ABSTRACT
This study investigated the potential ability of the fluorescent probe Ly-CHO to detect formaldehyde (FA) in living cells and tumor-bearing mice. Ly-CHO exhibited great selectivity, excellent sensitivity, and rapid response to FA, making it a valuable tool for tracking FA concentration changes. The probe was also found to target lysosomes specifically. Furthermore, Ly-CHO showed an obvious fluorescence increase in endogenous CHO detection after adding tetrahydrogen folic acid (THFA). This study validated Ly-CHO's possibility for FA imaging in vivo, with potential applications in understanding formaldehyde-related diseases.
Subject(s)
Fluorescent Dyes , Neoplasms , Humans , Animals , Mice , Lysosomes , HeLa Cells , Formaldehyde , Optical Imaging , WaterABSTRACT
Mitochondria, as an energy-producing powerhouse in live cells, is considered to be directly linked to cellular health. However, dysfunctional mitochondria and abnormal mitochondria pH would possibly activate mitophagy, cell apoptosis and intercellular acidification process. In this work, we synthesized a novel near infrared fluorescent probe (FNIR-pH) for measurement of mitochondrial pH based on the hemicyanine skeleton as a fluorophore. The FNIR-pH probe functioned as a mitochondrial pH substrate and exhibited quick and sensitive turn-on fluorescence responses to mitochondrial pH in basic solution due to the deprotonation of hydroxy group in the structure. From pH 3.0 to 10.0, the FNIR-pH exhibited almost 100-fold increase in fluorescence intensity at 766 nm wavelength. The FNIR-pH also displayed superior selectivity to various metal ions, excellent photostability, and low cytotoxicity, which facilitated further biological application. Owing to the proper pKa value of 7.2, the FNIR-pH paved the way for real-time monitoring of mitochondria pH changes in live cells and sensitive sensing of mitophagy. Moreover, the FNIR-pH probe was also implemented for fluorescent imaging of tumor-bearing mice to validate its potential application for in vivo imaging of bioanalytes and biomarkers.
Subject(s)
Fluorescent Dyes , Mitophagy , Humans , Animals , Mice , Fluorescent Dyes/chemistry , Mitochondria/chemistry , HeLa Cells , Hydrogen-Ion ConcentrationABSTRACT
A fluorescent probe was developed for the detection of phosgene based on 1,8-naphthalimide, of which o-diaminobenzene was used as the recognition moiety. The probe does not fluoresce due to nonradiative decay. The probe reacts rapidly with phosgene via an intramolecular cyclization reaction, which induces large fluorescence due to increased rigidity in the resulting molecule and a low detection limit (0.23 nM). This probe has excellent selectivity for phosgene against competing interference analytes and, in the form of probe-loaded test paper, is an extremely sensitive method for phosgene sensing in the gas phase below 1 ppm concentrations.
Subject(s)
Phosgene , Gases , Fluorescent Dyes , Naphthalimides , Spectrometry, Fluorescence/methodsABSTRACT
Structural flexibility plays an essential role in many biological processes. B-factor is an important indicator to measure the flexibility of protein or RNA structures. Many methods were developed to predict protein B-factors, but few studies have been done for RNA B-factor prediction. In this paper, we proposed a new method RNAbval to predict RNA B-factors using random forest. The method was developed using a comprehensive set of features, including the sequence profile and predicted solvent accessibility. RNAbval achieved an improvement of 9.2-20.5 percent over the state-of-the-art method on two benchmark test datasets. The proposed method is available at http://yanglab.nankai.edu.cn/RNAbval/.
Subject(s)
Computational Biology/methods , RNA , Sequence Analysis, RNA/methods , Crystallography, X-Ray , Machine Learning , Pliability , Proteins/chemistry , Proteins/metabolism , RNA/chemistry , RNA/genetics , RNA/metabolism , Solvents/chemistry , Solvents/metabolismABSTRACT
BACKGROUND: The role of narrow band imaging (NBI) for surveillance colonoscopy in patients with inflammatory bowel disease (IBD) is debatable. We aim to compare NBI versus other endoscopic techniques in surveillance of IBD basing on current evidences. METHODS: A systematic search of PubMed, Embase, and the Cochrane Library databases was conducted for relevant studies. To assess the detection efficacy, we estimated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. To assess the differentiation efficacy, we estimated sensitivity and specificity of NBI with reference to histology. All outcome variables were pooled using a random-effects model. Heterogeneity was tested by the Q statistic and I statistic. RESULTS: A total of 10 studies involving 938 participants were included. Statistically significant differences were not found in the likelihood of detecting patients with dysplastic lesions [RR, 1.11; 95% confidence interval (CI), 0.83-1.48] nor in the likelihood of detecting dysplastic lesions by targeted biopsies (RR, 0.76; 95% CI, 0.51-1.12) between NBI and other techniques, and there was also no difference in the likelihood of detecting dysplastic subtypes. NBI required shorter procedural time compared with other techniques (MD, -10.23; 95% CI, -11.53 to -8.92). The sensitivity and specificity of NBI to differentiate neoplastic lesions from non-neoplastic lesions were 0.64 (95% CI, 0.50-0.77) and 0.74 (95% CI, 0.69-0.79), respectively, and the area under the curve (AUC) was 0.7626. CONCLUSIONS: Although a shorter procedural time is needed, the clinical application of NBI for both dysplasia detection and neoplasia differentiation in IBD is not superior to other endoscopic techniques.