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1.
Surg Laparosc Endosc Percutan Tech ; 34(2): 201-205, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38571322

RESUMO

BACKGROUND: With the aging of the global population, the incidence rate of acute cholecystitis is increasing. Laparoscopic cholecystectomy is considered as the first choice to treat acute cholecystitis. How to effectively avoid serious intraoperative complications such as bile duct and blood vessel injury is still a difficult problem that puzzles surgeons. This paper introduces the application of laparoscopic cholecystectomy, a new surgical concept, in acute difficult cholecystitis. METHODS: This retrospective analysis was carried out from January 2019 to January 2021. A total of 36 patients with acute difficult cholecystitis underwent 3-step laparoscopic cholecystectomy. The general information, clinical features, surgical methods, surgical results, and postoperative complications of the patients were analyzed. RESULTS: All patients successfully completed the surgery, one of them was converted to laparotomy, and the other 35 cases were treated with 3-step laparoscopic cholecystectomy. Postoperative bile leakage occurred in 2 cases (5.56%), secondary choledocholithiasis in 1 case (2.78%), and hepatic effusion in 1 case (2.78%). No postoperative bleeding, septal infection, and other complications occurred, and no postoperative colon injury, gastroduodenal injury, liver injury, bile duct injury, vascular injury, and other surgery-related complications occurred. All 36 patients were discharged from hospital after successful recovery. No one died 30 days after surgery, and there was no abnormality in outpatient follow-up for 3 months after surgery. CONCLUSIONS: Three-step laparoscopic cholecystectomy seems to be safer and more feasible for acute difficult cholecystitis patients. Compared with traditional laparoscopic cholecystectomy or partial cholecystectomy, 3-step laparoscopic cholecystectomy has the advantages of safe surgery and less complications, which is worth trying by clinicians.


Assuntos
Colecistectomia Laparoscópica , Colecistite Aguda , Humanos , Colecistectomia Laparoscópica/métodos , Estudos Retrospectivos , Colecistectomia/métodos , Colecistite Aguda/cirurgia , Colecistite Aguda/etiologia , Ductos Biliares/lesões
2.
PLoS One ; 19(4): e0300890, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38578756

RESUMO

A correlation has been reported to exist between exposure factors (e.g. liver function) and acute pancreatitis. However, the specific causal relationship remains unclear. This study aimed to infer the causal relationship between liver function and acute pancreatitis using the Mendelian randomisation method. We employed summary data from a genome-wide association study involving individuals of European ancestry from the UK Biobank and FinnGen. Single-nucleotide polymorphisms (SCNPs), closely associated with liver function, served as instrumental variables. We used five regression models for causality assessment: MR-Egger regression, the random-effect inverse variance weighting method (IVW), the weighted median method (WME), the weighted model, and the simple model. We assessed the heterogeneity of the SNPs using Cochran's Q test. Multi-effect analysis was performed using the intercept term of the MR-Egger method and leave-one-out detection. Odds ratios (ORs) were used to evaluate the causal relationship between liver function and acute pancreatitis risk. A total of 641 SNPs were incorporated as instrumental variables. The MR-IVW method indicated a causal effect of gamma-glutamyltransferase (GGT) on acute pancreatitis (OR = 1.180, 95%CI [confidence interval]: 1.021-1.365, P = 0.025), suggesting that GGT may influence the incidence of acute pancreatitis. Conversely, the results for alkaline phosphatase (ALP) (OR = 0.997, 95%CI: 0.992-1.002, P = 0.197) and aspartate aminotransferase (AST) (OR = 0.939, 95%CI: 0.794-1.111, P = 0.464) did not show a causal effect on acute pancreatitis. Additionally, neither the intercept term nor the zero difference in the MR-Egger regression attained statistical significance (P = 0.257), and there were no observable gene effects. This study suggests that GGT levels are a potential risk factor for acute pancreatitis and may increase the associated risk. In contrast, ALP and AST levels did not affect the risk of acute pancreatitis.


