bluuebunny/crossref_metadata_2025_split huggingface dataset:
Connexin29 and connexin32 at oligodendrocyte and astrocyte gap junctions and in myelin of the mouse central nervous system
Authors: Nagy James I. , Ionescu Andrei V. , Lynn Bruce D. , Rash John E. 
Published: July 2003

AbstractThe cellular localization, relation to other glial connexins (Cx30, Cx32, and Cx43), and developmental expression of Cx29 were investigated in the mouse central nervous system (CNS) with an anti‐Cx29 antibody. Cx29 was enriched in subcellular fractions of myelin, and immunofluorescence for Cx29 was localized to oligodendrocytes and myelinated fibers throughout the brain and spinal cord. Oligodendrocyte somata displayed minute Cx29‐immunopositive puncta around their periphery and intracellularly. In developing brain, Cx29 levels increased during the first few postnatal weeks and were highest in the adult brain. Immunofluorescence labeling for Cx29 in oligodendrocyte somata was intense at young ages and was dramatically shifted in localization primarily to myelinated fibers in mature CNS. Labeling for Cx32 also was localized to oligodendrocyte somata and myelin and absent in Cx32 knockout mice. Cx29 and Cx32 were minimally colocalized on oligodendrocytes somata and partly colocalized along myelinated fibers. At gap junctions on oligodendrocyte somata, Cx43/Cx32 and Cx30/Cx32 were strongly associated, but there was minimal association of Cx29 and Cx43. Cx32 was very sparsely associated with astrocytic connexins along myelinated fibers. With Cx26, Cx30, and Cx43 expressed in astrocytes and Cx29, Cx32, and Cx47 expressed in oligodendrocytes, the number of connexins localized to gap junctions of glial cells is increased to six. The results suggested that Cx29 in mature CNS contributes minimally to gap junctional intercellular communication in oligodendrocyte cell bodies but rather is targeted to myelin, where it, with Cx32, may contribute to connexin‐mediated communication between adjacent layers of uncompacted myelin. J. Comp. Neurol. 464:356–370, 2003. © 2003 Wiley‐Liss, Inc.
Distribution of transient receptor potential channels in the rat carotid chemosensory pathway
Authors: Buniel Maria C.F. , Schilling William P. , Kunze Diana L. 
Published: July 2003

AbstractGlomus cells in the carotid body respond to decreases in oxygen tension of the blood and transmit this sensory information in the carotid sinus nerve to the brain via neurons in the petrosal ganglion. G‐protein‐coupled membrane receptors linked to phospholipase C may play an important role in this response through the activation of the cation channels formed by the transient receptor potential (TRP) proteins. In the present study, expression of TRPC proteins in the rat carotid body and petrosal ganglion was examined using immunohistochemical techniques. TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7 were present in neurons throughout the ganglion. TRPC1 was expressed in only 28% of petrosal neurons, and of this population, 45% were tyrosine hydroxylase (TH)‐positive, accounting for essentially all the TH‐expressing neurons in the ganglion. Because TH‐positive neurons project to the carotid body, this result suggests that TRPC1 is selectively associated with the chemosensory pathway. Confocal images through the carotid body showed that TRPC1/3/4/5/6 proteins localize to the carotid sinus nerve fibers, some of which were immunoreactive to an anti‐neurofilament (NF) antibody cocktail. TRPC1 and TRPC3 were present in both NF‐positive and NF‐negative fibers, whereas TPRC4, TRPC5, and TRPC6 expression was primarily localized to NF‐negative fibers. Only TRPC1 and TRPC4 were localized in the afferent nerve terminals that encircle individual glomus cells. TRPC7 was not expressed in sensory fibers. All the TRPC proteins studied were present in type I glomus cells. Although their role as receptor‐activated cation channels in the chemosensory pathway is yet to be established, the presence of TRPC channels in glomus cells and sensory nerves of the carotid body suggests a role in facilitating and/or sustaining the hypoxic response. J. Comp. Neurol. 464:404–413, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructure and synaptic targets of tectothalamic terminals in the cat lateral posterior nucleus
Authors: Kelly Larry R. , Li Jianli , Carden W. Breckinridge , Bickford Martha E. 
Published: July 2003

