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Biomedical subjects

M Tatsuta

Publications and source records attributed to M Tatsuta.

At least 325 records · Page 18Linked to original sources
PubMed1977

Effect of prolonged administration of gastrin on experimental carcinogenesis in rat stomach induced by N-methyl-N' -nitro-N-nitrosoguanidine.

The effects of gastrin on gastric acid secretion and on the incidence of gastric carcinoma induced by N-methyl-N'-nitro-N-nitrosoquanidine were investigated in rats. At Week 50 after the start of the experiment, it was found that prolonged administration of gastrin after treatment with N-methyl-N'-nitro-N-nitrosoquanidine resulted in a significant increase in gastric acid secretion and a significant reduction in the incidence of adenocarcinomas of the glandular stomach. The administration of gastrin did not influence the histological appearance of the few gastric adenocarcinomas that did develop.

Adenocarcinoma↗
PubMed1977

Studies on serum gastrin of the patients with gastric cancer.

In patients with gastric cancer who were to undergo gastrectomy, the fasting serum gastrin concentration in the peripheral vein was estimated by radioimmunoassay. The blood samples were also collected from the gastric veins and artery during the time of operations. These gastrin values were compared with morphological findings in the resected stomach. No significant differences in serum gastrin concentration was found between the patients of gastric cancer and normal subjects. In the patients with mucosal atrophy in the oxyntic gland area but with no atrophy in the pyloric gland area, however, significant increase in serum gastrin concentration was observed. In cases where fundal atrophy was accompanied by atrophy in the pyloric gland area, the increase was not observed. The amount of gastrin content in cancer tissue was negligible. These results indicate that the increase in serum gastrin concentration in some patients with gastric cancer might be due to the accompanied atrophy of oxyntic glands in the stomach.

Adult↗
PubMed1976

Gastric ulcers in the fundic gland area.

Gastric ulcers have been thought to occur only in the pyloric gland area. However, endoscopic examinations using the Congo red test showed that 18 of the ulcers examined (7.8%) were surrounded by an acid-secreting area, and so were in the fundic gland area. Histological examination of specimens obtained by gastrectomy also showed that five of the lesions examined (4.5%) were located in the fundic gland area. Ulcers in the fundic gland area were found most frequently in the angle and lower gastric body, adjacent to acid-secreting boundary. These ulcers were associated with little or no fundal gastritis, whereas ulcers in the pyloric gland area were usually associated with moderate or severe fundal gastritis. Unlike ulcers of similar depth in the pyloric gland area, ulcers surrounded by normal fundic mucosa healed rapidly and completely. No recurrence of these ulcers was seen in a 1-year endoscopic follow-up period.

Adult↗
PubMed1975

Location, healing, and recurrence of gastric ulcers in relation to fundal gastritis.

The influence of fundal gastritis on the location, healing, and recurrence of gastric ulcers was studied by the endoscopic Congo red test. Results indicated a close correlation between the location of ulcers and the extent of fundal gastritis. In general, ulcers were more proximal when fundal gastritis was more severe. Of the ulcers examined, 62.5% of those not associated with fundal gastritis failed to heal, whereas 85.7% of those associated with severe fundal gastritis healed within 3 months. The presence of severe fundal gastritis was associated with a high rate of recurrence of gastric ulcers.

Gastric Mucosa↗
PubMedDate not supplied

Contrast enhancement with Gd-EOB-DTPA in MR imaging of hepatocellular carcinoma in mice: a comparison with superparamagnetic iron oxide.

The purpose of this study was to evaluate the ability of the new liver-specific magnetic resonance contrast agent gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) to detect hepatocellular carcinoma (HCC). Seventeen mice with 66 chemically induced HCCs underwent magnetic resonance imaging with both Gd-EOB-DTPA (30 mumol/kg) and superparamagnetic iron oxide (SPIO; 10 mumol/kg). After enhancement, lesion-to-liver contrast-to-noise ratios (CNRs) of 47 detected HCCs increased negatively from 3.7 +/- 10.7 (mean +/- SD) to -55.1 +/- 25.8 with Gd-EOB-DTPA (P < .001) and increased positively from 10.4 +/- 10.4 to 26.1 +/- 16.3 with SPIO (P < .001). The improvement of CNR after administration of SPIO was less in smaller lesions (< 4 mm), whereas that after administration of Gd-EOB-DTPA was independent of lesion size. However, Gd-EOB-DTPA positively enhanced four HCCs (8.5%), both highly differentiated (grade 1) and moderately differentiated (grade 2). Gd-EOB-DTPA allows the conspicuous detection of small HCCs; however, moderately differentiated HCCs occasionally may be positively enhanced.

