Loss of the ability to generate large burst-forming unit-like megakaryocytic colonies from thawed cord blood in semisolid cultures after short term suspension culture.

BACKGROUND AND OBJECTIVES: Total colony-forming cells from thawed cord blood units (CBUs) include megakaryocytic colony-forming units (CFU-Mks), which survive the freezing process. The aim of this study was to evaluate whether different megakaryocytic progenitors from unseparated CBUs survive the freezing process and a short-term liquid culture. MATERIALS AND METHODS: Thawed samples of CBUs were cultured in liquid medium. During the cultures, serial samples were drawn to assess the growth of different megakaryocytic progenitors in a semisolid collagen medium with identical cytokines as in the liquid medium. Megakaryocytic cells were detected using immunohistochemistry and flow cytometry. RESULTS: In suspension culture, the megakaryocytic progenitors almost completely lost the ability to generate large (burst-forming unit-like, BFU-like) megakaryocytic colonies in semisolid cultures (large colonies, median count per chamber d0: 7.25 vs. d7: 1.5; P < 0.0001), whereas the number of small colonies (median count per chamber d0: 7.25 vs. d7: 16.0; P = 0.0505) peaked at day seven. Further 7-day culture in suspension resulted in the decline of small colonies as well (d7: 16.0 vs. d14: 5.75; P = 0.0088). Total CFU-Mk count declined from 23.3 (range 12.5-34.0) at d0 to 7.25 (range 1.0-13.5) at d14 (P < 0.0001). CONCLUSION: Immediately post-thaw, CBUs possess an ability to generate large BFU-like megakaryocytic colonies, whereas the colonies were not detectable in most CBUs in semisolid culture after a short suspension culture. Small CFU-Mks were observed throughout the cultures. It may be that the BFU-Mk colonies matured and acquired CFU-Mk behaviour.

Customer-oriented counseling for physical activity in older people: study protocol and selected baseline results of a randomized-controlled trial (ISRCTN 07330512).

The objective of this study is to describe the rationale, design and selected baseline results of a 2-year randomized-controlled trial (RCT) on the effects of physical activity counseling in community-living older people. After a four-phase screening and data-collection process targeting all independently living people in the city center of Jyväskylä, Finland, six hundred and thirty-two 75-81-year-old cognitively intact, sedentary persons who were able to move independently outdoors at least minimally and willing to take part in the RCT were randomized into intervention and control groups. At baseline, over half of the subjects exercised less than two to three times a month and two-thirds were willing to increase their physical activity level. The desire to increase physical activity was more common (86%) among subjects with mobility limitation compared with those without (60%, P=0.004). The intervention group received an individualized face-to-face counseling session, followed by phone contacts every 3 months throughout the intervention. The study outcomes include physical activity level, mobility limitation, functional impairments, disability, mood, quality of life, use of services, institutionalization and mortality. The screening and recruitment process was feasible and succeeded well, and showed that unmet physical activity needs are common in older people.