Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diphosphoryl lipid A (DPLA) obtained from the nontoxic lipopolysaccharide (LPS) of Rhodopseudomonas sphaeroides ATCC 17023 did not induce interleukin-1 release by murine peritoneal macrophages. However, it blocked this induction by toxic deep-rough chemotype LPS (ReLPS) from Escherichia coli D31m4. Previously, we obtained similar results on the induction of tumor necrosis factor (TNF) by macrophages. These results showed that DPLA is able to block in vitro the induction of two important mediators of gram-negative bacterial sepsis. We then wanted to determine whether DPLA could also block the induction of TNF by LPS in animals. Mice were treated with 100 micrograms of R. sphaeroides DPLA and challenged 60 min later with 1.0 micrograms of ReLPS from E. coli. The serum TNF level was measured after 60 min. Treatment of mice with this DPLA blocked the rapid and transient rise of TNF caused by ReLPS. This result suggested that R. sphaeroides DPLA might be able to protect animals against endotoxin shock caused by gram-negative bacterial infection.
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PMID:Diphosphoryl lipid A obtained from the nontoxic lipopolysaccharide of Rhodopseudomonas sphaeroides is an endotoxin antagonist in mice. 198 57

While the production of tumor necrosis factor (TNF) and interleukin-6 (IL-6) in septic shock and other inflammatory states is well established, the role of interleukin-8 (IL-8), a recently described neutrophil chemoattractant and activator, has yet to be fully elucidated. Using lipopolysaccharide (LPS)-stimulated human whole blood as an ex vivo model of sepsis, the kinetics of messenger RNA (mRNA) up-regulation and protein release of these cytokines were examined. Two waves of cytokine gene activation were documented. TNF and IL-6 were induced in the first wave with mRNA levels peaking between 2-4 hours and then rapidly declining. TNF and IL-6 protein peaked at 4-6 hours and then stabilized. IL-8 mRNA and protein were induced in the first wave, reached a plateau between 6-12 hours, and rose again in a second wave which continued to escalate until the end of the 24 hour study. These data demonstrate the complex patterns of cytokine gene expression and suggest that production of early mediators may augment continued expression of IL-8 to recruit and retain neutrophils at a site of inflammation.
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PMID:Kinetics of TNF, IL-6, and IL-8 gene expression in LPS-stimulated human whole blood. 198 98

Using a model of sepsis induced by parenteral challenge of mice with bacterial lipopolysaccharide (LPS), the authors analyzed the in vivo expression of interleukin-1 (IL-1) alpha,beta and tumor necrosis factor (TNF). Both TNF and IL-1 alpha,beta were detected in hepatic sinusoidal macrophages (Kupffer cells), immunohistochemically. Kinetic analysis showed a clear sequence of synthesis. Tumor necrosis factor was produced first, reaching maximal expression at 1 hour after LPS challenge, then rapidly disappeared. IL-1 beta followed, reaching maximal expression at 2 to 3 hours, then dropped off by 6 hours. Interleukin-1 alpha expression reached a peak at 6 hours and had disappeared by 18 hours. Analysis of serum bioactivity also revealed sequential expression that correlated with immunohistochemical findings. Tumor necrosis factor was maximal at 1 hour and IL-1 at 6 hours. The IL-1 bioactivity was not due to interleukin-6 (IL-6), as this was depleted from specimens by immunoabsorption. Also IL-6 bioactivity reached maximal levels at 3 hours, earlier than IL-1. Pretreatment with 4 mg/kg dexamethasone significantly decreased Kupffer cell expression of TNF and IL-1 alpha (about 80% and 60% suppression, respectively) but had less effect on IL-1 beta expression (about 30% suppression). Accordingly, serum levels of TNF were suppressed by 75% while serum IL-1 was decreased by 39%, indicating differential sensitivity of these cytokines to glucocorticoids. Endogenous corticosteroid levels increased as TNF levels decreased, supporting the contention that glucocorticoids regulate TNF synthesis. In contrast, IL-1 levels rose concurrently with corticosterone. These data indicate a sequential activation of cytokine gene expression in vivo, which may be critical to the cascade of events leading to septic shock, and provide evidence that Kupffer cells are a major source of cytokines in endotoxemia. Finally, the differential sensitivity of cytokine expression to glucocorticoids may in part explain the inadequacy of the latter in the treatment of sepsis.
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PMID:In vivo biologic and immunohistochemical analysis of interleukin-1 alpha, beta and tumor necrosis factor during experimental endotoxemia. Kinetics, Kupffer cell expression, and glucocorticoid effects. 199 64

