Complete Genome Sequence of a Metronidazole-Resistant Helicobacter pylori Strain

We report here the complete genome sequence of a metronidazole-resistant Helicobacter pylori strain (MET^r). The MET^r strain was obtained under exposure of H. pylori 26695 on agar plates with low metronidazole concentrations. The genome data provide insight into the genomic changes of H. pylori under selection by metronidazole in vitro.

Trolox and ascorbic acid reduce direct and indirect oxidative stress in the IPEC-J2 cells, an in vitro model for the porcine gastrointestinal tract

Oxidative stress in the small intestinal epithelium is a major cause of barrier malfunction and failure to regenerate. This study presents a functional in vitro model using the porcine small intestinal epithelial cell line IPEC-J2 to examine the effects of oxidative stress and to estimate the antioxidant and regenerative potential of Trolox, ascorbic acid and glutathione monoethyl ester. Hydrogen peroxide and diethyl maleate affected the tight junction (zona occludens-1) distribution, significantly increased intracellular oxidative stress (CM-H₂DCFDA) and decreased the monolayer integrity (transepithelial electrical resistance and FD-4 permeability), viability (neutral red) and wound healing capacity (scratch assay). Trolox (2 mM) and 1 mM ascorbic acid pre-treatment significantly reduced intracellular oxidative stress, increased wound healing capacity and reduced FD-4 permeability in oxidatively stressed IPEC-J2 cell monolayers. All antioxidant pre-treatments increased transepithelial electrical resistance and viability only in diethyl maleate-treated cells. Glutathione monoethyl ester (10 mM) pre-treatment significantly decreased intracellular oxidative stress and monolayer permeability only in diethyl maleate-treated cells. These data demonstrate that the IPEC-J2 oxidative stress model is a valuable tool to screen antioxidants before validation in piglets.

Nitric oxide released from luminal s-nitroso-N-acetylcysteine increases gastric mucosal blood flow

Nitric oxide (NO)-mediated vasodilation plays a key role in gastric mucosal defense, and NO-donor drugs may protect against diseases associated with gastric mucosal blood flow (GMBF) deficiencies. In this study, we used the ex vivo gastric chamber method and Laser Doppler Flowmetry to characterize the effects of luminal aqueous NO-donor drug S-nitroso-N-acetylcysteine (SNAC) solution administration compared to aqueous NaNO2 and NaNO3 solutions (pH 7.4) on GMBF in Sprague-Dawley rats. SNAC solutions (600 μM and 12 mM) led to a rapid threefold increase in GMBF, which was maintained during the incubation of the solutions with the gastric mucosa, while NaNO2 or NaNO3 solutions (12 mM) did not affect GMBF. SNAC solutions (600 μM and 12 mM) spontaneously released NO at 37 °C at a constant rate of 0.3 or 14 nmol·mL-1·min-1, respectively, while NaNO2 (12 mM) released NO at a rate of 0.06 nmol·mL-1·min-1 and NaNO3 (12 mM) did not release NO. These results suggest that the SNAC-induced GMBF increase is due to their higher rates of spontaneous NO release compared to equimolar NaNO2 solutions. Taken together, our data indicate that oral SNAC administration is a potential approach for gastric acid-peptic disorder prevention and treatment.

Colitis-induced neuroplasticity disrupts motility in the inflamed and post-inflamed colon

Effective colonic motility involves an intricate pattern of excitatory and inhibitory neuromuscular signals that arise from the enteric neural circuitry of the colon. Recent investigations have demonstrated that inflammation leads to a variety of changes in the physiological properties of the neurons in this circuitry, including hyperexcitability of neurons at the afferent end of the peristaltic reflex, synaptic facilitation, and attenuated inhibitory neuromuscular transmission. Furthermore, links have been established between these changes and disrupted motor activity in the colon, and we now know that some of these changes persist long after recovery from inflammation. It is highly likely that inflammation-induced neuroplasticity, which is not detectable by clinical diagnostics, contributes to disrupted motility in active and quiescent inflammatory bowel disease and in functional gastrointestinal disorders.

Collagen XVII expression correlates with the invasion and metastasis of colorectal cancer

Collagen XVII has a well-established role as an adhesion molecule and a cell surface receptor located in the type I hemidesmosome of stratified epithelia. Its ectodomain is constitutively shed from the cell surface and suggested to regulate the adhesion, migration, and signaling of cutaneous epithelial cells. Collagen XVII was not previously thought to be expressed by colon epithelial cells. Immunohistochemical analysis of tissue microarray samples of 141 cases of colorectal carcinoma showed that collagen XVII is expressed in normal human colonic mucosa and colorectal carcinoma. In colorectal carcinoma, increased collagen XVII expression was significantly associated with higher TNM stage. It also correlated with infiltrative growth pattern and tumor budding as well as lymph node and distant metastasis. Increased collagen XVII expression was associated with decreased disease-free and cancer-specific survival. Immunofluorescence staining of collagen XVII and its well-known binding partner laminin γ2 chain demonstrated a partial colocalization in normal and tumor tissue. In vitro, the overexpression of murine collagen XVII promoted the invasion of CaCo-2 colon carcinoma cells through Matrigel (BD Biosciences; Bedford, MA). To conclude, this study reports for the first time the expression of collagen XVII in colon epithelium and the association of increased collagen XVII immunoexpression with poor outcome in colorectal carcinoma.

Role of liver in modulating the release of inflammatory cytokines involved in lung and multiple organ dysfunction in severe acute pancreatitis

The objective of this study was to understand the role of liver in modulating remote organ dysfunction during severe acute pancreatitis (SAP). We used sodium taurocholate and endotoxin to induce SAP in the rats and confirmed the development of this condition by measuring serum and ascite levels of the biomarkers of liver and lung damage. Our results showed that expression of tumor necrosis factor (TNF)-α was up-regulated sequentially, first in the gut, then in the liver, and finally in lung. Moreover, the SAP-induced increase in the expressions of TNF-α and IL-6 occurring in gut, liver, and lung was directly related to the increase in time. However, in liver and lung, the transcriptional activity of NF-κB and expression of TNF-α at 4 and 8 h were not increased. The distribution sequence of the pro-inflammatory cytokines to various organs was determined by their detection in the blood from portal vein and inferior vena cava. Although liver received TNF-α during 0.5-8 h of the SAP induction, the release of this cytokine into vena cava was not increased in this period of time. In conclusion, our results suggest that the aggravation of SAP leading to development of MODS exhibited the gut-liver-lung cytokine axis. Furthermore, this study indicates that liver performs both protective and stimulatory activities in the modulation of pro-inflammatory cytokine generation and their distribution to remote organs, such as lungs.

