Host genetics and gut microbiota cooperatively contribute to azoxymethane-induced acute toxicity in Collaborative Cross mice.

Azoxymethane (AOM) is a widely used carcinogen to study chemical-induced colorectal carcinogenesis and is an agent for studying fulminant hepatic failure. The inter-strain susceptibility to acute toxicity by AOM has been reported, but its association with host genetics or gut microbiota remains largely unexplored. Here a cohort of genetically diverse Collaborative Cross (CC) mice was used to assess the contribution of host genetics and the gut microbiome to AOM-induced acute toxicity. We observed variation in AOM-induced acute liver failure across CC strains. Quantitative trait loci (QTL) analysis revealed three chromosome regions significantly associated with AOM toxicity. Genes located within these QTL, including peroxisome proliferator-activated receptor alpha (Ppara), were enriched for enzyme activator and nucleoside-triphosphatase regulator activity. We further demonstrated that the protein level of PPARα in liver tissues from sensitive strains was remarkably lower compared to levels in resistant strains, consistent with protective role of PPAR family in liver injury. We discovered that the abundance levels of gut microbial families Anaeroplasmataceae, Ruminococcaceae, Lactobacillaceae, Akkermansiaceae and Clostridiaceae were significantly higher in the sensitive strains compared to the resistant strains. Using a random forest classifier method, we determined that the relative abundance levels of these microbial families predicted AOM toxicity with the area under the receiver-operating curve (AUC) of 0.75. Combining the three genetic loci and five microbial families increased the predictive accuracy of AOM toxicity (AUC of 0.99). Moreover, we found that Ruminococcaceae and Lactobacillaceae acted as mediators between host genetics and AOM toxicity. In conclusion, this study shows that host genetics and specific microbiome members play a critical role in AOM-induced acute toxicity, which provides a framework for analysis of the health effects from environmental toxicants.

MyD88-dependent inflammasome activation and autophagy inhibition contributes to Ehrlichia-induced liver injury and toxic shock.

Severe hepatic inflammation is a common cause of acute liver injury following systemic infection with Ehrlichia, obligate Gram-negative intracellular bacteria that lack lipopolysaccharide (LPS). We have previously shown that type I IFN (IFN-I) and inflammasome activation are key host-pathogenic mediators that promote excessive inflammation and liver damage following fatal Ehrlichia infection. However, the underlying signals and mechanisms that regulate protective immunity and immunopathology during Ehrlichia infection are not well understood. To address this issue, we compared susceptibility to lethal Ixodes ovatus Ehrlichia (IOE) infection between wild type (WT) and MyD88-deficient (MyD88-/-) mice. We show here that MyD88-/- mice exhibited decreased inflammasome activation, attenuated liver injury, and were more resistant to lethal infection than WT mice, despite suppressed protective immunity and increased bacterial burden in the liver. MyD88-dependent inflammasome activation was also dependent on activation of the metabolic checkpoint kinase mammalian target of rapamycin complex 1 (mTORC1), inhibition of autophagic flux, and defective mitophagy in macrophages. Blocking mTORC1 signaling in infected WT mice and primary macrophages enhanced bacterial replication and attenuated inflammasome activation, suggesting autophagy promotes bacterial replication while inhibiting inflammasome activation. Finally, our data suggest TLR9 and IFN-I are upstream signaling mechanisms triggering MyD88-mediated mTORC1 and inflammasome activation in macrophages following Ehrlichia infection. This study reveals that Ehrlichia-induced liver injury and toxic shock are mediated by MyD88-dependent inflammasome activation and autophagy inhibition.

Amatoxin-Containing Mushroom Poisonings: Species, Toxidromes, Treatments, and Outcomes.

