Aldehyde dehydrogenases of the rat colon: comparison with other tissues of the alimentary tract and the liver

Intracolonic bacteria have previously been shown to produce substantial amounts of acetaldehyde during ethanol oxidation, and it has been suggested that this acetaldehyde might be associated with alcohol-related colonic disorders, as well as other alcohol-induced organ injuries. The capacity of colonic mucosa to remove this bacterial acetaldehyde by aldehyde dehydrogenase (ALDH) is, however, poorly known. We therefore measured ALDH activities and determined ALDH isoenzyme profiles from different subcellular fractions of rat colonic mucosa. For comparison, hepatic, gastric, and small intestinal samples were studied similarly. Alcohol dehydrogenase (ADH) activities were also measured from all of these tissues. Rat colonic mucosa was found to possess detectable amounts of ALDH activity with both micromolar and millimolar acetaldehyde concentrations and in all subcellular fractions. The ALDH activities of colonic mucosa were, however, generally low when compared with the liver and stomach, and they also tended to be lower than in small intestine. Mitochondrial low K(m) ALDH2 and cytosolic ALDH with low K(m) for acetaldehyde were expressed in the colonic mucosa, whereas some cytosolic high K(m) isoenzymes found in the small intestine and stomach were not detectable in colonic samples. Cytosolic ADH activity corresponded well to ALDH activity in different tissues: in colonic mucosa, it was approximately 6 times lower than in the liver and about one-half of gastric ADH activity. ALDH activity of the colonic mucosa should, thus, be sufficient for the removal of acetaldehyde produced by colonic mucosal ADH during ethanol oxidation. It may, however, be insufficient for the removal of the acetaldehyde produced by intracolonic bacteria. This may lead to the accumulation of acetaldehyde in the colon and colonic mucosa after ingestion of ethanol that might, at least after chronic heavy alcohol consumption, contribute to the development of alcohol-related colonic morbidity, diarrhea, and cancer.     

Diagnosis of otitis media with effusion by acoustic reflectometry

Colonization of human gastric mucosa with Helicobacter pylori leads to chronic active gastritis and induces the occurrence of an acquired mucosa-associated lymphoid tissue (MALT) in the stomach. This remodelling of the gastric mucosa together with chronic antigen persistence may induce autoimmune reactions. The aim of this study was to investigate humoral autoimmune reactions to human gastric mucosa in H. pylori gastritis and their clinical relevance. Sera from patients with dyspeptic symptoms were tested for presence of IgG immunoglobulins against H. pylori. Gastric infection with H. pylori and alterations of gastric mucosa were demonstrated by histological examination of gastric biopsy specimens. All sera were tested for reactivity against human gastric mucosa by immunohistochemistry. Two different in-situ binding sites of antigastric autoantibodies were observed. Binding to canalicular structures within parietal cells was significantly correlated with antibodies to H. pylori, elevated basal gastrin levels and atrophy of gastric corpus glands. Our data indicate that autoimmune reactions to antigens in the human gastric mucosa occur in H. pylori gastritis and that they may play a role in the pathogenesis of the disease.     

Giant mitochondria in hepatocytes: a diagnostic hint for alcoholic liver disease

One hundred and sixty-five coded liver biopsy specimens were studied by light microscopy to evaluate the occurrence and diagnostic significance of giant mitochondria, which have been identified as periodic acid-Schiff-negative globular hyaline cytoplasmic inclusions of regular outline, clearly distinguishable from Mallory bodies. In 4 cases, electron microscopy confirmed that these globules were in fact enlarged mitochondria. The incidence of giant mitochondria was significantly higher in patients with high alcohol consumption (72%) than in those with low or no alcohol intake (10%). Their presence was related to the amount of daily ethanol consumption and to the shortness of abstinence before the biopsy. It was independent of other changes in the liver, and was detected with similar frequency in biopsies showing different alcoholic liver diseases. Our study emphasizes that giant mitochondria may be detected by light microscopy in a high proportion of alcoholics, and rarely in nonalcoholic liver diseases. Although less specific, they are much more frequent than Mallory bodies. Consequently they should be considered as a diagnostic hint of recent and heavy alcoholsm.     

