bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth conelike sensorimotor structures are characteristic features of postmigratory, premyelinating oligodendrocytes
Authors: Fox Michael A. , Afshari Fatemah S. , Alexander John K. , Colello Raymond J. , Fuss Babette 
Published: December 2005

AbstractDuring development, postmigratory, premyelinating oligodendrocytes extend processes that navigate through the central nervous system (CNS) environment, where they recognize a number of extracellular cues, including axonal segments to be myelinated. Ultimately this recognition event leads to the formation of the CNS myelin sheath. However, the morphological structures and molecular mechanisms that control such oligodendroglial pathfinding are poorly understood. Here we show that postmigratory, premyelinating oligodendrocyte processes possess at their distal tips expansions that ultrastructurally resemble growth cones of postmigratory neurons and that we will refer to as OLG‐growth cones. OLG‐growth cones are highly motile and capable of mediating process outgrowth, retraction, and branching. In addition, they express regulators of cytoskeletal organization, GAP43 and cofilin, that are known to mediate neuronal growth cone navigation. In a choice situation, processes of postmigratory, premyelinating oligodendrocytes and their OLG‐growth cones have the ability to selectively avoid a nonpermissive substrate, that is, collagen IV. Thus, our findings provide, for the first time, a detailed characterization of sensorimotor structures present at the tips of postmigratory, premyelinating oligodendrocyte processes. Furthermore, the data presented here suggest that, although the cellular mechanisms involved in growth cone steering may be similar for postmigratory neuronal and oligodendroglial cells, extracellular cues may be interpreted in a cell‐type–specific fashion. © 2005 Wiley‐Liss, Inc.
Expression of two temporally distinct microglia‐related gene clusters after spinal cord injury
Authors: Byrnes Kimberly R. , Garay Jorge , Di Giovanni Simone , De Biase Andrea , Knoblach Susan M. , Hoffman Eric P. , Movsesyan Vilen , Faden Alan I. 
Published: December 2005

AbstractThe dual role of microglia in cytotoxicity and neuroprotection is believed to depend on the specific, temporal expression of microglial‐related genes. To better clarify this issue, we used high‐density oligonucleotide microarrays to examine microglial gene expression after spinal cord injury (SCI) in rats. We compared expression changes at the lesion site, as well as in rostral and caudal regions after mild, moderate, or severe SCI. Using microglial‐associated anchor genes, we identified two clusters with different temporal profiles. The first, induced by 4 h postinjury to peak between 4 and 24 h, included interleukin‐1β, interleukin‐6, osteopontin, and calgranulin, among others. The second was induced 24 h after SCI, and peaked between 72 h and 7 days; it included C1qB, Galectin‐3, and p22phox. These two clusters showed similar expression profiles regardless of injury severity, albeit with slight decreases in expression in mild or severe injury vs. moderate injury. Expression was also decreased rostral and caudal to the lesion site. We validated the expression of selected cluster members at the mRNA and protein levels. In addition, we demonstrated that stimulation of purified microglia in culture induces expression of C1qB, Galectin‐3, and p22phox. Finally, inhibition of p22phox activity within microglial cultures significantly suppressed proliferation in response to stimulation, confirming that this gene is involved in microglial activation. Because microglial‐related factors have been implicated both in secondary injury and recovery, identification of temporally distinct clusters of genes related to microglial activation may suggest distinct roles for these groups of factors. © 2005 Wiley‐Liss, Inc.
Bystander killing of neurons by cytotoxic T cells specific for a glial antigen
Authors: McPherson Scott W. , Heuss Neal D. , Roehrich Heidi , Gregerson Dale S. 
Published: December 2005

