bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust Bayesian estimation of the hemodynamic response function in event‐related BOLD fMRI using basic physiological information
Authors: Marrelec Guillaume , Benali Habib , Ciuciu Philippe , Pélégrini‐Issac Mélanie , Poline Jean‐Baptiste 
Published: April 2003

AbstractIn BOLD fMRI data analysis, robust and accurate estimation of the Hemodynamic Response Function (HRF) is still under investigation. Parametric methods assume the shape of the HRF to be known and constant throughout the brain, whereas non‐parametric methods mostly rely on artificially increasing the signal‐to‐noise ratio. We extend and develop a previously proposed method that makes use of basic yet relevant temporal information about the underlying physiological process of the brain BOLD response in order to infer the HRF in a Bayesian framework. A general hypothesis test is also proposed, allowing to take advantage of the knowledge gained regarding the HRF to perform activation detection. The performances of the method are then evaluated by simulation. Great improvement is shown compared to the Maximum‐Likelihood estimate in terms of estimation error, variance, and bias. Robustness of the estimators with regard to the actual noise structure or level, as well as the stimulus sequence, is also proven. Lastly, fMRI data with an event‐related paradigm are analyzed. As suspected, the regions selected from highly discriminating activation maps resulting from the method exhibit a certain inter‐regional homogeneity in term of HRF shape, as well as noticeable inter‐regional differences. Hum. Brain Mapping 19:1–17, 2003. © 2003 Wiley‐Liss, Inc.
Demand on verbal working memory delays haemodynamic response in the inferior prefrontal cortex
Authors: Thierry Guillaume , Ibarrola Danielle , Démonet Jean‐François , Cardebat Dominique 
Published: April 2003

AbstractEvent‐related functional magnetic resonance imaging was used to test the involvement of the inferior prefrontal cortex in verbal working memory. Pairs of French nouns were presented to ten native French speakers who had to make semantic or grammatical gender decisions. Verbal working memory involvement was manipulated by making the categorization of the second noun optional. Decisions could be made after processing the first noun only (RELEASE condition) or after processing the two nouns (HOLD condition). Reaction times suggested faster processing for gender than for semantic category in RELEASE. Despite the absence of anatomical difference across tasks and conditions in the wide activated network, the haemodynamic response peak latencies of the inferior prefrontal cortex were significantly delayed in HOLD versus RELEASE while no such peak delay was observed in the superior temporal gyrus. Interestingly, this pattern did not interact with language tasks. This study shows that cognitive manipulation can influence haemodynamic time‐course and suggests that the main cognitive process determining inferior prefrontal activation is verbal working memory rather than specific linguistic processes such as grammatical or semantic analysis. Hum. Brain Mapping 19:37–46, 2003. © 2003 Wiley‐Liss, Inc.
Brain activations during motor imagery of locomotor‐related tasks: A PET study
Authors: Malouin Francine , Richards Carol L. , Jackson Philip L. , Dumas Francine , Doyon Julien 
Published: April 2003

AbstractPositron emission tomography (PET) was used to study the involvement of supraspinal structures in human locomotion. Six right‐handed adults were scanned in four conditions while imagining locomotor‐related tasks in the first person perspective: Standing (S), Initiating gait (IG), Walking (W) and Walking with obstacles (WO). When these conditions were compared to a rest (control) condition to identify the neural structures involved in the imagination of locomotor‐related tasks, the results revealed a common pattern of activations, which included the dorsal premotor cortex and precuneus bilaterally, the left dorsolateral prefrontal cortex, the left inferior parietal lobule, and the right posterior cingulate cortex. Additional areas involving the pre‐supplementary motor area (pre‐SMA), the precentral gyrus, were activated during conditions that required the imagery of locomotor movements. Further subtractions between the different locomotor conditions were then carried out to determine the cerebral regions associated with the simulation of increasingly complex locomotor functions. These analyses revealed increases in rCBF activity in the left cuneus and left caudate when the W condition was compared to the IG condition, suggesting that the basal ganglia plays a role in locomotor movements that are automatic in nature. Finally, subtraction of the W from the WO condition yielded increases in activity in the precuneus bilaterally, the left SMA, the right parietal inferior cortex and the left parahippocampal gyrus. Altogether, the present findings suggest that higher brain centers become progressively engaged when demands of locomotor tasks require increasing cognitive and sensory information processing. Hum. Brain Mapping 19:47–62, 2003. © 2003 Wiley‐Liss, Inc.
Cerebral information transfer during word processing: Where and when does it occur and how fast is it?
Authors: Schack Baerbel , Weiss Sabine , Rappelsberger Peter 
Published: April 2003

