Helicobacter pylori, NSAIDs and gastrointestinal haemorrhage

Silver nanoparticles synthesized from Quercus brantii ameliorated ethanol-induced gastric ulcers in rats by decreasing oxidative stress and improving antioxidant systems

Gastric ulcers are caused by an imbalance between aggressive and defensive factors. The green synthesis of silver nanoparticles is becoming a new and promising method in the treatment of gastrointestinal ulcers. This study was conducted to investigate the protective and antioxidant effects of silver nanoparticles synthesized from Quercus brantii extract (NSQBE) on gastric damage induced by alcohol in rats. In this study, silver nanoparticles were produced by the green synthesis method using oak extract. The structure and morphology of nanoparticles were confirmed by various techniques such as UV-Vis spectroscopy, fourier transforms infrared spectrometer (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), and dynamic light scattering )DLS(. For the animal studies, 30 male Wistar rats weighing 200 ± 20 g were randomly selected and divided into five groups (the normal, ethanolic, NSQBE treatment (received doses of 20 and 5 mg/kg), and standard (received a dose of 50 mg/kg of ranitidine) groups. After the rats were euthanized, their stomach was removed. A part of the stomach tissue of rats was used for histopathological studies, and the other part was used to study biochemical parameters such as the level of reactive oxygen species (ROS), protein carbonyl oxidation (PCO), malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) and reduced glutathione (GSH) as well as nitric oxide (NO). Our results showed that in the ethanol group, the levels of ROS, MDA, PCO, and serum NO were higher than in the normal group. In addition, reduced GSH, CAT, SOD, tissue NO, gastric mucus, and antioxidant potential were decreased. In rats pretreated with NSQBE and ranitidine, the levels of ROS, MDA, PCO, and serum NO decreased, and the levels of GSH, CAT, SOD, tissue NO, gastric mucus, and antioxidant potential were increased in comparison to the ethanol group. The results of this study showed that silver nanoparticles synthesized using Quercus brantii are a promising approach for the treatment of gastric ulcers.

[Endoscopic therapy of esophageal diseases]

The esophagus is one of the areas of the gastrointestinal tract, for which therapeutic concepts have changed the most over the last two decades. The most decisive advance is the development of endoscopic resection techniques for early esophageal carcinomas. These methods provide excellent short- and long-term results combined with very low morbidity and negligible mortality rates in comparison with surgical esophagectomy, especially in case of mucosal Barrett's adenocarcinoma. In addition, the endoscopic myotomy techniques in Zenker's diverticulum and spastic achalasia are new, attractive endoscopic treatment modalities.

Does Helicobacter pylori Exacerbate Gastric Mucosal Injury in Users of Nonsteroidal Anti-Inflammatory Drugs? A Multicenter, Retrospective, Case-Control Study

Background/Aims

The interaction between nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori remains controversial. We retrospectively investigated whether H. pylori infection exacerbates severe gastric mucosal injury among chronic NSAID users.

Methods

From January 2010 to December 2013, a total of 245 long-term NSAID (including low-dose aspirin) users who had undergone an esophagogastroduodenoscopy and had been evaluated for H. pylori infection were enrolled at Okayama University Hospital and Tsuyama Chuo Hospital. The degree of gastric mucosal injury was assessed according to the modified Lanza score (MLS). Severe gastric mucosal injury was defined as an MLS ≥4. Univariate and multivariate logistic regression analyses were performed.

Results

In the univariate analysis, age ≥75 years (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.3 to 4.2), H. pylori-positivity (OR, 2.0; 95% CI, 1.2 to 3.5), and the concomitant use of proton pump inhibitors (PPIs) (OR, 0.48; 95% CI, 0.26 to 0.86) were significantly associated with severe gastric mucosal injury. The multivariate analysis was adjusted by age and sex and demonstrated that H. pylori-positivity (OR, 1.8; 95% CI, 1.0 to 3.3) and the concomitant use of PPIs (OR, 0.53; 95% CI, 0.28 to 0.99) significantly contributed to severe gastric mucosal injury.

Conclusions

H. pylori infection exacerbates severe gastric mucosal injury among chronic NSAID users.

Identification of Helicobacter pylori infected patients, using administrative data

BACKGROUND

Helicobacter pylori is a prevalent organism implicated in peptic ulcer disease.

