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1.
Proc Natl Acad Sci U S A ; 120(15): e2216934120, 2023 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-37011188

RESUMEN

Cells continuously sense external forces from their microenvironment, the extracellular matrix (ECM). In turn, they generate contractile forces, which stiffen and remodel this matrix. Although this bidirectional mechanical exchange is crucial for many cell functions, it remains poorly understood. Key challenges are that the majority of available matrices for such studies, either natural or synthetic, are difficult to control or lack biological relevance. Here, we use a synthetic, yet highly biomimetic hydrogel based on polyisocyanide (PIC) polymers to investigate the effects of the fibrous architecture and the nonlinear mechanics on cell-matrix interactions. Live-cell rheology was combined with advanced microscopy-based approaches to understand the mechanisms behind cell-induced matrix stiffening and plastic remodeling. We demonstrate how cell-mediated fiber remodeling and the propagation of fiber displacements are modulated by adjusting the biological and mechanical properties of this material. Moreover, we validate the biological relevance of our results by demonstrating that cellular tractions in PIC gels develop analogously to those in the natural ECM. This study highlights the potential of PIC gels to disentangle complex bidirectional cell-matrix interactions and to improve the design of materials for mechanobiology studies.


Asunto(s)
Matriz Extracelular , Hidrogeles , Matriz Extracelular/fisiología , Comunicación Celular
2.
Nano Lett ; 24(10): 3257-3266, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38426843

RESUMEN

The extracellular matrix (ECM) orchestrates cell behavior and tissue regeneration by modulating biochemical and mechanical signals. Manipulating cell-material interactions is crucial for leveraging biomaterials to regulate cell functions. Yet, integrating multiple cues in a single material remains a challenge. Here, near-infrared (NIR)-controlled multifunctional hydrogel platforms, named PIC/CM@NPs, are introduced to dictate fibroblast behavior during wound healing by tuning the matrix oxidative stress and mechanical tensions. PIC/CM@NPs are prepared through cell adhesion-medicated assembly of collagen-like polyisocyanide (PIC) polymers and cell-membrane-coated conjugated polymer nanoparticles (CM@NPs), which closely mimic the fibrous structure and nonlinear mechanics of ECM. Upon NIR stimulation, PIC/CM@NPs composites enhance fibroblast cell proliferation, migration, cytokine production, and myofibroblast activation, crucial for wound closure. Moreover, they exhibit effective and toxin removal antibacterial properties, reducing inflammation. This multifunctional approach accelerates healing by 95%, highlighting the importance of integrating biochemical and biophysical cues in the biomaterial design for advanced tissue regeneration.


Asunto(s)
Materiales Biocompatibles , Cicatrización de Heridas , Especies Reactivas de Oxígeno , Materiales Biocompatibles/farmacología , Polímeros/farmacología , Matriz Extracelular , Hidrogeles/farmacología , Antibacterianos/farmacología
3.
BMC Anesthesiol ; 23(1): 204, 2023 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-37312027

RESUMEN

BACKGROUND: Patients who undergo gastrointestinal endoscopy often require propofol-based sedation combined with analgesics. At present, the efficacy and safety of esketamine as an adjunct to propofol for sedation during endoscopic procedures in patients remains controversial. Moreover, there is no universal agreement regarding the appropriate dose of esketamine supplementation. This study aimed to assess the efficacy and safety of esketamine as an adjunct to propofol for sedation during endoscopic procedures in patients. METHODS: Seven electronic databases and three clinical trial registry platforms were searched and the deadline was February 2023. Randomized controlled trials (RCTs) evaluating the efficacy of esketamine for sedation were included by two reviewers. Data from the eligible studies were combined to calculate the pooled risk ratio or standardized mean difference. RESULTS: Eighteen studies with 1962 esketamine participants were included in the analysis. As an adjunct to propofol, the administration of esketamine reduced the recovery time compared to normal saline (NS). However, there was no significant difference between the opioids group and ketamine group. For propofol dosage, the administration of esketamine required a lower propofol dosage compared to the NS group and opioids group].For complications, the esketamine group had fewer complications compared to the NS group and opioid group in patients, but there were no significant differences between the esketamine group and ketamine group. Notably, the coadministration of esketamine was associated with a higher risk of visual disturbance compared to the NS group. In addition, we used subgroup analysis to investigate whether 0.2-0.5 mg/kg esketamine was effective and tolerable for patients. CONCLUSION: Esketamine as an adjunct to propofol, is an appropriate effective alternative for sedation in participants undergoing gastrointestinal endoscopy. However, considering the possibility of its psychotomimetic effects, esketamine should be used with caution.


