bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycoligands Tuning the Magnetic Anisotropy of NiII Complexes
Authors: Charron Gaëlle , Bellot François , Cisnetti Federico , Pelosi Giorgio , Rebilly Jean‐Noël , Rivière Eric , Barra Anne‐Laure , Mallah Talal , Policar Clotilde 
Published: February 2007

AbstractTwo organic ligands based on a sugar‐scaffold derived from galactose and possessing three O‐CH2‐pyridine pendant arms at the 3‐, 4‐, and 5‐positions of the galactopyranose that act as chelates afford mononuclear complexes when reacted with a NiII salt. The magnetization behavior in the form of M=f(H/T) plots suggests the presence of appreciable magnetic anisotropy within the two complexes. The analysis of the EPR spectra performed at two different temperatures (7 and 17 K) and at three frequencies (190, 285, and 380 GHz) leads to the conclusion that the anisotropy has a high degree of axiality (E/D=0.17 for the two complexes), but with a different sign of the D parameter. The spin hamiltonian parameters D and E were reproduced for the two complexes by using calculations based on the angular overlap model (AOM). The structural difference between the two complexes responsible of the sign of the D parameters was also determined using AOM calculations. A thorough analysis of the structures showed that the structural differences in the coordination sphere of the two complexes responsible of the different D parameter sign result from the nature of the sugar scaffolds. In complex 1, the sugar scaffold imposes an intramolecular hydrogen bond with one of the atoms linked to NiII; this arrangement leads to a distorted coordination sphere and positive D value, while the absence of such a hydrogen bond in complex 2 leads to a less distorted environment around the Ni center and to a negative D value.
Asymmetric Total Synthesis of (−)‐Pironetin Employing the SAMP/RAMP Hydrazone Methodology
Authors: Enders Dieter , Dhulut Sylvie , Steinbusch Daniel , Herrbach Audrey 
Published: February 2007

AbstractA convergent asymmetric total synthesis of pironetin (1), a polyketide with immunosuppressive, antitumor, and plant‐growth regulating activities is described. The synthesis was realized by coupling between the C8–C14 2 and C7–C2 15 fragments, respectively, by using a Mukaiyama‐aldol reaction. The stereogenic centers of each fragment were generated by employing the SAMP/RAMP hydrazone (SAMP=(S)‐1‐amino‐2‐methoxymethylpyrrolidine, RAMP=(R)‐1‐amino‐2‐methoxymethylpyrrolidine) methodology as a key step. An asymmetric α‐alkylation of diethyl ketone permitted the introduction of the C10 stereogenic center of 2, whereas the stereocenters C4 and C5 of 15 were installed by an asymmetric aldol reaction. Finally, the formation of the α,β‐unsaturated δ‐lactone was achieved by ring‐closing metathesis in the presence of catalytic amounts of titanium tetraisopropoxide.
Stereoselective disposition of fenoprofen in plasma and synovial fluid of patients with rheumathoid arthritis
Authors: Miranda Silva Carolina De , Marques Maria Paula , Barissa Giuliano Rodrigo , Donadi Eduardo Antônio , Da Silva Lucienir Maria , Lanchote Vera Lucia 
Published: February 2007

AbstractThe simultaneous disposition of fenoprofen enantiomers in synovial fluid and plasma was studied in 11 patients with arthritis and chronic knee effusions treated with a single oral dose of 600 mg rac‐fenoprofen. A plasma sample and a synovial fluid sample were collected simultaneously from each patient up to 16 h after the administration of fenoprofen. A stereospecific assay for fenoprofen using LC–MS–MS was developed and applied successfully to the analysis of the enantiomers in plasma (LOQ = 10 ng of each enantiomer/ml) and synovial fluid (LOQ = 25 ng of each enantiomer/ml). The values of the area under the curve (AUC) for the S‐(+)‐fenoprofen eutomer were ∼2.5 times higher in plasma than in synovial fluid (256 vs 104 μg h/ml), while the values for the R‐(−)‐fenoprofen distomer were about four times higher in plasma than in synovial fluid (42.5 vs 10.5 μg h/ml). These data demonstrate accumulation of the S‐(+)‐fenoprofen eutomer in plasma and in synovial fluid, with concentrations versus time AUC (+)/(−) ratios of 6.0 in plasma and 9.9 in synovial fluid, suggesting a greater accumulation of the eutomer at the active site represented by synovial fluid than in plasma. This result demonstrates the importance of enantioselective methods and of analysis of synovial fluid rather than plasma in studies of the pharmacokinetics–pharmacodynamics of fenoprofen. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Influence of the chirality of (R)‐(−)‐ and (S)‐(+)‐carvone in the central nervous system: A comparative study
Authors: De Sousa Damião Pergentino , De Farias nóbrega Franklin Ferreira , De Almeida Reinaldo Nóbrega 
Published: February 2007

