinases often regulate virus infectivity and pathogenicity by phosphorylating viral proteins. The Barley stripe mosaic virus (BSMV) γb protein plays versatile roles in virus infection and the coevolutionary arms race between plant defense and viral counter-defense. Here, we identified that the autophosphorylated cytosolic serine/threonine/tyrosine (STY) protein kinase 46 of Nicotiana benthamiana (NbSTY46) phosphorylates and directly interacts with the basic motif domain (aa 19-47) of γb in vitro and in vivo. Overexpression of wild-type NbSTY46, either transiently or transgenically, suppresses BSMV replication and ameliorates viral symptoms, whereas silencing of NbSTY46 leads to increased viral replication and exacerbated symptom. Moreover, the antiviral role of NbSTY46 requires its kinase activity, as the NbSTY46T436A mutant, lacking kinase activity, not only loses the ability to phosphorylate and interact with γb but also fails to impair BSMV infection when expressed in plants. NbSTY46 could also inhibit the replication of Lychnis ringspot virus, another chloroplast-replicating hordeivirus. In summary, we report a function of the cytosolic kinase STY46 in defending against plant viral infection by phosphorylating a viral protein in addition to its basal function in plant growth, development, and abiotic stress responses.

5.
Cell Death Dis ; 12(2): 145, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33542185

RESUMO

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play critical roles in human diseases. We aimed to clarify the role of lncRNA X-inactive specific transcript (XIST)/miR-149-3p/forkhead box P3 (FOXP3) axis in ovarian cancer (OC) cell growth. XIST, miR-149-3p and FOXP3 expression in OC tissues and cell lines was assessed, and the predictive role of XIST in prognosis of OC patients was analyzed. The OC cell lines were screened and accordingly treated with silenced/overexpressed XIST plasmid or miR-149-3p mimic/inhibitor, and then the proliferation, invasion, migration, colony formation ability, apoptosis, and cell cycle distribution of OC cells were measured. Effect of altered XIST and miR-149-3p on tumor growth in vivo was observed. Online website prediction and dual luciferase reporter gene were implemented to detect the targeting relationship of lncRNA XIST, miR-149-3p, and FOXP3. XIST and FOXP3 were upregulated, whereas miR-149-3p was downregulated in OC tissues and cells. High XIST expression indicated a poor prognosis of OC. Inhibition of XIST or elevation of miR-149-3p repressed proliferation, invasion, migration, and colony formation ability, and promoted apoptosis and cell cycle arrest of HO-8910 cells. In SKOV3 cells upon treatment of overexpressed XIST or reduction of miR-149-3p, there exhibited an opposite tendency. Based on online website prediction, dual luciferase reporter gene, and RNA pull-down assays, we found that there was a negative relationship between XIST and miR-149-3p, and miR-149-3p downregulated FOXP3 expression. This study highlights that knockdown of XIST elevates miR-149-3p expression to suppress malignant behaviors of OC cells, thereby inhibiting OC development.

6.
Cell ; 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33545087

RESUMO

Lungfishes are the closest extant relatives of tetrapods and preserve ancestral traits linked with the water-to-land transition. However, their huge genome sizes have hindered understanding of this key transition in evolution. Here, we report a 40-Gb chromosome-level assembly of the African lungfish (Protopterus annectens) genome, which is the largest genome assembly ever reported and has a contig and chromosome N50 of 1.60 Mb and 2.81 Gb, respectively. The large size of the lungfish genome is due mainly to retrotransposons. Genes with ultra-long length show similar expression levels to other genes, indicating that lungfishes have evolved high transcription efficacy to keep gene expression balanced. Together with transcriptome and experimental data, we identified potential genes and regulatory elements related to such terrestrial adaptation traits as pulmonary surfactant, anxiolytic ability, pentadactyl limbs, and pharyngeal remodeling. Our results provide insights and key resources for understanding the evolutionary pathway leading from fishes to humans.

7.
Scand J Urol ; : 1-6, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33615988

RESUMO

Based on a nationwide register data we recently reported a link between male infertility and increased risk of early onset prostate cancer. However, mortality due to prostate cancer, which can be regarded as the ultimate proxy for its clinical significance, especially in the context of over-diagnosis and over-treatment, could not be explored in the previous study, since the follow-up period in most cases was too short. Data therefore must be retrieved from other cohorts, with longer follow-up. We sourced data from a population-based prospective cohort including 11,343 men aged over 45 years, enrolled in the 1970s. The results showed that childless men have higher risk for prostate cancer related mortality (HR: 1.49, 95% CI: 1.09-2.03, p = 0.01) compared to men with children, in particular when only married men, who most probably are involuntary childless, were considered (HR 1.54, 95% CI 1.13 - 2.10, p = 0.006). However, the prostate cancer incidence did not differ (HR = 1.04, 95% CI: 0.88-1.24). In conclusion, our results show that childless men are at higher risk for dying from prostate cancer, probably due to a more aggressive form of the disease.