Asunto(s)
Ketamina , Propofol , Humanos , Ketamina/efectos adversos , Analgésicos Opioides , Propofol/efectos adversos , Endoscopía Gastrointestinal/efectos adversos , Solución Salina
4.
Int J Mol Sci ; 24(20)2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-37895155

RESUMEN

Valsa pyri-induced pear Valsa canker is among the most prevalent diseases to impact pear quality and yields. Biocontrol strategies to control plant disease represent an attractive alternative to the application of fungicides. In this study, the potential utility of Bacillus atrophaeus strain HF1 was assessed as a biocontrol agent against pear Valsa canker. Strain HF1 suppressed V. pyri mycelium growth by 61.20% and induced the development of malformed hyphae. Both culture filtrate and volatile organic compounds (VOCs) derived from strain HF1 were able to antagonize V. pyri growth. Treatment with strain HF1-derived culture filtrate or VOCs also induced the destruction of hyphal cell membranes. Headspace mixtures prepared from strain HF1 were analyzed, leading to the identification of 27 potential VOCs. Of the thirteen pure chemicals tested, iberverin, hexanoic acid, and 2-methylvaleraldehyde exhibited the strongest antifungal effects on V. pyri, with respective EC50 values of 0.30, 6.65, and 74.07 µL L-1. Fumigation treatment of pear twigs with each of these three compounds was also sufficient to prevent the development of pear Valsa canker. As such, these results demonstrate that B. atrophaeus strain HF1 and the volatile compounds iberverin, hexanoic acid, and 2-methylvaleraldehyde exhibit promise as novel candidate biocontrol agents against pear Valsa canker.


Asunto(s)
Ascomicetos , Pyrus , Pyrus/microbiología , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología
5.
Macromol Rapid Commun ; 43(11): e2200135, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35365902

RESUMEN

The development of biomimetic extracellular matrix (ECM) with fibrous structure and complex nonlinear mechanics has been attracting intensive attention over the past decades both in material science and tissue engineering. Polyisocyanopeptide (PIC) hydrogels are a class of fully synthetic materials that can mimic biogels, such as fibrin and collagen, in nearly all aspects, particularly the micron-sized gel network and the strong strain-stiffening behavior in the biological regime. Here, a biomimetic PIC/hydroxyapatite (HA) hybrid composite through an enzymatic biomineralization strategy is constructed. HA biominerals grew on PIC bundles in situ catalyzed by the embedded alkaline phosphatase (ALP), which further crosslinked the gel networks and reinforced the mechanical property of PIC hydrogels. Significantly, PIC/HA composites exhibited ultra-responsive nonlinear mechanics with higher sensitivity to mechanical stress compared with those without biomineralization. As a consequence, the presence of HA can provide cell adhesion sites for PIC gels and induce osteogenic differentiation of pre-osteoblasts by virtue of the changes in mechanical properties. With these outstanding properties, therefore, PIC/HA composites present promising prospects in bone tissue engineering as biomimetic ECM.


Asunto(s)
Durapatita , Osteogénesis , Durapatita/química , Hidrogeles/química , Osteoblastos , Ingeniería de Tejidos , Andamios del Tejido/química
6.
Pharmacoepidemiol Drug Saf ; 31(9): 932-943, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35729705

RESUMEN

PURPOSE: Supplementing investigator-specified variables with large numbers of empirically identified features that collectively serve as 'proxies' for unspecified or unmeasured factors can often improve confounding control in studies utilizing administrative healthcare databases. Consequently, there has been a recent focus on the development of data-driven methods for high-dimensional proxy confounder adjustment in pharmacoepidemiologic research. In this paper, we survey current approaches and recent advancements for high-dimensional proxy confounder adjustment in healthcare database studies. METHODS: We discuss considerations underpinning three areas for high-dimensional proxy confounder adjustment: (1) feature generation-transforming raw data into covariates (or features) to be used for proxy adjustment; (2) covariate prioritization, selection, and adjustment; and (3) diagnostic assessment. We discuss challenges and avenues of future development within each area. RESULTS: There is a large literature on methods for high-dimensional confounder prioritization/selection, but relatively little has been written on best practices for feature generation and diagnostic assessment. Consequently, these areas have particular limitations and challenges. CONCLUSIONS: There is a growing body of evidence showing that machine-learning algorithms for high-dimensional proxy-confounder adjustment can supplement investigator-specified variables to improve confounding control compared to adjustment based on investigator-specified variables alone. However, more research is needed on best practices for feature generation and diagnostic assessment when applying methods for high-dimensional proxy confounder adjustment in pharmacoepidemiologic studies.


