bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuronal correlates of spontaneous fluctuations in fMRI signals in monkey visual cortex: Implications for functional connectivity at rest
Authors: Shmuel Amir , Leopold David A. 
Published: May 2008

AbstractRecent studies have demonstrated large amplitude spontaneous fluctuations in functional‐MRI (fMRI) signals in humans in the resting state. Importantly, these spontaneous fluctuations in blood‐oxygenation‐level‐dependent (BOLD) signal are often synchronized over distant parts of the brain, a phenomenon termed functional‐connectivity. Functional‐connectivity is widely assumed to reflect interregional coherence of fluctuations in activity of the underlying neuronal networks. Despite the large body of human imaging literature on spontaneous activity and functional‐connectivity in the resting state, the link to underlying neural activity remains tenuous. Through simultaneous fMRI and intracortical neurophysiological recording, we demonstrate correlation between slow fluctuations in BOLD signals and concurrent fluctuations in the underlying locally measured neuronal activity. This correlation varied with time‐lag of BOLD relative to neuronal activity, resembling a traditional hemodynamic response function with peaks at ∼6 s lag of BOLD signal. The correlations were reliably detected when the neuronal signal consisted of either the spiking rate of a small group of neurons, or relative power changes in the multi‐unit activity band, and particularly in the local field potential gamma band. Analysis of correlation between the voxel‐by‐voxel fMRI time‐series and the neuronal activity measured within one cortical site showed patterns of correlation that slowly traversed cortex. BOLD fluctuations in widespread areas in visual cortex of both hemispheres were significantly correlated with neuronal activity from a single recording site in V1. To the extent that our V1 findings can be generalized to other cortical areas, fMRI‐based functional‐connectivity between remote regions in the resting state can be linked to synchronization of slow fluctuations in the underlying neuronal signals. Hum Brain Mapp 2008. © 2008 Wiley‐Liss, Inc.
The brain's orienting response: An event‐related functional magnetic resonance imaging investigation
Authors: Friedman David , Goldman Robin , Stern Yaakov , Brown Truman R. 
Published: May 2008

AbstractAn important function of the brain's orienting response is to enable the evaluation of novel, environmental events in order to prepare for potential behavioral action. Here, we assessed the event‐related hemodynamic (erfMRI) correlates of this phenomenon using unexpected (i.e., novel) environmental sounds presented within the context of an auditory novelty oddball paradigm. In ERP investigations of the novelty oddball, repetition of the identical novel sound leads to habituation of the novelty P3, an ERP sign of the orienting response. Repetition also leads to an enhancement of a subsequent positivity that appears to reflect semantic analysis of the environmental sounds. In this adaptation for erfMRI recording, frequent tones were intermixed randomly with infrequent target tones and equally infrequent novel, environmental sounds. Subjects responded via speeded button press to targets. To assess habituation, some of the environmental sounds were repeated two blocks after their initial presentation. As expected, novel sounds and target tones led to activation of widespread, but somewhat different, neural networks. Contrary to expectation, however, there were no significant areas in which activation was reduced in response to second compared to first presentations of the novel sounds. Conversely, novel sounds relative to target tones engendered activity in the inferior frontal gyrus (BA 45) consistent with semantic analysis of these events. We conclude that a key concomitant of the orienting response is the extraction of meaning, thereby enabling one to determine the significance of the environmental perturbation and take appropriate goal‐directed action. Hum Brain Mapp 2009. © 2008 Wiley‐Liss, Inc.
Cytochrome c oxidase biogenesis: New levels of regulation
Authors: Fontanesi Flavia , Soto Ileana C. , Barrientos Antoni 
Published: May 2008

AbstractEukaryotic cytochrome c oxidase (COX), the last enzyme of the mitochondrial respiratory chain, is a multimeric enzyme of dual genetic origin, whose assembly is a complicated and highly regulated process. COX displays a concerted accumulation of its constitutive subunits. Data obtained from studies performed with yeast mutants indicate that most catalytic core unassembled subunits are posttranslationally degraded. Recent data obtained in the yeast Saccharomyces
cerevisiae have revealed another contribution to the stoichiometric accumulation of subunits during COX biogenesis targeting subunit 1 or Cox1p. Cox1p is a mitochondrially encoded catalytic subunit of COX which acts as a seed around which the full complex is assembled. A regulatory mechanism exists by which Cox1p synthesis is controlled by the availability of its assembly partners. The unique properties of this regulatory mechanism offer a means to catalyze multiple‐subunit assembly. New levels of COX biogenesis regulation have been recently proposed. For example, COX assembly and stability of the fully assembled enzyme depend on the presence in the mitochondrial compartments of two partners of the oxidative phosphorylation system, the mobile electron carrier cytochrome c and the mitochondrial ATPase. The different mechanisms of regulation of COX assembly are reviewed and discussed. © 2008 IUBMB IUBMB Life, 60(9): 557–568, 2008
Cross‐linking of extruded collagen fibers—A biomimetic three‐dimensional scaffold for tissue engineering applications
Authors: Zeugolis Dimitrios I. , Paul Gordon R. , Attenburrow Geoffrey 
Published: May 2008

