Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
1.
Aging (Albany NY) ; 16(13): 10765-10783, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38985127

RESUMO

The calcitonin receptor (CALCR) is an essential protein for maintaining calcium homeostasis and has been reported to be upregulated in numerous cancers. However, the molecular role of CALCR in renal cell carcinoma (RCC) is not well understood. In this study, we identified the overexpression of CALCR in RCC using human tissue chip by immunohistochemical (IHC) staining, which was associated with a poor prognosis. Functionally, CALCR depletion inhibited RCC cell proliferation and migration, and induced cell apoptosis and cycle arrest. CALCR is also essential for in vivo tumor formation. Mechanistically, we demonstrated that CALCR could directly bind to CD44, preventing CD44 protein degradation and thereby upregulating CD44 expression. Moreover, a deficiency in CD44 significantly attenuated the promoting role of CALCR on RCC cell proliferation, migration and anti-apoptosis capacities. Collectively, CALCR exacerbates RCC progression via stabilizing CD44, offering a fundamental basis for considering CALCR as a potential therapeutic target for RCC patients.


Assuntos
Apoptose , Carcinoma de Células Renais , Proliferação de Células , Progressão da Doença , Receptores de Hialuronatos , Neoplasias Renais , Humanos , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/genética , Receptores de Hialuronatos/metabolismo , Receptores de Hialuronatos/genética , Neoplasias Renais/patologia , Neoplasias Renais/metabolismo , Neoplasias Renais/genética , Linhagem Celular Tumoral , Animais , Movimento Celular , Camundongos , Masculino , Regulação Neoplásica da Expressão Gênica , Feminino
2.
Heliyon ; 10(13): e34144, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39071693

RESUMO

Carbon fiber reinforced composite structures have been a research hotspot in recent years, with 9 specimens designed for static tests under bending and torsion loads of CFRP concrete filled steel tubes. The torque angle (T-θ) curve was studied from an experimental perspective. Subsequently, a reasonable finite element model was established using ABAQUS software. In addition, the effects of changes in parameters such as the number of steel concrete strength, bending ratio, and steel ratio on C-CF-CFRP-ST bending and torsion specimens were studied through numerical parameter research. Finally, equations of bearing capacity of CFRP-concrete filled steel tube under coupled bending and torsion are proposed.

3.
Materials (Basel) ; 17(12)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38930264

RESUMO

In order to study the bending-shear performance of CFRP concrete-filled steel tubes, static tests were conducted on 15 circular concrete-filled CFRP steel tube bending-shear specimens. For all specimens, Ds was 120 mm, ts was 2 mm, and ml was 1. The shear displacement (V-Δ) curve of the specimen and the collaborative work between the steel tube and CFRP are discussed. ABAQUS was applied to simulate the V-Δ curve and failure mode of the specimen. We explored the effects of CFRP layers, material strength, the steel ratio, and the shear span ratio on the bending-shear performance of components. The experimental results show that a steel tube and CFRP can work together. As the shear span ratio increased, the bearing capacity and stiffness of the specimen decreased. An increase in the number of transverse CFRP layers could improve the bearing capacity of the specimen, but it had no significant effect on the stiffness. Calculating the elastic stage stiffness and bearing capacity of 15 short columns of test and FE curves revealed an average error of 6.71% and a mean square error of 0.83 for the elastic stage stiffness. The simulation results of the established finite element model are in good agreement with the experimental results. The average error of the bearing capacity was 3.88%, with a mean square error of 0.94. Based on experimental and finite element results, the moment shear correlation equation for concrete-filled CFRP steel tube bending-shear members is presented.

