The effect of anaesthesia and surgery on plasma cytokine production

The aim of this study was to investigate cytokine production in response to anaesthesia [total intravenous anaesthesia (TIVA) with propofol, sufentanil and atracurium] and surgery (laparoscopic vs. open cholecystectomy). Forty adult patients, ASA I-II, undergoing elective laparoscopic (group 1) or open (group 2) cholecystectomy were studied. Venous blood samples for measurement of interleukin (IL)-1beta, IL-2, IL-4, IL-6, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were taken before the induction of anaesthesia, pre-incisionaly, at the end of anaesthesia and surgery and 24-h postoperatively. Pre-incisionaly, in both groups, IL-1beta, IL-4, IL-6, TNF-alpha and IFN-gamma did not show a significant change, whereas IL-2 showed a significant decrease (p < 0.005 in group 1 and p < 0.001 in group 2) compared with pre-induction levels. By the end of anaesthesia and surgery, IL-1beta, IL-2, IL-4, IL-6 and TNF-alpha showed a significant increase in group 2 (p < 0.005 for IL-1beta, IL-2 and IL-4, and p < 0.05 for IL-6 and TNF-alpha); while in group 1, only IL-2 showed a significant increase (p < 0.01) and IFN-gamma showed a significant decrease (p < 0.05) compared with pre-incisional levels. By 24-h postoperatively, IL-1beta, IL-4, IL-6 and TNF-alpha had decreased significantly in group 2 (p < 0.005 for IL-4 and p < 0.05 for the others); whereas in group 1, IL-2 and IFN-gamma showed a significant increase (p < 0.005) compared with the end of anaesthesia and surgery level. In conclusion, TIVA with propofol, sufentanil and atracurium does not seem to have a significant effect on IL-1beta, IL-4, IL-6, TNF-alpha and IFN-gamma release. IL-2 was the only cytokine to show a significant decrease due to the effect of anaesthesia alone in both groups. The cytokine response to open cholecystectomy stimulated both the pro-inflammatory (IL-1beta, IL-6 and TNF-alpha) and the anti-inflammatory (IL-4) components, while this response was absent in laparoscopic cholecystectomy.     

Small-dose propofol sedation attenuates the formation of reactive oxygen species in tourniquet-induced ischemia-reperfusion injury under spinal anesthesia

The release of a tourniquet produces reactive oxygen species (ROS), which can cause ischemia-reperfusion injury. We investigated the effects on ROS production in 22 adult ASA physical status I-II patients sedated with small-dose propofol infusion and IV midazolam undergoing elective total knee replacement under intrathecal anesthesia, allocated randomly to one of two groups. In the Propofol group, sedation was performed with propofol 0.2 mg/kg followed by infusion at a rate of 2 mg. kg(-1). h(-1). In the Control group, IV midazolam 5 mg was given. ROS production was measured by lucigenin chemiluminescence analysis. Blood samples were obtained from the radial artery after spinal anesthesia, 1 min before release of the tourniquet and 5 and 20 min after reperfusion. The ischemic time was approximately 70 min. ROS production decreased nonsignificantly before reperfusion in both groups but increased significantly 5 and 20 min after reperfusion in the Midazolam group. In the Propofol group, no significant increase of ROS production was found. We conclude that small-dose propofol infusion attenuates ROS production in tourniquet-induced ischemia-reperfusion injury. IMPLICATIONS: Small-dose propofol sedation, compared with IV midazolam, attenuates free radical production after release of the tourniquet during total knee replacement under spinal anesthesia.     

The effects of propofol and midazolam on canine left ventricular contractility

Pronounced decrease in arterial blood pressure during propofol or midazolam infusion for sedation of critically ill patients, has raised the possibility that they have a direct negative inotropic action. Accordingly, in the current study, changes in the left ventricular (LV) contractility were examined during i.v. infusion of these two sedatives in anesthetized dogs. Myocardial contractility was assessed with the slope (Ees) of the LV end-systolic pressure-volume relationship and the slope (Msw) of the LV end-diastolic volume-stroke work relationship. Propofol was administered at 5, 10 and 20 mg.kg-1.h-1, and midazolam at 0.3, 0.6 and 1.2 mg.kg-1.h-1 over 60 min. Propofol caused dose-dependent decrease in Ees (55 +/- 7 during the low dose to 27 +/- 3 mmHg.ml-1 during the high dose, P < 0.05) and in Msw (91 +/- 8 during the low dose to 67 +/- 6 erg.cm-3 x 10(-3) during the high dose, P < 0.05). Midazolam, also, decreased in Ees and Msw significantly. No significant differences were observed between three different doses of midazolam. It is concluded that propofol shows the dose-dependent inhibition of myocardial contractility, but midazolam induces dose-independent inhibition.     

