102 research outputs found

    Basal astrocyte and microglia activation in the central nervous system of Familial Hemiplegic Migraine Type I mice

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    Background Gain-of-function missense mutations in the alpha(1A) subunit of neuronal Ca(V)2.1 channels, which define Familial Hemiplegic Migraine Type 1 (FHM1), result in enhanced cortical glutamatergic transmission and a higher susceptibility to cortical spreading depolarization. It is now well established that neurons signal to surrounding glial cells, namely astrocytes and microglia, in the central nervous system, which in turn become activated and in pathological conditions can sustain neuroinflammation. We and others previously demonstrated an increased activation of pro-algogenic pathways, paralleled by augmented macrophage infiltration, in both isolated trigeminal ganglia and mixed trigeminal ganglion neuron-satellite glial cell cultures of FHM1 mutant mice. Hence, we hypothesize that astrocyte and microglia activation may occur in parallel in the central nervous system. Methods We have evaluated signs of reactive glia in brains from naive FHM1 mutant mice in comparison with wild type animals by immunohistochemistry and Western blotting. Results Here we show for the first time signs of reactive astrogliosis and microglia activation in the naive FHM1 mutant mouse brain. Conclusions Our data reinforce the involvement of glial cells in migraine, and suggest that modulating such activation may represent an innovative approach to reduce pathology

    Expression of GPR17 receptor in a murine model of perinatal brain neuroinflammation and its possible interaction with Wnt pathway

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    Oligodendrocyte precursor cells (OPCs) are generated in specific germinal regions and progressively maturate to myelinating cells. Oligodendrocytes (OLs) differentiation is regulated by a complex interplay of intrinsic, epigenetic and extrinsic factors, including Wnt and the G protein-coupled receptor referred to as GPR17 (Mitew et al., 2014). This receptor responds to both extracellular nucleotides (UDP, UDP-glucose) and cysteinyl-leukotrienes (Ciana et al., 2006), endogenous signaling molecules involved in inflammatory response and in the repair of brain lesions. GPR17 is highly expressed in OPCs during the transition to immature OLs, but it is down-regulated in mature cells. Accordingly, GPR17-expressing OPCs are already present in mice at birth, increase over time, reach a peak at P10, before the peak of myelination, and then decline in the adult brain (Boda et al., 2011). Of note, in cultured OPCs, early GPR17 silencing has been shown to profoundly affect their ability to generate mature OLs (Fumagalli et al., 2011, 2015). Myelination defects characterize many brain disorders, including perinatal brain injury caused by systemic inflammation (Favrais et al., 2011), which is a leading cause of preterm birth. It has already been suggested that an imbalance in the Wnt/\u3b2-catenin/TCF4 pathway could be involved in the maturation arrest of OLs that is observed in premature infants (Yuen et al., 2014). No data are currently available on GPR17 in perinatal brain injury and on its possible interaction with Wnt pathway. Based on these premises, the aim of this work was to assess if the maturational blockade of OLs due to mild systemic perinatal inflammation, induced by intraperitoneal injections of interleukin-1\u3b2 (IL- 1\u3b2), is accompanied by defects in GPR17 expression and whether the Wnt pathway is involved in the regulation of GPR17. Data showed that in newborn mice exposed to IL-1\u3b2, which induces a blockade of oligodendrocyte maturation, GPR17 expression is not affected at early time point (P5), but it is downregulated at P10, when its expression should be maximal. Moreover, in vitro studies revealed that the maturation blockade of the oligodendroglial cell line Oli-Neu, after treatment with a Wnt Agonist II, is accompanied by a severe inhibition of GPR17 expression. In conclusion, our data have shown that myelination defects observed in perinatal brain injury are associated with defects in GPR17 expression; further studies are needed to characterize the molecular link between Wnt pathway and GPR17 receptor

