Matrix metalloproteinase gene expression in chronic gastric ulcer: a potential role of eosinophils in perforation

Risk of gastrointestinal perforation in patients taking oral fluoroquinolone therapy: An analysis of nationally representative cohort

Background

Fluoroquinolone is a commonly prescribed antimicrobial agent, and up to 20% of its users registers adverse gastroenterological symptoms. We aimed to evaluate the association between use of fluoroquinolone and gastrointestinal tract perforation.

Methods

We conducted a nested case-control study on a national health insurance claims database between 1998 and 2011. The use of fluoroquinolones was classified into current (< 60 days), past (61–365 days prior to the index date) and any prior year use of fluoroquinolones. We used the conditional logistic regression model to estimate rate ratios (RRs), adjusting or matching by a disease risk score (DRS).

Results

We identified a cohort of 17,510 individuals diagnosed with gastrointestinal perforation and matched them to 1,751,000 controls. Current use of fluoroquinolone was associated with the greatest increase in risk of gastrointestinal perforations after DRS score adjustment (RR, 1.90; 95% CI, 1.62–2.22). The risk of gastrointestinal perforation was attenuated for past (RR, 1.33; 95% CI, 1.20–1.47) and any prior year use (RR, 1.46; 95% CI, 1.34–1.59). To gain insights into whether the observed association can be explained by unmeasured confounder, we compared the risk of gastrointestinal perforation between fluoroquinolone and macrolide. Use of macrolide, an active comparator, was not associated with a significant increased risk of gastrointestinal perforation (RR, 1.11, 95%CI, 0.15–7.99). Sensitivity analysis focusing on perforation requiring in-hospital procedures also demonstrated an increased risk associated with current use. To mitigate selection bias, we have also excluded people who have never used fluoroquinolone before or people with infectious colitis, enteritis or gastroenteritis. In both of the analysis, a higher risk of gastrointestinal perforation was still associated with the use of fluoroquinolone.

Conclusions

We found that use of fluoroquinolones was associated with a non-negligible increased risk of gastrointestinal perforation, and physicians should be aware of this possible association.

Anti-ulcer effect and potential mechanism of licoflavone by regulating inflammation mediators and amino acid metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza is the dry root and rhizome of the leguminous plant, Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat. or Glycyrrhiza glabra L., which was firstly cited in Shennong's Herbal Classic in Han dynasty and was officially listed in the Chinese Pharmacopoeia, has been widely used in China during the past millennia. Licoflavone is the major component of Glycyrrhiza with anti-ulcer activity. The present study is based on clarifying the anti-ulcer effect of licoflavone, aiming at elucidating the possible molecule mechanisms of its action for treating gastric ulcer rats induced by acetic acid.

MATERIALS AND METHODS

Rats were divided into 7 groups, and drugs were administered from on the day after the onset of gastric ulcer (day 3) until day 11 of the experiment once daily continuously. The plasma were analyzed by high-performance liquid chromatography combined with time-of-flight mass spectrometry (HPLC/ESI-TOF-MS), significant different metabolites were investigated to explain its therapeutic mechanism. Furthermore, quantitative real time polymerase chain reaction (RT-PCR) analysis was performed to detect the expression of RNA in stomach tissue for verifying the above results.

RESULTS

Licoflavone can effectively cure the gastric ulcer, particularly the middle dose group. According to the statistical analysis of the plasma different metabolites from each groups and the expression of genes in tissues, sixteen significant different metabolites, including histamine, tryptophan, arachidonic acid, phingosine-1-phosphate etc., contributing to the treatment of gastric ulcer were discovered and identified. In RT-PCR analysis, the results of the expression of RNA were corresponded with what we discovered.

CONCLUSIONS

Our study indicated licoflavone plays the role of treating gastric ulcer by regulating inflammation mediators and amino acid metabolism. We demonstrated that metabolomics technology combined with gene technology is a useful tool to search different metabolites and to dissect the potential mechanisms of traditional Chinese medicine (TCM) in treating gastric ulcer.