Assuntos
Pancreatite , Humanos , Pancreatite/genética , Doença Aguda , Estudo de Associação Genômica Ampla , Causalidade , Fosfatase Alcalina/genética , Corantes , Nonoxinol , gama-Glutamiltransferase , Fígado , Análise da Randomização Mendeliana
3.
World J Clin Cases ; 11(27): 6613-6617, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37900229

RESUMO

BACKGROUND: Internal hernia is a rare cause of acute abdomen and intestinal obstruction in adults. Internal abdominal hernias include paraduodenal, perigastric, foramen of Winslow, intersigmoid, and post-anastomotic hernias and can be congenital or acquired. Internal hernias occur in 1%-2% of patients, and transmesocolic hernias are extremely rare. This report presents a patient with a transverse mesocolic hernia with a preoperative diagnosis of small intestinal obstruction. CASE SUMMARY: A 45-year-old Chinese woman was admitted to the hospital with middle and upper abdominal pain for 2 d, abdominal distension, and vomiting. After abdominal computed tomography, she was diagnosed with an internal abdominal hernia complicated by small intestinal obstruction and underwent emergency laparoscopic surgery. The patient recovered well and was discharged 6 d postoperatively. CONCLUSION: Transmesocolic hernias must be considered in adult patients with signs and symptoms of intestinal obstruction, even without a history of abdominal trauma or surgery.

4.
Ann Transl Med ; 10(14): 798, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35965828

RESUMO

Background: Pancreatic acinar cells are susceptible to nuclear factor kappa B (NF-κB)-mediated inflammation and resulting cell necrosis during early acute pancreatitis. As adenosine monophosphate-activated protein kinase alpha (Ampkα)/sirtuin 1 (Sirt1) pathway activity attenuates NF-κB activity, we examined whether the Ampkα/Sirt1 axis affects the progression of acute pancreatitis and associated lung injury in vivo. Furthermore, we explored the role of the ciliary protein sperm flagellar 2 (Spef2, Kpl2) in regulating Ampkα/Sirt1 activity in vitro and in vivo. Methods: Pancreatic injury, oxidative stress, acinar cell necrosis and apoptosis, acinar levels of Ampkα/Sirt1/NF-κB signaling activity, NF-kB-mediated inflammatory markers, and markers of associated lung injury were measured in rat models of acute pancreatitis following pharmacological Ampkα activation with A769662 or self-complementary recombinant adeno-associated virus serotype 6 (scAAV6)-mediated Spef2 overexpression. Additional in vivo rescue studies involving Ampkα silencing and/or constitutively active (CA)-Sirt1 overexpression were performed in acute pancreatitis rats. In vitro immunoblotting and Ampkα activity assays were conducted in the pancreatic acinar cell line AR42J. Results: Pharmacological Ampkα activation or Spef2 overexpression reduced acute pancreatitis severity, oxidative stress, necrosis, apoptosis, NF-kB-mediated inflammatory markers, and the degree of associated lung injury. Spef2 overexpression in AR42J cells in vitro promoted AmpkαThr172 phosphorylation and Ampkα activity. In vivo rescue studies revealed that Spef2's suppressive effect on acute pancreatitis and associated lung injury is mediated via the Ampkα/Sirt1 axis. Conclusions: This study established the existence of a Spef2/Ampkα/Sirt1 axis in pancreatic acinar cells that is involved in the regulation of NF-κB-mediated acinar cell inflammation and resulting cell necrosis during acute pancreatitis.

