Reactive Astrocyte Gliosis: Production of Inhibitory Molecules

The astrocytic cell responses to injury have been extensively studied in a variety of experimental models, and the term “astrogliosis” is often used to describe the astrocyte reactions to injury. Cells responding in these ways to injury are often referred to as “reactive astrocytes.” Glial scarring appears to be a critical feature of wound healing in the central nervous system (CNS), since elimination of the mitotically active contingent of reactive astrocytes leads to increase in the size of the wound. Reactive astrogliosis is a term coined for the morphological and functional events seen in astrocytes responding to CNS injury. The concept of reactive astrogliosis and its molecular and cellular definition in spinal cord injury (SCI) is still incomplete. Producing several inhibitory molecules discourages regeneration of axons in the injured spinal cord. This inhibition is compounded by the poor regenerative ability of most CNS axons. This is probably a more achievable therapeutic target than axon regeneration, and an effective treatment would be of assistance to the majority of patients with partial cord injuries. Of course, understanding about astrogliosis and producing mediators and inhibitory molecules such as signaling pathways help us to develop new treatment strategies for SCI

Toward a PV-based algorithm for the dynamical core of hydrostatic global models

The diabatic contour-advective semi-Lagrangian (DCASL) algorithms previously constructed for the shallow-water and multilayer Boussinesq primitive equations are extended to multilayer non-Boussinesq equations on the sphere using a hybrid terrain-following-isentropic (sigma-) vertical coordinate. It is shown that the DCASL algorithms face challenges beyond more conventional algorithms in that various types of damping, filtering, and regularization are required for computational stability, and the nonlinearity of the hydrostatic equation in the sigma- coordinate causes convergence problems with setting up a semi-implicit time-stepping scheme to reduce computational cost. The prognostic variables are an approximation to the Rossby-Ertel potential vorticity Q, a scaled pressure thickness, the horizontal divergence, and the surface potential temperature. Results from the DCASL algorithm in two formulations of the sigma- coordinate, differing only in the rate at which the vertical coordinate tends to with increasing height, are assessed using the baroclinic instability test case introduced by Jablonowski and Williamson in 2006. The assessment is based on comparisons with available reference solutions as well as results from two other algorithms derived from the DCASL algorithm: one with a semi-Lagrangian solution for Q and another with an Eulerian grid-based solution procedure with relative vorticity replacing Q as the prognostic variable. It is shown that at intermediate resolutions, results comparable to the reference solutions can be obtained.Publisher PDFPeer reviewe

Contra-lateral Auditory Brainstem Responses in Dyslexia

How to Cite This Article: Akbari M, Joghataei MT, Poorbakhat A, Jenabi MS. Contra-lateral auditory Brainstem Responses in Dyslexia. Iran J Child Neurol. Autumn 2016; 10(4): 10-15. AbstractObjectiveDyslexia is a neurological dysfunction (also known as a learning disability) that characterized by disability in reading in spite of normal intelligence. Bothe genetic and environmental risk factors are contributing into the condition.Diagnosis of dyslexia is based on examination and investigation of the patient’s memorial, spelling, visual, and reading skills. It is the most common learning disability, affecting 3%–10% of the school population. Modern neuroimaging techniques such as functional magnetic resonance imaging (fMRI) have shown a correlation between both functional and structural differences in the brains of children with reading difficulties. Hence, to address this issue, the auditory brainstem responses of children with dyslexia were investigated.  Materials &Methods Fifty two children with dyslexia (30 males, 22 females) were selected after examination by speech therapist. In addition, fifty two control children were included as well. The IPSI and contralateral ABR tests were conducted on both cases and controls. Click stimuli were used at 75 nHL intensity. The study focused on absolute latency of wave V in both groups. ResultsAbsolute latency of wave V in contralateral showed differences between children with dyslexia and control group, but no significant results were found in IPSI testing. ConclusionThe current data provide an evidence for brainstem and its function in signal processing and the role of brainstem nucleus on processing and delivering the information to each hemisphere.  References1. Lyon GR, Shaywitz SE, Shaywitz BA. 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Cerebral lateralization: Biological mechanisms, associations, and pathology. Cambridge, MA: MIT Press. 1987.18. Weintraub S, Mesulam MM. Developmental learning disabilities. Arch Neurol. 1983;40(8):463-8.19. Cohen L, Dehaene S. Neuroimage Specialization within the ventral stream.2004; 22(1):466-76.20. Simos PG1, Fletcher JM, Bergman E, Breier JI, Foorman BR, Castillo EM, Davis RN, Fitzgerald M, Papanicolaou AC. Neurology. 2002;58(8):1203-13.21. Wible, B, Nicol, T, Kraus N. Correlation between brainstem and cortical auditoryprocesses in normal and language-impaired children. Brain. 2005; 128: 417–423.22. Starr A, Picton T, Sininger Y, Hood I, Berlin C. Auditory neuropathy. Brain. 1996; 119:741-753.23. Zhang, Y. and Suga, N. Corticofugal feedback for collicular plasticity evoked by electric stimulation of the inferior colliculus. Neurophysiol. 2005; 94: 2676–2682.24. Hood L J. Clinical applications of the auditory brainstem response. Singular Publishing Group. 1998; 49-63.25. Dobie R A, Berlin C I. Binaural interaction in human auditory evoked responses. Archives of Otolaryngology. 1979; 105: 391-398.26. MollerA R, Jannetta P J. Auditory evoked potentials recorded from the cochlearnucleus and its vicinity in man. Journal of Neurosurgery. 1983; 59(6): 1013–1018.27. Moller A R, Jho H D, Yokota M, Janetta P J. Contribution from crossed and uncrossed brainstem structures to the brainstem auditory evoked potentials: a study in humans. Laryngoscope. 1995; 105(6): 596–605.28. Wible B, Nicol T, Kraus N. Correlation between brainstem and cortical auditory processes in normal and language-impaired children. Brain. 2005; 128, 417–423.29. Stone J L, Calderon-Arnulphi M, Watson K S. Brainstem auditory evoked potentials- a review and modified studies in healthy subjects. Journal of Clinical Neurophysiology. 2009; 26(3): 167–175.30. Parkkonen L, Fujiki N, Mäkelä J P. Sources of auditory brainstem responses21 revisited: contribution by magnetoencephalography. 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COVID-19 AND FEAR, WHICH COMES FIRST?