First-pass metabolism of ethanol is predominantly gastric

Oral consumption of alcohol results in much lower blood alcohol concentrations (BACs) than does the same dose administered intravenously, suggesting significant first-pass metabolism (FPM). The questions remain, however, (1) whether this difference truly represents FPM or simply reflects slower absorption of alcohol, and (2) if there is FPM, is it mainly of gastric or hepatic origin. To study this, rats were given the same dose alcohol (1 g/kg) by either intragastric intubation or by intravenous, intraportal, and intraduodenal infusions at a rate that mimicked the loss of alcohol from the stomach. Higher BAC levels after intravenous than intragastric alcohol indicated true FPM. Higher levels after intraportal or intraduodenal infusions (in fact, comparable to those obtained with the intravenous route) demonstrated negligible FPM when the route of delivery bypassed the stomach, yet included the liver. Furthermore, rats that had developed portosystemic shunts after ligation of the portal ven exhibited blood alcohol curves and FPM equivalent to those of sham-operated controls, indicating that FPM is not dependent on first-pass flow through the liver, but reflects gastric metabolism. The absence of significant hepatic FPM is attributable to the saturation of hepatic alcohol dehydrogenase by recirculating alcohol, resulting in no appreciable increase in metabolism secondary to newly absorbed alcohol. Finally, the in vivo gastric metabolism of alcohol in pylorus-ligated rats was demonstrated by significantly lower BACs when alcohol was administered intragastrically than when an amount identical to that lost from the ligated stomach was given intraportally. Thus, the lower BACs with oral as opposed to intravenous alcohol are not simply a consequence of slow absorption, but result from FPM occurring predominantly in the stomach.     

Finding a balance point: a process central to understanding family caregiving in Taiwanese families

Mammalian alcohol dehydrogenases ADH1 (class I ADH) and ADH4 (class IV ADH) function as retinol dehydrogenases contributing to the synthesis of retinoic acid, the active form of vitamin A involved in growth and development. Xenopus laevis ADH1 and ADH4 genes were isolated using polymerase chain reaction primers corresponding to conserved motifs of vertebrate ADHs. The predicted amino acid sequence of Xenopus ADH1 was clearly found to be an ortholog of ADH1 from the related amphibian Rana perezi. Phylogenetic tree analysis of the Xenopus ADH4 sequence suggested this enzyme is likely to be an ADH4 ortholog, and this classification was more confidently made when based also on the unique expression patterns of Xenopus ADH1 and ADH4 in several retinoid-responsive epithelial tissues. Northern blot analysis of Xenopus adult tissues indicated nonoverlapping patterns of ADH expression, with ADH1 mRNA found in small intestine, large intestine, liver, and mesonephros and ADH4 mRNA found in esophagus, stomach, and skin. These nonoverlapping tissue-specific patterns are identical to those previously observed for mouse ADH1 and ADH4, thus providing further evidence that Xenopus ADH1 and ADH4 are orthologs of mouse ADH1 and ADH4, respectively. During Xenopus embryonic development ADH1 mRNA was first detectable by Northern blot analysis at stage 35, whereas ADH4 mRNA was undetectable through stage 47. Whole-mount in situ hybridization indicated that ADH1 expression was first localized in the pronephros during Xenopus embryogenesis, thus conserved with mouse embryonic ADH1 which is first expressed in the mesonephros. ADH4 expression was not detected in Xenopus embryos by whole-mount in situ hybridization but was localized to the gastric mucosa of the adult stomach, a property shared by mouse ADH4. Conserved expression of ADH1 and ADH4 in retinoid-responsive epithelial tissues of amphibians and mammals argue that these enzymes may perform essential retinoid signaling functions during development of the pronephros, mesonephros, liver, and lower digestive tract in the case of ADH1 and in the skin and upper digestive tract in the case of ADH4.     

Disseminated carcinomatosis of the bone marrow occurring 11 years after subtotal gastrectomy for gastric cancer]

A 44-year-old man was admitted to our hospital because of purpura, increased serum alkaline phosphatase, and thrombocytopenia. He had undergone subtotal gastrectomy for gastric cancer 11 years earlier. A biopsy specimen of the bone marrow revealed metastatic mucin-forming, moderately differentiated adenocarcinoma. Because the primary tumor was not detected in any other organ, the gastric cancer the patient was treated for 11 years earlier was suspected as the primary tumor. Microangiopathic hemolytic anemia and disseminated intravascular coagulation developed during the clinical course, and the patient deteriorated despite treatment with anticoagulants. Finally, he died of pulmonary carcinomatous lymphangitis. Autopsy revealed a small number of adenocarcinomatous cells in the lymphoduct of the remaining stomach in spite of its mucosa being intact. We concluded that the bone marrow was infiltrated by cancer cells which originated in the stomach 11 years before. It is unclear why adenocarcinoma cells remained dormant for as long as 11 years in the gastric lymphoduct and bone marrow.     

