Present and future trends in selected areas of clinical enzymology.

Recently developed enzyme tests that are used in (a) identifying high risk populations, (b) diagnosing cancer, (c) following treatment response of cancer patients, and (d) the selection of cancer therapy are summarized. The diagnostic role of methionine adenosyltransferase and CSF monoamine oxidase activity measurements in the diagnosis of schizophrenia are discussed. The role of N-acetyltransferase in the conversion of serotonin to melatonin in the pineal gland and the importance of these changes for the synchronization of the functioning of cells throughout the organism are described. New developments in the determination of immunoreactive trypsin in the early diagnosis of pancreatic diseases are summarized.