bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of the paratemnus elongatus pseudoscorpion venom in the uptake and binding of the L‐glutamate and GABA from rat cerebral cortex
Authors: dos Santos Wagner Ferreira , Coutinho‐Netto Joaquim 
Published: February 2006

AbstractL‐Glu is the most important and widespread excitatory neurotransmitter of the vertebrates. Four types of receptors for L‐glu have been described. This neurotransmitter modulates several neuronal processes, and its dysfunction causes chronic and acute diseases. L‐Glu action is terminated by five distinct transporters. Antagonists for these receptors and modulators of these transporters have anticonvulsant and neuroprotective potentials, as observed with the acylpoliamines and peptides isolated from spiders, solitary and social wasp venoms. On the other hand, the major inhibitory neurotransmitter in mammalian nervous tissue is the GABA. Drugs that enhance GABA neurotransmission comprise effective approaches to protecting the brain against neuronal injury. Is this study, we demonstrate for the first time the inhibition of the [3H]L‐glu binding to its specific sites in synaptosomal membranes from rat cerebral cortex, produced by 0.027 U of Paratemnus elongatus venom (EC50). The venom of P. elongatus changes Km and Vmax into the high affinity uptake of the L‐glu and decreases Km and Vmax into the parameters of the GABA uptake from rat synaptosomes. This leads us to speculate on the possible presence of selective and specific compounds in this venom that act in L‐glu and GABA dynamics, and therefore, that can serve as tools and new drug models for understanding these neurotransmissions. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:27–34, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20113
Monitoring of an industrial wastewater plant employing finite‐time convergence observer
Authors: Aguilar‐López Ricardo , Martínez‐Guerra Rafael , Mendoza‐Camargo Juan , Neria‐González María Isabel 
Published: February 2006

AbstractIn this paper, the estimation of non measured variables (bioreactor biomass and settler biomass concentrations) is addressed. The plant is subjected to sudden step disturbances on the inlet oxygen flow, such that an observer with finite‐time convergence is required, to maintain adequate estimation performance. The observer structure contains a fractional power of the estimation error which is proposed to ensure the convergence properties needed. Under the assumptions considered, a mathematical analysis is performed to demonstrate the convergence of the estimation error and the convergence time is also calculated. The performance of the observer is illustrated with numerical experiments and compared with standard nonlinear Luenberger observer. Copyright © 2006 Society of Chemical Industry
Quiescent gemmules of the freshwater sponge, Spongilla lacustris (Linnaeus, 1759), contain remarkably high levels of Hsp70 stress protein and hsp70 stress gene mRNA
Authors: Schill Ralph O. , Pfannkuchen Martin , Fritz Gisela , Köhler Heinz‐r. , Brümmer Franz 
Published: February 2006

AbstractWith the onset of changing environmental conditions in autumn, the freshwater sponge Spongilla lacustris (Linnaeus, 1759) produces resistant stages (gemmules) which are in the state of quiescence. Gemmules stored at 8°C remained quiescent; however, germination occurred within 24 hr after the water temperature was increased to 22.5°C. Sponges hatched through the micropyle and subsequently built new spicules and a new canal system. The molecular and biochemical mechanisms which enable the gemmules to survive long periods of adverse conditions are not known. For the first time we focused on the role of the stress protein Hsp70 and the expression of hsp70 mRNA in S. lacustris during the development of gemmules in the state of quiescence into growing sponges. The partial sequence of hsp70 seems to be a true hsp gene since transcription could be clearly enhanced by temperature elevation. The results showed a large pool of cellular Hsp70 and hsp70 mRNA in gemmules during the state of quiescence. Within hours after a temperature trigger, the Hsp70 level decreased slowly and reached approximately the level of an adult sponge. Hsp70 presumably allows gemmules to stabilize their proteins and membranes during dormancy from autumn to spring when water temperatures change. J. Exp. Zool. 305A, 2006. © 2006 Wiley‐Liss, Inc.
Developmental and evolutionary origins of the vertebrate dentition: molecular controls for spatio‐temporal organisation of tooth sites in osteichthyans
Authors: Fraser Gareth J. , Graham Anthony , Smith Moya M. 
Published: February 2006

