The adenoma miss rate of blue-laser imaging vs. white-light imaging during colonoscopy: a randomized tandem trial.

Background and study aims The aim of the present study was to determine whether blue-laser imaging (BLI) reduced the miss rate of colon adenomatous lesions compared with conventional white-light imaging (WLI). Patients and methods This was a prospective randomized study of patients undergoing screening and/or surveillance colonoscopy at Saga Medical School, Japan. A total of 127 patients were randomized to tandem colonoscopy with BLI followed by WLI (BLI-WLI group) or WLI followed by WLI (WLI-WLI group). The main outcome measure was the adenoma miss rate. Results The proportion of patients with adenomatous lesions was 62.5 % (40 /64) in the BLI-WLI group and 63.5 % (40 /63) in the WLI-WLI group. The total number of adenomatous lesions detected in the first inspection of the BLI-WLI and WLI-WLI groups was 179 and 108, respectively, compared with 182 and 120 in the second inspection, respectively. The miss rate in the BLI-WLI group was (1.6 %), which was significantly less than that in the WLI-WLI group (10.0 %, P = 0.001). Conclusions Colonoscopy using BLI resulted in a lower colon adenoma miss rate than WLI.Trial registration UMIN 000015677.

[Mecobalamin improved pernicious anemia in an elderly individual with Hashimoto's disease and diabetes mellitus].

A 73-year-old Japanese man with Hashimoto's disease and diabetes mellitus received regular medical checkups for type 2 diabetes care. Blood tests indicated macrocytic anemia (red blood cell count, 279×104 /µL; hemoglobin, 12.2 g/dL; hematocrit, 34.0%; mean corpuscular volume, 121.9 fL). The laboratory data demonstrated a normal folic acid level with a low vitamin B12 level. An endoscopic examination indicated no signs of gastric or intestinal bleeding. Positive results for anti-intrinsic factor antibodies were strongly suggestive of pernicious anemia. The patient refused cobalamin injections to treat the anemia. However, the oral administration of mecobalamin for the treatment of diabetic neuropathy was simultaneously initiated. Subsequently, the anemia gradually improved. Oral mecobalamin was presumably effective for pernicious anemia management. Anemia is frequently observed in elderly patients, and the incidence of pernicious anemia increases with age. Anemia is conventionally treated with cobalamin injections. Currently, the oral administration of mecobalamin is not the typical treatment for anemia. However, as in our case, a few reports have documented positive results following oral mecobalamin treatment. Moreover, oral mecobalamin is a fairly recent, novel, noninvasive mode of treatment, making it ideal for elderly patients, who are generally frail. This case suggests the efficacy of mecobalamin for the treatment of pernicious anemia.

Risk factors for resistance to proton pump inhibitor maintenance therapy for reflux esophagitis in Japanese women over 60 years.

AIM: The aim of this study was to evaluate risk factors for proton pump inhibitor (PPI) resistance in older Japanese female patients with reflux esophagitis evaluated by physicians. METHODS: The study included 462 Japanese female patients aged over 60 years with reflux esophagitis who received PPI maintenance therapy for more than 6 months. RESULTS: The characteristics of all 462 patients were: age: 76.4 ± 7.6 years, height: 147.2 ± 6.1 cm, weight: 49.9 ± 8.4 kg and body mass index: 24.0 ± 3.5. The reflux esophagitis grades were A in 69.5%, B in 15.8%, C in 9.1% and D in 5.6%. Helicobacter pylori was positive in 60.6%. Regarding PPI maintenance therapy for clinical symptoms evaluated by the attending physicians, 66.7% were 'good control', 26.8% were 'reasonable control' and 6.5% were 'bad control: resistant'. PPI maintenance therapy was less effective in patients with more severe reflux esophagitis of grades C and D (OR: 0.027; 95% CI: 0.010-0.077) and negative H. pylori infection status (OR: 4.470; 95% CI: 1.631-12.247). Lumbar kyphosis and hiatus hernia were risk factors for severity grading of reflux esophagitis. CONCLUSIONS: PPI maintenance therapy evaluated by attending physicians indicated that reflux esophagitis severity and negative H. pylori status were risk factors for treatment resistance.

Perforation and postoperative bleeding of endoscopic submucosal dissection in gastric tumors: analysis of 1190 lesions in low- and high-volume centers in Saga, Japan.

