Articles: brain-injuries.
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Journal of neurotrauma · Jun 1995
A new model for rapid stretch-induced injury of cells in culture: characterization of the model using astrocytes.
The purpose of this study was to develop a simple, reproducible model for examining the morphologic, physiologic, and biochemical consequences of stretch-induced injury on tissue-cultured cells of brain origin. Rat cortical astrocytes from 1- to 2-day-old rats were cultured to confluency in commercially available 25-mm-diameter tissue culture wells with a 2-mm-thick flexible silastic bottom. A cell injury controller was used to produce a closed system and exert a rapid positive pressure of known amplitude (psi) and duration (msec). ⋯ LDH release was also proportional to the amplitude of cell stretch, with maximum release occurring within 2 h of injury. In summary we have developed a simple, reproducible model to produce graded, strain-related injuries in cultured cells. Our continuing experiments suggest that this model can be used to study the biochemistry and physiology of injury as well as serve as a tool to examine the efficacy of therapeutic agents.
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Journal of neurotrauma · Jun 1995
Posttraumatic brain hypothermia provides protection from sensorimotor and cognitive behavioral deficits.
The purpose of this study was to determine the degree of sensorimotor and cognitive protection conferred by posttraumatic brain hypothermia. Baseline measurements were taken on sensorimotor tasks involving forelimb placing and beam-walking, as well as on a spatial navigational task utilizing the water maze. Twenty-four hours after the last baseline measurements, normothermic (37 degrees C) animals were subjected to a fluid percussion pulse (1.9-2.4 atm) over the right parietal sensorimotor cortex. ⋯ In the water maze, there was a distinction between groups in the ability to navigate 48 h after TBI. TBI-N animals performed significantly worse than sham and TBI-H animals (both p < 0.01), whereas there was no significant difference between the scores of sham and TBI-H animals. The present data demonstrate that moderate postinjury brain hypothermia can provide protection from sensorimotor and cognitive behavioral deficits as well as neuropathology in a model of traumatic brain injury associated with early neuronal and microvascular injury.
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Anesthesia and analgesia · Jun 1995
Influence of isoflurane, fentanyl, thiopental, and alpha-chloralose on formation of brain edema resulting from a focal cryogenic lesion.
The objective of this study was to analyze the effects of various anesthetics on the formation of brain edema resulting from a focal cryogenic lesion. Thirty rabbits (six per group) were anesthetized with isoflurane (1 minimum alveolar anesthetic concentration [MAC] 2.1 vol%), fentanyl (bolus 5 micrograms/kg; infusion rate 1.0-0.5 micrograms.kg-1.min-1), thiopental (32.5 mg.kg-1.h-1), or alpha-chloralose (50 mg/kg). Control animals (sham operation, no lesion) received alpha-chloralose (50 mg/kg). ⋯ Brain tissue samples were collected at multiple sites close to and distant from the lesion. Mean arterial pressure, arterial PCO2 and PO2, hematocrit, body temperature, and blood glucose were not different between groups during the posttraumatic course (except for an increased arterial pressure with alpha-chloralose compared to thiopental 4-6 h after trauma). The specific gravity of cortical gray matter was significantly reduced up to a distance of 6 mm from the center of the lesion in animals anesthetized with isoflurane, thiopental, or alpha-chloralose and up to 9 mm in animals given fentanyl.(ABSTRACT TRUNCATED AT 250 WORDS)
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Depending on the clinical symptomatology, computed tomography (CT) is the predominant examination technique. CT reliably shows live-threatening intra- or extracerebral hemorrhage. ⋯ In many cases localized edema can be identified, but because of the normally very narrow cortical sulci in children and younger people, the general post-traumatic brain swelling is often diagnosed only retrospectively. Magnetic resonance tomography is more sensitive than CT concerning subtle changes in the depth of the white matter and should be used for follow-up studies as a supplementary examination.
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To determine the prevalence of abnormal computed tomography (CT) scans and define high-risk clinical variables in patients with mild head injury. ⋯ Abnormalities on CT scans in patients with mild head trauma are fairly common, although the need for neurosurgical intervention is rare. Clinical decision rules can be used to identify those patients with more serious intracranial pathology. Such strategies should be validated prospectively in various ED settings.