Systemic Endotoxemia Research Articles

Endotoxemia Following Multiple Trauma: Risk Factors and Prognostic Implications.

To evaluate the prevalence and time course of systemic endotoxemia following severe multiple trauma, to define its risk factors, and to explore the correlation between post-trauma endotoxemia and organ dysfunction. Prospective single-center cohort study. Emergency department and ICU of adult tertiary care level I trauma center. Forty-eight severely injured (Injury Severity Score ≥ 16) patients, admitted to ICU within 24 hours of injury. None. Endotoxemia was not evident on initial presentation, but developed subsequently in 75% of patients, even in the absence of Gram-negative infection. Nonsurviving patients had higher endotoxin levels than survivors on day 1 (endotoxemia, 0.48 vs 0.28; p = 0.048). Shock at admission, or surgery within the first 48 hours after trauma, was associated with higher endotoxin levels and predicted subsequent maximal endotoxemia, after adjusting for other significant covariates. Maximal endotoxemia levels were higher in patients who developed organ dysfunction, reflected in a cumulative Multiple Organ Dysfunction Score greater than 25, and patients with an intermediate endotoxemia level (≥ 0.4) had more cardiovascular dysfunction. It is the first study to detect increasing levels of endotoxemia following multiple trauma. Shock and early surgery predict the development of endotoxemia; endotoxemia is particularly associated with cardiovascular dysfunction. However, Gram-negative infections are uncommon in these patients, suggesting that the gastrointestinal tract is the dominant reservoir of endotoxin. Endotoxin may be an appropriate therapeutic target in patients who have sustained severe multiple trauma.

Gut barrier function and systemic endotoxemia after laparotomy or laparoscopic resection for colon cancer: A prospective randomized study.

PURPOSE:The gut barrier is altered in certain pathologic conditions (shock, trauma, or surgical stress), resulting in bacterial and/or endotoxin translocation from the gut lumen into the systemic circulation. In this prospective randomized study, we investigated the effect of surgery on intestinal permeability (IP) and endotoxemia in patients undergoing elective colectomy for colon cancer by comparing the laparoscopic with the open approach.PATIENTS AND METHODS:A hundred twenty-three consecutive patients underwent colectomy for colon cancer: 61 cases were open resection (OR) and 62 cases were laparoscopic resection (LR). IP was measured preoperatively and at days 1 and 3 after surgery. Serial venous blood sample were taken at 0, 30, 60, 90, 120, and 180 min, and at 12, 24, and 48 h after surgery for endotoxin measurement.RESULTS:IP was significantly increased in the open and closed group at day 1 compared with the preoperative level (P < 0.05), but no difference was found between laparoscopic and open surgery group. The concentration endotoxin systemic increased significantly in the both groups during the course of surgery and returned to baseline levels at the second day. No difference was found between laparoscopic and open surgery. A significant correlation was observed between the maximum systemic endotoxin concentration and IP measured at day 1 in the open group and in the laparoscopic group.CONCLUSION:An increase in IP, and systemic endotoxemia were observed during the open and laparoscopic resection for colon cancer, without significant statistically difference between the two groups.

Zinc transporter Slc39a14 regulates inflammatory signaling associated with hypertrophic adiposity.