AbstractThe repair of tissue defects remains a challenging clinical problem. Extruded collagen fibers comprise a promising scaffold for anterior cruciate ligament and tendon reconstruction; however the engineering of these fibers has still to be improved to bring this material to clinical practice. In this study, for the first time we investigated the influence of a wide range of cross‐linking approaches (chemical, physical, and biological) on the properties of these fibers. Ultrastructural evaluation revealed a closely packed interfiber structure independent of the cross‐linking method employed. The thermal properties were dependent on the cross‐linking method employed and closely matched native tissues. The stress–strain curves were found to depend on the water content of the fibers, which was influenced by the cross‐linking method. An inversely proportional relationship between both dry and wet fiber diameter and stress at break was found, which indicates that tailored‐made biomaterials can be produced. Overall, the chemical stabilizations were more potent than both physical and biological approaches. Bifunctional agents such as hexamethylene diisocyanate and ethylene glycol diglycidyl ether or agents that promote matrix formation such as glutaraldehyde produced fibers with properties similar to those of native or synthetic fibers to suit a wide range of tissue engineering applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Spatial and temporal changes in the morphology of preosteoblastic cells seeded on microstructured tantalum surfaces
Authors: Justesen J. , Lorentzen M. , Andersen L. K. , Hansen O. , Chevallier J. , Modin C. , Füchtbauer A. , Foss M. , Besenbacher F. , Duch M. , Pedersen F. S. 
Published: May 2008

AbstractIt has been widely reported that surface morphology on the micrometer scale affects cell function as well as cell shape. In this study, we have systematically compared the influence of 13 topographically micropatterned tantalum surfaces on the temporal development of morphology, including spreading, and length of preosteoblastic cells (MC3T3‐E1). Cells were examined after 0.5, 1, 4, and 24 h on different Ta microstructures with vertical dimensions (heights) of 0.25 and 1.6 μm. Cell morphologies depended upon the underlying surface topography, and the length and spreading of cells varied as a function of time with regard to the two‐dimensional pattern and vertical dimension of the structure. Microstructures of parallel grooves/ridges caused elongated cell growth after 1 and 4 h in comparison to a flat, nonstructured, reference surface. For microstructures consisting of pillars, cell spreading was found to depend on the distance between the pillars with one specific pillar structure exhibiting a decreased spreading combined with a radical change in morphology of the cells. Interestingly, this morphology on the particular pillar structure was associated with a markedly different distribution of the actin cytoskeleton. Our results provide a basis for further work toward topographical guiding of cell function. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Tissue reaction to matrices of reconstituted keratin polymer implanted subcutaneously in sheep
Authors: Peplow Philip V. , Dias George J. , Teixeira Fernanda , Kelly Robert J. 
Published: May 2008

AbstractFour different modifications of the keratin polymer were made as small rods and inserted into the subcutaneous tissue of the hind limbs of adult female sheep. Material 1 was porous, whereas materials 2, 3, and 4 had little or no internal porosity. The tissue response to each material was determined with regard to the extent of the inflammatory reaction and formation of a fibrous capsule around the implant, and the integrity and morphological appearance of the implant was assessed. An inflammatory cell infiltrate and fibrous capsule formed at an early stage around implants of material 1. Subsequently the inflammation decreased, the fibrous capsule became more mature, and the implants became cavitated and invaded by mono‐ and multi‐nucleated macrophages, fibroblasts and blood vessels, with breakdown of the implant material occurring at its periphery. Similar changes were observed for implants made of materials 2 and 4. Implants of material 3 were remarkable in that, while surrounded by an inflammatory infiltrate and a fibrous capsule, they did not show any disturbance even at 24 weeks. The fibrous capsule around material 3 was thinner than that around material 1 at 6 to 24 weeks (both materials prepared using ammonium thioglycollate). No difference in capsule thickness was found for materials 2 and 4 (both materials prepared using thioglycollic acid). © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Effects of packaging environments on free radicals in γ‐irradiated UHMWPE resin powder blend with vitamin E
Authors: Ridley M. D. , Jahan M. S. 
Published: May 2008