5.
Sensors (Basel) ; 22(7)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35408408

RESUMO

The ability to discern subtle image changes over time is useful in applications such as product quality control, civil engineering structure evaluation, medical video analysis, music entertainment, and so on. However, tiny yet useful variations are often combined with large motions, which severely distorts current video amplification methods bounded by external constraints. This paper presents a novel use of spectra to make motion magnification robust to large movements. By exploiting spectra, artificial limitations and the magnification of small motions are avoided at similar frequency levels while ignoring large ones at distinct spectral pixels. To achieve this, this paper constructs spline-kerneled chirplet transform (SCT) into an empirical Bayesian paradigm that applies to the entire time series, giving powerful spectral resolution and robust performance to noise in nonstationary nonlinear signal analysis. The important advance reported is Bayesian-rule embedded SCT (BE-SCT); two numerical experiments show its superiority over current approaches. For applying to spectrum-aware motion magnification, an elaborate analytical framework is established that captures global motion, and use of the proposed BE-SCT for dynamic filtering enables a frequency-based motion isolation. Our approach is demonstrated on real-world and synthetic videos. This approach shows superior qualitative and quantitative results with less visual artifacts and more local details over the state-of-the-art methods.


Assuntos
Algoritmos , Artefatos , Teorema de Bayes , Movimento (Física) , Movimento
6.
Ecotoxicol Environ Saf ; 232: 113256, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35131585

RESUMO

In this study, γ-aminobutyric acid (GABA) was examined as an additional supplement to improve the ammonia stress resistance of S. pharaonis. Specifically, we added different doses of GABA (0, 20, 40, 60, 80, and 100 mg/kg) to food, cultivated S. pharaonis in regular seawater for 8 weeks and then in 8.40 mg/L ammonia seawater for 48 h and then investigated the accumulation of ammonia (the hepatic ammonia content), ammonia detoxification process (the urea content), antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT) enzyme activities), immune response (the serum haemolytic complement (C3) and lysozyme (LYZ) contents), membrane lipid peroxidation (malondialdehyde (MDA)) and histopathology of the liver. The results showed that ammonia poisoning could induce ammonia and MDA accumulation and subsequently lead to oxidative stress (decreases in SOD and CAT activities), immunosuppression (reductions in the haemolytic C3 and LYZ content), and histopathological injury in the liver. The application of GABA had a significant effect on alleviating the adverse effect of ammonia poisoning, and 80-100 mg/kg treatment exerted the best effect. This treatment significantly reduced the ammonia and MDA contents, significantly increased the urea content, increased the SOD, CAT, C3 and LYZ activities, reduced the MDA content, suppressed membrane lipid peroxidation, and significantly improved the histopathological injury to the liver. In summary, the results could provide a new method for mitigating liver damage, alleviating the physiological and metabolic disorders caused by ammonia stress in cuttlefish, and provide a theoretical basis for the application of GABA in alleviating ammonia poisoning.


Assuntos
Sepia , Amônia/metabolismo , Amônia/toxicidade , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Decapodiformes , Imunidade , Estresse Oxidativo , Superóxido Dismutase/metabolismo , Ácido gama-Aminobutírico/metabolismo
7.
Prep Biochem Biotechnol ; 52(6): 648-656, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34694209

RESUMO

In the present study, ultrasound-assisted extraction was employed to extract the general flavone from celery leaves using response surface methodology and BP neural network model with a genetic algorithm (GA). The effects of temperature, time, solid-liquid ratio, and ethanol concentration on the extraction results were assessed by Box-Behnken design. Further optimization of the process was performed by GA-BP. Our results showed that the optimal conditions were an ethanol concentration of 70.31%, a temperature of 67.2 °C and an extraction time of 26.6 min. In addition, significant antioxidant activity and in vitro bacteriostasis were observed. We found that the total flavonoids of the celery leaves exerted a strong inhibitory effect on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Additionally, considerable DPPH· and ·OH scavenging effects were exerted by flavonoids. Therefore, flavonoids from celery leaves can be considered natural antioxidants and bacterial inhibitors.