Zinc is a signaling molecule in numerous metabolic pathways, the coordination of which occurs through activity of zinc transporters. The expression of zinc transporter Zip14 (Slc39a14), a zinc importer of the solute carrier 39 family, is stimulated under proinflammatory conditions. Adipose tissue upregulates Zip14 during lipopolysaccharide-induced endotoxemia. A null mutation of Zip14 (KO) revealed that phenotypic changes in adipose include increased cytokine production, increased plasma leptin, hypertrophied adipocytes, and dampened insulin signaling. Adipose tissue from KO mice had increased levels of preadipocyte markers, lower expression of the differentiation marker (PPARγ), and activation of NF-κB and STAT3 pathways. Our overall hypothesis was that ZIP14 would play a role in adipocyte differentiation and inflammatory obesity. Global Zip14 KO causes systemic endotoxemia. The observed metabolic changes in adipose metabolism were reversed when oral antibiotics were administrated, indicating that circulating levels of endotoxin were in part responsible for the adipose phenotype. To evaluate a mechanism, 3T3-L1 cells were differentiated into adipocytes and treated with siRNA to knock down Zip14. These cells had an impaired ability to mobilize zinc, which caused dysregulation of inflammatory pathways (JAK2/STAT3 and NF-κB). The Zip14 deletion may limit the availability of intracellular zinc, yielding the unique phenotype of inflammation coupled with hypertrophy. Taken together, these results suggest that aberrant zinc distribution observed with Zip14 ablation impacts adipose cytokine production and metabolism, ultimately increasing fat deposition when exposed to endotoxin. To our knowledge, this is the first investigation into the mechanistic role of ZIP14 in adipose tissue regulation and metabolism.

Duodenojejunal Bypass Leads to Altered Gut Microbiota and Strengthened Epithelial Barriers in Rats.

Gastrointestinal bypass changes the gut microbiota and decreases systemic endotoxemia in obese subjects. Epithelial barrier integrity is crucial for confining enteric bacteria in the lumen and preventing gut-derived endotoxemia. The effect of bypass surgery on intestinal barrier functions remains poorly understood. This study aimed to evaluate the changes in intestinal permeability and gut barrier between rats receiving Roux-en-Y duodenojejunal bypass (DJB) or sham operation (SO). Eighteen Sprague-Dawley rats were assigned to DJB or SO groups. Tissues of the alimentary, biliopancreatic, and common limbs in the small intestine, and the colon, were collected 2weeks after operation. Mucosa-associated bacteria were quantified by colony forming units. Intestinal permeability was determined by mucosal-to-serosal dextran flux measured in Ussing chambers. Expression of occludin and proliferating cell nuclear antigen (PCNA) in the intestinal mucosa was examined by western blots. Enteric bacterial numbers were increased in the alimentary and common limbs after DJB. Reduced dextran permeability was found in the alimentary limb, common limb, and colon after DJB. Moreover, increased villus height and crypt depth were found to be associated with higher mucosal levels of occludin and PCNA levels in the alimentary and common limbs after DJB. DJB in rats altered gut microbiota and reduced intestinal permeability due to increased epithelial proliferation and tight junctional protein expression. Our results show that bypass surgery led to fortification of the intestinal barrier functions, which may provide an explanation for the decreased risk of systemic endotoxemia in postoperative patients.

Clinical science workshop: targeting the gut-liver-brain axis.

A clinical science workshop was held at the ISHEN meeting in London on Friday 11th September 2014 with the aim of thrashing out how we might translate what we know about the central role of the gut-liver-brain axis into targets which we can use in the treatment of hepatic encephalopathy (HE). This review summarises the integral role that inter-organ ammonia metabolism plays in the pathogenesis of HE with specific discussion of the roles that the small and large intestine, liver, brain, kidney and muscle assume in ammonia and glutamine metabolism. Most recently, the salivary and gut microbiome have been shown to underpin the pathophysiological changes which culminate in HE and patients with advanced cirrhosis present with enteric dysbiosis with small bowel bacterial overgrowth and translocation of bacteria and their products across a leaky gut epithelial barrier. Resident macrophages within the liver are able to sense bacterial degradation products initiating a pro-inflammatory response within the hepatic parenchyma and release of cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin-8 into the systemic circulation. The endotoxemia and systemic inflammatory response that are generated predispose both to the development of infection as well as the manifestation of covert and overt HE. Co-morbidities such as diabetes and insulin resistance, which commonly accompany cirrhosis, may promote slow gut transit, promote bacterial overgrowth and increase glutaminase activity and may need to be acknowledged in HE risk stratification assessments and therapeutic regimens. Therapies are discussed which target ammonia production, utilisation or excretion at an individual organ level, or which reduce systemic inflammation and endotoxemia which are known to exacerbate the cerebral effects of ammonia in HE. The ideal therapeutic strategy would be to use an agent that can reduce hyperammonemia and reduce systemic inflammation or perhaps to adopt a combination of therapies that can address both.