BACKGROUND: This retrospective study aimed to determine risk factors associated with serious complications of endoscopic submucosal dissection of gastric tumors in multicenters compared between high- and low-volume centers. METHODS: Between 2001 and 2010, gastric endoscopic submucosal dissection was performed in 1190 lesions of 1082 patients in five hospitals in Saga, three high-volume and two low-volume centers. Risk factors for serious complications were evaluated. Patients' background characteristics were evaluated, including anticoagulants use and underlying diseases. RESULTS: Postoperative bleeding was detected in 75 patients (6.9%), and perforation was detected in 40 patients (3.7%). Most postoperative bleeding and perforation cases were recovered with endoscopic procedures, although one case of each complication was treated by emergency surgery. Multivariate analysis indicated that risk factors for perforation were tumor location, massive submucusal invasion, endoscopists' experience of 100-149 cases and hypertension, and that risk factors for postoperative bleeding were tumor location, resected tumor size, and scar lesion. The serious complications were not different between high- and low-volume centers. CONCLUSIONS: The present study indicated that risk factors for perforation during endoscopic submucosal dissection were tumor, endoscopist and patient related, although risk factors for postoperative bleeding were tumor related. There was no difference in complications between high- and low-volume centers.

Chemopreventive effect of mofezolac on beef tallow diet/azoxymethane-induced colon carcinogenesis in rats.

BACKGROUND/AIMS: We have previously shown that long-term consumption of 10% beef tallow diet promotes colon carcinogenesis in both saline- and azoxymethane (AOM)-treated rats. Here, we investigated the effects of mofezolac, a selective COX-1 inhibitor, on beef tallow-fed rats with saline- or AOM treatment. METHODOLOGY: Male SD rats were intraperitoneally injected with saline or AOM and fed 10% beef tallow diet with or without 1200 ppm mofezolac. At 12 weeks, aberrant crypt foci (ACF) were examined. At 44 weeks, tumors were counted, the proliferation and expression of COX-1 and 8-catenin on normal-appearing colonic mucosa was evaluated using the BrdU incorporation assay and Western blotting respectively. RESULTS: Mofezolac decreased the number of ACF at 12 weeks (p < 0.05) and reduced tumor multiplicity and incidence at 44 weeks in beef tallow-fed rats with AOM treatment (p < 0.05). At 44 weeks, reduction of the BrdU-positive cells (p < 0.05) and beneficial distribution changes of these cells within the colon crypts in both groups with mofezolac supplementation were observed. The expression of COX-1 and beta-catenin also reduced in mofezolac-added groups simultaneously (p < 0.05). CONCLUSIONS: This study suggested that mofezolac suppressed beef tallow-promoted colon carcinogenesis in rats, which probably was, appropriate for populations with high fat intake.

Conjugated linoleic acid suppresses colon carcinogenesis in azoxymethane-pretreated rats with long-term feeding of diet containing beef tallow.

BACKGROUND: We have indicated previously that long-term feeding of beef tallow increases colorectal cancer in rats. In this study, we investigated the effects of conjugated linoleic acid (CLA) on colon carcinogenesis in rats under long-term feeding of beef tallow diets, pretreated with azoxymethane (AOM). METHODS: Six-week-old male Sprague-Dawley rats were fed with 10% beef tallow diet only, 10% beef tallow with 1% CLA in triglyceride form (CLA-TG), or 10% beef tallow with 1% CLA in free fatty acid form (CLA-FFA). Colon carcinogenesis was induced by two intraperitoneal injections of AOM. Aberrant crypt foci (ACFs) were examined at 12 weeks. Cancer, cell proliferation, apoptosis, Wnt signaling, and the arachidonic acid cascade were examined at 44 weeks. RESULTS: At 12 weeks, CLA-TG and CLA-FFA attenuated the increase in ACFs induced by 10% beef tallow and AOM pretreatment. At 44 weeks, both forms of CLA attenuated multiple colon cancers, and CLA-FFA reduced the incidence of colon cancer to 50% of that seen with CLA-TG. CLA-TG and CLA-FFA decreased the number of 5-bromo-2'-deoxyuridine-positive cells in AOM-pretreated rats fed with 10% beef tallow. CLA-FFA increased the number of apoptotic cells and the activity of caspase-3 in the colon mucosa, and CLA-TG enhanced the activity of caspase-3. Both forms of CLA suppressed Wnt signaling and the arachidonic acid cascade in rats treated with beef tallow and AOM. CONCLUSION: These results suggested that CLA-TG and CLA-FFA suppressed colon carcinogenesis in rats with long-term feeding of a 10% beef tallow diet, through several mechanisms. The results of the present study with rats might be applicable to humans.

