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1.
Br J Cancer ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877108

RESUMO

BACKGROUND: Targeting DNA damage repair factors, such as DNA-dependent protein kinase catalytic subunit (DNA-PKcs), may offer an opportunity for effective treatment of multiple myeloma (MM). In combination with DNA damage-inducing agents, this strategy has been shown to improve chemotherapies partially via activation of cGAS-STING pathway by an elevated level of cytosolic DNA. However, as cGAS is primarily sequestered by chromatin in the nucleus, it remains unclear how cGAS is released from chromatin and translocated into the cytoplasm upon DNA damage, leading to cGAS-STING activation. METHODS: We examined the role of DNA-PKcs inhibition on cGAS-STING-mediated MM chemosensitivity by performing mass spectrometry and mechanism study. RESULTS: Here, we found DNA-PKcs inhibition potentiated DNA damage-inducing agent doxorubicin-induced anti-MM effect by activating cGAS-STING signaling. The cGAS-STING activation in MM cells caused cell death partly via IRF3-NOXA-BAK axis and induced M1 polarization of macrophages. Moreover, this activation was not caused by defective classical non-homologous end joining (c-NHEJ). Instead, upon DNA damage induced by doxorubicin, inhibition of DNA-PKcs promoted cGAS release from cytoplasmic chromatin fragments and increased the amount of cytosolic cGAS and DNA, activating cGAS-STING. CONCLUSIONS: Inhibition of DNA-PKcs could improve the efficacy of doxorubicin in treatment of MM by de-sequestrating cGAS in damaged chromatin.

2.
Anal Chem ; 96(17): 6683-6691, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38619493

RESUMO

Hydrogen peroxide (H2O2) and ascorbic acid (AA), acting as two significant indicative species, correlate with the oxidative stress status in living brains, which have historically been considered to be involved mainly in neurodegenerative disorders such as Alzheimer's disease, Huntington's disease, and Parkinson's disease (PD). The development of efficient biosensors for the simultaneous measurement of their levels in living brains is vital to understand their roles played in the brain and their interactive relationship in the progress of these diseases. Herein, a robust ratiometric electrochemical microsensor was rationally designed to realize the determination of H2O2 and AA simultaneously. Therefore, a specific probe was designed and synthesized with both recognition units responsible for reacting with H2O2 to produce a detectable signal on the microsensor and linkage units helping the probe modify onto the carbon substrate. A topping ingredient, single-walled carbon nanotubes (SWCNTs) was added on the surface of the electrode, with the purpose of not only facilitating the oxidation of AA but also absorbing methylene blue (MB), prompting to read out the inner reference signal. This proposed electrochemical microsensor exhibited a robust ability to real-time track H2O2 and AA in linear ranges of 0.5-900 and 10-1000 µM with high selectivity and accuracy, respectively. Eventually, the efficient electrochemical microsensor was successfully applied to the simultaneous measurement of H2O2 and AA in the rat brain, followed by microinjection, and in the PD mouse brain.


Assuntos
Ácido Ascórbico , Encéfalo , Técnicas Eletroquímicas , Peróxido de Hidrogênio , Nanotubos de Carbono , Peróxido de Hidrogênio/análise , Ácido Ascórbico/análise , Animais , Camundongos , Encéfalo/metabolismo , Nanotubos de Carbono/química , Técnicas Biossensoriais , Eletrodos
3.
J Med Genet ; 60(10): 939-950, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37012052

