Bacterial Translocation In Cirrhotic Rats Research Articles

56-Year-Old-Man With Fever, Altered Mental Status, and Abdominal Pain

56-Year-Old-Man With Fever, Altered Mental Status, and Abdominal Pain

Effect of long-term acid gastric inhibition on bacterial translocation in cirrhotic rats.

Bacterial translocation (BT) related to intestinal bacterial overgrowth (IBO) plays an important role in the pathogenesis of bacterial infections in cirrhosis. Inhibition of acid gastric secretion promotes IBO and might favor BT. We evaluated the effect of long-term inhibition of acid gastric secretion on BT in cirrhotic rats. Cirrhotic rats with and without ascites induced by oral CCl4 and controls were randomized to treatment with a daily subcutaneous injection of placebo, ranitidine (50 mg/kg), or pantoprazole (8 mg/kg) during 2 weeks. Continuous pH-metry was performed for 2 h before and at the end of treatment; thereafter, a laparotomy to obtain samples of blood, mesenteric lymph nodes, ascites, spleen, liver, and cecal stools was performed. Ranitidine and pantoprazole increased gastric pH as compared with placebo (P<0.001). However, antisecretory drugs increased the incidence of BT only in ascitic rats treated with ranitidine (P<0.05) or pantoprazole (P=0.07) when compared with placebo-treated ascitic rats or cirrhotic rats without ascites treated with the same drug. Cirrhotic ascitic rats treated with pantoprazole showed a trend toward an increased incidence of IBO (P=0.08), a higher ileal malondialdehyde level (P<0.01), and an increased production of tumor necrosis factor-α (P<0.05). Although inhibition of acid gastric secretion increased gastric pH in all animals, the incidence of BT increased only in ascitic rats, and it was associated with a trend toward an increase in IBO incidence, a higher ileal malondialdehyde level, and an increased production of serum tumor necrosis factor-α. Therefore, antisecretory drugs should be carefully administered to cirrhotic ascitic patients.

Relation between red blood cell distribution width and mortality after acute myocardial infarction

predictor of impaired peak leg blood flow in patients with chronic heart failure. QJM 1998;91:199–203. [8] Perez-Paramo M, Munoz J, Albillos A, et al. Effect of propranolol on the factors promoting bacterial translocation in cirrhotic rats with ascites. Hepatology 2000;31:43–8. [9] Kincaid EH, Miller PR, Meredith JW, et al. Enalaprilat improves gut perfusion in critically injured patients. Shock 1998;9:79–83. [10] Shewan LG, Coats AJ. Ethics in the authorship and publishing of scientific articles. Int J Cardiol 2010;144:1–2. [11] Coats AJ. Ethical authorship and publishing. Int J Cardiol 2009;131:149–50.

Nonalcoholic Fatty Liver Disease: Cytokine-Adipokine Interplay and Regulation of Insulin Resistance

Nonalcoholic fatty liver disease (NAFLD), the major reason for abnormal liver function in the Western world, is associated with obesity and diabetes and is characterized by insulin resistance (IR). IR is regulated by mediators released from cells of the immune system or adipocytes and proinflammatory cytokines such as tumor necrosis factor-α (TNFα). The importance of TNFα in human and animal fatty liver diseases, both caused by genetic manipulation and overnutrition, has been shown convincingly. Furthermore, neutralization of TNFα activity improves IR and fatty liver disease in animals. Adiponectin is a potent TNFα-neutralizing and anti-inflammatory adipokine and in vitro and experimental animal studies have proven the importance of this mediator in counteracting inflammation and IR. Anti-inflammatory effects of adiponectin are exerted both by suppressing TNFα synthesis and by induction of anti-inflammatory cytokines such as interleukin-10 or interleukin-1–receptor antagonist. Therefore, the balance between various mediators, either derived from the immune system or adipose tissue, appears to play an important role in hepatic and systemic insulin action and in the development of fatty liver disease.

Pharmacologic treatment of portal hypertension in the prevention of community-acquired spontaneous bacterial peritonitis

