排序方式: 共有35条查询结果,搜索用时 15 毫秒
21.
Hynes J Leftheris K Wu H Pandit C Chen P Norris DJ Chen BC Zhao R Kiener PA Chen X Turk LA Patil-Koota V Gillooly KM Shuster DJ McIntyre KW 《Bioorganic & medicinal chemistry letters》2002,12(17):2399-2402
C-3 Amido-indoles were found to selectively bind to the CB2 receptor. SAR studies led to optimized compounds with excellent in vivo potency against LPS induced TNF-alpha release in murine models of cytokine production. 相似文献
22.
Broňa Brejová Askar Gafurov Dana Pardubská Michal Sabo Tomáš Vinař 《Algorithms for molecular biology : AMB》2017,12(1):17
Background
Isometric gene tree reconciliation is a gene tree/species tree reconciliation problem where both the gene tree and the species tree include branch lengths, and these branch lengths must be respected by the reconciliation. The problem was introduced by Ma et al. in 2008 in the context of reconstructing evolutionary histories of genomes in the infinite sites model.Results
In this paper, we show that the original algorithm by Ma et al. is incorrect, and we propose a modified algorithm that addresses the problems that we discovered. We have also improved the running time from \(O(N^2)\) to \(O(N\log N)\), where N is the total number of nodes in the two input trees. Finally, we examine two new variants of the problem: reconciliation of two unrooted trees and scaling of branch lengths of the gene tree during reconciliation of two rooted trees.Conclusions
We provide several new algorithms for isometric reconciliation of trees. Some questions in this area remain open; most importantly extensions of the problem allowing for imprecise estimates of branch lengths.23.
Summary In recent years, public concern about indoor mould growth has increased dramatically in the United States. In this study,
lactic acid bacteria (LAB), which are known to produce antimicrobial compounds important in the biopreservation of food, were
evaluated to determine if the same antimicrobial properties can be used to inhibit mould fungi that typically colonize wood.
Based on biomass measurement, cell-free supernatants from Lactobacillus casei subsp. rhamnosus and Lactobacillus acidophilus grown in deMan Rogosa Sharpe (MRS) broth inhibited 95–100% growth of three mould fungi and one stain fungus associated with
wood-based building materials. Lactic acid and four unknown compounds ⩽ kDa molecular weight were fractionated from the culture
supernatant by thin layer chromatography and high-performance liquid chromatography. Antifungal activity, which was attributed
to one or more unknown metabolites, was retained during heating and neutralization. A 1:2 dilution of L. casei supernatant inhibited 100% growth of all test fungi. 相似文献
24.
Kobayashi M Kikuchi O Sasaki T Kim HJ Yokota-Hashimoto H Lee YS Amano K Kitazumi T Susanti VY Kitamura YI Kitamura T 《American journal of physiology. Endocrinology and metabolism》2012,302(5):E603-E613
Diabetes is characterized by an absolute or relative deficiency of pancreatic β-cells. New strategies to accelerate β-cell neogenesis or maintain existing β-cells are desired for future therapies against diabetes. We previously reported that forkhead box O1 (FoxO1) inhibits β-cell growth through a Pdx1-mediated mechanism. However, we also reported that FoxO1 protects against β-cell failure via the induction of NeuroD and MafA. Here, we investigate the physiological roles of FoxO1 in the pancreas by generating the mice with deletion of FoxO1 in the domains of the Pdx1 promoter (P-FoxO1-KO) or the insulin 2 promoter (β-FoxO1-KO) and analyzing the metabolic parameters and pancreatic morphology under two different conditions of increased metabolic demand: high-fat high-sucrose diet (HFHSD) and db/db background. P-FoxO1-KO, but not β-FoxO1-KO, showed improved glucose tolerance with HFHSD. Immunohistochemical analysis revealed that P-FoxO1-KO had increased β-cell mass due to increased islet number rather than islet size, indicating accelerated β-cell neogenesis. Furthermore, insulin-positive pancreatic duct cells were increased in P-FoxO1-KO but not β-FoxO1-KO. In contrast, db/db mice crossed with P-FoxO1-KO or β-FoxO1-KO showed more severe glucose intolerance than control db/db mice due to decreased glucose-responsive insulin secretion. Electron microscope analysis revealed fewer insulin granules in FoxO1 knockout db/db mice. We conclude that FoxO1 functions as a double-edged sword in the pancreas; FoxO1 essentially inhibits β-cell neogenesis from pancreatic duct cells but is required for the maintenance of insulin secretion under metabolic stress. 相似文献
25.
