The kinetics of colloid osmotic hemolysis. II. Photohemolysis

Pooler, John P.

doi:10.1016/0005-2736(85)90539-5

Cited by 43 publications

(38 citation statements)

References 19 publications

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“…Post-irradiation or ''DPH'' has been investigated in most experiments at different temperatures. The generally accepted colloidosmotic mechanism postulates that photochemical damage to the RBC membrane leads to cation efflux, followed by cell swelling and rupture [7,18]. The [4,6,11].…”

Section: Discussionmentioning

confidence: 99%

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

Al-Akhras

2006

Med Bio Eng Comput

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Photosensitization by protoporphyrin IX (PpIX) is accelerated at different irradiation temperatures, different dark incubation temperatures (Tinc) and different irradiation times. The applicability of Gompertz function to the fractional photohemolysis ratio, a and the rate of fractional photohemolysis, b is found to be the most appropriate model to fit the experimental data with minimum parameters and minimum errors. The reduction in Gompertz parameters, the fractional ratio values of a, and increase in the fractional rate values b, for 20 microM PpIX irradiated with black light at low irradiation temperature 5 degrees C and higher Tinc 37 degrees C was noticed. The parameter a has higher values at lower irradiation time and lower irradiation temperatures which indicates a longer photohemolysis process and longer t 50. Values of the parameter b were found to be strongly temperature-dependent, and always increase with increasing irradiation time and Tinc with lower values at lower irradiation time and lower Tinc. There are no significant changes in the lysis of RBCs process at irradiation temperatures equal to or higher than 35 degrees C. Similarly, no significant change on t50 at higher irradiation time at Tinc 24 and 37 degrees C. In conclusion, Gompertz analysis technique adapts to study the photohemolysis process at different conditions as a best-fit model.

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Section: Discussionmentioning

confidence: 99%

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

Al-Akhras

2006

Med Bio Eng Comput

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“…This model extends the colloidosmotic model [37] by attributing membrane rupture to the combined effects of cell swelling induced by damage to the anion transport protein and thermallyactivated photochemical damage to structural membrane proteins. The importance of the latter effect probably depends on the specific photosensitiser and the reaction conditions.…”

Section: Resultsmentioning

confidence: 99%

“…The colloid osmotic kinetics model of Pooler proposes a specific mechanism for the thermal stage of hemolysis based on changes of membrane permeability to sodium and potassium ions [37] . Further investigation based on osmotic fragility measurements has led to an osmolarity-dependent fractional lysis that simulated lysis curves.…”

Section: Resultsmentioning

confidence: 99%

In Vitro Studies on the Effect of Phototoxicity of A New Photosensitizer Extracted from Flowers and Aerial Parts of Cichorium pumilum

Al-Akhras¹,

Amin²,

Mohammad³

et al. 2007

American J. of Pharmacology and Toxicology

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New photosensitizers have been extracted from the flowers and aerial parts of the Cichorium Pumilum Jacq (chicory). Chicory grows naturally in local wild areas and is known to cause quick death of only white sheep during its flowering season in autumn. Some of those isolated photosensitizers are yet to be further characterized. Preliminary investigations show a high degradation of isolated photosensitizers under direct sunlight (solar irradiance 450-950W m¯2). This in vitro study also shows a very high photohemolysis rate at a concentration of 0.95 mg mL¯1. The extracted compounds are also found to be temperature dependent. Multiple absorption peaks are also shown for tested extract both in ultraviolet region (at the wavelengths 314, 360nm) and in the visible region (at 445, 492 and 667nm). Results of the present investigation clearly show the potential of the light-and temperature-dependent extracted compounds as a new member of the photodynamic therapeutics. It is possible therefore that the claimed chicory-induced death of white sheep is simply a direct result of phototoxicity.

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“…If ion permeable red cells were stored in a medium containing an impermeable sugar, such as sucrose, much of the hemolysis could be inhibited. Pooler (1985) demonstrated further, using a mathematic model, that hemolysis of ion permeable cells was colloidal osmotic in nature. At ionic equilibrium, there is a greater osmotic pressure intracellularly than extracellularly because of the intracellular osmotic agent, hemoglobin.…”

Section: Dimethylmethylene Bluementioning

confidence: 94%

“…Investigation of an alternative red cell additive solution that lacked the impermeable ion, citrate, resulted in much higher levels of hemolysis (25%) than a citrate-containing additive solution (2% hemolysis) (Wagner et al 2002c). The large difference in hemolysis levels of virucidally treated red cells stored in two different additive solutions may be explained by studies carried out by Pooler (1985). In those studies, red cells were treated with an agent that did not cause immediate hemolysis, but instead resulted in ionpermeable red cells.…”

Section: Dimethylmethylene Bluementioning

confidence: 95%

Investigation of photosensitizing dyes for pathogen reduction in red cell suspensions

Wagner

Skripchenko

2003

Biotechnic & Histochemistry

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Despite recent advances in blood safety by careful donor selection and implementation of infectious disease testing, transmission of viruses, bacteria and parasites by transfusion can still rarely occur. One approach to reduce the residual risk from currently tested pathogens and to protect against the emergence of new ones is to investigate methods for pathogen inactivation. The use of photosensitizing dyes for pathogen inactivation has been studied in both red cell and platelet blood components. Optimal properties of sensitizing dyes for use in red cell suspensions include selection of dyes that traverse cell and viral membranes, bind to nucleic acids, absorb light in the red region of the spectrum, inactivate a wide range of pathogens, produce little red cell photodamage from dye not bound to nucleic acid and do not hemolyze red cells in the dark. Early research at the American Red Cross focused on the use of a class of dyes with rigid structures, such as the phenothiazine dyes, beginning with the prototypical sensitizer methylene blue. Results revealed that methylene blue phototreatment could inactivate extracellular virus, but resulted in undesirable defects in the red cell membrane that resulted in enhanced hemolysis that became evident during extended refrigerated blood storage. In addition, methylene blue phototreatment could neither inactivate intracellular viruses nor appreciably inactivate bacteria under conditions of extracellualar viral killing. Attempts to improve intracellular viral inactivation led to the investigations of more hydrophobic phenothiazines, such as methylene violet or dimethylmethylene blue. Although these dyes could inactivate intracellular virus, problems with increased red cell membrane damage and hemolysis persisted or increased. Further studies using red cell additive storage solutions containing high levels of the impermeable ion, citrate, to protect against colloidal osmotic hemolysis as well as competitive inhibitors to limit sensitizer binding to red cell membranes revealed that photoinduced hemolysis stemmed from dye bound to the red cell membrane as well as dye free in solution. Use of red cell additive solutions to prevent colloidal-osmotic hemolysis and use of novel flexible dyes that only act as sensitizers when bound to their targets are two techniques that currently are under investigation for reducing red cell damage. Ultimately, the decision to implement a photodynamic method for pathogen reduction will be determined by weighing the risks of unintended adverse consequences of the procedure itself, such as the potential for genotoxicity and allergic reactions, against the cost and benefits of its implementation.

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The kinetics of colloid osmotic hemolysis. II. Photohemolysis

Cited by 43 publications

References 19 publications

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

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

In Vitro Studies on the Effect of Phototoxicity of A New Photosensitizer Extracted from Flowers and Aerial Parts of Cichorium pumilum

Investigation of photosensitizing dyes for pathogen reduction in red cell suspensions

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