bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation by GD3 of the proinflammatory response of microglia mediated by interleukin‐15
Authors: Gómez‐Nicola Diego , Doncel‐Pérez Ernesto , Nieto‐Sampedro Manuel 
Published: February 2006

AbstractThe interleukin (IL)‐15‐dependent immune responses of murine microglia were strongly affected by low concentrations of the ganglioside GD3. The ganglioside binding to IL‐15 inhibited the proinflammatory effects of the cytokine, reducing IL‐15‐dependent T‐cell proliferation as well as mRNA expression for IL‐15Rα, p65, and NFATc2 in the N13 murine microglial cell line. Treatment of primary murine microglial cultures with GD3 abolished IL‐15 production, without affecting cellular viability, but decreased the production of nitric oxide, a direct sensor of inflammation and nuclear factor‐κB activity. We conclude that low doses of GD3 could inhibit specific proinflammatory mechanisms and modulate the inflammatory environment, leading to a less reactive scene. Microglial cells are one of the main actors in the inflammatory events that follow CNS trauma or an autoimmune disease episode, modulating the internal production of cytokines, growth factors, and other homeostatic molecules that may determine the evolution and outcome of tissue damage. Proinflammatory cytokines have a relevant role in the initial events, and modulation of their activity by gangliosides could cut down their harmful effects and interfere with invasion of the CNS by peripheral immune cells. The antiinflammatory properties of GD3 could be significant in the treatment of pain subsequent to CNS damage. © 2006 Wiley‐Liss, Inc.
Regulation of human neural precursor cells by laminin and integrins
Authors: Flanagan Lisa A. , Rebaza Liza M. , Derzic Stanislava , Schwartz Philip H. , Monuki Edwin S. 
Published: February 2006

AbstractDeciphering the factors that regulate human neural stem cells will greatly aid in their use as models of development and as therapeutic agents. The extracellular matrix (ECM) is a component of stem cell niches in vivo and regulates multiple functions in diverse cell types, yet little is known about its effects on human neural stem/precursor cells (NSPCs). We therefore plated human NSPCs on four different substrates (poly‐L‐ornithine, fibronectin, laminin, and matrigel) and compared their responses with those of mouse NSPCs. Compared with the other substrates, laminin matrices enhanced NSPC migration, expansion, differentiation into neurons and astrocytes, and elongation of neurites from NSPC‐derived neurons. Laminin had a similar spectrum of effects on both human and mouse cells, highlighting the evolutionary conservation of NSPC regulation by this component of the ECM. Flow cytometry revealed that human NSPCs express on their cell surfaces the laminin‐binding integrins α3, α6, α7, β1, and β4, and function‐blocking antibodies to the α6 subunit confirmed a role for integrins in laminin‐dependent migration of human NSPCs. These results define laminin and its integrin receptors as key regulators of human NSPCs. © 2006 Wiley‐Liss, Inc.
Noradrenergic regulation of galanin expression in the supraoptic nucleus in the rat hypothalamus. An ex vivo study
Authors: Melnikova Victoria I. , Raison Danièle , Hardin‐Pouzet Hélène , Ugrumov Mikhail V. , Calas Andre , Grange‐Messent Valerie 
Published: February 2006

AbstractGalanin is coexpressed with vasopressin and oxytocin in magnocellular neurons of the rat neuroendocrine hypothalamus. Various physiological stimuli, such as osmotic stimulation or lactation, that affect vasopressin and oxytocin expression and release also modulate galanin expression. Magnocellular neurons are highly innervated by noradrenergic inputs from the brainstem. The noradrenergic system plays a critical excitatory role in the activation of vasopressin‐expressing and oxytocin‐expressing neurons. Here, we have evaluated the possible regulation of Gal expression by noradrenaline in the magnocellular neurons of supraoptic nucleus in an ex vivo acute model of rat hypothalamic slices. The slices containing the supraoptic nucleus were incubated with 10–4 M noradrenaline for 1 or 4 hr. The levels of galanin and galanin mRNA were estimated by semiquantitative immunohistochemistry and in situ hybridization, respectively. Our results show that the amount of galanin‐immunopositive material in the cell bodies of the magnocellular neurons increased significantly after incubation with noradrenaline compared with control slices at the same time point and that this effect was more pronounced after 4 hr than after 1 hr. In situ hybridization showed that radiolabeling of the supraoptic nucleus with a radioactive galanin probe increased slightly after 1 hr of incubation and increased considerably after 4 hr of incubation with noradrenaline. Our study shows that galanin may be a target in the regulation of the hypothalamic magnocellular–neurohypophysial system by noradrenaline. © 2006 Wiley‐Liss, Inc.
Semisynthetic sphingoglycolipid LIGA20 is neuroprotective against human immunodeficiency virus‐gp120‐mediated apoptosis
Authors: Bachis Alessia , Mocchetti Italo 
Published: February 2006