Association of cytokine polymorphic inheritance and in vitro cytokine production in anti-CD3/CD28-stimulated peripheral blood lymphocytes.

BACKGROUND: Genetic variations in cytokine genes are thought to regulate cytokine protein production. However, studies using T cell mitogens have not always demonstrated a significant relationship between cytokine polymorphisms and in vitro protein production. Furthermore, the functional consequence of a polymorphism at position -330 in the IL-2 gene has not been described. We associated in vitro protein production with cytokine gene polymorphic genotypes after costimulation of cultured peripheral blood lymphocytes. METHODS: PBL were isolated from forty healthy volunteers. Cytokine protein production was assessed by enzyme-linked immunosorbent assay. Polymorphisms in interleukin- (IL) 2, IL-6, IL-10, tumor necrosis factor (TNF-alpha), tumor growth factor (TGF-beta), and interferon (IFN-gamma) were determined by polymerase chain reaction (PCR). RESULTS: Statistical difference between protein production and cytokine polymorphic variants in the IL-10, IFN-gamma, and TNF-alpha genes was not evident after 48-hour stimulation with concanavalin-A. In contrast, after anti-CD3/CD28 stimulation significant differences (P<0.05) were found among high and low producers for IL-2, IL-6, and among high, intermediate, and low producers for IFN-gamma, and IL-10. Augmented levels of IL-2 in individuals that were homozygous for the polymorphic IL-2 allele were due to an early and sustained enhancement of IL-2 production. No association was found among TNF-alpha and TGF-beta genotypes and protein production. CONCLUSION: Polymorphisms in IL-2, IL-6, IL-10, and IFN-gamma genes are associated with their protein production after anti-CD3/CD28 stimulation. The profound effect of the IL-2 gene polymorphism in homozygous individuals may serve as a marker for those that could mount the most vigorous allo- or autoimmune responses, or perhaps become tolerant more easily.     

Bone-resorbing activity and prostaglandin E produced by human periodontal ligament cells in vitro

Human periodontal ligament (PDL) cells were derived from healthy premolars extracted for orthodontic treatment and were utilized for in vitro experiments in passages 4-6. Human PDL cells were seeded in tissue culture tubes and incubated with interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), indomethacin, parathyroid hormone (PTH), or their combinations, for 1 h. The medium was then replaced with serum-free BGJb medium and incubated for 24 h without further additions. Prostaglandin E (PGE) concentrations in the conditioned media (CM) were measured by radioimmunoassay, and bone-resorbing activity was measured using 45Ca-labeled neonatal mouse calvariae. The results of this study indicated that (1) unstimulated cultured PDL cells produced PGE, and PDL CM stimulated bone resorption; (2) cytokine-treated (IL-1 alpha, IL-1 beta, and TNF-alpha) PDL cells had increased production of PGE and bone-resorbing activity compared to unstimulated PDL cells; (3) indomethacin completely inhibited PGE production from unstimulated PDL cells but only partially inhibited bone-resorbing activity, indicating that PDL cells produced nonprostaglandin bone-resorbing factor(s); (4) IFN-gamma did not change PGE or bone-resorbing activity production by cytokine-stimulated PDL cells; and (5) PTH treatment of PDL cells in addition to cytokines (IL-1 alpha, IL-1 beta, and TNF-alpha) had additive effects on the production of bone-resorbing activity and synergistic effects on PGE production compared to cytokine treatment alone.     

Modulation of interleukin-6 by beta2-adrenoceptor in endotoxin-stimulated renal macrophage cells.