Amatoxins are produced primarily by 3 species of mushrooms: Amanita, Lepiota, and Galerina. Because amatoxin poisonings are increasing, the objective of this review was to identify all amatoxin-containing mushroom species, present a toxidromic approach to earlier diagnoses, and compare the efficacies and outcomes of therapies. To meet these objectives, Internet search engines were queried with keywords to select peer-reviewed scientific articles on amatoxin-containing mushroom poisoning and management. Descriptive epidemiological analyses have documented that most mushroom poisonings are caused by unknown mushrooms, and most fatal mushroom poisonings are caused by amatoxin-containing mushrooms. Amanita species cause more fatal mushroom poisonings than other amatoxin-containing species, such as Galerina and Lepiota. Amanita phalloides is responsible for most fatalities, followed by Amanita virosa and Amanita verna. The most frequently reported fatal Lepiota ingestions are due to Lepiota brunneoincarnata, and the most frequently reported fatal Galerina species ingestions are due to Galerina marginata. With the exception of liver transplantation, the current treatment strategies for amatoxin poisoning are all supportive and have not been subjected to rigorous efficacy testing in randomized controlled trials. All patients with symptoms of late-appearing gastrointestinal toxicity with or without false recovery or quiescent periods preceding acute liver insufficiency should be referred to centers providing liver transplantation. Patients with amatoxin-induced acute liver insufficiency that does not progress to liver failure will have a more favorable survival profile with supportive care than patients with amatoxin-induced acute liver failure, about half of whom will require liver transplantation.

HBV-Associated Acute Liver Failure After Immunosuppression and Risk of Death.

BACKGROUND & AIMS: Acute liver failure (ALF) caused by hepatitis B virus (HBV) infection can occur after immunosuppressive treatment and be fatal, although it might be preventable. We aimed to characterize the causes, clinical course, and short-term outcomes of HBV-associated ALF after immune-suppressive therapy, compared with patients with HBV-associated ALF without immunosuppression (control subjects). METHODS: We performed a retrospective multicenter study of 156 consecutive patients diagnosed with HBV-associated ALF (22 with a solid or blood malignancy) enrolled in the Acute Liver Failure Study Group registry from January 1998 through April 2015. We collected data on results of serologic and hepatic biochemistry analyses, grade of hepatic encephalopathy, Model for End-Stage Liver Disease score, and King's College criteria. We also collected data on clinical features, medical therapies, and complications in the first 7 days following study enrollment. Logistic regression was used to identify factors associated with transplant-free survival at 21 days in HBV-associated ALF (the primary outcome). RESULTS: Among patients with HBV-associated ALF, 28 cases (18%) occurred after immunosuppressive therapy (15 patients received systemic corticosteroids and 21 received chemotherapy); and 128 cases did not (control subjects, 82%). Significantly greater proportions of patients with HBV-associated ALF after immunosuppression were nonwhite persons, and had anemia or thrombocytopenia than controls (P < .02 for all). The serologic profile of HBV infection, severity of liver failure (based on MELD score), and complications (hepatic encephalopathy or need for mechanical ventilation, vasopressors, or renal replacement therapy) were similar between the groups (P > .17 for all). Factors associated with 21 day transplant-free survival were increased MELD score (odds ratio ∼OR, 0.894 (95% confidence interval 0.842-0.949 per increment), requirement for mechanical ventilation (OR 0.111(0.041-0.300), and immunosuppressive therapy (OR 0.274(0.082-0.923)). CONCLUSIONS: Within a cohort study of patients with HBV-associated ALF, 18% had received immunosuppressive therapy. Significantly smaller proportions of patients with HBV-associated ALF after immunosuppression survive beyond 21 days than patients with HBV-associated ALF who did not receive immunosuppression. Patients undergoing chemotherapy should be screened for HBV infection and given appropriate antiviral therapies to reduce preventable mortality.

[Microflora changes in upper digestive tract and bile in acute liver failure mice].

Objective: To study the changes of upper digestive tract and bile flora associated with acute liver failure in mice. Methods: Mice were randomly divided into 2 groups: control group and acute liver failure group (group M). Acute liver failure in group M was induced by intraperitoneal injection of D-galactosamine (D-GaIN). The information of relative abundance and diversity were observed by high-throughput sequencing of V3 + V4 region in 16 S rDNA from bacteria of oral cavity, stomach, duodenal and bile.Bacterial translocation and changes associated with acute liver injury were identified by LEfSe (LDA effect size) analysis. Results: At the phylum level, compared with control group, the relative abundance of TM7 in oral cavity and stomach increased in group M. At the family level, compared with control group, group M resulted in a significant decrease in Pasteurellaceae in the stomach (P<0.05) and a increase in Lactobacillaceae in the bile (P<0.05). Conclusion: The diversity of bacteria and relative abundance of each bacterium in upper digestive tract and the bile are significantly changed during the process of acute liver injure in mice.

[Gastrointestinal bleeding and acute hepatic failure by leptospirosis: an entity that should not be forgotten]. / Hemorragia digestiva e insuficiencia hepática aguda por leptospirosis: una entidad que no debemos olvidar.