AbstractMany terpenes are used therapeutically, and as flavor and fragrance materials. (R)‐(−)‐Carvone, the main constituent of spearmint oil, and (S)‐(+)‐carvone, found as major component of caraway and dill seed oils, have several applications and are used in cosmetic, food, and pharmaceutical preparations. In this study, the effect of enantiomers of carvone on the central nervous system (CNS) was evaluated in mice. The LD50 value was 484.2 mg/kg (358.9–653.2) for (S)‐(+)‐carvone, and 426.6 (389.0–478.6) mg/kg for (R)‐(−)‐carvone. Both enantiomers caused depressant effects, such as decrease in the response to the touch and ambulation, increase in sedation, palpebral ptosis, and antinociceptive effects. (S)‐(+)‐ and (R)‐(−)‐carvone caused a significant decrease in ambulation. (R)‐(−)‐Carvone appeared to be more effective than its corresponding enantiomer at 0.5 and 2.0 h after administration. However, (S)‐(+)‐carvone was slightly more potent at 1 h. In potentiating pentobarbital sleeping time, (R)‐(−)‐carvone was more effective than (S)‐(+)‐carvone at 100 mg/kg, but was less potent at 200 mg/kg compared to the (+)‐enantiomer, indicating a sedative action. (S)‐(+)‐Carvone at the dose of 200 mg/kg increased significantly the latency of convulsions induced by PTZ and PIC, but (R)‐(−)‐carvone was not effective against these convulsions. These results suggest that (S)‐(+)‐carvone and (R)‐(−)‐carvone have depressant effect in the CNS. (S)‐(+)‐Carvone appears to have anticonvulsant‐like activity. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Central Nicotinic Receptors: Structure, Function, Ligands, and Therapeutic Potential
Authors: Romanelli M. Novella , Gratteri Paola , Guandalini Luca , Martini Elisabetta , Bonaccini Claudia , Gualtieri Fulvio 
Published: February 2007

AbstractThe growing interest in nicotinic receptors, because of their wide expression in neuronal and non‐neuronal tissues and their involvement in several important CNS pathologies, has stimulated the synthesis of a high number of ligands able to modulate their function. These membrane proteins appear to be highly heterogeneous, and still only incomplete information is available on their structure, subunit composition, and stoichiometry. This is due to the lack of selective ligands to study the role of nAChR under physiological or pathological conditions; so far, only compounds showing selectivity between α4β2 andα7 receptors have been obtained. The nicotinic receptor ligands have been designed starting from lead compounds from natural sources such as nicotine, cytisine, or epibatidine, and, more recently, through the high‐throughput screening of chemical libraries. This review focuses on the structure of the new agonists, antagonists, and allosteric ligands of nicotinic receptors, it highlights the current knowledge on the binding site models as a molecular modeling approach to design new compounds, and it discusses the nAChR modulators which have entered clinical trials.
Inhibition of Bcr‐Abl Phosphorylation and Induction of Apoptosis by Pyrazolo[3,4‐d]pyrimidines in Human Leukemia Cells
Authors: Manetti Fabrizio , Pucci Annalisa , Magnani Matteo , Locatelli Giada A. , Brullo Chiara , Naldini Antonella , Schenone Silvia , Maga Giovanni , Carraro Fabio , Botta Maurizio 
Published: February 2007

AbstractA series of pyrazolo[3,4‐d]pyrimidines, previously found to be Src inhibitors, was tested for their ability to inhibit proliferation of three Bcr‐Abl‐positive human leukemia cell lines (K‐562, KU‐812, and MEG‐01), on the basis of the experimental evidence that various Src inhibitors are also active against Bcr‐Abl kinase (the so called dual Src/Abl inhibitors). They reduce Bcr‐Abl tyrosine phosphorylation and promote apoptosis of the Bcr‐Abl‐expressing cells. A cell‐free enzymatic assay on isolated c‐Abl confirmed that such compounds directly inhibit Abl activity. Finally, molecular modeling simulations were also performed to hypothesize the binding mode of the compounds into the Abl binding site.
Survival and death of mature avian motoneurons in organotypic slice culture: Trophic requirements for survival and different types of degeneration
Authors: Brunet Núria , Tarabal Olga , Portero‐Otín Manel , Oppenheim Ronald W. , Esquerda Josep E. , Calderó Jordi 
Published: February 2007

