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)

Sepsis and systemic inflammatory response syndrome (SIRS) are associated with an exacerbated production of both pro- and anti-inflammatory mediators that are mainly produced within tissues. Although a systemic process, the pathophysiological events differ from organ to organ, and from organ to peripheral blood, leading to the concept of compartmentalization. The nature of the insult (e.g. burn, hemorrhage, trauma, peritonitis), the cellular composition of each compartment (e.g. nature of phagocytes, nature of endothelial cells), and its micro-environment (e.g. local presence of granulocyte-macrophage colony stimulating factor [GM-CSF] in the lungs, low levels of arginine in the liver, release of endotoxin from the gut), and leukocyte recruitment, have a great influence on local inflammation and on tissue injury. High levels of pro-inflammatory mediators (e.g. interleukin-1 [IL-1], tumor necrosis factor [TNF], gamma interferon [IFN-gamma], high mobility group protein-1 [HMGB1], macrophage migration inhibitory factor [MIF]) produced locally and released into the blood stream initiate remote organ injury as a consequence of an organ cross-talk. The inflammatory response within the tissues is greatly influenced by the local delivery of neuromediators by the cholinergic and sympathetic neurons. Acetylcholine and epinephrine contribute with IL-10 and other mediators to the anti-inflammatory compensatory response initiated to dampen the inflammatory process. Unfortunately, this regulatory response leads to an altered immune status of leukocytes that can increase the susceptibility to further infection. Again, the nature of the insult, the nature of the leukocytes, the presence of circulating microbial components, and the nature of the triggering agent employed to trigger cells, greatly influence the immune status of the leukocytes that may differ from one compartment to another. While anti-inflammatory mediators predominate within the blood stream to avoid igniting new inflammatory foci, their presence within tissues may not always be sufficient to prevent the initiation of a deleterious inflammatory response in the different compartments.
 ...
PMID:Compartmentalization of the inflammatory response in sepsis and SIRS. 1671 87

Triggering receptor expressed on myeloid cell-1 (TREM-1) is a recently described receptor that has many effects on polymorphonuclear neutrophil (PMN), as the engagement of this receptor on PMN can induce phagocytosis, respiratory burst and degranulation. We studied the effects of aging on TREM-1 engagement in human PMN. PMN from elderly were found to have impaired response following TREM-1 engagement. Notably they were not able to modulate the TREM-1-induced respiratory burst as PMN from young did. TREM-1 engagement could not reverse PMN survival following incubation with LPS or GM-CSF in the elderly whereas it did in the young. The phosphorylation of TREM-1 signal transduction molecules was altered with aging. Finally, TREM-1 engagement could not drive the recruitment of TREM-1 in the lipid-rafts of the elderly explaining in part the altered response. The observed alterations in TREM-1 response are possibly an important contributing factor in the higher incidence of sepsis-related deaths in the elderly population.
 ...
PMID:Effects of aging on triggering receptor expressed on myeloid cells (TREM)-1-induced PMN functions. 1733 1

It has recently been appreciated that patients with severe sepsis and septic shock suffer from altered innate and adaptive immune responses, leading to an impaired clearance of microorganisms. This explains their difficulty to fight their primary bacterial infection and their propensity to develop superinfections. A depressed immunological surveillance in some of these patients is also responsible for a reactivation of dormant viruses, such as cytomegalovirus. Leukocyte functions are profoundly affected during sepsis. Circulating phagocytes show a marked decrease in their capacity to mount a pro-inflammatory reaction in response to microorganisms. Monocytes express low levels of major histocompatibility class II molecules. These phenotypic changes are known as 'immune paralysis'. Massive lymphocyte and dendritic cell apoptosis has also been reported in patients dying of sepsis, responsible, at least in part, for the impairment of adaptive responses. This was highlighted by the defective skin tests to common antigens documented already three decades ago in patients with sepsis. Patients with severe sepsis and septic shock may therefore benefit from treatments aimed at stimulating innate and adaptive immune responses. The aims of immune stimulation are: (1) to help bacterial killing at the primary focus of infection; (2) to prevent the development of nosocomial infections; and (3) to prevent the reactivation of dormant viruses. Therapeutic strategies based on 'boosting' immune responses with interferon gamma, G-CSF, and more recently with GM-CSF have been initiated. Although results of pilot studies are encouraging, these will need to be confirmed in larger clinical studies. As a word of caution, one should not induce deleterious overwhelming inflammatory reactions, and therefore close monitoring of immune and inflammatory responses during immune stimulation therapy is necessary.
 ...
PMID:Immunostimulation is a rational therapeutic strategy in sepsis. 1738 Jul 86

