Sentence examples for more physiological oxygen from inspiring English sources

To mimic the environment in the growing embryo at the stage when hemato-endothelial progenitors start to develop, we examined the role of hypoxia (5% O2 tension) during hematopoietic commitment to reflect more physiological oxygen levels.

In particular, we hypothesized that culture at a more physiological oxygen percentage has a dual role in the chondrocyte metabolism, by enhancing their biosynthetic activity and at the same time reducing the expression of matrix degradative enzymes.

This article investigates the effect of low (more physiological) oxygen percentage on the biosynthetic and catabolic activity of human articular chondrocytes (HAC) at different phases of in vitro culture.

Fraker et al 42 have recently developed a culturing device with a perfluorohydrocarbone-silicone membrane that maintains a more physiological oxygen supply to the islets, minimizing overnight losses and boosting viability.

We thus aimed our study at investigating the effect of a low (more physiological) oxygen percentage both on the cartilage tissue forming capacity of human articular chondrocytes (HAC), and on their pro-catabolic, matrix degradative activity.

Moreover, the expression of cartilage specific genes and/or the extent of matrix protein synthesis/deposition was reported to be up-regulated [ 6- 9, 12, 15- 22], down-regulated [ 10, 23- 26] or not modulated at all [ 6, 9] by culture under more physiological oxygen percentages.

For instance, as compared to culture under normoxic conditions (18 to 21% oxygen), culture at more physiological, low oxygen percentages (1 to 8%) has been reported to increase [ 7- 10], decrease [ 11, 12] or have no effect on the chondrocyte proliferation rate [ 6, 13- 15].

In agreement with these data, we discovered that culturing cells under 21% oxygen conditions also increased the percentage of fragile telomeres compared to more physiological 2% oxygen culture conditions (Fig. 4A).

In this study we found that culture at low, more physiological (5%) oxygen percentage has a dual role in HAC metabolism, namely to enhance the proteoglycan and collagen synthesis and at the same time to reduce the activity of two key catabolic enzymes involved in cartilage breakdown (that is, MMP-1 and MMP-13).

20% O2 was used as a control, since the cells were isolated and cultured under 20% O2, and an experimental setup using lower and more physiological levels of oxygen exposure as a control is not feasible in an in vitro setup.

On the other hand, oxygen carriers allow for lower, more physiological perfusion flow rates.