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1.
Int J Nanomedicine ; 18: 1777-1791, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37041816

RESUMO

Introduction: A limitation of hemoglobin-based oxygen carriers (HBOCs) as oxygen therapeutics is unpolymerized hemoglobin, which induces vasoconstriction leading to hypertension. The removal of unpolymerized hemoglobin from polymerized hemoglobin (PolyHb) is complex, expensive, and time-consuming. Methods: Herein, we developed a method to completely polymerize hemoglobin almost without unpolymerized hemoglobin. Hemoglobin was adsorbed on the anion-exchange resin Q Sepharose Fast Flow or DEAE Sepharose Fast Flow, and acetal, a crosslinker prepared from glutaraldehyde and ethylene glycol, was employed to polymerize the hemoglobin. The polymerization conditions, including reaction time, pH, resin type, and molar ratios of glutaraldehyde to ethylene glycol and hemoglobin to acetal, were optimized. The blood pressure and blood gas of mice injected with PolyHb were monitored as well. Results: The optimal polymerization condition of PolyHb was when the molar ratio of glutaraldehyde to ethylene glycol was 1:20, and the molar ratio of 10 mg/mL hemoglobin adsorbed on anion-exchange resin to glutaraldehyde was 1:300 for 60 min. Under optimized reactive conditions, hemoglobin was almost completely polymerized, with <1% hemoglobin remaining unpolymerized, and the molecular weight of PolyHb was more centrally distributed. Furthermore, hypertension was not induced in mice by PolyHb, and there were also no pathological changes observed in arterial oxygen, blood gas, electrolytes, and some metabolic indicators. Conclusion: The findings of this study indicate that the use of solid-phase polymerization and acetal is a highly effective and innovative approach to HBOCs, resulting in the almost completely polymerized hemoglobin. These results offer promising implications for the development of new methods for preparing HBOCs.


Assuntos
Acetais , Oxigênio , Animais , Camundongos , Oxigênio/metabolismo , Glutaral/química , Polimerização , Sefarose , Hemoglobinas/metabolismo , Etilenoglicóis , Ânions
2.
Nano Res ; 16(1): 1242-1251, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35966151

RESUMO

With the increasing global threat of various diseases and infections, it is essential to develop a fast, low-cost, and easy-to-use point-of-care testing (POCT) system for inspections at all levels of medical institutions and self-examination at home. In this work, gold magnetic nanoparticles (GMNPs) are used as the key material, and a rapid visual detection method is designed through integrating loop-mediated isothermal amplification (LAMP) and lateral flow assay (LFA) biosensor for detecting a variety of analytes which includes whole blood, buccal swabs, and DNA. It is worth to note that the proposed method does not need DNA extraction. Furthermore, uracil DNA glycosylase (UDG) is employed to eliminate carrier contamination for preventing false positive results. The whole detection process can be finished within 25 min. The accuracy of detection is measured by assessing the polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) C677T. The detection limit of the newly developed extraction-free detection system for MTHFR C677T is 0.16 ng/µL. A preliminary clinical study of the proposed method is carried out by analyzing 600 clinical samples (including 200 whole blood samples, 100 buccal swabs, and 300 genomic DNA samples). The results indicate that the proposed method is 100% consistent with the sequencing results which provides a new choice for POCT and shows a broad application prospect in all levels of medical clinics and at home. Electronic Supplementary Material: Supplementary material (details for MTHFR C677T primer sequences, the cell count results of samples at different dilution ratios, genotyping results and frequency samples, a Hardy-Weinberg equilibrium test, the sensitivity of the system, detection results of multiple samples, and optimization of the system) is available in the online version of this article at 10.1007/s12274-022-4692-9.