A major toxicity of the cancer chemotherapeutic agent cisplatin is acute renal failure. Sepsis is a common cause of acute renal failure in humans and patients who receive cisplatin are at increased risk for sepsis. Accordingly, this study examined the interactions between cisplatin and endotoxin in vivo with respect to renal function and cytokine production. Mice were treated with either a single dose of cisplatin or two doses of LPS administered 24 h apart, or both agents in combination. Administration of 10 mg/kg cisplatin had no effect on blood urea nitrogen or creatinine levels throughout the course of the study. LPS resulted in a modest rise in blood urea nitrogen at 24 and 48 h, which returned to normal by 72 h. In contrast, mice treated with both cisplatin and LPS developed severe renal failure and an increase in mortality. Urine, but not serum, TNF-alpha levels showed a synergistic increase by cisplatin and LPS. Urinary IL-6, MCP-1, KC, and GM-CSF also showed a synergistic increase with cisplatin+LPS treatment. The renal dysfunction induced by cisplatin+LPS was completely dependent on TLR4 signaling and partially dependent on TNF-alpha production. Increased cytokine production was associated with a moderate increase in infiltrating leukocytes which was not different between cisplatin+LPS and LPS alone. These results indicate that cisplatin and LPS act synergistically to produce nephrotoxicity which may involve proinflammatory cytokine production.
 ...
PMID:Endotoxin and cisplatin synergistically induce renal dysfunction and cytokine production in mice. 1749 92

Granulocyte-macrophage-colony-stimulating factor (GM-CSF) plays a critical role in innate immunity by stimulating the differentiation of tissue macrophages via the transcription factor PU.1. Previous studies showed that GMCSF-deficient(GM-CSF-/-) mice had susceptibility to and impaired clearance of group B streptococcal bacteria by macrophages. For these studies, we hypothesized that GM-CSF-/- mice have increased susceptibility to peritonitis caused by immune dysfunction of peritoneal macrophages. We examined the role of peritoneal macrophages in pathogen clearance, cytokine responses, and survival in a murine cecal ligation and puncture (CLP) model of peritonitis/sepsis. Surprisingly, CLP minimally affected survival in GM-CSF-/- mice while markedly reducing survival in wild-type mice. This was not explained by differences in the composition of microbial flora, rates of bacterial peritonitis, or sepsis, all of which were similar in GM-CSF-/- and wild-type mice. However, survival correlated with peritoneal and serum TNF-alpha and IL-6 levels that were significantly lower in GM-CSF-/- than in control mice. After peritoneal LPS instillation, GM-CSF-/- mice also had improved survival and reduced TNF-alpha and IL-6 responses. In vitro studies demonstrated reduced secretion of TNF-alpha and IL-6 by peritoneal macrophages isolated from sham GM-CSF-/- mice as compared with macrophages from sham control mice. Peritoneal instillation of GM-CSF-/-/PU.1+ macrophages, but not GM-CSF-/-/PU.1+ macrophages into GM-CSF-/- mice conferred susceptibility to death after CLP or peritoneal LPS exposure. These results demonstrate that GM-CSFY/PU.1-dependent peritoneal macrophage responses are a critical determinant of survival after experimentally induced peritonitis/sepsis or exposure to LPS and have implications for therapies to treat such infections.
 ...
PMID:Granulocyte-macrophage-colony-stimulating factor-dependent peritoneal macrophage responses determine survival in experimentally induced peritonitis and sepsis in mice. 1827 45