4.
Ying Yong Sheng Tai Xue Bao ; 34(6): 1541-1546, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37694416

RESUMO

The development of precise climate risk zoning for chilling injury of Morchella esculenta can provide scientific basis for agricultural cultivation planning, dynamic assessment of chilling injury, and disaster prevention strategies. Based on meteorological data from 17 counties (cities) that located below the altitude of 3000 m in the Western Sichuan Plateau from 2011 to 2020, we analyzed the critical meteorological conditions for M. esculenta disasters in typical years. With the average yearly cold accumulation and cold injury frequency during the first day when the temperature remained stable between 5 ℃ and 10 ℃ during mushroom emergence as zoning indicators, we established a geographical spatial distribution model of the cold injury index, and then divided the risk level of M. esculenta cold injury in the Western Sichuan Plateau, evaluated the risk of cold injury. The results showed that the temperature index for chilling injury risk of M. esculenta in the study area was the daily minimum temperature ≤2.0 ℃. The daily average temperature <6.0 ℃ would cause slow growth or the cessation of growth, which was set as a warning indicator for chilling injury risk. Along the Dadu River and Minjiang River basins, the frequency of chilling injury on M. esculenta increased from south to north. Wenchuan, Maoxian, and Lixian had the fewest overall chilling injuries during the study period, whereas Jiulong, Yajiang, and Batang had the most. The duration for cold injury was mainly 1-3 d, followed by 4-5 d, and rarely for >5 d. The frequency of chilling injury lasting for more than 5 d in Xiangcheng, Batang, Jiulong, Yajiang, and Xiaojin was more than that lasting for 4-5 d. The annual average days of chilling injury of was 3.0-27.4 d, the daily average minimum temperature was -0.84-1.36 ℃, the extreme lowest temperature was -5.8-0.1 ℃, and the average accumulated cold was 0.16-9.64 ℃·d during the period of chilling injury. With the increases of elevation and latitude, the average days of chilling injury and the average accumulated cold increased. The largest duration of chilling injury was 3-20 d, the maximum accumulated cold was 0.44-13.34 ℃·d. The risk of chilling injury to M. esculenta increased from south to north and from low elevation to high elevation. The suitable planting areas were distributed in strips and branches along the direction of mountains and rivers, mainly in the flat areas of low mountains and valleys below the altitude of 2200 m, including Kangding, Luding, Danba, Wenchuan, Lixian, Maoxian, Jiuzhaigou, and Songpan.


Assuntos
Lesão por Frio , Temperatura Baixa , Humanos , China , Medição de Risco
5.
Angew Chem Int Ed Engl ; 62(33): e202305817, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37345904

RESUMO

Photocatalytic water splitting is a promising approach to generating sustainable hydrogen. However, the transport of photoelectrons to the catalyst sites, usually within ps-to-ns timescales, is much faster than proton delivery (∼µs), which limits the activity. Therefore, the acceleration of abstraction of protons from water molecules towards the catalytic sites to keep up with the electron transfer rate can significantly promote hydrogen production. The photobasic effect that is the increase in proton affinity upon excitation offers means to achieve this objective. Herein, we design photobasic carbon dots and identify that internal pyridinic N sites are intrinsically photobasic. This is supported by steady-state and ultrafast spectroscopic measurements that demonstrate proton abstraction within a few picoseconds of excitation. Furthermore, we show that in water, they form a unique four-level lasing scheme with optical gain and stimulated emission. The latter competes with photocatalysis, revealing a rather unique mechanism for efficiency loss, such that the stimulated emission can act as a toggle for photocatalytic activity. This provides additional means of controlling the photocatalytic process and helps the rational design of photocatalytic materials.

6.
Nat Commun ; 14(1): 357, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36690612

RESUMO

Electricity-driven asymmetric catalysis is an emerging powerful tool in organic synthesis. However, asymmetric induction so far has mainly relied on forming strong bonds with a chiral catalyst. Asymmetry induced by weak interactions with a chiral catalyst in an electrochemical medium remains challenging due to compatibility issues related to solvent polarity, electrolyte interference, etc. Enabled by a properly designed phase-transfer strategy, here we have achieved two efficient electricity-driven catalytic asymmetric bromocyclization processes induced by weak ion-pairing interaction. The combined use of a phase-transfer catalyst and a chiral phosphate catalyst, together with NaBr as the bromine source, constitutes the key advantages over the conventional chemical oxidation approach. Synergy over multiple events, including anodic oxidation, ion exchange, phase transfer, asymmetric bromination, and inhibition of Br2 decomposition by NaHCO3, proved critical to the success.


Assuntos
Fosfatos , Estrutura Molecular , Ânions/química , Oxirredução , Catálise
7.
Materials (Basel) ; 15(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36500115

RESUMO

The connection method of lengthening the steel tube of concrete filled circular steel tubes by inner lining tube and threaded connection is proposed. Taking the length, depth, and position of the thread as the basic parameters, 12 concrete filled circular steel tubes connected by thread through inner lining tube were designed and manufactured, and an axial compressive test was carried out. The axial compressive loading-longitudinal compressive displacement curves, axial compressive loading-strain of steel tube curves, and failure mode of the specimens were analyzed, and the effects of different parameters on the axial compressive bearing capacity and stiffness of the specimens were studied. The results show that the axial compressive loading-longitudinal compressive displacement curves of the specimen can be divided into the elastic stage, elasto-plastic stage, and plastic reinforcement stage in the range of parameters studied in this paper. The bearing capacity and stiffness of the specimens connected by thread through inner lining tube are no worse than those of the unconnected specimen or the specimen connected by weld. Bearing capacity and stiffness of the specimen increase with the increase of thread length. The calculation method of the axial compressive bearing capacity of concrete filled circular steel tubes connected by thread through inner lining tube are suggested.

