Ana Belén Toaquiza, Verónica Alvear, Katy Bolaños, Angie López, Carlos Zapata, Raquel Toaquiza, Nicolás E. Ottone, María Revelo-Cueva,

Sheet plastination with polyester resin or P40 sheet plastination is a technique that ensures the creation of rigid and semi-transparent anatomical slices, making it easier to study macroscopic sectional anatomy. This technique follows the same steps as the basic plastination technique described by its creator, Professor Gunther von Hagens: dehydration, impregnation, and curing. The Animal Anatomy Laboratory at Universidad Central del Ecuador had previously only used the silicone plastination technique. The aim of this work was to apply the sheet plastination technique with polyester resin, specifically with Biodur® P40, for the first time to create didactic material from bovine brains. The methodology involved fixing a bovine brain in 20% formalin for two months, followed by dehydration with acetone at -20 °C. The forced impregnation process with Biodur® P40 was carried out at room temperature for 24 hours, followed by curing in the shade from sunlight. Protocols published by other authors were followed, with some practical adaptations such as the use of expanding polyurethane foam to provide greater support to the cutting blocks. Additionally, 6 mm (¼") PVC hose and office plasticine were used for assembling and sealing the chambers, respectively. Overall, the technique implementation was relatively easy, and twenty-four brain slices with rigid consistency and no apparent alterations in the morphology of the anatomical structures were obtained. The slices were sequentially arranged on a wooden base to not only facilitate the study of sectional anatomy but also to encourage students to use this technique in the animal anatomy laboratory.

Marc A. Pizzimenti, Xiaoliu Zhang, Jessica E. Goetz, and Punam K. Saha,

Analytical strategies to interpret computed tomography data for the study of osteoporosis require gross anatomical specimens that closely approximate the bone marrow matrix while maintaining the structural integrity of the trabecular network. Here we investigated if paraffin, gelatin-matrix, or silicone polymer impregnated bone specimens maintained the trabecular network and bone density of specimens used for comparative studies in osteoporosis. Distal tibia specimens (n = 12) from cadaveric human legs were used for this study. Multi-row detector computed tomography (MDCT) scans were completed on each specimen, with selected specimens re-scanned using micro-computed tomography (µCT), at different times to evaluate trabecular integrity. Once scanned, bones were de-marrowed using a solvent-based procedure. De-marrowed specimens were then impregnated, under vacuum controlled conditions, with either a silicone polymer, gelatin matrix solution, or paraffin wax, and re-scanned. µCT analysis demonstrated a high Pearson correlation coefficient in trabecular bone network area density between the native and de-marrowed states (r = 0.99). Quantitatively, paraffin impregnated specimens demonstrated the highest congruence in MCDT bone volume fraction (r = 0.92) and trabecular network area (r = 0.94) measures. These results were more robust in the µCT data (bone volume fraction, r = 0.97; and trabecular network area, r = 0.99). Additionally, of the impregnating procedures, paraffin wax provided the best qualitative specimens for handling, storage, and processing time. These data suggest that paraffin demonstrates a space occupying matrix that effectively protects the trabecular network and maintains the ability to quantify important biomechanical measures for assessing bone integrity. The preserved specimens will serve as standard models for comparison when developing algorithms for studying osteoporosis.