RESUMO

BACKGROUND: Although retinitis pigmentosa (RP) is the most common type of hereditary retinal dystrophy, approximately 25%-45% of cases remain without a molecular diagnosis. von Willebrand factor A domain containing 8 (VWA8) encodes a mitochondrial matrix-targeted protein; its molecular function and pathogenic mechanism in RP remain unexplained. METHODS: Family members of patients with RP underwent ophthalmic examinations, and peripheral blood samples were collected for exome sequencing, ophthalmic targeted sequencing panel and Sanger sequencing. The importance of VWA8 in retinal development was demonstrated by a zebrafish knockdown model and cellular and molecular analysis. RESULTS: This study recruited a Chinese family of 24 individuals with autosomal-dominant RP and conducted detailed ophthalmic examinations. Exome sequencing analysis of six patients revealed heterozygous variants in VWA8, namely, the missense variant c.3070G>A (p.Gly1024Arg) and nonsense c.4558C>T (p.Arg1520Ter). Furthermore, VWA8 expression was significantly decreased both at the mRNA and protein levels. The phenotypes of zebrafish with VWA8 knockdown are similar to those of clinical individuals harbouring VWA8 variants. Moreover, VWA8 defects led to severe mitochondrial damage, resulting in excessive mitophagy and the activation of apoptosis. CONCLUSIONS: VWA8 plays a significant role in retinal development and visual function. This finding may provide new insights into RP pathogenesis and potential genes for molecular diagnosis and targeted therapy.


Assuntos
Retinose Pigmentar , Peixe-Zebra , Animais , Humanos , Mitofagia/genética , Mutação/genética , Linhagem , Retinose Pigmentar/diagnóstico , Peixe-Zebra/genética
4.
Angew Chem Int Ed Engl ; 63(16): e202400422, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38380500

RESUMO

An overreactive stress granule (SG) pathway and long-lived, stable SGs formation are thought to participate in the progress of neurodegenerative diseases (NDs). To understand if and how SGs contribute to disorders of neurotransmitter release in NDs, we examined the interaction between extracellular isolated SGs and vesicles. Amperometry shows that the vesicular content increases and dynamics of vesicle opening slow down after vesicles are treated with SGs, suggesting larger vesicles are formed. Data from transmission electron microscopy (TEM) clearly shows that a portion of large dense-core vesicles (LDCVs) with double/multiple cores appear, thus confirming that SGs induce homotypic fusion between LDCVs. This might be a protective step to help cells to survive following high oxidative stress. A hypothetical mechanism is proposed whereby enriched mRNA or protein in the shell of SGs is likely to bind intrinsically disordered protein (IDP) regions of vesicle associated membrane protein (VAMP) driving a disrupted membrane between two closely buddled vesicles to fuse with each other to form double-core vesicles. Our results show that SGs induce homotypic fusion of LDCVs, providing better understanding of how SGs intervene in pathological processes and opening a new direction to investigations of SGs involved neurodegenerative disease.


Assuntos
Catecolaminas , Doenças Neurodegenerativas , Humanos , Catecolaminas/metabolismo , Doenças Neurodegenerativas/metabolismo , Grânulos de Estresse , Microscopia Eletrônica , Microscopia Eletrônica de Transmissão
5.
Eur Radiol ; 33(3): 1982-1991, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36241919

RESUMO

OBJECTIVES: To analyze myocardial fibrosis in dilated cardiomyopathy (DCM) patients with no late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) using T1 mapping and extracellular volume (ECV) and investigate the potential correlation with left ventricular (LV) dilation and dysfunction. METHODS: The study included 41 DCM patients without LGE and 79 healthy controls. T1 and ECV were compared between the two groups using multivariable logistic regression analysis. The correlations between histological and functional parameters were evaluated using Pearson's correlation. RESULTS: Mean native myocardial T1 and ECV were significantly higher in the DCM group compared to controls (p ≤ 0.001, respectively). Multivariable logistic regression revealed that ECV (mean, minimum), LV ejection fraction (LVEF), and LV end-diastolic diameter (LVEDD) were independent discriminators for LGE-negative DCM; the area under the curve (AUC) of LVEF, LVEDD, ECV mean, and ECV minimum were 0.97, 0.96, 0.88, and 0.68, respectively. In the DCM group, LVEDD and LVEF were positively and negatively correlated with ECV, respectively. LVEDV index and LV end-systolic volume (LVESV) index were positively correlated with native-T1 and ECV, and the absolute value of LV global strain had a negative correlation with ECV. CONCLUSIONS: Early myocardial fibrosis in DCM could be detected by prolonged native T1 and elevated ECV despite the absence of LGE on CMR. Moreover, the change of histological characteristics of myocardium in DCM was correlated with LV dilation and dysfunction. KEY POINTS: • At an early stage, patients with DCM may have myocardial fibrosis despite the absence of LGE. • T1 mapping and ECV are efficient methods for early detection of potential myocardial fibrosis. • Increased native T1 and ECV are correlated with left ventricular dilation and dysfunction in LGE-negative DCM patients.