Given that beta-blockers reduce the incidence of bacterial translocation in cirrhotic rats, the aim of this study was to compare the long-term incidence of spontaneous bacterial peritonitis in cirrhotic patients submitted to pharmacologic versus endoscopic treatment to prevent variceal rebleeding. Two hundred and thirty patients with variceal hemorrhage were included in two previous randomized trials performed to compare the efficacy of medication (nadolol plus isosorbide mononitrate, n=115) versus endoscopic treatment (n=115) with sclerotherapy or ligation for the prevention of rebleeding. The mean follow-up was 23+/-1.4 months. The characteristics of the patients and the number of patients on long-term prophylaxis with norfloxacin were similar in both groups. The incidence of spontaneous bacterial peritonitis was lower in the medication group (9 versus 14.7%, P=NS). The probability of spontaneous bacterial peritonitis was also lower in the medication group (6 versus 12% at 1 year, 22 versus 36% at 5 years; P=0.08), due to a significantly lower probability of community-acquired spontaneous bacterial peritonitis in this group (1 versus 10% at 1 year, 18 versus 32% at 5 years; P=0.02). Patients with no hemodynamic response to therapy had a significantly higher probability to develop community-acquired spontaneous bacterial peritonitis during follow-up than hemodynamic responders (P<0.03). Long-term probability of developing community-acquired spontaneous bacterial peritonitis is lower in patients submitted to pharmacologic treatment for preventing variceal rebleeding than in those submitted to endoscopic treatment. Long-term pharmacologic prophylaxis of variceal rebleeding contributes to the prevention of community-acquired spontaneous bacterial peritonitis.

Spontaneous bacterial peritonitis: a historical perspective: Kerr DNS, Pearson DT, Read AE. Infection of ascitic fluid in patients with hepatic cirrhosis [Gut 1963; 4: 394–398]; Conn HO. Spontaneous peritonitis and bacteremia in Laennec's cirrhosis caused by enteric organisms. A relatively common but rarely recognized syndrome [Ann Intern Med 1964; 60: 568–580

Spontaneous bacterial peritonitis: a historical perspective: Kerr DNS, Pearson DT, Read AE. Infection of ascitic fluid in patients with hepatic cirrhosis [Gut 1963; 4: 394–398]; Conn HO. Spontaneous peritonitis and bacteremia in Laennec's cirrhosis caused by enteric organisms. A relatively common but rarely recognized syndrome [Ann Intern Med 1964; 60: 568–580

Effect of anti-TNF therapy on bacterial translocation in cirrhotic rats with ascites

Effect of anti-TNF therapy on bacterial translocation in cirrhotic rats with ascites

A polymerase chain reaction-based method detects a high incidence of bacterial translocation in cirrhotic rats with negative conventional cultures

A polymerase chain reaction-based method detects a high incidence of bacterial translocation in cirrhotic rats with negative conventional cultures

Intestinal mucosal oxidative damage and bacterial translocation in cirrhotic rats.

Bacterial translocation plays an important role in the pathogenesis of spontaneous bacterial peritonitis mainly due to intestinal bacterial overgrowth. Alterations in the functional integrity of the intestinal barrier caused by an increased production of free radical metabolites as a consequence of portal hypertension could also facilitate bacterial translocation in cirrhotic rats. The aim of the study was to determine intestinal mucosal lipid peroxidation and neutrophil infiltration and their relationship with portal hypertension and bacterial translocation in cirrhotic rats. Eighteen male Sprague-Dawley rats with cirrhosis induced by carbon tetrachloride, administered by gavage, and eight control rats were included in the study. Samples of jejunum, ileum and caecum were obtained by laparotomy for the determination of malondialdehyde and myeloperoxidase as indexes of lipid peroxidation and neutrophil infiltration, respectively. Samples of ascitic and pleural fluids, mesenteric lymph nodes and ileal stools were obtained for the culture of microoganisms. The concentration of malondialdehyde was significantly higher in ileal and caecal, but not in jejunal mucosa, in cirrhotic rats, mainly in those with ascites (P< 0.01), as compared to control rats (P< 0.01), and in cirrhotic rats with bacterial translocation compared to those without bacterial translocation (P< 0.01). No differences between groups were observed in the concentrations of myeloperoxidase in jejunum, ileum or caecum. A direct correlation between ileal malondialdehyde and portal pressure was observed (P< 0.01). Cirrhotic rats, particularly those with ascites and bacterial translocation, show increased malondialdehyde levels in ileal and caecal mucosa. These results suggest that mucosal oxidative damage in ileum and caecum could favour bacterial translocation in cirrhotic rats.

Effect of cisapride on intestinal bacterial and endotoxin translocation in cirrhosis.

To investigate the effects of cisapride on intestinal bacterial overgrowth (IBO), bacterial and endotoxin translocation, intestinal transit and permeability in cirrhotic rats. All animals were assessed with variables including bacterial and endotoxin translocation, intestinal bacterial overgrowth, intestinal transit and permeability. Bacterial translocation (BT) was assessed by bacterial culture of MLN, liver and spleen, IBO by a jejunal bacterial count of the specific organism, intestinal permeability by determination of the 24-hour urinary (99m)Tc-DTPA excretion and intestinal transit by measurement of the distribution of (51)Cr in the intestine. Bacterial translocation (BT) and IBO was found in 48 % and 80 % cirrhotic rats respectively and none in control rats. Urinary excretion of (99m)Tc-DTPA in cirrhotic rats with BT (22.2+/-7.8) was greater than these without BT (10.5+/-2.9). Intestinal transit (geometric center ratio) was significantly delayed in cirrhotic rats (0.31+/-0.06) and further more delayed in cirrhotic rats with BT (0.24+/-0.06) than these without BT (0.38+/-0.11). Cirrhotic rats with IBO had significantly higher rates of intestinal bacterial and endotoxin translocation, slower intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT was closely associated with IBO and the injury of intestinal barrier. Compared with the placebo group, cisapride-treated rats had lower rates of bacterial/endotoxin translocation and IBO, which was closely associated with increased intestinal transit and improved intestinal permeability by cisapride. These results indicate that endotoxin and bacterial translocation in cirrhotic rats may be attributed to IBO and increased intestinal permeability. Cisapride that accelerates intestinal transit and improve intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation.

