A new application of Gompertz function in photohemolysis: the effect of temperature on red blood cell hemolysis photosensitized by protoporphyrin IX

IntroductionThe recently developed protoporphyrin IX-triple state lifetime technique measures mitochondrial oxygenation tension (mitoPO2) in vivo at the bedside. MitoPO2might be an early indicator of oxygen disbalance in cells of critically ill patients and therefore may support clinical decisions regarding red blood cell (RBC) transfusion. We aim to investigate the effect of RBC transfusion and the associated changes in haemoglobin concentration on mitoPO2 and other physiological measures of tissue oxygenation and oxygen balance in critically ill patients with anaemia. We present the protocol and pilot results for this study.Methods and analysisWe perform a prospective multicentre observational study in three mixed intensive care units in the Netherlands with critically ill patients with anaemia in whom an RBC transfusion is planned. The skin of the anterior chest wall of the patients is primed with a 5-aminolevulinic acid patch for 4 hours for induction of mitochondrial protoporphyrin-IX to enable measurements of mitoPO2, which is done with the COMET monitoring device. At multiple predefined moments, before and after RBC transfusion, we assess mitoPO2 and other physiological parameters of oxygen balance and tissue oxygenation. Descriptive statistics will be used to describe the data. A linear mixed-effect model will be used to study the association between RBC transfusion and mitoPO2 and other traditional parameters of oxygenation, oxygen delivery and oxygen balance. Missing data will be imputed using multiple imputation methods.Ethics and disseminationThe institutional ethics committee of each participating centre approved the study (reference P16.303), which will be conducted according to the 1964 Helsinki declaration and its later amendments. The results will be submitted for publication in peer-reviewed journals and presented at scientific conferences.Trial registration numberNCT03092297.

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A direct and simultaneous detection of zinc protoporphyrin IX, free protoporphyrin IX, and fluorescent heme degradation product in red blood cell hemolysates

Free Radical Research ◽

10.1080/10715760500522630 ◽

2006 ◽

Vol 40 (3) ◽

pp. 285-294 ◽

Cited By ~ 8

Author(s):

Qiuying Chen ◽

Rhoda Elison Hirsch

Keyword(s):

Blood Cell ◽

Red Blood Cell ◽

Degradation Product ◽

Simultaneous Detection ◽

Protoporphyrin Ix ◽

Zinc Protoporphyrin ◽

Heme Degradation

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Effect of Temperature and Flow Rate on the Cell-Free Area in the Microfluidic Channel

Membranes ◽

10.3390/membranes11020109 ◽

2021 ◽

Vol 11 (2) ◽

pp. 109

Author(s):

Angeles Ivón Rodríguez-Villarreal ◽

Manuel Carmona-Flores ◽

Jordi Colomer-Farrarons

Keyword(s):

Blood Cell ◽

Flow Rate ◽

Red Blood Cell ◽

Microfluidic Channel ◽

Cell Manipulation ◽

Effect Of Temperature ◽

Autologous Plasma ◽

Interesting Task ◽

Flow Rate Increase ◽

Free Area

Blood cell manipulation in microdevices is an interesting task for the separation of particles, by their size, density, or to remove them from the buffer, in which they are suspended, for further analysis, and more. This study highlights the cell-free area (CFA) widening based on experimental results of red blood cell (RBC) flow, suspended in a microfluidic device, while temperature and flow rate incrementally modify RBC response within the microflow. Studies of human red blood cell flow, at a concentration of 20%, suspended in its autologous plasma and phosphate-buffered saline (PBS) buffer, were carried out at a wide flow rate, varying between 10 and 230 μL/min and a temperature range of 23 °C to 50 °C. The plotted measures show an increment in a CFA near the channel wall due to cell flow inertia after a constricted channel, which becomes more significant as temperature and flow rate increase. The temperature increment widened the CFA up to three times. In comparison, flow rate increment increased the CFA up to 20 times in PBS and 11 times in plasma.

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