Assuntos
Cardiomiopatias , Cardiomiopatia Dilatada , Humanos , Meios de Contraste , Imagem Cinética por Ressonância Magnética , Gadolínio , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/patologia , Cardiomiopatia Dilatada/patologia , Miocárdio/patologia , Função Ventricular Esquerda , Fibrose , Valor Preditivo dos Testes
6.
Eur Radiol ; 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37889269

RESUMO

OBJECTIVES: To investigate the incremental prognostic value of left ventricular (LV) entropy in a large multi-center population with coronary atherosclerotic heart disease (CAD). BACKGROUND: Current risk stratification of patients with CAD is imprecise and not accurate enough. METHODS: A total of 314 CAD patients who underwent cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) at two medical centers in China between October 2015 and July 2022 were included in this study. Additionally, the 193 patients under 3.0-T field also underwent CMR T1 mapping. LV entropy and extracellular volume (ECV) were calculated from the LGE image of LV myocardium, and major adverse cardiac events (MACEs) were analyzed. RESULTS: Among 314 patients, 110 experienced MACE during a median follow-up of 13 months. The risk of MACE was significantly increased in the high entropy group (log-rank p < 0.001). Entropy maintained an independent association with MACE in a multivariable model including left ventricular ejection fraction (LVEF) and LGE (HR = 1.78; p = 0.001). In addition, the primary endpoint events prognostic value was significantly improved by adding LV entropy to the baseline multivariable model (C-statistic improvement: 0.785-0.818, Delong test: p = 0.001). Similarly, among 193 3.0-T field patients, adding LV entropy to the multivariable baseline model significantly improved the prognostic value of the model for MACE (C-statistic improvement: 0.820-0.898, Delong test: p = 0.004). CONCLUSION: CMR-assessed LV entropy is a powerful independent predictor of MACE in patients with CAD, incremental to common clinical and CMR risk factors, including LVEF, LGE, Native T1, and ECV. CLINICAL RELEVANCE STATEMENT: Left ventricular entropy is a powerful independent predictor of major adverse cardiac events in patients with coronary atherosclerotic heart disease, incremental to common clinical and cardiac magnetic resonance risk factors. KEY POINTS: • Left ventricular entropy, a novel cardiac magnetic resonance parameter of myocardial heterogeneity, demonstrated a robust prognostic association with major adverse cardiac events beyond guideline-based, clinical risk markers. • Entropy can have an important role in the primary prevention of major adverse cardiac events in patients with coronary atherosclerotic heart disease. • Compared with late gadolinium enhancement, extracellular volume, and native T1, entropy could be used to more comprehensively characterize the heterogeneity of left ventricular myocardium.

7.
Ecotoxicol Environ Saf ; 255: 114815, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36948008

RESUMO

Metallic elements play a pivotal role in maternal and fetal health. Metals can cross the placental barrier and be absorbed by fetuses, where they may affect closure of the neural tube during embryonic development. Neural tube defects (NTDs), which result from aberrant closure of the neural tube three to four weeks post-conception, have a multifactorial and complex etiology that combines genetic variants and environmental exposure. Recent advances in population-level association studies have investigated the link between maternal environmental exposure and NTDs, particularly the influence of metals on the incidence of NTDs. Herein, we present a broad and qualitative review of current literature on the association between maternal and prenatal metal exposure via the maternal peripheral blood, amniotic fluid, placenta, umbilical cord, and maternal hair, and the risk of developing NTDs. Specifically, we identify the various aggravating or attenuating effects of metallic exposure on the risk of NTD formation. This review provides novel insights into the association between environmental metals and NTDs and has important applications for NTD prevention and mitigating environmental exposure to metals.


