bluuebunny/crossref_metadata_2025_split huggingface dataset:
Late cretaceous plesiosaurs from northern Patagonia, Argentina
Authors: Gasparini Z. , Salgado L. , Parras A. 
Published: March 2007

AbstractDuring the Late Campanian‐Danian interval the South Atlantic Ocean invaded a large part of Patagonia in different events making an archipelago. Plesiosaurs from northern Patagonia of Late Campanian‐Early Maastrichtian age were found in the Allen Formation. The sedimentology and faunal content, mainly at the Pellegrini Lake, suggest marginal marine environments, such as coastal plains, lagoons or estuaries. Toward the end of the Maastrichtian a new relative sea‐level rise occurred, and the plesiosaurs are recorded in sediments of deeper marine environments of inner or middle platform.As pelagic reptiles, plesiosaurs had the potential capacity of worldwide distribution. Polycotylids and elasmosaurids have been found in northern Patagonia. There are at least two morphotypes (here determined as Elasmosauridae gen. et sp. indet. and Plesiosauroidea gen. et sp. indet.) which are also recorded in the south of the Eastern Pacific (Chile). Another plesiosaur found in central Patagonia, Aristonectes, with controversial phylogenetic relationships, suggests that some of them inhabited southwestern Gondwana (Argentina, Chile and the Antarctic Peninsula). Whether any of these taxa of northwestern Patagonia reached a south gondwanan distribution, is still controversial. However, at least in New Zealand there are plesiosaurs with similar characteristics, particularly in the limbs, to those found in plesiosaurs from Patagonia and Chile; hence, this hypothesis should not be discarded. Evidences of south Gondwanan distribution in other pelagic reptiles such as mosasaurs have been reported. Copyright © 2007 John Wiley & Sons, Ltd.
Bayesian inverse analysis of neuromagnetic data using cortically constrained multiple dipoles
Authors: Auranen Toni , Nummenmaa Aapo , Hämäläinen Matti S. , Jääskeläinen Iiro P. , Lampinen Jouko , Vehtari Aki , Sams Mikko 
Published: March 2007

AbstractA recently introduced Bayesian model for magnetoencephalographic (MEG) data consistently localized multiple simulated dipoles with the help of marginalization of spatiotemporal background noise covariance structure in the analysis [Jun et al., (2005): Neuroimage 28:84–98]. Here, we elaborated this model to include subject's individual brain surface reconstructions with cortical location and orientation constraints. To enable efficient Markov chain Monte Carlo sampling of the dipole locations, we adopted a parametrization of the source space surfaces with two continuous variables (i.e., spherical angle coordinates). Prior to analysis, we simplified the likelihood by exploiting only a small set of independent measurement combinations obtained by singular value decomposition of the gain matrix, which also makes the sampler significantly faster. We analyzed both realistically simulated and empirical MEG data recorded during simple auditory and visual stimulation. The results show that our model produces reasonable solutions and adequate data fits without much manual interaction. However, the rigid cortical constraints seemed to make the utilized scheme challenging as the sampler did not switch modes of the dipoles efficiently. This is problematic in the presence of evidently highly multimodal posterior distribution, and especially in the relative quantitative comparison of the different modes. To overcome the difficulties with the present model, we propose the use of loose orientation constraints and combined model of prelocalization utilizing the hierarchical minimum‐norm estimate and multiple dipole sampling scheme. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.
Cognitive function, P3a/P3b brain potentials, and cortical thickness in aging
Authors: Fjell Anders M. , Walhovd Kristine B. , Fischl Bruce , Reinvang Ivar 
Published: March 2007

AbstractThe purpose of the study was to assess the relationship between the P3a/P3b brain potentials, cortical thickness, and cognitive function in aging. Thirty‐five younger and 37 older healthy participants completed a visual three‐stimuli oddball ERP (event‐related potential)‐paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire cortical mantle. In the young, thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to cortical thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that cortical thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional cortical thickness and P3 remained. It is concluded that thickness in specific cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.
Voxel‐based morphometry study of brain volumetry and diffusivity in amyotrophic lateral sclerosis patients with mild disability
Authors: Agosta F. , Pagani E. , Rocca M.A. , Caputo D. , Perini M. , Salvi F. , Prelle A. , Filippi M. 
Published: March 2007

AbstractAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive and simultaneous degeneration of upper and lower motor neurons. The pathological process associated to ALS, albeit more pronounced in the motor/premotor cortices and along the corticospinal tracts (CST), does not spare extra‐motor brain gray (GM) and white (WM) matter structures. However, it remains unclear whether such extra‐motor cerebral abnormalities occur with mildly disabling disease, and how irreversible tissue loss and intrinsic tissue damage are interrelated. To this end, we used an optimized version of voxel‐based morphometry (VBM) analysis to investigate the patterns of regional GM density changes and to quantify GM and WM diffusivity alterations of the entire brain from mildly disabled patients with ALS. A high‐resolution T1‐weighted 3D magnetization‐prepared rapid acquisition gradient echo and a pulsed gradient spin–echo single shot echo–planar sequence of the brain were acquired from 25 mildly disabled patients with ALS and 18 matched healthy controls. An analysis of covariance was used to compare volumetry and diffusivity measurements between patients and controls. Compared with controls, ALS patients had significant clusters of locally reduced GM density (P < 0.001) in the right premotor cortex, left inferior frontal gyrus (IFG), and superior temporal gyrus (STG), bilaterally. In ALS patients contrasted to controls, we also found significant clusters of locally increased MD (P < 0.001) in the splenium of the corpus callosum and in the WM adjacent to the IFG, STG, and middle temporal gyrus (MTG) of the right hemisphere, and in the WM adjacent to the MTG and lingual gyrus in the left hemisphere. Compared with controls, ALS patients also had significant clusters of locally decreased FA values (P < 0.001) in the CST in the midbrain and corpus callosum, bilaterally. This study supports the notion that ALS is a multisystem disorder and suggests that extra‐motor involvement may be an early feature of the disease. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.
Dissociation between MEG alpha modulation and performance accuracy on visual working memory task in obsessive compulsive disorder
Authors: Ciesielski Kristina T. , Hämäläinen Matti S. , Geller Daniel A. , Wilhelm Sabine , Goldsmith Timothy E. , Ahlfors Seppo P. 
Published: March 2007

AbstractOscillatory brain activity in the alpha band (8–13 Hz) is modulated by cognitive events. Such modulation is reflected in a decrease of alpha (event‐related desynchronization; ERD) with high cognitive load, or an increase (event‐related synchronization) with low cognitive demand or with active inhibition of distractors. We used magnetoencephalography to investigate the pattern of prefrontal and parieto‐occipital alpha modulation related to two variants of visual working memory task (delayed matching‐to‐sample) with and without a distractor. We tested nonmedicated, nondepressed patients suffering obsessive‐compulsive disorder (OCD), and pair‐matched healthy controls. The level of event‐related alpha as a function of time was estimated using the temporal‐spectral evolution technique. The results in OCD patients indicated: (1) a lower level of prestimulus (reference) alpha when compared to controls, (2) a task‐phase specific reduction in event‐related alpha ERD in particular for delayed matching‐to‐sample task with distractor, (3) no significant correlations between the pattern of modulation in prefrontal and parietal‐occipital alpha oscillatory activity. Despite showing an abnormally low alpha modulation, the OCD patients' performance accuracy was normal. The results suggest a relationship of alpha oscillations and the underlying thalamocortical network to etiology of OCD and an involvement of a compensatory mechanism related to effortful inhibition of extrinsic and intrinsic interference. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.
Atlas‐based multichannel monitoring of functional MRI signals in real‐time: Automated approach
Authors: Lee Jong‐Hwan , O'Leary Heather M. , Park Hyunwook , Jolesz Ferenc A. , Yoo Seung‐Schik 
Published: March 2007

