Treatment of Mild Traumatic Brain Injury with an Erythropoietin-Mimetic Peptide

Mild traumatic brain injury (mTBI) results in an estimated 75–90% of the 1.7 million TBI-related emergency room visits each year. Post-concussion symptoms, which can include impaired memory problems, may persist for prolonged periods of time in a fraction of these cases. The purpose of this study was to determine if an erythropoietin-mimetic peptide, pyroglutamate helix B surface peptide (pHBSP), would improve neurological outcomes following mTBI. Sixty-four rats were randomly assigned to pHBSP or control (inactive peptide) 30 μg/kg IP every 12 h for 3 days, starting at either 1 hour (early treatment) or 24 h (delayed treatment), after mTBI (cortical impact injury 3 m/sec, 2.5 mm deformation). Treatment with pHBSP resulted in significantly improved performance on the Morris water maze task. Rats that received pHBSP required 22.3±1.3 sec to find the platform, compared to 26.3±1.3 sec in control rats (p=0.022). The rats that received pHBSP also traveled a significantly shorter distance to get to the platform, 5.0±0.3 meters, compared to 6.1±0.3 meters in control rats (p=0.019). Motor tasks were only transiently impaired in this mTBI model, and no treatment effect on motor performance was observed with pHBSP. Despite the minimal tissue injury with this mTBI model, there was significant activation of inflammatory cells identified by labeling with CD68, which was reduced in the pHBSP-treated animals. The results suggest that pHBSP may improve cognitive function following mTBI

Morphological variation within an individual Pleistocene Diprotodon optatum Owen, 1838 (Diprotodontinae; Marsupialia): Implications for taxonomy within diprotodontoids

A comprehensive understanding of morphological and morphometrical variation for systematically important characters is a prerequisite for reliable taxonomic analyses of extinct morphospecies. However, perception of such variation is commonly limited due to a paucity of fossil material that forms the basis of such analyses. Here we report a new record of Pleistocene Diprotodon optatum Owen, 1838 (Diprotodontoidea) represented by near-complete upper tooth rows that exhibit a high degree of individual variation within systematically important upper premolars. The individual possesses features (e.g. development of parastyle, anterocristae and anterior longitudinal groove) that are considered to be close to the polar extremes of premolar variation within the morphospecies, but occurring on either side of the palate. Although such morphologies were previously recognized on the basis of isolated specimens, they have never been observed as having occurred on either side of the tooth row within a single indvidual. The observation of such extreme variation in premolar form within a single individual means that although the diprotodontoid P3 may serve some systematic importance in distinguishing certain taxa, the weight placed upon perceived differences within any single character of the premolar must be gauged by an understanding of broader variation within the group