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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

O-specific polysaccharide has been isolated on autohydrolysis of lipopolysaccharide from Yersinia intermedia O: 4.33 (strain 1476) and shown to consist of the yersiniose B (3.6-dideoxy-4-C-(1-hydroxyethyl)-xylo-hexose) and 2-acetamido-2-deoxy-D-galactose residues in a molar ratio of 1 : 2. Acid hydrolysis, methylation. solvolysis with anhydrous hydrogen fluoride. and 13C-NMR studies indicate the polysaccharide to be composed of trisaccharide repeating units of the following structure: (Formula: see text).
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PMID:[Structure of the O-specific polysaccharide chain of the lipopolysaccharide from Yersinia intermedia serotype O:4.33]. 245 23

The O-specific polysaccharide chain of the Pseudomonas aurantiaca IMV 31 lipopolysaccharide contains N-acetyl-L-fucosamine (FucNAc) and di-N-acetyl-D-bacillosamine (2,4-diacetamido-2,4,6-trideoxyglucose, Bac(NAc)2) in the ratio 2:1. On the basis of methylation, solvolysis with anhydrous hydrogen fluoride, and computer-assisted analysis of 13C-NMR spectrum, it was concluded that the trisaccharide repeating unit of the polysaccharide possesses the following structure: structure: ----3)-beta-D-Bac(NAc)2-(1----3)-alpha-L-FucNAc-(1----3)-alpha-L- FucNAc-(1----.
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PMID:[Antigenic polysaccharides of bacteria. 31. The structure of the O-specific polysaccharide chain of Pseudomonas aurantiaca IMB 31 lipopolysaccharide]. 245 32

Structural studies were carried out on the O-polysaccharide fraction obtained by mild acid treatment of the lipopolysaccharide from Pseudomonas aeruginosa IID 1009 (ATCC 27585). The O-polysaccharide was composed of L-rhamnose, N-acetyl-D-quinovosamine, and N-acetyl-L-galactosaminuronic acid in a molar ratio of 1:1:1. The results from analysis of fragments obtained by hydrogen fluoride hydrolysis of O-polysaccharide, together with data on methylation analysis and nuclear magnetic resonance spectroscopic analysis, led to the most likely structure of the repeating units of the polymer chain ----4)L-GalNAcA(alpha 1----3)D-QuiNAc(alpha 1----3)L-Rha(alpha 1----, in which about 70% of the rhamnose residues were O-acetylated at C-2. This structure coincides with that of the repeating unit of Lanyi 02 a,b polysaccharides.
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PMID:The structure of the O-polysaccharide from Pseudomonas aeruginosa IID 1009 (ATCC 27585). 250 Apr 29

The effect of two chemically dissimilar cyclooxygenase inhibitors was studied in pentobarbital-anesthetized endotoxic pigs. Animals in groups II-IV were infused with Escherichia coli lipopolysaccharide (LPS, 150 micrograms/kg) and resuscitated with normal saline (1.2 ml.kg-1.min-1). Animals in group I (n = 4) were resuscitated as above but were not infused with LPS. Animals in group II (n = 7) served as endotoxic controls. Pigs in groups III (n = 6) and IV (n = 5) were pre- and posttreated with ibuprofen (10 mg/kg bolus then 10 mg.kg-1.h-1 and meclofenamate (5 mg/kg then 5 mg.kg-1.h-1, respectively. Ileal intramucosal hydrogen ion concentration [( H+]) was estimated tonometrically. In group I, cardiac index (CI), mean arterial pressure (MAP), superior mesenteric arterial perfusion (QSMA), and mesenteric O2 delivery (DO2) increased significantly, but other variables were unchanged. After infusion of LPS in group II, MAP and systemic vascular resistance index were markedly diminished but CI was well preserved. In this group, QSMA, systemic DO2, and mesenteric DO2 decreased, whereas systemic O2 uptake (VO2) and gut [H+] increased; mesenteric VO2 was unchanged. Compared with pigs in group II, pigs treated with ibuprofen or meclofenamate manifested improved systemic and mesenteric DO2. In groups III and IV, QSMA remained normal, increased systemic VO2 was not observed, and gut intramucosal acidosis was ameliorated. Increased intramucosal [H+] in group II suggests that QSMA was inadequate. The salutary effects of ibuprofen and meclofenamate suggest that inadequate mesenteric perfusion was mediated, at least in part, by cyclooxygenase-derived metabolites or arachidonic acid.
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PMID:Systemic and mesenteric O2 metabolism in endotoxic pigs: effect of ibuprofen and meclofenamate. 251 12

