bluuebunny/crossref_metadata_2025_split huggingface dataset:
Taurine elevates dopamine levels in the rat nucleus accumbens; antagonism by strychnine
Authors: Ericson Mia , Molander Anna , Stomberg Rosita , Söderpalm Bo 
Published: June 2006

AbstractThe mesolimbic dopamine (DA) system, projecting from the ventral tegmental area (VTA) to the nucleus accumbens (nAcc), is involved in reward‐related behaviours and addictive processes, such as alcoholism and drug addiction. It was recently suggested that strychnine‐sensitive glycine receptors (GlyR) in the nAcc regulate both basal and ethanol‐induced mesolimbic DA activity via a neuronal loop involving endogenous activation of nicotinic acetylcholine receptors (nAChR) in the VTA. However, as the nAcc appears to contain few glycine‐immunoreactive cell bodies or fibres, the question as to what may be the endogenous ligand for GlyRs in this brain region remains open. Here we have investigated whether the amino acid taurine could serve this purpose using in vivo microdialysis in awake, freely moving male Wistar rats. Local perfusion of taurine (1, 10 or 100 mm in the perfusate) increased DA levels in the nAcc. The taurine (10 mm)‐induced DA increase was, similarly to that previously observed after ethanol, completely blocked by (i) perfusion of the competitive GlyR antagonist strychnine in the nAcc, (ii) perfusion of the nAChR antagonist mecamylamine (100 µm) in the VTA, and (iii) systemic administration of the acetylcholine‐depleting drug vesamicol (0.4 mg/kg, i.p). The present results suggest that taurine may be an endogenous ligand for GlyRs in the nAcc and that the taurine‐induced elevation of DA levels in this area, similarly to that observed after local ethanol, is mediated via a neuronal loop involving endogenous activation of nAChRs in the VTA.
Swedish and Lithuanian employed women's subjective well‐being
Authors: Daukantaite Daiva , Zukauskiene Rita 
Published: June 2006

National differences in subjective well‐being (SWB) and relationships between SWB and socio‐demographic factors were investigated in samples of middle‐aged employed Swedish (N = 316) and Lithuanian (N = 308) women. The results showed that the Swedish women scored significantly higher on each SWB component than their counterparts in Lithuania, except in extrinsic job satisfaction. For the Swedish sample, the largest mean differences between different socio‐demographic groups were found for global life satisfaction between married/co‐habiting and single women and between women who had at least one child and those without children. For the Lithuanian sample, the largest differences in all SWB components were found between women characterised by high or low education/income.
The radical scavenger CR‐6 protects SH‐SY5Y neuroblastoma cells from oxidative stress‐induced apoptosis: effect on survival pathways
Authors: Sanvicens Nuria , Gómez‐Vicente Violeta , Messeguer Angel , Cotter Thomas G. 
Published: June 2006

AbstractReactive oxygen species (ROS) and oxidative stress have long been linked to cell death of neurons in many neurodegenerative conditions. However, the exact molecular mechanisms triggered by oxidative stress in neurodegeneration are at present unclear. In the current work we have used the human neuroblastoma SH‐SY5Y cell line as a model for studying the molecular events occurring after inducing apoptosis with H2O2. We show that treatment of SH‐SY5Y cells with H2O2 up‐regulates survival pathways during early stages of apoptosis. Subsequently, the decline of anti‐apoptotic protein levels leads to the activation of the calcium‐dependent proteases calpains and the cysteine proteases caspases. Additionally, we demonstrate that CR‐6 (3,4‐dihydro‐6‐hydroxy‐7‐methoxy‐2,2‐dimethyl‐1(2H)‐benzopyran) acts as a scavenger of ROS and prevents apoptosis by enhancing and prolonging up‐regulation of survival pathways. Furthermore, we show that pre‐treatment of SH‐SY5Y cells with a cocktail containing CR‐6, the pan‐caspase inhibitor zVAD‐fmk (zVal‐Ala‐Asp‐fluoro‐methylketone) and the calpain inhibitor SJA6017 confers almost total protection against apoptosis. In summary, the present work characterizes the molecular mechanisms involved in oxidative stress‐induced apoptosis in SH‐SY5Y cells. Our findings highlight the relevance of CR‐6, alone or in combination with other drugs, as potential therapeutic strategy for the treatment of neurodegenerative diseases.
Chaperone protein 14‐3‐3 and protein kinase A increase the relative abundance of low agonist sensitivity human α4β2 nicotinic acetylcholine receptors in Xenopus oocytes
Authors: Exley Richard , Moroni Mirko , Sasdelli Federica , Houlihan Lee M. , Lukas Ronald J. , Sher Emanuele , Zwart Ruud , Bermudez Isabel 
Published: June 2006