Asunto(s)
Aprendizaje Automático , Farmacoepidemiología , Factores de Confusión Epidemiológicos , Bases de Datos Factuales , Atención a la Salud , Humanos
7.
Plant Dis ; 106(1): 207-214, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34227835

RESUMEN

Botryosphaeria dothidea causes white rot, which is among the most devastating diseases affecting apple crops globally. In this study, we assessed B. dothidea resistance to carbendazim by collecting samples from warts on the infected branches of apple trees or from fruits exhibiting evidence of white rot. All samples were collected from different orchards in nine provinces of China in 2018 and 2019. In total, 440 B. dothidea isolates were evaluated, of which 19 isolates from three provinces were found to exhibit carbendazim resistance. We additionally explored the fitness and resistance stability of these isolates, revealing that they were no less fit than carbendazim-sensitive isolates in terms of pathogenicity, sporulation, and mycelial growth and that the observed carbendazim resistance was stable. Sequencing of the ß-tubulin gene in carbendazim-resistant isolates showed the presence of a substitution at codon 198 (GAG to GCG) that results in an alanine substitution in place of glutamic acid (E198A) in all 19 resistant isolates. A loop-mediated isothermal amplification (LAMP) method was then developed to rapidly and specifically identify this E198A mutation. This LAMP method offers value as a tool for rapidly detecting carbendazim-resistant isolates bearing this E198A mutation and can thus be used for the widespread monitoring of apple crops to detect and control the development of such resistance.


Asunto(s)
Ascomicetos , Malus , Ascomicetos/genética , Bencimidazoles , Carbamatos/farmacología
8.
BMC Pulm Med ; 21(1): 143, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33933054

RESUMEN

BACKGROUND: Acute kidney injury (AKI) is a frequent complication of community acquired pneumonia (CAP). However, the impact of AKI on in-hospital outcomes of patients with CAP in the Chinese population remains unclear. METHODS: Patients diagnosed with CAP were evaluated in this retrospective observational study. Multiple Cox regression models were employed to identify the association between AKI and in-hospital mortality and 30-day mortality, respectively. RESULTS: A total of 4213 patients were recruited; 950 (22.5%) patients were diagnosed with AKI. Independent risk factors for AKI were age, male gender, hypertension, cardiac dysfunction, diabetes, chronic kidney disease, acute respiratory failure, use of diuretics, use of vasoactive drugs, and CURB-65. Cox proportional hazards regression revealed AKI, use of angiotensin receptor blocker, hypertension, CURB-65, acute respiratory failure, and use of vasoactive drugs to be independent risk factors for both in-hospital and 30-day mortality. Compared to patients without AKI, those suffering AKI were found to have 1.31-fold (HR 1.31, 95% CI, 1.04-1.66; P = 0.023) and 1.29-fold (HR 1.29, 95% CI, 1.02-1.62; P = 0.033) increased in-hospital and 30-day mortality risks, respectively. In addition, patients with AKI were likely to require admission to intensive care unit (ICU) (42.9% versus 11.4%; P < 0.001), mechanical ventilation (33.8% versus 9.3%; P < 0.001), invasive mechanical ventilation (25.9% versus 5.8%; P < 0.001), non-invasive mechanical ventilation (25.4% versus 7.1%; P < 0.001), and experienced a longer duration of hospital stay (14 days versus 10 days; P < 0.001) than those without AKI. However, no significant difference in ICU stay (11 days versus 10 days; P = 0.099) and duration of mechanical ventilation (8 days versus 8 days; P = 0.369) between AKI and non-AKI groups was found. CONCLUSION: AKI was common in Chinese patients with CAP. Patients with CAP who developed AKI had worse in-hospital outcomes.


