Mucosal expression and luminal release of epidermal and transforming growth factors in patients with duodenal ulcer before and after eradication of Helicobacter pylori

Tricholoma matsutake-Derived Peptides Show Gastroprotective Effects against Ethanol-Induced Acute Gastric Injury

Acute gastric injury caused by ethanol is a frequent disorder of the gastrointestinal tract. In this study, we investigated the potential gastroprotective effects of Tricholoma matsutake-derived peptides against ethanol-triggered acute gastric injury and the associated mechanisms. Peptides SDLKHFPF and SDIKHFPF significantly attenuated the ethanol-induced decrease in GES-1 cell survival (82.39 ± 1.93 and 80.10 ± 1.08% vs 56.58 ± 1.86%), inhibited GES-1 cell apoptosis, and alleviated the ethanol-induced gastric mucosal injury (64.76 ± 3.98 and 49.29 ± 3.25%), ulcer index (3.33 ± 0.47 and 4.67 ± 0.47 vs 6.67 ± 0.47), and histopathological changes in mice. Peptide treatment inhibited the phosphorylation and nuclear translocation of nuclear factor kappa B (NF-κB), the secretion of tumor necrosis factor-α, interleukin-6, and endothelin-1. In addition, T. matsutake peptide pretreatment increased growth factor secretion, upregulated B-cell lymphoma-2, downregulated Bcl-2-associated X (Bax), and cleaved cysteinyl aspartate specific proteinase 3, thereby promoting gastric cell survival. These findings strongly suggest that T. matsutake peptides attenuate ethanol-induced inflammatory responses and apoptosis by suppressing NF-κB signaling activation, thereby enhancing gastric epithelial barrier functions.

Gastrin: From Physiology to Gastrointestinal Malignancies

Abetted by widespread usage of acid-suppressing proton pump inhibitors (PPIs), the mitogenic actions of the peptide hormone gastrin are being revisited as a recurring theme in various gastrointestinal (GI) malignancies. While pathological gastrin levels are intricately linked to hyperplasia of enterochromaffin-like cells leading to carcinoid development, the signaling effects exerted by gastrin on distinct cell types of the gastric mucosa are more nuanced. Indeed, mounting evidence suggests dichotomous roles for gastrin in both promoting and suppressing tumorigenesis. Here, we review the major upstream mediators of gastrin gene regulation, including inflammation secondary to Helicobacter pylori infection and the use of PPIs. We further explore the molecular biology of gastrin in GI malignancies, with particular emphasis on the regulation of gastrin in neuroendocrine neoplasms. Finally, we highlight tissue-specific transcriptional targets as an avenue for targetable therapeutics.

Endoscopic characteristics of infection-associated peptic ulcers

BACKGROUND

Aside from Helicobacter pylori, another cause for the development or worsening of gastrointestinal ulcers is scrub typhus, an acute febrile disease caused by Orientia tsutsugamushi. We aimed to compare the endoscopic characteristics of peptic ulcers caused by these infectious agents.

METHODS

This retrospective case-control study involved patients who underwent upper gastrointestinal endoscopy at Chosun University Hospital in Korea. We compared endoscopic features and demographic characteristics between patients with H. pylori infection and those with O. tsutsugamushi infection.

RESULTS

A total of 141 patients with peptic ulcer were included in the study. Compared to patients with O. tsutsugamushi infection (n = 62; age, 63.8 ± 12.1 years; male sex, 42%), those with H. pylori infection (n = 79; age, 53.0 ± 14.8 years; male sex, 81%) were younger and more likely to be male (P < .001 for both). Patients with O. tsutsugamushi infection were more likely to have multiple lesions (40/62, 64.5% vs 37/79, 46.8%; P = .042) and irregular-shaped lesions (27/62, 43.6% vs 20/79, 25.3%; P = .031). Patients with H. pylori infection had higher incidence of hemorrhagic ulcers (26/79, 32.9% vs 8/62, 12.9%; P = .007), and lesions occurred most often in the duodenum (43.0%), followed by the antrum (36.7%), body (34.2%), and angle (12.7%) of the stomach. In patients with O. tsutsugamushi infection, lesions occurred most often in the antrum (70.97%), followed by the duodenum (35.5%), body (22.6%), and angle (14.5%) of the stomach. In both groups, gastric ulcer lesions occurred most often in the antrum, followed by the body and angle of the stomach (36.7% vs 70.97%, 34.2% vs 22.6%, and 12.7% vs 14.5% for gastric ulcers associated with H. pylori and O. tsutsugamushi infection, respectively). Patients with O. tsutsugamushi infection had significantly higher incidence of ulcers on the antrum (70.97% vs 36.7%, P < .001) and the greater curvature (45.2% vs 24.0%, P = .012). Finally, 35.5% of patients with gastric ulcer caused by scrub typhus also had duodenal ulcer.

