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1.
Wei Sheng Yan Jiu ; 50(5): 805-813, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34749876

RESUMO

OBJECTIVE: To establish a method for determination of the common and emerging halogenated carboxylic acids(HCAs) in drinking water by ion chromatography(IC) and quadrupole-orbitrap(Q-Orbitrap) high resolution mass spectrometry(HRMS) combined the traditional quantitative detection with semi-target analysis. METHODS: Effects on the type of chromatographic column, the composition of mobile phase, the flow rate of acetonitrile added post column, the column temperature, and the injection volume were studied in detail for IC-HRMS method, also for HRMS conditions. Drinking water sample was directly injected into IC-HRMS for analysis after filtration. The chromatography separation was performed on an AS21 anion exchange chromatography column(2 mm×250 mm) with the gradient elution using 800 mmol/L methylamine-water as mobile phase, and acetonitrile was added after column. The detection was conducted on HRMS with the electrospray ionization negative mode. And the quantitative analysis of 8 haloacetic acids(HAAs) and semi-target screening of 19 HCAs were achieved by full MS/dd-MS~2 mode. RESULTS: Good linearity(r>0.996) was obtained for each of 8 HAAs for IC-HRMS. The method detection limits(MDLs) and method quantification limits(MQLs) were in the range of 0.50-2.5 µg/L and 1.7-8.3 µg/L, respectively. Intra-and inter-day relative standard deviations(RSDs) were in the range of 1.50%-11.0% and 4.58%-10.9%, respectively. The recoveries were in the range of 61.3%-117%(n=6). The proposed method was applied to analyze 39 drinking water samples, and dichloroacetic acid and trichloroacetic acid were detected and quantified, with concentrations ranging from 1.35 to 48.0 µg/L. Besides, five HCAs(difluoroacetic acid, trifluoroacetic acid, bromochloroacetic acid, monochloropropionic acid and dichloropropionic acid) were preliminary identified with semi-target screening method. CONCLUSION: The developed method was simple, rapid, no sample preparation except filtration and low reagent cosumption, which could meet the need of drinking water monitoring and achieve comprehensive screening of HCAs in drinking water. In addition, full MS/dd-MS~2 data acquisition mode could provide retrospective analysis of existing data by adding the emerging or interesting HCAs into the screening compound database.


Assuntos
Água Potável , Ácidos Carboxílicos/análise , Cromatografia Líquida de Alta Pressão , Estudos Retrospectivos , Espectrometria de Massas em Tandem
2.
Eur J Med Chem ; 226: 113864, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34626877

RESUMO

Pathogenic bacteria use an intercellular chemical communication system called quorum sensing (QS) to control the expression of cellular functions such as virulence factors, biofilm formation, toxin production, and antibiotic resistance in a manner that is highly dependent on population density. Hence, since the emergence of QS, there has been a great interest in exploiting the QS mechanism as a new drug target. Therefore, blocking the QS mechanism can be an effective strategy to control infection and solve the problem of drug resistance. So far, there is no clinically approved anti-QS drug that can disable the circuits of QS systems. This review discusses the quorum-sensing network systems and novel anti-QS inhibitors in some Gram-negative bacteria.

3.
J Cancer ; 12(13): 4039-4048, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093808

RESUMO

Hepatocellular carcinoma (HCC) is one of the most common malignancies globally and the second leading cause of cancer-related death. Low-density lipoprotein (LDL) receptor-related protein 1B (LRP1B) is one of the commonly mutated genes in HCC, but its role in HCC remains unclear. In this study, we analyzed the role of LRP1B mutation in HCC. The bioinformatics results show that LRP1B had a frequency of mutation in HCC patients, and LRP1B mutation was associated with a higher tumor mutation burden (TMB), and survival analysis proved that the prognosis of HCC patients with LRP1B mutation was poor. Univariate and multivariate COX regression analysis indicated that LRP1B mutation was an independent risk factor in evaluating HCC patients' prognosis. Correlation analysis showed that LRP1B mutation status was associated with the infiltration of 2 types of immune cells and higher expression of immune checkpoint gene human endogenous retrovirus-H long terminal repeat-associating protein 2 (HHLA2) in HCC patients. In summary, the results show that LRP1B mutation is associated with the higher TMB and poor prognosis of patients with HCC, and it was an independent risk factor for clinical outcomes of HCC patients. LRP1B gene mutations can serve as predictors in HCC patients with higher TMB and higher expression of HHLA2. The results of this study will be beneficial to future studies on targeted therapy and immunotherapy for HCC.

