Regression of fundic gland polyps following acquisition of Helicobacter pylori.

The prevalence of Helicobacter pylori infection is very low in patients with fundic gland polyps (FGPs) of the stomach. We report here two cases with multiple FGPs that regressed following new H pylori acquisition. Patient Nos I and II had multiple FGPs in normal fundic mucosa without inflammatory changes or atrophy. Both were not infected with H pylori. Following acquisition of H pylori infection however, all FGPs in both patients completely disappeared except for one FGP in patient No I. Although the size of the remaining polyp in patient No I was greatly reduced after H pylori acquisition, it became enlarged again after eradication. Interestingly, in the remaining polyp, we found an activating beta-catenin gene mutation whereas no such mutations were detected in FGPs of patient No II. Thus H pylori infection may have an inhibitory effect on the development of FGPs.

The possible involvement of micro-organisms other than Helicobacter pylori in the development of rectal MALT lymphoma in H. pylori-negative patients.

It remains unclear whether lymphoma of the mucosa-associated lymphoid tissue (MALT) in the extragastric organs is related to Helicobacter pylori infection or not. This report describes three patients with rectal MALT lymphoma negative for H. pylori infection, all of whom showed disease regression after being treated with antibiotics. One patient had MALT lymphoma in both the descending colon and the rectum; the other two patients had rectal disease only. None of the patients had chronic gastritis which was detectable either endoscopically or histologically and H. pylori infection was completely ruled out by various methods, including a urease breath test. These patients received antibiotic therapy. In all the patients, regression of MALT lymphoma was observed endoscopically and histologically, and polymerase chain reaction revealed that a previously observed rearranged band of immunoglobulin heavy chain had also disappeared after antibiotic treatment. These cases therefore suggest involvement of micro-organisms other than H. pylori in the development of rectal MALT lymphoma.

Analysis of cytokines in the early development of gastric secondary lymphoid follicles in Helicobacter pylori-infected BALB/c mice with neonatal thymectomy.

Immunological interaction between the host and Helicobacter pylori seems to play a critical role in follicular formation in gastric mucosa. We reported H. pylori-induced follicular gastritis model using neonatally thymectomized mice. In this study, we investigated the involvement of various cytokines in this model. BALB/c mice were thymectomized on the third day after birth (nTx). At 6 weeks old, these mice were orally infected with H. pylori. Histological studies showed that follicular formation occurred from 8 weeks after the infection and that most of the infiltrating lymphocytes were CD4(+) and B cells. Neutrophils increased transiently at 1 week after the infection. Gamma interferon, interleukin-7 (IL-7), and IL-7 receptor were expressed in the stomach of the nTx mice irrespective of the infection. In contrast, expressions of the tumor necrosis factor alpha, IL-4 and lymphotoxin-alpha genes were remarkably upregulated by the infection. Our findings suggest that follicular formation may require cooperative involvement of a Th2-type immune response, tumor necrosis factor alpha and lymphotoxin-alpha in addition to the Th1-type immune response in H. pylori-induced gastritis in nTx mice.

A patient with improvement of ulcerative colitis after appendectomy.

Recently, several retrospective studies have shown an inverse association between appendectomy and development of ulcerative colitis. We describe a 21-year-old man with distal ulcerative colitis and appendiceal involvement. The patient passed bloody stools continually during the 3 years before admission. Macroscopic and microscopic findings showed chronic moderate inflammation of the appendix and rectum. The ratio of CD4 to CD8 lymphocytes isolated from rectal and appendiceal mucosa was increased (4.3 and 3.8, respectively) compared with controls (n = 11; 1.0 in the rectum and 1.4 in the appendix). Clinical symptoms and colonoscopic and microscopic findings improved significantly after appendectomy. In addition, the amount of interferon gamma secreted from rectal lymphocytes was reduced to 89 pg/mL after surgery (before appendectomy, 254 pg/mL). However, interleukin 4 production was below detectable levels both before and after appendectomy. These findings suggest that appendectomy resulted in altered T-helper (Th)1/Th2 balance in this patient. In the 3 years since surgery, the patient has been in good condition without recurrence of symptoms. This is the first report demonstrating therapeutic benefit of appendectomy in a patient with ulcerative colitis and potential mechanistic relationship.

