bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gamma knife radiosurgery for central neurocytoma
Authors: Kim Chae‐Yong , Paek Sun Ha , Jeong Sang Soon , Chung Hyun‐Tai , Han Jung Ho , Park Chul‐Kee , Jung Hee‐Won , Kim Dong Gyu 
Published: October 2007

AbstractBACKGROUND.Little is known about long‐term results of gamma knife (GK) stereotactic radiosurgery (SRS) as a primary or a secondary postoperative therapy for central neurocytomas (CNs). The authors retrospectively reviewed long‐term outcomes of 13 patients with CN treated with GK SRS.METHODS.Thirteen patients were treated with GK SRS as a primary (6 patients) or a secondary postoperative therapy (7 patients). Follow‐up clinical status and brain magnetic resonance imaging (MRI) were thoroughly analyzed. The functional status of patients was assessed with the Karnofsky Performance Scale during follow‐up.RESULTS.The median follow‐up period for clinical status and imaging studies was 61 months (range, 6 months to 96 months). Tumors decreased in 5 patients who received GK SRS as a primary treatment. However, the tumor recurred in 2 patients treated with a secondary GK SRS after surgery from the residual tumor bed that was not covered by the GK SRS. Parenchymal changes and secondary malignancies were not found in follow‐up MRIs of all 13 patients. The Karnofsky Performance Scale score of all patients, except for 1 patient who suffered from an unrelated anteriorly communicating arterial aneurysmal rupture, did not change after GK SRS.CONCLUSIONS.GK SRS may be useful as a primary or a secondary postoperative therapy for the treatment of CN. However, more attention should be paid to residual or recurrent CN during treatment, and regular long‐term follow‐up MRI should be mandatory to validate the procedure. Cancer 2007 © 2007 American Cancer Society.
Ectopia of meningeal fibroblasts and reactive gliosis in the cerebral cortex of the mouse model of muscle‐eye‐brain disease
Authors: Yang Yuan , Zhang Peng , Xiong Yufang , Li Xiaofeng , Qi Yue , Hu Huaiyu 
Published: October 2007

AbstractCongenital muscular dystrophies with brain malformations, such as muscle‐eye‐brain disease, exhibit neural ectopias caused by overmigration of neurons. Such overmigration is evident in protein O‐mannose β‐1,2‐N‐acetylglucosaminyltransferase (POMGnT1) knockout mouse, a model of muscle‐eye‐brain disease, caused by breaches in the pial basement membrane. We hypothesize that breaches in pial basement membrane disrupt the neural‐meningeal boundary, resulting in ectopia of meningeal fibroblasts in the cerebral cortex and reactive gliosis. To test this hypothesis, the cerebral cortices of developing and adult POMGnT1 knockout mice were analyzed by immunostaining with cell‐specific markers and by electron microscopy. The upper half of the cerebral cortex in the knockout mouse contained increased numbers of fibroblasts closely associated with capillaries. During development of the cerebral cortex in the knockout mice, breaches in pial basement membrane allowed emigration of overmigrated neurons into the developing pia‐arachnoid, scattering its mesenchymal cells throughout the diffuse cell zone and resulting in ectopia of mesenchyme‐derived fibroblasts in the upper half of the cortex. Glial fibrillary acidic protein (GFAP) immunostaining revealed that the upper half of the cerebral cortex in the knockout also contained increased numbers of cells with morphologies typical of reactive astrocytes compared with the wild type. Moreover, most of the GFAP‐positive reactive astrocytes were in close contact with ectopic fibroblasts, suggesting that they were induced by the fibroblasts. Collectively, the data support the hypothesis that the cerebral cortex of POMGnT1 knockout mice is characterized by migration defects leading to disruption of the pia‐arachnoid, ectopia of fibroblasts in the cortex, and reactive gliosis. J. Comp. Neurol. 505:459–477, 2007. © 2007 Wiley‐Liss, Inc.
Otolith endorgan input to the Mauthner neuron in the goldfish
Authors: Szabo Theresa M. , McCormick Catherine A. , Faber Donald S. 
Published: October 2007

