Anne Delvaux

Interleukin 10 prevents necrosis in murine experimental acute pancreatitis

BACKGROUND/AIMS Inflammatory events are believed to play an important role in the pathogenesis of acute pancreatitis. Interleukin 10 (IL-10) recently emerged as a major anti-inflammatory cytokine, inhibiting the secretion of proinflammatory cytokines by monocytes and/or macrophages. The potential protective role of IL-10 in a model of acute necrotizing pancreatitis in mice was tested. METHODS Animals received two intraperitoneal injections of either 1000 U recombinant IL-10 or control supernatant before and during induction of acute pancreatitis with repeated cerulein injections (seven intraperitoneal injections of 50 micrograms/kg at hourly intervals). RESULTS Systemic amylase and lipase release peaked 9 hours after the first cerulein injection. This peak was significantly reduced by IL-10 treatment. Histologically, edema and inflammation of the pancreas were observed in both groups, whereas necrosis was dramatically reduced in IL-10-treated animals. Serum tumor necrosis factor levels were undetectable in this model; reverse-transcriptase polymerase chain reaction analysis of resected pancreatic tissues performed at the time of maximal morphological alterations showed a dramatically decreased expression of tumor necrosis factor alpha messenger RNA after IL-10 treatment compared with control pancreatitis. CONCLUSIONS IL-10 is able to decrease the severity of experimental acute pancreatitis, mainly by inhibiting the development of acinar necrosis. Inhibition of local tumor necrosis factor alpha might explain, at least in part, the protective effect of IL-10.

lnterleukin-10 Inhibits Lipopolysaccharide-Induced Tumor Necrosis Factor and Interleukin-1β Production in the Brain without Affecting the Activation of the Hypothalamus-Pituitary-Adrenal Axis

Interleukin (IL) 10 inhibits endotoxin (lipopolysaccharide; LPS) induced tumor necrosis factor (TNF) production in vivo and in vitro. In turn, IL-10 is induced by LPS and acts as a negative feedback t

Applications of electrodialysis for acid pickling wastewater treatment

Abstract In acid pickling before electroplating, the effective acid concentration deteriorates while the dissolved metal concentration increases continuously. By introducing electrodialysis (ED) between this operation and the following rinsing baths, these disadvantages are largely rectified. Recovered acid is continuously returned to the pickling bath and the amount of waste is drastically reduced. Depleted solution is reused in rinsing baths. Moreover, ED can avoid metallic impurity build-up in the acid pickling bath. First manipulations conducted on our laboratory equipment failed. So, ion-exchange membranes (IEMs) were characterized by conductivity measurements and polarization curves. Afterwards, a new selection of IEMs was performed. Faradic yields were calculated for various commercial anion- and cation-exchange membranes (AEMs and CEMs) in a Hittorf cell and ED conditions were refined. The relation between the hydrodynamics of ED and the limiting current density was checked by new measurements based on a tracer method successfully applied to electrochemical cells by our laboratory.

Modulation of the release of cytokines and reduction of the shock syndrome induced by anti-CD3 monoclonal antibody in mice by interleukin-10.

Since IL-10 was recently shown to inhibit several T cell functions in vitro, we investigated the effects of IL-10 on the cytokine release syndrome induced in mice by the 145–2C11 anti-CD3 mAb. As OKT3 in man, this mAb induces a massive polyclonal T cell activation before to induce immunosuppression. First, we found that administration of 1000 U of recombinant mouse IL-10 (mIL-10) 30 min before injection of 10 μg of the 145–2C11 antimouse CD3 mAb markedly reduced the systemic release of IFN-γ and TNF. In contrast, IL-10 pretreatment did not significantly modify the release of IL-6. To determine the effect of IL-10 pretreatment on the endogenous secretion of IL-10 induced by the 145–2C11 mAb, mice were injected with human IL-10 (hIL-10) which does not cross-react in the ELISA for mIL-10 determination. While hIL-10 was as efficient as mIL-10 in reducing TNF and IFN-γ release, it did not modify peak serum levels of IL-10. The modulation of cytokine production by mIL-10 was associated with a significant reduction of the toxicity of the 145–2C11 mAb, as assessed by the attenuation of hypothermia and by the reduced lethality in D-galac-tosamine-sensitized mice. We conclude that IL-10 differentially regulates the in vivo production of cytokines and decreases the systemic toxicity induced by the 145–2C11 mAb. These observations suggest potential therapeutic applications of IL-10 in organ transplantation, especially in association with anti-CD3 mAb.

Characterization of D-myo-inositol 1,4,5-trisphosphate phosphatase in rat brain.