Asunto(s)
Lesión Renal Aguda/etiología , Infecciones Comunitarias Adquiridas/complicaciones , Mortalidad Hospitalaria , Neumonía/complicaciones , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/patología , Anciano , Anciano de 80 o más Años , China/epidemiología , Infecciones Comunitarias Adquiridas/terapia , Progresión de la Enfermedad , Femenino , Humanos , Unidades de Cuidados Intensivos , Tiempo de Internación/estadística & datos numéricos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Neumonía/terapia , Modelos de Riesgos Proporcionales , Respiración Artificial , Estudios Retrospectivos , Factores de Riesgo
9.
Chron Respir Dis ; 17: 1479973120940677, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32924598

RESUMEN

Hospital-acquired acute kidney injury (HA-AKI) is associated with poor prognosis. In this study, we evaluated whether serum cystatin C on admission could predict AKI in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The retrospective study was conducted using data on adult inpatients with AECOPD from January 2014 to January 2017. A total of 1035 patients were included, among which 79 (7.6%) with HA-AKI were identified. Univariate and multivariate logistic regression analyses were used to investigate predictors of HA-AKI in patients with AECOPD. HA-AKI was associated with poor prognosis, and patients with HA-AKI had higher inpatient mortality (34.2% vs. 2.6%, p < 0.001). Furthermore, after adjusting for confounders, HA-AKI was an independent risk factor for inpatient mortality for patients with AECOPD (odds ratio (OR) 11.02; 95% confidence interval (CI) 4.77-25.45; p < 0.001). Four independent risk factors for HA-AKI (age, levels of urea and cystatin C, and platelet count on admission) were identified in patients with AECOPD. Cystatin C (OR 5.22; 95% CI 2.49-10.95; p < 0.001) was a significant independent predictor of AKI in patients with AECOPD. HA-AKI in patients with AECOPD could be identified with a sensitivity of 73.5% and a specificity of 75.9% (area under the curve (AUC) = 0.803, 95% CI 0.747-0.859) by cystatin C level (cutoff value = 1.3 mg/L) and with a sensitivity of 75.9% and a specificity of 82.0% (AUC = 0.853, 95% CI 0.810-0.896) using a model comprising all significant predictors. Serum cystatin C has the potential for use to predict the risk of HA-AKI in patients with AECOPD.


Asunto(s)
Lesión Renal Aguda , Enfermedad Pulmonar Obstructiva Crónica , Lesión Renal Aguda/diagnóstico , Adulto , Biomarcadores , Cistatina C , Hospitales , Humanos , Pronóstico , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Estudios Retrospectivos
10.
Angew Chem Int Ed Engl ; 59(7): 2720-2724, 2020 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-31917502

RESUMEN

Hybrid biomimetic hydrogels with enhanced reactive oxygen species (ROS)-generation efficiency under 600 nm light show high antibacterial activity. The hybrid gels are composed of helical tri(ethylene glycol)-functionalized polyisocyanides (PICs) and a conformation-sensitive conjugated polythiophene, poly(3-(3'-N,N,N-triethylammonium-1'-propyloxy)-4-methyl-2,5-thiophene chloride) (PMNT). The PIC polymer serves as a scaffold to trap and align the PMNT backbone into a highly ordered conformation, resulting in redshifted, new sharp bands in the absorption and fluorescence spectra. Similar to PIC, the hybrid closely mimics the mechanical properties of biological gels, such as collagen and fibrin, including the strain stiffening properties at low stresses. Moreover, the PMNT/PIC hybrids show much higher ROS production efficiency under red light than PMNT only, leading to an efficient photodynamic antimicrobial effect towards various pathogenic bacteria.


Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Materiales Biomiméticos/farmacología , Hidrogeles/farmacología , Fotoquimioterapia , Antibacterianos/síntesis química , Antibacterianos/química , Antifúngicos/síntesis química , Antifúngicos/química , Bacillus subtilis/efectos de los fármacos , Materiales Biomiméticos/química , Candida albicans/efectos de los fármacos , Cianuros/química , Cianuros/farmacología , Escherichia coli/efectos de los fármacos , Hidrogeles/síntesis química , Hidrogeles/química , Pruebas de Sensibilidad Microbiana , Polímeros/química , Polímeros/farmacología , Tiofenos/química , Tiofenos/farmacología
11.
Bioorg Med Chem ; 27(6): 944-954, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30777660

