For this study bone samples from 14 postmenopausal women have been analyzed: a) Femoral neck samples (n = 10) which had been part of a former study [29] and [30] and were kindly provided by N. Loveridge (Department of Medicine, University of Cambridge, Cambridge). Five of these samples were from patients suffering from an osteoporotic femoral neck fracture and 5 samples were from forensic autopsies of individuals without metabolic bone diseases age matched with

that of osteoporotic fractures. The average age of these individuals was 81.5 years ranging from 74 to 92 years. b) Femoral head samples (n = 4), which were obtained PD332991 during hip replacement surgery. The individuals suffered an osteoporotic femoral neck fracture and were 60 to 80 years old with an average age of 77.5 years. Measurements were performed in both trabecular and cortical bone regions for the femoral neck samples and only in the trabecular region for the femoral head samples resulting in a total of 35 areas of about 500 μm × 650 μm. The term mineralized bone matrix will describe both the osteons and the interstitial bone in the osteonal bone region and bone packets

in cancellous bone Cabozantinib clinical trial region. To the best of our knowledge, none of the patients has been exposed to higher Pb concentrations than the natural levels in their living areas. The study was in accordance with and approved by the local ethics committee (Institutional Review Board of the Medical University of Vienna). As already described in earlier publications [31] and [32], the samples have been prepared as blocks of undecalcified in polymethylmethacrylate (PMMA) embedded bone tissue. The femoral neck samples were cut in the transversal plane and the femoral head samples perpendicular to the articular surface (frontal plane). The section surfaces were manufactured by grinding with sand paper and Phosphoribosylglycinamide formyltransferase subsequently polishing with diamond suspension (3 and 1 μm grain size) on a precision polishing device (PM5: Logitech Ltd., Glasgow, UK) or by milling with a diamond ultra miller (SP2600:

Leica Microsystems GmbH, Wetzlar, Germany). The entire embedding and surface preparation procedure was tested to be free of detectable Zn, Sr and Pb contaminations. Quantitative backscattered electron imaging (qBEI) is a validated technique to visualize and quantify the calcium (Ca) concentration distribution in bone based on the backscattering of electrons from the sample surface in a scanning electron microscope (SEM). Areas with bright gray levels reflect matrix with high Ca content, whereas areas with dark gray levels indicate low Ca content. Cement lines, the transition zones between different bone packets and osteons usually show a higher mineral content than the adjacent mineralized bone matrix [26] and [33].