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)

The cellular signaling events leading to the systemic inflammatory response syndrome and sepsis in monocytes/macrophages activated by lipopolysaccharide (LPS) are well understood. LPS is a glycolipid component of Gram-negative bacterial cell wall. It exerts its effect through the lipid A moiety. LPS binds to monocytes/macrophages via a membrane-bound receptor, CD14, an interaction which is optimized in the presence of plasma factors, LPS-binding protein, and septin. Although LPS is known to bind to other receptors, the roles of these receptors in transmembrane signaling and activation of monocytes/macrophages are not as well understood as is that of the CD14 receptor. Intracellular events in response to LPS stimulation are mediated by phospholipase (PL) C, protein kinases, PLA2, and PLD. Activation of PLC by LPS results in the release of diacylglycerol and inositol 1,4,5-trisphosphate. The former mediates the stimulation of protein kinase C, and the latter induces an increase in intracellular calcium concentration. LPS stimulation of monocytes/macrophages also results in the phosphorylation and activation of several protein kinases, including protein tyrosine kinases which mediate cytokine production, and mitogen-activated protein kinase which activates cytosolic PLA2 to release arachidonate. LPS also plays a role in cellular proliferation and differentiation. Upregulation of the secretory form of PLA2 has also been documented in response to LPS. PLD is stimulated by LPS to release phosphatidic acid (PA). PA can activate the respiratory burst by increasing diacylglycerol production and by modulating the effects of guanine nucleotide-binding proteins. Therapeutic strategies to decrease the clinical effects of sepsis would logically include agents which block at initial receptor-ligand interaction, as well as those which attenuate the intracellular events that follow LPS stimulation. Early in vivo studies are promising, but clearly much work remains to be done.
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PMID:Signaling events in monocytes and macrophages. 758 75

The concentrations of endotoxin, interleukin-6 (IL-6) and group II phospholipase-A2 (PLA2-II) were measured in serum or plasma during cytotoxic chemotherapy, fever of unknown origin and sepsis in 56 patients with hematological malignancies and during sepsis and viral infections in 22 non-hematological patients. High concentrations of IL-6, PLA2-II and endotoxin were detected in sepsis, the levels being similarly elevated in hematological and non-hematological patients. The levels of IL-6 and PLA2-II correlated closely with that of C-reactive protein (CRP). The levels of PLA2-II and IL-6 declined earlier than the level of CRP during the course of antimicrobial treatment. The levels of IL-6 also rose earlier than the level of CRP. The ability of IL-6 and PLA2-II and endotoxin to discriminate between sepsis and other causes of fever was comparable to that of CRP. IL-6 and PLA2-II are, together with CRP, valuable tools for the detection of sepsis in patients with hematological malignancies who undergo cytotoxic medication. Endotoxin is not suitable for routine laboratory diagnosis of sepsis.
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PMID:Endotoxin, interleukin-6 and phospholipase-A2 as markers of sepsis in patients with hematological malignancies. 778 12

We determined the plasma levels of type-II phospholipase A2 (type II PLA2), platelet-activating factor acetylhydrolase (PAFAH) leukotriene B4 (LTB4) and of several complements (C3a, C4a, and C5a), which are considered to be among the cytokines and eicosanoids involved in vascular endothelial disorders and that vary in concentration during sepsis. We investigated the relationship between those levels and those of ET-1 and TM levels in plasma. Plasma levels of type II PLA2, PAFAH, LTB4, C3a, C4a, ET-1, and TM at the time that sepsis was diagnosed in 30 patients were 218.3 +/- 179.9 ng/ml, 23.92 +/- 9.66 nmol/min/ml, 90.35 +/- 31.49 pg/ml, 838.73 +/- 2.30 pg/ml, 1951.46 +/- 1697.78 pg/ml, 6.98 +/- 4.08 pg/ml and 7.80 +/- 3.34 ng/ml, respectively. The C5a plasma level was below the limit of detection in all cases. There were significant correlations between type II PLA2 and ET-1 plasma levels (r = 0.39, p = 0.032) and C3a and ET-1 plasma levels (r = 0.60, p = 0.03). There were also significant correlations between type II PLA2 and TM levels in plasma (r = 0.76, p = 0.0017), PAFAH and TM plasma levels (r = 0.53, p = 0.037), LTB4 and TM plasma levels (r = 0.46, p = 0.016) and C4a and TM plasma levels (r = 0.58, p = 0.037). Results suggest that the elevation of type II PLA2, PAFAH, LTB4 and complement in plasma is involved in vascular endothelial disorders in patients with sepsis.
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PMID:Relationships between plasma levels of type-II phospholipase A2, PAF-acetylhydrolase, leukotriene B4, complements, endothelin-1, and thrombomodulin in patients with sepsis. 793 1