AbstractThe recent appreciation of the fact that the pulvinar and lateral posterior (LP) nuclei receive two distinct types of cortical input has sparked renewed interest in this region of the thalamus. A key question is whether the primary or “driving” inputs to the pulvinar/LP complex originate in cortical or subcortical areas. To begin to address this issue, we examined the synaptic targets of tectothalamic terminals within the LP nucleus. Tectothalamic terminals were labeled using the anterograde transport of biotinylated dextran amine (BDA) or Phaselous leucoagglutinin placed in the superior colliculus or using immunocytochemical staining for substance P, a neurotransmitter found to be used by the tectothalamic pathway (Hutsler and Chalupa [ 1991] J. Comp. Neurol. 312:379–390). Our results suggest that most tectothalamic terminals are large and occupy a proximal position on the dendritic arbor of LP relay cells. In the medial LP, tectothalamic terminals labeled by the transport of neuronal tracers or substance P immunocytochemistry can form tubular clusters that surround the proximal dendrites of relay cells. In a rostral and lateral subdivision of the lateral LP nucleus (LPl‐2), tectothalamic terminals form more typical glomerular arrangements. When compared with existing physiological data, these results suggest that a unique integration of tectal and cortical inputs may contribute to the response properties of LP neurons. J. Comp. Neurol. 464:472–486, 2003. © 2003 Wiley‐Liss, Inc.
Temporal and spatial distribution of activated caspase‐3 after subdural kainic acid infusions in rat spinal cord
Authors: Nottingham Stephanie A. , Springer Joe E. 
Published: July 2003

AbstractThe molecular events initiating apoptosis following traumatic spinal cord injury (SCI) remain poorly understood. Soon after injury, the spinal cord is exposed to numerous secondary insults, including elevated levels of glutamate, that contribute to cell dysfunction and death. In the present study, we attempted to mimic the actions of glutamate by subdural infusion of the selective glutamate receptor agonist, kainic acid, into the uninjured rat spinal cord. Immunohistochemical colocalization studies revealed that activated caspase‐3 was present in ventral horn motor neurons at 24 hours, but not 4 hours or 96 hours, following kainic acid treatment. However, at no time point examined was there evidence of significant neuronal loss. Kainic acid resulted in caspase‐3 activation in several glial cell populations at all time points examined, with the most pronounced effect occurring at 24 hours following infusion. In particular, caspase‐3 activation was observed in a significant number of oligodendroglia in the dorsal and ventral funiculi, and there was a pronounced loss of oligodendroglia at 96 hours following treatment. The results of these experiments indicate a role for glutamate as a mediator of oligodendroglial apoptosis in traumatic SCI. In addition, understanding the apoptotic signaling events activated by glutamate will be important for developing therapies targeting this cell death process. J. Comp. Neurol. 464:463–471, 2003. © 2003 Wiley‐Liss, Inc.
Xenopus laevis CB1 cannabinoid receptor: Molecular cloning and mRNA distribution in the central nervous system
Authors: Cottone Erika , Salio Chiara , Conrath Marie , Franzoni Maria Fosca 
Published: July 2003

AbstractIn the present research we isolated and characterized Xenopus laevis CB1 cannabinoid receptor mRNA. The CB1 coding sequence shows a high degree of identity with those of other vertebrates, mammals included, confirming that CB1 receptor is conserved over the course of vertebrate evolution. Notably, the similarity between the X. laevis CB1 sequence and that of the urodele amphibian Taricha granulosa is not higher than the similarity existing between Xenopus and mammals, thus supporting phylogenetic distance between anurans and urodeles. By means of in situ hybridization histochemistry, CB1 mRNA expression and distribution was investigated in the X. laevis central nervous system. As revealed, CB1 mRNA‐containing neurons are numerous in the prosencephalon, especially in the olfactory bulbs, telencephalic pallium, and hypothalamus. In the midbrain and hindbrain, labeled cells were observed in the mesencephalic tegmentum and dorsolateral romboencephalon. Abundant CB1 mRNA positive neurons are localized throughout the gray matter of the spinal cord, in particular in the dorsal and ventral fields, where labeled motor neurons are also observed. The distribution of CB1 mRNA in the Xenopus CNS is generally consistent with the CB1‐like‐immunohistochemistry results we have previously obtained, showing in amphibians a well developed cannabinergic system almost comparable to that described in mammals. However, some differences, such as the abundance of CB1 mRNA‐containing neurons in the olfactory system and the rich CB1 spinal innervation, are found. J. Comp. Neurol. 464:487–496, 2003. © 2003 Wiley‐Liss, Inc.
GABA‐ and glycine‐like immunoreactivity in axons and dendrites contacting the central terminals of rapidly adapting glabrous skin afferents in rat spinal cord
Authors: Watson Alan H.D. 
Published: July 2003

