Publications by authors named "Nishaka William"

Background: The ACP 215 automated cell processor is used to glycerolize and deglycerolize red cell concentrates (RCCs). Its primary advantage over the COBE 2991, previously used to cryopreserve RCCs, is that it maintains a closed system enabling extended post-thaw expiry. However, it was observed that post-deglycerolization hematocrits (Hct) of units processed with the LN236 kit are markedly lower than those processed using the COBE 2991.

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Understanding red blood cell (RBC) subpopulations is crucial for comprehending donor variability and enhancing transfusion outcomes. This review highlights the significance of RBC subpopulations, focusing on the properties of biologically young and old RBCs and underscores how donor variability impacts transfusion outcomes. The role of senescent RBCs in adverse transfusion reactions and the emerging significance of circulating erythroid cells (CECs) is discussed.

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Red cell concentrate (RCC) cryopreservation allows for long-term storage of RCCs with rare phenotypes. Currently, tubing segments are not produced for these frozen units. Pre-transfusion compatibility testing therefore requires thawing and deglycerolization of the whole unit.

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Red blood cell (RBC) transfusions facilitate many life-saving acute and chronic interventions. Transfusions are enabled through the gold-standard hypothermic storage of RBCs. Today, the demand for RBC units is unfulfilled, partially due to the limited storage time, 6 weeks, in hypothermic storage.

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Granted with a potent ability to interact with and tolerate oxidative stressors, RBCs scavenge most reactive oxygen and nitrogen species (RONS) generated in circulation. This essential non-canonical function, however, renders RBCs susceptible to damage when vascular RONS are generated in excess, making vascular redox imbalance a common etiology of anemia, and thus a common indication for transfusion. This accentuates the relevance of impairments in redox metabolism during hypothermic storage, as the exposure to chronic oxidative stressors upon transfusion could be exceedingly deleterious to stored RBCs.

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Donor sex can alter the RBC 'storage lesion' progression, contributing to dissimilarities in blood product quality, and thus adverse post-transfusion reactions. The mechanisms underlying the reduced sensitivity of female RBCs to storage-induced stress are partially ascribed to the differential effects of testosterone, progesterone, and estrogen on hemolytic propensity. Contributing to this is the increased proportion of more robust, biologically 'young' subpopulations of RBCs in females.

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Transfusion of red blood cells (RBCs) is one of the most valuable and widespread treatments in modern medicine. Lifesaving RBC transfusions are facilitated by the cold storage of RBC units in blood banks worldwide. Currently, RBC storage and subsequent transfusion practices are performed using simplistic workflows.

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Adenosine triphosphate (ATP) levels guide many aspects of the red blood cell (RBC) hypothermic storage lesions. As a result, efforts to improve the quality of hypothermic-stored red cell concentrates (RCCs) have largely centered around designing storage solutions to promote ATP retention. Considering reduced temperatures alone would diminish metabolism, and thereby enhance ATP retention, we evaluated: (a) whether the quality of stored blood is improved at -4°C relative to conventional 4°C storage, and (b) whether the addition of trehalose and PEG400 can enhance these improvements.

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Respiratory transfusion reactions represent some of the most severe adverse reactions related to receiving blood products. Of those, transfusion-related acute lung injury (TRALI) is associated with elevated morbidity and mortality. TRALI is characterized by severe lung injury associated with inflammation, pulmonary neutrophil infiltration, lung barrier leak, and increased interstitial and airspace edema that cause respiratory failure.

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One of the greatest concerns in the subzero storage of cells, tissues, and organs is the ability to control the nucleation or recrystallization of ice. In nature, evidence of these processes, which aid in sustaining internal temperatures below the physiologic freezing point for extended periods of time, is apparent in freeze-avoidant and freeze-tolerant organisms. After decades of studying these proteins, we now have easily accessible compounds and materials capable of recapitulating the mechanisms seen in nature for biopreser-vation applications.

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Background: Circulating CD71 red blood cells (RBCs) have been reported to play an immunomodulatory role in vivo, which may contribute to adverse donor-recipient sex-mismatched transfusion outcomes. However, it is not clear how CD71 RBC quantity in red cell concentrates (RCCs) is affected by manufacturing methods and donor factors such as donor sex, donor age, pre-donation hemoglobin (Hb), venous Hb (Hb ) levels, and donation frequency.