Occult bleeding, haematochezia and the endurance athlete: what are the risks?

Objective. To examine the risks of visceral ischaemia associated with participation in endurance sport, including gastro-intestinal bleeding and systemic endotoxaemia. Methods. A systematic search of the Ovid/Medline data-base from January 1996 to May 2015, combining the terms ischaemia/visceral ischaemia/gastro-intestinal haemorrhage/bleeding/ and endotoxins with exercise/endurance exercise/physical endurance/marathon/ultra-marathon/triathlon, supplemented by a review of reference lists and personal files. Results. Around 20% of participants in marathons and other endurance events develop objective manifestations of visceral ischaemia in the first 2 days following a race, usually occult gastro-intestinal bleeding. A small proportion of athnletes develop overt bleeding. This generally resolves over a few days, although there are 2 reported cases that required a partial colectomy, and 1 reported death. In some individuals, plasma levels of bacterial endotoxins may also rise. Conclusions. Once other more dangerous diagnoses have been excluded, the blood loss associated with exercise-induced visceral ischaemia can usually be treated expectantly. A watch must be kept for anaemia secondary to repeated blood loss, but the risks of bleeding requiring colectomy and bacterial sepsis seem too small either to require other specific treatment or to influence clinical advice on the wisdom of participating in ultra-endurance events.

Inflammation: A novel target of current therapies for hepatic encephalopathy in liver cirrhosis.

Hepatic encephalopathy (HE) is a severe neuropsychiatric syndrome that most commonly occurs in decompensated liver cirrhosis and incorporates a spectrum of manifestations that ranges from mild cognitive impairment to coma. Although the etiology of HE is not completely understood, it is believed that multiple underlying mechanisms are involved in the pathogenesis of HE, and one of the main factors is thought to be ammonia; however, the ammonia hypothesis in the pathogenesis of HE is incomplete. Recently, it has been increasingly demonstrated that inflammation, including systemic inflammation, neuroinflammation and endotoxemia, acts in concert with ammonia in the pathogenesis of HE in cirrhotic patients. Meanwhile, a good number of studies have found that current therapies for HE, such as lactulose, rifaximin, probiotics and the molecular adsorbent recirculating system, could inhibit different types of inflammation, thereby improving the neuropsychiatric manifestations and preventing the progression of HE in cirrhotic patients. The anti-inflammatory effects of these current therapies provide a novel therapeutic approach for cirrhotic patients with HE. The purpose of this review is to describe the inflammatory mechanisms behind the etiology of HE in cirrhosis and discuss the current therapies that target the inflammatory pathogenesis of HE.

Junctional Adhesion Molecule A Promotes Epithelial Tight Junction Assembly to Augment Lung Barrier Function

Epithelial barrier function is maintained by tight junction proteins that control paracellular fluid flux. Among these proteins is junctional adhesion molecule A (JAM-A), an Ig fold transmembrane protein. To assess JAM-A function in the lung, we depleted JAM-A in primary alveolar epithelial cells using shRNA. In cultured cells, loss of JAM-A caused an approximately 30% decrease in transepithelial resistance, decreased expression of the tight junction scaffold protein zonula occludens 1, and disrupted junctional localization of the structural transmembrane protein claudin-18. Consistent with findings in other organs, loss of JAM-A decreased β1 integrin expression and impaired filamentous actin formation. Using a model of mild systemic endoxotemia induced by i.p. injection of lipopolysaccharide, we report that JAM-A(-/-) mice showed increased susceptibility to pulmonary edema. On injury, the enhanced susceptibility of JAM-A(-/-) mice to edema correlated with increased, transient disruption of claudin-18, zonula occludens 1, and zonula occludens 2 localization to lung tight junctions in situ along with a delay in up-regulation of claudin-4. In contrast, wild-type mice showed no change in lung tight junction morphologic features in response to mild systemic endotoxemia. These findings support a key role of JAM-A in promoting tight junction homeostasis and lung barrier function by coordinating interactions among claudins, the tight junction scaffold, and the cytoskeleton.