AbstractThe object of the present study was to determine the nature and distribution of synaptic contacts on the terminals of rapidly adapting mechanosensory afferents innervating the glabrous skin of the rat foot. Afferents were physiologically characterized by intracellular recording, before injection with neurobiotin and preparation for electron microscopy. Axon terminals were serially sectioned and immunolabeled with antibodies against GABA and glycine using a postembedding immunogold method. Afferent boutons in lamina III were often surrounded by several presynaptic axons and postsynaptic dendrites (thus forming type II glomeruli), while boutons in laminae IV–V had only simple, nonglomerular interactions. In both regions triadic synaptic arrangements where presynaptic interneurons contact both afferent boutons and their postsynaptic dendrites were present in 50–75% of boutons. Approximately three‐quarters of presynaptic axons were immunoreactive for both GABA and glycine and most of the remainder for GABA alone. Most postsynaptic dendrites were not immunoreactive. Comparisons are made with information from similar studies of other rat and cat afferents conducting in the Aαβ range. This demonstrates that although the principles of control may be similar for cutaneous afferents of this type there are significant differences between cutaneous and 1a muscle afferents in the rat. There are also differences in detail between the interactions of afferents of the same modality in rat and cat; in the rat there are greater numbers of presynaptic axons per bouton and a greater proportion of boutons receive axo‐axonic contacts and are involved in synaptic triads. J. Comp. Neurol. 464:497–510, 2003. © 2003 Wiley‐Liss, Inc.
Comparative distribution of neuropeptide Y Y1 and Y5 receptors in the rat brain by using immunohistochemistry
Authors: Wolak Michael L. , deJoseph M. Regina , Cator Allison D. , Mokashi Ashwini S. , Brownfield Mark S. , Urban Janice H. 
Published: July 2003

AbstractNeuropeptide Y (NPY) Y1 and Y5 receptor subtypes mediate many of NPY's diverse actions in the central nervous system. The present studies use polyclonal antibodies directed against the Y1 and Y5 receptors to map and compare the relative distribution of these NPY receptor subtypes within the rat brain. Antibody specificity was assessed by using Western analysis, preadsorption of the antibody with peptide, and preimmune serum controls. Immunostaining for the Y1 and Y5 receptor subtypes was present throughout the rostral‐caudal aspect of the brain with many regions expressing both subtypes: cerebral cortex, hippocampus, hypothalamus, thalamus, amygdala, and brainstem. Further studies using double‐label immunocytochemistry indicate that Y1R immunoreactivity (‐ir) and Y5R‐ir are colocalized in the cerebral cortex and caudate putamen. Y1 receptor ir was evident in the central amygdala, whereas both Y1‐ and Y5‐immunoreactive cells and fibers were present in the basolateral amygdala. Corresponding with the physiology of NPY in the hypothalamus, both Y1R‐ and Y5R‐ir was present within the paraventricular (PVN), supraoptic, arcuate nuclei, and lateral hypothalamus. In the PVN, Y5R‐ir and Y1R‐ir were detected in cells and fibers of the parvo‐ and magnocellular divisions. Intense immunostaining for these receptors was observed within the locus coeruleus, A1–5 and C1–3 nuclei, subnuclei of the trigeminal nerve and nucleus tractus solitarius. These data provide a detailed and comparative mapping of Y1 and Y5 receptor subtypes within cell bodies and nerve fibers in the brain which, together with physiological and electrophysiological studies, provide a better understanding of NPY neural circuitries. J. Comp. Neurol. 464:285–311, 2003. © 2003 Wiley‐Liss, Inc.
Proposed parameters for monitoring quality of virgin olive oil (Koroneiki cv)
Authors: Psomiadou Eleni , Karakostas Konstantinos X. , Blekas Georgios , Tsimidou Maria Z. , Boskou Dimitrios 
Published: July 2003

AbstractThe overall quality of virgin olive oil (VOO) is closely related to its oxidative stability that is usually evaluated through the stability index measured by the Rancimat apparatus. Quality characteristics and also pro‐oxidant and antioxidant content for 52 Greek VOO samples (Koroneiki cv) were used to build up a model capable of predicting stability. Collinearity diagnostics, variable selection, and regression analysis were applied to the experimental data to locate the contribution of each parameter to the keeping quality of the samples. The predictive ability of the model was confirmed for a second VOO ample set of the same cultivar. It was found that except for the peroxide value, which negatively influences the stability, other important parameters were α‐tocopherol, total polar phenol and total chlorophyll content. It is concluded that the colorimetric determination of total polar phenols, the spectrometric determination of total chlorophylls and the high‐performance liquid chromatography analysis of α‐tocopherol, not presently included in the established methods of official analysis, can be used for a better evaluation of VOO quality. These parameters, which can be easily adopted as routine methods by the industry, seem to be of utmost importance for shelf life prediction and expiration dating if applied for the promotion of the most competitive products in the international olive oil market.
Epoxidation of a conjugated linoleic acid isomer
Authors: Jie Marcel S. F. Lie Ken , Lam Corey N. W. , Ho Janette C. M. , Lau Maureen M. L. 
Published: July 2003

