From Inflammation to Oncogenesis: Tracing Serum DCLK1 and miRNA Signatures in Chronic Liver Diseases.

Chronic liver diseases, fibrosis, cirrhosis, and HCC are often a consequence of persistent inflammation. However, the transition mechanisms from a normal liver to fibrosis, then cirrhosis, and further to HCC are not well understood. This study focused on the role of the tumor stem cell protein doublecortin-like kinase 1 (DCLK1) in the modulation of molecular factors in fibrosis, cirrhosis, or HCC. Serum samples from patients with hepatic fibrosis, cirrhosis, and HCC were analyzed via ELISA or NextGen sequencing and were compared with control samples. Differentially expressed (DE) microRNAs (miRNA) identified from these patient sera were correlated with DCLK1 expression. We observed elevated serum DCLK1 levels in fibrosis, cirrhosis, and HCC patients; however, TGF-ß levels were only elevated in fibrosis and cirrhosis. While DE miRNAs were identified for all three disease states, miR-12136 was elevated in fibrosis but was significantly increased further in cirrhosis. Additionally, miR-1246 and miR-184 were upregulated when DCLK1 was high, while miR-206 was downregulated. This work distinguishes DCLK1 and miRNAs' potential role in different axes promoting inflammation to tumor progression and may serve to identify biomarkers for tracking the progression from pre-neoplastic states to HCC in chronic liver disease patients as well as provide targets for treatment.

Factors Associated with Difficulty Maintaining Insufflation of the Colon During Endoscopy.

BACKGROUND: Insufflation of the colon allows for adequate visualization of the mucosal tissue and advancement of the endoscope during colonoscopy. Most colonoscopies are performed with sedation to mitigate discomfort and enhance the colonoscopy experience for both the patient and the endoscopist. AIM: We aimed to evaluate factors associated with difficulty maintaining insufflation. METHODS: A cross-sectional study of individuals undergoing colonoscopy at the Oklahoma City Veterans Affairs Medical Center was performed. Experiencing difficulty maintaining air insufflation during colonoscopy was assessed with a questionnaire completed by the performing endoscopist at the end of procedure. Information regarding procedure times, sedation used, demographics, comorbidities, surgical history, and medications used was extracted from the medical record. A multivariate regression analysis was performed to identify factors associated with difficulty maintaining air insufflation. A P value < 0.05 was considered significant. RESULTS: 996 Patients were included for the analysis. Difficulty with insufflation was reported in 240 (24%) colonoscopies; mean age of 63.8 ± 10.4 years old and 13% were female. Fellow trainees were involved in 669 (67%) colonoscopies. Older age (OR 1.02, P 0.03, CI [1.00-1.04]), diabetes (OR 1.5, 95% CI [1.03, 2.05]), fellow's involvement (OR 2.6. (95% CI [1.68, 4.09]), total procedure time (OR 1.02, 95% CI [1.00, 1.03]), mean number of adenomas (OR 1.05, 95% CI [1.00, 1.09]), and MAC use (OR 2.6, 95% CI [1.80, 3.85]) were independent predictors for difficulty in maintaining air insufflation. CONCLUSION: Our findings suggest that endoscopists should be cognizant of colon insufflation issues in older, diabetic patients undergoing colonoscopies under deep sedation, particularly if prolonged procedure is anticipated or encountered.

Stress-induced ulcer bleeding in critically ill patients.

Increased knowledge of risk factors and improved ICU care has decreased the incidence of stress-related bleeding. Not all critically ill patients need prophylaxis for SRMD and withholding such prophylaxis in suitable low-risk candidates is a reasonable and cost-effective approach. Mechanical ventilation for more than 48 hours and coagulopathy are the main risk factors for stress-induced upper GI bleeding. Although intravenous H2RAs can prevent clinically important bleeding, their benefits seem to be limited by the rapid development of tolerance. The availability of intravenous formulations of PPIs makes it possible to critically compare their prophylactic efficacy and safety to different classes of acid-suppressive agents, such as H2RAs, in critically ill patients. The appropriate dose of PPI and the role of newer PPI formulations need to be further defined along with proposed guidelines for the use of intravenous and oral/enteral formulations of PPIs in patients at risk for stress-related mucosal damage.

