bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acetylcholine innervation of the adult rat thalamus: Distribution and ultrastructural features in dorsolateral geniculate, parafascicular, and reticular thalamic nuclei
Authors: Parent Martin , Descarries Laurent 
Published: October 2008

AbstractThe acetylcholine (ACh) innervation of thalamus arises mainly from the brainstem pedunculopontine and laterodorsal tegmental nuclei. By using immunocytochemistry with a monoclonal antibody against whole rat choline acetyltransferase (ChAT), we quantified the distribution and characterized the ultrastructural features of these nerve terminals (axon varicosities) in the dorsolateral geniculate (DLG), parafascicular (PF), and reticular thalamic (Rt) nuclei of adult rat. The regional density of ACh innervation was the highest in PF (2.1 × 106 varicosities/mm3), followed by Rt (1.7 × 106) and DLG (1.3 × 106). In single thin sections, ChAT‐immunostained varicosity profiles appeared comparable in shape and content in the three nuclei, but significantly larger in PF than in DLG and Rt. The number of these profiles displaying a synaptic junction was also much higher in PF than in DLG and Rt, indicating that all ChAT‐immunostained varicosities in PF were synaptic, but only 39% in DLG and 33% in Rt. The hypothesis that glutamate corelease might account for the maintenance of the entirely synaptic ACh innervation in PF was refuted by the lack of colocalization of ChAT and vesicular glutamate transporter 2 (VGLUT2) in PF axon varicosities after dual immunolabeling. These data suggest that diffuse as well as synaptic transmission convey modulatory effects of the ACh input from brainstem to DLG and Rt during waking. In contrast, the entirely synaptic ACh input to PF should allow for a direct relaying of the information from brainstem, affecting basal ganglia function as well as perceptual awareness, including attention and pain perception. J. Comp. Neurol. 511:678–691, 2008. © 2008 Wiley‐Liss, Inc.
Types of taste circuits synaptically linked to a few geniculate ganglion neurons
Authors: Zaidi Faisal N. , Todd Krista , Enquist Lynn , Whitehead Mark C. 
Published: October 2008

AbstractThe present study evaluates the central circuits that are synaptically engaged by very small subsets of the total population of geniculate ganglion cells to test the hypothesis that taste ganglion cells are heterogeneous in terms of their central connections. We used transsynaptic anterograde pseudorabies virus labeling of fungiform taste papillae to infect single or small numbers of geniculate ganglion cells, together with the central neurons with which they connect, to define differential patterns of synaptically linked neurons in the taste pathway. Labeled brain cells were localized within known gustatory regions, including the rostral central subdivision (RC) of the nucleus of the solitary tract (NST), the principal site where geniculate axons synapse, and the site containing most of the cells that project to the parabrachial nucleus (PBN) of the pons. Cells were also located in the rostral lateral NST subdivision (RL), a site of trigeminal and sparse geniculate input, and the ventral NST (V) and medullary reticular formation (RF), a caudal brainstem pathway leading to reflexive oromotor functions. Comparisons among cases, each with a random, very small subset of labeled geniculate neurons, revealed “types” of central neural circuits consistent with a differential engagement of either the ascending or the local, intramedullary pathway by different classes of ganglion cells. We conclude that taste ganglion cells are heterogeneous in terms of their central connectivity, some engaging, predominantly, the ascending “lemniscal,” taste pathway, a circuit associated with higher order discriminative and homeostatic functions, others engaging the “local,” intramedullary “reflex” circuit that mediates ingestion and rejection oromotor behaviors. J. Comp. Neurol. 511:753–772, 2008. © 2008 Wiley‐Liss, Inc.
Limited intravascular coupling in the rodent brainstem and retina supports a role for glia in regional blood flow
Authors: Kuo Ivana Y. , Chan‐Ling Tailoi , Wojcikiewicz Richard J. , Hill Caryl E. 
Published: October 2008