Chronic gastric ulceration causes matrix metalloproteinases-9 and -3 augmentation: alleviation by melatonin

Matrix metalloproteinases (MMPs) are a family of zinc-dependent enzymes capable of degradation of extracellular matrix (ECM) and key player in various inflammatory diseases. We investigated the regulation of MMPs in chronic gastric ulceration in mice. We generated chronic gastric ulcers in mice by indomethacin and examined the activity and expression of MMP-9 and -3 in stomach. Melatonin (N-acetyl-5-methoxytryptamine) treatment has also been applied to mice to characterize the changes in expression and activities of MMPs in gastric tissues. We observed significant upregulation of MMP-9 and -3 expressions and activities in stomach with increasing doses and duration of indomethacin that corroborated with increased activity of activator protein (AP)-1. Substantial damage in gastric epithelial layer was found during chronic ulceration. Melatonin suppressed MMP-9 and -3 expressions and activities during prevention and healing of chronic gastric ulcers. It also suppressed protein oxidation, lipid peroxidation and antioxidant enzymes. Additionally, expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-8 was significantly high in ulcerated stomachs while melatonin treatment blocked them to control level. We found elevated phosphorylation of extracellular-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK) during chronic gastric ulceration, which were significantly reversed by melatonin. Moreover, expression of NF-κB, c-fos and c-jun were inhibited by melatonin resulting down regulation of MMP-9 and -3 expressions. In summary, oxidative stress is preceded by chronic inflammation that enhances the expression of MMP-9 and -3, while melatonin arrests both of them via reduction of AP-1 activity during protection of ulcer.

Upregulation of collagenase-1 and -3 in indomethacin-induced gastric ulcer in diabetic rats: role of melatonin

Collagenases are key proteases involved in inflammation and injury. We addressed whether collagenases have an association with the susceptibility of gastric injury under diabetes as well as the effect of melatonin on collagenases in ulcerated gastric tissues. Diabetes was induced in rats by a single dose of streptozotocin (STZ) followed by gastric ulceration using indomethacin, and melatonin's action was studied by its application prior to indomethacin exposure. Ulcer indices and damage were elevated significantly in gastric tissues of diabetic compared with nondiabetic rats. Melatonin reversed the effect of indomethacin during protection of gastric ulcers in diabetic rats. Matrix metalloproteinase (MMP)-13 (i.e., collagenase-3) was upregulated in diabetic gastric mucosa and enhanced further upon ulceration while melatonin ameliorated their activity. In addition, gastric tissues showed enhanced expression of both MMP-1 (i.e., collagenases-1) and -13 significantly in diabetic rats compared with nondiabetic animals and more so during ulceration while tissue inhibitors of metalloproteinase-1 (TIMP-1) showed an opposite trend. MMP-2 activities exhibited a ∼50% downregulation during gastric ulceration which were rescued by melatonin. Moreover, increased expression of both MMP-1 and -13 was mediated by activator protein-1 activation via extracellular signal-regulated kinase 1/2 which were parallel to upregulation of tumor necrosis factor-α, interleukin-1β, and heat shock protein-70 during ulceration. Melatonin arrested collagenase expression by downregulation of these signaling molecules thereby halting the progression of the disease. We conclude that diabetic gastric tissues are susceptible to ulceration and associated with MMP-1 and -13 upregulation in indomethacin-induced injury. Additionally, melatonin protects the gastric damage under diabetes via regulation of both MMP-1 and -13.

Synergism between prior Anisakis simplex infections and intake of NSAIDs, on the risk of upper digestive bleeding: a case-control study

Background

The aim of this study was to investigate the relationship between prior Anisakis infections and upper gastrointestinal bleeding (UGIB), and its interaction with non-steroidal anti-inflammatory drug (NSAID) intake.

Methods/Principal Findings

We conducted a hospital-based case-control study covering 215 UGIB cases and 650 controls. Odds ratios (ORs) with their confidence intervals (95% CIs) were calculated, as well as the ratio of the combined effects to the sum of the separate effects of Anisakis allergic sensitization and NSAIDs intake. Prior Anisakis infections were revealed by the presence of anti-Anisakis IgE antibodies specific to the recombinant Ani s 1 and Ani s 7 allergens used as the targets in indirect ELISA. Prior Anisakis infections (OR 1.74 [95% CI: 1.10 to 2.75]) and the intake of NSAIDs (OR 6.63 [95% CI: 4.21 to 10.43]) increased the risk of bleeding. Simultaneous NSAIDs intake and Anisakis allergic sensitization increased the risk of UGIB 14-fold (OR = 14.46 [95% CI: 6.08 to 34.40]). This interaction was additive, with a synergistic index of 3.01 (95% CI: 1.18–7.71).

