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)

Although lymphocyte-derived cytokines are known to augment macrophage cytokine production in vitro, their effect on macrophage tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) secretion during gram-negative bacterial sepsis has not been characterized. The purpose of this study was to examine the effect of lymphocyte-derived cytokines on macrophage TNF-alpha and IL-6 secretion during gram-negative bacterial peritonitis. To examine this problem, uninfected and infected mice were studied. Mice were infected with Escherichia coli O111:B4 and two subgroups were examined consisting of those pretreated iv 1 hr prior to bacterial challenge with either (1) saline or (2) anti-E. coli O111:B4 LPS mAb 2A3, the latter administered to abrogate the effects of LPS in vivo. Thus, three groups of mice were studied in relation to pretreatment and infectious challenges: (1) saline/saline (control); (2) saline/E. coli (saline); and (3) mAb 2A3/E. coli (mAb 2A3). Nonadherent splenocytes (> 95% lymphocytes by histologic staining criteria) harvested 16 hr later from mice in each group were incubated in culture ex vivo for 3 hr to obtain supernatants containing lymphocyte-derived cytokines. These supernatants containing lymphocyte-derived cytokines then were incubated in vitro with naive splenic macrophages with or without E. coli O111:B4 LPS. Macrophage TNF-alpha and IL-6 levels were determined using L929 and B9 bioassays.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lymphocyte-derived cytokines augment macrophage tumor necrosis factor-alpha and interleukin-6 secretion during experimental gram-negative bacterial sepsis. 779 54

Animal study results have suggested a role in sepsis for human interleukin for DA1.a cells/leukemia inhibitory factor (HILDA/LIF). HILDA/LIF and interleukin-6 (IL-6) levels were prospectively studied by serial ELISAs in 34 septic patients. HILDA/LIF was detected in 11 of 34 patients at plasma levels of 100-37,000 pg/mL. Peak HILDA/LIF levels correlated with increased temperature and creatinine and IL-6 and with decreased arterial CO2 (P < .05). Multivariate analysis showed that shock and decreased arterial CO2 accounted for 75% of peak HILDA/LIF plasma variations (R2 = .753). Fatal outcome was most often associated with detectable HILDA/LIF (> 56 pg/mL) and peak IL-6 plasma levels > 850 pg/mL (sensitivity, 83%; specificity, 87%), but both (at respective levels of > 480 and > 850 pg/mL) were associated with fatal outcome. HILDA/LIF was detected in septic patients exhibiting shock, and its levels correlated with higher mortality and shorter survival.
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PMID:Increased plasma levels of human interleukin for DA1.a cells/leukemia inhibitory factor in sepsis correlate with shock and poor prognosis. 779 71

The potential effects of cytokines on hepatocellular transport functions remain undefined. Interleukin-6 (IL-6) is a cytokine that is produced in sepsis, hepatitis, and other inflammatory conditions often associated with cholestasis. Using cultured rat hepatocytes, we have investigated the effects of IL-6 on hepatocellular bile salt uptake. Because hepatocyte Na(+)-K(+)-adenosinetriphosphatase (ATPase) produces the electrochemical gradient that drives sodium-dependent bile salt contransport, we also examined the effects of IL-6 on Na(+)-K(+)-ATPase activity. Hepatocytes cultured for 20 h in media containing IL-6 exhibited a dose-dependent noncompetitive inhibition of [3H]taurocholate uptake, which was maximal at an IL-6 dose of 100 U/ml. IL-6 treatment had no effect on hepatocyte sodium-independent taurocholate uptake. Northern blotting of RNA from cultured hepatocytes revealed that IL-6 had no effect on steady-state RNA levels of the Na(+)-taurocholate transporter (Ntcp). Hepatocytes incubated with IL-6 for 20 h, however, exhibited a 55% decrease in hepatocyte Na(+)-K(+)-ATPase activity. This effect also was dose dependent, with maximal inhibition occurring at an IL-6 dose of 100 U/ml. Similar treatment with IL-6 did not influence hepatocyte Mg(2+)-ATPase activity. The inhibition of Na(+)-K(+)-ATPase activity induced by IL-6 provides a putative mechanism for the observed inhibition of sodium-dependent taurocholate uptake. Since modulation of bile salt transport and Na(+)-K(+)-ATPase activity occurred at IL-6 concentrations comparable to the serum levels observed in patients with severe inflammatory states, these findings have potential pathophysiological relevance for the cholestasis of sepsis and other inflammatory disorders.
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PMID:Interleukin-6 inhibits hepatocyte taurocholate uptake and sodium-potassium-adenosinetriphosphatase activity. 781 Jun 56