8.
Perfusion ; : 2676591221131485, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36342821

RESUMO

Fine particulate matter <2.5 µm in diameter (PM2.5) has been validated to associate with cardiovascular diseases (CVD) incidence and mortality. So far, no study has quantitatively evaluated the relationship between the atmospheric PM2.5 exposure and ischemic heart disease (IHD). We conducted a meta-analysis to illustrate the relationship between PM2.5 and IHD. Published articles were systematically searched (until June 2022) from PubMed, EMBASE, Cochrane Library. A random-effect model was performed to summarize the total relative risks (RRs) and 95% confidence intervals (CIs). Meta-analysis was performed using Stata 12.0 software. A total of 28 studies among 23 cohorts (23.38 million individuals and 256256 IHD cases) were included. With PM2.5 increasing 10 µg/m3, the total RRs of IHD incidence and mortality were 1.07 (95% CI: 0.99-1.17), 1.21 (95% CI: 1.15-1.28), respectively. In sub-analyses, our study revealed that the combined RRs of exposure to PM2.5 on IHD mortality in Asian and European population [1.11 (95% CI: 0.93-1.33); 1.06 (95% CI: 1.02-1.11)] were much lower compared with American and Canadian people [1.27 (95% CI: 1.17-1.37); 1.30 (95% CI: 1.24-1.35)]. Furthermore, study duration, size and some adjustments were related with the total RR. Our findings indicated that exposure of an increase in the concentration of atmospheric PM2.5 may increase the risk of IHD incidence and mortality. Further evidence is needed to confirmed the association.

9.
Polymers (Basel) ; 14(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36015607

RESUMO

Concrete-filled CFRP steel tube (CF-CFRP-ST) structures often suffer from shear loading in practical engineering, such as joints with diagonal braces. To study the shear properties of CF-CFRP-ST, we take the concrete strength and the longitudinal CFRP layers as the main parameters, and static shear tests of overall 9 circular concrete-filled CFRP-steel tube (C-CF-CFRP-ST) and 3 circular concrete-filled steel tube (C-CFST) are carried out. The research is carried out from two aspects: experiment and finite element. The experimental results show that the shear loading-displacement curves of the specimens can be divided into elastic stage, strengthening stage, and softening stage. The increases of the strength of the concrete and the layers of the transverse CFRP can both enhance the shearing load carrying capacity of the specimen. With the increase of concrete strength, there is no obvious change in the shape of the shear stress-shear strain curves of the specimens, and the shear stress and the stiffness of the curve in the elastic stage of the specimen are slightly increased. The shear loading-displacement curves of the specimens are simulated by using finite element software ABAQUS and it is found that the predicted results agree reasonably well with the test results. Then, the whole process of loading and the parameters of the main influencing factors are analyzed. Finally, the calculation equation of CFRP concrete-filled steel tubular shear capacity is established.

10.
Front Bioeng Biotechnol ; 10: 926253, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35957639

RESUMO

Polar bears can live in an extremely cold environment due to their hairs which possess some remarkable properties. The hollow structure of the hair enables the bear to absorb energy from water, and the white and transparent hairs possess amazing optical properties. However, the surface morphology function of bear hairs has been little-studied. Herein, we demonstrate that the micro-structured scales distributed periodically along the hair can absorb maximal radiative flux from the Sun. This polar bear hair effect has the ability for the hair surface not to reflect radiation with a wavelength of about 500 nm. Mimicking the polar bears' solar performance in the fabrication of nanofibers will certainly stimulate intelligent nanomaterials for efficient solar energy absorption. Therefore, a new technology is discussed in this work for the fabrication of periodic unsmooth nanofibers toward solar energy harvesting.