This study aims to elucidate the in vivo metabolic response of different liver cells following a short-term (30 min) infusion of a nonlethal dose of human recombinant tumor necrosis factor (TNF). In vivo glucose uptake of different tissues and isolated liver cells was determined by a sequential double-labeling version of the tracer 2-deoxyglucose technique. Following TNF administration glucose uptake was increased in the liver, lung, spleen, and skin while it was not changed in muscle and testis. In response to TNF infusion neutropenia developed which was sustained for 40 min. The number of lymphocytes in the blood was also decreased after the termination of TNF infusion. This short-term infusion of TNF, however, was not accompanied by marked sequestration of leukocytes into the liver. In vivo glucose uptake in response to TNF was doubled in the Kupffer cells and increased by 56% in hepatic endothelial cells. Glucose uptake of parenchymal cells was not significantly affected. The prompt increase of glucose uptake in the reticuloendothelial cells of the liver, primarily in the Kupffer cells, following TNF administration suggests that a similar metabolic response of these cells to sepsis may be mediated at least in part by TNF. It is suggested that the increased glucose uptake by the hepatic nonparenchymal cells is a reflection of the immunomodulatory effect of TNF.
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PMID:Tumor necrosis factor increases in vivo glucose uptake in hepatic nonparenchymal cells. 199 33

Infections due to gram-negative bacteria and other organisms can lead to septicemia and shock in some patients. Endotoxins, which cause these pathophysiological events, stimulate macrophages to elaborate tumor necrosis factor and other lymphokines. These lymphokines can augment free radical generation by polymorphonuclear leukocytes, macrophages and other cells, which may ultimately produce respiratory distress syndrome, multiorgan failure and irreversible shock seen in septicemia. This is supported by our results presented here that there is indeed an increase in free radical generation and lipid peroxidation in patients with septicemia. In addition, analysis of plasma lipid profile in these patients showed that gamma-linolenic, dihomogamma-linolenic and arachidonic acids of n-6 series and alpha-linolenic and eicosapentaenoic acids of the n-3 series are decreased in their plasma phospholipid fraction. These results suggest that free radicals, lipid peroxides, and alteration in essential fatty acid metabolism may have a role in the pathogenesis of septicemia.
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PMID:Free radical generation, lipid peroxidation and essential fatty acids in patients with septicemia. 201 12

To study the effect of plasma removal vs plasma administration on the appearance of tumor necrosis factor (TNF) and interleukin 1 in septic shock, 24 anesthetized piglets were inoculated with live Escherichia coli. Plasma exchange with albumin was performed in one group. Fresh-frozen plasma was administered to a second group. A third group served as nontreated controls. Following plasma exchange, a reduction in both TNF and interleukin 1 levels occurred, whereas plasma infusion was followed by a decrease in TNF levels only. No significant differences were observed between the two treated groups with respect to survival or cardiovascular performance, with both being significantly enhanced compared with the controls. High levels of TNF and interleukin 1 correlated with depressed cardiovascular performance in the early phase of the shock. Our results confirm the important role of TNF and interleukin 1 as early mediators of septic shock. However, the benefit of reducing cytokine activity in later stages of septicemia seems to be dubious.
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PMID:Tumor necrosis factor and interleukin 1 appearance in experimental gram-negative septic shock. The effects of plasma exchange with albumin and plasma infusion. 202 43

Human recombinant interleukin-1 alpha (IL-1) has a diverse range of physiological activities which may be beneficial or deleterious to the host. Pretreatment with doses of IL-1 has been shown to protect mice against a subsequent lethal bacterial injection; however, the protective effects of a single intravenous (iv) dose of IL-1 have not been well characterized. The current experiments were performed to determine the best dose, timing, and duration of action of a single iv dose of IL-1 against a subsequent lethal challenge with intraperitoneal endotoxin (LPS) or experimental sepsis induced by cecal ligation and puncture (CLP). Female C57B1/6 mice treated with iv IL-1 24 hr prior to 30 mg/kg LPS ip had improved survival compared to saline-treated controls (P less than 0.01). IL-1 was also protective when given 6 to 72 hr, but not 2 or 96 hr, prior to LPS. IL-1 protection against LPS lethality was similar to protection seen with an iv dose of tumor necrosis factor (TNF). After CLP, survival was improved with IL-1 versus saline pretreatment (P = 0.02). Unlike previous work with TNF, no toxicity or lethality was observed at any dose of IL-1 administered. A single iv dose of IL-1 protects against the lethality of LPS and CLP in mice. IL-1 may be a useful treatment strategy in patients at risk for the development of life-threatening sepsis.
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PMID:Human recombinant interleukin-1 alpha protection against the lethality of endotoxin and experimental sepsis in mice. 203 79

