Staphylococcal enterotoxin B-induced acute inflammation is inhibited by dexamethasone: important role of CXC chemokines KC and macrophage inflammatory protein 2.

This study was conducted to examine the anti-inflammatory mechanisms of dexamethasone during leukocyte recruitment and expression of the CXC chemokines macrophage inflammatory protein 2 (MIP-2) (CXCL2) and cytokine-induced neutrophil chemoattractant (KC) (CXCL1) in staphylococcal enterotoxin B (SEB)-induced acute inflammation. To do this, SEB was injected into murine air pouches with or without dexamethasone pretreatment for 2 h. SEB induced infiltration of leukocytes in a dose- and time-dependent manner, with the maximal response observed after 4 h of treatment with 10 microg of SEB.

Roquinimex inhibits dextran sodium sulfate-induced murine colitis.

Objective: Roquinimex is a modulator of the immune system and has been shown to attenuate induction of several inflammatory and autoimmune diseases. The objective of the present study was to determine the efficacy of roquinimex in a model of murine colitis.

Materials And Methods: For this purpose, Balb/c mice were exposed to 5% dextran sodium sulfate (DSS) in the drinking water for five to six days.

CC chemokines induce P-selectin-dependent neutrophil rolling and recruitment in vivo: intermediary role of mast cells.

1. Based on in vitro chemotaxis experiments, it is widely held that CC chemokines, such as macrophage inflammatory protein-1alpha (MIP-1alpha) and macrophage chemotactic protein-1 (MCP-1) mainly support lymphocyte trafficking. 2.

Docosahexaenoic acid inhibits cytokine-induced expression of P-selectin and neutrophil adhesion to endothelial cells.

Dietary polyunsaturated fatty acids, such as docosahexaenoic acid, may inhibit pathological processes involving endothelial cell activation. Herein, it was found that treatment of endothelial cells with docosahexaenoic acid dose dependently reduced neutrophil adhesion provoked by tumor necrosis factor-alpha (TNF-alpha). In fact, pretreatment with 100 microM of docosahexaenoic acid for 24 h decreased TNF-alpha-induced neutrophil adhesion by 50%.

Acute mast cell-dependent neutrophil recruitment in the skin is mediated by KC and LFA-1: inhibitory mechanisms of dexamethasone.

This study examined adhesive and signaling pathways and anti-inflammatory mechanisms of dexamethasone in acute mast cell-dependent neutrophil recruitment in the skin in mice. Mast cell activation dose- and time-dependently triggered influx of predominately neutrophils and secretion of cytokine-induced neutrophil chemoattractant (KC). Neutralization of KC attenuated neutrophil recruitment upon mast cell activation.

Fundamental and distinct roles of P-selectin and LFA-1 in ischemia/reperfusion-induced leukocyte-endothelium interactions in the mouse colon.

Objective: To study the adhesive mechanisms underlying ischemia/reperfusion (I/R)-induced leukocyte-endothelium interactions in the colon.

Summary Background Data: Leukocyte recruitment is a key feature in I/R-induced tissue injury, but the mechanisms regulating leukocyte rolling and adhesion in the colon are not known. The authors recently developed a new model to study the molecular mechanisms of I/R-provoked leukocyte-endothelium interactions in the colon microcirculation using inverted intravital fluorescence microscopy.

Allopurinol and superoxide dismutase protect against leucocyte-endothelium interactions in a novel model of colonic ischaemia-reperfusion.

Background: Leucocyte recruitment is a key feature in ischaemia-reperfusion (I/R)-triggered tissue injury. However, the mechanisms underlying leucocyte-endothelium interactions in the large bowel remain elusive because of a previous lack of models to examine the colonic microcirculation. The aim of this study was to develop and validate a novel method for studying reperfusion-induced leucocyte-endothelium interactions in the colon.

Anastomotic healing in the rat colon: comparison between a radiological method, breaking strength and bursting pressure.

Background And Aims: While mechanical parameters (breaking strength, bursting pressure) are used to measure colonic anastomotic healing, reported values are inconsistent. This study developed a novel approach to study colonic anastomotic repair and compared it with mechanical methods.