8.
PLoS One ; 16(2): e0245876, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33571243

RESUMO

NUDIX hydrolase type 5 (NUDT5) is a kind of ADP-ribose pyrophosphatase and nucleotide metabolizing enzyme in cell metabolism. Previous studies have shown NUDT5 expression affected chromosome remodeling, involved in cell adhesion, cancer stem cell maintenance and epithelial to mesenchyme transition in breast cancer cells. Nevertheless, the role of NUDT5 in breast cancer progression and prognosis has not yet been systematically studied. This study explored the association of NUDT5 with the tumor development and poor prognosis in patients with breast cancer. Our results show that the levels of NUDT5 were upregulated in breast cancer cell lines and breast tumor tissues, and the expression of NUDT5 in breast tumor tissues increased significantly when compared with adjacent non-tumorous tissues by immunohistochemical staining of tissue microarrays. Breast cancer patients with high NUDT5 expression had a worse prognosis than those with low expression of NUDT5. In addition, the knockdown of NUDT5 suppressed breast cancer cell lines proliferation, migration and invasion, and dramatically inhibited the AKT phosphorylation at Thr308 and expression of Cyclin D1. The opposite effects were observed in vitro following NUDT5 rescue. Our findings indicated that the high expression of NUDT5 is probably involved in the poor prognosis of breast cancer via the activation of the AKT / Cyclin D pathways, which could be a prognostic factor and potential target in the diagnosis and treatment of breast cancer.

9.
J Am Acad Dermatol ; 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33607181

RESUMO

BACKGROUND: Patients with psoriatic disease may be more susceptible to methotrexate hepatotoxicity than those with rheumatoid arthritis (RA) but direct evidence is lacking. OBJECTIVE: To compare liver disease risk among patients with psoriasis (PsO), psoriatic arthritis (PsA), and RA receiving methotrexate METHODS: In a population-based cohort study, Danish individuals with PsO, PsA, or RA receiving methotrexate during 1997-2015 were compared with respect to four outcomes: mild liver disease, moderate-to-severe liver disease, cirrhosis, and cirrhosis-related hospitalization. RESULTS: Among 5,687, 6,520, and 28,030 individuals with PsO, PsA, and RA, respectively, the incidence rate of any liver disease was greatest for PsO, followed by PsA, and lowest for RA. Compared to patients with RA, patients with PsO were 1.6-3.4 times more likely to develop one of the liver disease outcomes while those with PsA were 1.3-1.6 times more likely to develop mild liver disease and cirrhosis after adjustment for demographics, smoking, alcohol use, comorbidities, and methotrexate dose. LIMITATIONS: Confounding by unmeasured variables, misclassification and surveillance bias CONCLUSION: PsO, PsA, and RA differentially influence liver disease risk in the setting of methotrexate use independent of other major risk factors. More conservative monitoring should be considered in patients receiving methotrexate for psoriatic disease, particularly PsO.

10.
J Hazard Mater ; 413: 125429, 2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33618273

RESUMO

Potentially toxic element (PTE) contamination is a common environmental issue in offshore regions worldwide. Water and sediment samples were collected from the Yellow River downstream and adjacent Laizhou Bay to investigate the residues, sources, and ecological risks of 11 typical PTEs (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sc, V, and Zn). The results indicated that the concentrations of PTEs in the sediments decreased from the Yellow River Estuary to the inner Laizhou Bay under the long-term effect of the Yellow River input. Principal component analysis (PCA) identified three potential sources: natural origins, coastal anthropogenic activities (e.g., oil exploration and steel refining), and marine production (e.g., marine aquaculture and transportation). Among the PTEs, Cd was the most significant contaminant, with a contamination factor (CF) of 2.06 ± 0.78. Furthermore, Cd was the most sensitive factor used in evaluating the overall ecological risk using Monte Carlo analysis, with a contribution of up to 96%. Although the overall contamination and risk levels were low in the bay, a higher pollution load index (PLI) and risk index (RI) adjacent to the Yellow River Estuary indicated that the Yellow River remained the primary contributor to the PTEs contamination in the bay.