Development of an oral drug delivery system targeting immune-regulating cells in experimental inflammatory bowel disease: a new therapeutic strategy.

Several studies have indicated the involvement of macrophages and dendritic cells in active inflammatory bowel disease (IBD). Manipulation of these cells is considered a very important therapeutic strategy for patients with IBD. We evaluated the effect of a new drug delivery system targeting microfold cells and macrophages with poly(DL-lactic acid) microspheres containing dexamethasone (Dx). Colitis was induced in BALB/c mice by 5% dextran sodium sulfate. Dx microspheres (n = 10) and only Dx (n = 10) were orally administered to dextran sodium sulfate-treated mice. Thereafter, serum levels and tissue distributions of Dx were investigated. To estimate the efficacy of this drug delivery system, we measured the histological score, myeloperoxidase activity and nitric oxide production, and gene expressions of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma in the colonic tissue. Serum Dx levels were not increased after oral administration of Dx microspheres. The tissue distribution of microspheres containing (125)I-labeled Dx in inflamed colon was significantly higher than in other organs. The histological score, myeloperoxidase activity, and nitric oxide production of the group treated with Dx microspheres were significantly lower than of those treated with Dx alone. Gene expressions of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma were down-regulated in mice treated with Dx microspheres. Microspheres containing glucocorticoids such as Dx, which target microfold cells and macrophages, can facilitate mucosal repair in experimental colitis and could be an ideal agent for treatment of human IBD.

Rat gastric mucosal cells express ICAM-1 and proinflammatory cytokines during indomethacin-induced mucosal injury.

Adhesion molecules and cytokines are known to be involved in the formation of acute gastric mucosal injury. However, it is not clear whether the gastric mucosal cells express these molecules and modulate the inflammation. To clarify whether gastric mucosal cells express intercellular adhesion molecule-1 (ICAM-1) and proinflammatory cytokines (tumor necrosis factor-alpha (TNF-alpha), interleukin-1-alpha (IL-1-alpha), and cytokine-induced neutrophil chemoattractant-2-beta (CINC-2-beta)) in the formation of gastric mucosal injury, we have used rat indomethacin-induced gastric mucosal lesions as an in vivo model. The gene expression of all cytokines and ICAM-1 increases at the early stages of indomethacin-induced gastritis (TNF-alpha and IL-1-alpha gene expression began to increase earlier than that of ICAM-1 and CINC-2-beta) and can mainly be detected in the gastric epithelial layer. To further identify the source of those molecules, the epithelial cells were separated into seven fractions according to their sizes by a counterflow elution. ICAM-1 and CINC-2-beta gene expressions are particularly enhanced in the middle-sized cell fractions that are rich in gastric mucous-producing cells. The effect of TNF-alpha or IL-1-alpha on the gene expression of ICAM-1 and cytokines was examined by using RGM-1 cells as a model for gastric mucosal cells. RGM-1 cells show an augmented ICAM-1 and proinflammatory cytokine expression in response to TNF-alpha or IL-1-alpha stimulation. Moreover, immunohistochemical staining also reveals an increase in ICAM-1 and CINC protein production in RGM-1 cells in response to TNF-alpha stimulation. We conclude that gastric mucosal cells express various cytokines and an adhesion molecule during the formation of acute gastric mucosal injury and that they may modulate the inflammation.

Effect of aging on gastrin receptor gene expression in rat stomach.

Gastrin is a pivotal humoral factor which regulates gastric acid secretion through its receptors. There is no report, however, concerning the age-related changes of gastrin receptor gene expression in the stomach. Northern blot analysis and in situ hybridization were performed to clarify the changes of gastrin receptor expression during the aging. In situ hybridization clarified that gastrin receptor mRNA was expressed mainly in enterochromaffin-like (ECL) cells in adult rat gastric mucosa. With aging, gastrin receptor gene expression in the stomach increased with the concomitant increase in histidine decarboxylase mRNA. Since histidine decarboxylase is a marker of gastric ECL cells, the augmented gastrin receptor mRNA in aged rats may be caused by the increased ECL cells in gastric mucosa during the aging.

