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INTRODUCTION: Biochemical markers of bone metabolism have been mainly determined manually until now and the precision and accuracy of these methods have not always been satisfactory. This has been shown in several external quality assessment schemes (EQAS). OBJECTIVE AND STUDY DESIGN: A study named BIOROSE was undertaken to evaluate new automated assays for serum markers of bone metabolism. The main focus was to evaluate the assay performance in a multicenter setting with 20 laboratories participating in Germany. The evaluation consists of a familiarization phase to determine precision and accuracy and an EQAS to evaluate the comparability between laboratories. MATERIALS: The parameters beta-CrossLaps (CTX), N-MID-Osteocalcin (OC) and intact parathyroid hormone (PTH) were measured with reagents including calibrators and control sera obtained from Roche Diagnostics, Mannheim, Germany, with electrochemiluminescence immunoassays (ECLIA) on the automated analyzer Elecsys 2010. RESULTS: We calculated for the control samples, PCB 1-3, the mean and median values from the measured values of all participating laboratories and used these as target values. From these target values, a recovery range for the participating laboratories was calculated for beta-CrossLaps, OC and intact PTH of better than 80-126% for PCB 2 and PCB 3, and for PCB 1 (low concentration range) for beta-CrossLaps 79-129%, OC 90-120% and intact PTH 78-126%. The between-day imprecision was 2.4-7.2% for beta-CrossLaps, 1.1-5.9% for OC and 1.7-5.5% for intact PTH in the elevated range (sample PCB 2). In the EQAS, the inter-laboratory imprecision for beta-CrossLaps in the sample with a value of 0.8 ng/ml (above the upper limit of normal, which is 0.6 ng/ml) was 9.8% on day 1 and 9.7% on day 2. CONCLUSION: The performance evaluation of automated assays for beta-CrossLaps, N-MID-Osteocalcin and intact parathyroid hormone in the BIOROSE multicenter study showed that the participating laboratories had no problems in setting up these methods and they yielded results for precision and accuracy that are superior to results achieved in external quality assessment schemes for manually performed methods. In addition, at the clinically important decision level of the upper limit of the normal range, all three tested analytes gave precise results that improved medical decisions.

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We describe the preparation of small unilamellar and multilamellar vesicles from hexadecylphosphocholine, cholesterol and 1,2-dipalmitoyl-sn-glycero-phosphoglycerol in the molar ratio 4/5/1. Particle size and chemical stability of two types of liposomes, small unilamellar vesicles and lyophilized, freshly resuspended multilamellar vesicles were proved to be stable for at least 12 months. Compared to hexadecylphosphocholine in free form, liposomal hexadecylphosphocholine showed remarkably reduced hemolysis which did not change during storage. Fluorescence microscopy showed the uptake of propidium iodide containing hexadecylphosphocholine liposomes by KB and MDA-MB 231 tumor cells. Free propidium iodide was not incorporated into these cells. Although cytotoxicity seemed to be reduced in liposomal preparations, hexadecylphosphocholine liposomes still affected cultured tumor cells to a great extent. In relatively low concentrations they induced shape alteration, smoothing of the cell surface and blebbing.