Mutant mouse p53 transgene elevates the chemical induction of tumors that respond to gene silencing with siRNA.

To study the role of mutant p53 in the induction and cure of tumors, we generated transgenic mice carrying mutant p53 (mp53) containing a 9 bp deletion in exon 6 in addition to wild-type p53, expressing both p53 and mp53. The mp53 cDNA was cloned from a radiation-induced mouse tumor and ligated to the chicken beta-actin promoter/CMV-IE enhancer in the expression vector. The presence of mp53 suppressed p21 expression in primary fibroblasts after ionizing irradiation, indicating the dominant-negative activity of mp53 in the mice. These mice developed fibrosarcomas after the subcutaneous injection of 3-methylcholanthrene with an incidence 1.7-fold higher than that of wild-type mice (42% excess). The tumors were then treated via a potent atelocollagen delivery system with small interfering RNA (siRNA), that targeted the promoter/enhancer of the expression vector, resulting in the suppression of tumor growth in 30% of 44 autochthonous tumors, including four cures, and their transplants, the total fraction corresponding to the tumor excess. This suppressive effect involved the induction of apoptosis. These results indicate that mp53 activity causes tumors that can be suppressed by subsequent silencing of mp53 in the presence of wild-type p53 alleles.

Demonstration of cerebellar atrophy in neuroacanthocytosis of 2 siblings.

SUMMARY: Neuroacanthocytosis is a rare hereditary disorder characterized by involuntary choreiform movements and erythrocytic acanthocytosis in the peripheral blood. Clinical manifestations of this disorder resemble those of Huntington disease (HD). Neuroimaging features of neuroacanthocytosis are atrophy and signal intensity change of the striata on MR imaging, as in HD. We report herein the cases of 2 siblings with neuroacanthocytosis showing cerebellar atrophy as well as atrophy and signal intensity changes of striata.

Complications after proximal gastrectomy with jejunal pouch interposition: report of a case.

We report a rare case of proximal gastrectomy complication as a result of a severe dilatation of a jejunal pouch interposed for reconstruction. A 44-year-old man who had early gastric cancer underwent proximal gastrectomy with a jejunal pouch interposition at our department. Fourteen months after the procedure, he began to complain of left hypochondrial fullness and reflux symptoms. He had difficulty eating and his quality of life (QOL) was markedly impaired. Barium meal revealed severe dilatation of the jejunal pouch. Decompression using a stomach tube and other measures only achieved temporary improvement. 4.5 years later, the dilated jejunal pouch was resected together with apyloroplasty and double tract reconstruction. Six months after this secondary surgery, the patient recorded no further complications. Food intake increased and QOL improved.

Helicobacter pylori infection prevents the occurrence of the tolerance phenomenon of histamine H2 receptor antagonists.

BACKGROUND: The attenuated anti-secretory activity of H2 receptor antagonists (H2RA) during continuous administration is referred to as the tolerance phenomenon. However, it is not clarified whether Helicobacter pylori infection affects the occurrence of tolerance to H2RA. It is also not clarified whether the tolerance phenomenon occurs to a new H2RA, lafutidine. AIM: To investigate the occurrence of the tolerance phenomenon in subjects with and without H. pylori infection during the continuous administration of lafutidine and famotidine. SUBJECTS AND METHODS: Subjects were 20 healthy male volunteers (seven H. pylori positive and 13 H. pylori negative cases). All subjects were examined by ambulatory intragastric pH monitoring five times without medication, on the first and 15th day of the administration of 20 mg b.d. famotidine and 10 mg b.d. lafutidine in a cross-over fashion. RESULTS: The tolerance phenomenon was not observed in H. pylori-positive subjects during the 15-day-long administration of both H2RAs. In contrast, the tolerance phenomenon was observed in H. pylori negative subjects, which has been previously reported. CONCLUSIONS: This study demonstrated that H. pylori infection affects the tolerance phenomenon during continuous administration of H2RAs.