AbstractDifferent regions of the brain have to interact to perform language processing. Such neural integration processes can be studied by measuring synchronization of oscillations. Coherence is the best known algorithm to study synchronization between two sites of the cortex with regard to selected oscillation frequencies. Phase coherence quantifies phase synchronization, in particular. In addition, cross phase (or simply phase) gives information about the direction and speed of the spread of oscillations. We use a new method to study short‐time phases between different sites of the cortex in order to explore transient neural networks during word processing. Particularly, processing of abstract and concrete nouns was investigated by dynamic phase analysis of the alpha1 frequency band (8–10 Hz). Abstract and concrete nouns turned out to induce different dynamic networks of information transfer. Whereas processing of concrete nouns excites a widespread network for about 800 msec, the interhemispheric interactions during abstract noun processing are restricted to 300–500 msec after word presentation. Further, the direction of cerebral information transfer differs for the two word categories. Additionally, it could be shown that the propagation speed of information is slower for concrete nouns than for abstract nouns. Hum. Brain Mapping 19:18–36, 2003. © 2003 Wiley‐Liss, Inc.
Incorporation of calcium phosphate enhances recombinant adeno‐associated virus‐mediated gene therapy in diabetic mice
Authors: Yang Ya‐Wun , Chao Chih‐Kai 
Published: April 2003

AbstractBackgroundIncreased efficiency of transgene expression is desired for virus‐mediated gene delivery. In the present study, we examined the effect of calcium phosphate (CaPi) on recombinant adeno‐associated virus (rAAV)‐mediated insulin therapy in diabetic animals.MethodsThe rAAV vector, rAAV.PEPCK.Ins.EGFP, containing the human insulin gene under control of the phosphoenolpyruvate carboxykinase (PEPCK) promoter and the enhanced green fluorescence protein (EGFP) gene driven by the cytomegalovirus (CMV) IE promoter, was employed in this study. C57BL/6J mice were made diabetic with streptozotocin (STZ), followed by injection into the livers with either rAAV alone, or noncovalent complexes with calcium phosphate. Body weight and blood glucose levels of the animals were routinely monitored after 6 h fasting. Secretion of human insulin in the rAAV‐transduced animals was determined by radioimmunoassay (RIA). Expression of human insulin in the livers of the animals was detected by immunohistochemical staining.ResultsCompared with the STZ‐treated control mice, administration of rAAV containing the human insulin gene significantly decreased blood glucose levels and maintained body weight of the diabetic animals. Complexation of rAAV with calcium phosphate enhanced the hypoglycemic effect of rAAV‐mediated gene transfer. Results obtained from both RIA and immunohistochemical staining demonstrated that incorporation of calcium phosphate enhanced rAAV‐mediated gene transfer in vivo, leading to higher expression and secretion of human insulin.ConclusionsAdministration of rAAV harboring the human insulin gene into livers of the STZ‐diabetic mice improved blood glucose levels, maintained body weight of the diabetic animals, and resulted in human insulin secretion. Complexation of rAAV with calcium phosphate significantly potentiated the efficiency of rAAV‐mediated diabetic gene therapy. Copyright © 2002 John Wiley & Sons, Ltd.
Multiple muscles in the AMD quail can be “cross‐corrected” of pathologic glycogen accumulation after intravenous injection of an [E1‐, polymerase‐] adenovirus vector encoding human acid‐α‐glucosidase
Authors: McVie‐Wylie A. J. , Ding E. Y. , Lawson T. , Serra D. , Migone F. K. , Pressley D. , Mizutani M. , Kikuchi T. , Chen Y. T. , Amalfitano A. 
Published: April 2003

