The Experts below are selected from a list of 3204 Experts worldwide ranked by ideXlab platform
Michael J Gidley - One of the best experts on this subject based on the ideXlab platform.
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digestion of isolated legume cells in a stomach duodenum model three mechanisms limit starch and protein hydrolysis
Food & Function, 2017Co-Authors: Rewati R Bhattarai, Sushil Dhital, Peng Wu, Xiao Dong Chen, Michael J GidleyAbstract:Retention of intact plant cells to the end of the small intestine leads to transport of entrapped macronutrients such as starch and protein for colonic microbial fermentation, and is a promising mechanism to increase the content of resistant starch in diets. However, the effect of gastro-intestinal bio-mechanical processing on the Intactness of plant cells and the subsequent resistance to enzymatic digestion of intracellular starch and protein are not well understood. In this study, intact cells isolated from legume cotyledons are digested in a laboratory model which mimics the mechanical and biochemical conditions of the rat stomach and duodenum. The resulting digesta are characterised in terms of cell (wall) integrity as well as intracellular starch and protein hydrolysis. The cells remained essentially intact in the model with negligible (ca. 2–3%) starch or protein digestion; however when the cells were mechanically broken and digested in the model, the hydrolysis was increased to 45–50% suggesting that intact cellular structures could survive the mixing regimes in the model stomach and duodenum sufficiently to prevent digestive enzyme access. Apart from intact cell walls providing effective barrier properties, they also limit digestibility by restricting starch gelatinisation during cooking, and significant non-specific binding of α-amylase is observed to both intact and broken cell wall components, providing a third mechanism hindering starch hydrolysis. The study suggests that the preservation of Intactness of plant cells, such as from legumes, could be a viable approach to achieve the targeted delivery of resistant starch to the colon.
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Intactness of cell wall structure controls the in vitro digestion of starch in legumes
Food & Function, 2016Co-Authors: Sushil Dhital, Rewati R Bhattarai, John Gorham, Michael J GidleyAbstract:Increasing the level of starch that is not digested by the end of the small intestine and therefore enters the colon (‘resistant starch’) is a major opportunity for improving the nutritional profile of foods. One mechanism that has been shown to be successful is entrapment of starch within an intact plant tissue structure. However, the level of tissue Intactness required for resistance to amylase digestion has not been defined. In this study, intact cells were isolated from a range of legumes after thermal treatment at 60 °C (starch not gelatinised) or 95 °C (starch gelatinised) followed by hydrolysis using pancreatic alpha amylase. It was found that intact cells, isolated at either temperature, were impervious to amylase. However, application of mechanical force damaged the cell wall and made starch accessible to digestive enzymes. This shows that the access of enzymes to the entrapped swollen starch is the rate limiting step controlling hydrolysis of starch in cooked legumes. The results suggest that a single cell wall could be sufficient to provide an effective delivery of starch to the large intestine with consequent nutritional benefits, provided that mechanical damage during digestion is avoided.
Yijiao Wang - One of the best experts on this subject based on the ideXlab platform.