CONCLUSION

This is the first study to compare endoscopic features of peptic ulcers caused by H. pylori and O. tsutsugamushi. Peptic ulcers in patients with H. pylori infection occurred predominantly in the antrum/body/lesser curvature and presented with single, round/oval lesions, while ulcers in patients with scrub typhus occurred predominantly in the antrum/greater curvature and presented with multiple, irregular lesions. Scrub typhus should be considered as a cause of duodenal ulcer in scrub typhus-endemic areas.

Activation of Helicobacter Pylori Causes Either Autoimmune Thyroid Diseases or Carcinogenesis in the Digestive Tract

Helicobacter pylori has been implicated in stimulation of immune system, development of autoimmune endocrinopathies as autoimmune thyroiditis (AT) and on other hand induction of immunosupresion activates gastric and extra-gastric diseases such as gastric ulcer or cancer. It causes persistent lifelong infection despite local and systemic immune response. Our results indicate that Helicobacter pylori might cause inhibition of the specific cellular immune response in Helicobacter pylori-infected patients with or without autoimmune diseases such as AT. We cannot also declare the carcinogenic effect in oropharynx. However the association of any infection agents and cancerogenesis exists. The adherence of Helicobacter pylori expression and enlargement of benign lymphatic tissue and the high incidence of the DNA of Helicobacter pylori in laryngopharyngeal and oropharyngeal cancer is reality. LTT appears to be a good tool for detection of immune memory cellular response in patients with Helicobacter pylori infection and AT. All these complications of Helicobacter pylori infection can be abrogated by successful eradication of Helicobacter pylori.

Salivary transforming growth factor alpha in patients with Sjögren's syndrome and reflux laryngitis

Introduction

Saliva plays a key role in the homeostasis of the digestive tract, through its inorganic components and its protein growth factors. Sjögren's syndrome patients have a higher prevalence of gastroesophageal reflux disease and laryngopharyngeal reflux. Decreased salivary transforming growth factor alpha levels were observed in dyspeptic patients, but there have been no studies in patients with Sjögren's syndrome and laryngopharyngeal reflux.

Objective

To compare the salivary transforming growth factor alpha levels of patients with Sjögren's syndrome and laryngopharyngeal reflux to those of healthy controls.

Methods

This is a prospective controlled study. Twelve patients with Sjögren's syndrome and laryngopharyngeal reflux and 11 controls were prospectively evaluated. Spontaneous and stimulated saliva samples were obtained to establish salivary transforming growth factor alpha concentrations.

Results

The salivary transforming growth factor alpha levels of patients were significantly higher than those of healthy controls. Five patients with laryngopharyngeal reflux also had erosive esophagitis; their salivary transforming growth factor alpha levels were comparable to controls.

Conclusion

Salivary transforming growth factor alpha level was significantly higher in patients with Sjögren's syndrome and laryngopharyngeal reflux when compared to the control group.

Inflammatory changes of the gastric mucosa and serum concentration of chosen growth factors in children

PURPOSE

To assess whether there is a correlation between the severity of gastritis and concentration of chosen growth factors in the serum of children infected with H. pylori.

MATERIAL AND METHODS

The study included 64 children of whom 50% (Group I) were infected with H. pylori and had gastritis; 18.7% (Group II) of the examined children had a positive titre of IgG against H. pylori and normal gastric mucosa. Controls (Group III) comprised 31.3%. The gastric mucosa was evaluated histopathologically according to the Sydney System. The serum concentrations of growth factors: EGF, TGF-alpha, VEGF, were determined using ELISA.

RESULTS

Mean concentrations of the growth factors were also the highest in Group I compared to Group II and Group III (EGF - 137.3+/-10.4 pg/mL, TGF-alpha - 0.4+/-1.2 pg/mL, VEGF - 146.8 pg/mL). Analysis of correlations between growth factors and the severity of gastritis as well as the activity of antral gastric mucosa inflammation proved that mean EGF concentration in H. pylori infected children was the highest (149.5+/-84.8 pg/mL) in severe gastritis, whereas mean concentrations of TGF-alpha (2.0+/-4.3 pg/mL) and of VEGF (148.1+/-92.6 pg/mL) were the highest in moderate gastritis. Mean concentrations of EGF (155.1+/-116.4 pg/mL) and of VEGF (156.0+/-118.9 pg/mL) were the highest in high activity antral gastritis, whereas the mean concentration of TGF-alpha was the highest (2.0+/-4.2 pg/ml) in moderate activity gastritis.