AbstractThe Mauthner (M‐) cell of the goldfish, Carassius auratus, triggers the rapid escape response of the fish in response to various stimuli, including visual and auditory. The large size and accessibility of the M‐cell make it an ideal model system for the study of synaptic transmission, membrane properties, and sensory‐motor gating. Although physiological recordings have suggested that afferents from all three of the inner ear endorgans (the saccule, lagena, and utricle) synapse directly on the ipsilateral M‐cell, the specific contacts and anatomical distributions of these inputs along the M‐cell lateral dendrite remain unknown. We traced specific branches of the auditory (VIIIth) nerve from the three otolith organs of the fish inner ear to the M‐cell. The goldfish sacculus gives rise to the vast majority of inputs that contact a large portion of the M‐cell lateral dendrite, and these inputs vary greatly in size. In contrast to the ubiquitous distribution of saccular inputs, those from the lagena are segregated to distal regions of the M‐cell and synapse on the distal dorsal branch of the lateral dendrite. Similarly, inputs from the utricle are also segregated to distal regions, synapsing on the ventral branch of the lateral dendrite. These results demonstrate that nerves from all three endorgans contact the M‐cell, with input‐specific segregation of synapses along the M‐cell lateral dendrite. J. Comp. Neurol. 505:511–525, 2007. © 2007 Wiley‐Liss, Inc.
Distinct populations of presympathetic‐premotor neurons express orexin or melanin‐concentrating hormone in the rat lateral hypothalamus
Authors: Kerman Ilan A. , Bernard René , Rosenthal Devin , Beals James , Akil Huda , Watson Stanley J. 
Published: October 2007

AbstractOrexin and melanin‐concentrating hormone (MCH) have been implicated in mediating a variety of different behaviors. These include sleep and wakefulness, locomotion, ingestive behaviors, and fight‐or‐flight response, as well as anxiety‐ and panic‐like behaviors in rodents. Despite such diversity, all these processes require coordinated recruitment of the autonomic and somatomotor efferents. We have previously mapped the locations of presympathetic‐premotor neurons (PSPMNs) in the rat brain. These putative dual‐function neurons send trans‐synaptic projections to somatomotor and sympathetic targets and likely participate in somatomotor‐sympathetic integration. A significant portion of these neurons is found within the dorsomedial (DMH) and lateral hypothalamus (LH), areas of the brain that contain MCH‐ and orexin‐ synthesizing neurons in the central nervous system. Thus, we hypothesized that hypothalamic PSPMNs utilize MCH or orexin as their neurotransmitter. To test this hypothesis, we identified PSPMNs by using recombinant strains of the pseudorabies virus (PRV) for trans‐synaptic tract tracing. PRV‐152, a strain that expresses enhanced green fluorescent protein, was injected into sympathectomized gastrocnemius muscle, whereas PRV‐BaBlu, which expresses β‐galactosidase, was injected into the adrenal gland in the same animals. By using immunofluorescent methods, we determined whether co‐infected neurons express MCH or orexin. Our findings demonstrate that PSPMNs synthesizing either MCH or orexin are present within LH, where they form two separate populations. PSPMNs located around the fornix express orexin, whereas those located around the cerebral peduncle are more likely to express MCH. These two clusters of PSPMNs within LH likely play distinct functional roles in autonomic homeostasis and stress coping mechanisms. J. Comp. Neurol. 505:586–601, 2007. © 2007 Wiley‐Liss, Inc.
Dendritic spread and functional coverage of starburst amacrine cells
Authors: Keeley Patrick W. , Whitney Irene E. , Raven Mary A. , Reese Benjamin E. 
Published: October 2007

AbstractThe network of starburst amacrine cells plays a fundamental role in the neural circuitry underlying directional selectivity within the retina. Individual sectors of the starburst dendritic field are directionally selective by virtue of a mutually inhibitory relationship between starburst amacrine cells with overlapping dendrites. These features of the starburst amacrine cell network suggest that starburst cells regulate their dendritic overlap to ensure a uniform coverage of the retinal surface. The present study has compared the dendritic morphology of starburst amacrine cells in two different strains of mice that differ in starburst amacrine cell number. The A/J (A) strain contains about one‐quarter fewer starburst amacrine cells than does the C57BL/6J (B6) strain, although the mosaics of starburst amacrine cells in both strains are comparably patterned. Dendritic field size, however, does not compensate for the difference in density, the A strain having a slightly smaller dendritic field relative to the B6 strain, yielding a significantly larger dendritic coverage factor for individual cells in the B6 strain. The area of the distal (output) annulus of the dendritic field occupies a comparable proportion of the overall field area in the two strains, but overlapping annuli establish a finer meshwork of co‐fasciculating processes in the B6 strain. These results would suggest that the architecture of the dendritic network, rather than the overall size of the dendritic field, is dependent on the density of starburst amacrine cells. J. Comp. Neurol. 505:539–546, 2007. © 2007 Wiley‐Liss, Inc.
Embedding Magnetic Nanoparticles into Polysaccharide‐Based Hydrogels for Magnetically Assisted Bioseparation
Authors: Liang Yuan‐Yuan , Zhang Li‐Ming , Jiang Wei , Li Wei 
Published: October 2007