AbstractEpoxidation of methyl (9Z, 11E)‐octadecadienoate (1) with various epoxidizing agents viz. m‐chloroperoxybenzoic acid, dimethyl dioxirane, methyltrioxorhenium/hydrogen peroxide, potassium peroxomonosulfate (Oxone, 2KHSO5 · KHSO4 · K2SO4)/tetrahydrothiopyran‐4‐one, and Novozyme 435/hydrogen peroxide is described. The reactions furnished the corresponding mono‐epoxy [methyl (11, 12E)‐epoxy‐(9Z)‐octadecenoate (2) and methyl (9, 10Z)‐epoxy‐(11E)‐octadecenoate (3)] and a mixture of diastereomers of syn‐ and anti‐diepoxy‐stearate [methyl (9, 10Z;11, 12E)‐diepoxystearate (4a‐4d)], which were identified by a combination of spectroscopic and spectrometric analyses.
A personal and provocative view on the European GMO situation
Authors: Leysen Roger J. F. 
Published: July 2003

AbstractThe author was, during his active career with the American Soybean Association in Brussels (Belgium), a direct witness when the GMO soybeans were first announced and introduced in the EU market. He reviews the responsibility of the different parties involved and expresses his personal opinion about the errors made during the initial phase. He specifically expresses his worries with regard to the unworkable, legislative situation in the EU.
Fast enantiomeric separation with vancomycin as chiral additive by co‐electroosmotic flow capillary electrophoresis: Increase of the detection sensitivity by the partial filling technique
Authors: Kang Jingwu , Wistuba Dorothee , Schurig Volker 
Published: July 2003

AbstractA fast and sensitive method is described by using vancomycin as a chiral additive for enantiomeric separation by capillary electrophoresis (CE). In order to overcome disadvantages associated with use of vancomycin as chiral additive in CE, several strategies including the dynamic coating technique, the co‐electroosmotic flow technique, and the partial filling technique were employed sequentially in this method. Using the polycationic polymer hexadimethrine bromide (HDB) as a buffer additive, the capillary wall was dynamically coated with a thin film formed by the adsorbed HDB. Consequently, the adsorption of vancomycin onto the capillary wall was minimized via electrostatic repulsion between the coating of the capillary wall and the vancomycin molecule. In addition, the reversed electroosmotic flow (from cathode to anode) produced by the positively charged capillary wall migrates in the same direction of negatively charged analytes (co‐electroosmotic flow electrophoresis). Thereby the electrophoretic mobility of negatively charged analytes were drastically accelerated leading to a short separation time of less than 3.4 min. The separation time was further reduced by the use of a short‐end‐injection technique. For example, the analysis time was achieved by as short as 55 s for a baseline separation of dansyl‐α‐amino‐n‐butyric acid. Concurrently, the partial filling technique was used to avoid the loss of detection sensitivity caused by the presence of vancomycin in the running buffer. The effect of several parameters, such as HDB concentration, buffer pH, plug length of the chiral selector, concentration of the chiral selector and applied voltage, on enantioselectivity were investigated toward optimization. Besides the advantage of a very short separation time, the method is characterized by high detection sensitivity, high selectivity, and high efficiency.
Cyclodextrin‐modified monolithic columns for resolving dansyl amino acid enantiomers and positional isomers by capillary electrochromatography
Authors: Chen Zilin , Ozawa Hiroshi , Uchiyama Katsumi , Hobo Toshiyuki 
Published: July 2003

