Brain research
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To investigate changes in the diffusion tensor imaging measures, axial diffusivity and radial diffusivity, in addition to the more commonly used fractional anisotropy and mean diffusivity, in patients with amyotrophic lateral sclerosis (ALS) using the voxel-based statistical analysis tool, tract based spatial statistics. ⋯ In ALS, axial diffusivity and radial diffusivity may be useful diffusion tensor imaging-derived indices to consider in addition to fractional anisotropy and mean diffusivity to aid in demonstrating neurodegenerative changes.
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Sex differences in human brain structure have repeatedly been described, but results are inconsistent. However, these studies hardly controlled for cycle phase of women or the use of hormonal contraceptives. Our study shows that these factors are not negligible, but have a considerable influence on human brain structure. ⋯ These sex-dependent effects were modulated by menstrual cycle phases and hormonal contraceptives. We found larger volumes in the right fusiform/parahippocampal gyrus during early follicular compared to mid-luteal cycle phase. Women using hormonal contraceptives showed significantly larger prefrontal cortices, pre- and postcentral gyri, parahippocampal and fusiform gyri and temporal regions, compared to women not using contraceptives.
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Oxidative stress plays an important role in the development of cognitive impairment in sepsis. Here we assess the effects of acute and extended administration of cannabidiol (CBD) on oxidative stress parameters in peripheral organs and in the brain, cognitive impairment, and mortality in rats submitted to sepsis by cecal ligation and perforation (CLP). To this aim, male Wistar rats underwent either sham operation or CLP. ⋯ After the test, the animals were killed and samples from lung, liver, kidney, heart, spleen, and brain (hippocampus) were obtained and assayed for TBARS formation and protein carbonyls. The acute and extended administration of CBD at different doses reduced TBARS and carbonyl levels in some organs and had no effects in others, ameliorated cognitive impairment, and significantly reduced mortality in rats submitted to CLP. Our data provide the first experimental demonstration that CBD reduces the consequences of sepsis induced by CLP in rats, by decreasing oxidative stress in peripheral organs and in the brain, improving impaired cognitive function, and decreasing mortality.
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The anticoagulant activated protein C (APC) protects neurons and vascular cells from injury through its direct cytoprotective effects that are independent of its anticoagulant action. Wild-type recombinant murine APC (wt-APC) exerts significant neuroprotection in mice if administered early after traumatic brain injury (TBI). Here, we compared efficacy and safety of a late therapy for TBI with wt-APC and 3K3A-APC, an APC analog with approximately 80% reduced anticoagulant activity but normal cytoprotective activity, using a controlled cortical impact model of TBI. ⋯ Three days post-TBI, the hemoglobin levels in the injured brain were increased by approximately 3-fold after wt-APC treatment compared to saline indicating an increased risk for intracerebral bleeding. In contrast, comparable levels of brain hemoglobin in 3K3A-APC-treated and saline-treated mice suggested that 3K3A-APC treatment did not increase risk for bleeding after TBI. Thus, compared to wt-APC, 3K3A-APC is more efficacious and safer therapy for TBI with no risk for intracerebral hemorrhage.
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A psychophysical method of response-dependent stimulation presented ascending and descending series of thermal stimulus intensities that maintained an average rating (setpoint) of mild pain (20 on a scale of 0-100) or moderate pain (35). Subjects were presented with alternating series of thermal stimuli that increased until ratings reached or exceeded the setpoint, then decreased until ratings equaled or were less than the setpoint, then increased, etc. ⋯ Thus, the nervous system detects and discriminates between ascending and descending trends in stimulus intensity and alters the magnitude of pain sensations in the direction of the trend of increasing or decreasing stimulus intensity. Ascending (sensitizing) trend effects may increase the magnitude of pathological pain in the absence of treatment, and descending (desensitizing) trend effects likely would enhance the efficacy of procedures that reduce pain sensitivity.