Assuntos
Defeitos do Tubo Neural , Efeitos Tardios da Exposição Pré-Natal , Humanos , Feminino , Gravidez , Placenta , Defeitos do Tubo Neural/induzido quimicamente , Defeitos do Tubo Neural/epidemiologia , Defeitos do Tubo Neural/genética , Tubo Neural , Feto
8.
World J Microbiol Biotechnol ; 39(11): 295, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37658165

RESUMO

Aspergillus is a well-studied fungal genus that is widely used in the processing of plant biomass in industries. This study investigated the effects of space exposure on the ability of Aspergillus costaricaensis, a filamentous fungus isolated from rotten orange peel, to degrade pectin. These fungal spores were carried into space by the Long March 5B carrier rocket and exposed to cosmic radiation for 79 h. After the flight, these spores were resuscitated, and then the growing strains were screened with pectin as the sole carbon source, and the pectinase activity was evaluated. A mutant with increased biomass accumulation ability and pectin-degrading activity compared to the ground control strain was obtained. Comparative transcriptome analysis revealed that several CAZymes genes were significantly upregulated in the mutant, especially those related to pectin degradation. Among the 44 pectinases identified from the annotated genome, 42 were up-regulated. The activities of these pectinases are able to synergistically break down the structure of pectin. In addition, the expression of some genes involved in metabolism, sugar transport, and stress response was altered. These results imply that space exposure might serve as a potential mutagenesis breeding technique, offering the opportunity to acquire biomass-degrading microbial strains with potential for industrial application.


Assuntos
Pectinas , Melhoramento Vegetal , Aspergillus/genética , Biomassa , Poligalacturonase/genética
9.
Medicina (Kaunas) ; 59(5)2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37241143

RESUMO

Background and Objectives: To assess the effects of fosfomycin compared with other antibiotics as a prophylaxis for urinary tract infections (UTIs) in men undergoing transrectal prostate biopsies. Materials and Methods: We searched multiple databases and trial registries without publication language or status restrictions until 4 January 2022. Parallel-group randomized controlled trials (RCTs) and non-randomized studies (NRS) were included. The primary outcomes were febrile UTI, afebrile UTI, and overall UTI. We used GRADE guidance to rate the certainty of evidence of RCTs and NRSs. The protocol was registered with PROSPERO (CRD42022302743). Results: We found data on five comparisons; however, this abstract focuses on the primary outcomes of the two most clinically relevant comparisons. Regarding fosfomycin versus fluoroquinolone, five RCTs and four NRSs with a one-month follow-up were included. Based on the RCT evidence, fosfomycin likely resulted in little to no difference in febrile UTIs compared with fluoroquinolone. This difference corresponded to four fewer febrile UTIs per 1000 patients. Fosfomycin likely resulted in little to no difference in afebrile UTIs compared with fluoroquinolone. This difference corresponded to 29 fewer afebrile UTIs per 1000 patients. Fosfomycin likely resulted in little to no difference in overall UTIs compared with fluoroquinolone. This difference corresponded to 35 fewer overall UTIs per 1000 patients. Regarding fosfomycin and fluoroquinolone combined versus fluoroquinolone, two NRSs with a one- to three-month follow-up were included. Based on the NRS evidence, fosfomycin and fluoroquinolone combined may result in little to no difference in febrile UTIs compared with fluoroquinolone. This difference corresponded to 16 fewer febrile UTIs per 1000 patients. Conclusions: Compared with fluoroquinolone, fosfomycin or fosfomycin and fluoroquinolone combined may have a similar prophylactic effect on UTIs after a transrectal prostate biopsy. Given the increasing fluoroquinolone resistance and its ease to use, fosfomycin may be a good option for antibiotic prophylaxis.


