Morpho-physiological Divergence Across Aquatic Oxygen Gradients in Fishes

2016 ◽  
pp. 13-40
Author(s):  
Lauren J. Chapman
Keyword(s):  
Oxygen Gradients

scholarly journals Dispersible oxygen microsensors map oxygen gradients in three-dimensional cell cultures

2017 ◽  
Vol 5 (10) ◽  
pp. 2106-2113 ◽  
Author(s):  
Sasha Cai Lesher-Pérez ◽  
Ge-Ah Kim ◽  
Chuan-hsien Kuo ◽  
Brendan M. Leung ◽  
Sanda Mong ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Three Dimensional ◽  
Oxygen Gradients ◽  
Oxygen Measurements ◽  
Dimensional Cell

Oxygen measurements in different microtissue culture environments were accomplished with the use of phase fluorimetry on dispersible oxygen microsensors.

Oxygen delivery and myocardial function in rabbit hearts perfused with cell-free hemoglobin

1992 ◽  
Vol 72 (2) ◽  
pp. 476-483 ◽  
Author(s):  
V. W. MacDonald ◽  
R. M. Winslow
Keyword(s):  
Oxygen Uptake ◽  
Myocardial Function ◽  
Oxygen Affinity ◽  
Left Ventricular ◽  
Rate Of Change ◽  
Free Hemoglobin ◽  
Langendorff Preparation ◽  
Oxygen Gradients ◽  
Developed Pressure ◽  
Krebs Henseleit Buffer

Isolated rabbit hearts were perfused with Krebs-Henseleit buffer that contained 1.5 g/dl hemoglobin Ao [HbAo; PO2 at which half-saturation of hemoglobin occurs = 12 Torr], human hemoglobin cross-linked between alpha-chains with bis(3,5-dibromosalicyl)fumarate (alpha alpha-Hb; PO2 at which half-saturation of hemoglobin occurs = 30 Torr), or fatty acid-free bovine serum albumin (BSA). Myocardial performance and oxygen uptake were determined at different aortic PO2's [arterial PO2 (PaO2)] by use of an isovolumic Langendorff preparation. Function and oxygen uptake were comparable among the three different groups of hearts at an average mean PaO2 of 557 Torr. As PaO2 decreased, myocardial function was preserved better in hearts perfused with hemoglobin than in hearts perfused with Krebs-Henseleit buffer alone or with BSA. Hearts perfused with either HbAo or alpha alpha-Hb exhibited similar 10% decreases in left ventricular developed pressure and rate of change in left ventricular developed pressure at PaO2 of 141 Torr compared with a 58% decrease with BSA. However, corresponding venous PO2's were lower with HbAo (20 Torr) than with alpha alpha-Hb (35 Torr), and oxygen uptake decreased by 36% with HbAo but remained constant with alpha alpha-Hb. These data suggest that although myocardial function can be sustained over a fairly broad range of hemoglobin oxygen affinities, tissue oxygen gradients and myocardial oxygen uptake are maintained better by cell-free hemoglobin with an oxygen affinity in the normal physiological range.

Oxygen gradients in tissue-engineered Pegt/Pbt cartilaginous constructs: Measurement and modeling

2004 ◽  
Vol 86 (1) ◽  
pp. 9-18 ◽  
Author(s):  
J. Malda ◽  
J. Rouwkema ◽  
D. E. Martens ◽  
E. P. le Comte ◽  
F. K. Kooy ◽  
...  
Keyword(s):  
Oxygen Gradients

scholarly journals Study Cellular Hypoxic Response under Cyclic Oxygen Gradients Generated in Microfluidic Devices Using Real-Time Fluorescence Imaging

2021 ◽  
Author(s):  
Dao-Ming Chang ◽  
Yi-Chung Tung
Keyword(s):  
Cell Culture ◽  
Intracellular Calcium ◽  
Real Time ◽  
Oxygen Tension ◽  
Calcium Concentration ◽  
A549 Cells ◽  
Cell Types ◽  
Hypoxic Response ◽  
Oxygen Gradient ◽  
Oxygen Gradients

Abstract In this paper, an integrated approach to study cellular hypoxic response under cyclic oxygen gradients is developed. In the experiments, a cell culture system based on a microfluidic device is constructed to generate cyclic oxygen gradients with fast response. The oxygen gradient is generated by alternatively introducing gases with specific compositions by a computer-controlled gas supply system into the microfluidic channels next to the cell culture one separated by thin channel walls. Observation of cellular hypoxic responses is performed using real-time fluorescence imaging of dyes sensitive to extra-and intra-cellular oxygen tensions as well as intracellular calcium concentrations. The capability of consistent cyclic oxygen gradient generation is confirmed by characterizing spatiotemporal oxygen tension profiles within the device. In the cell experiments, cellular hypoxic responses of human aortic smooth muscle cells (AoSMCs) and lung carcinoma epithelium (A549) cells including intracellular oxygen and calcium levels are measured. The relationships between the oxygen probe intensity and extracellular oxygen tension for both cell types are highly linear, and difference between the intensity measured from the two cell types is observed between 4 to 8% O2 culture environment. In addition, both cell types show detectable intracellular calcium concentration variation when the environmental O2 varies between normoxia and lower than 4%. The AoSMCs and A549 cells show decrease and increase of the intracellular calcium concentration during hypoxic response when facing change from normoxia to hypoxia environments, respectively. With the capability of real-time cellular responses monitoring under cyclic oxygen gradients, the developed approach provides a useful scheme to investigate cellular hypoxic response in vitro under microenvironments mimicking various in vivo physiological and pathological conditions.

Oxygen gradients in animal-cell bioreactors

1995 ◽  
Vol 18 (1-2) ◽  
pp. 27-34 ◽  
Author(s):  
J. Tramper
Keyword(s):  
Animal Cell ◽  
Oxygen Gradients ◽  
Animal Cell Bioreactors

Measurement of tissue oxygen with a fluorescent probe

1976 ◽  
Vol 41 (4) ◽  
pp. 598-602 ◽  
Author(s):  
I. S. Longmuir ◽  
J. A. Knopp
Keyword(s):  
Oxygen Consumption ◽  
Fluorescence Quenching ◽  
Fluorescent Probe ◽  
Spatial Resolution ◽  
Tissue Oxygen ◽  
Quenching Of Fluorescence ◽  
Oxygen Gradients ◽  
Geometrical Factors

Evidence is presented that pyrenebutyric acid is nontoxic at the concentrations required for the measurement of fluorescence quenching by physiological concentrations of oxygen. It appears that this molecule can be used tomeasure tissue oxygen since it does not interfere with oxygen consumption. Equally, tissue components do not interfere with the quenching of fluorescence to such an extent as to invalidate the method. The spatial resolution of the technique is limited by some tissue geometrical factors which do not,however, appear to be great enough to prevent its use to measure intercapillary oxygen gradients.

scholarly journals Generating linear oxygen gradients across 3D cell cultures with block-layered oxygen controlled chips (BLOCCs)

2020 ◽  
Vol 12 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Matthew W. Boyce ◽  
William C. Simke ◽  
Rachael M. Kenney ◽  
Matthew R. Lockett
Keyword(s):  
Cell Cultures ◽  
Cell Microenvironment ◽  
3D Cell Cultures ◽  
Oxygen Gradients

BLOCCs are readily assembled structures of laser cut acrylic and silicone, capable of imposing physiologically relevant oxygen gradients across 3D cell cultures. With sensors and cell-based readouts, we quantified cell-microenvironment relationships.

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