Short-term hyperoxia-induced functional and morphological changes in rat hippocampus.

Excess oxygen (O) levels may have a stimulating effect, but in the long term, and at high concentrations of O, it is harmful to the nervous system. The hippocampus is very sensitive to pathophysiological changes and altered O concentrations can interfere with hippocampus-dependent learning and memory functions. In this study, we investigated the hyperoxia-induced changes in the rat hippocampus to evaluate the short-term effect of mild and severe hyperoxia.

Mild hypoxia-induced structural and functional changes of the hippocampal network.

Hypoxia causes structural and functional changes in several brain regions, including the oxygen-concentration-sensitive hippocampus. We investigated the consequences of mild short-term hypoxia on rat hippocampus . The hypoxic group was treated with 16% O for 1 h, and the control group with 21% O.

Muscle damage in response to a single bout of high intensity concentric exercise in patients with Pompe disease.

Background: In Pompe disease, resistance exercise could be an effective treatment to delay motor function impairment, however, the acute effects of this exercise modality are unclear.

Methods: In a prospective cohort study, we compared responses to a single bout of resistance exercise by serum markers of muscle damage and quantitative muscle magnetic resonance imaging (MRI) in patients (n=12) and age- and gender-matched healthy controls (n=12). Participants performed 50 maximal effort concentric knee flexions on a dynamometer.

Physical Validation of a Residual Impedance Rejection Method during Ultra-Low Frequency Bio-Impedance Spectral Measurements.

Accurate and reliable measurement of the electrical impedance spectrum is an essential requirement in order to draw relevant conclusions in many fields and a variety of applications; in particular, for biological processes. Even in the state-of-the-art methods developed for this purpose, the accuracy and efficacy of impedance measurements are reduced in biological systems, due to the regular occurrence of parameters causing measurement errors such as residual impedance, parasitic capacitance, generator anomalies, and so on. Recent observations have reported the necessity of decreasing such inaccuracies whenever measurements are performed in the ultra-low frequency range, as the above-mentioned errors are almost entirely absent in such cases.

Rapid non-classical effects of steroids on the membrane receptor dynamics and downstream signaling in neurons.

Contribution to Special Issue on Fast effects of steroids. Although rapid effects of steroid hormones on membrane receptors and intracellular signaling molecules have been extensively studied in neurons, we are only beginning to understand the molecular mechanisms behind these non-classical steroid actions. Single molecule tracking (SMT) studies on live cells demonstrated that surface trafficking of membrane receptors determines their ligand binding properties and downstream signaling events.

Identifying non-toxic doses of manganese for manganese-enhanced magnetic resonance imaging to map brain areas activated by operant behavior in trained rats.

Manganese-enhanced magnetic resonance imaging (MEMRI) offers unique advantages such as studying brain activation in freely moving rats, but its usefulness has not been previously evaluated during operant behavior training. Manganese in a form of MnCl, at a dose of 20mg/kg, was intraperitoneally infused. The administration was repeated and separated by 24h to reach the dose of 40mg/kg or 60mg/kg, respectively.

Oxidative stress induces transient O-GlcNAc elevation and tau dephosphorylation in SH-SY5Y cells.

O-linked β-N-acetlyglucosamine or O-GlcNAc modification is a dynamic post-translational modification occurring on the Ser/Thr residues of many intracellular proteins. The chronic imbalance between phosphorylation and O-GlcNAc on tau protein is considered as one of the main hallmarks of Alzheimer's disease. In recent years, many studies also showed that O-GlcNAc levels can elevate upon acute stress and suggested that this might facilitate cell survival.

Detection and genome analysis of a novel (dima)rhabdovirus (Riverside virus) from Ochlerotatus sp. mosquitoes in Central Europe.

During an investigation for potential arboviruses present in mosquitoes in Hungary (Central Europe) three highly similar virus strains of a novel rhabdovirus (family Rhabdoviridae) called Riverside virus (RISV, KU248085-KU248087) were detected and genetically characterized from Ochlerotatus sp. mosquito pools collected from 3 geographical locations using viral metagenomic and RT-PCR methods. The ssRNA(-) genome of RISVs follows the general genome layout of rhabdoviruses (3'-N-P-M-G-L-5') with two alternatives, small ORFs in the P and G genes (Px and Gx).

Mechanism of the "dark" axonal degeneration in the central nervous system.

Background And Purpose: In the central nervous tissue, two types of transsection-resulted axonal degeneration are generally accepted: "watery" and "dark". The present paper deals with the assumption that the mechanism of this kind of "dark" axonal degeneration has a relationship with that of the "dark" neuronal degeneration.

Methods: A minute stab wound is inflicted in the parietal cortex of the rat brain.

Changes of PACAP level in cerebrospinal fluid and plasma of patients with severe traumatic brain injury.

PACAP has well-known neuroprotective potential including traumatic brain injury (TBI). Its level is up-regulated following various insults of the CNS in animal models. A few studies have documented alterations of PACAP levels in human serum.

Association of myasthenia gravis with polymorphisms in the gene of histamine N-methyltransferase.

Introduction: Histamine N-methyltransferase (HNMT) is the main metabolizing enzyme of histamine. Histamine modulates immune responses and plays a role in the pathogenesis of autoimmune disorders.

Methods: The non-synonymous HNMT C314T polymorphism and the A939G single-nucleotide polymorphism (SNP) influencing HNMT mRNA stability were genotyped in 213 patients with myasthenia gravis (MG) and 342 healthy controls.

Aquaporin-4 distribution in control and stressed astrocytes in culture and in the cerebrospinal fluid of patients with traumatic brain injuries.