Conclusions

Prior Anisakis infection is an independent risk factor for UGIB, and the joint effect with NSAIDs is 3 times higher than the sum of their individual effects.

Anisakiasis is a worldwide re-emerging disease produced by the consumption of raw, lightly cooked, smoked or marinated fish containing live Anisakis larvae. In acute anisakiasis, mucosal lesions generated by the larvae may provoke upper gastrointestinal bleeding (UGIB). However, the effect of past unnoticed Anisakis infections as a risk factor for UGIB, and a possible synergism with other risk factors such as NSAIDs intake, have never been investigated. In this case-control study we observed that: i) prior Anisakis infections and NSAIDs intake are two independent risk factors for UGIB, and ii) that both risk factors act synergistically to the extent that their joint effect is 3 times higher than the sum of their individual effects. We concluded that, in countries where Anisakis infections are frequent, it would be wise to determine parasite-specific IgE antibodies and to conduct a closer follow-up of patients who consume raw or lightly cooked fish and who are prescribed NSAIDs for long periods.

Induction of matrix metalloproteinase-9 and -3 in nonsteroidal anti-inflammatory drug-induced acute gastric ulcers in mice: regulation by melatonin

The pathogenesis of gastric ulcer is associated with remodeling of extracellular matrix (ECM) by various matrix metalloproteinases (MMPs). However, how MMPs are regulated during nonsteroidal anti-inflammatory drug (NSAID)-induced acute gastric ulceration is not well studied. In this study, different NSAIDs (80 mg/kg b.w.) were applied to generate acute gastric ulcer in the BALB/c mouse and the regulation of MMPs were investigated. NSAIDs caused dose-dependent induction in MMP-9 and -3 activities and expressions in ulcerated gastric tissues along with significant infiltration of inflammatory cells and disruption of gastric mucosal layer. In addition, an increase in tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-8 expression, excessive generation of hydroxyl radical ((*)OH), and protein oxidation and lipid peroxidation were observed in acute ulcerated gastric tissues. In this study, the efficacy of melatonin on activities of MMP-9 and -3 during prevention of gastric ulcers was tested. Melatonin at a dose of 60 mg/kg b.w. downregulated MMP-9 and -3 both at the enzyme and protein levels in mouse gastric tissues during prevention as well as healing of acute gastric ulcers. It also blocked oxidative stress via inhibition of protein oxidation, lipid peroxidation, (*)OH generation and SOD-2 expression. Moreover, it suppressed myeloperoxidase activity and expressions of TNF-alpha, IL-1beta and IL-8. This study documents for the first time that induction of MMP-9 and -3 activities accompany NSAID-induced inflammation and oxidative stress in gastric tissues and indicates that, melatonin may be a preventive or therapeutic remedy for gastric ulcers.

Non-allergic Eosinophilic Inflammation

Much is known about the eosinophilic processes associated with antigens, tumors, and infection, yet data on other causes of eosinophilic inflammation are scarce. This paper investigates the locations and causes of other nonrespiratory eosinophilic inflammation. Although eosinophilic inflammation can involve locomotor, urinary, cardiovascular, nervous, gastrointestinal, and other mucosal surfaces, such inflammation also can accompany tissue trauma, foreign-body reactions, and necrotic or granulomatous processes. Despite their cytolytic/histolytic effects, eosinophil leukocytes are a component of tissue remodeling, can be antigen-presenting cells, and have a role in the reproductive system and in blood coagulation. The study of various types of eosinophilic inflammation may increase our understanding of the biological responses of eosinophil leukocytes to different inflammatory stimuli.

Candida albicans infection delays duodenal ulcer healing in cysteamine-induced duodenal ulcers in rats

A low curability of ulcers infected with Candida has been reported in the literature. The aim of the study reported here was to investigate experimentally whether Candida infection affects the healing of ulcers. Candida albicans (the Candida group) or saline (the control group) was administered intragastrically into rats with a cysteamine-induced duodenal ulcer. The duodenal lesions, vascular endothelial growth factor A (VEGF-A) and proliferating cell nuclear antigen (PCNA) were assessed. On Day 7 post-administration, 70.4% rats of the Candida group had a duodenal ulcer compared with 33.3% in the control group (P < 0.05). The duodenal ulcer in the Candida group was significantly larger and deeper than that in the control group. The number of VEGF-A- and PCNA-positive cells was smaller and the area of VEGF-A expression was lower in the Candida group. Using a rat model, we have demonstrated that Candida infection can delay the wound healing process of duodenal ulcers by means of a low expression of VEGF-A and PCNA.