AbstractWe report an automated method to simultaneously monitor blood‐oxygenation‐level‐dependent (BOLD) MR signals from multiple cortical areas in real‐time. Individual brain anatomy was normalized and registered to a pre‐segmented atlas in standardized anatomical space. Subsequently, using real‐time fMRI (rtfMRI) data acquisition, localized BOLD signals were measured and displayed from user‐selected areas labeled with anatomical and Brodmann's Area (BA) nomenclature. The method was tested on healthy volunteers during the performance of hand motor and internal speech generation tasks employing a trial‐based design. Our data normalization and registration algorithm, along with image reconstruction, movement correction and a data display routine were executed with enough processing and communication bandwidth necessary for real‐time operation. Task‐specific BOLD signals were observed from the hand motor and language areas. One of the study participants was allowed to freely engage in hand clenching tasks, and associated brain activities were detected from the motor‐related neural substrates without prior knowledge of the task onset time. The proposed method may be applied to various applications such as neurofeedback, brain‐computer‐interface, and functional mapping for surgical planning where real‐time monitoring of region‐specific brain activity is needed. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
The engagement of mid‐ventrolateral prefrontal cortex and posterior brain regions in intentional cognitive activity
Authors: Dove Anja , Manly Tom , Epstein Russell , Owen Adrian M. 
Published: March 2007

AbstractIt is now widely recognized that cognitive processes are carried out by a distributed network of brain areas, some of which are involved in perceptual processing of a stimulus, whilst others are involved in cognitive control processes required to carry out certain tasks. In this study, differential contributions of higher visual areas and of an area involved in cognitive control processes were investigated in a task requiring participants to simply look at a stimulus or to look with the intention of remembering. Varying the extent to which intentional cognitive processes were required and the stimulus material in this task allowed the analysis of “top‐down” and “bottom‐up” influences on these areas, respectively. Significant increases in the mid‐ventrolateral prefrontal cortex (mid‐VLPFC) were only observed when the stimuli were viewed with an intention in mind, irrespective of the stimulus type. In contrast, activity in the parahippocampal place area and the fusiform face area, was only modulated in conditions requiring intentional control when stimuli were presented that also elicited activity in these regions during passive viewing. These findings help to clarify the complimentary role that the mid‐VLPFC and posterior higher visual areas play in controlled and relatively automatic memory processing. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
Age has no influence on mobilization of peripheral blood stem cells in acute myeloid leukemia
Authors: Ferrara Felicetto , Viola Assunta , Copia Carolina , Falco Claudio , D'Elia Rossella , Tambaro Francesco Paolo , Correale Pasqualino , D'Amico Maria Rosaria , Vicari Laura , Palmieri Salvatore 
Published: March 2007

AbstractThe upper age limit for autologous stem cell transplantation (ASCT) in acute myeloid leukemia (AML) is increasing and peripheral blood (PB) represents the standard source of stem cell (SC). However, no data are available on the impact of age on SC mobilization in AML. We analyzed a cohort of 150 consecutive AML patients in first complete remission in order to make a comparison between patients up to 60 years and above 60 years, by evaluating CD34+ cells mobilization into PB and the number of leukapheresis needed to collect at least one single SC graft. The successful mobilization rate (>2 × 106 CD34+ cells/kg) was comparable between the two groups (87% vs. 80%, p = 0.29). In addition, no statistically significant difference was found in terms of either median number of CD34+ cells collected (p = 0.54) or CD34+ cells peak in PB (p = 0.70). Both groups of patients needed a median of two apheresis and no difference was found in the median number of CD34+ cells collected per single apheresis (p = 0.67). Finally, no correlation was found between age and total number of CD34+ cells collected (r = 0.003, p = 0.58). We conclude that age has no impact on mobilization of PBSCs in AML. Copyright © 2007 John Wiley & Sons, Ltd.
Comparative developmental toxicities of the three major metabolites of N‐methyl‐2‐pyrrolidone after oral administration in rats
Authors: Saillenfait A. M. , Sabaté J. P. , Gallissot F. 
Published: March 2007