4.
Mol Ther Nucleic Acids ; 25: 37-52, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34168917

RESUMO

Hepatocellular carcinoma (HCC) belongs to the most frequent cancer with a high death rate worldwide. Thousands of long non-coding RNAs (lncRNAs) have been confirmed to influence the development of human cancers, including HCC. Nevertheless, the biological role of PRR34 antisense RNA 1 (PRR34-AS1) in HCC remains obscure. Here, we observed via quantitative real-time reverse transcriptase polymerase chain reaction (quantitative real-time RT-PCR) that PRR34-AS1 was highly expressed in HCC cells. Functional assays revealed that PRR34-AS1 promoted HCC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) process in vitro and facilitated tumor growth in vivo. In addition, western blot analysis and TOP Flash/FOP Flash reporter assays verified that PRR34-AS1 stimulated Wnt/ß-catenin pathway in HCC cells. Furthermore, RNA immunoprecipitation (RIP), RNA pull-down, and luciferase reporter assays uncovered that PRR34-AS1 sequestered microRNA-296-5p (miR-296-5p) to positively modulate E2F transcription factor 2 (E2F2) and SRY-box transcription factor 12 (SOX12) in HCC cells. Importantly, chromatin immunoprecipitation (ChIP) and luciferase reporter assays uncovered that E2F2 transcriptionally activated PRR34-AS1 in turn. Further, rescue experiments reflected that PRR34-AS1 affected HCC progression through targeting miR-296-5p/E2F2/SOX12/Wnt/ß-catenin axis. Our findings found that PRR34-AS1 elicited oncogenic functions in HCC, which indicated that PRR34-AS1 might be a novel therapeutic target for HCC.

5.
Aging (Albany NY) ; 13(8): 12207-12223, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33952719

RESUMO

In this study, we determined the involvement of SOX2 and its downstream signaling molecules in hepatocellular carcinoma (HCC) progression. We carried out lentiviral transfection in HepG2 cells to determine the roles of SOX2, CCAT1, EGFR, miR-222-5p, and CYLD in HepG2 cells. We first determined the interaction between SOX2 and CCAT1 and that between miR-222-5p and CYLD and their effect on tumor growth in vivo was analyzed in HCC-xenograft bearing nude mice xenografts. SOX2 and CCAT1 were highly expressed in HCC tissues and HepG2 cells. SOX2 bound to the regulatory site of CCAT1. Silencing of SOX2 or CCAT1 inhibited HepG2 cell proliferation, migration, and invasion as well as decreased the expression of CCAT1 and EGFR. CCAT1 silencing reduced EGFR expression, but EGFR expression was increased in HCC tissues and HepG2 cells, which promoted proliferation, migration, and invasion in vitro. EGFR upregulated miR-222-5p, leading to downregulation of CYLD. miR-222-5p inhibition or CYLD overexpression repressed cell functions in HepG2 cells. SOX2 silencing decreased CCAT1, EGFR, and miR-222-5p expression but increased CYLD expression. Loss of SOX2 also reduced the growth rate of tumor xenografts. In summary, SOX2-mediated HCC progression through an axis involving CCAT1, EGFR, and miR-222-5p upregulation and CYLD downregulation.