AbstractWe describe β‐ and γ‐cyclodextrins (β‐ and γ‐CD)‐modified monolithic columns prepared by sol‐gel process and chemical modifications. The monolithic silica column was fabricated inside a fused‐silica capillary with 100 μm inner diameter by sol‐gel process. The monolithic silica matrix was chemically modified chiral selectors of β‐ or γ‐CDs with a spacer of 3‐glycidoxypropyltrimethoxysilane by on‐column reactions. γ‐CD‐modified monolithic column has successfully been applied for the separation of dansyl amino acid enantiomers. β‐CD‐modified monolithic column has been used for the separation of the positional isomers of o‐, m‐, and p‐cresols and the enantioseparation of racemates of benzoin and several dansyl amino acids by capillary electrochromatography, respectively. For the separation of neutral positional isomers, a positive electric field was applied. However, for the separation of negatively charged analytes, a negative electric field was applied at the inlet of column. The separation efficiency of 5.0×104 theoretical plates/m for dansyl‐L‐threonine was obtained at electric field strength of −300 V/cm in the mobile phase of 50 mM 2‐(N‐morpholino)ethanesulfonic acid (MES)‐Tris/methanol (70/30) buffer at pH 7.0. L‐Enantiomers were eluted as the first peak. Scanning electron micrograph showed that monolithic columns have the morphology of continuous skeleton and large through‐pores.
Direct chiral resolution of tartaric acid by ion‐pair capillary electrophoresis using an aqueous background electrolyte with (1R,2R)‐(–)‐1,2‐diaminocyclohexane as a chiral counterion
Authors: Kodama Shuji , Yamamoto Atsushi , Matsunaga Akinobu , Hayakawa Kazuichi 
Published: July 2003

AbstractChiral resolution of native DL‐tartaric acid was achieved by ion‐pair capillary electrophoresis (CE) using an aqueous‐ethanol background electrolyte with (1R,2R)‐(−)‐1,2‐diaminocyclohexane (R‐DACH) as a chiral counterion. Factors affecting chiral resolution and migration time of tartaric acid were studied. By increasing the viscosity of the background electrolyte and the ion‐pair formation, using organic solvents with a lower relative dielectric constant, resulted in a longer migration time. The optimum conditions for both high resolution and short migration time of tartaric acid were found to be a mixture of 65% v/v ethanol and 35% v/v aqueous solution containing 30 mM R‐DACH and 75 mM phosphoric acid (pH 5.1) with an applied voltage of −30 kV at 25°C, using direct detection at 200 nm. By using this system, the resolution (Rs) of racemic tartaric acid was approximately 1. The electrophoretic patterns of tartaric and malic acids suggest that two carboxyl groups and two hydroxyl groups of tartaric acid are associated with the enantioseparation of tartaric acid by the proposed CE method.
Separation of aminoalkanephosphonic acid enantiomers by indirect UV detection capillary electrophoresis with application of cyclodextrins
Authors: Rudzińska Ewa , Wieczorek Piotr , Kafarski Paweł 
Published: July 2003

AbstractIndirect UV detection capillary electrophoresis (CE) was used for the separation of aminoalkanephosphonic acid (AP) enantiomers by applying commercially available cyclodextrins as chiral discriminators. The results show that the separation of the enantiomers depends on pH of the background electrolyte, the molar ratio of cyclodextrin to aminophosphonic acid, and on the type of the applied chiral selector. Optimization of process conditions allowed enantiomeric baseline separation or partial separation of 12 out of 14 α‐aminophosphonic acids studied. This type of CE might therefore be successfully used for routine determination of enantiomeric purity of aminophosphonic acids.
Simultaneous chiral discrimination of multiple profens by cyclodextrin‐modified capillary electrophoresis in normal and reversed polarity modes
Authors: La Sookie , Kim Jiyung , Kim Jung‐Han , Goto Junichi , Kim Kyoung‐Rae 
Published: July 2003

AbstractSimultaneous enantioseparations of nine profens for their accurate chiral discrimination were achieved by capillary electrophoresis (CE) in the normal polarity (NP) mode with a single cyclodextrin (CD) system and in the reversed polarity (RP) mode with a dual CD system. The single CD system in the NP mode employed heptakis(2,3,6‐tri‐O‐methyl)‐β‐cyclodextrin (TMβCD) added at 75 mM–100 mM 2‐(N‐morpholino)ethanesulfonic acid buffer (pH 6.0) as the optimum run buffer. The dual CD system operated in the RP mode used 30 mM TMβCD and 1.0% anionic carboxymethyl‐β‐cyclodextrin dissolved in pH 3.0, 100 mM phosphoric acid‐triethanolamine buffer containing 0.01% hexadimethrine bromide added to reverse the electroosmotic flow. Fairly good enantiomeric resolutions and the opposite enantiomer migration orders were achieved in the two modes. Relative migration times to internal standard under respective optimum conditions were characteristic of each enantiomer with good precision (< 2% relative standard deviation, RSD), thereby enabling to crosscheck the chemical identification of profens and also their accurate chiralities. The method linearity in the two modes was found to be adequate (r ≥ 0.9991) for the chiral assay of the profens investigated. Simultaneous enantiomeric purity test of ibuprofen, ketoprofen and flurbiprofen in a mixture was feasible in a single analysis by the present method.