不同胰岛素给药方式救治糖尿病酮症酸中毒临床研究

目的：比较不同胰岛素给药方式治疗糖尿病酮症酸中毒（DKA）的临床疗效。方法：82例DKA患者随机分为胰岛素泵持续皮下输液胰岛素（CSⅡ）组和微量泵持续静脉泵入胰岛素（CXqI）组各41例,分别给予胰岛素泵持续皮下输注胰岛素和小剂量胰岛素持续微量泵静脉泵入不同胰岛素给药方式,观察两组治疗后血糖变化、血糖达标时间、尿酮体变化、pH值变化、胰岛素平均日用量、平均低血糖次数及平均住院时间。结果：两组治疗后空腹血糖、餐后血糖显著下降及血糖达标时间显著缩短差异无统计学意义（P〉0．05）;CSII组尿酮体转阴时间（22．3±7．4）h短于CVII组（32．1±12．1）h（P〈0．01）;CSII组PH值恢复时间（9．4±2．5）h短于CVII组（15．7±3．5）h（P〈0．01）;CSII组平均胰岛素日用量为（47±5）U比CVII组（58＋7）U少（P〈0．01）;CSII组人均低血糖次数为（0．6±O．5）次／人。少于CVII组（1．5±0．8）次／人（P〈O．01）;CSII组住院时间（9．8±1．2）天明显比CVII组（12．5±2．0）天短（P〈0．01）。结论：CSII相较于CVII能更快更有效的纠正代谢紊乱,减少胰岛素日用量,缩短住院时间,从而提高临床疗效。具有较高的安全性及患者依从性。     

Biochemical characterization of cultivated Cordyceps bassiana mycelia and fruiting bodies by 1H nuclear magnetic resonance spectroscopy

In this study, nuclear magnetic resonance techniques coupled with multivariate data analysis were used for the metabolic profiling of mycelia and fruiting bodies of the entomopathogenic fungi, Cordyceps bassiana according to developmental stages. A direct extraction method using two deuterated solvents of D₂O and CDCl₃ was used to investigate the relative levels of identified metabolites in each extraction condition in the mycelium and fruiting body formation stages. There was a clear separation among mycelia and fruiting bodies with various developmental stages in partial least-squares discriminant analysis (PLS-DA) derived score plots. During the transition from mycelia to fruiting bodies, the major metabolic change observed was the conversion of glucose to mannitol, and beauvericin to phenylalanine and 1-hydroxyisovaleric acid. In the developmental stages of fruiting bodies studied, there was a clear separation between stage 3 and the other stages in PLS-DA derived score plots. Nineteen compounds including 13 amino acids, 2 nucleosides, 3 organic acids, and glucose showed the highest levels in stage 3 fruiting bodies. The flavonoid content in the fruiting bodies showed similar levels during stages 1, 2, and 3, whereas the level at stage 4 was significantly decreased compared to the other stages. Results suggest that the fruiting body of C. bassiana is richer in natural resources at stage 3 compared to the other fruiting body stages due to its high abundance of compounds including total flavonoids. The metabolome information acquired in this study can be useful criteria for the quality control of commercial use of C. bassiana.     

Inhibitory effect of α-ketoglutaric acid on α-glucosidase: integrating molecular dynamics simulation and inhibition kinetics