AbstractBackgroundPreviously, in murine models of acid maltase deficiency (AMD), we demonstrated that intravenous administration of an improved adenovirus (Ad) vector encoding human acid alpha glucosidase (hGAA) resulted in liver transduction, followed by high‐level hepatocyte‐mediated secretion of hGAA into the plasma space. The hGAA secreted by the liver was taken up and targeted to muscle cell lysosomes. The levels of hGAA achieved by this approach resulted in clearance of lysosomal glycogen accumulations; in some muscle tissues the effect was prolonged (>6 months). We next wished to demonstrate whether this approach could be generalized across divergent species. To accomplish this goal, we determined whether a similar approach would also result in efficacy, but in a quail model of AMD.MethodsAn [E1‐, E2b‐]Ad vector encoding hGAA was intravenously injected into AMD quails. At several time points thereafter, plasma, liver, and multiple muscle tissues were assayed for evidence of hGAA gene expression, liver‐mediated hGAA secretion, uptake of hGAA by skeletal muscles, and evidence of glycogen correction in AMD skeletal muscles. These results were compared with those obtained from mock‐injected AMD or wild‐type quails.ResultsIntravenous [E1‐, E2b‐]Ad/hGAA vector injection resulted in high‐level liver transduction and hepatic secretion of precursor forms of hGAA. The hepatically secreted hGAA was found to not only be efficiently taken up by cardiac and skeletal muscles, but was also proteolytically cleaved and processed equivalently to the quail‐GAA protein detected in wild‐type quails. The observations suggest that the signals regulating muscle cell uptake (but not proteolytic cleavage) of lysosomal enzymes are conserved and recognized across divergent species of vertebrates. Importantly, once localized to skeletal muscle lysosomes, the hGAA was able to effectively clear the glycogen accumulations present in AMD quail muscles.ConclusionsAdenovirus‐mediated transduction of the hGAA gene, followed by hepatic secretion, uptake, and cross‐correction of the pathologic glycogen accumulation noted in multiple muscles of both the AMD mouse and AMD quail, adds support to the notion that gene transfer strategies (Ad‐mediated or other agents) targeting liver tissues with the hGAA gene are likely to be highly efficacious in humans affected by AMD. Copyright © 2002 John Wiley & Sons, Ltd.
Drug‐selected co‐expression of P‐glycoprotein and gp91 in vivo from an MDR1‐bicistronic retrovirus vector Ha‐MDR‐IRES‐gp91
Authors: Sugimoto Yoshikazu , Tsukahara Satomi , Sato Shigeo , Suzuki Mutsumi , Nunoi Hiroyuki , Malech Harry L. , Gottesman Michael M. , Tsuruo Takashi 
Published: April 2003

AbstractBackgroundRetroviral transduction of human hematopoietic stem cells is an attractive strategy in gene therapy; however, transduction efficiency and duration of transgene expression may not be satisfactory in current protocols. Co‐expression of a human multidrug resistance gene (MDR1) with a therapeutic gene affords selectable growth advantage to genetically modified cells.MethodsA bicistronic retrovirus vector, Ha‐MDR‐IRES‐gp91, was constructed for the co‐expression of MDR1 and gp91, a gene responsible for X‐linked chronic granulomatous disease (X‐CGD). Drug‐selected co‐expression of P‐glycoprotein and gp91 was evaluated in transduced cells.ResultsEpstein‐Barr virus‐transformed B cells from X‐CGD patients transduced with Ha‐MDR‐IRES‐gp91 co‐expressed human P‐glycoprotein and gp91, and acquired superoxide‐generating activity. Human CD34‐positive cells from an X‐CGD patient were transduced with Ha‐MDR‐IRES‐gp91 and subsequently treated with 2 ng/ml vincristine. After 13 days, 20% of Ha‐MDR‐IRES‐gp91‐transduced cells were P‐glycoprotein‐ and gp91‐positive by FACS analysis. The superoxide‐generating activity of the transduced population was 27% of that of normal cells. Mice transplanted with Ha‐MDR‐IRES‐gp91‐transduced bone marrow cells showed co‐expression of P‐glycoprotein and gp91 in peripheral blood mononuclear cells. By administering paclitaxel, the proportions of P‐glycoprotein‐ and gp91‐positive cells were increased in all the four mice examined. When mice transplanted with Ha‐MDR‐IRES‐gp91‐transduced cells were repeatedly administered paclitaxel, the ratios of P‐glycoprotein‐ and gp91‐positive cells were maintained for over 1 year.ConclusionsThese results suggest that MDR1‐bicistronic vectors may be useful to select the transduced hematopoietic cells in vivo. This may lead to the sustained expression of transgenes in the blood cells of patients treated with stem cell gene therapy. Copyright © 2003 John Wiley & Sons, Ltd.
Induction of T cell tolerance to a protein expressed in the cytoplasm through retroviral‐mediated gene transfer
Authors: Tian Chaorui , Bagley Jessamyn , Kaye Joel , Iacomini John 
Published: April 2003

AbstractBackgroundHost immune responses to foreign gene products have been shown to lead to the elimination of genetically modified cells, and are a major barrier to successful therapeutic gene therapy. We have shown that immunological tolerance to retrovirally transduced cell surface proteins can be induced by expressing the gene encoding these products in bone marrow derived cells. Here, we investigate if expression of foreign gene products in bone marrow derived cells can be used to induce tolerance to cytoplasmic proteins.MethodsBalb/c mice were reconstituted with syngeneic bone marrow cells transduced with retrovirus carrying the gene encoding enhanced green fluorescent protein (eGFP), or mock‐transduced bone marrow cells. After reconstitution, mice were immunized with cells expressing eGFP, and T cells were tested for the ability to kill eGFP‐expressing targets in in vitro cytotoxic T lymphocyte (CTL) assays.ResultsT cells from Balb/c mice reconstituted with mock‐transduced bone marrow were able to kill target cells expressing eGFP. In contrast, T cells from mice reconstituted with eGFP‐transduced bone marrow were unable to kill targets expressing eGFP. In addition, we observed that T cell responses to eGFP in C57BL/6 mice were minimal even under highly immunogenic conditions.ConclusionsThese data suggest that expression of foreign gene products in bone marrow derived cells is capable of inducing T cell tolerance to proteins expressed exclusively in the cytoplasm. Copyright © 2003 John Wiley & Sons, Ltd.
Concurrent delivery of GM‐CSF and endostatin genes by a single adenoviral vector provides a synergistic effect on the treatment of orthotopic liver tumors
Authors: Tai Kuo‐Feng , Chen Pei‐Jer , Chen Ding‐Shinn , Hwang Lih‐Hwa 
Published: April 2003