3.
Curr Issues Mol Biol ; 44(6): 2683-2694, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35735624

RESUMO

Excessive reactive oxygen species (ROS), a highly reactive substance that contains oxygen, induced by ultraviolet A (UVA) cause oxidative damage to skin. We confirmed that hemin can catalyze the reaction of tyrosine (Tyr) and hydrogen peroxide (H2O2). Catalysis was found to effectively reduce or eliminate oxidative damage to cells induced by H2O2 or UVA. The scavenging effects of hemin for other free-radical ROS were also evaluated through pyrogallol autoxidation, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·)-scavenging assays, and phenanthroline-Fe2+ assays. The results show that a mixture of hemin and tyrosine exhibits strong scavenging activities for H2O2, superoxide anion (O2-·), DPPH·, and the hydroxyl radical (·OH). Furthermore, the inhibition of oxidative damage to human skin keratinocyte (HaCaT) cells induced by H2O2 or UVA was evaluated. The results show that catalysis can significantly reduce the ratio of cell apoptosis and death and inhibit the release of lactate dehydrogenase (LDH), as well as accumulation of malondialdehyde (MDA). Furthermore, the resistance to apoptosis was found to be enhanced. These results show that the mixture of hemin and tyrosine has a significantly protective effect against oxidative damage to HaCaT cells caused by UVA, suggesting it as a protective agent for combating UVA damage.

4.
Anal Chem ; 94(11): 4686-4694, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35271257

RESUMO

Insertions/deletions (indels) variations have been recognized as a promising marker for the development of various diseases. However, methods used for the genotyping of indels in studies were tedious, complicated, and required sophisticated or expensive instruments, as well as complex data analysis, which makes it difficult to meet the demand of point of care testing. Herein, we presented a fast and accurate biosensor (T-ARMS-PCR-LFA) by the combination of tetra-primer amplification refractory mutation system polymerase chain reaction (T-ARMS-PCR) and GoldMag lateral flow assay (LFA) for visual genotyping of ACE I/D polymorphism. ACE I/D can be distinguished by employing four primers in one PCR reaction, and genotyping results were presented by the visual inspection of colors on the nitrocellulose membrane of LFA strips within 5 min. And 50 of the human genomic DNA samples were used for the detection of ACE I/D to further validate the accuracy of the T-ARMS-PCR-LFA system. As a demonstration, we showed that ACE I/D could be genotyped using a low amount of DNA sample (25 ng) with an accuracy of 100%, without complicated operation steps and data analysis, which is better than that of the conventional method (agarose gel electrophoresis analysis after common PCR). In conclusion, the biosensor is highly applicable for genotyping specific large indel variants in clinical practices, which enables rapid clinical decision-making, improves the management of disease diagnosis, and facilitates personalized medicine.


Assuntos
Técnicas de Genotipagem , Peptidil Dipeptidase A , Polimorfismo de Nucleotídeo Único , DNA/genética , Genótipo , Humanos , Mutação , Peptidil Dipeptidase A/genética , Reação em Cadeia da Polimerase/métodos
5.
Artigo em Inglês | MEDLINE | ID: mdl-32915745

RESUMO

Diagnostic pathology is the foundation and gold standard for identifying carcinomas, and the accurate quantification of pathological images can provide objective clues for pathologists to make more convincing diagnosis. Recently, the encoder-decoder architectures (EDAs) of convolutional neural networks (CNNs) are widely used in the analysis of pathological images. Despite the rapid innovation of EDAs, we have conducted extensive experiments based on a variety of commonly used EDAs, and found them cannot handle the interference of complex background in pathological images, making the architectures unable to focus on the regions of interest (RoIs), thus making the quantitative results unreliable. Therefore, we proposed a pathway named GLobal Bank (GLB) to guide the encoder and the decoder to extract more features of RoIs rather than the complex background. Sufficient experiments have proved that the architecture remoulded by GLB can achieve significant performance improvement, and the quantitative results are more accurate.