Risk factors for complications of endoscopic submucosal dissection in gastric tumors: analysis of 478 lesions.

PURPOSE: Endoscopic submucosal dissection (ESD) technique has facilitated en bloc removal of widely spread lesions from the stomach. This retrospective study aimed to determine factors associated with serious complications of ESD. METHODS: Between December 2001 and March 2007, we have performed ESD for 478 lesions in 436 patients. We experienced 39 patients with post-operative bleeding and 17 patients with perforation. Risk factors of patients who received ESD in gastric mucosal tumors for complications were evaluated, focusing on resected size, location, scar lesions, operation time, and experience of endoscopists. We evaluated the patients' background characteristics including sex, age, body mass index (kg/m(2)), drug history of anticoagulant, and underlying diseases including cerebrovascular disorder, ischemic heart disease, liver dysfunction, renal dysfunction, hyperuricemia, hypertension and diabetes mellitus. RESULTS: Multivariate analysis indicated a risk factor for perforation was long operation time. Multivariate analysis indicated a significant risk factor for post-operative bleeding was size of the resected tumor. CONCLUSIONS: This study indicated risk factors for serious complications of ESD. Large resected tumor size was a risk factor for post-operative bleeding, while long operation time was a risk factor for perforation. Information regarding operation risk factors should be useful for planning strategies for ESD.

Endoscopic hemostasis with metallic hemoclips for iatrogenic Mallory-Weiss tear caused by endoscopic examination.

AIM: Applied endoscopic techniques including mucosal resection, sclerotherapy and endoscopic retrograde cholangiopancreatography (ERCP) have been advanced and iatrogenic complications including Mallory-Weiss tear (MWT) occasionally occur in daily endoscopic procedures. The present study aimed to examine the advantages of clipping for MWT complications that occur during endoscopic examination. METHODS: Over 10 years, we experienced 47 patients with bleeding caused by MWT. Metallic hemoclips were applied for 38 patients for hemostasis. These patients were categorized into two groups: 18 patients in group A whose bleeding tear occurred during endoscopic examination in an iatrogenic condition, and 20 patients in group B visited the emergency unit due to other etiology of MWT. RESULTS: The background characteristics, including length of tears, were not different between the two groups. Initial hemostasis was 100% in groups A and B. Rebleeding was 0/18 (0%) in group A and 1/20 (5 %) in group B. Number of patients who received blood transfusion was significantly higher in group B (group A: 0/18, group B: 4/20). Hemoglobin level before hemostasis was 12.5 g/dL in group A which was not different to that in group B, 10.9 g/dL. CONCLUSION: Application of hemoclips was effective for bleeding MWT during endoscopic procedures, which warranted prophylactic application of hemoclips on MWT during endoscopic examination.

Long-term ingestion of reduced glutathione suppressed an accelerating effect of beef tallow diet on colon carcinogenesis in rats.

PURPOSE: We have shown previously that long-term feeding of beef tallow increases colorectal cancer in rats. This study investigated the effects of enzymic antioxidant, reduced glutathione (GSH), on colon carcinogenesis in rats fed with beef tallow. METHODS: Colon carcinogenesis was induced by intraperitoneal injection of azoxymethane (AOM) to rats. Rats were fed with 10% beef tallow supplemented with or without 1% GSH in drinking water. Aberrant crypt foci (ACF) and expression of beta-catenin in colonic mucosa were examined at 12 weeks. Cancers, related substances of oxidative stress and arachidonic acid cascade in plasma and normal colonic mucosa were determined at 44 weeks. RESULTS: GSH attenuated the number of ACF increased by beef tallow, but GSH had no influence on expression of beta-catenin increased by AOM. Incidence of colon cancer was no different with or without GSH, but GSH attenuated the number of colon cancers in each rat. GSH suppressed plasma malondialdehyde concentration. GSH increased GSH concentration and activities of catalase, glutathione peroxidase and superoxide dismutase in colonic mucosa, and decreased cyclooxygenase-2, prostaglandin E2 and thromboxane B2 levels. CONCLUSIONS: This study indicated that GSH suppressed the number of ACF, but the attenuation of colon carcinogenesis was limited to the number of colon cancers, although anti-oxidative effects and suppressive effects of arachidonic acid cascade were demonstrated by several indexes. These results suggested that colon carcinogenesis enhanced by beef tallow was partly caused by oxidative stress and arachidonic acid cascade, which were reduced by GSH.