Methods: We determined CD71 RBCs and Hb levels in whole blood (WB) from healthy donors (42 male/38 female).

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Background: Preparing small-dose red cell concentrates (RCCs) is a common practice for pediatric and neonatal transfusions. However, there is a lack of quality monitoring data to indicate that both the preparation and storage of small-dose RCCs does not alter in vitro red cell quality. The present study seeks to provide data to support this practice.

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Dimethyl sulphoxide (DMSO) used in haematopoietic stem cell (HSC) cryopreservation has been linked to an increased incidence of adverse reactions following transplantation. In the interest of reducing the required DMSO concentrations, we have evaluated the use of unilamellar liposomes to internalize the non-toxic, cell-impermeable disaccharide, trehalose into HSCs and characterized the cryoprotective efficacy of this strategy. A fluorescent marker, 5(6)-carboxyfluorescein (200 μmol/L), was used for trehalose internalization following a 5 h incubation at 37 °C with liposome concentrations ranging from 0.

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Background: Gamma irradiation of red cell concentrates (RCCs) is regularly used to prevent transfusion-associated graft-versus-host disease (TA-GvHD) in at-risk patients. While studies have indicated that irradiated RCCs exhibit increased hemolysis, there have been no efforts to differentiate between free- and microvesicle (MV)-bound hemoglobin (Hb). As an increase in the proportion of free-Hb in irradiated RCCs could alter vascular function, we sought to characterize differences in the state of extracellular Hb based on the timing of irradiation.

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In recent years there have been several advancements in organ preservation that have yet to see widespread clinical translation. While static cold storage (SCS) at 2 °C-4 °C continues to be the state-of-the-art strategy, it contributes to the current shortage of transplantable organs due to the limited preservation times it affords combined with the limited ability of marginal grafts to tolerate SCS. The era of optimizing storage solutions to minimize SCS-induced hypothermic injury has largely plateaued in its improvements, resulting in a shift towards the use of machine perfusion systems to provide continuous metabolic support, or the use of sub-zero storage temperatures to leverage the protection brought forth by a reduction in metabolic demand.

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Immediate post-thaw evaluation of membrane integrity has proven to yield overestimates of cell survival under conditions that preclude intracellular ice formation (IIF). However, prominent theories on the mechanisms of intracellular nucleation suggest a damaged membrane can reseal, prompting us to evaluate whether immediate post-thaw assessments of membrane integrity can in fact underestimate cell survival under conditions that promote IIF. HUVEC and HepG2 monolayers were treated with 1.

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To promote the recovery of cells that undergo intracellular ice formation (IIF), it is imperative that the recrystallization of intracellular ice is minimized. Hepatocytes are more prone to IIF than most mammalian cells, and thus we assessed the ability of novel small molecule carbohydrate-based ice recrystallization inhibitors (IRIs) to permeate and function within hepatocytes. HepG2 monolayers were treated with N-(4-chlorophenyl)-d-gluconamide (IRI 1), N-(2-fluorophenyl)-d-gluconamide (IRI 2), or para-methoxyphenyl-β-D-glycoside (IRI 3) and fluorescent cryomicroscopy was used for real time visualization of intracellular ice recrystallization.

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Minimizing ice recrystallization injury in tissues and organs has historically been sought using biological antifreeze proteins. However, the size of these compounds can limit permeation and their potential immunogenicity disqualifies them from use in several cryopreservation applications. Novel small molecule carbohydrate-derived ice recrystallization inhibitors (IRIs) are not subject to these constraints, and thus we sought to evaluate the ability of a highly active IRI to permeate liver tissue and control recrystallization.

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While various fixation techniques for observing ice within tissues stored at high sub-zero temperatures currently exist, these techniques require either different fixative solution compositions when assessing different storage temperatures or alteration of the sample temperature to enable alcohol-water substitution. Therefore, high-subzero cryofixation (HSC), was developed to facilitate fixation at any temperature above -80 °C without sample temperature alteration. Rat liver sections (1 cm) were frozen at a rate of -1 °C/min to -20 °C, stored for 1 h at -20 °C, and processed using classical freeze-substitution (FS) or HSC.

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