Toru Ueki

Distribution of activated complement, C3b, and its degraded fragments, iC3b/C3dg, in the colonic mucosa of ulcerative colitis (UC)

The third component of complement (C3) is central to both the classical and alternative pathways in complement activation. In this study, involvement of C3 activation in the mucosal injury of UC was investigated. We examined the distribution of activated (C3b) and degraded fragments (iC3b/C3dg) of C3, terminal complement complex (TCC), and complement regulatory proteins in normal and diseased colonic mucosa including UC and other types of colitis using immunohistochemical techniques at the level of light and electron microscopy. While C3b and iC3b/C3dg staining was negligible in the normal mucosa, iC3b/C3dg and, to a lesser extent, C3b were deposited in UC mucosa along the epithelial basement membrane. The deposition was enhanced in relation to the severity of mucosal inflammation (C3b, P < 0.05; iC3b/C3dg, P < 0.01). Epithelial deposition of TCC was not observed in most UC mucosa. Immunoelectron microscopy showed that C3b and iC3b/C3dg were distributed mainly along the epithelial basement membrane and the underlying connective tissue in a granular, studded manner, and weakly present along the basolateral surface of epithelial cells. These C3 fragments were also deposited in inflammatory control mucosa such as ischaemic and infectious colitis. Our findings suggest that deposition of the C3 fragments occurs in inflamed colonic mucosa of diverse etiologies, including UC, but to define a role of the deposition in the development of mucosal injury in UC awaits direct study.

Detection of decay-accelerating factor in stool specimens of patients with colorectal cancer

BACKGROUND & AIMS Colorectal cancers have an increased expression of decay-accelerating factor (DAF). The aim of this study was to determine whether stool specimens of patients with colorectal cancer contain increased amounts of DAF. METHODS DAF was measured using an immunoassay in the stool specimens of 40 persons with colorectal cancer, 18 with colorectal adenomatous polyps, 13 with upper gastrointestinal cancer, and 41 without gastrointestinal disease. RESULTS Stool DAF concentrations in patients with colorectal cancer (0-9.8 ng/g stool; median, 1.6 ng/g) were significantly higher than those in patients with adenoma (0-6.4 ng/g; median, 0 ng/g) (P < 0.05), patients with upper gastrointestinal cancer (0-3.1 ng/g; median, 0 ng/g) (P < 0.05), and subjects without gastrointestinal disease (0-3.4 ng/g; median, 0 ng/g) (P < 0.01). Resection of colorectal cancers caused a marked decrease in stool DAF concentrations. The stool DAF test was positive in a substantial portion of patients with colorectal cancer whose tumors were small ( < 2 cm), at an early TNM stage, or unassociated with fecal occult blood positivity. The sensitivity of the test for colorectal cancer was 55%, and the specificity was 85%. CONCLUSIONS The measurement of stood DAF deserves evaluation as a test for detection of colorectal cancer.

Prediction of the ablated area by the spread of microbubbles during radiofrequency ablation of hepatocellular carcinoma

Abstract: Background/Aim: Radiofrequency ablation (RFA) is effective for the treatment of hepatocellular carcinoma (HCC). To prevent the ablation of adjacent organs and vessels, the spread of microbubbles generated by heating during RFA was observed by ultrasonography (US) and used to predict the ablated area; however, several reports documented that discrepancies existed between the spread of microbubbles and the ablated area.

Carbon dioxide insufflation is useful for obtaining clear images of the bile duct during peroral cholangioscopy (with video)

BACKGROUND Peroral cholangioscopy (POCS) is useful for the diagnosis of various bile duct lesions. However, it is often difficult to obtain clear images because of bile or biliary sludge in the bile duct, even after vigorous irrigation of the bile duct with saline solution. Therefore, this study investigated whether inflation with carbon dioxide (CO(2)) yields clearer images of the bile duct than conventional saline solution irrigation during POCS. OBJECTIVE To evaluate the clinical utility and safety of CO(2) insufflation into the bile duct to obtain clear images in POCS observations by comparing this method with conventional saline solution irrigation. SETTING A single center. DESIGN Case-control study. PATIENTS Nineteen patients with suspected biliary diseases. INTERVENTIONS CO(2) insufflation into the bile duct during POCS. MAIN OUTCOME MEASUREMENTS The quality and safety of this method. RESULT The quality of the images of the bile duct lumen with CO(2) insufflation (10 patients) was significantly superior to those with saline solution irrigation (9 patients) in both clarity (P < .05) and color (P < .05). In particular, extremely clear images could be obtained from the middle part of common bile duct to the right and left hepatic duct. No serious POCS-related complications occurred. There was no significant change in the venous partial pressure of the CO(2) level during the procedure. LIMITATIONS The number of patients examined was small. CONCLUSIONS CO(2) insufflation is useful for obtaining clear images of the bile duct during POCS, which makes it possible to determine the qualitative diagnosis and the extent of various bile duct lesions.