Does eradication of Helicobacter pylori reduce the risk of carcinogenesis in the residual stomach after gastrectomy for early gastric cancer? Comparison of mucosal lesions in the residual stomach before and after Helicobacter pylori eradication.

BACKGROUND AND AIMS: After partial gastrectomy, the mucosa of the residual stomach usually undergoes severe changes, and these lesions are known to be pre-cancerous. Recently, Helicobacter pylori has been highlighted as an agent that induces such mucosal alterations. In the present study, we evaluated whether eradication of H. pylori reduced the risk of carcinogenesis. PATIENTS AND METHODS: The subjects were 12 patients who underwent distal gastrectomy with Billroth I anastomosis for early gastric cancer and were positive for H. pylori. We performed endoscopy and biopsy both before and after H. pylori eradication therapy to assess changes in the gastric mucosa. RESULTS: After eradication therapy, no mucosal edema or erythema was detected. On histological examination, mononuclear cell infiltration had decreased and there was complete absence of neutrophil infiltration. The Ki-67 labeling index and the tissue IL-8 level had also decreased significantly, compared with before eradication. CONCLUSION: Before H. pylori eradication, the mucosa of the residual stomach may be at high risk of carcinogenesis due to induction of mucosal damage and active gastritis by H. pylori. Such changes were almost completely normalized by eradication therapy, so the eradication of H. pylori may reduce the risk of H. pylori-associated carcinogenesis in patients who have undergone gastrectomy for early gastric cancer.

Morphological changes in the rat exocrine pancreas after pancreatic duct ligation.

In the present study, morphological changes of the exocrine pancreas in rats after pancreatic duct ligation were examined with light microscopy (hematoxylin-eosin, TUNEL, and PCNA staining) and scanning electron microscopy in order to elucidate the effects of increased pancreatic duct pressure. On the fifth day after pancreatic duct ligation, ductular proliferation, periductal fibrosis, and disappearance of acini were observed. TUNEL and PCNA staining demonstrated many apoptotic acinar cells and proliferating ductal cells immediately after ligation, which reached a maximal number on the 2nd or 3rd day. Tortuous or helical interlobular pancreatic ducts with inner surfaces containing many crater-like depressions and long cilia were found after ligation. These changes were almost identical to those observed in the pancreatic tissue of model chronic pancreatitis rats, WBN/Kob rats, and stroke-prone spontaneously hypertensive (SHRSP) rats. In summary, the morphological changes observed after pancreatic duct ligation were similar to those of chronic pancreatitis, therefore, the characteristic changes of pancreatic ducts observed in chronic pancreatitis may be caused by increased pancreatic duct pressure.

Effects of rabeprazole, lansoprazole and omeprazole on intragastric pH in CYP2C19 extensive metabolizers.

AIM: To investigate the inhibitory effects on gastric acid secretion of three proton pump inhibitors, omeprazole, lansoprazole and rabeprazole, using a three-way crossover design in healthy Helicobacter pylori-negative,S-mephenytoin 4'-hydroxylase (CYP2C19) homo- and hetero-extensive metabolizers. METHODS: Eight healthy Japanese male volunteers were enrolled. After the administration of rabeprazole (10 mg/day), lansoprazole (30 mg/day) or omeprazole (20 mg/day), intragastric pH monitoring was commenced from 24 h before the first proton pump inhibitor dose, and continued for days 1-3 after proton pump inhibitor administration. The pH electrode was used for 48 h and changed just before pH monitoring on day 2. RESULTS: For the administration of 10 mg/day rabeprazole, the mean ratios of the 24-h pH > or = 3 holding time were 5.7 +/- 1.1%,13.6 +/- 2.2%, 35.3 +/- 2.7% and 62.8 +/- 3.1% for the pre-treatment day and days 1, 2 and 3, respectively. The same ratios for lansoprazole (30 mg/day) were 5.7 +/- 0.7%, 7.4 +/- 1.5%, 13.6 +/- 3.4% and 26.6 +/- 4.9%; the same ratios for 20 mg/day omeprazole were 5.9 +/- 0.9%, 6.1 +/- 1.2%, 11.4 +/- 2.8% and 16.4 +/- 4.6%. The mean ratio of the 24-h pH > or = 3 holding time of days 1-3 increased significantly compared to the pre-treatment day (P < 0.01) with the administration of rabeprazole and lansoprazole. The magnitude of inhibition of gastric acid secretion after rabeprazole administration was stronger than that after lansoprazole. A significant elevation of the mean ratio of the 24-h pH > or = 3 holding time was demonstrated on days 2 and 3 with omeprazole (P < 0.01). CONCLUSIONS: In H. pylori-negative CYP2C19 extensive metabolizers, rabeprazole (10 mg/day) shows a faster onset of rising intragastric pH and a stronger inhibition of gastric acid secretion than do lansoprazole (30 mg/day) or omeprazole (20 mg/day).