Assuntos
Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , RNA Longo não Codificante/genética , Fatores de Transcrição SOXB1/metabolismo , Adulto , Idoso , Animais , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Estudos de Casos e Controles , Movimento Celular/genética , Proliferação de Células/genética , Enzima Desubiquitinante CYLD/genética , Progressão da Doença , Regulação para Baixo , Receptores ErbB/genética , Feminino , Técnicas de Silenciamento de Genes , Voluntários Saudáveis , Células Hep G2 , Hepatectomia , Humanos , Fígado/patologia , Fígado/cirurgia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , Camundongos , MicroRNAs/metabolismo , Pessoa de Meia-Idade , RNA Longo não Codificante/metabolismo , Fatores de Transcrição SOXB1/genética , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Anticancer Agents Med Chem ; 21(7): 811-824, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32329698

RESUMO

BACKGROUND: Isoquinoline analogs are an important, structurally diverse class of compounds that are extensively used as pharmaceuticals. Derivatives containing the isoquinoline scaffold have become a focus of therapeutic research because of their wide range of biological characteristics. Examples of these drugs, many of which are in clinical application or at the pre-clinical stage, are used to treat a broad swathe of ailments, such as tumors, respiratory diseases, infections, nervous system diseases, cardiovascular and cerebrovascular diseases, endocrine and metabolic diseases. METHODS: Data were collected from PubMed, Web of Science, and SciFinder, through searches of drug names. RESULTS: At least 38 isoquinoline-based therapeutic drugs are in clinical application or clinical trials, and their chemical structure and pharmacokinetics are described in detail. CONCLUSION: The isoquinoline ring is a privileged scaffold which is often preferred as a structural basis for drug design, and plays an important role in drug discovery. This review provides a guide for pharmacologists to find effective preclinical/clinical drugs and examines recent progress in the application of the isoquinoline scaffold.

7.
J Cancer ; 12(24): 7507-7517, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35003370

RESUMO

Background: LINC02560 is a new 477 bp long non-coding RNA located in 19q13.43. However, the expression of LINC02560 in colorectal cancer (CRC) has not been reported, and its correlation with tumor development and function is still unclear. Methods: The expression of LINC02560 in CRC was first analyzed in the cancer genome atlas (TCGA) combined with The Genotype-Tissue Expression(GTEx) databases and then validated by clinical CRC samples and cell lines. The association between LINC02560 expression and clinicopathologic variables was analyzed by the Wilcoxon Rank SUM test. Cox regression analysis and Kaplan-Meier plots were used to assess the prognostic value of LINC02560 in CRC. The correlation between the expression level of LINC02560 and the 24 immune cells in tumor microenvironment (TME) was analyzed by single sample gene set enrichment analysis (ssGSEA). Gene set enrichment analysis (GSEA) was conducted to detect potential biological processes associated with LINC02560 in CRC. Results: LINC02560 was significantly up-regulated in CRC in comparison to normal samples. There are significant differences in the expression of LINC02560 in different subgroups of N stage, M stage, carcinoembryonic antigen (CEA) level, residual tumor, TP53 status and pathological stage. The high LINC02560 expression indicated poor overall survival (OS) and progress free interval (PFI) in patients with CRC. Moreover, the multivariate Cox analysis demonstrated that the expression of LINC02560 was an independent prognosis-predicting factor for OS in CRC patients. GSEA indicated that high expression of LINC02560 was involved in MAPK, Wnt, and PPAR signaling pathways and participated in humoral immune processes. We also identified that LINC02560 expression had a negative correlation with 4 kinds of immune cells. Conclusions: In summary, our research results indicate that LINC02560 may be a potential prognostic biomarker. It is involved in the occurrence and development of CRC and may affect the prognosis of CRC patients by regulating immune cells in the TME.

8.
BMC Endocr Disord ; 20(1): 74, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460870

RESUMO

BACKGROUND: Radioisotope scanning is important to diagnose subacute thyroiditis (SAT), but it's not always available. So we aim to establish a diagnostic scale for SAT without radioisotope scanning. METHODS: The suspected SAT patients hospitalized in Yuebei people's Hospital from January 2012 to December 2016 were selected and divided into study group and control group according to whether they were diagnosed as SAT. The clinical indexes of two groups were collected and the diagnostic scale of SAT was established by using binary logistic regression analysis. The effectiveness of the scale was evaluated by ROC curve. RESULTS: Of 309 patients, 58.25% of patients were confirmed with SAT and the remaining 41.75% of patients were not diagnosed with SAT. After univariate analysis, variables which were considered statistically different(P < 0. 05) between the two groups were selected as independent variables and the diagnosis of SAT was taken as dependent variable in the binary logistic regression model. The logistic regression model consisted of 4 variables, each was thyroid tenderness, firm on palpation, increased ESR and elevated thyroid hormone level. The P value of Omnibus tests was≤0. 001 and the Nagelkerke R Square was 0. 915. The diagnostic scoring scale was established with these four variables according to their regression coefficient. The area under the ROC curve for this diagnostic scale was 0. 991(95% confidence interval, 0. 982-0.999). The highest Youden index was 0. 912, the corresponding cut-off point was 7. Internally validation shows a sensitivity of 92. 78% and a specificity of 98.45% of our scale. CONCLUSIONS: We established and validated a diagnostic scale for SAT without the need for radioisotope scanning for the first time. It has good application in institutions that do not have radioisotope machines or among pregnant and lactating women.