A local imbalance between MMP and TIMP may have an implication on the severity and course of appendicitis

BACKGROUND

Matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs) have been demonstrated to be involved in inflammatory conditions in the intestine. The purpose of this study was to investigate whether the alterations of the MMP/TIMP balance might reflect the course of the inflammatory process in acute appendicitis and if the expression and localisation of MMPs and TIMP is variable in the various clinical manifestations of appendicitis.

MATERIALS AND METHODS

The study comprises 40 patients (26 men and 14 women) having emergency appendectomy and a control group constituting of 10 patients (5 men and 5 women) having a hemicolectomy for other reasons. MMP and TIMP expressions were assessed and compared in tissue specimens from phlegmonous (n = 15), gangrenous (n = 7), perforated appendicitis (n = 11) and controls with noninflamed appendices (n = 10) by means of enzyme-linked immunosorbent assay technique. Localisation of the enzymes was performed by immunohistochemistry.

RESULTS

MMP-1 was significantly higher in gangrenous and perforated appendicitis compared with phlegmonous appendicitis and controls (p < 0.05) while MMP-2 was significantly lower in gangrenous appendicitis compared with phlegmonous appendicitis and controls. MMP-2 was also lower in perforated appendicitis when compared with controls (p < 0.01). Elevated expression of MMP-9 was demonstrated in all groups of appendicitis compared with the controls (p < 0.001).

CONCLUSIONS

MMP-9 is the most abundantly expressed MMP of those investigated in inflamed appendix. We postulate that a local imbalance between MMP-9 and TIMP-1 may trigger a perforation. These results suggest that MMPs might be useful as biomarkers of appendices prone to perforation.

Candida albicans aggravates duodenal ulcer perforation induced by administration of cysteamine in rats

BACKGROUND

Candida sp are frequently isolated from the ascitic fluid of patients with perforated ulcers. The present study was performed to examine whether Candida infection may be involved in the process of ulcer perforation.

METHODS

Male Wistar rats were divided into a saline group (n = 15) and a Candida group (n = 17). Cysteamine-HCl (Sigma; 31 mg/100 g) was administered thrice on day 1 to both groups of animals. Candida albicans at a density of 10(8) in 0.5 mL of saline was administered 1 h before, and 12 h and 24 h after the first administration of cysteamine in the Candida group.

RESULTS

Perforated duodenal ulcers were observed in 94.1% of the rats in the Candida group, but only 26.7% of the rats in the saline group (P < 0.01). The area of the duodenal ulcers in the Candida group was 40.89 +/- 33.07 mm2, whereas that in the saline group was 16.53 +/- 20.4 mm2 (P < 0.05). The mortality rate was significantly higher in the Candida group than in the saline group. In the Candida group, colonization by C. albicans was recognized at the ulcer base, surrounded by marked granulocytic infiltration. The number of eosinophils infiltrating the ulcer base was also significantly greater in the Candida group than in the saline group. Immunohistochemical analysis revealed the expression of secretory aspartyl protease (SAP) in the region of the ulcer showing colonization by C. albicans in the Candida group.

CONCLUSION

Candida albicans aggravates duodenal ulcer perforation in the experimental model of cysteamine-induced duodenal ulcer perforation. The present findings suggest that SAP and host-parasite relationships, including granulocyte-dependent mechanisms, may be involved in the aggravation of ulcer perforation by C. albicans.

Increased concentration of tissue-degrading matrix metalloproteinases and their inhibitor in complicated diverticular disease

OBJECTIVE

Complicated diverticular disease is associated with extensive structural changes of the colonic wall. Turnover of extracellular matrix (ECM) plays a pivotal role in this process. Proteolytic enzymes, including matrix metalloproteinases (MMPs), are capable of degrading most components of ECM. Their activity is regulated by inhibitors, tissue inhibitors of metalloproteinases (TIMPs). Disturbances of the MMP-TIMP balance can cause tissue degradation or fibrosis. The aim of this study was to assess the concentration and distribution of MMPs and TIMPs in colonic biopsies.