BACKGROUND: Activation of the cAMP signaling pathway by means of beta2-adrenoceptor agonists has been shown to up-regulate interleukin-6 (IL-6) gene expression and to stimulate IL-6 production in macrophage cells. However, whether beta2-adrenoceptor activation can also modify the rate of IL-6 production in macrophage cells activated by the bacterial endotoxins has not yet been determined. Using renal resident macrophage cells treated with endotoxin, lipopolysaccharide (LPS), and beta2-adrenoceptor agonist, terbutaline, we investigated the role of cAMP pathway, tumor necrosis factor (TNF)-alpha and mitogen-activated protein kinase (MAPK) pathway (p42/p44) in regulating IL-6 production. METHODS: IL-6 protein, mRNA, and promoter activity were measured in these cells exposed to LPS (1 microg/ml) and/or terbutaline (10(-9) to 10(-6) M). Furthermore, the time course effects of terbutaline on cAMP, MAPK (p42/p44), and TNF-alpha release were evaluated in the cells. RESULTS: Terbutaline at high concentrations (10(-6) M) significantly up-regulated IL-6 by approximately 25% (P<0.05), whereas at a lower concentration (10(-8) M), it down-regulated IL-6 production by 42% (P<0.05). Terbutaline (10(-8) and 10(-6) M) caused a concentration- and time-dependent stimulation of cAMP (P<0.05) and TNF production (P<0.05) and a time-dependent decrease in MAPK activity (P<0.05). Following the addition of a cAMP inhibitor, IL-6 promoter activity was correlated with TNF-alpha levels and MAPK activity. CONCLUSIONS: A biphasic effect of beta2-adrenoceptor agonist on IL-6 production in renal resident macrophage cells became apparent when LPS was exposed to the cells. The terbutaline-induced down-regulation of IL-6 gene production was mediated by an inhibitory effect of terbutaline on TNF-alpha, which was exerted through the MAPK and cAMP pathways, whereas the up-regulation appeared to be due to a direct action of intracellular cAMP.     

Protein kinase C involvement in interleukin-6 production by parathyroid hormone and tumor necrosis factor-alpha in UMR-106 osteoblastic cells.

The cytokine interleukin-6 (IL-6) is increased in bone and bone cells by several resorptive stimuli, including parathyroid hormone (PTH), IL-1beta, and tumor necrosis factor-alpha (TNF-alpha). The current studies were designed to determine the contribution of the protein kinase C (PKC) signaling pathway to the effects of these three agents to increase IL-6 in UMR-106 rat osteoblastic cells. Cells were pretreated with vehicle (dimethylsulfoxide [DMSO]) or the phorbol ester, phorbol 12,13-dibutyrate (PDB; 300 nM) for 48 h to down-regulate phorbol-sensitive PKC isozymes. Either PTH (0.1-10 nM), IL-1beta (0.1-10 nM), or TNF-alpha (5 nM and 10 nM) was then added for 24 h in the continued presence of vehicle or PDB. PKC isozymes were visualized by Western immunoblotting and IL-6 was determined by bioassay. PDB pretreatment caused a partial down-regulation of the conventional alpha-PKC and betaI-PKC isozymes and complete down-regulation of the novel delta-isoenzyme and epsilon-isozymes but it had no effect on the atypical zeta-PKC isozyme. PDB pretreatment reduced IL-6 responses to 5 nM and 10 nM PTH by 61% and 33%, respectively, reduced IL-6 responses to 5nM and 10 nM TNF-a by 54% and 42%, respectively, and failed to inhibit the IL-6 responses to 0.1-10 nM IL-1beta. The PDB pretreatment protocol significantly enhanced PTH-stimulated cyclic adenosine monophosphate (cAMP) production. The PKC inhibitor calphostin C also decreased IL-6 responses to PTH. Thus, in this osteoblast cell line, the PKC pathway is an important component of the signaling pathway for the IL-6 production stimulated by PTH and TNF-alpha but not that from IL-1beta.     