Assuntos
Cintilografia , Hormônios Tireóideos/sangue , Tireoidite Subaguda/sangue , Tireoidite Subaguda/diagnóstico , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Glândula Tireoide/metabolismo
9.
J Cell Mol Med ; 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32077624

RESUMO

Circular RNAs (circRNAs) have been identified in diverse cancers for their role in regulating multiple cellular processes by antagonizing microRNAs (miRNAs or miRs). However, the role of circRNA hsa_circ_0000092 in hepatocellular carcinoma (HCC) still remains enigmatic. Therefore, we aimed to investigate the specific mechanism of hsa_circ_0000092 in HCC. Differentially expressed circRNAs associated to HCC were initially analysed. The expression of hsa_circ_0000092, miR-338-3p and HN1 in HCC tissues and cell lines was examined. Next, the interaction among hsa_circ_0000092, miR-338-3p and HN1 was determined by dual-luciferase reporter, RNA pull-down and northern blot assays. Subsequently, a series of mimic, inhibitor or siRNA plasmids were delivered into HCC cells to validate the effects of hsa_circ_0000092, miR-338-3p and HN1 in controlling cell proliferation, migration, invasion and angiogenesis in vitro. Furthermore, the role of hsa_circ_0000092 in tumour growth of HCC in vivo was assessed with hsa_circ_0000092 depleted with siRNA. The hsa_circ_0000092/miR-338-3p/HN1 axis was predicted to participate in the development of HCC. hsa_circ_0000092 and HN1 were highly expressed while miR-338-3p was poorly expressed in HCC tissues and cell lines. hsa_circ_0000092 could competitively bind to miR-338-3p to up-regulate HN1 expression. Moreover, depleted hsa_circ_0000092 or elevated miR-338-3p was shown to suppress HCC cell proliferation, migration, invasion and angiogenesis in vitro via down-regulation of HN1. Furthermore, silencing hsa_circ_0000092 was demonstrated to suppress tumour growth in HCC in vivo. The results of this study suggested that hsa_circ_0000092 impaired miR-338-3p-mediated HN1 inhibition to aggravate the development of HCC, indicating that hsa_circ_0000092 is a potential candidate marker and therapeutic target for HCC.

10.
J Chromatogr A ; 1614: 460710, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31784082

RESUMO

To monitor the existing and emerging halogenated carboxylic acids (HCAs) in drinking water, a sensitive and rapid ultra-high performance liquid chromatography-quadrupole orbitrap high-resolution mass spectrometry method for simultaneous target quantification of 10 haloacetic acids (HAAs) and semi-target screening of 19 HCAs was developed. After filtration, drinking water samples were injected into the instrument. HCAs were separated on an HSS T3 column and detected by a type of non-target scan in the electrospray ionization negative mode. For target quantification of 10 HAAs, good linearity was obtained and the correlation coefficients were higher than 0.995. The limits of detection were in the range of 0.050-2.0 µg/L. The recoveries were in the range of 89.7%-108%, 83.4%-121%, 77.1%-116% and 80.2%-104% at levels of 2.5, 5.0, 10 and 20 µg/L, respectively, with relative standard deviations of 1.26%-16.9%. For semi-target screening of 19 HCAs, several criteria including accurate m/z, predicted retention time, deduced fragment ions and simulated isotope pattern were used for identification. The method was applied to analyzing 41 drinking water samples successfully. Five HAAs were detected by target quantification, with dichloroacetic acid and trichloroacetic acid exceeding the limits suggested by the U.S. Environmental Protection Agency and the World Health Organization. Eight HCAs were preliminary identified by semi-target screening, and three of them were further confirmed with reference standards purchased later.


