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Biomedical subjects

M Tatsuta

Publications and source records attributed to M Tatsuta.

At least 235 records · Page 13Linked to original sources
PubMed1988

Inhibitory effect of prolonged administration of tetragastrin on experimentally induced intestinal metaplasia in Wistar rats.

The effect of tetragastrin on the induction of intestinal metaplasia by intragastric administration of 5% NaOH solution was investigated in Wistar rats. The prolonged administration of tetragastrin in depot form from 1 week after NaOH treatment resulted in a significant increase in basal gastric acid secretion and a significant reduction in the incidence and number of intestinal metaplasia in experiment week 35. A histologic examination showed goblet cell metaplasia and intestinal metaplasia without Paneth cells in rats treated only with olive oil. Only goblet cell metaplasia was found in rats treated with tetragastrin. These results show that the prolonged administration of tetragastrin to rats after NaOH treatment increases gastric acid secretion and suppresses the induction of intestinal metaplasia.

Animals↗
PubMed1988

Inhibitory effect of prolonged administration of cysteamine on experimental carcinogenesis in rat stomach induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effect of cysteamine (2-aminoethanethiol hydrochloride) on the incidence and histology of gastric adenocarcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was investigated in inbred Wistar rats. Prolonged administration of 25 or 50 mg per kg body weight of cysteamine after treatment with MNNG for 25 weeks significantly reduced the incidence and number of adenocarcinomas of the glandular stomach. Histological examination showed that the adenocarcinomas that did develop in rats treated with these 2 doses of cysteamine had high mucin-producing activity. Furthermore, treatment with cysteamine caused significant increases in serum gastrin level and gastric acid secretion, together with significant decreases in the antral mucosal pH and the labelling indices of pyloric and oxyntic gland mucosae and gastric cancer. These findings indicate that cysteamine inhibits the development of gastric adenocarcinomas and that its effect may be related to decreasing proliferation of cells in the gastric mucosae.

Adenocarcinoma↗
PubMed1988

Effect of cimetidine on inhibition by tetragastrin of carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of combined administration of cimetidine and tetragastrin on gastric acid secretion, the labeling index of the gastric mucosa, and the incidence of gastric adenocarcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in inbred Wistar rats. Prolonged administration of tetragastrin in depot form after treatment with N-methyl-N'-nitro-N-nitrosoguanidine resulted in a significant increase in gastric acid secretion, a significant decrease in the labeling index of the antral mucosa, and a significant decrease in the incidence of adenocarcinomas of the glandular stomach. Administration of cimetidine at 20 mg, but not 10 mg, per kg body weight with tetragastrin significantly reduced the gastric acid secretion induced by tetragastrin alone but did not influence the labeling index of the antral mucosa or the inhibitory effect of tetragastrin on gastric carcinogenesis. These findings indicate that gastric acid secretion has no influence on the development of gastric adenocarcinomas and that the inhibitory effect of tetragastrin on gastric carcinogenesis may be related to its effect in decreasing proliferation of cells in the antral mucosa.

Adenocarcinoma↗
PubMed1988

Inhibition by tetragastrin of experimental carcinogenesis in rat colon: effect of wheat bran consumption.

The effect of dietary wheat bran consumption on the anticarcinogenic action of tetragastrin upon colon carcinogenesis induced by azoxymethane was investigated in 122 inbred Wistar rats. Rats were given a control fiber-free diet or the same basal diet plus 20% wheat bran. From week 5, they were given 250 micrograms per kg body weight of tetragastrin in depot form every other day until the end of the experiment at week 45. Prolonged administration of tetragastrin resulted in a significant reduction of the incidence and number of colonic tumors per rat in the group given the fiber-free diet. The adenocarcinomas that did develop in this group had high mucin-producing activity, unlike the cancers produced in controls without tetragastrin. However, administration of tetragastrin had little or no influence on the incidence, number or histology of colonic tumors in the group given basal diet plus wheat bran. Dietary supplementation with wheat bran alone had little or no effect on the development or histology of colonic tumors. Before and during the administration of carcinogens, addition of fiber to the diet resulted in a significant fall in the colonic pH and a significant increase in the crypt column length, but administration of tetragastrin did not have an additive effect on the crypt column length in rats fed diet supplemented with fiber.

Adenocarcinoma↗
PubMed1988

Effect of cigarette smoking on extent of acid-secreting area and intestinal metaplasia in the stomach.