AbstractTo explore pathways to neuron loss in inflammatory diseases, transgenic mice expressing β‐galactosidase (β‐gal) in either astrocytes or photoreceptor cells, or both, were inoculated with activated, β‐gal‐specific cytotoxic CD8 T lymphocytes (CTLs). β‐gal‐positive astrocytes in brain were rapidly attacked, with particular damage in cerebellum. Substantial loss of cerebellar granule cells was found, even though these neurons did not express β‐gal. The small number of β‐gal‐positive retinal astrocytes present in these mice was also rapidly destroyed by transferred CTLs, but without detectable consequences for retinal neurons. However, in mice with photoreceptor cell‐specific β‐gal expression, near‐total destruction of photoreceptor cells was produced by CTL transfer. Attack on photoreceptor cells displayed minimal inflammation, and onset was a week later than onset of astrocyte‐directed disease. CTL transfer into F1 mice expressing β‐gal in both astrocytes and photoreceptor cells confirmed that pathogenesis directed against antigen expressed in glia versus neurons proceeded in two distinct, independent phases. β‐gal‐positive retinal astrocytes were severely affected by 5 days post‐transfer, followed by rapid resolution. Photoreceptor cells in the same retina were unaffected until 12 days post‐transfer. The susceptibility of photoreceptor cells was not enhanced by the prior CTL attack on β‐gal‐expressing retinal astrocytes. The results demonstrate that extensive bystander killing of neurons can occur in vivo as a result of direct CTL attack on surrounding astrocytes. Antigen‐expressing retinal neurons were also efficiently killed by CTLs, but by a mechanism that was substantially delayed and dissociated from the killing of retinal astrocytes. © 2005 Wiley‐Liss, Inc.
Adult olfactory ensheathing glia promote the long‐distance growth of adult retinal ganglion cell neurites in vitro
Authors: Leaver S.G. , Harvey A.R. , Plant G.W. 
Published: December 2005

AbstractIn vivo, transplanted adult olfactory ensheathing glia (OEG) and adult Schwann cells (SC) can support the regrowth of at least some transected axons within adult CNS neuropil. In the present study, we developed an in vitro adult rat retinal explant model to explore the influence of primary adult SC and OEG on retinal ganglion cell (RGC) neurite regrowth in the presence of glial cells endogenous to the retina. Retinal quadrants were plated RGC‐side down onto aclar hats coated with either pure collagen (type 1), collagen with OEG, collagen with SCs, or collagen coated with both OEG and SCs. Regrowing retinal neurites extended onto the pure collagen substrate, largely in association with astrocytes that migrated out from the explants (mean number of neurites: 144 ± 65 SEM). The additional presence of OEG (669 ± 122), but not SCs (97 ± 41), supported the regrowth of significantly greater numbers of RGC neurites. Furthermore, this OEG‐stimulated regeneration was over significantly greater distances; >68% of neurites extended > 500 μm from the explant, compared with explants plated onto SCs or collagen alone (15% and 29%, respectively). When OEG and SCs were co‐cultured the number of regenerating neurites was reduced (397 ± 81) compared with the pure OEG treatment. Analysis of explants on pure collagen substrates fed with media conditioned by purified OEG or SC showed no increase in neurite outgrowth compared with control treatments, suggesting that the enhanced growth in the presence of OEG is a contact‐mediated effect. The observed differences between the abilities of OEG and SC to support the growth of CNS‐derived fibers in the presence of astrocytes support the suggestion that OEG may be better suited for direct transplantation into CNS neuropil following injury. © 2005 Wiley‐Liss, Inc.
Notes on the Cladoceran and Copepod Fauna of the Uvs Nuur Basin (Northwest Mongolia)
Authors: Flößner Dietrich , Horn Wolfgang , Paul Markus 
Published: December 2005

AbstractIn the catchment area of Lake Uvs Nuur (Northwest Mongolia) samples of branchiopods and copepods were collected in 15 different lentic water bodies. The waters differ in respect to water chemistry, salt content (fresh, saline), water depth (shallow, deep), catchment area and surrounding landscape and vegetation (semi‐desert, steppe areas, alpine regions). 38 species of cladocerans and 16 species of copepods were found. The salt waters (> 0.5 g/l up to 20 g/l) housed altogether 31 species; the fresh waters (< 0.5 g/l) had a distinctly larger number of species (40 species). The populated waters are briefly characterized with regard to morphometry, macrophytes and fish stock. 12 species – 8 Cladocera and 4 Copepoda – have not previously been recorded from Mongolia. Morphological and taxonomical remarks are made on certain species. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact of Environmental Variables and Food Availability on Rotifer Assemblage in the Karstic Barrage Lake Visovac (Krka River, Croatia)
Authors: Špoljar Maria , Habdija Ivan , Primc‐Habdija Biserka , Sipos Laszlo 
Published: December 2005

