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

The effects of Escherichia coli lipopolysaccharide (LPS) on adenylate cyclase have been tested using renal tubular membranes and renal glomeruli isolated from rats. E. Coli LPS did not stimulate glomerular and tubular basal adenylate cyclase activity whereas it was an activator in the presence of fluoride. The effect of E. Coli LPS was immediate but was greater after 20 min preincubation. Maximum stimulation of both glomerular and tubular fluoride sensitive adenylate cyclase occurred at 125 microgram/ml of E. Coli LPS with an apparent Km (dose corresponding to 50% of maximum stimulation) of 30 microgram/ml. Above 125 microgram/ml there was a decrease in adenylate cyclase activity. E. Coli LPS produced an increase in the maximum velocity of both enzymes but did not affect their affinity for adenosine triphosphate. E. Coli LPS did not potentiate the effect of parathyroid hormone on glomerular and tubular adenylate cyclase. The lipid A moiety which is common to all LPS whatever the original strain gave results similar to those obtained with the entire LPS. This effect was specific and did not depend on the phospholipidic structure in general since no activation was obtained in the presence of phosphatidylserine.
Nephron 1977
PMID:Effects of Escherichia coli lipopolysaccharide on renal glomerular and tubular adenylate cyclase. 33 75

Interleukin 6 (IL-6) is an autocrine growth factor of cultured mesangial cells (MC) and intraglomerular IL-6 production is suggested to be closely associated with the pathogenesis of human mesangial proliferative glomerulonephritis (mesPGN). In this study, to elucidate the mechanisms regulating the intraglomerular production of IL-6, we examined what kinds of stimuli are significant in the induction of IL-6 synthesis in vitro and in vivo. Incubation of cultured mesangial cells with interleukin 1 (IL-1) or bacterial lipopolysaccharide (LPS) induced significant IL-6 production, and intravenous injection of IL-1 or LPS into normal BALB/c mice induced significant intraglomerular IL-6 mRNA expression. Furthermore, we indicated in this study that IL-6 mRNA expression was augmented in the glomeruli of mice with immune complex-mediated glomerulonephritis.
Nephron 1992
PMID:Induction of interleukin 6 synthesis in mouse glomeruli and cultured mesangial cells. 143 93

CD23 is a surface marker of activated B cells as well as a low-affinity Fc receptor for IgE. In this study, we enumerated CD23-positive peripheral blood lymphocytes and evaluated their clinical significance in patients with IgA nephropathy (IgAN). Twenty-five patients with IgAN and 16 patients with non-IgA proliferative glomerulonephritis (PGN) were studied. Twenty-seven healthy adults served as controls. CD23-bearing cells were enumerated by flow cytometry, and serum IgE levels were measured by latex photometric immunoassay. Significant increases in the number of CD23-positive cells were observed in patients with IgAN (p less than 0.01) and PGN (p less than 0.05) compared with controls. A significant elevation of serum IgE levels was also observed in the patients with IgAN and PGN (p less than 0.05). No positive correlation between the number of CD23-positive cells and serum IgE levels was observed. We also examined the induction of surface CD23 expression on peripheral lymphocytes by interleukin (IL)-2, IL-3, IL-4, IL-5, IL-6, interferon (IFN)-gamma, IFN-alpha, phytohemagglutinin, concanavalin A, pokeweed mitogen, lipopolysaccharide and phorbol myristate acetate. IL-4 was revealed to have a significantly potent effect on the induction of cell surface CD23 compared with other stimulants. It was concluded that many patients with IgAN or PGN show high serum IgE levels and/or high CD23-positive cell counts in their peripheral blood, suggesting that hyperactivation of B cells might be involved in the development of IgAN and non-IgA PGN. It appeared that IL-4 may play a significant role in the etiology of these types of glomerulonephritis.
Nephron 1992
PMID:Increase of CD23-positive cells in peripheral blood from patients with IgA nephropathy and non-IgA proliferative glomerulonephritis. 153 1