Abstractα4 and β2 nicotinic acetylcholine (nACh) receptor subunits expressed heterologously in Xenopus oocytes assemble into a mixture of receptors with high and low agonist sensitivity whose relative abundance is influenced by the heteropentamer subunit ratio. We have found that inhibition of protein kinase A by KT5720 decreased maximal [3H]cytisine binding and acetylcholine (ACh)‐induced current responses, and increased the relative proportion of α4β2 receptors with high agonist sensitivity. Mutation of serine 467, a putative protein kinase A substrate in a chaperone protein binding motif within the large cytoplasmic domain of the α4 subunit, to alanine or asparate decreased or increased, respectively, maximal [3H]cytisine binding and ACh response amplitude. Expression of α4S467A mutant subunits decreased steady levels of α4 and the relative proportion of α4β2 receptors with low agonist sensitivity, whilst expression of α4S467D increased steady levels of α4 and α4β2 receptors with low agonist sensitivity. Difopein, an inhibitor of chaperone 14‐3‐3 proteins, decreased [3H]cytisine binding and ACh responses and increased the proportion of α4β2 with high sensitivity to activation by ACh. Thus, post‐translational modification affecting steady‐state levels of α4 subunits provides a possible means for physiologically relevant, chaperone‐mediated variation in the relative proportion of high and low agonist sensitivity α4β2 nACh receptors.
Glutamate‐induced octamer DNA binding and transcriptional control in cultured radial glia cells
Authors: López‐Bayghen Esther , Cruz‐Solís Irma , Corona Matilde , López‐Colomé Ana María , Ortega Arturo 
Published: June 2006

AbstractGlutamate, the main excitatory neurotransmitter in the vertebrate brain, is critically involved in gene expression regulation in neurons and in glia cells. Neuron–glia interactions provide the framework for synaptic plasticity. Retinal and cerebellar radial glia cells surround glutamatergic excitatory synapses and sense synaptic activity through glutamate receptors expressed in their membranes. Several glutamate‐dependent membrane to nuclei signaling cascades have been described in these cells. Octamer DNA binding factors, namely Oct‐1 and Oct‐2 recognize similar DNA sequences on regulatory regions, but their final transcriptional effect depends on several factors. By these means, different responses can be achieved in different cell types. Here, we describe a comparison between the glutamate‐induced DNA binding of octamer factors and their functional activities in two important types of radial glia, retinal Müller and cerebellar Bergmann glial cells. While Oct‐1 is expressed in both cell types and in both glutamate treatments results in an increase in Oct‐1 DNA binding, this complex is capable of transactivating a reporter gene only in Müller glia cells. In contrast, Oct‐2 expression is restricted to Bergmann glia cells in which glutamate treatment results in an augmentation of Oct‐2 DNA binding complexes and the repression of kainate binding protein gene transcription. Our present findings demonstrate a differential role for Oct‐1 and Oct‐2 transcription factors in glial glutamate signaling, and further strengthen the notion of an important role for glial cells in glutamatergic transactions in the central nervous system.
The LGI1/Epitempin gene encodes two protein isoforms differentially expressed in human brain
Authors: Furlan Sandra , Roncaroli Federico , Forner Francesca , Vitiello Libero , Calabria Elisa , Piquer‐Sirerol Salomé , Valle Giorgio , Perez‐Tur Jordi , Michelucci Roberto , Nobile Carlo 
Published: June 2006

