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OBJECTIVE To establish comprehensive quality evaluation method based on multi-index components combined with multivariate statistical analysis， and to comprehensively evaluate the quality of Periploca forrestii. METHODS Taking 11 batches of P. forrestii medicinal materials from different areas in Guizhou as samples， the contents of neochlorogenic acid， cryptochlorogenic acid， chlorogenic acid， procyanidin A2， isochlorogenic acid A and isochlorogenic acid C were determined by HPLC. Clustering heat map analysis， grey correlation analysis（GRA） and technique for order preference by similarity to ideal solution（TOPSIS） were used to evaluate the quality of P. forrestii. RESULTS The results of methodological investigation of content determination were in accordance with the relevant regulations， and the linear relationship and accuracy of each component were good in their respective sampling range. The contents of chlorogenic acid， cryptochlorogenic acid， neochlorogenic acid， procyanidin A2， isochlorogenic acid A and isochlorogenic acid C in 11 batches of samples were 3.650-7.302， 0.888-2.575， 1.371- 2.386， 0.947-1.469， 0.084-0.169 and 0.725-1.067 mg/g， respectively. The content of each component was significantly different， with the highest content of chlorogenic acid and the lowest content of isochlorogenic acid A. The comprehensive results of cluster heat map， GRA and TOPSIS analysis showed that the comprehensive quality of S5 and S10 was relatively good. CONCLUSIONS The established method is accurate， stable and simple. Combined with multivariate statistical analysis method， it can be used for quality evaluation of P. forrestii. The quality of samples from Jiuzhou Town and Caiguan Town of Xixiu District in Anshun City of Guizhou Province are relatively good among 11 different origin samples.
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OBJECTIVE To provide reference for quality control of Gentiana rhodantha. METHODS Taking 52 batches of G. rhodantha as subject， ultra-high performance liquid chromatography （UPLC） fingerprint was adopted. The similarity of 52 batches of medicinal materials samples was evaluated by the Similarity Evaluation System for Chromatographic Fingerprints of Traditional Chinese Medicine （2004A edition）； the content of mangiferin was determined； chemometric analyses [cluster analysis， principal component analysis （PCA） and orthogonal partial least squares-discriminant analysis （OPLS-DA）] were performed. RESULTS UPLC fingerprints of 52 batches of G. rhodantha were established， 17 common peaks were identified， and 6 of them were identified， which were loganic acid （peak 1）， neomangiferin （peak 3）， swertiamarin （peak 5）， dangyin （peak 6）， mangiferin （peak 7） and isoorientin （peak 9）. The similarities of 52 batches of medicinal materials samples were all greater than 0.9； cluster analysis showed that S1-S46， S48-S52 clustered into one class， and S47 alone； PCA results showed that the cumulative variance contribution rate of the first six principal components was 82.928%； OPLS-DA results showed that the corresponding components of swertiamarin， mangiferin and chemical composition represented by peak 4， 14， 15， 16 were the main iconic components affecting the quality differences of G. rhodantha medicinal materials. The contents of mangiferin in 52 batches of medicinal material samples ranged from 18.2 to 101.0 mg/g， mostly in accordance with 2020 edition of Chinese Pharmacopoeia. CONCLUSIONS The established UPLC fingerprint and chemometric analysis methods combined with content determination method of mangiferin can comprehensively evaluate the quality of G. rhodantha.
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Polyarteritis nodosa (PAN) is a rare vasculitis that mainly involves small and medium arteries. It often occurs at the points where the vessels bifurcate, leading to microaneurysm formation, thrombosis, aneurysm rupture and bleeding, and infarction of organs.About a third of cases are associated with hepatitis B virus (HBV) infection.All tissues and organs of the body can be affected, with skin, joints and peripheral nerves being the most common.The pathological changes were fibrinoid necrosis, inflammatory cell infiltration and luminal thrombosis in the acute stage, and fibrous hyperplasia in the chronic stage.Overall outcomes for the disease have improved in recent decades, mainly reflecting early diagnosis and more effective treatments.The main treatments for PAN are glucocorticoid and cyclophosphamide.Patients with HBV-associated PAN should receive antiviral therapy and plasma exchange.
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OBJECTIVE To establish a method for simultaneous determi nation of six components in Melastoma dodecandrum and investigate its correlation with antioxidant activity. METHODS Ultra high-performance liquid chromatography （UPLC）method was adopted. The contents of gallic acid ，protocatechuic acid ，isovitexin，rutin and ellagic acid in 23 batches of M. dodecandrum were determined by quantitative analysis of multi-components by single-marker （QAMS）method，using vitexin as the internal reference. Then 1，1-diphenyl-2-picrylhydrazyl（DPPH）free radical method ，2，2′-azino-bis（3-ethylbenzothiazoline-6-sulfonic acid ） diammonium salt （ABTS）method and ferric ion reduction/antioxidant power （FRAP）method were applied to determine the antioxidant activity of 23 batches of M. dodecandrum . Grey correlation analysis and bivariate correlation analysis were used to evaluate the correlation between six components and antioxidant activity. RESULTS The content of vitexin were 0.021％-0.182％. The contents of gallic acid ，protocatechuic acid ，isovitexin，rutin and ellagic acid by QAMS method were 0.008％-0.042％， 0.003％-0.023％，0.071％-0.283％，0.013％-0.140％ and 0.006％-0.021％，respectively. Compared with the results of external standard method ，P was greater than 0.05. Grey correlation analysis showed that the grey correlation coefficients between the contents of six components an d antioxidant activity was 0.727 6- 0.866 9. Bivariate correlation analysis showed that the contents of vitexin ，isovitexin and rutin were positively correlated with antioxidant activity （P＜0.05 or P＜0.01），the content of gallic acid and protocatechuic acid were negatively correlated with antioxidant activity （P＜0.05）. There was no significant correlation between ellagic acid and antioxidant activity.CONCLUSIONS QAMS method is successfully established for the simultaneous determination of six components in M. dodecandrum. The six components in M. dodecandrum are highly correlated with antioxidant activity.