AIM

To validate administrative data for diagnosis of H. pylori-infected patients.

METHODS

Administrative data identified patients with ICD-9 code for H. pylori (041.86) or prescription of eradication therapy; diagnosis was confirmed by chart abstraction. Multivariable regression assessed predictors of infection considering drug therapy, ICD-9 code 041.86, procedure code, in-patient or out-patient diagnostic code, age, gender and race to generate an algorithm for validation.

RESULTS

The test cohort of 531 patients (361 potential cases; 170 random controls) was primarily male (94%), Caucasian (59%) and elderly [67 years (s.d. 10)]. The positive predictive value (PPV) of ICD-9 code 041.86 was 100% and 97.4% if from an in-patient or out-patient encounter, respectively. Eradication drug therapy had a PPV of 73.7% (triple therapy) and 97.7% (quadruple therapy). The strongest predictors were out-patient ICD-9 code 041.86 (OR 8.1; 95% CI: 7.0-9.1); eradication drug therapy (OR 7.4; 95% CI: 6.6-8.3); oesophagogastroduodenoscopy (OR 3.5; 95% CI: 3.3-3.6); and age > or =70 (OR 1.2; 95% CI: 1.1-1.4). An algorithm including these data elements yielded a c-statistic of 0.93 and PPV of 97.9%.

CONCLUSIONS

Administrative data can diagnose H. pylori-infected patients. The diagnostic algorithm includes presence of eradication drug therapy overlapping with an out-patient ICD-9 code 041.86 among elderly adults.

A prospective study of faecal calprotectin and lactoferrin in the monitoring of acute radiation proctitis in prostate cancer treatment

OBJECTIVE

Acute radiation proctitis is a relevant complication of pelvic radiation. The purpose of this study was to investigate two markers of gut inflammation as non-invasive diagnostic tools to evaluate acute radiation proctitis.

MATERIAL AND METHODS

Twenty patients who underwent radiotherapy for prostate cancer took part in this prospective study. Radiation-induced toxicity was evaluated weekly during radiotherapy in compliance with the CTC toxicity criteria. Stool samples from patients were examined before treatment, weekly during radiotherapy and 2 weeks after the end of radiotherapy using enzyme-linked immunosorbent assay for calprotectin and lactoferrin and correlated with the CTC toxicity.

RESULTS

Calprotectin and lactoferrin faecal values increased significantly during radiation treatment and decreased about 2 weeks after cessation of radiation. Faecal concentrations of calprotectin and lactoferrin correlated with the documented radiation proctitis symptoms (all grades together) in 15/20 patients (75%). With respect to changes in faecal concentrations and correspondence to proctitis symptoms, both markers showed parallel results in 90% of the patients. On comparing calprotectin and lactoferrin concentrations between the 4th week of radiation and the 1st week, it was found that patients with any grade of toxicity exhibited a significantly higher increase in calprotectin (p = 0.044) and lactoferrin (p = 0.05), respectively, compared with those without toxicity.

CONCLUSIONS

Calprotectin and lactoferrin faecal values changed during radiation treatment and after cessation of radiation, with correlation to acute proctitis symptoms in most of the patients. Before markers are used to monitor acute radiation proctitis, further experience should be acquired. Patients will be followed to determine the predictive value of the two tested markers for chronic radiation proctitis.

Duodenal Carbonic Anhydrase: Mucosal Protection, Luminal Chemosensing, and Gastric Acid Disposal

The duodenum serves as a buffer zone between the stomach and jejunum. Over a length of only 25 cm, large volumes of strong acid secreted by the stomach must be converted to the neutral-alkaline chyme of the hindgut lumen, generating large volumes of CO2, which the duodenum then absorbs. The duodenal mucosa consists of epithelial cells connected by low-resistance tight junctions, forming a leaky epithelial barrier. Despite this high permeability, the epithelial cells, under intense stress from luminal mineral acid and highly elevated P(CO2), maintain normal functioning. Furthermore, the duodenum plays an active role in foregut acid-base homeostasis, absorbing large amounts of H+ and CO2 that are recycled by the gastric parietal cells. Prompted by the high expression of cytosolic and membrane carbonic anhydrase (CAs) in duodenal epithelial cells, and the intriguing observation that CA activity appears to augment cellular acid stress, we formulated a novel hypothesis regarding the role of CA in duodenal acid absorption, epithelial protection, and chemosensing. In this review, we will describe how luminal CO2/H+ traverses the duodenal epithelial cell brush border membrane, acidifies the cytoplasm, and is sensed in the subepithelium.

Evidence-Based Recommendations for Older Adults With Helicobacter pylori or Those Using Nonsteroidal Anti-Inflammatory Drugs

Currently, about half the world's population is infected with Helicobacter pylori. This organism is known to cause peptic ulcers and places patients at higher risk for gastric cancer. Older adults are more susceptible to the negative effects of Helicobacter pylori infection. In addition, this population consumes large amounts of nonsteroidal anti-inflammatory drugs and typically demonstrates a high incidence of atrophic gastritis, both of which place them at even higher risk for gastrointestinal disease. Consequently, older adults should be carefully assessed for gastrointestinal irritation, peptic ulcer, and gastric cancer. Age-specific therapy can result in improved outcomes related to a lower incidence of nonadherence with medications, decreasing hospital admissions, lowering costs of care, and increasing quality of life.

Effect of helicobacter pylori infection on the risk of upper gastrointestinal bleeding in users of nonsteroidal anti-inflammatory drugs

PURPOSE

We evaluated whether infection with Helicobacter pylori, including specific cytotoxic-associated antigen (CagA)-positive strains, increase the risk of upper gastrointestinal bleeding in users of nonsteroidal anti-inflammatory drugs (NSAIDs).

METHODS

Cases with upper gastrointestinal bleeding and recent NSAID use, including aspirin, who were admitted during 2001, were compared with age- and sex-matched outpatient controls who had recent NSAID use. H. pylori infection was diagnosed by serum antibodies or the (13)C-urea breath test; and CagA seropositivity was diagnosed by enzyme-linked immunoassay.

RESULTS

H. pylori was detected significantly more frequently in cases of bleeding than controls (79% [63/80] vs. 56% [45/80], P = 0.004). Cases of bleeding were more likely than controls to have a history of peptic ulcer (34% [n = 27] vs. 13% [n = 10], P = 0.003), previous upper gastrointestinal bleeding (19% [n = 15] vs. 6% [n = 5], P = 0.03), recent dyspepsia (29% [n = 23] vs. 15% [n = 12], P = 0.06), and <3 months of NSAID use (58% [n = 46] vs. 40% [n = 32], P = 0.04). CagA positivity was not associated with gastrointestinal bleeding. In a multivariate analysis, H. pylori infection was the only significant risk factor for upper gastrointestinal bleeding (odds ratio = 1.7; 95% confidence interval: 1.2 to 2.5; P = 0.004).

CONCLUSION

H. pylori infection almost doubles the risk of upper gastrointestinal bleeding among users of NSAIDs.

Transcriptional activation of the murine Muc5ac mucin gene in epithelial cancer cells by TGF-beta/Smad4 signalling pathway is potentiated by Sp1

The nucleotide sequence of the pMS1 clone was submitted to the GenBank Nucleotide Sequence Database under accession number AF288076. Changes in the expression of mucin genes in gastrointestinal cancers is thought to contribute to the development of the disease. In our laboratory we have shown previously that MUC5AC is aberrantly expressed in rectosigmoid villous adenomas. However, the regulatory mechanisms underlying that altered profile of expression is unknown. In order to study its regulation at the transcriptional level, we have isolated and characterized 5.5 kb of the 5'-flanking region of the mouse Muc5ac mucin gene. The promoter is flanked by a TATA box and a transcriptional start site is located 22 bp downstream of the TATA box. Analysis of the sequence showed a high density of binding sites for Smad4, an essential factor in the signalling cascade activated by TGF-beta (transforming growth factor-beta), and Sp1, an important factor in the regulation of MUC5AC. This led us to study Muc5ac regulation by TGF-beta. We show that exogenous addition of TGF-beta to the cells induces Muc5ac endogenous expression, promoter activity and Smad4 binding to the promoter. By co-transfection studies we show that Smad4 is essential for Muc5ac promoter activation and that it does not synergize with Smad2 or Smad3. By gel-retardation and co-transfection assays, we identified Sp1 and Sp3 as important regulators of Muc5ac expression and showed that Smad4 and Sp1 act in a co-operative manner to transactivate Muc5ac promoter activity. Altogether these results bring new insights into the molecular mechanisms of TGF-beta-mediated up-regulation of Muc5ac and enhance our understanding as to how Muc5ac is regulated in certain pathologies of the gastrointestinal tract.

