Evaluation of interventions to prevent vasovagal reactions among whole blood donors: rationale and design of a large cluster randomised trial.

BACKGROUND: Vasovagal reactions (VVRs) are the most common acute complications of blood donation. Responsible for substantial morbidity, they also reduce the likelihood of repeated donations and are disruptive and costly for blood services. Although blood establishments worldwide have adopted different strategies to prevent VVRs (including water loading and applied muscle tension [AMT]), robust evidence is limited. The Strategies to Improve Donor Experiences (STRIDES) trial aims to reliably assess the impact of four different interventions to prevent VVRs among blood donors. METHODS: STRIDES is a cluster-randomised cross-over/stepped-wedge factorial trial of four interventions to reduce VVRs involving about 1.4 million whole blood donors enrolled from all 73 blood donation sites (mobile teams and donor centres) of National Health Service Blood and Transplant (NHSBT) in England. Each site ("cluster") has been randomly allocated to receive one or more interventions during a 36-month period, using principles of cross-over, stepped-wedge and factorial trial design to assign the sequence of interventions. Each of the four interventions is compared to NHSBT's current practices: (i) 500-ml isotonic drink before donation (vs current 500-ml plain water); (ii) 3-min rest on donation chair after donation (vs current 2 min); (iii) new modified AMT (vs current practice of AMT); and (iv) psychosocial intervention using preparatory materials (vs current practice of nothing). The primary outcome is the number of in-session VVRs with loss of consciousness (i.e. episodes involving loss of consciousness of any duration, with or without additional complications). Secondary outcomes include all in-session VVRs (i.e. with and without loss of consciousness), all delayed VVRs (i.e. those occurring after leaving the venue) and any in-session non-VVR adverse events or reactions. DISCUSSION: The STRIDES trial should yield novel information about interventions, singly and in combination, for the prevention of VVRs, with the aim of generating policy-shaping evidence to help inform blood services to improve donor health, donor experience, and service efficiency. TRIAL REGISTRATION: ISRCTN: 10412338. Registration date: October 24, 2019.

Enhanced Memory for Fair-Related Faces and the Role of Trait Anxiety.

The current research examined whether fair consideration-a social norm that people inherently prefer to confirm-would modulate face recognition. Each neutral face was associated with fair or unfair offers via an economic decision task, the Ultimatum Game (UG) task. After the UG, participants were asked to identify the faces of proposers who made different offers. Enhanced memory was observed for fair-related compared to unfair-related faces. Furthermore, high trait anxiety was associated with reduced memory for fair-related faces. These results were further confirmed by signal detection theory. The current research provided initial evidence that people showed enhanced memory for faces that made fair offers from the economic decision task, and that high trait anxiety was associated with reduced fair-related memory. Possible neural mechanisms and the implication in economic and social situations have been discussed.

A prostaglandin D-synthase-positive mast cell gradient characterizes scalp patterning.

BACKGROUND: Pattern (androgenetic) alopecia is commonly encountered in scalp biopsies obtained for non-scarring hair loss. Prostaglandin D-synthase is known to be elevated in bald vs. non-alopetic scalp of patients with androgenetic alopecia. We hypothesized that this difference in pattern of prostaglandin D-synthase expression may constitute a developmental pattern inherent to normal as well as alopecic scalp skin, thus defining a 'field' vulnerable to acquired hair loss. METHODS: We immunohistochemically mapped prostaglandin D-synthase expression from supra-auricular to vertex scalp skin of 11 cadavers. RESULTS: We found significantly more dermal mast cells immunoreactive for prostaglandin D-synthase in the vertex compared to the lateral aspects of the scalp, with a decrement that spatially approximated the pattern of androgenetic alopecia. This difference was present in both balding and non-balding scalps and was independent of gender. Dual labeling established dermal cells expressing prostaglandin D-synthase as mast cells. CONCLUSIONS: These data indicate that scalp is spatially programmed via mast cell prostaglandin D-synthase distribution in a manner reminiscent of the pattern seen in androgenetic alopecia.