Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the current work, we evaluated the effect of extracellular acidification on neutrophil physiology. Neutrophils suspended in bicarbonate-buffered RPMI 1640 medium adjusted to acidic pH values (pH 6.5-7.0) underwent: 1) a rapid transient increase in intracellular free calcium concentration levels; 2) an increase in the forward light scattering properties; and 3) the up-regulation of surface expression of CD18. By contrast, extracellular acidosis was unable to induce neither the production of H2O2 nor the release of myeloperoxidase. Acidic extracellular pH also modulated the functional profile of neutrophils in response to conventional agonists such as FMLP, precipiting immune complexes, and opsonized zymosan. It was found that not only calcium mobilization, shape change response, and up-regulation of CD18 expression but also production of H2O2 and release of myeloperoxidase were markedly enhanced in neutrophils stimulated in acidic pH medium. Moreover, extracellular acidosis significantly delayed neutrophil apoptosis and concomitantly extended neutrophil functional lifespan. Extracellular acidification induced an immediate and abrupt fall in the intracellular pH, which persisted over the 240-s analyzed. A similar abrupt drop in the intracellular pH was detected in cells suspended in bicarbonate-supplemented PBS but not in those suspended in bicarbonate-free PBS. A role for intracellular acidification in neutrophil activation is suggested by the fact that only neutrophils suspended in bicarbonate-buffered media (i.e., RPMI 1640 and bicarbonate-supplemented PBS) underwent significant shape changes in response to extracellular acidification. Together, our results support the notion that extracellular acidosis may intensify acute inflammatory responses by inducing neutrophil activation as well as by delaying spontaneous apoptosis and extending neutrophil functional lifespan.
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PMID:Extracellular acidification induces human neutrophil activation. 1020 29

The characterisation and selection of membranes by means of an immunofiltration assay is described. The chemical composition of the membranes was: nitro-cellulose, polyamide, polyvinylidene difluoride, polyethersulfone, cellulose acetate, regenerated cellulose, cellulose nitrate, and glass fibre. In order to characterise the membranes according to their binding capacity, immobilisation stability, sensitivity and hydrodynamic properties, two basic immunofiltration formats were performed. In both formats, enzyme label (horseradish peroxidase, HRP) and colorimetric detection were used. In the immobilised antibody format, three monoclonal antibodies (mAb) against the insecticide carbaryl were immobilised on the membranes by passive adsorption. In the immobilised hapten format, two haptens conjugated to bovine serum albumin (BSA) were immobilised. Immobilon-P was the best membrane with regard to the characterisation criteria and permitted the filtration of large volume (5.0 ml) through the membrane without release of the receptor. The immobilisation of the receptor (antibody or haptenic conjugate) was pH dependent. Good results with regard to mAb-antigen recognition, were obtained using 50 mM carbonate/bicarbonate buffer, pH 9.6. However, the most sensitive assays were achieved using, 10 mM phosphate buffer, 137 mM NaCl, 2.7 mM KCI (PBS), pH 7.4 as immobilisation buffer. Furthermore, all these results permit the choice of the best membrane for the rapid and sensitive determination of carbaryl. This study will assist the development of dipsticks, immunoelectrodes, membrane-based immunoreactors or immunoconcentration devices that are based on the use of membranes as immunosupports.
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PMID:Selection and characterisation of membranes by means of an immunofiltration assay. Application to the rapid and sensitive determination of the insecticide carbaryl. 1035 11

This study was aimed at verifying whether tissue transglutaminase (tTG) is the sole autoantigen eliciting anti-endomysial antibodies in coeliac disease (CoD) and investigating tTG expression in normal and coeliac mucosa. Twelve anti-endomysial-positive coeliac sera and 12 anti-endomysial-negative control sera (10 microl, diluted 1:5-1:400 in PBS pH 7.3) were preincubated with 10, 20 or 50 microg guinea pig liver tTG at 4 degrees C overnight. Monkey oesophagus tissue slides were then tested with tTG-preincubated and non-preincubated sera to search for IgA anti-endomysial reactivity by indirect immunofluorescence. Moreover, six sections of monkey oesophagus were incubated with an anti-tTG mouse MoAb, six sections with an anti-cytokeratin mouse MoAb and six sections with only 3% bovine serum albumin. Finally, endoscopic duodenal biopsy sections obtained from 12 patients affected by untreated CoD, six patients affected by treated CoD and 10 biopsied controls were immunohistochemically stained with a peroxidase-conjugated anti-tTG MoAb. Our results show that (i) preincubation with tTG abolished endomysial immunofluorescence in most, but not in all, coeliac sera; (ii) the incubation of anti-tTG MoAb with sections of monkey oesophagus resulted in an immunofluorescence staining pattern similar but not identical to that of anti-endomysial-positive coeliac sera; (iii) although tTG expression was present at muscularis mucosae and pericryptal fibroblast in both normal and coeliac mucosa, it was slightly more marked and evident in the latter. Although our absorption experiment was performed with guinea pig liver tTG, we confirm that tTG is the predominant antigen of endomysial antibodies, but we speculate that, at least in some patients, it is not the only one.
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PMID:Transglutaminase and coeliac disease: endomysial reactivity and small bowel expression. 1059 54

The present study was aimed at investigating whether the expression of Fas ligand (FasL) by CHO cells transfected with IL-4 (CHO/IL-4) or IL-10 (CHO/IL-10) genes would improve the effect of the cytokine. DBA/ 1 mice immunized with type II collagen were treated with suboptimal doses of transfected CHO cells (a single s. c. injection of 2 x 10(5) cells) around onset of arthritis. Severe collagen-induced arthritis (CIA) developed in the control groups injected with PBS, CHO /beta-galactosidase/FasL, CHO/IL-4 or CHO/IL-10 cells. In contrast, administration of CHO/IL-4/FasL, but not CHO/IL-10/FasL, cells significantly reduced the clinical severity and resulted in rapid and sustained suppressive effect. Amelioration of CIA was not due to a prolonged in vivo secretion of IL-4 since expression of FasL by CHO cells shortened the in vivo survival of the xenogeneic cells. In fact, administration of FasL(+) cells was associated with a decreased proportion of Mac1(+) neutrophils in the blood and an increased expression of myeloperoxidase at the site of engineered cell engraftment. These findings suggest that the mechanism underlying the beneficial effect of IL-4 delivered by cells expressing FasL involves the combination of the anti-inflammatory properties of IL-4 and the apoptosis of Fas(+) Mac1(+) granulocytes participating in the pathogenic process.
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PMID:Expression of Fas ligand improves the effect of IL-4 in collagen-induced arthritis. 1060 54

F1-antigen purified from Yersinia pestis was covalently linked to 5-mm diameter filter paper discs plasticized with polyvinyl alcohol-glutaraldehyde. These discs were used both for ELISA and dot-ELISA for the detection of anti-F1 IgG in rabbits. The best conditions were achieved using 1.25 microg of F1 antigen/disc, 3% w/v skim milk in PBS as blocking agent, anti-IgG peroxidase conjugate diluted 12,000 times, and serum from rabbits immunized or not against Y. pestis, diluted 6,400 times. The absorbance values obtained from the comparative study between this procedure and conventional ELISA were not significantly different but the low cost of the reagents employed in ELISA using the filter paper discs plasticized with polyvinyl alcohol-glutaraldehyde makes this method economically attractive.
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PMID:The use of filter paper plasticized with polyvinyl alcohol-glutaraldehyde in ELISA. 1088 Oct 58