Therapeutic use of carminomycin in soft tissue sarcomas

Under endoscopic control, biopsy specimens were taken from the oxyntic gland area of the stomach before and after administration of pentagastrin, synthetic secretin, and 13-norleucine motilin (13-nle-motilin), respectively. In 29 volunteers, the basal rate of 14C-leucine incorporation into mucosal protein averaged 41.2 +/- 7.7 X 103 cpm/mg protein (mean +/- S.D.). One and 4 hours after s.c. administration of pentagastrin (6 mug/kg body weight), values were significantly increased (p less than 0.05) by 18.9 and 21.8%, respectively, with respect to the basal level. One hour after an intravenous shot of 2 CU per kg body weight of secretin, gastric mucosal protein synthetis was not substantially inhibited, whereas a 1-hour continuous i.v. infusion of 13-nle-motilin (0.4 mug/kg body weight, hr) significantly decreased 14C-leucine incorporation rates by 17.5% (p less than 0.05). In contrast to rats, 1 hour after s.c. pentagastrin, protein synthesis in human duodenal mucosa was not altered. From these results it may be concluded that pentagastrin has a trophic influence on gastric mucosa in man. Moreover, the data presented are compatible with the hypothesis that gastrin and motilin may be involved in the regulation of human gastric mucosal protein synthesis.     

Which relapse criteria best predict the mortality risk of treated alcoholics?

We examined which relapse criteria best predict the mortality risk of treated male alcoholics. The subjects were 172 male alcoholics who had previously been hospitalized. Using three criteria which defined relapse as failure to maintain abstinence from alcohol, alcohol abuse, or dependence, the relapse of each subject had been evaluated during a previous 3-year outcome study. Relative mortality risks in the next 3 years classified by the three relapse criteria were compared. The follow-up rate was 93.6% and 31 subjects died. The age-corrected relative mortality risk for subjects failing to maintain abstinence compared with abstainers was 5.32, while the relative mortality risks for the group abusing alcohol and for the group suffering alcohol dependence were 2.23 and 2.56, respectively. These results suggest that relapse defined as failure to maintain abstinence predicts a higher relative mortality risk than do criteria defining in terms of alcohol abuse and alcohol dependence.     

Hormonal (ACTH, cortisol, beta-endorphin, and met-enkephalin) and cardiovascular responses to hyperthermic stress in chronic alcoholics

Chronic alcohol drinking causes profound alterations in hypothalamic-pituitary function. In the present study, endocrine [corticotropin (ACTH), beta-endorphin, cortisol, and met-enkephalin] and cardiovascular (blood pressure) changes in response to hyperthermic stress (sauna at 90 degrees C for 30 min) were evaluated in 25 normal men (25 to 50 years old) and in 48 male alcoholic subjects (34 to 56 years old) after 5 weeks of abstinence. Significantly lower increments in systolic blood pressure were observed in alcoholics than in control subjects. Furthermore, alcoholics showed lower ACTH, beta-endorphin, and cortisol increments in response to sauna than normal controls. In contrast, sauna-induced hyperthermia did not change significantly the circulating met-enkephalin levels in either normal controls or chronic alcoholics. These data suggest that an impairment in the adaptive response to stress affects alcoholic men even after a few weeks of abstinence from alcohol.     

Gastric acidity in a double ulcer (of the stomach and duodenum)

Gastric salt-acid secretion was studied in three comparative patient groups with gastric ulcer, endoscopically confirmed, combination of gastric and duodenal ulcers. In the patients with double localization of the ulcer (stomach and duodenum) - hyperacidity was determined after pentagastrin stimulation. Acid-salt secretion was higher than that of the patients with gastric ulcer and was close to the secretion of those with duodenal ulcer, being but with a high standard deviation, necessitates consideration to be given to each concrete case of treatment. No discrepancy in the volume of gastric secretion before meals was established, thus impugning the role of pylor stasis in the genesis of secondary gastric ulceration. The incidence of atrophic gastritis in case of gastric and double ulcer is almost identical, hence attention is paid to the duodeno-gastric reflux as an eventual cause for damaging gastric mucosa with its successive ulceration in the patients with duodenal ulcer of many years. That is the reason, drugs enhancing the resistance of gastric mucosa as well as methoclopramid intake are proposed additionally to the drugs, neutralizing or blocking the gastric acid-salt secretion.     

