Pig paramyxovirus of the blue eye disease binding to a 116 kda glycoprotein expressed in pig neuronal membranes

Pig paramyxovirus of the blue eye disease (PPBED) is a novel member of the paramyxoviridae family which infects pigs. In neonatal pigs it causes neurological damage, whereas in adult pigs it affects the reproductive function. As PPBED damages the new-born pig central nervous system (CNS), it is important to study whether PPBED binds to the membrane proteins of all brain tissue, or selectively binds to neuronal tissue of the brain stem, olfactory bulb, hippocampus, cerebellum, frontal, temporal and parietal brain cortex. It is also important to establish whether it also infects neurones obtained from new-born, 60-day-old and adult pigs, and the role of carbohydrate residues in virus binding. The effect on virus binding of polyclonal antibodies against viral envelope proteins was also studied. Binding studies were performed using dot blot and virus overlay protein binding assays. PPBED was able to bind to membrane proteins from all brain regions, particularly to a protein band of approximately 116 kDa. Neuraminidase treatment of neuronal membrane proteins decreased virus binding; subsequent treatments with ?-galactosidase and manosidase did not increase virus binding inhibition. N-glycosidase F and trypsin also decreased virus binding, but not the O-glycanase. Antibodies against viral haemagglutinin-neuraminidase blocked virus binding more efficiently than antibodies against viral fusion protein. In conclusion: (1) PPBED is able to bind to pig neurones of all brain regions studied and at all ages analysed; (2) a 116 kDa membrane protein containing sialic acid residues with an N-linked oligosaccharide chain was specifically recognized; (3) PPBED haemagglutinin-neuraminidase protein seems to play a central role in neural receptor recognition

TRESK-like potassium channels in leukemic T cells

In this study, we present patch-clamp characterization of the background potassium current in human lymphoma (Jurkat cells), generated by voltage-independent 16 pS channels with a high (?100-fold) K +/Na+ selectivity. Depending on the background K + channels density, from few per cell up to ?1 open channel per ?m2, resting membrane potential was in the range of -40 to -83 mV, approaching E K = -88 mV. The background K+ channels were insensitive to margotoxin (3 nM), apamine (3 nM), and clotrimazole (1 ?M), high-affinity blockers of the lymphocyte Kv1.3, SKCa2, and IKCa1 channels. The current depended weakly on external pH. Arachidonic acid (20 ?M) and Hg 2+ (0.3-10 ?M) suppressed background K+ current in Jurkat cells by 75-90%. Background K+ current was weakly sensitive to TEA+ (IC50 = 14 mM), and was efficiently suppressed by externally applied bupivacaine (IC50 = 5 ?M), quinine (IC 50 = 16 ?M), and Ba2+ (2 mM). Our data, in particular strong inhibition by mercuric ions, suggest that background K+ currents expressed in Jurkat cells are mediated by TWIK-related spinal cord K+ (TRESK) channels belonging to the double-pore domain K+ channel family. The presence of human TRESK in the membrane protein fraction was confirmed by Western blot analysis. � 2008 Springer-Verlag

Electrophysiological and morphological alterations in peripheral nerves by the pig paramyxovirus of blue eye disease in neonatal pigs

The pig paramyxovirus of blue eye disease (PPBED) produces central nervous system (CNS) damage leading to death in piglets. However, when PPBED was injected into the muscle and came into contact with hind limb peripheral nerves and was transported to the CNS, it did not cause death and could be a mechanism by which to induce protection. This study analyses whether PPBED causes electrophysiological and morphological alterations in infected hind limb peripheral nerves. It also studies, whether PPBED induces the onset of haemagglutination inhibitory antibodies (HIA) when it is transported to the spinal cord after medial gastrocnemius (MG) intramuscular injection. PPBED was detected by an immunohistochemical method and nerve morphology was studied using electron microscopy. The physiological status of the nerve was evaluated with electrophysiological techniques. The electrical threshold of the infected MG nerve increased four- or five-fold compared to that in the ipsilateral lateral gastrocnemius or in the MG nerve on the control side. The infected nerve fibres underwent myelin sheet disarrangement and their internal fibre diameter decreased. PPBED induced the onset of HIA