Animals↗
PubMedDate not supplied

Hydroxyl free radical production by the reaction of N-methyl-N'-nitro-N-nitrosoguanidine with hydrogen peroxide without exposure to light.

We examined hydroxyl free radical (.OH) production in the mixture of H2O2 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) without exposure to light using the electron spin resonance spin-trapping technique. When the mixtures were protected from exposure to light, .OH was formed at pH 6.5 and above; it was not formed at pH 5.0 and below, consistent with our previous report. The amount of .OH trapped depended on the concentrations of MNNG and H2O2 and the pH. Nitrite ion was also detected colorimetrically at pH 6.5 and above, but not detected at pH 5.0 and below in the mixtures without exposure to light. Moreover, its production depended on the concentrations of MNNG and H2O2 and the pH. The formation of N-methyl-N'-nitroguanidine in the mixture at pH 7.8 was confirmed by thin-layer chromatography and melting point. These results suggest that nucleophilic attack by H2O2 on the nitroso nitrogen of MNNG results in the formation of N-methyl-N'-nitroguanidine and peroxynitrous acid, which degrades homolytically to yield .OH and nitrogen dioxide, resulting in the production of nitrite ion, at pH 6.5 and above without exposure to light.

Free Radicals↗
PubMedDate not supplied

Suppression by verapamil of bombesin-enhanced peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane in wistar rats.

BACKGROUND: The effects of combined administration of bombesin and verapamil hydrochloride (verapamil), a calcium channel blocker, on the incidence of peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane (AOM) and the labeling index of intestinal cancers were investigated in male Wistar rats. METHODS: From the beginning of the experiment, rats were given 10 weekly subcutaneous injections of AOM (7.4 mg/kg body weight) and subcutaneous injections of bombesin (40 microg/kg body weight) every other day, and from week 16, intraperitoneal injections of verapamil (10 or 20 mg/kg body weight) every other day until the end fo the experiment in week 45. RESULTS: Bombesin significantly increased the incidence of intestinal tumors and cancer metastasis to the peritoneum. Although verapamil administered at either dose had little or no effect on the enhancement of intestinal carcinogenesis by bombesin or on the location, histologic type, depth of involvement, labeling index, apoptotic index or tumor vascularity of intestinal cancers, it significantly decreased the incidence of cancer metastasis. Verapamil also significantly decreased the incidence of lymphatic invasion of adenocarcinomas, which was enhanced by bombesin. CONCLUSION: These findings indicate that verapamil inhibits cancer metastasis through actions that do not affect the growth of intestinal cancers.

Adenocarcinoma↗
PubMedDate not supplied

Effectiveness of intrathoracic chemothermotherapy for malignant pleurisy due to Ewing's sarcoma: a case report.

This paper describes a case of malignant pleurisy which showed evidence of the effectiveness of a new mode of cancer treatment, intrathoracic chemothermotherapy (ICT). ICT consisted of a bolus intrathoracic injection of 50 mg cis-diamminedichloroplatinum (CDDP) and local heating using 8 MHz radiofrequency waves for 60 min. A patient with multiple lung metastases and malignant pleurisy on both sides due to Ewing's sarcoma was treated on the right side with ICT, along with concomitant systemic administration of 50 mg CDDP. Intrathoracic temperatures were monitored by insertion of thermocouple temperature sensors, and temperatures of 43 degrees C or over were successfully maintained for about 40 min during each of three treatments. Although the patient died 3 months later of advanced metastases in the left lung and malignant pleurisy on the left side, lung metastases in the right lung were stable on radiographs, and autopsy results showed no cancerous lesions in the right thoracic cavity, which had been treated with ICT. Since no effective response had been obtained clinically or histologically before starting ICT, despite frequent administration of anti-cancer drugs, we conclude that heat acted synergistically with CDDP on drug-resistant cells in this case.

Adult↗
PubMedDate not supplied

Diagnosis of pancreatic cancer by cytology and measurement of oncogene and tumor markers in pure pancreatic juice aspirated by endoscopy.

BACKGROUND/AIMS: Cytological examination of pancreatic juice is useful in the diagnosis of an occult cancer of the pancreas. The early diagnosis of pancreatic carcinoma using traditional radiographic or ultrasonographic methods is extremely difficult. METHODOLOGY: In order to detect an early pancreatic cancer, cytological examination, measurement of tumor marker, and detection of K-ras point mutation were performed using the samples of pure pancreatic juice aspirated endoscopically in patients who had symptoms or findings that suggested pancreatic disease. RESULTS: By routine ERP-cytology, positive cytologic results were obtained in 15 (4%) out of 359 patients without a mass. With the aid of intra-operative cytodiagnosis, all 15 occult neoplasms of the pancreas were successfully resected. One patient died from another disease without evidence of recurrence. However, the other patients were alive with no evidence of recurrence for an average of 5.5 years following surgery. The patients who had negative ERP-cytology results were observed, but no further cases of pancreatic cancer were found. The CEA levels in the pure pancreatic juice were significantly higher in patients with pancreatic cancer than in those with pancreatitis. K-ras point mutation at codon 12 was detected not only in cases of pancreatic cancer, but also in cases of chronic pancreatitis as well as control subjects. CONCLUSIONS: Cytological examination of pancreatic juice is useful in the diagnosis of an early and potentially curable in situ cancer of the pancreas. The CEA levels in the pure pancreatic juice provided useful information for differentiating the pancreatic cancer from chronic pancreatitis. K-ras point mutation at codon 12 in pancreatic juice was considered to be useful in identifying patients at high risk for the development of pancreatic cancer.