Leptospirosis disease is caused by the spirochete Leptospira. It is a worldwide distribution zoonosis, with predominance in the tropics. In Spain, it is not frequent but some cases have been noticed especially in humid areas surrounded by rivers, lakes or ponds, such as Catalonia, Andalucia or the Valencian Community. It is transmitted by a variety of animals such as cows or rats, that are infected either by direct contact with these animals or their urine, or indirectly by consuming or being in contact with water contaminated by their urine. The clinical manifestations are very variable, being asymptomatic or not very symptomatic in most of the patients. Unusually, leptospirosis presents with a first phase with fever, myalgias, liver injury or different organs hemorrhage, followed by a second phase with the presence of jaundice due to hepatic failure. Weil's disease is a kind of severe leptospirosis characterized by hepatic failure with jaundice and acute renal failure, associated with high mortality rates.The diagnosis is based on serological techniques and DNA detection by PCR. The treatment consists of life support measures and antibiotic therapy. A patient with Weil's disease and leptospirosis digestive bleeding is presented, with a fulminant clinical course. In order to achieve an early diagnosis, the need to keep this entity in mind must be emphasized, especially in favorable epidemiological environments as the one of this patient.

Mesenchymal stem cells alleviate bacteria-induced liver injury in mice by inducing regulatory dendritic cells.

UNLABELLED: Fulminant hepatic failure (FHF) is a clinical syndrome characterized by sudden and severe impairment of liver function. Mesenchymal stem cells (MSCs) have been proposed as a promising therapeutic approach for FHF. In this study we used Propionibacterium acnes (P. acnes)-primed, lipopolysaccharide (LPS)-induced liver injury in mice as an animal model of human FHF. We demonstrated that administration of MSCs significantly ameliorated liver injury and improved the survival rates of mice subjected to P. acnes plus LPS-induced FHF. Allogeneic MSCs showed similar treatment efficacy as autologous MSCs did in FHF. Treatment efficacy of MSCs could be attributed to decreased infiltration and activation of CD4(+) T cells in the liver, inhibition of T helper 1 cells, and induction of regulatory T cells (Tregs). Moreover, decreased DNA copies of P. acnes were detected in the liver of MSC-treated mice. Intriguingly, a distinct liver population of CD11c(+) MHCII(hi) CD80(lo) CD86(lo) regulatory dendritic cells (DCs) was induced by MSCs. Moreover, these DCs induced Treg differentiation through transforming growth factor-ß production. Further mechanistic studies demonstrated that MSC-derived prostaglandin E2 and one of its receptors, EP4, played essential roles in the differentiation of CD11c(+) B220(-) DC precursors into regulatory DCs in a phosphoinositide 3-kinase-dependent manner. CONCLUSION: MSCs induce regulatory DCs from CD11c(+) B220(-) DC precursors. This study elucidates an immunoregulatory mechanism of MSCs and lays a foundation for application of MSCs in FHF therapy.

Ethyl pyruvate prevents inflammatory factors release and decreases intestinal permeability in rats with D-galactosamine-induced acute liver failure.

BACKGROUND: The pathogenesis and progression of acute liver failure (ALF) are closely associated with intestinal endotoxemia because of the high permeability of the intestinal wall. Treatment with ethyl pyruvate (EP) has been shown to protect liver failure effectively. The current study aimed to explore the relationship between proinflammatory cytokines and intestinal permeability, and to investigate whether EP administration might prevent the release of multiple proinflammatory cytokines and decrease intestinal permeability and therefore, protect the liver from injury. METHODS: The ALF model was induced by D-galactosamine in rats. The rats were randomly divided into control (saline, i.p.), model (D-galactosamine, 1.2 g/kg, i.p.), prevention [EP injection (40 mg/kg) 2 hours ahead of D-galactosamine] and treatment groups (EP injection 2 hours after D-galactosamine). Samples were obtained at 12 and 24 hours after ALF induction, respectively. The histology of liver and intestinal tissue was assessed. Serum alanine aminotransferase, endotoxin, D(-)-lactate, diamine oxidase (DAO), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and high mobility group box-1 (HMGB1) were evaluated. The survival of rats was also recorded. RESULTS: The rats in model group showed severe damage to liver tissue and intestinal mucosa 12 and 24 hours after ALF induction. EP significantly improved liver or intestinal injury. In addition, serum endotoxin, D(-)-lactate, DAO, TNF-alpha, IFN-gamma and HMGB1 levels were significantly increased in the model group compared with the control group. There was a positive correlation between intestinal permeability and proinflammatory cytokines. EP significantly reduced serum endotoxin, D(-)-lactate, DAO, TNF-alpha, IFN-gamma and HMGB1 levels. The median survival time was significantly prolonged in both prevention and treatment groups (126 and 120 hours compared with 54 hours in the model group). CONCLUSIONS: EP has protective and therapeutic effects on intestinal mucosa. EP decreases intestinal permeability, and inhibits the release of multiple proinflammatory cytokines in rats with ALF.