MATERIAL AND METHODS

Twenty-seven patients who had undergone sigmoid colectomy were included in the study. Full-thickness biopsies from affected and non-affected parts of each resected specimen were collected. Expressions of the proteins MMP-1, -2, -3, -9, TIMP-1 and TIMP-2 were quantified by ELISA and localized by immunohistochemistry.

RESULTS

The concentrations of MMP-1, MMP-2 and TIMP-1 were significantly higher in affected tissue than concentrations in non-affected tissue (MMP-1 p=0.005, MMP-2 p=0.0003 and TIMP-1 p<0.0001). In affected segments in general, there was an increased expression in the entire bowel wall, predominantly for MMP-2, MMP-3 and TIMP-1.

CONCLUSIONS

Concentrations of MMP-1, MMP-2 and TIMP-1 were increased in intestinal segments affected by complicated diverticular disease and distributed throughout the entire bowel wall, which may explain the structural changes.

Helicobacter pylori encoding the pathogenicity island activates matrix metalloproteinase 1 in gastric epithelial cells via JNK and ERK

Helicobacter pylori colonizes the human gastric epithelium and induces an inflammatory response that is a trigger for gastric carcinogenesis. Matrix metalloproteinases (MMPs) have recently been shown to be up-regulated in gastric epithelial cells infected with H. pylori and might contribute to the pathogenesis of peptic ulcer. The aim of this study was to extend the knowledge about the effect of H. pylori infection on MMP-1 expression by gastric epithelial cells, the kinetics of induction, the pathogenetic properties of the bacterium, and the intracellular signaling pathways required for MMP-1 up-regulation. Expression of MMP-1 was induced more than 10-fold by co-culture of AGS+cells with H. pylori strains carrying the pathogenicity island (PAI). H. pylori strains with mutations in the PAI and a defective type IV secretion system had no effect on MMP-1. Double immunofluorescence revealed strong MMP-1 staining in epithelial cells of gastric biopsies at sites of bacterial attachment. In vitro, MMP-1 is up-regulated by interleukin-1beta and tumor necrosis factor-alpha, but these regulatory mechanisms are not operating in H. pylori infection as shown by inhibitory antibodies. Specific inhibitors of JNK kinase and ERK1/2 kinase were found to suppress the H. pylori-induced MMP-1 expression and activity. AGS cells treated with antisense MMP-1 showed a significantly reduced potential to degrade reconstituted basement membrane. Our results suggest that in gastric epithelial cells, H. pylori up-regulates MMP-1 in a type IV secretion system-dependent manner via JNK and ERK1/2. Induction of MMP-1 is further implicated in complex processes induced by H. pylori, resulting in tissue degradation and remodeling of the gastric mucosa.

Elevation of histidine decarboxylase activity in the stomach of mice by ulcerogenic drugs

Histamine is involved in the development of gastric lesions. To examine the contribution of the histamine-forming enzyme, histidine decarboxylase, to drug-induced gastric lesions, we compared the effects of aspirin, indomethacin and dexamethasone on histidine decarboxylase activity in mice. Administration of these drugs, orally or intraperitoneally, elevated histidine decarboxylase activity in the stomach but not in the liver, lung or spleen, dexamethasone being the most potent. In contrast, acetaminophen (a non-ulcerogenic drug) was inactive. These results and our previously reported findings (elevation of histidine decarboxylase activity by lipopolysaccharide, interleukin-1 and tumour necrosis factor, and by different types of stress) suggest that an elevation of histidine decarboxylase activity in the stomach may be a common feature of the responses to ulcerogenic stimuli. The possible participation of histidine decarboxylase in gastric lesions is discussed on the basis of the known actions of histamine, our findings and the effect of histamine H(2) receptor antagonists on histidine decarboxylase activity.

