Erratum

The first four paragraphs were deleted from the Materials and Methods section of “Interaction of Plasma Proteins and Lipoproteins with Amphotericin B” by Janina Brajtburg et al. (June 1984),which appeared on pages 986–7. The insert should start after line 4 on page 987. The relevant section is reprinted below.

Materials and Methods

Materials. AmB as Fungizone^® (E. R. Squibb, Princeton, NJ) dissolved in water was used in most experiments. Sodium deoxycholate alone, used in amounts equal to those found in Fungizone, did not affect the assays. AmB without the deoxycholate carrier (Calbiochem-Behring, San Diego) was used in some assays and gave the same results as Fungizone.

Amphotericin B methyl ester (ArnE) was obtained from E.R. Squibb. [¹⁴C]-labeled AmE (specific activity, 1.2 rnCi/mmol) was prepared from the parent compound (AmB) in the laboratory of Dr. K. Rinehart (Department of Chemistry, University of Illinois, Urbana) by the procedure of Pandey and Rinehart [8]. The chemical purity of the radioactive AmE preparation was verified by thin-layer chromatography and proton magnetic resonance. Its level of biologic activity against C. albicans and RBCs was equal to that of unlabeled ArnE. The level of antifungal activity of [¹⁴C]-labeled ArnE was found to be only slightly lower than that of AmB, as had been observed by other investigators using unlabeled ArnE [9].AmB without sodium deoxycholate and [¹⁴C]-labeled ArnE were dissolved in dimethyl sulfoxide before use, and 5-µ1 portions wereadded to l-ml samples. The same concentration of solvent used without antibiotic (0.50/0) had no effect on any assay.

Cholesterol, cholesteryl ester, human serum albumin (HSA), and dipalmitoyl phosphatidylcholine were purchased from Sigma Chemical (St. Louis).

Preparation ofplasma, sera, and lipoproteins. Blood was taken from normal volunteers who had been fasting for 9–15 hr and from patients receiving AmB for the treatment of systemic fungal infections; a 10-ml sample was obtained from each patient 1 hr after an iv infusion of AmB had been completed. Blood from normal volunteers and patients was put into tubes with 1 mg of EDTA/ml of blood. Plasma was separated by two centrifugations at 3,000g for 5 min. Lipoprotein-deficient serum (LPDS) was prepared from normal plasma by two centrifugations at 105,000 g for 24 hr in a solution containing 0.3 mM EDTA and KBr (density, 1.215 g/ml) and removal of the lipoproteins from the upper layer of the centrifuge tubes. The LPDS was then dialyzed against EDTA-saline (a NaCI solution with a density of 1.0063 g/ml and supplemented with 0.3 mMEDTA; pH 7.4). Thrombin was added to LPDS for the removal of clotting factors. LPDS contained <10.0 µg of cholesterol/ml. Delipidated LPDS was prepared from LPDS by extraction with an acetone-ether mixture [10]. As expected, this material contained no measurable cholesterol.