AbstractApoptosis and neuronal atrophy are commonly seen in patients infected with the human immunodeficiency virus type 1 (HIV‐1) in the late phase of infection. The HIV‐1 envelope glycoprotein gp120 has been suggested to be a causal agent of neuronal loss. Therefore, blocking gp120 neurotoxicity may be an effective way to reduce the neuronal degeneration seen in HIV patients. Brain‐derived neurotrophic factor (BDNF) prevents gp120‐mediated apoptosis in cerebellar granule cells. However, BDNF poorly crosses the blood–brain barrier and therefore may not be a suitable therapy for HIV patients. LIGA20 is a semisynthetic sphingoglycolipid that may be a valid alternative to BDNF. In fact, it has been shown that LIGA20 mimics the neuroprotective properties of BDNF. The present study was undertaken to characterize the relative potency of LIGA20 to antagonize gp120‐mediated apoptosis. Cerebellar granule cells were exposed to gp120IIIB (5 nM) or stromal‐cell derived factor‐1 (SDF), the natural ligand for the CXCR4 receptor to which gp120 binds, alone or in combination with LIGA20 (5 μM), and cell death/survival was determined 12 and 24 hr later by various markers of apoptosis. LIGA20 blocked the neurotoxic effect of gp120 and SDF. The neurotrophic effect of LIGA20 was reversed by K252a, a tyrosine kinase inhibitor used to block TrkB signaling, suggesting the involvement of TrkB activation. These findings provide the rationale for exploring the ability of compounds that mimic BDNF activity to reduce neuronal cell death in HIV‐1‐positive patients. © 2006 Wiley‐Liss, Inc.
Leukemia inhibitory factor is produced by myelin‐reactive T cells from multiple sclerosis patients and protects against tumor necrosis factor‐α‐induced oligodendrocyte apoptosis
Authors: Vanderlocht Joris , Hellings Niels , Hendriks Jerome J.A. , Vandenabeele Frank , Moreels Marjan , Buntinx Mieke , Hoekstra Dick , Antel Jack P. , Stinissen Piet 
Published: February 2006

AbstractIn multiple sclerosis (MS), damage to oligodendrocytes is believed to be caused by an aberrant immune response initiated by autoreactive T cells. Increasing evidence indicates that these T cells are not exclusively detrimental but might also exert protective effects. We report for the first time that myelin‐reactive T‐cell clones from eight MS patients (6/19) and five healthy controls (4/11) produce leukemia inhibitory factor (LIF), a member of the neuropoietic family of neurotrophins. In addition, T‐cell clones specific for tetanus toxoid, CD4+ and CD8+ T cells, and monocytes, but not B cells, secreted LIF. LIF‐producing T lymphocytes and macrophages were also identified immunohistochemically in both active and chronic‐active MS lesions. We further demonstrated dose‐dependent protective effects of LIF on tumor necrosis factor‐α‐induced apoptosis of oligodendrocytes. In conclusion, our data demonstrate that peripheral and CNS‐infiltrating T cells from MS patients produce LIF, a protective factor for oligodendrocytes. This study emphasizes that secretion of LIF may contribute to the neuroprotective effects of autoreactive T cells. © 2006 Wiley‐Liss, Inc.
Trkb receptors modulation of glutamate release is limited to a subset of nerve terminals in the adult rat hippocampus
Authors: Pereira Daniela B. , Rebola Nelson , Rodrigues Ricardo J. , Cunha Rodrigo A. , Carvalho Arsélio P. , Duarte Carlos B. 
Published: February 2006