Design and synthesis of hederagenin derivatives modulating STING/NF-κB signaling for the relief of acute liver injury in septic mice.

Systemic inflammatory responses often result in sepsis and inhibition of inflammation is one strategy for sepsis treatment. In this study, we designed and synthesized 32 novel hederagenin (HD) derivatives with modifications at the A-ring, C-28, and C-23 positions and screened their anti-inflammatory activities in vitro, finding multiple compounds with potential anti-inflammatory activity. Of these, compound 1 was the most effective and was used for subsequent investigations into its mechanism of action and in vivo activity. In vivo assessments of anti-inflammatory activity showed that compound 1 reduced inflammation in a mouse model of sepsis with acute liver injury caused by lipopolysaccharide (LPS). Compound 1 also inhibited STING, p-IRF3, p-TBK1, p-p65, and p-IκB proteins in cGAS-STING-associated signaling. These findings indicated that compound 1 reduced inflammation through inhibition of STING expression and hence reducing activation of STING and nuclear factor-κB (NF-κB) signaling. Our work demonstrated that compound 1 is a promising lead compound for designing and developing anti-sepsis drugs.

Infectious complications in pediatric acute liver failure.

OBJECTIVES: Acute liver failure (ALF) is rare in children but carries high mortality. Infectious complications (IC) in adults are an important cause of mortality; however, there are few data in the pediatric population. The aim of the study was to determine the incidence of IC and their effects on the outcome in children with ALF. MATERIALS AND METHODS: The present study is a retrospective review of the case records of children presenting with ALF to our center. All patients with ALF received antibiotics and antifungal as prophylaxis from day 1 and high-dose acyclovir was given to neonates only (stopped when herpes simplex was ruled out). Biochemical parameters, duration of ventilation and intensive care, overall hospital stay, and patient outcome were compared between patients with IC and non-IC. RESULTS: A total of 145 children (78 boys), median (range) age 4.22 (1 day-16 years) years, were studied. Thirty-seven of 145 (25%) patients had proven IC. The predominant infections included 14 episodes of bacteremia in 13 patients and lower respiratory tract infection and urinary tract infection in 10 and 8 patients, respectively. IC occurred in patients after a median (range) duration of 16 (0-54) days of admission. Median (range) duration of hospital stay in patients with IC was 38 (1-201) days and was significantly higher than in those without IC (10 [1-74] days), P < 0.0001. Overall mortality was 21% (31), of which 7% (11) was from the IC group and 14% (20) from the non-IC group; the difference was not statistically significant. CONCLUSIONS: Infections were more frequent after 2 weeks of admission. Patients with sepsis had longer hospital stays and prolonged ventilation. Invasive fungal infections were rare in pediatric ALF with adequate doses of antifungal prophylaxis.

Acute liver failure, autoimmune hepatitis, and leptospirosis: a case report.

The etiology of acute liver failure varies widely in children, but the most common causes are viral hepatitis, drugs, and toxins. We report herein a case of autoimmune hepatitis and acute liver failure caused by leptospirosis, which is involved rarely in etiology.

[The study on bacteria invading the intestinal mucosa barrier in mice with fulminant hepatic failure].