Gastroduodenal mucosal defense: an integrated protective response

PURPOSE OF REVIEW

The remarkable resistance of the mucosal lining the upper gastrointestinal tract to concentrated gastric acid remains one of the biggest unsolved mysteries of upper gastrointestinal physiology. Even with the discovery of the involvement of Helicobacter pylori in gastroduodenal injury, the mechanism by which the organism causes injury remains unresolved. In the past year, there have been striking findings regarding trefoil peptides, the protective effect of regulatory peptides such as adrenomedullin, and the influence of H. pylori on the junctions that join the epithelial cells.

RECENT FINDINGS

Trefoil peptide-2-deficient mice were more susceptible to gastric injury from nonsteroidal anti-inflammatory agents, confirming that trefoil peptides increased the barrier properties of the pre-epithelial mucus gel. With regard to H. pylori, the gastric mucosa of mice deficient in the tyrosine phosphatase receptor type Z were not damaged by H. pylori vacuolating cytotoxin. Proton pump inhibition appears to be equally or more effective in upper gastrointestinal mucosal protection compared with other interventions such as exogenous prostaglandins or H. pylori eradication.

SUMMARY

Peptic ulcer disease, although declining in prevalence, appears to be increasing in virulence, perhaps because of the overall aging of the population and improved intensive care unit care. Although H. pylori and nonsteroidal anti-inflammatory drugs have been identified as key pro-ulcerogenic factors, many ulcers may also result from a deficiency of other, unknown host protective factors. A more detailed understanding of the host factors involved in mucosal protection will thus help identify novel therapeutic targets aimed at the prevention and treatment of upper gastrointestinal mucosal injury.

Effect of Helicobacter pylori on delay in ulcer healing induced by aspirin in rats

Helicobacter pylori and nonsteroidal anti-inflammatory drugs (NSAIDs) are major pathogenic factors in peptic ulcer disease but whether these two factors exert synergistic or antagonistic effects on ulcer healing has been a subject of controversy. We compared the effect of aspirin alone with that of aspirin combined with H. pylori on gastric acid secretion and healing of acetic acid gastric ulcers in rats. The H. pylori colonization of gastric mucosa was determined by viable H. pylori culture, histology and assessment of bacterial DNA using polymerase chain reaction (PCR). The area of ulcers, gastric blood flow, mucosal generation of prostaglandin E(2) and plasma gastrin levels and expression of cyclooxygenase-1, cyclooxygenase-2 and growth factors was determined. Aspirin delayed significantly the healing of chronic gastric ulcers, decreased the gastric blood flow at the ulcer margin and gastric mucosal prostaglandin E(2) generation being without significant influence on gastric acid output. H. pylori acquisition that produced moderate gastric inflammation at the ulcer margin delayed significantly the healing of gastric ulcers, decreased significantly both the gastric blood flow at the ulcer margin and the gastric secretion while raising significantly the gastric mucosal prostaglandin E(2) generation and plasma gastrin levels. H. pylori infection attenuated the aspirin-induced inhibition of ulcer healing and accompanying fall in the gastric blood flow. Both aspirin and H. pylori up-regulated significantly cyclooxygenase-2 messenger RNA (mRNA) and protein but not that of cyclooxygenase-1 at the ulcer margin. Aspirin reduced significantly the transforming growth factor alpha- and vascular endothelial growth factor mRNAs, but these effects were significantly attenuated by H. pylori. We conclude that H. pylori antagonizes, in part, aspirin-induced delay of ulcer healing due to suppression of acid secretion, the enhancement in prostaglandin E(2) possibly derived from cyclooxygenase-2 and the overexpression of transforming growth factor alpha and vascular endothelial growth factor in the ulcer area.