Coding of Pathologic Diagnoses

Hydroxyapatite Crystallization in the Presence of Amino Acids with Uncharged Polar Side Groups: Glycine, Cysteine, Cystine, and Glutamine

“…On the other hand, calcification is the most frequent cause of the clinical failure of cardiac valve bioprostheses fabricated from porcine aortic valves. , The mineral deposits of the human atherotic aorta consist mainly of calcium apatite (71%), with an average Ca/P ratio of ∼1.7. The same ratio appears in the mature skeletal biomineral, leading to the conclusion that both approximate hydroxyapatite in composition.…”

The Crystallization of Hydroxyapatite in the Presence of Lysine

“…Hydroxyapatite [Ca 5 (PO 4 ) 3 OH, HAP], is the most stable calcium phosphate salt under physiological conditions. It has been suggested as the model compound for the study of hard tissue calcification such as bone and teeth and in many undesirable cases of pathological mineralization of articular cartilage (5,6), cardiac valves (7)(8)(9), and stones in kidney (10). The role of various biological molecules as modulators of biomineralization has also been appreciated (11)(12)(13)(14)(15)(16).…”

Bioprosthetic heart valves: the need for a quantum leap

“…Although cellular elements have been recognized as primary calcification sites for a long time, the process of calcification was mainly explained by passive processes. The breakdown of an active gradient of a 10000 times higher Ca 2+ concentration in the extracellular space, and its uninhibited influx as a consequence of cell death, disintegration and breakdown of the energy‐dependent calcium pump Ca 2+ ‐ATPase, was seen as a main mechanism of early nucleation [43,44]. It was hypothesized that phosphorus‐containing sites such as phospholipids and proteolipids, as well as enzymic systems metabolizing high‐energy phosphates such as Ca 2+ ‐ATPase, passively attract Ca 2+ [44].…”

“…The breakdown of an active gradient of a 10000 times higher Ca 2+ concentration in the extracellular space, and its uninhibited influx as a consequence of cell death, disintegration and breakdown of the energy‐dependent calcium pump Ca 2+ ‐ATPase, was seen as a main mechanism of early nucleation [43,44]. It was hypothesized that phosphorus‐containing sites such as phospholipids and proteolipids, as well as enzymic systems metabolizing high‐energy phosphates such as Ca 2+ ‐ATPase, passively attract Ca 2+ [44]. When more than 10 years ago it was discovered that alkaline phosphatase activity was still detectable after glutaraldehyde fixation [45], it did not lead to a revisiting of cross‐link chemistry.…”