Biomedical subjects

Ryo Shimoda

Publications and source records attributed to Ryo Shimoda.

10 recordsLinked to original sources

PubMed2007

Adipocytes and preadipocytes promote the proliferation of colon cancer cells in vitro.

Obesity, a risk factor for colon cancer, is associated with elevated serum levels of leptin, a protein produced by adipocytes. The aim of the present study was to clarify the effects of adipose tissue on colon cancer proliferation by using cultured cell lines. To achieve this, colon cancer cells (CACO-2, T84, and HT29) were cocultured with adipose tissue, isolated mature adipocytes, and isolated preadipocytes in a three-dimensional collagen gel culture system. The adipocytes and preadipocytes used were isolated from C57BL/6J and leptin-deficient ob/ob mice. Proliferation of the cancer cells was evaluated by nuclear bromodeoxyuridine uptake. The adipose tissue, mature adipocytes, and preadipocytes isolated from C57BL/6J mice significantly increased the proliferation of the colon cancer cells. This trophic effect of mature adipocytes on the cancer cell lines was observed only for cells from lean littermates and not for those from ob/ob mice. In contrast, the trophic effect of preadipocytes was not abolished in ob/ob mice, and this finding was supported by the result that leptin had a trophic effect on cancer cells. In conclusion, adipocytes were able to enhance the proliferation of colon cancer cells in vitro, partly via leptin, suggesting that adipose tissues, including mature adipocytes and preadipocytes, may promote the growth of colorectal cancer.

Adipocytes, White↗

PubMed2006

A pilot randomized control study to evaluate endoscopic resection using a ligation device for rectal carcinoid tumors.

AIM: Rectal carcinoid tumors smaller than 10 mm can be resected with local excision using endoscopy. In order to remove rectal carcinoid tumors completely, we evaluated endoscopic mucosal resection with a ligation device in this pilot control randomized study. METHODS: Fifteen patients were diagnosed with rectal carcinoid tumor (less than 10 mm) in our hospital from 1993 to 2002. There were 9 males and 6 females, with a mean age 61.5 years (range, 34-77 years). The patients had no complaints of carcinoid syndrome symptoms. Fifteen patients were randomly divided into 2 groups: 7 carcinoid tumors were treated by conventional endoscopic resection, and 8 carcinoid tumors were treated by endoscopic resection using a ligation device. RESULTS: All rectal carcinoid tumors were located at the middle to distal rectum. The size of the tumors varied from 3 mm to 10 mm and background characteristics of the patients were not different in the two groups. The rate of complete removal of carcinoid tumors using a ligation device (100%, 8/8) was significantly higher than that of conventional endoscopic resection (57.1%, 4/7). The three patients had tumor involvement of deep margin, for which additional treatment was performed. No complications occurred during or after endoscopic resection using a ligation device. All patients in the both groups were alive during the 3-year observation period. CONCLUSION: Endoscopic resection using a ligation device is a useful and safe method for resection of small rectal carcinoid tumors.

Adult↗

PubMed2006

Role of Helicobacter pylori infection and nonsteroidal anti-inflammatory drug use in bleeding peptic ulcers in Japan.

BACKGROUND: Helicobacter pylori infection and nonsteroidal anti-inflammatory drugs (NSAIDs) are well-known major causes of peptic ulcers. This study aimed to characterize the features of bleeding peptic ulcers in Japan. METHODS: This prospective study evaluated 116 patients revealed to have bleeding peptic ulcers from January 2000 to December 2002. RESULTS: Eighty-eight of the 116 patients (75.9%) had H. pylori infection. Seventy (60.3%) patients were positive for H. pylori with no history of NSAID use (group A), and 18 (15.5%) were positive for H. pylori with a history of NSAID use (group B). Among the H. pylori-negative patients, 15 (12.9%) were associated with NSAID use (group C). Thirteen (11.2%) patients had no H. pylori infection or history of NSAID use (group D). Among the 33 patients with a history of NSAID use, 11 were on-demand NSAID users and 14 took daily low-dose aspirin. The patients in groups B and C were significantly older that those in groups A and D, and they more frequently had coexisting diseases compared with group A. In group D, 11 patients had atrophic changes revealed by endoscopic examination, suggesting a past H. pylori infection, and these atrophic changes remained at the time of bleeding. Many of the patients in group D had serious comorbidity. Compared with healthy control subjects, the concentrations of both phosphatidylcholine and phosphatidylethanolamine were significantly decreased in the antral gastric mucosa in all patient groups. CONCLUSIONS: NSAID use contributed to bleeding ulcers in 28.4% of patients; thus, low-dose aspirin or on-demand NSAID use may cause bleeding ulcers. There were only two (1.7%) confirmed cases of H. pylori-negative, non-NSAID ulcers.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2005

Dysphagia associated with gastroesophageal reflux disease is improved by proton pump inhibitor.