Assuntos
Apium , Flavonoides , Extratos Vegetais , Folhas de Planta , Algoritmos , Apium/química , Bacillus subtilis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Etanol/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Redes Neurais de Computação , Extratos Vegetais/farmacologia , Folhas de Planta/química , Staphylococcus aureus/efeitos dos fármacos , Temperatura , Fatores de Tempo
8.
Brief Bioinform ; 22(6)2021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34037687

RESUMO

As the best substitute for antibiotics, antimicrobial peptides (AMPs) have important research significance. Due to the high cost and difficulty of experimental methods for identifying AMPs, more and more researches are focused on using computational methods to solve this problem. Most of the existing calculation methods can identify AMPs through the sequence itself, but there is still room for improvement in recognition accuracy, and there is a problem that the constructed model cannot be universal in each dataset. The pre-training strategy has been applied to many tasks in natural language processing (NLP) and has achieved gratifying results. It also has great application prospects in the field of AMP recognition and prediction. In this paper, we apply the pre-training strategy to the model training of AMP classifiers and propose a novel recognition algorithm. Our model is constructed based on the BERT model, pre-trained with the protein data from UniProt, and then fine-tuned and evaluated on six AMP datasets with large differences. Our model is superior to the existing methods and achieves the goal of accurate identification of datasets with small sample size. We try different word segmentation methods for peptide chains and prove the influence of pre-training steps and balancing datasets on the recognition effect. We find that pre-training on a large number of diverse AMP data, followed by fine-tuning on new data, is beneficial for capturing both new data's specific features and common features between AMP sequences. Finally, we construct a new AMP dataset, on which we train a general AMP recognition model.


Assuntos
Algoritmos , Peptídeos Antimicrobianos/química , Biologia Computacional/métodos , Processamento de Linguagem Natural , Software , Peptídeos Antimicrobianos/farmacologia , Bases de Dados Genéticas , Reprodutibilidade dos Testes
9.
BMC Bioinformatics ; 22(1): 216, 2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33902446

RESUMO

BACKGROUND: Carbonylation is a non-enzymatic irreversible protein post-translational modification, and refers to the side chain of amino acid residues being attacked by reactive oxygen species and finally converted into carbonyl products. Studies have shown that protein carbonylation caused by reactive oxygen species is involved in the etiology and pathophysiological processes of aging, neurodegenerative diseases, inflammation, diabetes, amyotrophic lateral sclerosis, Huntington's disease, and tumor. Current experimental approaches used to predict carbonylation sites are expensive, time-consuming, and limited in protein processing abilities. Computational prediction of the carbonylation residue location in protein post-translational modifications enhances the functional characterization of proteins. RESULTS: In this study, an integrated classifier algorithm, CarSite-II, was developed to identify K, P, R, and T carbonylated sites. The resampling method K-means similarity-based undersampling and the synthetic minority oversampling technique (SMOTE-KSU) were incorporated to balance the proportions of K, P, R, and T carbonylated training samples. Next, the integrated classifier system Rotation Forest uses "support vector machine" subclassifications to divide three types of feature spaces into several subsets. CarSite-II gained Matthew's correlation coefficient (MCC) values of 0.2287/0.3125/0.2787/0.2814, False Positive rate values of 0.2628/0.1084/0.1383/0.1313, False Negative rate values of 0.2252/0.0205/0.0976/0.0608 for K/P/R/T carbonylation sites by tenfold cross-validation, respectively. On our independent test dataset, CarSite-II yield MCC values of 0.6358/0.2910/0.4629/0.3685, False Positive rate values of 0.0165/0.0203/0.0188/0.0094, False Negative rate values of 0.1026/0.1875/0.2037/0.3333 for K/P/R/T carbonylation sites. The results show that CarSite-II achieves remarkably better performance than all currently available prediction tools. CONCLUSION: The related results revealed that CarSite-II achieved better performance than the currently available five programs, and revealed the usefulness of the SMOTE-KSU resampling approach and integration algorithm. For the convenience of experimental scientists, the web tool of CarSite-II is available in http://47.100.136.41:8081/.


