Biomedical subjects

M Tatsuta

Publications and source records attributed to M Tatsuta.

At least 91 records · Page 5Linked to original sources

PubMed1997

Enhancement by monochloramine of the development of gastric cancers in rats: a possible mechanism of Helicobacter pylori-associated gastric carcinogenesis.

The effects of cytotoxic monochloramine on the development of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in Wistar rats. After oral administration of drinking water containing the carcinogen and regular chow pellets for 25 weeks, rats received regular chow pellets or chow pellets containing 20% ammonium acetate, and normal tap water or water containing 30 mM sodium hypochlorite, with or without s.c. injection of taurine, until the end of the experiment in week 52. Treatment with both ammonium acetate and sodium hypochlorite significantly increased the incidence of gastric cancers in week 52, while the concomitant use of taurine with ammonium acetate and sodium hypochlorite significantly attenuated the enhanced gastric carcinogenesis. Spectrophotometric examinations revealed that taurine scavenged monochloramine. These findings suggest that Helicobacter pylori-associated gastric carcinogenesis may be mediated by monochloramine.

Animals↗

PubMed1997

Clinicopathologic features and endoscopic resection of duodenal adenocarcinomas and adenomas with the submucosal saline injection technique.

BACKGROUND: Endoscopic resection with the submucosal saline injection technique has been used to treat early duodenal cancers and adenomas. However, indications for endoscopic treatment of these cancers have not been established. METHODS: We used the submucosal saline injection method to treat 14 early duodenal cancers and adenomas to evaluate its safety and effectiveness. A 0.9% NaCl solution was injected into the submucosal layer near the tumor through needle forceps to elevate the tumor, which was then resected with electrocoagulation. Resected specimens were examined to assess depth of involvement, completeness of resection, and histologic type. Reports of early duodenal cancers in the Japanese literature were reviewed to analyze the relationship among lymph node metastasis, submucosal invasion, and tumor size. RESULTS: All tumors were completely removed "en bloc" (12 tumors) or in a "piecemeal" fashion (two tumors). The largest tumor was 20 mm in diameter. No serious complications occurred during or after treatment. Review of Japanese literature showed that lymph node metastasis did not occur when protruding or elevated tumors were less than 50 mm in diameter but did occur when depressed tumors, with or without marginal elevation, were more than 10 mm in diameter. CONCLUSIONS: Endoscopic resection with the submucosal saline injection technique is a safe and effective treatment for early duodenal cancers and adenomas. Protruding or elevated tumors less than 50 mm in diameter can be removed completely. However, because of possible lymph node metastasis, depressed tumors with or without marginal elevation should be removed surgically.

Adenocarcinoma↗

PubMed1997

Inhibition by ginsenoside Rg3 of bombesin-enhanced peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane in Wistar rats.

The effects of concomitant use of bombesin and ginsenoside Rg3 on the incidence of peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane were investigated in male inbred Wistar rats. From the start of the experiment, rats were given weekly s.c. injections of azoxymethane (7.4 mg/kg body weight) for 10 weeks and s.c. injection of bombesin (40 microg/kg body weight) every other day, and from week 20, s.c. injections of ginsenoside Rg3 (2.5 or 5.0 mg/kg body weight) every other day until the end of the experiment in week 45. Bombesin significantly increased the incidence of intestinal tumors and cancer metastasis to the peritoneum in week 45. It also significantly increased the labeling index of intestinal cancers. Although administration of a higher dose of ginsenoside Rg3 with bombesin had little or no effect on the enhancement of intestinal carcinogenesis by bombesin, the location, histologic type, depth of involvement, infiltrating growth pattern, labeling and apoptotic indices and tumor vascularity of intestinal cancers, it significantly decreased the incidence of cancer metastasis. These findings indicate that ginsenoside Rg3 inhibits cancer metastasis through activities that do not affect the growth or vascularity of intestinal cancers.

Adenocarcinoma↗

PubMed1997

Usefulness of simple endoscopic aspiration cytology of pancreatic juice for diagnosis of early pancreatic neoplasm. A prospective study.