AbstractRegional synaptic activity induces local increases in perfusion that are coupled to upstream vasodilation and improved blood flow. In the cerebral circulation, it has been proposed that astrocytes mediate the link between the initiating stimulus and local vasodilation through propagated intracellular calcium waves. In the systemic circulation the mechanism by which local vasodilation triggers upstream alterations in blood flow involves electrotonic propagation of hyperpolarization via endothelial gap junctions, although less is known concerning the cerebral circulation. The present study aimed to investigate the extent of coupling in microvessels of the rodent brainstem and retina and the subtypes of intracellular calcium stores that might mediate astrocytic signaling. Within the brainstem, connexins (Cxs) 37 and 40 were restricted to the endothelium of pial vessels and larger penetrating arterioles, whereas astrocytic Cxs30 and 43 were found closely associated with pre‐ and postsynaptic neurons and nearby microvessels. Within the rat retina, Cxs37 and 40 were expressed in large radiating arterioles, but were not found in smaller vessels on the retinal surface or in the deeper retinal layers. These Cxs were absent from all retinal vessels in mice. Astrocytes, expressing Cxs30 and 43 in the rat, but only Cx43 in the mouse, were found closely associated with superficial, but not deeper blood vessels. Inositol‐trisphosphate receptors (IP3R) 1 and 2 were expressed within brainstem astrocytes, whereas IP3R1 and 3 were expressed within retinal astrocytes. Limited intravascular coupling and the proximity of astrocytic networks to blood vessels supports a role for glia in activity‐dependent alterations in central blood flow. J. Comp. Neurol. 511:773–787, 2008. © 2008 Wiley‐Liss, Inc.
Spatiotemporal characteristics of astroglial death in the rat hippocampo‐entorhinal complex following pilocarpine‐induced status epilepticus
Authors: Kim Duk‐Soo , Kim Ji‐Eun , Kwak Sung‐Eun , Choi Kyung‐Chan , Kim Dae‐Won , Kwon Oh‐Shin , Choi Soo‐Young , Kang Tae‐Cheon 
Published: October 2008

AbstractAstroglial reactive gliosis in the rat hippocampus at 8 weeks after pilocarpine‐induced status epilepticus. GFAP (red) positive reactive astrocytes in the stratum lacunosum‐moleculare show strong GS (green) immunoreactivity, while GFAP‐positive astrocytes show no GS immunoreactivity in the molecular layer of the dentate gyrus. Blue is DAPI counterstaining. J. Comp. Neurol. 511:581–598, 2008. © 2008 Wiley‐Liss, Inc.
Contralateral projections of the rat anterior olfactory nucleus
Authors: Illig Kurt R. , Eudy Jennifer D. 
Published: October 2008

AbstractThe anterior olfactory nucleus (AON) is a central olfactory cortical structure that has heavy reciprocal connections with both the olfactory bulb (OB) and piriform cortex. While it has been firmly established that the AON is a primary source of bilateral projections in the olfactory system through extensive connections with both the ipsilateral and contralateral OB, AON, and piriform cortex, few studies have examined this circuitry in detail. In the present study we used small injections of the anterograde tracer Phaseolus vulgaris leucoagglutinin (PHA‐L) and the retrograde tracer FluoroGold in specific subregions of the AON to explore the topography of the interconnections between the left and right AONs. Labeled fibers were found in the contralateral AON following injections in all areas. However, detailed quantitative analyses revealed that different regions of the AON have distinct patterns of interhemispheric innervation; contralateral fibers were most heavily targeted to dorsal and lateral AON subregions, while the medial and ventral areas received relatively light projections. These results demonstrate important features of the interhemispheric circuitry of the AON and suggest separate functional roles for subregions of the AON in olfactory information processing. J. Comp. Neurol. 512:115–123, 2009. © 2008 Wiley‐Liss, Inc.
Percolation for the vacant set of random interlacements
Authors: Sidoravicius Vladas , Sznitman Alain‐Sol 
Published: October 2008

AbstractWe investigate random interlacements on ℤd, d ≥ 3. This model, recently introduced in [8], corresponds to a Poisson cloud on the space of doubly infinite trajectories modulo time shift tending to infinity at positive and negative infinite times. A nonnegative parameter u measures how many trajectories enter the picture. Our main interest lies in the percolative properties of the vacant set left by random interlacements at level u. We show that for all d ≥ 3 the vacant set at level u percolates when u is small. This solves an open problem of [8], where this fact has only been established when d ≥ 7. It also completes the proof of the nondegeneracy in all dimensions d ≥ 3 of the critical parameter u* of [8]. © 2008 Wiley Periodicals, Inc.
Fetal size in mid‐ and late pregnancy is related to infant alertness: The generation R study
Authors: Henrichs Jens , Schenk Jacqueline J. , Schmidt Henk G. , Arends Lidia R. , Steegers Eric A.P. , Hofman Albert , Jaddoe Vincent W.V. , Verhulst Frank C. , Tiemeier Henning 
Published: October 2008

