Potentiation of C56-initiated lysis by leucocyte cationic proteins, myelin basic proteins and lysine-rich histones

Synthetic polycations such as poly-L-lysine (PLL) have recently been shown to enhance C56-initiated lysis by neutralization of serum-derived inhibitors of the C567 complex, collectively designated C567-INH. In the present report we have examined the effect of several naturally occurring polycations on C56-initiated lysis. Lysosomal granule extracts from rabbit peritoneal exudate cells were found to potentiate C56-initiated lysis via counteraction of C567-INH in the fluid phase; this was dependent upon the amount of C567-INH present and independent of cell concentration. The basic proteins of guinea-pig, bovine, and monkey myelin as well as lysine-rich histones also potentiated EC567 formation, but this effect seemed to occur predominantly at the cell surface. The presence of biologically derived cationic proteins at sites of complement activation during inflammation thus might lead to enhanced tissue damage by favouring the formation of cell-C567 intermediates by either or both of these mechanisms.     

Macromolecular interactions of [14C-ring]melphalan in blood

The pharmacokinetics and macromolecular interactions of [14C-ring]melphalan (L-PAM) in blood were studied in rats following a single oral dose (20 mg/kg, 0.1 mCi/kg). Radioactivity levels were monitored in blood over a period of 72 hr. The highest levels of radioactivity were observed at 2 hr. The decline of radioactivity from the blood was biphasic with T1/2 alpha = 7 hr and T1/2 beta = 75 hr. The radioactive species in plasma corresponded to unchanged L-PAM and its two known hydrolytic products 4,2-hydroxyethyl 2-chloroethylamino-L-phenylalanine (L-MOH) and 4-[bis(2-hydroxyethyl)amino]-L-phenylalanine (L-DOH). In addition, four other major, previously unknown, metabolites of L-PAM were detected in plasma. At 72 hr, most of the radioactivity was bound to macromolecular components, 26% to plasma macromolecules and 62% in red blood cells. Covalent binding to blood cells was mainly to membrane proteins. Binding to hemoglobin and other soluble components of the red cells was also observed, with a 5000-fold greater affinity for membranes. These studies suggest extensive interaction of melphalan, or its metabolites, with membrane and soluble proteins of red blood cells.     

Comparison of urethral swabs, urine, and urinary sediment for the isolation of Chlamydia

In 70 male patients with urethritis, Chlamydia was recovered from 18 urethral swabs (26%), 5 urinary sediments (7%), and 3 urine specimens (4%). All Chlamydia isolates were recovered from urethral swabs.     

Use of Edman's method for splitting actinoidin peptides and aglycone

Phenylthiohydantoins of amino acids isolated from actinoidine (n-oxyphenylglycine, 3-chlor-4-oxyphenylglycine, actinoidinic amino acid) were prepared. Their spectral and chromagraphic properties were studied. Splitting of the aglycone of actinoidine and the prodlcts of its incomplete acid hydrolysis (peptides Y-Phe and B-Y-Phe) was achieved with the Edman method. Parital structure of tripeptide B-Y-Phe (4NH2-group) was proposed. Tripeptide B-Y Phe constitutes about 80 per cent of the antibiotic aglycone part.