    Volterra equations perturbed by noise

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    We consider a linear abstract Volterra integrodifferential equation in a Hilbert space, forced by a Gaussian process. The equation involves a completely monotone convolution kernel with a singularity at t = 0 and a sectorial linear spatial operator. Existence and uniqueness of a weak solution is established. Furthermore we give conditions such that the solution converges to a stationary process. Our method consists in a state space setting so that the corresponding solution process is Markovian, and the tools of linear analytic semigroup theory can be utilized

    The influence og growth promotant antibiotics and management system on the presence and prevalence of salmonella in swine

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    Food contamination due to Salmonella is the cause oflarge numbers of human food-borne illnesses worldwide. Reduction in fecal shedding and prevention of new Salmonella infections in livestock during the late finishing/marketing phase of production are critical control points associated with human food safety. The objectives of this research were to compare the effects of various treatments on the shedding of Salmonella during the late finishing phase of production in littermate swine reared nnder different management conditions. The treatments compared were: 1) multi-site segregated early weaning (SEW) versus continuous flow (CF) rearing of swine, 2) growth promotant antibiotics (medicated) versus no feed antibiotics (unmedicated), 3) 24 hour fasting versus full- feeding

    Adenosine Triphosphate–Binding Cassette Transporters Are Not Involved In the Detoxification of Azadirachta indica Extracts In Anopheles stephensi Larvae

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    Detoxifying pathways of mosquitoes against the neem (Azadirachta indica) extracts are still unclear. The aim of the present study was to investigate the role of adenosine triphosphate-binding cassette (ABC) transporters in this process in Anopheles stephensi, one of the main malaria vectors in southern Asia. Third-stage larvae of An. stephensi were fed with fish food alone or in combination with neem extract at 0.5%, 1%, 5%, and 10%. Six ABC-transporter genes from 3 different subfamilies (B, C, and G) were analyzed to assess their relative expression compared with controls. A bioassay was also performed to assess larval mortality rate at different concentrations and in combination with verapamil, an ABC-transporter inhibitor. No significant variation in the expression levels of any transporter belonging to the B, C, and G subfamilies was detected. Furthermore, the use of verapamil did not induce an increase in mortality at any of the tested neem extract concentrations, indicating that ABC transporters are not involved in the detoxification of neem extracts in An. stephensi larvae

    SNX27, a protein involved in down syndrome, regulates GPR17 trafficking and oligodendrocyte differentiation

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    The G protein-coupled receptor 17 (GPR17) plays crucial roles in myelination. It is highly expressed during transition of oligodendrocyte progenitor cells to immature oligodendrocytes, but, after this stage, it must be down-regulated to allow generation of mature myelinating cells. After endocytosis, GPR17 is sorted into lysosomes for degradation or recycled to the plasma membrane. Balance between degradation and recycling is important for modulation of receptor levels at the cell surface and thus for the silencing/activation of GPR17-signaling pathways that, in turn, affect oligodendrocyte differentiation. The molecular mechanisms at the basis of these processes are still partially unknown and their characterization will allow a better understanding of myelination and provide cues to interpret the consequences of GPR17 dysfunction in diseases. Here, we demonstrate that the endocytic trafficking of GPR17 is mediated by the interaction of a type I PDZ-binding motif located at the C-terminus of the receptor and SNX27, a recently identified protein of the endosome-associated retromer complex and whose functions in oligodendrocytes have never been studied. SNX27 knock-down significantly reduces GPR17 plasma membrane recycling in differentiating oligodendrocytes while accelerating cells' terminal maturation. Interestingly, trisomy-linked down-regulation of SNX27 expression in the brain of Ts65Dn mice, a model of Down syndrome, correlates with a decrease in GPR17+ cells and an increase in mature oligodendrocytes, which, however, fail in reaching full maturation, eventually leading to hypomyelination. Our data demonstrate that SNX27 modulates GPR17 plasma membrane recycling and stability, and that disruption of the SNX27/GPR17 interaction might contribute to pathological oligodendrocyte differentiation defects. GLIA 2016. GLIA 2016;64:1437\u20131460