Effects of N-alpha-methyl-histamine on human H(2) receptors expressed in CHO cells.

BACKGROUND: Production of N-alpha-methyl-histamine (NAMH), a histamine H(3) receptor (H3R) agonist, is reportedly promoted in Helicobacter pylori infected human gastric mucosa. NAMH was suggested to act directly on histamine H(2) receptors (H2Rs) in animals to stimulate acid secretion and to be a H2R agonist. As H2Rs and H3Rs play different roles in gastric acid secretion, it is very important to verify that NAMH is a H2R agonist. AIMS: To determine whether NAMH is a H2R agonist, as well as a H3R agonist. METHODS: We used a Chinese hamster ovary (CHO) cell line expressing human H2Rs (CHO-H2R) and control CHO cells. Expression of human H2Rs was confirmed by tiotidine binding. cAMP production in CHO-H2R and control cells in response to histamine or NAMH was measured. cAMP production in response to 10(-7) M NAMH was also measured in the presence or absence of the H2R antagonist famotidine and the H3R antagonist thioperamide. RESULTS: NAMH dose dependently stimulated cAMP productions in CHO-H2R cells. This production was inhibited by famotidine but not by thioperamide. Control CHO cells were unresponsive to either histamine or NAMH. In addition, the effect of NAMH, in terms of cAMP production in CHO-H2R cells, was more potent than that of histamine-that is, with a lower EC(50) concentration and higher maximal cAMP production. Both NAMH and histamine, but not R-alpha-methyl-histamine, effectively inhibited [(3)H] tiotidine binding to CHO-H2R cells. CONCLUSIONS: NAMH, which is produced in the gastric mucosa by H pylori, is a potent H2R agonist as well as a H3R agonist.

Safety and efficacy of glucagon as a premedication for upper gastrointestinal endoscopy--a comparative study with butyl scopolamine bromide.

BACKGROUND: Glucagon inhibits digestive motility and is used for endoscopic premedication; however, its effect on cardiopulmonary function during endoscopy has not yet been fully investigated. AIM: To clarify the efficacy and safety of glucagon compared with butyl scopolamine bromide as upper gastrointestinal endoscopy premedication. METHODS: Two hundred and forty consecutive patients over 40 years of age, referred for upper gastrointestinal endoscopy, without any complications, were studied. These patients were randomly premedicated with butyl scopolamine bromide (SC group) or glucagon (G group). Time course changes in blood pressure, arterial oxygen saturation, heart rate and the number of retching episodes during endoscopy were examined. The efficacy of glucose tablets after upper gastrointestinal endoscopy to prevent hypoglycaemia caused by glucagon was evaluated. Cardiopulmonary parameters were also examined in 77 complicated patients with glucagon premedication (GC group). RESULTS: A continuous increase in heart rate during upper gastrointestinal endoscopy was observed in the SC group, but not in the G and GC groups. Blood pressure, arterial oxygen saturation and number of retching episodes were not different between the groups. Hypoglycaemia-related symptoms were frequent in the G group without glucose tablets, but were prevented by the administration of glucose. CONCLUSIONS: Glucagon has a weaker effect on cardiopulmonary function during upper gastrointestinal endoscopy than butyl scopolamine bromide. Glucose administration prevents hypoglycaemia-related symptoms caused by glucagon.