Human monocytes upon stimulation with bacterial lipopolysaccharide release two cytokines which modulate the functions of neutrophilic granulocytes (PMN), a monocyte-derived chemotaxin (MOC) and tumor necrosis factor (TNF). Both cytokines stimulated the adherence of PMN on protein-coated nylon-fibers. Whereas MOC is one of the four most potent chemoattractants known, TNF was a most powerful inhibitor of PMN chemotactic migration towards several chemotactic factors including MOC. Neither cytokine stimulated the release of superoxide anion (O2-) or hydrogen peroxide (H2O2) from PMN in suspension. However, TNF, but not MOC, caused the release of considerable amounts of H2O2 and O2- from PMN attached to nylon fibers. The two cytokines have similar effects on the adherence, opposing effects on chemotactic migration and different effects on the oxidative burst of PMN.
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PMID:Stimulation of human neutrophilic granulocytes by two monocyte-derived cytokines. 254 Jun 39

Macrophage cell lines were used in these studies as a model system to dissect the biochemical and functional mosaic of the macrophage activation process. In particular, the requirements for the induction of tumoricidal and bactericidal activity in the RAW 264.7 and WEHI-3 cell lines by interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS) were determined. Changes in expression of a series of macrophage markers traditionally associated with macrophage activation were monitored during stimulation of the cells in order to determine whether a detectable pattern of activation-associated changes is associated with the development of a particular functional activity. These markers included changes in the cell surface expression of major histocompatibility complex-encoded Class I and Class II antigens and antigens in the Mac-1/LFA-1 family, alterations in the levels of membrane enzymes (5' nucleotidase and alkaline phosphodiesterase), and production of secretory products including hydrogen peroxide and the monokines interleukin-1, interferons-alpha/beta, and tumor necrosis factor-alpha. Our results demonstrate that a given homogeneous macrophage population expresses a distinct subset of functional activities in response to single, defined activating signals such as IFN-gamma and LPS. The display of a variety of macrophage surface antigens, enzymes, and secreted products is activated simultaneously by such treatment; however, the particular pattern of such activation-associated markers cannot reproducibly be used to predict the ability of an activated cell to perform a particular function. The results also suggest that macrophage cell lines expressing differential response patterns following IFN-gamma stimulation provide a valuable system for dissection of the molecular and cell biology of macrophage activation.
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PMID:Differential induction of activation markers in macrophage cell lines by interferon-gamma. 254 31

We tested the hypothesis that lipopolysaccharide (LPS) leads to an imbalance between mesenteric oxygen delivery (DO2) and gut metabolic demand for oxygen, even when cardiac index (CI) is within the normal range. Two groups of pentobarbital-anesthetized pigs (13 to 17 kg) were studied. The first group (LPS; n = 9) was infused over 20 min with Escherichia coli LPS (100 micrograms/kg) and resuscitated with normal saline (1.2 ml/kg.min). The second group (NS; n = 5) was not infused with LPS, but was resuscitated in the same way as the LPS group. Superior mesenteric arterial (SMA) blood flow and ileal intramucosal hydrogen ion concentration, [H+], were determined using a Doppler-shift probe and a tonometric catheter, respectively. Infusing LPS did not affect CI, although mean arterial pressure and systemic vascular resistance were significantly reduced. SMA flow and mesenteric DO2 decreased significantly in the LPS group. Although mesenteric oxygen utilization was well preserved in both groups, ileal intramucosal [H+] was significantly higher in endotoxic animals. These data support the idea that mesenteric oxygen consumption is flow-limited in this clinically relevant porcine model of septic shock.
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PMID:Effect of lipopolysaccharide on intestinal intramucosal hydrogen ion concentration in pigs: evidence of gut ischemia in a normodynamic model of septic shock. 273 25

