[Image diagnosis of acute pancreatitis].
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Biomedical subjects
Publications and source records attributed to M Tatsuta.
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The effects of prolonged administration of the gamma-aminobutyric acid receptor agonist muscimol on enhanced induction of gastric carcinogenesis by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in spontaneously hypertensive rats (SHR), and on the norepinephrine concentration in the gastric wall and the labeling index of gastric mucosa were investigated. SHR and normotensive Wistar Kyoto (WKY) rats as controls were given a solution of MNNG (25 micrograms/ml) for 25 weeks and then i.p. injections of 0.5 mg/kg body weight of muscimol every other day. In control WKY rats, gastric cancers were found in 1 (7%) of 14 rats examined at week 52. In SHR treated with NaCl solution only, the incidence of gastric cancers was significantly increased to 50% compared with that in control WKY rats. However, treatment of SHR with muscimol significantly increased its incidence to 12% compared with the value in SHR treated with NaCl solution only. The norepinephrine concentration in the gastric wall and the labeling index of the gastric mucosa were significantly greater in SHR than in WKY rats. Prolonged administration of muscimol to SHR significantly reduced the norepinephrine concentration in the antral portion of the gastric wall or the labeling index of the antral epithelial cells. These findings indicate that long-term treatment of SHR with muscimol attenuated the enhancement of gastric carcinogenesis in SHR.
BACKGROUND: Although cytologic examination of pure pancreatic juice obtained with a duodenofiberscope has been useful for the diagnosis of pancreatic carcinoma, the rate of false-negative results is reported to be high. To eliminate these false-negative results, the authors developed a new technique, endoscopic retrograde intraductal catheter aspiration cytology, especially for an accurate cytologic diagnosis of carcinoma of the body or tail of the pancreas. METHODS: The accuracy of conventional cytologic examination of pure pancreatic juice was assessed in 25 patients with pancreatic carcinoma, 29 patients with pancreatitis, and 52 control subjects. Pure pancreatic juice was collected from the pancreatic duct by endoscopic cannulation using a videoimaging duodenoscope after intravenous administration of secretin. The new endoscopic retrograde intraductal catheter aspiration technique was used in four patients with carcinoma of the body or tail of the pancreas and five patients with localized pancreatitis in whom a correct diagnosis was not made by previous cytologic examination of pure pancreatic juice. RESULTS: Positive cytologic findings were obtained in 76% of the patients with pancreatic carcinoma. Positive cytologic results were more frequent in patients with carcinoma of the head of the pancreas than in those with carcinoma of the body or tail. By the new technique, positive cytologic results were obtained in all of the patients with pancreatic carcinoma. This technique caused no severe complications. CONCLUSIONS: This procedure of endoscopic retrograde intraductal catheter aspiration cytology seems useful for diagnosis of pancreatic carcinoma.
The effects of chemical sympathectomy induced by 6-hydroxydopamine (6-OHDA) on the enhanced induction of gastric carcinogenesis by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in spontaneously hypertensive rats (SHR), and the norepinephrine (NE) concentrations in their gastric wall and the labeling index of gastric epithelial cells were investigated. SHR rats and normotensive Wistar Kyoto rats (WKY) as controls were given MNNG (25 micrograms/ml) in their drinking water for 25 weeks and then i.p. injections of 6-OHDA (42 mg/kg twice within 24 hr, and then 105 mg/kg every 2 weeks from 1 week later). In control group (WKY rat + NaCl), gastric cancers were found in 2 (11%) of 18 rats examined in week 52. In SHR rats treated with NaCl solution only, the incidence of gastric cancers significantly increased, to 53% compared with that in control WKY rats. Treatment of SHR rats with 6-OHDA significantly decreased its incidence to 12% compared with the value in SHR rats treated with NaCl solution only. Prolonged administration of 6-OHDA to SHR rats significantly reduced the NE concentration in the antral portion of the gastric wall and the labeling index of antral epithelial cells. These findings indicate that prolonged i.p. treatment with 6-OHDA attenuated the normally higher incidence of MNNG-induced gastric cancer in SHR rats.