11.
Phytochem Anal ; 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33619832

RESUMO

INTRODUCTION: The fruits of Areca catechu, also called areca nuts, are widely used as popular masticatory and traditional herbal medicine in Asia. Besides arecoline and related alkaloids, limited information is available about further primary and secondary metabolites and their potential biological activities. OBJECTIVE: Here we aimed to further enhance our knowledge on phytochemical profiles of A. catechu and Areca triandra fruits. We intended to comprehensively identify metabolites in A. catechu and A. triandra fruits. METHODOLOGY: Metabolites were identified by ultra-performance liquid chromatography triple-quadrupole tandem mass spectrometry (UPLC-MS/MS). The occurrence of 12 selected bioactive compounds in 4 different developmental stages of A. catechu and A. triandra was quantified by LC-MS/MS. RESULTS: A total of 791 metabolites was identified. Of these, 115 metabolites could successfully be mapped to 44 Kyoto Encyclopedia of Genes and Genomes metabolic pathways, and 154 metabolites occurred at significantly different levels in A. catechu compared to A. triandra. Several components with known biological activities were identified for the first time in A. catechu and A. triandra. The abundance of many of these new components was similar in A. catechu and A. triandra, but significantly different between the pericarp and the seeds of A. catechu fruits. CONCLUSIONS: Metabolic profiles indicate that fruits of the Areca species compared here have similar primary and secondary metabolites. Our findings provide new insights into A. catechu and A. triandra as valuable sources for traditional medicine and they pave the way for further studies to potentially improve the underlying pharmaceutical and physiological effects.

12.
Microbiol Immunol ; 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33433029

RESUMO

Proteins newly synthesized from messenger RNA (mRNA) undergo post-translational modifications (PTMs) such as phosphorylation, glycosylation, methylation, and ubiquitination. These PTMs have important roles in protein stability, localization, as well as conformation and have been reported as involved in HBV propagation. Although ubiquitination plays an essential role in HBV life cycles, the involvement of ubiquitin-like proteins (UBLs) in HBV life cycles has been understudied. Via comprehensive gain- and loss-of-function screening of UBLs, we observed that neddylation, a PTM in which neural precursor cell, expressed developmentally downregulated 8 (NEDD8) is conjugated to substrate proteins, was required for efficient HBV propagation. We also found that overexpression of sentrin-specific protease 8 (SENP8), which cleaves conjugated NEDD8, suppressed HBV propagation. Further, the catalytic activity of SENP8 was required for the suppression of HBV propagation. These results indicated that the reduction of neddylation negatively regulated HBV propagation. In addition, we demonstrated that suppression of HBV propagation via SENP8 overexpression was independent of HBx and HBV promoter activity. Therefore, our data suggested that neddylation plays an important role in the late stages of HBV life cycles. This article is protected by copyright. All rights reserved.

13.
Org Lett ; 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33475370

RESUMO

Herein, we disclose an efficient cobalt-catalyzed three-component coupling of benzamides, diazo compounds, and tert-butyl hydroperoxide, which provides an efficient approach to construct C(sp2)-C(sp3) and C-O bonds in one-pot accompanied with C-H activation. This protocol features low catalyst loading (4 mol %), the avoidance of additives, and excellent functional group compatibility, providing three-component coupling adducts with high yields under mild conditions (up to 88%). Mechanism studies show that the reaction may involve a radical process.

14.
Artigo em Inglês | MEDLINE | ID: mdl-33478932

RESUMO

BACKGROUND: Current guidelines for the treatment of patients with necrotizing acute pancreatitis (NAP) recommend that invasive intervention for pancreatic necrosis should be deferred to 4 or more weeks from disease onset to allow necrotic collections becoming "walled-off". However, for patients showing signs of clinical deterioration, especially those with persistent organ failure (POF), it is controversial whether this delayed approach should always be adopted. In this study, we aimed to assess the impact of differently timed intervention on clinical outcomes in a group of NAP patients complicated by POF. METHODS: All NAP patients admitted to our hospital from January 2013 to December 2017 were screened for potential inclusion. They were divided into two groups based on the timing of initial intervention (within 4 weeks and beyond 4 weeks). All the data were extracted from a prospectively collected database. RESULTS: Overall, 131 patients were included for analysis. Among them, 100 (76.3%) patients were intervened within 4 weeks and 31 (23.7%) underwent delayed interventions. As for organ failure prior to intervention, the incidences of respiratory failure, renal failure and cardiovascular failure were not significantly different between the two groups (P > 0.05). The mortality was not significantly different between the two groups (35.0% vs. 32.3%, P = 0.83). The incidences of new-onset multiple organ failure (8.0% vs. 6.5%, P = 1.00), gastrointestinal fistula (29.0% vs. 12.9%, P = 0.10) and bleeding (35.0% vs. 35.5%, P = 1.00), length of ICU (30.0 vs. 22.0 days, P = 0.61) and hospital stay (42.5 vs. 40.0 days, P = 0.96) were comparable between the two groups. CONCLUSION: Intervention within 4 weeks did not worsen the clinical outcomes in NAP patients complicated by POF.

