Infectious diseases are a serious global problem, which not only take an enormous human toll but also incur tremendous economic losses. In combating infectious diseases, rapid and accurate diagnostic ...tests are required for pathogen identification at the point of care (POC). In this review, investigations of diagnostic strategies for infectious diseases that are based on aptamers, especially nucleic acid aptamers, oligonucleotides that have high affinities and specificities toward their targets, are described. Owing to their unique features including low cost of production, easy chemical modification, high chemical stability, reproducibility, and low levels of immunogenicity and toxicity, aptamers have been widely utilized as bio-recognition elements (bio-receptors) for the development of infection diagnostic systems. We discuss nucleic acid aptamer-based methods that have been developed for diagnosis of infections using a format that organizes discussion according to the target pathogenic analytes including toxins or proteins, whole cells and nucleic acids. Also included is, a summary of recent advances made in the sensitive detection of pathogenic bacteria utilizing the isothermal nucleic acid amplification method. Lastly, a nucleic acid aptamer-based POC system is described and future directions of studies in this area are discussed.
•Aptamer-based diagnostic strategies for infectious diseases are summarized.•Novel, homogenous, aptamer-based nucleic acid sensing strategies are described.•A description is given of recent advances for sensitive pathogen detection utilizing isothermal nucleic acid amplification.•Aptamer-based POC diagnostic systems as well as future directions of studies in this area are discussed.
•An enzyme-free, label-free and cost-effective approach is developed to detect miRNA-141.•We evaluate the concentration of miR-141 based on CHA and fluorescence enhancement of DNA-AgNCs nearby G-rich ...DNA.•Diagnostic capability was demonstrated by measuring miR-141 in human blood serum.•This strategy would be expanded to detect other miRNAs.
We herein describe a simple, enzyme-free, and label-free strategy for the detection of miRNA based on target-triggered catalytic hairpin assembly (CHA) and fluorescence enhancement of DNA-silver nanoclusters (DNA-AgNCs). This strategy employs two hairpin probes that are rationally designed to contain AgNCs and guanine (G)-rich DNA sequence, respectively. In principle, the two hairpin probes, which exist independently, form a hybridized complex in the presence of target miRNA through CHA reaction, thereby inducing strong fluorescence signal of AgNCs by the presence of G-rich sequence placed in close proximity. Importantly, target miRNA is released after the first CHA reaction, which promotes another CHA reaction, consequently leading to the significantly enhanced fluorescence signal of AgNCs. Based on this one-step, homogeneous, and isothermal amplification method, we successfully detected the target miRNA with high selectivity and sensitivity. In addition, the practical applicability of this strategy was also demonstrated by analyzing the target miRNA in human serum.
When imaging cells, nuclear counterstaining is imperative; however, many commercial nuclear-staining dyes based on nucleic acid intercalation result in nonspecific signals in the cytoplasm. Here, we ...propose a new strategy that stains the nucleus with high specificity by in situ formation of DNA-templated copper nanoparticles (CuNPs). We demonstrated that genomic DNA in the nucleus enabled rapid formation of highly fluorescent CuNPs immediately following addition of a copper ion source and ascorbate as a reducing agent. Moreover, we found that RNA and mitochondrial DNA, largely responsible for nonspecific cytoplasmic signals from commercial nuclear-staining dyes, did not mediate the formation of the highly fluorescent CuNPs, resulting in highly specific nuclear staining at a reduced cost relative to commercially available methods. Furthermore, we verified the compatibility of the proposed method with other fluorescence-labeling techniques. These results demonstrated the efficacy of this method and its promise as a powerful tool for cell imaging.
•Sonochemically synthesized protein-inorganic hybrid nanoflowers exhibited an intrinsic peroxidase-like activity.•Glucose oxidase-copper hybrid nanoflowers possessed dual enzymatic activity.•The ...nanoflower-based biosensor showed high selectivity and sensitivity for glucose detection.•Diverse glucose levels in human blood were successfully determined with excellent reproducibility and reliability.
We have found that protein-inorganic hybrid nanoflowers, prepared by an ultrafast sonication-mediated self-assembly of proteins and copper ions, exhibit an intrinsic peroxidase-mimicking activity, which is significantly higher than that of control materials formed in the absence of proteins. By employing glucose oxidase (GOx) as a protein component, the novel synthetic method was applied to construct GOx copper nanoflowers capable of promoting glucose-induced cascade enzymatic reactions. In the presence of target glucose, GOx, entrapped in the hybrid nanoflowers, generates H2O2 through its catalytic action; this subsequently induces peroxidase-mediated oxidation by the hybrid nanoflowers to convert the selected substrate, Amplex UltraRed (AUR), to a highly fluorescent product. Using this strategy, the target glucose was reliably determined down to 3.5 μM with high selectivity. The practical diagnostic utility of the assay system was also verified by using it to detect glucose in human blood serum. This sonochemical strategy has great potential to be extended for the construction of various oxidative enzyme-inorganic hybrid nanoflowers that are capable of detecting clinically important target molecules.