Bacterial translocation and endotoxemia after pringle maneuver in cirrhotic rats.

Pringle maneuver (Pm) is advocated for the reduction of blood loss during liver surgery, while postoperative infections continue to be a frequent complication after hepatic resection and liver transplantation. To investigate the effect of the Pringle maneuver on systemic bacterial translocation and endotoxemia in cirrhotic rats and cirrhotic rats with selective intestinal decontamination. A total of 100 male Sprague-Dawley cirrhotic rats were randomly divided into five equal groups: sham operation, Pm of 10 min, Pm of 20 min, Pm of 30 min, and pretreatment. Tissue samples from mesenteric lymph nodes, liver, lungs, portal, and vena cava vein blood were obtained for culture after 30 min and 24 h of the operation. Endotoxin levels were measured in portal vein and vena cava blood. Portal vein and vena cava blood endotoxin concentrations increased significantly after 30 min, especially 24 h of operation in the Pm of 20 min and Pm of 30 min groups. A significant increase in contaminated mesenteric lymph nodes, liver, portal, and vena cava blood was noted 24 h later. The incidence of gut bacterial translocation increased with the duration extension of Pm. Escherichia coli was the most common bacteria isolated from the tissues. There was a significant decrease of portal vein and vena cava blood endotoxin concentrations and the incidence of bacterial translocation by selective intestinal decontamination. There is endotoxemia immediately after Pringle maneuver and gut bacteria translocation 24 h later. The incidence of gut bacterial translocation increases with the duration extension of Pm. Selective intestinal decontamination can decrease bacteria translocation and endotoxemia.

Interleukin-22 alleviates metabolic disorders and restores mucosal immunity in diabetes.

The connection between an altered gut microbiota and metabolic disorders such as obesity, diabetes, and cardiovascular disease is well established. Defects in preserving the integrity of the mucosal barriers can result in systemic endotoxaemia that contributes to chronic low-grade inflammation, which further promotes the development of metabolic syndrome. Interleukin (IL)-22 exerts essential roles in eliciting antimicrobial immunity and maintaining mucosal barrier integrity within the intestine. Here we investigate the connection between IL-22 and metabolic disorders. We find that the induction of IL-22 from innate lymphoid cells and CD4(+) T cells is impaired in obese mice under various immune challenges, especially in the colon during infection with Citrobacter rodentium. While innate lymphoid cell populations are largely intact in obese mice, the upregulation of IL-23, a cytokine upstream of IL-22, is compromised during the infection. Consequently, these mice are susceptible to C. rodentium infection, and both exogenous IL-22 and IL-23 are able to restore the mucosal host defence. Importantly, we further unveil unexpected functions of IL-22 in regulating metabolism. Mice deficient in IL-22 receptor and fed with high-fat diet are prone to developing metabolic disorders. Strikingly, administration of exogenous IL-22 in genetically obese leptin-receptor-deficient (db/db) mice and mice fed with high-fat diet reverses many of the metabolic symptoms, including hyperglycaemia and insulin resistance. IL-22 shows diverse metabolic benefits, as it improves insulin sensitivity, preserves gut mucosal barrier and endocrine functions, decreases endotoxaemia and chronic inflammation, and regulates lipid metabolism in liver and adipose tissues. In summary, we identify the IL-22 pathway as a novel target for therapeutic intervention in metabolic diseases.

Patients with type 1 diabetes show signs of vascular dysfunction in response to multiple high-fat meals.