AbstractThe vulnerability for behavioral problems is partly shaped in fetal life. Numerous studies have related indicators of intrauterine growth, for example, birth weight and body size, to behavioral development. We investigated whether fetal size in mid‐ and late pregnancy is related to infant irritability and alertness. In a population‐based birth cohort of 4,255 singleton full‐term infants ultrasound measurements of fetal head and abdominal circumference in mid‐ and late pregnancy were performed. Infant irritability and alertness scores were obtained by the Mother and Baby Scales at 3 months and z‐standardized. Multiple linear regression analyses revealed curvilinear associations (inverted J‐shape) of measures of fetal size in both mid‐ and late pregnancy with infant alertness. Fetal size characteristics were not associated with infant irritability. These results suggest that alterations of intrauterine growth affecting infant alertness are already detectable from mid‐pregnancy onwards. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 51: 119–130, 2009
Poor in vitro induction of FOXP3 and ICOS in type 1 cytokine environment activated T‐cells from children with type 1 diabetes
Authors: Honkanen Jarno , Skarsvik Susanne , Knip Mikael , Vaarala Outi 
Published: October 2008

AbstractBackgroundType 1 diabetes (T1D) is characterised by loss of tolerance to beta‐cell antigens, and the insulin‐producing beta‐cells in the pancreatic islets are destroyed by the host's own immune system. Immunological risk factors associated with T1D are related to the defects in the polarization of T‐cells and in the function of regulatory T (Treg)‐cells. We set out to study whether an impaired induction of regulatory mechanisms during the generation of T‐cell responses upon stimulation is associated with T1D.MethodsNaive T‐cells were isolated from 18 children with recent T1D (0–14days from diagnosis; mean age 9.3 years), 11 children who had had T1D for at least 1 year (mean age 10.6) and 14 non‐diabetic children (mean age 8.1). CD45RA+ T‐cells were stimulated with PHA for 72 h in type 1 cytokine [interleukin (IL)‐12 and anti‐IL‐4] or type 2 cytokine (IL‐4 and anti‐IL‐12) environment. T‐cell polarization and regulation related markers were analysed by quantitative reverse transcription polymerase chain reaction (QRT‐PCR) (Th1 promoting T‐bet, Th2 promoting GATA‐3 and regulation related FOXP3, ICOS and NFATc2).ResultsChildren with recently diagnosed T1D showed decreased induction of FOXP3, ICOS and NFATc2 in T‐cells activated in type 1 cytokine milieu (p = 0.007, p = 0.001, and p = 0.02), whereas no differences between the diabetic and healthy children were seen in the up‐regulation of activation markers, T‐bet and GATA‐3.ConclusionsThe poor induction of factors that mediate down‐modulation of T‐cell responses upon stimulation in type 1 cytokine environment may contribute to the development of autoreactive type 1 responses in T1D. Copyright © 2008 John Wiley & Sons, Ltd.
Surface Energetics to Assess Microbial Adhesion onto Fluidized Chromatography Adsorbents
Authors: Vennapusa R. R. , Binner S. , Cabrera R. , Fernandez‐Lahore M. 
Published: October 2008

AbstractCell‐to‐support interaction and cell‐to‐cell aggregation phenomena have been studied in a model system composed of intact yeast cells and agarose‐based chromatography adsorbent surfaces. Biomass components and beaded adsorbents were characterized by contact angle determinations with three diagnostic liquids and, complementarily, by zeta potential measurements. Such experimental characterization of the interacting surfaces has allowed the calculation of interfacial free energy of interaction in aqueous media vs. distance profiles. The extent of biomass adhesion was inferred from calculations performed assuming standard chromatographic conditions, but different adsorption modes. Several stationary support/mobile phase systems were considered, i.e., ion exchange, hydrophobic interaction, and pseudo‐affinity. The calculated interaction energy minima revealed marginal attraction between cells and cation exchangers or agarose‐matrix beads (U ≤ |10–20| kT) but strong attraction with anion exchangers (U ≥ |200–1000| kT). Other systems including hydrophobic interaction and chelating beads showed intermediate energy minimum values (U <$>\approx<$> |40–100| kT) for interaction with biological particles. However, the calculations also showed that working conditions in the presence of salt can promote cell aggregation apart from cell‐to‐support interaction. Predictions based on the application of the XDLVO approach were confirmed by independent experimental methods, e.g., biomass deposition experiments and laser diffraction spectroscopy. The understanding of biomass attachment onto chromatographic supports can help in alleviating process limitations normally encountered during direct (primary) sequestration of bioproducts.
Systematic Approach to Solvent Selection for Biphasic Systems with a Combination of COSMO‐RS and a Dynamic Modeling Tool
Authors: Peters M. , Zavrel M. , Kahlen J. , Schmidt T. , Ansorge‐Schumacher M. , Leitner W. , Büchs J. , Greiner L. , Spiess A. C. 
Published: October 2008