AbstractWe have developed an organotypic culture technique that uses slices of chick embryo spinal cord, in which trophic requirements for long‐term survival of mature motoneurons (MNs) were studied. Slices were obtained from E16 chick embryos and maintained for up to 28 days in vitro (DIV) in a basal medium. Under these conditions, most MNs died. To promote MN survival, 14 different trophic factors were assayed. Among these 14, glial cell line‐derived neurotrophic factor (GDNF) and vascular endothelial growth factor were the most effective. GDNF was able to promote MN survival for at least 28 DIV. K+ depolarization or caspase inhibition prevented MN death but also induced degenerative‐like changes in rescued MNs. Agents that elevate cAMP levels promoted the survival of a proportion of MNs for at least 7 DIV. Examination of dying MNs revealed that, in addition to cells exhibiting a caspase‐3‐dependent apoptotic pattern, some MNs died by a caspase‐3‐independent mechanism and displayed autophagic vacuoles, an extremely convoluted nucleus, and a close association with microglia. This organotypic spinal cord slice culture may provide a convenient model for testing conditions that promote survival of mature‐like MNs that are affected in late‐onset MN disease such as amyotrophic lateral sclerosis. J. Comp. Neurol. 501:669–690, 2007. © 2007 Wiley‐Liss, Inc.
Functional dissection of the neural substrates for gravitaxic maze behavior in Drosophila melanogaster
Authors: Baker Dean Adam , Beckingham Kathleen Mary , Armstrong James Douglas 
Published: February 2007

AbstractIn animals, sensing gravity is supported by mechanosensory neurons that send information to the central brain for integration along with other modalities. In Drosophila, candidate sensory organs for detecting the gravity vector were predicted from the results of a recent forward genetic screen. This analysis also suggested possible roles for the central complex and antennal system in Drosophila. Using the same vertical maze assay employed in the original screen, we investigated the roles of these candidate neural structures by spatial and temporal inactivation of synaptic transmission with the GAL4/UAS‐shibire[ts1] system. We correlate changes in the maze behavior of flies with specific inhibition of synaptic transmission for key brain neuropil that includes the central complex and antenno‐glomerular tract. Further, our results point toward a minimal, or nonexistent, role for the mushroom bodies. J. Comp. Neurol. 501:756–764, 2007. © 2007 Wiley‐Liss, Inc.
Localization of EphA4 in axon terminals and dendritic spines of adult rat hippocampus
Authors: Tremblay Marie‐ève , Riad Mustapha , Bouvier David , Murai Keith K. , Pasquale Elena B. , Descarries Laurent , Doucet Guy 
Published: February 2007

AbstractEph receptors and their ephrin ligands assume various roles during central nervous system development. Several of these proteins are also expressed in the mature brain, and notably in the hippocampus, where EphA4 and ephrins have been shown to influence dendritic spine morphology and long‐term potentiation (LTP). To examine the cellular and subcellular localization of EphA4 in adult rat ventral hippocampus, we used light and electron microscopic immunocytochemistry with a specific polyclonal antibody against EphA4. After immunoperoxidase labeling, EphA4 immunoreactivity was found to be enriched in the neuropil layers of CA1, CA3, and dentate gyrus. In all examined layers of these regions, myelinated axons, small astrocytic leaflets, unmyelinated axons, dendritic spines, and axon terminals were immunolabeled in increasing order of frequency. Neuronal cell bodies and dendritic branches were immunonegative. EphA4‐labeled dendritic spines and axon terminals corresponded to 9–19% and 25–40% of the total number of spines and axon terminals, respectively. Most labeled spines were innervated by unlabeled terminals, but synaptic contacts between two labeled elements were seen. The vast majority of synaptic junctions made by labeled elements was asymmetrical and displayed features of excitatory synapses. Immunogold labeling of EphA4 was located mostly on the plasma membrane of axons, dendritic spines, and axon terminals, supporting its availability for surface interactions with ephrins. The dual preferential labeling of EphA4 on pre‐ or postsynaptic specializations of excitatory synapses in adult rat hippocampus is consistent with roles for this receptor in synaptic plasticity and LTP. J. Comp. Neurol. 501:691–702, 2007. © 2007 Wiley‐Liss, Inc.
Cellular and subcellular localization of Huntington aggregates in the brain of a rat transgenic for Huntington disease
Authors: Petrasch‐Parwez Elisabeth , Nguyen Huu‐Phuc , Löbbecke‐Schumacher Marlen , Habbes Hans‐Werner , Wieczorek Stefan , Riess Olaf , Andres Karl‐Hermann , Dermietzel Rolf , Von Hörsten Stephan 
Published: February 2007

