Biomedical Engineering Reference
In-Depth Information
1.5
Pathological Calcification of Calcium
Orthophosphates
In the body of mammals, osteoblasts and odontoblasts fix ions
of calcium and orthophosphate and then precipitate biological
apatite onto an organic matrix. This is the process of physiological
biomineralization that is restricted to the specific sites in skeletal
tissues, including growth plate cartilage, bones, teeth and antlers
[107, 454]. Normally, mammals are supposed to die with calcium
orthophosphates located in bones and teeth (and antlers for male
deer) only and nowhere else, because under the normal conditions
soft tissues are not mineralized. Unfortunately, owing to ageing,
various diseases and under certain pathological conditions blood
vessels, muscles, extracellular matrix of articular cartilaginous
tissues of the joints and some internal organs are calcified as well.
This process is called pathological calcification or ectopic (bio)
mineralization and leads to a morbidity and a mortality [107, 454,
783]. In general, any type of abnormal accumulation of calcium
orthophosphates in wrong places is accounted for by a disruption of
systemic defense mechanism against calcification [784].
To the best of my knowledge, the first paper on a negative influence
of unwanted depositions of calcium orthophosphates in the body was
published as early as in 1911 [785]. This finding was confirmed in
later studies [786, 787]. Unwanted depositions always lead to various
diseases, for instance: soft tissue calcification (in damaged joints,
blood vessels, dysfunctional areas in the brain, diseased organs,
scleroderma, prostate stones) [230, 231, 232, 788-793], kidney
and urinary stones [27, 794-797], dental pulp stones and dental
calculus [187, 188, 190, 223, 229, 798-800], salivary stones [801],
gall stones, pineal gland calcification, atherosclerotic arteries and
veins [85, 802-805], coronary calcification [806], cardiac skeleton,
damaged cardiac valves [807], calcification on artificial heart valves
[808-812], carpal tunnel [813], cataracts [814], malacoplakia,
calcified menisci [815, 816], dermatomyositis [817, 818], and still
other diseases [107]. In addition, there is a metastatic calcification
of nonosseous viable tissue occurring throughout the body [819,
820], but it primarily affects the interstitial tissue of the blood
vessels, kidney, lungs and gastric mucosa. A metastatic calcification
is defined as a deposition of calcium orthophosphates in previously
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