The effects of chemical sympathectomy induced by 6-hydroxydopamine (6-OHDA) and administration of the acetylcholinesterase inhibitor neostigmine, singly or together, on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and on the tissue catecholamine concentration of the gastric wall and the labeling index of the gastric mucosa, were investigated in inbred Wistar rats. Rats received s.c. injections of neostigmine (0.075 mg/kg), and/or i.p. injections of 6-OHDA (42 mg/kg twice within 24 hr, and then 105 mg/kg every 2 weeks from 1 week later) 25 weeks after oral treatment with MNNG. Prolonged administration of 6-OHDA or neostigmine significantly reduced the incidence of gastric cancers by week 52, and in combination they had a significantly greater inhibitory effect. 6-OHDA and/or neostigmine had no influence on the histology of gastric cancers. Administration of 6-OHDA, but not neostigmine, significantly decreased the norepinephrine concentration in the antral portion of the gastric wall. The labeling index of the antral mucosa was decreased significantly by treatment with 6-OHDA or neostigmine, and decreased even more significantly by 6-OHDA plus neostigmine. Our findings indicate that 6-OHDA and neostigmine have protective effects against gastric carcinogenesis and that in combination their effects are additive. These results imply that the activities of the sympathetic and parasympathetic autonomic systems together influence gastric carcinogenesis.
From January 1987 to December 1990, five cases of early depressed cancer of the large intestine were seen. Endoscopically, almost all of these tumors were located in the proximal colon and looked like a reddish depression (similar to the sucker of an octopus). Histologically, all of these cancers were well differentiated and tended to reach deeper layers at an early stage. Four (80%) of these cancers were not associated with adenoma and were thought to have arisen de novo.
The effect of thyroxine (T4) on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), and on the labeling index of colon mucosa were investigated in Wistar rats. Rats were given AOM by injection once a week for 10 weeks, together with T4 in depot form until the end of the experiment. Administration of T4 resulted in a significant increase in 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 depths of involvement of colon adenocarcinomas. Furthermore, it caused a significant increase in the labeling index of the colon during, but not after, AOM treatment. Our findings indicate that T4 enhances the development of colon tumors, which may be related to its effect in increasing proliferation of epithelial cells in the colon mucosa during administration of the carcinogen.
The effects of bombesin on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), and on their metastases to the peritoneum and/or lymph nodes, were investigated in Wistar rats. Rats received weekly s.c. injections of AOM for 10 weeks, and s.c. injections of bombesin in depot form every other day until the end of the experiment in week 30. Administration of bombesin significantly increased the incidence of colon tumors in week 30. It had no influence on the histological features or depths of involvement of colon adenocarcinomas, but significantly increased the incidence of cancer metastasis to the peritoneum and/or lymph nodes. It also caused a significant increase in the labeling index of the colon epithelial cells. Our findings indicate that bombesin enhances the development and metastasis of colon tumors, and that this effect may be related to its effect in increasing proliferation of epithelial cells of the colon.
The effects of vaso-active intestinal peptide (VIP) on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in Wistar rats given VIP every other day for 27 weeks after oral administration of MNNG for 25 weeks. In week 52, administration of VIP caused a significant increase in the incidence of gastric cancers, but did not influence their histological appearance. VIP significantly increased the labeling indices of the antral mucosa. Our findings indicate that VIP enhances gastric carcinogenesis, and that this effect may be related to its effect in increasing cell proliferation of the antral epithelial cells.