AbstractBrain‐derived neurotrophic factor (BDNF) modulates glutamatergic excitatory transmission in hippocampal primary cultures by acting at a presynaptic locus. Although it has been suggested that BDNF also modulates adult hippocampus glutamatergic transmission, this remains a matter of controversy. To clarify a putative role for this neurotrophin in the modulation of glutamate release we applied exogenous BDNF to isolated adult rat hippocampal nerve terminals. BDNF, at 100 ng/ml, potentiated by 25% the K+‐evoked release of [3H]glutamate from hippocampal synaptosomes. The small effect of BDNF on [3H]glutamate release correlated with a modest increase in phospholipase Cγ (PLCγ) phosphorylation, and with the lack of effect of BDNF on extracellular‐signal regulated kinase (ERK) and Akt phosphorylation. Immunocytochemistry studies demonstrated that only about one‐third of glutamatergic synaptosomes were positive for TrkB immunoreactivity. Furthermore, biotinylation and subsynaptic fractionation studies showed that only one‐fourth of total full‐length TrkB was present at the plasma membrane, evenly distributed between the presynaptic active zone and the postsynaptic density. These results indicate that BDNF modulates synaptic transmission presynaptically in a small subset of hippocampal glutamatergic synapses that contain TrkB and that express the receptor on the plasma membrane. © 2006 Wiley‐Liss, Inc.
S100B protects LAN‐5 neuroblastoma cells against Aβ amyloid‐induced neurotoxicity via RAGE engagement at low doses but increases Aβ amyloid neurotoxicity at high doses
Authors: Businaro R. , Leone S. , Fabrizi C. , Sorci G. , Donato R. , Lauro G.M. , Fumagalli L. 
Published: February 2006

AbstractAt the concentrations normally found in the brain extracellular space the glial‐derived protein, S100B, protects neurons against neurotoxic agents by interacting with the receptor for advanced glycation end products (RAGE). It is known that at relatively high concentrations S100B is neurotoxic causing neuronal death via excessive stimulation of RAGE. S100B is detected within senile plaques in Alzheimer's disease, where its role is unknown. The present study was undertaken to evaluate a putative neuroprotective role of S100B against Aβ amyloid‐induced neurotoxicity. We treated LAN‐5 neuroblastoma cultures with toxic amounts of Aβ25‐35 amyloid peptide. Our results show that at nanomolar concentrations S100B protects cells against Aβ‐mediated cytotoxicity, as assessed by 3‐(4,5‐dimethyl‐thiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase‐mediated dUTP‐fluorescein isothiocyanate nick end‐labeling (TUNEL) experiments, by countering the Aβ‐mediated decrease in the expression of the anti‐apoptotic factor Bcl‐2. This effect depends on S100B binding to RAGE because S100B is unable to contrast Aβ‐mediated neurotoxicity in neurons overexpressing a signaling‐deficient RAGE mutant lacking the cytosolic and transducing domain. Our data suggest that at nanomolar doses S100B counteracts Aβ peptide neurotoxicity in a RAGE‐mediated manner. However, at micromolar doses S100B is toxic to LAN‐5 cells and its toxicity adds to that of the Aβ peptide, suggesting that additional molecular mechanisms may be involved in the neurotoxic process. © 2006 Wiley‐Liss, Inc.
Early social enrichment augments adult hippocampal BDNF levels and survival of BrdU‐positive cells while increasing anxiety‐ and “depression”‐like behavior
Authors: Branchi Igor , D'Andrea Ivana , Sietzema Jantine , Fiore Marco , Di Fausto Veronica , Aloe Luigi , Alleva Enrico 
Published: February 2006