AbstractWe evaluated the impact of 18 environmental variables (physico‐chemical, nutrients, food resources) on rotifer assemblage in the sub‐Mediterranean karstic barrage Lake Visovac. In terms of the space‐time distribution the highest density of rotifers was noted in the summer period (average 386 ind/l, relative annual abundance 62%), and in the epilimnetic layer (average 309 ind/l, relative annual abundance 58%). A total of 41 rotifer taxa belonging to 22 genera and 14 families were identified. Three rotifer species: Gastropus stylifer, Synchaeta tremula and Trichocerca birostris were dominant and perennial during the annual investigation. Pearson's product‐moment correlations and canonical correlation analysis suggest that temperature, pH values, alkalinity, chemical oxygen demand and chlorophyll a concentration significantly influenced rotifer density. According to rotifer food collection and selection, in Visovac Lake macrofilter‐feeders predominated, and microfilter‐feeders were in a minority. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Population Density of the Crayfish, Orconectes limosus, in Relation to Fish and Macroinvertebrate Densities in a Small Mesotrophic Lake – Implications for the Lake's Food Web
Authors: Haertel‐Borer Susanne S. , Zak Dominik , Eckmann Reiner , Baade Ulrich , Hölker Franz 
Published: December 2005

AbstractThe population density of Orconectes limosus in a mesotrophic lake was assessed in the context of fish and macroinvertebrate biomasses, and crayfish consumption by fish. The average O. limosus (≥6 cm total length) abundance and biomass in the littoral zone was 2200 ind ha–1 and 32.2 kg ha1, respectively. O. limosus biomass accounted for a large percentage (49%) of the lake's macroinvertebrate biomass. O. limosus was equal to 35% of the non‐predatory fish biomass and to 81% of the predatory fish biomass. O. limosus comprised 15 and 48% of the annual consumption of pike and predatory perch, respectively. Altogether, O. limosus was identified as quantitatively important for the lake's littoral food web, and might also subsidize the pelagic food web. This strengthens the need for an integrated view on lake food webs. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Bag‐Sampler: A Simple Device for Collecting Zooplankton in Shallow Vegetated Ponds
Authors: Frisch Dagmar , Wohltmann Andreas 
Published: December 2005

AbstractZooplankton in temporary ponds is often collected with gear originally designed for lakes, and mostly unsuitable for sampling shallow habitats. We describe a new simple and inexpensive device for sampling zooplankton in very shallow, vegetated temporary ponds. We tested the sampling efficiency by comparing species composition and density of cyclopoid copepods, an important component of the zooplankton, by sampling with both the new bag sampler and a plastic beaker frequently employed for collections of zooplankton in small waterbodies. With the bag sampler we collected a larger number of species and higher densities of copepods due to its higher efficiency in vegetated areas and near the sediment. The beaker appeared to sample almost only the water surface. The samples collected with the bag sampler revealed a distinct distribution of copepod life cycle stages in a shallow pond, which differed between depths and microhabitats. Additional advantages of the bag sampler are its small size and weight, and the possibility of fast exchange of sample bags between sample locations, thus preventing accidental faunal exchange between sample locations. We conclude that the bag sampler is a device especially useful for sampling zooplankton of shallow ponds and wetlands rich in vegetation, for diversity studies as well as for quantitative sampling. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transparent micro‐ and nanopatterned poly(lactic acid) for biomedical applications
Authors: Mills Christopher A. , Navarro Melba , Engel Elisabeth , Martinez Elena , Ginebra Maria Pau , Planell Josep , Errachid Abdelhamid , Samitier Josep 
Published: December 2005

