Annals of biomedical engineering
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An important medical problem with high mortality is shock, sepsis and multi-organ failure. They have currently no treatments other than alleviation of symptoms. Shock is accompanied by strong markers for inflammation and involves a cascade of events that leads to failure in organs even if they are not involved in the initial insult. ⋯ Digestive enzymes also generate cytotoxic mediators, which together are transported into the systemic circulation via the portal venous system, the intestinal lymphatics and via the peritoneum. They cause various degrees of cell and organ dysfunction that can reach the point of complete organ failure. Blockade of digestive enzymes in the lumen of the intestine in experimental forms of shock serves to reduce breakdown of the mucosal barrier and autodigestion of the intestine, organ dysfunctions and mortality.
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Head impact exposure in youth football has not been well-documented, despite children under the age of 14 accounting for 70% of all football players in the United States. The objective of this study was to quantify the head impact exposure of youth football players, age 9-12, for all practices and games over the course of single season. A total of 50 players (age = 11.0 ± 1.1 years) on three teams were equipped with helmet mounted accelerometer arrays, which monitored each impact players sustained during practices and games. ⋯ While the acceleration magnitudes among 9-12 year old players tended to be lower than those reported for older players, some recorded high magnitude impacts were similar to those seen at the high school and college level. Head impact exposure in youth football may be appreciably reduced by limiting contact in practices. Further research is required to assess whether such a reduction in head impact exposure will result in a reduction in concussion incidence.
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Sports-related concussion is the most common athletic head injury with football having the highest rate among high school athletes. Traditionally, research on the biomechanics of football-related head impact has been focused at the collegiate level. Less research has been performed at the high school level, despite the incidence of concussion among high school football players. ⋯ The impact frequency was found to be greater during games compared to practices with an average number of impacts per session of 15.5 and 9.4, respectively. However, the median cumulative risk weighted exposure based on combined probability was found to be greater for practices vs. games. These data will provide a metric that may be used to better understand the cumulative effects of repetitive head impacts, injury mechanisms, and head impact exposure of athletes in football.
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Traumatic brain injury (TBI) resulting from explosive-related blast overpressure is a topic at the forefront of neurotrauma research. Compromise of the blood-brain barrier (BBB) and other cerebral blood vessel dysfunction is commonly reported in both experimental and clinical studies on blast injury. This study used a rifle primer-driven shock tube to investigate cerebrovascular injury in rats exposed to low-impulse, pure primary blast at three levels of overpressure (145, 232, and 323 kPa) and with three survival times (acute, 24, and 48 h). ⋯ The number and size of lesions increased with peak overpressure level, but no significant difference was seen between survival times. Despite laterally directed blast exposure, equal numbers of lesions were found in each hemisphere of the brain. These observations suggest that cerebrovascular injury due to primary blast is distinct from that associated with conventional TBI.
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Highly sensitive methods for the assessment of clot structure can aid in our understanding of coagulation disorders and their risk factors. Rapid and simple clot diagnostic systems are also needed for directing treatment in a broad spectrum of cardiovascular diseases. Here we demonstrate a method for micro-elastometry, named resonant acoustic spectroscopy with optical vibrometry (RASOV), which measures the clot elastic modulus (CEM) from the intrinsic resonant frequency of a clot inside a microwell. ⋯ Since CEM is known to primarily depend upon fibrin content and network structure, we investigated the CEM of purified clots formed with varying amounts of fibrinogen and thrombin. We found that RASOV was sensitive to changes of fibrinogen content (0.5-6 mg/mL), as well as to the amount of fibrinogen converted to fibrin during clot formation. We then simulated plasma hypercoagulability via hyperfibrinogenemia by spiking whole blood to 150 and 200% of normal fibrinogen levels, and subsequently found that RASOV could detect hyperfibrinogenemia-induced changes in CEM and distinguish these conditions from normal blood.