RESUMEN

The dysfunction and mutual compensatory activation of RAF-MEK-ERK and PI3K-PDK1-AKT pathways have been demonstrated as the hallmarks in several primary and recurrent cancers. The strategy of concurrent blocking of these two pathways shows clinical merits on effective cancer therapy, such as combinatory treatments and dual-pathway inhibitors. Herein, we report a novel prototype of dual-pathway inhibitors by means of merging the core structural scaffolds of a MEK1 inhibitor and a PDK1 inhibitor. A library of 43 compounds that categorized into three series (Series I-III) was synthesized and tested for antitumor activity in lung cancer cells. The results from structure-activity relationship (SAR) analysis showed the following order of antitumor activity that 3-hydroxy-5-(phenylamino) indolone (Series III) > 3-alkenyl-5-(phenylamino) indolone (Series I) > 3-alkyl-5-(phenylamino) indolone (Series II). A lead compound 9za in Series III showed most potent antitumor activity with IC50 value of 1.8 ±â€¯0.8 µM in A549 cells. Moreover, antitumor mechanism study demonstrated that 9za exerted significant apoptotic effect, and cellular signal pathway analysis revealed the potent blockage of phosphorylation levels of ERK and AKT in RAF-MEK-ERK and PI3K-PDK1-AKT pathways, respectively. The results reported here provide robust experimental basis for the discovery and optimization of dual pathway agents for anti-lung cancer therapy.


Asunto(s)
Indoles/química , Indoles/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Transducción de Señal/efectos de los fármacos , Células A549 , Aminación , Compuestos de Anilina/síntesis química , Compuestos de Anilina/química , Compuestos de Anilina/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Benzodioxoles/síntesis química , Benzodioxoles/química , Benzodioxoles/farmacología , Línea Celular Tumoral , Diseño de Fármacos , Humanos , Indoles/síntesis química , Neoplasias Pulmonares/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Fosfatidilinositol 3-Quinasa/metabolismo , Inhibidores de Proteínas Quinasas/síntesis química , Proteínas Proto-Oncogénicas c-akt/metabolismo , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora/metabolismo , Quinasas raf/metabolismo
12.
J Membr Biol ; 250(5): 483-492, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28852814

RESUMEN

Calcium-activated chloride channels (CaCCs) play vital roles in a variety of physiological processes. Dysfunction of the CaCCs is implicated in many diseases. Drug discovery targeting at CaCCs has recently become possible with the determination that TMEM16A is the molecular identity of CaCCs. In this study, we demonstrated that resveratrol (RES), a Chinese traditional medicine compound, is a novel activator of TMEM16A. The yellow fluorescence protein quenching assay and measurement of intracellular calcium fluorescence intensity show that RES activates TMEM16A channels in an intracellular Ca2+-independent way. The data of inside-out patch clamp revealed that RES dose-dependently activates TMEM16A (EC50 = 47.92 ± 9.35 µM). Furthermore, RES enhanced the contractions of the ileum of guinea pigs by activating the TMEM16A channel, which indicated that RES might be a promising drug for the treatment of gastrointestinal hypomotility. As RES was able to induce TMEM16A channel activation, TMEM16A can be added to the list of RES drug targets.


Asunto(s)
Anoctamina-1/agonistas , Señalización del Calcio/efectos de los fármacos , Agonistas de los Canales de Cloruro/farmacología , Motilidad Gastrointestinal/efectos de los fármacos , Íleon/fisiología , Proteínas de Neoplasias/agonistas , Estilbenos/farmacología , Animales , Anoctamina-1/genética , Anoctamina-1/metabolismo , Agonistas de los Canales de Cloruro/química , Relación Dosis-Respuesta a Droga , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Cobayas , Células HEK293 , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Plantas Medicinales , Resveratrol , Estilbenos/química
13.
Macromol Rapid Commun ; 38(5)2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28117511

RESUMEN

The CO2 -responsive and biocatalytic assembly based on conjugated polymers has been demonstrated by combining the signal amplification property of the polythiophene derivative (PTP) and the catalytic actions of carbonic anhydrase (CA). CO2 is applied as a new trigger mode to construct the smart assembly by controlling the electrostatic and hydrophobic interactions between the PTP molecules in aqueous solution, leading to the visible fluorescence changes. Importantly, the assembly transformation of PTP can be specifically and highly accelerated by CA based on the efficient catalytic activity of CA for the inter-conversion between CO2 and HCO3- , mimicking the CO2 -associated biological processes that occurred naturally in living organisms. Moreover, the PTP-based assembly can be applied for biomimetic CO2 sequestration with fluorescence monitoring in the presence of CA and calcium.