Patients with brain metastases (BM) can benefit from radiotherapy (RT), although the long-term benefits of RT remain unclear. We searched a Korean national health insurance claims database and ...identified 135,740 patients with newly diagnosed BM during 2002-2017. Propensity score matching (PSM) was used to evaluate survival according to RT modality, which included whole-brain radiotherapy (WBRT) and/or stereotactic radiosurgery (SRS). The 84,986 eligible patients were followed for a median interval of 6.6 months, and 37,046 patients underwent RT (43.6%). After the PSM, patients who underwent RT had significantly better overall survival after 1 year (42.4% vs. 35.3%, P < 0.001), although there was no significant difference at 2.6 years, and patients who did not undergo RT had better survival after 5 years. Among patients with BM from lung cancer, RT was also associated with a survival difference after 1 year (57.3% vs. 32.8%, P < 0.001) and a median survival increase of 3.7 months. The 1-year overall survival rate was significantly better for SRS than for WBRT (46.4% vs. 38.8%, P < 0.001). Among Korean patients with BM, especially patients with primary lung cancer, RT improved the short-term survival rate, and SRS appears to be more useful than WBRT in this setting.
Metal ion, an astonishing illusionist: In a new concept, “illusionary” polymerase activity is intentionally triggered at T–T and C–C mismatched primers by Hg2+ and Ag+ ions, respectively. A novel ...strategy to construct molecular‐scale logic gates utilizes the nonnatural polymerase activity induced by the metal ions by rational design of the primers and selection of the type of DNA polymerase (see picture).
We herein developed a simple and ultrafast electrochemical DNA detection method by utilizing the oxidase-mimicking activity of cerium oxide nanoparticles (CeO2). In the sensor, the presence of DNA, ...which electrostatically interacts with CeO2 and 3,3′,5,5′-tetramethylbenzidine (TMB) substrate, limits the formation of CeO2-TMB complex that is required for the oxidase-like reaction. As a result, the oxidase-mimicking activity of CeO2 is not effectively exerted, leading to the significantly diminished electrochemical current signal. With this novel strategy, we successfully determined DNA amplicon derived from Escherichia coli (E. coli) with the total assay time less than 6 min even without the post-purification of DNA amplicon.
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•A simple and ultrafast electrochemical DNA detection method is devised.•It is the first report to use oxidase-mimicking activity of cerium oxide nanoparticles for electrochemical target DNA detection.•This method contains advantageous features such as simplicity, rapidity, and cost-effectiveness.•This method could be employed to detect a broad range of targets including proteins, small molecules, and inorganic ions.
We developed a one-step and label-free, electrochemical DNA detection method using metal ion-mediated molecular beacon (MB) probe specially designed to have target-specific sequence in its loop and ...Pb2+-binding aptamer in its stem. In the absence of target DNA, MB probe, after the interaction with Pb2+, forms the intramolecular stem-loop hairpin structure, which limits Pb2+ to freely diffuse onto the electrode surface, leading to the low electrochemical signal. In contrast, the presence of target DNA that forms the hybridization complex with MB probe, breaks down the intramolecular stem-loop structure of MB probe, and releases Pb2+ that is freely diffused onto the electrode surface to generate the high electrochemical signal. By employing this method, the target DNA from Chlamydia trachomatis, one of the major pathogens causing sexually transmitted disease was successfully detected with the high selectivity.
A one-step and label-free, electrochemical DNA detection method was developed by utilizing metal ion-mediated molecular beacon (MB) probe. Display omitted
•This is the first report to utilize metal ion-mediated MB probe for DNA detection.•The diffusion coefficients of Pb2+ in different situations were analyzed.•This method does not require the complicated and multi-step procedures.•Patient DNA samples were utilized for verifying the diagnostic capability.
In this study, we sought to identify relevant factors in healthy behavior practices, including not only individual-level variables but also regional and physical environments. Data from the Korea ...Community Health Survey (KCHS) of Gyeongsangnam-do in 2018 were used, with data from 16,519 of the 17,947 individuals (excluding 1428 individuals who had missing values) who participated in the survey. Healthy behavior practices were defined as meeting the criteria for all three modifiable healthy behaviors (non-smoking, moderate alcohol consumption, regular walking). A decision tree analysis was performed. In men, healthy behavior practices were lower in the unemployed population, in those aged 40−50 years, living in rural residential areas, and with stress. For women who lived in areas with small populations (<100,000 population), healthy behavior practices were below-average. Men and women who had below-average healthy behavior practices reported poor access to places for exercise and fair or poor self-rated health statuses. It is necessary to implement a health behavior practice intervention that considers not only individual characteristics but also access to local exercise facilities and residential area characteristics (urban, rural). Since age is an important variable in healthy behaviors for both men and women, customized programs that consider age should be provided.
Plant extracts including secondary metabolites have anti-inflammatory and anti-obesity activities. This study was conducted to investigate the anti-obesity properties of fermented
(AW) and
(GW) in ...vitro and in mice. The metabolite profiling of AW and GW extracts was performed using UHPLC-LTQ-Orbitrap-MS/MS, and gene expression was analyzed using real-time PCR for adipocyte difference factors. The anti-obesity effects in mice were measured using serum AST, ALT, glucose, TG, and cholesterol levels. Metabolites of the plant extracts after fermentation showed distinct differences with increasing anti-obesity active substances. The efficacy of inhibitory differentiation adipogenesis of 3T3-L1 adipocytes was better for GW than AW in a concentration-dependent manner. RT-PCR showed that the GW extract significantly reduced the expression of genes involved in adipocyte differentiation and fat accumulation (C/EBPα, PPARγ, and Fas). In C57BL/6 mice fed the HFD, the group supplemented with AW and GW showed reduced liver weight, NAS value, and fatty liver by suppressing liver fat accumulation. The GW group significantly reduced ALT, blood glucose, TG, total cholesterol, and LDL-cholesterol. This study displayed significant metabolite changes through biotransformation in vitro and the increasing anti-obesity effects of GW and AW in mice. GW may be applicable as functional additives for the prevention and treatment of obesity.
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