Assuntos
Fosfomicina , Infecções Urinárias , Masculino , Humanos , Fosfomicina/uso terapêutico , Antibioticoprofilaxia/métodos , Próstata/patologia , Antibacterianos/uso terapêutico , Infecções Urinárias/epidemiologia , Infecções Urinárias/prevenção & controle , Infecções Urinárias/tratamento farmacológico , Biópsia/efeitos adversos , Fluoroquinolonas/uso terapêutico
10.
Zhongguo Zhong Yao Za Zhi ; 48(16): 4295-4301, 2023 Aug.
Artigo em Zh | MEDLINE | ID: mdl-37802856

RESUMO

Ziziphi Spinosae Semen(ZSS) is an edible TCM derived from the dried ripe seeds of Ziziphus jujube Mill. var. spinosa(Bunge)Hu ex H. F. Chou(Rhamnaceae), which has the effects of nourishing the heart, tonifying the liver, calming the heart, tranquilizing the mind, arresting sweating, and promoting fluid production, and is widely used in the treatment and health care of diseases related to cardiovascular, nervous, and immune systems. Jujuboside B(JuB), one of the main active ingredients of ZSS, possesses various pharmacological effects with application values. This paper reviewed the chemical structure and pharmacological effects of JuB. JuB has sedative, hypnotic, antitumor, anti-platelet, anti-inflammatory, and other biological activities, which shows the potential thera-peutic effects on insomnia, tumors, coronary artery disease, airway inflammation, and liver injury. However, there are some limitations to the results of current studies. More comprehensive studies, including basic research and clinical trials, need to be carried out to provide more reliable evidence.


Assuntos
Medicamentos de Ervas Chinesas , Saponinas , Distúrbios do Início e da Manutenção do Sono , Ziziphus , Humanos , Medicamentos de Ervas Chinesas/farmacologia , Saponinas/farmacologia , Hipnóticos e Sedativos , Ziziphus/química
11.
Anal Chem ; 94(25): 9130-9139, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35694821

RESUMO

Hydrogen peroxide (H2O2), one of the most stable and abundant reactive oxygen species (ROS), acting as a modulator of dopaminergic signaling, has been intimately implicated in Parkinson's disease, creating a critical need for the selective quantification of H2O2 in the living brain. Current natural or nanomimic enzyme-based electrochemical methods employed for the determination of H2O2 suffer from inadequate selectivity and stability, due to which the in vivo measurement of H2O2 in the living brain remains a challenge. Herein, a series of 5-(1,2-dithiolan-3-yl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pentanamide (DBP) derivatives were designed by tuning the substitute groups and sites of a boric acid ester, which served as probes to specifically react with H2O2. Consequently, the reaction products, 5-(1,2-dithiolan-3-yl)-N-(4-hydroxyphen-yl)pentanamide (DHP) derivatives, converted the electrochemical signal from inactive into active. After systematically evaluating their performances, 5-(1,2-dithiolan-3-yl)-N-(3-chloro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pentanamide (o-Cl-DBP) was finally identified as the optimized probe for H2O2 detection as it revealed the fastest reaction time, the largest current density, and the most negative potential. In addition, electrochemically oxidized graphene oxide (EOGO) was utilized to produce a stable inner reference. The designed electrochemical microsensor provided a ratiometric strategy for real-time tracking of H2O2 in a linear range of 0.5-600 µM with high selectivity and accuracy. Eventually, the efficient electrochemical microsensor was successfully applied to the measurement of H2O2 in Parkinson's disease (PD) mouse brain. The average levels of H2O2 in the cortex, striatum, and hippocampus in the normal mouse and PD mouse were systematically compared for the first time.


Assuntos
Peróxido de Hidrogênio , Doença de Parkinson , Animais , Encéfalo , Técnicas Eletroquímicas/métodos , Camundongos , Doença de Parkinson/diagnóstico
12.
Clin Genet ; 101(4): 381-389, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34761376

RESUMO

Neural tube defects (NTDs) are the most severe birth defects and the main cause of newborn death; posing a great challenge to the affected children, families, and societies. Presently, the clinical diagnosis of NTDs mainly relies on ultrasound images combined with certain indices, such as alpha-fetoprotein levels in the maternal serum and amniotic fluid. Recently, the discovery of additional biomarkers in maternal tissue has presented new possibilities for prenatal diagnosis. Over the past 20 years, "omics" techniques have provided the premise for the study of biomarkers. This review summarizes recent advances in candidate biomarkers for the prenatal diagnosis of fetal NTDs based on omics techniques using maternal biological specimens of different origins, including amniotic fluid, blood, and urine, which may provide a foundation for the early prenatal diagnosis of NTDs.