Clinical significance of increased gelatinolytic activity in the rectal mucosa during external beam radiation therapy of prostate cancer

PURPOSE

Rectal toxicity (proctitis) is a dose-limiting factor in pelvic radiation therapy. Mucosal atrophy, i.e., net extracellular matrix degradation, is a prominent feature of radiation proctitis, but the underlying mechanisms are not known. We prospectively examined changes in matrix metalloproteinase (MMP)-2 and MMP-9 (gelatinase A and B) in the rectal mucosa during radiation therapy of prostate cancer, as well as the relationships of these changes with symptomatic, structural, and cellular evidence of radiation proctitis.

METHODS AND MATERIALS

Seventeen patients scheduled for external beam radiation therapy for prostate cancer were prospectively enrolled. Symptoms of gastrointestinal toxicity were recorded, and endoscopy with biopsy of the rectal mucosa was performed before radiation therapy, as well as 2 and 6 weeks into the treatment course. Radiation proctitis was assessed by endoscopic scoring, quantitative histology, and quantitative immunohistochemistry. MMP-2 and MMP-9 were localized immunohistochemically, and activities were determined by gelatin zymography.

RESULTS

Symptoms, endoscopic scores, histologic injury, and mucosal macrophages and neutrophils increased from baseline to 2 weeks. Symptoms increased further from 2 weeks to 6 weeks, whereas endoscopic and cellular evidence of proctitis did not. Compared to pretreatment values, there was increased total gelatinolytic activity of MMP-2 and MMP-9 at 2 weeks (p = 0.02 and p = 0.004, respectively) and 6 weeks (p = 0.006 and p = 0.001, respectively). Active MMP-2 was increased at both time points (p = 0.0001 and p = 0.002). Increased MMP-9 and MMP-2 at 6 weeks was associated with radiation-induced diarrhea (p = 0.007 and p = 0.02, respectively) and with mucosal neutrophil infiltration (rho = 0.62).

CONCLUSIONS

Pelvic radiation therapy causes increased MMP-2 and MMP-9 activity in the rectal mucosa. These changes correlate with radiation-induced diarrhea and granulocyte infiltration and may contribute to abnormal connective tissue remodeling in radiation proctitis.

Eosinophil infiltration and activation at the gastric ulcer margin in rats

BACKGROUND

Recruitment and activation of eosinophils have been studied intensely in asthma and other allergic diseases. Less is known about the infiltration and behaviour of eosinophils during gastric ulcer healing.

AIM

To examine the tissue infiltration and activation of eosinophils in the ulcer margin at different time points after ulcer induction (days 1-15).

METHODS

Eosinophil peroxidase (EPO) staining and transmission electron microscopy (TEM) were used to observe eosinophil infiltration and activation in rats with acetic-acid-induced ulcer in the oxyntic mucosa. The distribution of macrophages was evaluated by immunocytochemistry using the macrophage-specific antibodies ED1 and ED2.

RESULTS

There was a prominent increase in eosinophils around the ulcer margin at day 1 after ulcer induction, which peaked at day 5. TEM revealed characteristic signs of eosinophil activation, including cytolysis and piecemeal degranulation. Eosinophil cytolysis was the major form of activation, seen most frequently at day 5. A few scattered apoptotic eosinophils could also be observed. In normal controls and sham-operated rats, activated eosinophils were detected rarely. The distribution pattern of infiltrated eosinophils closely resembled that of macrophages at the ulcer margin. However, in the central part of the granulation tissue (at day 5) only macrophages could be found.

CONCLUSIONS

There is marked infiltration and signs of activation of eosinophils together with macrophages at the margin of newly formed ulcers.

Vascular smooth muscle cells and pericytes express MMP-1, MMP-9, TIMP-1 and type I procollagen in inflammatory bowel disease

AIMS

Matrix metalloproteinases (MMPs) are involved in tissue remodelling, which is one of the important aspects of inflammatory disease. To assess the balance between the matrix degradation and production, we analysed the in situ expression of MMP-1, -3, -8 and -9, tissue inhibitor of metalloproteinases (TIMP)-1 and -2, and type I procollagen (PC-I) in inflammatory bowel disease.