Assuntos
Algoritmos , Proteínas , Carbonilação Proteica , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , Máquina de Vetores de Suporte
10.
RNA Biol ; 17(6): 892-902, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32138598

RESUMO

Piwi-interacting RNAs (piRNAs) are indispensable in the transposon silencing, including in germ cell formation, germline stem cell maintenance, spermatogenesis, and oogenesis. piRNA pathways are amongst the major genome defence mechanisms, which maintain genome integrity. They also have important functions in tumorigenesis, as indicated by aberrantly expressed piRNAs being recently shown to play roles in the process of cancer development. A number of computational methods for this have recently been proposed, but they still have not yielded satisfactory predictive performance. Moreover, only one computational method that identifies whether piRNAs function in inducting target mRNA deadenylation been reported in the literature. In this study, we developed a two-layered integrated classifier algorithm, 2lpiRNApred. It identifies piRNAs in the first layer and determines whether they function in inducting target mRNA deadenylation in the second layer. A new feature selection algorithm, which was based on Luca fuzzy entropy and Gaussian membership function (LFE-GM), was proposed to reduce the dimensionality of the features. Five feature extraction strategies, namely, Kmer, General parallel correlation pseudo-dinucleotide composition, General series correlation pseudo-dinucleotide composition, Normalized Moreau-Broto autocorrelation, and Geary autocorrelation, and two types of classifier, Sparse Representation Classifier (SRC) and support vector machine with Mahalanobis distance-based radial basis function (SVMMDRBF), were used to construct a two-layered integrated classifier algorithm, 2lpiRNApred. The results indicate that 2lpiRNApred performs significantly better than six other existing prediction tools.


Assuntos
Algoritmos , Biologia Computacional/métodos , RNA Interferente Pequeno/genética , Software , Fenômenos Químicos , Bases de Dados de Ácidos Nucleicos , Humanos , RNA Interferente Pequeno/química , Reprodutibilidade dos Testes
11.
Talanta ; 199: 491-498, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30952289

RESUMO

It's important to eliminate matrix interference for accurate detecting antibiotic residues in complex food samples. In this study, we designed a zero-backgrounded fluorescence aptasensor to achieve on-site detection of antibiotic residues, with chloramphenicol (CAP) as representative analyte. Moreover, a three stir-bars assisted target recycling system (TSBTR) was designed to achieve triple signal amplification and increase the sensitivity. The bars included one magnetic stir-bar modified with two kinds of long DNA chains, and two gold stir-bars modified with Y shape-duplex DNA probes respectively. In the presence of CAP, the target could recurrently react with the probes on the bars and replace a large amount of long DNA chains into supernatant. After then, the bars were taken out and SYBR green dye was added to the solution. The dye can specifically intercalate into the duplex structures of DNA chains to emit fluorescence while not emitting a signal in its free state. Under the optimized experimental conditions, a wide linear response range of 5 orders of magnitude from 0.001 ng mL-1 to 10 ng mL-1 was achieved with a detection limit of 0.033 pg mL-1 CAP. The assay was successfully employed to detect CAP in food samples (milk & fish) with consistent results with ELISA's. High selectivity and sensitivity were attributed to the zero background signal and triple signal-amplification strategy. Moreover, the detection time can be shortened to 40 min due to that three signal amplified process can occur simultaneously. The fluorescent aptasensor was also label- and enzyme-free. All these ensure the platform to be rapid, cost-effective, easily-used, and is especially appropriate for detection antibiotics in food safety.


Assuntos
Antibacterianos/análise , Aptâmeros de Nucleotídeos/química , Fluorescência , Análise de Alimentos , Contaminação de Alimentos/análise , Animais , Ensaio de Imunoadsorção Enzimática , Peixes , Inocuidade dos Alimentos , Leite/química , Espectrometria de Fluorescência
12.
Talanta ; 197: 491-499, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771967