AbstractUltra‐high molecular weight polyethylene (UHMWPE) powder (GUR 1020) was blended with high concentration (20%) of vitamin E (α‐Tocopherol (α‐T)) for direct detection of α‐T radicals in presence of PE radicals. Samples were γ‐irradiated in sealed packages filled with N2, or in open air. Free radicals were measured in open air environment for 71 days using electron spin resonance (ESR) technique. When irradiated in air, both α‐T and α‐T‐resin produced identical ESR signals characteristics of tochopheroxyl radicals (α‐T‐O•), suggesting that PE radicals are quenched by α‐T. There was no indication of growth of oxygen‐induced radicals (OIR) either. However, when α‐T‐resin was irradiated in N2, presence of both PE and α‐T radicals were evident in the ESR spectra. And, OIR were produced by the same samples when they were subsequently exposed to air (for 71 days). Oxidation data recorded 85 days after postirradiation aging in air using Fourier transform infra‐red (FTIR) spectroscopy, however, did not show any measurable difference between samples irradiated in N2 and air. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Controlled release of glial‐derived neurotrophic factor from fibrin matrices containing an affinity‐based delivery system
Authors: Wood Matthew D. , Borschel Gregory H. , Sakiyama‐Elbert Shelly E. 
Published: May 2008

AbstractThis research evaluated the controlled release of glial‐derived neurotrophic factor (GDNF) from an affinity‐based delivery system (ABDS) as potential treatment for peripheral nerve injury. The ABDS consisted of a bidomain peptide containing a transglutaminase substrate, allowing crosslinking into fibrin matrices, and a heparin‐binding domain based on the antithrombin‐III heparin‐binding domain, heparin, and GDNF, which was sequestered based on its heparin‐binding affinity. The objective of this research was to determine the release rate and biological activity of GDNF released from the ABDS in vitro. The ratio of peptide to heparin was found to modulate the rate of GDNF release. The biological activity of GDNF released from the ABDS was assayed using chick dorsal root ganglia (DRGs) neurite extension. Neurite extension was equivalent for fibrin matrices containing the ABDS for all concentrations of GDNF tested versus DRGs grown with GDNF in the media. Furthermore, neurite extension was enhanced in fibrin matrices containing 100 ng/mL of GDNF with the ABDS versus matrices with GDNF at a simliar dose but no ABDS. These results suggest that GDNF can be retained and released in a biologically activity form from the ABDS, and thus this approach may prove useful for the treatment of peripheral nerve injury. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Adipose tissue engineering in vivo with adipose‐derived stem cells on naturally derived scaffolds
Authors: Flynn L. , Prestwich G. D. , Semple J. L. , Woodhouse K. A. 
Published: May 2008

AbstractPlacental decellular matrix (PDM) and PDM combined with cross‐linked hyaluronan (XLHA) scaffolds, seeded with primary human adipose‐derived stem cells (ASC), were investigated in a subcutaneous athymic mouse model. The in vivo response at 3 and 8 weeks was characterized using histological and immunohistochemical staining. Fibrous capsule formation was assessed and the relative number of adipocytes in each scaffold was quantified. Undifferentiated ASC were localized using immunostaining for human vimentin. Unilocular and multilocular adipocytes were identified by intracellular lipid accumulation. Staining for murine CD31 assessed implant vascularization. Both scaffolds macroscopically maintained their three‐dimensional volume and supported mature adipocyte populations in vivo. There was evidence of implant integration and a host contribution to the adipogenic response. The results suggested that incorporating the XLHA had a positive effect in terms of angiogenesis and adipogenesis. Overall, the PDM and PDM with XLHA scaffolds showed great promise for adipose tissue regeneration. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
HDGF is dephosphorylated during the early steps of endothelial cell apoptosis in a caspase‐dependent way
Authors: Clermont Frederic , Gonzalez Nathalie Suarez , Communi David , Franken Sebastian , Dumont Jacques E. , Robaye Bernard 
Published: May 2008