This study aimed to determine whether dysphagia associated with gastroesophageal reflux disease was effectively treated with rabeprazole, a proton pump inhibitor. Sixty-eight outpatients with gastroesophageal reflux-associated dysphagia were enrolled in this study. Endoscopic esophagitis was confirmed in 52 of 68 subjects. The proton pump inhibitor rabeprazole was administered at 20 mg daily for 8 weeks. Rabeprazole was administered for a further 6 months to 16 subjects whose dysphagia was improved (10 mg/day) and 5 of these underwent 24-hr esophageal pH monitoring before and after treatment. Dysphagia was completely resolved in 40 of 68 subjects, which were categorized in Group I. Dysphagia improved partially in 20 subjects and was unchanged in 8 subjects. These 28 subjects were categorized into Group II. Comparison was made between Group I and Group II and multivariate analysis demonstrated that the only factor that correlated with the effect of rabeprazole on dysphagia was "improvement in heartburn symptoms." There were no relapses of symptoms during the 6-month follow-up period, and pH monitoring showed sustained suppression of acid secretion. The results indicate that rabeprazole is effective in the treatment of dysphagia associated with gastroesophageal reflux disease. We were, however, unable to elicit any factors that could predict the therapeutic effect of rabeprazole before commencing treatment.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2003

Endoscopic injection sclerotherapy for esophageal varices in cirrhotic patients without hepatocellular carcinoma: a comparison of longterm survival between prophylactic therapy and emergency therapy.

BACKGROUND: This study aimed to determine whether prophylactic endoscopic injection sclerotherapy prolonged survival in patients with esophageal varices complicated by liver cirrhosis in the absence of hepatocellular carcinoma, compared with emergency sclerotherapy. METHODS: The subjects included 160 patients suffering from esophageal varices complicated by liver cirrhosis without hepatocellular carcinoma. Sixty-eight patients underwent emergency therapy for bleeding varices and the remaining 92 patients underwent prophylactic sclerotherapy. All subjects continued to receive therapy until the varices disappeared. RESULTS: Five-year survival was significantly better in the prophylactic group compared with the emergency group. During the 5-year observation period, 20 of the 68 patients in the emergency group experienced rebleeding and 5 patients died as a result of rebleeding. These rates were significantly higher than those in the prophylactic group (1 of 9 patients with bleeding died among the 92 prophylactic sclerotherapy patients). Multivariate analysis showed that prophylactic therapy and Child's C hepatic function were significant factors for 5-year survival. CONCLUSIONS: Prophylactic sclerotherapy for esophageal varices might be more effective in prolonging longterm survival of patients complicated by liver cirrhosis in the absence of hepatocellular carcinoma, compared with emergency sclerotherapy.

Adult↗

PubMed2003

Endoscopic injection sclerotherapy for esophageal varices in cirrhotic patients with hepatocellular carcinoma: risk factors for survival.

GOALS: We previously showed that endoscopic injection sclerotherapy (EIS) prolonged survival in patients with esophageal varices complicated by hepatocellular carcinoma (HCC) and liver cirrhosis. Here, we evaluated risk factors that affect EIS outcomes. Among factors, the difference between prophylactic and emergency EIS was of interest, and we analyzed precisely. STUDY: Subjects were 134 patients with esophageal varices complicated by HCC and liver cirrhosis: 38 underwent emergent therapy for bleeding varices and 96 underwent prophylactic sclerotherapy. RESULTS: During 2-year observation, 22 of the 38 (57.9%) and 38 of the 96 (39.6%) died. Analysis by univariate Cox's proportional hazard model indicated that prognosis of patients receiving emergency EIS was inferior to those with prophylactic EIS. However, multivariate Cox's analysis showed that emergency EIS itself extended survivals of those with esophageal varices complicated by HCC and liver cirrhosis. Patients' hepatic function (Child-Pugh classes) and tumor sizes were also statistically significant factors for survival. Neither prophylactic nor emergency EIS prolonged survival of patients with Child C hepatic function or those with HCCs larger than 5 cm. CONCLUSIONS: The prophylactic sclerotherapy for esophageal varices prolongs long-term survival of patients with liver cirrhosis and HCC, better than emergency therapy. However, EIS itself had no beneficial effect on patients with poor disease status.

Esophageal and Gastric Varices↗

PubMed2003

Evaluation of endoscopic hemostasis with metallic hemoclips for bleeding gastric ulcer: comparison with endoscopic injection of absolute ethanol in a prospective, randomized study.

OBJECTIVE: Although metallic hemoclips have been used for hemostasis of bleeding ulcer, there have been few prospective trials to evaluate their efficacy. In this study, a prospective, randomized trial was performed to evaluate endoscopic hemoclipping for bleeding gastric ulcer in comparison with endoscopic injection of absolute ethanol. METHODS: During the period 1995-1998, 126 gastric ulcer patients with bleeding or nonbleeding visible vessel were considered for entry. They were randomly assigned to one of three groups: endoscopic hemostasis performed with injection of absolute ethanol (group I, n = 42), hemoclipping (group II, n = 42), and a combination of the two methods (group III, n = 42). RESULTS: The permanent hemostatic rate was 85.7% in group I, 90.5% in group II, and 92.9% in group III. The mean volume of blood transfusion was 313 +/- 77 ml in group I, 274 +/- 54 ml in group II, and 163 +/- 42 ml in group III, which was significantly less than in groups I or II (p < 0.05). No patients required emergency surgery. Five patients died within a month after initial hemostasis as a result of unrelated conditions. CONCLUSIONS: Endoscopic hemostasis with hemoclips for bleeding gastric ulcer was as effective and safe as that with injection of absolute ethanol, and a combination of ethanol injection and hemoclips did not result in a great advantage over the two individual procedures.