Abstract

The inhibition of α-glucosidase is used as a key clinical approach to treat type 2 diabetes mellitus and thus, we assessed the inhibitory effect of α-ketoglutaric acid (AKG) on α-glucosidase with both an enzyme kinetic assay and computational simulations. AKG bound to the active site and interacted with several key residues, including ASP68, PHE157, PHE177, PHE311, ARG312, TYR313, ASN412, ILE434 and ARG439, as detected by protein–ligand docking and molecular dynamics simulations. Subsequently, we confirmed the action of AKG on α-glucosidase as mixed-type inhibition with reversible and rapid binding. The relevant kinetic parameter IC₅₀ was measured (IC₅₀ = 1.738?±?0.041?mM), and the dissociation constant was determined (K_{i Slope} = 0.46?±?0.04?mM). Regarding the relationship between structure and activity, a high AKG concentration induced the slight modulation of the shape of the active site, as monitored by hydrophobic exposure. This tertiary conformational change was linked to AKG inhibition and mostly involved regional changes in the active site. Our study provides insight into the functional role of AKG due to its structural property of a hydroxyphenyl ring that interacts with the active site. We suggest that similar hydroxyphenyl ring-containing compounds targeting key residues in the active site might be potential α-glucosidase inhibitors. Abbreviations AKG alpha-ketoglutaric acid

pNPG 4-nitrophenyl-α-d-glucopyranoside

ANS 1-anilinonaphthalene-8-sulfonate

MD molecular dynamics.

Communicated by Ramaswamy H. Sarma     

Non-linear molecular pattern classification using molecular beacons with multiple targets

In vitro pattern classification has been highlighted as an important future application of DNA computing. Previous work has demonstrated the feasibility of linear classifiers using DNA-based molecular computing. However, complex tasks require non-linear classification capability. Here we design a molecular beacon that can interact with multiple targets and experimentally shows that its fluorescent signals form a complex radial-basis function, enabling it to be used as a building block for non-linear molecular classification in vitro. The proposed method was successfully applied to solving artificial and real-world classification problems: XOR and microRNA expression patterns.     

Comparison of Expression of Inflammatory Cytokines in the Spinal Cord Between Young Adult and Aged Beagle Dogs

Aging is an inevitable process that occurs in the whole body system accompanying with many functional and morphological changes. Inflammation is known as one of age-related factors, and inflammatory changes could enhance mortality risk. In this study, we compared immunoreactivities of inflammatory cytokines, such as interleukin (IL)-2 (a pro-inflammatory cytokine), its receptor (IL-2R), IL-4 (an anti-inflammatory cytokine), and its receptor (IL-4R) in the cervical and lumbar spinal cord of young adult (2–3 years old) and aged (10–12 years old) beagle dogs using immunohistochemistry and western blotting. IL-2 and IL-2R-immunoreactive nerve cells were found throughout the gray matter of the cervical and lumbar spinal cord of young adult and aged dogs. In the spinal cord neurons of the aged dog, immunoreactivity and protein levels were apparently increased compared with those in the young adult dog. Change patterns of IL-4- and IL-4R-immunoreactive cells and their protein levels were also similar to those in IL-2 and IL-2R; however, IL-4 and IL-4R immunoreactivity in the periphery of the neuronal cytoplasm in the aged dog was much stronger than that in the young adult dog. These results indicate that the increase of inflammatory cytokines and their receptors in the aged spinal cord might be related to maintaining a balance of inflammatory reaction in the spinal cord during normal aging.     

Crystal structure of human cytosolic aspartyl‐tRNA synthetase,a component of multi‐tRNA synthetase complex

Human cytosolic aspartyl‐tRNA synthetase (DRS) catalyzes the attachment of the amino acid aspartic acid to its cognate tRNA and it is a component of the multi‐tRNA synthetase complex (MSC) which has been known to be involved in unexpected signaling pathways. Here, we report the crystal structure of DRS at a resolution of 2.25 Å. DRS is a homodimer with a dimer interface of 3750.5 Ų which comprises 16.6% of the monomeric surface area. Our structure reveals the C‐terminal end of the N‐helix which is considered as a unique addition in DRS, and its conformation further supports the switching model of the N‐helix for the transfer of tRNA^Asp to elongation factor 1α. From our analyses of the crystal structure and post‐translational modification of DRS, we suggest that the phosphorylation of Ser146 provokes the separation of DRS from the MSC and provides the binding site for an interaction partner with unforeseen functions.Proteins 2013; 81:1840–1846. © 2013 Wiley Periodicals, Inc.     