AbstractWe were looking by a proteomic approach for new phospho‐proteins involved during the early steps of the TNF + cycloheximide (CHX)‐induced apoptosis—preceding mitochondrial membrane permeabilization—of endothelial cells (BAEC). In the present study, we observed on the autoradiography from 2D gel of 32P‐labeled samples a string of proteins undergoing a complete dephosphorylation after 1 h of stimulation with TNF + CHX—while mitochondrial membrane permeabilization was observed after 3 h—identified the different spots by mass spectrometry as one and only protein, HDGF, and confirmed the identity by western blot. The intensity of the 2D phosphorylation pattern of HDGF was correlated with the amount of apoptosis induced by TNF + CHX and TNF or CHX alone and this event was inhibited by the Caspase specific inhibitor zVADfmk. Moreover the TNF + CHX‐treatment did not affect the nuclear localization of GFP‐HDGF. Taken together, our data suggest an involvement of HDGF during the initiation phase of the apoptotic process downstream from an initiator Caspase and a regulation of this protein by phosphorylation in the nucleus. J. Cell. Biochem. 104: 1161–1171, 2008. © 2008 Wiley‐Liss, Inc.
Expression and tyrosine phosphorylation of Crk‐associated substrate lymphocyte type (Cas‐L) protein in human neutrophils
Authors: Nakamoto Tetsuya , Seo Sachiko , Sakai Ryuichi , Kato Takayuki , Kutsuna Haruo , Kurokawa Mineo , Noda Masaki , Miyasaka Nobuyuki , Kitagawa Seiichi 
Published: May 2008

AbstractCrk‐associated substrate lymphocyte type (Cas‐L) protein, also known as human enhancer of filamentation 1 (Hef1) or neural precursor cell‐expressed, developmentally down‐regulated gene 9 (Nedd9), belongs to the Cas family of adapter proteins, which are involved in integrin signaling. Previous reports showed that Cas‐L is expressed preferentially in lymphocytes and epithelial cells. Cas‐L mediates signals from integrins, T‐cell receptors, B‐cells receptors, and transforming growth factor beta, leading to cell movement and cell division. Here, we report the expression of Cas‐L in neutrophils. Cas‐L was tyrosine‐phosphorylated when human neutrophils were stimulated by fMLP, tumor necrosis factor‐alpha (TNF), or lipopolysaccharide. The tyrosine phosphorylation of Cas‐L in fMLP‐ or TNF‐ stimulated neutrophils was further enhanced by adhesion of the cells to their substrates. Cas‐L was found to be localized at focal adhesions in stimulated neutrophils based on immunofluorescence microscopy. These findings suggest that Cas‐L is one of the targets of inflammatory cytokines and is also modulated by cell adhesion process in neutrophils. J. Cell. Biochem. 105: 121–128, 2008. © 2008 Wiley‐Liss, Inc.
Zm401, a short‐open reading‐frame mRNA or noncoding RNA, is essential for tapetum and microspore development and can regulate the floret formation in maize
Authors: Ma Jinxia , Yan Bingxue , Qu Yanying , Qin Fangfang , Yang Yantao , Hao Xiujing , Yu Jingjuan , Zhao Qian , Zhu Dengyun , Ao Guangming 
Published: May 2008

AbstractIn flowering plants, pollen formation depends on the differentiation and interaction of two cell types in the anther: the reproductive cells, called microsporocytes, and somatic cells that form the tapetum. Previously, we cloned a pollen specific gene, zm401, from a cDNA library generated from the mature pollen of Zea mays. Expression of partial cDNA of zm401 in maize and ectopic expression of zm401 in tobacco suggested it may play a role in anther development. Here we present the expression and functional characterization of this pollen specific gene in maize. Zm401 is expressed primarily in the anthers (tapetal cells as well as microspores) in a developmentally regulated manner. That is, it is expressed from floret forming stage, increasing in concentration up to mature pollen. Knockdown of zm401 significantly affected the expression of ZmMADS2, MZm3‐3, and ZmC5, critical genes for pollen development; led to aberrant development of the microspore and tapetum, and finally male‐sterility. Zm401 possesses highly conserved sequences and evolutionary conserved stable RNA secondary structure in monocotyledon. These data show that zm401 could be one of the key growth regulators in anther development, and functions as a short‐open reading‐frame mRNA (sORF mRNA) and/or noncoding RNA (ncRNA). J. Cell. Biochem. 105: 136–146, 2008. © 2008 Wiley‐Liss, Inc.
p21 activated kinase 5 activates Raf‐1 and targets it to mitochondria
Authors: Wu Xiaochong , Carr Heather S. , Dan Ippeita , Ruvolo Peter P. , Frost Jeffrey A. 
Published: May 2008