The gastrointestinal microbiota and colorectal cancer

The human gut is home to a complex and diverse microbiota that contributes to the overall homeostasis of the host. Increasingly, the intestinal microbiota is recognized as an important player in human illness such as colorectal cancer (CRC), inflammatory bowel diseases, and obesity. CRC in itself is one of the major causes of cancer mortality in the Western world. The mechanisms by which bacteria contribute to CRC are complex and not fully understood, but increasing evidence suggests a link between the intestinal microbiota and CRC as well as diet and inflammation, which are believed to play a role in carcinogenesis. It is thought that the gut microbiota interact with dietary factors to promote chronic inflammation and CRC through direct influence on host cell physiology, cellular homeostasis, energy regulation, and/or metabolism of xenobiotics. This review provides an overview on the role of commensal gut microbiota in the development of human CRC and explores its association with diet and inflammation.

Overexpression of miR-595 and miR-1246 in the sera of patients with active forms of inflammatory bowel disease

BACKGROUND

MicroRNAs (miRNAs) are dysregulated in the inflammatory bowel diseases, Crohn's disease (CD) and ulcerative colitis (UC), which arise due to dysfunctional host-microbe interactions and impairment of the barrier function of the intestine. Here, we sought to determine whether circulating miRNAs are biomarkers of active colonic CD and UC and can provide insights into disease pathogenesis. Comparison was made with serum miRNAs in patients with rheumatoid arthritis (RA).

METHODS

Total serum RNA from patients with colonic CD, UC, and RA, and normal healthy adults was screened for disease-associated miRNAs by microarray analysis, with subsequent validation by quantitative reverse-transcription polymerase chain reaction. MiRNA targets were identified by luciferase reporter assays.

RESULTS

MiR-595 and miR-1246 were significantly upregulated in the sera of active colonic CD, UC, and RA patients, compared with healthy subjects; and in active colonic CD and UC compared with inactive disease. Luciferase reporter assays indicated that miR-595 inhibits the expression of neural cell adhesion molecule-1 and fibroblast growth factor receptor 2.

CONCLUSIONS

Serum miR-595 and miR-1246 are biomarkers of active CD, UC, and RA. These findings gain significance from reports that miR-595 impairs epithelial tight junctions, whereas miR-1246 indirectly activates the proinflammatory nuclear factor of activated T cells. miR-595 targets the cell adhesion molecule neural cell adhesion molecule-1, and fibroblast growth factor receptor 2, which plays a key role in the differentiation, protection, and repair of colonic epithelium, and maintenance of tight junctions. miR-595 and miR-1246 warrant testing as potential targets for therapeutic intervention in the treatment of inflammatory bowel disease.

Why is initial bacterial colonization of the intestine important to infants' and children's health?

Microbial colonization of the infant occurs during a critical time window for immune and gastrointestinal development. Infant colonization sets the stage for the adult microbiome. This review is a broad survey of the factors affecting infant colonization and the downstream effects on gastrointestinal health and disease. Major topics affecting colonization include initial inoculation dependent on birth mode, the impact of breast-feeding, and inside-out modulation of the developing microbiome by the immune system. Major outcomes of colonization include the timing-dependent education of the neonatal immune system, which is interconnected with barrier function and metabolism. These all engage in further continuing cross-talk with the microbiome, genetics, and nutrition. This review also briefly examines mechanisms of disease resulting from disrupted colonization as well as nutritional and microbial therapies.

Role of farnesoid X receptor and bile acids in alcoholic liver disease

Alcoholic liver disease (ALD) is one of the major causes of liver morbidity and mortality worldwide. Chronic alcohol consumption leads to development of liver pathogenesis encompassing steatosis, inflammation, fibrosis, cirrhosis, and in extreme cases, hepatocellular carcinoma. Moreover, ALD may also associate with cholestasis. Emerging evidence now suggests that farnesoid X receptor (FXR) and bile acids also play important roles in ALD. In this review, we discuss the effects of alcohol consumption on FXR, bile acids and gut microbiome as well as their impacts on ALD. Moreover, we summarize the findings on FXR, FoxO3a (forkhead box-containing protein class O3a) and PPARα (peroxisome proliferator-activated receptor alpha) in regulation of autophagy-related gene transcription program and liver injury in response to alcohol exposure.

Clinicopathological significance of wnt/β-catenin signaling pathway in esophageal squamous cell carcinoma

BACKGROUND/AIM

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors. It has been reported that Wnt signaling pathway plays an important role in Esophageal Cancer progression, metastasis and invasion. However the clinicopathological significance of Wnt2, GSK3β, and β-catenin in ESCC has been little reported. In the present study, the aim of this study was to investigate the clinicopathologic and prognosis roles of Wnt2, GSK3β, and β-catenin in ESCC tissue.

METHODS

265 ESCC samples were analyzed by immunohistochemistry using Wnt2, GSK3β, and β-catenin antibodies. Then, correlation of Wnt2, GSK3β, and β-catenin expression with clinicopathological features and prognosis of ESCC patients was statistically analyzed.

RESULTS

Cytoplasmic Wnt2 overexpression was detected in 55.5% (147 of 265) ESCCs, which was significantly correlated with the degree of differentiation (P=0.031). Cytoplasmic GSK3β overexpression was detected in 7.2% (19 of 265) ESCCs, and aberrant β-catenin expression was identified in 54.3% (144 of 265) of ESCCs. The positive rate of Wnt2 significantly increased with the malignant degree of Kazak ESCC patients. The aberrant β-catenin expression in GSK3β-negative ESCC was significantly associated with the ethnic, tumor size, tumor location, degree of differentiation, AJCC stage, lymph node status. Furthermore, the expression of β-catenin implicated the ethnic difference (P=0.019). In Kaplan-Meier curve analysis, no significant correlation was observed between the expression of Wnt2, GSK3β, β-catenin and the poor prognosis of ESCCs.

CONCLUSION

The aberrant β-catenin expression could be an adverse underlying factor in carcinogenesis and progression of ESCC. There was a different statistical signification for β-catenin in Kazakhs to compare with Hans.

Toward beta cell replacement for diabetes

The discovery of insulin more than 90 years ago introduced a life-saving treatment for patients with type 1 diabetes, and since then, significant progress has been made in clinical care for all forms of diabetes. However, no method of insulin delivery matches the ability of the human pancreas to reliably and automatically maintain glucose levels within a tight range. Transplantation of human islets or of an intact pancreas can in principle cure diabetes, but this approach is generally reserved for cases with simultaneous transplantation of a kidney, where immunosuppression is already a requirement. Recent advances in cell reprogramming and beta cell differentiation now allow the generation of personalized stem cells, providing an unlimited source of beta cells for research and for developing autologous cell therapies. In this review, we will discuss the utility of stem cell-derived beta cells to investigate the mechanisms of beta cell failure in diabetes, and the challenges to develop beta cell replacement therapies. These challenges include appropriate quality controls of the cells being used, the ability to generate beta cell grafts of stable cellular composition, and in the case of type 1 diabetes, protecting implanted cells from autoimmune destruction without compromising other aspects of the immune system or the functionality of the graft. Such novel treatments will need to match or exceed the relative safety and efficacy of available care for diabetes.

