Biomedical subjects

H Iishi

Publications and source records attributed to H Iishi.

At least 91 records · Page 5Linked to original sources

PubMed1995

Ornithine decarboxylase inhibitor attenuates NaCl enhancement of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effects of combined administration of NaCl and the ornithine decarboxylase (ODC) inhibitor 1,3-diaminopropane (DAP) on the incidence and number of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and on the ODC activity of the gastric wall and the labeling index of the gastric mucosa were investigated in inbred Wistar rats. Rats were given drinking water with or without 2.5 g/l DAP and chow pellets with and without 10% NaCl ad libitum after 25 weeks of oral administration of MNNG. At week 52 feeding 10% NaCl resulted in significant increases in the incidence of gastric cancers, in the ODC activity of the antral portion of the gastric wall and in the labeling index of antral epithelial cells. Administration of both NaCl and DAP significantly reduced the enhancements by NaCl of gastric carcinogenesis, ODC activity of the antral wall and the labeling index of antral epithelial cells. These results suggest that inhibition of ODC attenuates NaCl enhancement of gastric carcinogenesis and that enhancement by NaCl of gastric carcinogenesis is mediated by polyamine biosynthesis.

Animals↗

PubMed1995

Scanning electron microscopic observations on gastric mucus secretion in rats, and the effects of tetraprenylacetone.

Mucus secretion in the gastric mucosa of rats was studied with a scanning electron microscope. After stimulation, two types of mucus secretion were observed: exocytosis and apical expulsion. Prolonged administration of tetraprenylacetone (TPA) significantly increased the number of mucus-secreting cells in both the gastric corpus and antrum 12 h after the last administration of TPA. In the secreting cells, apical expulsion was significantly more frequent among TPA-treated than in untreated rats. TPA also significantly increased the hexosamine concentration in both gastric corpus and antrum. These findings indicate that TPA stimulates both the content and the secretion of gastric mucus, and that its secretion is chiefly through apical expulsion.

Animals↗

PubMed1995

Effects of Helicobacter pylori infection on healing and recurrence of gastric ulcers.

OBJECTIVES: The effects of Helicobacter pylori infection on the healing and recurrence of gastric ulcers were investigated. METHODS: Eighty-five and 17 patients with endoscopically-proven gastric ulcer with and without H. pylori infection, respectively, received 800 mg of cimetidine daily. Healing of ulcer and H. pylori infection were assessed at wk 12. After the 12-wk-treatment period, 67 and 16 patients with healed ulcer positive and negative for H. pylori infection, respectively, received maintenance treatment (cimetidine 400 mg daily). Ulcer recurrence and H. pylori infection were assessed at or within 24 wk from the beginning of maintenance treatment. Variables influencing ulcer healing and recurrence were analyzed by multiple regression analysis. RESULTS: Ulcer healing at wk 12 was similar in patients with and without H. pylori infection, occurring in 16 (89%) of 18 patients without H. pylori infection, compared with 67 (87%) of 77 patients with H. pylori infection. At or within 24 wk from the start of maintenance therapy, ulcer recurrence was significantly more frequent in patients with H. pylori infection than in those without: it occurred in three (20%) of 15 patients without H. pylori infection, but in 37 (58%) of 64 patients with infection. Multiple regression analysis showed that H. pylori infection was related most closely to ulcer recurrence independently. CONCLUSION: H. pylori infection had a significant independent influence on gastric ulcer recurrence, but not initial ulcer healing.

Adult↗

PubMed1994

Ornithine decarboxylase inhibitor attenuates bombesin enhancement of intestinal carcinogenesis and metastasis induced by azoxymethane.