Assuntos
Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Calibragem
6.
Anal Biochem ; 627: 114265, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34062149

RESUMO

Point-of-care testing (POCT) demands for rapidly obtaining test results by means of portable analytical instruments and auxiliary reagents at the sampling site. It's important for tumor marker to be recognized and detected in early clinical diagnosis. Many studies focused on producing small portable devices that would allow fast, accurate, and on-site detection. This study aimed to report a magnetic quantitative lateral flow immunoassay (LFIA) system based on poly (acrylic acid) (PAA)-modified gold magnetic nanoparticles (PGMNs) for detecting prostate-specific antigen (PSA) qualitatively and quantitatively. The result was easily achievable with a portable magnetic reader within 15 min. Under optimal conditions, as low as 0.17 ng/mL PSA could be detected. The method was validated using a well-established Solin electrochemiluminescence immunoassay and showed high consistency in detecting 84 serum samples (R2 = 0.98). The quantitative LFIA based on PGMNs established in this study was proven to be rapid, accurate, sensitive, and inexpensive. As a POCT, it can be potentially developed for the quantitative diagnosis of other disease-related protein biomarkers.


Assuntos
Ouro/química , Imunoensaio/métodos , Nanopartículas de Magnetita/química , Antígeno Prostático Específico/isolamento & purificação , Neoplasias da Próstata/diagnóstico , Resinas Acrílicas/química , Biomarcadores Tumorais/sangue , Humanos , Limite de Detecção , Magnetismo , Masculino , Testes Imediatos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Sensibilidade e Especificidade
7.
Biol Proced Online ; 23(1): 2, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413084

RESUMO

BACKGROUND: Angiotensin-converting enzyme (ACE) plays a major role in blood pressure regulation and cardiovascular homeostasis. The wide distribution and multifunctional properties of ACE suggest it's involvement in various pathophysiological conditions. RESULTS: In this study, a novel visual detection method for ACE I/D polymorphisms was designed by integrating direct PCR without the need for DNA extraction using gold magnetic nanoparticles (GMNPs)-based lateral flow assay (LFA) biosensor. The entire detection procedure could enable the genotyping of clinical samples in about 80 min. The detection limit was 0.75 ng and results could be obtained in 5 min using the LFA device. Three hundred peripheral blood samples were analyzed using the direct PCR-LFA system and then verified by sequencing to determine accuracy and repeatability. A clinical preliminary study was then performed to analyze a total of 633 clinical samples. CONCLUSIONS: After grouping based on age, we found a significant difference between the genotypes and the age of patients in the CHD group. The introduction of this method into clinical practice may be helpful for the diagnosis of diseases caused by large fragment gene insertions/deletions.

8.
Nanoscale ; 12(18): 10098-10105, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32350488

RESUMO

Rapid and simple detection of single nucleotide polymorphism (SNP) is vital for individualized diagnosis and eventual treatment in the current clinical setting. In this study, we developed a tetra-primer ARMS-PCR combined lateral flow assay (T-ARMS-PCR-LFA) method for simultaneous visual detection of two alleles. By using four primers labeled with digoxin, biotin and Cy5 separately in one PCR reaction, the amplified allele-specific products could be captured by streptavidin and the anti-Cy5 antibody on two separated test lines of a LFA strip, which allows the presentation of both alleles within the single LFA strip. Both DNA and whole blood can be used as templates in this genotyping method in which the whole detection process is completed within 75 minutes. The performance assay of T-ARMS-PCR-LFA demonstrates the accuracy, specificity and sensitivity of this method. One hundred human whole blood samples were used for MTHFR C677T genotyping in T-ARMS-PCR-LFA. The concordance rate of the results detected was up to 100% when compared with that of the sequencing results. Collectively, this newly developed method is highly applicable for SNP screening in clinical practices.


Assuntos
DNA/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Reação em Cadeia da Polimerase/métodos , Alelos , Anticorpos/química , Anticorpos/imunologia , DNA/sangue , Primers do DNA/química , Primers do DNA/metabolismo , Digoxina/química , Digoxina/imunologia , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único
9.
BMC Bioinformatics ; 21(1): 112, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32183709

