Yoshiharu Chijiiwa

Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography.

Intraductal papillary-mucinous tumors of the pancreas: Differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

Pretreatment staging of endoscopically early gastric cancer with a 15 MHz ultrasound catheter probe

BACKGROUND The usefulness of and problems associated with an ultrasound catheter probe in the pretreatment staging of endoscopically early gastric cancer remain unexplored. METHODS Endoscopic ultrasonography using a 15 MHz catheter probe of 2.6 mm diameter was performed in a prospective study to determine the pretherapy staging of endoscopically early gastric cancer in 78 patients. The results of the ultrasound images were compared with the histologic findings of the specimens obtained by endoscopic mucosal resection or surgical resection. RESULTS The accuracy of the catheter probe for depth of invasion of endoscopically early gastric cancers was 67% (52 of 78 patients). The accuracy in determining depth of invasion in relation to endoscopic type was significantly higher for the elevated type (91%) than for the depressed type of early cancer (56%) (p < 0.01). The staging accuracy classified by histologic type was significantly higher for differentiated (86%) than for undifferentiated (18%) cancer (p < 0.01). Staging accuracy decreased as tumor size increased. The accuracy, sensitivity, and specificity for nodal staging were 80%, 17%, and 90%, respectively. CONCLUSIONS A 15 MHz ultrasound catheter probe is most useful for determining depth of invasion when the tumor is histologically differentiated and endoscopically of the small elevated type early gastric cancer, but it is unreliable in the diagnosis of metastatic lymph nodes.

An Inverse Correlation of Human Peripheral Blood Regulatory T Cell Frequency with the Disease Activity of Ulcerative Colitis

Evidence suggests that CD4+CD25+ regulatory T cells play a crucial role in the suppression of intestinal inflammation. However, their role in the suppression of inflammatory bowel disease has not yet been addressed. We examined the proportion of regulatory T cells in inflammatory bowel disease. First, we isolated CD4+CD45RO+CD25+ T cells from the peripheral blood of healthy persons and showed that these cells suppressed T cell proliferation profoundly and expressed FoxP3 abundantly, revealing that they are regulatory cells. Then the proportion of CD45RO+CD25+ in peripheral blood CD4+ T cells was analyzed in patients and healthy controls by flow cytometry. CD4+CD45RO+CD25+ T cell frequency was significantly lower in active ulcerative colitis than in the control and inactive ulcerative colitis. CD4+CD45RO+CD25+ T cell frequency was inversely correlated with the clinical and endoscopic severity of ulcerative colitis. These results suggest that a deficiency of regulatory T cells is associated with the progression of ulcerative colitis.

Preoperative staging of colorectal cancer by a 15 MHz ultrasound miniprobe

BACKGROUND Our objective was to examine the accuracy of a 15 MHz ultrasound miniprobe in the pre-operative staging of colorectal cancer by assessing the depth of tumor infiltration and involvement of pericolonic lymph nodes. METHODS Thirty-three patients with colorectal cancer who underwent ultrasonography with a miniprobe were studied prospectively. The results of this imaging were compared with the histologic findings of the resected specimens. RESULTS The accuracy of the miniprobe for depth of invasion (T category) was 82% (27 of 33) for all tumors, 76% (13 of 17) in pT1 cases, and 88% (14 of 16) in pT2 to pT4 cases. The accuracy of the miniprobe for nodal staging (N category) was 87% (26 of 30) overall. The sensitivity was 63% (5 of 8), the specificity was 95% (21 of 22), the positive predictive value was 83% (5 of 6), and the negative predictive value was 88% (21 of 24). CONCLUSIONS The miniprobe is an accurate method for the preoperative TN staging of colorectal cancer. We recommend its preoperative use because the results may influence the surgical approach.

Endosonography probe-guided endoscopic mucosal resection of gastric neoplasms

the stomach following endoscopic volvulus reduction in a poor surgical candidate. This novel approach resulted in persistence of normal gastric position as documented by UGI series 1 year later. Further data is needed on the long-term follow-up of patients with various types of symptomatic volvulus managed endoscopically in regards to the significance and frequency of recurrence. In conclusion, we have described a new maneuver, the alpha-loop technique, for endoscopic reduction of gastric volvulus. We used this technique to successfully reduce gastric volvulus in 7 out of 8 patients with no procedural complications. The major benefit of endoscopic volvulus reduction was to allow time for elective surgical repair of abdominal pathology (paraesophageal hernia) predisposing to volvulus formation. The role of the alpha-loop technique as a definitive therapy in poor surgical candidates and in patients with idiopathic volvulus requires further evaluation.

Interaction between atrial natriuretic peptide and vasoactive intestinal peptide in guinea pig cecal smooth muscle