Asunto(s)
Dióxido de Carbono/metabolismo , Anhidrasa Carbónica II/metabolismo , Polímeros/metabolismo , Agua/metabolismo , Biocatálisis , Dióxido de Carbono/química , Anhidrasa Carbónica II/química , Tamaño de la Partícula , Polímeros/química , Solubilidad , Propiedades de Superficie , Agua/química
14.
Anal Chem ; 88(12): 6593-7, 2016 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-27252118

RESUMEN

Detection of carbon dioxide (CO2) is of fundamental importance in diverse applications ranging from environmental analysis to agricultural production. In this work, a hybrid probe based on guanidinium-pendent oligofluorene (G-OF) and water-soluble conjugated polythiophene (PTP) has been developed for the turn on detection of CO2 with low background signal, taking advantage of the efficient fluorescence quenching of the tight aggregate of G-OF/PTP. In the presence of CO2, the electrostatic repulsion between G-OF and PTP can be effectively enhanced through protonation of the side chains, leading to the disaggregation and thus the "turn-on" fluorescence. The strategy allows for the light-up visible detection of CO2 with high sensitivity. Importantly, this system is capable of sensitively monitoring the concentration changes of CO2 in the process of the photosynthesis, which represents a concept to monitor the photosynthesis based on water-soluble conjugated polymers.


Asunto(s)
Dióxido de Carbono/análisis , Fluorenos/química , Guanidina/análogos & derivados , Fotosíntesis , Polímeros/química , Tiofenos/química , Zea mays/fisiología , Técnicas Biosensibles/métodos , Dióxido de Carbono/metabolismo , Fluorescencia , Modelos Moleculares , Solubilidad , Espectrometría de Fluorescencia/métodos , Electricidad Estática , Agua/química , Zea mays/química
15.
J Membr Biol ; 249(1-2): 57-63, 2016 04.
Artículo en Inglés | MEDLINE | ID: mdl-26708576

RESUMEN

TMEM16A is the molecular basis of calcium-activated chloride channels and shows Ca(2+)-dependent gating. It is critical to understand how the Ca(2+) sensors dynamically control the gate of TMEM16A. However, the detailed mechanism by which the calcium ions bind and open the channel is still obscure. In this study, the authors confirmed that there are two Ca(2+) sensors which cooperatively couple together in TMEM16A. Our data show that mutations at both Ca(2+)-sensitive domains, E447Y and E702Q-E705Q, weaken the Ca(2+) affinity for TMEM16A channel. The EC50 for WT, E447Y, and E702Q-E705Q are 0.53 ± 0.11, 14.5 ± 0.3, and 26.5 ± 3.6 µM, respectively. The triple mutation, including both of the Ca(2+) sensors, E447Y-E702Q-E705Q, with EC50 as 55.6 ± 5.1 µM, results in much further right-shifted dose response curve than the single sensor's mutations (E447Y, E702Q-E705Q) do, which indicates that there is a cooperation between the two Ca(2+)-sensitive domains. We also found that the divalent cations, both Ca(2+) and Sr(2+), share common mechanism of gating the TMEM16A.


Asunto(s)
Sitios de Unión , Calcio/química , Canales de Cloruro/química , Animales , Anoctamina-1 , Calcio/metabolismo , Cationes Bivalentes/química , Cationes Bivalentes/metabolismo , Línea Celular , Canales de Cloruro/genética , Canales de Cloruro/metabolismo , Humanos , Activación del Canal Iónico , Ratones , Mutación , Unión Proteica , Dominios y Motivos de Interacción de Proteínas/genética
16.
J Comput Aided Mol Des ; 29(11): 1035-43, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26481648

RESUMEN

Calcium-activated chloride channels (CaCCs) play vital roles in a variety of physiological processes. Transmembrane protein 16A (TMEM16A) has been confirmed as the molecular counterpart of CaCCs which greatly pushes the molecular insights of CaCCs forward. However, the detailed mechanism of Ca(2+) binding and activating the channel is still obscure. Here, we utilized a combination of computational and electrophysiological approaches to discern the molecular mechanism by which Ca(2+) regulates the gating of TMEM16A channels. The simulation results show that the first intracellular loop serves as a Ca(2+) binding site including D439, E444 and E447. The experimental results indicate that a novel residue, E447, plays key role in Ca(2+) binding. Compared with WT TMEM16A, E447Y produces a 30-fold increase in EC50 of Ca(2+) activation and leads to a 100-fold increase in Ca(2+) concentrations that is needed to fully activate the channel. The following steered molecular dynamic (SMD) simulation data suggests that the mutations at 447 reduce the Ca(2+) dissociation energy. Our results indicated that both the electrical property and the size of the side-chain at residue 447 have significant effects on Ca(2+) dependent gating of TMEM16A.