Effect of Lactobacillus johnsonii La1 and antioxidants on intestinal flora and bacterial translocation in rats with experimental cirrhosis

Background/Aims: Probiotics and antioxidants could be alternatives to antibiotics in the prevention of bacterial infections in cirrhosis. The aim of the present study was to determine the effect of Lactobacillus johnsonii La1 and antioxidants on intestinal flora, endotoxemia, and bacterial translocation in cirrhotic rats. Methods: Twenty-nine Sprague–Dawley rats with cirrhosis induced by CCl 4 and ascites received Lactobacillus johnsonii La1 10 9 cfu/day in vehicle (antioxidants: vitamin C+glutamate) ( n=10), vehicle alone ( n=11), or water ( n=8) by gavage. Another eight non-cirrhotic rats formed the control group. After 10 days of treatment, a laparotomy was performed to determine microbiological study of ileal and cecal feces, bacterial translocation, endotoxemia, and intestinal malondialdehyde (MDA) levels as index of intestinal oxidative damage. Results: Intestinal enterobacteria and enterococci, bacterial translocation (0/11 and 0/10 vs. 5/8, P<0.01), and ileal MDA levels ( P<0.01) were lower in cirrhotic rats treated with antioxidants alone or in combination with Lactobacillus johnsonii La1 compared to cirrhotic rats receiving water. Only rats treated with antioxidants and Lactobacillus johnsonii La1 showed a decrease in endotoxemia with respect to cirrhotic rats receiving water ( P<0.05). Conclusions: Antioxidants alone or in combination with Lactobacillus johnsonii La1 can be useful in preventing bacterial translocation in cirrhosis.

Relationship between intestinal mucosal iNOS mRNA expression and intestinal bacterial translocation in cirrhotic rats

Relationship between intestinal mucosal iNOS mRNA expression and intestinal bacterial translocation in cirrhotic rats

Relationship between intestinal mucosal iNOS mRNA expression and intestinal bacterial translocation in cirrhotic rats

Relationship between intestinal mucosal iNOS mRNA expression and intestinal bacterial translocation in cirrhotic rats

Effect of propranolol on the factors promoting bacterial translocation in cirrhotic rats with ascites.

Bacterial translocation appears to be an important mechanism in the pathogenesis of spontaneous infections in cirrhosis. Cirrhotic patients are commonly treated with beta-adrenoceptor blockers, but the impact of this treatment in the factors promoting bacterial translocation has not been investigated. This study was aimed at investigating in cirrhotic rats with ascites the effect of propranolol on intestinal bacterial load, transit, and permeability of the bowel and on the rate of bacterial translocation. Bacterial translocation to mesenteric lymph nodes and intestinal bacterial overgrowth, permeability (urinary excretion of (99m)Tc-diethylenetriaminepentaacetic acid [(99m)Tc-DTPA]), and transit (geometric center ratio of (51)Cr) were assessed in 29 rats with carbon tetrachloride (CCl(4)) cirrhosis and 20 controls. These variables were then measured in 12 placebo- and in 13 propranolol-treated ascitic cirrhotic rats. Bacterial translocation was present in 48% of the cirrhotic rats and in none of the controls. Cirrhotic rats with intestinal bacterial overgrowth had a significantly higher rate of translocation and slower intestinal transit than those without it. Among the 15 rats with overgrowth and a (99m)Tc-DTPA excretion greater than 10%, 15 had translocation and 2 had bacterial peritonitis. Only 1 of the 14 rats with either intestinal overgrowth or a (99m)Tc-DTPA excretion greater than 10% presented translocation. Compared with the placebo group, propranolol-treated animals had significantly lower portal pressure, faster intestinal transit, and lower rates of bacterial overgrowth and translocation. In ascitic cirrhotic rats, bacterial translocation results from intestinal overgrowth and severe damage to gut permeability. In this setting, intestinal overgrowth is associated with intestinal hypomotility. Propranolol accelerates the intestinal transit, decreasing the rates of bacterial overgrowth and translocation.

Bacterial translocation in cirrhotic rats stimulates eNOS-derived NO production and impairs mesenteric vascular contractility.

