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)

Lipopolysaccharide (LPS), a part of the Gram-negative bacteria cell wall, is a potent inducer of tumor necrosis factor (TNF). TNF is an important mediator in Gram-negative infections such as meningococcal septic shock, but its harmful action can be prevented by the natural occurring soluble (s) TNF receptors (sTNFR) sp55 and sp75. In this study, the effect of LPS on release of sTNFR was investigated. First, we found a selective increase in human whole-blood sp75 TNFR levels following LPS stimulation, accompanied by no increase in sp55. Separating the different blood cell populations, mononuclear cells (PBMC) selectively released sp75 upon LPS stimulation, while LPS induced a minor increase in sp75 release from polymorphonuclear granulocytes. Interestingly, in co-cultures of PBMC and granulocytes, the release of LPS-induced sp75 TNFR was enhanced. Second, adherent monocytes were also found to selectively release sp75 TNFR upon LPS stimulation, where Neisseria meningitidis LPS was found to be 100-1000 times more potent in inducing sp75 release than Escherichia coli LPS. Using flow cytometry, the monocyte membrane distribution of both TNFR were found to be increased after LPS stimulation. Third, human umbilical vein endothelial cells selectively released sp55 TNFR after stimulation with LPS. We conclude that mononuclear and endothelial cells might be the main sources of soluble p75 and p55 TNFR, respectively, observed in Gram-negative sepsis, although these receptors are released in vivo more rapidly than they are in vitro.
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PMID:Polymorphonuclear granulocytes enhance lipopolysaccharide-induced soluble p75 tumor necrosis factor receptor release from mononuclear cells. 758 51

Septic shock following gram-negative infection is a leading cause of mortality in critically ill patients, accounting for nearly 200,000 deaths a year. The exaggerated production of tumor necrosis factor-alpha (TNF alpha) is known to contribute to hemodynamic collapse and the hematological dyscrasia associated with gram-negative sepsis. Although previous studies have shown TNF alpha antibodies and TNF immunoadhesins to be effective in experimental gram-negative sepsis, we postulated that administration of a novel construct of two modified soluble p55 receptors linked to polyethylene glycol (PEG-BP-30) would also attenuate the hemodynamic and hematologic alterations to lethal Escherichia coli septic shock in non-human primates. Nine adult female and male baboons (Papio anubis), weighing 10-17 kg, were anesthetized and invasively monitored. The nine animals were randomized to receive either 0.2 mg/kg body wt PEG-BP-30 (n = 3), 5.0 mg/kg body wt PEG-BP-30 (n = 3), or placebo (n = 3). One hour after pretreatment, animals were infused with 5-10 x 10(10) CFU/kg of live E. coli iv and vital signs were recorded for the next 8 hr. Arterial blood was drawn for baseline parameters and throughout the study to obtain total and differential white blood cell and platelet counts and cytokine levels (TNF alpha, IL-1 beta, IL-6, IL-8). E. coli bacteremic baboons receiving only placebo demonstrated a significant fall in mean blood pressure and leukopenia. Two of the three animals expired. In contrast, five of the six baboons receiving the PEG-BP-30 survived and these animals exhibited markedly attenuated declines in blood pressure and leukocyte numbers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:PEG-BP-30 monotherapy attenuates the cytokine-mediated inflammatory cascade in baboon Escherichia coli septic shock. 763 Jan 20

Concentrations of interleukin (IL)-6, soluble IL-6 receptor (sIL-6R), and soluble tumor necrosis factor receptor (sTNFR) p55 and p75 were measured in 25 patients with sepsis syndrome. Sequential blood samples were drawn from patients during a 7-h period. IL-6 concentrations were 34-763,000 pg/mL; they were higher in nonsurvivors than survivors, but the difference was not statistically significant. In septic patients, the median sIL-6R concentration was significantly lower than in 19 healthy volunteers (43 vs. 80 ng/mL). sIL-6R concentrations in survivors were not significantly different than those in nonsurvivors. There was a negative correlation between IL-6 and sIL-6R in septic patients (r = -.72). In patients with moderately impaired renal function, sIL-6R levels were not affected, but the concentrations of sTNFRs were significantly higher.
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PMID:Circulating interleukin-6 receptor in patients with sepsis syndrome. 762 19