The effects of combined administration of bombesin (40 micrograms/kg body weight) and the ornithine decarboxylase (ODC) inhibitor, 1,3-diaminopropane (DAP), on the development of large and small intestinal tumors and the incidence of their metastasis to the peritoneum induced by azoxymethane (AOM, 7.4 mg/kg body weight), the ODC activity of the intestinal wall, and the labeling index of the intestinal mucosa and tumor were investigated in inbred Wistar rats. Rats received weekly s.c. injections of AOM for 10 weeks, s.c. injections of bombesin every other day, and drinking water containing DAP (2.5 g/l) until the end of the experiment at week 40. Administration of bombesin significantly increased the incidence of intestinal tumors at week 40. It had no influence on the location, size, histological features or depth of involvement of intestinal adenocarcinomas, but significantly increased the incidence of their metastasis to the peritoneum. It also resulted in a significant increase in the intestinal ODC activity and labeling index. Administration of DAP with bombesin significantly reduced the enhancement of intestinal carcinogenesis by bombesin. Although the combined use of DAP with bombesin had little or no influence on the location, size, histological features, or depth of involvement of intestinal cancers, the incidence of their metastasis was significantly reduced. DAP significantly attenuated bombesin enhancement of the intestinal ODC activity and labeling index. These findings indicate that ODC inhibition attenuated the enhancement of intestinal carcinogenesis and metastasis to the peritoneum.

Adenocarcinoma↗

PubMed1994

Cytologic examination of pancreatic juice for differential diagnosis of benign and malignant mucin-producing tumors of the pancreas.

BACKGROUND: A new clinical type of pancreatic tumor, the mucin-producing tumor, has been recognized recently. However, it is not always easy to distinguish benign from malignant tumors preoperatively. In this study, three different methods of differentiating mucin-producing tumors of the pancreas were compared. METHODS: Endoscopic ultrasonography, endoscopic retrograde pancreatography, and cytologic examination of pancreatic juice were performed in 14 patients who had mucin-producing pancreatic tumors (11 carcinomas and 3 adenomas). Pancreatic juice was collected endoscopically without papillotomy. RESULTS: The sensitivity, specificity, and overall accuracy of endoscopic ultrasonography were 82%, 90%, and 79%, respectively; those of endoscopic retrograde pancreatography were 91%, 91%, and 86%; and those of cytologic examination were 91%, 100%, and 93%. CONCLUSION: Cytologic examination of pancreatic juice was the best of these three methods for differentiating benign from malignant mucin-producing pancreatic tumors.

Adenocarcinoma, Mucinous↗

PubMed1994

Protection by galanin against gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of prolonged administration of the neuropeptide galanin on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine, the norepinephrine concentration in the gastric wall, and the labeling index of the gastric mucosa were investigated in Wistar rats. The rats received 2 or 4 micrograms/kg body weight of galanin s.c. every other day after 25 weeks oral treatment with the carcinogen. Prolonged administration of galanin at 4 micrograms/kg body weight, but not at 2 micrograms/kg body weight, significantly decreased the incidence of gastric cancers in experimental week 52. However, it did not influence the histological types of cancers. Galanin at 4 micrograms/kg body weight also significantly decreased the labeling index of the antral epithelial cells but not the norepinephrine concentration in the gastric wall. These findings indicate that galanin inhibits gastric carcinogenesis and suggest that its effect may be related to the suppression of proliferation of the antral epithelial cells.

Animals↗

PubMed1994

Expression of c-myc mRNA as an aid in histologic differentiation of adenoma from well differentiated adenocarcinoma in the stomach.

BACKGROUND: Using prospective follow-up studies, the authors examined the value of the expression of c-myc mRNA in biopsy specimens obtained from elevated gastric lesions as an aid in the differentiating between adenomas and well differentiated elevated-type adenocarcinomas. METHODS: By in situ hybridization, the authors determined the expression of c-myc mRNA in biopsy specimens of elevated gastric lesions. The 31 patients who had borderline lesions with and without overexpression of c-myc were followed with repeated endoscopic examinations and gastric biopsies. RESULTS: Endoscopic follow-up examinations showed that gastric cancer was detected in 5 of 11 patients (46%) with elevated lesions that stained positively for c-myc mRNA during an observation period of 15 months (range, 2-32 months). The cancers were confirmed histologically in gastrectomy specimens. No cancers were found in patients with elevated lesions that stained negatively. The difference was statistically significant (P < 0.01). CONCLUSIONS: The overexpression of c-myc mRNA may present a new tool for distinguishing between adenomas and well differentiated adenocarcinomas of the elevated type.

