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N Oshitani

Publications and source records attributed to N Oshitani.

60 records · Page 4Linked to original sources
PubMed1986

The leading cord method of colonofiberscopy.

Although the colonofiberscope has undergone various modifications and improvements, the insertion principle remains unchanged; that is, pushing and rotation and the elasticity of the scope itself are inevitable. It often is difficult to maintain proper balance among these dynamic factors; imbalance prevents deep insertion. Over-elongation of the scope leads to insertion failure, particularly if there are adhesions of the sigmoid colon, overextension of the colon, or transverse colon ptosis. Our "leading cord" method is an excellent aid to colonofiberscopy. It can be inserted from the clamp hole of a conventional fiberscope and hardened to straighten the scope, thereby permitting deep insertion. With this technique the region from the rectum to the descending colon, as well as a ptosed transverse colon, can be straightened. Our clinical experience indicates that the rate of successful insertions in colonofiberscopy will be increased considerably with this complementary device.

Colonoscopes↗
PubMedDate not supplied

In situ generation of nitric oxide by myenteric neurons but not by mononuclear cells of the human colon.

1. Production of nitric oxide (NO) is implicated in the pathogenesis of inflammatory bowel disease. However, the cells responsible for the production of NO in situ in the human colon remain unknown. 2. Surgical samples from 12 patients with ulcerative colitis, eight patients with Crohn's disease and 10 controls were studied. Possible generation of NO was visualized by reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activity in human colon. Immunohistological staining for various NO synthase (NOS) isoforms (endothelial, neuronal and inducible), nitrotyrosine and interleukin-2 was also performed. 3. Reduced NADPH diaphorase activity was not found in lamina propria mononuclear cells, but was found in colonic epithelium, endothelium and myenteric neurons and their processes. 4. The NADPH-diaphorase activity positive processes were significantly less common in colon from patients with Crohn's disease compared with control colon. 5. Endothelial NOS was constitutively expressed on colonic endothelium. 6. Neuronal NOS was constitutively expressed on myenteric neurons. 7. Expression of inducible NOS (iNOS) was increased in the epithelium and endothelium of the colon of patients with ulcerative colitis. 8. No correlation was found between expression of iNOS and NADPH diaphorase activity. 9. Nitrotyrosine was expressed by lamina propria leucocytes, but not by epithelium. 10. Interleukin-2 was expressed on both leucocytes and myenteric neurons. 11. Colonic epithelium, endothelium and myenteric neurons synthesize NO. Myenteric neurons were principally responsible for NO production and NO may act as a neurotransmitter in the enteric nervous system.

Adult↗
PubMedDate not supplied

Endoscopic resection of small rectal carcinoid tumours using an aspiration method with a transparent overcap.

Rectal carcinoid tumours are often small and rarely metastatic. Endoscopic resection may, therefore, be the best treatment for small tumours. We diagnosed rectal carcinoid tumours in four women and three men (mean age 53 years; range, 43 - 63) between 1994 and 1999. Tumour depth was evaluated using a high-frequency ultrasonographic probe in five of the seven patients. All tumours were resected by endoscopic mucosal resection using an aspiration method with a transparent overcap. Histologically, all tumours were located within the submucosal layer. Tumour cells were found at the resected margin of the lateral side in one patient, and at the bottom of the margin in another. Both patients were followed up with frequent endoscopy, and no local recurrences have been detected at 1-year or 4-year follow-ups. Ultrasonographic examination before resection is useful to estimate tumour depth. Endoscopic resection by an aspiration method with a transparent overcap is safe and effective for the treatment of small rectal carcinoid tumours.

Adult↗