For detection of early cancer of the pancreas, endoscopic aspiration cytology of pancreatic juice without endoscopic retrograde pancreatography was performed in 64 consecutive outpatients who had symptoms or findings that suggested pancreatic disease. Patients with positive or suspicious cytologic results or abnormal US findings were admitted and underwent detailed examinations. Positive and suspicious cytologic results were obtained in 2 and 10 patients, respectively. Of those with positive and suspicious cytologic results, two, and one patient, respectively, were ultimately found to have pancreatic neoplasms. Of these three resected specimens, one was in situ carcinoma and two presented marked atypia. All patients were alive with no evidence of recurrence. No further cases of pancreatic neoplasm were found. Complications from the procedure did not develop in any patient. This technique is useful in the diagnosis of early neoplasms of the pancreas, because it is simple and safe to perform for outpatients.

Aged↗

PubMed1997

Structure and expression of the human SM22alpha gene, assignment of the gene to chromosome 11, and repression of the promoter activity by cytosine DNA methylation.

To investigate the molecular mechanisms that control expression of smooth muscle cell (SMC) differentiation genes, we have isolated the human SM22a gene, which is composed of five exons and four introns, spanning an approximately 6-kilobase (kb) genomic DNA at chromosome region 11q23.2. Expression of the SM22a messenger RNA was detected in serum-stimulated cell cultures including SMC, undifferentiated skeletal muscle-lineage cells, and fibroblasts, and it was down-regulated in SMC of balloon-injured atheromatous human vessels. A major transcription start site of the SM22alpha gene is located at 75 base-pairs (bp) upstream of the ATG start codon. Analysis of the 2.6 kb 5'-upstream sequence demonstrated that two CArG/SRF-boxes and two GC-box/Sp1-binding sites were present at bp -147 and -274, and at bp -233 and -1635, respectively. The nucleotide sequences of the two CArG/SRF-boxes and the proximal GC-box/Sp1 binding site are 100% conserved with those of the murine SM22alpha genes [Solway, J., Seltzer, J., Samaha, F.F., Kim, S., Alger, L.E., Niu, Q., Morriesey, E.E., Ip, H.S., and Parmacek, M.S. (1995) J. Biol. Chem. 270, 13460-13469; Kemp, P.R., Osbourn, J.K., Grainger, D.J., and Metcalf, C. (1995) Biochem. J. 310, 1037-1043]. Cell transfection assays using a luciferase reporter gene construct containing the 455-bp 5'-flanking region (positions -26 to -480) showed that methylation of the CpG dinucleotides within this segment reduces its transcriptional activity. The results imply a novel mechanism for transcriptional control of the SMC differentiation-specific gene promoter.

Amino Acid Sequence↗

PubMed1997

Characterization of the carrot beta-tubulin gene coding a divergent isotype, beta-2.

Four different beta-tubulin clones were isolated from carrot genomic and cDNA libraries. Their nucleotide sequences were determined 1 and their predicted amino acids were compared with each other. The predicted amino acid composition of the C-terminal region of three of them (beta-1, 3, 4) resembled one another, but that of one isotype (beta-2) was divergent. The beta-2 tubulin included two hydroxyl amino acids, serine and threonine, and consisted of a lower number of negatively charged amino acids than the others in the C-terminal region. The predicted hydrophobicity profile of the beta-2 tubulin around the residue 200 is less hydrophobic than beta-1, but it is still more hydrophobic than those of animal and fungal beta-tubulins. The beta-2 gene was transcribed in cultured cells and flowers, while the beta-1 gene was ubiquitously transcribed in cultured cells, roots, shoots and flowers. When the predicted amino acids of plant tubulin were compared with those of other organisms, substitutions from non-polar amino acids to those with hydroxyl group were conspicuous in the region corresponding to the third exon in the plant genes.

Amino Acid Sequence↗

PubMed1997

[A case of malignant hemangioendothelioma of the lung with rapid growth of pulmonary metastasis].