Anticytokine therapies have been promulgated in gram-negative sepsis as a means of preventing or neutralizing excessive production of proinflammatory cytokines. However, systemic administration of cytokine inhibitors is an inefficient means of targeting excessive production in individual tissue compartments. In the present study, human gene transfer was used to deliver to organs of the reticuloendothelial system antagonists that either inhibit tumor necrosis factor-alpha (TNF-alpha) synthesis or block its interactions with cellular receptors. Mice were treated intraperitoneally with cationic liposomes containing 200 micrograms of either a pCMV (cytomegalovirus)/p55 expression plasmid that contains the extracellular domain and transmembrane region of the human p55 TNF receptor, or a pcD-SR-alpha/hIL-10 expression plasmid containing the DNA for human interleukin 10. 48 h later, mice were challenged with lipopolysaccharide (LPS) and D-galactosamine. Pretreatment of mice with p55 or IL-10 cDNA-liposome complexes improved survival (p < 0.01) to LPS-D-galactosamine. In additional studies, intratracheal administration of IL-10 DNA-liposome complexes 48 h before an intratracheal LPS challenge reduced pulmonary TNF-alpha levels by 62% and decreased neutrophil infiltration in the lung by 55% as measured by myeloperoxidase activity (both p < 0.05). Gene transfer with cytokine inhibitors is a promising option for the treatment of both the systemic and local sequelae of septic shock.
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PMID:Human tumor necrosis factor receptor (p55) and interleukin 10 gene transfer in the mouse reduces mortality to lethal endotoxemia and also attenuates local inflammatory responses. 776 15

The aim of this study was to compare the ability of both a 55- and 75-kD soluble tumor necrosis factor receptor immunoglobulin G fusion protein (sTNFR-IgG) in protecting against death in a murine model of gram-negative sepsis. Pretreatment with 250 micrograms of the p75 construct delayed but did not avert death in this model, reducing peak bioactive TNF-alpha levels after infection from 76.4 ng ml-1 in control mice to 4.7 ng ml-1 in the treated group (p < 0.05, two-sample t test). However, these low levels of bioactive TNF-alpha persisted in the p75 fusion protein-treated animals compared with the controls and were sufficient to mediate delayed death. In contrast, pretreatment with 200 micrograms of the p55 sTNFR-IgG gave excellent protection against death with complete neutralization of circulating TNF. Studies of the binding of TNF-alpha with the soluble TNFR fusion proteins showed that the p75 fusion construct exchanges bound TNF-alpha about 50-100-fold faster than the p55 fusion protein. Thus, although both fusion proteins in equilibrium bind TNF-alpha with high affinity, the TNF-alpha p55 fusion protein complex is kinetically more stable than the p75 fusion construct, which thus acts as a TNF carrier. The persistent release of TNF-alpha from the p75 fusion construct limits its therapeutic effect in this model of sepsis.
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PMID:Protective effect of 55- but not 75-kD soluble tumor necrosis factor receptor-immunoglobulin G fusion proteins in an animal model of gram-negative sepsis. 796 92

To assess the role of tumor necrosis factor (TNF) in the appearance of soluble TNF receptors (sTNFRs), 20 consecutive patients with a clinical diagnosis of sepsis were studied as were 7 chimpanzees after administration of endotoxin (4 ng/kg) with or without pentoxifylline. The patients had markedly elevated serum levels of sTNFR-p55 and sTNFR-p75 compared with healthy controls (P < .0001 for both receptors). The levels of both soluble receptors correlated with simultaneously measured immunoreactive TNF concentrations (p55: r = .63, P < .01; p75: r = .69, P < .001). In the chimpanzees, endotoxin induced subsequent rises in the serum concentrations of TNF and sTNFRs. Although pentoxifylline reduced the TNF response to intravenous endotoxin to 20% (P < .05), the appearance of sTNFRs was only moderately inhibited (sTNFR-p55 to 79% on average, P < .05; sTNFR-p75 to 77%, P = .12). These results indicate that TNF either does not play an important role in the appearance of sTNFRs in systemic infection or that a small amount of TNF remaining in the circulation after some bacterial challenges is sufficient to preserve the secretion of its soluble receptors.
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PMID:Release of soluble receptors for tumor necrosis factor in clinical sepsis and experimental endotoxemia. 839 70

Over a period of 14 days a longitudinal analysis was performed on the effects of filgrastim (recombinant human granulocyte colony stimulating factor, rhG-CSF) administered to 20 postoperative/posttraumatic patients at risk of or with sepsis. The following parameters were determined: leukocyte counts, serum cytokine levels and the surface expression of functional antigens and adhesion molecules. Filgrastim (1 mu g/kg.day) was infused continuously on the first 3 days and tapered to 0.5 mu g/kg.day on the following 4 days or until discharge from the surgical intensive care unit. During infusion of filgrastim, G-CSF levels increased in 16 out of the 20 patients within 48 h. In these 16 patients, leukocyte counts increased in 15 out of 16 patients. Expression of CD64 was upregulated within 24 h. The expression of CD32 was upregulated in 8 out of 9 patients with an initial expression < 55%. LAM-1 expression was downregulated in all patients revealing an initial expression of LAM-1 > 40%. Soluble ICAM increased in 9 out of 11 patients. IL-8 decreased in all 6 patients presenting initial values of IL-8 > 90 pg/ml. IL-1RA increased in 10 patients. Filgrastim had no effect on the expression of CD14, CD16 and CD34 and on the levels of TNF-alpha and sTNF-R type I (p55). In conclusion, infusion of filgrastim in postoperative/post traumatic patients at risk of and with sepsis resulted in improved generation and function of neutrophils and appeared to counterregulate hyperactivation of proinflammatory processes.
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PMID:Filgrastim (RHG-CSF) related modulation of the inflammatory response in patients at risk of sepsis or with sepsis. 883 41