11.
Polymers (Basel) ; 14(7)2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35406346

RESUMO

To study the behavior of square concrete-filled CFRP (carbon fiber polymer) steel tubular under bending-torsional load, nine square section concrete-filled CFRP steel tubular specimens are designed. The T-θ curve and failure mode of square concrete-filled CFRP steel tubular are studied under a bending-torsional load. Based on the test results, a finite element modeling method is proposed by using the finite element software ABAQUS, and the simulation results are compared with the experimental results. The results show that the simulation is in good agreement with the experimental results. On the basis of verifying the reliability of the model, the whole stress process and parameter analysis of the component are studied, and the calculation expression of bearing capacity of square concrete-filled CFRP steel tubular under bending-torsion load is proposed. The predicted specimen-bearing capacity of the proposed calculation expression of the bearing capacity of square concrete-filled CFRP steel tubular under bending-torsion load is basically consistent with the test results.

12.
Zhongguo Zhong Yao Za Zhi ; 47(23): 6529-6532, 2022 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-36604900

RESUMO

According to Provisions for Drug Registration and Categories and Requirements of Application Dossiers for Traditional Chinese Medicine(TCM), non-clinical safety research/toxicology research should be conducted for classical compound Chinese medicine prescriptions(Categories 3.1 and 3.2), and the data should be submitted at the application for the marketing authorization. Based on the requirements of toxicology research in Categories and Requirements of Application Dossiers for Traditional Chinese Medicine, this study further refined and clarified the requirements of toxicology research on classical compound Chinese medicine preparations(Categories 3.1 and 3.2).


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Medicamentos de Ervas Chinesas/toxicidade , Prescrições , Prescrições de Medicamentos
13.
J Colloid Interface Sci ; 606(Pt 2): 1087-1100, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34507164

RESUMO

Photoreduction of CO2 to useful ingredients remains a great challenge due to the high energy barrier of CO2 activation and poor product selectivity. Herein, Polyvinyl pyrrolidone (PVP) coordinated BiOBr was synthesized by a facile chemical precipitation method at room temperature. The CO2 photoreduction behaviors of PVP coordinated BiOBr were evaluated with H2O without sacrificial agent under the simulated sunlight. The evolution rates of CO and CH4 are 263.2 µmol g-1h-1 and 3.3 µmol g-1h-1, which are 8 times and 2 times higher than those of pure BiOBr respectively. Furthermore, the coordination of PVP on BiOBr surface enhances greatly the selectivity of product CO, which is close to 100%. Loading PVP onto BiOBr could not only induce and stabilize the oxygen vacancy, but also increase the charge density of BiOBr via the ligand to metal charge transfer (LMCT), which could be beneficial to the adsorption and activation of CO2 molecule. The photoreduction mechanism of CO2 for PVP coordinated BiOBr was proposed based on the improved charge density of BiOBr by the experimental results and Density functional theory (DFT) calculations. This finding provides a new pathway to boost the conversion efficiency and selectivity for the activation of CO2 photoreduction and new molecule insights into the role of PVP in photocatalysis.

14.
J Vis ; 21(10): 11, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34520509

RESUMO

There is a cross-modal mapping between auditory pitch and many visual properties, but the relationship between auditory pitch and motion speed is unexplored. In this article, the ball and baffle are used as the research objects, and an object collision experiment is used to explore the perceptual influence of auditory pitch on motion speed. Since cross-modal mapping can influence perceptual experience, this article also explores the influence of auditory pitch on action measures. In Experiment 1, 12 participants attempted to release a baffle to block a falling ball on the basis of speed judgment, and after each trial, they were asked to rate the speed of the ball. The speed score and baffle release time were recorded and used for analysis of variance. Since making explicit judgments about speed can alter the processing of visual paths, another group of participants in Experiment 2 completed the experiment without making explicit judgments about speed. Our results show that there is a cross-modal mapping between auditory pitch and motion speed, and high or low tones cause perception shift to faster or slower speeds.


Assuntos
Percepção de Movimento , Percepção da Altura Sonora , Estimulação Acústica , Percepção Auditiva , Humanos , Julgamento , Movimento (Física)
15.
Mutagenesis ; 36(6): 401-406, 2021 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-34516639