We measured serum levels of endotoxin, cytokines, and eicosanoids and investigated their relationship to serum complement levels in patients with sepsis. Serum endotoxin (Et) levels (5.3 +/- 2.4 pg/ml) were within the normal range, but levels of tumor necrosis factor-alpha (TNF-alpha, 114 +/- 104.94 pg/ml), interleukin 6 (IL-6, 86.7 +/- 50.9 pg/ml), interleukin 8 (IL-8, 86.8 +/- 49.7 pg/ml), type-II phospholipase A2 (type II PLA2, 211.3 +/- 193.9 ng/ml), leukotriene B4 (LTB4, 88.7 +/- 27.2 pg/ml), thromboxane B2 (TXB2, 58.7 +/- 50.9 pg/ml) and 6-keto-prostaglandin F1 alpha (PGF1 alpha, 21.0 +/- 11.0 pg/ml) levels were above normal. Levels of C3a (1088.4 +/- 83.8.7 ng/ml) and C4a (1951.5 +/- 1697.8 ng/ml) were also above normal; C3 (66.0 +/- 25.6 mg/dl) and C4 (23.6 +/- 5.3 mg/dl) were within the normal range, and C5a was lower than the detectable limit in all but one of the subjects. Serum TNF-alpha was significantly correlated with C3a (p < 0.001). Serum IL-6 had a significant negative correlation with C3 (p = 0.002) and C4 (p = 0.010). Type II PLA2 was significantly correlated with C3a (p < 0.001). There were no significant correlations between serum Et or IL-8 and serum C3, C4, C3a or C4a. Our findings suggest that increased levels of TNF-alpha, IL-6, and Type II PLA/ in patients with sepsis contribute to activation of the complement system.
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PMID:Blood cytokine and complement levels in patients with sepsis. 793 3

PLA2 is a family of regulatory enzymes that control eicosanoid synthesis and PAF production. PLA2 must be tightly regulated within the cell or cell destruction results. Circulatory release of PLA2 occurs in states of profound illness including sepsis, shock, severe injury, and pancreatitis, all of which are linked to the development of ARDS and MOF. Experimental and clinical evidence suggests that PLA2 may serve a primary regulatory role in the development of these inflammatory disorders. This evidence suggests that inhibitors of PLA2 activation could play an important role in future intensive care management.
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PMID:Phospholipase A2 regulates critical inflammatory mediators of multiple organ failure. 812 Nov 78

Phospholipase A2 (EC 3.1.1.4; PLA2) is detected in serum by determination of either the catalytic activity of the enzyme or the concentration of the enzyme protein by immunoassays. The most sensitive methods for determining PLA2 catalytic activity are radiometric assays, with a substrate of synthetic phospholipid (e.g., phosphatidylcholine or phosphatidylethanolamine) containing a 14C- or 3H-labeled fatty acid at the sn-2-position. Membranes of autoclaved Escherichia coli grown in the presence of radioactive oleic acid may also be used as a substrate. The released fatty acids are separated from the unreacted substrate and quantified by liquid scintillation counting. PLA2 catalytic activities are increased in serum in sepsis, acute pancreatitis, peritonitis, multiple injuries, rheumatoid arthritis, and other arthropathies. Immunoassays--radioimmunoassay, enzyme-linked immunosorbent assay, or time-resolved fluoroimmunoassay--are based on the use of either polyclonal or monoclonal antibodies to purified PLA2s. Specific assays have been developed for both pancreatic group I PLA2 (PLA2-I) and nonpancreatic group II PLA2 (PLA2-II). The cellular source of PLA2-I in serum is the pancreatic acinar cell. Increased serum PLA2-I values have been reported in acute pancreatitis, pancreatic cancer, and abdominal trauma. Increased PLA2-II values are found in conditions involving inflammation, e.g., sepsis, infections, acute pancreatitis, various forms of arthritis, cancer, complications of pregnancy, and postoperative states. Good correlations have been found in serum samples between the catalytic activity of PLA2 and the concentration of PLA2-II but not PLA2-I. PLA2-II may represent an acute-phase protein. The cellular source of the PLA2-II in serum is unknown; it is present in large amounts in cartilage and Paneth cells, prostatic gland cells, seminal fluid, lacrimal gland cells, and tears, but cannot be demonstrated by immunohistochemical or immunochemical methods in inflammatory cells.
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PMID:Serum phospholipases A2 in inflammatory diseases. 825 15

