Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lipopolysaccharides (LPSs) from Escherichia coli, Serratia marcescens, and Salmonella typhimurium, at doses from 1 to 100 ng/ml, strongly enhanced growth inhibition of Candida albicans by human polymorphonuclear leukocytes (PMN) in vitro. Flow cytometry analysis demonstrated that LPS markedly augmented phagocytosis of Candida cells by increasing the number of yeasts ingested per neutrophil as well as the number of neutrophils capable of ingesting fungal cells. LPS activation caused augmented release of lactoferrin, an iron-binding protein which itself could inhibit the growth of C. albicans in vitro. Antibodies against lactoferrin effectively and specifically reduced the anti-C. albicans activity of both LPS-stimulated and unstimulated PMN. Northern (RNA blot) analysis showed enhanced production of mRNAs for interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 and in neutrophils within 1 h of stimulation with LPS. The cytokines were also detected in the supernatant of the activated PMN, and their synthesis was prevented by pretreatment of LPS-stimulated PMN with protein synthesis inhibitors, such as emetine and cycloheximide. These inhibitors, however, did not block either lactoferrin release or the anti-Candida activity of LPS-stimulated PMN. These results demonstrate the ability of various bacterial LPSs to augment neutrophil function against C. albicans and suggest that the release of a candidastatic, iron-binding protein, lactoferrin, may contribute to the antifungal effect of PMN. Moreover, the ability to produce cytokines upon stimulation by ubiquitous microbial products such as the endotoxins points to an extraphagocytic, immunomodulatory role of PMN during infection.
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PMID:Lactoferrin release and interleukin-1, interleukin-6, and tumor necrosis factor production by human polymorphonuclear cells stimulated by various lipopolysaccharides: relationship to growth inhibition of Candida albicans. 139 74

Tumor necrosis factor (TNF) has been implicated as a proximal mediator of the septic syndrome. To evaluate the possible role of TNF in leukocyte activation in septicemia, we performed a cross-over saline-controlled study in six healthy men who were intravenously injected with recombinant human TNF (50 micrograms/m2), and analyzed changes in circulating white blood cells and parameters for neutrophil and monocyte activation. TNF elicited a very rapid neutropenia, reaching a nadir after 15 minutes, followed by a neutrophilia. Lymphocytes showed a sustained decrease, whereas monocytes declined transiently. TNF injection was also associated with neutrophil activation, as reflected by a mean fivefold increase in the plasma concentrations of elastase-alpha 1-antitrypsin complexes and a mean sevenfold increase in plasma lactoferrin levels. Serum neopterin, a marker of monocyte activation, was significantly increased 24 hours after the administration of TNF. These changes occurred in the absence of detectable complement activation, as indicated by unchanged C3a-desarg plasma values. Serum interleukin-6 showed a nearly 40-fold increase after TNF injection, whereas interleukin-1 remained undetectable throughout. We conclude that the systemic release of TNF, triggered early after invasive infection, may be involved in the alterations in circulating leukocyte numbers and in the activation of leukocytes, during the development of the septic syndrome.
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PMID:Effects on leukocytes after injection of tumor necrosis factor into healthy humans. 173 11

In severe acute pancreatitis (SAP), the mechanisms leading to adult respiratory distress syndrome (ARDS) are usually attributed to the release of active enzymes and vasoactive substances from the pancreas. Thoracic duct drainage has been proposed as a means of removing the portion of these substances that drain through retroperitoneal lymphatics before they reach the systemic circulation. This technique was used in six patients with ARDS complicating SAP. The levels of proinflammatory cytokines (tumor necrosis factor-alpha [TNF alpha], interleukin-1 [IL-1], and interleukin-6 [IL-6]), neutrophil enzymes (myeloperoxidase and lactoferrin), and pancreatic enzymes (amylase, lipase and trypsin) were measured in plasma and lymph in the first 24 h of ARDS and then on Day 2, Day 4, and at the end of the drainage (Day 8). High plasma concentrations of these products were measured. A moderate lymph-to-plasma gradient was observed for IL-6, lipase, and trypsin, while similar levels in plasma and lymph were recorded for the other substances. Plasma levels of pancreatic enzymes were weakly correlated with the lung injury score and lymph level of cytokines. These results suggest that in patients with ARDS due to SAP, cytokines as well as pancreatic enzymes could contribute to the development of the lung injury, and that lymphatics are potential vectors of these mediators.
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PMID:Lymphatic release of cytokines during acute lung injury complicating severe pancreatitis. 758 88

