Publications (17) View all
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Article: Pre-treatment with low-dose endotoxin prolongs survival from experimental lethal endotoxic shock: Benefit for lethal peritonitis by Escherichia coli.
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ABSTRACT: Although LPS tolerance is well-characterized, it remains unknown if it is achieved even with single doses of lipopolysaccharide (LPS) and if it offers protection against lethal bacterial infections. To this end, C57B6 mice were assigned to groups A (sham); B (saline i.p followed after 24h by i.p 30mg/kg LPS); and C (3mg/kg LPS i.p followed after 24h by i.p 30mg/kg LPS). Survival was monitored and animals were sacrificed early after lethal challenge for measurement of tumour necrosis factor-alpha (TNFα) in serum; isolation of splenocytes and cytokine stimulation; and flow-cytometry for apoptosis and TREM-1. Experiments were repeated with mice infected i.p by Escherichia coli after challenging with saline or LPS. Mortality of group B was 72.2% compared with 38.9% of group C (p: 0.020). Serum TNFα of group C was lower than group B. Expression of TREM-1 of group C on monocytes/neutrophils was greater than group B. Release of TNFα, of IFNγ and of IL-17 from splenocytes of group C was lower than group B and the opposite happened for IL-10 showing evidence of cellular reprogramming. In parallel, apoptosis of circulating lymphocytes and of splenocytes of group C was greater compared with group B. Pre-treatment of mice challenged by E. coli with low dose LPS led to 0% mortality compared with 90% of saline pre-treated mice; in these mice, splenocytes improved over-time their capacity for release of IFNγ. It is concluded that single low doses of LPS lead to early reprogramming of the innate immune response and prolong survival after lethal E. coli challenge.Cytokine 04/2013; · 3.02 Impact Factor -
Article: Bacterial translocation in an experimental model of multiple organ dysfunctions.
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ABSTRACT: BACKGROUND: In order to investigate the hypothesis that bacterial translocation from the intestine contributes to death after multiple organ dysfunction syndrome (MODS), a sterile MODS model was studied. METHODS: MODS was induced in 139 male C57BL/6 mice by lipopolysaccharide (LPS) (endotoxin) infusion followed by zymozan infusion in four groups: Α, sham-operation; Β, LPS; C, LPS + 0.8 g/kg zymozan; and D, LPS + 1.2 g/kg zymozan. Mice were sacrificed at 24 and 48 h for quantitative tissue cultures, isolation, and stimulation of splenocytes, measurement of apoptosis of lymphocytes and macrophages, and of serum LPS and survival. Some mice with MODS were treated with the antibiotic ertapenem. RESULTS: Enterobacteriaceae and Enterococcus spp were isolated from tissues. Group D had the highest bacterial load and the shortest survival. Release of interleukin-10, of interleukin-17, and of intgerferon-γ by splenocytes and the rate of apoptosis did not concur with immune paralysis. Serum LPS concentrations were higher in mice with MODS versus controls. Ertapenem prolonged survival and decreased the bacterial load. CONCLUSIONS: Bacterial translocation seems to be an important contributor leading from MODS to death and suggests a change in therapy towards adaptation of antimicrobial treatment upon early signs of MODS.Journal of Surgical Research 02/2013; · 2.25 Impact Factor -
Article: Deficient Candida-Specific T-Helper 17 Response During Sepsis.
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ABSTRACT: Patients with sepsis in the intensive care unit (ICU) are prone to develop Candida infections. Here, we investigated Candida-induced T-helper 17 (Th17) responses during experimental human endotoxemia and in patients with sepsis admitted to the ICU. Peripheral blood mononuclear cells were stimulated with Candida albicans. The Th17 response was significantly lower during endotoxemia, compared with baseline. Patients with gram-negative sepsis had a significantly lower Th17 response as compared to healthy controls. These data demonstrate that the Th17 response is deficient during endotoxin-related systemic inflammation, which likely represents an important risk factor for increased susceptibility to develop Candida infection in patients with sepsis.The Journal of Infectious Diseases 09/2012; · 6.41 Impact Factor -
Article: Enhanced interleukin-1β production of PBMCs from patients with gout after stimulation with Toll-like receptor-2 ligands and urate crystals.
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ABSTRACT: INTRODUCTION: Monosodium urate monohydrate (MSU) crystals synergize with various toll-like receptor (TLR) ligands to induce cytokine production via activation of the NOD-like receptor (NLR) family, pyrin domain-containing 3 (NLPR3) inflammasome. This has been demonstrated in vitro using human cell lines or monocytes of healthy volunteers. In the present study, we have investigated the effect of MSU crystals and of their combination with TLR ligands in peripheral blood mononuclear cells (PBMC) of patients with gout. METHODS: PBMCs from 18 patients with primary gout and 12 healthy donors were exposed to MSU crystals in the presence or absence of saturated fatty acid C18:0 (free fatty acid, TLR2 ligand), palmitoyl-3-cystein (Pam3Cys, TLR1/2 ligand) and fibroblast stimulating factor-1 (FSL-1, TLR 2/6 ligand). Production of IL-1β, IL-6, IL-8, IL-17 and tumor necrosis factor alpha (TNFα) was determined by ELISA. mRNA transcripts of IL-1β were measured by real-time PCR. RESULTS: MSU crystals alone failed to induce IL-1β, IL-6 or TNFα in both patients and control groups, but a stronger synergy between MSU/Pam3Cys and MSU/C18:0 for the induction of IL-1β was found in patients with gout compared to healthy controls. IL-6, but not IL-8, followed the kinetics of IL-1β. No production of the neutrophil-recruiting IL-17 was detectable after stimulation of the patients' PBMCs with MSU in both the presence or absence of TLR ligands. No change of gene transcripts of IL-1β after stimulation with MSU and Pam3Cys or with MSU and C18:0 was found. A positive correlation was found between synergy in IL-1β production from PBMCs of patients between C18:0 and MSU crystals, as well as the annual number of attacks of acute gouty arthritis (rs: +0.649, P: 0.022). CONCLUSIONS: The synergy between MSU crystals and TLR-2 ligands is more prominent in patients with gout than in controls. This is likely mediated by the enhanced maturation of pro-IL-1β into IL-1β.Arthritis research & therapy 07/2012; 14(4):R158. · 4.27 Impact Factor -
Article: Function of blood monocytes among patients with orofacial infections.
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ABSTRACT: Few data are available on the significance of the integrity of the innate immune system among patients with orofacial infections. This was assessed in the present study. Peripheral blood mononuclear cells (PBMCs) were isolated from 23 patients with orofacial infections before surgical debridement and from 12 healthy volunteers. PBMCs were stimulated with bacterial endotoxin (LPS) and with Pam3Cys. Concentrations of interleukin (IL)-1β, IL-6 and tumor necrosis factor-alpha (TNFα) were estimated in supernatants by an enzyme immunoassay. Concentrations of estimated cytokines released from PBMCs of healthy volunteers and of patients did not differ. Intensity of cytokine release after stimulation was related with the time until complete resolution of the infection (p: 0.046). It is concluded that adequate functions of blood monocytes are associated with favorable outcome after surgery for orofacial abscesses. It seems, however, that impairment of monocyte function predisposes to infection persistence.Journal of cranio-maxillo-facial surgery: official publication of the European Association for Cranio-Maxillo-Facial Surgery 04/2012; · 1.25 Impact Factor
