Background-Faecal concentrations of the protein calprotectin have been found to be elevated in patients with colorectal neoplasia, suggesting that it might be used as a screening tool for colorectal cancer as well as adenomas. Aims-To measure the sensitivity and specificity of faecal calprotectin for the detection of adenomas in high risk individuals undergoing colonoscopy. Also, to investigate between and within stool variability of calprotectin concentrations. Subjects-A total of 814 patients planned for colonoscopy were included for the following indications: positive faecal occult blood test, 25; neoplasia surveillance, 605; newly detected polyp, 130; and family risk, 54. Methods-Two faecal samples from each of two stools were analysed using the PhiCal ELISA test device (Nycomed Pharma AS). Results-Adenoma patients had significantly higher calprotectin levels than normal subjects (median 9.1 (95% confidence interval 7.5-10.1) v 6.6 (5.6-7.4)mg/l). There was no significant decrease in calprotectin levels after polypectomy. Levels in cancer patients were significantly higher than those in all other subgroups (median 17.6 mg/l (11.5-31.0)). With a cut oV limit of 10 mg/l, the sensitivity for cancer was 74% and for adenoma 43%. Corresponding specificity values were 64% for no cancer and 67% for no neoplasia (cancer+adenoma). Specificity varied from 71% for one stool sample to 63% for four samples. Stool variability was small, suggesting that two spots from one stool were as discriminative as two spots from each of two stools. Conclusions-The sensitivity and specificity of faecal calprotectin levels as a marker for colorectal adenoma and carcinoma justifies its use in high risk groups, but specificity is too low for screening of average risk persons. Lack of a decrease in levels after polypectomy may be due to a more widespread leucocyte migration into the intestinal lumen than that at the polyp site, and needs further investigation. (Gut 2000;46:795-800)

A mouse monoclonal antibody (LICR-LON/HT13) has been developed to a cell-surface antigen carried on a human germ-cell tumour xenograft (HX39). After radioiodination, the antibody localized in vivo preferentially in xenografted tumours as opposed to normal mouse tissue, whereas tumor uptake did not occur with normal mouse IgG or nonspecific monoclonal IgG. This selective localization could be abolished by simultaneous injection of an excess of the unlabelled LICR-LON/HT13. The kinetics of and factors influencing localization have been examined. Tumour weight was important in that the smaller the tumour the better the localization. LICR-LON/HT13 was found to localize also in other xenografted germ-cell tumours, but not in non-germ-cell tumour xenografts. Thus monoclonal antibodies are capable of selective in vivo localization of human tumours in an animal model, and their clinical value should now be assessed.

Recent changes in the provision of colorectal services',2 have led the authors to train a nurse endoscopist in colorectal practice'. MethodsA registered general nurse was trained in flexible sigmoidoscopy and clinical coloproctology in accordance with an agreed protocol. The training took place during routine endoscopy lists in a medium-sized district general hospital. Under the direct supervision of a consultant (V.M.), the nurse (R.R.) was trained in the three main elements of colorectal endoscopy.First, theoretical training covered the anatomy, physiology, pathology and clinical aspects of gastrointestinal disease, with special emphasis on the colorectum. Second, general endoscopy equipment training covered the mechanisms, cleaning and maintenance of flexible sigmoidoscopes; the principles and practice of infection control and the function and organization of endoscopy units were also taught. Third, flexible sigmoidoscopy training consisted of observation, performance of supervised procedures and postsigmoidoscopy management in 200 cases.Fifty procedures were observed, during which continuous teaching of the clinical and technical aspects of endoscopy took place. The trainee then performed 50 supervised procedures. The first 25 were withdrawals and were part of colonoscopy in sedated patients. Following these, 50 flexible sigmoidoscopies were performed, with the trainer immediately available.The nurse also learnt to use the proctoscope and to inject haemorrhoids, following the practice of the consultant to perform injection at the time of flexible sigmoidoscopy. AssessmentBoth the consultant trainer and pupil were assessed by an independent consultant gastroenterologist (G.W.)Video recordings were made of 50 trainer and 50 pupil procedures. Data recorded included duration of procedure, depth of insertion, level of colon reached, quality of examination and diagnostic accuracy. The pupil performed 150 solo procedures in her training and assessment. The endoscopist was not identified on the pro forma or video recordings. The assessor scored each criterion and each procedure.Scores for the pupil and trainer were totalled and compared. The pupil was considered able to perform competent and safe Paper accepted 10 July 1996 flexible sigmoidoscopy when her scores were equal to or within 15 per cent of those of the trainer. ResultsTotal scores did not show any statistically significant difference between trainer and pupil. Quality and accuracy scores were all 94-97 per cent. Trainer and pupil achieved 60cm insertion in similar numbers of cases (72 and 71 per cent), and reached the descending colon in one-half (50 and 49 per cent) of cases.Competence in theoretical and endoscopy training was achieved in all areas with 'proficiency' marks awarded in all criteria in the training package.No complication occurred throughout the training or the assessment. DiscussionThe training protocol was stricter and more thorough than the training of medical personnel recommended by the British Society of Gastroenterology. Assessment by...

SUmmARY The use of monoclonal antibodies which can be raised to antigens of choice offers a selective and specific approach for the detection of tumours both in vivo and at a cellular level in biopsy specimens. We demonstrate that a monoclonal antibody raised to human teratoma will localise in a teratoma, growing as a xenograft in immune-suppressed mice.