AbstractThe leucine‐rich, glioma inactivated 1 (LGI1)/Epitempin gene has been linked to two phenotypes as different as gliomagenesis and autosomal dominant lateral temporal epilepsy. Its function and the biochemical features of the encoded protein are unknown. We characterized the LGI1/Epitempin protein product by western blot analysis of mouse and human brain tissues. Two proteins of about 60 and 65 kDa were detected by an anti‐LGI1 antibody within the expected molecular mass range. The two proteins appeared to reside in different subcellular compartments, as they were fractionated by differential centrifugation. The specificity of both polypeptides was validated by cell transfection assay and mass spectrometry analysis. Immunoblot analysis of protein distribution in various zones of the human brain revealed variable amounts of both proteins. Notably, these proteins were more abundant in the temporal neocortex than in the hippocampus, the difference in abundance of the 65‐kDa product being particularly pronounced. These results suggest that the two protein isoforms encoded by LGI1/Epitempin are differentially expressed in the human brain, and that higher expression levels of these proteins in the lateral temporal cortex may underlie the susceptibility of this brain region to the epileptogenic effects of LGI1/Epitempin mutations.
RS‐α‐lipoic acid protects cholinergic cells against sodium nitroprusside and amyloid‐β neurotoxicity through restoration of acetyl‐CoA level
Authors: Bielarczyk Hanna , Gul Sylwia , Ronowska Anna , Bizon‐Zygmanska Dorota , Pawelczyk Tadeusz , Szutowicz Andrzej 
Published: June 2006

AbstractThe work presented here verifies the hypothesis that RS‐α‐lipoic acid may exert its cholinoprotective and cholinotrophic activities through the maintenance of appropriate levels of acetyl‐CoA in mitochondrial and cytoplasmic compartments of cholinergic neurons. Sodium nitroprusside (SNP) and amyloid‐β decreased pyruvate dehydrogenase, choline acetyltransferase activities, acetyl‐CoA content in mitochondria and cytoplasm, as well as increased fraction of non‐viable, trypan blue positive cells in cultured differentiated cholinergic SN56 neuroblastoma cells. Lipoic acid totally reversed toxin‐evoked suppression of choline acetyltrasferase and pyruvate dehydrogenase activities, as well as mitochondrial and cytoplasmic acetyl‐CoA levels, and partially attenuated increase of cell mortality. Significant negative correlations were found between enzyme activities, acetyl‐CoA levels and cell mortality in different neurotoxic and neuroprotective conditions employed here. The level of cytoplamic acetyl‐CoA correlated with mitochondrial acetyl‐CoA, whereas choline acetyltransferase activity followed shifts in cytoplasmic acetyl‐CoA. Thus, we conclude that, in cholinergic neurons, particular elements of the pyruvate–acetyl‐CoA–acetylcholine pathway form a functional unit responding uniformly to nerotoxic and neuroprotectory conditions.
Muscarinic cationic current in gastrointestinal smooth muscles: signal transduction and role in contraction
Authors: Unno T. , Matsuyama H. , Okamoto H. , Sakamoto T. , Yamamoto M. , Tanahashi Y. , Yan H.‐D. , Komori S. 
Published: June 2006

Summary1 The muscarinic receptor plays a key role in the parasympathetic nervous control of various peripheral tissues including gastrointestinal tract. The neurotransmitter acetylcholine, via activating muscarinic receptors that exist in smooth muscle, produces its contraction.2 There is the opening of cationic channels as an underlying mechanism. The opening of cationic channels results in influxes of Ca2+via the channels into the cell and also via voltage‐dependent Ca2+channels which secondarily opened in response to the depolarization, providing an amount of Ca2+for activation of the contractile proteins.3 Electrophysiological and pharmacological studies have shown that the cationic channels as well as muscarinic receptors exist in many visceral smooth muscle cells. However, the activation mechanisms of the cationic channels are still unclear.4 In this article, we summarize the current knowledge of the muscarinic receptor‐operated cationic channels, focusing on the receptor subtype, G protein and other signalling molecules that are involved in activation of these channels and on the molecular characterisitics of the channel. This will improve strategies aimed at developing new selective pharmacological agents and understanding the activation mechanism and functions of these channels in physiological systems.
Muscarinic cholinoceptor activation modulates DNA synthesis and CD40 expression in fibroblast cells
Authors: Casanova M. , Furlán C. , Sterin‐Borda L. , Borda E. S. 
Published: June 2006