Malignant hemangioendothelioma of the lung is very rare and difficult to diagnose. The growth is rapid and the prognosis is very unfavorable. We report an operated case of the disease with rapid growth of pulmonary metastasis. The silver, vimentin and factor VIII stainings were available for diagnosis of this disease. The 46-year-old female patient died of bleeding from the pulmonary metastasis eight months after the operation without other distant metastasis. Even if a lung tumor is pointed out and thought to be benign, frequent follow up is necessary. Furthermore, we recommend positive lung biopsy by thoracotomy or video-assisted-thoracic-surgery.

Female↗

PubMed1997

[Hepatic arterial chemotherapy for liver cancer over a period of 8 years].

Hepatic arterial chemotherapy was performed for 27 patients with primary (3), metastatic liver cancer (21), and 3 other cases, over a period of 8 years. Chemotherapy was performed by intermittent hepatic arterial infusion of 5-FU or FAM (in case of metastatic tumor from colorectal cancer), FAM (from gastric cancer), and CDDP or Farmorubicin (HCC). Hepatic resection was performed in 10 cases of metastatic tumor from colorectal cancer, and 8 cases of 10 were curative operation. The 5-year survival rates of curative liver resection group, and non-curative liver resection or non-resection group were 57.1% and 12.5%, respectively. As is the case with metastatic cancer from gastric cancer, pancreatic cancer, and hepatocellular carcinoma (HCC), the prognosis was poor except for one CR case of HCC. We concluded that hepatic arterial chemotherapy may be recommended for a curative resected case of liver metastasis from colorectal cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

[A case of liver metastasis of gastric leiomyosarcoma successfully treated by transarterial hepatic chemo-embolization and intra hepato-arterial chemotherapy repeated with infusion-a-port].

The patient was a 68-year-old male, who underwent total gastrectomy for giant leiomyosarcoma of the stomach and then had multiple hepatic metastases one year and six months later. Thus, transarterial hepatic chemo-embolization therapy with Lipiodol, adriamycin and gelfoam was given. Moreover, using a reservoir catheter and infusion arterial port, intermittent arterial infusion therapy with adriamycin, cyclophosphamide, and vincristine was attempted. In the metastasis lesion where there were rich blood vessels, Lipiodol was accumulated and the tumor was reduced on abdominal CT. The result indicated the efficacy of this treatment.

Aged↗

PubMed1996

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

The effect of neurotensin on hepatocarcinogenesis by N-nitrosomorpholine (NNM) was investigated in Sprague-Dawley rats. Rats were given drinking water containing NNM for 8 weeks and alternate-day injections of neurotensin from the beginning until the end of the experiment. Preneoplastic and neoplastic lesions stained for placental type glutathione-S-transferase (GST-P) were examined histochemically. Administration of neurotensin significantly increased the percentage area and the number of GST-P-positive lesions, and the labeling indices of pre-neoplastic lesions and adjacent liver. These findings indicate that neurotensin enhances hepatocarcinogenesis and that this effect may be related to its effect in increasing cell proliferation in preneoplastic lesions.

Animals↗

PubMed1996

Inhibition by the calmodulin antagonist trifluoperazine of experimental hepatocarcinogenesis induced by N-nitrosomorpholine in Sprague-Dawley rats.

The effect of the calmodulin antagonist trifluoperazine on hepatocarcinogenesis induced by N-nitrosomorpholine (NNM) and on the ornithine decarboxylase (ODC) activity and labeling index of the liver were investigated in male Sprague-Dawley rats. Rats were given drinking water containing NNM for 8 weeks, and from the beginning of the experiment, received s.c. injections of 15 or 30 mg/kg body weight of trifluoperazine in depot form every other day until the end of the experiment. Preneoplastic and neoplastic lesions staining positively for glutathione-S-transferase, placental type (GST-P) were examined histochemically. In week 16, quantitative histological analysis showed that prolonged administration of 30 mg but not 15 mg/kg body weight of trifluoperazine resulted in significant reductions in the number and percentage area of GST-P-positive hepatic lesions. Trifluoperazine also caused significant decreases in the ODC activity of the liver and in the labeling indices of enzyme-altered lesions and their adjacent hepatocytes. These findings indicate that trifluoperazine inhibits carcinogenesis and suggest that this effect may be closely related to its effect in inhibiting ODC activity and cell proliferation in the enzyme-altered lesions and their adjacent liver.

Animals↗

PubMed1996

Inhibition by amiloride of experimental carcinogenesis induced by azaserine in rat pancreas.

The effects of prolonged administration of the diuretic amiloride on pancreatic carcinogenesis induced by azaserine and on the labeling index of carcinogen-induced pancreatic lesions were investigated in Wistar rats. Rats were given 25 weekly injections of 10 mg/kg body weight azaserine and also 5 mg/kg body weight amiloride every other day until the end of the experiment at week 62. Carcinogen-induced pancreatic lesions were examined by histochemical techniques and were classified as ATPase-positive or ATPase-negative. In week 62, quantitative histologic analysis showed that prolonged administration of amiloride significantly reduced the number and size (as percent of parenchyma) of ATPase-positive pancreatic lesions, which are closely correlated with the subsequent development of pancreatic cancer. Amiloride also significantly decreased the labeling index of carcinogen-induced pancreatic lesions, but not of the surrounding acinar cells. In contrast, amiloride has no significant influence on the number and size of ATPase-negative pancreatic lesions. These findings indicate that amiloride inhibits pancreatic carcinogenesis, and that this effect may be related to the reduction of ATPase-positive lesions and to amiloride's inhibition of cell proliferation in neoplastic lesions of the pancreas.

Adenosine Triphosphatases↗

PubMed1996

Inhibition by verapamil of cholecystokinin-enhancement of pancreatic carcinogenesis induced by azaserine in Wistar rats.

The effect of a calcium channel blocker, verapamil, on cholecystokinin (CCK)-enhancement of pancreatic carcinogenesis induced by azaserine was investigated in Wistar rats. During and after 25 weekly injections of azaserine, each rat received alternate-day injections of CCK-octapeptide (CCK-8) and/or verapamil. Carcinogen-induced pancreatic lesions staining for mu class glutathione S-transferase (GST-mu) were examined histochemically at week 62. Prolonged administration of CCK-8 significantly increased the number and area as a percentage of parenchyma of GST-mu-positive lesions. Concomitant administration of verapamil significantly attenuated the enhancing effect of CCK-8. These findings indicate that calcium may play an important role in CCK-enhancement of pancreatic carcinogenesis.

Animals↗

PubMed1996

Tissue norepinephrine depletion as a mechanism for calcium chloride inhibition of gastric carcinogenesis in rats after treatment with N-methyl-N'-nitro-N-nitrosoguanidine and sodium chloride.

The effects of oral calcium chloride (CaCl2) on sodium chloride (NaCl)-enhanced induction of gastric carcinogenesis by the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine, and the norepinephrine (NE) concentration in the gastric wall, were investigated in Wistar rats. Animals were given the carcinogen for 25 weeks and then chow pellets containing 10% NaCl with or without 8% or 4% CaCl2. In week 52, the incidence of gastric cancers, the NE concentration in the antral portion of gastric wall and the labelling index of antral epithelial cells were significantly greater in rats fed NaCl alone than in untreated control rats. Concomitant oral treatment with CaCl2 at 8%, but not 4%, significantly reduced the incidence of gastric cancers, the NE concentration in the antral portion of gastric wall and the labelling index of the antral epithelial cells in week 52 compared with those in rats fed NaCl alone. Because NE concentration reflects sympathetic nervous system activity, our findings suggest that the sympathetic nervous system could play a role in NaCl-enhanced gastric carcinogenesis. Our findings also suggest that NE depletion by CaCl2 may be related to its inhibition of NaCl-enhanced carcinogenesis.

Animals↗

PubMed1996

The later administration of progesterone more rapidly activates dormant mouse mammary tumor cells initiated by 3'-methyl-4-dimethylaminoazobenzene.