The effect of 17beta-estradiol on production of cytokines in cultures of peripheral blood

Estrogen's action on bone may be mediated by cytokines produced by monocytes. We have reported a decreased ratio of interleukin-1beta (IL-1beta) to interleukin-1 receptor antagonist (IL-1ra) produced by whole blood cultures in vivo in women taking hormone replacement therapy (HRT). Also, one study has shown an effect of estradiol on tumor necrosis factor-alpha (TNF-alpha) secretion by separated monocytes in vitro. The aim of this study was to evaluate the effect of estrogen in vitro on the secretion of cytokines using whole blood cultures. Subjects consisted of 12 healthy postmenopausal women, ages 57-69 years, 4-20 years since menopause. Cytokines IL-1beta, interleukin-1alpha (IL-1alpha), IL-1ra, interleukin-6 (IL-6), TNF-alpha, and granulocyte macrophage-colony stimulating factor (GM-CSF) were measured in unstimulated and in stimulated (500 ng/mL lipopolysaccharide [LPS]) whole blood cultures treated with 17beta-estradiol (E(2)) at concentrations of 10(-12)--10(-6) mol/L. We found significant decreases in the spontaneous secretion of IL-6, TNF-alpha, IL-1ra, IL-1beta, and ratio of IL-1beta/IL-1ra compared with control, at physiological concentrations of E(2). The action of E(2) was blocked by the use of the antiestrogen ICI 182780 in coculture. A decrease in cytokine secretion was not observed when the inactive form of estrogen, 17alpha-estradiol, was used in place of 17beta-estradiol. GM-CSF and IL-1alpha were not detectable in unstimulated cultures. Cytokine levels measured in stimulated cultures were not attenuated by treatment with E(2). We conclude that E(2) inhibits the spontaneous secretion of cytokines measured in whole blood cultures at physiological concentrations, and that the powerful stimulatory effect of LPS prevents any significant inhibition by E(2) in stimulated cultures.     

Intestinal graft versus native liver cytokine expression in a rat model of intestinal transplantation: effect of donor-specific cell augmentation

INTRODUCTION: Immunomodulation by portal vein delivery of donor antigen reduces intestinal graft rejection. We investigated the impact of portal venous donor-specific cell augmentation (blood versus bone marrow) on cytokine expression in intestinal grafts versus native livers. METHODS: Ten groups of intestinal transplants (brown Norway male to Lewis female rats) varied by (1). the type of donor-specific cell augmentation and (2). the use and dose of tacrolimus-based immunosuppression. Tissue samples for histologic analysis and cytokine mRNA analysis were obtained at designated time points. RESULTS: Without immunosuppression, no type of cell augmentation reduced the rate of rejection. With immunosuppression, outcome was significantly better after portal donor-specific blood transfusion (versus bone marrow infusion). Irrespective of the type of cell augmentation, severe rejection caused strong intragraft expression of IL-1alpha, IL-1beta, IFN-gamma, and TNF-alpha; liver expression mainly involved TNF-alpha. Of note, nonimmunosuppressed, cell-augmented rats showed hardly any differences in cytokine expression in their grafts versus significant increases in their native livers. With immunosuppression, bone marrow infusion (versus blood transfusion) increased intragraft cytokine expression of IL-1alpha, IL-1beta, IFN-gamma, as well as TNF-alpha, and liver expression of IL-1beta. CONCLUSIONS: (1). Rejection and donor-specific cell augmentation independently caused differences in intragraft versus native liver cytokine expression after intestinal transplants. (2). Portal donor-specific blood transfusion (versus bone marrow infusion) lowered the incidence of rejection and diminished intragraft cytokine up-regulation. (3). In our study, TNF-alpha appeared to be the cytokine most strongly associated with rejection.     

Variations in IB1/JIP1 expression regulate susceptibility of beta-cells to cytokine-induced apoptosis irrespective of C-Jun NH2-terminal kinase signaling