AbstractThe formation of structures in poly(lactic acid) has been investigated with respect to producing areas of regular, superficial features with dimensions comparable to those of cells or biological macromolecules. Nanoembossing, a novel method of pattern replication in polymers, has been used for the production of features ranging from tens of micrometers, covering areas up to 1 cm2, down to hundreds of nanometers. Both micro‐ and nanostructures are faithfully replicated. Contact‐angle measurements suggest that positive microstructuring of the polymer (where features protrude from the polymer surface) produces a more hydrophilic surface than negative microstructuring. The ability to structure the surface of the poly(lactic acid), allied to the polymer's postprocessing transparency and proven biocompatibility, means that thin films produced in this way will be useful for bioengineers studying the interaction of micro‐ and nanodimensioned features with biological specimen, with regard to tissue engineering, for example. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Alkaline‐treated poly(ϵ‐caprolactone) films: Degradation in the presence or absence of fibroblasts
Authors: Peña Juan , Corrales Teresa , Izquierdo‐Barba Isabel , Serrano M. Concepción , Portolés M. Teresa , Pagani Raffaella , Vallet‐Regí María 
Published: December 2005

AbstractIn the first stage, we observed the study of the degradation behavior of alkaline‐treated poly(ϵ‐caprolactone) (PCL) in two biologically‐related media: phosphate buffered saline (PBS) and Dulbecco's modified Eagle's medium (DMEM) for 18 months, finding a much accelerated degradation in the last one. As expected, the degradation in the presence of cells is much pronounced even considering that the study is limited to 6 months. The characterization of the degraded substrates by chemiluminescence (CL) allows to explain the modifications of the substrate and their relations with transitory oxidative stress phenomena described in the fibroblasts seeded onto the PCL membranes. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Comparison of endothelial cells grown on different stent materials
Authors: Yeh Hung‐I , Lu Shao‐Kou , Tian Tin‐Yi , Hong Ray‐Ching , Lee Wun‐Hsing , Tsai Cheng‐Ho 
Published: December 2005

AbstractWe compared the behavior of endothelial cells grown on stent materials. Human umbilical vein endothelial cells (HUVEC) were seeded (200 or 800 cells/mm2) onto different metallic sheets, including 316 stainless steel (low carbon; 316LSS), nitinol, and 316LSS coated with TiN or TiO2. Cells seeded onto tissue culture‐treated polystyrene dish coated with gelatin were used as controls. Forty‐eight hours later, the cells were examined by Western blotting, immunofluorescence microscopy, and scanning electron microscopy (SEM). The results showed that for either seeding values, the levels of cellularity on TiN and TiO2 are comparable or higher, and those on 316LSS and nitinol are lower compared to the controls (p < 0.05). SEM demonstrated that cells are well‐attached on the metallic surface with various amount of cellular processes. In metals seeded with 800 cells/mm2, Western blotting showed that the overlying cells expressed less amounts of endothelial nitric oxide synthase (eNOS), Von Willebrand factor (VWF), and connexin43 protein compared to the controls (p < 0.05). Immunofluorescence microscopy confirmed the results of immunoblotting. In conclusion, stent materials affect HUVEC's growth and protein expression profile. Down‐regulation of eNOS, VWF, and connexin43 gap junctions is a common phenomenon in the cells growing on the examined metallic materials, suggesting the existence of endothelial dysfunction in the arterial segments containing the stents made of such materials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Silicon inhibition effects on the polymerase chain reaction: A real‐time detection approach
Authors: Wang Wei , Wang Hai‐Bin , Li Zhi‐Xin , Guo Zeng‐Yuan 
Published: December 2005

AbstractIn the miniaturization of biochemical analysis systems, biocompatibility of the microfabricated material is a key feature to be considered. A clear insight into interactions between biological reagents and microchip materials will help to build more robust functional bio‐microelectromechanical systems (BioMEMS). In the present work, a real‐time polymerase chain reaction (PCR) assay was used to study the inhibition effects of silicon and native silicon oxide particles on Hepatitis B Virus (HBV) DNA PCR amplification. Silicon nanoparticles with different surface oxides were added into the PCR mixture to activate possible interactions between the silicon‐related materials and the PCR reagents. Ratios of silicon nanoparticle surface area to PCR mixture volume (surface to volume ratio) varied from 4.7 to 235.5 mm2/μL. Using high speed centrifugation, the nanoparticles were pelleted to tube inner surfaces. Supernatant extracts were then used in subsequent PCR experiments. To test whether silicon materials participated in amplifications directly, in some cases, entire PCR mixture containing silicon nanoparticles were used in amplification. Fluorescence histories of PCR amplifications indicated that with the increase in surface to volume ratio, amplification efficiency decreased considerably, and within the studied ranges, the higher the particle surface oxidation, the stronger the silicon inhibition effects on PCR. Adsorption of Taq polymerase (not nucleic acid) on the silicon‐related material surface was the primary cause of the inhibition phenomena and silicon did not participate in the amplification process directly. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
The hydroperoxy radical as a hydrogen bond acceptor. HOOHCl complexes—Ab initio study
Authors: Bil Andrzej , Latajka Zdzisław 
Published: December 2005