Reflux esophagitis and Helicobacter pylori infection in patients with scleroderma.

OBJECTIVE: This study aimed to evaluate the possible effects of Helicobacter pylori (H. pylori) infection in reflux esophagitis with scleroderma. PATIENTS AND METHODS: There were a total of 138 patients with scleroderma in our hospital between October 1998 and June 2005. Among these patients, 64 consecutive patients of scleroderma, who did not receive medication for gastrointestinal diseases, underwent endoscopy after informed consent. H. pylori was examined using an H. pylori IgG ELISA. The endoscopists graded esophageal mucosal breaks according to the Los Angeles Classification of Esophagitis. RESULTS: Among the 64 patients, 37 patients (57.8%) were positive for H. pylori infection. Reflux esophagitis was observed in 10 of 37 H. pylori-positive patients and in 19 of 27 H. pylori-negative patients. Significantly fewer H. pylori-infected patients had reflux esophagitis than H. pylori-negative patients (p<0.01). The odds ratio for H. pylori infection and reflux esophagitis was 0.16 (95%CI; 0.052-0.47). CONCLUSION: These findings suggest an important role for H. pylori infection in reflux esophagitis with scleroderma.

Comparison of the efficacy of granulocyte and monocyte/macrophage adsorptive apheresis and leukocytapheresis in active ulcerative colitis patients: a prospective randomized study.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel disease associated with recurring inflammation of the colorectal mucosa. Recently, cytapheresis has emerged as a new treatment for patients with UC. Removal methods are mainly performed with beads [granulocyte and monocyte/macrophage adsorptive apheresis (GMCAP)] or filters [leukocytapheresis (LCAP)]. Both treatments have been reported to be effective for active UC. There have been few trials, however, comparing the efficacy of GMCAP and LCAP. In this study, we prospectively evaluated the efficacy of LCAP and GMCAP for the treatment of active UC. METHODS: Thirty-nine patients [18 male, 21 female; mean age 38.7 years; duration of disease 6 years; clinical activity index (CAI) >6 points] with moderate-to-severe active UC were randomly assigned to the LCAP (n=21) or GMCAP group (n=17). Adacolumn (cellulose acetate beads; Japan Immunoresearch Laboratories, Takasaki, Japan) for GMCAP and Cellsorba EX (polyethylene phthalate fibers; Asahi Medical Co. Ltd, Tokyo, Japan) for LCAP were used for leukocyte removal. Patients received two sessions of cytapheresis in the first week, followed by four weekly administrations. Steroid doses were tapered if patients achieved clinical improvement. When the CAI score had decreased by 5 points or more, the patient was considered to have improved. RESULTS: Thirteen patients in the GMCAP group and 14 in the LCAP group achieved clinical improvement. No significant difference was found in clinical response and clinical course between LCAP and GMCAP. Hemoglobin levels were significantly decreased immediately after one session of cytapheresis in the LCAP group. No severe adverse effects were observed in any of the patients. No significant differences were observed in any clinical parameters predictive of a response to either LCAP or GMCAP. But in all patients receiving cytapheresis, a high CAI score was a significant risk factor for treatment failure. All of the cytapheresis nonresponders had CAI scores >or=16. CONCLUSION: Both GMCAP and LCAP were effective treatments for active UC. Patients with severe UC and a high CAI score were, however, refractory to treatment.

Case series of endoscopic balloon dilation to treat a stricture caused by circumferential resection of the gastric antrum by endoscopic submucosal dissection.

BACKGROUND: Endoscopic submucosal dissection (ESD) plays an important role in the management of gastric neoplasms. There are few reports regarding stricture development caused by ESD of gastric neoplasms. OBJECTIVE: The present study aimed to determine the incidence of gastric stricture formation after ESD of gastric neoplasms and to report on the outcome and management of this complication: endoscopic intervention (ie, balloon dilation) versus surgery; the outcome of balloon dilation (success or failure/perforation). DESIGN: A case series from a retrospective review of gastric ESDs performed at Saga Medical School over a defined period of time. SETTING: Double-center territory, referral hospital. PATIENTS: An evaluation was performed in 532 patients with gastric mucosal tumors treated by ESD. A stricture was reported in 5 patients. All the 5 cases were located in the antrum. ESD that was performed in the cardia or the proximal stomach did not induce a stricture. RESULTS: Of the 5 cases of symptomatic gastric outlet obstruction, 1 patient required surgical intervention because of a near total gastric outlet obstruction not amenable to endoscopic intervention. The 4 patients underwent step-serial through-the-scope balloon dilations; in 2 patients, the procedure was successful, but in the other 2 patients, the procedure was complicated by a gastric perforation (50% incidence of perforation). LIMITATION: A retrospective study. CONCLUSIONS: Circumferential or subcircumferential resection by ESD in the antrum caused a stricture. Balloon dilation of the ESD gastric outlet obstruction might be a choice, but it is a risky treatment.

