C-kit-negative Extragastrointestinal Stromal Tumor Originating in the Mesentery Misdiagnosed as an Ovarian Tumor before Surgery

Gastrointestinal stromal tumors (GISTs) are rare digestive system malignancies with extragastrointestinal stromal tumors (EGISTs) being even less. Diagnosing GISTs usually requires the identification of c-kit (CD117) expression by immunohistochemical staining. A 53-year-old woman complaining of dyspepsia was referred for the evaluation of a 1.5-cm extrinsic compression at the greater curvature of the proximal antrum. EUS revealed a multiseptated mass with positive Doppler findings. Abdominal CT showed that she harbored a large, 20-cm mass in her abdominal cavity, most likely arising from the right ovary. Surgery revealed a hypervascular tumor arising from the mesentery and attached to the gastric lesser curvature. Pathological examination revealed negativity for c-kit, but positivity for the protein “Discovered on GIST-1” (DOG1), confirming the EGIST diagnosis. Herein, we report this rare case of a c-kit-negative EGIST originating in the mesentery, which was diagnosed based on staining for DOG1

An Empirical Study on the Bias of Generative Image Compression

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Determination of Hexanal in Rice Using an Automated Dynamic Headspace Sampler Coupled to a Gas Chromatograph-Mass Spectrometer

Korea Food Research Institute [ER102000, ER111001]; National Nature Scientific Foundation of China-Korea Joint Research Project [20911140274]The aim of this study was to establish a method for the determination of hexanal as a lipid oxidation marker in rice. For the sample preparation, ground rice exhibited better sensitivity and reproducibility for the analysis of hexanal than whole rice. A total flow of purge gas of 300 mL at 20 mL/min of purge was sufficient to obtain the necessary sensitivity for the analysis of hexanal in rice. The total time for sample preparation and analysis for individual samples was approximately 15 min. A low incubation temperature of 30 degrees C was chosen, not only to reduce the effect of water, but also to avoid excess lipid oxidation and loss of hexanal during the analysis. The limits of detection and quantification were 3.7 and 5.1 ng/g, respectively. Good linearity was obtained in the range from 5.1-500.0 ng/g. The recoveries of hexanal in rice were greater than 97.0 and 107.0% at the spiked levels of 5 and 50 ng/g, respectively, with relative standard deviations of 3.3 and 6.1%, respectively

Simultaneous determination of four bioactive compounds in Korean rice wine (makgeolli) by solvent extraction coupled with gas chromatography-mass spectrometry

Makgeolli is a traditional Korean rice wine reported to have anticancer, anti-inflammatory, and antioxidant effects. We developed an approach involving solvent extraction coupled with gas chromatography-mass spectrometry to determine four bioactive compounds, farnesol (FOH), squalene (SQ), and newly identified 4-vinyl guaiacol (4-VG) and 2,4-di-tert-butylphenol (DTBP), in makgeolli. The method was validated with the linearity, limit of detection, limit of quantification, intra- and inter-day precision, and accuracy. The validated method was then applied to several makgeolli, beer, and wine samples. 4-VG and DTBP were identified in all beverages, but FOH and SQ were only identified in makgeolli

Structural basis for the transglycosylase activity of a GH57-type glycogen branching enzyme from Pyrococcus horikoshii

Glycogen branching enzyme (GBE) catalyzes the formation of alpha-1,6-branching points during glycogenesis by cleaving alpha-1,4 bonds and making new a-1,6 bonds. Most GBEs belong to the glycoside hydrolase 13 family (GH13), but new GBEs in the GH57 family have been isolated from Archaea. Here, we determined the crystal structure of a GH57 GBE from the hyperthermophilic archaeon Pyrococcus horikoshii (PhGBE) at a resolution of 2.3 angstrom. PhGBE exhibits both alpha-1,6-branching activity and endo-alpha-1,4 hydrolytic activity. PhGBE has a central (beta/alpha)(7)-barrel domain that contains an embedded helix domain and an alpha-helix-rich C-terminal domain. The active-site cleft is located at the interface of the central and C-terminal domains. Amino acid substitution at Trp22, which is separate from the catalytic nucleophilic residue, abolished both enzymatic activities, indicating that Trp22 might be responsible for substrate recognition. We also observed that shortening of the flexible loop near the catalytic residue changed branched chain lengths of the reaction products with increased hydrolytic activity. Taken together, our findings propose a molecular mechanism for how GH57 GBEs exhibit the two activities and where the substrate binds the enzyme.OAIID:RECH_ACHV_DSTSH_NO:T201702142RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079611CITE_RATE:2.559DEPT_NM:농생명공학부EMAIL:[email protected]_YN:YN

Determination of E,E-farnesol in Makgeolli (rice wine) using dynamic headspace sampling and stir bar sorptive extraction coupled with gas chromatography-mass spectrometry

Korea Food Research Institute [ER122000, ER136001]; Ministry for Food, Agriculture, Forestry and Fisheries of Korea; National Nature Scientific Foundation of China-Korea Joint Research Project [20911140274]; Nature Scientific Foundation of Fujian [2009J01042]In this paper, we analysed the volatile and semi-volatile compounds, including E,E-farnesol in Makgeolli which is a traditional type of Korean fermented rice wines. Forty-one compounds including alcohols, 1-butanol-3-methyl acetate, E,E-farnesol, stearol, and phytane, were separated and quantified by dynamic headspace sampling (DHS) and stir bar sorptive extraction (SBSE) coupled with gas chromatography-mass spectrometry. SBSE has been found to be an effective method for analysing E,E-farnesol levels in Makgeolli. The experimental parameters related to the extraction efficiency of the SBSE method, such as ethanol concentration and filtration, were studied and optimised. The linear dynamic range of the SBSE method for E,E-farnesol ranged from 0.02 to 200 ng ml(-1) with R-2 = 0.9974. The limit of detection and limit of quantification of the SBSE method were 0.02 and 0.05 ng ml(-1), respectively. The relative standard deviation of intra- and inter-day reproducibility was less than 6.2% and 9.9%, respectively. (C) 2013 Elsevier Ltd. All rights reserved

Determination of Hexanal as an Oxidative Marker in Vegetable Oils Using an Automated Dynamic Headspace Sampler Coupled to a Gas Chromatograph/Mass Spectrometer

Research Foundation of Korea [F01-2009-000-10024-0]; Korea Food Research Institute [N01207, ER102000]; National Nature Scientific Foundation of China-Korea [20911140274]An automated dynamic headspace sampler coupled to a gas chromatograph/mass spectrometer was evaluated as an oxidative marker to determine hexanal content in vegetable oils. For the effective analysis, a cooled injection system (CIS) was used to focus and to introduce the hexanal desorbed from the Tenax TA. The temperature of the CIS was maintained at -60 degrees C for 12 min before desorbing the hexanal. Hexanal was separated on a capillary column (DB-5, 0.25 mm x 60 m, 0.25 mu m in film thickness) from 50 to 230 degrees C, followed by mass spectrometer-selected ion monitoring analysis at m/z 56. The instrumental response to hexanal was highly linear from 10 ng mL(-1) to 1 mu g mL(-1) (r(2) = 0.9999). The relative standard deviation (RSD) of intra- and inter-day repeatability was acceptable, with values of less than 3.88 and 4.25%, respectively. The LOD and LOQ of hexanal were determined by gas chromatograph/mass spectrometer-selected ion monitoring to be 3.3 and 9.8 ng mL(-1), respectively. The acid value, peroxide value and fatty acid composition revealed a good correlation with the hexanal concentration