Severe muscle damage induced by high carbohydrate intake from elemental diet in a patient with Crohn's disease.

Crohn's disease is associated with complications in multiple organs. However, there are very few reported cases of patients with Crohn's disease with muscle symptoms and/or high serum creatine phospho-kinase (CPK) levels. We report here a patient with Crohn's disease who experienced skeletal muscle damage with extremely high serum CPK level during treatment with an elemental diet. The non-parenteral administration of large amounts of carbohydrate and limited glycogen degradation capability may be a possible causative mechanism for this elemental diet-induced muscle damage.

Expression of protooncogene c-kit and its ligand stem cell factor (SCF) in gastric carcinoma cell lines.

We examined 13 human gastric carcinoma cell lines for the expression of both c-kit and stem cell factor (SCF). Expression of mRNAs was detected by both Northern blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR), and expression of translated proteins was detected by western blotting. Using RT-PCR we confirmed the expression of c-kit in five (ECC12, TMK1, MKN7, GCIY, and HGC27) cell lines. Northern blot analysis showed coexpression of both c-kit and SCF in ECC12 and expression of SCF in five other (MKN74, MKN1 OKAJIMA, KATOIII, and TMK1) cell lines. SCF stimulated both tyrosine phosphorylation of c-kit and growth of ECC12, whereas it did not stimulate those of GCIY. The sizes of c-kit transcript and protein in GCIY were slightly smaller than those of the reported ones, suggesting the presence of a biologically inactive truncated form of c-kit in GCIY. The present study suggests that c-kit/SCF system might play an important role in the carcinogenesis and tumor growth of ECC12 and that the truncated form of c-kit in GCIY might not be associated with malignant transformation.

Fatal liver cirrhosis and esophageal variceal hemorrhage in a patient with type IIIa glycogen storage disease.

A 45-year-old woman with type IIIa glycogen storage disease (GSD IIIa) died of variceal hemorrhage secondary to liver cirrhosis. The postmortem examination disclosed increased intracellular glycogen in the liver as well as in the heart and skeletal muscle. Although most liver injuries in GSD IIIa have been considered to be non-progressive in adulthood, liver cirrhosis can be a cause of death in some patients.

Helicobacter pylori induces proinflammatory cytokines and major histocompatibility complex class II antigen in mouse gastric epithelial cells.

Although Helicobacter pylori has been reported to stimulate the release of various cytokines from gastric tissue, it remains unknown whether normal and nontumorous gastric epithelial cells produce these cytokines. Therefore, in this study, we used a normal mouse gastric surface mucous cell line (GSM06) to determine whether gastric epithelial cells produce proinflammatory cytokines in response to H. pylori. The expression of MHC class II antigen was also examined, to investigate whether gastric epithelial cells participate in the immune response to H. pylori. In the study, GSM06 cells were incubated with H. pylori or its lipopolysaccharide (LPS). Proinflammatory cytokines were detected by Northern and Western blot analysis. The expression of MHC class II antigen was examined by fluorescence activated cell sorter (FACS) analysis. Genetic expression of proinflammatory cytokines such as interleukin-1alpha, tumor necrosis factor-alpha, and cytokine-induced neutrophil chemoattractant-2beta was enhanced by both intact and sonicated H. pylori, but not by H. pylori LPS. The expression of MHC class II antigen was induced by H. pylori more strongly than by interferon-gamma. We conclude that H. pylori induces the expression of proinflammatory cytokines and MHC class II antigen in gastric epithelial cells. Gastric epithelial cells may act as antigen-presenting cells and participate in the immune response to H. pylori infection.

Distribution of prostaglandin E receptors in the rat gastrointestinal tract.