Pneumolysin is a cytoplasmic virulence factor of Streptococcus pneumoniae that can interfere with phagocyte function in vitro. We have examined the effects of pneumolysin in vitro and in vivo and have found that it protects intravenously injected pneumococci against infection-induced host resistance. We employed a virulent capsular type 2 pneumococcal strain, D39, and its isogenic pneumolysin-negative mutant, PLN. Strain D39 exhibited exponential net growth in mice (doubling time, 1.4 h); 24 to 28 h after infection with 10(4) CFU, the numbers of pneumococci reached 10(9) to 10(10) CFU/ml and the mice died. Strain PLN yielded identical net growth in mice until reaching 10(6) to 10(7) CFU/ml at 12 to 18 h postinfection. At this time, the increase in the level of PLN CFU per milliliter ceased and remained constant for several days. PLN exhibited wild-type growth kinetics in mice when coinfected simultaneously with strain D39. This observation suggests that pneumolysin exerts its effects at a distance. By 12 to 18 h postinfection with PLN, mice exhibited the following evidence of an induced inflammatory response: (i) elevated plasma interleukin-6, (ii) a halt in the net growth of PLN, and (iii) control of the net growth of pneumolysin-producing D39 pneumococci upon subsequent challenge. Our data suggest that pneumolysin plays a critical role in sepsis during the first few hours after infection by enabling pneumococci to cause acute sepsis rather than a chronic bacteremia. However, once chronic bacteremia was established, it appeared that pneumolysin was no longer able to act as a virulence factor.
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PMID:A pneumolysin-negative mutant of Streptococcus pneumoniae causes chronic bacteremia rather than acute sepsis in mice. 782 9

The neutrophil is an important effector cell of the host response to sepsis. Tumor necrosis factor-alpha (TNF-alpha), a cytokine mediator of the septic response, is rapidly released following endotoxemia or gram-negative bacteremia. Interleukin-6 (IL-6) is another cytokine mediator of the host response to sepsis whose role is less well understood than that of TNF-alpha. It is known to be elevated in gram-negative sepsis, where peak levels have been correlated with mortality. This study examined the effect of IL-6 alone and in combination with TNF-alpha on three neutrophil functions--CD18 adhesion receptor expression, phagocytosis, and superoxide anion generation. Neutrophils from human volunteers were incubated with amounts of IL-6 ranging from 10 to 1000 ng/ml. At a concentration of 1000 ng/ml, IL-6 increased neutrophil phagocytosis of opsonized bacteria (826 +/- 255 x 10(3) MESF vs 552 +/- 103 MESF, P < 0.05) and also increased neutrophil superoxide anion generation (18.41 +/- 1.86 vs 12.6 nmol O2-/10(6) PMN/10 min, P < 0.05). Lesser amounts of IL-6 had no effect on phagocytosis or superoxide generation. IL-6 did not increase neutrophil CD18 adhesion receptor expression. Combining IL-6 with TNF-alpha at doses of 100 ng/ml and 100 U/ml, respectively, neutrophil phagocytosis (221 +/- 455 MESF vs 552 +/- 103 MESF) and superoxide generation (23.18 +/- 1.86 vs 12.6 nmol O2-/10(6) PMN/10 min) were significantly (P < 0.05) increased above control by an amount similar to that seen with 1000 U/ml TNF-alpha alone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Tumor necrosis factor-alpha and interleukin-6 selectively regulate neutrophil function in vitro. 786 62