Methods And Materials: We created standardized four- and eight-suture colonic anastomoses and performed contrast enemas in rats.

Evaluation of gastric acid secretion at endoscopy with a modified Congo red test.

Background: Markedly decreased or absent gastric acid production is associated with a number of clinically significant conditions, and identification of patients with hypo/achlorhydria may be important. However, current methods of assessing impaired acid secretion are unreliable, time-consuming, and/or complex. The aim of this prospective study was to evaluate a modified endoscopic Congo red test for the diagnosis of hypo/achlorhydria by correlation with a standard gastric acid secretory test.

Protective effect of low molecular weight heparin on experimental colitis: role of neutrophil recruitment and TNF-alpha production.

Objective: The purpose of this study was to examine the impact and mechanism of action of low molecular weight heparin (LMWH) in a model of murine colitis.

Materials And Methods: Balb/c mice were exposed to 5% dextran sodium sulfate (DSS) in the drinking water for five days. LMWH (500 units/kg/day) was administered by subcutaneous injection prior to and throughout the treatment period with DSS.

Leukocyte rolling is exclusively mediated by P-selectinin colonic venules.

1. The objective of the present study was to examine the role of the endothelial selectins (i.e.

Lactobacillus plantarum 299v inhibits Escherichia coli-induced intestinal permeability.

The purpose of this work was to investigate whether a probiotic bacterium, Lactobacillus plantarum 299v, could affect Escherichia coli-induced passage of mannitol across the intestinal wall. Sprague-Dawley rats were pretreated for one week by either tube feeding with L. plantarum 299v twice daily, free access to L.

Protective effect of Linomide on TNF-alpha-induced hepatic injury.

Background/aims: Linomide is an immunomodulator that ameliorates several autoimmune and inflammatory diseases. We assessed the effect of Linomide on microvascular perfusion failure, leukocyte recruitment and hepatocellular injury induced by tumor necrosis factor alpha (TNF-alpha) and D-Galactosamine (Gal).

Methods: After 3 days of Linomide pretreatment (1, 10 and 100 mg/kg/day), rats were challenged with TNF-alpha/Gal for 24 h.

Low molecular weight heparin inhibits tumor necrosis factor alpha-induced leukocyte rolling.

Objective: Heparins may exert several anti-inflammatory actions. This study investigated the impact of low molecular weight heparin (LMWH) on tumor necrosis factor (TNF)-alpha-provoked leukocyte rolling, adhesion and extravascular accumulation.

Materials And Methods: Leukocyte-endothelium interactions and tissue accumulation of leukocytes were induced by TNF-alpha in Balb/c mice and analyzed by the use of intravital microscopy in the mouse cremaster muscle microcirculation.

Isolated liver perfusion permits administration of high doses of chemotherapeutic agents. Comparison with hepatic artery infusion.

Tumor cells are dependent on glutamine metabolism and acivicin, which is a selective glutamine antagonist, has been shown to effectively retard tumor growth in several malignancies. However, systemic treatment with acivicin is associated with significant side effects. The purpose of the present study was to examine whether use of an in vivo isolated liver perfusion model may allow administration of lethal doses of acivicin and compare it to regional infusion of acivicin in the hepatic artery.

Leukocyte recruitment in hepatic injury: selectin-mediated leukocyte rolling is a prerequisite for CD18-dependent firm adhesion.

Background/aims: This study was designed to examine the role of selectins and CD18 in leukocyte recruitment in hepatic injury induced by tumor necrosis factor-alpha (TNF-alpha) and galactosamine (Gal) in vivo.

Methods: Intravital fluorescence microscopy of the hepatic microcirculation was used to quantify leukocyte-endothelium interactions provoked by 24 h of systemic TNF-alpha/Gal challenge in rats. Hepatic injury was evaluated with liver enzymes.

Role of CD18-dependent neutrophil recruitment in skin and intestinal wound healing.