The effect of peritoneal dialysate on the capacity of peripheral blood polymorphonuclear (PMNL) and mononuclear leukocytes (MNC) to release leukotriene B4 (LTB4) and tumor necrosis factor alpha (TNF alpha) was investigated in vitro. Following density gradient separation, aliquots of 5 x 10(6) PMNL or MNC were incubated in peritoneal dialysis fluid containing 1.5% glucose or Hanks' buffer (= control) for 1-2 h at 37 degrees C. TNF alpha and LTB4 production was stimulated with Escherichia coli lipopolysaccharide (LPS) and calcium ionophore A23187, respectively. MNC incubated in buffer and LPS produced (mean +/- SD) 1,006 +/- 522 pg TNF alpha/5 x 10(6) cells; no significant amounts of TNF alpha were detectable in the presence of dialysate. An inhibition of TNF alpha release was also observed in MNC exposed to bicarbonate-buffered dialysates (pH 7.40) and 4.25% and 1.5% glucose solution with physiologic osmolality. Incubation of PMNL in Hanks' buffer followed by A23187 stimulation led to production of 29.1 +/- 19.2 ng LTB4/5 x 10(6) cells, whereas glucose-incubated cells were refractory to ionophore stimulation (less than 0.1 ng LTB4/5 x 10(6) cells). The failure of dialysate-exposed leukocytes to release inflammatory mediators in response to adequate stimuli may contribute to the impairment of cellular host defense in the setting of continuous ambulatory peritoneal dialysis.
Nephron 1991
PMID:Leukotriene B4 and tumor necrosis factor release from leukocytes: effect of peritoneal dialysate. 165 27

A significant increase in gelatinolytic activity was observed in cultures of glomeruli from Heymann nephritic rats. Zymography of the culture medium indicated that the main gelatinase species has a molecular weight of 98 kilodaltons (kDa) and the characteristics of metalloproteinase. The 98-kDa gelatinase was detected in the culture medium of glomerular epithelial cells but not in those of endothelial and mesangial cells. Interleukin-1 beta, tumor necrosis factor-alpha and lipopolysaccharide dose-dependently increased gelatinase production by epithelial cells. These results suggest that the gelatinase secreted by cytokine-stimulated glomerular epithelial cells participates in the pathological process of Heymann nephritis.
Nephron 1990
PMID:Gelatinase secretion by glomerular epithelial cells. 196 1

We produced in Bacillus subtilis the complete, as well as the N-terminal two-thirds, OmpA protein of Escherichia coli (called here Bac-OmpA and Bac-OmpA-dN, respectively). These Bac-OmpA proteins were used to examine the immunological properties of different parts of OmpA, free of lipopolysaccharide and other components of the outer membrane. The full-length Bac-OmpA was indistinguishable from the authentic protein isolated from E. coli (Coli-OmpA) both as immunogen and as antigen in enzyme immunoassay (EIA). The N-terminal Bac-OmpA-dN was a poor immunogen which gave rise to significantly lower titers of anti-OmpA antibody than did the full-length OmpA preparations. When used as an antigen in EIA, the Bac-OmpA-dN detected anti-OmpA antibody in serum samples from animals immunized with the full-length OmpA much less efficiently than did either Bac-OmpA or Coli-OmpA. The periplasmic C-terminal domain therefore appears to be an immunodominant epitope of the purified OmpA protein. Also, when rabbits and mice were immunized with intact, live or dead E. coli, the antibody response detected by EIA with the full-length protein, Bac-OmpA, was much stronger than that detected with the N-terminal two-thirds, Bac-OmpA-dN. Similar results were obtained with the OmpA of Salmonella typhimurium. Because the ompA gene of enterobacteria is highly conserved, the Bac-OmpA might be useful as a group-specific EIA antigen to diagnose diseases caused by members of the family Enterobacteriaceae.
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PMID:A strong antibody response to the periplasmic C-terminal domain of the OmpA protein of Escherichia coli is produced by immunization with purified OmpA or with whole E. coli or Salmonella typhimurium bacteria. 211 Dec 85

