After 12 weeks of diet correction, the HFD-fed immature mice show no relative improvement in femoral BVF or other trabecular parameters, while the femoral BVF of mature mice tends to recover to that of the lean controls. The results of this study demonstrate a complex interplay between growth, aging, anatomic site and excessive dietary fat on cancellous bone homeostasis in male mice and require further study to elucidate the biological mechanisms underpinning these effects. The authors have no conflicts of interest and nothing to disclose.

The authors would like to thank Mr. Michael Thullen for his excellent technical assistance with micro-CT and Robert Maynard for his assistance with histology Roxadustat and serum assays. The study was supported by NIAMS/NIH grant P30AR061307 and the AO Trauma Research Fund. Jason Inzana is supported by the NSF Graduate Research Fellowship2012116002. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Science Foundation, National Institutes of Health, or AO Foundation. “
“When tissue of living organisms is analyzed by highly sensitive chemical analytic methods, specific chemical elements in very minute quantities (< ppm) can be found. These so called trace elements can be essential and/or non-essential for the living organism

[1]. However, the role of many trace elements in tissues CX-5461 cell line e.g. bone is poorly understood [2]. Great efforts have been undertaken to determine the incorporated amounts of various trace elements in bone [3] and [4]. Since in general the chemical analysis is based on destructive methods, the information about the spatial distribution of the trace elements within the tissue is usually lost. Previous studies lacked spatial

distribution and merely differentiated between cortical and trabecular bone [5], [6], [7], [8], [9] and [10]. New developments in synchrotron radiation technology allow now analyzing in a non-destructive way, spatially resolved trace elements like zinc (Zn), strontium (Sr) and lead (Pb) in bone tissue. For example using synchrotron radiation induced confocal micro X-ray Thymidine kinase fluorescence analysis (SR μ-XRF) we found a highly specific accumulation of Pb and Zn in the transition zone between mineralized and nonmineralized articular cartilage compared to subchondral bone [11] and [12]. Moreover this method is also able to detect and map different elements simultaneously [13]. Zn, Sr and Pb are trace elements, present in sufficient concentrations in bone so they can be easily mapped with the multi-elemental SR μ-XRF method. Zn is an important essential trace element in multiple biological processes and a reduced intake may lead to chronic diseases [14]. Zn is also present in bone tissue and it has been reported to play an important role in bone metabolism [15], [16] and [17].