Alginate encapsulant incorporating CXCL12 supports long-term allo- and xenoislet transplantation without systemic immune suppression

Islet transplantation represents a potentially curative approach for individuals with Type I Diabetes. The requirement for systemic immune suppression to control immune-mediated rejection of transplanted islets and the limited human islet supply represent significant roadblocks to progress for this approach. Islet microencapsulation in alginate offers limited protection in the absence of systemic immunosuppression, but does not support long-term islet survival. The chemokine, CXCL12, can repel effector T cells while recruiting immune-suppressive regulatory T cells (Tregs) to an anatomic site while providing a prosurvival signal for beta-cells. We proposed that coating or encapsulating donor islets with CXCL12 would induce local immune-isolation and protect and support the function of an allo- or xenograft without systemic immune suppression. This study investigated the effect of alginate microcapsules incorporating CXCL12 on islet function. Islet transplantation was performed in murine models of insulin-dependent diabetes. Coating of islets with CXCL12 or microencapsulation of islets with alginate incorporating the chemokine, resulted in long-term allo- and xenoislet survival and function, as well as a selective increase in intragraft Tregs. These data support the use of CXCL12 as a coating or a component of an alginate encapsulant to induce sustained local immune-isolation for allo- or xenoislet transplantation without systemic immunosuppression.

Reshaping faecal gut microbiota composition by the intake of trans-resveratrol and quercetin in high-fat sucrose diet-fed rats

Diet-induced obesity is associated to an imbalance in the normal gut microbiota composition. Resveratrol and quercetin, widely known for their health beneficial properties, have low bioavailability, and when they reach the colon, they are targets of the gut microbial ecosystem. Hence, the use of these molecules in obesity might be considered as a potential strategy to modulate intestinal bacterial composition. The purpose of this study was to determine whether trans-resveratrol and quercetin administration could counteract gut microbiota dysbiosis produced by high-fat sucrose diet (HFS) and, in turn, improve gut health. Wistar rats were randomised into four groups fed an HFS diet supplemented or not with trans-resveratrol [15 mg/kg body weight (BW)/day], quercetin (30 mg/kg BW/day) or a combination of both polyphenols at those doses. Administration of both polyphenols together prevented body weight gain and reduced serum insulin levels. Moreover, individual supplementation of trans-resveratrol and quercetin effectively reduced serum insulin levels and insulin resistance. Quercetin supplementation generated a great impact on gut microbiota composition at different taxonomic levels, attenuating Firmicutes/Bacteroidetes ratio and inhibiting the growth of bacterial species previously associated to diet-induced obesity (Erysipelotrichaceae, Bacillus, Eubacterium cylindroides). Overall, the administration of quercetin was found to be effective in lessening HFS-diet-induced gut microbiota dysbiosis. In contrast, trans-resveratrol supplementation alone or in combination with quercetin scarcely modified the profile of gut bacteria but acted at the intestinal level, altering the mRNA expression of tight-junction proteins and inflammation-associated genes.

The Link between Autoimmunity and Lymphoma: Does NOTCH Signaling Play a Contributing Role?

An association between certain autoimmune conditions and increased risk of developing lymphoma is well documented. Recent evidence points to NOTCH signaling as a strong driver of autoimmunity. Furthermore, a role for NOTCH in various lymphomas, including classical Hodgkin lymphoma, non-Hodgkin lymphoma, and T cell lymphoma has also been described. In this mini-review, we will outline what is known about involvement of NOTCH signaling in those autoimmune conditions, such as rheumatoid arthritis and primary Sjörgren’s syndrome, which show an increased risk for subsequent diagnosis of lymphoma. Furthermore, we will detail what is known about the lymphomas associated with these autoimmune conditions and how aberrant or sustained NOTCH signaling in the immune cells that mediate these diseases may contribute to lymphoma.

Commensal bacterial internalization by epithelial cells: An alternative portal for gut leakiness

Co-existing paracellular and transcellular barrier defect in intestinal epithelium was documented in inflammatory bowel disease, celiac disease, and intestinal obstruction. Mechanisms regarding tight junction disruption have been extensively studied; however, limited progress has been made in research on bacterial transcytosis. Densely packed brush border (BB), with cholesterol-based lipid rafts in the intermicrovillous membrane invagination, serves as an ultrastructural barrier to prevent direct contact of luminal microbes with the cellular soma. Evidence in in vitro epithelial cell cultures and in vivo animal models of bowel obstruction and antibiotic-resistant bacterial infection had indicated that nonpathogenic, noninvasive enteric bacteria may hijack the lipid raft-mediated endocytic pathways. Our studies have shown that low dose interferon-gamma (IFNγ) causes long myosin light chain kinase (MLCK)-dependent terminal web (TW) contraction and BB fanning, allowing bacteria to pass through the consequently widened intermicrovillous cleft to be endocytosed via caveolin-associated lipid rafts. Activation of intracellular innate immune receptors by bacteria-containing endosomes may further induce inflammatory and oxidative stress, leading to secondary tight junction damage. The finding of bacterial internalization preceding tight junction damage suggests that abnormal bacterial uptake by epithelial cells may contribute to the initiation or relapse of chronic intestinal inflammation.

HIV and the gut microbiota, partners in crime: breaking the vicious cycle to unearth new therapeutic targets

The gut microbiota plays a key role in health and immune system education and surveillance. The delicate balance between microbial growth and containment is controlled by the immune system. However, this balance is disrupted in cases of chronic viral infections such as HIV. This virus is capable of drastically altering the immune system and gastrointestinal environment leading to significant changes to the gut microbiota and mucosal permeability resulting in microbial translocation from the gut into the peripheral blood. The changes made locally in the gut have far-reaching consequences on the other organs of the body starting in the liver, where microbes and their products are normally filtered out, and extending to the blood and even brain. Microbial translocation and their downstream effects such as increased indolamine 2,3-dioxygenase (IDO) enzyme expression and activity create a self-sustaining feedback loop which enhances HIV disease progression and constitute a vicious cycle of inflammation and immune activation combining viral and bacterial factors. Understanding this self-perpetuating cycle could be a key element in developing new therapies aimed at the gut microbiota and its fallout after infection.

[Autoimmune pancreatitis. Evidence based management guidelines of the Hungarian Pancreatic Study Group]

Autoimmune pancreatitis is a rare disease which can even mimic pancreatic tumor, however, unlike the latter, it requires not surgical but conservative management. Correct diagnosis and differential diagnosis of autoimmune pancreatitis and treatment of these patients requires up-to-date and evidence based management guidelines. The Hungarian Pancreatic Study Group proposed to prepare an evidence based guideline based on the available international guidelines and evidences. The preparatory and consultation task force appointed by the Hungarian Pancreatic Study Group translated and complemented and/or modified the international guidelines if it was necessary. 29 relevant clinical questions in 4 topics were defined (Basics; Diagnosis; Differential diagnostics; Therapy). Evidence was classified according to the UpToDate(®) grading system. The draft of the guidelines was presented and discussed at the consensus meeting on September 12, 2014. All clinial questions were accepted with almost total (more than 95%) agreement. The present guideline is the first evidence based autoimmune pancreatitis guideline in Hungary. The guideline may provide very important and helpful data for tuition of autoimmune pancreatitis, for everyday practice and for establishing proper finance. Therefore, the authors believe that these guidelines will widely become a basic reference in Hungary.