AbstractBiphasic aqueous‐organic systems are important reaction systems for catalytic processes. This is especially true for biocatalysis where the range of accessible products can be significantly extended. In such systems, the aqueous phase is the reactive phase in which the biocatalyst is dissolved and the organic phase is nonreactive and acts as substrate reservoir and as in situ product extraction solvent. Here, the choice of the nonreactive phase is highly important for the overall performance of the system. In this contribution, a systematic approach to solvent selection for biphasic aqueous‐organic systems is presented with respect to partition coefficients. The model reaction is the stereoselective carbon‐carbon coupling of two 3,5‐dimethoxy‐benzaldehyde molecules to (R)‐3,3',5,5'‐tetramethoxy‐benzoin catalyzed by benzaldehyde lyase (EC 4.1.2.38) from Pseudomonas fluorescens. A systematic approach to solvent selection consisting of two steps is proposed: Firstly, the conductor‐like screening model for real solvents (COSMO‐RS) is used to facilitate a fast solvent screening. Since this is an ab initio approach it allows a pre‐screening without laborious experimental input. The proposed ranking of solvents, based on the ratio of partition coefficients at infinite dilution, is a sound basis for the successive steps. Secondly, a dynamic model is fitted to experimental data in order to obtain detailed and reliable results for mass transfer and partition coefficients. Therefore, the method makes efficient use of the experimental data and substantiates quantitative results with guided experiments.
Thermodynamic Constraints in Kinetic Modeling: Thermodynamic‐Kinetic Modeling in Comparison to Other Approaches
Authors: Ederer M. , Gilles E. D. 
Published: October 2008

AbstractKinetic models of reaction networks may easily violate the laws of thermodynamics and the principle of detailed balance. In large network models, the constraints that are imposed by these laws are particularly difficult to address. This hinders modeling of biochemical reaction networks. Thermodynamic‐kinetic modeling is a method that provides a thermodynamically sound and formally appealing way for deriving dynamic model equations of reaction systems. State variables of this approach are thermokinetic potentials that describe the ability of compounds to drive a reaction. A compound has a parameter called capacity, which is the ratio of its concentration and thermokinetic potential. A reaction is described by its resistance which is the ratio of the thermokinetic driving force and flux. In these aspects, the formalism is similar to the modeling formalism for electrical networks and an analogous graphical representation is possible. The thermodynamic‐kinetic modeling formalism is equivalent to the traditional kinetic modeling formalism with the exception that it is not possible to build thermodynamically infeasible models. Here, the thermodynamic‐kinetic modeling formalism is reviewed, compared to other approaches, and some of its advantages are worked out. In contrast to other approaches, thermodynamic‐kinetic modeling does not rely on an explicit enumeration of stoichiometric cycles. It is capable of describing rate laws far from equilibrium. Further, the parameterization by capacities and resistances is particularly intuitive and powerful.
Exploiting the Link between Protein Rigidity and Thermostability for Data‐Driven Protein Engineering
Authors: Radestock S. , Gohlke H. 
Published: October 2008

AbstractUnderstanding and exploiting the relationship between microscopic structure and macroscopic stability is important for developing strategies to improve protein stability at high temperatures. The thermostability of proteins has been repeatedly linked to an enhanced structural rigidity of the folded native state. In the current study, the rigidity of protein structures from mesophilic and thermophilic organisms along a thermal unfolding trajectory is directly probed. In order to perform this, protein structures were modeled as constraint networks, and the rigidity in these networks was quantified using the Floppy Inclusion and Rigid Substructure Topography (FIRST) method. During the thermal unfolding, a phase transition was observed that defines the rigidity percolation threshold and corresponds to the folded‐unfolded transition in protein folding. Using concepts from percolation theory and network science, a higher phase transition temperature was observed for ca. two‐thirds of the proteins from thermophilic organisms compared to their mesophilic counterparts, when applied to a data set of 20 pairs of homologues. From both the analysis of the microstructure of the constraint networks and monitoring the macroscopic behavior during the thermal unfolding, direct evidence was found for the “corresponding states” concept, which states that mesophilic and thermophilic enzymes are in corresponding states of similar flexibility at their respective optimal temperature. Finally, the current approach facilitated the identification of structural features from which a destabilization of the structure originates upon thermal unfolding. These predictions show a good agreement with the experimental data. Therefore, the information might be exploited in data‐driven protein engineering by pointing to residues that should be varied to obtain a protein with higher thermostability.
Fragmentation of Fluorinated Model Compounds Exposed to Oxygen Radicals: Spin Trapping ESR Experiments and Implications for the Behaviour of Proton Exchange Membranes Used in Fuel Cells
Authors: Danilczuk M. , Coms F. D. , Schlick S. 
Published: October 2008