Nitric oxide (NO) has been implicated in the arterial vasodilation and associated vascular hyporesponsiveness to vasoconstrictors observed in liver cirrhosis. Bacteria, potent activators of NO and TNF-alpha synthesis, are found in the mesenteric lymph nodes (MLNs) of ascitic cirrhotic rats. Here, we investigated the impact of bacterial translocation (BT) to MLNs on TNF-alpha production, vascular NO release, and contractility in the mesenteric vasculature of ascitic cirrhotic rats. Vascular response to the alpha-adrenoagonist methoxamine, which is diminished in the superior mesenteric arterial beds of cirrhotic rats, is further blunted in the presence of BT. BT promoted vascular NO release in cirrhotic rats, an effect that depended on pressure-induced shear stress and was blocked by the NO inhibitor N(omega)-nitro-L-arginine. Removing the endothelium had the same effect. Endothelial NO synthase (eNOS), but not the inducible isoform (iNOS), was present in mesenteric vasculature of cirrhotic rats with and without BT, and its expression was enhanced compared with controls. TNF-alpha was induced in MLNs by BT and accumulated in parallel in the serum. This TNF-alpha production was associated with elevated levels of tetrahydrobiopterin (BH(4)), a TNF-alpha-stimulated cofactor and enhancer of eNOS-derived NO biosynthesis and NOS activity in mesenteric vasculature. These findings establish a link between BT to MLNs and increased TNF-alpha production and elevated BH(4) levels enhancing eNOS-derived NO overproduction, further impairing contractility in the cirrhotic mesenteric vasculature.

Intestinal bacterial overgrowth and bacterial translocation in cirrhotic rats with ascites

Background/Aims: Translocation of indigenous bacterial from the gut lumen of cirrhotic animals to mesenteric lymph nodes appears to be an important step in the pathogenesis of spontaneous bacterial peritonitis. However, the sequence of events leading to translocation remains unclear. One of the most predictable risk factors for translocation is overgrowth of gut bacterial flora. The present study was designed to compare the intestinal aerobic bacterial flora of cecal stools at the time of sacrifice between cirrhotic and normal rats and to evaluate the role of intestinal aerobic bacterial overgrowth in bacterial translocation in cirrhotic rats. Methods: Thirty-five male Sprague-Dawley rats with carbon tetrachloride-induced cirrhosis and ascites and 10 normal rats were included in this study. Cirrhotic rats were sacrificed when ill and samples of ascitic fluid, mesenteric lymph nodes and cecal stool were taken for detecting quantitatively aerobic bacteria. Results: Total intestinal aerobic bacterial count in cecal stool at the time of sacrifice was significantly increased in cirrhotic rats with bacterial translocation with or without spontaneous bacterial peritonitis compared to cirrhotic rats without bacterial translocation ( p<0.001 and p<0.001, respectively) and to normal rats ( p<0.001 and p<0.001, respectively). Of the 42 species of bacteria translocating to the mesenteric lymph nodes, 41 (97.6%) were found in supranormal numbers in the stool at the time of sacrifice. Conclusions: Carbon tetrachloride-induced cirrhotic rats with bacterial translocation have increased total intestinal aerobic bacteria count, and intestinal bacterial overgrowth appears to play an important role in bacterial translocation in this experimental model of cirrhosis in rats.

Bacterial translocation in cirrhotic rats. Its role in the development of spontaneous bacterial peritonitis.

Bacterial translocation occurs in ascitic cirrhotic rats, but its association with ascites infection is unknown. The aim of this study was to assess the relation between bacterial translocation and ascites infection in cirrhotic rats. Male Sprague-Dawley rats were induced to cirrhosis with intragastric CCl4. Ascitic fluid, portal and peripheral blood, mesenteric lymph nodes, liver and spleen samples were cultured before death in those cirrhotic rats with less (group A) or more (group B) than 250 polymorphonuclear neutrophils/mm3 in ascitic fluid, as well as in healthy control rats. Histological examination of jejunum, ileum, and caecum was also performed. Bacterial translocation occurred in 45% of ascitic rats (without differences between groups A and B), but in 0% controls (p = 0.01). Bacterial translocation was associated with positive ascitic fluid culture in 60% of the cases. In all of them the same bacterial species was isolated in both mesenteric lymph node and ascitic fluid. Submucosal caecal oedema (100%), ileal lymphangiectasia (41%), and caecal inflammatory infiltrate (41%) occurred in ascitic rats, the last being associated with ascitic fluid positive culture (p = 0.04). These results suggests that bacterial translocation occurs frequently in ascitic cirrhotic rats, and may play a permissive, but not unique, part in a number of ascites infections. Whether histological changes seen in cirrhotic ascitic rats favour bacterial translocation remains to be elucidated.