AbstractThe developmental toxicity of the three main metabolites of N‐methyl‐2‐pyrrolidone (NMP) was studied in Sprague‐Dawley rats. Pregnant rats were given 5‐hydroxy‐N‐methyl‐2‐pyrrolidone (5‐HNMP; 0, 250, 500, 750 or 1000 mg kg−1 day−1), N‐methylsuccinimide (MSI; 0, 500, 750, 1000 or 1250 mg kg−1 day−1), or 2‐hydroxyN‐methylsuccinimide (2‐HMSI; 0, 250, 500, 1000 or 1500 mg kg−1 day−1), by gavage, on gestational days (GD) 6–20. No evidence of maternal toxicity was observed in dams given 5‐HNMP. Administration of 2‐HMSI resulted in overt maternal toxicity at 500 mg kg−1 day−1 and higher doses, as indicated by a significant reduction in weight gain and food consumption at the beginning of treatment. There was no evidence of embryo/fetal toxicity in any of the groups treated with 5‐HNMP or 2‐HMSI. MSI produced marked developmental toxicity in the presence of maternal effects. Maternal body weight gain and food consumption were affected at 750 mg kg−1 day−1 MSI, and above. A significant increase in post‐implantation loss occurred at 1250 mg kg−1 day−1 MSI, and the incidence of fetuses with external or with visceral malformations was significantly increased at 1000 and 1250 mg kg−1 day−1 MSI. Malformations mainly consisted of anasarca, cardiovascular defects and diaphragmatic hernia. Fetal weight was significantly reduced at 1000 and 1250 mg kg−1 day−1. The incidence of skeletal variations (predominantly cervical ribs, and delayed ossification of skull bones and sternebrae) was significantly elevated at 750 mg kg−1 day−1 and higher doses. However, MSI was much less potent than the parent compound. These results indicate that the embryotoxic and teratogenic effects of NMP are not attributable to these metabolites. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of a lipopolysaccharide mediated neutrophilic hepatitis model in Sprague Dawley rats
Authors: Rose Robert , Banerjee Atrayee , Ramaiah Shashi K. 
Published: March 2007

AbstractSeveral studies have investigated the role of neutrophils during endotoxin‐mediated liver injury, yet the precise mechanism for endotoxin‐mediated hepatic neutrophil transmigration is unknown. The primary objective of this study was to establish a reliable lipopolysaccharide (LPS)‐mediated necro‐hepatitis model to investigate the mechanisms of hepatic neutrophil infiltration following LPS administration. Male Sprague Dawley rats were administered a single (5 or 10 mg kg−1, i.v.) or repeated injection of LPS (10 mg kg−1, i.v., 24 h apart) with appropriate controls (i.v. saline) and were killed at various time points following LPS injection. Significant hematologic changes included neutrophilia, elevation of the neutrophil to lymphocyte ratio and toxic changes in neutrophils. Biochemical changes were observed in several liver (aspartate aminotransferase AST, gamma glutamyl transferase GGT) and kidney (blood urea nitrogen BUN) associated parameters generally at the earliest time points. Histopathology revealed a time‐dependent neutrophil and mononuclear infiltration around the periportal areas in the single dose study and multifocal midzonal coagulative necrosis in the repeated dose study. The neutrophil adhesion molecule, CD 11b was up‐regulated in single and repeat dose studies. Based on these studies, a reliable LPS‐mediated hepatitis model with necrosis was developed by intravenous administration of LPS in a repeat dose fashion. Midzonal hepatic necrosis, peripheral neutrophilia, hepatic neutrophil infiltration and up‐regulation of CD11b were the most significant and consistent markers of LPS mediated effects in this model. Copyright © 2007 John Wiley & Sons, Ltd.
Seasonal variations in spontaneous levels of DNA damage; implication in the risk assessment of environmental chemicals
Authors: Verschaeve L. , Koppen G. , Gorp U. Van , Schoeters G. , Jacobs G. , Zwijzen C. 
Published: March 2007

AbstractThe alkaline comet assay was used to investigate DNA damage levels in white blood cells of 45 normal healthy subjects. Therefore blood was sampled at four different periods, namely in February, June, August and November of the same year. Higher DNA damage levels were found in summertime, as well as higher levels of 1‐hydroxypyrene in urine in this period. This suggests a higher exposure to polycyclic hydrocarbons in the summer compared with other periods of the year. The observed seasonal variation in DNA damage levels is in agreement with some, but in contradiction with other data. Seasonal variations in DNA damage levels can easily be explained by the existence of different confounders that may influence the results of a biomonitoring study. Besides sunlight and environmental pollution, also diet, allergy and physical exercise, for example, were already identified as important influencing factors. The investigation confirms that the blood sampling period is crucial in the planning and interpretation of biomonitoring studies. Copyright © 2007 John Wiley & Sons, Ltd.
Sliding wear behavior of submicron‐grained alumina in biological environment
Authors: Singha Roy R. , Mondal A. , Chanda A. , Basu D. , Mitra M. K. 
Published: March 2007

