Table 3 : Hypoxia dynamics in the early initiation phase INI controls P cells conversion and select a unique proliferation pattern
not influenced by the later natural hypoxic development in culture.


Sample OCB
sediment
Counting Time (h) ATD cysts T cells Cell
conversion
Encysted
MAS
MAT cells SRT cells (t-SRL) AGT n(t)

3a OCB/MO 36 4.08 3.06 P/S, S/T D21-4 D25-6 D16 AGT5-6 6 (36)
    60** 4.08 3.96 -- D21-4 D25-7 D17 AGT24 1 (24
3b OCB/MH 24 -- 2.76 P/T -- D21 D11 AGT24 1 (24)
    36* -- 5.22 -- -- D21-3 D13 AGT6 2 (12)
3c OCB/MH 48 -- 3.12 P/T -- D21-2 D12 AGT24 2 (48)
    60* -- 4.56 -- -- D21-3 D13 AGT11-12 1 (12)

Cell fractions in 106 units. The average generation time AGT was estimated by the equation AGT=t:n. In this equation "t" is the population age at the
moment of counting and "n" the number of cell divisions performed by cycling cells. The average generation time AGT is a real indicator for niche quality
and cycling cell response.
Parallel cultures (samples 3a-3c) were started with 1.02x106 (sample 3a), 1.04x106 (sample 3c) and 1.28x106 (sample 3b) P cells and using a 5 mg OCB
dose by SARC/t0. First counting occurred at t24 (sample 3b), t36 (sample 3a) and t48 (sample 3c). After measuring, bottom sediments were restored by
re-centrifugation (SARC). Re-evaluation occurred 12 h* or 24 h** later.
The fate of each culture was different, depending on the range of hypoxia developed by the OCB sediment during the early initiation phase INI (t0-t2).
The most oxidative MO sediment in the sample 3a induces P/S conversion and fast cycling (AGT6) while the most hypoxic MH sediments in the samples
3b-3c decided for P/T conversion and slow cycling (AGT24). Culture sediments in the samples 3a-3c pointed out the preferences of the more oxygenic
s-SRL and more hypoxic t-SRL stem cell lines for different hypoxic niches and pO2 levels.

Vladimir F Niculescu Stem Cell Biology and Research  2015 2:2DOI : 10.7243/2054-717X-2-2