Fine reconstruction of the pancreatic ductular system at the onset of pancreatitis.

The three-dimensional structure of the pancreatic ductular system (from the intercalated duct to the intercellular secretory canaliculus) is controversial and unclear. The aim of this study is to reveal the three-dimensional structure of the pancreatic ductular sysytem at the onset of pancreatitis. One day following rat pancreatic duct ligation, dilated lumina from the pancreatic ductular system were reconstructed by light microscopic and scanning electron microscopic examination of pancreatic tissue serial sections. The existence of the intra-acinar duct, which is formed only by centroacinar cells and interconnects the adjacent central lumina in an acinus, was demonstrated. The intercellular secretory canaliculi, which are the terminal parts of the pancreatic ductular system, anastomose and end blindly in the intercellular space located between adjacent lateral surfaces of the acinar cells. The intercalated ducts, the intra-acinar ducts, the central lumina, and the intercellular secretory canaliculi are arranged together in a complex connecting and branching system. However, there were no anastomoses found among the central lumina or acini.

Study on endoscopic esophageal mucosal resection with ligating device. I--Clinical study.

BACKGROUND/AIMS: EEMRL (endoscopic esophageal mucosal resection with a ligating device) has become increasingly popular. In this article, we review 13 clinical cases of EEMRL. METHODOLOGY: Since 1993, we have performed EEMRL to treat 15 lesions in 13 patients. Twelve squamous cell carcinomas (mucosal cancer in 10 and submucosal cancer in 2) were included among the 15 lesions. RESULTS: EEMRL failed to achieve complete resection of the 2 submucosal lesions (3.0 and 2.8 cm in maximum diameter). However, esophageal lesions could be removed successfully when 2.5 cm or less in maximum diameter. The procedure was not associated with any complication. CONCLUSIONS: Our clinical study showed that this technique may be indicated for esophageal cancer with a maximum diameter < or = 2.5 cm and confined to the mucosa. EEMRL is a technically easy and minimally invasive therapy which could be useful for the treatment of early esophageal cancer.

Study on endoscopic esophageal mucosal resection with ligating device. II--Experimental study.

BACKGROUND/AIMS: This study reports on animal experiments regarding the safety of endoscopic esophageal mucosal resection with a ligating device (EEMRL), as well as the amount of mucosa which can be removed by this technique, the depth of resection and the feasibility of piecemeal resection. METHODOLOGY: Three experiments were performed in six mongrel dogs under general anesthesia. RESULTS: When EEMRL was done without submucosal injection of saline, resection reached the muscular layer and caused esophageal perforation. The average dimensions of the mucosal pieces resected using 8-, 10-, and 12-mm devices was 13 x 10 mm, 18 x 15 mm, and 22 x 18 mm, respectively. Resection reached the mid-plane of the submucosa and the depth was almost uniform. After piecemeal resection, there was no macroscopically visible mucosa at the resection site and each mucosal piece was resected along the mid-plane of the submucosa. CONCLUSIONS: The experimental study indicated that submucosal injection of saline is essential to prevent esophageal perforation. It also showed that EEMRL allows resection up to the mid-plane of the submucosa, that the 12-mm device allows en bloc resection of lesions < or = 15 mm in diameter and that EEMRL is suitable for piecemeal resection.

Lifting of lesions during endoscopic mucosal resection (EMR) of early colorectal cancer: implications for the assessment of resectability.

