Tadatsugu Ohno

Angiomyolipoma of the colon: A new entity in colonic polypoid lesions

SummaryA 67-year-old man with angiomyolipoma on the sigmoid colon is reported. The colonic polyp was pedunculated and diagnosed histologically after endoscopic polypectomy. Angiomyolipoma is one of the benign hamartomas arising principally in the kidneys of patients with or without tuberous sclerosis. Extrarenal angiomyolipoma is rare and this may be the first report of colonic angiomyolipoma.

Campylobacter pylori in Japan: Bacteriological feature and prevalence in healthy subjects and patients with gastroduodenal disorders

SummaryThe presence ofCampylobacter pylori was investigated in biopsy specimens obtained during gastrofiberscopy from 103 consecutive patients prospectively. Patients included 25 with gastric ulcer, 4 with duodenal ulcer, 5 with coexisting gastroduodenal ulcer, 31 with gastroduodenal ulcer with gastritis, 27 with gastritis, 3 with gastric polyps and 8 with gastric cancer. Results were compared with 20 healthy control subjects who were endoscopically normal. Two specimens each were taken from 3 sites in the stomach. One part was used for a histological study to examine the presence of the organisms. The other part was cultured using Skirrow’s agar microaerophilically. Conventional microflora andC. pylori were examined in gastric contents of some cases. Bacteriological features of isolated strains of C.pylori were identical to the NCTC strain. C.pylori was the most dominant organism in gastric contents at any pH level. Detection rates of C.pylori by bacteriological culture were 96% in gastric ulcer, 100% in duodenal ulcer, 80% in coexisting gastroduodenal ulcer, 84% in gastroduodenal ulcer with gastritis, 70% in gastritis, 100% in gastric polyps and 100% in gastric cancer, and the percentages recognized by histological studies were 81,100,100, 84, 71, 67, and 57%, respectively. The values in healthy controls were 55% by histological and bacteriological methods (P<0.001 compared with overall ulcer patients). These results supported the close association between C.pylori and gastroduodenal diseases.

N-nitrosamines in the stomach with special reference toin vitro formation, and kinetics after intragastric or intravenous administration in rats

SummaryTo study the implications of nitrosation in the stomach, the formation of N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) from nitrite and secondary amines was examinedin vitro under conditions simulating gastric juice. Kinetics of NDMA were investigated after intragastric or intravenous administration of 0.2mg/kg of NDMA in rats. NDMA and NDEA were measured using combined gas chromatography and thermal energy analyzer. Nitrite levels in human gastric juice were less than 10µg/ml. Optimal pH for nitrosation was between 2.0 to 3.5. Nitrosamine formation reached maximum concentration at 3 to 6 hours. The maximum ratios of nitrosation were 0.15 and 0.11% in NDMA/nitrite and NDEA/nitrite, respectively. In the kinetic study, the highest blood levels of NDMA were observed at 5 min, reaching 174±40 and 374±40 ng/ml after administration into the stomach and duodenum, respectively. Then they decreased exponentially and were not detectable after 4 hours. Tissue levels of NDMA in the liver, spleen, kidney, lung and brain showed 70% of the blood levels. Urinary excretion of intravenously administered NDMA during the first 4 hours was less than 0.2%. These results supported the hypothesis that nitrosation occurred in gastric juice under optimal conditions, and indicated that nitrite levels were the limiting factor for nitrosation. Quick disappearance from the gastrointestinal tract suggested that the pathologic implication of nitrosamines formed in the stomach could be important for other organs.

N-Nitrosamines in gastric juice of patients with gastric ulcer before and during treatment with histamine H2-receptor antagonists

SummaryThe clinical implications of N-nitrosamines (NAs) were studied by analyzing their concentration in the gastric juice of 72 healthy subjects and 279 patients with gastric ulcer before and during treatment with histamine H2-receptor antagonists. NAs were measured by combined gas chromatography and thermal energy analyzer. The detection ratios of N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) in the patients were 35.3% and 34.6%, respectively, which were significantly higher than the corresponding values in healthy subjects (19.4% and 16.7%, P<0.01). Analysis among the patients showed that this trend was mainly due to higher values in patients who were given histamine H2-receptor antagonists, as their detection ratios increased to 40.2% (NDMA) and 39.9% (NDEA). Patients without histamine H2receptor antagonists showed moderate increases of detection ratios (NDMA; 24.2% NDEA; 22.6%) compared with healthy controls. The differences in these values between those receiving and not receiving histamine H2-receptor antagonists were statistically significant (P<0.01). The maximum concentrations of NDMA and NDEA were 7.9 and 9.8 ng/ml in patients, and 1.2 and 1.3 ng/ml in healthy subjects (the difference between the 2 groups P<0.02). These results indicated that patients with gastric ulcer had higher detection ratios and concentrations of NDMA and NDEA in gastric juice and that, while significant increases occurred during treatment with histamine H2-receptor antagonists, the extent of increase was below toxic or experimental carcinogenic levels.

Granular cell tumor of the ascending colon: A case report

SummaryA granular cell tumor (granular cell myoblastoma) of the ascending colon in a 48-year old male is reported. The tumor was detected by barium enema study as a sessile polyp, and colonofiberscopy revealed submucosal tumor. It was removed by endoscopic polypectomy. Macroscopic examination showed the characteristic features of granular cell tumor. The avidin-biotin-peroxidase complex (ABC) method for detection of S-100 protein demonstrated that the cytoplasm of tumor cells and the pleomorphic nuclei were strongly stained with anti-S-100 protein serum, which supports the concept of the Schwann cell origin of granular cell tumor.

Gastric mucosal barrier in the rats fed with protein deficient diet or treated with carbon tetrachloride

SummaryThe effects of protein deficient diet and liver damage on the gastric mucosal barrier were studied in 32 Sprague-Dawley rats. The animals were divided into 4 groups according to their dietary regimens, CC14 induced liver damage and/or serotonin administration. Group 1 (control) was fed standard rat chow. Group II was fed a nonprotein diet for 2 weeks. GroupIII and IV were fed standard rat chow and given 1 ml of CCU per/Kg body weight intraperitoneally twice weekly for 12 weeks’. Rats in Group IV were also injected with 20 mg per/Kg of serotonin intraperitoneally 30 minutes prior to surgery. After pyloric ligation, an acid test solution composed of 100 mM HCl, 10mM NaCl, 5 mM KC l and 5g per litre of PEG was instilled into the stomach and fluxes of Na+, K+, H+ and Cl~ ions across the gastric mucosa were measured.Compared to Group I, rats in GroupII,III and IV demonstrated an increased net negative hydrogen flux (p< 0.05). An increased net negative chloride flux (p< 0.05) was also demonstrated in Group II and IV, but no increase was noted in GroupIII. There were no significant differences in fluxes of sodium and potassium ions. As mentioned above, a lack of protein in the diet, liver damage or both, renders the gastric mucosa of the rat more susceptible to injury. In the gastric mucosa of these rats, there have occurred more increase in the negative net fluxes of hydrogen and chloride ion, which may indicate the reduction of defence mechanism against a mucosal damage.