AbstractBased on the preparation of biocompatible polysaccharide‐based hydrogels with stimuli‐responsive properties by the copolymerization of maleilated carboxymethyl chitosan with N‐isopropylacrylamide, novel magnetic hybrid hydrogels were fabricated by the in situ embedding of magnetic iron oxide nanoparticles into the porous hydrogel networks. Scanning electron microscopy (SEM) and thermogravimetric (TG) analyses showed that the size, morphology, and content of the iron oxide nanoparticles formed could be modulated by controlling the amount of maleilated carboxymethyl chitosan. As confirmed by X‐ray diffractometry (XRD), equilibrium swelling ratio, and differential scanning calorimetry (DSC) measurements, the embedding process did not induce a phase change of the magnetic iron oxide nanoparticles, and the resultant hybrid hydrogels could retain the pH‐ and temperature‐responsive characteristics of their hydrogel precursors. By investigating the partition coefficients of bovine serum albumin as a model protein, this magnetic hydrogel material was found to hold a potential application in magnetically assisted bioseparation.
Icosahedral and Ring‐Shaped Allotropes of Arsenic
Authors: Karttunen Antti J. , Linnolahti Mikko , Pakkanen Tapani A. 
Published: October 2007

AbstractWe predict the existence of two novel families of arsenic nanostructures: icosahedral cages and ring‐shaped chains. Quantum chemical calculations on the cages, rings, and the experimentally known allotropes of arsenic suggest the nanostructures to be thermodynamically stable. The icosahedral cages are modifications of the gray allotrope of arsenic, while the ring‐shaped chains are structurally related to the red allotrope of phosphorus. Comparisons between the analogous allotropes of arsenic and phosphorus show distinct differences. While phosphorus favors the ring‐shaped chains over the icosahedral cages, large cages become favorable for arsenic. From the thermodynamical point of view, experimental preparation of the proposed families of arsenic nanostructures is expected to be viable.
Structures and Electronic Properties of C56Cl8 and C56Cl10 Fullerene Compounds
Authors: Chen De‐Li , Tian Wei Quan , Feng Ji‐Kang , Sun Chia‐Chung 
Published: October 2007

AbstractStimulated by the recent observation of the first C56Cl10 chlorofullerene (Science, 2004, 304, 699), we performed a systematic density functional study of the structures and properties of C56Cl10 and related compounds. The fullerene derivatives C56Cl8 and C56Cl10 based on the parent fullerene C56(C2v:011), rather than those from the most stable C56 isomer with D2 symmetry, are predicted to possess the lowest energies, and they are highly aromatic. Further investigations show that the heats of formation of the C56Cl8 and C56Cl10 fullerene derivatives are highly exothermic, that is, −48.59 and −48.89 kcal mol−1 per Cl2 (approaching that of C50Cl10), suggesting that adding eight (or ten) Cl atoms releases much of the strain of pure C56(C2v:011) fullerene and leads to highly stable derivatives. In addition, C56Cl8 and C56Cl10 possess large vertical electron affinities, especially for C56Cl8 with value of 3.20 eV, which is even larger than that (3.04 eV) of C50Cl10, indicating that they are potential good electron acceptors with possible photonic/photovoltaic applications. Finally, the 13C NMR chemical shifts and infrared spectra of C56Cl8 and C56Cl10 are simulated to facilitate future experimental identification.
Insights into the Molecular Structure and Reactivity of α,ω‐Dialkoxy‐Substituted Ethyne and Butadiyne
Authors: Gleiter Rolf , Werz Daniel B. , Rominger Frank , Zhutov Evgeny , Zefirov Nikolay S. , Proskurnina Marina V. 
Published: October 2007