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contrast enhanced ultrasonography diagnosis of fundal localized type of gallbladder adenomyomatosis
BMC Gastroenterology, 2015Co-Authors: Shao-shan Tang, Liping Huang, Yao Wang, Yijiao WangAbstract:Adenomyomatosis of gallbladder is an acquired hyperplastic lesion, characterized by focal or diffuse thickening of the gallbladder with intramural cysts or echogenic areas with comet tail on ultrasonography. But in some cases, especially in the localized fundal type of adenomyomatosis, the intramural anechoic cystic spaces are uncertainty which causes difficult to differential adenomyomatosis from GB cancer. The purpose of this study was to determine the accuracy of real-time contrast-enhanced ultrasonography(CEUS) in the diagnosis of the fundal localized type of gallbladder adenomyomatosis. We performed a retrospective study of 21 patients with pathologically proven fundal localized type of gallbladder (GB) adenomyomatosis. All patients underwent preoperative grayscale ultrasound (US) and real-time CEUS examination. The study’s reviewers made the diagnosis of adenomyomatosis according to the presence of the focal thickening of the fundal gallbladder wall with intramural cyst or intramural echogenic foci on grayscale US or CEUS. The diagnostic accuracy of US and CEUS was compared. The enhanced pattern and degree of Intactness of the GB wall were also recorded. The fundal portion of the GB wall showed localized thickness in all 21 patients. Small anechoic spaces or intramural echogenic foci were detected in 14 (66.7 %) and 21 (100 %) of cases respectively, and the Intactness of the GB wall’s outer hyper-echoic layer was demonstrated in 17 (81 %) and 20 (95 %) on grayscale US and CEUS, respectively. The accuracy rate of the above two examination modalities was significantly different (p < 0.05). In the arterial phase of the CEUS, areas of focal thickened GB wall were iso-enhanced in 18 cases and hyper-enhanced in 3 cases. All 21 cases appeared to show heterogeneous enhancement with small non-enhancement spaces. The mucosal and serosal layers of the GB wall surrounding the lesions were enhanced, which presented as two “hyper-echoic lines” in the arterial phase of CEUS. In the venous phase of the CEUS, 19 lesions were iso-enhanced and 2 lesions were hypo-enhanced. The small non-enhancement spaces were more clearly during the venous phase. The small non-enhancement space is a characteristic finding of the fundal localized type of gallbladder adenomyomatosis on CEUS. CEUS could increase the degree of visualization of Rokitansky-Aschoff sinuses (RAS) and Intactness of the GB wall, which play an important role in differential diagnosis.
Xuejun Chen - One of the best experts on this subject based on the ideXlab platform.
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contrast enhanced ultrasonography in differential diagnosis of focal gallbladder adenomyomatosis and gallbladder cancer
Clinical Hemorheology and Microcirculation, 2018Co-Authors: Haixia Yuan, Peishan Guan, Qing Yu, Wenping Wang, Xuejun ChenAbstract:BACKGROUND: Focal gallbladder adenomyomatosis (ADM) is a common disease that mimics gallbladder cancer (GBC) on ultrasonography. OBJECTIVE: Here we aim to assess the value of contrast-enhanced ultrasound (CEUS) in differentiating ADM from GBC. METHODS: Forty-one histopathologically proven focal ADMs and 34 GBCs (≤T2 stage) were enrolled in the study. Lesion location, blood flow signals, contrast pattern and appearance on contrast-enhanced ultrasound (CEUS) were compared respectively. RESULTS: Lesions were detected in fundus, body, neck at the rates of 61.0% (25/41), 26.8% (11/41) and 12.2% (5/41), respectively, in ADM patients, in comparison to 29.4% (10/34), 32.4% (11/34) and 38.2% (13/34), respectively, in GBC patients (p = 0.009). Blood flow signals were detected in 19.5% (8/41) of cases in ADMs, compared to 58.8% (20/34) in GBCs (p = 0.001). On CEUS, iso-enhancement, hypo-enhancement, intramural anechoic space and Intactness of GB wall were detected in 41.5% (17/41), 39.0% (16/41), 56.1% (23/41) and 80.5% (33/41) cases of ADMs, in contrast to 17.6% (6/34), 20.6% (7/34), 20.6% (7/34) and 17.6% (6/34) of GBCs (p = 0.001, p = 0.001, p = 0.002, p < 0.001, respectively). The prior Youden's index were 0.81 based on Intactness of GB wall on CEUS. CONCLUSION: Combined with CEUS helps improve the differential diagnosis accuracy of focal gallbladder ADMs.
Norbert Rolland - One of the best experts on this subject based on the ideXlab platform.