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

We have investigated beta 2-microglobulin (beta 2M) synthesis and release by blood leukocytes and isolated mononuclear phagocytes. Recent interest in beta 2M has developed since the discovery that this protein forms amyloid fibrils in patients undergoing long-term, chronic hemodialysis and that these patients have greatly elevated levels of monomeric beta 2M in their circulation. Since hemodialysis-related factors that increase beta 2M production are unknown, we evaluated beta 2M production by freshly prepared leukocytes and monocyte-derived macrophages under a variety of conditions. We utilized a novel enzyme-linked immunoabsorbant assay to quantitate beta 2M concentrations, and monitored interleukin-1 and beta 2M synthesis by immunoprecipitation. Incubation of leukocytes with Cuprophan or Hemophan does not increase beta 2M release. Adherence of macrophages onto polystyrene or Cuprophan membranes induces neither interleukin-1 nor beta 2M synthesis or release. In contrast, interaction of macrophages with lipopolysaccharide, gamma-interferon, tumor necrosis factor, or interleukin-1 induces synthesis and release of beta 2 M, indicating that beta 2 M synthesis is increased during macrophage activation. Exposing leukocytes or macrophages to changes in osmotic or oncotic pressure induces a rapid release of beta 2M and interleukin-1 into the cellular medium. These results suggest that during hemodialysis, beta 2M production is more likely to result from endotoxin contamination, or osmotic and oncotic changes, rather than direct interaction of mononuclear phagocytes with Cuprophan membranes.
Nephron 1989
PMID:Hemodialysis-related induction of beta-2-microglobulin and interleukin-1 synthesis and release by mononuclear phagocytes. 250 49

Recent evidence indicates that stress can suppress immune responses and thus increase the severity of viral and neoplastic diseases. Although, the mechanisms for stress-induced modulation of immunologic competence are unclear, neuroendocrine hormones are thought to be involved. A direct suppressive effect could result from the action of neuroendocrine hormones on lymphokine and monokine release. The central role of interleukin-1 (IL-1) in regulating cellular immune responses to infection and neoplasms stimulated the present study evaluating the effects of neuroendocrine hormones on IL-1 production. Norepinephrine and epinephrine inhibited the capacity of gamma interferon and lipopolysaccharide to stimulate IL-1 production from mouse peritoneal macrophages. Moreover, when intracellular and extracellular levels of IL-1 were quantitated, the studies demonstrated a catecholamine-mediated block in IL-1 synthesis without effect on its release. We also observed that exogenous cyclic AMP (cAMP) administered to mouse macrophages suppressed IL-1 production. This, coupled with the capacity of norepinephrine and epinephrine to enhance intracellular cAMP levels in macrophages, strongly suggested that the catecholamine-induced suppression of IL-1 production may be mediated by elevated intracellular cAMP levels. These findings demonstrate that selected stress-related neuroendocrine hormones can modulate IL-1 production by macrophages and further support the hypothesis that alteration of macrophage function by neuropeptides and neurohormones is a significant feature of stress-induced enhancement of viral and neoplastic disease.
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PMID:Catecholamine-induced suppression of interleukin-1 production. 302 61

Smooth lipopolysaccharide (sLPS) of Brucella abortus was prepared and fractionated by a modification of the procedures of Moreno et al. (J. Bac. 138:361-369, 1979). Washed B. abortus cells were disrupted by 21 freeze-quick thaw cycles with ultrasonication to separate the non-membrane-bound material. Ultrasonicated bacteria were used for preparation of membrane-bound sLPS (approximately f5, the main crude sLPS fraction described by Moreno et al.). Phenol extraction was repeated 3 times and then washed with H2O 10 times to remove most of the chromogen, polysaccharides and nucleic acids, eliminating the need for enzyme treatment as described previously. The membrane-bound sLPS was fractionated into 3 to 5 groups according to the extent of dialysis and centrifugation, these fractions required only 80 ng for positive ELISA, about 0.2 ng for positive Limulus lysate tests, and reacted well with precipitating antibodies in the serum from a strain 2308 infected cow. They had marked differences in precipitin curves and chemical composition. The protein content varied from 16% to 42% as determined by dye binding test and 17 to 60% by Lowry phenol method using bovine serum albumin as the standard, which implies that the proteins associated with LPS may also play important roles in the complex for the immunochemical interactions and the heterogeneity of B. abortus lipopolysaccharide protein complex. As compared with previous reports, a higher yield of sLPS, ranging from 3.6% to 7.7% of dried bacteria, was obtained. Group f5A, which had a standard bell shaped curve in the precipitin assay, is one of the major fractions in all three strains (1119.3, 19 and 2308). The amount of other subfractions obtained varied with batches or strains of B. abortus. These results provide a new profile of the immunochemical reactivities and the heterogeneity on B. abortus smooth membrane-bound endotoxins.
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PMID:Immunochemical and partial chemical characterization of fractions of membrane-bound smooth lipopolysaccharide-protein complex from Brucella abortus. 311 18


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