AbstractThe molecular structure derived by X‐ray crystallography and the He(I) photoelectron spectrum of bis(tert‐butoxy)butadiyne (4a) are reported. Bis(tert‐butoxy)ethyne (3a) and 4a were treated with highly electrophilic [η2‐bis(tert‐butylsulfonyl)ethyne](carbonyl)(η5‐cyclopentadienyl)cobalt (10). In both cases a CpCo‐stabilized cyclobutadiene ring resulted substituted by two tert‐butylsulfonyl groups and either two tert‐butoxy groups (→11) or one tert‐butoxy group and one tert‐butoxyethynyl group (→12). The structural data of 11 and of (η4‐tetrakis(tert‐butoxy)cyclopentadienone)(cyclopentadienyl)cobalt (15) are reported and compared with related species. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Rearrangement of S‐(2‐Aminoethyl) Thiophosphates to N‐(2‐Mercaptoethyl)phosphoramidates
Authors: Chen Menglin , Maetzke Alice , Knak Jensen Svend J. , Gothelf Kurt V. 
Published: October 2007

AbstractA novel rearrangement of S‐(2‐aminoethyl) thiophosphates to N‐(2‐mercaptoethyl)phosphoramidates was discovered and developed. The reaction proceeds smoothly at room temperature under basic conditions and the resulting thiol could subsequently be alkylated. The reaction mechanism is investigated by electron structure calculations using density functional theory at the B3LYP/6‐31G(d) and B3LYP/6‐311+G(d,p) levels. The calculations indicate that the reaction proceeds in a two step process when two explicit solvent molecules are included. In the presence of water the rearrangement reaction proceeds in competition with hydrolysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Market microstructure effects on volatility at the TAIFEX
Authors: Webb Robert I. , Muthuswamy Jayaram , Segara Reuben 
Published: October 2007

AbstractThis study examines whether changes in the frequency of market clearing or changes in trading hours on competing exchanges that use different auction systems affect the volatility of futures prices. In particular, this study exploits a natural experiment in the frequency of market clearing of stock index futures contracts traded on the Taiwan Futures Exchange (TAIFEX) to assess whether successive increases in the frequency of market clearing are associated with changes in the volatility of futures prices. The impact of changes in the trading hours on the TAIFEX and on the competing Singapore Exchange (SGX) where a similar Taiwanese stock index futures contract trades under a continuous auction market regime is also examined. The evidence for the impact of an increase in the frequency of market clearing on volatility is mixed. However, the introduction of simultaneous opening times for the TAIFEX (which batches orders at the open) and the SGX (which does not) is associated with a significant reduction in the volatility in SGX Taiwanese stock index futures prices. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:1219–1243, 2007
Predicting the brain response to treatment using a Bayesian hierarchical model with application to a study of schizophrenia
Authors: Guo Ying , DuBois Bowman F. , Kilts Clinton 
Published: October 2007

AbstractIn vivo functional neuroimaging, including functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), is becoming increasingly important in defining the pathophysiology of psychiatric disorders such as schizophrenia, major depression, and Alzheimer's disease. Furthermore, recent studies have begun to investigate the possibility of using functional neuroimaging to guide treatment selection for individual patients. By studying the changes between a patient's pre‐ and post‐treatment brain activity, investigators are gaining insights into the impact of treatment on behavior‐related neural processing traits associated with particular psychiatric disorders. Furthermore, these studies may shed light on the neural basis of response and nonresponse to specific treatments. The practical limitation of such studies is that the post‐treatment scans offer little guidance to treatment selection in clinical settings, since treatment decisions precede the availability of post‐treatment brain scans. This shortcoming represents the impetus for developing statistical methodology that would provide clinicians with predictive information concerning the effect of treatment on brain activity and, ultimately, symptom‐related behaviors. We present a prediction algorithm that uses a patient's pretreatment scans, coupled with relevant patient characteristics, to forecast the patient's brain activity following a specified treatment regimen. We derive our predictive method from a Bayesian hierarchical model constructed on the pre‐ and post‐treatment scans of designated training data. We perform estimation using the expectation–maximization algorithm. We evaluate the accuracy of our proposed prediction method usingK‐fold cross‐validation, quantifying the error using two new measures that we propose for neuroimaging data. The proposed method is applicable to both PET and fMRI studies. We illustrate its use with a PET study of working memory in patients with schizophrenia and an fMRI data example is also provided. Hum Brain Mapp 29:1092–1109, 2007. © 2007 Wiley‐Liss, Inc.
Activation of septal 5‐HT1A receptors alters spatial memory encoding, interferes with consolidation, but does not affect retrieval in rats subjected to a water‐maze task
Authors: Koenig Julie , Cosquer Brigitte , Cassel Jean‐Christophe 
Published: October 2007