CONCLUSIONS

In the children with H. pylori infection, serum concentrations of EGF, TGF-alpha, VEGF were the highest in moderate and severe antral gastritis.

Helicobacter pylori and benign upper digestive disease

Acute infection with Helicobacter pylori causes hypochlorhydria and gastrointestinal upset. As the infection persists, patients develop chronic antral-predominant or pangastritis. Gastric and duodenal ulcers arise from chronic mucosal inflammation and disordered acid secretion in the stomach. With successful eradication of H. pylori, non-NSAID-related gastric and duodenal ulcers heal even without long-term acid suppression. More importantly, peptic ulcers and their complications rarely recur. Clearing H. pylori infection also reduces the risk of mucosal injury in NSAID and aspirin users; the protective effects are more pronounced in NSAID-naïve and aspirin users. H. pylori is unlikely to be the cause of gastro-oesophageal reflux disease. However, a patient's reflux symptoms may be more difficult to control after clearing the infection. Although there is little evidence to support a causal relationship between H. pylori and non-ulcer dyspepsia, treatment of the infection gives a modest improvement of symptoms.

Multifocal atrophic gastritis: pathogenesis and therapeutic implications

OBJECTIVE

This study, carried out on 51 patients with multifocal atrophic gastritis (MAG) and 92 age and sex-matched dyspeptic controls, was designed to examine both exocrine (gastric acid) and endocrine (gastrin) gastric secretion before and after therapeutic intervention including Helicobacter pylori eradication and vitamin C treatment.

METHODS

Fasting and gastrin-releasing peptide-induced gastric acid secretion, serum levels of gastrin and proinflammatory (IL-1beta, IL-8, TNF-alpha) as well as gastric mucosal gene expression of ornithine decarboxylase (ODC), cyclooxygenase 2 (COX-2) and growth factors (epidermal growth factor and transforming growth factor alpha) were determined before and after the eradication of Helicobacter pylori and therapy with large doses (1 g/d) of vitamin C for 3 months.

RESULTS

The H. pylori eradication, assessed by C-urea breath test, and vitamin C therapy failed to reverse the histological atrophy of the gastric mucosa but improved significantly the functional status of the atrophied mucosa, especially its exocrine and endocrine secretory activities, attenuated the expression of premalignant markers such as ODC and COX-2, raised the production of growth factors and diminished the release of proinflammatory cytokines.

CONCLUSIONS

These results indicate that MAG may be considered as an environmental disease of the gastric mucosa, whose functional status can be improved by the eradication of H. pylori combined with antioxidant therapy with large doses of vitamin C.

Protective role of heat shock protein 27 in gastric mucosal injury

Heat shock protein 27 (HSP27) mediates cytoprotective effects through its function as a molecular chaperone and through the phosphorylation-dependent stabilization of actin filaments. The role of HSP27 in gastric ulcer formation and healing is, however, unknown. The expression of HSP27 was studied in human gastric tissue specimens obtained from patients with gastric ulcers and from healthy Helicobacter pylori-negative individuals, who received low-dose aspirin, rofecoxib, and the combination in a prospective study. The susceptibility of the gastric mucosa to indomethacin-induced lesions was further studied in transgenic mice overexpressing human HSP27 (Tg(huHSP27)) and compared with wild-type mice (Wt). The expression of HSP27, COX-1, and COX-2 was investigated in Tg(huHSP27) mice and Wt mice by immunohistochemistry and western blot analysis. While no specific changes in HSP27 expression were found following exposure of healthy human gastric mucosa to oral administration of aspirin or refocoxib, chronic gastric ulcers showed strong HSP27 expression at the ulcer base and margins. Here it was expressed by granulation tissue and regenerating surface epithelium. In Tg(huHSP27) mice, overexpression of HSP27 led to a significant decrease of indomethacin-induced erosions and ulcers compared with Wt mice. COX-1 and COX-2 levels did not change. HSP27 is involved in chronic gastric ulcer repair mechanisms in humans, while overexpression of human HSP27 in gastric epithelial cells in mice reduces the susceptibility to non-steroidal anti-inflammatory drug (NSAID)-induced gastric ulceration. This indicates that HSP27 expression is critical for mucosal protection in the stomach.