The production of tumor necrosis factor (TNF-alpha), and interleukin 1 beta (IL-1 beta), IL-6, sTNFR-p55, sTNFR-p75 and their pharmacomodulation were evaluated in a model of septic shock induced in CD-1 mice by cecal ligation and puncture (CLP). This model of sepsis, which resembles the clinical situation of bowel perforation and peritonitis with subsequent septic shock was compared with that induced by administration of pure endotoxin (LPS). TNF-alpha was detectable in serum, liver, spleen and lungs during the first 4 h, with a peak 2 h after CLP. IL-1 beta was measurable in serum after 24 h, and levels increased significantly in spleen and liver 4 and 8 h after CLP. IL-6 levels increased significantly in serum throughout the first 16 h after CLP. sTNFR-p55 and p75 increased in both models of shock but with different kinetics. Cytokines were also detectable after LPS injection, with kinetics similar to those after CLP but a significantly higher level. Pretreatment with dexamethasone (DEX) and ibuprofen (IBU), significantly reduced survival, while TNF did not affect it. Only pentoxifylline (PTX) significantly increased survival in mice with CLP. However DEX protected the mice from LPS mortality. In conclusion, by inhibiting TNF-alpha with DEX and PTX survival was reduced or unchanged respectively, suggesting that the modulation of this cytokine does not play significant role in sepsis and septic shock induced by CLP, unlike treatment with LPS. The negative effects of IBU suggests a protective role by prostaglandins in sepsis induced by LPS.
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PMID:[The effect of some drugs on the levels of selected cytokines in experimental septic shock]. 942 82

Despite considerable progress, peritonitis and sepsis remain life-threatening conditions. To improve the understanding of the pathophysiology encountered in sepsis, a new standardized and highly reproducible murine model of abdominal sepsis termed colon ascendens stent peritonitis (CASP) was developed. In CASP, a stent is inserted into the ascending colon, which generates a septic focus. CASP employing a stent of 14-gauge diameter (14G stent) results in a mortality of 100% within 18 to 48 h after surgery. By inserting stents of small diameters, mortality can be exactly controlled. Thus, CASP surgery with insertion of a 22G or 18G stent (22G or 18G CASP surgery) results in 38 or 68% mortality, respectively. 14G CASP surgery leads to a rapid invasion of bacteria into the peritoneum and the blood. As a consequence, endotoxemia occurs, inflammatory cells are recruited, and a systemic inflammatory response syndrome develops. Interestingly, the most pronounced upregulation of inflammatory cytokines (gamma interferon [IFN-gamma], tumor necrosis factor alpha [TNF-alpha] and interleukin-12) is observed in spleen and lungs. CASP surgery followed by stent removal at specific time intervals revealed that all animals survived if intervention was performed after 3 h, whereas removal of the septic focus after 9 h did not prevent death, suggesting induction of autonomous mechanisms of a lethal inflammatory response syndrome. 18G CASP surgery in IFN-gamma receptor-deficient (IFNgammaR-/-) mice revealed an essential role of IFN-gamma in survival of sepsis, whereas TNF receptor p55-deficient (TNFRp55-/-) mice did not show altered survival rates. In summary, this study describes a novel animal model that closely mimics human sepsis and appears to be highly suitable for the study of the pathophysiology of abdominal sepsis. Importantly, this model demonstrates a protective role of IFN-gamma in survival of bacterial sepsis.
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PMID:Essential role of gamma interferon in survival of colon ascendens stent peritonitis, a novel murine model of abdominal sepsis. 957 21

Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) have been implicated as key mediators in inflammation, morbidity, and mortality associated with sepsis. We examined the role of IL-6 and TNF-alpha signaling on hypothermia, fever, cachexia, anorexia, and survival during sepsis induced by cecal ligation and puncture (CLP) in male and female gene knockout mice. Male wild-type mice developed an initial hypothermia and subsequent fever during sepsis. Male IL-6 knockout mice did not develop fever; rather, they maintained a profound hypothermia during sepsis. Male TNF p55/p75 receptor (TNFR) knockout mice had attenuated hypothermia, but developed a virtually identical fever as wild-type mice. Cachexia did not differ between male wild-type and IL-6 or TNFR knockout mice, whereas anorexia was prolonged in IL-6 knockout mice. Due to the rapid lethality of sepsis in female mice, survival was the only variable we were able to statistically compare among female genotypes. Female wild-type mice had significantly decreased survival compared with male wild-type mice. Survival was significantly enhanced in male and female TNFR knockout mice compared with their wild-type controls. Lack of IL-6 did not affect male or female lethality. These data support the hypothesis that IL-6 is a key mediator of fever and food intake, whereas TNF is responsible for the initial hypothermia and lethality of sepsis in both sexes of mice. The enhanced lethality of CLP-treated female mice supports a role for sex steroids during sepsis.
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PMID:Role of IL-6 and TNF in thermoregulation and survival during sepsis in mice. 968 88


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