We previously reported that interleukin-1beta (IL-1beta) alone does not cause apoptosis of beta-cells, whereas when combined with gamma-interferon (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), it exerts a distinct apoptotic effect. Studies in beta-cell lines indicated that IL-1beta reduced expression of islet brain (IB)-1/JNK interacting protein (JIP)-1, a JNK scaffold protein with antiapoptotic action. We examined whether variations in IB1/JIP-1 expression in purified primary beta-cells affect their susceptibility to cytokine-induced apoptosis. Exposure to IL-1beta for 24 h decreased cellular IB1/JIP-1 content by 66 +/- 17%; this IL-1beta effect was maintained in the presence of TNF-alpha + IFN-gamma, which did not influence IB1/JIP-1 levels by themselves. Addition of IL-1beta to TNF-alpha + IFN-gamma increased apoptosis from 20 +/- 2% to 59 +/- 5%. A similar increase in TNF-alpha + IFN-gamma-induced apoptosis was produced by adenoviral expression of antisense IB1/JIP-1 and was not further enhanced by addition of IL-1beta, indicating that IL-1beta-mediated suppression of IB1/JIP-1 in beta-cells increases their susceptibility to cytokine-induced apoptosis. However, adenovirally mediated overexpression of IB1/JIP-1 also potentiated TNF-alpha + IFN-gamma-induced apoptosis, suggesting that the antiapoptotic effect of IB1/JIP-1 depends on well-defined cellular levels. We conclude that the IB1/JIP-1 level in beta-cells can control their susceptibility to apoptosis independent of JNK signaling.     

In vitro restoration of post-operatively decreased IFN-gamma levels after cardiac surgery and its effect on pro- and anti-inflammatory mediators

BACKGROUNDS: A decreased synthesis of interferon gamma (IFN-gamma) by TH 1 lymphocytes after cardiac operations with cardiopulmonary bypass (CPB) is part of the inflammatory response to local operative and systemic traumas. The consequences of this mechanism on the release of pro- and anti-inflammatory cytokines remain unclear. To evaluate the role of IFN-gamma, we added recombinant IFN-gamma to peripheral blood mononuclear cells (PBMCs) on the first post-operative day in an attempt to restore pre-operative values and then measured the release of pro- and anti-inflammatory cytokines in vitro. METHODS: PBMCs of 10 patients scheduled for elective coronary artery bypass grafting (CABG) were obtained pre-operatively (d0) and on the first (d1) and third (d3) post-operative days. The release of IL-6, IL-8, TNF-alpha, IFN-gamma, IL-10, IL-2, and IL-4 was studied after stimulation (48 h) with PHA (phytohemagglutinin) and LPS (lipopolysaccharide) in the absence or presence of recombinant human IFN-gamma. RESULTS: Endogenous IFN-gamma synthesis was suppressed on d1. Adding exogenous IFN-gamma restored IFN-gamma levels to normal on d1 and doubled IFN-gamma levels on d0 and d3. The addition of IFN-gamma increased TNF-alpha levels up to 250% on d1 and IL-2 synthesis by 75% on d1 and d3; the IL-2 levels, however, were still significantly depressed. The addition of recombinant IFN-gamma did not affect the synthesis of IL-6, IL-8, IL-10, and IL-4. CONCLUSIONS: Contrary to our expectations, the in vitro release of IL-6 and IL-8 as well as IL-10 and IL-4 was not influenced by the addition of IFN-gamma. However, TNF-alpha production in isolated PBMC cultures increased significantly on the first post-operative day. This may indicate a hyper-reactivity of PBMCs to IFN-gamma and suggests that the decrease in IFN-gamma synthesis might prevent an excessive stimulation of the non-specific immune system by high TNF-alpha levels after cardiac surgery.     

Impaired monocyte cytokine production in critically ill patients with acute renal failure

BACKGROUND: Plasma levels of pro- and anti-inflammatory cytokines are predictive of mortality in patients with acute renal failure (ARF). Anti-inflammatory strategies are postulated to be beneficial in treatment. However, there are few studies simultaneously examining monocyte cytokine production and plasma cytokine levels in patients with ARF. METHODS: Study populations consisted of 20 critically ill patients with ARF, 19 critically ill patients without ARF (CRIT ILL), 28 healthy subjects (HS), 19 patients with chronic kidney disease (CKD), and 15 patients with end-stage renal disease (ESRD). Monocyte intracellular content of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interleukin-8, and tumor necrosis factor-alpha (TNF-alpha) was determined by flow cytometry in whole blood. Plasma interleukin 6 and TNF-alpha concentrations were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: At baseline, there were no differences in intracellular monocyte cytokine levels between groups. After lipopolysaccaride stimulation, monocyte production of IL-1beta, TNF-alpha, and IL-6 in ARF patients was reduced by 41%, 84%, and 45%, respectively, compared to healthy subjects (P < 0.01 in each case), and similarly reduced compared to CKD and ESRD patients, and were similar to CRIT ILL patients. Plasma IL-6 levels were significantly higher in ARF patients than healthy subjects, CKD, and ESRD patients (all P < 0.001). CONCLUSION: Critically ill patients with acute renal failure have impaired monocyte cytokine production and elevated plasma cytokine levels in a pattern that closely resembles critically ill patients without ARF, and that is dissimilar to CKD and ESRD patients.     

