Association of multiple sclerosis and sudden sensorineural hearing loss

Peer reviewe

Efficacy of salbutamol via Easyhaler®unaffected by low inspiratory flow

AbstractThe fine particle dose delivered via dry powder inhalers (DPIs) is often affected by the inspiratory flow rate generated during inhalation. This has clinical implications, since the fine particle dose determines the amount of drug reaching the lungs. With Easyhaler®DPI the fine particle dose remains relatively constant over the range of inspiratory flow rates from 30–60 l min−1. The aim of this study was to confirm that clinical efficacy is maintained even at low flow rates by comparing the bronchodilating effect of salbutamol (100 μ g) delivered via Easyhaler®at a target inspiratory flow of 30 l min−1with the same dose of salbutamol via pressurised metered-dose inhaler (pMDI) plus spacer.This was a double-blind, randomized, cross-over study with double-dummy technique. Twenty-one paediatric and adult asthmatic patients completed the study, which was conducted over 2 study days. The main outcome parameter was forced expiratory volume in 1 sec (FEV1). The patients were trained to generate a low peak inspiratory flow rate (PIFR) of 30 l min−1, and the actual PIFR through Easyhaler®was recorded.The average PIFR through Easyhaler®was 28·7 l min−1. The difference in the maximum value of FEV1(FEV1max) between the treatments after drug inhalation was 0·01 l. The mean of FEV1maxwas 2·67 l after pMDI plus spacer compared to 2·69 l after Easyhaler®. Improvements in FEV1were clinically significant. No significant differences between treatments were found.A reasonably low inspiratory flow rate through Easyhaler®produces an equivalent improvement in lung function to a correctly used pMDI plus spacer. Hence, Easyhaler®can be used with confidence in patients who may have difficulty in generating a high inspiratory flow rate, such as children and the elderly

Prediction of neo-adjuvant chemotherapy response in bladder cancer : the impact of clinical parameters and routine biomarkers

Purpose To investigate the role of clinical parameters and immunohistochemical (IHC) biomarkers in their feasibility to predict the effect of neo-adjuvant chemotherapy (NAC) in patients with muscle-invasive urothelial bladder cancer (MIBC). Materials and methods The first 76 consecutive patients with MIBC treated with NAC and radical cystectomy in two University hospitals in Finland between 2008 and 2013 were chosen for this study. After excluding patients with non-urothelial cancer, less than two cycles of chemotherapy, no tissue material for IHC analysis or non-muscle-invasive bladder cancer in re-review, 59 patients were included in the final analysis. A tissue microarray block was constructed from the transurethral resection samples and IHC stainings of Ki-67, p53, Her-2 and EGFR were made. The correlations between histological features in transurethral resection samples and immune-histochemical stainings were calculated. The associations of clinicopathological parameters and IHC stainings with NAC response were evaluated. Factors affecting survival were estimated. Results The complete response rate after NAC was 44%. A higher number of chemotherapy cycles was associated with better response to neo-adjuvant chemotherapy. No response to neo-adjuvant chemotherapy and female gender was associated with decreased cancer-specific survival. The IHC stainings used failed to show an association with neo-adjuvant chemotherapy response and overall or cancer specific survival. Conclusions Patients who do not respond to neo-adjuvant chemotherapy do significantly worse than responders. This study could not find clinical tools to distinguish responders from non-responders. Further studies preferably with larger cohorts addressing this issue are warranted to improve the selection of patients for neo-adjuvant chemotherapy.Peer reviewe

Raphe-mediated signals control the hippocampal response to SRI antidepressants via miR-16

Serotonin reuptake inhibitor (SRI) antidepressants such as fluoxetine (Prozac), promote hippocampal neurogenesis. They also increase the levels of the bcl-2 protein, whose overexpression in transgenic mice enhances adult hippocampal neurogenesis. However, the mechanisms underlying SRI-mediated neurogenesis are unclear. Recently, we identified the microRNA miR-16 as an important effector of SRI antidepressant action in serotonergic raphe and noradrenergic locus coeruleus (LC). We show here that miR-16 mediates adult neurogenesis in the mouse hippocampus. Fluoxetine, acting on serotonergic raphe neurons, decreases the amount of miR-16 in the hippocampus, which in turn increases the levels of the serotonin transporter (SERT), the target of SRI, and that of bcl-2 and the number of cells positive for Doublecortin, a marker of neuronal maturation. Neutralization of miR-16 in the hippocampus further exerts an antidepressant-like effect in behavioral tests. The fluoxetine-induced hippocampal response is relayed, in part, by the neurotrophic factor S100β, secreted by raphe and acting via the LC. Fluoxetine-exposed serotonergic neurons also secrete brain-derived neurotrophic factor, Wnt2 and 15-Deoxy-delta12,14-prostaglandin J2. These molecules are unable to mimic on their own the action of fluoxetine and we show that they act synergistically to regulate miR-16 at the hippocampus. Of note, these signaling molecules are increased in the cerebrospinal fluid of depressed patients upon fluoxetine treatment. Thus, our results demonstrate that miR-16 mediates the action of fluoxetine by acting as a micromanager of hippocampal neurogenesis. They further clarify the signals and the pathways involved in the hippocampal response to fluoxetine, which may help refine therapeutic strategies to alleviate depressive disorders