AbstractSliding wear behavior of sintered alumina with grain sizes between 0.45 and 4 μm was studied in bovine serum environment with unidirectional pin‐on‐disc wear testing machine. Submicron grained alumina of average grain size of G = 0.45 μm exhibits lowest wear factor among the others. It was found that grain pull out or localized grain dislodgement caused by coalescence of grain boundary microcracks is the basic wear mechanism of submicron grained alumina though the extent of cracking and pull‐out was substantially less than that with higher grained material. However, in few cases, some areas where substantial volume of material was removed following pull‐out of cluster of grains have also been observed. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Micro‐CT based quantification of non‐mineralized tissue on cultured hydroxyapatite scaffolds
Authors: Hilldore Amanda , Wojtowicz Abigail , Johnson Amy Wagoner 
Published: March 2007

AbstractAn improved method to determine material volumes from microcomputed tomography (micro‐CT) data is presented. In particular, the method can account for materials with significantly overlapping peaks and small volumes. The example case is a hydroxyapatite scaffold cultured with osteoprogenitor cells. The histogram obtained from the micro‐CT data is decomposed into a Gaussian attenuation distribution for each material in the sample, including scaffold, pore and surface tissue, and background. This is done by creating a training set of attenuation data to find initial parameters and then using a nonlinear curve fit, which produced R2 values greater than 0.998. To determine the material volumes, the curves that simulated each material are integrated, allowing small volume fractions to be accurately quantified. Thresholds for visualizing the samples are chosen based on volume fractions of the Gaussian curves. Additionally, the use of dual‐material regions helps accurately visualize tissue on the scaffold, which is otherwise difficult because of the large volume fraction of scaffold. Finally, the curve integration method is compared with Bayesian estimation and intersection thresholding methods. The pore tissue is not represented at all by the Bayesian estimation, and the intersection thresholding method is less accurate than the curve integration method. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
PD98059 enhanced insulin, cytokine, and growth factor activation of xanthine oxidoreductase in epithelial cells involves STAT3 and the glucocorticoid receptor
Authors: Roberts Laura E. , Fini Mehdi A. , Derkash Noi , Wright Richard M. 
Published: March 2007

AbstractPD98059 and U0126 are organic compound inhibitors frequently used to block the activity of the MEK‐1/2 protein kinase. In the present work, promoter activation analyses of xanthine oxidoreductase (XOR) in epithelial cells uncovered the unexpected opposite effect of these inhibitors on activation of XOR. Activation of an XOR‐luciferase fusion gene was studied in stably transfected epithelial cells. The XOR reporter gene was activated by the epidermal growth factors (EGF), prolactin, and dexamethasone and by the acute phase cytokines (APC) IL‐1, IL‐6, and TNFα as previously reported for its native gene, and insulin further stimulated activation induced with acute phase cytokines or growth factors. Activation of the proximal promoter was blocked by inhibitors of the glucocorticoid receptor (GR), p38 MAP kinase, and U0126. Unexpectedly, PD98059 activated the promoter and significantly enhanced expression induced by insulin, APC, or growth factors. Analysis of the XOR upstream DNA and proximal promoter revealed primary roles for the GR and STAT3 in mediating the effects of PD98059 on XOR activation and protein complex formation with the promoter. STAT3 phosphotyrosine‐705 was rapidly induced by PD98059, dexamethasone, and insulin. XOR activation by PD98059, dexamethasone, or insulin was superinduced by a constitutively active derivative of STAT3, while a dominant negative derivative of STAT3 blocked the enhancing effect of PD98059 on XOR activation. These data demonstrate a previously unrecognized effect of PD98059 on STAT3 and the GR that could have unanticipated consequences when used to infer the involvement of the MEK‐1/2 protein kinase. J. Cell. Biochem. 101: 1567–1587, 2007. © 2007 Wiley‐Liss, Inc.