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)

It has been suggested that major surgery induces polymorphonuclear leukocyte (PMNL) dysfunction, which exposes patients to the development of sepsis. Conversely, the sepsis response and multisystem organ failure in patients after surgery is thought to be mediated by activated PMNLs. In a preliminary attempt to investigate this paradox, we studied functional (hydrogen peroxide production) and phenotypic (the adhesion/complement receptor CD11b) markers of PMNL activation in 28 patients undergoing elective major resectional surgery; 11 (39%) of these patients developed postoperative sepsis (the septic group). The mean (SEM) preoperative level of neutrophil CD11b expression (97.8 [6.2] mean channel fluorescence [MCF] and 101.42 [7.9] MCF; P = .74) and hydrogen peroxide production (109.51 [4.91] MCF and 104.53 [6.3] MCF; P = .5) were similar for the uncomplicated and septic groups, respectively. However, on the first postoperative day, both mean CD11b expression and hydrogen peroxide production were greater in those patients who subsequently developed postoperative sepsis (192.5 [38] MCF vs 128.6 [8.1] MCF for the septic group vs the uncomplicated group, respectively [P < .05], and 120.43 [2.56] MCF vs 109.61 [3.05] MCF for the septic group vs the uncomplicated group, respectively [P < .0001]). We suggest that an exaggerated PMNL activation response to surgery is an early event in those patients destined to develop postsurgical sepsis.
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PMID:Polymorphonuclear leukocyte activation. An early marker of the postsurgical sepsis response. 809 29

We investigated the pathogenesis of septic liver injury in rats caused by cecal ligation and puncture. In this model, numerous neutrophils accumulated in the liver in parallel with the development of liver dysfunction. The supernatants of hepatic macrophages isolated from these septic rats 24 hr after cecal ligation and puncture had enhanced chemotactic activities for human neutrophils. These results suggest that in sepsis, hepatic macrophages attract neutrophils to the liver. Human neutrophils preincubated in this macrophage supernatant had the following biological activities not seen in the sham-operated controls. (a) They became more adherent to cultured endothelial cells through up-regulation of adhesion molecules such as CD11b/CD18, (b) their chemiluminescence was markedly elevated. These functional changes of cecal ligation and puncture hepatic macrophages were the same as those in endotoxin-pretreated hepatic macrophages after isolation from normal rats. Therefore we suspect that hepatic macrophages are activated by portal vein endotoxin in sepsis. These activated hepatic macrophages secreted chemical mediators of inflammation, including leukotriene B4 and tumor necrosis factor. In conclusion, hepatic macrophages seem to interact closely with neutrophils and play an important role in the pathogenesis of septic liver injury.
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PMID:Potential role of hepatic macrophages in neutrophil-mediated liver injury in rats with sepsis. 809 95

We describe a flow cytometric method to evaluate upregulation of peripheral blood neutrophil and monocyte integrin CD11b in vivo. To avoid spontaneous upregulation in vitro, buffy coat cells were separated on ice and all subsequent cell handling steps were carried out at 0-4 degrees C. Such leukocytes were 95-100% viable, as determined by PI staining. Buffy coat leukocytes were double-stained with CD11b PE-conjugated and CD14 FITC-conjugated monoclonal antibodies and, in addition, with the nucleic acid dye LDS-751. After staining, firstly, LDS-751 positive (+ve) leukocytes, and, secondly, CD14 +ve monocytes were collected in live mode. Aggregated and irrelevant cells were gated out on the basis of their LDS-751 staining pattern and cellular light scattering properties, and the CD11b expression on neutrophils and monocytes was determined. Upregulation of CD11b in vitro was significantly affected by factors such as cell handling temperature, pre-fixation of blood samples, and density gradient separation of the cells. Incubation of aliquots of buffy coat cell suspension supplemented with FMLP for 5 min or without FMLP supplement for 15 min at 37 degrees C significantly increased CD11b expression without affecting cell viability. We have demonstrated that CD11b is expressed at maximal levels on arthritic synovial fluid neutrophils and CD14 +ve cells, and at increased but submaximal levels on peripheral blood neutrophils and monocytes of patients recovering from sepsis. The results suggest that the method can be used to evaluate in vivo upregulation of CD11b.
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PMID:Flow cytometric determination of CD11b upregulation in vivo. 837 Sep 26

Endotoxin challenge causes metabolic dysfunction mediated by TNF, and sequestration of leukocytes. NPC 15669, N-carboxy-L-leucine, N-[2,7-dimethylfluoren-9-yl)methyl] ester, inhibits leukocyte recruitment into inflammatory lesions in animals, and inhibits endotoxin-induced neutropenia and lymphopenia in mice. This study was carried out to determine whether the ability of NPC 15669 to inhibit leukocyte sequestration is sufficient to promote survival after endotoxin challenge. To inhibit leukocyte sequestration directly, mice were treated with anti-CD11a (LFA-1) or anti-CD11b (Mac-1) before endotoxin challenge. Anti-CD11b partly inhibited neutropenia and lymphopenia in response to challenge with LPS, but anti--CD11a had little effect on leukopenia. At doses of 100 and 1000 micrograms/kg, anti-CD11b increased survival to endotoxin challenge from 0 to 20 and 40%, respectively, whereas anti-CD11a was without effect. These observations, coupled with the finding that NPC 15669 does not inhibit endotoxin-induced TNF release suggest that inhibition of leukocyte sequestration can increase survival after endotoxin challenge, and that NPC 15669 or antibodies to Mac-1 may represent effective therapies for gram-negative sepsis and shock.
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PMID:Mice treated with a leumedin or antibody to Mac-1 to inhibit leukocyte sequestration survive endotoxin challenge. 846 78