AbstractThe rainbow trout (Oncorhynchus mykiss) as a developmental model surpasses both zebrafish and mouse for a more widespread distribution of teeth in the oro‐pharynx as the basis for general vertebrate odontogenesis, one in which replacement is an essential requirement. Studies on the rainbow trout have led to the identification of the initial sequential appearance of teeth, through differential gene expression as a changing spatio‐temporal pattern, to set in place the primary teeth of the first generation, and also to regulate the continuous production of replacement tooth families. Here we reveal gene expression data that address both the field and clone theories for patterning a polyphyodont osteichthyan dentition. These data inform how the initial pattern may be established through up‐regulation at tooth loci from a broad odontogenic band. It appears that control and regulation of replacement pattern resides in the already primed dental epithelium at the sides of the predecessor tooth. A case is presented for the developmental changes that might have occurred during vertebrate evolution, for the origin of a separate successional dental lamina, by comparison with an osteichthyan tetrapod dentition (Ambystoma mexicanum). The evolutionary origins of such a permanent dental lamina are proposed to have occurred from the transient one demonstrated here in the trout. This has implications for phylogenies based on the homology of teeth as only those developed from a dental lamina. Utilising the data generated from the rainbow trout model, we propose this as a standard for comparative development and evolutionary theories of the vertebrate dentition. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
From conical to spatulate: Intra‐ and interspecific changes in tooth shape in closely related cichlids (Teleostei; Cichlidae: Eretmodini)
Authors: Vandervennet E. , Wautier K. , Verheyen E. , Huysseune A. 
Published: February 2006

AbstractThe Eretmodini are closely related cichlids endemic to Lake Tanganyika with very divergent oral tooth shapes, ranging from spatulate in Eretmodus to conical in Tanganicodus. To study how closely related cichlids can generate such divergent tooth shapes, we investigated how the enamel organ directs the development of spatulate teeth in Eretmodus cf. cyanostictus (lineage A), both in ontogeny and in adults, and of conical teeth in adult Tanganicodus cf. irsacae, using 3D‐reconstructions from serially sectioned tooth germs. The spatulate oral tooth shape that characterizes adult E. cf. cyanostictus (lineage A) is preceded early in ontogeny by a conical tooth shape. We propose two possible hypotheses to account for changes in the folding of the enamel organ (in particular its epithelio‐mesenchymal boundary) capable of generating such distinct tooth shapes. Different arguments lead us to favor the hypothesis of an asymmetric growth and differentiation of the enamel organ, such that the tip of a conical tooth corresponds to one “corner” of a spatulate tooth. Applying current molecular models of tooth shape variation, this would imply the existence of asymmetric fields of inhibition. Whether such asymmetric growth reflects the reutilization of a simple mechanism operating in ontogeny has to be clarified. J. Morphol. © 2006 Wiley‐Liss, Inc.
Variations due to analysis technique in intracellular pH measurements in simulated and in vivo 31P MR spectra of the human brain
Authors: Hamilton Gavin , Allsop Joanna M. , Patel Nayna , Forton Daniel M. , Thomas Howard C. , O'Sullivan Catherine P.A. , Hajnal Joseph V. , Taylor‐Robinson Simon D. 
Published: February 2006

AbstractPurposeTo investigate variation in pH generated by different analysis techniques and to find the most robust method, 31P MR brain spectra were acquired in vivo. Three different methods were used to measure the chemical shift of inorganic phosphate (Pi) relative to phosphocreatine (PCr).Materials and MethodsEight healthy volunteers were scanned four times, and manual measurement of the chemical shift in a frequency domain spectrum using the manufacturer's software was compared with values produced by a frequency‐domain analysis method (NMR1) and a prior‐knowledge‐based time‐domain technique (MRUI). To explain the in vivo data, simulations of brain spectra, modified in ways typical of real variations in vivo, were produced and the pH was measured using manual measurement and MRUI.ResultsDifferent measurement techniques produced systematically different pH values, with manual measurement producing the lowest variability (manual measurement: pH = 6.999, CoV = 0.297; NMR1: pH = 7.042, CoV = 0.501; MRUI: pH = 7.036, CoV = 0.606). While MRUI more accurately measured the pH of unaltered simulations, it was systematically affected by altering the simulated spectra. Manual measurement was unaffected.ConclusionManual measurement produces the most consistent pH value, and there is no benefit in using more complex automated spectral fitting methods to measure the pH. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
The atmospheric pressure Meerwein reaction
Authors: Meurer Eduardo C. , Eberlin Marcos N. 
Published: February 2006