Indigestible material attenuated changes in apoptosis in the fasted rat jejunal mucosa.

We have previously demonstrated that fasting induced apoptosis and decreased cell proliferation in the rat intestinal mucosa. The aim was to investigate the effect of expanded polystyrene as indigestible material on apoptosis and cell proliferation in rat small intestinal mucosa during fasting. Male SD rats were divided into 3 groups. The first group was fed with chow and water ad libitum. The second group fasted for 72 hrs. The third group was fasted for 24 hrs and was fed expanded polystyrene. Intestinal apoptosis was evaluated by percent fragmented DNA assay, terminal deoxynucleotidyl transferase-mediated dUDP-biotin nick end-labeling (TUNEL) staining, and caspase-3 assay. Cell proliferation was analyzed by 5-bromo-2'-deoxyuridine (5-BrdU) uptake. Truncal vagotomy was performed to evaluate a role of the central nervous system. In the 72-hr fasted rat, mucosal height of the rat jejunum was decreased to 73% of that in rats fed ad libitum, and this decrease was partly restored to 90% in rats fed expanded polystyrene. The fragmented DNA was increased in fasted rats (28.0%) when compared with that in rats fed ad libitum (2.6%). The increase in fragmented DNA in fasted rats was recovered by feeding them expanded polystyrene (8.3%). TUNEL staining confirmed this result. The effect of polystyrene on apoptosis was decreased by truncal vagotomy. Expression of cleaved caspase-3 was increased in fasted rats, which was then decreased by feeding of expanded polystyrene. In contrast to apoptosis, feeding of expanded polystyrene had no reconstructive effect on 5-BrdU uptake in the intestinal epithelium, which was decreased by fasting to 60% of that in rats fed ad libitum. In conclusion, feeding of indigestible material partly restored the decrease in intestinal mucosal length in the fasted rats through the apoptotic pathway without any influence on BrdU uptake. Further exploration focused on the mechanism of this effect of indigestible material is required.

Suppression of intestinal mucosal apoptosis by ghrelin in fasting rats.

Ghrelin is mainly produced in the stomach and has several physiologic functions. The aim of this study was to investigate whether ghrelin regulates apoptosis in the small intestinal mucosa of fasting rats. Intestinal mucosal apoptosis was evaluated as the percentage of fragmented DNA, villus height, and terminal deoxynucleotidyl transferase-mediated dUDP-biotin nick end-labeling (TUNEL) staining and by Western blot analysis of caspase-3 in 48-hr fasting rats. Crypt cell proliferation was evaluated by counting the number of 5-bromo-2-deoxyuridine (BrdU) positive cells. Ghrelin was administered intraperitoneally at dosages of 2.5, 25, and 250 microg/kg per 48 hrs by continuous infusion via an Alzet micro-osmotic pump or injections at 12-hr intervals. Ghrelin was also infused in rats that underwent truncal vagotomy. The lowest dosage of ghrelin (2.5 microg/kg per 48 hrs) was administered into the third cerebroventricle. Ghrelin treatment attenuated the percentage of fragmented DNA in the small intestinal mucosa in 48-hr fasting rats in a dose-dependent manner. Continuous infusion of ghrelin and injections of ghrelin at 12-hr intervals suppressed intestinal apoptosis almost equally. This effect on apoptosis was not attenuated by truncal vagotomy. Cerebroventricular infusion of ghrelin also attenuated intestinal apoptosis. The antiapoptotic effect of ghrelin was confirmed by decreased TUNEL staining, recovery of the villus height, and decreased expression of caspase-3. BrdU uptake indicated that ghrelin enhanced cell proliferation in the intestinal crypt. Taken together, these data indicate that ghrelin enhanced intestinal growth with the suppression of small intestinal mucosal apoptosis in 48-hr fasting rats, suggesting that ghrelin controls intestinal function through the regulation of intestinal apoptosis.

A case of advanced colonic cancer that developed from residual laterally spreading tumor treated by piecemeal endoscopic mucosal resection.