RESUMO

BACKGROUND: Lung cancer is the leading cause of cancer-related deaths in both men and women in the United States, and it has a much lower five-year survival rate than many other cancers. Accurate survival analysis is urgently needed for better disease diagnosis and treatment management. RESULTS: In this work, we propose a survival analysis system that takes advantage of recently emerging deep learning techniques. The proposed system consists of three major components. 1) The first component is an end-to-end cellular feature learning module using a deep neural network with global average pooling. The learned cellular representations encode high-level biologically relevant information without requiring individual cell segmentation, which is aggregated into patient-level feature vectors by using a locality-constrained linear coding (LLC)-based bag of words (BoW) encoding algorithm. 2) The second component is a Cox proportional hazards model with an elastic net penalty for robust feature selection and survival analysis. 3) The third commponent is a biomarker interpretation module that can help localize the image regions that contribute to the survival model's decision. Extensive experiments show that the proposed survival model has excellent predictive power for a public (i.e., The Cancer Genome Atlas) lung cancer dataset in terms of two commonly used metrics: log-rank test (p-value) of the Kaplan-Meier estimate and concordance index (c-index). CONCLUSIONS: In this work, we have proposed a segmentation-free survival analysis system that takes advantage of the recently emerging deep learning framework and well-studied survival analysis methods such as the Cox proportional hazards model. In addition, we provide an approach to visualize the discovered biomarkers, which can serve as concrete evidence supporting the survival model's decision.


Assuntos
Biomarcadores/análise , Neoplasias Pulmonares/mortalidade , Análise de Sobrevida , Algoritmos , Aprendizado Profundo , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/genética , Masculino , Redes Neurais de Computação , Modelos de Riscos Proporcionais
10.
iScience ; 7: 170-179, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30245369

RESUMO

Developing a sensitive, low-cost, and easy-to-use point-of-care testing system for genotyping is important for informing treatment decisions and predicting the risk of underlying diseases. Conventional methods normally require complex operational procedures as well as expensive and sophisticated instruments. Here, we report a general approach that enables us to detect the genotype of multiple sample types directly without DNA purification. Moreover, the PCR results can be further quantitatively analyzed based on a magnetic lateral flow assay (MLFA) system, which avoids multiple steps needed for conventional nucleic acid biosensors. As a demonstration, we show that three genotypes of aldehyde dehydrogenase 2 (ALDH2) can be identified using a small volume of sample with an accuracy of 100% and a sensitivity of 1.0 × 102 cells/µL, which are better than those of the gold standard methods. We believe that the direct PCR-MLFA system represents a significant advance toward the development of portable, sensitive biomedical platforms.

11.
Biosens Bioelectron ; 115: 70-76, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29803102

RESUMO

Genotyping of single nucleotide polymorphisms (SNPs) in point-of-care (POC) settings could be further improved through simplifying the treatment of samples. In this study, we devised an accurate, rapid and easy-to-use SNP detection system based on direct loop-mediated isothermal amplification (LAMP) without DNA extraction, known as Direct-LAMP. Samples from various sources (including whole blood, dried blood spot, buccal swab and saliva), treated with NaOH, can be used directly in amplification. The turnaround time was about 30 min from sample collection to provision of results. The accuracy was evaluated by assessing the polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T and aldehyde dehydrogenase-2 (ALDH2) Glu504Lys, which are better known for their critical role in folate and ethanol metabolism, respectively. Completely consistent genotyping results reveal that Direct-LAMP is generally concordant with sequencing. This system can serve as a very promising platform in the fields of disease predisposition, drug metabolism and personalized medicine.


Assuntos
Aldeído-Desidrogenase Mitocondrial/isolamento & purificação , Técnicas Biossensoriais , Técnicas de Genotipagem , Metilenotetra-Hidrofolato Redutase (NADPH2)/isolamento & purificação , Aldeído-Desidrogenase Mitocondrial/genética , Genótipo , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Sistemas Automatizados de Assistência Junto ao Leito , Polimorfismo de Nucleotídeo Único/genética
12.
J Chromatogr Sci ; 56(7): 636-643, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29701750