AbstractWe have already shown that the in‐vacuum gas‐phase Meerwein reaction of (thio)acylium ions is general in nature and useful for class‐selective screening of cyclic (thio)epoxides. Herein we report that this gas‐phase reaction can also be performed efficiently at atmospheric pressure under both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) conditions. This alternative expands the range of molecules that can be reacted by gas‐phase Meerwein reaction. Phenyl epoxide, thiirane, 3‐methoxy‐2,2‐dimethyloxirane, propylene oxide, 2,2′‐bioxirane, trans‐1,3‐diphenyl‐2,3‐epoxypropan‐1‐one, epichloridrine and propylene oxide are shown to react efficiently in both ESI and APCI conditions. Tetramethylurea (TMU) and (thio)TMU were both used as dopants, being co‐injected with either toluene, acetonitrile or methanol solutions of the (thio)epoxides, with similar results. In both ESI and APCI, (thio)TMU is protonated preferentially, and these labile species dissociate promptly to yield (CH3)2NC+O and (CH3)2NCS+, which are the least acidic and most reactive (thio)acylium ions so far tested in the gas‐phase Meerwein reaction. Under the low‐energy ESI conditions set to favor both the formation of the (thio)acylium ion and ion/molecule reactions, (CH3)2NCO(S)+ react competitively with (thio)TMU to form acylated (thio)TMU and with the (thio)epoxide to form the characteristic Meerwein products. Enhanced selectivity in structural characterization or for the screening of (thio)epoxides is achieved by performing on‐line collision‐induced dissociation of Meerwein products, particularly for the more structurally complex (thio)epoxides. Copyright © 2006 John Wiley & Sons, Ltd.
Pre‐ and post‐dialysis quantitative dosage of thymidine in urine and plasma of a MNGIE patient by using HPLC‐ESI‐MS/MS
Authors: la Marca G. , Malvagia S. , Casetta B. , Pasquini E. , Pela I. , Hirano M. , Donati M. A. , Zammarchi E. 
Published: February 2006

AbstractMitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive disorder characterized by severe gastrointestinal dysmotility, cachexia, ptosis, ophthalmoparesis, peripheral neuropathy and leukoencephalopathy. The disease is due to a thymidine phosphorylase defect. This enzyme catalyses the phosphorolysis of thymidine to thymine and deoxyribose 1‐phosphate. For this reason, increased levels of thymidine in plasma and urine are found in MNGIE patients. Haemodialysis can reduce circulating plasma thymidine levels and can be beneficial in some MNGIE patients. We developed a fast analytical method based on HPLC‐ESI‐MS/MS capable of identifying pyrimidine nucleotides (thymine, cytosine, uracil) and nucleosides (thymidine, citidine, uridine) in plasma and urine after direct dilution of the samples without pre‐treatment.In the patient studied, we observed a significant reduction of plasmatic and urinary thymidine levels during and after dialysis. However, we noted a progressive reduction of the initial thymidine level after some dialytic trials. This method will be useful not only for thymidine level follow‐up during dialysis in MNGIE patients but also for the improvement of the diagnosis or diagnostic suspect in other pyrimidine defects such as dihydropyrimidine dehydrogenase deficiency, dihydropyrimidinase deficiency and ureidopropionase deficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Collision‐induced dissociation pathways of yeast sphingolipids and their molecular profiling in total lipid extracts: a study by quadrupole TOF and linear ion trap–orbitrap mass spectrometry
Authors: Ejsing Christer S. , Moehring Thomas , Bahr Ute , Duchoslav Eva , Karas Michael , Simons Kai , Shevchenko Andrej 
Published: February 2006

AbstractThe yeast Saccharomyces cerevisiae synthesizes three classes of sphingolipids: inositolphosphoceramides (IPCs), mannosyl‐inositolphosphoceramides (MIPCs), and mannosyl‐diinositolphosphoceramides (M(IP)2C). Tandem mass spectrometry of their molecular anions on a hybrid quadrupole time‐of‐flight (QqTOF) instrument produced fragments of inositol‐containing head groups, which were specific for each lipid class. MSn analysis performed on a hybrid linear ion trap–orbitrap (LTQ Orbitrap) mass spectrometer with better than 3 ppm mass accuracy identified fragment ions specific for the amide‐linked fatty acid and the long chain base moieties in individual molecular species. By selecting m/z of class‐specific fragment ions for multiple precursor ion scanning, we profiled yeast sphingolipids in total lipid extracts on a QqTOF mass spectrometer. Thus, a combination of QqTOF and LTQ Orbitrap mass spectrometry lends itself to rapid, comprehensive and structure‐specific profiling of the molecular composition of sphingolipids and glycerophospholipids in important model organisms, such as fungi and plants. Copyright © 2006 John Wiley & Sons, Ltd.
Gender differences in response of hippocampus to chronic glucocorticoid stress: Role of glutamate receptors
Authors: Liu Howard H. , Payne H. Ross , Wang Bin , Brady Scott T. 
Published: February 2006

