Journal of neurotrauma
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Journal of neurotrauma · Feb 2019
The Impact of Cervical Spinal Cord Contusion on the Laryngeal Resistance in the Rat.
The present study was designed to investigate laryngeal function responses to chemoreceptor activation after unilateral high-cervical spinal cord contusion in rats. Adult male Sprague-Dawley rats received laminectomy or unilateral contusion at the C2 spinal cord. Both respiratory airflow and subglottal pressure were measured in spontaneously breathing rats at three days, two weeks, or six weeks after spinal surgery. ⋯ These data suggest that cervical spinal cord injury not only influences the breathing pattern, but it also impacts upper airway function through modulation of laryngeal resistance. An attenuated laryngeal closure response may negatively impact the ability to prevent irritant inhalation and maintenance of the functional residual capacity. This may contribute to the provocation of pulmonary disease after cervical spinal cord injury.
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Journal of neurotrauma · Jan 2019
Relative Deficiency of Plasma ADAMTS13 Activity and Elevation of Human Neutrophil Peptides in Patients with Traumatic Brain Injury.
Traumatic microvascular injury (tMVI) is a universal endophenotype of traumatic brain injury (TBI) that is responsible for significant neurological morbidity and mortality. The mechanism underlying tMVI is not fully understood. The present study aims to determine plasma levels of von Willebrand factor (VWF), a disintegrin and metalloprotease with thrombospondin type 1 repeats (ADAMTS) 13 activity, and human neutrophil peptides (HNP) 1-3 and to correlate these biomarkers with functional outcomes after moderate-severe TBI. ⋯ This resulted in a dramatic reduction in the ratio of ADAMTS13 activity to VWFAg or ADAMTS13 to VWFAc in all 5 post-TBI days. Cluster analysis demonstrated that high median plasma levels of VWFAg and HNP1-3 were observed in the cluster with a high mortality rate. These results demonstrate that a relative deficiency of plasma ADAMTS13 activity, resulting from activation of neutrophils and endothelium, may contribute to the formation of microvascular thrombosis and mortality after moderate-severe TBI.
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Journal of neurotrauma · Jan 2019
Orthopedic Injured versus Uninjured Comparison Groups for Neuroimaging Research in Mild Traumatic Brain Injury.
To address controversy surrounding the most appropriate comparison group for mild traumatic brain injury (mTBI) research, mTBI patients 12-30 years of age were compared with an extracranial orthopedic injury (OI) patient group and an uninjured, typically developing (TD) participant group with comparable demographic backgrounds. Injured participants underwent subacute (within 96 h) and late (3 months) diffusion tensor imaging (DTI); TD controls underwent DTI once. Group differences in fractional anisotropy (FA) and mean diffusivity (MD) of commonly studied white matter tracts were assessed. ⋯ The mTBI and OI groups had generally similar longitudinal results. Findings suggest that different conclusions about group-level DTI analyses could be drawn, depending on the selected comparison group, highlighting the need for additional research in this area. Where possible, mTBI studies may benefit from the inclusion of both OI and TD controls.
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Journal of neurotrauma · Jan 2019
Acute Inflammatory Biomarker Responses to Diffuse Traumatic Brain Injury in the Rat Monitored by a Novel Microdialysis Technique.
Neuroinflammation is a major contributor to the progressive brain injury process induced by traumatic brain injury (TBI), and may play an important role in the pathophysiology of axonal injury. The immediate neuroinflammatory cascade cannot be characterized in the human setting. Therefore, we used the midline fluid percussion injury model of diffuse TBI in rats and a novel microdialysis (MD) method providing stable diffusion-driven biomarker sampling. ⋯ Therefore, diffuse TBI was associated with an increased level of 18 of the 27 inflammatory biomarkers at one through six time points, during the observation period whereas the remaining 9 biomarkers were unaltered. The study shows that diffuse TBI induces an acute increase in a number of inflammatory biomarkers. The novel MD technique provides stable MD sampling suitable for further studies on the early neuroinflammatory cascade in TBI.
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Journal of neurotrauma · Jan 2019
Interleukin-1 receptor 1 deletion in focal and diffuse experimental traumatic brain injury in mice.
Important differences in the biology of focal and diffuse traumatic brain injury (TBI) subtypes may result in unique pathophysiological responses to shared molecular mechanisms. Interleukin-1 (IL-1) signaling has been tested as a potential therapeutic target in preclinical models of cerebral contusion and diffuse TBI, and in a phase II clinical trial, but no published studies have examined IL-1 signaling in an impact/acceleration closed head injury (CHI) model. We hypothesized that genetic deletion of IL-1 receptor-1 (IL-1R1 KO) would be beneficial in focal (contusion) and CHI in mice. ⋯ Surprisingly, cognitive outcome in mice with global deletion of IL-1R1 was improved in CHI, but worse after CCI without affecting lesion size, edema, or infiltration of CD11b+/CD45+ leukocytes in CCI. IL-1R1 may induce unique biological responses, beneficial or detrimental to cognitive outcome, after TBI depending on the pathoanatomical subtype. Brain endothelium is a hitherto unrecognized source of mature IL-1β in both models.