Asunto(s)
Calcio/química , Canales de Cloruro/química , Simulación de Dinámica Molecular , Proteínas de Neoplasias/química , Aminoácidos/química , Anoctamina-1 , Sitios de Unión/genética , Calcio/metabolismo , Canales de Cloruro/metabolismo , Mutación , Proteínas de Neoplasias/metabolismo
17.
Pest Manag Sci ; 80(6): 3010-3021, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38318950

RESUMEN

BACKGROUND: Valsa canker caused by Valsa pyri is one of the most destructive diseases of pear, leading to severe yield and economic losses. Volatile organic compounds (VOCs) from endophytes have important roles in the regulation of plant disease. In this study, we investigated the biocontrol activity of the endophytic fungus Aspergillus niger strain La2 and its antagonistic VOCs against pear Valsa canker. RESULTS: Strain La2 exhibited an obvious inhibitory effect against V. pyri. A colonization assay suggested that strain La2 could complete its life cycle on pear twigs. The symptoms of pear Valsa canker were weakened on detached pear twigs after treatment with strain La2. In addition, VOCs from strain La2 also significantly suppressed mycelial growth in V. pyri. Based on the results of headspace solid-phase microextraction/gas chromatography-mass spectrometry analysis, six possible VOCs produced by strain La2 were detected, of which 2,4-di-tert-butylphenol and 4-methyl-1-pentanol were the main antagonistic VOCs in terms of their effect on pear Valsa canker in vitro and in vivo. Further results showed that 4-methyl-1-pentanol could destroy the V. pyri hyphal structure and cell membrane integrity. Importantly, the activities of pear defense-related enzymes (polyphenol oxidase, phenylalanine ammonia lyase and superoxide dismutase) were enhanced after 4-methyl-1-pentanol treatment in pear twigs, suggesting that 4-methyl-1-pentanol might induce a plant disease resistance response. CONCLUSION: Aspergillus niger strain La2 and its VOCs 2,4-di-tert-butylphenol and 4-methyl-1-pentanol have potential as novel biocontrol agents of pear Valsa canker. © 2024 Society of Chemical Industry.


Asunto(s)
Aspergillus niger , Enfermedades de las Plantas , Pyrus , Compuestos Orgánicos Volátiles , Pyrus/microbiología , Compuestos Orgánicos Volátiles/farmacología , Compuestos Orgánicos Volátiles/metabolismo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Endófitos/fisiología , Agentes de Control Biológico/farmacología
18.
Front Pharmacol ; 15: 1287321, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38584600

RESUMEN

Ethnopharmacological relevance: Pelvic inflammatory disease (PID) is a frequently occurring gynecological disorder mainly caused by the inflammation of a woman's upper genital tract. Generally, antibiotics are used for treating PID, but prolonged use poses potential risks of gut bacterial imbalance, bacterial resistance, super bacteria production, and associated adverse reactions. Traditional Chinese medicine (TCM) has shown unique advantages in various ailments and has received widespread clinical research attention. Fuke Qianjin (FUKE) capsule is an approved National Medical Products Administration (NMPA License No. Z20020024) Chinese herbal prescription that has been widely used individually or in combination with other Western medicines for the treatment of various gynecological inflammatory diseases, including chronic cervicitis, endometritis, and chronic PID. Aim: This clinical trial was designed to assess the safety and efficacy of FUKE capsule in mild-to-moderate symptomatic PID patients. Materials and methods: This phase 2, randomized, double-blind, positive controlled clinical trial was conducted in mild-to-moderate symptomatic PID patients at a single center in Pakistan from 21 September 2021 to 11 March 2022. Eligible female participants were randomly assigned to a test and a control group with a ratio of 1:1. The test group subjects received two metronidazole (METRO) tablets and one doxycycline hyclate (DOXY) simulant at a time, twice daily for 14 days, and two Fuke Qianjin (FUKE) capsules, three times a day after a meal for 28 days. Subjects in the control group received two METRO tablets and one DOXY tablet at a time, twice daily for 14 days, and two FUKE simulant capsules, three times a day after meal for 28 days. The primary efficacy outcome was an improvement in pelvic pain symptoms assessed through a visual analog scale (VAS). The secondary outcomes were the improvement in secondary efficacy symptoms like local physical signs, clinical assessment of leucorrhea and cervical secretions through laboratory examination, and improvement in the maximum area of pelvic effusion assessed through gynecological ultrasound after the treatment. The safety outcomes were assessed through vital signs, laboratory tests, electrocardiogram findings, and adverse events/serious adverse events. Results: A total of 198 subjects with active PID were randomly assigned to a test group (n = 99) and a control group (n = 99). The baseline characteristics of the subjects in the two groups were similar. In the intention-to-treat analysis, the primary efficacy was 84.9% for the test group and 71.6% for the control group, with a statistically significant difference (p = 0.0370; 95% CI -0.2568 to -0.0088). The secondary clinical efficacy was 88.4% for the test group and 82.7% for the control group, with no significant difference (p = 0.2977; 95% CI -0.1632 to 0.0501). The improvement in local physical signs was 95.8% for the test group and 76.9% for the control group, with no significant difference (p = 0.0542; 95% CI -0.3697 to -0.0085). The inter-group non-inferiority comparison showed that the upper limit of the 95% CI was less than 0.15 and thus met the non-inferiority requirements of the test group to the control group. The results of clinical signs of leucorrhea and cervical secretions showed that there was no difference in the rate of improvement between the test and control groups, indicating that FUKE was non-inferior to DOXY. A total of 14 adverse events in eight subjects were observed in the trial, with an incidence rate of 4.7%. Four subjects in each group experienced seven adverse events with 4.5% and 4.8% incidence rates of adverse reactions in the test and control groups, with no statistically significant differences (p = 0.2001). No serious adverse events occurred in the trial. Conclusion: The results of this trial indicate that the test drug (Fuke Qianjin capsule) is non-inferior to the control drug (doxycycline hyclate tablet) in treating mild-to-moderate PID patients with comparable efficacy, safety, and tolerability to the control drug. Clinical Trial Registration: www.clinicaltrials.gov, identifier NCT04723069.