Beyond Maastricht IV: are standard empiric triple therapies for Helicobacter pylori still useful in a South-European country?

Background

Empiric triple treatments for Helicobacter pylori (H. pylori) are increasingly unsuccessful. We evaluated factors associated with failure of these treatments in the central region of Portugal.

Methods

This single-center, prospective study included 154 patients with positive ¹³C-urea breath test (UBT). Patients with no previous H. pylori treatments (Group A, n = 103) received pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and clarithromycin (CLARI) 500 mg 12/12 h, for 14 days. Patients with previous failed treatments (Group B, n = 51) and no history of levofloxacin (LVX) consumption were prescribed pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and LVX 250 mg 12/12 h, for 10 days. H. pylori eradication was assessed by UBT 6–10 weeks after treatment. Compliance and adverse events were assessed by verbal and written questionnaires. Risk factors for eradication failure were determined by multivariate analysis.

Results

Intention-to-treat and per-protocol eradication rates were Group A: 68.9% (95% CI: 59.4–77.1%) and 68.8% (95% CI: 58.9–77.2%); Group B: 52.9% (95% CI: 39.5–66%) and 55.1% (95% CI: 41.3–68.2%), with 43.7% of Group A and 31.4% of Group B reporting adverse events. Main risk factors for failure were H. pylori resistance to CLARI and LVX in Groups A and B, respectively. Another independent risk factor in Group A was history of frequent infections (OR = 4.24; 95% CI 1.04–17.24). For patients with no H. pylori resistance to CLARI, a history of frequent infections (OR = 4.76; 95% CI 1.24–18.27) and active tobacco consumption (OR = 5.25; 95% CI 1.22–22.69) were also associated with eradication failure.

Conclusions

Empiric first and second-line triple treatments have unacceptable eradication rates in the central region of Portugal and cannot be used, according to Maastricht recommendations. Even for cases with no H. pylori resistance to the used antibiotics, results were unacceptable and, at least for CLARI, are influenced by history of frequent infections and tobacco consumption.

The diagnostic challenges of autoimmune pancreatitis

Autoimmune pancreatitis is a rare but important differential diagnosis from pancreatic cancer. This autoimmune disease can mimic pancreatic cancer by its clinical symptoms, including weight loss and jaundice. Furthermore imaging findings may include a mass of the pancreas. Here we present the case of a 67-year-old male patient diagnosed with autoimmune pancreatitis but showing the well-known symptoms of pancreatic cancer. This emphasizes the difficulties of histological findings and the importance of the correct diagnostic process.

A case of isolated splenic tuberculosis

•

We discuss a case of isolated splenic tuberculosis.

•

Extra-pulmonary tuberculosis can present in the immunocompetent patient.

•

Splenectomy is indicated when GI bleeding due to portal hypertension and splenomegaly occurs, as well as failure of medical therapy, cytopenia and multiple splenic abscess.

There are few cases of isolated splenic tuberculosis reported in the literature internationally, and nearly none from western medical centers. The incidence of tuberculosis has declined in the United States since the 1950s, with 11,585 reported cases in 2009, 21% of which were exclusively extrapulmonary. Splenic tuberculosis occurs mostly as part of miliary tuberculosis in immunocompromised patients. Isolated splenic tuberculosis is extremely rare, particularly in the immunocompetent patient. Patients susceptible to acquiring splenic tuberculosis usually have one of the following risk factors: immunosuppression, preceding pyogenic infections, splenic abnormalities, prior trauma to the spleen, sickle cell disease and other hemopathies, and in the immunocompetent patient another body site infected by M. tuberculosis. In this report we present the case of a young immunocompetent male with no other significant past medical history with isolated splenic tuberculosis.

Signaling between two interacting sensor kinases promotes biofilms and colonization by a bacterial symbiont

Cells acclimate to fluctuating environments by utilizing sensory circuits. One common sensory pathway used by bacteria is two-component signaling (TCS), composed of an environmental sensor [the sensor kinase (SK)] and a cognate, intracellular effector [the response regulator (RR)]. The squid symbiont Vibrio fischeri uses an elaborate TCS phosphorelay containing a hybrid SK, RscS, and two RRs, SypE and SypG, to control biofilm formation and host colonization. Here, we found that another hybrid SK, SypF, was essential for biofilms by functioning downstream of RscS to directly control SypE and SypG. Surprisingly, although wild-type SypF functioned as an SK in vitro, this activity was dispensable for colonization. In fact, only a single non-enzymatic domain within SypF, the HPt domain, was critical in vivo. Remarkably, this domain within SypF interacted with RscS to permit a bypass of RscS's own HPt domain and SypF's enzymatic function. This represents the first in vivo example of a functional SK that exploits the enzymatic activity of another SK, an adaptation that demonstrates the elegant plasticity in the arrangement of TCS regulators.

Functional dyspepsia and brain-gut peptides

Functional dyspepsia (FD) is a frequently occurring gastrointestinal disorder, but its etiology and pathogenesis are still unclear because it is associated with multiple factors. As a typically physical and psychological disease, the role of psychological factors in the pathogenesis of FD involves the brain-gut axis, mainly abnormal stimulation processing by the central nervous system and abnormal levels of brain-gut peptides. Brain-gut peptides are the molecular basis of the action of the brain-gut axis, and the brain-gut axis affects the occurrence of FD by regulating the levels of brain-gut peptides. So far, 15 brain-gut peptides associated with FD have been found, which are predominantly expressed in the hypothalamus, medulla oblongata, spinal cord and gastrointestinal mucosa. The aim of this study is to clarify the relationship between brain-gut peptide levels and the occurrence of FD based on brain-gut peptide in terms of their secretion and mechanisms of action.

Unfavorable outcome of antiviral therapy in cytomegalovirus-positive ulcerative colitis may be due to inappropriate study inclusion in meta-analysis

Some previous articles reported that antiviral treatment was effective to reduce the colectomy rate in ulcerative colitis (UC) patients with cytomegalovirus (CMV) infection. Kopylov et al recently carried out a systematic review and meta-analysis to evaluate the impact of antiviral therapy on CMV-positive UC. The results showed that patients who received antiviral treatment had a higher risk of 30-d colectomy. We found that in this meta-analysis, some studies were inappropriately included, leading to an unfavorable outcome of anti-CMV therapy in UC patients.

Management of perianal fistulas in Crohn’s disease: An up-to-date review

Perianal disease is one of the most disabling manifestations of Crohn’s disease. A multidisciplinary approach of gastroenterologist, colorectal surgeon and radiologist is necessary for its management. A correct diagnosis, based on endoscopy, magnetic resonance imaging, endoanal ultrasound and examination under anesthesia, is crucial for perianal fistula treatment. Available medical and surgical therapies are discussed in this review, including new local treatment modalities that are under investigation.

