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Analysis of 40 weight loss compounds adulterated in health supplements by liquid chromatography quadrupole linear ion trap mass spectrometry

Zeng Y, Xu Y, Kee CL, Low MY, Ge X

Drug Test Anal, 2016 Mar;8(3-4):351-6.
PMID: 26305055 DOI: 10.1002/dta.1846

In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) with scheduled multiple reaction monitoring (MRM) enhanced product ion (EPI) method was developed for simultaneous determination of 40 compounds with weight loss effect, including bisacodyl, phenolphthalein, and sibutramine and its metabolites, etc. They might be adulterated in health supplements to get prominent weight loss effect. The samples were analyzed using a Q-Trap 5500 coupled with high performance liquid chromatography (HPLC) and a CORTECS ultra performance liquid chromatography (UPLC) C18 column (100 mm x 2.1 mm x1.6 µm). Scheduled MRM was used as survey scan, MS2 spectra acquired in the EPI mode were used to perform library searching to increase the confidence of detection. Limits of detection were less than 10 ng/g for the majority of the analytes. A total of 447 weight loss products were tested in our laboratory in the past three years. Among these samples, 119 samples were found to be adulterated with one or more weight loss compounds, including sibutramine, its metabolites benzyl sibutramine and desmethyl sibutramine; phenolphthalein; bisacodyl; furosemide; liothyronine (T3); and thyroxine (T4). Copyright © 2015 John Wiley & Sons, Ltd.
Mapping flood by the object-based method using backscattering coefficient and interference coherence of Sentinel-1 time series

Zhang X, Chan NW, Pan B, Ge X, Yang H

Sci Total Environ, 2021 Nov 10;794:148388.
PMID: 34217078 DOI: 10.1016/j.scitotenv.2021.148388

The SAR has the ability of all-weather and all-time data acquisition, it can penetrate the cloud and is not affected by extreme weather conditions, and the acquired images have better contrast and rich texture information. This paper aims to investigate the use of an object-oriented classification approach for flood information monitoring in floodplains using backscattering coefficients and interferometric coherence of Sentinel-1 data under time series. Firstly, the backscattering characteristics and interference coherence variation characteristics of SAR time series are used to analyze whether the flood disaster information can be accurately reflected and provide the basis for selecting input classification characteristics of subsequent SAR images. Subsequently, the contribution rate index of the RF model is used to calculate the importance of each index in time series to convert the selected large number of classification features into low dimensional feature space to improve the classification accuracy and reduce the data redundancy. Finally, the SAR image features in each period after multi-scale segmentation and feature selection are jointly used as the input features of RF classification to extract and segment the water in the study area to monitor floods' spatial distribution and dynamic characteristics. The results showed that the various attributes of backscatter coefficients and interferometric coherence under time series could accurately correspond with the actual flood risk, and the combined use of backscattering coefficient and interferometric coherence for flood extraction can significantly improve the accuracy of flood information extraction. Overall, the object-based random forest method using the backscattering coefficient and interference coherence of Sentinel-1 time series for flood extraction advances our understanding of flooding's temporal and spatial dynamics, essential for the timely adoption of adaptation and mitigation strategies for loss reduction.
Fulltext Paraneoplastic Secretion of Multiple Phosphatonins From a Deep Fibrous Histiocytoma Causing Oncogenic Osteomalacia

Leow MKS, Dogra S, Ge X, Chuah KL, Liew H, Loke KSH, et al.

J Clin Endocrinol Metab, 2021 04 23;106(5):e2299-e2308.
PMID: 33462615 DOI: 10.1210/clinem/dgaa964

CONTEXT: Literature suggests that oncogenic osteomalacia is usually caused by a benign mesenchymal tumor secreting fibroblast growth factor subtype-23 (FGF-23), but the involvement of other phosphatonins has only been scarcely reported. We have previously published a seemingly typical case of oncogenic osteomalacia. Following curative neoplasm resection, we now report unique molecular characteristics and biology of this tumor.
CASE DESCRIPTION: A 25-year-old man had been diagnosed with severe oncogenic osteomalacia that gradually crippled him over 6 years. 68Ga-DOTA-TATE positron emission tomography/computed tomography scan localized the culprit tumor to his left sole, which on resection revealed a deep fibrous histiocytoma displaying a proliferation of spindle cells with storiform pattern associated with multinucleated giant cells resembling osteoclasts. Circulating FGF-23, which was elevated more than 2-fold, declined to undetectable levels 24 h after surgery. Microarray analysis revealed increased tumor gene expression of the phosphatonins FGF-23, matrix extracellular phosphoglycoprotein (MEPE) and secreted frizzled-related protein subtype 4, with elevated levels of all 3 proteins confirmed through immunoblot analysis. Differential expression of genes involved in bone formation and bone mineralization were further identified. The patient made an astonishing recovery from being wheelchair bound to fully self-ambulant 2 months postoperatively.
CONCLUSION: This report describes oncogenic osteomalacia due to a deep fibrous histiocytoma, which coincidentally has been found to induce profound muscle weakness via the overexpression of 3 phosphatonins, which resolved fully upon radical resection of the tumor. Additionally, genes involved in bone formation and bone remodeling contribute to the molecular signature of oncogenic osteomalacia.
Fulltext PGG.SNV: understanding the evolutionary and medical implications of human single nucleotide variations in diverse populations

Zhang C, Gao Y, Ning Z, Lu Y, Zhang X, Liu J, et al.

Genome Biol, 2019 10 22;20(1):215.
PMID: 31640808 DOI: 10.1186/s13059-019-1838-5

Despite the tremendous growth of the DNA sequencing data in the last decade, our understanding of the human genome is still in its infancy. To understand the implications of genetic variants in the light of population genetics and molecular evolution, we developed a database, PGG.SNV ( https://www.pggsnv.org ), which gives much higher weight to previously under-investigated indigenous populations in Asia. PGG.SNV archives 265 million SNVs across 220,147 present-day genomes and 1018 ancient genomes, including 1009 newly sequenced genomes, representing 977 global populations. Moreover, estimation of population genetic diversity and evolutionary parameters is available in PGG.SNV, a unique feature compared with other databases.