    Subclinical Leber's hereditary optic neuropathy with pediatric acute spinal cord onset: More than meets the eye

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    Background: Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by visual loss consequent to optic nerve atrophy. In some cases, LHON is associated with heterogeneous neurological extraocular manifestations and is referred to as "Leber plus disease"; rarely it is associated with a multiple sclerosis (MS)-like syndrome known as Harding disease, but no pediatric extraocular acute spinal onset is reported. Case presentation: We describe the case of a 5-year-old girl carrying the G3460A mtDNA mutation who was referred to clinical examination for bilateral upper and lower limb weakness with no sign of optic neuropathy. Spinal cord MRI showed hyperintense signal alterations in T2-weighted and restricted diffusion in DWI sequences in the anterior portion of the cervical and dorsal spinal cord resembling a spinal cord vascular injury. No association between this mutation and pediatric spinal cord lesions has previously been reported. Alternative diagnostic hypotheses, including infective, ischemic and inflammatory disorders, were not substantiated by clinical and instrumental investigations. Conclusions: Our case reports a novel pediatric clinical manifestation associated with the m.3460G > A mtDNA mutation, broadening the clinical spectrum of this disease. Early identification of new cases and monitoring of carriers beginning in childhood is important to prevent neurological deterioration and preserve long-term function

    Optimization of growth media components for polyhydroxyalkanoate (PHA) production from organic acids by Ralstonia eutropha

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    We employed systematic mixture analysis to determine optimal levels of acetate, propionate, and butyrate for cell growth and polyhydroxyalkanoate (PHA) production by Ralstonia eutropha H16. Butyrate was the preferred acid for robust cell growth and high PHA production. The 3-hydroxyvalerate content in the resulting PHA depended on the proportion of propionate initially present in the growth medium. The proportion of acetate dramatically affected the final pH of the growth medium. A model was constructed using our data that predicts the effects of these acids, individually and in combination, on cell dry weight (CDW), PHA content (%CDW), PHA production, 3HV in the polymer, and final culture pH. Cell growth and PHA production improved approximately 1.5-fold over initial conditions when the proportion of butyrate was increased. Optimization of the phosphate buffer content in medium containing higher amounts of butyrate improved cell growth and PHA production more than 4-fold. The validated organic acid mixture analysis model can be used to optimize R. eutropha culture conditions, in order to meet targets for PHA production and/or polymer HV content. By modifying the growth medium made from treated industrial waste, such as palm oil mill effluent, more PHA can be produced.Malaysia. Ministry of Science, Technology and Innovation (MOSTI

    FLOW FIELD IN THE VANED DIFFUSER OF A CENTRIFUGAL PUMP AT DIFFERENT VANE SETTING ANGLES

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    ABSTRACT Particle image velocimetry (2D-PIV) has been used for the investigation of the time averaged flow field inside the vaned diffuser of a centrifugal pump operating at best efficiency point. Pump performances and the diffuser flow field were analysed for three different vane setting angles. It was evidenced that flow coefficient at the best efficiency point decreases with the diffuser setting angle reduction. From 2D-PIV measurements in five different blade to blade planes, spanwise averaged flow angles and velocity distribution were computed. It was evidenced an influence of the diffuser setting angle on the span-wise distribution of the flow rate and of the absolute mass averaged flow angle at impeller discharge. An overturning, at the diffuser discharge was also evidenced for the two highest setting angles. 2D-PIV flow fields are presented in three different pseudo-secondary planes in order to enlighten the cross flows affecting the diffuser flow field

    Penetration of roxithromycin into bronchial secretions

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    The penetration of an antibacterial agent into the bronchial secretions is a crucial factor in determining its clinical efficacy in the treatment of bacterial respiratory infections. Roxithromycin is a novel macrolide compound active against the most frequent respiratory pathogens. Following administration of 150 mg p.o., we observed a prompt penetration of the compound into bronchial secretions of critically ill patients. Elevated concentrations above the MICs of the commonest susceptible pathogens are reached and maintained until the next administration
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