129 research outputs found
A Climate History of Boone County, Missouri, From Tree-Ring Analysis of Eastern Redcedar
A ring-width index, constructed from analyses of eastern redcedar (Juniperus virginiana L.) trees, for central Boone County, Missouri, is presented. Correlations between summer temperatures, spring rainfall and the index are shown. Some possible interpretations of past climate history, based on the index, are listed for selected time periods back to 1650 AD
Whole Blood Resuscitation and Association with Survival in Injured Patients with an Elevated Probability of Mortality.
BACKGROUND: Low-titer group O whole blood (LTOWB) resuscitation is becoming common in both military and civilian settings and may represent the ideal resuscitation intervention. We sought to characterize the safety and efficacy of LTOWB resuscitation relative to blood component resuscitation.
STUDY DESIGN: A prospective, multicenter, observational cohort study was performed using 7 trauma centers. Injured patients at risk of massive transfusion who required both blood transfusion and hemorrhage control procedures were enrolled. The primary outcome was 4-hour mortality. Secondary outcomes included 24-hour and 28-day mortality, achievement of hemostasis, death from exsanguination, and the incidence of unexpected survivors.
RESULTS: A total of 1,051 patients in hemorrhagic shock met all enrollment criteria. The cohort was severely injured with \u3e70% of patients requiring massive transfusion. After propensity adjustment, no significant 4-hour mortality difference across LTOWB and component patients was found (relative risk [RR] 0.90, 95% CI 0.59 to 1.39, p = 0.64). Similarly, no adjusted mortality differences were demonstrated at 24 hours or 28 days for the enrolled cohort. When patients with an elevated prehospital probability of mortality were analyzed, LTOWB resuscitation was independently associated with a 48% lower risk of 4-hour mortality (relative risk [RR] 0.52, 95% CI 0.32 to 0.87, p = 0.01) and a 30% lower risk of 28-day mortality (RR 0.70, 95% CI 0.51 to 0.96, p = 0.03).
CONCLUSIONS: Early LTOWB resuscitation is safe but not independently associated with survival for the overall enrolled population. When patients were selected with an elevated probability of mortality based on prehospital injury characteristics, LTOWB was independently associated with a lower risk of mortality starting at 4 hours after arrival through 28 days after injury
Early Cold Stored Platelet Transfusion Following Severe Injury: A Randomized Clinical Trial
OBJECTIVE: To determine the feasibility, efficacy, and safety of early cold stored platelet transfusion compared with standard care resuscitation in patients with hemorrhagic shock.
BACKGROUND: Data demonstrating the safety and efficacy of early cold stored platelet transfusion are lacking following severe injury.
METHODS: A phase 2, multicenter, randomized, open label, clinical trial was performed at 5 US trauma centers. Injured patients at risk of large volume blood transfusion and the need for hemorrhage control procedures were enrolled and randomized. The intervention was the early transfusion of a single apheresis cold stored platelet unit, stored for up to 14 days versus standard care resuscitation. The primary outcome was feasibility and the principal clinical outcome for efficacy and safety was 24-hour mortality.
RESULTS: Mortality at 24 hours was 5.9% in patients who were randomized to early cold stored platelet transfusion compared with 10.2% in the standard care arm (difference, -4.3%; 95% CI, -12.8% to 3.5%; P =0.26). No significant differences were found for any of the prespecified ancillary outcomes. Rates of arterial and/or venous thromboembolism and adverse events did not differ across treatment groups.