BackgroundA high-fat diet promotes postprandial systemic inflammation and metabolic endotoxemia. We investigated the effects of three consecutive high-fat meals on endotoxemia, inflammation, vascular function, and postprandial lipid metabolism in patients with type 1 diabetes.MethodsNon-diabetic controls (n = 34) and patients with type 1 diabetes (n = 37) were given three high-caloric, fat-containing meals during one day. Blood samples were drawn at fasting (8:00) and every two hours thereafter until 18:00. Applanation tonometry was used to assess changes in the augmentation index during the investigation day.ResultsThree consecutive high-fat meals had only a modest effect on serum LPS-activity levels and inflammatory markers throughout the day in both groups. Of note, patients with type 1 diabetes were unable to decrease the augmentation index in response to the high-fat meals. The most profound effects of the consecutive fat loads were seen in chylomicron and HDL-metabolism. The triglyceride-rich lipoprotein remnant marker, apoB-48, was elevated in patients compared to controls both at fasting (p = 0.014) and postprandially (p = 0.035). The activities of the HDL-associated enzymes PLTP (p < 0.001), and CETP (p = 0.007) were higher and paraoxonase (PON-1) activity, an anti-oxidative enzyme bound to HDL, decreased in patients with type 1 diabetes (p = 0.027).ConclusionsIn response to high-fat meals, early signs of vascular dysfunction alongside accumulation of chylomicron remnants, higher augmentation index, and decreased PON-1 activity were observed in patients with type 1 diabetes. The high-fat meals had no significant impact on postprandial LPS-activity in non-diabetic subjects or patients with type 1 diabetes suggesting that metabolic endotoxemia may be more central in patients with chronic metabolic disturbances such as obesity, type 2 diabetes, or diabetic kidney disease.

An altered intestinal mucosal microbiome in HIV-1 infection is associated with mucosal and systemic immune activation and endotoxemia.

HIV-1 infection disrupts the intestinal immune system, leading to microbial translocation and systemic immune activation. We investigated the impact of HIV-1 infection on the intestinal microbiome and its association with mucosal T cell and dendritic cell (DC) frequency and activation, as well as with levels of systemic T cell activation, inflammation and microbial translocation. Bacterial 16S ribosomal DNA sequencing was performed on colon biopsies and fecal samples from subjects with chronic, untreated HIV-1 infection and uninfected control subjects. Colon biopsies of HIV-1 infected subjects had increased abundances of Proteobacteria and decreased abundances of Firmicutes compared to uninfected donors. Furthermore at the genus level, a significant increase in Prevotella and decrease in Bacteroides was observed in HIV-1 infected subjects, indicating a disruption in the Bacteroidetes bacterial community structure. This HIV-1-associated increase in Prevotella abundance was associated with increased numbers of activated colonic T cells and myeloid DCs. Principal coordinates analysis demonstrated an HIV-1-related change in the microbiome that was associated with increased mucosal cellular immune activation, microbial translocation and blood T cell activation. These observations suggest that an important relationship exists between altered mucosal bacterial communities and intestinal inflammation during chronic HIV-1 infection.

Immune dysfunction in cirrhosis

Innate and adaptive immune dysfunction, also referred to as cirrhosis-associated immune dysfunction syndrome, is a major component of cirrhosis, and plays a pivotal role in the pathogenesis of both the acute and chronic worsening of liver function. During the evolution of the disease, acute decompensation events associated with organ failure(s), so-called acute-on chronic liver failure, and chronic decompensation with progression of liver fibrosis and also development of disease specific complications, comprise distinct clinical entities with different immunopathology mechanisms. Enhanced bacterial translocation associated with systemic endotoxemia and increased occurrence of systemic bacterial infections have substantial impacts on both clinical situations. Acute and chronic exposure to bacteria and/or their products, however, can result in variable clinical consequences. The immune status of patients is not constant during the illness; consequently, alterations of the balance between pro- and anti-inflammatory processes result in very different dynamic courses. In this review we give a detailed overview of acquired immune dysfunction and its consequences for cirrhosis. We demonstrate the substantial influence of inherited innate immune dysfunction on acute and chronic inflammatory processes in cirrhosis caused by the pre-existing acquired immune dysfunction with limited compensatory mechanisms. Moreover, we highlight the current facts and future perspectives of how the assessment of immune dysfunction can assist clinicians in everyday practical decision-making when establishing treatment and care strategies for the patients with end-stage liver disease. Early and efficient recognition of inappropriate performance of the immune system is essential for overcoming complications, delaying progression and reducing mortality.

