Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
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.
 ...
PMID:Polymorphonuclear granulocytes enhance lipopolysaccharide-induced soluble p75 tumor necrosis factor receptor release from mononuclear cells. 758 51

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.
 ...
PMID:Circulating interleukin-6 receptor in patients with sepsis syndrome. 762 19

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.
 ...
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.
 ...
PMID:Release of soluble receptors for tumor necrosis factor in clinical sepsis and experimental endotoxemia. 839 70

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.
 ...
PMID:[The effect of some drugs on the levels of selected cytokines in experimental septic shock]. 942 82

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.
 ...
PMID:Role of IL-6 and TNF in thermoregulation and survival during sepsis in mice. 968 88

Despite overwhelming evidence that enhanced production of the p75 tumor necrosis factor receptor (p75TNF-R) accompanies development of specific human inflammatory pathologies such as multi-organ failure during sepsis, inflammatory liver disease, pancreatitis, respiratory distress syndrome, or AIDS, the function of this receptor remains poorly defined in vivo. We show here that at levels relevant to human disease, production of the human p75TNF-R in transgenic mice results in a severe inflammatory syndrome involving mainly the pancreas, liver, kidney, and lung, and characterized by constitutively increased NF-kappaB activity in the peripheral blood mononuclear cell compartment. This process is shown to evolve independently of the presence of TNF, lymphotoxin alpha, or the p55TNF-R, although coexpression of a human TNF transgene accelerated pathology. These results establish an independent role for enhanced p75TNF-R production in the pathogenesis of inflammatory disease and implicate the direct involvement of this receptor in a wide range of human inflammatory pathologies.
 ...
PMID:A critical role of the p75 tumor necrosis factor receptor (p75TNF-R) in organ inflammation independent of TNF, lymphotoxin alpha, or the p55TNF-R. 976 13

Sepsis and pneumonia are major causes of morbidity and mortality in the neonatal period. The symptoms are variable and unspecific. So far, no reliable diagnostic test for neonatal infection has been found. In this study we measured serum levels of soluble tumor necrosis factor receptors (sTNFR) p55 and p75 in non-infected and infected neonates, and evaluated the diagnostic value of these mediators as tests for early detection of neonates with sepsis or pneumonia. Blood was collected on admission and after 3-4 days from 161 neonates consecutively admitted to the Neonatal Intensive Care Unit (NICU) during the first week of life. Twenty two neonates suffered from infection and 127 were classified as non-infected (controls). Samples were analyzed for p55 and p75, C-reactive protein (CRP) and white blood cell count with differential. Both preterm and term infected neonates had initially higher concentrations of p55 (both p <0.01) and p75 (p = 0.01 and p = 0.05, respectively) than controls. In non-infected neonates p55 levels decreased in the perinatal period, whereas p75 levels remained stable. Levels of both p55 and p75 decreased in neonates with infection during the perinatal period. CRP was a more specific parameter than p55 and p75 (CRP: 97%, p55: 65% and p75: 75%) whereas the sensitivity of all three parameters was at similar levels (CRP: 59%, p55: 70% and p75: 67%). We conclude that assessment of sTNFR may not improve accuracy in the diagnosis of early onset neonatal sepsis compared to the use of CRP.
 ...
PMID:Increased serum concentrations of soluble tumor necrosis factor receptors p55 and p75 in early onset neonatal sepsis. 980 75

Recent studies suggest that release of cytokines during inflammatory states such as septic shock leads to hypocholesterolemia. To examine whether tumor necrosis factor alpha (TNF), which is the major cytokine in inflammatory disease, causes hypocholesterolemia, we measured serum levels of total (bioactive and receptor-bound) TNF, cholesterol, Apo B, and Apo A1 in seven patients with septic shock over a period of 8 days. Since elevated serum TNF levels are accompanied by the release of soluble TNF receptors, levels of TNF receptors p55 and p75 were also measured. Patients with septic shock had significantly higher serum TNF and TNF receptor levels compared with healthy controls. Increased cytokine levels were accompanied by a significant decline in total serum cholesterol apolipoprotein A1 and B. In vitro studies with cultured human skin fibroblasts, human umbilical vein endothelial cells, and HepG2 hepatoma cells showed that TNF increased the degradation of 125I-labeled low-density lipoprotein in all the cell lines tested. Recombinant soluble TNF receptors inhibited the TNF-induced stimulation of low-density lipoprotein receptor in a concentration-dependent manner. However, the calculated ratio of TNF receptors to total TNF measured in serum of these patients was not able to counteract the stimulatory effect of TNF, possibly due to the higher molar excess of TNF receptors required to achieve this effect in vitro. Our data strengthen the hypothesis that serum values of total TNF determine the extent of hypocholesterolemia during sepsis and septic shock despite the presence of a high concentration of TNF receptors. Studies with recombinant TNF also confirm the role of TNF in hypocholesterolemia in inflammation.
 ...
PMID:Association of serum tumor necrosis factor levels with decrease of cholesterol during septic shock. 984 Jun 52

Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta regulate leukocyte activation and trafficking. To assess the role of MIP-1alpha and MIP-1beta in human inflammation, healthy subjects were studied during experimental endotoxemia with prior administration of ibuprofen, a cyclooxygenase inhibitor, or dimeric p75 tumor necrosis factor (TNF)-alpha receptor, a TNF antagonist; septic patients were also studied. Following endotoxin, blood levels of both MIP-1 molecules rose acutely and fell to baseline by 6 h (P=. 001). While MIP-1 mediates fever in animals independent of cyclooxygenase blockade, in subjects given endotoxin and ibuprofen, MIP-1 levels increased and fever was suppressed. MIP-1 levels were not diminished by inhibiting circulating TNF-alpha in humans. In septic patients, elevated levels of MIP-1alpha and MIP-1beta were detected within 24 h of sepsis and fell in parallel with TNF-alpha and interleukin-6 (P<.01). MIP-1alpha and MIP-1beta increase during acute inflammation but are not associated with fever in endotoxemic humans during cyclooxygenase blockade.
 ...
PMID:Detection of macrophage inflammatory protein (MIP)-1alpha and MIP-1beta during experimental endotoxemia and human sepsis. 984 32


1 2 3 Next >>