13 research outputs found

    Infusion of five percent dextrose increases mortality and morbidity following six minutes of cardiac arrest in resuscitated dogs

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    The aim of this study was to assess the effect of dextrose administration during and following cardiac resuscitation on mortality and morbidity. Thirty-one dogs anesthetized with halothane were subjected to six minutes of ventricular fibrillation and were resuscitated with open chest cardiac message. All dogs were successfully resuscitated. Thirteen received no dextrose infusion and were fully ambulatory, eating and drinking at 24 hours. Ten of the 18 dogs receiving an infusion of 5% dextrose died before 24 hours and the eight that survived were profoundly impaired. Significantly greater neurologic deficits were recorded for dogs with higher blood glucose concentrations. We conclude that the inclusion of dextrose in fluids used in resuscitation increases mortality and morbidity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26775/1/0000328.pd

    Morphometric evaluation of brain infarcts in rats and gerbils

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    The Levine rat prepartion, the gerbil stroke model, and appropriate control animals were used to determine if the 2,3,5-triphenyltetrazolium chloride (TTC) would selectively identify noninfarcted versus infarcted cerebral tissue. The TTC is frequently used to quantify infarcted myocardial tissue and has been shown to have great specificity, reproducibility, and efficacy. The TTC produces a red product upon reaction with the respiratory enzymes (dehydrogenases) present in non-infarcted tissues. Irreversibly damaged tissues, lacking dehydrogenases, do not form red reaction products. Six gerbil brains and seven rat brains were incubated with the TTC, and the unreacted areas were macroscopically identified. The brains were fixed and sectioned for routine hematoxylin and eosin staining to determine the specificity of the TTC. The TTC was found to react selectively only with non-infarcted cerebral tissue. The gross brain sections were evaluated by macroscopic morphometric analysis, and the unreacted area was always ipsilateral to ligation and correlated with histologic identification of infarct. The brains from neurologically intact animals demonstrated neither macroscopic nor histological evidence of infarction. This technique allows macroscopic quantification of infarct size by planimetry. The average area of infarct for the neurologically impaired rats was 34.7% and it was 31.4% for the impaired gerbils. The percentage of surface area of each infarcted slice was found to correlate with the severity of the neurologic deficit. We conclude that the TTC staining is effective for macroscopically delineating cerebral infarcts in rats and gerbils, thus permitting quantification of infarct size.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25989/1/0000055.pd

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    [beta]-Hydroxybutyrate and response to hypoxia in the ground squirrel, Spermophilus tridecimlineatus

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    1. 1. Previous studies have suggested that elevated ketone levels are associated with increased survival time in rodents exposed to hypoxia. In this study the association between whole blood BHB ([beta]-hydroxybutyrate) and hypoxic surivaval time was investigated in hibernating and non-hibernating ground squirrels and in rats.2. 2. Non-hibernating ground squirrels and rats were exposed to hypoxia (4.5% O2). One hundred per cent of ground squirrels survived 1 hr of hypoxia vs 20% of rats.3. 3. Ketone levels were significantly higher in ground squirrels than rats during hypoxia, and rats surviving the longest had the highest ketone levels. 4. When hibernation was induced in ground squirrels there was a significant increase in [beta]-hydroxybutyrate from 0.45 to 1.6 mM (P = 0.0005).4. 5. Ground squirrel heart mitochondrial respiratory control ratios and ATP synthesis rates indicated no preferential ketone utilization which might suggest a possible extramitochondrial role of BHB during hypoxia.5. 6. We conclude that elevated blood BHB levels are associated with increased hypoxic survival and they may have evolved in response to life-threatening hypoxia as experienced during hibernation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28833/1/0000668.pd
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