The accuracy of ultrasonographic examination combined with measurement of elastase 1 levels for early detection of pancreatic cancer was evaluated prospectively. Abdominal ultrasonographic examination and measurement of serum elastase 1 levels were done within 2 weeks after the initial visit to the clinic in a total of 2098 patients older than 35 years of age with symptoms suggesting pancreatic disease. Those in which one or both of these examinations had abnormal results underwent additional tests such as endoscopic retrograde cholangiopancreatography and computed tomography. Of those with pancreatosonograms with abnormal results with or without abnormally high serum elastase 1 levels, 19 patients eventually were found to have pancreatic cancer. No patients with pancreatic cancer, a normal level of serum elastase 1, and a pancreatosonogram with normal results were found, but follow-up studies revealed one pancreatic cancer in 189 patients after technically unsatisfactory ultrasonographic examination. In 9 (45%) of the 20 cases detected in this study, the pancreatic cancers were resectable, and two (10%) were less than 2.0 cm in longest diameter. These findings indicate that this combined examination is useful for early detection of pancreatic cancer. However, no pancreatic cancer was found in patients with abnormally high serum elastase 1 levels without a pancreatosonogram with abnormal results. Moreover, a combination of ultrasonographic examination and measurement of the elastase 1 level did not raise the diagnostic accuracy over that of ultrasonographic examination alone. These findings indicate that ultrasonographic examination alone is useful in screening for early pancreatic cancer.
The effects of 6-hydroxydopamine (6-OHDA) on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), and on norepinephrine (NE) concentration in the colon wall and the labelling index of the colon mucosa were investigated in Wistar rats. Rats received sub-cutaneous (s.c.) injections of AOM once a week for 10 weeks, and throughout 35 weeks were also given intraperitoneal (i.p.) injections of 6-OHDA. Prolonged administration of 6-OHDA was found to cause a significant reduction in the incidence and number of colon tumors. However, it had no influence on the histological features or depths of involvement of colon tumors and/or adenocarcinomas. Its administration also caused significant decreases in the NE concentration in the colon wall and in the labelling index of the colon mucosa. Our findings indicate that 6-OHDA has a protective effect against colon carcinogenesis, and that the activity of the sympathetic nervous system may have an important influence on colon carcinogenesis.
The effects of combined administration of bombesin and the ornithine decarboxylase (ODC) inhibitor 1,3-diaminopropane (DAP) on the incidence and number of gastric tumors induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), the ODC activity of the gastric wall and the labelling index of the gastric mucosa were investigated in inbred Wistar rats. Rats were given drinking water containing MNNG (50 micrograms/ml) for 25 weeks and then drinking water containing DAP (2.5 g/l) and/or injections of 40 micrograms/kg body weight of bombesin in depot form every other day. Administration of bombesin alone resulted in significant increases in the incidence of gastric cancers, the ODC activity of the antral portion of the gastric wall and the labelling index of the antral mucosa. Administration of DAP with bombesin significantly reduced enhancement by the latter of gastric carcinogenesis, ODC activity of the antral portion of the gastric wall and the labelling index of the antral mucosa. Our results suggest that ODC inhibition attenuated the enhancement of gastric carcinogenesis by bombesin, and that this enhancement by bombesin was mediated by polyamine biosynthesis.
The effects of ad libitum feeding of synthetic, low-protein diets on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), on the norepinephrine concentration in the colon wall tissue and on the labelling index of colon mucosa were investigated in Wistar rats. Rats received 10 weekly injections of 7.4 mg/kg body weight of AOM and were given synthetic diets of equal calorie content containing 25% casein (normal-protein diet), 10% casein (low-protein diet) or 5% casein (very-low-protein diet). Administration of the low- and very-low-protein diets resulted in significant increases in the incidence and number of colon tumors at week 30. However, it did not affect the histology of the colon tumors. The low- and very-low-protein diets also resulted in significant increases in norepinephrine concentration in the proximal and distal portions of the colon wall and in the labelling indices of both parts of the colon mucosa. Our findings indicate that low- and very-low-protein diets enhance colon carcinogenesis and that this may be related to their effects in increasing the norepinephrine level in the colon wall and in stimulating proliferation of colon epithelial cells.
