Audiovisual aids: guidelines for the use of overhead projector.

The overhead projector is a versatile audio-visual (AV) aid. When used effectively, it can render a presentation very impressive. It is easy to maintain and operate, and offers considerable flexibility of text and image projection. It is the most commonly used AV aid in teaching institutions and an appreciation of its strengths and weaknesses can be useful to teachers and students alike.

Nd-YAG laser therapy for palliation of obstructed colorectal carcinomas.

Twenty three cases of colorectal carcinoma with partial or complete obstruction were managed by laser ablation of tumour tissue. There were 14 males and 9 females with a mean age of 63 years (30-87). Nineteen cases (82.6%) were in the rectosigmoid while two cases each were in the anal canal and descending colon. Fifteen (65.2%) were proliferative growths and the remaining (8, 34.7%) were circumferential growths. Prior dilatation under fluoroscopic control was done where required. Lumen was achieved in a single sitting in 14 (60.8%) cases, while in the others two to five sittings were required. None of the patients required colostomy. Thirteen (56.5%) of these patients have died during the follow up period, lasting from 4 to 27 months (mean 10.4 months). There were no major complications related to the procedure.