Effects of N-acetylcysteine plus mesalamine on prostaglandin synthesis and nitric oxide generation in TNBS-induced colitis in rats.

The aim of the present studies was to examine mechanisms by which the rectally administered combination of N-acetylcysteine (NAC) plus mesalamine (5-ASA) affects inducers of inflammation to promote mucosal healing and reduce tissue inflammation in chemically (trinitrobenzene sulfonic acid, TNBS) induced colitis in rats. Experimental findings demonstrate that dual therapy with NAC plus 5-ASA was superior to individual agents in reducing histological measures of colitis. NAC alone and in combination with 5-ASA suppressed COX2 gene expression and prostaglandin E(2) (PGE(2)) levels to control values. Furthermore, NAC plus 5-ASA reduced nitrate generation, an expression of inducible nitric oxide synthase (iNOS) activity, to basal levels and these results were significantly lower than those observed with either NAC or 5-ASA alone. In conclusion, these results indicate that NAC plus 5-ASA exerts therapeutic benefit, in part by countering the actions of PGE(2) and the deleterious effects of oxidative and nitrosative stress induced by TNBS colitis.

Metastatic prostatic carcinoma presenting as fulminant hepatic failure.

A 68-year-old male presented with progressive abdominal pain, dyspnea, weight loss, and dysuria. Lab work revealed elevated creatine phosphokinase levels, prostate-specific antigen level (approximately 60 ng/mL), and elevated liver enzymes. He was admitted to the intensive care unit for worsening respiratory distress and confusion. He continued to deteriorate, and his bilirubin peaked at 8.5 mg/dL. The patient subsequently died, and an autopsy revealed extensive hepatic necrosis with diffuse intravascular and intraparenchymal permeation of metastatic prostatic carcinoma. Fulminant hepatic failure remains a rare presentation of metastatic prostatic carcinoma, with a rapidly progressive course toward hepatic coma and death. A high index of suspicion is needed to investigate the possibility of palliative chemotherapy.

Luminal antioxidants enhance the effects of mesalamine in the treatment of chemically induced colitis in rats.

UNLABELLED: Previous experiments in rats with chemically induced colitis have shown that the antioxidant N-acetylcysteine plus mesalamine (5-ASA) exerted a significantly greater therapeutic effect in promoting mucosal healing when compared to either agent alone. The aims of the present study were to compare the effects of three antioxidants plus mesalamine vs. 5-ASA alone in treatment of colitis induced by trinitrobenzene sulfonic acid (TNBS) in rats. METHODS: Three days following induction of TNBS colitis, rats received 8 days of rectal therapy with 5-ASA, or 5-ASA plus vitamin C (ascorbic acid), 5-ASA plus phenyl butylnitrone (PBN) and 5-ASA plus vitamin E (alpha-tocopherol). Distal colonic tissues were examined for microscopic colitis and myeloperoxidase (MPO) activity. RESULTS: Global assessments of microscopic colitis induced by TNBS indicated that 5-ASA alone significantly changed colonic injury by -31%. Combination therapy with ascorbic acid plus 5-ASA or alpha-tocopherol plus 5-ASA caused further significant change in TNBS colitis by -65 and -82%, respectively. Each of these values was significantly below scores observed with 5-ASA as monotherapy. Reduction in colitis with PBN plus 5-ASA was not different from 5-ASA alone. MPO activity was decreased significantly in response to monotherapy with 5-ASA and each of the antioxidants plus 5-ASA when compared to TNBS. alpha-Tocopherol plus 5-ASA, however, was the only treatment strategy that reduced significantly MPO activity below that recorded for 5-ASA alone. In conclusion, our results indicate that antioxidants other than N-acetylcysteine significantly enhance the therapeutic effectiveness of 5-ASA in the treatment of TNBS colitis. alpha-Tocopherol plus 5-ASA exerted profound anti-inflammatory and reparative effects upon colitis induced by TNBS.

Evolution of Brunner gland hamartoma associated with Helicobacter pylori infection.