Protective effect of Lai Fu Cheng Qi decoction on severe acute pancreatitis-induced myocardial injury in a rat model

The aim of the present study was to evaluate the effects of Lai Fu Cheng Qi decoction on myocardial injury in rats with severe acute pancreatitis (SAP). In total, 30 rats were randomly divided into sham, SAP and decoction treatment groups. SAP was induced by a retrograde pancreatic duct injection of 5% sodium taurocholate in the SAP and decoction treatment groups. Rats in decoction treatment group also received intragastric administration of Lai Fu Cheng Qi decoction. The serum levels of creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were detected using an automatic biochemical analyzer. In addition, myocardial Na⁺-K⁺-ATPase activity was analyzed using a spectrophotometric method and the mitochondrial membrane potential was measured by flow cytometry. Myocardial apoptosis was assessed using a TUNEL assay and pathological changes to the heart and pancreas were detected by hematoxylin and eosin staining. Compared with the rats in the sham group, rats in the SAP and decoction treatment groups exhibited significantly higher levels of serum CK-MB and LDH, apoptosis index and pathological scores, and had significantly lower levels of Na⁺-K⁺-ATPase activity and mitochondrial membrane potential. However, when compared with the SAP group, the serum levels of CK-MB and LDH, the pathological scores of the pancreas and heart, and the myocardial cell apoptosis index in the decoction treatment group were significantly lower. Furthermore, the Na⁺-K⁺-ATPase activity and mitochondrial membrane potential were significantly increased in the decoction treatment group when compared with the SAP group. Therefore, Lai Fu Cheng Qi decoction was shown to exert a protective effect on myocardial injury induced by SAP in rats.

Search for novel candidate mutations for metronidazole resistance in Helicobacter pylori using next-generation sequencing

Metronidazole resistance is a key factor associated with Helicobacter pylori treatment failure. Although this resistance is mainly associated with mutations in the rdxA and frxA genes, the question of whether metronidazole resistance is caused by the inactivation of frxA alone is still debated. Furthermore, it is unclear whether there are other mutations involved in addition to the two genes that are associated with resistance. A metronidazole-resistant strain was cultured from the metronidazole-susceptible H. pylori strain 26695-1 by exposure to low concentrations of metronidazole. The genome sequences of both susceptible and resistant H. pylori strains were determined by Illumina next-generation sequencing, from which putative candidate resistance mutations were identified. Natural transformation was used to introduce PCR products containing candidate mutations into the susceptible parent strain 26695-1, and the metronidazole MIC was determined for each strain. Mutations in frxA (hp0642), rdxA (hp0954), and rpsU (hp0562) were confirmed by the Sanger method. The mutated sequence in rdxA was successfully transformed into strain 26695-1, and the transformants showed resistance to metronidazole. The transformants containing a single mutation in rdxA showed a low MIC (16 mg/liter), while those containing mutations in both rdxA and frxA showed a higher MIC (48 mg/liter). No transformants containing a single mutation in frxA or rpsU were obtained. Next-generation sequencing was used to identify mutations related to drug resistance. We confirmed that the mutations in rdxA are mainly associated with metronidazole resistance, and mutations in frxA are able to enhance H. pylori resistance only in the presence of rdxA mutations. Moreover, mutations in rpsU may play a role in metronidazole resistance.

Notoginsenoside R1 attenuates experimental inflammatory bowel disease via pregnane X receptor activation

Notoginsenoside R1 (R1) is the main bioactive component in Panax notoginseng, an old herb medicine widely used in Asian countries in the treatment of microcirculatory diseases. However, little is known about the effect of R1 on inflammatory bowel disease (IBD). The present study demonstrated that R1 alleviated the severity of dextran sulfate sodium-induced colitis in mice by decreasing the activity of myeloperoxidase, the production of cytokines, the expression of proinflammatory genes, and the phosphorylation of IκB kinase, IκBα, and p65 in the colon. Further studies indicated that R1 dose-dependently activated human/mouse pregnane X receptor (PXR), a known target for decreasing inflammation in IBD, and upregulated the expression of genes involved in xenobiotic metabolism in colorectal cells and the colon. Ligand pocket-filling mutant (S247W/C284W or S247W/C284W/S208W) of the human PXR abrogated the effect of R1 on PXR activation. Time-resolved fluorescence resonance energy transfer PXR competitive binding assay confirmed R1 (ligand) binding affinity. In addition, PXR overexpression inhibited nuclear factor-κB (NF-κB)-luciferase activity, which was potentiated by R1 treatment. PXR knockdown by small interfering RNA demonstrated the necessity of PXR in R1-induced upregulation of the expression of xenobiotic-metabolizing enzymes and downregulation of NF-κB activity. Finally, the anti-inflammatory effect of R1 was confirmed in trinitrobenzene sulfonic acid-induced colitis in mice. These findings suggest that R1 attenuates experimental IBD possibly via the activation of intestinal PXR signaling.

Visceral abdominal obesity is associated with an increased risk of irritable bowel syndrome

OBJECTIVES

There are several studies considering obesity as the risk factor for various lower gastrointestinal symptoms. But the relationship between visceral abdominal obesity and the incidence of irritable bowel syndrome (IBS) is not studied yet. The aim of this study was to investigate the association between visceral adipose tissue (VAT) and the risk of IBS.

METHODS

This is a case-control study comparing the VAT area between subjects with IBS (IBS group) and controls without IBS (non IBS group), who underwent abdomen computerized tomography (CT) for routine health checkup from January 2012 to August 2013 in a health promotion center. A telephone survey was retrospectively conducted to diagnose IBS by Rome III criteria. The association between IBS and abdominal obesity was evaluated by measuring VAT, subcutaneous adipose tissue (SAT), VAT/SAT ratio, body mass index (BMI) and waist circumference (WC).

RESULTS

The prevalence of IBS was 19.9% (67/336) among all enrolled subjects. In the univariate analysis, VAT area, VAT/SAT ratio, waist circumference, the presence of reflux esophagitis and the ratio of females were significantly higher in the IBS group than in the non IBS group. However, a higher BMI or a higher SAT area is not associated with an increased risk of IBS. In the multivariate analysis, a higher VAT area (odds ratio (OR)=9.42, 95% confidence interval (CI): 2.90-30.64, highest tertile vs. lowest tertile, P=0.001), VAT/SAT ratio (OR=10.15, 95% CI: 3.05-33.58, highest tertile vs. lowest tertile, P=0.001) and waist circumference (OR=7.81, 95% CI: 2.13-28.66, highest tertile vs. lowest tertile, P=0.002) were independently associated with a risk of IBS. Only in the IBS-D group, not in the IBS-C, visceral adiposity was associated with an increased risk of IBS.