CD11/CD18 is an important adhesion molecule mediating recruitment of leukocytes, which, in turn, may cause postoperative injury in the skin and gastrointestinal tract. The objective of the present study was to investigate the effects of inhibiting the function of CD18 on surgery-induced dermal and intestinal infiltration of neutrophils and on the healing of surgical skin flaps and colonic anastomosis. A flap in the dorsal skin or an end-to-end colonic anastomosis were created in Sprague-Dawley rats.

Redundant function of macrophage inflammatory protein-2 and KC in tumor necrosis factor-alpha-induced extravasation of neutrophils in vivo.

Tumor necrosis factor-alpha (TNF-alpha) stimulates the expression CXC chemokines, i.e. macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (KC), and neutrophil extravasation.

CXC chemokines, MIP-2 and KC, induce P-selectin-dependent neutrophil rolling and extravascular migration in vivo.

The purpose of this study was to examine the impact of CXC chemokines, i.e. macrophage inflammatory protein-2 (MIP-2) and KC, on leukocyte-endothelium interactions in detail and to evaluate the role of P-selectin by use of intravital microscopy in the mouse cremaster muscle.

Inhibition of selectin function and leukocyte rolling protects against dextran sodium sulfate-induced murine colitis.

Background: The selectin family of adhesion molecules (P-, E- and L-selectin) plays an important role in inflammatory reactions by mediating interactions between leukocytes and activated endothelial cells. However, a recent study using gene-targeted mice has suggested that adhesion molecules (P- and E-selectin and ICAM-1) may not be relevant targets in intestinal inflammation. The objective of the present study was to re-evaluate the potential role of selectins in experimental colitis in wild-type mice using the polysaccharide fucoidan, which inhibits the function of P- and L-selectin.

Important role of CD18 in TNF-alpha-induced leukocyte adhesion in muscle and skin venules in vivo.

Objective: To examine the role of CD 18 in tumor necrosis factor-alpha (TNF-alpha)-induced leukocyte adhesion and extravasation in vivo.

Material: Male wild-type (WT) and mutated mice with hypomorphic expression of CD 18.

Methods: Intravital microscopy was used to quantitate leukocyte-endothelium interactions provoked by TNF-alpha (0.

Linomide abolishes leukocyte adhesion and extravascular recruitment induced by tumor necrosis factor alpha in vivo.

The immunomodulator Linomide (roquinimex) ameliorates the development of numerous inflammatory and immunological diseases, including sepsis, arthritis, and encephalomyelitis. However, the mechanism underlying this protective effect of Linomide remains unclear. In this study, we wanted to evaluate the effect of Linomide treatment on the different steps in the extravasation process of leukocytes stimulated by tumor necrosis factor alpha (TNF-alpha) in vivo.

Diverting colostomy increases anastomotic leakage in the rat colon.

In the present study, we examined the effect of a diverting colostomy on the intestinal healing of colonic anastomosis in the rat. For this purpose, we created a colonic stenosis 2 days prior to the formation of a distal one-layer end-to-end anastomosis with or without a proximal double-barreled deviation colostomy in the rats. Radiological examination of anastomotic leakage was performed daily for 4 days and on day 7 after the operation.

The polysaccharide fucoidan inhibits microvascular thrombus formation independently from P- and L-selectin function in vivo.

Background: Adhesion molecules of the selectin family (mainly P- and L-selectin) have been suggested to mediate interactions between platelets, leukocytes and endothelial cells in thrombus formation. The polysaccharide fucoidan has anticoagulative properties, but is also able to bind and block the function of the selectins. Here, we investigated in vivo (i) if fucoidan can prevent microvascular thrombus formation, and (ii) whether this is potentially mediated by the inhibition of P-and/or L-selectin.

Expression and function of MIP-2 are reduced by dexamethasone treatment in vivo.

1. The objective of this study was to examine the effect of dexamethasone on tumour necrosis factor-alpha (TNF-alpha)-induced expression and function of macrophage inflammatory protein-2 (MIP-2) and neutrophil recruitment. For this purpose, we used air pouches raised on the dorsal skin of C57/B16 mice.