Assuntos
Ácidos Carboxílicos/análise , Cromatografia Líquida de Alta Pressão/métodos , Água Potável/química , Espectrometria de Massas/métodos , Halogenação , Limite de Detecção
11.
Chem Pharm Bull (Tokyo) ; 67(10): 1088-1098, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31582628

RESUMO

In this study, we synthesized four series of novel L-homoserine lactone analogs and evaluated their in vitro quorum sensing (QS) inhibitory activity against two biomonitor strains, Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. Studies of the structure-activity relationships of the set of L-homoserine lactone analogs indicated that phenylurea-containing N-dithiocarbamated homoserine lactones are more potent than (Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone (C30), a positive control for biofilm formation. In particular, compared with C30, QS inhibitor 11f significantly reduced the production of virulence factors (pyocyanin, elastase and rhamnolipid), swarming motility, the formation of biofilm and the mRNA level of QS-related genes regulated by the QS system of PAO1. These results reveal 11f as a potential lead compound for developing novel antibacterial quorum sensing inhibitors.


Assuntos
4-Butirolactona/análogos & derivados , Antibacterianos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , 4-Butirolactona/síntese química , 4-Butirolactona/química , 4-Butirolactona/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Molecular , Pseudomonas aeruginosa/crescimento & desenvolvimento , Percepção de Quorum/genética , Relação Estrutura-Atividade
12.
Mol Ther Nucleic Acids ; 18: 351-362, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31629962

RESUMO

Accumulating studies have implicated the role of long non-coding RNAs (lncRNAs) in the pathogenesis of hepatocellular carcinoma (HCC) through the regulating transcription and mRNA stability. A recent report has linked Rac GTPase-activating protein 1 (RACGAP1) to the early recurrence of HCC. The current study aimed to ascertain whether MAGI2 antisense RNA 3 (MAGI2-AS3) influences the development of HCC by regulating RACGAP1. MAGI2-AS3 expression was initially quantified in both the HCC tissues and cell lines. In order to elucidate the role of MAGI2-AS3 in the development of HCC, MAGI2-AS3 was overexpressed or silenced in HCC cells after which cell proliferation, apoptosis, invasion, and migration were evaluated. Chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP), and biotin-labeled RNA pull-down assays were conducted to determine the interactions among MAGI2-AS3, KDM1A, and RACGAP1. Finally, the effects of MAGI2-AS3 and RACGAP1 on the tumorigenesis of transplanted HCC cells in nude mice were evaluated. MAGI2-AS3 was found to be under-expressed in HCC tissues and cell lines. The restoration of MAGI2-AS3 was identified to markedly inhibit HCC cell growth, migrating ability, and invasiveness, and promote cell apoptosis. Interaction between MAGI2-AS3 and KDM1A was identified. KDM1A recruited by MAGI2-AS3 was found to promote H3K4me2 demethylation at the RACGAP1 promoter, which ultimately decreased the expression of RACGAP1. We also identified that RACGAP1 knockdown eliminated the stimulatory effects of MAGI2-AS3 silencing on the malignant phenotypes of HCC cells. Additionally, the expression of MAGI2-AS3 reduced tumor weight and size in HCC transplanted nude mice. Taken together, the key observations of the current study demonstrate the potential of MAGI2-AS3 as a tumor suppressor and a promising target for HCC treatment.