CONCLUSIONS

Visceral adiposity measured by VAT, VAT/SAT, and waist circumference is associated with an increased risk of IBS, especially of IBS-D. However, neither SAT nor BMI are associated with an increased risk of IBS.

The effectiveness of endoscopic submucosal dissection followed by chemoradiotherapy for superficial esophageal cancer

BACKGROUND

To evaluate the risks and benefits of endoscopic submucosal dissection (ESD) in addition to chemoradiotherapy (CRT) for the treatment of superficial esophageal squamous cell carcinoma (SESCC).

METHODS AND MATERIALS

We retrospectively reviewed the treatment outcomes of 47 patients with SESCC treated between October 2000 and December 2011. Sixteen patients with invasion into the submucosal layer (T1b) or the muscularis mucosa (m3) with positive vascular invasion were treated with CRT after ESD (ESD-CRT group). The lymph node area was irradiated to a total dose of 40-44 Gy and a boost radiation was administered if PET-positive lymph nodes or positive margins were observed. The remaining 31 patients received definitive CRT only (dCRT group).

RESULTS

The radiation field was significantly larger in the ESD-CRT group; the "long T" was used in 11 patients (35.4%) in the dCRT group and 15 (93.7%) in the ESD-CRT group (p = 0.0001). The total radiation dose was smaller in the ESD-CRT group; 40 Gy was used in 10 patients (62.5%) in the ESD-CRT group and all but one patient in the dCRT group received ≥60 Gy (p = 0.00001). The 3-year overall survival rates in the dCRT and ESD-CRT groups were 63.2% and 90.0% respectively (p = 0.118). Recurrence developed in nine patients (29.0%) in the dCRT group and one (6.3%) in the ESD-CRT group. Local recurrence was observed in six patients (19%) in the dCRT group and none in the ESD-CRT-group (p = 0.029). Pericardial effusion (≥Grade 3) occurred in three patients (9.7%) in the dCRT group and none in the ESD-CRT group.

CONCLUSIONS

ESD followed by CRT is an effective and safe approach for SESCC at m3 or T1b. This combination of ESD and CRT improves the local control rate, and it could decrease the number of cardiac toxicities due to a radiation-dose reduction relative to CRT alone.

LPS receptor subunits have antagonistic roles in epithelial apoptosis and colonic carcinogenesis

Colorectal carcinoma (CRC) is characterized by unlimited proliferation and suppression of apoptosis, selective advantages for tumor survival, and chemoresistance. Lipopolysaccharide (LPS) signaling is involved in both epithelial homeostasis and tumorigenesis, but the relative roles had by LPS receptor subunits CD14 and Toll-like receptor 4 (TLR4) are poorly understood. Our study showed that normal human colonocytes were CD14(+)TLR4(-), whereas cancerous tissues were CD14(+)TLR4(+), by immunofluorescent staining. Using a chemical-induced CRC model, increased epithelial apoptosis and decreased tumor multiplicity and sizes were observed in TLR4-mutant mice compared with wild-type (WT) mice with CD14(+)TLR4(+) colonocytes. WT mice intracolonically administered a TLR4 antagonist displayed tumor reduction associated with enhanced apoptosis in cancerous tissues. Mucosa-associated LPS content was elevated in response to CRC induction. Epithelial apoptosis induced by LPS hypersensitivity in TLR4-mutant mice was prevented by intracolonic administration of neutralizing anti-CD14. Moreover, LPS-induced apoptosis was observed in primary colonic organoid cultures derived from TLR4 mutant but not WT murine crypts. Gene silencing of TLR4 increased cell apoptosis in WT organoids, whereas knockdown of CD14 ablated cell death in TLR4-mutant organoids. In vitro studies showed that LPS challenge caused apoptosis in Caco-2 cells (CD14(+)TLR4(-)) in a CD14-, phosphatidylcholine-specific phospholipase C-, sphingomyelinase-, and protein kinase C-ζ-dependent manner. Conversely, expression of functional but not mutant TLR4 (Asp299Gly, Thr399Ile, and Pro714His) rescued cells from LPS/CD14-induced apoptosis. In summary, CD14-mediated lipid signaling induced epithelial apoptosis, whereas TLR4 antagonistically promoted cell survival and cancer development. Our findings indicate that dysfunction in the CD14/TLR4 antagonism may contribute to normal epithelial transition to carcinogenesis, and provide novel strategies for intervention against colorectal cancer.

Multidrug efflux pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus bacterial food pathogens

Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations.

Evaluation of Interleukin-10 Levels in Patients Diagnosed with Chronic Hepatitis

OBJECTIVE

One of the most important factors playing a role in chronic hepatitis B pathogenesis is cytokine release and one of the cytokines with anti-inflammatory characteristic is interleukin-10 (IL-10). The aim of the present study is to examine IL-10 levels in patients with chronic hepatitis B.

SUBJECTS AND METHODS

Sixty-three patients with chronic hepatitis B disease who had not received any antiviral treatment were included in the study. Serum IL-10 level was investigated by enzyme-linked immunosorbent assay (ELISA) method. In the control group, 25 healthy individuals with mean age similar to the patient population were included. Control and patient groups were compared and data were statistically analysed.

RESULTS

Interleukin-10 levels of 25 patients with hepatitis B virus (HBV) DNA levels between 2000 and 20 000 IU/mL were compared with those of 25 subjects in the control group, and the level in the chronic hepatitis B group was statistically significantly higher (p < 0.05). Interleukin-10 levels of 38 patients with HBV DNA > 20 000 IU/mL were statistically significantly higher than those in the control group. When chronic hepatitis B patients were compared among themselves, IL-10 levels increased as HBV DNA levels increased. Also, when IL-10 levels of hepatitis B 'e' antigen (HBeAg) positive patients were compared with those of HBeAg negative patients, the difference was not statistically significant.

CONCLUSION

It is believed that decreasing IL-10 levels by various methods would have significant contributions in disease progression and treatment. Moreover, IL-10 level may be an important marker in HBeAg seroconversion and evaluation of treatment response.

Five-aminosalicylic Acid: an update for the reappraisal of an old drug

Inflammatory bowel disease (IBD) comprises several conditions with chronic or recurring immune response and inflammation of the gastrointestinal apparatus, of which ulcerative colitis and Crohn's disease are the commonest forms. This disease has a significant prevalence and it is of an unknown aethiology. Five-aminosalicylic acid (5-ASA) and its derivatives are among the oldest drugs approved for the treatment of the IBD. In this review we reapprise aspects of 5-ASA mechanism of action, safety, and efficacy that in our opinion make it a valuable drug that can be fruitfully tailored in personalised treatments as a therapeutic option alongside other immune-modifying agents.

Interactions of Salmonella with animals and plants

Salmonella enterica species are Gram-negative bacteria, which are responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruits with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i) attachment to host surfaces; (ii) entry processes; (iii) multiplication; (iv) suppression of host defense mechanisms; and to point out similarities and differences between animal and plant infections.