Induction and intracellular localization of a 72-kDa heat shock protein in rat gastric mucosa after water-immersion stress

We investigated the expression and changes in the intracellular localization of a 72-kDa heat shock protein (HSP72) in rat gastric pyloric and fundic mucosa before and after water-immersion stress. Severe mucosal damage was found in the fundic mucosal area of the stomach after this stress. However, no mucosal lesion developed in the pyloric mucosal area. HSP72 in both the soluble and insoluble fractions of the pyloric and the fundic mucosal areas was significantly increased after water-immersion stress, peaking 6h after the initiation of the stress. The increase in HSP72 was more significant in the pyloric mucosal area than in the fundic mucosal area under both normal and stress conditions. The increase of HSP72 in the pyloric mucosal cells occurred prior to the formation of the mucosal lesions, whereas the increase of HSP72 in the fundic mucosal cells was observed after ulcer formation. An immunohistochemical study showed that HSP72 was constitutively expressed in the cytoplasm of the gastric mucosal cells, and that the intranuclear induction of HSP72 was remarkably intense in the pyloric mucosal cells, especially in the proliferative zone, compared with the fundic mucosal cells. Our results may suggest that HSP72 has an important cytoprotective function in gastric mucosal cells and that there is a "biophysical" difference between pyloric and the fundic mucosal cells.     

Interleukin-12 expression is focally enhanced in the gastric mucosa of pediatric patients with Crohn's disease

The stomach is frequently involved in children suffering from Crohn's disease (CD). Diagnosis of specific gastritis may be difficult when granulomas are absent. We have used in situ hybridization to examine the expression of interleukin (IL)-12, a key cytokine in the Th1 response. IL-12 p35 and p40 antisense probes were used to examine ileal specimens from 9 children with CD and gastric biopsies from 24 children (13 with CD, 6 with Helicobacter pylori chronic gastritis, and 5 with a normal gastric mucosa). In all patients with CD, many clusters of IL-12-positive cells were present in the lamina propria. This was the case in the ileal specimens as well as in gastric mucosa showing granulomatous gastritis or nongranulomatous gastritis. The same distribution patterns were found for the IL-12 p35 and p40. In three patients with Helicobacter pylori gastritis, few scattered IL-12-positive cells were found. No positive cells were found in the normal gastric mucosa. The focally enhanced IL-12 expression in the gastric mucosa of pediatric patients with CD, with or without specific lesions, suggests that both are indeed linked to the disease and supports the major part of IL-12 in initiating and maintaining of the cascade resulting in the Th1 responses.     

PCR analysis of T. whippelii DNA in a case of Whipple's disease: effect of antibiotics and correlation with histology

A 58-yr-old man developed severe weight loss, arthralgias, and diarrhea. Endoscopic examination of the stomach and duodenum revealed thickened folds of duodenal mucosa. Biopsy of the gastric mucosa was negative, whereas duodenal biopsy revealed blunted epithelial villi and PAS-positive foamy macrophages within the lamina propria. Bacilli typical of those associated with Whipple's disease were found by electron microscopy. The diagnosis was confirmed by polymerase chain reaction (PCR) assay, which detected a portion of the 16S ribosomal RNA gene sequence corresponding to the Whipple bacillus (Tropheryma whippelii) in duodenum, stomach, and liver biopsies before therapy. T. whippelii DNA was eliminated from all tissues tested within 3 months of starting antibiotic treatment, but the histological improvement lagged behind the clinical and molecular evidence of improvement.     

Effect of gastric secretion on penetration of N-3H-methyl-N-nitro-N-nitrosoguanidine into gastric mucosa of rats