AIMS: In order to study the role of prostaglandin in the regulation of the gastrointestinal functions, gene expression of prostaglandin receptors along the rat gastrointestinal tracts were investigated. METHODS: Rats were used for the study. The combination of counterflow elutriation separation of mucosal cells and Northern blot analysis was used to detect the gene expression of prostaglandin receptors in gastrointestinal tracts. RESULTS: In small intestine and colon, prostaglandin E2 EP1 and EP3 receptor mRNAs were mainly localized in the deeper intestinal wall containing muscle layers. EP4 receptor gene expression, on the other hand, was detected in the intestinal mucosal layer. In the stomach, EP1 mRNA was detected in gastric muscle layers, whereas EP3 and EP4 receptor gene expression was mainly present in the gastric mucosal layer containing epithelial cells. In gastric epithelial cells, parietal cells were found to have both EP3 and EP4 receptors. At lower concentrations, prostaglandin E2 inhibited gastric acid secretion by parietal cells probably through EP4 receptors. At higher concentrations, however, it stimulated it. On the other hand, mucous cells possessed only EP4 receptor mRNA. CONCLUSIONS: Thus, it is suggested that prostaglandin E2 modulates gastrointestinal functions through at least three different prostaglandin receptors (EP1, EP3, and EP4), each of which has a distinct contribution in the gastrointestinal tract.

"Mediterranean lymphoma" treated with antibiotics.

We report a case of Mediterranean lymphoma treated with antibiotics. A 74-year-old woman visited the hospital due to abdominal pain. Endoscopic examination showed erosions and ulcerations on duodenal mucosa. Biopsy specimens histologically revealed massive infiltration of small-sized lymphocytes and plasma cells in subepithelial mucosa. Immunoperoxidase staining showed that the infiltrating cells were positively stained with anti-alpha heavy chain. Serum IgA concentration was elevated and immunoelectrophoresis of the serum demonstrated monoclonal protein composed of alpha heavy chain. During the antibiotic treatment her symptoms disappeared and serum IgA concentration was normalized. Endoscopic examination also showed healing of the duodenal ulceration. The similarities between Mediterranean lymphoma and gastric mucosa-associated lymphoid tissue (MALT) type lymphoma, both of which may be related to bacterial infection and can be treated with antibiotics, are discussed in this report.

Involvement of beta-adrenergic receptor kinase-1 in homologous desensitization of histamine H2 receptors in human gastric carcinoma cell line MKN-45.

The poorly differentiated human gastric carcinoma cell line MKN-45 possesses histamine H2 receptors which are homologously desensitized by histamine. In order to clone the cDNA of a receptor kinase specific for H2 receptors, we performed RT-PCR at a low annealing temperature using oligo-DNA primers bearing the conserved sequences of the kinase domain of the G protein-coupled receptor kinase (GRK) family. However, we were able to isolate only cDNAs for beta-adrenergic receptor kinase 1 (beta ARK1) and GRK6. Interestingly, treatment of MKN-45 cells with beta ARK1 antisense phosphorothioate oligo-DNA (PON) resulted in significant loss of desensitization of H2 receptors by histamine, whereas GRK6 antisense PON had no effect. Thus, beta ARK1 appears to be involved in the homologous desensitization of H2 receptors in MKN-45 cells.

Erythropoietin stimulates proliferation of rat-cultured gastric mucosal cells.

Most anemic patients with chronic renal failure have gastric mucosal lesions. However, these gastric lesions are often improved after the administration of recombinant human erythropoietin (rHuEPO). We have used the rat gastric mucosal cell line RGM-1, to examine the possibility that rHuEPO might directly stimulate the growth of gastric mucosal cells in vitro. Our results show that rHuEPO dose-dependently increased [3H]thymidine incorporation into RGM-1 cells and their expression of c-myc gene. In addition, 125I-rHuEPO specifically bound to RGM-1 cells, and moreover, erythropoietin receptor gene expression was detected by RT-PCR. We conclude that rHuEPO has a direct growth-promoting effect on RGM-1 cells, suggesting possible usefulness of rHuEPO administration for the treatment of gastric mucosal damage in patients with chronic renal failure.