Molecular and functional interactions between tumor necrosis factor-alpha receptors and the glutamatergic system in the mouse hippocampus : implications for seizure susceptibility

Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine acting on two distinct receptor subtypes, namely p55 and p75 receptors. TNF-alpha p55 and p75 receptor knockout mice were previously shown to display a decreased or enhanced susceptibility to seizures, respectively, suggesting intrinsic modifications in neuronal excitability. We investigated whether alterations in glutamate system function occur in these naive knockout mice with perturbed cytokine signaling that could explain their different propensity to develop seizures. Using Western blot analysis of hippocampal homogenates, we found that p55(-/-) mice have decreased levels of membrane GluR3 and NR1 glutamate receptor subunits while GluR1, GluR2, GluR6/7 and NR2A/B were unchanged as compared to wild-type mice. In p75(-/-) mice, GluR2, GluR3, GluR6/7 and NR2A/B glutamate receptor subunits were increased in the hippocampus while GluR1 and NR1 did not change. Extracellular single-cell recordings of the electrical activity of hippocampal neurons were carried out in anesthetized mice by standard electrophysiological techniques. Microiontophoretic application of glutamate increased the basal firing rate of hippocampal neurons in p75(-/-) mice versus wild-type mice, and this effect was blocked by 2-amino-5-phosphopentanoic acid and 6-nitro-7-sulfamoyl-benzo(f)quinoxaline-2,3-dione denoting the involvement of N-methyl-D-aspartic acid and AMPA receptors. In p55(-/-) mice, hippocampal neurons responses to glutamate were similar to wild-type mice. Spontaneous glutamate release measured by in vivo hippocampal microdialysis was significantly decreased only in p55(-/-) mice. No changes were observed in KCl-induced glutamate release in both receptor knockout mice strains versus wild-type mice. These findings highlight specific molecular and functional interactions between p55 and p75 receptor-mediated signaling and the glutamate system. These interactions may be relevant for controlling neuronal excitability in physiological and pathological conditions.peer-reviewe

Serum levels of cytokines and C-reactive protein in acute ischemic stroke patients, and their relationship to stroke lateralization, type, and infarct volume

There is increasing evidence that inflammation plays an important role in the progression of acute ischemic stroke (AIS). The primary aims of this study were to examine the serum levels of 13 cytokines, C-reactive protein (CRP), glucose, and hemoglobin in AIS patients, and their relationship to stroke lateralization, type, and infarct volume. Forty-five patients with AIS were evaluated. Blood samples were taken within 72 h, and volumetric analyses performed within 1–7 days after AIS onset. Cytokines were measured in serum from all patients and from 40 control subjects using Luminex Bio-Plex XMap technology. The levels of interleukin (IL)-1ra (p < 0.001), IL-6 (p < 0.001), IL-8 (p < 0.001), IL-9 (p = 0.038), IL-10 (p = 0.001), IL-12 (p = 0.001), IL-18 (p < 0.001), and GRO-α (CXCL1) (p = 0.017) were significantly higher in the AIS patients than in the controls. The IL-8 level was significantly correlated with age in the patient group (r = 0.52, p < 0.001). None of the variables were found to be associated with stroke lateralization. Infarct volume was significantly positively correlated with CRP level (r = 0.47, p = 0.005). Patients with radiologically confirmed infarctions had significantly elevated serum levels of GRO-α (p = 0.023). The cytokine profile of the AIS patients supports not only earlier findings of a proinflammatory response but also early activation of endogenous immunosuppressive mechanisms. Novel findings of this study are elevated serum levels of IL-9 and GRO-α. Elevated GRO-α in AIS patients with radiologically confirmed infarctions suggests that GRO-α is specific for stroke of known etiology. Our results indicate that CRP plays an important role in the progression of cerebral tissue injury

COX-2, CB2 and P2X7-immunoreactivities are increased in activated microglial cells/macrophages of multiple sclerosis and amyotrophic lateral sclerosis spinal cord

