Platelet dysfunction reversal with cold-stored vs room temperature-stored platelet transfusions.

ABSTRACT: Platelets are stored at room temperature for 5 to 7 days (room temperature-stored platelets [RSPs]). Because of frequent and severe shortages, the US Food and Drug Administration recently approved up to 14-day cold-stored platelets (CSPs) in plasma. However, the posttransfusion function of CSPs is unknown and it is unclear which donors are best suited to provide either RSPs or CSPs. In this study, we sought to evaluate the posttransfusion platelet function and its predictors for platelets stored for the maximum approved storage times (7-day RSPs and 14-day CSPs) in healthy volunteers on acetylsalicylic acid (ASA). We conducted a randomized crossover study in 10 healthy humans. Individuals donated 1 platelet unit, stored at either 22°C or 4°C based on randomization. Before transfusion, participants ingested ASA to inhibit endogenous platelets. Transfusion recipients were tested for platelet function and lipid mediators. Platelet units were tested for lipid mediators only. A second round of transfusion with the alternative product was followed by an identical testing sequence. RSPs reversed platelet inhibition significantly better in αIIbß3 integrin activation-dependent assays. In contrast, CSPs in recipients led to significantly more thrombin generation, which was independent of platelet microparticles. Lysophosphatidylcholine-O species levels predicted the procoagulant capacity of CSPs. In contrast, polyunsaturated fatty acid concentrations predicted the aggregation response of RSPs. In summary, we provide, to our knowledge, the first efficacy data of extended-stored CSPs in plasma. Our results suggest that identifying ideal RSP and CSP donors is possible, and pave the way for larger studies in the future. This trial is registered at www.ClinicalTrials.gov as #NCT0511102.

The Influence of Goal Commitment and Partner Status on Team Assignment Outcomes.

The present study replicated and extended research on the influence of team assignment methods on task performance and fairness perceptions. This study examined the influence of team assignment methods, goal commitment, and partner status on team member performance and fairness perceptions in a laboratory setting. The assignment conditions were comprised of three variables: assignment method (random, self-decision, and ability), performer status (assigned or unassigned), and partner status (unassigned team member stayed or left during task performance). A significant interaction was found between assignment method and performer status when the unassigned team member left during task performance, but not when the unassigned team member stayed. Random and self-decision assignment methods resulted in higher levels of goal commitment and task performance than did ability-based assignment conditions. Lastly, goal commitment was found to mediate the relationship between assignment method and task performance. The implications of these findings for the task performance and organizational justice literatures, as well as for managers in general, are discussed.

Perception in consequences of free riding.

This study examined the relationships between perceptions of group members' free riding and group outcomes using Mulvey and Klein's 1998 perceived free riding scale. In a laboratory study, three free riding conditions were created (no free riding, free riding, free riding with justification) in which 97 college students performed two short number-finding tasks as members of temporary ad hoc three-person groups. 55% of the students were male and the average age was 22.9 yr. (SD= 3.0). Participants' perceptions of free riding were negatively related to commitment to the assigned group goal, task performance, and goals for group performance and individual performance. In the condition wherein free riding was justified by low ability, participants set lower goals for their future task performance than did those in the other two conditions.