RESUMO

Simultaneous and sensitive detection of various antibiotic residues in one sample is essential to evaluation of food safety status. Herein, a multiplexed electrochemical aptasensor for multiplex antibiotics detection, with kanamycin (KANA) and ampicillin (AMP) as representative analytes, was designed by using metal ions encoded apoferrtin probes and double stirring bars-assisted target recycling for signal amplification. The encoded probes were prepared by apoferritin loading Cd2+ and Pb2+ ions and labeling with duplex DNAs (aptamers corresponding to KANA and AMP hybrid with its complementary DNA sequence), respectively. In the presence of KANA and AMP, the targets can recurrently react with the probes on the bars, and then replace a lot of Apo-Mencoded signal tags into supernatant. The peak currents of Cd2+and Pb2+from the tags corresponding with the concentrations of KANA and AMP were detected by square wave voltammetry in one run. As a result, KANA and AMP can be detected simultaneously within the range from 0.05 pM to 50 nM. And the detection limits were 18 fM KANA and 15 fM AMP (S/N = 3). The assay was testified to detect KANA and AMP residues with consistent results of ELISA in samples, e.g. milks and fishes. The assay was highly-sensitive, selective, cost-effective and easy-to-operate due to Apo-M encoded probes with high loading capacity of signal source substances. Moreover, double stirring bar-assisted target recycling, which was enzyme-free and could overcome matrix interference, was fabricated for signal amplification. Thus, the assay showed potential advantages for sensitively screening of antibiotic residues in foods.


Assuntos
Antibacterianos/análise , Apoferritinas/química , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Corantes Fluorescentes/química , Animais , Cádmio/química , Peixes , Chumbo/química , Leite/química
13.
J Chromatogr A ; 1589: 173-181, 2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30635170

RESUMO

It is crucially important to rapidly, simultaneously, and sensitively determine trace amounts of heavy metal ions in complex samples. Herein, a stirring bar modified with two kinds of encoded hairpin DNA probes (H0 and H0') was used in a multiplexed strategy allowing for specific extraction of Hg2+ and Ag+ coupled to microchip electrophoresis (MCE) separation and LED induced fluorescence (LIF) detection. The extraction step utilizes stir bars, which are functionalized with designed hairpin DNA probes (H0 with TT and H0' with CC mismatches in stems). This allows the specific capture of Hg2+ and Ag+ through CAg+C and THg2+T interactions. These complexes are then enzymatically degraded by the action of exonuclease III (Exo III). The ions released during this enzymatic reaction can initiate a new cycle of interactions with hairpin structures and enzymatic reactions and so on. This cyclic step is specific to the presence of Hg2+ and Ag+ and represents the first round of amplification of the presence of the selected ions. The resulting single strand DNAs on the stirring bars after enzymatic degradation were used in the second step as primers to trigger the catalytic hairpin assembly (CHA) in the presence of a couple of hairpin structures in solution. Such a reaction allows producing duplexes that can be monitored by MCE-LIF. The fluorescence intensity of CHA products (IP) increased and that of hairpin DNAs (IR) decreased with the increase of target concentrations. The signal ratios (IP/IR and IP'/IR') consisted of targets. The assay was employed for Hg2+ and Ag+ detection in several mediums including water, milk, and fish samples with complex matrices. The results showed that the assay could avoid matrix interference to increase the sensitivity. Therefore, the multiplexed assay was ideal to simultaneously and quickly detect metal ions in complex samples.


Assuntos
Eletroforese em Microchip/métodos , Mercúrio/química , Sondas Moleculares/química , Prata/química , Animais , DNA , DNA de Cadeia Simples , Exodesoxirribonucleases , Peixes , Íons , Leite
14.
RSC Adv ; 9(31): 17975-17978, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-35520559

RESUMO

A catalytic amount of CuCl and Cs2CO3 was employed to synthesize a variety of 2-substituted benzo[b]furans and indoles by an intramolecular cyclization of 2-alkynyl phenols and tosylanilines. This protocol features mild conditions, high yields and broad substrate scope, which makes it a practical method for the synthesis of 2-substituted benzo[b]furans and indoles.