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Ion channels mediate ion transport across membranes, and play vital roles in processes of matter exchange, energy transfer and signal transduction in living organisms. Recently, structural studies of ion channels have greatly advanced our understanding of their ion selectivity and gating mechanisms. Structural studies of voltage-gated potassium channels elucidate the structural basis for potassium selectivity and voltage-gating mechanism; structural studies of voltage-gated sodium channels reveal their slow and fast inactivation mechanisms; and structural studies of transient receptor potential (TRP) channels provide complex and diverse structures of TRP channels, and their ligand gating mechanisms. In the article we summarize recent progress on ion channel structural biology, and outlook the prospect of ion channel structural biology in the future.
Subject(s)
Ion Channel Gating , Physiology , Ion Channels , Voltage-Gated Sodium Channels , Chemistry , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To study the risk factor of perioperative complication in gastric cancer patients with radical therapy and its influence on prognosis.</p><p><b>METHODS</b>Clinical, pathological and follow-up data of 1 148 gastric cancer patients undergoing radical gastrectomy at Tianjin Medical University Affiliated Tumor Hospital between January 2009 and August 2011 were retrospectively collected. Pearson 2 test and Logistic regression analysis were used to analyze the risk factor of perioperative complication. Cox regression analysis was used to evaluate the influence of perioperative complications on the prognosis in patients after radical gastrectomy. Kaplan-Meier survival curve was applied to calculate the survival.</p><p><b>RESULTS</b>Of 1 148 patients, 851 were male, 297 were female, age ranged from 19 to 89 (average 59.9) years. Perioperative complication occurred in 312 cases (27.2%), including 140 cases of pulmonary infection and 53 cases of abdominal infection. Multivariate Logistic regression analysis showed that ≥65 years old (OR:0.736, 95%CI: 0.558 to 0.971, P=0.030), serum albumin less than 35 g/L(OR:2.626, 95%CI: 1.479 to 4.665, P=0.001), Borrmann type IIII((OR: 0.748, 95%CI: 0.610 to 0.917, P=0.005), tumor site at upper 1/3 of stomach (OR:1.326, 95%CI:1.167 to 1.506, P=0.000), combined organ resection(OR:0.624, 95%CI:0.428 to 0.909, P=0.014) were independent risk factors of perioperative complication. Tumor site at upper 1/3 of stomach (OR:1.649, 95%CI: 1.368 to 1.988, P=0.000), ≥65 years old (OR:0.548, 95%CI:0.379 to 0.792, P=0.001), without intraoperative chemotherapy (OR:1.671, 95%CI:1.146 to 2.437, P=0.008) were independent risk factors of perioperative pulmonary infection; Borrmann type IIII((OR:0.576, 95%CI:0.369 to 0.900, P=0.015), with intraoperative chemotherapy (OR:0.431, 95%CI:0.230 to 0.810, P=0.009), intraoperative blood loss ≥400 ml(OR:0.411, 95%CI:0.176 to 0.959, P=0.040) and combined organ resection (OR:0.412, 95%CI:0.215 to 0.789, P=0.008) were independent risk factors of perioperative intraperitoneal infection. Cox regression analysis revealed that without intraoperative chemotherapy, proximal subtotal or total gastrectomy, TNM stage III(, N3 stage lymph node metastasis, positive soft tissue outside lymph node, combined organ resection and organ failure were independent risk factors affecting the prognosis of gastric cancer patients after radical resection (all P<0.05), however the perioperative complication was not independent risk factor affecting the prognosis (P=0.259). The median survival time was 35 months, and 5-year survival rate was around 38.7%. The median survival time of gastric cancer patients with operative complications and without complications were 28.0 and 36.5 months, and the 5-year survival rates were 37.2% and 39.3%, whose difference was not statistically significant (P=0.259).</p><p><b>CONCLUSION</b>There is a higher risk of perioperative complication in those gastric cancer patients with old age, preoperative low serum albumin level, tumor site at upper 1/3 of stomach, Borrmann type IIII(, intraoperative combined organ resection, while the perioperative complication has no significant effects on the long-term survival.</p>
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Under natural environments, plants and algae have evolved various photosynthetic acclimation mechanisms in response to the constantly changing light conditions. The state transition and long-term response processes in photosynthetic acclimation involve remodeling and composition alteration of thylakoid membrane. A chloroplast protein kinase named Stt7/STN7 has been found to have pivotal roles in both state transition and long-term response. Here we report the crystal structures of the kinase domain of a putative Stt7/STN7 homolog from Micromonas sp. RCC299 (MsStt7d) in the apo form and in complex with various nucleotide substrates. MsStt7d adopts a canonical protein kinase fold and contains all the essential residues at the active site. A novel hairpin motif, found to be a conserved feature of the Stt7/STN7 family and indispensable for the kinase stability, interacts with the activation loop and fixes it in an active conformation. We have also demonstrated that MsStt7d is a dualspecifi city kinase that phosphorylates both Thr and Tyr residues. Moreover, preliminary in vitro data suggest that it might be capable of phosphorylating a consensus N-terminal pentapeptide of light-harvesting proteins Micromonas Lhcp4 and Arabidopsis Lhcb1 directly. The potential peptide/protein substrate binding site is predicted based on the location of a pseudo-substrate contributed by the adjacent molecule within the crystallographic dimer. The structural and biochemical data presented here provide a framework for an improved understanding on the role of Stt7/STN7 in photosynthetic acclimation.