The pathogenesis of Brunner gland hamartoma of the duodenum is unknown. This case report describes the chronology of the development of Brunner gland hamartoma from Brunner gland hyperplasia over a 12-year interval. The study subject, a 64-year-old man with chronic iron deficiency anemia, underwent serial upper endoscopies during this period. Repeated endoscopies demonstrated the evolution of Brunner gland hyperplasia, as manifest endoscopically by a submucosal mass, to a pedunculated polyp with histologic features of Brunner gland hamartoma. The duodenal polypoid mass was removed by snare polypectomy. The patient also had a chronic Helicobacter pylori infection of the stomach. This report details the time-dependent evolution of Brunner gland hyperplasia to hamartoma in association with chronic gastric H. pylori infection.

Obscure GI bleeding due to gastrointestinal stromal tumor (GIST) diagnosed by capsule endoscopy.

Gastrointestinal stromal tumor (GIST) is a submucosal tumor which is most commonly found in the stomach and less commonly in small bowel. Small bowel GIST can be difficult to diagnose by conventional imaging and endoscopy techniques. We report a case of obscure GI bleeding due to a stromal tumor (GIST) of the jejunum diagnosed by video capsule endoscopy.

Histamine stimulation of MMP-1(collagenase-1) secretion and gene expression in gastric epithelial cells: role of EGFR transactivation and the MAP kinase pathway.

BACKGROUND AND AIMS: GPCR stimulation by various ligands including histamine has been shown to transactivate the epidermal growth factor receptor (EGFR). This study examines the functional interactions between the H2 receptor and the EGFR in the regulation of matrix metalloproteinase-1 (MMP-1) secretion and gene expressions in cultured gastric epithelial cells. METHODS: AGS cells were incubated for up to 24 h with either histamine or heparin binding-epidermal growth factor (HB-EGF) and MMP-1 release was determined by immunoassay. MMP-1 responses to histamine and HB-EGF were further tested by the use of H2 receptor antagonist, EGFR inhibitor and mitogen activator protein kinase (MAPK) inhibitor. The role of EGFR in MMP-1 release was further tested in cells transfected with specific EGFR siRNA. EGFR and ERK1/2 phosphorylation was determined by Western blot analysis. MMP-1 gene expression was determined by RNase protection assay (RPA). RESULTS: Histamine and HB-EGF caused a dose-dependent release of MMP-1 with maximal responses that were 2.7- and 4.5-fold greater, respectively, than control, P<0.001. Famotidine prevented histamine-mediated MMP-1 release and AG1478 and EGFR siRNA completely inhibited MMP-1 secretion stimulated by both histamine and HB-EGF. Both histamine and HB-EGF stimulation of MMP-1 release was associated with activation of ERK1/2. MAPK inhibition also prevented histamine-and HB-EGF-induced MMP-1 secretion. Results of MMP-1 gene expression, either stimulatory or inhibitory, paralleled responses to MMP-1 secretion. CONCLUSION: Histamine stimulation of the H2 receptor on AGS cells evoked MMP-1 secretion and gene up regulation that was dependent on transactivation of the EGFR and downstream activation of MAPK.

Gastroparesis.

Gastroparesis is a symptomatic disorder of the stomach characterized by slow or delayed gastric emptying. Diabetes and idiopathic factors account for over 60% of gastroparesis cases. Symptoms associated with delayed gastric emptying include nausea, vomiting, abdominal bloating and early satiety. Delayed gastric emptying due to gastroparesis is managed by dietary adjustments, prokinetic medications, avoidance of medications that retard gastric motor activity and optimizing glycemic control in diabetic patients. Electrical stimulation and gastric pacing are an evolving treatment option for patients who do not respond to standard medical therapy. This article provides a review of gastric motility, the etiologies of gastroparesis and therapeutic approaches to this disorder.

Antioxidant therapy with N-acetylcysteine plus mesalamine accelerates mucosal healing in a rodent model of colitis.

The aims of this study were to examine the ability of the antioxidant N-acetylcysteine (NAC) and mesalamine (5-ASA) alone and in combination to affect TNBS-induced colitis in rat. Three days following induction of TNBS colitis rats were randomized to receive daily intracolonic treatment with NAC, 5-ASA, and NAC plus 5-ASA for 5 or 8 days. At the end of the treatment period macroscopic and microscopic colonic injuries were scored. Myeloperoxidase (MPO) activity and cytokine gene expression were measured in colonic tissues. Results indicated that treatment with NAC plus 5-ASA caused a significantly greater reduction in colonic injury than either agent alone. Furthermore, combination therapy inhibited significantly MPO activity and inflammatory cytokine gene expression in the distal colon of TNBS-treated animals. The beneficial effects of NAC plus 5-ASA on reduction of colonic injury and promotion of healing were most evident after 8 days of treatment.