Metabolic activity of osteoblasts retrieved from osteoarthritic patients after stimulation with mediators involved in periprosthetic loosening

OBJECTIVE: To compare the effects of polymethylmetacrylate (PMMA), interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) on osteoarthritic (OA) human osteoblasts (Ob). METHODS: Ob cell cultures were prepared from metaphyseal trabecular bone of OA patients (n=9). Their cellular metabolic activity was characterized by measuring alkaline phosphatase (ALPase), osteocalcin (Oc), osteoprotegerin (OPG), prostaglandin E2 (PGE2), IL-6, macrophage colony-stimulating factor (M-CSF) and soluble receptor activator of NF-kappaB ligand (sRANKL) in supernatants after Ob stimulation with PMMA, IL-1beta, IL-6 or TNF-alpha. RESULTS: IL-6 and PGE2 production by Ob was significantly increased by all mediators used. PMMA and TNF-alpha both stimulated M-CSF and sRANKL production whereas PMMA decreased and TNF-alpha augmented OPG release by Ob. The ratio sRANKL/OPG was significantly increased with PMMA and TNF-alpha, and treatment with anti-IL-6 antibodies did not alter this ratio. ALPase levels remained constant while only PMMA affected Oc production. Subclassification of patients into high or low endogenous producers of IL-6 and PGE2 before stimulation of Ob indicated that the two subgroups maintained similar responses to stimulation by all mediators. CONCLUSION: PMMA and TNF-alpha have comparable dual action on Ob, lowering their anabolic capacity and favoring production of bone resorption activators, an action not mediated by IL-6. This study confirms the important role of PMMA in implant loosening. However, the pertinence of high and low metabolic activities in OA Ob remains unclear, but could be involved in the pathophysiology of bone disease and aseptic loosening.     

The cytokines IL-1beta and IL-1 receptor antagonist, IL-2 and IL-2 soluble receptor-alpha, IL-6 and IL-6 soluble receptor, TNF-alpha and TNF soluble receptor I, and IL10 in drained and systemic blood after major orthopaedic surgery.

OBJECTIVE: To measure the concentration of the cytokines interleukin-1beta (IL-1beta), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumour necrosis factor-alpha (TNF-alpha) and the modulators of their function interleukin-1 receptor antagonist (IL-1Ra), interleukin-2 soluble receptor alpha (IL-2 sRalpha), interleukin-6 soluble receptor (IL-6sR) and soluble tumour necrosis factor receptor I (sTNFR-I) in systemic and drained blood for the first six hours after a major orthopaedic operation. DESIGN: Prospective study. SETTING: University hospital, Oslo. PATIENTS: 8 patients operated on for thoracic scoliosis. MAIN OUTCOME MEASURE: Concentrations of IL-1beta, IL-2, IL-6, IL-10, TNF-alpha, IL-1Ra, IL-2 sRalpha , IL-6sR, and sTNFR-I were measured together with haemoglobin (Hb) concentration, white cell count (WCC), and differential count in arterial and drained blood at wound closure and 1, 2, 4, and 6 hours postoperatively. RESULTS: IL-1beta and IL-6 concentrations increased significantly in drained blood, whereas that of TNF-alpha increased only in arterial blood. The modulating factors IL-1Ra, sTNFR-I, and IL-10 were increased both in arterial and drained blood. IL-6sR had decreased slightly at 6 hours in drained blood. No IL-2 was found and IL-2 sRalpha decreased simultaneously with the haemodilution. In arterial blood there was a granulocytosis and in drained blood a relative lymphocytosis. CONCLUSION: Cytokine responses to surgical trauma include modulating factors such as soluble receptors and receptor antagonists that have different responses systemically and locally.     

Unopposed interleukin-1 is necessary for increased plasma cytokine and eicosanoid levels to develop in severe sepsis.