Adenocarcinoma↗

PubMed1994

Monoamine oxidase B inhibitor enhances experimental carcinogenesis in rat colon induced by azoxymethane.

The effects of prolonged administration of the monoamine oxidase (MAO)-A inhibitor N-methyl-N-propargyl-3-(2,4-dichlorophenoxy)propylamine (clorgyline) and the MAO-B inhibitor N-methyl-N-2-propynyl-benzylamine (pargyline) on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), and on the norepinephrine (NE) concentration in the colon wall and the labeling index of colon mucosa were investigated in Wistar rats. Rats were treated s.c. with 7.4 mg/kg body weight of AOM once a week for 10 weeks, and also s.c. with 5 mg/kg body weight of clorgyline or 50 mg/kg body weight of pargyline in 0.9% NaCl until the end of the experiment. Treatment with pargyline significantly increased the incidence of colon tumors in week 35. However, it did not influence the histological appearance of the colon tumors or the histological types and depth of involvement of colon adenocarcinomas. Furthermore, it significantly increased the NE concentration in the colon wall and the labeling index of the colon mucosa during and after AOM-treatment. In contrast, clorgyline had no influence on the development or histological appearance of colon tumors. These findings indicate that the MAO-B inhibitor, but not the MAO-A inhibitor, enhanced colon carcinogenesis, and that its effect may be related to its effect in increasing the NE concentration in the colon wall and subsequently increasing the proliferation of colon epithelial cells.

Animals↗

PubMed1994

Diagnosis of colorectal tumors by the endoscopic Congo red-methylene blue test.

The endoscopic Congo red-methylene blue test was performed on 51 tumors of the large intestine. Results revealed that colorectal adenocarcinomas and adenomas bleached the Congo red and methylene blue sprayed over their surface and so appeared in sharp contrast to the bluish red mucosa of unaffected areas. No bleaching of the dyes was observed on the surface of non-neoplastic polyps. Moderately differentiated adenocarcinomas, submucosal or advanced cancers, and adenomas with severe atypia bleached the dyes most frequently. Thus this test facilitates early detection of colorectal tumors.

Adenocarcinoma↗

PubMed1994

Inhibitory effect of sialoadenectomy on hepatocellular tumourigenesis in male mice induced by 3'-methyl-4-dimethylaminoazobenzene.

Male C57BL/6xDS-F1 mice that had been treated with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) neonatally were subjected to sialoadenectomy (removal of the submandibular salivary glands) 60 days after birth. The development of adenomatous nodules and carcinomas in the livers of these mice was compared with the livers of males without sialoadenectomy. The incidence of adenomatous nodules in sialoadenectomized males at 6, 8, 10, and 12 months was significantly lower than that in sham-operated animals. Carcinomas were found in the livers of both sham-operated and sialoadenectomized males that were 10 and 12 months old and were less frequent in sialoadenectomized males although the difference was significant only at the age of 12 months. Sialoadenectomy decreased the serum concentration of epidermal growth factor (EGF) by about 40%. The present results indicate that sialoadenectomy inhibits the development of hepatocellular tumours induced by 3'-Me-DAB in male mice, an effect which may be caused by decrease in the serum level of EGF.

Adenoma↗

PubMed1994

Inhibition by shi-quan-da-bu-tang (TJ-48) of experimental hepatocarcinogenesis induced by N-nitrosomorpholine in Sprague-Dawley rats.

The effect of Shi-Quan-Da-Bu-Tang (TJ-48) on hepatocarcinogenesis induced by N-nitrosomorpholine (NNM) was investigated in male Sprague-Dawley rats. Rats were given drinking water containing NNM for 8 weeks, and also from the start of the experiment, regular chow pellets containing 2.0 or 4.0% TJ-48 until the end of the experiment. Preneoplastic and neoplastic lesions staining for the placental type of glutathione-S-transferase (GST-P) or gamma-glutamyl transpeptidase (GGT) were examined histochemically. In week 15, quantitative histological analysis showed that prolonged administration of either 2.0 or 4.0% TJ-48 in the diet significantly reduced the size, volume and/or number of GST-P-positive and GGT-positive hepatic lesions. This treatment also caused a significant increase in the proportion of interleukin-2 receptor-positive lymphocytes among the lymphocytes infiltrating the tumours as well as a significant decrease in the labelling index of preneoplastic lesions. These findings indicate that TJ-48 inhibits the growth of hepatic enzyme-altered lesions, and suggests that its effect may be in part due to activation of the immune system.