Stress ulcer bleeding.

Although upper gastrointestinal (GI) bleeding from stress-related mucosal disease (SRMD) in critically ill patients is common, significant bleeding with hemodynamic instability is not. Risk factor assessment can assist in identifying patients with a greater likelihood of developing significant SRMD. Prophylaxis against stress ulcer bleeding with luminal agents (eg, antacids and sucralfate) or drugs that inhibit acid secretion (eg, histamine 2-receptor antagonists and proton-pump inhibitors) can reduce major bleeding but has little or no effect on mortality. Currently, the mainstays of prophylactic therapy for SRMD are intravenously administered H2RAs and PPIs. Wider usage of PPIs reflects their enhanced efficacy in suppressing acid secretion as well as lack of tolerance for H2RAs. Guidelines for the prophylactic use of H2RAs or PPIs in treatment of SRMD will require large, randomized studies that also examine cost effectiveness of individual strategies.

Inhibition of epidermal growth factor receptor activation enhances in vivo histamine-stimulated gastric acid secretion in the rat.

Epidermal growth factor (EGF) and transforming growth factor alpha (TGFalpha) have been shown to inhibit gastric acid secretion through stimulation of the EGF receptor (EGFR). In this study we examined in vivo the effects of inhibition of the EGFR on histamine-stimulated acid secretion in the rat. Submaximal (1.5 mg/kg/hr) histamine-stimulated acid secretion was measured (microEq H(+)/2 hr) during infusion of EGFRtk inhibitors and ranitidine in anesthetized rats. EGFR phosphorylation in gastric mucosal tissue lysates was measured by Western blot analysis. Submaximal histamine-stimulated acid secretion was increased significantly by the EGFR inhibitors tyrphostin (Tyr) A46 and Tyr AG1478. Tyr A46 prevented TGFalpha (10 microg/kg/hr)-mediated inhibition of maximal (5.0 microg/kg/hr) histamine-stimulated acid output. Histamine caused a fourfold increase in EGFR phosphorylation which was inhibited by both Tyr and ranitidine. We conclude that the EGFRtk inhibitors, Tyr A46 and Tyr AG1478, significantly increased submaximal histamine-stimulated acid output and Tyr A46 prevented TGFalpha inhibition of histamine-stimulated acid secretion. These observations suggest that the EGFR is involved, in vivo, in the regulation of gastric acid secretion.

Sporadic colonic hamartomas in adults: a retrospective study.

BACKGROUND: Colonic hamartomas are uncommon in adults. The aims of this study were to determine (1) the prevalence of colonic hamartomas in an adult population undergoing colonoscopy and (2) the clinical, endoscopic, and histologic features of colonic hamartomas in adult patients. METHODS: A pathology database identified 19 adult patients of 12,707 patients with colonic hamartomas in the 11-year study period from January 1992 to October 2002. An endoscopic computer database provided information about the number of colonoscopies performed and the presence or the absence of colonic polyp(s) in study patients. Charts of patients with colonic hamartomas were reviewed, and clinical and demographic data were collated. RESULTS: Nineteen patients were found to have colonic hamartomas. The mean age of these patients was 55 years, with an age distribution ranging from 25 to 81 years. The prevalence of colonic hamartomas in this study population was 0.15%. The prevalence of hamartomas in patients with colon polyps at index colonoscopy was 0.073%. Colonic hamartomas were more common in men than in women. The indication for colonoscopy for the majority (68%) of patients was hematochezia or the presence of occult blood in the stool. Three fourths of the polyps were greater than 1 cm in diameter, and 89% were pedunculated. Two thirds of the hamartomatous polyps were localized to the rectosigmoid region. Endoscopic characteristics of hamartomas were indistinguishable from adenomas. CONCLUSIONS: Colonic hamartomas in adults are rare. They tend to be single, pedunculated, and localized predominantly in the rectosigmoid region. Endoscopic resection of colonic hamartomas was successful in all patients.