Clinical conditions with low gastric acid secretion have been associated with increased risk of gastric cancer. There has also been concern about gastric acid inhibition and N-nitroso compound formation in the stomach. This study investigates the effect of gastric acid secretion on the penetration of N-3H-methyl-N-nitro-N-nitrosoguanidine, an N-nitroso compound and gastric carcinogen, into the gastric mucosa of rats. Gastric acid secretion was stimulated by pentagastrin (40 microg/kg/hr) and inhibited by omeprazole (40 micromol/kg) before mucosal exposure to N-3H-methyl-N-nitro-N-nitrosoguanidine. Penetration of the carcinogen was evaluated by light microscopic identification of cells in the S-phase labeled with N-3H-methyl-N-nitro-N-nitrosoguanidine. This population of double-labeled cells is considered at risk from N-methyl-N-nitro-N-nitrosoguanidine-induced carcinogenesis. The percentage of double-labeled cells was significantly higher in antrum than in corpus mucosa (P < 0.0001). Stimulation or inhibition of gastric acid secretion did not affect the penetration of N-3H-methyl-N-nitro-N-nitrosoguanidine in antrum or corpus mucosa. We conclude that modulation of gastric acid secretion does not affect the penetration of the carcinogen into the gastric mucosa nor does it explain the different penetration of the carcinogen into corpus and antrum mucosa.     

Meta-analysis of the effects of alcohol dehydrogenase genotype on alcohol dependence and alcoholic liver disease

The purpose of this paper is to assemble and evaluate existing data on the effect of genetic variation in ADH2 and ADH3 on the risk of alcohol dependence, and on the risk of alcoholic liver disease. Calculations of odds ratios and their confidence limits, and tests for heterogeneity of the results from the available studies, have been performed. It is clear that possession of the ADH2-2 allele decreases the risk of alcohol dependence, but it increases the risk of alcoholic liver disease among alcoholics. ADH3 variation also has significant effects on alcohol dependence, which may be due to linkage to ADH2; the ADH3 effect differs significantly between Asian and European subjects. Therefore ADH genotype has substantial effects on risk of alcohol dependence and alcoholic liver disease, but more work is needed on the generalizability of these findings to non-Asian populations, and on possible mechanisms.     

Post-traumatic regeneration of the epithelium of the gastric and intestinal mucous membranes of dogs

The work was devoted to the study of the sources of reparative regeneration of the epithelium of the gastric and intestinal mucosa. A number of surgical interventions on the stomach and intestine of 1 dogs were performed for the solution of this problem. On the basis of the investigations carried out the leading role in the regeneration of the gastric and intestinal mucosa was found to be played by uninjured epithelium surrounding the area of the surgical intervention. This was confirmed by the fact that a mucosa-free intestinal pedicle graft implanted into the defect of the wall of the stomach was covered by gastric mucosa; a stomach graft devoid of own mucosa became covered with intestinal mucosa when displaced in the form of a cylindrical "insertion" into the intestinal tube; mucosa-free stomach pouch became obliterated; this could be reliably attributed to the absence of the main source of regeneration -- uninjured mucosal epithelium along the periphery of the defect. No regeneration of the epithelium of the gastric mucosa from the implanted cells was revealed; this served as an additional confirmation of the fact that regeneration under conditions of the mentioned experiments occurred on account of creeping of epithelial cells surrounding the area of the surgical intervention over the free surface of mucosa.     

Blood activities of antioxidant enzymes in alcoholics before and after withdrawal

Since free radicals and peroxides seem to be involved in the toxicity of alcohol, several authors have examined the variations of blood activities of antioxidant enzymes in alcoholics, but published results are somewhat conflicting. In this study, erythrocyte (E) activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT), and plasma (P) activities of SOD and GPX were measured in 58 male alcoholics without evidence of severe liver disease before and after a 21-day weaning period, and in a control group of 78 healthy men. Before abstinence, E-SOD and E-GPX activities were, respectively, 6.8% and 13.0% lower in alcoholics than in controls (p < or = .05 and p < or = .01, respectively), whereas the slight increases of E-CAT, P-SOD and P-GPX were not statistically significant. After 21 days of abstinence, no change in activities of the erythrocyte enzymes was noticed; conversely, P-SOD activity was reduced by 8.3% (p < or = .01) and P-GPX by 23.3% (p < or = .001). Variations of blood antioxidant enzymes observed in patients were of limited amplitude and do not allow the use of either of them as markers of alcohol abuse.     