Although the low molecular weight degradation products of fibrinogen (FgDP) and fibrin (FbDP) are known to inhibit lymphocyte blastogenesis, the effect of purified macro-molecular FgDP and FbDP (molecular weight, 90 to 200 Kd) is unclear. We have examined the effect of these latter FgDP and FbDP and find that products that contain the D domain inhibit lymphocyte proliferation in response to T-cell mitogens, allogeneic mononuclear leukocytes, and anti-CD3 in vitro. Plasmic digestion of D1 in the absence of calcium with removal of the C-terminal end of the gamma chain or disruption of the gamma-gamma C-terminal cross-link site of D-dimer (DD) by puffadder venom (PAV-D) abrogates their inhibitory potential. Prior incubation of monocytes with DD or D1 inhibits subsequent lymphocyte transformation. Binding studies with radiolabeled DD and PAV-D confirm that monocytes interact only with DD. This specific binding may be competitively inhibited by monoclonal antibodies to CD11b/CD18 or by peptide analogues of the C-terminal gamma chain of fibrinogen that mimic the adhesion recognition site of integrins. We postulate that DD and D1 bind to CD11b/CD18 on adherent monocytes and modulate lymphocyte activation. These products are typically present in the plasma of patients with disseminated intravascular coagulation with sepsis and could therefore influence inflammatory processes in vivo.
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PMID:Fibrin and fibrinogen degradation products with an intact D-domain C-terminal gamma chain inhibit an early step in accessory cell-dependent lymphocyte mitogenesis. 849 35

SK&F 107647, a novel synthetic low-molecular-weight peptide, has demonstrated potent antiinfective activities in murine models of fungal and viral infection. To determine if the hematoregulatory activities of SK&F 107647 could offer protection over conventional antibiotic therapy or as a single agent in animal models of bacterial sepsis, rats were implanted intraperitoneally with a live bacteria-containing fibrin-thrombin clot. Rats pretreated subcutaneously or orally with SK&F 107647 and then infected with either a gram-negative (Escherichia coli) or a gram-positive (Staphylococcus aureus) bacteria-containing clot demonstrated significantly improved survival over control formulation-treated animals. Treated animals showed increased effector cell activation, measured by CD11b expression on neutrophils and monocytes, and up to 1000-fold reduction in the number of E. coli recovered from blood. Thus, the hematoregulatory activities of SK&F 107647 can increase natural host resistance to infections caused by both gram-negative and gram-positive bacteria.
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PMID:Treatment of experimental gram-negative and gram-positive bacterial sepsis with the hematoregulatory peptide SK&F 107647. 853 60

The integrin CD11b is an important adhesion molecule mediating the transendothelial migration of circulating polymorphonuclear granulocytes into an inflammatory region. The expression of CD11b is closely related to the ability to polymerize actin, a major component of the cytoskeleton within the phagocyte. In this study we compared the CD11b expression as well as the polymerization of actin of isolated neutrophils from patients endangered by sepsis with cells from healthy donors. The patient population was subdivided into a group of patients with severe thermal injuries and a group of patients who were admitted to an intensive care unit on suspicion of sepsis. The following results were obtained: (1) cells from burn patients, but not from non-burn patients, showed a reduced basal expression of CD11b during the first week after the burn trauma; (2) stimulation with the chemotactic peptide formyl-Met-Leu-Phe (FMLP) led to a strong overexpression of CD11b on the cells from the burn patients, this effect was not observed using cells of the second subgroup; (3) the content of polymerized actin was reduced within resting and stimulated cells from burn patients during the first 2 weeks postinjury, non-burn patient cells showed an enhanced F-actin content within the first week; (4) the ability of burn and non-burn patient cells to polymerize actin after stimulation with FMLP was slightly impaired during the first week post injury/admission. The results demonstrate that cells from patients endangered by sepsis show dysfunctions on the level of adhesion molecule expression and the strongly related actin polymerization.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of the adhesion molecule CD11b and polymerization of actin by polymorphonuclear granulocytes of patients endangered by sepsis. 855 83