Lipopolysaccharide treatment induces adaptive cytoprotection in the portal hypertensive gastric mucosa of rats

Objective: Upper gastrointestinal bleeding in patients with cirrhosis and portal hypertension is a frequent complication that potentially modifies the survival of these patients. This phenomenon may occur due to excessive endotoxin translocation, leading to system debugging liver overload, and systemic endotoxemia, with excessive production of mediators by immune cells. The presence of these inflammatory mediators may increase the susceptibility of gastric mucosa to lesions induced by various damaging agents. As such, this study aimed to determine the resistance of portal hypertensive gastric mucosa to endotoxin and ethanol stimulation. Methods: Portal hypertension was induced in rats by bile duct ligation or portal vein stenosis (PVS) while controls underwent a sham operation. The effect of endotoxin on the gastric mucosa was evaluated by acute or chronic LPS treatment. Ethanol-induced damage was assessed using ex vivo gastric chamber experiments. Gastric blood flow was measured by laser Doppler flowmetry. Results: Acute LPS treatment intensified the ethanol-induced gastric damage in the healthy (control) group in a dose-dependent manner (0.3-3 mg/kg). In contrast, the gastric mucosa of the PVS group presented tolerance after a single dose of LPS (3 mg/kg). Chronic LPS treatment (1 mg/kg) significantly reduced the gastric mucosal lesion area in both the PVS and control groups. Additionally, the cirrhotic animals were found not to survive the minimum dose of LPS. Conclusion: Our results suggest that chronic LPS treatment induces adaptative cytoprotection to ethanol-induced injury in the gastric mucosa of PVS and healthy rats; however, acute LPS treatment increases mortality in cirrhotic rats.

Lipopolysaccharide-binding protein (LBP) serum levels in children with OSA and obesity

Obstructive sleep apnea (OSA) has been linked to obesity and the metabolic syndrome (MetS). All these conditions are further tightly linked to inflammation, the origin of the latter still being under debate. In recent years, the gut microbiota and/or gut permeability have emerged as important factors in the vicious cycle of obesity, MetS and inflammation. The gut microbiota, which serves as reservoir for bacterial lipopolysaccharides (LPS), could be altered by OSA and trigger inflammation. Lipopolysaccharide-binding protein (LBP) is a 65-kDa acute-phase protein derived from the liver which has been viewed as a surrogate marker of underlying low level endotoxemia brought about by LPS from the gut. We hypothesized that systemic LBP levels would be higher in obese children and in those with OSA. Consecutive snoring and non-snoring children (mean age: 6.8 ± 1.3 years) were included after they underwent overnight polysomnographic evaluation and a fasting blood sample was drawn the morning after the sleep study. Children were subidivided into 4 sub-groups based on the presence of obesity (BMI z score > 1.65) or OSA (obstructive AHI > 2/hrTST). Plasma LBP levels were assayed using commercial ELISA kits. Of the children studied to date ( n = 56), non-obese controls had lowest levels of LBP, and the presence of obesity without OSA was associated with significant increases in LBP levels ( p < 0.03). Non-obese children with OSA exhibited LBP leves that were similar to those of obese children without OSA ( p < 0.01 vs. non-obese without OSA), with obese children with OSA demonstrating the highest LBP levels of all 4 groups ( p < 0.02 vs. all 3 other groups). Systemic low level endotoxemia and resultant systemic inflammation is present in children who are either obese or suffer from OSA, and is particularly prominent when both conditions are present. We postulate that altered sleep and other factors facilitating obesity such as high fat diet may disrupt the gut microbiome, and lead to increased systemic LPS leaks with resultant inflammation. NIH HL65270.