AbstractProtonacceptor properties of the HOO radical were investigated previously by means of ab initio as well as topological Atoms in Molecules (AIM) and Electron Localization Function (ELF) methods. It was pointed out that in the radical there are three nonequivalent positions most susceptible to protonation, and on this basis three structures of possible hydrogen bonded complexes were proposed. Results reported in the present article concern all possible 1:1 complexes formed by HCl and HOO molecules, and fully confirm suppositions given on the basis of the above‐mentioned investigations. There are three various complexes referring to the local minima, and the transition structure predicted by topological methods has been found as well. The cyclic structure appeared to be the most stable one, which confirms conclusions given in the experimental article. Apart from structure optimization, harmonic as well as anharmonic spectra of the complexes have been simulated. Anharmonicity of HCl stretching vibration was of special interest, as the frequency of this vibration characterizes the ClH · · · O hydrogen bond in these complexes. To obtain values of these frequencies the one‐dimensional Hamiltonian has been diagonalized numerically. The potential for this Hamiltonian has been taken from a set of single‐point scanning of the part of the Potential Energy Surface (PES) connected with this vibration. The potential calculated on the MP2 level leads to the result close to the experimental value, whereas the B3LYP method is inappropriate for the purpose of PES investigation of these complexes. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 287–295, 2006
Polymer‐grafted banana (Musa paradisiaca) stalk as an adsorbent for the removal of lead(II) and cadmium(II) ions from aqueous solutions: kinetic and equilibrium studies
Authors: Shibi Indira G , Anirudhan Thayyath S 
Published: December 2005

AbstractThis study examined the effectiveness of a new adsorbent prepared from banana (Musa paradisiaca) stalk, one of the abundantly available lignocellulosic agrowastes, in removing Pb(II) and Cd(II) ions from aqueous solutions. The adsorbent (PGBS‐COOH) having a carboxylate functional group at its chain end was synthesized by graft copolymerization of acrylamide on to banana stalk, followed by functionalization. Batch adsorption experiments were carried out as a function of solution pH, ionic strength, contact time, metal concentration, adsorbent dose and temperature. A pH range of 5.5–8.0 was found to be effective for the maximum removal for both Pb(II) and Cd(II). Metal uptake was found to decrease with increase in ionic strength due to the expansion of the diffuse double layer and, more importantly, the formation of some chloro complexes (since NaCl was used in the adjustment of ionic strength), which do not appear to be adsorbed to the same extent as cations [M2+ and M(OH)+]. The kinetic studies showed that an equilibrium time of 3 h was needed for the adsorption of Pb(II) and Cd(II) on PGBS‐COOH and adsorption processes followed a pseudo‐second‐order equation. The Langmuir isotherm model fitted the experimental equilibrium data well. The maximum sorption capacity for Pb(II) and Cd(II) ions was 185.34 and 65.88 mg g−1, respectively, at 30 °C. The thermodynamic parameters such as changes in free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were derived to predict the nature of adsorption. The isosteric heat of adsorption was found to be independent of surface coverage. Adsorption experiments were also conducted using a commercial cation exchanger, Ceralite IRC‐50, for comparison. Synthetic wastewater samples were treated with the adsorbent to demonstrate its efficiency in removing Pb(II) and Cd(II) ions from industrial wastewaters. Acid regeneration was tried for several cycles with a view to recovering the sorbed metal ions and also restoring the sorbent to its original state. Copyright © 2005 Society of Chemical Industry