Occupational Health: Will Work for Air

man, 1965; Zamcheck & Martin, 1981), pancreatic oncofetal antigen (POA) (Banwo et al., 1974; Nishida et al., 1985), pancreatic carcinoma associated antigen (PCAA) (Schultz & Yunis, 1979; Shimano et al., 1981), DU-PAN 2 (Metzgar et al., 1984; Sawabu et al., 1986) and CA19-9 (Koprowski et al., 1979; Magnani et al., 1983; Haglund et al., 1986). As most of the marker antibodies so far characterised have been found to recognise carbohydrate rather than protein epitopes (Feizi, 1985), a previous study was carried out to determine whether further tumour marker glycoproteins could be more efficiently identified using a combination of SDS-polyacrylamide gel electrophoresis and blotting with a panel of lectins chosen for their ability to identify different carbohydrate epitopes. This approach proved successful demonstrating the presence of a high molecular weight glycoprotein in approximately one-third (12/34) of the pancreatic cancer sera but in none of the 96 controls (Ching & Rhodes, 1988). Further characterisation showed this serum marker to be a mucin (Ching & Rhodes, 1987a). This has subsequently been developed into an enzyme-linked peanut lectin assay (PNAELLA) (Ching & Rhodes, 1989) for total peanut lectin binding glycoproteins in serum. This assay has proved equivalent in efficacy to CA19-9 serum radioimmunoassay and the two tests together have a combined sensitivity of 85% for pancreatic cancer (Ching & Rhodes, 1989). Although proving useful as a serum test for pancreatic cancer, the epitope for CA19-9 is known to be present in normal pancreatic tissue (Atkinson et al., 1982) and juice (Kalthoff et al., 1986), bile (Albert et al., 1987) and colon (Afdhal et al., 1987) in a way analogous to CEA (Go et al., 1975; Huitric et al., 1976; Ichihara et al., 1988). This study