Studies on the structure of a novel peptide antibiotic, K-582

A novel peptide antibiotic, K-582, which exhibited significant growth inhibition of Candida, viruses and ascites tumor in mice, was found in the culture medium of a strain of Metarhizium anisopliae by Kondo et al. (J. Antibiotics 33, 535-542 (1980) ]. K-582 consisted of two components, designated K-582 A and K-582 B. Threonine, tyrosine, ornithine, and an unusual amino acid were common in both peptides, but lysine was an extra component of K-582 A. The unusual amino acid was identified to be threo-gamma-hydroxy-L-arginine (OHArg) by means of mass, nuclear magnetic resonance and infrared spectrometries of the derivatives and the related compounds. The threonine and the arginine were assigned to be L-configuration, and the ornithine and the tyrosine to be D-configuration in both K-582 A and K-582 B, and the lysine to be L-configuration by comparison of their optical rotatory dispersion spectra with those of standard amino acids. The elucidation of primary structure revealed that they were closely related heptapeptides with the following sequence: K-582 A:H-Arg-OHArg-Orn-Thr-Orn-Lys-Tyr-OH; K-582 B:H-Arg-OHArg-Orn-Thr-Orn-OHArg-Tyr-OH, and had the identical sequence in terms of the configuration of their constituents, namely L-L-D-L-D-L-D.     

Combined use of brushing cytology and endoscopic retrograde pancreatography for the early detection of pancreatic cancer

Seventy-two cases of pancreatic cancer were examined by brushing cytology combined with endoscopic retrograde pancreatography. The results of this combined method were better than those reported for the exfoliative cytologic study of pancreatic fluid. The method detected a minute cancer of the main pancreatic duct that was not detected with any other method. The cells obtained by this technique had very well-preserved cytoplasm and nuclear chromatin, which facilitated making a correct diagnosis. Though this method can be applied only to the main pancreatic duct, it is effective for the diagnosis of ductal cell carcinoma, especially those located at the head of the pancreas, which is the most common site for pancreatic cancer. It is a safe procedure, with no complications seen in this series. The differentiation of carcinoma cells from the benign atypical cells of chronic pancreatitis is illustrated and emphasized.