Assuntos
Defeitos do Tubo Neural , Diagnóstico Pré-Natal , Líquido Amniótico , Biomarcadores , Criança , Feminino , Humanos , Recém-Nascido , Defeitos do Tubo Neural/diagnóstico por imagem , Defeitos do Tubo Neural/genética , Gravidez , Diagnóstico Pré-Natal/métodos
13.
Stem Cells ; 39(9): 1192-1206, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33970551

RESUMO

Amniotic fluid-derived mesenchymal stromal cells (AFMSCs) present different features, depending on the isolation timing and culture conditions. The lack of uniform experimental standards hinders the comparison of results from different studies on AFMSCs. Moreover, understanding the molecular mechanisms that underlie the features of AFMSCs isolated at different embryonic developmental stages might allow the obtention of more viable and highly proliferative AFMSCs through genetic modification. We isolated AFMSCs from pregnant rats at embryonic day (E)12, E15, E18, and E21 and compared their cell proliferation capacity and transcriptome. The cell counting kit-8 assay and RNA sequencing revealed that E12 and E15 AFMSCs showed different characteristics from E18 and E21 AFMSCs. Therefore, AFMSCs were divided into two groups: early (E12 and E15) and late (E18 and E21) pregnancy-stage groups. Next, we screened the gene/microRNA pair Abca4/miR-351-3p that was related to cell proliferation. Abca4 knockdown/overexpression suggested that this gene represses the proliferation of AFMSCs, which is a newly discovered function of this gene. Finally, dual luciferase reporter gene assays confirmed that miR-351-3p targeted the coding sequence of Abca4 and regulated AFMSC proliferation. miR-351-3p promotes AFMSC proliferation via targeting the coding sequence of Abca4. Our findings provide a molecular foundation for further research for obtaining AFMSCs with a higher proliferation capacity.


Assuntos
Células-Tronco Mesenquimais , MicroRNAs , Líquido Amniótico , Animais , Contagem de Células , Proliferação de Células/genética , Feminino , MicroRNAs/genética , Gravidez , Ratos
14.
Nanotechnology ; 34(7)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36332230

RESUMO

Hierarchical domain structures associated with oxygen octahedra tilting patterns were observed in lead-free (Bi1/2Na1/2)TiO3ceramics using aberration-corrected high-resolution transmission electron microscopy (HRTEM). Three types of domains are induced by distinct mechanisms: the 'orientation-domain' is induced at micrometer scale formed by different tilting orientations of the oxygen octahedra, the 'meso-chemical-domain' occurs at a few tens of nanometer scale by chemical composition variation on the A-site in the ABO3perovskite structure, and the 'nano-cluster-region' runs across several unit-cells with apparent A-site cation segregation with oxygen vacancies clustering around Na cations. Based on HRTEM amplitude contrast imaging (ACI), the correlation between the oxygen octahedral tilting pattern and compositional non-stoichiometry was established. The role of the hierarchical domain structure associated with the tilting patterns of the oxygen octahedra on the ferroelectric behavior of (Bi1/2Na1/2)TiO3is also discussed.

15.
Anal Bioanal Chem ; 414(9): 2809-2839, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34825272

RESUMO

Hydrogen sulfide (H2S) is a biologically signaling molecule that mediates a wide range of physiological functions, which is frequently misregulated in numerous pathological processes. As such, measurement of H2S holds great attention due to its unique physiological and pathophysiological roles. Currently, a variety of methods based on the H2S-involved reactions have been reported for detection of endogenous H2S, bearing the advantages of good specificity and high sensitivity. This review describes in detail the types of reactions, their mechanisms, and their applications in biological research, thus hopefully providing some guidelines to the researchers in this field for further investigation.


