Publications by authors named "Jason Acker"

Introduction: Granulocyte concentrates (GC) are leukocyte preparations enriched in neutrophils that can potentially save neutropenic patients from life-threatening, antimicrobial-resistant infections. The main challenge of GC transfusions is preserving the viability and antimicrobial activity of neutrophils beyond 24 h to reduce the logistical burden on collection centers and increase the availability of this cell therapy. Thus, the aim of this study was to explore extending the ex vivo viability and antimicrobial activity of GC neutrophils up to 72 h with a unique combination of the clinically-approved additives Plasma-Lyte, SAGM, AS-3 and Alburex.

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Background: The effect of a liberal red-cell transfusion strategy as compared with a restrictive strategy in patients during the critical care period after an aneurysmal subarachnoid hemorrhage is unclear.

Methods: We randomly assigned critically ill adults with acute aneurysmal subarachnoid hemorrhage and anemia to a liberal strategy (mandatory transfusion at a hemoglobin level of ≤10 g per deciliter) or a restrictive strategy (optional transfusion at a hemoglobin level of ≤8 g per deciliter). The primary outcome was an unfavorable neurologic outcome, defined as a score of 4 or higher on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability) at 12 months.

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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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Variation in the quality of stored red cell concentrates (RCCs) has been linked to the biological age distribution of red blood cell (RBCs) subpopulations within blood products. Teen male RCCs contain higher proportions of biologically old RBC subpopulations, with poorer quality. This study sought to assess the contribution of donor sex and age on the deformability characteristics of different ages of RBC subpopulations in stored RCCs.

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Article Synopsis
  • Red cell concentrates (RCCs) at Canadian Blood Services can be stored for up to 10 years, but accidental warming above -65°C can lead to their discard to prevent issues during transfusion.
  • A study tested 30 RCCs that experienced warming events of different durations, comparing their quality after thawing to 10 control samples that were not warmed.
  • Results showed that RCCs with a single warming event maintained quality similar to controls, suggesting policies could allow for the retention of these units rather than automatic disposal.
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The successful use of human induced pluripotent stem cells (iPSCs) for research or clinical applications requires the development of robust, efficient, and reproducible cryopreservation protocols. After cryopreservation, the survival rate of iPSCs is suboptimal and cell line-dependent. We assessed the use of ice recrystallization inhibitors (IRIs) for cryopreservation of human iPSCs.

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Background: Despite preterm newborns often requiring blood transfusions, we have an incomplete understanding of the impact of adult packed red blood cell (pRBC) transfusions on fetal red blood cell (RBC) oxygen affinity. We investigated the influence of adult pRBC on oxygen binding in fetal RBCs obtained from the umbilical cord of preterm newborns. This included exploring the influence of the biological age of adult pRBCs on the oxygen affinity of fetal blood.

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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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This Editorial introduces and contextualizes the papers of the Virtual Special Issue: Advancing the Cryopreservation of Cells, Tissues and Organs Using Model Biological Systems.

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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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Red blood cell (RBC) transfusion is a critical therapy for those with sickle cell disease (SCD). Alloimmunization is frequent for those with SCD and may limit the availability of matched RBC. Cryopreserved RBCs, from family members or donors with a similar RBC antigen profile could provide a viable alternative to avoid further alloimmunization and prevent hemolytic transfusion-related events.

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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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RBC transfusions are a vital clinical therapy to treat anemic patients. The in vivo assessment of red blood cell (RBC) quality post-transfusion is critical to ensuring that the introduction of new RBC products meet established regulatory and clinical quality requirements. Although in vitro quality control testing is routinely performed by blood manufacturers, it is crucial that in vivo tests are performed during the evaluation and regulatory process of new RBC products.

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Background: Donors possess heterogeneous red cell concentrates (RCCs) in terms of the biological age of their red blood cells (RBCs) as a direct result of various donor-dependent factors influencing rates of erythropoiesis. This study aimed to estimate the median biological age of RBCs in RCCs based on donor age and sex to investigate inherent differences in blood products' biological ages over hypothermic storage using estimated median densities (EMDs).

Study Design: Sixty RCCs were collected from four donor groups; male and female teenagers (17-19 years old) and seniors (75+ years old).

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Background And Objectives: Donor factors influence the quality characteristics of red cell concentrates (RCCs) and the lesions that develop in these heterogeneous blood products during hypothermic storage. Teen male donors' RCCs contain elevated levels of biologically old red blood cells (RBCs). The aim of this study was to interrogate the quality of units of different donor ages and sexes to unravel the complex interplay between donor characteristics, long-term cold storage and, for the first time, RBC biological age.

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Article Synopsis
  • Doctors have gotten better at taking care of injured patients both before they reach the hospital and in the emergency room, which helps them live longer.
  • However, many people still die from bleeding because there aren't enough treatments specifically for it.
  • There are also big gaps in understanding how injuries affect the body’s response, so researchers are looking for new ways to improve treatments for trauma in the future.
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Transfusion of red blood cells (RBCs) has been associated with adverse outcomes. Mechanisms may be related to donor sex and biological age of RBC. This study hypothesized that receipt of female blood is associated with decreased post-transfusion recovery (PTR) and a concomitant increased organ entrapment in rats, related to young age of donor RBCs.

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Background: Severe T-cell lymphopenia of uncertain clinical significance has been observed in frequent apheresis platelet donors. Two commonly used plateletpheresis instruments are the Trima Accel, which uses a leukoreduction system (LRS) chamber to trap leukocytes and the Fenwal Amicus, which does not use an LRS chamber.

Study Design And Methods: We performed an international, multicenter, observational study comparing T-cell populations in frequent platelet donors collected exclusively using the Trima instrument (n = 131) or the Amicus instrument (n = 77).

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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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Article Synopsis
  • Teenagers (16-19 years) and older adults (≥75 years) are both at risk of iron deficiency and anemia as blood donors, but are underrepresented in research on red blood cell (RBC) transfusion effectiveness.
  • This study assessed the quality of RBC concentrates from 150 donors in these age groups, focusing on various measures of RBC health and characteristics, such as hemolysis and bioactivity.
  • Results showed that RBCs from teenage donors had different physical traits compared to those from older donors, including higher susceptibility to oxidative hemolysis, impacting their storage and transfusion outcomes.
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