[Angiotensin converting enzyme activity in the blood of dogs with posthemorrhagic hypotension].
In 1984 and 1985 a questionnaire was applied to 5611 railway transport workers in Croatia. Out of them, those satisfying the criteria of the Geneva Convention (1980) of the International Working Group for the Early Detection of Colorectal Carcinoma (3379) were supplied with the Hemdetect test. Of these 3379 workers, 2428 (71.8%) returned the "consumed" test after three days: in 114 of them the Hemdetect test was positive. Since in this way 5 patients with colorectal carcinoma (4.85%), 17 with polyps (16.5%), and 3 with polyposis (2.92%) were detected, it is maintained that the Hemdetect test is very useful, in fact unavoidable in attempts at the secondary prevention of colorectal carcinoma and the lesions proceeding it. Although the 34.95% of so-called false positive results obtained by the Hemdetect test diminish its significance because of a reduced specificity, it should not be excluded from practical work on the secondary prevention of colorectal carcinoma--it should in fact be put ahead of other tests, because it is simple, easily applied, readily acceptable by examinees, and less costly than the use of immunochemical methods.