LeBlanc A, Lin C, Evans H, Shackelford L, Martin C, Hedrick T
Department of Medicine, Baylor College of Medicine, Houston, Texas, USA.
Magn Reson Med. 1999 Mar;41(3):495-8. doi: 10.1002/(sici)1522-2594(199903)41:3<495::aid-mrm11>3.0.co;2-v.
Bone biopsies indicate that during immobilization bone marrow adipose tissue increases while the functional cellular fraction decreases. One objective of our Spacelab flight experiment was to determine, using in vivo volume-localized magnetic resonance spectroscopy (VLMRS), whether bone marrow composition was altered by space flight. Four crew members of a 17 day Spacelab mission participated in the experiment. The apparent cellular fraction and transverse relaxation time (T2) were determined twice before launch and at several times after flight. Immediately after flight, no significant change in the cellular fraction was found. However, the T2 of the cellular, but not the fat component increased following flight, although to a variable extent, in all crew members with a time course for return to baseline lasting several months. The T2 of seven control subjects showed no significant change. Although these observations may have several explanations, it is speculated that the observed T2 changes might reflect increased marrow osteoblastic activity during recovery from space flight.
骨活检表明，在制动期间骨髓脂肪组织增加，而功能性细胞部分减少。我们的太空实验室飞行实验的一个目标是，使用体内体积定位磁共振波谱（VLMRS）来确定太空飞行是否会改变骨髓组成。一个为期17天的太空实验室任务的四名机组人员参与了该实验。在发射前两次以及飞行后的几个时间点测定了表观细胞部分和横向弛豫时间（T2）。飞行后立即发现细胞部分没有显著变化。然而，在所有机组人员中，飞行后细胞成分（而非脂肪成分）的T2增加，尽管程度不同，且恢复到基线的时间过程持续数月。七名对照受试者的T2没有显著变化。尽管这些观察结果可能有多种解释，但据推测，观察到的T2变化可能反映了太空飞行恢复期间骨髓成骨细胞活性增加。