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purification of intact chloroplasts from arabidopsis and spinach leaves by isopycnic centrifugation
Current protocols in pharmacology, 2008Co-Authors: Daphne Seigneurinberny, Daniel Salvi, Jacques Joyard, Norbert RollandAbstract:Chloroplasts are plant-specific organelles. They are the site of photosynthesis but also of many other essential metabolic pathways, such as syntheses of amino acids, vitamins, lipids, and pigments. This unit describes the isolation and purification of chloroplasts from Arabidopsis and spinach leaves. Differential centrifugation is first used to obtain a suspension enriched in chloroplasts (crude chloroplasts extract). In a second step, Percoll density gradient centrifugation is used to recover pure and intact chloroplasts. The Basic Protocol describes the purification of chloroplasts from Arabidopsis leaves. This small flowering plant is now widely used as a model organism in plant biology as it offers important advantages for basic research in genetics and molecular biology. The Alternate Protocol describes the purification of chloroplasts from spinach leaves. Spinach, easily available all through the year, remains a model of choice for the large-scale preparation of pure chloroplasts with a high degree of Intactness. Curr. Protoc. Cell Biol. 40:3.30.1-3.30.14. © 2008 by John Wiley & Sons, Inc. Keywords: chloroplast; Arabidopsis; spinach; purification; leaves
Shao-shan Tang - One of the best experts on this subject based on the ideXlab platform.
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contrast enhanced ultrasonography diagnosis of fundal localized type of gallbladder adenomyomatosis
BMC Gastroenterology, 2015Co-Authors: Shao-shan Tang, Liping Huang, Yao Wang, Yijiao WangAbstract:Adenomyomatosis of gallbladder is an acquired hyperplastic lesion, characterized by focal or diffuse thickening of the gallbladder with intramural cysts or echogenic areas with comet tail on ultrasonography. But in some cases, especially in the localized fundal type of adenomyomatosis, the intramural anechoic cystic spaces are uncertainty which causes difficult to differential adenomyomatosis from GB cancer. The purpose of this study was to determine the accuracy of real-time contrast-enhanced ultrasonography(CEUS) in the diagnosis of the fundal localized type of gallbladder adenomyomatosis. We performed a retrospective study of 21 patients with pathologically proven fundal localized type of gallbladder (GB) adenomyomatosis. All patients underwent preoperative grayscale ultrasound (US) and real-time CEUS examination. The study’s reviewers made the diagnosis of adenomyomatosis according to the presence of the focal thickening of the fundal gallbladder wall with intramural cyst or intramural echogenic foci on grayscale US or CEUS. The diagnostic accuracy of US and CEUS was compared. The enhanced pattern and degree of Intactness of the GB wall were also recorded. The fundal portion of the GB wall showed localized thickness in all 21 patients. Small anechoic spaces or intramural echogenic foci were detected in 14 (66.7 %) and 21 (100 %) of cases respectively, and the Intactness of the GB wall’s outer hyper-echoic layer was demonstrated in 17 (81 %) and 20 (95 %) on grayscale US and CEUS, respectively. The accuracy rate of the above two examination modalities was significantly different (p < 0.05). In the arterial phase of the CEUS, areas of focal thickened GB wall were iso-enhanced in 18 cases and hyper-enhanced in 3 cases. All 21 cases appeared to show heterogeneous enhancement with small non-enhancement spaces. The mucosal and serosal layers of the GB wall surrounding the lesions were enhanced, which presented as two “hyper-echoic lines” in the arterial phase of CEUS. In the venous phase of the CEUS, 19 lesions were iso-enhanced and 2 lesions were hypo-enhanced. The small non-enhancement spaces were more clearly during the venous phase. The small non-enhancement space is a characteristic finding of the fundal localized type of gallbladder adenomyomatosis on CEUS. CEUS could increase the degree of visualization of Rokitansky-Aschoff sinuses (RAS) and Intactness of the GB wall, which play an important role in differential diagnosis.