RESUMO

A rapid and simple high-performance liquid chromatography-ultraviolet method was developed for the separation and quantification of 15 sulfonamides (SAs) in foods of animal origin without the need of clean-up procedure. A mixture of acetonitrile-formic acid-ammonium acetate-water was used as the mobile phase to separate 15 SAs on a C18 column with gradient. The selected SAs were separated completely from the matrix mixture based on different retention behaviors at different concentration of acetonitrile. The effects of the additive of formic acid and ammonium acetate in mobile phases on the separation of SAs were also investigated. The additive can greatly improve the resolution between SAs and impurities, so that the SAs can be quantified directly under the optimized chromatographic condition the sample preparation which does not need extra sample clean-up procedure. Complete baseline separation of 15 SAs was achieved in <40 min, the linear range is 0.01-130 µg/mL with a correlation coefficient R2-value > 0.999. Excellent method reproducibility was found by intra- and inter-day precisions with the relative standard deviation <9.5%. The detection limit was <11.0 ng/mL and it can be used for routine screening of the SA residues in foods of animal origin.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Carne/análise , Sulfonamidas/análise , Animais , Bovinos , Limite de Detecção , Modelos Lineares , Leite/química , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Suínos
13.
Anal Chem ; 90(5): 3430-3436, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29451781

RESUMO

Single nucleotide polymorphisms (SNPs) are closely related to genetic diseases, but current SNP detection methods, such as DNA microarrays that include tedious procedures and expensive, sophisticated instruments, are unable to perform rapid SNPs detection in clinical practice, especially for those multiple SNPs related to genetic diseases. In this study, we report a sensitive, low cost, and easy-to-use point-of-care testing (POCT) system formed by combining amplification refractory mutation system (ARMS) polymerase chain reaction with gold magnetic nanoparticles (GMNPs) and lateral flow assay (LFA) noted as the ARMS-LFA system, which allow us to use a uniform condition for multiple SNPs detection simultaneously. The genotyping results can be explained by a magnetic reader automatically or through visual interpretation according to the captured GMNPs probes on the test and control lines of the LFA device. The high sensitivity (the detection limit of 0.04 pg/µL with plasmid) and specificity of this testing system were found through genotyping seven pathogenic SNPs in phenylalanine hydroxylase gene ( PAH, the etiological factor of phenylketonuria). This system can also be applied in DNA quantification with a linear range from 0.02 to 2 pg/µL of plasmid. Furthermore, this ARMS-LFA system was applied to clinical trials for screening the seven pathogenic SNPs in PAH of 23 families including 69 individuals. The concordance rate of the genotyping results detected by the ARMS-LFA system was up to 97.8% compared with the DNA sequencing results. This method is a very promising POCT in the detection of multiple SNPs caused by genetic diseases.


Assuntos
Técnicas de Genotipagem/instrumentação , Fenilcetonúrias/genética , Sistemas Automatizados de Assistência Junto ao Leito , Reação em Cadeia da Polimerase/instrumentação , Polimorfismo de Nucleotídeo Único , Desenho de Equipamento , Técnicas de Genotipagem/economia , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Fenilcetonúrias/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito/economia , Reação em Cadeia da Polimerase/economia , Análise de Sequência de DNA/economia , Análise de Sequência de DNA/instrumentação , Fatores de Tempo
14.
Sci Rep ; 7(1): 8346, 2017 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-28827701

RESUMO

Epidermal growth factor receptor (EGFR) mutations predict better outcomes with EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). Most common activating mutations include in-frame deletion in exon 19 and L858R substitution in exon 21, which account for >90% of all EGFR mutations in NSCLC. In this study, a PCR-GoldMag lateral flow assay (PCR-GoldMag LFA) was developed for the visual detection of delE746-A750 and L858R of EGFR mutations. Forty formalin-fixed paraffin-embedded (FFPE) tissue samples of NSCLC patients were analyzed using PCR-GoldMag LFA system and verified by direct sequencing and TaqMan-PCR detection methods. Results showed that EGFR mutations were detected in 34 cases among the 40 samples (85%) by PCR-GoldMag LFA method. Among the 34 cases, 5 cases were simultaneously detected with delE746-A750 in exon 19 and L858R mutation in exon 21. Compared with sequencing, only 4 samples were detected as delE746-A750, which revealed higher sensitivity of PCR-GoldMag LFA detection method than direct sequencing. TaqMan-PCR method verified the L858R mutation and was in 100% agreement with our method. These results indicated that our method has obvious advantages to analyze clinical samples and offers a more sensitive alternative to direct sequencing for the detection of EGFR mutations.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Mutação , Reação em Cadeia da Polimerase/instrumentação , Reação em Cadeia da Polimerase/métodos , Carcinoma Pulmonar de Células não Pequenas/patologia , Estudos de Casos e Controles , Receptores ErbB/genética , Genótipo , Humanos , Neoplasias Pulmonares/patologia , Estudos Prospectivos
15.
Mol Med Rep ; 14(5): 4153-4161, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27665864