13.
Clin Res Hepatol Gastroenterol ; 43(6): 715-721, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30962170

RESUMO

Accumulating evidences have shown that microRNA-200c (miR-200c) expression is associated with the prognosis of many types of human cancer. However, the prognostic value of miR-200c in hepatocellular carcinoma (HCC) is still unknown. In the present study, the expression of miR-200c in paired HCC and adjacent non-tumor tissues from 148 patients was determined by quantitative real-time PCR (qRT-PCR), and we analyzed its association with clinicopathological characteristics and prognosis of HCC patients. Our results showed that the expression of miR-200c was significantly decreased in HCC tissues compared with adjacent non-tumor tissues (P < 0.0001). Correlation analysis showed that miR-200c expression was significantly associated with tumor size (P = 0.021), serum AFP level (P = 0.016), TNM stage (P = 0.019) and vein invasion (P = 0.026). Patients with lower miR-200c expression had significantly worse overall survival (OS, P = 0.023) and recurrence-free survival (RFS, P = 0.002). The multivariate Cox regression analysis revealed that miR-200c expression was an independent prognostic factor for OS (hazard ratio (HR) [95% CI] = 2.226 [1.235-4.012], P = 0.008) and RFS (HR [95% CI] = 2.662 [1.618-4.38], P < 0.001). In conclusion, our results suggest that the miR-200c expression was significantly down-regulated and associated with poor prognosis in HCC.


Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidade , MicroRNAs/genética , Adulto , Idoso , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida
14.
Oncotarget ; 8(50): 87955-87970, 2017 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-29152133

RESUMO

Background: Our previous investigations have shown that the variants of X-ray repair complementing 4 (XRCC4) may be involved in hepatocellular carcinoma (hepatocarcinoma) tumorigenesis. This study aimed to investigate the possible prognostic significance of XRCC4 expression for hepatocarcinoma patients and possible value for the selection of transarterial chemoembolization (TACE) treatment. Materials and Methods: We conducted a hospital-based retrospective analysis (including 421 hepatocarcinoma cases) to analyze the effects of XRCC4 on hepatocarcinoma prognosis and TACE. The levels of XRCC4 expression were tested using immunohistochemistry. The sensitivity of cancer cells to anti-cancer drug doxorubicin was evaluated using the half-maximal inhibitory concentration (IC50). Results: XRCC4 expression was significantly correlated with pathological features including tumor stage, liver cirrhosis, and micro-vessel density. XRCC4 expression was an independent prognostic factor of hepatocarcinoma, and TACE treatments had no effects on prognosis of hepatocarcinoma patients with high XRCC4 expression. More intriguingly, TACE improved the prognosis of hepatocarcinoma patients with low XRCC4 expression. Functionally, XRCC4 overexpression increased while XRCC4 knockdown reduced the IC50 of cancer cells to doxorubicin. Conclusions: These results suggest that XRCC4 may be an independent prognostic factor for hepatocarcinoma patients, and that decreasing XRCC4 expression may be beneficial for post-operative adjuvant TACE treatment in hepatocarcinoma.

15.
J AOAC Int ; 100(6): 1869-1878, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28786377

RESUMO

An analytical method was developed for the simultaneous determination of 11 aminoglycoside (AG) antibiotics, including amikacin, paromomycin, dihydrostreptomycin, gentamicin C1a, hygromycin, kanamycin, netilmicin, spectinomycin, sisomicin, streptomycin, and tobramycin in honey, milk, and pork samples by LC with tandem MS and molecularly imprinted polymer (MIP) SPE. The AG antibiotics in milk and homogenated meat samples were extracted with a solution composed of 10 mmol/L potassium dihydrogen phosphate, 0.4 mmol/L EDTA-Na2, and 2% trichloroacetic acid. For honey samples, the extractant was 50 mmol/L potassium dihydrogen phosphate. The extracts were cleaned up with MIP SPE cartridges. The separation was performed on a zwitter ionic-HILIC column (50 × 2.1 mm, 3.5 µm), with the mobile phase consisting of methanol, 0.3% formic acid, and 175 mmol/L ammonium formate at 0.50 mL/min in gradient elution. A triple-quadrupole mass spectrometer equipped with an electrospray ionization source, which was operated in positive mode, was used for detection. The quantification was based on matrix-matched calibration curves. The method was applied to real samples with three different matrixes. The LODs of the method were 2-30 µg/kg and the LOQs were 7-100 µg/kg; the average recovery ranged from 78.2 to 94.8%; intraday RSDs and interday RSDs were ≤15 and ≤18%, respectively; and the absolute values of matrix effect for all AGs were RSDs ≤23%.