Based on the hypothesis that tumor necrosis factor (TNF) causes the lethality of gram-negative sepsis and previous work of tolerance to the lethal effects of TNF induced by repetitive exposure to sublethal intraperitoneal doses of human recombinant (r) TNF, we studied the protective role of a single sublethal intravenous dose of either rTNF (100 micrograms/kg) or recombinant interleukin-1 (rIL-1; 10(5) units/kg) or both before a subsequent lethal intravenous dose of rTNF (800 to 1000 micrograms/kg) in C3H/HEN mice. Mice were treated with a single intravenous dose of saline, rTNF, rIL-1 or both cytokines and challenged within 2 hours to 10 days with a lethal dose of rTNF. Mice treated with rTNF showed significant protection against the lethal effects of TNF when the treatment dose was given only 2 hours before the lethal dose, but maximal protection required a 24-hour interval and lasted as long as 8 days. The treatment dose of rTNF was toxic, and it resulted in occasional treatment deaths. Mice treated with rIL-1 showed maximal protection when treatment was given only 2 hours before challenge and protection lasted for 8 days. No toxicity was apparent secondary to IL-1 treatment. The combination of rIL-1 and rTNF was not as effective as either cytokine alone. The results suggest that rTNF or rIL-1 may be clinically useful in the prevention and treatment of sepsis lethality by the induction of tolerance to the lethal effects of TNF. The more promising cytokine appears to be rIL-1 because it has less toxicity and more rapid induction of full therapeutic effectiveness.
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PMID:Tumor necrosis factor and interleukin-1 protection against the lethal effects of tumor necrosis factor. 204 87

The plasma level of interleukin-1 beta (IL-1 beta) was determined in normal individuals, patients with disseminated intravascular coagulation (DIC), patients in the pre-DIC period (within 7 days before the onset of DIC), and non-DIC patients to examine the relationship between DIC and the plasma IL-1 beta level. The plasma IL-1 beta level was 0-0.085 ng/ml in normal individuals, with little difference being seen according to related age. It was significantly higher in the DIC group (0.19 +/- 0.19 ng/ml) than in the pre-DIC group (0.05 +/- 0.08 ng/ml) or the non-DIC group (0.09 +/- 0.01 ng/ml). The plasma IL-1 beta level was not markedly elevated in leukemia patients, even in the DIC group, but it was significantly increased in the DIC group of solid cancer patients and was generally elevated in patients with sepsis. It was markedly elevated to 0.39 +/- 0.26 ng/ml in patients with organ failure. When mononuclear cells were incubated with lipopolysaccharide, it was found that IL-1 beta, tumor necrosis factor, and tissue factor (TF) were released into the medium, and there was an increase of TF release from endothelial cells incubated with this medium. These results suggest that the increase in IL-1 beta reflected the activation of monocytes and may be an important factor in DIC and its associated organ failure.
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PMID:Plasma level of IL-1 beta in disseminated intravascular coagulation. 205 18

Although antibiotics have reduced mortality, the most recent clinical trials in sepsis and meningitis have been directed at the host inflammatory response in an attempt to improve outcome. Endotoxin, cell wall constituents and toxins are potent inducers of small molecular weight proteins (cytokines) from a variety of host cells. Several lines of investigation have implicated tumor necrosis factor-alpha (TNF-alpha) as a cytokine mediator of sepsis and septic shock. A recent study has been able to measure plasma TNF-alpha concentrations in patients with meningococcemia and demonstrated a correlation with prognostic groups related to mortality. Therefore, TNF-alpha, probably through its effects on other mediators, has an effect in sepsis. New speculation regarding morbidity in bacterial meningitis focuses on cytokine activity in the central nervous system. Cerebrospinal fluid (CSF) from experimental animals with meningitis contains increased amounts of interleukin-1 beta (IL-1 beta) and TNF alpha. These IL-1 beta levels correlated directly with duration of fever and neurological sequelae. Children with Haemophilus influenzae, type b meningitis treated with dexamethasone had significantly reduced levels of CSF IL-1 beta compared to placebo-treated controls.
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PMID:The immunology of sepsis and meningitis--cytokine biology. 209 Dec 57


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