RESUMO

The repeated-dose liver micronucleus (RDLMN) assay is a novel method for detecting genotoxic chemicals. Two carcinogens methyl carbamate (MC) and 1,3-propane sultone (PS) were evaluated for the liver micronucleus in a 14-day repeated-dose study with Crl: CD (SD) IGS rats. Additionally, micronucleated reticulocytes (MN-RET) in peripheral blood and DNA damage (alkaline comet assay) in the liver were also assessed in the same animals. Ten groups of five male Crl: CD (SD) IGS rats were treated once daily with MC (300, 600 or 1200 mg/kg/day), PS (37.5, 75 or 150 mg/kg/day), negative control or three positive controls by oral gavage for 15 days. Blood samples were collected at 3 h after the last administration for determining MN-RET frequencies (%MN-RET), and the livers were sampled for determining the frequency of micronuclei and DNA damage. MC was negative in the comet assay, liver micronucleus assay and reticulocyte micronucleus assay, while PS was positive in all three assays. These results are consistent with the previous genotoxic findings of MC and PS. Therefore, the liver micronucleus assay can be effectively integrated into repeated-dose studies in animals. Moreover, integration of multiple genotoxicity end points into one study can reduce the number of animals, boost the experimental efficiency, and provides a comprehensive evaluation of the genotoxic potential of chemicals.


Assuntos
Carbamatos/toxicidade , Núcleo Celular/efeitos dos fármacos , Fígado/efeitos dos fármacos , Reticulócitos/efeitos dos fármacos , Tiofenos/toxicidade , Animais , Carcinógenos/toxicidade , Aberrações Cromossômicas , Ensaio Cometa/métodos , Dano ao DNA , Relação Dose-Resposta a Droga , Esquema de Medicação , Masculino , Testes para Micronúcleos/métodos , Ratos , Ratos Sprague-Dawley
16.
Ying Yong Sheng Tai Xue Bao ; 32(7): 2525-2533, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34313071

RESUMO

Based on the distribution data of Tricholoma matsutake obtained from field investigation and literature, the ecological-niche factor analysis (ENFA) and the maximum entropy model (MaxEnt) were used to simulate the distribution law and suitable area of T. matsutake in the western Sichuan Plateau. The prediction was made for the future changes in the suitable area of T. matsutake by analyzing the relationship between climate factors and dynamic distribution. The results showed that the area under curve (AUC) values of both the model training set and validation set were greater than 0.90, indicating that the model prediction results were extremely accurate. The environmental variables affecting the potential distribution of T. matsutake were mainly the lowest temperature in the coldest month, the coldest season precipitation, annual temperature difference and soil type, with accumulative contribution of 90.3%. The niche parameters of suitable distribution areas of T. matsutake were as follows: the lowest temperature in the coldest month was -18.5--5.4 ℃, the coldest season precipitation was less than 15.7 mm, the annual temperature difference was 39.5-45 ℃, and soil type was semi-leached soil, including dry red soil, cinnamon soil, gray cinnamon soil, black soil and grey forest soil. The suitable areas of T. matsutake were distributed in the southwest, south, central and east of the plateau at an altitude range of 1900-3600 m. The highly suita-ble areas were mainly distributed in some towns of Yajiang, Xiangcheng, Kangding, Jiulong, Daocheng, Litang, Batang, Danba, Maerkang, Xiaojin, Jinchuan, Lixian, Maoxian, etc. The moderately and lowly suitable areas were located in some towns of Derong, Daofu, Xinlong, Luhuo, Baiyu, Luding, Rangtang, Wenchuan, Heishui, Jiuzhaigou. The highly suitable areas were discontinuously distributed according to the direction of rivers and mountains. The moderately suitable areas were connected with the highly suitable areas, while the lowly suitable areas were the extension of the highly and moderately suitable areas. Future climate change would be beneficial to the growth of T. matsutake on the western Sichuan Plateau, while the climate-suitable areas would show an overall increasing trend. Suitable areas in the low-altitude Minjiang River Basin would be more affected by climate change than those located in high-altitude areas.


Assuntos
Tricholoma , Agaricales , China , Mudança Climática , Ecossistema
18.
Bosn J Basic Med Sci ; 21(1): 81-92, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32343942