BACKGROUND AND STUDY AIMS: This study assessed the indications for and limitations of endoscopic mucosal resection (EMR) for early colorectal cancer, focusing on the way in which the lesion lifts after submucosal injection. PATIENTS AND METHODS: The study included 94 patients with early colorectal cancer who received EMR treatment. The lifting of the lesion after submucosal injection was analyzed (classified as completely lifted/soft; completely lifted/hard; incompletely lifted; and non-lifted) along with the endoscopic findings, pathological findings, and clinical course. RESULTS: Almost all completely lifted/soft lesions were mucosal cancers. Some of the completely lifted/hard lesions were staged as sm2. The incompletely lifted lesions included stages sm1 to sm3. Non-lifting lesions were almost always deeper than sm3. The lifting condition was significantly associated with the depth of invasion, and the lesion type was related to the extent of lifting but not to tumor size or recurrent disease. Recurrent disease was noted in three patients who underwent piecemeal EMR. CONCLUSIONS: The indication for EMR is easily assessed on the basis of the lifting characteristics of the tumor after submucosal injection, which was found to be significantly related to the depth of invasion. The factor limiting the indication for EMR is not the size of a tumor, but its lifting condition.

Genomic organization, transcription start sites, and chromosomal location of the Drosophila cortactin gene.

An actin filament binding protein cortactin was initially identified as a major phosphotyrosine-containing protein in v-Src-transformed chicken embryo fibroblast cells. The mouse, human, and Drosophila homologs were independently identified as a signaling molecule involved in a mitogenic response, as a product of a putative oncogene EMS1, and as a molecule interacting with a scaffolding protein ZO-1, respectively. In this report, we describe the cloning of the Drosophila cortactin gene, which consists of four exons and three introns, covering 3 kilobases in length. All exon-intron junctions are well matched with the GT/AG consensus sequence. S1 nuclease mapping revealed one major and several minor transcription start sites. The cytological location of the Drosophila cortactin gene is between chromosome segments 93B3 and 93B7.

Effect of intratumoral OK-432 administration of thymidine phosphorylase expression in human gastric carcinoma.

It is known that thymidine phosphorylase (dThdPase) is increased in various types of malignant tumors and is induced by cytokines. In this study, we have investigated the effects of OK-432, which induces multiple cytokines, on dTHdPase expression and angiogenesis in human gastric carcinomas. We examined 25 patients who underwent gastrectomy for gastric carcinoma. OK-432 was directly injected in tumors in 16 (OK group) of 25 patients via endoscopy before operation and the other 9 patients were not treated (control group). The dThdPase activity in carcinoma tissues of the OK group was significantly higher than that of the control group (P < 0.05). The amounts of IL-1 alpha, IFN-alpha, and IFN-gamma in carcinomas in the OK group were significantly higher than in the controls (P < 0.05), and these were significantly correlated with the dThdPase activity. Intratumoral OK-432 administration enhances the expression of dThdPase in gastric carcinoma cells by inducing various cytokines.

Prevalence of functional dyspepsia and its relationship with Helicobacter pylori infection in a Japanese population.

AIM: To investigate the prevalence of functional dyspepsia and Helicobacter pylori infection and their relationship in a Japanese population. METHODS: Two thousand five hundred people who visited Shimane Institute of Health Science for their annual medical check-up from September 1998 to August 1999 were prospectively enrolled in the study. After routine medical examination, including an upper gastrointestinal study and an ultrasonographic examination, all subjects were asked standard questions to check for the presence of any symptoms that suggested dyspepsia. Helicobacter pylori infection was determined by using a serum IgG antibody concentration with an ELISA. RESULTS: Of the 2,500 persons investigated, 2,263 showed no abnormal finding in any medical examination. The presence or absence of symptoms and H. pylori infection was investigated in these 2,263 cases. Of these, 201 people (8.9%) experienced nausea, fullness and/or early satiety and were diagnosed as having dysmotility-like dyspepsia, while 118 people (5.2%) experienced pain localized to the epigastrium and were diagnosed as having ulcer-like dyspepsia. The frequency of these symptoms had a tendency to decline with age, although this was not statistically significant. In contrast, the rate of H. pylori infection increased with age. There was no significant relationship between H. pylori infection and any type of functional dyspepsia. CONCLUSIONS: Helicobacter pylori infection does not influence the prevalence of the dysmotility-like and ulcer-like dyspeptic symptoms.