Aged↗
PubMedDate not supplied

Endoscopic resection with a two-channel videoendoscope for gastric carcinoid tumors.

BACKGROUND/AIMS: Endoscopic resection has been used to treat hypergastrinemia-associated early carcinoid tumors of the stomach. However, indications for endoscopic treatment of these tumors have not been established. Moreover, endoscopic resection of these tumors is often difficult with conventional polypectomy, because these tumors are often located in the submucosal layer. To completely remove these tumors, we used a two-channel videoendoscope with which both grasping forceps and a polypectomy snare could be used simultaneously. METHODOLOGY: At Osaka Medical Center for Cancer and Cardiovascular Diseases, eight carcinoid tumors in six patients were removed with a two-channel videoendoscope. Reports of early carcinoid tumor in Japanese literature were reviewed to analyze the relationship between lymph node metastasis and the size and depth of involvement of these tumors. RESULTS: Six carcinoid tumors were completely removed "en bloc", but two tumors were incompletely removed. In these two patients, submucosal tumor invasion was observed on the excision line. To completely remove these tumors, the oral side, but not the top, of the tumor should be strongly grasped and pulled toward the center of the lumen as far as possible by the grasping forceps, which had been passed through the snare loop. Endoscopic follow-up studies showed no local recurrence in any patients with and without complete tumor resection during the average observation period of 30 months. A review of histological reports in Japanese literature showed that lymph node metastasis did not occur when the tumors were less than 10 mm in diameter, and could be completely removed by an endoscope. CONCLUSIONS: Endoscopic resection with a two-channel videoendoscope is a useful and safe method for resection of small carcinoid tumors of the stomach.

Aged↗
PubMedDate not supplied

Unusual extension of lung cancer into the left atrium via the pulmonary vein.

Four operative cases of lung cancer with intra-atrial extension via the pulmonary vein were reviewed. Three of them had circulatory as well as respiratory symptoms, and their performance status (PS) was extremely poor. In two cases, after assessment of the cardiac involvement using two-dimensional echocardiography and/or CT-scan, we successfully removed the tumor en bloc through combined left atrial resection and radical left pneumonectomy with cardiopulmonary bypass. In both cases, the postoperative course was uneventful, and PS 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 examinations. However, the lumens of the resected pulmonary veins were filled with tumor tissue. One patient developed a massive embolism, never regained consciousness, and died on the second postoperative day. The last case was discharged without trouble, although the intra-atrial portion of the tumor dislodged intraoperatively into the circulation. As a result, he developed multiple brain metastases four months after the operation. There were no clear patterns in terms of the histological type or tumor location in these cases. On the other hand, all the tumors showed rapid growth and comprised a large mass in the lung parenchyma. Especially the cardiac and intravascular portions of each tumor were less differentiated and more necrotic than the primary focus in the lung. We conclude that radical surgery using a 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 tumor emboli.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMedDate not supplied

Evaluation of gastric ulcer healing with mucosal microvascular architecture.

BACKGROUND/AIMS: There is presently no consensus on how long treatment of gastric ulcers should be continued to prevent ulcer recurrence. Therefore, we investigated the histologic state of healing, and the recurrence of gastric ulcers with Helicobacter pylori infection classified by gastric mucosal microvascular architecture as completely and incompletely healed. MATERIAL AND METHODS: We obtained biopsy specimens from healed gastric ulcers in 71 patients who had been treated for eight weeks with omeprazole. The gastric mucosal microvascular architecture of the biopsy specimens was observed by the alkaline phosphatase staining method. RESULTS: We found a significant correlation between the mucosal microvascular architecture in the biopsy specimens and the histologic state of ulcer healing Recurrences were significantly more frequent in ulcers classified by microvascular architecture as incompletely healed than in completely healed ulcers. CONCLUSION: Observing the microvascular architecture of healed gastric ulcers is very useful for judging the state of healing, and therapy should be continued until ulcers are classified by this method as completely healed.

Anti-Ulcer Agents↗