The healing effect of TGF-α on gastric ulcer induced by acetylsalicylic acid in rats

The present study was designed to investigate the effects of microemulsion and aqueous solution containing transforming growth factor alpha (TGF-alpha) and/or aprotinin administered intragastrically (i.g.) on healing of acute gastric ulcers induced by acetylsalicylic acid (ASA). The microemulsion was prepared by modification of the microemulsion formulation described in our previous study. Acute gastric lesions were induced by the application of ASA (150 mg/kg in 1.5 ml of 0.2N HCl i.g.). TGF-alpha in solution or microemulsion formulations were administered at a dose of 10 microg/kg per 24h i.g. for 2 days. The effects of TGF-alpha on the healing was evaluated with the measurement of ulcer score, basal gastric acid secretion, total protein content of gastric fluid, gastric mucus level and histological analysis. The results indicated that the highest decrease in ulcer area was observed in group treated with microemulsion containing TGF-alpha plus aprotinin (TA-ME). TGF-alpha in microemulsion formulation was more effective than TGF-alpha in solution formulation in the increase of gastric mucus secretion, in the decrease of gastric acid secretions and ulcer scores. Histological evaluation of the gastric mucosa samples revealed that, best recovery was obtained in the TA-ME treated group.

Gastric and duodenal mucosal protein fractional synthesis and growth factor expression in patients with H. pylori-associated gastritis before and after eradication of the organism

Our purpose was to study the effect of Helicobacter pylori (HP) on mucosal protein fractional synthesis (MPFS) and growth factor expression. 14C-leucine incorporation, and TGF-alpha, beta-FGF, and EGF-receptor levels were assessed in gastric and duodenal mucosa in 20 patients with HP-associated gastritis and repeated after treatment of the gastritis, with or without eradication of the organism. At entry, MPFS in the fundus, antrum, and duodenum was 43.1, 38.2, and 28.3%/day, respectively. Following HP eradication, fundal and antral rates fell to 28.1 and 21.4%/day (P < 0.05), whereas the duodenum was unchanged. MPFS in the patient subset not eradicated remained similar to entry values (35.9, 31.6, and 25.4%/day). Expression of TGF-alpha, beta-FGF, and EGF receptors was unchanged. Eradication of HP results in reduction of gastric, but not duodenal, MPFS and has no effect on the growth factors measured. Increased MPFS associated with HP gastritis may relate to the potential for neoplastic transformation.

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Effect of Helicobacter pylori infection on epidermal growth factor receptor (EGFR) expression and cell proliferation of gastric epithelial mucosa: correlation to macroscopic and microscopic diagnosis

Our aim was to compare the expression of EGFR and proliferative cell nuclear antigen (PCNA) in different histological and endoscopic diagnostic groups, in cases of Helicobacter pylori infection, in vivo. Paraffin embedded human gastric biopsy samples (86) were analysed by EGFR and PCNA immunohistochemistry and classified both on the basis of histology and endoscopic findings. In normal epithelia (NE), a positive correlation was found between PCNA and EGFR and in H. pylori-negative gastritis with and without intestinal metaplasia (P < 0.01). On the other hand, a negative correlation was detected between the two immunohistochemical findings in H. pylori-associated gastritis with intestinal metaplasia (HPGIM) and in the atrophic gastritis (AG) group. In HPGIM the percentage of EGFR-positive cells was significantly lower (32.4 +/- 30.4) when compared to either the NE (50.3 +/- 23.7) or H. pylori-negative gastritis with intestinal metaplasia (HNGIM) (48.3 +/- 23.7). In AG, EGFR was significantly lower when compared to the NE (P < 0.05). Based on the endoscopic findings, a significant decrease of EGFR expression was found in gastric ulcer cases as compared to NE, gastritis or erosion cases (P < 0.01). PCNA showed no significant alterations between the NE and gastritis, AG groups. The presence of H. pylori has an inverse effect on PCNA and EGFR expression in HPGIM.

Immunohistochemical expression of transforming growth factor alpha and epidermal growth factor receptor in pancreatic endocrine tumors

Coexpression of transforming growth factor alpha (TGF-alpha) and its receptor epidermal growth factor receptor (EGFR) is known to be associated with aggressive biologic behavior and adverse clinical outcome in a variety of tumors, including pancreatic adenocarcinomas. However, very little information is currently available as to whether this is true of pancreatic endocrine tumors (PETs) as well. Thirty-five PETs were retrospectively studied for immunohistochemical expression of TGF-alpha, the intracellular and extracellular domains of EGFR, and various hormonal secretory products. Proliferative activity was additionally studied (in 20 cases only) using the MIB-1 antibody. Thirty-one (89%) of 35 tumors were reactive for 1 or more of the peptide hormones tested; 22 (63%) tumors were positive for TGF-alpha; and 23 (65%) were positive for the intracellular and/or extracellular domain of EGFR. Based on their TGF-alpha and EGFR expression, these tumors could be classified into 4 groups. Of the 10 tumors in group I (positive for TGF-alpha and the complete EGFR molecule), 3 were malignant, 6 were >2 cm in diameter, 5 were functional, and 1 had a proliferative index of >40%. The 12 tumors in group II (positive for TGF-alpha but negative for the intracellular and/or extracellular domain of EGFR) included 4 malignant tumors, 4 PETs >2 cm in diameter, 8 functional, and 1 with a proliferative index of >40%. The 7 PETs in group III (positive for the intracellular/extracellular domain of EGFR alone) included 3 malignant tumors, 3 PETs >2 cm in diameter, and 3 functional tumors. The 6 tumors in group IV (completely negative for both TGF-alpha and EGFR) included 4 malignant tumors, 3 PETs >2 cm in diameter, and 4 functional lesions. Therefore, immunohistochemical expression of TGF-alpha and EGFR, either alone or in concert, shows no correlation with size, functional status, secretory profile, or biologic behavior and hence cannot be used as a marker of malignancy in this group of tumors.