We measured the levels of soluble intercellular adhesion molecule-1 (sICAM-1), CD11a, CD11b, CD18, endotoxin, and various inflammatory cytokines to clarify the relationship between adhesive molecules and cytokines in sepsis. We studied 21 patients with sepsis (sepsis group) and 13 patients with trauma not complicated by infection (trauma group). The mean sICAM-1 level was significantly higher in the sepsis group than in the trauma group. No significant difference was observed in the CD11a, CD11b, and CD18 levels between the two groups. The sICAM-1 levels significantly correlated with the levels of endotoxin, tumor necrosis factor alpha (TNF-alpha), and IL-8, but CD11a, CD11b, and CD18 levels did not correlate with endotoxin or cytokine levels. These findings suggest that ICAM-1 production is induced by endotoxins and cytokines produced in excess by inflammatory reactions and that endotoxins and cytokines are involved in qualitative, but not quantitative changes in LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18).
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PMID:Changes in adhesion molecule levels in sepsis. 882 72

Five-day-old infant rats were injected intraperitoneally (i.p.) with anti-CD11b monoclonal antibody (1 B6) at a dose of 2 mg/kg or phosphate-buffered saline (PBS) either 1 h before or 3 or 24 h after inoculation with 10(5) cfu Haemophilus influenzae type b (Hib). When administered 1 h before infection, 23% of the 1B6- versus 17% of the PBS-treated rats and 87% of the 1B6- versus 83% of the PBS-treated animals died at 24 and 48 h, respectively. There was a similar mortality for 1B6 or PBS treatment at 3 h after infection. Thirteen of 15 (87%) 1B6 animals versus 16/17 (94%) PBS animals had positive CSF cultures at 48 h. No differences in mortality were observed in separate experiments where animals received 1B6 or PBS 3 or 24 h after infection with Hib and were treated with a single ampicillin dose (100 mg/kg) 24 h after infection. The median CSF white blood cell count/mm3 was 5627 and 4860 for the animals with meningitis receiving 1B6 and PBS, respectively, although the 1B6-treated animals had a lower percentage of polymorphonuclear cells in the CSF (P = 0.05). Histologic examination of the meninges, choroid plexus and cochlea showed a slight decrease in the numbers of inflammatory cells in animals treated with 1B6. 1B6 did not change the incidence of meningitis and only slightly decreased the degree of inflammation within the central nervous system, although animals treated with 1B6 have an altered CSF leucocyte response with the presence of more mononuclear cells as opposed to polymorphonuclear cells in their CSF. 1B6 may play a role in inhibiting neutrophil emigration to sites of inflammation within the central nervous system but is not beneficial in decreasing mortality in an infant rat model of H. influenzae type b sepsis and meningitis.
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PMID:Anti-CD11b monoclonal antibody in an infant rat model of Haemophilus influenzae type b sepsis and meningitis. 906 41

Sepsis and trauma have similarities in their immunopathologic profiles. Both conditions can result in multi-system organ failure which is sometimes associated with cytokine generation and inflammatory cell activation. Furthermore, decreases in peripheral blood monocyte expression of HLA-DR have been noted in both human sepsis and trauma. However, the magnitude, onset, and time course of such stimuli are often difficult to ascertain in human studies. Thus, to study a more detailed in vivo immunologic profile in these conditions, rat models were employed. Our aim was to describe and analyze cytokine and peripheral blood immunophenotype patterns in bacterially induced rat sepsis and to compare this to rat ischemia-reperfusion injury. Sprague-Dawley rats underwent either bacterial injection with enterotoxin producing Staphylococcus aureus or hind limb ischemia/ reperfusion. Two bacterial doses which were either lethal or sublethal at 24-48 hours were utilized. Peripheral blood neutrophils and B-lymphocytes were studied for expression of beta-integrins (CD11b and CD11b/c) and I-A, respectively, using flow cytometry. Corresponding plasma levels of TNF alpha and interferon gamma were measured by ELISA. At 24 hr, a lethal bacterial lethal bacterial dose injection resulted in significantly higher levels of neutrophil CD11b/c expression (p < 0.005) compared with ischemia-reperfusion treatment. B-cell I-A expression was also higher in lethal sepsis. Gamma interferon levels were significantly higher in lethal sepsis compared with ischemia-reperfusion (p = 0.005). Studies over time showed that CD11b expression and interferon gamma were both more marked at 6 hr than at 24 hr in lethal sepsis. This pattern was not observed in sublethal sepsis or in ischemia-reperfusion. CD11b/c expression on the other hand remained elevated at comparable levels at 6 and 24 hr in lethal sepsis. B-cell I-A expression in ischemia-reperfusion and sublethal sepsis decreased at 24 hr compared with baseline. Lethal sepsis in rats injected with enterotoxin producing staphylococcus results in phasic alterations in neutrophil CD11b and plasma interferon levels prior to death. In analogy to the findings of monocyte decreases in DR expression observed in human trauma and sepsis, rat B-cell I-A expression showed decreases in sublethal sepsis as well as in ischemia-reperfusion injury. However, this was not observed in lethal sepsis. These findings have implications in understanding the immunologic/inflammatory changes observed in human sepsis and trauma.
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PMID:The pattern of inflammation in rat sepsis due to enterotoxin-producing Staphylococcus aureus: a comparison with ischemia-reperfusion injury. 915 Nov 99


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