Preliminary experiments have suggested that guinea pig L2C B-cell leukemia cells were able to evade macrophage-mediated lysis. To determine whether the L2C cells were resistant to macrophage cytotoxic activity or whether factors associated with the L2C leukemia contributed to a generalized inhibition of macrophage cytotoxic activity, pulmonary macrophages from strain 2 guinea pigs with L2C leukemia were tested for their ability to lyse the susceptible K562 cell line after activation by lipopolysaccharide (LPS) or lymphokines. In addition, the potential presence of soluble inhibitors of macrophage tumoricidal activity in serum-free culture supernatants and in serum from strain 2 guinea pigs terminally ill with the leukemia was tested by determining the effects of leukemic guinea pig serum (LGPS) or L2C-conditioned medium (CM) on the tumoricidal activity of normal pulmonary macrophages. Macrophages from guinea pigs terminally ill with L2C leukemia were demonstrated to be depressed in their cytotoxic activity against the K562 cell after stimulation by either LPS or lymphokines when compared to normal macrophages. The lymphokine-stimulated cytotoxic activity of normal macrophages was inhibited in the presence of LGPS or CM. Oxidative burst activity of normal macrophages, as measured by zymosan-stimulated production of superoxide and hydrogen peroxide, was also inhibited under these conditions. The data presented here suggests that soluble factors associated with L2C leukemia cells can suppress oxidative burst activity of macrophages in vitro and that this effect may contribute to the ability of the leukemia cells to evade macrophage-mediated cytotoxicity.
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PMID:Effects of L2C leukemia on macrophage-mediated responses. 282 44

This study addresses macrophage activation in guinea-pigs vaccinated with radiation-attenuated cercariae of Schistosoma mansoni. Peritoneal exudate macrophages elicited in vaccinated animals by mineral oil injection were activated to kill larval schistosomes in vitro. Killing efficiency is dependent upon the cell: target ratio employed and is enhanced by, but is not strictly dependent on, the presence of specific antibodies. Macrophages co-cultured with parasites release superoxide radicals and hydrogen peroxide, but the use of inhibitors has shown that neither of these reactive oxygen intermediates are the causal agents of cellular cytotoxicity in this system. Oil-elicited macrophages from naive guinea-pigs do not show comparable activation; they can, however, be activated in vitro by incubation with culture supernatant fluids from schistosome antigen-stimulated spleen, or lymph node cells harvested from vaccinated guinea-pigs. Naive macrophages activated in this way kill schistosomula in vitro and release the activation markers IL-1 and superoxide anion. The macrophage-activating factor (MAF) present in spleen cell culture supernatant fluids has a MW of 35,000-55,000, but does not have the chemical characteristics of gamma-interferon. In this study MAF is shown to be released by a population of lymph node cells that does not adhere to nylon-wool columns, that responds well in proliferation assays to schistosome antigens and to the T-cell mitogen concanavalin A, but does not respond to the B-cell mitogen lipopolysaccharide. These cells have been identified as small lymphocytes.
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PMID:Immunity to Schistosoma mansoni in guinea-pigs vaccinated with radiation-attenuated cercariae. T-cell activation of macrophages for larval killing. 283 8

A clinical isolate and a soil isolate of Chromobacterium violaceum were compared to determine differences in virulence-related characteristics. Purified lipopolysaccharide (endotoxin) from the virulent, clinical strain was more reactive than that from the avirulent soil strain as determined by the Limulus amebocyte lysate assay. There were no differences in hemolysin or cyanide production between the two strains. The virulent strain was more resistant to phagocytosis and intracellular killing by human polymorphonucleocytes. The clinical strain showed a superoxide dismutase activity 30% higher and a catalase activity fivefold higher than the activities of the soil-isolated strain. The clinical strain also was capable of producing approximately twice as much hydrogen peroxide during growth as compared with the soil isolate. This study suggests that virulence of C. violaceum may be, at least in part, associated with endotoxin, and some protection of the virulent, clinical strain from phagocytic attack is afforded by elevated levels of superoxide dismutase and catalase.
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PMID:A comparative study of virulent and avirulent strains of Chromobacterium violaceum. 284 71


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