The association of cigarette smoking and other variables with the extent of the acid-secreting area and intestinal metaplasia were investigated by multivariate analysis. Studies were made by the endoscopic Congo red-methylene blue test developed in our hospital. In this test, acid-secreting areas and areas of intestinal metaplasia could be identified as discolored areas and areas staining blue with methylene blue, respectively. In multivariate analysis, the following variables were associated with a reduction in the size of the acid-secreting area in decreasing order of importance: the smoking index and age. The following factors had little or no influence on the size of the acid-secreting area: sex, and the consumption of aspirin and nonsteroidal, nonsalicylate, antiinflammatory drugs (NSNSAIDs). In general, in patients with a high smoking index, the acid-secreting area was small. Smoking had an influence in both younger and older patients and had more influence in females than in males. Multivariate analysis also shows that the following factors were associated with an increase in the area of intestinal metaplasia in decreasing order of importance: the extent of the acid-secreting area, age, and the smoking index. The following factors had little or no influence on the area of intestinal metaplasia: the consumption of aspirin and NSNSAIDs and sex. In general, in patients with little or no acid-secreting area, the area of intestinal metaplasia was extensive. These findings indicate that smoking is associated with reduction in the size of the acid-secreting area and so in development of intestinal metaplasia.

Adult↗
PubMed1988

Morphological changes in a human scirrhous gastric carcinoma cell line (KATO-III) when cultured in collagen-coated dishes.

The morphological differences between cells of a human scirrhous gastric carcinoma cell line (KATO-III) cultured in plastic dishes and in collagen-coated dishes were examined by phase-contrast and electron microscopy. When KATO-III cells were inoculated into plastic dishes, a few cells became attached to the surface of the dishes and the rest remained in suspension. However, when they were inoculated into collagen-coated dishes, they all remained in suspension. In both types of dish, most of the cells in suspension were single although a few were in clusters. The cells in suspension in collagen-coated dishes differed in morphology from those in the plastic dishes. They had abundant cytoplasm, well-developed Golgi complexes, and many microvillus-like cell protrusions. Moreover, they had hemidesmosome-like and desmosome-like structures on their surface and an increased amount of intracytoplasmic desmosome-like structures. The cells in clusters in the collagen-coated dishes were closely connected by junctional complexes, such as tight junctions, desmosomes and interdigitations, whereas those in plastic dishes were linked only by desmosomes. These results suggest that collagen affects the morphology of human scirrhous carcinoma cells.

Adenocarcinoma, Scirrhous↗
PubMed1988

Diagnosis of simultaneous multiple gastric cancers by the endoscopic Congo red--methylene blue test.

The clinicopathological features of simultaneous multiple gastric cancers, and the accuracy of their diagnosis by routine endoscopic examination were analyzed. In addition, the accuracies of diagnosis of coexisting early gastric cancers by routine endoscopic examination and by the endoscopic Congo red--methylene blue test developed in our hospital were compared. The results showed that multiple cancers occurred frequently in elderly male patients, in patients with early gastric cancer of the flat and elevated types and the depressed type without converging folds, and in patients with advanced cancer of Borrmann type I. These patients frequently have early cancers of the flat or depressed types without converging folds, and advanced cancers of Borrmann type I. The coexisting lesions are very difficult to diagnose by routine endoscopic examination: a correct diagnosis of coexisting early cancers was made in only 28.3% of the cases by routine endoscopic examination. But with the Congo red--methylene blue test, the diagnostic rate was raised significantly to 88.9%. In this test, Congo red and methylene blue are sprayed on the surface of the stomach and are bleached within 2 to 5 minutes on the surface of a tumor, but not on the surface of unaffected mucosa.

Aged↗
PubMed1988

Value of gastric juice carcinoembryonic antigen in identifying high-risk patients for gastric cancer.

The relationship of the level of carcinoembryonic antigen (CEA) in the gastric juice to the extent of intestinal metaplasia and gastric cancer, and clinical values of gastric CEA for identifying high-risk patients for gastric cancer were examined. A significant correlation was found between the levels of gastric CEA and the distribution of intestinal metaplasia. Studies were made by the endoscopic Congo red-methylene blue test developed at our hospital. Gastric CEA levels were significantly higher in patients with localized and diffuse intestinal metaplasia than in those with no intestinal metaplasia. The mean levels of gastric CEA in patients with well-differentiated adenocarcinomas were significantly higher than in those with diffuse intestinal metaplasia. They were also significantly higher in patients with poorly differentiated adenocarcinomas than in patients with no intestinal metaplasia, but not significantly higher than in those with diffuse intestinal metaplasia. Endoscopic follow-up examinations show that gastric cancer was detected in only 1 patient with a gastric CEA level of 10 ng/ml or more, but in none of those with gastric CEA of less than 10 ng/ml, during the average observation period of 4.3 years. These results indicate that gastric CEA is produced both by intestinal metaplasia and well- and poorly differentiated adenocarcinomas, and that gastric CEA is useful in identifying high-risk patients for gastric cancer.

Carcinoembryonic Antigen↗
PubMed1988

Comparison of photodynamic inactivation of experimental stomach tumors sensitized by acridine orange or hematoporphyrin derivatives.