Blood contact with artificial surfaces during cardiopulmonary bypass (CPB) triggers a systemic inflammatory response in which complement, granulocytes and cytokines play a major role. Heparin-coated CPB circuits were recently shown to reduce complement and granulocyte activation in such circumstances. The present study comprised 20 complex heart operations, 10 with heparin-coated circuits (group HC) and 10 controls (group C), with evaluation of changes in terminal complement complex, the granulocyte enzymes myeloperoxidase and lactoferrin, and the cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8). Standard heparin dose and uncoated cardiotomy reservoir were used in all cases. In both groups the levels of enzymes and terminal complement complex rose significantly, beginning at conclusion of CPB, above base values, without significant intergroup differences. IL-6 and IL-8 also increased significantly, but tended to be lower in the HC group, starting at CPB end and continuing until 20 hours postoperatively: for IL-6 the difference was significant at CPB end (83 +/- 18 vs 197 +/- 39 micrograms/l, p = 0.21). Significantly increased inflammatory response was thus found during complex heart operations even with use of heparin-coated CPB sets. The heparin-coating of circuits seems to diminish cytokine production.
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PMID:Circulating cytokines and granulocyte-derived enzymes during complex heart surgery. A clinical study with special reference to heparin-coating of cardiopulmonary bypass circuits. 878 69

Cardiopulmonary bypass has been implicated in triggering a multisystem inflammatory response caused by blood contact with the artificial surfaces of the circuit. This leads to increased morbidity levels because of cytotoxic enzymes released from activated neutrophils. Recently, it was discovered that certain inflammatory mediators are permeable to the membrane of the hemoconcentrator. As a result, this study was undertaken to quantitatively characterize the nature of this movement by deriving a sieving coefficient (S) for four inflammatory mediators: myeloperoxidase, elastase, interleukin-6, and lactoferrin. The results show no permeability through the hemoconcentrator for the two neutrophil derived enzymes myeloperoxidase and elastase (S = 0, p > 0.05). Conversely, although larger than the pore size of the hemoconcentrator, lactoferrin sieves through unrestricted (S = 1.030 +/- 0.037, p < 0.0001). Interleukin-6 is removed in concentrations greater than those found in the blood, which yields a sieving coefficient significantly greater than 1.0 (S = 1.246 +/- 0.042, p < 0.0001). In addition to sieving coefficients, this study offers theories as to why these mediators acted as such. One conclusion is that certain mediators are efficaciously removed by the hemoconcentrator and, with additional study, may result in an attenuated inflammatory response.
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PMID:Derivation of sieving coefficients to determine the efficacy of the hemoconcentrator in removal of four inflammatory mediators produced during cardiopulmonary bypass. 915 85

In this double-blind, cross-over, placebo-controlled, randomized study, two groups of eight healthy male volunteers were challenged with endotoxin (4 ng/kg) on two occasions, once in conjunction with placebo and once with granulocyte colony-stimulating factor (G-CSF; 5 microg/kg). In group 1, G-CSF was administered intravenously 2 hours before endotoxin challenge; in group 2, G-CSF was administered subcutaneously 24 hours before endotoxin challenge. In group 1, G-CSF significantly enhanced the release of tumor necrosis factor (TNF), interleukin-6 (IL-6), IL-8, IL-1 receptor antagonist (IL-1ra), and soluble TNF receptors. In group 2, G-CSF significantly reduced IL-8 concentrations and modestly attenuated TNF and IL-6 levels. In this group, IL-1ra and soluble TNF receptors were enhanced by G-CSF pretreatment and lipopolysaccharide (LPS)-induced soluble TNF receptor release was further augmented, whereas LPS-induced IL-1ra concentrations remained unaltered. Both pretreatments with G-CSF increased LPS-induced peripheral neutrophilia; the expression of CD11b, CD18, and CD67; and the release of elastase and lactoferrin. Both pretreatments also down-regulated neutrophil L-selectin expression and prevented the endotoxin-induced pulmonary neutrophil accumulation during the first 2 hours after endotoxin challenge. These data indicate that two different pretreatments with G-CSF result in differential effects on LPS-induced cytokine release but similar effects on LPS-induced neutrophil activation and changes in expression of cell surface molecules. Finally, regardless of the effects of G-CSF on LPS-induced cytokine release, G-CSF blocks LPS-induced pulmonary granulocyte accumulation.
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PMID:Modulation of cytokine release and neutrophil function by granulocyte colony-stimulating factor during endotoxemia in humans. 926 59

