Influence of serum uric acid levels on prognosis and survival in amyotrophic lateral sclerosis: a meta-analysis

Uric acid (UA) is considered to be one of the most important antioxidants in the blood. While high UA levels are found in many disease states, low UA levels are reported in many neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS). Various studies showed consistently that ALS patients have lower serum UA levels than healthy individuals, more prominently in cases with bulbar onset and longer disease duration. A systematic search of PubMed was conducted to retrieve published studies on UA levels in ALS patients. A meta-analysis was performed on published studies comparing UA levels between ALS patients and controls. This meta-analysis revealed highly statistically significant (p < 0.0001) lower UA levels and a very large size effect in 311 ALS patients compared to 515 controls as a group, as well as calculated for men and women separately. Many studies indicate that patients with neurodegenerative diseases, including ALS, have low UA levels. Our meta-analysis strengthens these findings in ALS patients, demonstrating highly statistically significant (p < 0.0001) lower UA levels in patients compared to controls, with very large total size effect, more prominent in men.     

Nighttime Fears and Fantasy–Reality Differentiation in Preschool Children

Nighttime fears are very common in preschool years. During these years, children’s fantasy–reality differentiation undergoes significant development. Our study was aimed at exploring the links between nighttime fears and fantasy–reality differentiation in preschool children. Eighty children (aged: 4–6 years) suffering from severe nighttime fears were compared with 32 non-fearful controls. Fears were assessed using child and parental reports. Children viewed images depicting fantastic or real entities and situations, and were asked to report whether these were imaginary or could occur in real life. The results revealed that children with nighttime fears demonstrated more fantasy–reality confusion compared to their controls. These differences in fantasy–reality differentiation were more pronounced in younger children. Additional significant associations were found between fantasy–reality differentiation and age and specific characteristics of the stimuli. These preliminary findings, suggesting a developmental delay in fantasy–reality differentiation in children with nighttime fears, have significant theoretical and clinical implications.     

Emotional brain rhythms and their impairment in post‐traumatic patients

Patients with post‐traumatic stress disorder (PTSD) suffer from a failure of cognitive control over emotional distracters. The physiological substrates of cognitive‐emotional interactions and their breakdown in disease are, however, unknown. Here, we studied brain activity in PTSD patients and healthy controls in response to emotion‐provoking pictures using electroencephalography and functional magnetic resonance imaging (fMRI). We demonstrate that in healthy individuals, emotion‐induced frontal theta rhythm modulates activity in the beta rhythm mainly in sensory‐motor regions. In contrast, in PTSD patients, beta activity is elevated irrespective of emotion, and is not modulated by frontal theta activity in response to negative emotion. EEG source localization and fMRI findings suggest that theta activity is localized to the prefrontal and anterior cingulate cortices while beta activity is localized to sensory‐motor regions. We further found that beta activity in sensory‐motor regions is related to the emotion‐induced slowing of the motor response in healthy controls while the excess frontal theta activity in PTSD is related to the intensity of negative emotional experience. These findings reveal for the first time the importance of brain electrical oscillations and coherence in emotional top‐down modulation and point to specific failure of these mechanisms in PTSD. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.     

Valproate decreases inositol biosynthesis.

BACKGROUND: Lithium and valproate (VPA) are used for treating bipolar disorder. The mechanism of mood stabilization has not been elucidated, but the role of inositol has gained substantial support. Lithium inhibition of inositol monophosphatase, an enzyme required for inositol recycling and de novo synthesis, suggested the hypothesis that lithium depletes brain inositol and attenuates phosphoinositide signaling. Valproate also depletes inositol in yeast, Dictyostelium, and rat neurons. This raised the possibility that the effect is the result of myo-inositol-1-phosphate (MIP) synthase inhibition. METHODS: Inositol was measured by gas chromatography. Human prefrontal cortex MIP synthase activity was assayed in crude homogenate. INO1 was assessed by Northern blotting. Growth cones morphology was evaluated in cultured rat neurons. RESULTS: We found a 20% in vivo reduction of inositol in mouse frontal cortex after acute VPA administration. As hypothesized, inositol reduction resulted from decreased MIP synthase activity: .21-.28 mmol/LVPA reduced the activity by 50%. Among psychotropic drugs, the effect is specific to VPA. Accordingly, only VPA upregulates the yeast INO1 gene coding for MIP synthase. The VPA derivative N-methyl-2,2,3,3,-tetramethyl-cyclopropane carboxamide reduces MIP synthase activity and has an affect similar to that of VPA on rat neurons, whereas another VPA derivative, valpromide, poorly affects the activity and has no affect on neurons. CONCLUSIONS: The rate-limiting step of inositol biosynthesis, catalyzed by MIP synthase, is inhibited by VPA; inositol depletion is a first event shown to be common to lithium and VPA.     

Cerebral activation of mitogen-activated protein kinases after circulatory arrest and low flow cardiopulmonary bypass.

OBJECTIVES: Mitogen-activated protein kinases (MAPK) are important intermediates in the signal transduction pathways involved in neuronal dysfunction following cerebral ischemia-reperfusion injury. One subfamily, extracellular regulated kinase 1/2, has been heavily implicated in the pathogenesis of post-ischemic neuronal damage. However, the contribution of extracellular regulated kinase 1/2 to neuronal damage following deep hypothermic circulatory arrest and low flow cardiopulmonary bypass is unknown. We attempted to correlate the extent of neuronal damage present following deep hypothermic circulatory arrest and low flow cardiopulmonary bypass with phosphorylated extracellular regulated kinase 1/2 expression in the cerebral vascular endothelium. METHODS: Piglets underwent normal flow cardiopulmonary bypass (n=4) deep hypothermic circulatory arrest (n=6) and low flow cardiopulmonary bypass (n=5). Brains were harvested following 24 h of post-cardiopulmonary bypass recovery. Cerebral cortical watershed zones, hippocampus, basal ganglia, thalamus, cerebellum, mesencephalon, pons and medulla were evaluated using hematoxylin and eosin staining. A section of ischemic cortex was evaluated by immunohistochemistry with rabbit polyclonal antibodies against phosphorylated extracellular regulated kinase 1/2. RESULTS: Compared to cardiopulmonary bypass controls, the deep hypothermic circulatory arrest and low flow cardiopulmonary bypass piglets exhibited diffuse ischemic changes with overlapping severity and distribution. Significant neuronal damage occurred in the frontal watershed zones and basal ganglia of the deep hypothermic circulatory arrest group (P<0.05). No detectable phosphorylated extracellular regulated kinase 1/2 immunoreactivity was found in the cardiopulmonary bypass controls; however, ERK 1/2 immunoreactivity was present in the cerebral vascular endothelium of the deep hypothermic circulatory arrest and low flow cardiopulmonary bypass groups. CONCLUSIONS: Our results indicate that phosphorylated extracellular regulated kinase 1/2 may play a prominent role in early cerebral ischemia-reperfusion injury and endothelial dysfunction. The pharmacologic inhibition of extracellular regulated kinase 1/2 represents a new and exciting opportunity for the modulation of cerebral tolerance to low flow cardiopulmonary bypass and deep hypothermic circulatory arrest.