Epidermal growth factor and its receptor in chronic active gastritis and gastroduodenal ulcer before and after Helicobacter pylori eradication

BACKGROUND

Helicobacteria pylori infection of gastroduodenal mucosa is strongly associated with gastritis and peptic ulcer disease. The aims of the present study were to compare the gastroduodenal mucosal levels of epidermal growth factor (EGF) and its receptor (EGFR) among H. pylori-negative controls and H. pylori infected patients with chronic active gastritis or gastroduodenal ulcer before and after H. pylori eradication.

METHODS

The protein levels of EGF in mucosal tissues and saliva were determined by a solid-phase enzyme-linked immunosorbent assay (ELISA). Repeat transcription-polymerase chain reaction and the following polymerase chain reaction ELISA were employed to examine the mucosal EGFR mRNA expression.

RESULTS

Mucosal injury and H. pylori infection increased EGF protein levels and EGFR mRNA expression in the antral mucosa. The concentration of EGF in saliva was not affected by mucosal damage or H. pylori infection. Successful H. pylori eradication normalized the EGFR mRNA back to its basal level 6 weeks after treatment. However, after unsuccessful eradication their high levels in the antrum persisted. All patients experienced ulcer healing after drug treatment, regardless of H. pylori eradication.

CONCLUSIONS

Mucosal damage increased the expression of EGF protein and EGFR mRNA in the gastric mucosa. H. pylori could induce the expression of EGFR but not the EGF in the antral mucosa. The expression of EGFR could be a contributing factor for ulcer healing in patients with H. pylori infection.

Effect of Helicobacter pylori eradication on cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) expression during gastric adaptation to aspirin (ASA) in humans

Gastric adaptation to aspirin is impaired in Helicobacter pylori infection, but the mechanisms underlying this phenomenon are unclear. In this study, we compared gastric mucosal expression of iNOS and COX-2 during 14 days of aspirin ingestion in the same subjects before and 3 months after eradication of H. pylori. Compared to non-infected controls, mucosal expression of COX-2 and iNOS was enhanced before and 3 months after eradication of H. pylori. During aspirin ingestion, mucosal expression of COX-2 remained unchanged before eradication of H. pylori, but increased gradually after successful antimicrobial treatment. Independent of H. pylori status, expression of iNOS increased at the beginning of aspirin intake, but then returned to initial values. We conclude that COX-2 but not iNOS might be involved in gastric adaptation to aspirin in humans and that this mechanism appears to be impaired in H. pylori infection.

Patterns of inflammation linked to ulcer disease

Peptic ulcers are accompanied by different patterns of chronic gastritis and duodenitis that generally run parallel to the topography of colonization by Helicobacter pylori (H. pylori). Duodenal ulcers arise on a background of a gastroduodenitis; the gastritis is antrum-predominant while the duodenitis requires acid-induced gastric metaplasia in the duodenal mucosa before bacterial colonization can occur. The colonized and inflamed metaplastic areas in the duodenum (and inflamed pre-pyloric antrum) are the initial sites of ulceration. Proximal gastric ulcers arise in a diffuse (pan-) gastritis or a corpus-predominant H. pylori gastritis when the weakened gastric mucosa (especially in the antrum-body transitional zone) is susceptible to ulceration even in the presence of subnormal acid production. These distinctive patterns of gastritis are sufficiently consistent for them to be used to predict ulcer risk.

Prospective evaluation of the prevalence of gastric Helicobacter pylori infection in patients with GERD, Barrett's esophagus, Barrett's dysplasia, and Barrett's adenocarcinoma

OBJECTIVE

This study was undertaken to prospectively determine the prevalence of gastric H. pylori infection in Barrett's esophagus and Barrett's complicated by dysplasia or adenocarcinoma.