Distribution of aquaporin-4 (AQP4) was studied by western analysis and immunofluorescence in rat astrocytes exposed to either hypothermic (30 °C) or hyperosmolar (0.45 M sucrose) stress, and in the cerebrospinal fluid (CSF) of patients who suffered traumatic brain injury (TBI). CSF was obtained from 5 healthy subjects and from 20 patients suffering from severe TBI.

Effect of PACAP in central and peripheral nerve injuries.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a bioactive peptide with diverse effects in the nervous system. In addition to its more classic role as a neuromodulator, PACAP functions as a neurotrophic factor. Several neurotrophic factors have been shown to play an important role in the endogenous response following both cerebral ischemia and traumatic brain injury and to be effective when given exogenously.

Concurrent hypermethylation of DNMT1, MGMT and EGFR genes in progression of gliomas.

Background: Gliomas are the most common neoplasm of the brain. High-grade gliomas often resist treatment even with aggressive surgical resection and adjuvant radiation and chemotherapy. Despite the combined treatment, they frequently recur with the same or higher-grade histology.

A biexponential DWI study in rat brain intracellular oedema.

Purpose: To examine the changes in MR parameters derived from diffusion weighted imaging (DWI) biexponential analysis in an in vivo intracellular brain oedema model, and to apply electron microscopy (EM) to shed more light on the morphological background of MR-related observations.

Materials And Methods: Intracellular oedema was induced in ten male Wistar rats (380-450g) by way of water load, using a 20% body weight intraperitoneal injection of 140mmol/L dextrose solution. A 3T MRI instrument was used to perform serial DWI, and MR specroscopy (water signal) measurements.

The influence of benzamil hydrochloride on the evolution of hyponatremic brain edema as assessed by in vivo MRI study in rats.

Objective: The present study was undertaken to reveal the influence of intracerebroventricular (ICV) benzamil on the dynamics of brain water accumulation in hyponatremic rats. Parameters of brain water homeostasis were continuously monitored, using in vivo magnetic resonance imaging (MRI) methods. The results were compared with those obtained in a previous study by tissue desiccation.

Clinical and biological heterogeneity of autoimmune myasthenia gravis.

Although myasthenia gravis (MG) has long been considered a well-established autoimmune disease associated with autoantibodies, which are convincingly pathogenic, accumulating data indicate both clinical and biological heterogeneity similar to many other putative autoimmune disorders. In a subset of patients, thymus plays a definite role: thymic autoimmunity results in generation of autoantibodies within the thymus, which cross-react with antigens at the neuromuscular junction, or thymoma leads to deficient central tolerance and impaired T cell selection. Heterogeneity on the autoantibody level may be associated with genetic heterogeneity and clinical phenotypes with different treatment responses.

A novel PARP inhibitor L-2286 in a rat model of impact acceleration head injury: an immunohistochemical and behavioral study.

We examined the neuro/axono-protective potential of a novel poly (ADP-ribose) polymerase (PARP) inhibitor L-2286 in a rat impact acceleration brain injury model. Male Wistar rats (n = 70) weighing 300-350 grams were used to determine the most effective intracerebroventricular (i.c.

Clinical and model research of neurotrauma.

Modeling traumatic brain injury represents a major challenge for neuroscientists - to represent extremely complex pathobiological processes kept under close surveillance in the most complex organ of a laboratory animal. To ensure that such models also reflect those alterations evoked by and/or associated with traumatic brain injury (TBI) in man, well-defined, graded, simple injury paradigms should be used with clear endpoints that also enable us to assess the relevance of our findings to human observations. It is of particular importance that our endpoints should harbor clinical significance, and to this end, biological markers ultimately associated with the pathological processes operant in TBI are considered the best candidate.

Calpain inhibition reduces axolemmal leakage in traumatic axonal injury.

Calcium-induced, calpain-mediated proteolysis (CMSP) has recently been implicated to the pathogenesis of diffuse (traumatic) axonal injury (TAI). Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP) alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal CMSP may contribute to axolemmal permeability alterations (APA) and pre-injury calpain-inhibition could reduce AP in a rat model of TAI.

Impaired function of innate T lymphocytes and NK cells in the acute phase of ischemic stroke.

Background: Functional alterations of innate lymphocytes, which can mount rapid immune responses and shape subsequent T cell reactions, were examined in the acute phase of ischemic stroke.

Methods: Frequencies, intracellular perforin and interferon-gamma (IFN-gamma) expression of Vdelta2 T cells, CD3+ CD56+ natural killer T (NKT)-like and NK cells were examined in the peripheral blood of 20 healthy controls and 28 patients within 6 h of the onset of acute ischemic stroke and after 72 h by flow cytometry. Cytokine production of isolated NKT-like and NK cells following in vitro activation was measured by cytometric bead array.

Update on protein biomarkers in traumatic brain injury with emphasis on clinical use in adults and pediatrics.

Purpose: This review summarizes protein biomarkers in mild and severe traumatic brain injury in adults and children and presents a strategy for conducting rationally designed clinical studies on biomarkers in head trauma.

Methods: We performed an electronic search of the National Library of Medicine's MEDLINE and Biomedical Library of University of Pennsylvania database in March 2008 using a search heading of traumatic head injury and protein biomarkers. The search was focused especially on protein degradation products (spectrin breakdown product, c-tau, amyloid-beta(1-42)) in the last 10 years, but recent data on "classical" markers (S-100B, neuron-specific enolase, etc.

Benzamil prevents brain water accumulation in hyponatraemic rats.

Background: It has been recently shown that A6 cells exposed to hyponatraemic stress respond with increased sodium uptake via activation of benzamil-sensitive sodium channels. This study was performed, therefore, to explore the possible involvement of benzamil-sensitive sodium channels and cellular sodium influx in brain oedema formation in hyponatraemic rats.

Methods: Four groups of male Wistar rats were studied (n = 13 in each group).