RESUMO

MiR-145 is reported to facilitate inflammation and is also associated with unsuccessful embryonic implantation. Whether miR-145 mediates inflammatory response underlying hydrosalpinx-induced defective endometrial receptivity (ER) remains unclear, and this study attempted to clarify this point. Endometrium samples were collected from hydrosalpinx patients (case, n = 243) and patients with tubal patency/obstruction (control, n = 187). The peripheral blood samples of cases and controls were collected to determine the genotypes of miR-145 SNPs. The value of miR-145 expression in the diagnosis and prognostic estimation of hydrosalpinx was assessed using ROC curve and regression analysis, respectively. Lipopolysaccharide (LPS) cell model was established with endometrial cells, and cells were transfected with miR-145 mimic, inhibitor, or negative control. MiR-145 and cytokine levels were quantified by quantitative reverse transcription PCR or western blot. MiR-145 expression was significantly higher in hydrosalpinx compared to control group, and high miR-145 expression was significantly associated with moderate/severe tube lesion, high pulsatility index (>1.06), and high resistance index (>0.61) in hydrosalpinx patients. ROC curve analysis indicated that monitoring miR-145 expression may be useful for the diagnosis of hydrosalpinx (AUC = 0.704). A alleles of rs41291957 (G>A) and rs353292 (G>A) were significantly associated with an increased risk of hydrosalpinx compared to G allele (p < 0.05), yet the mutant allele of rs353291 (A>G) and rs4705343 (T>C) significantly reduced susceptibility to hydrosalpinx compared to the wild type allele. Treatments with miR-145 mimic and LPS in endometrial cells significantly increased the levels of transforming growth factor-ß1, tumor necrosis factor -α, interleukin (IL)-6, and IL-8 compared to negative control, while treatment with miR-145 inhibitor decreased the cytokine levels. In conclusion, abnormally expressed miR-145 may be involved in hydrosalpinx-induced ER defects by regulating the inflammatory response.


Assuntos
Endométrio/metabolismo , Endométrio/patologia , Doenças das Tubas Uterinas/genética , MicroRNAs/genética , Adulto , Biomarcadores/metabolismo , Células Cultivadas , Diagnóstico Diferencial , Endométrio/citologia , Doenças das Tubas Uterinas/diagnóstico , Feminino , Genótipo , Haplótipos , Humanos , Polimorfismo de Nucleotídeo Único , Prognóstico
19.
J Pharm Biomed Anal ; 180: 113041, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31855724

RESUMO

Gastric cancer (GC) is the third most common cause of cancer death worldwide, and the incidence of GC is higher in males than females. To investigate the gastric cellular response to hormone therapy, we developed a cell pseudotargeted metabolomics method based on liquid chromatography-hybrid triple quadrupole linear ion trap mass spectrometry (LC-QTRAP MS). Chromatographic separation, sample analysis and metabolite extraction were optimized in an integrated manner. The established pseudotargeted method, which combined nontargeted and targeted analyses, exhibited high selectivity, good repeatability and wide metabolome coverage. The method was then applied to discover differential metabolites from hormone-stimulated gastric cancer cells compared with the controls for the first time. The results demonstrated that hormone had subtle but phenotypically important alterations in nucleotide metabolism, amino acid metabolism, glycolysis, tricarboxylic acid (TCA) cycle, aminoacyl-tRNA biosynthesis and so on, which indicate that the developed method is a powerful tool for effective screening of endogenous polar metabolites in cell samples.


Assuntos
Hormônios/metabolismo , Metabolômica/métodos , Neoplasias Gástricas/metabolismo , Espectrometria de Massas em Tandem/métodos , Aminoácidos/análise , Aminoácidos/metabolismo , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Ciclo do Ácido Cítrico/efeitos dos fármacos , Di-Hidrotestosterona/metabolismo , Estradiol/metabolismo , Glicólise/efeitos dos fármacos , Humanos , Nucleotídeos/análise , Nucleotídeos/metabolismo , RNA de Transferência/análise , RNA de Transferência/biossíntese
20.
Artigo em Inglês | MEDLINE | ID: mdl-31677481

RESUMO

Amino acids play key roles in cellular protein biosynthesis and energy metabolism pathways. In this study, a simple, rapid and sensitive method was developed for the simultaneous determination of 24 free amino acids in cell samples using hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS/MS). Cell samples were deproteinized with methanol/H2O (80:20, v/v) without intricate derivatization process. The analytes were separated on a Waters BEH Amide column (2.1 mm × 100 mm, 1.7 µm), and accomplished within 5 min at a flow rate of 0.2 mL/min. The good linearity was obtained for all analytes (r2 > 0.99) with the limits of quantification from 0.1 to 25 ng/mL. The intra- and inter-day precision ranged from 0.35 to 10.36% and from 2.22 to 9.93%, respectively. The recoveries of most analytes were between 80% and 120% with RSD less than 10.0%. The developed method was then applied to the direct analysis of 24 underivatized amino acids in human gastric cancer cell line MGC803 treated with the antitumor candidate drug J3, and significant differences in the concentration levels of amino acids were also assessed.


Assuntos
Aminoácidos/análise , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Linhagem Celular Tumoral , Humanos , Interações Hidrofóbicas e Hidrofílicas , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA