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effects of enteric LPS in equine whole blood and monocytes and inhibit LPS-induced expression of mRNA for TNF-α, IL-1B, IL-6, and IL-10 by monocytes. Materials and Methods Horses —A group of 19 adult horses determined to be healthy on the basis of

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in American Journal of Veterinary Research

inflammation through different pathways. 7–9 For instance, PARP1 induces release of high mobility group box 1, a proinflammatory mediator that can induce macrophage activation and TNF-α production. 10 Activation of PARP1 is also involved in inflammatory

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in American Journal of Veterinary Research

, catecholamines have immunomodulatory properties, most commonly inhibiting LPS-stimulated production of proinflammatory cytokines, including TNF-α, IL-6, and IL-1β, and stimulating production of the anti-inflammatory cytokine IL-10. 3 This effect of

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in American Journal of Veterinary Research

. Endotoxin then binds to receptors on inflammatory cells, which leads to activation of NF-κB and results in formation of proinflammatory mediators, such as TNF-α. 5 Ultimately, systemic manifestations of endotoxemia (such as fever, tachycardia, and

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in American Journal of Veterinary Research

and inhibited organism killing and phagosome acidification. Alternatively, MAPK JNK induced expression of TNF-α and prevented killing of MAP organisms. 11 Overall, results of these studies indicate that the MAPK p38 and MAPK JNK signaling pathways

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in American Journal of Veterinary Research

rates. 6–8 Inflammation associated with transfusion results, in part, from the accumulation of cytokines in stored blood products. 1,2 Interleukin-1β, IL-8, and TNF-α are cytokines that increase in concentration in human whole blood and PRBCs during

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in American Journal of Veterinary Research

by macrophages. 2 Enhanced release of TNF-α, IL-1, and IL-6 is considered a hallmark of sepsis and hemorrhagic shock. 3 These cytokines promote a multitude of changes, including fever; increased production of acute-phase proteins; hypotension

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in American Journal of Veterinary Research

leukocytes, especially when they are activated, 9–19 and this integrin plays a role in the adherence of leukocytes to the endothelium during inflammation. Different molecules, such as chemokines, fibrinogen, selectins, and cytokines such as TNF-α, can

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in American Journal of Veterinary Research

Summary

We examined the effect of infusion of lipopolysaccharide (lps) on serum tumor necrosis factor alpha (tnfα) concentration and clinical attitude in 2- to 3-day-old colostrum-fed (cf) and colostrum-deprived (cd) foals. Eleven cf and 8 cd neonatal foals were given a bolus IV infusion of Escherichia coli O55:B5 lipopolysaccharide (0.5 µg kg of body weight) in sterile saline (0.9% NaCl) solution. Four cf and 2 cd foals were given saline solution alone. Serum IgG concentration and serum anti-lps IgG(T) antibody titer were determined for each foal prior to infusion. A depression index was used to score clinical abnormalities. Serum tnfα concentration was estimated by use of an in vitro cytotoxicity bioassay that used WEHI 164 clone 13 cells as targets. The cytotoxic serum factor was identified as tnfα by immunoprecipitation with caprine antisera raised against the 15 NH2- terminal amino acids of human tnfα. Tumor necrosis factor alpha was not detected in any preiniusion serum samples nor in any samples from foals given saline solution alone. Serum tnfα concentration increased in all lps-infused foals and peaked between 60 and 90 minutes after infusion. Serum tnfα concentrations, expressed as mean percentage of peak serum tnfα concentration, persisted longer in cd foals given lps than in cf foals given lps. All lps-infused foals displayed clinical signs of endotoxemia, but mean depression index scores of the cf and cd foals given lps were not significantly different at any time. Serum tnfα concentrations were correlated with depression index scores in both lps-infused groups. Mean rectal temperature increased by 1 hour and remained high for 4 hours after infusion in cf foals given lps . Mean rectal temperature in cd foals given lps was significantly less than that for cf foals given lps 1 and 2 hours after infusion and was higher than mean rectal temperature prior to infusion 3 and 4 hours after infusion. Neither preinfusion total serum IgG concentration nor serum anti-lps IgG(T) antibody titer correlated with peak serum tnfα concentration in the 19 lps-infused foals.

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in American Journal of Veterinary Research

Summary

Objectives of this investigation were to extract and isolate protein fractions inhibitory to the cytotoxic properties of tumor necrosis factor-α (tnf-α). In this context, mixed populations of wbc were harvested from equine blood and were stimulated with a combination of a synthetic chemotactic peptide and a calcium ionophore. Several methods were subsequently applied for the initial preparation of cell-free crude protein extracts, including fractional precipitation with gradient concentrations of ammonium sulfate and preparative-scale isoelectric focusing. In addition, protein fractions were harvested from extracts of concentrated equine urine. Protein extracts of urinary origin were further separated by gel-filtration column chromatography.

Identification of protein fractions possessing properties inhibitory to the cytotoxic characteristics of tnf-α was facilitated by a tissue culture-based technique for the biological assay of tnf-α-mediated cytotoxicity. Purified protein extracts possessed a marked ability to inhibit or neutralize the cytotoxic properties of tnf-α, on the basis of survival of murine fibrosarcoma cell populations, compared with appropriate negative and positive reference controls. Relative purity of inhibitors and estimation of approximate molecular weight were established by conventional reducing and nonreducing sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. Equine inhibitory protein fractions from mixed wbc populations, purified in the manner described, had molecular weights of 70,000 to 80,000 and 28,000. An analogous protein fraction of 28 kDa also was isolated from equine concentrated urine. Estimated isoelectric point of tnf-α inhibitor protein fractions was between pH of 5.5 and 6.1. These physical characteristics of equine tnf-α inhibitor protein fractions were similar to those described for a membrane-associated tnf-α receptor protein shed from chemotaxin- and calcium-ionophor-stimulated human wbc populations.

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in American Journal of Veterinary Research