Summary 1 The aim of the present work was to examine the role of muscarinic acetylcholine receptors (mAChR) on DNA synthesis and CD40 expression in human fibroblast cells. Neonatal human skin fibroblast cultures were stimulated with carbachol in presence or absence of specific antagonists and the following parameters were measured: identification of mAChR subtypes, DNA synthesis, inositol phosphates (InsP) production and CD40 expression. 2 Human fibroblasts express mAChR with Kd 0.47 ± 0.11 nm and Bmax 236 ± 22 fmol mg protein−1. Carbachol stimulates DNA synthesis, InsP and the expression of CD40. All these effects were inhibited by atropine, mustard hydrochloride (4‐DAMP) and pirenzepine but not by AF‐DX 116 and tropicamide, indicating that M3 and M1 mAChR are implicated in carbachol action. The relative Ki of the antagonists obtained by competition binding assay was in parallel to the relative potency for blocking both carbachol‐stimulated InsP accumulation and DNA synthesis. 3 The intracellular pathway leading to carbachol‐induced biological effects involved phospholipase C and calcium/calmodulin, as U‐73122 and trifluoroperazine blocked carbachol effects, respectively. Calphostin C, a protein kinase C inhibitor, had no effect, indicating that this enzyme does not participate in the system. 4 These results may contribute to a better understanding of the modulatory role of the parasympathetic muscarinic system on normal human fibroblast function.
Confluent and reticulated papillomatosis Gougerot‐Carteaud successfully treated with minocycline
Authors: Löwenstein Melitta , Metzler Gisela , Röcken Martin , Schaller Martin 
Published: June 2006

SummaryConfluent and reticulated papillomatosis is a rare dermatosis of unknown etiology mostly affecting young males and females most common in adolescence. The eruption consists of confluent, flat, brown papules forming a pigmented reticulated pattern. It occurs primarily in the intermammary and epigastric regions but may spread to the axillae. A 27‐yearold patient with typical clinical and histologic features of confluent and reticulated papillomatosis responded well to oral minocycline.
Antiphospholipid antibodies and hyperhomocysteinaemia in patients with vascular occlusive disease
Authors: Meschengieser Susana , Gennari Laura , Alberto Maria , Sanchez-Luceros Analia , Blanco Alicia , Lazzari Maria , Casais Patricia 
Published: June 2006

SummaryHyperhomocysteinemia (HHcy), lupus anticoagulant (LA) and anticardiolipin antibodies (ACA) are independent risk factors for thrombosis. Even though risks are cumulative, the clinical impact of the association is unknown. Preliminary data suggested that HHcy might be associated with transient LA and ACA, disappearing after lowering HHcy. We prospectively evaluated the association of HHcy and LA/ACA, the effect of lowering HHcy with folic acid in LA behavior, and the correlation of the initial dRVVT with LA behavior after folic acid in 210 patients with thrombosis and adverse pregnancy outcomes. Prevalence of HHcy among patients with LA/ACA was 40%. Thirty-one patients exhibited only HHcy (15%; Group 1), 106 (50%; Group 2) had only LA/ACA, while 73 (35%; Group 3) had both. After therapy, 63% and 64% of LA/ACA remained positive in Group 3 and 2, respectively. We observed a trend towards a more positive dRVVT in persistent LA after lowering HHcy. No differences in clinical presentation or in outcomes after two years of followup were observed among the groups. Even though the association of HHcy and LA/ACA is common in patients with thrombosis, it might have no prognostic implications if Hcy levels are lowered. Currently, no laboratory findings correlate with LA behavior, which is independent of homocysteine levels and vitamin treatment.
Factor V Leiden mutation and pregnancy-related venous thromboembolism: What is the exact risk?
Authors: Schved Jean-Francois , Daures Jean-Pierre , Biron-Andreani Christine 
Published: June 2006

SummaryThe magnitude of the association of factor V Leiden mutation with pregnancy-related venous thrombosis remains unclear. Our objective was to undertake a systematic review and a meta-analysis of the literature to estimate precisely the association of factor V Leiden mutation with the risk of first,or recurrent,pregnancy-related venous thromboembolism. Studies published before October 2005 were identified by Medline®. Using both fixed and random effect models, odds ratios (OR) with accompanying 95% confidential intervals (CI) were calculated for the factor V Leiden mutation and the clinical end-point (Yusuf-Peto adaptation of the Mantel-Haenszel, DerSimonian and Laird method).We identified 13 studies including 7 cohorts and 6 case control studies relating to factor V Leiden and pregnancy-related venous thrombosis.The results from the cohorts showe a pooled OR of 4.46 (95% CI,1.82–10.94;7,879 pooled women), with no evidence of statistical heterogeneity (p=0.36), for the risk of a first venous thromboembolism during pregnancy or the postpartum period associated with the factor V Leiden mutation.Case-control studies revealed a higher risk ( OR 8.6,95% CI, 5.85–12.63; 1,524 pooled women) with significant heterogeneity (p<0.005). Because of insufficient data, an analysis for the risk of recurrence could not be performed. Our findings emphasize the fact that limited data are available on this topic.This meta-analysis provides clinicians with an estimate of the average risk of a first thrombosis occurring during pregnancy in women carrying the factor V Leiden to assist the management of such women.
Detection and quantification of mature circulating endothelial cells using flow cytometry and immunomagnetic beads: A methodological comparison
Authors: Goon Patrick , Boos Christopher , Stonelake Paul , Blann Andrew , Lip Gregory 
Published: June 2006