The beta(2) integrin cell adhesion molecules (CAM) mediate polymorphonuclear leukocyte (PMNL) emigration in most inflamed tissues, but, in the lung, other yet to be identified CAMs appear to be involved. In Lewis rats, the intratracheal injection of Escherichia coli-LPS induced acute (6-h) PMNL accumulation in the lung parenchyma (280 x 10(6) by myeloperoxidase assay; PBS control = 35 x 10(6)) and bronchoalveolar lavage fluid (BALF = 27 x 10(6); PBS = 0.1 x 10(6)). Parenchymal accumulation was not inhibited by a blocking Ab to beta(2) integrins and only minimally inhibited (20.5%; p < 0.05) in BALF. We examined the role of alpha(4)beta(1) and alpha(5)beta(1) integrins and of selectins in this PMNL recruitment. Treatment with mAbs to alpha(4)beta(1) or alpha(5)beta(1), even in combination, had no effect on PMNL accumulation induced by intratracheal LPS. However, anti-alpha(4) combined with anti-beta(2) mAbs inhibited PMNL recruitment to the parenchyma by 56% (p < 0.001) and to BALF by 58% (p < 0.01). The addition of anti-alpha(5) mAb to beta(2) plus alpha(4) blockade inhibited PMNL accumulation further (by 79%; p < 0.05). In contrast, blockade of L-, P-, and E-selectins in combination or together with beta(2), alpha(4), and alpha(5) integrins had no effect. LPS-induced BALF protein accumulation was not inhibited by treatment with anti-beta(2) plus alpha(4) mAbs, but was prevented when alpha(5)beta(1) was also blocked. Thus, while selectins appear to play no role, alpha(4)beta(1) and alpha(5)beta(1) function as major alternate CAMs to the beta(2) integrins in mediating PMNL migration to lung and to pulmonary vascular and epithelial permeability.
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PMID:The alpha 4 beta 1 (very late antigen (VLA)-4, CD49d/CD29) and alpha 5 beta 1 (VLA-5, CD49e/CD29) integrins mediate beta 2 (CD11/CD18) integrin-independent neutrophil recruitment to endotoxin-induced lung inflammation. 1125 23

We examined whether the lung injury produced in rats by intraperitoneal injection of the superantigen, staphylococcal enterotoxin B (SEB), could be inhibited by intravenous preadministration of human urinary trypsin inhibitor (UTI), which exhibits multipotent inhibitory effects on serine proteinases such as plasmin, chymotrypsin, or human leukocyte elastase or cathepsin G, since preliminary experiments showed the ability of UTI to bind lipopolysaccharides and bacterial toxins. For ligand blotting analysis, four kinds of toxins were run on a slab gel and the binding of UTI to the toxins was visualized by immunoblotting. Lung tissue from 26 rats was used for immunohistochemistry using a mouse antirat CD 45 mAb and an antirat macrophage mAb. Lung tissue from 31 rats was used for measurement of myeloperoxidase activity before and after intraperitoneal injection of SEB, after infusion of PBS, UTI, PBS-SEB or UTI-SEB combination. Ten of the 26 rats described above were used for electron microscopy. Rat sera were used for measurement of TNF-alpha. Statistical analysis was performed using the Mann-Whitney U-test. Intraperitoneal injection of SEB caused an increase in the number of punctate areas of haemorrhage on the surface of the lung with time, and histological examination revealed lung injuries with different extents, vasculitis where inflammatory cells were concentrated, and infiltration of numbers of eosinophils into the alveolar septa. However, preadministration of UTI for rats markedly attenuated lung injury and vasculitis induced by intraperitoneal injection of SEB. This revealed, from a marked reduction in the number of inflammatory cells and the extent of injury, a marked inhibition of serum TNF-alpha production and reduction of myeloperoxidase content of rat lungs compared to controls. UTI may have defensive effects to infection by suppressing the early responses of stimulated cells to activated stimulus such as SEB as well as the release of stimulant-mediated cytokines via trapping of bacterial toxins.
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PMID:Suppression of superantigen-induced lung injury and vasculitis by preadministration of human urinary trypsin inhibitor. 1126 57

The effect of pH on the kinetics of the bioelectrocatalytic reduction of H(2)O(2) catalysed by horseradish peroxidase (HRP) has been studied at -50 mV vs. Agmid R:AgCl on HRP-modified Au electrodes placed in a wall-jet flow-through electrochemical cell. Native HRP (nHRP) and a nonglycosylated recombinant form containing a six-histidine tag at the C-terminus, C(His)rHRP, produced by genetic engineering of nonglycosylated recombinant HRP using an E. coli expression system, have been used for adsorptive modification of Au electrodes. A favourable adsorption of C(His)rHRP on pre-oxidized Au from a protein solution at pH 6.0 provided a high and stable current response to H(2)O(2) due to its bioelectrocatalytic reduction based on direct (mediator-less) electron transfer (ET) between Au and the active site of HRP. The heterogeneous ET rate constant, k(s), calculated from experimental data on direct ET, on mediated ET in the presence of catechol as well as from microbalance data, increased more than 30 times when changing from nHRP to C(His)rHRP. For both forms of HRP, the increasing efficiency of bioelectrocatalysis with increasing [H(3)O(+)] was observed. The values of the apparent k(s) between C(His)rHRP and Au changed from a value of 12+/-2 s(-1) in PBS at pH 8.0 to a value of 434+/-62 s(-1) at pH 6.0; a similar k(s)-pH dependence was also observed for nHRP, providing the possibility to consider the reaction mechanism involving the participation of a proton in the rate-determining step of the charge transfer.
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PMID:Effect of pH on direct electron transfer in the system gold electrode-recombinant horseradish peroxidase. 1178 47

In this paper the production of antibodies against saxitoxin (STX) is described, as is the optimization and comparison of two competitive ELISA formats (direct and indirect) for the detection of this toxin. Tests were performed in a 96-well microplate using the toxin-specific polyclonal antibodies produced in our laboratory, obtained from rabbits immunized with saxitoxin-keyhole limpet hemocyanin (STX-KLH). In indirect ELISA format saxitoxin, conjugated to bovine serum albumin (STX-BSA) was coated onto the microtitre plate and incubated with standard toxin and anti-STX antibody. A goat anti-rabbit IgG Peroxidase conjugate was used to enable detection. In the direct ELISA format, STX standard, STX conjugate to horseradish peroxidase (STX-HRP), and enzyme substrate/chromogen solution were sequentially added to the microplate after antibody coating.Results showed the saxitoxin detection limit to be 3 and 10 pg mL(-1) for direct and indirect ELISA formats, respectively. The suitability of the assay for quantification of saxitoxin in mussels was also studied. Samples were spiked with saxitoxin before and after sample treatment to study the extraction efficiency and matrix effect, respectively. After treatment, samples were analysed at 1:1000 v/v dilution in PBS to minimize the matrix effect and to detect the regulatory limit of 40-80 micro g saxitoxin per 100 g mussels as stipulated by the Food and Drug Administration. The efficiency of extraction of saxitoxin was from 72 to 102%. These data were confirmed by liquid chromatography coupled with fluorimetric detection, the technique currently used for quantitative determination of toxins in seafood.
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PMID:Production of antibodies and development of highly sensitive formats of enzyme immunoassay for saxitoxin analysis. 1219 23

The role of macrophages in Pseudomonas aeruginosa corneal infection in susceptible (cornea perforates), C57BL/6 (B6) vs resistant (cornea heals), BALB/c mice was tested by depleting macrophages using subconjunctival injections of clodronate-containing liposomes before corneal infection. Both groups of inbred mice treated with clodronate-liposomes compared with PBS-liposomes (controls) exhibited more severe disease. In B6 mice, the cornea perforated and the eye became extremely shrunken, whereas in BALB/c mice, the cornea perforated rather than healed. The myeloperoxidase assay detected significantly more PMN in the cornea of both groups of mice treated with clodronate-liposomes vs PBS-liposomes. In independent experiments, ELISA analysis showed that protein levels for IL-1 beta, macrophage-inflammatory protein 2, and macrophage-inflammatory protein 1 alpha, all regulators of PMN chemotaxis, also were elevated in both groups of mice treated with clodronate-liposomes. Bacterial plate counts in B6 mice treated with clodronate-liposomes were unchanged at 3 days and were higher in control-treated mice at 5 days postinfection (p.i.), whereas in BALB/c mice, bacterial load was significantly elevated in the cornea of mice treated with clodronate-liposomes at both 3 and 5 days p.i. mRNA expression levels for pro (IFN-gamma and TNF-alpha)- and anti (IL-4 and IL-10)-inflammatory cytokines also were determined in BALB/c mice treated with clodronate-liposomes vs control-treated mice. Expression levels for IFN-gamma were significantly elevated in mice treated with clodronate-liposomes at 3 and 5 days p.i., while IL-10 levels (mRNA and protein) were reduced. These data provide evidence that macrophages control resistance to P. aeruginosa corneal infection through regulation of PMN number, bacterial killing and balancing pro- and anti-inflammatory cytokine levels.
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PMID:Macrophages restrict Pseudomonas aeruginosa growth, regulate polymorphonuclear neutrophil influx, and balance pro- and anti-inflammatory cytokines in BALB/c mice. 1273 70


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