Osteoblasts Subjected To Spaceflight And Simulated Space Shuttle Launch Conditions
acceleration; bone cells; bone-formation; Cell Biology; cells; Developmental Biology; differentiation; flight; gene-expression; growing rats; in-vitro; messenger-rna expression; microgravity; vibration; weightlessness
To understand further the effects of spaceflight on osteoblast-enriched cultures, normal chicken calvarial osteoblasts were flown aboard shuttle flight STS-77, and the total number of attached cells was determined. Spaceflight and control cultures were chemically fixed 3 h and 3 d after launch. These fixed cultures were processed for scanning electron microscopy (SEM). The SEM analysis showed that with just 3 d of exposure to spaceflight, coverslip cultures contained 300 +/- 100 cells/mm(2), whereas 1G control samples contained a confluent monolayer of cells (2400 +/- 200 cells/mm(2)). Although the cultures flown in space experienced a drastic decline in cell number in just 3 d, without further experimentation it was impossible to determine whether the decline was a result of microgravity, the harsh launch environment, or some combination of these factors. Therefore, this research attempted to address the effect of launch by subjecting osteoblasts to conditions simulating shuttle launch accelerations, noise, and vibrations. No differences, compared with controls, were seen in the number of total or viable cells after exposure to these various launch conditions. Taken together, these data indicate that the magnitude of gravitational loading (3G maximum) and vibration (7.83G rms maximum) resulting from launch does not adversely affect osteoblasts in terms of total or viable cell number immediately, but launch conditions, or the microgravity environment itself, may start a cascade of events that over several d contributes to cell loss.
Kacena M A; Todd P; Landis W J
In Vitro Cellular & Developmental Biology-Animal
2003
2003-11
Journal Article or Conference Abstract Publication
n/a
Vascular-mineral Spatial Correlation In The Calcifying Turkey Leg Tendon
bone; calcification; calcifying tendon; cartilage; Cell Biology; collagen; computed tomography; digital sheath; growing rats; growth-plate; mineralization; Orthopedics; osteogenesis; rabbit; tibial epiphyseal plate; vascularity
Certain avian tendons are known to mineralize normally in a gender-related manner. These tendons have unique properties, as well as several features common to calcifying cartilage and bone in other vertebrate species. In cartilage and bone, mineralization has been associated with a vascular and microvascular origin, but such a relationship has not been established in the avian tendon. Here the vasculature and mineral deposition in the calcifying leg tendon of the turkey have been documented for the first time utilizing a combination of histology, immunochemistry, radiology, and novel three-dimensional image reconstruction methods based on computed tomography. The data describe the blood supply to turkey leg tendon and show that the vascularity of this tissue is correlated with the onset of mineralization: At local levels of structural hierarchy, a vascular bed precedes mineral formation and the sites of vascular invasion correspond spatially with those of mineral deposition. Relatively unvascularized tendon regions remain uncalcified. These results support the concept that vascularization and mineralization are functionally related in the tendon, and they suggest that vascular invasion provides a mechanism underlying subsequent mineral deposition in this tissue.
Landis W J; Kraus B L H; Kirker-Head C A
Connective Tissue Research
2002
2002-10
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1080/03008200290001320" target="_blank" rel="noreferrer noopener">10.1080/03008200290001320</a>