Immunological faecal occult blood testing: a discriminatory test to identify colorectal cancer in symptomatic patients.

INTRODUCTION: Current investigation for patients with colorectal symptoms without overt rectal bleeding is undertaken by colonoscopy or by flexible sigmoidoscopy and barium enema. A large majority of patients do not have colorectal cancer. There exists no instant, objective measure to discriminate patients who are likely to have colorectal cancer and therefore require expedient investigation. AIM: To evaluate the sensitivity and specificity of immunological faecal occult blood testing (FOBT) in patients with colorectal symptoms without overt rectal bleeding. METHODS: Consecutive patients referred for urgent colonic investigation, were prospectively studied. A faecal sample was obtained from each one and subjected to immunological FOB which tested either negative or positive. All patients then underwent complete colonic imaging. The correlation between FOBT status and results from colonic imaging was studied. RESULTS: Of 126 tested, thirty patients (26.8%) were FOBT positive. One hundred and twelve patients underwent complete colonic imaging. In the FOBT positive group colonic imaging identified 17 cases of histologically proven adenocarcinoma, 1 recurrent squamous cell carcinoma of anus, 1 adenomatous polyp, 6 cases of diverticulosis, and no pathology in 5 cases. In the 82 FOBT negative patients, no cancers were found. Overall the Immunological Faecal Occult Blood Test was found to have 100% sensitivity and 86.3% specificity. CONCLUSION: Immunological faecal occult blood testing is a sensitive and specific test in identifying colorectal cancer and may be useful in identifying those patients who warrant urgent investigation. Routine clinical application may be useful in the allocation of resources.

Oral arginine does not stimulate basal or augment exercise-induced GH secretion in either young or old adults.

BACKGROUND: Growth hormone (GH) helps maintain body composition and metabolism in adults. However, basal and peak GH decline with age. Exercise produces a physiologic GH response that is subnormal in elderly people. Arginine (Arg) infusion can augment GH secretion, but the efficacy of oral Arg to improve GH response to exercise has not been explored. We investigated whether oral Arg increases GH secretion in young and old people at rest and during exercise. METHODS: Twenty young (Y: 22.1 +/- 0.9 y; SEM) and 8 old (O: 68.5 +/- 2.1 y) male and female subjects underwent three different trials following determination of their one-repetition maximum strength (1-RM); exercise only (EO; 3 sets, 8-10 reps at 85% of 1-RM; on 12 separate resistive lifts), Arg only (5.0 g), or Arg + exercise. Blood samples were collected between successive lifts, and GH (ng x ml(-1)) was determined via RIA. RESULTS: In Y vs O: Basal GH secreted (area under the curve) was 543.6 +/- 84.0 vs 211.5 +/- 63.0. During EO, values were 986.6 +/- 156.6 and 517.8 +/- 85.5. Both were significantly lower in the older individuals (p < .05). Oral Arg alone did not result in any increase in GH secretion at rest (310.8 +/- 73.2 vs 262.9 +/- 141.2). When Arg was coadministered during exercise, GH release was not affected in either the young or old and appeared to be blunted in the young compared to the exercise only trial in the young. CONCLUSION: Based upon these findings, we concluded that oral Arg does not stimulate GH secretion and may impair GH release during resistive exercise.