RESUMO

A polymerase chain reaction-gold magnetic nanoparticles lateral flow assay (PCR-GoldMag LFA) has been developed via integrating multiplex amplification refractory mutation system PCR (multi­ARMS­PCR) with GoldMag­based LFA for the visual detection of single­nucleotide polymorphisms (SNPs). This assay was applied to genotype Apolipoprotein E (ApoE). ApoE genotyping is important due to the predictive value for the development of coronary artery disease and Alzheimer's disease. The method requires two steps: i) Simultaneous amplifications of the two polymorphic codons (ApoE 158 and 112), performed in separated reactions using multi­ARMS­PCR; and ii) detection of the wild­type and mutant PCR products via dual immunoreactions, which can be performed in ~5 min. Within two LFAs, anti­digoxin antibody­conjugated GoldMag probes bind digoxin­labeled wild­type PCR products, and anti­fluorescein isothiocyanate (FITC) antibody-conjugated GoldMag probes bind FITC­labeled mutant PCR products. All PCR products are biotin labeled and are detected by streptavidin-coated regions on the LFA strip, resulting in a red color. The current approach is capable of detecting the SNPs of ApoE in ~1.5 h, with a broad detection range from 10­1,000 ng of genomic DNA. Thus, the present protocol may facilitate simple, fast and cost­effective screening for important SNPs, as demonstrated by the evaluation of the prevalence of ApoE variants in a Han Chinese cohort.


Assuntos
Apolipoproteínas E/genética , Genótipo , Técnicas de Genotipagem/métodos , Polimorfismo de Nucleotídeo Único/genética , Apolipoproteínas E/sangue , China , Códon , Humanos , Reação em Cadeia da Polimerase/métodos
16.
Sci Rep ; 6: 26533, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27246657

RESUMO

Single-nucleotide polymorphisms (SNPs) represent the most widespread type of genetic variation (approximately 90%) in the human genome, and the demand to overcome such variation has received more attention now than ever before. The capacity to rapidly assess SNPs that correlate with disease predisposition, drug efficacy and drug toxicity is a key step for the development of personalized medicine. In this work, a rapid one-step SNP detection method, real-time loop-mediated isothermal amplification (RT-LAMP), was first applied for CYP2C19 polymorphisms testing. The optimized method was established with specifically designed primers for target amplification by real-time detection in approximately 30 min under isothermal conditions. RT-LAMP amplified few copies of template to produce significant amounts of product and quantitatively detected human DNA with compatible specificity and sensitivity. The success in the establishment of this RT-LAMP protocol for CYP2C19 polymorphism testing is significant for the extension of this technique for the detection of other SNPs, which will further facilitate the development of personalized medicine.


Assuntos
Citocromo P-450 CYP2C19/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Polimorfismo de Nucleotídeo Único , Primers do DNA/genética , Humanos , Medicina de Precisão , Temperatura
17.
ACS Appl Mater Interfaces ; 8(13): 8834-40, 2016 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-27007980

RESUMO

Environmental biofouling caused by the formation of biofilm has been one of the most urgent global concerns. Silver nanoparticles (NPs), owing to their wide-spectrum antimicrobial property, have been widely explored to combat biofilm, but their extensive use has raised growing concern because they persist in the environment. Here we report a novel hybrid nanocomposite that imparts enhanced antimicrobial activity and low cytotoxicity yet with the advantage of reduced silver loading. The nanocomposite consists of Pt/Ag bimetallic NPs (BNPs) decorated on the porous reduced graphene oxide (rGO) nanosheets. We demonstrate that the enhanced antimicrobial property against Escherichia coli is ascribed to the intricate control of the interfaces between metal compositions, rGO matrix, and bacteria, where the BNPs lead to a rapid release of silver ions, and the trapping of bacteria by the porous rGO matrix further provides high concentration silver ion sites for efficient bacteria-bactericide interaction. We envision that our facile approach significantly expands the design space for the creation of silver-based antimicrobial materials to achieve a wide spectrum of functionalities.