The cytokines interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF alpha) have been implicated in the pathophysiology of sepsis and the systemic inflammatory response syndrome (SIRS). The anti-endotoxin antibody, HA-1A (Centoxin), introduced as a treatment for sepsis, was withdrawn because of possible toxicity in some patients. There has been little investigation of the effects of HA-1A on cytokine production. Sixty-one whole blood samples from 15 intensive care unit (ICU) patients with SIRS were incubated for 24 h with HA-1A and concentrations of cytokines determined. Concentrations of IL-6 exceeded those in samples incubated without HA-1A by more than 25% in five patients, of whom four died. One death occurred among 10 patients for whom IL-6 concentrations did not increase (P = 0.03). Incubation with HA-1A did not increase concentrations of IL-1 beta or TNF alpha. HA-1A did not affect cytokine production in whole blood from healthy subjects. HA-1A may induce IL-6 production in whole blood from some ICU patients and this response is associated with increased mortality. Immune therapies for treatment of sepsis and SIRS require careful evaluation of their ability to affect cytokine production, before they are introduced for general use.
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PMID:In vitro effects of HA-1A (Centoxin) on cytokine production in whole blood from intensive care unit patients. 788 Jun 71

Cytokines seem to play an important role in the metabolic disturbances that are commonly associated with sepsis. In this study, we analyzed the effect of tumor necrosis factor, interleukin-1 and interleukin-6, as well as that of tumor necrosis factor in combination with interleukin-1 or interleukin-6, both on free fatty acids and on phospholipid synthesis by isolated rat hepatocytes. All three cytokines and combinations caused inhibited D-[U-14C]glucose incorporation into phosphatidylcholine (tumor necrosis factor = 6.39 +/- 1.13 pmol/microgram protein vs. control = 12.90 +/- 0.98 pmol/microgram protein, n = 7; p < 0.001). However, when [U-14C]palmitate was used as radioactive precursor, tumor necrosis factor, either alone or in the presence of the other cytokines, stimulated phosphatidylcholine synthesis. D-[U-14C]glucose incorporation into free fatty acids and triacylglycerol was also significantly stimulated, whereas phosphatidylinositol labeling was found inhibited by the assayed cytokines. Our results demonstrate an effect of sepsis-related cytokines, more evident for tumor necrosis factor, on hepatocyte lipid synthesis either from glucose or palmitate. Also, the findings support the hypothesis that cytokine-induced changes in hepatocyte lipid synthesis can contribute to the impairment in lipidic metabolism seen in patients with sepsis.
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PMID:Effect of different sepsis-related cytokines on lipid synthesis by isolated hepatocytes. 792 34

Previous studies have shown that tumor necrosis factor alpha (TNF-alpha) plays a pathophysiologic role in sepsis induced in rat pups by group B streptococci (GBS). In this model, TNF-alpha is also partially responsible for the induction of interleukin-6 (IL-6). The present study was undertaken to investigate the role of IL-6 in neonatal BALB/c mice infected with type III GBS. The effect of anti-IL-6 monoclonal antibodies and recombinant IL-6 on lethality and TNF-alpha production was investigated. In mouse pups infected with GBS strain COH1, plasma IL-6 reached levels of 3,067 +/- 955 and 1,923 +/- 891 U/ml when measured at 22 and 48 h, respectively (P < 0.05 compared with uninfected controls). Pretreatment with 25 micrograms of anti-IL-6 antibodies totally prevented the increase in circulating IL-6 bioactivity at both 22 and 48 h after infection (P < 0.05). Treatment with anti-IL-6 also induced a moderate decrease in survival time of mice infected with lethal doses of strains COH1 and COH31, as evidenced by increased lethality (P < 0.05) at 24 to 48 h but not at 96 h. Mouse recombinant IL-6 (12,500 U) given 6 h before challenge with strains COH1 and COH31 consistently increased survival time, as evidenced by decreased (P < 0.05) lethality at 48 to 72 h but not at 96 h. The effects of IL-6 pretreatment were dose dependent, since no protection was observed with doses lower than 12,500 U. In addition, no effects on lethality were noted when IL-6 was given at the time of challenge or at later times. TNF-alpha elevations (P < 0.05 compared with uninfected controls) were measured at 12, 22, and 48 h after challenge with strain COH1 (68 +/- 28, 233 +/- 98, and 98 +/- 34 U, respectively). Pretreatment with IL-6 significantly (P < 0.05) decreased plasma TNF-alpha levels at 12 and 22 h, with 55 and 69% inhibitions, respectively. Anti-IL-6 had an opposite effect, as evidenced by a 145% increase (P < 0.05) in TNF-alpha levels at 48 h after challenge. Collectively, our data are compatible with the hypothesis that IL-6 is involved in negative feedback regulation of plasma TNF-alpha levels in experimental GBS sepsis. In this model, IL-6 pretreatment can increase survival time. Future studies will be needed to investigate the mechanisms underlying this effect.
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PMID:Beneficial effects of interleukin-6 in neonatal mouse models of group B streptococcal disease. 792 80

Interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF) are important mediators of fever and inflammation, and are involved in the pathogenesis of sepsis. There is only limited data on serum concentrations of these proinflammatory cytokines in patients with fever and neutropenia, and their interrelationship and correlation with body temperature and clinical disease early in the febrile response during neutropenia have not been studied. Immunoreactive TNF, IL-1 beta, IL-6, and IL-8 in serum samples serially obtained from 14 adult patients with neutropenia and fever considered or documented to be due to infection were measured. IL-6 and Il-8 were consistently elevated in all patients, and correlated well with each other and with body temperature. Median peak concentration of IL-6 and IL-8 were 400 pg/ml (range: 100 to 41,000 pg/ml), and 1,025 pg/ml (range: 600 to 26,000 pg/ml), respectively, and levels of both cytokines rapidly declined in patients responding to antimicrobial therapy. Despite frequent sampling before and after the temperature peaks TNF and IL-1 beta, conversely, were less frequently detectable, with median peak values of < 10 pg/ml (range: < 10 to 150 pg/ml) for TNF, and 17 pg/ml (range: < 10 to 36 pg/ml) for IL-1 beta, respectively. The role of neutro- and monocytopenia with depletion of important cytokine producing and target cells in this particular cytokine response pattern needs to be further studied.
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PMID:Kinetics and correlation with body temperature of circulating interleukin-6, interleukin-8, tumor necrosis factor alpha and interleukin-1 beta in patients with fever and neutropenia. 792 10

The proinflammatory cytokines have been implicated in mediating myocardial dysfunction associated with myocardial infarction, severe congestive heart failure, and sepsis. We tested the hypothesis that cytokine levels are elevated after uncomplicated coronary artery bypass grafting and associated with episodes of postoperative myocardial ischemia and dysfunction. Coronary artery bypass grafting was performed under general anesthesia with moderate systemic hypothermia and cold-blood potassium cardioplegic solution. Tumor necrosis factor-alpha and interleukin-6 levels were determined by bioassays, and interleukin-8 levels were measured by a sandwich enzyme-linked immunosorbent assay. Myocardial function and ischemic episodes were assessed by intraoperative transesophageal echocardiography and perioperative 12-channel Holter monitoring. A total of 22 patients were studied, with no deaths or complications. Arterial tumor necrosis factor-alpha rose in a bimodal distribution, peaking at 2 and 18 to 24 hours after the operation (at 20.2 +/- 6.4 pg/ml, [mean +/- standard error of the mean]) and 5.8 +/- 1.6 pg/ml, respectively; before cardiopulmonary bypass: 0.90 +/- 0.20 pg/ml, p < 0.001 for both peaks) then progressively declined to levels before bypass. Arterial interleukin-6 was maximally elevated immediately on termination of cardiopulmonary bypass and peaked again 12 to 18 hours after cardiopulmonary bypass (at 7520 +/- 2439 pg/ml and 6216 +/- 1928 pg/ml, respectively; before bypass: 746 +/- 187 pg/ml, p < 0.0001 for both peaks). Arterial interleukin-8 levels were more variable but followed a similar pattern, peaking in the early period after cardiopulmonary bypass and again at 16 to 18 hours after the operation (at 4110 +/- 1403 pg/ml and 1760 +/- 1145 pg/ml, respectively; before bypass: 461 +/- 158, p < 0.05 for both peaks). By multivariate analysis, the aortic crossclamp time was independently predictive of postoperative cytokine levels. Left ventricular wall motion abnormalities were associated with both interleukin-6 and interleukin-8 levels, worsening scores being associated with increasing levels (for interleukin-6, p = 0.003; for interleukin-8, p = 0.05). Postoperative myocardial ischemic episodes were associated with interleukin-6 levels, six of seven (85%) patients with episodes of myocardial ischemia after a peak in interleukin-6 concentrations (p < 0.01). We conclude that proinflammatory cytokines are elevated after uncomplicated coronary revascularization and may contribute to postoperative myocardial ischemia and segmental wall motion abnormalities.
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PMID:Relationship of the proinflammatory cytokines to myocardial ischemia and dysfunction after uncomplicated coronary revascularization. 793 95


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