AbstractGlucocorticoids (GC) play critical roles in the pathophysiological reactions to environmental stress. In brain, morphological changes were examined in hippocampal CA3 neurons with 2 weeks of chronic elevation of GC in male and female mice. Molecular correlates and underlying mechanisms paralleling these morphologic changes in hippocampus were investigated. Although the hippocampal neurons in the CA3 area in male mice atrophy with chronically elevated GC, female mice show minimal morphological changes with comparable GC regimens. These sexual morphological differences correlate with differences in the postsynaptic dense protein (PSD95) as well as the spectrum of glutamate receptors induced by GC treatment in male and female mice, including NMDA, AMPA, and KA receptors. These findings suggest that synaptic receptor composition is adapted to the unique physiological requirements of males and females and illuminate underlying mechanisms of GC/stress responses in the brain. © 2006 Wiley‐Liss, Inc.
Effects of Lamotrigine on field potentials, propagation, and long‐term potentiation in rat prefrontal cortex in multi‐electrode recording
Authors: Huang Chin‐Wei , Hsieh Yi‐Jung , Tsai Jing‐Jane , Huang Chao‐Ching 
Published: February 2006

AbstractLamotrigine (LTG) is an anti‐epileptic drug that is widely used clinically in various neuropsychiatric disorders. Although consensus is found on the general mode of action by LTG on voltage‐gated sodium current, its effect on field potential, neuropropagation, and long‐term potentiation, especially in prefrontal cortex (PFC), is still not understood completely. We investigated LTG effects on synaptic response in rat prefrontal cortical slice with the aid of a novel multi‐electrode dish (MED64) system. The amplitude and propagation of field excitatory postsynaptic potentials (fEPSP), presynaptic fiber volleys (PrV) were expressed dimensionally in the MED64 system. Lamotrigine (3–100 μM) inhibited the amplitude and propagation of fEPSP and PrV in a concentration dependent manner. It exerted a predominant presynaptic action, as indicated by the increment in paired‐pulse facilitation. Stimulating dependency with reduction fEPSP was seen in the presence of LTG at clinically relevant concentrations as well as with PrV, both in amplitude and propagation. In addition, the depression of PrV amplitudes in the presence of LTG showed a use‐dependent fashion. As to LTP in PFC, it was not fEPSP amplitude but propagation reduced by LTG. In PFC, LTG exerts its use‐ and concentration‐dependent inhibitory effect on presynaptic action and depresses fEPSP amplitude and propagation in a clinically relevant concentration. LTP was preserved in its fEPSP amplitude but not propagation in PFC in the presence of LTG. © 2006 Wiley‐Liss, Inc.
Glutamate receptor agonist kainate enhances primary dendrite number and length from immature mouse cortical neurons in vitro
Authors: Monnerie Hubert , Le Roux Peter D. 
Published: February 2006

AbstractGlutamate is an important regulator of dendrite development that may inhibit, (during ischemic injury), or facilitate (during early development) dendrite growth. Previous studies have reported mainly on the N‐methyl‐D‐aspartate (NMDA) receptor‐mediated dendrite growth‐promoting effect of glutamate. In this study, we examined how the non‐NMDA receptor agonist kainate influenced dendrite growth. E18 mouse cortical neurons were grown for 3 days in vitro and immunolabeled with anti‐microtubule‐associated protein 2 (MAP2) and anti‐neurofilament (NF‐H), to identify dendrites and axons, respectively. Exposure of cortical neurons to kainate increased dendrite growth without affecting neuron survival. This effect was dose‐dependent, reversible and blocked by the α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazoleproprionate (AMPA)/kainate receptor antagonist NBQX and the low‐affinity kainate receptor antagonist NS‐102, but not by the AMPA receptor antagonist CFM‐2. In addition, the NMDA receptor antagonist MK‐801 had no effect on kainate‐induced dendrite growth. Immunolabeling and Western blot analysis of kainate receptors using antibodies against the GluR6 and KA2 subunits, demonstrated that the immature cortical neurons used in this study express kainate receptor proteins. These results suggest that kainate‐induced non‐NMDA receptor activation promotes dendrite growth, and in particular primary dendrite number and length, from immature cortical neurons in vitro, and that kainate receptors may be directly involved in this process. Furthermore, these data support the possibility that like NMDA receptors, kainate receptor activation may also contribute to early neurite growth from cortical neurons in vitro. © 2006 Wiley‐Liss, Inc.
Ataxin 10 induces neuritogenesis via interaction with G‐protein β2 subunit
Authors: Waragai Masaaki , Nagamitsu Shinichiro , Xu Weidong , Li Yu Jiang , Lin Xi , Ashizawa Tetsuo 
Published: February 2006