The treatment of female C57BL/6 x DS-F1 mice with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) at 10, 12, 14, 16 and 18 days of age resulted in the development of hepatocellular adenomatous nodules after 10 months of age. Ovariectomy in these mice at 1 month of age hastened the development of adenomatous nodules, which then first appeared at 8 months of age. The incidence of adenomatous nodules in females ovariectomized at the age of 1 month was much higher than that in intact females of the same age. These results showed that the ovaries exerted a suppressive effect on the development of adenomatous nodules. To determine the time from which the ovaries exert this suppressive effect, females were ovariectomized at 4, 6, 8, and 10 months of age, and the incidences of adenomatous nodules were compared at 10 and 12 months of age. Delayed ovariectomy after 8 months of age did decrease the incidence of adenomatous nodules at 10 and 12 months of age, but ovariectomy after 4 and 6 months of age did not. When the incidence of adenomatous nodules in females ovariectomized at 10 months of age was examined over the subsequent 6 months, it became significantly higher after 14 months of age compared with that in intact females. The results show that the ovariectomy has the promoting effect on the development of adenomatous nodules in the liver induced by 3'-Me-DAB after 6 months of age.
The effects of the dopamine agonist 2-bromo-alpha-ergocryptine methanesulfonate (bromocriptine) on the incidence, number and histology of gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in Wistar rats. Rats were given 1 or 2 mg kg-1 body weight of bromocriptine subcutaneously every other day in depot form after 25 weeks of oral treatment with MNNG. Prolonged administration of bromocriptine at both dosages every other day resulted in a significant increase in the incidence and number of gastric cancers of the glandular stomach by week 52. Bromocriptine treatment did not influence the histological type of gastric cancer, but caused a significant increase in the labelling index of epithelial cells of the antrum. These findings indicate that the dopamine agonist bromocriptine promotes gastric carcinogenesis, and that this effect may be related to its effect in increasing proliferation of epithelial cells in the antral mucosa.
The effects on gastric emptying and gastrointestinal symptoms of treatment with cisapride alone and in combination with domperidone were investigated in 25 patients with chronic idiopathic dyspepsia. In a double-blind study, 9 patients were randomly assigned to receive cisapride 2.5 mg three times daily, and 8 patients to receive placebo. After 7 days of treatment, gastric emptying was significantly accelerated and the score of gastrointestinal symptoms was significantly reduced in patients treated with cisapride. Placebo treatment had no significant effect. A randomized, double-blind crossover study of 8 patients compared the effects of combined treatment with cisapride 2.5 mg plus domperidone 10 mg three times daily for 7 days against the effects of cisapride plus placebo. Administration of cisapride plus domperidone gave significantly higher gastric emptying and lower gastrointestinal symptoms than cisapride plus placebo.
The effect of gamma-butyrolactone (GBL) on inhibition by baclofen of gastric carcinogenesis was investigated in Wistar rats. In week 52, baclofen significantly decreased the incidence of gastric cancers. Concomitant treatment with GBL significantly increased gastric acid secretion but had no influence on the inhibition by baclofen of gastric carcinogenesis. This finding suggest that GBL significantly increased the sensitivity of gamma-aminobutyric acid (GABA) receptor to GABA mimetics in gastric acid secretion but not in the inhibitory effect of gastric carcinogenesis.
The effects of the gamma-amino-n-butyric acid (GABA)A receptor agonist muscimol, and the GABAB receptor agonist baclofen, on colon carcinogenesis induced by azoxymethane in Wistar rats were tested. Administration of either muscimol or baclofen had no influence on the incidence of colon tumors at week 30. However, almost all the colon tumors that developed in rats treated with baclofen were adenomas, whereas in the control group the tumors were mainly adenocarcinomas. In contrast, administration of muscimol did not affect the histological types of the colon tumors. These findings indicate that baclofen inhibits the growth of colon tumors via the GABAB receptor.