Sepsis is a common clinical problem that is responsible for an increasing number of deaths. Many new therapies for severe sepsis have been developed but few have shown benefit in rigorous clinical trials. To date the most successful therapies are relatively simple clinical interventions: appropriate broad spectrum antibiotics; early goal directed therapies to restore tissue oxygen delivery; physiological dose hydrocortisone in patients with relative adrenal insufficiency; intensive insulin therapy to maintain normoglycemia; and lung-protective ventilation strategies. The only adjunctive therapy supported by strong evidence of benefit is Activated Protein C. Experimental therapies are being developed with improved in vitro and animal models and better understanding of the pathophysiology of sepsis in humans. Neutralization of the triggers of inflammation, such as endotoxin, and inhibition of the signal transduction mechanisms are promising new strategies. Statins may be beneficial in prevention of sepsis and as adjunctive treatments. Reconstitution of the immune response with interferon-gamma or granulocyte-macrophage colony stimulating factor may reverse immunoparesis in severe sepsis. Many other molecular targets have been identified for possible therapeutic intervention, but there are still fundamental difficulties to be overcome in demonstrating efficacy in clinical trials.
 ...
PMID:New therapies for sepsis. 1847 86

The relative role of complement and CD14 in E. coli-induced cytokine synthesis in an in vitro human whole blood model of sepsis was examined. Fresh lepirudin-anticoagulated whole blood was incubated with E. coli for 2h. Monoclonal antibodies or a C5a receptor antagonist were used to block complement. Inflammatory mediators (n=27) were measured by multiplex technology, selected cytokine mRNA by real time PCR, and CD11b, oxidative burst and phagocytosis by flow cytometry. E. coli significantly increased 18 of the 27 inflammatory mediators, including proinflammatory cytokines (TNF-alpha, IL-6, INF-gamma and IL-1beta), chemokines (IL-8, MCP-1, MIP-1alpha, MIP-1beta, eotaxin and IP-10), growth factors (VEGF, FGF-basic, G-CSF and GM-CSF) and other interleukins (IL-9, IL-15 and IL-17). Notably, the increases in all mediators were abolished by a combined inhibition of CD14 and complement using anti-C2 and anti-factor D in combination, whereas the relative effect of the inhibition of complement and CD14 varied. In comparison, a C5a receptor antagonist and anti-CD14 in combination reduced cytokine synthesis less efficiently. Real time PCR analysis confirmed that the cytokine synthesis was blocked at the mRNA level. Similarly, E. coli-induced CD11b up-regulation, oxidative burst and phagocytosis was totally inhibited by CD14, anti-C2 and anti-factor D in combination after 2h incubation. In conclusion, the combined inhibition of complement using anti-C2, anti-factor D and CD14 almost completely inhibits the E. coli-induced inflammatory response. The combined approach may therefore be a new treatment regimen in Gram-negative sepsis.
 ...
PMID:Combined inhibition of complement and CD14 abolish E. coli-induced cytokine-, chemokine- and growth factor-synthesis in human whole blood. 1860 53

The persistent inflammatory response induced by a severe burn increases patient susceptibility to infections and sepsis, potentially leading to multi-organ failure and death. In order to use murine models to develop interventions that modulate the post-burn inflammatory response, the response in mice and the similarities to the human response must first be determined. Here, we present the temporal serum cytokine expression profiles in burned mice in comparison to sham mice and human burn patients. Male C57BL/6 mice were randomized to control (n=47) or subjected to a 35% TBSA scald burn (n=89). Mice were sacrificed 3, 6, 9, 12, 24, and 48 h and 7, 10, and 14 days post-burn; cytokines were measured by multi-plex array. Following the burn injury, IL-6, IL-1beta, KC, G-CSF, TNF, IL-17, MIP-1alpha, RANTES, and GM-CSF were increased, p<0.05. IL-2, IL-3, and IL-5 were decreased, p<0.05. IL-10, IFN-gamma, and IL-12p70 were expressed in a biphasic manner, p<0.05. This temporal cytokine expression pattern elucidates the pathogenesis of the inflammatory response in burned mice. Expression of 11 cytokines were similar in mice and children, returning to lowest levels by post-burn day 14, confirming the utility of the burned mouse model for development of therapeutic interventions to attenuate the post-burn inflammatory response.
 ...
PMID:Cytokine expression profile over time in burned mice. 1901 96