CONCLUSIONS AND RELEVANCE: In severely injured patients, early cold stored platelet transfusion is feasible, safe and did not result in a significant lower rate of 24-hour mortality. Early cold stored platelet transfusion did not result in a higher incidence of arterial and/or venous thrombotic complications or adverse events. The storage age of the cold stored platelet product was not associated with significant outcome differences
Rapid production of human liver scaffolds for functional tissue engineering by high shear stress oscillation-decellularization
The development of human liver scaffolds retaining their 3-dimensional structure and extra-cellular matrix (ECM) composition is essential for the advancement of liver tissue engineering. We report the design and validation of a new methodology for the rapid and accurate production of human acellular liver tissue cubes (ALTCs) using normal liver tissue unsuitable for transplantation. The application of high shear stress is a key methodological determinant accelerating the process of tissue decellularization while maintaining ECM protein composition, 3D-architecture and physico-chemical properties of the native tissue. ALTCs were engineered with human parenchymal and non-parenchymal liver cell lines (HepG2 and LX2 cells, respectively), human umbilical vein endothelial cells (HUVEC), as well as primary human hepatocytes and hepatic stellate cells. Both parenchymal and non-parenchymal liver cells grown in ALTCs exhibited markedly different gene expression when compared to standard 2D cell cultures. Remarkably, HUVEC cells naturally migrated in the ECM scaffold and spontaneously repopulated the lining of decellularized vessels. The metabolic function and protein synthesis of engineered liver scaffolds with human primary hepatocytes reseeded under dynamic conditions were maintained. These results provide a solid basis for the establishment of effective protocols aimed at recreating human liver tissue in vitro
Accounting for Ecosystem Alteration Doubles Estimates of Conservation Risk in the Conterminous United States
Previous national and global conservation assessments have relied on habitat conversion data to quantify conservation risk. However, in addition to habitat conversion to crop production or urban uses, ecosystem alteration (e.g., from logging, conversion to plantations, biological invasion, or fire suppression) is a large source of conservation risk. We add data quantifying ecosystem alteration on unconverted lands to arrive at a more accurate depiction of conservation risk for the conterminous United States. We quantify ecosystem alteration using a recent national assessment based on remote sensing of current vegetation compared with modeled reference natural vegetation conditions. Highly altered (but not converted) ecosystems comprise 23% of the conterminous United States, such that the number of critically endangered ecoregions in the United States is 156% higher than when calculated using habitat conversion data alone. Increased attention to natural resource management will be essential to address widespread ecosystem alteration and reduce conservation risk
Whole-body tissue stabilization and selective extractions via tissue-hydrogel hybrids for high-resolution intact circuit mapping and phenotyping
To facilitate fine-scale phenotyping of whole specimens, we describe here a set of tissue fixation-embedding, detergent-clearing and staining protocols that can be used to transform excised organs and whole organisms into optically transparent samples within 1–2 weeks without compromising their cellular architecture or endogenous fluorescence. PACT (passive CLARITY technique) and PARS (perfusion-assisted agent release in situ) use tissue-hydrogel hybrids to stabilize tissue biomolecules during selective lipid extraction, resulting in enhanced clearing efficiency and sample integrity. Furthermore, the macromolecule permeability of PACT- and PARS-processed tissue hybrids supports the diffusion of immunolabels throughout intact tissue, whereas RIMS (refractive index matching solution) grants high-resolution imaging at depth by further reducing light scattering in cleared and uncleared samples alike. These methods are adaptable to difficult-to-image tissues, such as bone (PACT-deCAL), and to magnified single-cell visualization (ePACT). Together, these protocols and solutions enable phenotyping of subcellular components and tracing cellular connectivity in intact biological networks
The interstitium in cardiac repair: role of the immune-stromal cell interplay
Cardiac regeneration, that is, restoration of the original structure and function in a damaged heart, differs from tissue repair, in which collagen deposition and scar formation often lead to functional impairment. In both scenarios, the early-onset inflammatory response is essential to clear damaged cardiac cells and initiate organ repair, but the quality and extent of the immune response vary. Immune cells embedded in the damaged heart tissue sense and modulate inflammation through a dynamic interplay with stromal cells in the cardiac interstitium, which either leads to recapitulation of cardiac morphology by rebuilding functional scaffolds to support muscle regrowth in regenerative organisms or fails to resolve the inflammatory response and produces fibrotic scar tissue in adult mammals. Current investigation into the mechanistic basis of homeostasis and restoration of cardiac function has increasingly shifted focus away from stem cell-mediated cardiac repair towards a dynamic interplay of cells composing the less-studied interstitial compartment of the heart, offering unexpected insights into the immunoregulatory functions of cardiac interstitial components and the complex network of cell interactions that must be considered for clinical intervention in heart diseases
Cognitive function following treadmill exercise in thermal protective clothing.
Occupational injuries are common among firefighters who perform strenuous physical exertion in extreme heat. The thermal protective clothing (TPC) worn by firefighters inhibits normal thermoregulation, placing the firefighter at risk of hypohydration and hyperthermia that may result in cognitive decline. We tested whether cognitive function changes after treadmill exercise in TPC. In an initial study (Cog 1), ten healthy volunteers performed up to 50 min of treadmill exercise while wearing TPC in a heated room. A battery of neurocognitive tests evaluating short-term memory, sustained and divided attention, and reaction time was administered immediately before and after exercise. In a follow-up study (Cog 2), 19 healthy volunteers performed a similar exercise protocol with the battery of cognitive tests administered pre-exercise, immediately post-exercise, and serially up to 120 min after exercise. Subjects performed 46.4 ± 4.6 and 48.1 ± 3.6 min of exercise in the Cog 1 and Cog 2, respectively. In both studies heart rate approached age predicted maximum, body mass was reduced 1.0-1.5 kg, and body core temperature increased to levels similar to what is seen after fire suppression. Neurocognitive test scores did not change immediately after exercise. Recall on a memory test was reduced 60 and 120 min after exercise. The mean of the 10 slowest reaction times increased in the 120 min after exercise. Fifty minutes of treadmill exercise in TPC resulted in near maximal physiologic strain but alterations in neurocognitive performance were not noted until an hour or more following exercise in TPC
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