Implantation of progesterone at 1 month of age induced the development of mammary tumors in female C57BL/6 x DS-F1 mice that had been treated with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) neonatally, and that had undergone ovariectomy and received implants of estradiol-17beta (E2) pellets at 1 month of age, and the incidence of mammary tumors became 100% at 15 months of age. On the other hand, no mammary tumors developed in these mice with implants of E2 pellets alone. Implantation of progesterone alone also induced no mammary tumors in mice that had been treated with 3'-Me-DAB neonatally, and had undergone ovariectomy at 1 month of age. Implantation of progesterone at 4, 6, 8, and 10 months of age also caused the prompt development of mammary tumors as implantation of progesterone at 1 month of age. When ages at which the incidence became 50% were estimated on curves of the incidences, these ages on implantation of progesterone at 1, 4, 6, 8, and 10 were about 11, 13, 14, 14, and 14 months of age. These results suggest that progesterone together with estrogen promotes the development of mammary tumors induced by 3'-Me-DAB, and that the later progesterone is administered, the more rapidly it activates dormant mammary tumor cells initiated by 3'-Me-DAB.

Aging↗

PubMed1996

More effective endoscopic resection with a two-channel colonoscope for carcinoid tumors of the rectum.

PURPOSE: Complete resection of small carcinoid tumors of the rectum is difficult with conventional polypectomy, because these tumors are most often located in the submucosal layer of the rectal wall. To completely remove these tumors, we used a two-channel videocolonoscope with which both a grasping forceps and a polypectomy snare could be used simultaneously. We evaluated its clinical usefulness in comparison with one-channel colonoscopic polypectomy. METHODS: At Osaka Medical Center for Cancer and Cardiovascular Diseases, seven carcinoid tumors in seven patients were removed with a one-channel videocolonoscope from 1985 to 1992. In 1993 and 1994, ten tumors in nine patients were removed with a two-channel colonoscope. RESULTS: The rate of complete removal of carcinoid tumors with a two-channel videocolonoscope (9 of 10 tumors, 90 percent) was significantly higher (P < 0.05) than with a one-channel videocolonoscope (2 of 7 tumors, 29 percent). No complications occurred during or after endoscopic resection with a two-channel colonoscope. CONCLUSIONS: Endoscopic resection with a two-channel colonoscope is a useful and safe method for resection of small carcinoid tumors of the rectum.

Carcinoid Tumor↗

PubMed1996

Endoscopic resection of large pedunculated colorectal polyps using a detachable snare.

BACKGROUND: Colonoscopic resection of pedunculated polyps with heads 1 cm or greater in diameter is difficult because of the risk of bleeding. To minimize this complication, we used a detachable snare that allowed endoscopic ligation of the stalk of a large pedunculated polyp and evaluated its safety and effectiveness in comparison with conventional endoscopic snare polypectomy. METHODS: Patients with pedunculated polyps with heads 1 cm or greater in diameter were randomly assigned to colonoscopic polypectomy with (N = 47) or without (N = 42) a detachable snare. Arterial pumping bleeding immediately after colonoscopic polypectomy or hematochezia resulting in a 10% or greater drop in hematocrit was defined as "bleeding." RESULTS: No bleeding occurred during or after polypectomy with a detachable snare, but bleeding occurred significantly more frequently (five patients, 12%) without a snare. Moreover, the use of a detachable snare reduced the duration of hospitalization after polypectomy. CONCLUSIONS: Colonoscopic polypectomy with a detachable snare may be safer than conventional polypectomy without a detachable snare for resection of large, pedunculated polyps.

Blood Loss, Surgical↗

PubMed1996

Intravenous midazolam as a sedative for colonoscopy: a randomized, double-blind clinical trial.

METHODS: Forty patients, aged between 36 and 60 years, scheduled to undergo colonoscopic removal of colorectal polyps were randomly assigned to receive 0.9% saline solution (n = 20) or 0.05 mg/kg body weight of midazolam (n = 20) intravenously. RESULTS: Midazolam significantly (P < 0.001) increased the tolerance of patients to colonoscopy. It had no significant effect on pulse or systolic blood pressure during endoscopy. Arterial oxygen saturation decreased significantly (P < 0.01) during endoscopy in patients pre-treated with midazolam, but it did not decrease by more than 5%. CONCLUSIONS: Intravenous midazolam is useful as a sedative for colonoscopy, but we recommend continuous oxygen saturation monitoring during endoscopy.

Adult↗