AbstractLow‐molecular weight model compounds (MCs) for Nafion membranes used in fuel cells were exposed at 300 K to·OH radicals produced by UV irradiation of aqueous H2O2solutions. The MCs contained fluorinated and partially fluorinated groups terminated by sulphonic or carboxylic acid groups. The fragmentation process in the MCs was studied by spin trapping electron spin resonance (ESR) methods, using 5,5‐dimethylpyrroline‐N‐oxide (DMPO), N‐tert‐butyl‐α‐phenylnitrone (PBN) and 2‐methyl‐2‐nitrosopropane (MNP) as the spin traps. The objective of these experiments was to assess the effect of the type of ionic groups (sulphonic or carboxylic) and of fluorine substitution on the spin adducts detected. DMPO experiments led to the detection of spin adducts of·OH and of carbon‐centred radicals (CCRs), and allowed the determination of the·OH attack site on the ionic and/or on the protiated or fluorinated groups. CCR adducts were also detected when using PBN as a spin trap; a key point in the interpretation of the PBN results was, however, the realisation that MNP is formed during PBN exposure to UV irradiation and oxygen or other oxidants such as H2O2. Experiments with MNP as the spin trap were the most informative in terms of structural details for adducts obtained from each MC. The results allowed the identification of CCRs present as adducts, based on large hyperfine splittings (hfs) from, and the number of, interacting19F nuclei; in addition, oxygen‐centred radicals (OCRs) as MNP adducts were also identified, with much lower hfs from19F nuclei. Taken together, the results deduced by spin trapping suggest that both sulphonic acid and acetic acid groups can be attacked by·OH radicals and confirm two possible degradation mechanisms in Nafion membranes: initiated at the backbone and at the side chain.
Frequent loss of the CDKN2C (p18INK4c) gene product in pituitary adenomas
Authors: Kirsch Matthias , Mörz Michael , Pinzer Thomas , Schackert Hans Konrad , Schackert Gabriele 
Published: October 2008

AbstractGenomic alterations of cyclin‐dependent kinase inhibitors have been demonstrated in a variety of tumor types including brain tumors. Among them, the cyclin‐dependent kinase inhibitor 2A (CDKN2A or p16INK4a) gene has been shown to be frequently deleted or inactivated in astrocytic tumors. The CDKN2C (p18INK4c) gene is functionally related to CDKN2A. Moreover, mice with targeted disruption of CDKN2C alone or combined CDKN2C and cyclin‐dependent kinase inhibitor 1B (CDKN1B or p27Kip1), or CDKN2C and TP53 gene disruption develop pituitary adenomas (PA) at high frequencies. The purpose of our study was to investigate genetic alterations of the CDKN2C gene by analysis of loss of heterozygosity (LOH), screening for mutations, analysis of promoter methylation, and protein expression in 38 PAs. In addition, genomic alterations and protein expression of the cell cycle genes CDKN2A and its alternatively spliced form, p14ARF, as well as the retinoblastoma RB1 gene were investigated. LOH at the CDKN2C gene locus was detected in 25% of pituitary adenomas, whereas the RB1 and CDKN2A loci were altered in only 10%. No mutations were detected within the coding regions of the CDKN2C gene. However, 39.5% of adenomas displayed CDKN2C promoter methylation. The absence of CDKN2C protein was correlated with LOH of the CDKN2C locus on chromosome 1 and with methylation of the CDKN2C promoter. This is the first report to describe that the tumor suppressor gene CDKN2C is frequently targeted by genomic alterations in pituitary adenoma. The most common genetic alteration was promoter methylation suggesting that inactivation of CDKN2C by this mechanism may play an important role in pituitary adenoma development. Additional Supporting Information may be found in the online version of this article. © 2008 Wiley‐Liss, Inc.