OBJECTIVE: To explore the mechanism of fulminate hepatic failure (FHF) complicated with spontaneous peritonitis (SBP) through the research of bacteria invading the intestinal mucosa barrier. METHODS: 240 BalB/c male mice were divided into four groups as isotonic NS group (n = 40), lipopolysaccharide (LPS) group (n = 40), galactosamine (GalN) group (n = 40) and FHF model group (n = 120). Each mouse received same volume of NS, LPS (10 ug/kg), GalN (800 mg/kg) or LPS (10 ug/kg)/GalN (800 mg/kg) intraperitoneal injection according to its group. 8 mice were executed at 2, 6, 9, 12 and 24 hours after injection, respectively, and the liver and intestinal tissue samples were taken at the same time. ALT was measured by automatic biochemical analyzer and was compared between groups using Mann-Whitney U test. Liver and intestinal tissue received HE staining. The ultrastructure of intestinal mucosa and the method by which bacteria invaded the intestinal mucosa were observed by transmission electron microscopy. All data were analyzed by SPSS13.0 statistic software. RESULTS: ALT level, results of hepatic pathology, mortality and clinical manifestations of mice in the FHF model group met the diagnostic criteria of FHF. Intestinal tissue was found with slight edema and little inflammatory cells infiltration through HE staining in all the 4 groups of mice 9 hours after injection. Microvilli were found broken, shed and shorten in the intestinal epithelial cells with incomplete tight junction (TJs) and obviously changed organelles in the FHF model group of mice observed by transmission electron microscope. Mass hemorrhagic necrosis of liver cells with remnant liver cells swelling and many inflammatory cells infiltration by HE staining in the FHF model group. But the changes in hepatic pathology and intestinal mucosa ultrastructure were not so obvious in the mice of NS, LPS and GalN groups. Bacteria penetrated the intestinal wall by pinocytosis 6 to 9 hours after injection in the FHF model group, the microvilli were broken off and TJs turned rupture in the areas that the bacteria penetrated. The bacteria were found in the form of cyst 12 hours after injection. CONCLUSION: LPS (10 mg/kg)/GalN (800 mg/kg) combined injection was successful in establishing the FHF mice model. The rupture of TJs may provide conditions for intestinal bacteria to penetrate the intestinal mucosa in FHF. Rupture of TJs may be one of the reasons why FHF was complicated with SBP.

Acute Liver Failure after Ingestion of Fried Rice Balls: A Case Series of Bacillus cereus Food Poisonings.

Bacillus cereus foodborne intoxications and toxicoinfections are on a rise. Usually, symptoms are self-limiting but occasionally hospitalization is necessary. Severe intoxications with the emetic Bacillus cereus toxin cereulide, which is notably resistant heat and acid during cooking, can cause acute liver failure and encephalopathy. We here present a case series of food poisonings in five immunocompetent adults after ingestion of fried rice balls, which were massively contaminated with Bacillus cereus. The patients developed a broad clinical spectrum, ranging from emesis and diarrhoea to life-threatening acute liver failure and acute tubular necrosis of the kidney in the index patient. In the left-over rice ball, we detected 8 × 106Bacillus cereus colony-forming units/g foodstuff, and cereulide in a concentration of 37 µg/g foodstuff, which is one of the highest cereulide toxin contaminations reported so far from foodborne outbreaks. This report emphasizes the potential biological hazard of contaminated rice meals that are not freshly prepared. It exemplifies the necessity of a multidisciplinary approach in cases of Bacillus cereus associated food poisonings to rapidly establish the diagnosis, to closely monitor critically ill patients, and to provide supportive measures for acute liver failure and-whenever necessary-urgent liver transplantation.

TLR4-NLRP3-GSDMD-Mediated Pyroptosis Plays an Important Role in Aggravated Liver Injury of CD38-/- Sepsis Mice.

Clinically, severe bacterial infection can cause septicemia and multiple organ dysfunction syndrome, especially liver injury. CD38 is closely related to many inflammatory pathways, but its role in liver injury caused by bacterial infection remains unclear. The purpose of this study is to discuss the specific role of CD38 in bacterial liver injury. Eight-week-old male C57BL/6 mice (WT, CD38-/- and CD38-/-TLR4mut) were used and stimulated with Escherichia coli (ATCC25922) or PBS, intraperitoneally. After 3 hours of bacterial stimulation, serum was collected to detect ALT and AST concentration, and liver tissue was harvested for hematoxylin and eosin staining and bacterial culture. The mRNA expressions of TLR4, NLRP3, IL-1ß, IL-18, and GSDMD were quantitatively determined by RT-qPCR. The expressions of TLR4, MyD88, TRIF, NF-κB p65, NLRP3, GSDMD, and cytokines were detected by Western blot. The expression and localization of ERK1/2 were detected by immunohistochemistry and Western blot. The results showed that bacterial stimulation could upregulate the expression of inflammatory cytokines, leading to hepatic dysfunction. Moreover, bacterial stimulation of CD38-deficient mice can aggravate the inflammatory response, the expressions of TLR4, NF-κB, and ERK1/2 were significantly increased, and the biomarkers related to pyroptosis also manifested more obvious pyroptosis. However, TLR4 mutation significantly alleviated inflammation and pyroptosis in the liver caused by bacteria, on the basis of CD38 deficiency. Overall, CD38 knockout exacerbates bacteria-induced liver damage through TLR4-NLRP3-GSDMD-mediated pyroptosis.