This case report showed a laterally spreading tumor treated by endoscopic mucosal resection that developed as an advanced colon cancer. A 74-year-old female was visited to treat a colon tumor that was pointed out at another hospital. Total colonoscopy revealed a laterally spreading tumor (LST) 25 mm in diameter in the cecum. The lesion was diagnosed as homogenous granular type LST (G-type LST) and treated by endoscopic piecemeal mucosal resection in January 2004. A tumor was recognized by follow-up endoscopic examination in April 2006. The scar of endoscopic piecemeal mucosal resection had developed to advanced colon cancer and was treated by laparoscopy-associated ileocecal resection with D3 lymph node resection. Previous reports indicated that G-type LST in the colon could be treated by piecemeal resection, but this report suggests that G-type LST resected by piecemeal endoscopic mucosal resection might develop to advanced colon cancer.

Dysphagia in adult Japanese is not equivalent to the grade of endoscopic reflux esophagitis.

OBJECTIVE: This study was aimed to evaluate the correlation between dysphagia, detected by nursing staff in a brief interview and endoscopic findings in reflux esophagitis. PATIENTS AND METHODS: A total of 8,031 Japanese subjects without medication for gastrointestinal disease were briefly asked about the presence of heartburn, dysphagia, odynophagia, and acid regurgitation by nursing staff before endoscopy for assessment of esophagitis utilizing the Los Angeles Classification. RESULTS: The grade of endoscopic esophagitis was not equivalent to symptoms of dysphagia in 8,031 subjects. We evaluated the characteristics of subjects who complained of only dysphagia. Univariate analysis indicated that non-smoking, and non-drinking females were associated with a higher risk for dysphagia, and multivariate analysis indicated the gender was associated with dysphagia. There was no association of dysphagia with herniation and distribution of age. CONCLUSION: This study indicated that dysphagia was not equivalent to the endoscopic findings according to a brief interview by nursing staff and that dysphagia might be more common in females and those who do not smoke or drink.

Long-term feeding of various fat diets modulates azoxymethane-induced colon carcinogenesis through Wnt/beta-catenin signaling in rats.

The Wnt signaling pathway plays an essential role in carcinogenesis, and the amount of fat intake and composition of dietary fatty acids are crucial factors for colon carcinogenesis. We investigated whether various dietary fats affected the Wnt signaling pathway of colon tumorigenesis in azoxymethane (AOM)-treated rats. Male Sprague-Dawley rats were given intraperitoneal injections of AOM and supplemented with 10% corn, olive, beef, and fish oil for 44 wk. Aberrant crypt foci (ACF) and tumors were examined at 12 and 44 wk. Normal appearing colon mucosal proliferation and apoptosis were evaluated by 5-bromo-2'-deoxyuridine (BrdU) incorporation and percentages of fragmented DNA, respectively. Expressions of beta-catenin, cyclin D(1), Wnt2, Wnt3, and Wnt5a of normal appearing colon mucosa were analyzed by Western blot analysis. Long-term dietary corn oil and beef tallow increased ACF, tumor incidence, and tumor numbers in AOM-treated rats. In contrast, both olive and fish oil inhibited them. Dietary corn oil and beef tallow increased BrdU incorporation and the expression of cytosolic beta-catenin and cyclin D(1) and decreased apoptosis in the colon mucosa. Expressions of Wnt2 and Wnt3 in rats fed with beef tallow and Wnt5a in rats fed with corn oil increased with or without AOM-treatment. BrdU-incorporated cells were often observed at the tops of crypts in rats fed with beef tallow, whereas this was not observed in rats fed with the other diet. Long-term high intake of corn oil and beef tallow enhanced cell proliferation through Wnt signaling and modulated the distribution of proliferating cells, which might contribute to promoting effects in colon tumorigenesis.

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.

[A case of relapsed ischemic colitis with colon cast-like stripped mucosa].

An 82-year-old woman who had 5 relapses of ischemic colitis was admitted with sudden lower abdominal pain. Colonoscopic examination performed on the 2nd day revealed colon cast-like stripped colonic mucosa in the lower portion of the descending colon. She was treated conservatively. After 2 weeks, ischemic colitis healed, with slight residual stenosis. Most reports of colon cast indicated that colon cast was caused by abdominal aneurysm, operation, or external wound. The only predisposing conditions in this case were arteriosclerosis of abdominal aorta and chronic constipation. Arteriosclerosis and chronic constipation might be the important risk factors of ischemic colitis with colon cast and relapsing of ischemic colitis.