Rat brain homogenates contain significant amounts of inositol 1,4,5-trisphosphate phosphatase in both 180,000xg (60 min) particulate and supernatant fractions. As other membrane-bound enzymes (e.g. guanylate cyclase), particulate inositol 1,4,5-trisphosphate phosphatase activity is highly sensitive to low concentrations of Triton X-100 (0.03%). Higher concentrations of detergent (1%) partially solubilized the enzyme. Thiol blocking agents (e.g. p-hydroxymercuribenzoate) inactivate inositol 1,4,5-trisphosphate phosphatase activity (an effect reversed with 2-mercaptoethanol). It is thus suggested that enzymatic activity requires the presence of -SH groups.

Interleukin 10 inhibits inflammatory cells infiltration in endotoxin-induced uveitis

Abstract• Background: Endotoxin-induced uveitis (EIU) is a model for acute anterior uveitis associated with a variety of pro-inflammatory cytokines and nitric oxide production. Interleukin 10 (IL-10) down-regulates these inflammatory mediators. We report a study of the effect of systemic administration of IL-10 on the inflammatory parameters of EIU. • Methods: Uveitis was induced in C3H/HeN mice by subcutaneous injection of 200 μg lipopolysaccharide (LPS) per mouse. Intraocular inflammation was assessed by leukocyte count and measurement of the protein concentration in the aqueous humor (AH). Mouse recombinant IL-10 at 1000 U or its vehicle alone were administered by three intravenous injections given 4.0 h and 0.5 h before and 8.0 h after LPS injection. • Results: The inflammatory cell infiltration in the eyes was significantly reduced in four of five experiments from 40% to 64% in the groups treated with IL-10 compared to the control groups (P<0.05). In contrast, the level of protein exudation in the anterior chamber (AC) was not significantly affected by IL-10 treatment. • Conclusion: IL-10 reduces the cellular infiltration in the ocular inflammation produced by endotoxin. This result suggests potential usefulness for IL-10 in the treatment of severe anterior uveitis with a strong cellular component.

IL-10 Inhibits the Primary Allogeneic T Cell Response to Human Peripheral Blood Dendritic Cells

Most of the immunosuppressive properties of IL-10 are related to its action on antigen presenting cells (APC). Until now, several mechanisms have been described by which IL-10 inhibits the ability of monocytes/macrophages to induce T cell activation. Indeed, IL-10 down-regulates their expression of MHC class II molecules1 as well as of ICAM-1 and B7-1 accessory molecules2,3. Moreover, the inhibition by IL-10 of IL-12 and IL-1 synthesis by monocytes was shown to be responsible for the inhibition of IFN-y production by peripheral blood mononuclear cells (PBMC)4. As far as the effects of IL-10 on dendritic cells are concerned, IL-10 was shown to inhibit the ability of mouse splenic dendritic cells to induce interferon (IFN)-y production by antigen-specific TH1 clones or alloreactive splenic T cells5. In addition, human epidermal Langerhans cells preincubated with IL-10 were found to be deficient in the triggering of a mixed lymphocyte reaction6. As a first approach to study the effects of IL-10 on human peripheral blood dendritic cells (PBDC), we analyzed the influence of IL-10 on a primary allogeneic T cell response induced by those cells.

The metabolism of inositol 4-monophosphate in rat mammalian tissues

Rat brain soluble fraction contains an enzymatic activity that dephosphorylates inositol 1,4-bisphosphate (Ins(1,4)P2). We have used anion exchange h.p.l.c. in order to identify the inositol monophosphate product of Ins(1,4)P2 hydrolysis (i.e. Ins(1)P1, Ins(4)P1 or both). When [3H]Ins(1,4)P2 was used as substrate, we obtained an inositol monophosphate isomer that was separated from the co-injected standard [3H]Ins(1)P1. This suggested an Ins(1,4)P21-phosphatase pathway leading to the production of the inositol 4-monophosphate isomer. The dephosphorylation of [32P]Ins(4)P1 was measured in rat brain, liver and heart soluble fraction and was Li+-sensitive. Chromatography of the soluble fraction of a rat brain homogenate on DEAE-cellulose resolved a monophosphate phosphatase activity that hydrolyzed both [3H]Ins(1)P1 and [4-32P]Ins(4)P1 isomers.

Plating in a barrel, how does it work?: A study of local mass transfer and current density distribution in a barrel

SummaryThe barrel plating study we have made has two different aspects. The first one describes the solution transfer from the tank to the barrel and how it manages to reach the parts. The main parameters that influence the solution distribution have been pointed out. The relative movement of the parts and the relative movement of the solution have been studied. Some laboratory prepared solutions simulating industrial electrolytes let us quantify these movements. Optical methods allow us to break down the relative motion in different representative static positions.The second aspect studies the current density and the diffusion limiting current density distribution. The current density distribution has been studied during representative static electrolysis with solution motion. It has also been evaluated via measurements of local galvanic potential in the barrel. Tracer methods have been used to measure the diffusion limiting current density.Through these two aspects, we have begun to develop a model to d...