AbstractEarly experiences affect brain function and behavior at adulthood. Being reared in a communal nest (CN), consisting of a single nest where three mothers keep their pups together and share care‐giving behavior from birth to weaning (postnatal day [PND] 25), provides an highly socially stimulating environment to the developing pup. Communal nest characterizes the natural ecologic niche of many rodent species including the mouse. At adulthood, CN reared mice, compared to mice reared in standard nesting laboratory condition (SN), show an increase in BDNF protein levels and longer survival of BrdU‐positive cells in the hippocampus. Open field and elevated plus maze results indicate that CN mice, although showing levels of exploratory and locomotor activity similar to those of SN mice, displayed increased anxiety‐like behavior, performing more thigmotaxis in the open field and spending less time in the open arms of the plus maze. Furthermore, CN mice displayed higher levels of immobility behavior in the forced swim test. Overall, these findings show that CN, an highly stimulating early social environment, increases adult neuronal plasticity, as suggested by high BDNF levels and augmented number of newly generated cells in the hippocampus, which is associated to an increased anxiety‐ and “depression”‐like behavior. These findings are discussed in the framework of the neurotrophin hypothesis of depression. © 2006 Wiley‐Liss, Inc.
Women, power, and sex composition in small groups: an evolutionary perspective
Authors: Colarelli Stephen M. , Spranger Jennifer L. , Hechanova Ma. Regina 
Published: February 2006

AbstractDespite the massive influx of women into the workforce, women have made only minor gains into top management positions. Most explanations for this asymmetry have been based on sex differences in socialization and traits. We propose that an evolutionary psychological perspective offers an alternative explanation: sex differences in power are due to differences in the way men and women use influence behaviors insmall groups, and these differences were sculpted, in part, by natural selection. This produced sex differences in psychological and physiological mechanisms—principally in the neuroendocrine system—that influence motivations to use influence in groups. We review studies on sex differences in influence in small groups. For each type of influence behavior that we examine—competition, dominance, and coalition formation—we discuss ultimate and proximate causes. We conclude with implications for future research and for public and organizational policy. Copyright © 2006 John Wiley & Sons, Ltd.
Influence of seasonal pressure patterns on temporal variability of vegetation activity in Central Siberia
Authors: Vicente‐Serrano Sergio M. , Grippa Manuela , Delbart Nicolas , Le Toan Thuy , Kergoat Laurent 
Published: February 2006

AbstractThis paper analyses the spatial distribution of the inter‐annual variability of vegetation activity in central Siberia and its relationship with atmospheric circulation variability. We used NOAA‐AVHRR NDVI series from Pathfinder Land Data Set at 1° of spatial resolution, and we calculated the annual vegetation activity in each pixel (aNDVI) from 1982 to 2001. Principal component analysis (PCA) was used to determine the general spatial patterns of inter‐annual variability of vegetation activity. We identified three main modes, which explain more than 50% of the total variance, each corresponding to a large region. By means of surface pressure grids, we analysed the main patterns of the seasonal atmospheric circulation in the study area: its variability was summarised by means of a few circulation modes and the patterns differ significantly between winter, spring and summer. However, a pattern with a North–South dipole structure represents the general spatial pattern of atmospheric circulation. We investigated the effect of seasonal atmospheric circulation patterns on the inter‐annual variation of vegetation activity. In general, the strongest relationships between the atmospheric circulation variability, climate and the aNDVI variability were found in areas where the climatic characteristics are more limiting for the vegetation development, such as the northern regions. This may be explained by the fact that in these areas the variability of atmospheric circulation modes determines summer temperatures, which have a direct impact on vegetation activity. Copyright © 2006 Royal Meteorological Society.
Assessing land degradation in the Monduli District, northern Tanzania
Authors: Kiunsi R. B. , Meadows M. E. 
Published: February 2006

AbstractOne of the many contentious issues facing the appropriate and accurate assessment of land degradation is the varying emphasis placed on vegetation degradation and soil degradation processes. This has led to the compartmentalization of land degradation assessment methods, depending on the particular perspective adopted. The land degradation assessment method presented here attempts to take into account both vegetation and soil degradation. This methodology is applied to the southern part of the Monduli District of northeast Tanzania, an area typifying the so‐called ‘affected drylands’ of Africa. Three sets of land cover maps synchronized against long‐term rainfall data (1960s, 1991 and 1999) were used to assess land degradation in the area. Utilizing these three sets of land cover maps as a basis for change detection, it is possible to distinguish areas that experienced changes in vegetation due to rainfall variability from those areas that were subject to changes consequent upon anthropological factors. All areas that displayed overall depletion of natural and semi‐natural vegetation due to human factors were deemed to have undergone land degradation, whereas areas that experienced inter‐annual land cover changes due to rainfall variability were classified as experiencing cover change due to ecosystem dynamics. This method provides a complete and appropriate assessment of land degradation in the study area and can be used to improve degradation assessment in other semiarid areas. Copyright © 2006 John Wiley & Sons, Ltd.
Subsurface drainage for reversing degradation of waterlogged saline lands
Authors: Sharma D. P. , Gupta S. K. 
Published: February 2006

