Related Experiment Video
Updated: Jun 16, 2026

A Simplified Model for Heterotopic Heart Valve Transplantation in Rodents
Published on: September 21, 2021
Development of mature lamellar bone with a hematopoietic compartment in an aortic valve homograft
Grzegorz J Lis1, Jan A Litwin, Boguslaw Kapelak
1Department of Histology, Jagiellonian University Medical College, Krakow, Poland. mmlis@cyf-kr.edu.pl
Abstract:
Two foci of mature lamellar bone with features of remodeling and with an adjacent hematopoietic compartment were revealed for the first time in an aortic valve homograft by hematoxylin and eosin staining and polarized light microscopy. The valve had been obtained originally from a 52-year-old non-beating-heart donor and implanted as 'fresh antibiotic-preserved' into the left ventricular outflow tract of a 21-year-old man, but was explanted after six years due to valvular insufficiency. The areas close to bone showed the presence of cells resembling osteoblasts, osteoclasts and degenerating chondrocytes. Von Kossa staining disclosed a small area of dystrophic calcification in the vicinity of one bone fragment, whereas the second fragment was accompanied by only weak, diffuse calcification. These findings shows that the formation of ectopic mature bone with secondary development of the hematopoietic compartment can occur in a relatively short time, and suggest that initiators of the process may be present in the grafted valve.
Related Concept Videos
Bone Formation by Endochondral Ossification
Growth of Cartilage and Bone Tissue
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...
Development of Blood Vessels
The initial formation of this system is facilitated by the small amount of yolk present in the ovum and yolk sac. Blood vessels originate from...
Spongy Bone
Spongy bone is more porous, and less dense compared to compact bone. It is composed of concentric lamellae that are arranged irregularly to form the trabecular network. In some bones, the spaces between trabeculae contain red marrow, where...