Today people have a few unanswered questions in their mind, such as "Do negative emotions will co-survive with the COVID-19 pandemic? Which one is worse? Which one will disappear quicker? Is there any connection between negative emotions and being infected by COVID-19 or the severity of infected individual\u27s symptoms ? How are we supposed to live with COVID-19 and adapt our emotional system to the virus for more than one upcoming year? These uncertainties could result in massive pressure on people. While there is no clear consensus regarding what establishes psychological stress on an individual, the effect of negative affect and psychological stress on increased susceptibility to disease due to altered immune functions is well established. Here we are going through the possible effect of emotions associated with the present pandemic on COVID-19 course of disease and severity of symptoms

Evaluation of attention bias in morphine and methamphetamine abusers towards emotional scenes during early abstinence: An eye-tracking study

Introduction: We hypothesized that inappropriate attention during the period of abstinence in individuals with substance use disorder can result in an inadequate perception of emotion and unsuitable reaction to emotional scenes. The main aim of this research was to evaluate the attentional bias towards emotional images in former substance abusers and compare it to healthy adults. Methods: Paired images of general scenes consisting of pleasant, unpleasant, and neutral images were presented to subjects for 3 s while their attentional bias and eye movements were measured by eye tracking. The participants were 72 male adults consisting of 23 healthy control, 24 morphine former abusers, and 25 methamphetamine former abusers. The former abusers were recruited from a private addiction quitting center and addiction rehabilitation campus. The healthy individuals were selected from general population. Number and duration of first fixation, duration of first gaze, and sustained attention towards emotional scenes were measured as the main variables and the data were analyzed using the repeated measures ANOVA. Results: A significant difference was observed between former morphine abusers and healthy control in terms of number and duration of first fixations and first gaze duration towards pleasant images. Discussion: Individuals with morphine use disorder have more problems with attending to emotional images compared to methamphetamine abusers and healthy people

In vitro differentiation of rat mesenchymal stem cells to hepatocyte lineage

Objective(s): Mesenchyme is a type of undifferentiated loose connective tissue that is derived mostly from mesoderm. Recently, mesenchymal stem cells (MSCs), as adult stem cells (ASCs) able to divide into a variety of different cells, are of utmost importance for stem cell research. In this research, ability of the liver extract to induce differentiation of rat derived omentum tissue mesenchymal stem cells (rOT-MSCs) into hepatocyte cells (HCs) was investigated. Materials and Methods: After isolation and confirmation of rOT-MSCs they were co-cultured with liver extract and hepatogenic differentiation was monitored. Expressions of mesenchymal stem cell markers were also analyzed via flow cytometry. Moreover, expressions of octamer-binding transcription factor-4 (Oct-4), Wilm's tumor suppressor gene-1 (WT-1), albumin (ALB), alpha fetoprotein (AFP), cytokeratin-18 (CK-18), and mRNAs were analyzed using RT-PCR on days 16, 18 and 21. ALB production was analyzed by immunocytochemistry and western blot. Furthermore, glycogen and urea production were determined via periodic acid-Schiff (PAS) staining and colorimetric assays respectively. Results: The phenotypic characterization revealed the positive expressions of CD90, CD44 and negative expression of CD45 in rOT-MSCs. These cells also expressed mRNA of Oct-4 and WT-1 as markers of omentum tissue. Differentiated rOT-MSCs in presence of 6 μg/ml liver extract expressed ALB, AFP, CK-18, glycogen and urea as specific markers of HCs. Conclusion: These observations suggest that liver extract is potentially able to induce differentiation of MSCs into hepatocyte lineage and can be considered an available source for imposing tissue healing on the damaged liver. � 2015, Mashhad University of Medical Sciences. All rights reserved