AbstractHuntington disease (HD) is a progressive neurodegenerative disorder characterized by emotional, cognitive, and motor dysfunctions. Aggregation of huntingtin is a hallmark of HD and, therefore, a crucial parameter for the evaluation of HD animal models. We investigated here the regional, cellular, and subcellular distribution of N‐terminal huntingtin aggregates and associated neuropathological changes in the forebrain of a rat transgenic for HD (tgHD). The tgHD rat brain showed enormously enlarged lateral ventricles and a similar atrophy of cortical and subcortical areas as known in HD patients. Huntingtin aggregates of varying size and forms were regionally identified in neuronal nuclei, cytoplasm, dendrites, dendritic spines, axons, and synaptic terminals, closely resembling the results described earlier for human HD brains and in established HD mouse models. Huntingtin aggregates in mitochondria support mitochondrial dysfunction as contributing to the disease pathogenesis. Dark cell degeneration was reminiscent of results in HD individuals and HD mouse models. Interestingly, huntingtin aggregates were especially well accumulated in two interacting limbic forebrain systems, the ventral striatopallidum and the extended amygdala, which may contribute to the early onset of emotional changes observed in the tgHD rat. In conclusion, the tgHD rat model reflects to a remarkable extent the cellular and subcellular neuropathological key features as observed in human HD and HD mouse brains and hints of changes in limbic forebrain systems, which may elucidate the emotional dysfunction in the tgHD rat and affective disturbances in HD patients. J. Comp. Neurol. 501:716–730, 2007. © 2007 Wiley‐Liss, Inc.
How do functional maps in primary visual cortex vary with eccentricity?
Authors: Xu Xiangmin , Anderson Tiffany J. , Casagrande Vivien A. 
Published: February 2007

AbstractIt is important to understand whether functional maps of primary visual cortex (V1) are organized differently at the representation of different eccentricities. By using optical imaging of intrinsic signals, we compared the maps of orientation and spatial frequency (SF) preference between central (0–3°) and paracentral (4–8°) V1 in the prosimian bush baby (Otolemur garnetti). No differences related to eccentricity were found for orientation selectivity or magnitude between central and paracentral V1. We found, however, that cardinal orientations were overrepresented in central but not in paracentral V1 and that isoorientation domain size tended to be smaller in the central representation. We demonstrated that spatial frequency was represented continuously across V1, and that the map of SF preference exhibited eccentricity‐dependent variations, with more territory devoted to higher SFs in central than in paracentral V1. Although there were no spatial relationships between orientation domains and cytochrome oxidase (CO) blobs or interblobs, CO blobs tended to prefer lower SFs than interblobs. Taken together with previous research, our data indicate that functional domains in V1 show eccentricity‐related differences in organization and also support the idea that different maps (with or without specific geometrical relationships) are organized for adequate coverage of each feature in visual space. J. Comp. Neurol. 501:741–755, 2007. © 2007 Wiley‐Liss, Inc.
Larval electroreceptors in the epidermis of mormyrid fish: II. The promormyromast
Authors: Denizot Jean‐Pierre , Bensouilah Mourad , Roesler Ritva , Schugardt Christian , Kirschbaum Frank 
Published: February 2007