Functional interaction between transforming growth factor alpha and capsaicin-sensitive sensory neurons in the rat stomach.

BACKGROUND AND AIMS: Transforming growth alpha (TGFalpha) and sensory neurons have been shown to promote gastric mucosal protection and healing. Aims were to examine in vitro interactions between gastric sensory neurons, the sensory neuropeptide calcitonin gene-related peptide (CGRP), and TGFalpha. METHODS: Gastric mucosal/submucosal tissue fragments from Sprague-Dawley (SD) rats were incubated in short-term (30 min) culture. Peptide release into media and TGFalpha tissue content were measured by radioimmunoassay. RESULTS: TGFalpha (1 x 10(-8) to 1 x 10(-6) M) caused dose-dependent stimulation of CGRP release. Maximal CGRP release (+87%) was observed with 1 x 10(-6) M TGFalpha: 28.6+/-3.8 vs. control of 15.5+/-2.7 pg/g tissue; P<0.05. Both CGRP (1 x 10(-7) to 1 x 10(-5) M) and capsaicin (1 x 10-(8) to 1 x 10(-6)M) significantly inhibited basal TGFalpha release in a dose-dependent fashion that ranged from -20% to -39%. In contrast, capsaicin-induced sensory denervation caused significant increases in both basal TGFalpha release and TGFalpha tissue content. CONCLUSION: Function interactions between TGFalpha and gastric sensory neurons are suggested by the observations that (1) TGFalpha stimulated CGRP release from gastric sensory neurons; (2) CGRP and acute capsaicin treatment inhibited TGFalpha release and; (3) capsaicin-induced sensory denervation caused significant increases in both gastric TGFalpha basal release and tissue content.

GABAergic mechanisms of gastroprotection in the rat: role of sensory neurons, prostaglandins, and nitric oxide.

gamma-Aminobutyric acid (GABA) is a neurotransmitter found in both the central and the peripheral nervous systems including the gastrointestinal tract. The aims of the present studies were to examine mechanisms by which GABA exerts gastroprotective effects against ethanol- and water-restraint stress (WRS)-induced gastric mucosal injury in the rat. GABA, administered intragastrically (400 mg/kg), induced gastroprotection against ethanol and WRS by activating gastric sensory neurons to release calcitonin gene-related peptide (CGRP) and promote nitric oxide (NO) synthesis and release. Furthermore, these protective effects of GABA were associated with an increase in gastric mucosal blood flow (GMBF) that was dependent on sensory neuron and NO systems. GABA-mediated protection involved GABAA receptor activation and prostaglandin generation. In conclusion, intraluminal GABA protects the stomach against ethanol- and WRS-induced injury by mechanisms which involve sensory neuron/CGRP/NO pathways and increases in GMBF and prostaglandin generation.

Mechanisms of transforming growth factor-alpha (TGF-alpha) induced gastroprotection against ethanol in the rat: roles of sensory neurons, sensory neuropeptides, and prostaglandins.

The mechanisms by which transforming growth factor-a (TGP-alpha) protects the stomach against mucosal injury are incompletely understood. The aim of this study was to examine the roles of sensory neurons, sensory neuropeptides and prostaglandins in TGFalpha gastroprotection against ethanol. Fasted rats received TGF-alpha (50 microg/kg, intraperitoneally) prior to orogastric ethanol (75% v/v, 1 ml). Gastric injury was quantitated 30 min after ethanol. Involvement of sensory neurons and the sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), were examined by capsaicin deafferentation and specific receptor antagonist infusion, respectively. Indomethacin (10 mg, intragastrically) was used to determine the role of prostaglandins in TGF-alpha-mediated gastroprotection. TGF-alpha significantly diminished ethanol-induced gastric lesion area to 5.7 +/- 0.8 mm2 vs 41.1 +/- 5.2 mm2 (p < 0.001). Sensory denervation and CGRP-receptor blockade abolished the TGF-alpha protective effect. In contrast, SP antagonist and indomethacin did not alter TGF-alpha gastroprotection. In conclusion, TGF-alpha-mediated gastroprotection involves sensory neuron activation and CGRP release and this protective effect did not involve substance P or prostaglandin generation.