BACKGROUND Transitioning from whole blood (WB) to components developed from efforts to maximize donor yield. Components are advantageous for specific derangements, but treating hemorrhage with components requires significantly more volume to provide similar effects to WB. Because storage lesion and waste remain problematic, this study examined hemostatic function of refrigerated WB stored for 35 days in anticoagulants citrate–phosphate‐dextrose‐adenosine (CPDA‐1), citrate–phosphate‐dextrose (CPD), or citrate–phosphate‐double dextrose (CP2D). METHODS Refrigerated WB units from healthy donors were sampled over 35 days. Global hemostatic parameters were measured by thromboelastometry, thrombogram, platelet aggregometry, and platelet adhesion to collagen under shear conditions. The effects of transfusion filtration and mixing 35‐day stored product with fresh WB were evaluated. RESULTS Countable platelets declined as aggregation clusters appeared in microscopy. While gross platelet agonist‐induced aggregation declined over time, normalization revealed aggregation responses in remaining platelets. Peak thrombin generation increased over time. Clot strength diminished over storage in tissue factor–activated samples (normalized by filtration of aggregates). Functional fibrinogen responses remained consistent throughout. Filtration was necessary to maintain consistent platelet adhesion to collagen beyond collection day. Few differences were observed between anticoagulants, and stored/fresh mixing studies normalized coagulation parameters. CONCLUSIONS WB is easier to collect, store, and transfuse. WB provides platelets, an oft‐neglected, critical resuscitation component, but their individual numbers decline as aggregates appear, resulting in diminished coagulation response. WB has better performance in these assays when examined at earlier time points, but expirations designated to specific anticoagulants appear arbitrary for hemostatic functionality, as little changes beyond 21 days regardless of anticoagulant.

The infection of Escherichia coli cells by bacteriophage lambda results in bifurcated means of propagation, where the phage decides between the lytic and lysogenic pathways. Although traditionally thought to be mutually exclusive, increasing evidence suggests that this lysis‐lysogeny decision is more complex than once believed, but exploring its intricacies requires an improved resolution of study. Here, with a newly developed fluorescent reporter system labeling single phage and E. coli DNAs, these two distinct pathways can be visualized by following the DNA movements in vivo. Surprisingly, we frequently observed an interesting “lyso‐lysis” phenomenon in lytic cells, where phage integrates its DNA into the host, a characteristic event of the lysogenic pathway, followed by cell lysis. Furthermore, the frequency of lyso‐lysis increases with the number of infecting phages, and specifically, with CII activity. Moreover, in lytic cells, the integration site attB on the E. coli genome migrates toward the polar region over time, leading to more spatial overlap with the phage DNA and frequent colocalization/collision of attB and phage DNA, possibly contributing to a higher chance for DNA integration.

Background: Platelets pose the greatest transfusion-transmitted infectious risk among blood products. Refrigeration of platelets can mitigate bacterial contamination and extend platelet shelf life. Implementation of pathogen reduction technologies (PRTs) at blood banks has become increasingly popular to protect against emerging and reemerging infectious diseases. In this study, we sought to evaluate the effects of Intercept PRT on platelets collected on different platforms and cold-stored for up to 21 days in plasma and platelet additive solution (PAS). Methods: Double-dose apheresis platelets were collected with use of a Trima or Amicus system into either 100% plasma or 65% InterSol PAS/35% plasma and split equally between two bags. One bag served as control, while the other received Intercept PRT treatment. Bags were stored unagitated in the cold and evaluated on Days 1, 7, 14, and 21 to assess platelet metabolism, activation, aggregation, and clot formation and retraction. Results: By Day 14 of storage, lactate levels reached approximately 13 mmol/L for all samples irrespective of Intercept treatment. Mean clot firmness dropped from the 62.2-to 67.5-mm range (Day 1) to the 28.4-to 51.3-mm range (Day 21), with no differences observed between groups. Clot weights of Intercepttreated Trima/plasma samples were significantly higher than control by Day 14 of storage (P = .004), indicating a reduced clot retraction function. Intercept treatment caused a higher incidence of plasma membrane breakdown in plasma-stored platelets (P = .0013; Trima/plasma Day 14 Control vs Intercept). Conclusions: Intercept treatment of platelets and subsequent cold storage, in plasma or PAS, results in comparable platelet metabolism platelets for up to 14 days of storage but altered clotting dynamics. Pathogen-reduced platelets with an extended shelf life would be beneficial for the deployed setting and would greatly impact transfusion practice among civilian transfusion centers.

Diagnostic test, level III.

BACKGROUND Cryoprecipitate's shelf life is limited due to concerns over decreased clotting factor activity and contamination with extended storage. Hemostatic characteristics of thawed cryoprecipitate stored up to 35 days at refrigerated and room temperatures were assessed. STUDY DESIGN AND METHODS Pooled cryoprecipitate was thawed and aliquoted for storage at 1–6°C or 21–24°C. Samples were tested immediately after thawing and at 4 h, 24 h, 72 h, and weekly for 35 days. At each time point fibrinogen, factor VIII (FVIII), and von Willebrand factor (vWF) were assessed. Thrombin generation and rotational thromboelastometry (ROTEM) were also performed. Further, packed red cells, platelet concentrates, frozen plasma, and stored cryoprecipitate were combined (1:1:1:1) to simulate massive transfusion and analyzed by ROTEM. Day 35 samples were cultured for bacterial contamination. RESULTS Precipitation was observed in refrigerated samples; however, these aggregates were easily resuspended upon warming in a 37°C water bath. No significant changes were observed in fibrinogen concentration or ROTEM at either temperature. FVIII and vWF declined significantly during storage. vWF, clot time, and thrombin generation were significantly better preserved with refrigeration. With simulated massive transfusion, fibrinogen function remained at or above the established range for whole blood at both storage temperatures. Bacterial contamination was not observed in cold stored or room temperature cryoprecipitate. CONCLUSION The fibrinogen concentration and function of cryoprecipitate at extended storage durations are adequate for fibrinogen replacement in critical bleeding. These results support extension of the shelf life of cryoprecipitate when used for fibrinogen replacement.