The inflammatory reaction of extracorporeal circuits can be assessed by measuring complement activation and the release of activation markers of leucocytes. The purpose of this study was to compare three commercially available membrane oxygenators with respect to complement (C3a), granulocyte (lactoferrin) and monocyte (interleukin-6, IL-6) activation. Thirty patients undergoing cardiac surgery were randomly assigned to undergo cardiopulmonary bypass (CPB) with one of the following oxygenators: a polypropylene hollow-fibre membrane (group 1; 2.2 m2), a polypropylene flat-sheet membrane (group 2; 3.1 m2) or a silicone envelope membrane (group 3, 3.5 m2). In all patients, a significant increase in C3a in plasma occurred during CPB with peak levels after the administration of protamine sulphate. In blood samples taken before aortic crossclamp release, at the end of CPB, and 20 min after protamine administration C3a was significantly lower in group 1 than in the other two groups. Lactoferrin increased significantly during CPB in all patients without a significant difference between the groups. IL-6 did not increase during CPB, but raised significantly after 4 h in the intensive care unit in all groups. Moreover, IL-6 was significant lower in group 1 than group 3. The data suggest that the polypropylene hollow-fibre membrane oxygenator, i.e. the oxygenator with the smallest surface area, is more biocompatible than the other types, probably because of a smaller contact surface area.
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PMID:Biocompatibility of three different membrane oxygenators: effects on complement, neutrophil and monocyte activation. 941 49

The aim of the study was to investigate whether lactoferrin can improve the immune competence of cells from patients with systemic inflammatory response syndrome (SIRS). We studied the effect of lactoferrin (LF) on the proliferative response of peripheral blood mononuclear cells (PBMC) to lipopolisaccharide (LPS) in vitro and its influence on production of 2 proinflammatory cytokines: interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha). Three groups of patients: septic survivors, septic nonsurvivors and multiple trauma patients, were investigated. Blood samples were taken upon admission to intensive care unit and after 2, 3 and 5 days. The proliferative response of PBMC in vitro was tested using 3-day culture with LPS. Cell proliferation/death was measured using MTT colorimetric method. The spontaneous and LPS-induced activity of TNF-alpha and IL-6 were measured with bioassays using indicator cell lines WEHI-164.13 and 7TD1, respectively. We demonstrated that LF inhibited the proliferative response, both spontaneous and LPS-induced, in all groups of patients. Lactoferrin alone was a good inducer of IL-6 and TNF-alpha production by monoclear cells in vitro. Addition of LF to the cultures of LPS-activated mononuclear cells stimulated IL-6 production, most markedly in the group of septic survivor patients (mean 1479, 1452, 1728, 1980 pg/ml on day 1, 2, 3 and 6 respectively). Lactoferrin also upregulated TNF-alpha production. That effect was very significant in the septic survivor patients (mean 7407, 6739, 7498 and 8509 pg/ml on day 1, 2, 3 and 5 respectively) and less pronounced in the group of trauma patients. We conclude that lactoferrin exhibited regulatory actions on the altered reactivity of PBMC from patients with sepsis and multiple injury. Lactoferrin is a good inducer of IL-6 and TNF-alpha production. However, in most cases of septic nonsurvivors LF could not abolish low reactivity of cells with regard to cytokine production.
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PMID:Lactoferrin effects on the in vitro immune response in critically ill patients. 970 49