Combined silencing of TGF-β2 and Snail genes inhibit epithelial-mesenchymal transition of retinal pigment epithelial cells under hypoxia

BACKGROUND

The formation of scar-like fibrous tissue in age-related macular degeneration (AMD) is associated with hypoxia. Under hypoxia, retinal pigment epithelial (RPE) cells can secret more transforming growth factor-β2 (TGF-β2), which is determined to induce epithelial-mesenchymal transition (EMT) at certain concentrations. Whether hypoxia can induce EMT by stimulating RPE cell line secrets TGF-β2 or not remains unknown. To gain a better understanding of the signaling mechanisms of fibrosis in AMD under hypoxic conditions, we investigated EMT in retinal pigment epithelial (RPE) cells and the effect of TGF-β2 and Snail in this process.

METHODS

Human RPE cell line (ARPE-19) was incubated with 5 % O2 for different periods of time. The expression of N-cadherin, α-smooth muscle actin (α-SMA), TGF-β2 , and Snail were determined by Western blot and real-time PCR. Cell proliferation was assessed by CCK8 kit. RNA interference was used for multi-gene silencing of TGF-β2 and Snail genes.

RESULTS

N-cadherin was decreased and mesenchymal cell marker α-SMA was increased after the ARPE-19 cell line was incubated with 5 % O2. Meanwhile, the proliferation capability of the cell line was increased. TGF-β2 and Snail expression were increased in a time-dependent manner under hypoxia. After multi-silencing TGF-β2 and Snail genes, N-cadherin was increased and α-SMA was reduced. Meanwhile, the proliferation of the cell line was suppressed.

CONCLUSIONS

Under hypoxic conditions, RPE cells undergo EMT. Endogenic TGF-β2 and Snail are involved in this process. Furthermore, knockdown of both TGF-β2 and Snail inhibited EMT to a greater extent than knockdown of either gene individually.

Codelivery of DNA and siRNA via arginine-rich PEI-based polyplexes

In this study, we formulated polyplexes with different compositions for codelivery of DNA and small-interfering RNA (siRNA). Since DNA and siRNA have distinctive and complementary morphological characteristics (DNA is long and winding and siRNA is short and rigid), we hypothesized that their codelivery using polyplex would enhance each other's transfection. To test this hypothesis, cationic polymer branched polyethylenimine (bPEI) as a standard transfecting agent and its derivative arginine-rich oligopeptide-grafted bPEI modified with polyethylene glycol (P(SiDAAr)5P3), synthesized in our laboratory, were used as carriers for transfection. Polyplexes at different nucleic acid to polymer weight ratios were characterized for transfection in breast cancer sensitive (MCF-7) and resistant (MCF-7/Adr) cell lines. Gene silencing effect of polyplexes was determined in MDA-MB-231-luc-D3H2LN cell line. The results demonstrated that the polyplexes formed with derivative P(SiDAAr)5P3 show significantly lower toxicity compared to polyplexes formed using bPEI. Further, codelivery resulted in 20-fold higher DNA transfection and 2-fold higher siRNA transfection as compared to the respective single nucleotide delivery. DNA transfection was ∼100-fold lower in resistant MCF-7/Adr cells than in sensitive MCF-7 cells. Confocal imaging and flow cytometry data demonstrated that enhanced transfection does not solely depend on DNA's cellular uptake, suggesting that other mechanisms contribute to increased transfection. DNA-co-siRNA delivery could be a promising therapeutic approach to achieve synergistic effects because it can simultaneously target and interfere with multiple regulatory levels in a cell to halt and reverse disease progression.

Expression and function of connexin 43 in human gingival wound healing and fibroblasts

Connexins (C×s) are a family of transmembrane proteins that form hemichannels and gap junctions (GJs) on the cell membranes, and transfer small signaling molecules between the cytoplasm and extracellular space and between connecting cells, respectively. Among C×s, suppressing C×43 expression or function promotes skin wound closure and granulation tissue formation, and may alleviate scarring, but the mechanisms are not well understood. Oral mucosal gingiva is characterized by faster wound closure and scarless wound healing outcome as compared to skin wounds. Therefore, we hypothesized that C×43 function is down regulated during human gingival wound healing, which in fibroblasts promotes expression of genes conducive for fast and scarless wound healing. Cultured gingival fibroblasts expressed C×43 as their major connexin. Immunostaining of unwounded human gingiva showed that C×43 was abundantly present in the epithelium, and in connective tissue formed large C×43 plaques in fibroblasts. At the early stages of wound healing, C×43 was strongly down regulated in wound epithelial cells and fibroblasts, returning to the level of normal tissue by day 60 post-wounding. Blocking of C×43 function by C×43 mimetic peptide Gap27 suppressed GJ-mediated dye transfer, promoted migration, and caused significant changes in the expression of wound healing-associated genes in gingival fibroblasts. In particular, out of 54 genes analyzed, several MMPs and TGF-β1, involved in regulation of inflammation and extracellular matrix (ECM) turnover, and VEGF-A, involved in angiogenesis, were significantly upregulated while pro-fibrotic ECM molecules, including Collagen type I, and cell contractility-related molecules were significantly down regulated. These responses involved MAPK, GSK3α/β and TGF-β signaling pathways, and AP1 and SP1 transcription factors. Thus, suppressed function of C×43 in fibroblasts promotes their migration, and regulates expression of wound healing-associated genes via AP1, SP1, MAPK, GSK3α/β and TGF-β signaling pathways, and may promote fast and scarless wound healing in human gingiva.

Traditional Chinese medicine formulas for irritable bowel syndrome: from ancient wisdoms to scientific understandings

Traditional Chinese Medicine (TCM) serves as the most common alternative therapeutic approach for Western medicine and benefits IBS patients globally. Due to the lack of scientific evidence in the past, TCM formulas were not internationally well recognized as promising IBS remedies. In this review, firstly, we present the etiology and therapy of IBS in terms of traditional Chinese medical theory. Secondly, we summarize the clinical randomized controlled trials (RCTs) of TCM formulas for IBS patients that are available in the literature (from 1998 to September 2013), in which 14 RCTs conducted of high quality were discussed in detail. Of the 14 selected trials, 12 of those concluded that TCM formulas provided superior improvement in the global symptoms of IBS patients over the placebo or conventional medicines. As well, all 14 RCTs suggested that TCM formulas have good safety and tolerability. Last but not least, we explore the pharmacological mechanisms of the anti-IBS TCM formulas available in the literature (from 1994 to September, 2013). Collectively, in combating IBS symptoms, most TCM formulas exert multi-targeting actions including the regulation of neurotransmitters and hormones in the enteric nervous system (ENS), modulation of smooth muscle motility in the gastrointestinal (GI) tract, modulation of the hypothalamic-pituitary-adrenal (HPA) axis, attenuation of intestinal inflammation and restoration of intestinal flora, etc. In conclusion, TCM formulas appear to be promising for IBS treatment. This review provides a useful reference for the public in furthering a better understanding and acceptance of TCM formulas as IBS remedies.