15.
Biosens Bioelectron ; 177: 112975, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33444898

RESUMO

The determination of indoor formaldehyde is of great importance to protect individuals against its well-known adverse impact on health. Here, we report on a design of a naked-eye readout self-powered electrochemical biosensor (SPEB) toward gaseous formaldehyde based on the efficient catalytic activity of the formaldehyde dehydrogenase/poly (methylene green)/buckypaper bioanode and the excellent electrochromic property of the Prussian blue (PB) cathode. The SPEB has a planar configuration and is covered with poly(vinyl alcohol) (PVA) as gel electrolyte to provide an inner lateral resistance large enough to enable the progressive discoloration of the patterned PB at cathode, which in turn, making the determination of gaseous formaldehyde feasible by measuring the distance consumed after 10-min exposure. The use of PVA gel electrolyte can also facilitate the observation of the color change due to its excellent transparency. The SPEB shows obvious responses to gaseous formaldehyde in a broad concentration range of 80 and 3000 ppb, covering the important permissible limits of indoor formaldehyde related to human health. The SPEB also exhibits satisfactory results in sensing gaseous formaldehyde released from the real plywood that is one of the dominating sources of the gaseous indoor formaldehyde. The results shown here demonstrate the good potential of the naked-eye readout SPEB as a fast, reliable, and portable tool for on-site determination of gaseous formaldehyde, with the appealing characteristics such as ease of operation, simplicity of configuration, and no requirement of external power sources.

16.
Microb Pathog ; 150: 104729, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33429053

RESUMO

The Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) cause a huge economic loss around the pig industry worldwide; the NADC30-like PRRSV have attracted much attention outbreaks in China in recent years. Recombination between PRRSV subtypes, point mutations, insertions and deletions that contribute to the emergence of new variants in the genome. In this study, the PRRSV-HB-16-China-2019 strain's full-length genomic sequence shares 93.0% nucleotide similarity to NADC30 PRRSV without any gene insertion. Compared with VR-2332, it has an NSP2 coding region that is different from NADC30, which has a discontinuous 206-aa (111-aa from position 323 to 433 and 95-aa from position 476 to 570) deletion. Compared with other NADC30-Like strains, it has a discontinuous 75-amino acid (75-aa from position 476 to 552) deletion, which was first reported. Notably, the strain, PRRSV-HB-16-China-2019, contained an addition a 1-aa deletion in ORF5 and a unique 3-nt deletion in 3'-UTR similar to NADC30, the strain is recombined between a NADC30-like strain and a vaccine strain named RespPRRS MLV(parental strain VR-2332). Our findings indicate that PRRSV-HB-16-China-2019 is a new NSP2-deletion NADC30-like strain with certain deletions and mutations. Our results show that the emergence of the new NADC30-like strain has increased the difficulty of PRRSV prevention in China.

17.
J Pathol ; 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33506979

RESUMO

The endometrium is unique as an accessible anatomic location that can be repeatedly biopsied and where diagnostic biopsies do not extirpate neoplastic lesions. We exploited these features to retrospectively characterize serial genomic alterations along the precancer/cancer continuum in individual women. Cases were selected based on 1) endometrial cancer diagnosis/hysterectomy 2) preceding serial endometrial biopsies including for some patients an early biopsy before a precancer histologic diagnosis. A comprehensive panel was designed for endometrial cancer genes. Formalin-fixed paraffin-embedded specimens for each cancer, preceding biopsies, and matched germline samples were subjected to barcoded high-throughput sequencing to identify mutations and track their origin and allelic frequency progression. In total, 92 samples from 21 patients were analyzed, providing an opportunity for new insights into early endometrial cancer progression. Definitive invasive endometrial cancers exhibited expected mutational spectra, and canonical driver mutations were detectable in preceding biopsies. Notably, ≥1 cancer mutations were detected prior to the histopathologic diagnosis of an endometrial precancer in the majority of patients. In 18/21 cases, ≥1 mutation was confirmed by abnormal protein levels or subcellular localization by immunohistochemistry, confirming genomic data and providing unique views of histologic correlates. In 19 control endometria, mutation counts were lower, with a lack of canonical endometrial cancer hotspot mutations. Our study documents the existence of endometrial lesions that are histologically indistinct but are bona fide endometrial cancer precursors. This article is protected by copyright. All rights reserved.