Alcohol-related cancers and aldehyde dehydrogenase-2 in Japanese alcoholics

Aldehyde dehydrogenase-2 (ALDH2) eliminates most of the acetaldehyde produced during alcohol metabolism. In some drinkers, a mutant ALDH2 allele contributes to diminished activity of the enzyme, dramatically increasing the risk for esophageal cancer. This study was designed to evaluate the ALDH2 gene polymorphism as a predictor of the development of cancers prevalent in Japanese alcoholics. We performed ALDH2 genotyping on lymphocyte DNA samples from Japanese alcoholic men (487 cancer-free; 237 with cancer, including 34 oropharyngolaryngeal, 87 esophageal, 58 stomach, 46 colon, 18 liver, 7 lung, 9 other sites, and 19 multiple primary cancers in two or three organs). The frequencies of the mutant ALDH2*2 allele were significantly higher in alcoholics with oropharyngolaryngeal (52.9%), esophageal (52.9%), stomach (22.4%), colon (21.7%) and esophageal cancer concomitant with oropharyngolaryngeal and/or stomach cancer (78.6%), than in cancer-free alcoholics (9.0%). After adjustment for age, daily alcohol consumption and amount of cigarette smoking, significantly increased risks (odds ratios) in the presence of the ALDH2 *2 allele were found for oropharyngolaryngeal (11.14), esophageal (12.50), stomach (3.49), colon (3.35), lung (8.20) and esophageal cancer concomitant with oropharyngolaryngeal and/or stomach cancer (54.20) but not for liver or other cancers. These results suggest a general role of acetaldehyde, a recognized animal carcinogen, in the development of human cancers.     

Helicobacter pylori: the mouth, stomach, and gut axis

The aim of this study was to identify the natural reservoir and route of transmission of Helicobacter pylori infection. Two hundred eight (208) dyspeptic patients (114 males, 94 females; peak age of cohort, 50-59.9) were recruited. Specimens were collected from saliva, supra- and subgingival dental plaque, tongue scrapings, and oropharyngeal swabs. At subsequent endoscopy, gastric antral biopsy was performed for the rapid urease test (RUT), microbiological culture, and, in some patients, histology. Gastric juice samples were aspirated, and in 50 patients duodenal aspirate was collected. Polymerase chain reaction (PCR) with primers targeted to the 16S rRNA sequence of H. pylori was also employed for each of the specimens. In those patients where H. pylori was detected from multiple sites (dental plaque, gastric juice, gastric biopsy, and duodenal aspirate), restriction endonuclease digestion with Hae III was performed to determine if they were epidemiologically linked. The results indicated that 15/208 patients (7%) tested positively for H. pylori by PCR in dental plaque; only 2 samples were positive by culture. In none of the other oral sites sampled was H. pylori detected by any test used in the study. Gastric juice and gastric biopsy specimens from 36/ 208 patients (17%) and 114/208 patients (55%), respectively, were positive by PCR. Duodenal aspirate from 6/50 patients (12%) also tested positively by PCR. All specimens tested by restriction endonuclease digestion with Hae III (15/15 patients) were positive in both antral biopsy and gastric juice specimens, as well as 5 specimens from the duodenal aspirate. Four of the dental plaque strains had restriction patterns similar to those of the stomach and duodenal sites, providing evidence that these sites were infected with the same strain of H. pylori. In conclusion, the results suggest that H. pylori selects the gastric mucosa as its preferred site. The detection in dental plaque could indicate that the oral cavity may act as a reservoir or sanctuary for the organism. Whether H. pylori is a resident or transient oral microorganism is still unclear, although it is more likely to be transient in nature.     

Decrease in glutamic acid decarboxylase level in the hypothalamus of spontaneously hypertensive rats

To elucidate the role of interleukin (IL)-6 and IL-8 in the pathogenesis of gastric ulcer in Helicobacter pylori-positive gastritis, in situ hybridization using digoxigenin-labeled cDNA probes for both cytokines was performed. Immunogold silver staining was added to further improve the sensitivity of this non-radioactive hybridization. The biopsy specimens were taken from eight patients with active gastric ulcer before treatment, in all of whom H. pylori was positive. Macrophages (the putative producers of these cytokines) were determined by immunohistochemistry using anti-CD68 monoclonal antibodies (KP-1). IL-6 mRNA was most abundantly expressed in the epithelium and in the infiltrating cells in tissue adjacent to gastric ulcer. Quantitative analysis disclosed a significant increase in cells positive for IL-6 mRNA near the ulcer margin compared to cells in the surrounding tissue. In contrast, cells positive for IL-8 mRNA were observed in equal proportions and evenly in the epithelium and over the entire layer of the gastric mucosa regardless of the presence of gastric ulcer. The majority of infiltrating cells positive for both IL-6 and IL-8 mRNA were thought to be macrophages because of their morphologic features and their immunohistochemical reactivity to CD68. These findings strongly suggest that IL-6 is overexpressed at the margin of gastric ulcer in H. pylori-positive gastritis.