AbstractIn irrigated agriculture of arid and semiarid regions waterlogging coupled with salinity is a serious problem. Experimental evidence at several locations has led to the realization that subsurface drainage is an essential intervention to reverse the processes of land degradation responsible for the formation of waterlogged saline lands. This paper presents the results of a study conducted from 1995 to 2000 to evaluate the impacts of subsurface drainage on soil properties, groundwater‐table behaviour and crop productivity in a waterlogged saline area of 2200 ha. A subsurface drainage system was installed at 1·6 m depth with 60 m drain spacing covering an area of 1200 ha (23 blocks) during 1997–99 and compared with an undrained block of 1000 ha. Subsurface drainage facilitated the reclamation of waterlogged saline lands and a decrease in the soil salinity (ECe, dS m−1) that ranged from 16·0 to 66·3 per cent in different blocks. On average, 35·7 per cent decrease in salt content was observed when compared with the initial value. Provision of subsurface drainage controlled the water‐table below the root zone during the monsoon season and helped in bringing the soil to optimum moisture content for the sowing of winter crops. In the drained area, the increase in yields of different crops ranged from 18·8 to 27·6 per cent. However, in the undrained area the yield of different crops decreased due to the increased waterlogging and soil salinity problems. Overall the results indicated that investment in subsurface drainage is a viable option for reversing the land degradation of waterlogged saline lands in a monsoon climate. Copyright © 2006 John Wiley & Sons, Ltd.
Femtosecond laser ablation elemental mass spectrometry
Authors: Hergenröder Roland , Samek Ota , Hommes Vanja 
Published: February 2006

AbstractLaser ablation mass spectrometry (LA‐MS) has always been an interesting method for the elemental analysis of solid samples. Chemical analysis with a laser requires small amounts of material. Depending on the analytical detection system, subpicogram quantities may be sufficient. In addition, a focused laser beam permits the spatial characterization of heterogeneity in solid samples typically with micrometer resolution in terms of lateral and depth dimensions. With the advent of high‐energy, ultra‐short pulse lasers, new possibilities arise. The task of this review is to discuss the principle differences between the ablation process of short (>1 ps) and ultra‐short (<1 ps) pulses. Based on the timescales and the energy balance of the process that underlies an ablation event, it will be shown that ultra‐short pulses are less thermal and cause less collateral damages than longer pulses. The confinement of the pulse energy to the focal region guarantees a better spatial resolution in all dimensions and improves the analytical figures of merit (e.g., fractionation). Applications that demonstrate these features and that will be presented are in‐depth profiling of multi‐layer samples and the elemental analysis of biological materials. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 25:551–572, 2006
Chemical cross‐linking and mass spectrometry to map three‐dimensional protein structures and protein–protein interactions
Authors: Sinz Andrea 
Published: February 2006

AbstractClosely related to studying the function of a protein is the analysis of its three‐dimensional structure and the identification of interaction sites with its binding partners. An alternative approach to the high‐resolution methods for three‐dimensional protein structure analysis, such as X‐ray crystallography and NMR spectroscopy, consists of covalently connecting two functional groups of the protein(s) under investigation. The location of the created cross‐links imposes a distance constraint on the location of the respective side chains and allows one to draw conclusions on the three‐dimensional structure of the protein or a protein complex. Recently, chemical cross‐linking of proteins has been combined with a mass spectrometric analysis of the created cross‐linked products. This review article describes the most popular cross‐linking reagents for protein structure analysis and gives an overview of the different available strategies that employ chemical cross‐linking and different mass spectrometric techniques. The challenges for mass spectrometry caused by the enormous complexity of the cross‐linking reaction mixtures are emphasized. The various approaches described in the literature to facilitate the mass spectrometric detection of cross‐linked products as well as computer software for data analyses are reviewed. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 25:663–682, 2006