15.
Talanta ; 189: 494-501, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30086951

RESUMO

Excessive intake of kanamycin (KANA) can cause some serious drug-resistant diseases, so it is urgent to develop some accurate and rapid analytical methods for monitor KANA residues in foodstuffs with complex matrix. Recently, many ratiometric assays were reported to be capable of overcoming matrix interference. Herein, a ratiometric and homogeneous assay for KANA detection based on microchip electrophoresis (MCE) was developed. First, by one single strand DNA (S-DNA) and one hairpin DNA (H-DNA), a novel R shape DNA probe (R-DNA) was prepared. After the probe was incubated with KANA, the S-DNA-KANA complex was formed, and H-DNA was released. Moreover, in the presence of exonuclease I (Exo-I), S-DNA-KANA complex would be digested to release the captured KANA for triggering target recycling and signal amplification. With the reaction going on, the fluorescence intensity of H-DNA (IH) increased and that of R-DNA (IR) decreased. They can be separated at different voltage intensities and converted to fluorescent signals for signal readout by MCE. The signal ratio of IH/IR was found to be linear toward target from 0.5 pg mL-1 to 10 ng mL-1, and the limit of detection was 150 fg mL-1. Moreover, it was successfully employed for KANA detection in milk and fish samples with consistent results of enzyme linked immune sorbent assay (ELISA). The R-DNA probe can quantitatively convert the amount of target to the intensity of DNA without label by MCE, and achieved exonuclease assisted signal amplification in homogenous solution. It was valuable to detect antibiotics residues in foodstuff with complex matrix. This approach broadened the application field of MCE to detect antibiotics without derivatization, which provided a promising platform for rapid screening of antibiotic residues in food.


Assuntos
Sondas de DNA/química , Eletroforese em Microchip/métodos , Exodesoxirribonucleases/metabolismo , Contaminação de Alimentos/análise , Canamicina/análise , Animais , Sondas de DNA/metabolismo , DNA de Cadeia Simples/química , DNA de Cadeia Simples/metabolismo , Estudos de Viabilidade , Peixes , Sequências Repetidas Invertidas , Canamicina/química , Limite de Detecção , Leite/química
16.
Analyst ; 143(11): 2696-2704, 2018 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-29774900

RESUMO

Recently, it has been crucial to be able to detect and quantify small molecular targets simultaneously in biological samples. Herein, a simple and conventional double-T type microchip electrophoresis (MCE) based platform for the multiplex detection of quality indicator molecule targets in urine, using ampicillin (AMPI), adenosine triphosphate (ATP) and estradiol (E2) as models, was developed. Several programmable hairpin probes (PHPs) were designed for detecting different targets and triggering isothermal polymerase-catalyzed target recycling (IPCTR) for signal amplification. Based on the target-responsive aptamer structure of PHP (Domain I), target recognition can induce PHP conformational transition and produce extension duplex DNA (dsDNA), assisted by primers & Bst polymerase. Afterwards, the target can be displaced to react with another PHP and initiate the next cycle. After several rounds of reaction, the dsDNA can be produced in large amounts by IPCTR. Three targets can be simultaneously converted to dsDNA fragments with different lengths, which can be separated and detected using MCE. Thus, a simple double-T type MCE based platform was successfully built for the homogeneous detection of multiplex targets in one channel. Under optimal conditions, the assay exhibited high throughput (48 samples per hour at most, not including reaction time) and sensitivity to three targets in urine with a detection limit of 1 nM (ATP), 0.05 nM (AMPI) and 0.1 nM (E2) respectively. The multiplex assay was successfully employed for the above three targets in several urine samples and combined the advantages of the high specificity of programmable hairpin probes, the excellent signal amplification of IPCTR, and the high through-put of MCE which can be employed for screening in biochemical analysis.


Assuntos
Aptâmeros de Nucleotídeos , Eletroforese em Microchip , Urinálise/métodos , Trifosfato de Adenosina/urina , Ampicilina/urina , Estradiol/urina , Humanos , Limite de Detecção
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