Age-associated changes on axonal regeneration and functional outcome after spinal cord injury in rats

This study was conducted to evaluate the association between aging and regenerative potential of spinal cord injury. Three groups of male Sprague�Dawley rats, including young (40 days), mature (5-6 months) and old (28-29 months) were spinally hemisected at the L1 level. The locomotor performance was assessed weekly for eight weeks after lesion using locomotors� rating scale developed by Basso, Bresnahan and Beattie (BBB). In the tracing study, retrograde labeled neuron was counted in the lateral vestibular nucleus for axonal regeneration. From 4-8 weeks, the functional recovery of the young and mature age rats was significantly increased in comparison to the old age group. At 8 weeks, young and mature animals achieved a plateau score of (mean ± SD), 17 ± 1.47 and 16.8 ± 0.70 respectively, and the old rats reached an average score of 13.8±1.63 (P<0.05). The mean number of labeled neurons in the vestibular nucleus in the young group (mean ± SD): 32.05 ± 1.03 increase significantly compared to the older age group 5.01 ± 1.31 (P<0.05). Current findings suggest that axonal repair and functional improvement decrease in aged animals after partial spinal cord injury. Thus, the aging process may affect the regenerative capacity of the injured central nervous system, and axonal regeneration is age dependent. © 2015 Tehran University of Medical Sciences. All rights reserved

COVID-19 AND FEAR, WHICH COMES FIRST?

Today people have a few unanswered questions in their mind, such as "Do negative emotions will co-survive with the COVID-19 pandemic? Which one is worse? Which one will disappear quicker? Is there any connection between negative emotions and being infected by COVID-19 or the severity of infected individual\u27s symptoms ? How are we supposed to live with COVID-19 and adapt our emotional system to the virus for more than one upcoming year? These uncertainties could result in massive pressure on people. While there is no clear consensus regarding what establishes psychological stress on an individual, the effect of negative affect and psychological stress on increased susceptibility to disease due to altered immune functions is well established. Here we are going through the possible effect of emotions associated with the present pandemic on COVID-19 course of disease and severity of symptoms

Berberine chloride pretreatment exhibits neuroprotective effect against 6-hydroxydopamine-induced neuronal insult in rat

Parkinson�s disease (PD) is a rather common movement disorder as a result of the degeneration of dopaminergic neurons within the substantianigra. Current treatments for PD afford symptomatic relief with no prevention of disease progression. Due to the neuroprotective and anti-apoptotic potential of the isoquinoline alkaloid berberine (BBR), this study was conducted to assess whether BBR pretreatment could attenuate behavioral and neuronal derangement in 6-hydroxydopamine (6-OHDA)-induced model of PD in the rat. Unilateral intrastriatal 6-OHDA-lesioned rats received BBR at doses of 25 and/or 50 mg/kg (i.p.) three times at an interval of 24 h, started 2 days before the surgery. After 1 week, apomorphine caused significant contralateral rotations and a significant reduction in the number of Nissl-stained and tyrosine-hydroxylase (TH)-positive neurons on the left side of the substantianigra. BBR pretreatment at a dose of 50 mg/kg significantly reduced rotations and prevented loss of TH-positive neurons. These results indicate pre-lesion administration of BBR could protect against 6-OHDA toxicity and this may be of benefit besides other available therapies in PD. © 2015 by School of Pharmacy Shaheed Beheshti University of Medical Sciences and Health Services

Prevention of diagnostic errors in position of conus medullaris in adult patients

Background: Finding the safe location of spinal cord for cerebrospinal fluid (CSF) during surgical procedures is very important due to its various nature for each patient as well as its potential peripheral nervous system hazards. The aim of this study was to find the relationship between the location of conus medullaris (CM) and gender, age and body mass index (BMI) in order to minimize the potential diagnostic errors. Methods: Magnetic resonance imaging (MRI) with T1-weighted sagittal spin echo sequences of the lumbar spine was studied in 350 patients older than 20 years, whom had been referred for imaging in order to assess the potential causes of low back pain of the lumbar spine, and were referred to Shahid Chamran MRI center in Sanandaj, located in the west of Iran in 2014. The results were compared with international standards to reveal the potential errors. Results: In different age groups, the mean position was variable ranging from T12-L1 intervertebral disc to upper part of L1 middle third, not clinically significant. The inter canal position of the spinal cord was toward dorsal. No significant relationship was found between CM and gender, age as well as BMI. Similar relationship was found for the spinal cord position in spinal column. Conclusion: There is a safe region of 2–4 vertebral bodies and intervertebral spaces during spinal block. It means that the variation of CM position and its end level could be a guidance to realize that why neurological symptoms may vary in different patients