BACKGROUND: While multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) are primarily inflammatory and degenerative disorders respectively, there is increasing evidence for shared cellular mechanisms that may affect disease progression, particularly glial responses. Cyclooxygenase 2 (COX-2) inhibition prolongs survival and cannabinoids ameliorate progression of clinical disease in animal models of ALS and MS respectively, but the mechanism is uncertain. Therefore, three key molecules known to be expressed in activated microglial cells/macrophages, COX-2, CB2 and P2X7, which plays a role in inflammatory cascades, were studied in MS and ALS post-mortem human spinal cord. METHODS: Frozen human post mortem spinal cord specimens, controls (n = 12), ALS (n = 9) and MS (n = 19), were available for study by immunocytochemistry and Western blotting, using specific antibodies to COX-2, CB2 and P2X7, and markers of microglial cells/macrophages (CD 68, ferritin). In addition, autoradiography for peripheral benzodiazepine binding sites was performed on some spinal cord sections using [3H] (R)-PK11195, a marker of activated microglial cells/macrophages. Results of immunostaining and Western blotting were quantified by computerized image and optical density analysis respectively. RESULTS: In control spinal cord, few small microglial cells/macrophages-like COX-2-immunoreactive cells, mostly bipolar with short processes, were scattered throughout the tissue, whilst MS and ALS specimens had significantly greater density of such cells with longer processes in affected regions, by image analysis. Inflammatory cell marker CD68-immunoreactivity, [3H] (R)-PK11195 autoradiography, and double-staining against ferritin confirmed increased production of COX-2 by activated microglial cells/macrophages. An expected 70-kDa band was seen by Western blotting which was significantly increased in MS spinal cord. There was good correlation between the COX-2 immunostaining and optical density of the COX-2 70-kDa band in the MS group (r = 0.89, P = 0.0011, n = 10). MS and ALS specimens also had significantly greater density of P2X7 and CB2-immunoreactive microglial cells/macrophages in affected regions. CONCLUSION: It is hypothesized that the known increase of lesion-associated extracellular ATP contributes via P2X7 activation to release IL-1 beta which in turn induces COX-2 and downstream pathogenic mediators. Selective CNS-penetrant COX-2 and P2X7 inhibitors and CB2 specific agonists deserve evaluation in the progression of MS and ALS

Enriched Monolayer Precursor Cell Cultures from Micro-Dissected Adult Mouse Dentate Gyrus Yield Functional Granule Cell-Like Neurons

BACKGROUND: Stem cell cultures are key tools of basic and applied research in Regenerative Medicine. In the adult mammalian brain, lifelong neurogenesis originating from local precursor cells occurs in the neurogenic regions of the hippocampal dentate gyrus. Despite widespread interest in adult hippocampal neurogenesis and the use of mouse models to study it, no protocol existed for adult murine long-term precursor cell cultures with hippocampus-specific differentiation potential. METHODOLOGY/PRINCIPAL FINDINGS: We describe a new strategy to obtain serum-free monolayer cultures of neural precursor cells from microdissected dentate gyrus of adult mice. Neurons generated from these adherent hippocampal precursor cell cultures expressed the characteristic markers like transcription factor Prox1 and showed the TTX-sensitive sodium currents of mature granule cells in vivo. Similar to granule cells in vivo, treatment with kainic acid or brain derived neurotrophic factor (BDNF) elicited the expression of GABAergic markers, further supporting the correspondence between the in vitro and in vivo phenotype. When plated as single cells (in individual wells) or at lowest density for two to three consecutive generations, a subset of the cells showed self-renewal and gave rise to cells with properties of neurons, astrocytes and oligodendrocytes. The precursor cell fate was sensitive to culture conditions with their phenotype highly influenced by factors within the media (sonic hedgehog, BMP, LIF) and externally applied growth factors (EGF, FGF2, BDNF, and NT3). CONCLUSIONS/SIGNIFICANCE: We report the conditions required to generate adult murine dentate gyrus precursor cell cultures and to analyze functional properties of precursor cells and their differentiated granule cell-like progeny in vitro

Nicotinamide Inhibits Alkylating Agent-Induced Apoptotic Neurodegeneration in the Developing Rat Brain

BACKGROUND: Exposure to the chemotherapeutic alkylating agent thiotepa during brain development leads to neurological complications arising from neurodegeneration and irreversible damage to the developing central nerve system (CNS). Administration of single dose of thiotepa in 7-d postnatal (P7) rat triggers activation of apoptotic cascade and widespread neuronal death. The present study was aimed to elucidate whether nicotinamide may prevent thiotepa-induced neurodegeneration in the developing rat brain. METHODOLOGY/PRINCIPAL FINDINGS: Neuronal cell death induced by thiotepa was associated with the induction of Bax, release of cytochrome-c from mitochondria into the cytosol, activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP-1). Post-treatment of developing rats with nicotinamide suppressed thiotepa-induced upregulation of Bax, reduced cytochrome-c release into the cytosol and reduced expression of activated caspase-3 and cleavage of PARP-1. Cresyl violet staining showed numerous dead cells in the cortex hippocampus and thalamus; post-treatment with nicotinamide reduced the number of dead cells in these brain regions. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) and immunohistochemical analysis of caspase-3 show that thiotepa-induced cell death is apoptotic and that it is inhibited by nicotinamide treatment. CONCLUSION: Nicotinamide (Nic) treatment with thiotepa significantly improved neuronal survival and alleviated neuronal cell death in the developing rat. These data demonstrate that nicotinamide shows promise as a therapeutic and neuroprotective agent for the treatment of neurodegenerative disorders in newborns and infants