METHODS

The prevalence of H. pylori was determined in Barrett's esophagus patients compared to a control population of patients with gastroesophageal reflux disease (GERD) only. All patients had a minimum of 10 gastric surveillance biopsies obtained. H. pylori colonization was determined upon the basis of hematoxylin and eosin and use of a modified Giemsa and or Steiner's silver stain of all gastric biopsy specimens.

RESULTS

Two hundred and eighty-nine Barrett's patients and 217 GERD control patients were included in the study. H. pylori was found in 95/289 (32.9%) of the Barrett's patients, compared with 96/217 (44.2%) of the GERD controls (NS). Forty-seven of the Barrett's patients had low-grade dysplasia/indefinite dysplasia, 14 high-grade dysplasia, and 20 Barrett's adenocarcinoma. When Barrett's was subgrouped according to absence of dysplasia, and presence of low-grade dysplasia, high-grade dysplasia, or adenocarcinoma, H. pylori prevalence was found to be significantly less for patients with Barrett's high-grade dysplasia (14.3%) and adenocarcinoma (15.0%) versus patients with GERD alone (44.2%), Barrett's alone (35.1%), or Barrett's with low-grade dysplasia (36.2%) (p = 0.016). This difference could not be explained by differences between Barrett's esophagus patients infected with H. pylori and those who were not with respect to gender, smoking history, alcohol consumption, use of proton pump inhibitor, or length of Barrett's mucosa.

CONCLUSIONS

Barrett's high-grade dysplasia and adenocarcinoma are significantly more prevalent in patients who are not infected with H. pylori. H. pylori appears to have a protective effect against the development of Barrett's adenocarcinoma.

Eradication of Helicobacter pylori normalizes elevated mucosal levels of epidermal growth factor and its receptor

OBJECTIVE

Helicobacter pylori (H. pylori) infection has been linked to gastric cancer. The factors that promote carcinogenesis remain unknown. Epidermal growth factor (EGF) has been shown to be a potent epithelial mitogen and oncoprotein when sustained over expression occurs. Our aim was to compare gastric mucosal levels of EGF and its receptor (EGFR) among controls, H. pylori infected subjects, and subjects following H. pylori eradication using quantitative flow cytometric analysis.

METHODS

Patients referred for evaluation of dyspepsia underwent EGD and six antral biopsies were performed (two each for rapid urease testing (RUT), histopathology, and flow cytometry). Controls were those found to be H. pylori negative while subjects had confirmed infection. The study patients were treated, then had repeat EGD with biopsies.

RESULTS

There were 17 controls and 28 cases. Mean EGF and EGFR values were 2.69 and 2.46 for controls and 4.67 and 4.64 for subjects. Subjects' mean EGF was 73% higher (p = .035) and EGFR was 88% higher (p = 0.029) than controls. After treatment, the subjects' mean values declined 55% (p = 0.0001) for EGF and 40% (p = 0.002) for EGFR. Three subjects had persistent infection and showed no change in their EGF/EGFR levels. No difference was found among factor levels with respect to endoscopic findings.

CONCLUSIONS

Both EGF and EGFR from gastric antral biopsies are increased nearly 2-fold in infection with H. pylori. Infection eradication reduces levels of both factors to those of controls. One major pathogenic mechanism for gastric mucosal hyperproliferation and possibly carcinogenesis related to H. pylori may be the over expression of EGF and increased receptor density of EGFR on gastric mucosal cells.

Immunolocalization of transforming growth factor-alpha and epidermal growth factor receptor in the rat gastroduodenal area

The maintenance of gastrointestinal epithelium integrity requires a fine balance between proliferation and differentiation as well as protection against gastric acid secretion. Transforming growth factor-alpha (TGF-alpha) regulates these functions by binding to epidermal growth factor receptor (EGF-R). This study was designed to identify the localization of TGF-alpha and EGF-R in the rat gastroduodenal region. In the stomach, the surface and gastric pit cells showed staining for TGF-alpha antibodies in the cytoplasm and basolateral and apical membranes. TGF-alpha and EGF-R were observed in the supranuclear region of the cells lining the gland. In the duodenum, the enterocytes coexpressed both TGF-alpha and EGF-R in the supranuclear area. The EGF-R was also observed in the apical membrane. Brunner's glands were positive for both TGF-alpha and EGF-R antibodies. Our results demonstrate the coexpression of TGF-alpha and EGF-R in the rat gastroduodenal area, which suggests a functional role for them in the establishment and maintenance of the epithelial renewal.