Pulmonary mucormycosis in a patient with acute liver failure: A case report and systematic review of the literature.

PURPOSE: Pulmonary mucormycosis is a highly lethal invasive fungal infection usually found in immunocompromised patients. We report herein the case of an adult woman who developed pulmonary mucormycosis with possible systemic dissemination after recovering from acute liver failure secondary to acetaminophen overdose. RESULTS: Our case developed an invasive pulmonary mucormycosis with probable systemic dissemination. She did not suffer from any immunocompromising disease other than severe acute liver failure. She did not survive the disease, although she received appropriate antifungal treatment. We also performed a systematic review of the literature on pulmonary mucormycosis, with or without dissemination, in immunocompetent patients. We found 16 cases of pulmonary or disseminated mucormycosis in immunocompetent patients. Fifty-seven percent of them died and none occurred after an acute liver failure episode. CONCLUSION: This case report is the first one to present an invasive pulmonary mucormycosis infection after acute liver failure in an adult patient. The clinical course of this disease is highly lethal, even in immunocompetent adults.

Betaine inhibits Toll-like receptor 4 responses and restores intestinal microbiota in acute liver failure mice.

Previous research has revealed that the gut microbiome has a marked impact on acute liver failure (ALF). Here, we evaluated the impact of betaine on the gut microbiota composition in an ALF animal model. The potential protective effect of betaine by regulating Toll-like receptor 4 (TLR4) responses was explored as well. Both mouse and cell experiments included normal, model, and betaine groups. The rat small intestinal cell line IEC-18 was used for in vitro experiments. Betaine ameliorated the small intestine tissue and IEC-18 cell damage in the model group by reducing the high expression of TLR4 and MyD88. Furthermore, the intestinal permeability in the model group was improved by enhancing the expression of the (ZO)-1 and occludin tight junction proteins. There were 509 operational taxonomic units (OTUs) that were identified in mouse fecal samples, including 156 core microbiome taxa. Betaine significantly improved the microbial communities, depleted the gut microbiota constituents Coriobacteriaceae, Lachnospiraceae, Enterorhabdus and Coriobacteriales and markedly enriched the taxa Bacteroidaceae, Bacteroides, Parabacteroides and Prevotella in the model group. Betaine effectively improved intestinal injury in ALF by inhibiting the TLR4/MyD88 signaling pathway, improving the intestinal mucosal barrier and maintaining the gut microbiota composition.

Acute liver failure complication of brucellosis infection: a case report and review of the literature.

BACKGROUND: Brucellosis is one of the most widespread zoonoses worldwide. It can affect any organ system, particularly the gastrointestinal system, but there is no report of acute liver failure as a brucellosis complication. CASE PRESENTATION: We present a case of acute liver failure secondary to brucellosis infection. A 75-year-old Hispanic man presented to a University Hospital in Chía, Colombia, with a complaint of 15 days of fatigue, weakness, decreased appetite, epigastric abdominal pain, jaundice, and 10 kg weight loss. On examination in an emergency room, abdomen palpation was normal with hepatosplenomegaly and the results of a liver function test were elevated. The diagnosis of brucellosis was confirmed by epidemiological contact and positive Rose Bengal agglutination with negative enzyme-linked immunosorbent assay immunoglobulin M for Brucella. He was then treated with doxycycline plus trimethoprim/sulfamethoxazole, with a favorable clinical outcome. CONCLUSIONS: The clinical presentation of brucellosis can be very imprecise because it can affect any organ system; however, there is no report of acute liver failure as a brucellosis complication. This is the first reported case in the Colombian literature of acute liver failure due to brucellosis. We found this case to be of interest because it could be taken into account for diagnosis in future appearances and we described adequate treatment and actions to be taken at presentation.

