A Weak Smoking Gun

According to Wikepedia, osteoblasts build bone tissue by producing both Type I bone collagen cells, and calcium salts. As the salts are produced this cell gradually and completely mineralizes itself until it finally dies with its remnant mineral matrix eventually to be destroyed by an osteoclast, the space then to be regenerated and on it goes.

During this process the collagen cell is likely to be surrounded by other similar cells and thus becomes trapped in mineral matrix. Thus living osteoblast collagen remnant cells embed in mineralized bone tissue and are now referred to as osteocytes. Osteocytes communicate with each other (see videos) via canals, and presumably play a significant role in calcification/ossification of the entire bone matrix.

With this understanding the blog presents our latest discovery, which, if you care to read and understand, in its very last sentence contains a weak smoking gun in support of positions I have taken regarding bone structures and calcification.

Noted: the scientists are dealing with equine bone, expected to find an osteocyte response to "strain", and failed in that expectation (last sentence). This seems a significant piece of research, although I am uncertain of their methods and lack their full report.

"Spatial Distribution of Osteocyte Lacunae in Equine Radii...Considerations of Micro damage, Detection, and Metabolism." (U. of Utah 2005):
"Osteocytes, which are embedded in bone matrix, are the most abundant cells in bone. Despite the ideal location of osteocytes to sense the local environment and influence bone remodeling, their functions, and the relative importance of these functions remains controversial. In this study, we tested several hypotheses that address the possibilities that population densities of osteocyte lacunae correlate with strain-remodeling-or metabolism related aspects of the local biomechanical environments (in mid cannon bone).

Ot.Lc N/B.AR data quantified in multiple cortical locations were analyzed for possible correlations with (1) structural and material characteristics(e.g. cortical thickness, percent ash, secondary osteon population density, mean osteon cross-sectional area, and predominant collagen fiber orientation), (2) strain characteristics, including prevalent strain magnitude and mode (tension, compression, shear),(3) hypothesized strain mode related micro damage characteristics, which might be perceived by osteocyte operational networks, , and (4) variations in remodeling dynamics and/or metabolism.

Results show relatively uniform Ot.Lc.N/BAr between regions with highly non-uniform strain and strain related environments and markedly heterogeneous structural and material organization.

These results suggest that population densities of these cells are poorly correlated with mechanobiological characteristics, including local variations in metabolic rate and strain magnitude/mode. Although osteocytes hypothetically evolved both as strain sensors and fatigue damage sensors able to direct the removal of damage as needed, the mechanisms that govern the distribution of these cells remain unclear.

The results of this study provide little or no evidence that the number of osteocyte lacunae has a functional role in mechantransduction pathways that are typically considered in bone adaptation."

I knew all that. The relevance, next post!

Training:
11/20: rain disappears, farm is a mess, but had sun today. Training to recommence 11/21, hopefully.