Lactoferrin (Lf) has been found in most biological fluids including amniotic fluid and cervical mucoids in pregnant women, and released from neutrophils in response to the inflammation. As Lf possesses antimicrobial properties, it is widely considered to be an important component of the host defence against microbial infections. It is known that premature labor is caused by amniotic infection with the increase of prostaglandin production. High concentration of the inflammatory cytokines: interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) in the amniotic fluid has been known. However, changes of Lf in amniotic fluid with infection has not been reported. In the present study, Lf concentrations in amniotic fluid were measured under the intra-uterine infections state and the biological significance of Lf was investigated. The effects of Lf on the IL-6 and IL-6mRNA production in cultured amnion cells were also investigated. The concentrations of Lf and IL-6 in amniotic fluid with CAM were 8.76 +/- 0.65 micrograms/ml and 6.92 +/- 4.88 ng/ml (n = 28) respectively and both were significantly higher (p < 0.01) than those without CAM [0.86 +/- 0.81 microgram/ml and 0.34 +/- 0.25 ng/ml (n = 31)]. Significant positive correlation (r = 0.91, p < 0.01) between Lf and IL-6 levels in amniotic fluid was found. IL-6 production induced by lipopolysaccharide (LPS) (100 ng/ml) in cultured amnion cells was significantly inhibited (p < 0.05) under the physiological concentration of Lf in amnion. Total RNA was extracted from the amniotic cells by guianizine solution. RT-PCR procedure and product analysis were performed from one microgram aliquote of total RNA. beta-actin was used as an international standard and c-DNA samples were followed by 30 cycles of PCR. RT-PCR product of IL-6 mRNA was detected by Southern hybridization. Expression of IL-6 mRNA was inhibited by the addition of Lf. From the results, the possibility that Lf might suppress amniotic IL-6 production under the condition of amniotic infection is suggested. It is also suggested that Lf might act as self defence mechanism from intra-uterine infection.
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PMID:Lactoferrin and interleukin-6 interaction in amniotic infection. 978 69

Lactoferrin (LF) is a multifunctional immunoregulatory protein that has been associated with host defense at mucosal surfaces through its antibacterial properties. The antibacterial and anti-inflammatory properties of LF were further explored with an animal model of experimental urinary tract infection. Bovine LF (bLF), human LF (hLF), and synthetic peptide sequences based on the antibacterial region of hLF (amino acid residues 16 to 40 [HLD1] and 18 to 40 [HLD2]) were given orally to female mice 30 min after the instillation of 10(8) Escherichia coli bacteria into the urinary bladder. The control groups received phosphate-buffered saline or water. C3H/Tif mice were treated with hLF or bLF, and C3H/HeN mice were treated with bLF only. The numbers of bacteria in the kidneys and bladder of C3H/Tif and C3H/HeN mice were significantly reduced 24 h later by the LF treatments compared to the findings for the control group. The hLF-treated group showed the strongest reduction compared with the vehicle-treated-group (P values were 0.009 and 0.0001 for the kidneys and bladder, respectively). The urinary leukocyte response was diminished in the hLF-treated group. The hLF treatment also significantly reduced the urinary interleukin-6 (IL-6) levels at 2 h and the systemic IL-6 levels at 24 h after infection (P values were 0.04 and < 0.002, respectively). In the bLF-treated animals, no such strong anti-inflammatory effects were obtained. In another series of experiments, C3H/Tif mice perorally treated with HLD1 or HLD2 also showed reduced numbers of bacteria in the kidneys compared with the vehicle-treated mice, although the results were significantly different only for HLD2 (P < 0.01). Analysis of urine from hLF-fed C3H/Tif mice showed that hLF was excreted into the urinary tract at 2 h after feeding. Testing of the in vitro bactericidal activity of LF (1 mg/ml) or the peptides (0.1 mg/ml) in mouse urine against the E. coli bacteria revealed moderate killing only by HLD2. In conclusion, these results demonstrate for the first time that oral administration of hLF or peptides thereof is effective in reducing infection and inflammation at a remote site, the urinary tract, possibly through transfer of hLF or its peptides to the site of infection via renal secretion. The antibacterial mechanism is suggested to involve bactericidal capacities of LF, fragments thereof, or its peptides.
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PMID:Human lactoferrin and peptides derived from a surface-exposed helical region reduce experimental Escherichia coli urinary tract infection in mice. 1099 90


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