19.
J Membr Biol ; 246(12): 893-902, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23996050

RESUMEN

The gating of Ca²âº-activated Cl⁻ channels is controlled by a complex interplay among [Ca²âº](i), membrane potential and permeant anions. Besides Ca²âº, Ba²âº also can activate both TMEM16A and TMEM16B. This study reports the effects of several divalent cations as regulators of TMEM16A channels stably expressed in HEK293T cells. Among the divalent cations that activate TMEM16A, Ca²âº is most effective, followed by Sr²âº and Ni²âº, which have similar affinity, while Mg²âº is ineffective. Zn²âº does not activate TMEM16A but inhibits the Ca²âº-activated chloride currents. Maximally effective concentrations of Sr²âº and Ni²âº occluded activation of the TMEM16A current by Ca²âº, which suggests that Ca²âº, Sr²âº and Ni²âº all regulate the channel by the same mechanism.


Asunto(s)
Cationes Bivalentes/metabolismo , Canales de Cloruro/metabolismo , Proteínas de Neoplasias/metabolismo , Anoctamina-1 , Calcio/metabolismo , Línea Celular , Expresión Génica , Células HEK293 , Humanos , Potenciales de la Membrana , Níquel/metabolismo , Estroncio/metabolismo , Transfección , Zinc/metabolismo
20.
Plant Methods ; 19(1): 17, 2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-36843020

RESUMEN

BACKGROUND: Plant shape and structure are important factors in peanut breeding research. Constructing a three-dimension (3D) model can provide an effective digital tool for comprehensive and quantitative analysis of peanut plant structure. Fast and accurate are always the goals of the plant 3D model reconstruction research. RESULTS: We proposed a 3D reconstruction method based on dual RGB-D cameras for the peanut plant 3D model quickly and accurately. The two Kinect v2 were mirror symmetry placed on both sides of the peanut plant, and the point cloud data obtained were filtered twice to remove noise interference. After rotation and translation based on the corresponding geometric relationship, the point cloud acquired by the two Kinect v2 was converted to the same coordinate system and spliced into the 3D structure of the peanut plant. The experiment was conducted at various growth stages based on twenty potted peanuts. The plant traits' height, width, length, and volume were calculated through the reconstructed 3D models, and manual measurement was also carried out during the experiment processing. The accuracy of the 3D model was evaluated through a synthetic coefficient, which was generated by calculating the average accuracy of the four traits. The test result showed that the average accuracy of the reconstructed peanut plant 3D model by this method is 93.42%. A comparative experiment with the iterative closest point (ICP) algorithm, a widely used 3D modeling algorithm, was additionally implemented to test the rapidity of this method. The test result shows that the proposed method is 2.54 times faster with approximated accuracy compared to the ICP method. CONCLUSIONS: The reconstruction method for the 3D model of the peanut plant described in this paper is capable of rapidly and accurately establishing a 3D model of the peanut plant while also meeting the modeling requirements for other species' breeding processes. This study offers a potential tool to further explore the 3D model for improving traits and agronomic qualities of plants.

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