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The caudal portion of the spinal cord of elasmobranch fish incorporates a diffuse neuroendocrine system. Using an antiserum raised against urotensin II from a teleost fish (goby) to facilitate purification, a peptide structurally related to urotensin II was isolated in pure form from an extract of neuroendocrine tissue from the spinal cord of the European common dogfish, Scyliorhinus canicula. The primary structure of the peptide was established as: Asn-Asn-Phe-Ser-Asp-Cys-Phe-Trp-Lys-Tyr-Cys-Val. The amino acid sequence was confirmed by chemical synthesis. A comparison of this sequence with those of the known teleost urotensin II peptides shows that the cyclic region of the molecule has been fully conserved between species and suggests that the presence of an acidic residue at position 5 and a hydrophobic residue at position 12 are important features for the biological activity of the peptide. The dogfish spinal cord extract also contained a high concentration of the calcium-binding protein, parvalbumin and the amino acid sequence at its NH2 terminus [residues (1-50)] was determined.

A brief account of the laboratory diagnosis of mycobacterial infections in 13 immunosuppressed patients, which were observed between 1967 and 1979 at one group of hospitals is presented. In nine patients, the infection was caused by Mycobacterium tuberculosis; of the "atypical" mycobacteria, M. fortuitum, M. haemophilum, M. kansasii and M. scrofulaceum (serotype Lunning) each caused one infection. These findings suggest that immunosuppressed patients are at risk of tuberculosis, despite the low incidence of the disease in Australia at the present time.