Atsushi Nobuoka

Primary intestinal lymphangiectasia successfully treated with octreotide

Abstract: A 21-year-old man with diarrhea and edema was admitted to our hospital and diagnosed with protein-losing enteropathy caused by primary intestinal lymphangiectasia. He was placed, in turn, on a low-fat diet, an elemental diet, and, subsequently, fasting therapy with total parenteral nutrition (TPN) support. However, his symptoms were not relieved, but, rather were exacerbated. On the 45th day of hospitalization, octreotide therapy was initiated. After 2 weeks of treatment, his clinical symptoms, as well as hypoproteinemia and hypoalbuminemia, gradually became alleviated. The improvement was confirmed in terms of scintigraphy, endoscopy, and histology of the duodenum. The patient remained healthy until 6 months after the commencement of octreotide treatment, when he discontinued octreotide at his own discretion, at which point the symptoms recurred. Resumption of the drug; however, again brought about remission, which has continued until the present, March 2000. Thus, octreotide therapy is one modality which may be useful for refractory primary intestinal lymphangiectasia.

Aberrant Crypt Foci as Precursors of the Dysplasia-Carcinoma Sequence in Patients with Ulcerative Colitis

Purpose: Long-standing ulcerative colitis (UC) predisposes patients to the development of colorectal cancer, but surveillance of colitis-associated cancer by detecting the precancerous lesion dysplasia is often difficult because of its rare occurrence and normal-looking appearance. In sporadic colorectal cancer, aberrant crypt foci (ACF) have been reported by many investigators to be precursor lesions of the adenoma-carcinoma sequence. In the present study, we analyzed the genetic background of ACF to determine whether they could be precursors for dysplasia, and we examined the usefulness of endoscopic examination of ACF as a surrogate marker for surveillance of colitis-associated cancer. Experimental Design: ACF were examined in 28 UC patients (19 patients with UC alone and 9 patients with UC and dysplasia; 2 of those patients with dysplasia also had cancer) using magnifying endoscopy. K-ras, APC, and p53 mutations were analyzed by two-step PCR RFLP, in vitro–synthesized protein assay, and single-strand conformation polymorphism, respectively. Methylation of p16 was analyzed by methylation-specific PCR. Results: ACF that appeared distinct endoscopically and histologically were identified in 27 out of 28 UC patients. They were negative for K-ras, APC, and p53 mutations but were frequently positive for p16 methylation (8 of 11; 73%). In dysplasia, K-ras and APC mutations were negative but p53 mutation (3 of 5; 60%) and p16 methylation (3 of 5; 60%) were positive. There was a significant stepwise increase in the number of ACF from patients with UC alone to patients with dysplasia and to patients with cancer. Univariate and multivariate analyses showed significant correlations between ACF and dysplasia. Conclusions: We have disclosed an ACF-dysplasia-cancer sequence in colitis-associated carcinogenesis similar to the ACF-adenoma-carcinoma sequence in sporadic colon carcinogenesis. This study suggests the use of ACF instead of dysplasia for the surveillance of colitis cancer and warrants further evaluation of ACF as a surveillance marker in large-scale studies.

Chemoprevention of colorectal cancer

Colorectal cancer is a disease with a high mortality rate and it has been increasing in prevalence worldwide. Chemoprevention, as well as primary and secondary prevention, for colorectal cancer have attracted much attention. Many chemopreventive trials have been performed, and several agents, including nonsteroidal antiinflammatory drugs, such as aspirin and sulindac, cyclooxygenase-2 selective inhibitors, such as celecoxib, vitamin D, folate, and calcium, have been shown to have some effect. In these chemopreventive trials, the targeted lesions used for evaluation were mainly polyps. However, the chemopreventive effects of some agents on polyps may require several years to evaluate. Further, larger polyps may not be susceptible to chemopreventive agents. Aberrant crypt foci (ACF) are tiny lesions at the earliest stage of colorectal carcinogenesis, which consist of large, thick crypts identified by dense, methylene blue staining. We succeeded in identifying human ACF in situ using magnifying endoscopy and found that the number of ACF, particularly dysplastic ACF, increased significantly from normal subjects to adenoma patients and then to cancer patients. We also found that the number, size, and dysplastic features of ACF are significantly correlated with the number of adenomas in adenoma patients. Thus, it was surmised that ACF are precursor lesions of the adenoma-carcinoma sequence in humans and that ACF may be the most appropriate lesions as targets for chemoprevention. We have shown that the number of ACF was significantly reduced in patients treated with sulindac. We are currently proceeding with a randomized, double-blind, chemopreventive trial targeting ACF.

A novel treatment for early gastrointestinal carcinoma by ultrasonic endoscopic mucosal stripping.

PurposeThe aim of this study was to clarify the indications for a new endoscopic mucosal resection (EMR) technique that employs a cavitational ultrasonic surgical aspirator (CUSA). Endoscopic mucosal resection has proved an effective technique for treating early mucosal gastrointestinal cancer. However, resecting a lesion larger than 2 cm en bloc requires special devices and a long processing time; and it engenders the risk of bleeding, perforation, and other complications.MethodsWe investigated application of the CUSA for detaching the mucosa from the muscularis propria of extracted porcine stomachs and then clarified the specification of an endoscopic ultrasonic scalpel for endoscopic mucosal resection by investigating characteristics of two original, handmade prototype cavitational ultrasonic surgical aspirators.ResultsUse of a cavitational ultrasonic surgical aspirator should improve the ease and safety of detaching the mucosa. A small, high-power ultrasonic cylindrical vibrator should be developed to make possible a probe-type scalpel with a piezoelectric vibrator mounted in the tip of a catheter. An ultrasonic transmission-type scalpel could lead to the development of a new endoscopic mucosal resection device for clinical use.ConclusionsThe CUSA should enable us to develop a safer, simpler, time-saving scalpel for endoscopic mucosal resection, although some resolvable technical problems remain. The CUSA might enable us to diagnose carcinoma invasion into the submucosa in aspirated specimens and then aspirate out the entire invading submucosal carcinoma.