Influence of different extraction techniques on recovery, purity, antioxidant activities, and microstructure of flaxseed gum.

Four extraction techniques (that is, hot water extraction [HWE], alkaline-acidic extraction [AAE], ultrasound assisted extraction [UAE], and microwave assisted extraction [MAE]) were compared for flaxseed gum extraction and their influence on the yield, purity, structural characterization (monosaccharide composition, molecular weight distribution, and microstructure by transmission electron microscope), and antioxidant activity (in terms of scavenging ability of 2,2-diphenyl-1-picrylhydrazyl [DPPH], 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid [ABTS], and reducing power) was investigated. The HWE achieved higher yield (8.96%) than UAE (7.84%) followed by MAE (7.01%) and AAE (6.44%). Moreover, the four flaxseed gum (FSG) samples exhibited the identical monosaccharide composition, but slight difference was observed in the content, whereas the molecular weight ratios exhibited significant difference. All samples displayed concentration-dependent manner for all antioxidant assays. UAE-FSG showed significant higher scavenging ability on DPPH free radical, ABTS free radical, reducing power, and ß-carotene bleaching assay followed by HWE-FSG, MAE-FSG, and AAE-FSG. Overall results showed that UAE was favorable to the purity of FSG, whereas HWE was more advantageous to improve the extraction yield and facile as it requires no special equipment. PRACTICAL APPLICATION: Extraction methods directly affect the recovery and purity of the extracted compound. Thus, this study could help in selection of appropriate extraction method for FSG. The results suggested that FSG possesses potential healthcare application in food industry because of their nutrition composition and antioxidant activities, and thus, it can be used for formulation of functional food as a natural antioxidant agent.

Analysis of risk factors for susceptibility of frequent gout attacks: A case-control study of 579 patients with primary gout / 中华内分泌代谢杂志

Objective@#To analyze the risk factors of frequent gout flare, and to evaluate its susceptibility to identify patients with≥2 acute attacks per year.@*Methods@#A total of 579 of cases gout patients with no history of taking urate lowering treatment (ULT) in recent 12 months were enrolled. The patients were divided into frequent group (gout episodes≥twice per year) and non-frequent group(gout attacks<twice per year). The clinical information was collected and relevant biochemical indices were detected.@*Results@#There were significant differences in involvement of upper limb joints, tophi, combining hypertension and renal stone between two groups. The two groups had no statistical differences in family history, gender, history of smoking and drinking, ratios of regular exercise, and combining diabetes, hepatic insufficiency, hypertriglyceridemia, hypercholesterolemia, and overweight/obesity. There was significant differences in the number of joints involved, the history of disease duration, the level of SUA and TG[(4.66±2.54) vs (2.77±1.64), (6.68±5.11) vs (5.14±3.89) years, (525.82±132.11) vs (489.33±139.81) μmol/L, (2.51±1.94) vs (2.05±1.22) mmol/L, P<0.05 or P<0.01]; There were no statistical differences in age of onset, SBP, DBP, age of initial diagnosis, fasting blood glucose, TC, creatinine, glomerular filtration rate, AST, ALT, body mass index, waist circumference, and waist-to-hip ratio. Logistic regression analysis indicated that a large number of joints involved and higher serum uric acid level were risk factors of frequent gout attacks. The ROC curve showed that the number of joints involved had qualified performance in identifying patients with frequent gout attacks. When the number of joints involved was >2, and the sensitivity, specificity, positive predictive value and negative predictive value were 77.8%, 43.3%, 85.6%, and 56.6%, respectively, and the difference was significant.@*Conclusion@#Higher SUA and a larger number of joints involved associate independently with frequent gout attacks. The number of joints involved at initial diagnosis>2, which can predict the frequent flare, and start ULT as earlier as possible. Patients with joints involved at initial diagnosis>2 are at greater risk of frequent gout flare.

Analysis of risk factors for susceptibility of frequent gout attacks: A case-control study of 579 patients with primary gout / 中华内分泌代谢杂志

Objective:To analyze the risk factors of frequent gout flare, and to evaluate its susceptibility to identify patients with≥2 acute attacks per year.Methods:A total of 579 of cases gout patients with no history of taking urate lowering treatment (ULT) in recent 12 months were enrolled. The patients were divided into frequent group (gout episodes≥twice per year) and non-frequent group(gout attacks<twice per year). The clinical information was collected and relevant biochemical indices were detected.Results:There were significant differences in involvement of upper limb joints, tophi, combining hypertension and renal stone between two groups. The two groups had no statistical differences in family history, gender, history of smoking and drinking, ratios of regular exercise, and combining diabetes, hepatic insufficiency, hypertriglyceridemia, hypercholesterolemia, and overweight/obesity. There was significant differences in the number of joints involved, the history of disease duration, the level of SUA and TG[(4.66±2.54) vs (2.77±1.64), (6.68±5.11) vs (5.14±3.89) years, (525.82±132.11) vs (489.33±139.81) μmol/L, (2.51±1.94) vs (2.05±1.22) mmol/L, P<0.05 or P<0.01]; There were no statistical differences in age of onset, SBP, DBP, age of initial diagnosis, fasting blood glucose, TC, creatinine, glomerular filtration rate, AST, ALT, body mass index, waist circumference, and waist-to-hip ratio. Logistic regression analysis indicated that a large number of joints involved and higher serum uric acid level were risk factors of frequent gout attacks. The ROC curve showed that the number of joints involved had qualified performance in identifying patients with frequent gout attacks. When the number of joints involved was >2, and the sensitivity, specificity, positive predictive value and negative predictive value were 77.8%, 43.3%, 85.6%, and 56.6%, respectively, and the difference was significant. Conclusion:Higher SUA and a larger number of joints involved associate independently with frequent gout attacks. The number of joints involved at initial diagnosis>2, which can predict the frequent flare, and start ULT as earlier as possible. Patients with joints involved at initial diagnosis>2 are at greater risk of frequent gout flare.

Comparison of human and Drosophila atlastin GTPases

Formation of the endoplasmic reticulum (ER) network requires homotypic membrane fusion, which involves a class of atlastin (ATL) GTPases. Purified Drosophila ATL is capable of mediating vesicle fusion in vitro, but such activity has not been reported for any other ATLs. Here, we determined the preliminary crystal structure of the cytosolic segment of Drosophila ATL in a GDP-bound state. The structure reveals a GTPase domain dimer with the subsequent three-helix bundles associating with their own GTPase domains and pointing in opposite directions. This conformation is similar to that of human ATL1, to which GDP and high concentrations of inorganic phosphate, but not GDP only, were included. Drosophila ATL restored ER morphology defects in mammalian cells lacking ATLs, and measurements of nucleotide-dependent dimerization and GTPase activity were comparable for Drosophila ATL and human ATL1. However, purified and reconstituted human ATL1 exhibited no in vitro fusion activity. When the cytosolic segment of human ATL1 was connected to the transmembrane (TM) region and C-terminal tail (CT) of Drosophila ATL, the chimera still exhibited no fusion activity, though its GTPase activity was normal. These results suggest that GDP-bound ATLs may adopt multiple conformations and the in vitro fusion activity of ATL cannot be achieved by a simple collection of functional domains.