Immune mechanisms in acetaminophen-induced acute liver failure

An overdose of acetaminophen (N-acetyl-p-aminophenol, APAP), also termed paracetamol, can cause severe liver damage, ultimately leading to acute liver failure (ALF) with the need of liver transplantation. APAP is rapidly taken up from the intestine and metabolized in hepatocytes. A small fraction of the metabolized APAP forms cytotoxic mitochondrial protein adducts, leading to hepatocyte necrosis. The course of disease is not only critically influenced by dose of APAP and the initial hepatocyte damage, but also by the inflammatory response following acetaminophen-induced liver injury (AILI). As revealed by mouse models of AILI and corresponding translational studies in ALF patients, necrotic hepatocytes release danger-associated-molecular patterns (DAMPs), which are recognized by resident hepatic macrophages, Kupffer cell (KC), and neutrophils, leading to the activation of these cells. Activated hepatic macrophages release various proinflammatory cytokines, such as TNF-α or IL-1β, as well as chemokines (e.g., CCL2) thereby further enhancing inflammation and increasing the influx of immune cells, like bone-marrow derived monocytes and neutrophils. Monocytes are mainly recruited via their receptor CCR2 and aggravate inflammation. Infiltrating monocytes, however, can mature into monocyte-derived macrophages (MoMF), which are, in cooperation with neutrophils, also involved in the resolution of inflammation. Besides macrophages and neutrophils, distinct lymphocyte populations, especially γδ T cells, are also linked to the inflammatory response following an APAP overdose. Natural killer (NK), natural killer T (NKT) and T cells possibly further perpetuate inflammation in AILI. Understanding the complex interplay of immune cell subsets in experimental models and defining their functional involvement in disease progression is essential to identify novel therapeutic targets for human disease.

Lower esophageal microbiota species are affected by the eradication of Helicobacter pylori infection using antibiotics

The aim of this study was to investigate the effect of Helicobacter pylori (H. pylori) infection on the lower esophageal microbiota and the eradication of H. pylori through the use of antibiotics. Forty-five BALB/C mice were randomly divided into negative control, infection and treatment groups. The mice were sacrificed and DNA was extracted from the lower esophageal microbiota. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was performed to determine the composition of the microbiota. Quantity One^® 1-D Analysis Software was used for the analysis of the DGGE profiles. The different bands from the groups were amplified with 16S rDNA V6 region primers. DNA sequencing and Basic Local Alignment Search Tool analysis were performed for the identification of the bands. H. pylori colonization led to severe ulcers in the stomachs of the mice, and these ulcers were alleviated by antibiotic treatment. The infection group had an increased number of bacterial species in the stomach compared with the control and treatment groups. DGGE fingerprinting of the lower esophagus showed that there were significant differences in the number of bands (P<0.05), diversity index and abundance among the groups (P<0.05); however, no significant differences in homogeneity were observed (P>0.05). Although the composition of flora species in the lower espohagus varied, the dominant species, and their relative contents, were similar in the control, infection and treatment groups. The present study provided a microecological basis for the understanding of the pathogenesis of lower esophageal diseases, following the eradication of H. pylori infection with antibiotics.

Role of Corticotropin-releasing Factor in Gastrointestinal Permeability

The interface between the intestinal lumen and the mucosa is the location where the majority of ingested immunogenic particles face the scrutiny of the vast gastrointestinal immune system. Upon regular physiological conditions, the intestinal micro-flora and the epithelial barrier are well prepared to process daily a huge amount of food-derived antigens and non-immunogenic particles. Similarly, they are ready to prevent environmental toxins and microbial antigens to penetrate further and interact with the mucosal-associated immune system. These functions promote the development of proper immune responses and oral tolerance and prevent disease and inflammation. Brain-gut axis structures participate in the processing and execution of response signals to external and internal stimuli. The brain-gut axis integrates local and distant regulatory networks and super-systems that serve key housekeeping physiological functions including the balanced functioning of the intestinal barrier. Disturbance of the brain-gut axis may induce intestinal barrier dysfunction, increasing the risk of uncontrolled immunological reactions, which may indeed trigger transient mucosal inflammation and gut disease. There is a large body of evidence indicating that stress, through the brain-gut axis, may cause intestinal barrier dysfunction, mainly via the systemic and peripheral release of corticotropin-releasing factor. In this review, we describe the role of stress and corticotropin-releasing factor in the regulation of gastrointestinal permeability, and discuss the link to both health and pathological conditions.

Recombinant interleukin-1 receptor antagonist attenuates the severity of chronic pancreatitis induced by TNBS in rats

Chronic pancreatitis (CP) is a common disease in the department of gastroenterology, with the main symptoms of exocrine and/or endocrine insufficiency and abdominal pain. The pathogenic mechanism of CP is still not fully clarified and the aims of treatment now are to relieve symptoms. In this study, we attempted to find a connection between interleukin-1β (IL-1β) and interleukin-1 receptor antagonist (IL-1Ra) in trinitrobenzene sulfonic acid (TNBS)-induced chronic pancreatitis, and then the therapeutic effect of recombinant IL-1Ra was also detected in the CP model. Chronic pancreatitis was induced by intraductal infusion of TNBS in SD rats followed by a consecutive administration of rIL-1Ra, and the histological changes and collagen content in the pancreas were measured, as well as the abdominal hypersensitivity. We found that rhIL-1Ra could attenuate the severity of chronic pancreatic injury, modulate the extracellular matrix secretion, focal proliferation and apoptosis, and cellular immunity in TNBS-induced CP. Interestingly, rIL-1Ra could also block the pancreatitis-induced referred abdominal hypersensitivity. In conclusion, IL-1Ra may play a protective role in CP and rIL-1Ra would be a potential therapeutic target for the treatment of CP, while its possible mechanisms and clinical usage still need further investigation.

[Evolution of ideas on microscopic colitis]

The literature review gives the present-day views of the definition, etiology, pathogenesis, diagnosis, and treatment of microscopic colitis (MC). In the present view, MC is an inflammatory bowel disease of unknown etiology, which is characterized by chronic watery diarrhea, no macroscopic signs of large bowel involvement in the presence of specific pathomorphological changes. There are two major forms of MC, which are similar in its clinical picture, yet, heterogeneous in histological criteria: collagenous colitis (CC) and lymphocytic colitis (LC). As of now, the prevalence of MC is about 100 cases per 100,000 population, which is similar with that in other inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease. MC generally prevails in women aged over 50 years. The etiology and pathogenesis of MC have not fully investigated. Watery diarrhea is as a predominant pathognomonic symptom in all the patients with MC. The major histological criterion for the diagnosis of CC is subepithelial collagen lining thickening (more than 10 pm) and that for LC is higher intraepithelial lymphocyte counts (more than 20 intraepithelial lymphocytes/100 epitheliocytes). The topical glucocorticosteroid budesonide is currently the only agent, the efficacy of which has been proven in both inducing and maintaining remission in patients with MC in many clinical trials.