Animals↗

PubMed1994

Addition of cisapride shortens colonoscopy preparation with lavage in elderly patients.

METHODS: The effect of pre-treatment with cisapride on colonoscopy preparation with lavage solution was compared in 120 out-patients less than 60 years and 73 out-patients 60 years or older, who were scheduled for total colonoscopy. By random allocation, patients were assigned to receive cisapride 10 mg or placebo 30 minutes before ingesting the magnesium citrate lavage solution. RESULTS: The cleansing results and patients' acceptance did not differ significantly in the two treatment groups in either age group. The time from the start of ingesting magnesium citrate until the rectal effluent became clear was significantly shorter in cisapride-treated patients of 60 years or more. Moreover, the residual fluid volume removed by suction during colonoscopy was significantly less in the patients above aged 60 years who received cisapride. CONCLUSION: These findings indicate that the combination of cisapride and magnesium citrate is more effective than magnesium citrate alone in cleansing the colon for colonoscopy in elderly patients.

Adult↗

PubMed1993

The association of Helicobacter pylori with differentiated-type early gastric cancer.

BACKGROUND: Recent studies have indicated that infection with Helicobacter pylori is closely associated with increased risk for gastric cancer. Previous studies, however, usually have been made on cases of advanced gastric cancer. METHODS: The Congo red-methylene blue test was performed on 19 healthy subjects, 24 patients with early gastric cancer of differentiated type, and 17 patients with early cancer of undifferentiated type. H. pylori infection was examined by culture of biopsy specimens obtained from noncancerous antral mucosa. RESULTS: H. pylori was detected in 19 (79%) of 24 patients with differentiated-type early gastric cancer, but in only 5 (29%) of 17 patients with undifferentiated-type early gastric cancer; this difference was statistically significant. It also was detected significantly more frequently in patients with differentiated cancers than in healthy subjects. CONCLUSIONS: H. pylori infection was closely associated with differentiated-type gastric cancers, but not with undifferentiated types.

Age Factors↗

PubMed1993

Enhancement by isoproterenol of hepatocarcinogenesis induced by N-nitrosomorpholine in Sprague-Dawley rats.

The effect of isoproterenol on hepatocarcinogenesis induced by N-nitrosomorpholine (NNM) was investigated in male Sprague-Dawley rats. Rats were given drinking water containing NNM for 8 weeks and s.c. injections of isoproterenol or vehicle every other day for 13 weeks. Pre-neoplastic and neoplastic lesions staining positive for gamma-glutamyl transpeptidase (GGT) or the placental type of glutathione-S-transferase (GST-P) were examined histochemically at week 13. Prolonged administration of isoproterenol resulted in a significant increase in the number of GGT-positive, but not GST-P-positive, lesions. The incidence, number and size of hepatocellular carcinomas were also significantly greater in rats treated with isoproterenol than in controls. Administration of isoproterenol significantly increased the intracellular cAMP and the labeling indices of pre-neoplastic lesions and adjacent liver. These findings indicate that isoproterenol enhances hepatocarcinogenesis and that this may be related to its enhancing effect, mediated by cAMP, on cell proliferation in neoplastic lesions and surrounding hepatocytes.

Animals↗

PubMed1993

Fundal atrophic gastritis as a risk factor for gastric cancer.