AbstractRaf‐1 is an important effector of Ras mediated signaling and is a critical regulator of the ERK/MAPK pathway. Raf‐1 activation is controlled in part by phosphorylation on multiple residues, including an obligate phosphorylation site at serine 338. Previously PAK1 and casein kinase II have been implicated as serine 338 kinases. To identify novel kinases that phosphorylate this site, we tested the ability of group II PAKs (PAKs 4–6) to control serine 338 phosphorylation. We observed that all group II PAKs were efficient serine 338 kinases, although only PAK1 and PAK5 significantly stimulated Raf‐1 kinase activity. We also showed that PAK5 forms a tight complex with Raf‐1 in the cell, but not A‐Raf or B‐Raf. Importantly, we also demonstrated that the association of Raf‐1 with PAK5 targets a subpopulation of Raf‐1 to mitochondria. These data indicate that PAK5 is a potent regulator of Raf‐1 activity and may control Raf‐1 dependent signaling at mitochondria. J. Cell. Biochem. 105: 167–175, 2008. © 2008 Wiley‐Liss, Inc.
A proof of Lindner's conjecture on embeddings of partial Steiner triple systems
Authors: Bryant Darryn , Horsley Daniel 
Published: May 2008

AbstractLindner's conjecture that any partial Steiner triple system of orderucan be embedded in a Steiner triple system of ordervif$v\equiv 1,3 \; ({\rm mod}\; 6)$and$v\geq 2u+1$is proved. © 2008 Wiley Periodicals, Inc. J Combin Designs 17: 63–89, 2009
Spontaneous unilateral dizygotic twin tubal pregnancy
Authors: Tam Teresa , Khazaei Ali 
Published: May 2008

AbstractSpontaneous dizygotic unilateral twin tubal pregnancy is an extremely rare occurrence with a high risk for pregnancy‐related mortality, and a diagnostic challenge for obstetricians. We present a case of a 27‐year‐old woman with spontaneous twin tubal pregnancy. Transvaginal color Doppler sonography revealed 2 separate gestational sacs within the right adnexa, each containing an embryo. Cytogenetic examination of the trophoblastic tissues confirmed the diagnosis of dizygotic twin ectopic pregnancy. Clinical signs and symptoms together with imaging studies help in the diagnosis of this rare variant of ectopic pregnancies. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Two cases of pregnant women with ovarian endometrioma mimicking a malignant ovarian tumor
Authors: Yoshida Shozo , Onogi Akira , Shigetomi Hiroshi , Tsuji Yoriko , Haruta Shoji , Naruse Katsuhiko , Kanayama Seiji , Noguchi Taketoshi , Sakata Mariko , Furukawa Naoto , Sado Toshiyuki , Yamada Yoshihiko , Kitanaka Takashi , Oi Hidekazu , Kobayashi Hiroshi 
Published: May 2008

AbstractThe detection of an ovarian mass during pregnancy is often a diagnostic challenge. We describe 2 cases of ovarian endometrioma during pregnancy with marked mural nodules on the cyst wall. The sonographic and MR imaging findings mimicked ovarian cancer. Surgical intervention may still be inevitable to exclude the possibility of malignancy. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Simulation of 2006 monsoon using T170L42 AGCM: sensitivity to convective parameterization schemes
Authors: Ratnam J. Venkata , Sikka D. R. , Banerjee Sudipta 
Published: May 2008

AbstractIn this study we used the National Center for Environmental Prediction (NCEP) T170L42 Global Forecast System model for simulating the monsoon of 2006 using two different cumulus parameterization schemes viz. the Simple Arakawa–Schubert (SAS) scheme and the Relaxed Arakawa–Schubert (RAS) scheme. The NCEP Coupled Forecast System (CFS) monthly forecast sea surface temperatures (SST) were used for simulating the monsoon season. It is seen that both the schemes forecast the mean seasonal rainfall close to the observed. However, there were differences in the spatial and temporal distribution of the rainfall. The spatial distribution of the precipitation simulated by the RAS scheme was comparable to the observed. The SAS scheme simulated realistic distribution of the rainfall in the months of June and July. In the months of August and September, the SAS scheme could not simulate the convective regions over the south and central Bay of Bengal, Arabian Sea and the Indian landmass. The SAS scheme simulated withdrawal‐like symptoms of the monsoon in the month of August itself. However, the same SAS scheme simulated more realistic rainfall distribution over the Bay of Bengal when the model was run with climatological SST and also when the model was run at a resolution of T62 and with CFS‐forecast SST. The onset of the monsoon over the Kerala coast of India simulated with both the schemes was within one pentad of the observed date of onset. Copyright © 2008 Royal Meteorological Society