Gastric adaptation to aspirin and Helicobacter pylori infection in man

The relationship between Helicobacter pylori infection and aspirin (ASA)-induced gastropathy and gastric adaptation to ASA remains unclear. We compared gastric damage and adaptation after repeated exposures to ASA in the same subjects without H. pylori infection and those infected by H. pylori before and after eradication of this H. pylori. Twenty-four volunteers in two groups (A and B), without H. pylori infection (group A) and with H. pylori infection (group B) before and after H. pylori eradication, were given ASA 2 g/day or placebo for 14 days. Mucosal damage was evaluated by endoscopy and gastric microbleeding; mucosal prostaglandin (PG) E₂ generation and luminal transforming growth factor (TGF)α were determined on days 0,3,7 and 14 of the ASA course. In all subjects, ASA-induced gastric damage reached a maximum on day 3. In H. pylori-positive subjects this damage was maintained at a similar level up to the 14th day of observation. Following H. pylori eradication, the damage was significantly lessened at day 14, as revealed by both endoscopy and microbleeding, and was accompanied by increased mucosal release of TGFα. Prostaglandin E₂ generation was significantly higher in H. pylori-positive subjects than after H. pylori eradication, but ASA treatment resulted in greater than 90% reduction of this generation independent of H. pylori status. Gastric adaptation to ASA is impaired in H. pylori-positive subjects but eradication of this bacterium restores this process.

Helicobacter pylori-positive peptic ulcer patients do not adapt to aspirin

BACKGROUND

Recent studies indicate that eradication of Helicobacter pylori might prevent peptic ulcer formation in patients treated with non-steroidal anti-inflammatory drugs (NSAIDs). On the other hand, gastric adaptation after repeated exposures to aspirin (ASA) is well documented but the influence of H. pylori on this process remains to be elucidated.

AIM

To compare gastric damage and adaptation following repeated exposures to ASA in a group of patients with H. pylori infection, before and after eradication of the bacterium, and in H. pylori-negative controls.

METHODS

Eight healthy volunteers without H. pylori infection and eight patients with duodenal ulcer (DU) history and H. pylori infection before and after H. pylori eradication were given ASA 2 g/day for a period of 14 days. Mucosal damage was evaluated by endoscopy and histology of biopsy samples. Gastric microbleeding, DNA synthesis in the gastric mucosa and mucosal expression, as well as luminal content of transforming growth factor-alpha (TGFalpha) were determined on days 0, 3, 7 and 14 of the ASA course.

RESULTS

In all patients aspirin-induced gastric damage reached a maximum on day 3. In H. pylori-positive patients, this damage was maintained at a similar level up to day 14, whereas in H. pylori-negative controls and H. pylori-eradicated patients this damage significantly lessened on day 14 and was accompanied by elevated DNA synthesis as well as increased mucosal expression and luminal release of TGFalpha.

Decreased prevalence of Helicobacter pylori infection in gastroesophageal reflux disease

BACKGROUND

An increased incidence of reflux esophagitis has been reported after eradication of H. pylori in patients with duodenal ulcer. To determine if H. pylori is associated with lower rates of esophagitis, we studied the prevalence of H. pylori infection in patients with and without reflux esophagitis and a subgroup of patients with concomitant peptic ulcer disease.

METHODS

Patients who underwent esophagogastroduodenoscopy and had diagnostic testing for H. pylori over a 30-month period were studied. H. pylori infection was determined by rapid urease testing, gastric histopathology, or serology. Reflux esophagitis was determined by endoscopic and/or histologic criteria.

RESULTS

Of 514 patients, 39.5% had H. pylori infection and 22.2% had reflux esophagitis. The prevalence of H. pylori infection in patients with reflux esophagitis was 30.7%, compared with 42.0% in patients without esophagitis (p = 0.039). The odds ratio for esophagitis risk with H. pylori infection was 0.61 (95% CI, 0.39-0.95). Neither patient age nor gender affected H. pylori prevalence. In patients with duodenal ulcer, H. pylori was present in 36.4% of patients with esophagitis and in 69.2% of patients without esophagitis (p = 0.018). The odds ratio for esophagitis with H. pylori infection in these patients was 0.25 (95% CI, 0.09-0.73).

CONCLUSIONS

Our study demonstrates that H. pylori infection is significantly less prevalent in patients with reflux esophagitis and may protect against its development. In duodenal ulcer patients, this effect was more dramatic. Further study is required to confirm these findings and elucidate mechanisms underlying possible beneficial effects of H. pylori.

The influence of Helicobacter pylori eradication on the gastric mucosal content of epidermal growth factor, transforming growth factor-alpha, and their common receptor

BACKGROUND

The relationship between the expression of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) and that of their receptor (EGF-R) in the Helicobacter pylori-infected gastric mucosa has not been completely elucidated. The aim of this study was to examine the interplay between H. pylori colonization and gastric mucosal growth factor content.