The role of atrophic gastritis of the gastric corpus (fundal atrophic gastritis) as a high-risk factor was investigated by studying operative findings and follow-up data on 690 patients with benign gastric diseases recorded at the Osaka Cancer Registry. The extent of fundal atrophic gastritis was determined by the endoscopic Congo red test. The patients were followed-up from the time of endoscopic examination (1968 to 1976) to December 31, 1987. The vital status of 654 patients (94.8%) at the end of the observation period was determined. During the follow-up period, 22 patients were found to have gastric cancer. The extent of fundal atrophic gastritis was shown to be closely related with the risk of developing gastric cancer. Patients who had been diagnosed as having severe fundal atrophic gastritis showed significantly higher risk of gastric cancer than patients who had been diagnosed as having little or no fundal atrophic gastritis (5.76-fold, calculated with adjustments for age, sex and the follow-up period). A positive linear relationship was found between the risk of developing gastric cancer and the extent of fundal atrophic gastritis. The observed number of gastric cancers was compared with the expected number calculated from the incidence in Osaka Prefecture. Analysis of the results showed that the observed and expected numbers of gastric cancers in patients with severe fundal atrophic gastritis were 11 and 4.8, respectively, the ratio of observed to expected numbers being 2.3 (p < 0.05). These findings indicate that severe fundal atrophic gastritis is a major risk factor for gastric cancer.

Adult↗

PubMed1993

Clinicopathological features and endoscopic diagnosis of superficial early adenocarcinomas of the large intestine.

From October 1987 to March 1991, 21 (8%) superficial early cancers were found among 256 early colorectal cancers (Dukes A and B1). Superficial early cancers were defined as early cancers less than 3 mm in height. These tumors were found scattered throughout the large intestine and were often observed as reddish spots, which were easily overlooked without careful observation. Histologically, 19 (90%) of them were well-differentiated adenocarcinomas, and five (24%) of them reached the submucosal layer. Eighteen (86%) of them were not associated with adenoma.

Adenocarcinoma↗

PubMed1993

Suppressive effect of estrogen on hepatocellular tumorigenesis induced in mice by 3'-methyl-4-dimethylaminoazobenzene.

Treatment of female C57BL/6 x DS-F1 mice with 3'-methyl-4- dimethylaminoazobenzene (3'-Me-DAB) neonatally resulted in the development of hepatocellular adenomatous nodules. Ovariectomy at 1 month of age greatly hastened the time of appearance of these nodules and significantly increased their incidence. The incidence of adenomatous nodules in females ovariectomized at 1 month of age was about 70% at 12 months of age, and was decreased to 4% by implantation of a pellet containing estradiol-17 beta (E2 pellet) at 1 month of age (at the time of ovariectomy). The incidence of adenomatous nodules at 12 months of age was not decreased significantly when the implanted E2 pellet was removed at 4 or 6 months of age, but was decreased significantly when it was removed at 8 or 10 months of age. Implantation of E2 pellets into ovariectomized females at 4 and 6 months of age decreased the incidence of adenomatous nodules as effectively as their implantation at 1 month of age. The implantation of E2 pellets into ovariectomized females at 8 or 10 months of age resulted in significantly lower incidences of adenomatous nodules at 12 months of age, than that in females ovariectomized at 1 month of age. The present results suggest that the ovarian hormone, estrogen suppresses the development of hepatocellular tumors induced by 3'-Me-DAB, exerting its effect from about 6 months of age.

Adenoma, Liver Cell↗

PubMed1993

Inhibition by amiloride of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of amiloride on the incidence and histological types of gastric cancers in Wistar rats induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and on the labelling index and proliferative fraction of gastric mucosa were investigated. After oral treatment with MNNG for 25 weeks, rats received s.c. injections of amiloride (0.25 mg kg-1 or 5.0 mg kg-1 body weight) in depot form every other day until the end of the experiment. Prolonged administration of 5.0 mg kg-1, but not 2.5 mg kg-1 of amiloride significantly decreased the incidence of gastric cancers in Week 52. However, it did not influence the histological features of the gastric cancers. It also significantly decreased the labelling index and proliferative fraction of the antral mucosa. These findings indicate that amiloride inhibits the development of gastric cancers, and that its effect may be related to its effect in decreasing cell proliferation of the antral mucosa.

Adenocarcinoma↗