Gastrointestinal stromal tumor with a novel mutation of KIT proto-oncogene.

The majority of human gastrointestinal mesenchymal tumors are gastrointestinal stromal tumors (GISTs). Recent reports have shown the existence of gain-of-function mutations in the juxta-membrane domain of receptor tyrosine kinase (KIT) in GISTs. We present a 77-year-old woman with GIST diagnosed by positive immunostaining of cluster designation (CD) 34 and KIT. This case had a novel mutation at codon 576 located in the juxta-membrane domain of KIT. Our results indicate the importance of mutations in this KIT region and suggest the possibility of the existence of other types of mutations in this region in GISTs.

Correlation between microsatellite instability and metachronous disease recurrence after endoscopic mucosal resection in patients with early stage gastric carcinoma.

BACKGROUND: Since endoscopic treatment was first evaluated and established as a treatment for patients with early stage gastric carcinoma, metachronous disease recurrence at other sites in the stomach after endoscopic treatment has become a major problem. METHODS: A retrospective case-control study was conducted on 10 patients with metachronous recurrence of gastric carcinoma after undergoing successful endoscopic mucosal resection (EMR) therapy for early stage gastric carcinoma and on 14 patients without recurrence. Gastric mucosal tissues obtained during the initial EMR were dissected, and DNA samples from the tumor tissue and surrounding nonneoplastic mucosa were extracted separately. Microsatellite instability (MSI) was tested in five microsatellite markers (D2S137, D3S1067, TP53, TGFbetaRII, and BAX). The authors also looked for K-ras codon 12 point mutations in the tumor tissues. In addition, immunohistochemical staining was done to test for the presence of proliferating cell nuclear antigen (PCNA), p53, hMSH2, and hMLH1 in the mucosal tissues. Finally, the correlation between the presence or absence of metachronous recurrence and the characteristics of the primary tumor (MSI, K-ras, p53, etc.) were investigated. RESULTS: Three of 10 patients with recurrent disease showed MSI in more than two microsatellite markers among 3-5 investigated site (MSI-H), whereas none of the patients with nonrecurrent disease did so. There was no significant correlation between metachronous recurrence after EMR and immunohistochemical staining reactions, including those for PCNA, p53, hMSH2, and hMLH1. None of the patients showed K-ras mutations. CONCLUSIONS: Thirty percent of patients with recurrent disease showed MSI-H, whereas none of the patients with nonrecurrent disease did so.

Role of hiatus hernia and gastric mucosal atrophy in the development of reflux esophagitis in the elderly.

BACKGROUND AND AIMS: The pathogenetic mechanism responsible for the increased prevalence of reflux esophagitis in the elderly remains controversial. The aim of this study was to determine if an increased occurrence of hiatus hernia (HH) and/or a lower rate of gastric mucosal atrophy (GMA) are the main causes of the increased prevalence of reflux esophagitis in elderly patients. METHODS: The prevalence of HH, GMA, and reflux esophagitis was investigated by reviewing the endoscopic films of 2788 consecutive patients examined during a 3-year period. RESULTS: The prevalence of esophagitis in males was higher than in females (11.6% vs 7.6%, P< 0.0005). The prevalence of reflux esophagitis and HH was found to increase with age in females, but not in male patients. The prevalence of reflux esophagitis in hernia-positive patients also increased with age in women, but not in men. Age, male gender, presence of HH, and closed-type of GMA were significant risk factors for the prevalence of esophagitis (P=0.0001, 0.0229, <0.0001, <0.0001, respectively). In addition, the risk ratios of HH and low-grade GMA for reflux esophagitis increased with age, and this tendency was higher in female patients than in males. CONCLUSIONS: Aging, male gender, HH and closed-type GMA are most likely the risk factors of endoscopically proven reflux esophagitis in Japanese patients.