Curcumin protects against the oxidative damage induced by the pesticide parathion in the hippocampus of the rat brain

One of the main concerns regarding organophosphate pesticides (OP) is their possible toxic effects. Doses that do not produce acute toxicity are capable of altering the structure and biochemistry of different tissues and organs by production of reactive oxygen species (ROS). Curcumin (CUR) is the main substance in Curcuma longa (Zingiberacea) rhizome that has strong antioxidant activity. However, the neuroprotective properties of curcumin against oxidative stress induced by prolonged exposure to parathion (PAR) is not clear. Objective: The present work evaluated the protective effect of curcumin against the oxidative damage induced in the rat hippocampus by the OP PAR. Methods: Forty female Wistar rats were distributed in four groups as follows: exposed to PAR by inhalation (PAR group); pre-treated with CUR and then exposed to PAR by inhalation, (CUR + PAR group); exposed to environmental air and treated with CUR in the food (CUR group); and exposed to environmental air (the control group). At the end of the handling process, the concentration of erythrocyte cholinesterase was monitored, as indicator of PAR intoxication and lipoperoxidation, immunohistochemistry for astrocytes, and activated microglia and apoptosis was determined in the hippocampus. Results: In the present study, we show that the administration of CUR (200 mg/kg body weight) significantly diminished the oxidative damage in the hippocampus of rats exposed to the OP PAR. Discussion: These data suggest that CUR may be an alternative to prevent neurodegenerative damage after pesticide exposure. W.S. Maney & Son Ltd 2012

Changes in the content of GFAP in the rat brain during pregnancy and the beginning of lactation

Several changes in brain function, including learning and memory, have been reported during pregnancy but the molecular mechanisms involved in these changes are unknown. Due to the fundamental role of glial cells in brain activity, we analyzed the content of glial fibrillary acidic protein (GFAP) in the hippocampus, frontal cortex, preoptic area, hypothalamus and cerebellum of the rat on days 2, 14, 18, and 21 of pregnancy and on day 2 of lactation by Western blot. A differential expression pattern of GFAP was found in the brain during pregnancy and the beginning of lactation. GFAP content was increased in the hippocampus throughout pregnancy, whereas a decrease was observed in cerebellum. GFAP content was increased in the frontal cortex and hypothalamus on days 14 and 18, respectively, with a decrease in the following days of pregnancy in both regions. In preoptic area a decrease in GFAP content was observed on day 14 with an increase on days 18 and 21. In the frontal cortex and cerebellum, GFAP content was increased on day 2 of lactation, while it was maintained as on day 21 of pregnancy in the other regions. Our data suggest a differential expression pattern of GFAP in the rat brain during pregnancy and the beginning of lactation that should be associated with changes in brain function during these reproductive stages. © 2010 Elsevier Ireland Ltd

Blue eye disease porcine rubulavirus (PoRv) infects pig neurons and glial cells using sialo-glycoprotein as receptor

Pig neural cells express glycoproteins with sialylated N-linked oligosaccharide chains (SNOC) which are used by the porcine rubulavirus (PoRv) as receptors. Pig neuronal or glial cell cultures were employed to investigate (a) whether PoRv infects such cells using a molecule expressing SNOC, and (b) the role of viral envelope glycoproteins in establishing the infection. Enriched neuronal or glial cell cultures were exposed to PoRv and infection was detected immunocytochemically. Neuronal cultures prepared from neonatal pigs were treated enzymatically to eliminate sialic acid or N-linked oligosaccharide chains. Primary neural cultures were exposed to anti-HN or anti-F preincubated with PoRv to study the role of the viral glycoproteins. In enriched cultures, PoRv infected neurons and glial cells, and sialic acid expressed in N-linked oligosaccharide chains appeared to play a central role in infection. It was concluded that HN and F viral glycoproteins are required to infect neurons and glial cells. � 2006 Elsevier Ltd. All rights reserved

