The efficacy of preoperative MRI features in the diagnosis of meningioma WHO grade and brain invasion

ObjectiveThe preoperative MRI scans of meningiomas were analyzed based on the 2021 World Health Organization (WHO) Central Nervous System (CNS) Guidelines, and the efficacy of MRI features in diagnosing WHO grades and brain invasion was analyzed.Materials and methodsThe data of 675 patients with meningioma who underwent MRI in our hospital from 2006 to 2022, including 108 with brain invasion, were retrospectively analyzed. Referring to the WHO Guidelines for the Classification of Central Nervous System Tumors (Fifth Edition 2021), 17 features were analyzed, with age, sex and meningioma MRI features as risk factors for evaluating WHO grade and brain invasion. The risk factors were identified through multivariable logistic regression analysis, and their receiver operating characteristic (ROC) curves for predicting WHO grades and brain invasion were generated, and the area under the curve (AUC), sensitivity and specificity were calculated.ResultsUnivariate analysis showed that sex, tumor size, lobulated sign, peritumoral edema, vascular flow void, bone invasion, tumor-brain interface, finger-like protrusion and mushroom sign were significant for diagnosing meningioma WHO grades, while these features and ADC value were significant for predicting brain invasion (P < 0.05). Multivariable logistic regression analysis showed that the lobulated sign, tumor-brain interface, finger-like protrusion, mushroom sign and bone invasion were independent risk factors for diagnosing meningioma WHO grades, while the above features, tumor size and ADC value were independent risk factors for diagnosing brain invasion (P < 0.05). The tumor-brain interface had the highest efficacy in evaluating WHO grade and brain invasion, with AUCs of 0.779 and 0.860, respectively. Combined, the variables had AUCs of 0.834 and 0.935 for determining WHO grade and brain invasion, respectively.ConclusionPreoperative MRI has excellent performance in diagnosing meningioma WHO grade and brain invasion, while the tumor-brain interface serves as a key factor. The preoperative MRI characteristics of meningioma can help predict WHO grade and brain invasion, thus facilitating complete lesion resection and improving patient prognosis

High-Resolution Colorimetric Assay for Rapid Visual Readout of Phosphatase Activity Based on Gold/Silver Core/Shell Nanorod

Nanostructure-based visual assay has been developed for determination of enzymatic activity, but most involve in poor visible color resolution and are not suitable for routine utilization. Herein, we designed a high-resolution colorimetric protocol based on gold/silver core/shell nanorod for visual readout of alkaline phosphatase (ALP) activity by using bare-eyes. The method relied on enzymatic reaction-assisted silver deposition on gold nanorod to generate significant color change, which was strongly dependent on ALP activity. Upon target ALP introduction into the substrate, the ascorbic acid 2-phosphate was hydrolyzed to form ascorbic acid, and then, the generated ascorbic acid reduced silver ion to metal silver and coated on the gold nanorod, thereby resulting in the blue shift of longitudinal localized surface plasmon resonance peak of gold nanorod accompanying a perceptible color change from red to orange to yellow to green to cyan to blue and to violet. Under optimal conditions, the designed method exhibited the wide linear range 5–100 mU mL^–1 ALP with a detection limit of 3.3 mU mL^–1. Moreover, it could be used for the semiquantitative detection of ALP from 20 to 500 mU mL^–1 by using the bare-eyes. The coefficients of variation for intra- and interassay were below 3.5% and 6.2%, respectively. Finally, this method was validated for the analysis of real-life serum samples, giving results matched well with those from the 4-nitrophenyl phosphate disodium salt hexahydrate (pNPP)-based standard method. In addition, the system could even be utilized in the enzyme-linked immunosorbent assay (ELISA) to detect IgG at picomol concentration. With the merits of simplification, low cost, user-friendliness, and sensitive readout, the gold nanorod-based colorimetric assay has the potential to be utilized by the public and opens a new horizon for bioassays

Structure determination of the theophylline-nicotinamide cocrystal: a combined powder XRD, 1D solid-state NMR, and theoretical calculation study

The crystal structure of a powder pharmaceutical cocrystal, theophylline-nicotinamide (1 : 1) crystal complex, is determined for the first time by using a combination of X-ray powder diffraction (XRPD), 1D solid state NMR, as well as density functional theory (DFT) calculations. With the aid of solid state NMR spectroscopy, a candidate structure can be determined from XRPD data by Rietveld refinement with acceptable residual variances. The structure was subjected to periodic geometry optimization, followed by NMR parameter calculations. The agreement between experimental and computed C-13 and N-15 NMR chemical shift values validates the refined structure as an accurate representation of the actual cocrystal structure. Intermolecular interactions existing in the cocrystal are further confirmed by the commonly used vibrational spectra. This study confirms that the straightforward synergistic approach offers a simple and credible way to solve the crystal structure of powder cocrystal samples