AbstractUsing Long‐Evans rats tested in a water maze, this study assessed the role of 5‐HT1A/5‐HT7 receptors of the medial septum in encoding, consolidation, and retrieval of spatial information. The testing protocol (acquisition: daily four‐trial sessions over three consecutive days; retention: probe trial on day 4) was first validated by showing that intraseptal infusions of lidocaine (LIDO; 40 μg/0.5 μL) disrupted acquisition and retrieval of the task. 8‐OH‐DPAT (4 μg/0.5 μL) infused before each acquisition session prevented learning/retention of the platform location, an effect attenuated by pretreatment with the 5‐HT1A receptor antagonist WAY 100635. With the 5‐HT7 antagonist SB 269970, the 8‐OH‐DPAT‐induced acquisition deficit seemed attenuated, but there was no subsequent retention. When infused immediately, 1, 4, or 6 h after each acquisition session, 8‐OH‐DPAT did not hinder consolidation. When the infusions were performed 2 h postacquisition, however, consolidation was disrupted. Finally, when infused before a probe trial after drug‐free acquisition, 8‐OH‐DPAT had no effect, suggesting no interference with retrieval processes. We also established that 8‐OH‐DPAT had no effects when the platform was visible, and altered neither home‐cage activity nor anxiety‐related behavior (elevated plus‐maze). Altogether, these results show that 5‐HT1A receptors in the septal region contribute both to declarative‐like information encoding and subsequently, within a given postacquisition time window, to its consolidation. They do not participate in the retrieval of recently learned declarative‐like information. These observations suggest that 5‐HT1A receptors of the medial septum contribute to a serotonin‐mediated mechanism involved in the encoding and consolidation, not the retrieval of spatial hippocampal‐ dependent knowledge. These results might have some relevance to approaches aimed at modifying serotonergic functions in the brain for the treatment of disorders such as depression, anxiety, post‐traumatic stress, and amnesia. © 2007 Wiley‐Liss, Inc.
An epigenetic induction of a right‐shift in hippocampal asymmetry: Selectivity for short‐ and long‐term potentiation but not post‐tetanic potentiation
Authors: Tang Akaysha C. , Zou Bende , Reeb Bethany C. , Connor John A. 
Published: October 2007

AbstractIn humans, it is well established that major psychological functions are asymmetrically represented between the left and right cerebral cortices. The developmental origin of such functional lateralization remains unknown. Using the rat as a model system, we examined whether exposing neonates briefly to a novel environment can differentially affect synaptic plasticity in the left and right hippocampi during adulthood. During the first 3 weeks of life, one half of the pups from a litter spent 3 min daily away from their familiar home environment (Novel) while their littermates remained in that familiar environment (Home). At adulthood (7‐months old), post‐tetanic potentiation (PTP) of excitatory post‐synaptic potentials (EPSPs), a very short‐lasting form of plasticity, was greater among the Novel than the Home rats in both left and right hippocampi. In contrast, the novelty‐induced increases in short‐ and long‐term potentiation (STP, LTP), two relatively longer‐lasting forms of plasticity, were found only in the right hippocampus. These findings demonstrate that a phase‐selective asymmetry in hippocampal synaptic plasticity can be induced epigenetically by seemingly small systematic differences in early life environment. The selectivity of this asymmetry for the longer‐lasting forms of synaptic plasticity suggests that the observed asymmetry in plasticity may contribute specifically to an asymmetric learning process which, in turn, may contribute to a functional asymmetry in the neocortex. © 2007 Wiley‐Liss, Inc.
Sexual orientation‐related differences in allocentric spatial memory tasks
Authors: Rahman Qazi , Koerting Johanna 
Published: October 2007

AbstractSpatial memory in mammals, including humans, appears highly sexually dimorphic. The present investigation sought to examine if spatial learning and spatial memory in humans is also linked to sexual orientation. This was achieved by using virtual reality versions of two classic paradigms developed in animal models of hippocampal functioning, the Morris Water Maze (MWM) and Radial Arm Maze (RAM). Here, we show that in contrast to heterosexual men, and in congruence with heterosexual women, homosexual men displayed significantly greater search latencies (spatial learning) during a virtual Morris Water Maze. During a virtual 8‐arm Radial Arm Maze, heterosexual males had significantly shorter search latency than heterosexual females, and did not differ from homosexual males. Statistical modeling revealed that variations in neurodevelopmental markers previously associated with human sexual orientation (2nd to 4th finger length ratios and older fraternal siblings) differentially predicted MWM probe trial performance and RAM search latencies only. These data may limit the number of possible neurodevelopmental pathways responsible for sexual variation in components of spatial learning and memory. © 2007 Wiley‐Liss, Inc.