Cytotoxic effect of curcumin on Giardia lamblia trophozoites

Giardia lamblia is one of the most important worldwide causes of intestinal infections produced by protozoa. Thus, the search for new alternative therapeutic approaches for this parasitic disease is very important. Common drugs used to control and eradicate this infection, frequently exhibit side effects that force patients to abandon treatment. The present work evaluates the anti-protozoan activity of curcumin, the main constituent of turmeric. Axenic G. lamblia (Portland 1 strain) cultures were exposed to different concentrations of curcumin. Its effects were evaluated on parasite growth, adhesion capacity and parasite morphology. We also evaluated the capacity of curcumin to induce an apoptosis-like effect. All curcumin concentrations inhibited trophozoite growth and adhesion in more than 50% in dose and time dependent manner. Morphological changes were described as protrusions formed under the cytoplasmic membrane, deformation due to swelling and cell agglutination. Curcumin induced apoptosis-like nuclear staining in dose and time dependent manner. In conclusion, curcumin exhibited a cytotoxic effect in G. lamblia inhibiting the parasite growth and adherent capacity, induced morphological alterations, provoked apoptosis-like changes. Future in vitro and in vivo experiments are endowed to elucidate the effect of curcumin in an experimental model of G. lamblia infection, analyze the involvement of ion channels in the swelling effect of curcumin during an apparent osmotic deregulation in G. lamblia trophozoites. This will lead to the proposal of the action mechanism of curcumin as well as the description of mechanism involved during the activation process for the apoptotic-like effect. © 2006 Elsevier B.V. All rights reserved

DNA damage in mouse lymphocytes exposed to curcumin and copper

Dietary polyphenolics. such as curcumin. have shown antioxidant and anti-inflammatory effects. Some antioxidants cause DNA strand breaks in excess of transition metal ions, such as copper. The aim of this study was to evaluate the in vitro effect of curcumin in the presence of increasing concentrations of copper to induce DNA damage in murine leukocytes by the comet assay. Balb-C mouse lymphocytes were exposed to 50 ?M curcumin and various concentrations of copper (10 ?M, 100 ?M and 200 ?M). Cellular DNA damage was detected by means of the alkaline comet assay. Our results show that 50 ?M curcumin in the presence of 100-200 ?M copper induced DNA damage in murine lymphocytes. Curcumin did not inhibit the oxidative DNA damage caused by 50 ?M H 2O2 in mouse lymphocytes. Moreover, 50 ?M curcumin alone was capable of inducing DNA strand breaks under the tested conditions. The increased DNA damage by 50 ?M curcumin was observed in the presence of various concentrations of copper, as detected by the alkaline comet assay

Influence of the composite materials surface microrelief on their optical properties

Проведен анализ влияния параметров компонентов, а также составляющих микрорельефа поверхности композитных материалов на их спектральную яркость и степень поляризации

Dopamine release modifies intracellular calcium levels in tyrosine hydroxylase-transfected C6 cells

Glioma cell line C6, transfected with tyrosine hydroxylase (TH) cDNA under the control of the glial fibrillary acid protein promoter (C6-THA cells), elicited a reduction in the apomorphine-induced turning behavior when they are implanted in Parkinson's disease models. Nevertheless, dopamine (Da) release has not been explicitly demonstrated nor has a possible mechanism of release been implicated. In this study, the in vitro Da release by C6 and C6-THA cells after chemical stimulation with KCl or glutamate was quantified using HPLC. Modifications in intracellular calcium levels in response to KCl stimulation and participation of Da receptor-mediated feedback in calcium regulation were also studied using FLUO 3 as a calcium concentration indicator. C6-THA cells release dopamine in basal conditions, and increase its release after KCl or glutamic acid stimulation. In a fraction of C6 and C6-THA cells, a transient intracellular calcium increase was observed after KCl stimulation, but C6-THA cells demonstrated a faster rate of calcium removal. C6 cells express mRNA from all five subtypes of Da receptors as demonstrated by real time PCR. D1 receptors were most abundant in C6 cells and its expression was further increased in C6-THA cells. Blocking D1-like receptors in C6-THA cells with the specific antagonist drug SCH-23390 induced a decrease in intracellular calcium removal rate, resembling non-manipulated C6 cells' calcium clearance. Da release by C6-THA cells could be related to calcium dependent mechanisms. Furthermore, production of Da by C6-THA cells seems to upregulate the expression of D1 receptors' mRNA. © 2007 Elsevier Inc. All rights reserved