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Xin-Gui Peng,Zhen Zhao,Di Chang,Yingying Bai,Qiuzhen Xu,Shenghong Ju 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.2
Objective: The purpose of the study was to non-invasively characterize and discriminate brown adipose tissue (BAT) from white adipose tissue (WAT) in rats using spectral computed tomography (CT) with histological validation. Materials and Methods: A lipid-containing phantom (lipid fractions from 0% to 100%) was imaged with spectral CT. An in vivo, non-enhanced spectral CT scan was performed on 24 rats, and fat concentrations of BAT and WAT were measured. The rats were randomized to receive intraperitoneal treatment with norepinephrine (NE) (n = 12) or saline (n = 12). Non-enhanced and enhanced spectral CT scans were performed after treatment to measure the elevation of iodine in BAT and WAT. The BAT/ aorta and WAT/aorta ratios were calculated and compared, after which isolated BAT and WAT samples were subjected to histological and uncoupling protein 1 (UCP1) analyses. Results: The ex-vivo phantom study showed excellent linear fit between measured fat concentration and the known gravimetric reference standard (r2 = 0.996). In vivo, BAT had significantly lower fat concentration than WAT (p < 0.001). Compared to the saline group, the iodine concentration of BAT increased significantly (p < 0.001) after injection of NE, while the iodine concentration of WAT only changed slightly. The BAT/aorta ratio also increased significantly after exposure to NE compared to the saline group (p < 0.001). Histological and UCP1 expression analyses supported the spectral CT imaging results. Conclusion: The study consolidates spectral CT as a new approach for non-invasive imaging of BAT and WAT. Quantitative analyses of BAT and WAT by spectral CT revealed different characteristics and pharmacologic activations in the two types of adipose tissue.
Sitagliptin attenuates endothelial dysfunction independent of its blood glucose controlling effect
Xin-Miao Chang,Fei Xiao,Qi Pan,Xiao-Xia Wang,Li-Xin Guo 대한생리학회-대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.5
Although the contributions of sitagliptin to endothelial dysfunction in diabetes mellitus were previously reported, the mechanisms still undefined. Autophagy plays an important role in the development of diabetes mellitus, but its role in diabetic macrovascular complications is unclear. This study aims to observe the effect of sitagliptin on macrovascular endothelium in diabetes and explore the role of autophagy in this process. Diabetic rats were induced through administration of high-fat diet and intraperitoneal injection of streptozotocin. Then diabetic rats were treated with or without sitagliptin for 12 weeks. Endothelial damage and autophagy were measured. Human umbilical vein endothelial cells were cultured either in normal glucose or in high glucose medium and intervened with different concentrations of sitagliptin. Rapamycin was used to induce autophagy. Cell viability, apoptosis and autophagy were detected. The expressions of proteins in c-Jun N-terminal kinase (JNK)-Bcl-2-Beclin-1 pathway were measured. Sitagliptin attenuated injuries of endothelium in vivo and in vitro. The expression of microtubuleassociated protein 1 light chain 3 II (LC3II) and beclin-1 were increased in aortas of diabetic rats and cells cultured with high-glucose, while sitagliptin inhibited the over-expression of LC3II and beclin-1. In vitro pre-treatment with sitagliptin decreased rapamycin-induced autophagy. However, after pretreatment with rapamycin, the protective effect of sitagliptin on endothelial cells was abolished. Further studies revealed sitagliptin increased the expression of Bcl-2, while inhibited the expression of JNK in vivo. Sitagliptin attenuates injuries of vascular endothelial cells caused by high glucose through inhibiting over-activated autophagy. JNK-Bcl-2-Beclin-1 pathway may be involved in this process.
Xin Xiong Chang,Nabisab Mujawar Mubarak,Shaukat Ali Mazari,Abdul Sattar Jatoi,Awais Ahmad,Mohammad Khalid,Rashmi Walvekar,E.C. Abdullah,Rama Rao Karri,M.T.H Siddiqui,Sabzoi Nizamuddin 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-
The concept of green chemistry has attracted attention due to the green synthesis and ecofriendly natureof the compounds leading to the green and sustainable chemical industries and processes. Chitosan is anecofriendly material, which is biodegradable, non-toxic, and biocompatible. It has the potential to bemodified into biofilms for various applications such as biomedical, packaging, and pharmaceutical fields. Nevertheless, some poor properties of chitosan restrict its wide applications. The incorporation ofnanocellulose fillers into chitosan matrix can enhance the mechanical and thermal properties of chitosan. Cellulose nanomaterials can be achieved through chemical and mechanical modifications. The commontype of nanocellulose are cellulose nanofibers (CNFs), cellulose nano-whiskers (CNWs), tunicate CNCs (t-CNCs), algae cellulose particles (AC) and bacterial cellulose particles (BC). Nanocellulose are applied asthe reinforcement fillers in various polymer matrices such as polysaccharides, proteins, lipids, polylacticacid etc. Deep eutectic solvents (DES) are relatively novel green solvents, which can be applied in variousfields. DES are widely applied in metal processing, polymer processing and synthesis. Even though thereare not much studies available on DES for synthesis of nanocomposite films; however they are used aseco-friendly solvents in manufacturing processes. This study reviews the discovery, structure, propertiesof chitosan and cellulose, their derivatives and applications. In addition, the paper also discusses theproperties of DES and their applications.
Xiaoqing Dong,Jingping Rao,Donald J. Huber,Xiaoxiao Chang,Fucun Xin 한국원예학회 2012 Horticulture, Environment, and Biotechnology Vol.53 No.4
Changes in surface wax composition of ‘Red Fuji’ apple (Malus domestica Borkh. ‘Red Fuji’) during development and during storage at 0 ± 1℃ after 1-methylcyclopropene (1-MCP) treatments were studied by the means of gas chromatography -mass spectrometry. Total wax increased during fruit development. During the storage at 0 ± 1℃, total waxes declined, and the decline was significantly delayed in 1-MCP–treated fruit. Total waxes were chromatographically separated into nonpolar and polar components. Nonacosane was the most abundant nonpolar wax, comprising 95% of total hydrocarbons. Polar wax components were comprised of nonacosan-10-ol (29%) and nonacosan-10-one (16%), along with a series of fatty acids and derivatives. Distinct patterns of wax changes were observed. Nonacosane, heptacosane and nonacosene increased during the development and decreased over seven months of fruit storage at 0 ± 1℃. Declines were delayed or slightly suppressed in 1-MCP–treated fruit. By contrast, nonacosan-10-ol, nonacosan-10-one, and 9, 12-octadecadienoic acid showed variable accumulation trends during the development but significant increases during storage that were strongly suppressed in 1-MCP–treated fruit. The association of wax changes with ethylene production and the responses to 1-MCP indicate that ethylene strongly influences wax composition in ‘Red Fuji’ apple fruit.