Neurosurgery
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In the late 8th century, the stage for Viking expansion was set by commercial expansion in northwest Europe, the pressure of an increasing population in limited territorial reserves, and the development of the Viking ships. The Norsemen traveled extensively over the oceans, south to the Holy Land, and north to the White Sea and settled over a wide area from Sicily to Greenland. Historical sources, including the reports by Adam of Bremen and the Icelandic Sagas, describe several expeditions from Greenland to Vinland (somewhere along the east coast of North America) in approximately AD 1000 and later. ⋯ They also excavated a smithy, outdoor cooking pits, boathouses, a bathhouse, and enclosures for cattle, in addition to several Viking artifacts. The finds were C dated to AD 990 +/- 30. The present report reviews historical and archaeological evidence indicating the sites to which the Vikings traveled and attempted to settle in the new world.
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Comparative Study
Concussion in professional football: comparison with boxing head impacts--part 10.
This study addresses impact biomechanics from boxing punches causing translational and rotational head acceleration. Olympic boxers threw four different punches at an instrumented Hybrid III dummy and responses were compared with laboratory-reconstructed NFL concussions. ⋯ Olympic boxers deliver punches with high impact velocity but lower HIC and translational acceleration than in football impacts because of a lower effective punch mass. They cause proportionately more rotational acceleration than in football. Modeling shows that the greatest strain is in the midbrain late in the exposure, after the primary impact acceleration in boxing and football.
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There are few large-volume studies of the repair of complete missile-caused peroneal nerve and peroneal division lesions. In this prospective study, the outcomes of such repairs are studied and the factors influencing the outcomes are analyzed. ⋯ After peroneal nerve or peroneal division repairs, a successful outcome is most probable with low-level lesions repaired in the first 3 months after injury using grafts smaller than 4 cm. Conversely, high-level repairs delayed for more than 7 months after injury and using grafts larger than 8 cm are probably not worthwhile.
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Epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2) play a critical role in neurogenesis. In the present study, we evaluated the additive effect of administering these two factors on post-ischemic progenitor cell proliferation, survival, and phenotypic maturation in the hippocampal dentate gyrus (DG) and the subventricular zone (SVZ) in the adult rat brain after transient middle cerebral artery occlusion. ⋯ Specific growth factor infusion enhances post-ischemic progenitor cell proliferation by 5 days of reperfusion and neuronal maturation by 21 days of reperfusion in both the DG and SVZ in the adult rat brain.
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Delayed repair of peripheral nerve injuries often results in poor motor functional recovery. This may be a result of the deterioration or loss of endoneurial pathways in the distal nerve stump before motor axons can regenerate into the stump. ⋯ We conclude that even 2 months of denervation of the distal nerve pathway is deleterious to regeneration and that protection of the pathway improves subsequent reinnervation and regeneration. Moreover, if the desired regeneration is motor, protection of the distal nerve pathway by a motor nerve conditions is better than a sensory nerve.