OBJECTIVE: The purpose of the study was to identify the changes in plasma prostaglandin, leukotriene, and cytokine levels during clinical severe sepsis for which interleukin-1 was necessary. SUMMARY BACKGROUND DATA: Circulating prostaglandins, leukotrienes, and cytokines have been implicated as causative agents of systemic inflammation due to sepsis. However, interactions between interleukin-1 and the other cytokine and eicosanoid mediators of severe sepsis are not well-defined. METHODS: As part of two sequential multisite, prospective, randomized, double-blind, placebo-controlled clinical trials, 37 patients with severe sepsis received interleukin-1 receptor antagonist (IL-1ra) 100-mg bolus followed by 2 mg/kg per hour intravenously for 72 hours (n = 20) or placebo (n = 17). Plasma thromboxane B2 (TxB2), prostaglandin 6-keto-F1alpha (PGI), leukotriene B4 (LTB4), leukotriene C4D4E4 (LTC4D4E4), interleukin-1 beta (IL-1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) were measured by enzyme-linked immunosorbent assay before study drug infusion (baseline) and at 24, 48, and 72 hours after the beginning of the study drug infusion. RESULTS: Differences between placebo and IL-1ra for plasma LTB4 were not significant, but only IL-1ra LTB4 increased from baseline. Plasma TxB2, PGI, LTC4D4E4, TNF, and IL-6, expressed as % baseline, decreased significantly in patients receiving IL-1ra compared with the placebo group (p < 0.05), whereas plasma IL-1 increased significantly. CONCLUSIONS: Interleukin-1 may be a necessary mediator of increased circulating PGI, TxB2, LTC4D4E4, TNF, and IL-6 levels in patients with severe sepsis. Plasma IL-1 and LTB4 are increased with infusion of IL-1 receptor antagonist. The clinical significance of IL-1 in modifying circulating eicosanoid and cytokine concentrations in clinical sepsis is not clear from the data.     

Fetal pig beta cells are resistant to the toxic effects of human cytokines

BACKGROUND: The cytokine tumour necrosis factor-alpha (TNF-alpha) is thought to be responsible for primary nonfunction of islets when transplanted. This, and two other cytokines, interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma) are also implicated in the autoimmune destruction of beta cells. It is unknown if the fetal pig beta cell, which is being transplanted as a treatment for type 1 diabetes, is affected by these cytokines. METHODS: We compared the effects of the cytokines on the function and viability of adult and fetal pig beta cells. The cells were cultured for up to 3 days in the presence of 2000 pg/ml of human IL-1beta, 1000 U/ml of TNF-alpha, and 1000 U/ml of IFN-gamma, as well as 1000 U/ml of porcine IFN-gamma. Cumulative insulin levels, insulin content, metabolic activity, and viability of these cells were examined. Additionally, nitric oxide production and the activity of antioxidant enzymes in these cells were also determined. RESULTS: TNF-alpha and the combination of the three human cytokines caused a transient increase in cumulative insulin levels. TNF-alpha alone enhanced insulin content on day 3. There was no effect of these human cytokines on mitochondrial function and viability. In contrast, porcine IFN-gamma inhibited fetal pig beta cell function and also caused their death. Adult pig islets are sensitive to the toxic effects of human TNF-alpha, IL-1beta, the combination of the three cytokines, and porcine IFN-gamma. The activity of the antioxidant enzymes catalase, glutathione peroxidase, and superoxide dismutase were significantly higher in fetal pig beta cells than in adult islets, implying that this may be the reason for the lack of adverse effects of the cytokines on the fetal beta cell. CONCLUSION: Fetal pig beta cells are resistant to the toxic effect of the human cytokines, TNF-alpha and IL-1beta, in vitro. This resistance suggests that fetal, but not adult beta cells, when transplanted into humans with type 1 diabetes may be protected from primary nonfunction and will be partially protected from autoimmune destruction.     

Comparison of cytokine levels in bilateral ear effusions in patients with otitis media secretoria.