SummaryMature circulating endothelial cells (CECs) are novel cellular markers of endothelial damage/dysfunction. The two main techniques of CEC enumeration are flow cytometry (FC) and immunomagnetic bead (IB) isolation. Both quantify CECs accurately, but a direct comparison of both methods has not been reported. We sought to assess the agreement between the two methods in two patient populations, and a group of healthy subjects, with emphasis given to methodological issues. We included 34 patients with acute coronary syndrome (ACS), 60 patients with primary breast cancer (PBC) and 30 healthy controls (HC). We quantified CECs using the IB method [CD146 and FITCUlex europaeus lectin-1] and FC [CD45, CD34 and CD146]. Bland-Altman plots suggested reasonable agreement (<5% of events >2 standard deviations from the mean) between FC and the IB methods for CEC quantification in whole blood in the two disease groups (ACS and PBC), but not among the HCs. There were no statistically significant differences in CEC levels by the two methods amongst all three patient groups. There is reasonable agreement between the FC and the IB methods for mature CEC quantification in whole blood, especially amongst disease groups. The agreement between the two methods appears to weaken in healthy controls, and at lower and higher absolute CEC counts.
Finite Element Methods for the Frequency Response Prediction of Bonded Composite Structures
Authors: Lips John A. , Kasper Eric P. , Welsh Jeffry S. 
Published: June 2006

The present study examines the effect bonded lap joints have on the frequency response of a given structure. The test article developed consist of carbon fiber composite sections joined with epoxy single-lap joints. The motivation for this study stems from the initial findings of previous works conducted at the Air Force Research Laboratory. This work shows the key factors affecting the influence of bonded lap joints on the system frequency to be: section stiffness, bond configuration and type, boundary conditions, and mass distribution. In addition, sensitivity analyses conducted give direction to the level of detail necessary to model bonded lap joints with adequate efficiency and accuracy. To aid in determining an effective and accurate methodology, the following sensitivity studies are conducted: element formulation, composite ply angle, and mesh discretization. Validation of these studies with experimental data for various configurations allow for an uncertainty assessment of the numerical data presented.
Using ancestry-informative markers to define populations and detect population stratification
Authors: Enoch Mary-Anne , Shen Pei-Hong , Xu Ke , Hodgkinson Colin , Goldman David 
Published: June 2006

A serious problem with case-control studies is that population subdivision, recent admixture and sampling variance can lead to spurious associations between a phenotype and a marker locus, or indeed may mask true associations. This is also a concern in therapeutics since drug response may differ by ethnicity. Population stratification can occur if cases and controls have different frequencies of ethnic groups or in admixed populations, different fractions of ancestry, and when phenotypes of interest such as disease, drug response or drug metabolism, also differ between ethnic groups. Although most genetic variation is inter-individual, there is also significant inter-ethnic variation. The International HapMap Project has provided allele frequencies for approximately three million single nucleotide polymorphisms (SNPs) in Africans, Europeans and East Asians. SNP variation is greatest in Africans. Statistical methods for the detection and correction of population stratification, principally Structured Association and Genomic Control, have recently become freely available. These methods use marker loci spread throughout the genome that are unlinked to the candidate locus to estimate the ancestry of individuals within a sample, and to test for and adjust the ethnic matching of cases and controls. To date, few case-control association studies have incorporated testing for population stratification. This paper will focus on the debate about the quantity and methods for selection of highly informative marker loci required to characterize populations that vary in substructure or the degree of admixture, and will discuss how these theoretically desirable approaches can be effectively put into practice.