Enhanced effect of inhibition of thrombin on endothelium in murine endotoxaemia: Specific inhibition of thrombocytopenia

In systemic endotoxaemia, bacterial lipopolysaccharide causes the rapid expression of tissue factor (TF) and disseminated intravascular coagulation and in animal models, anticoagulants limit pathology and promote survival. Recent studies have emphasised the importance of TF expressed by mononuclear cells for initiating thrombin generation during endotoxaemia and suggested that endothelial cell TF is of little relevance. However, the precise importance of endothelium for intravascular thrombin generation has not been established. In this study, we compared the effect of equivalent levels of hirudin tethered to either endothelium or platelets and monocytes. CD31-Hir-Tg mice express a vesicle-targeted, membrane-tethered hirudin fusion protein on endothelium, platelets and monocytes. Bone marrow chimeras between these mice and C57BL/6 were generated The level of intravascular hirudin expressed during endotoxaemia was quantified by inhibition studies using an anti-hirudin antibody and reference to the circulating thrombin anti-thrombin complexes generated in control mice given soluble hirudin. Antibody inhibition studies indicated that individual chimeras expressed similar levels of hirudin fusion protein on endothelium alone as on platelets and leukocytes combined and accordingly, the levels of thrombin anti-thrombin complexes and fibrinogen in each chimera were similar, indicating equivalent inhibition of thrombin generation. However, mice with hirudin on endothelium alone developed significantly less thrombocytopenia. These results suggest a hitherto unrecognized role of endothelium in thrombin-dependent platelet sequestration during endotoxaemia. The data have implications for the development of therapeutic strategies based on targeted anticoagulation to limit disseminated intravascular coagulation.

Increased concentrations of C-reactive protein but not high-mobility group box 1 in dogs with naturally occurring sepsis

Sepsis is difficult to diagnose and remains a common mortality cause worldwide in both humans and animals. The uterine infection pyometra causes sepsis in more than half of affected dogs and therefore allows the natural physiological development of sepsis to be studied. To find a sepsis-specific biochemical marker that could be combined with conventional clinical criteria for a more robust and quick diagnosis of sepsis, we measured systemic concentrations of high-mobility group box 1 (HMGB1) in 23 healthy control dogs and in 27 dogs with pyometra, 74% of which had sepsis. We also measured concentrations of the major acute phase protein C-reactive protein (CRP) and an indicator for endotoxaemia, prostaglandin F2α metabolite (PGM) to assess the relative contribution of HMGB1 to the detection of systemic inflammation and endotoxaemia. We found that HMGB1 concentrations, in line with concentrations of CRP and PGM, were significantly increased in dogs with pyometra, and that concentrations of CRP, but not HMGB1, were significantly higher in dogs with sepsis compared to dogs without sepsis. Although serum HMGB1 did not differ between dogs with or without sepsis and was not correlated with either CRP or PGM concentrations, HMGB1 was correlated with the total white blood cell counts, suggesting an independent regulation and involvement in inflammation.

Intestinal permeability, systemic endotoxemia, and bacterial translocation after open or laparoscopic resection for colon cancer: a prospective randomized study.

In this prospective randomized study, we investigated the effect of surgery on intestinal permeability (IP), endotoxemia, and bacterial translocation (BT) in patients undergoing elective colectomy for colon cancer by comparing the laparoscopic with the open approach. Seventy-two consecutive patients underwent colectomy for colon cancer: 35 cases open resection and 37 cases laparoscopic resection. IP was measured preoperatively and at days 1 and 3 after surgery. Serial venous blood sample were taken at 0, 30, 60, 90, 120, and 180 min and at 12, 24, and 48 h after surgery for endotoxin measurement. Tissue sample were taken from the liver, spleen, and mesenteric lymph nodes and were weighed under sterile conditions. IP was significantly increased in the open and closed group at day 1 compared with the preoperative level (p < 0.05), but no difference was found between laparoscopic and open surgery group. The concentration endotoxin systemic increased significantly in the both group during the course of surgery but returned to baseline levels at the second day 2. No difference was found between laparoscopic and open surgery. A significant correlation was observed between the maximum systemic endotoxin concentration and IP measured at D1 in the open group and in the laparoscopic group. The incidence of BT increased in laparoscopic and open group after bowel mobilization, compared with the before mobilization (p < 0.05). There was not a statistically significant difference in BT value between the two groups. An increase in IP, systemic endotoxemia, and BT were observed during the open and laparoscopic resection for colon cancer, without significant statistically difference between the two groups.