BACKGROUNDS & AIMS The role of atrial natriuretic peptide (ANP) in gastrointestinal motility is still unclear. The aim of this study was to investigate the relationship between ANP and vasoactive intestinal peptide (VIP) in guinea pig cecal circular smooth muscle cells. METHODS The inhibition of 125I-ANP binding or 125I-VIP binding to cecal smooth muscle cells was assessed using unlabeled peptides (i.e., ANP, ANP fragments, VIP, secretin, and peptide histidine isoleucine); the effect of ANP, ANP fragments, and VIP on muscle contraction stimulated by 1 mumol/L carbachol was assessed; and the inhibitory effects of ANP 1-11 on VIP-induced relaxation, ANP 1-11 and VIP 10-28 (a VIP antagonist) on ANP-induced relaxation, and nitric oxide production inhibitors on ANP-induced relaxation were assessed. RESULTS The specific binding of 125I-ANP was inhibited completely by unlabeled ANP and VIP in a dose-dependent manner but only slightly inhibited by secretin and peptide histidine isoleucine. ANP 1-11 and C-atrial natriuretic factor inhibited the binding of 125I-ANP with a lower affinity than ANP. ANP only partly inhibited 125I-VIP binding. ANP and VIP inhibited 1 mumol/L carbachol-induced contraction in a dose-dependent manner. ANP 1-11 significantly inhibited VIP-induced relaxation. ANP 1-11, VIP 10-28, and NO production inhibitors completely inhibited ANP-induced relaxation. CONCLUSIONS The results of the study showed that ANP 1-11 antagonized ANP-induced relaxation and that ANP stimulated NO production and subsequently induced relaxation via a receptor to which VIP binds.

Two Endothelin Receptors (ETA and ETB) Expressed on Circular Smooth Muscle Cells of Guinea Pig Cecum

BACKGROUND/AIMS The functional receptors for endothelin (ET) in colonic smooth muscle are still unknown. This study investigated the expression of ET receptors in isolated circular smooth muscle cells of guinea pig cecum. METHODS Inhibition of 125I-ET-1 binding was examined using unlabeled ET-1, ET-2, ET-3, sarafotoxin 6c (S6c), and ETA antagonists. Expression of the ET-receptor message was investigated using reverse-transcription polymerase chain reaction. The contractile potency of the ET family and the inhibitory effect of ETA antagonists on ET-1-induced contraction were also investigated. RESULTS Unlabeled ET-1, ET-2, and ET-3 inhibited the specific binding of 125I-ET-1 in a concentration-dependent manner, but the inhibitory effect of ET-3 was smaller than those of ET-1 and ET-2. At a 10(-6) mol/L concentration of S6c, the specific binding of 125I-ET-1 was 24.7%. S6c had clearly reached maximal inhibition. Abundant polymerase chain reaction products for both the ETA and the ETB message were observed. ET-1 and ET-2 showed similar contractile potency, but ET-3-induced and S6c-induced contractions were significantly less potent than the ET-1-induced contraction. A significant response to S6c was obtained at a concentration as low as 10(-10) mol/L. The ETA antagonists BQ-123 and FR 139317 significantly inhibited ET-1-induced contraction. CONCLUSIONS The results show a direct contractile effect of ETs on circular smooth muscle of guinea pig cecum and the presence of both ETA- and ETB-receptor subtypes.

The beneficial effect of mesalazine on esophageal ulcers in intestinal Behcet's disease

Intestinal Behcets disease in a 19-year-old girl was diagnosed because of the history of recurrent oral aphthous ulcers and typical endoscopic findings of esophageal and ileal ulcers. Her symptoms (e.g., dysphagia and retrosternal pain) were gradually relieved by treatment with prednisolone and total parenteral nutrition. However, about one month later, oral and esophageal ulcers appeared again. Mesalazine was added. Oral and esophageal ulcers healed promptly, and have not relapsed for about one year. Although mesalazine appears to act locally in the small intestine and colon, the therapeutic effect of mesalazine in this case may be explained by the systemic antiinflammatory effect. This case suggests that mesalazine is an effective drug and is a good candidate in the treatment of intestinal Behcets disease, especially accompanied with esophageal involvement.

Rectal carcinoid tumor: endoscopic ultrasonographic detection and endoscopic removal

Eight patients with rectal carcinoid tumors were examined by endoscopic ultrasonography (EUS) to assess the depth of invasion of the rectal wall. All resected tumors were contained within the submucosa and their depth of invasion was correctly diagnosed by EUS before treatment. Perirectal lymph nodes were not delineated by EUS. Four patients who were treated only with endoscopic polypectomy were completely cured as were four patients who had a surgical resection. EUS is useful in selecting the candidates for endoscopic removal or local resection and thus may help to avoid unnecessary radical surgery.

Suitability of the expanded indication criteria for the treatment of early gastric cancer by endoscopic submucosal dissection: Japanese multicenter large-scale retrospective analysis of short- and long-term outcomes

Abstract Objective. The criteria for endoscopic resection for early gastric cancer include absolute and expanded indications. Consensus already exists for the absolute indications. However, the suitability of the expanded indications must be validated by long-term outcome analyses since such lesions have only recently become resectable with the development of endoscopic submucosal dissection. The aim of this study is to clarify the suitability of the expanded indications for the treatment of early gastric cancer with endoscopic submucosal dissection. Materials and methods. The medical records of 1161 patients with early gastric cancers (1332 lesions) treated by endoscopic submucosal dissection and meeting the criteria for absolute or expanded indications without additional treatment with gastrectomy were divided into absolute indication group or expanded indication group. Results. Complete resection rates were 96.4% and 93.4% in absolute and expanded indication groups, respectively, with no significant differences between the groups. Delayed bleeding rates were significantly higher in the expanded indication group, whereas all cases were successfully managed conservatively. The 5-year overall survival and recurrence-free rates were 93.7%/99.77% and 90.49%/98.90% in the absolute and the expanded indication groups, respectively, with no significant differences between the groups for either measure. Multivariate analyses revealed that affected horizontal margin and tumor location were independent predictive factors for recurrence. Conclusion. The expanded indication group showed excellent post-endoscopic submucosal dissection short-term and long-term outcomes compared with the absolute indications group, demonstrating that expanded indications are suitable for endoscopic submucosal dissection for early gastric cancer.