Because cytokines have been utilized in treatment of sepsis in neonates, we studied the effects of interferon-gamma (IFN-gamma) and GM-CSF on killing of intracellular methicilin-resistant Staphylococcus aureus (MRSA) by human monocyte derived macrophages (MDM) in the presence of daptomycin (Dap), rifampin (Rif), gentamicin (Gen), and combinations of these drugs. MDM infected with MRSA were treated with Dap (1 x MIC), Gen (0.5 x MIC), or Rif (1 x MIC), singly or in combination, with or without cytokines. MDM were lysed and viable bacteria counted. With antibiotics, MDM activated by IFN-gamma had a more rapid and prolonged bacterial killing effect than MDM activated by GM-CSF. This effect was most obvious with the triple-drug combination. In contrast, GM-CSF reduced intracellular killing under most experimental conditions compared to the effect of antibiotics alone. Dap alone and two- and three-drug combinations demonstrated significant killing effect for the 48 h of the assay. IFN-gamma enhanced rapid intracellular killing of MRSA in the presence of triple-drug treatment or Dap alone. GM-CSF in combination with the antibiotics reduced killing under most conditions studied. Further studies to confirm these observations with IFN-gamma-activated MDM and other MRSA strains are needed to support clinical trials for difficult-to-treat MRSA infections.
 ...
PMID:IFN-gamma enhances killing of methicillin-resistant Staphylococcus aureus by human monocytes more effectively than GM-CSF in the presence of daptomycin and other antibiotics. 2058 May 68

Although it has recently been shown that A/J mice are highly susceptible to Staphylococcus aureus sepsis as compared to C57BL/6J, the specific genes responsible for this differential phenotype are unknown. Using chromosome substitution strains (CSS), we found that loci on chromosomes 8, 11, and 18 influence susceptibility to S. aureus sepsis in A/J mice. We then used two candidate gene selection strategies to identify genes on these three chromosomes associated with S. aureus susceptibility, and targeted genes identified by both gene selection strategies. First, we used whole genome transcription profiling to identify 191 (56 on chr. 8, 100 on chr. 11, and 35 on chr. 18) genes on our three chromosomes of interest that are differentially expressed between S. aureus-infected A/J and C57BL/6J. Second, we identified two significant quantitative trait loci (QTL) for survival post-infection on chr. 18 using N(2) backcross mice (F(1) [C18A]xC57BL/6J). Ten genes on chr. 18 (March3, Cep120, Chmp1b, Dcp2, Dtwd2, Isoc1, Lman1, Spire1, Tnfaip8, and Seh1l) mapped to the two significant QTL regions and were also identified by the expression array selection strategy. Using real-time PCR, 6 of these 10 genes (Chmp1b, Dtwd2, Isoc1, Lman1, Tnfaip8, and Seh1l) showed significantly different expression levels between S. aureus-infected A/J and C57BL/6J. For two (Tnfaip8 and Seh1l) of these 6 genes, siRNA-mediated knockdown of gene expression in S. aureus-challenged RAW264.7 macrophages induced significant changes in the cytokine response (IL-1 beta and GM-CSF) compared to negative controls. These cytokine response changes were consistent with those seen in S. aureus-challenged peritoneal macrophages from CSS 18 mice (which contain A/J chromosome 18 but are otherwise C57BL/6J), but not C57BL/6J mice. These findings suggest that two genes, Tnfaip8 and Seh1l, may contribute to susceptibility to S. aureus in A/J mice, and represent promising candidates for human genetic susceptibility studies.
 ...
PMID:Two genes on A/J chromosome 18 are associated with susceptibility to Staphylococcus aureus infection by combined microarray and QTL analyses. 2082 97


<< Previous 1 2 3 4 5 6 7 Next >>