Assuntos
Sulfeto de Hidrogênio , Transdução de Sinais
16.
Environ Res ; 204(Pt C): 112289, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34743809

RESUMO

The sensitive detection of malachite green (MG) in aquaculture wastewater is necessary for its residual poses a great threat to the living systems. Herein, the flower-like C3N4 (f-C3N4) nanostructure induced by Al sheet in the hydrothermal process is constructed. Subsequently, Ag nanowires (AgNWs) supported on Al/f-C3N4 and the strong interaction between AgNWs and Al/f-C3N4 are confirmed by XPS, Raman spectroscopy, UV-vis diffuse reflectance and fluorescence spectroscopy. Importantly, the portable Al/f-C3N4/AgNWs substrate shows the outstanding SERS response for MG, which is attributed to enhanced electromagnetic effect of AgNWs on large amount of corrugated and creviced regions in the flower-like Al/f-C3N4 and the charge transfer among the components. Also, the prepared Al/f-C3N4 nanostructure provides large specific surface area and abundant "N" active sites for AgNWs, and the high enrichment ability of Al/f-C3N4 towards MG molecules by the strong π-π stacking interaction. The detection limit of Al/f-C3N4/AgNWs for MG is as low as 8.38 × 10-12 mol L-1. The substrate can be reproduced and reused for at least 7 cycles, and the activity can still be kept after laid up for 49 days. Importantly, it unfolds a good sensitivity and selectivity for MG in actual water sample. Results indicate that the Al/f-C3N4/AgNWs substrate has a promising potential in practical application for trace detection of MG.


Assuntos
Nanofios , Prata , Alumínio , Nanofios/química , Nitrilas , Corantes de Rosanilina , Prata/química
17.
Anal Chem ; 93(49): 16598-16607, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34844405

RESUMO

Ascorbic acid (AA), a major antioxidant in the central nervous system (CNS), is involved in withstanding oxidative stress that plays a significant role in the pathogenesis of Parkinson's disease (PD). Exploring the AA disturbance in the process of PD is of great value in understanding the molecular mechanism of PD. Herein, by virtue of a carbon fiber electrode (CFE) as a matric electrode, a three-step electrochemical process for tailoring oxygen-containing groups on graphene was well designed: potentiostatic deposition was carried out to fabricate graphene oxide on CFE, electrochemical reduction that assisted in removing the epoxy groups accelerated the electron transfer kinetics of AA oxidation, and electrochemical oxidation that increased the content of the carbonyl group (C═O) generated an inner-reference signal. The mechanism was solidified by ab initio calculations by comparing AA absorption on defected models of graphene functionalized with different oxygen groups including carboxyl, hydroxyl, epoxy, and carbonyl. It was found that epoxy groups would hinder the physical absorption of AA onto graphene, while other functional groups would be beneficial to it. Biocompatible polyethylenedioxythiophene (PEDOT) was further rationally assembled to improve the antifouling property of graphene. As a result, a new platform for ratiometric electrochemical measurements of AA with high sensitivity, excellent selectivity, and reproducibility was established. In vivo determination of AA levels in different regions of living mouse brains by the proposed method demonstrated that AA decreased remarkably in the hippocampus and cortex of a subacute PD mouse than those of a normal mouse.


Assuntos
Grafite , Doença de Parkinson , Animais , Ácido Ascórbico , Camundongos , Oxigênio , Reprodutibilidade dos Testes
18.
Anal Chem ; 93(21): 7647-7656, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34014093