AbstractSpinocerebellar ataxia type 10 (SCA10) is a dominantly inherited disorder caused by an intronic ATTCT pentanucleotide repeat expansion. The ATXN10 gene encodes a novel protein, ataxin 10, known previously as E46L, which is widely expressed in the brain. Ataxin 10 deficiency has been shown recently to cause increased apoptosis in primary cerebellar cultures, thus implicated in SCA10 pathogenesis. The biologic functions of ataxin 10 remain largely unknown. By using yeast‐two‐hybrid screening of a human brain cDNA library, we identified the G‐protein β2 subunit (Gβ2) as an ataxin 10 binding partner, and the interaction was confirmed by coimmunoprecipitation and colocalization in mammalian cells in culture. Overexpression of ataxin 10 in PC12 cells induced neurite extension and enhanced neuronal differentiation induced by nerve growth factor (NGF). Moreover, coexpression of ataxin 10 and Gβ2 potently activated the Ras‐MAP kinase‐Elk‐1 cascade. Dominant negative Ras or inhibitor of MEK‐1/2 (U0126) aborted this activation, and blocked morphologic changes, whereas inhibition of TrkA receptor by K252a had no effects. Our data suggest that the ataxin 10‐Gβ2 interaction represents a novel mechanism for inducing neuritogenesis in PC12 cells by activating the Ras‐MAP kinase‐Elk‐1 cascade. © 2006 Wiley‐Liss, Inc.
Kinetics of the uptake of SO2 on mineral oxides: Improved initial uptake coefficients at 298 K from pulsed Knudsen cell experiments
Authors: Seisel Sabine , Keil Thorsten , Lian Yu , Zellner Reinhard 
Published: February 2006

AbstractThe uptake of SO2 on γ‐Fe2O3, γ‐Al2O3, and Saharan dust has been studied at T = 298 K using a Knudsen cell reactor operated in a steady‐state as well as in a pulsed mode. The initial uptake coefficients determined in the steady‐state mode have been found to be affected by surface saturation as well as bulk diffusion of SO2 resulting in an apparent dependence of the initial uptake coefficients on the sample mass of the mineral oxides. However, by operating the Knudsen cell in the pulsed mode with shorter response time, these effects could be suppressed. Initial uptake coefficients of γini (Fe2O3) = (8.8 ± 0.4) × 10−2, γini (Al2O3) = (7.4 ± 0.9) × 10−3, and γini (Saharan dust) = (7.6 ± 0.5) × 10−2 were derived. This suggests that Fe2O3 is an important component in determining the reactivity of mineral dusts. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 242–249, 2006
Rate constant estimation for C1 to C4 alkyl and alkoxyl radical decomposition
Authors: Curran H. J. 
Published: February 2006

AbstractRate coefficients for alkyl and alkoxy radical decomposition are important in combustion, biological, and atmospheric processes. In this paper, rate constant expressions for C1C4 alkyl and alkoxy radicals decomposition via β‐scission are recommended based on the reverse, exothermic reaction, the addition of a hydrogen atom or an alkyl radical to an olefin or carbonyl species with the decomposition reaction calculated using microscopic reversibility. The rate expressions have been estimated based on a wide‐range study of available experimental data. Rate coefficients for hydrogen atom and alkyl radical addition to an olefin show a strong temperature curvature. In addition, it is found that there is a correlation between the activation energy for addition and (i) the type of atom undergoing addition and (ii) whether this radical adds to the internal or terminal carbon atom of the olefin. Rate coefficients for alkoxy radical decomposition show a strong correlation to the ionization potential of the alkyl radical leaving group and on the enthalpy of reaction. It is shown that the activation energy for alkyl radical addition to a carbonyl species can be estimated as a function of the alkyl radical ionization potential and enthalpy of reaction. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 250–275, 2006