Assuntos
Aminoglicosídeos/análise , Análise de Alimentos/métodos , Mel/análise , Leite/química , Carne Vermelha/análise , Animais , Antibacterianos/análise , Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Imagem Molecular/métodos , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos
16.
J Chromatogr Sci ; 53(2): 345-52, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24846281

RESUMO

The combination of the molecular technique, the multivariate strategy and microchip capillary electrophoresis (MCE) was applied to rapid and sensitive analysis of genetically modified (GM) soybean in food samples. A multiplex-touchdown polymerase chain reaction (PCR) system was developed for simultaneously amplifying three target sequences in Roundup Ready soybean (RRS). Response surface methodology was introduced to determine the optimal separation condition in MCE with good resolution and short analytical time. The detection of the PCR products of RRS was completed within 4 min under the optimal conditions. The specificity of the method was evaluated by testing non-GM soybean materials and three GM maize varieties (MON810, Bt176 and Bt11). A sensitivity of 0.1% GM organisms content was obtained, which was remarkably lower than the labeling threshold for transgenic food defined as 0.9% in the European regulation. The relative standard deviation of migration time was in the range of 0.17-0.95%. The proposed method was rapid, sensitive and specific and can be used to identify and detect GM soybean in food samples.


Assuntos
DNA de Plantas/genética , Eletroforese Capilar/métodos , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase/métodos , Soja/genética , DNA de Plantas/análise , Análise de Regressão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
J Chromatogr Sci ; 53(6): 925-31, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25480455

RESUMO

A comprehensive ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) procedure for detection of nine ß-agonists in animal-derived food is described. The method was based on enzymatic hydrolysis with ß-glucuronidase from Helix pomatia, followed by a liquid-liquid extraction procedure with perchloric acid and a solid-phase extraction scheme using two kinds of cartridges, HLB and MCX. The influence of sample solution pH in the extraction recovery was studied, and pH 4.0 was found to give the best recovery. The analytes were eluted with methanol containing 4% ammonia. A validation procedure for quantitative analysis of ß-agonists in animal-derived food was performed. The three kinds of internal standards, d3-salbutamol, d6-ractopamine and d9-clenpenterol, were applied in the sample preparation and detection of UHPLC/MS/MS. The recoveries from spiked samples ranged between 74.9 and 106.9%. The relative standard deviations of detection were at 0.7-9.6%. The limits of detection and quantification were 0.01-0.05 and 0.03-0.20 µg/kg, respectively. The effect of sample matrix in the detection was discussed in detail.


Assuntos
Agonistas Adrenérgicos beta/análise , Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Etanolaminas/análise , Carne/análise , Animais , Cromatografia Líquida/métodos , Rim/química , Limite de Detecção , Modelos Lineares , Fígado/química , Reprodutibilidade dos Testes , Suínos , Espectrometria de Massas em Tandem/métodos , Drogas Veterinárias/análise
18.
Food Chem ; 141(3): 2697-706, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23871013

RESUMO

The study systematically investigated free, conjugate and total phenolics (phenolic acids and flavonoids) in leaves of 19 Chinese and one American sweetpotato cultivars grown in China. Three extraction/hydrolytic methods (direct extraction and acidic and basic hydrolysis) for sample preparation were employed to obtain different forms of phenolics. Twenty-nine phenolics were separated and identified using HPLC-DAD and HPLC-ESI-MS/MS. Three quercetin glycosides were characterised for the first time from this plant. Contents of the principal phenolics identified were determined by the HPLC-DAD procedure, which was validated in terms of linearity, precision, accuracy and limit of detection and quantification. Moreover, to the best of our knowledge, it is the first to reveal and demonstrate artifacts of esterification during acidic methanolic and ethanolic hydrolysis, and chromatographic behaviours, UV spectra and MS data of 20 hydroxycinnamic acid methyl and ethyl esters were obtained using acidic methanolic and ethanolic hydrolysis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ipomoea batatas/química , Fenóis/química , Extratos Vegetais/química , Folhas de Planta/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Cromatografia Líquida de Alta Pressão/instrumentação , Ipomoea batatas/classificação , Folhas de Planta/classificação , Espectrometria de Massas em Tandem/métodos
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