Assuntos
Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Nanocompostos/química , Antibacterianos , Escherichia coli/patogenicidade , Grafite/administração & dosagem , Grafite/química , Humanos , Nanocompostos/administração & dosagem , Platina/química , Prata/química
18.
Nanoscale ; 8(6): 3579-87, 2016 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-26804455

RESUMO

Current techniques for single nucleotide polymorphism (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticle (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amounts from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1721 individuals for the C677T genotypes. The concordance rate of the genotyping results detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven to be rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes.


Assuntos
Técnicas de Genotipagem/métodos , Ouro/química , Nanopartículas Metálicas/química , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Nucleotídeo Único , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase/métodos
19.
J Food Drug Anal ; 24(2): 277-283, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-28911579

RESUMO

A rapid and simple high-performance liquid chromatography-UV method was developed for the separation and quantification of salbutamol, ractopamine, and clenbuterol in pork. A mixture of acetonitrile-formic acid-ammonium acetate was used as the mobile phase to separate three ß-agonists on a C18 column with gradient. The effects of the addition of formic acid and ammonium acetate to mobile phases on the separation of ß-agonists were investigated. These additives can greatly improve the resolution and sensitivity. Under the optimized chromatographic condition, this separation does not need extra sample preparation. Complete baseline separation of three ß-agonists was achieved in < 20 minutes; the linear range is 0.2-50 µg/L with a correlation coefficient R2 value of > 0.99. Excellent method reproducibility was found by intra- and interday precisions with a relative standard deviation of < 3%. The detection limit (S/N = 3) was found to be <0.05 µg/L; this method can be used for routine screening of the ß-agonist residues in foods of animal origin before being identified by confirmatory methods.


Assuntos
Carne Vermelha , Albuterol , Animais , Cromatografia Líquida de Alta Pressão , Clembuterol , Análise de Alimentos , Fenetilaminas , Reprodutibilidade dos Testes , Suínos
20.
Int J Mol Med ; 36(5): 1319-26, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26329478

RESUMO

In this study, a lateral flow immunochromatographic assay (LFIA) system for the detection of immunoglobulin M (IgM) antibodies, related to TORCH [(T)oxoplasmosis, (O)ther agents, (R)ubella (also known as German Measles), (C)ytomegalovirus, and (H)erpes simplex virus infections], based on gold magnetic nanoparticles, was established. Following modification with poly(methacrylic acid), the gold magnetic nanoparticles conjugated with an anti­human IgM antibody (µ­chain specific) to construct a probe. A lateral flow assay device was constructed based on these conjugates. IgM antibodies to four types of pathogens, notably toxoplasmosis, rubella virus, cytomegalovirus and herpes simplex virus type 2, were detected using this device. Compared with commercial colloidal gold­based LFIA strips, our method exhibited higher sensitivity. No interference with triglycerides, hemoglobin and bilirubin occurred, and no cross­reactivity was noted among the four pathogens. The gold magnetic nanoparticle­LFIA strips were used to assess 41 seropositive and 121 seronegative serum samples. The sensitivity was 100% (162/162) and the specificity was 100% (162/162). This method cannot only be used for the detection of TORCH IgM-specific antibodies, but it can potentially be developed for use in the diagnosis of other acute or recently identified autoimmune diseases.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Ouro/química , Herpes Simples/imunologia , Imunoglobulina M/imunologia , Nanopartículas de Magnetita/química , Rubéola (Sarampo Alemão)/imunologia , Toxoplasmose/imunologia , Cromatografia de Afinidade/métodos , Humanos
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