Bernard A. Prior Michael A. Alexander Vina Yang Thomas W Jeffries 《Biotechnology letters》1988,10(1):37-42
Summary When the oxygen supply to an aerobic chemostat culture ofCandida shehatae growing on D-xylose was reduced to oxygen-limited and anoxic conditions, accumulation of ethanol occurred, the specific activity of alcohol dehydrogenase (ADH) increased up to four-fold and the number of ADH isozymes detected increased from one to three. ADH in crude extracts prepared from anoxically-grown cells had a lower affinity for but was more tolerant to ethanol than in extracts prepared from aerobically grown cells. ADH activity appeared to be sufficient for ethanol production byC. shehatae under anoxic conditions.Maintained in cooperation with the University of Wisconsin-Madison. The use of trade, firm or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the US Department of any product or service to the exclusion of others which may be suitable. 相似文献
26.
Zhu X Heunks LM Versteeg EM van der Heijden HF Ennen L van Kuppevelt TH Vina J Dekhuijzen PN 《American journal of physiology. Lung cellular and molecular physiology》2005,288(1):L16-L26
Oxidants may play a role in hypoxia-induced respiratory muscle dysfunction. In the present study we hypothesized that hypoxia-induced impairment in diaphragm contractility is associated with elevated peroxynitrite generation. In addition, we hypothesized that strenuous contractility of the diaphragm increases peroxynitrite formation. In vitro force-frequency relationship, isotonic fatigability, and nitrotyrosine levels were assessed under hypoxic (Po(2) approximately 6.5 kPa) and hyperoxic (Po(2) approximately 88.2 kPa) control conditions and also in the presence of authentic peroxynitrite (60 min), ebselen (60 min), and the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine acetate (L-NMMA) (90 min). A hypoxia-induced downward shift of the force-frequency relationship was associated with elevated nitrotyrosine level in the diaphragm. During hypoxia, both ebselen and L-NMMA decreased nitrotyrosine levels but did not affect force generation. Strenuous contractions impaired force generation but did not affect nitrotyrosine levels in the diaphragm during hypoxia. But under hyperoxic conditions, fatiguing contractions were associated with elevated diaphragm nitrotyrosine levels. Under hyperoxic conditions exogenous peroxynitrite impaired force generation and increased nitrotyrosine level. These studies show that hypoxia-induced impairment in diaphragm contractility is associated with increased diaphragm protein nitration, but no causal relationship was found between diaphragm nitrotyrosine formation and in vitro force generation. 相似文献
27.
A new and simple method for the purification of extracellular levansucrase from Zymomonas mobilis from highly viscous fermentation broth was developed. After incubation of the fermentation broth with a fructose-polymer cleaving enzyme preparation (Fructozyme, Novozymes, DK) for 48 h, levansucrase precipitated as aggregates and was redissolved in a 3 M urea solution. By ongoing size-exclusion chromatography on Sephacryl S-300 the final levansucrase preparation was purified 100-fold and exhibited a specific activity of 25-35 U/mg(protein). The levansucrase was stable in 3 M urea solution for at least four months without inactivation. To maximize the enzyme yield the dynamic changes of extracellular levansucrase activity during fermentation were investigated. The highest levansucrase activity was observed during the logarithmic phase of growth (15-19 h of fermentation). 相似文献
28.
Bonafide claudin proteins are functional and structural components of tight junctions and are largely responsible for barrier formation across epithelial and endothelial membranes. However, current advances in the understanding of claudin biology have revealed their unexpected functions in the brain. Apart from maintaining blood‐brain barriers in the brain, other functions of claudins in neurons and at synapses have been largely elusive and are just coming to light. In this review, we summarize the functions of claudins in the brain and their association in neuronal diseases. Further, we go on to cover some recent studies that show that claudins play signaling functions in neurons by regulating trafficking of postsynaptic receptors and controlling dendritic morphogenesis in the model organism Caenorhabditis elegans. 相似文献
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The data on the completing level of a number of medical preparations on the basis of immobilized proteins, in particular, on the basis of enzymes are given. The firms and companies which successfully cooperate in the field of development of commercial programs for such preparations are listed. On the basis of own study a possibility to create some effective antitumor compounds in the next future is shown. The urgent and prospective application of the immobilized enzymes instead of the native ones in the medicine is grounded. 相似文献