18.
Environ Sci Technol ; 55(4): 2369-2380, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33507750

RESUMO

Chalcopyrite, galena, and sphalerite commonly coexist with pyrite in sulfidic waste rocks. The aim of this work was to investigate their impact, potentially by galvanic interaction, on pyrite oxidation and acid generation rates under simulated acid and metalliferous drainage conditions. Kinetic leach column experiments using single-minerals and pyrite with one or two of the other sulfide minerals were carried out at realistic sulfide contents (total sulfide <5.2 wt % for mixed sulfide experiments), mimicking sulfidic waste rock conditions. Chalcopyrite was found to be most effective in limiting pyrite oxidation and acid generation with 77-95% reduction in pyrite oxidation over 72 weeks, delaying decrease in leachate pH. Sphalerite had the least impact with reduction of pyrite dissolution by 26% over 72 weeks, likely because of the large band gap and poor conductivity of sphalerite. Galena had a smaller impact than chalcopyrite on pyrite oxidation, despite their similar band gaps, possibly because of the greater extent of oxidation and the significantly reduced surface areas of galena (area reductions of >47% for galena vs <1.5% for chalcopyrite) over 72 weeks. The results are directly relevant to mine waste storage and confirm that the galvanic interaction plays a role in controlling acid generation in multisulfide waste even at low sulfide contents (several wt %) with small probabilities (≤0.23%) of direct contact between sulfide minerals in mixed sulfide experiments.

19.
Comput Med Imaging Graph ; 88: 101848, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33385932

RESUMO

Brain extraction is a fundamental prerequisite step in neuroimage analysis for fetus. Due to surrounding maternal tissues and unpredictable movement, brain extraction from fetal Magnetic Resonance (MR) images is a challenging task. In this paper, we propose a novel deep learning-based multi-step framework for brain extraction from 3D fetal MR images. In the first step, a global localization network is applied to estimate probability maps for brain candidates. Connected-component labeling algorithm is applied to eliminate small erroneous components and accurately locate the candidate brain area. In the second step, a local refinement network is implemented in the brain candidate area to obtain fine-grained probability maps. Final extraction results are derived by a fusion network with the two cascaded probability maps obtained from previous two steps. Experimental results demonstrate that our proposed method has superior performance compared with existing deep learning-based methods.

20.
Biomed Pharmacother ; 135: 111199, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33401221

RESUMO

Osteoarthritis (OA) is a heterogeneous disease that is consistently difficult to treat due to the complexity of the regulatory network involved in OA pathogenesis, especially in terms of cartilage degeneration. As a C-2 epimer of glucose, d-mannose can alleviate bone loss and repress immunopathology by upregulating regulatory T cells; however, the role of d-mannose in OA-related cartilage degeneration remains unknown. In this study, we investigated the chondroprotective effect of d-mannose in vitro and in vivo on OA. We found that incubating interleukin (IL)-1ß-treated rat chondrocytes with d-mannose restrained OA degeneration by elevating cell proliferation, strongly activating autophagy, reducing apoptosis, and downregulating catabolism. Additionally, oral gavage administration of d-mannose to monosodium iodoacetate (MIA)-treated rats revealed that a median (1.25 g/kg/day) rather than high or low dose of d-mannose suppressed OA progression and attenuated OA development based on lower macroscopic scores for cartilage, decreased histological scores for cartilage and synovium, strongly activated autophagy, and downregulated catabolism. In terms of a downstream mechanism, we showed that d-mannose might attenuate OA degeneration by activating autophagy in IL-1ß-treated rat chondrocytes by promoting the phosphorylation of 5' AMP-activated protein kinase (AMPK). Our in vitro findings revealed that d-mannose delayed IL-1ß-induced OA degeneration in rat chondrocytes by enhancing autophagy activation through the AMPK pathway. Furthermore, the in vivo results indicated that a median dose of d-mannose suppressed MIA-induced OA development. These results suggested that d-mannose exhibits chondroprotective effects and represents a potential disease-modifying drug and novel therapeutic agent for OA.

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