RESUMO

Chloride ion (Cl-), one of the most important anions in the brain, has been confirmed to participate in the pathological process of Parkinson's disease (PD). As such, the development of a reliable method for in vivo measurements of Cl- is extremely appealing, especially for understanding the pathogenesis of PD. We herein designed a facile electrochemical microbiosensor (ECMB), based on in situ self-assembly of Ag nanoparticles (Ag NPs) coated on Ti3C2Tx. The uniform nanosized Ag NPs were reduced by Ti3C2Tx by a simple dipping process, endowing the ECMB with excellent specificity toward Cl- detection and remarkably reproducible preparation process. Meanwhile, electro-oxidized graphene oxide was introduced as an inner reference, thus avoiding the environmental interference of the complicated brain systems to increase the determination accuracy. An extensive in vitro study revealed that the proposed ECMB would be a robust candidate for real-time monitoring of Cl- in the PD mouse brain with high selectivity, accuracy, and reproducibility. Moreover, the availability and reliability toward in vivo Cl- monitoring of the designed ECMB were well confirmed by comparing with the standard Volhard's method. Finally, by virtue of the successful employment of the developed detecting platform in the in vivo measurement of Cl- in the PD mouse brain, systematic analysis and comparison of the average levels of Cl- in the three regions including cortex, striatum, and hippocampus of brains from normal and PD model mice have been achieved.


Assuntos
Nanopartículas Metálicas , Doença de Parkinson , Animais , Encéfalo , Cloretos , Técnicas Eletroquímicas , Camundongos , Reprodutibilidade dos Testes , Prata , Titânio
19.
J Vasc Surg ; 74(1): 217-224, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33340700

RESUMO

OBJECTIVE: Arteriovenous fistula (AVF) is the preferred access for hemodialysis. Percutaneous transluminal angioplasty (PTA) has become a choice for AVF stenosis, and ultrasound has been used in PTA more frequently. METHODS: This single-center retrospective cohort study analyzed 129 patients who underwent PTA in the First Affiliated Hospital of Chongqing Medical University from January 2016 to December 2016. Angioplasty was performed using a noncompliant high-pressure balloon. The process was visualized by duplex scan. Our inclusion criteria were as follows: (1) stenoses or occlusions were located at the juxta-anastomosis site: the first 5 cm of the vein distal to the anastomosis; (2) stenosis was confirmed with the following conditions: (a) flow rates are <500 mL/min in the brachial artery and <200 mL/min in the fistula during dialysis, and (b) the stenosis diameter is <1.7 mm. We used the Kaplan-Meier curve to show the postintervention primary and secondary patency rates of patients with stenosis and occlusion. RESULTS: Altogether, 129 patients with 76 males were analyzed. Moreover, 104 have AVFs on the left arm, and only one patient had an ulnar-basilic AVF, whereas others had a radial-cephalic AVF. The postintervention primary patency rates are better in occlusion cases (P < .05), whereas secondary patency rates have no difference. The postintervention primary patency rates are better in patients without diabetes mellitus (P < .05), whereas the secondary patency rates had no difference. CONCLUSIONS: For juxta-anastomosis site stenosis or occlusion, PTA can be used to obtain satisfactory results.


Assuntos
Angioplastia com Balão , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Oclusão de Enxerto Vascular/terapia , Diálise Renal , Ultrassonografia Doppler Dupla , Ultrassonografia de Intervenção , Extremidade Superior/irrigação sanguínea , Grau de Desobstrução Vascular , Adulto , Idoso , Angioplastia com Balão/efeitos adversos , Feminino , Seguimentos , Oclusão de Enxerto Vascular/diagnóstico por imagem , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
20.
Analyst ; 146(20): 6202-6210, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34519726

RESUMO

Chloride ion (Cl-), the most common anion in animal brain, has been verified to play a vital role in maintaining normal physiological processes. Thus, development of a reliable platform to determine Cl- is of great significance for brain research involving Cl-. In this work, a ratiometric electrochemical microsensor (REM) for the in vivo measurement of cerebral Cl- was designed. To prepare REM, uniform Ag nanoparticles (Ag NPs) with nano-level sizes were synthesized via an adsorption-reduction process, which served as selective recognition elements for Cl- determination, while methylene blue (MB) was absorbed and acted as an inner reference unit to avoid the environmental interference of complicated brain systems. As a result, this developed REM exhibited high sensitivity and selectivity, as well as good stability, reproducibility and anti-biofouling. This reliable approach was established to monitor Cl- in mouse brain.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Animais , Cloretos , Técnicas Eletroquímicas , Camundongos , Reprodutibilidade dos Testes , Prata
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