When do benefits turn to risks? Impact of a 900 mL whole blood donation on Special Forces performance.

BACKGROUND: Special Forces (SF) teams operate in remote environments with limited medical support. As a result, they may need to rely on buddy transfusions to treat bleeding teammates. Considering that 450 mL has no direct impact on their combat performances, it might be tempting to take more blood from a compatible donor to save a hemorrhaging teammate. This study investigates the effect of a 900 mL blood donation on SF operator performance and recovery time following this donation. STUDY DESIGN AND METHODS: Participants underwent a multifactorial assessment including measures of physiological parameters, vigilance, and physical performance. Results from the day of blood donation were compared with baseline values obtained 1 week earlier (i.e., immediate effect), as well as repeated testing at 7, 14, and approximately 30 days after blood donation (i.e., recovery period). RESULTS: Hemoglobin levels and heart rate were affected by giving blood. The participants also experienced a significant decrease in physical performance of more than 50% immediately after blood donation. Recovery was slow over the following weeks, remaining significantly different from baseline until full recovery around day 30. However, participants were still able to respond to a simple stimulus and adjust their response, if necessary, even immediately after donating blood. DISCUSSION: A 900 mL blood donation greatly affects the physical fitness of SF operators. A donation may be worthwhile if it is the only life-saving procedure available and does not endanger the donor's life. The donor would then become a patient and unable to complete the mission.

Quantitative real-time RT-PCR analysis in desert locusts reveals phase dependent differences in neuroparsin transcript levels.

In different parts of the world, locust swarms cause severe ecological and economic damage. However, the physiological mechanisms underlying this gregarization process remain elusive. In this study, we present a detailed quantitative analysis of two neuroparsin precursor (Scg-NPP1 and Scg-NPP2) transcripts in the brain, fat body, gut, gonads and accessory glands of male and female, gregarious and solitarious desert locusts (Schistocerca gregaria). These transcripts are generally more abundant in solitarious than in gregarious animals. In contrast to their gregarious congeners, solitarious locusts contain detectable Scg-NPP1 and Scg-NPP2 transcript levels in the fat body. Moreover, our data reveal temporal changes of neuroparsin mRNA levels in the brains and fat bodies of adult isolated-reared locusts. This paper provides the first scientific evidence for phase-dependent transcriptional regulation of neuropeptide hormone encoding genes.