METHODS

By means of a solid-phase enzyme-linked immunosorbent assay EGF, TGF-alpha, and EGF-R levels and interleukin-1beta (IL-1beta) content, which is considered a marker of chronic inflammation, were evaluated in the antral mucosa of 24 H. pylori-positive patients before and 8 weeks after eradication therapy.

RESULTS

After therapy H. pylori was eradicated in 19 patients. The eradication was accompanied by a significant decrease in IL-1beta content and an increase in EGF and TGF-alpha levels. On the other hand, in the five patients in whom the bacterium was not eradicated EGF, TGF-alpha, and EGF-R levels were quite similar to those assayed before therapy, whereas IL-1beta content was still high.

CONCLUSIONS

These results suggest that H. pylori exerts an inhibitory effect on the mucosal expression of EGF and TGF-alpha, which are likely involved in the gastric mucosa repair process.

Epidermal growth factor and transforming growth factor alpha in duodenal ulcer and non-ulcer dyspepsia patients before and after Helicobacter pylori eradication

BACKGROUND

Epidermal growth (EGF) and transforming growth factor alpha (TGFalpha) are potent gastric secretory inhibitors, mitogens, and mucosal protectors, but the impact of Helicobacter pylori infection on their mucosal expression and luminal release has not been clarified.

METHODS

In this study, gene and immunoreactive and immunohistochemical expressions of EGF and TGFalpha were assessed in the gastric mucosa of 15 H. pylori-negative healthy normals, in 22 H. pylori-positive duodenal ulcer patients (DU) and in 24 H. pylori-positive non-ulcer dyspepsia patients (NUD). All studies in DU and NUD patients were repeated after 2 weeks of triple therapy (amoxicillin + clarithromycin + omeprazole) and 4 weeks and 2 years later.

RESULTS

Immunohistochemical expression of EGF and TGFalpha in H. pylori-positive DU and NUD was significantly higher than in H. pylori-negative normals, and this increase persisted at 2 and 4 weeks after therapy but normalized 2 years later. EGF mRNA was detected in the gastric mucosa of H. pylori-positive DU before and at 2 and 4 weeks after H. pylori eradication, but it was not found 2 years after the eradication of H. pylori or in gastric mucosa of H. pylori-negative control subjects. TGFalpha mRNA was detected in the gastric mucosa independently of H. pylori status, with the stronger expression observed in the gastric mucosa of H. pylori-positive DU and NUD before eradication than after this procedure. Plasma gastrin, which was significantly increased in H. pylori-positive DU, normalized already after 2 weeks of triple therapy. The eradication rate as determined by histology after triple therapy reached 86.3% in DU patients and 90.5% in NUD patients. Two years after the eradication the H. pylori reinfection rate was 4.5% among DU patients and 4.2% among NUD. Treatment of DU patients with triple therapy resulted in complete ulcer healing.

CONCLUSIONS

1) Chronic H. pylori infection and resulting antral gastritis are associated with increased plasma gastrin and increased mucosal cell proliferation, probably due to enhanced expression of EGF and TGFalpha, and 2) the H. pylori eradication results in a decrease in plasma gastrin, but the increase in gastric TGFalpha and EGF content is sustained, suggesting that they may be involved in ulcer healing.

Infection of Helicobacter pylori in gastric adaptation to continued administration of aspirin in humans

BACKGROUND & AIMS

Involvement of Helicobacter pylori in aspirin-induced gastropathy and adaptation to aspirin remains unclear. The aim of this study was to compare gastric damage and adaptation after repeated exposures to acetylsalicylic acid in the same subjects before and after eradication of H. pylori.

METHODS

Before and after H. pylori eradication, 8 volunteers were given aspirin, 2 g/day during 14 days. Mucosal damage was evaluated by endoscopy and histological analysis of biopsy samples. Gastric microbleeding, DNA synthesis, prostaglandin E2 generation, and luminal contents of transforming growth factor alpha and its immunohistochemical expression were determined on days 0, 3, 7, and 14 of aspirin course.

RESULTS

In all subjects, aspirin-induced gastric damage that reached maximum on day 3. In H. pylori-positive subjects, this damage was maintained at a similar level up to day 14. After H. pylori eradication, the damage was significantly lessened both in endoscopy and histology at day 14 and accompanied by increased mucosal expression and luminal release of transforming growth factor alpha. Prostaglandin E2 generation was significantly greater in H. pylori-positive subjects than after H. pylori eradication, but aspirin treatment resulted in >90% reduction of this generation independent of H. pylori status.

CONCLUSIONS

Gastric adaptation to aspirin is impaired in H. pylori-positive subjects, but eradication of this bacterium restores this process.