AbstractPromormyromasts were found in the epidermis of the head of the larvae of five species of mormyrids bred in captivity. The promormyromast is a larval electroreceptor belonging to the specific lateral line system. In 12‐day‐old larvae this electroreceptor is characterized by a single sensory cell and two types of accessory cells. One type of accessory cell has dark cytoplasm, few microtubules, and contacts the sensory cell directly, whereas a second type has pale cytoplasm, many microtubules, and forms an outer layer not directly in contact with the sensory cell. This second type is referred to as a long pyriform accessory cell. This assembly of cells is situated below an intraepidermal cavity filled with acid polysaccharides. The bordering epidermal cells extend microvilli into the intraepidermal cavity. The apexes of the sensory cell, and of the two types of accessory cells, also open into the intraepidermal cavity but bear no microvilli. The promormyromast is innervated by an unmyelinated sensory nerve fiber passing through the basal membrane, which then splits into several branches between the accessory cells. These branches contact the periphery of the sensory cell with terminal boutons. At the site of each contact a ribbon‐like structure surrounded by vesicles is present in the cytoplasm of the sensory cell. In older larvae of Campylomormyrus cassaicus, membrane foldings develop at the periphery of the pyriform accessory cells and accessory cell staining properties change just before transformation to become a mormyromast. The functional role of the promormyromast of the larval mormyrids is discussed. J. Comp. Neurol. 501:810–823, 2007. © 2007 Wiley‐Liss, Inc.
Colocalization of metabotropic glutamate receptors in rat dorsal root ganglion cells
Authors: Carlton Susan M. , Hargett Gregory L. 
Published: February 2007

AbstractGlutamate is the main excitatory transmitter in both central and peripheral nervous systems. Discovery of metabotropic glutamate receptors (mGluRs) made it clear that glutamate can have excitatory or inhibitory effects on neuronal function, with group I mGluRs enhancing cell excitability but group II and III mGluRs decreasing excitability. The present study investigated the colocalization of mGluR subtypes representing groups I, II, or III in rat L5 dorsal root ganglion (DRG) cells. The analyses show that group III has the highest expression, with 75.0% of DRG cells expressing mGluR8, followed by group II, with 51.6% expressing mGluR2/3, followed by group I, with only 6.8% expressing mGluR1α. mGluR8 is expressed by small, medium, and large diameter cells. In contrast, mGluR1α and mGluR2/3 are expressed by mainly small and medium cells. Approximately half of cells expressing group I mGluR1α also express either group II mGluR2/3 or group III mGluR8. These mGluR1α double‐labeled populations are not likely to overlap since >1.0% of mGluR1α are triple‐labeled. As expected from the high percentage of single‐labeled mGluR2/3 and mGluR8 cells, there is a considerable population of double‐labeled cells with ≈30% of each population expressing both receptors. Due to the fact that the number of mGluR1α‐expressing cells in the DRG is low, the percentage of triple‐labeled cells is also low (≈1–2%). The prevalence of groups II and III indicate that glutamate could have a substantial inhibitory effect of primary afferent function, reducing and/or fine‐tuning sensory input before transmission to the spinal cord. These anatomical data highlight the potential inhibitory role glutamate may play in peripheral sensory transmission. J. Comp. Neurol. 501:780–789, 2007. © 2007 Wiley‐Liss, Inc.
Morphology and electrophysiological properties of hamster spinal dorsal horn neurons that express VGLUT2 and enkephalin
Authors: Schneider Stephen P. , Walker Tracy M. 
Published: February 2007

AbstractThe excitatory amino acid glutamate mediates transmission at spinal synapses, including those formed by sensory afferent fibers and by intrinsic interneurons. The identity and physiological properties of glutamatergic dorsal horn neurons are poorly characterized despite their importance in spinal sensory circuits. Moreover, many intrinsic spinal glutamatergic synapses colocalize the opioid peptide enkephalin (ENK), but the neurons to which they belong are yet to be identified. Therefore, we used immunohistochemistry and confocal microscopy to investigate expression of the VGLUT2 vesicular glutamate transporter, an isoform reported in nonprimary afferent spinal synapses, and ENK in electrophysiologically identified neurons of hamster spinal dorsal horn. VGLUT2 immunoreactivity was localized in restricted fashion to axon varicosities of neurons recorded from laminae II–V, although the occurrence of immunolabeling in individual varicosities varied widely between cells (39 ± 36%, n = 31 neurons). ENK colocalized with VGLUT2 in up to 77% of varicosities (17 ± 21%, n = 21 neurons). The majority of neurons expressing VGLUT2 and/or ENK had axons with dense local terminations or projections consistent with propriospinal functions. VGLUT2 and ENK labeling were not correlated with cellular morphology, intrinsic membrane properties, firing patterns, or synaptic responses to sensory afferent stimulation. However, VGLUT2 expression was significantly higher in neurons with depolarized resting membrane potential. The results are new evidence for a population of dual‐function dorsal horn interneurons that might provide another mechanism for limiting excitation within dorsal horn circuits during periods of strong sensory activation. J. Comp. Neurol. 501:790–809, 2007. © 2007 Wiley‐Liss, Inc.