Equipment Design↗

PubMed2003

Intracerebroventricular administration of leptin-induced apoptosis in the rat small intestinal mucosa.

The localization of leptin and leptin receptors in the stomach and small intestine has been reported. Their function is still unknown, although leptin is a hormone that regulates appetite and fat-related metabolism. The small intestine is one of the important organs for regulating metabolism. The purpose of the present study was to investigate whether leptin regulates apoptosis in the small intestinal mucosa. Intestinal apoptosis was evaluated by percent fragmented DNA, electrophoresis, TUNEL staining, and western blotting analysis of caspase-3. Mucosal apoptosis in the rat jejunum and ileum was evaluated at 0, 3, 6, 12, and 24 hrs after injection. Rats were tested after ad libitum feeding and 24-hr fasting to exclude the anorectic effect of leptin. Leptin was injected intraperitoneally (ip) at a dose of 200 microg/rat and infused into the rat third cerebroventricle (icv) at a dose of 8 microg/rat. Leptin at a dose of 8 microg/rat significantly induced intestinal apoptosis in the small intestine at 3 and 6 hrs after icv administration in both ad libitum feeding and 24-hr fasted rats. This increase in apoptosis was not attenuated by vagotomy. Intestinal apoptosis increased 12 and 24 hrs after ip injection of leptin at a dose of 200 microg/rat. The peak of the increase in apoptosis in icv rats appeared earlier than that in ip rats. Leptin induced jejunal and ileal mucosal apoptosis in the rat, indicating that leptin might control intestinal function through the regulation of intestinal apoptosis.

Animals↗

PubMed2003

Characteristics of gastroesophageal reflux disease in Japan: increased prevalence in elderly women.

The aim of this study was to examine the characteristics of gastroesophageal reflux disease in Japan. We evaluated the correlation between clinical symptoms and endoscopic findings in an age- and sex-specific manner. This study included 6010 Japanese subjects who had not received medication or undergone laparotomy for gastrointestinal disease. All subjects were questioned in regard to clinical symptoms by paramedical personnel before endoscopic examination. Esophageal mucosal breaks were evaluated according to the Los Angeles Classification of Esophagitis. The ratio of subjects with each complaint to all subjects is as follows: heartburn, 27.0%; dysphagia, 16.9%; odynophagia, 19.2%; acid regurgitation, 7.1%. The proportion of each grade was grade A, 9.6%; grade B, 4.6%; and grade C + D, 2.0%. The most common related symptom for endoscopic esophagitis among these four symptoms was heartburn (odds ration, 2.5), although about 40% of subjects with severe esophagitis of grade C or D did not complain of heartburn. Regarding odynophagia, acid regurgitation, and dysphagia, odds ratios were about 1.0. The age-related ratio of esophagitis and severe disease with grades C and D increased in women over 60 years of age. An age-related slouched position was related to the increased esophagitis in these elderly women. Male subjects whose body mass index was more than 25 tended to show a greater prevalence in the age group 30-50 years. The prevalence of hiatal herniation increased in an age-related manner. These data indicate the characteristics of esophagitis in Japan are as follows: (1) the prevalence of reflux esophagitis is about 15% and most of these cases are grade A or B; and (2) the prevalence of severe esophagitis increases in older women, who do not always complain of clinical symptoms.

Adult↗

PubMed2002

Normalization of phospholipids concentration of the gastric mucosa was observed in patients with peptic ulcer after eradication of Helicobacter pylori.

BACKGROUND: Phospholipids concentration in the gastric mucosa decreased in patients with Helicobacter pylori infection. The aim of this study is to examine the effects of eradication of H. pylori on decreasing the phospholipids concentration in the gastric mucosa in patients with gastric or duodenal ulcer. MATERIALS AND METHODS: Phospholipids (phosphatidylcholine, phosphatidylethanolamine, and sphingonomyeline) were measured in biopsy specimens from the antrum and corpus using thin-layer chromatography. In H. pylori positive patients with gastric ulcer (n = 26) and duodenal ulcer (n = 13), and H. pylori negative controls (n = 20), the biopsy specimens were obtained before and 3 months after eradication. Eradication was performed using lansoprazole, amoxycillin, and clarithromycin. RESULTS: Compared with the H. pylori negative control group, the concentrations of phosphatidylcholine and phosphatidylethanolamine decreased significantly in the gastric ulcer group in both antrum and corpus mucosa, and in the duodenal ulcer group in antrum mucosa. This decrease returned to the control level after eradication. CONCLUSIONS: This study demonstrates that the eradication of H. pylori in patients with peptic ulcer normalized the decrease of phosphatidylcholine and phosphatidylethanolamine in the gastric mucosa.

2-Pyridinylmethylsulfinylbenzimidazoles↗