Oral Activated Charcoal Adsorbent (AST-120) Ameliorates Chronic Kidney Disease-Induced Intestinal Epithelial Barrier Disruption

Background: Chronic kidney disease (CKD) impairs intestinal barrier function which by allowing influx of noxious products causes systemic inflammation. We have recently shown that intestinal barrier dysfunction in CKD is due to degradation of epithelial tight junction (TJ) which is, in part, mediated by influx of urea and its conversion to ammonia by microbial urease. We hypothesized that by adsorbing urea and urea-derived ammonia, oral activated charcoal (AST-120) may ameliorate CKD-induced intestinal epithelial barrier disruption and systemic inflammation. Methods: Rats were randomized to the CKD or control groups. The CKD group was fed a chow containing 0.7% adenine for 2 weeks. They were then randomized to receive a chow with or without AST-120 (4 g/kg/day) for 2 weeks. Rats consuming regular diet served as controls. Animals were then euthanized, colons were removed and processed for Western blot and immunohistology, and plasma was used to measure endotoxin and oxidative and inflammatory markers. Results: Compared with the controls, the untreated CKD rats showed elevated plasma endotoxin, IL-6, TNF-α, MCP-1, CINC-3, L-selectin, ICAM-1, and malondialdehyde, and depletions of colonic epithelial TJ proteins, claudin-1, occludin, and ZO1. Administration of AST-120 resulted in partial restoration of the epithelial TJ proteins and reduction in plasma endotoxin and markers of oxidative stress and inflammation. Conclusions: CKD animals exhibited depletion of the key protein constituents of the colonic epithelial TJ which was associated with systemic inflammation, oxidative stress and endotoxemia. Administration of AST-120 attenuated uremia-induced disruption of colonic epithelial TJ and the associated endotoxemia, oxidative stress and inflammation.

CNS-Targeted Production of IL-17A Induces Glial Activation, Microvascular Pathology and Enhances the Neuroinflammatory Response to Systemic Endotoxemia

Interleukin-17A (IL-17A) is a key cytokine modulating the course of inflammatory diseases. Whereas effector functions of IL-17A like induction of antimicrobial peptides and leukocyte infiltration could clearly be demonstrated for peripheral organs, CNS specific effects are not well defined and appear controversial. To further clarify the functional significance of IL-17A in the CNS, we generated a transgenic mouse line with astrocyte-restricted expression of the IL-17A gene. GFAP/IL-17A transgenic mice develop normally and do not show any signs of neurological dysfunction. However, histological characterization revealed astrocytosis and activation of microglia. Demyelination, neurodegeneration or prominent tissue damage was not observed but a vascular pathology mimicking microangiopathic features was evident. Histological and flow cytometric analysis demonstrated the absence of parenchymal infiltration of immune cells into the CNS of GFAP/IL-17A transgenic mice. In GFAP/IL-17A mice, LPS-induced endotoxemia led to a more pronounced microglial activation with expansion of a distinct CD45high/CD11b+ population and increased induction of proinflammatory cytokines compared with controls. Our data argues against a direct role of IL-17A in mediating tissue damage during neuroinflammation. More likely IL-17A acts as a modulating factor in the network of induced cytokines. This novel mouse model will be a very useful tool to further characterize the role of IL-17A in neuroinflammatory disease models.