Human non-pancreatic PLA2 has been the object of intense scrutiny for a relatively short period of time. Its role in physiology remains enigmatic. While PLA2 may serve to remodel or remove peroxidised or senescent phospholipids, the enormous magnitude of its upregulation during infectious or inflammatory episodes is consistent with a role in host defense. However, the nature of this role remains elusive. Attempts to relegate this enzyme to the genre of acute phase reactants have not been helpful in unravelling its role. Difficulty in obtaining adequate amounts of native snp-PLA2 prior to the availability of recombinant snp-PLA2 led to the widespread use of snake venom homologs, particularly in studies of the biology of PLA2. This review has underscored the pitfalls inherent in that approach given the major differences between some venom PLA2s as compared to snp-PLA2. In addition, it bears reiterating that the complex composition of venom allows for potentiation of PLA2 activity by other constituents present in venom. Whether human host defense networks employ this interactive strategy is largely unknown. Nonetheless, in spite of these reservations, some very compelling data have emerged in recent years implicating snp-PLA2 in the initiation or potentiation of local and systemic inflammatory processes. These include sepsis and associated acute lung injury as well as inflammatory arthritides, with rheumatoid arthritis as the prototype. The mechanisms of snp-PLA2 homeostasis are considerably better understood, and it has become apparent that snp-PLA2 is an integral part of a larger network of proinflammatory cytokines, growth factors and lipid mediators. The interrelationship between the functions of secretory and cytosolic PLA2s remains to be defined. A number of selective PLA2 inhibitors have been identified which will allow for discrimination between the actions of these classes of PLA2. The availability of synthetic inhibitors in conjunction with endogenous modulators of PLA2s will shift the biology of PLA2 from the realm of the inferential to that of the mechanistic.
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PMID:Extracellular phospholipase A2 expression and inflammation: the relationship with associated disease states. 825 75

Group II phospholipase A2 (PLA2-II) is an inflammatory enzyme, which has been shown to be an acute-phase protein and to correlate with the severity of sepsis. In a prospective study, the concentration of PLA2-II in the sera of 46 patients with sepsis and nonseptic bacterial and viral infections was measured by a fluoroimmunoassay. The serum concentration of PLA2-II in patients with infections (median, 164.5 micrograms/L; range, 5.07-1,740 micrograms/L) was elevated 46-fold above normal concentrations (median, 3.61 micrograms/L; range, 1.32-25.25 micrograms/L). The concentration of PLA2-II was higher in patients with sepsis (median, 284.5 micrograms/L; range, 12.95-1,574 micrograms/L) and nonseptic bacterial infections (median, 210.6 micrograms/L; range, 5.07-1,740 micrograms/L) than in those with viral infections (median, 46.78 micrograms/L; range 11.46-275.9 micrograms/L) (P = .0042). The concentration of PLA2-II correlated well with the concentration of C-reactive protein (CRP) (r = .613, P = .0001) but not with the concentration of pancreatic PLA2 (r = .089, P = .365). Measuring the serum concentration of PLA2-II is useful as an adjunct to the determination of CRP concentrations for differentiating bacterial from viral infection.
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PMID:Group II phospholipase A2 in sera of febrile patients with microbiologically or clinically documented infections. 828 27

Group II PLA2 has been implicated in inflammatory processes in both man and other animals and has been shown to be involved in inflammatory conditions, such as arthritis and sepsis. Transgenic mice expressing the human group II PLA2 gene have been generated using a 6.2-kb genomic fragment. These mice express the group II PLA2 gene abundantly in liver, lung, kidney, and skin, and have serum PLA2 activity levels approximately eightfold higher than nontransgenic littermates. The group II PLA2 transgenic mice reported here exhibit epidermal and adnexal hyperplasia, hyperkeratosis, and almost total alopecia. The chronic epidermal hyperplasia and hyperkeratosis seen in these mice is similar to that seen in a variety of dermatopathies, including psoriasis. However, unlike what is seen with these dermatopathies, no significant inflammatory-cell influx was observed in the skin of these animals, or in any other tissue examined. These mice provide an important tool for examining group II PLA2 expression, and for determining the role of group II PLA2 in normal and disease physiology. They serve as an in vivo model for identifying inhibitors of group II PLA2 activity and gene expression.
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PMID:Expression of human group II PLA2 in transgenic mice results in epidermal hyperplasia in the absence of inflammatory infiltrate. 863 92

Plasma levels of type II phospholipase A2 (type II PLA2), cytokines and endotoxin were determined in patients with sepsis to investigate their interrelations and their role in the patient's prognosis. Type II PLA2 was measured by radioimmunoassay, tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and IL-8 were each measured by enzyme-linked immunosorbent assay (ELISA). Endotoxin was determined by a method based on an endotoxin-specific synthetic substrate. Plasma levels of type II PLA2 were significantly higher in the patients who died of sepsis than in those who survived the illness. There was a significant correlation between type II PLA2 and TNF-alpha and IL-6. Type II PLA2, TNF-alpha, IL-6, and IL-8 may be useful as indices of disease severity. The results suggest that TNF-alpha and IL-6 stimulate the production of type II PLA2 in the plasma of patients with sepsis.
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PMID:Plasma levels of type II phospholipase A2 and cytokines in patients with sepsis. 874 87


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