METHODS AND RESULTS

Immunohistochemistry using frozen sections was performed in 17 patients with ulcerative colitis (UC) and 16 with Crohn's disease (CD). In both UC and CD, MMPs and TIMPs were expressed by inflammatory cells as well as by fibroblastic cells most prominently in actively inflamed areas in ulcer bases, but sparsely in intact inflamed mucosa in both UC and CD. In UC, inflamed mucosa with erosions expressed these substances focally. Fibroblasts also expressed PC-I. We identified that vascular smooth muscle cells of venules in ulcer bases expressed MMP-1 and -9, TIMP-1 and PC-I. These venules also expressed E-selectin, a cell adhesion molecule to facilitate the leucocyte extravasation, and vascular endothelial growth factor (VEGF) receptor 2, consistent with their property of newly formed vessels.

CONCLUSIONS

Our results suggest that MMPs are involved in the tissue remodelling, angiogenesis and promotion of leucocyte extravasation in the actively inflamed area in the ulcer base in both UC and CD. MMP-1 expression in the mucosa may be related to the initial step of ulceration in UC. Therapeutic manipulation of extracellular matrix turnover would be an effective therapy to alleviate active inflammation and accelerate ulcer healing.

Anti-inflammatory and tissue-protectant drug effects: results from a randomized placebo-controlled trial of gastritis patients at high risk for gastric cancer

BACKGROUND

The inflammatory process involving Helicobacter pylori-associated gastritis is thought to lead to epithelial damage and contribute to the development of gastric cancer. Evidence exists from animal and in vitro studies suggesting that tetracyclines have both anti-inflammatory and tissue-protectant effects unrelated to their antimicrobial activity. We attempted to modulate components of H. pylori's inflammatory process by: (i) eliminating the infection; (ii) using tetracycline to alter the host's reaction to the infection without reducing the bacterial load; and (iii) using calcium to counteract the effect of excessive dietary salt.

METHODS

We conducted a 16-week placebo-controlled clinical trial with 374 H. pylori-associated gastritis patients randomly assigned to one of five groups: (1) triple therapy consisting of metronidazole, amoxicillin and bismuth subsalicylate for 2 weeks, followed by bismuth alone for 14 weeks; (2) calcium carbonate; (3) triple therapy and calcium carbonate; (4) tetracycline; or (5) placebo.

RESULTS

Subjects in the tetracycline and triple therapy groups, but not the calcium carbonate only group, showed a reduction in inflammation and epithelial damage vs. those in the placebo group, independent of a change in H. pylori density and other factors. Our results also indicate that epithelial damage may be affected by mechanisms independent of H. pylori density or inflammation.

CONCLUSION

The results are consistent with the hypothesis that tetracycline can decrease inflammation independent of a reduction in the bacterial load. More research is needed to investigate mechanisms leading to epithelial damage which are independent of H. pylori density and inflammation.

Helicobacter pylori and Meckel's diverticula

BACKGROUND

Helicobacter pylori is known to infect only gastric mucosa and is strongly associated with gastroduodenal ulceration. The authors studied whether H. pylori colonizes the gastric mucosa of Meckel's diverticula, and determined its relationship to "gastritis" and bleeding.

METHODS

A 10-year retrospective review identified 45 children with Meckel's diverticulum. Hematoxylin-eosin and Diff-Quik stains were used to assess the presence and severity of gastritis, and to highlight organisms in the resected diverticula. Cases with organisms were then studied with antibodies specific for H. pylori using immunoperoxidase methods.

RESULTS

Twenty-eight children, 7 months to 12.6 years of age, had lower gastrointestinal hemorrhage caused by Meckel's diverticulum and had positive radionuclide scans. All had acid-secreting mucosa in their diverticula, and ulceration. "Chronic gastritis" and eosinophilia were constant findings; "acute gastritis" was present in four patients. Twenty specimens exhibited lymphoid follicles in the gastric mucosa. Seventeen patients with Meckel's diverticula (age range, 1 month-14.7 years) who presented with acute abdominal pain associated with intussusception were used for comparison. Acid-secreting gastric mucosa was seen in four patients. H. pylori was identified in only one of the 45 patients; this patient had ulceration and moderate "acute gastritis."

CONCLUSIONS

H. pylori does not colonize a substantial number of children who have ulcerated and bleeding Meckel's diverticulum in the presence of acid-secreting mucosa. Although H. pylori is a notable cause of ulceration, the authors confirm that ulceration is possible in its absence, and alternative mechanisms of ulceration are important. The presence of lymphoid follicles in Meckel's diverticula, unlike gastric biopsies, is not associated with H. pylori.