Molecular dynamics simulations of carbon nanotube oscillators deformed by encapsulated copper nanowires

Pure carbon nanotube (CNT) oscillators are compared to the corresponding CNT oscillators encapsulating copper nanowires (Cu@CNTs) by molecular dynamics simulations. The classical oscillation theory provides a fairly good estimate of the mass dependence of the operating frequency when the CNT surface is not deformed by the Cu nanowire. The structural deformations of the CNT induced by the encapsulated copper nanowire have a greater effect on the oscillation frequency than the mass of the copper nanowire. The excess forces of the Cu@CNT oscillator are slightly higher than those of the CNT oscillator and the excess van der Waals forces induced by the inter-wall interactions are 17 times higher than the excess forces induced by the Cu nanowire–CNT interactions.     

Gastrokine 1 regulates NF‐κB signaling pathway and cytokine expression in gastric cancers

Gastrokine 1 (GKN1) plays an important role in the gastric mucosal defense mechanism and also acts as a functional gastric tumor suppressor. In this study, we examined the effect of GKN1 on the expression of inflammatory mediators, including NF‐κB, COX‐2, and cytokines in GKN1‐transfected AGS cells and shGKN1‐transfected HFE‐145 cells. Lymphocyte migration and cell viability were also analyzed after treatment with GKN1 and inflammatory cytokines in AGS cells by transwell chemotaxis and an MTT assay, respectively. In GKN1‐transfected AGS cells, we observed inactivation and reduced expression of NF‐κB and COX‐2, whereas shGKN1‐transfected HFE‐145 cells showed activation and increased expression of NF‐κB and COX‐2. GKN1 expression induced production of inflammatory cytokines including IL‐8 and ‐17A, but decreased expression of IL‐6 and ‐10. We also found IL‐17A expression in 9 (13.6%) out of 166 gastric cancer tissues and its expression was closely associated with GKN1 expression. GKN1 also acted as a chemoattractant for the migration of Jurkat T cells and peripheral B lymphocytes in the transwell assay. In addition, GKN1 significantly reduced cell viability in both AGS and HFE‐145 cells. These data suggest that the GKN1 gene may inhibit progression of gastric epithelial cells to cancer cells by regulating NF‐κB signaling pathway and cytokine expression. J. Cell. Biochem. 114: 1800–1809, 2013. © 2013 Wiley Periodicals, Inc.     

Changes in expression of proteins involved in alleviation of Fe-deficiency by sulfur nutrition in Brassica napus L.

In order to characterize the significance of sulfur (S) nutrition in protein expression under iron (Fe)-deficient conditions, gel-based proteomic analysis was performed with the leaves of Brassica napus exposed to S and Fe combined treatments: sufficient in S and Fe (+S/+Fe, control), sufficient S but Fe deprived (+S/?Fe), deprived S but sufficient Fe (?S/+Fe), and deprived S and Fe (?S/?Fe). The resulting data showed that 15 proteins were down-regulated due to production of oxidative damage as indicated by H₂O₂ and O ₂ ^?1 localizations and due to leaf chlorosis in leaves in S-deprived leaves either in presence (?S/+Fe) or absence of Fe (?S/?Fe), whereas these down-regulated proteins were well expressed in the presence of S (+S/?Fe) compared to control (+S/+Fe). In addition, two proteins were up-regulated under S-deprived condition in presence (?S/+Fe) and absence of (?S/?Fe) Fe. The functional classification of these identified proteins was estimated that 40 % of the proteins belong to chloroplast precursor, and rest of the proteins belongs to hypothetical proteins, RNA binding, secondary metabolism and unknown proteins. On the other hand, five protein spots from S deprived (?S/+Fe) and ten spots from Fe deprived (?S/?Fe) conditions were absent, whereas they were well expressed in presence of S (+S/?Fe) compared to control plants (+S/+Fe). These results suggest that sulfur nutrition plays an important role in alleviating protein damage in Fe-deficient plants and adaptation to Fe-deficiency in oilseed rape.