Methylprednisolone prevents bacterial translocation in thioacetamide-induced liver failure in rats.

BACKGROUND/AIMS: Steroids have been shown to prevent intestinal oxidative stress. We investigated the effects of methylprednisolone on intestinal oxidative damage and bacterial translocation in thioacetamide-induced liver failure in rats. MATERIALS AND METHODS: Group 1 (n=8) was the control group. In group 2 (n=8), the thioacetamide group, rats received 300 mg/kg intraperitoneal thioacetamide daily for 2 days. In group 3 (n=8), the thioacetamide+methylprednisolone group, treatment with methylprednisolone (30 mg/kg intraperitoneal) was commenced 48 h before the first dose of thioacetamide. In group 4 (n=8), the methylprednisolone group, the rats received only methylprednisolone (30 mg/kg intraperitoneal). RESULTS: Serious hepatic and intestinal oxidative damage and high bacterial translocation frequencies were observed in the thioacetamide group compared with those of the controls. Bacterial translocation frequency in the thioacetamide+methylprednisolone group was significantly lower than that in the thioacetamide group (p<0.05). Intestinal thiobarbituric acid-reactive substances and myeloperoxidase levels and tissue damage scores for the intestines in the thioacetamide+methylprednisolone group were lower than those in the thioacetamide group (p<0.01, p<0.01, and p<0.0001, respectively). CONCLUSION: Our findings suggest that methylprednisolone reduces bacterial translocation by preventing intestinal oxidative damage in this model of acute liver failure in rats.

Fulminant hepatic failure caused by Salmonella paratyphi A infection.

We report a case of fulminant hepatic failure associated with Salmonella paratyphi A infection, in a 29-year-old patient who was admitted to the intensive care unit (ICU) with fever of two days, headache and vomiting followed by behavioural changes and disorientation. On examination, the patient appeared acutely ill, agitated, confused, and deeply jaundiced. Temperature 38.5 degrees of C, pulse 92/min, blood pressure 130/89 mmHg. Both samples of blood grew S. paratyphi A, which was sensitive to ceftriaxone and ciprofloxacin. Ceftriaxon was administered with high-dose dexamethasone. Two weeks after treatment with ceftriaxon, the patient was discharged in satisfactory condition.

Toll-like receptor 2 mediates inflammatory cytokine induction but not sensitization for liver injury by Propioni- bacterium acnes.

Recognition of Gram-positive bacteria by Toll-like receptor 2 (TLR2) induces activation of proinflammatory pathways. In mice, sensitization with the Gram-positive Propionibacterium acnes followed by a challenge with the TLR4 ligand, lipopolysaccharide (LPS), results in fulminant hepatic failure. Here, we investigated the role of TLR2 in liver sensitization to LPS-induced injury. Stimulation of Chinese hamster ovary cells and peritoneal macrophages with heat-killed P. acnes required expression of TLR2 but not of TLR4, suggesting that P. acnes was a TLR2 ligand. Cell activation by P. acnes was myeloid differentiation primary-response protein 88 (MyD88)-dependent, and it was augmented by coexpression of CD14 in mouse peritoneal macrophages. In vitro, P. acnes behaved as a TLR2 ligand and induced TLR4 hetero- and TLR2 homotolerance in peritoneal macrophages. In vivo priming of wild-type mice with P. acnes, but not with the selective TLR2 ligands peptidoglycan and lipotheicoic acid, resulted in hepatocyte necrosis, hyperelevated serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, interferon-gamma (IFN-gamma), and IL-12 (p40/p70), and increased RNA expression of proinflammatory cytokines (IL-12p40, IL-1alpha, IL-6, IL-1beta, IL-18, IFN-gamma) in the liver after a LPS challenge. Furthermore, P. acnes priming sensitized TLR2-deficient (TLR2-/-) but not MyD88-/- mice to LPS-induced injury, evidenced by hepatocyte necrosis, increased levels of serum TNF-alpha, IFN-gamma, IL-6, and liver proinflammatory cytokine mRNA expression. IFN-gamma, a cytokine sensitizing to endotoxin, was induced by P. acnes in splenocytes of TLR2-/- and TLR9-/- but not MyD88-/- mice. These results suggest that although P. acnes triggers TLR2-mediated cell activation, TLR2-independent but MyD88-dependent mechanisms mediate in vivo sensitization by P. acnes for LPS-induced liver injury.