The photodynamic inactivations of Walker carcinosarcoma 256 stomach tumors by the concomitant use of acridine orange (AO) and argon laser, and by the combined use of hematoporphyrin derivatives (HPD) and dye laser were compared. Wistar rats bearing stomach tumors of 4-6 mm in diameter 5-10 days after their implantation were injected intraperitoneally with 40 mg/kg body weight of AO or HPD, and 24 h later their stomach tumors were exposed to argon laser at 488 nm or dye laser at 630 nm, respectively, at an intensity of 15 mW/cm2 for 20 min. Temperature rise was less than 3 degrees C during irradiation. Seven days after irradiation, complete or partial necrosis with sparing of the surrounding mucosa was seen histologically in all rats treated by the two therapy methods. Phase contrast and electron microscopy showed nuclear pyknosis and damage to the inner layer of the nuclear envelope in tumor cells treated with AO and argon laser, while cytotoxicity involved damage to the outer layer of the nuclear envelope and intracytoplasmic organelles in tumor cells treated with HPD and dye laser. This difference between AO and HPD is considered to be a difference in their intracellular localization in tumor cells.

Acridine Orange↗
PubMed1988

[Four operative cases of lung carcinoma with intra-atrial extension via the pulmonary vein].

We experienced four operative cases of lung carcinoma with intra-atrial extension via the pulmonary vein. In two cases, after assessment of the cardiac involvement, we performed extensive surgery under cardiopulmonary bypass. Their postoperative courses were uneventful, and their performance status was improved. However, seven months later one patient died of widespread metastases, while the other is alive but has recurrence. The other two patients underwent ordinary lobectomy because there were no abnormal findings in the hilar examination. However, the lumen of the resected pulmonary vein was filled with tumor tissue. One patient had massive embolism and died on the second postoperative day. The last case had residual tumor dislodging from the left atrium to the aorta. Though he was discharged without any complication, he developed multiple brain metastases 4 months after operation. We conclude that extensive surgery using cardiopulmonary bypass for lung cancer patients with such intracardiac involvement is effective for improvement of PS and reduces the risk of sudden death due to cardiac failure or emboli. Accurate diagnosis of intracardiac extension in these unusual cases is important.

Aged↗
PubMed1988

Enhancement by vagotomy of experimental induction of intestinal metaplasia and atypical glandular hyperplasia in Wistar rats.

The effect of truncal vagotomy on the induction of intestinal metaplasia and atypical glandular hyperplasia by intragastric instillation of 5% NaOH solution was investigated in Wistar rats. Truncal vagotomy resulted in significant increases in the incidences and numbers of intestinal metaplasia and atypical glandular hyperplasias in experimental week 52. Histological examinations show that unlike goblet cell metaplasia and mild atypical glandular hyperplasia in the sham-operated rats, intestinal metaplasia without Paneth cells and moderate atypical glandular hyperplasia were more frequent in rats treated with NaOH solution and vagotomy. These findings indicate that the promoting effect of truncal vagotomy on gastric carcinogenesis may be related to its enhanced effect on induction of intestinal metaplasia and atypical glandular hyperplasia.

Animals↗
PubMed1988

Early carcinoma of the stomach after gastric surgery: comparison with early carcinoma in the non-operated stomach.

The relationships between the gross and histological types of early gastric carcinoma and non tumorous gastric mucosa were investigated in 12 cases of carcinoma of the stomach after operation and 46 cases of cardiac carcinoma within 5 cm of the squamocolumnar junction. Histological studies were made by examining specimens obtained by gastrectomy. Grossly elevated and histologically differentiated carcinomas were statistically more frequent after gastric surgery, than before. Comparison between cases of elevated and differentiated adenocarcinoma that had undergone gastric surgery with those that had not showed that atrophic gastritis and intestinal metaplasia in the surrounding mucosa of the tumor were significantly slighter after gastric operation than in unoperated cases. Results suggested that early carcinomas developing after gastric surgery are different from those in the upper portion of the unoperated stomach.

Cardia↗
PubMed1988

Effect of a defined diet in liquid form on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effect of ad libitum feeding of a defined diet in liquid form on the incidence of gastric adenocarcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was investigated in Wistar rats. Fresh defined diet was supplied once every 24 h from 2 weeks before oral administration of MNNG to the end of the experiment in week 52. Oral administration of the defined diet resulted in significant decrease in the incidence of gastric cancers in experimental week 52. It also caused a significant increase in the incidence of atypical glandular hyperplasia, which is a precursor of gastric cancer. Furthermore, administration of the defined diet for 30 and 52 weeks also resulted in significant decrease in the serum gastrin level and the marked gastric mucosal hypoplasia. These findings indicate that the defined diet in liquid form inhibited the development of gastric cancers and that this effect may have been related to its effect in decreasing proliferation of cells in the antral mucosa.

Animals↗