OBJECTIVE: The aim of this study was to clarify the site of primary pathology in otitis media with effusion. STUDY DESIGN AND SETTING: The levels of the inflammatory mediators TNF-alpha, TNF-beta, IL-1beta, IL-8, IL-6, IL-4, IL-2, IL-5, IL-10, and IFN-gamma were measured in 54 pairs (108 samples) using specific enzyme-linked immunosorbent assays (ELISAs). RESULTS: The levels of pro-inflammatory cytokines TNF-alpha, TNF-beta, IL-1beta, IL-8, anti-inflammatory cytokines IL-5, IL-4, IL-10, IL-6, and cytokines with immunoregulatory potential IFN-gamma, IL-2 were different between both ears of the same patient. CONCLUSION: The results suggest that in one individual both ears have different immunological processes or rates and this has implications on using the opposite ear as a control in clinical trials. SIGNIFICANCE: Profiles of interlink of examined cytokines within the samples of both ear effusions were significantly different. A significant bilateral difference was found in the levels of IFN-gamma.     

Intracellular monocyte cytokine production and CD 14 expression are up-regulated in severe vs mild chronic heart failure.

BACKGROUND: The role of circulating monocytes in the process of low-grade inflammation, characteristic of chronic heart failure (CHF), has recently been questioned. Lipopolysaccharide (LPS) desensitization has been proposed to mediate reduced monocyte cytokine elaboration in patients with severe CHF. METHODS: Intracellular monocyte production of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor (TNF)-alpha, and monocyte CD 14 expression were measured flow-cytometrically without and after 8-hour LPS stimulation in 46 patients with CHF and in a healthy control group. RESULTS: Basal cytokine concentrations were similar for the control and the mild CHF groups (New York Heart Association [NYHA] Class I or II). After LPS stimulation, IL-6 (p=0.002) and TNF-alpha levels (p=0.001) were lower in the latter group, whereas IL-1 beta production was comparable. For the moderate-severe CHF patients, unstimulated IL-1 beta (p=0.04) was higher, whereas IL-6 (p=0.2) and TNF-alpha (p=0.1) levels were not different from the controls. Measurement of LPS-stimulated cytokine production showed no differences between the control group and patients with moderate-severe CHF (all p= 0.5). Upon comparing mild vs moderate-severe CHF patients, higher levels of unstimulated cytokine production (IL-1 beta, p=0.002; IL-6, p=0.01; TNF-alpha, p=0.003), stimulated IL-1 beta (p=0.002) and IL-6 (p=0.008) were found in the latter patients. CD 14 expression in the moderate-severe CHF group was higher than in the mild-CHF group (p = 0.03) and was strongly related to stimulated IL-1 beta (r=0.62, p<0.0001), IL-6 (r=0.56, p=0.0002) and TNF-alpha (r=0.41, p=0.006) production. CONCLUSIONS: CD 14 expression and monocyte cytokine production, both unstimulated and after LPS stimulation, are increased in moderate-severe CHF when compared with mild CHF. These data suggest that circulating monocytes, possibly via increased CD 14 expression, may play a significant role in the immunologic dysbalance observed in advanced CHF.     

体外循环下异丙酚靶控输注系统的准确性

目的 评价体外循环下异丙酚靶控输注系统的准确性.方法 择期体外循环下行心脏瓣膜置换术患者20例,ASAⅡ或Ⅲ级,年龄25～64岁,体重50～70 kg.静脉注射咪达唑仑、芬太尼和维库溴铵行麻醉诱导,气管插管后机械通气.麻醉维持采用嵌入Tackley药代动力学参数的靶控输注系统输注异丙酚至术毕,血浆靶浓度为1μ/ml.于体外循环前(T1)、体外循环开始后1、5、10、20、40、60 min(T2-7)、体外循环结束后5、10 min(T8,9)时采集桡动脉血样3 ml,采用反相高效液相色谱法测定血浆异丙酚浓度,计算异丙酚靶控输注系统的偏离度、精确度、摆动度及分散度.结果 T1时异丙酚实测浓度高于血浆靶浓度(P<0.05),T2-4时异丙酚实测浓度与血浆靶浓度差异无统计学意义(P>0.05),T5-9时异丙酚实测浓度高于血浆靶浓度(P<0.05).异丙酚靶控输注系统的偏离度为21%、精确度为29%、摆动度为21%及分散度为-0.06%/h.结论 心脏手术患者体外循环时,采用嵌入Tackley药代动力学参数的异丙酚靶控输注系统的准确性超出临床可接受范围.