AbstractBackgroundThe immune resistance of large tumors represents a major problem for cancer immunotherapy, whereas the need for repeated injections of high doses of recombinant anti‐angiogenic proteins represents a similar problem for anti‐angiogenic therapy. To test whether antitumor activity could be increased by combining the above two mechanisms, this study examined the therapeutic effect of combination gene therapy using a murine granulocyte‐macrophage colony‐stimulating factor (mGM‐CSF) gene and a human endostatin (hED) gene on a rat orthotopic liver tumor model.MethodsAn adenoviral vector was constructed that simultaneously carried two transcriptional cassettes, for the expression of mGM‐CSF and hED, respectively, or that carried a single cassette of either gene. The adenoviruses were intratumorally administered to 3‐day‐old or 7‐day‐old tumors. Moreover, the antitumor effects of the combination therapy and monotherapy were assessed and compared.ResultsThe double‐gene‐containing adenoviral vector expressed transgenes as efficiently as the single‐gene‐containing vector. Moreover, the adenovirally expressed endostatin was biologically active, as demonstrated in vitro and in vivo. Results from animal experiments demonstrated a synergistic antitumor effect induced by the combined mGM‐CSF and hED therapy. The combination of hED with mGM‐CSF enhanced tumor‐specific CTL activity, but did not interfere with the infiltration of cellular effectors in the tumor regions. The blood vessel density of the liver tumors markedly reduced as a result of hED expression in both monotherapy and combination therapy. Furthermore, combination therapy significantly increased the number of apoptotic cells in the tumor regions.ConclusionsThe experimental results suggest that the combined gene therapy against tumor cells and the tumor vascular system using antitumor immune mechanisms and anti‐angiogenic mechanisms holds promise as a strategy for treating cancers. Copyright © 2003 John Wiley & Sons, Ltd.
Antioxidant activity of ginger extract in sunflower oil
Authors: Zia‐ur‐Rehman  , Salariya A M , Habib Farzana 
Published: April 2003

AbstractThe antioxidant activity of dichloromethane extract from ginger was evaluated during 6 months of storage of refined sunflower oil at 25 and 45 °C. Free fatty acid (FFA) content, peroxide value (POV) and iodine value (IV) were used as criteria to assess ginger extract as an antioxidant. After 6 months of storage at 45 °C, sunflower oil containing 1600 and 2400 ppm ginger extract showed lower FFA contents (0.083 and 0.080%) and POVs (24.5 and 24.0 meq kg−1) than the control sample (FFA contents 0.380%, POV 198.0 meq kg−1). Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) showed FFA contents of 0.089 and 0.072% and POVs of 26.5 and 24.7 meq kg−1 respectively after 6 months of storage at 45 °C. Similarly, after 6 months of storage at 45 °C, IVs of sunflower oil containing 1600 and 2400 ppm ginger extract were 80 and 92 respectively, higher than that of the control sample (53). However, IVs of sunflower oil treated with 200 ppm BHA and BHT were 94 and 96 respectively after 6 months of storage at 45 °C. These results illustrate that ginger extract at various concentrations exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT). Ginger extract also showed good thermal stability and exhibited 85.2% inhibition of peroxidation of linoleic acid when heated at 185 °C for 120 min. Therefore the use of ginger extract in foods is recommended as a natural antioxidant to suppress lipid oxidation.© 2003 Society of Chemical Industry
Effect of endo‐xylanase‐containing enzyme preparations and laccase on the solubility of rye bran arabinoxylan
Authors: Andersson Roger , Eliasson Christina , Selenare Mangala , Kamal‐Eldin Afaf , Åman Per 
Published: April 2003

AbstractThree commercial enzyme preparations with endo‐xylanase activity, namely Bio‐Feed Wheat, Bio‐Feed Plus and Grindamyl H 640, and laccase have been tested for their effects on the solubilisation of arabinoxylan (AX) in rye bran or autoclaved rye bran. Autoclaving efficiently increased the availability of AX for enzymatic degradation. Both Bio‐Feed Wheat (a monocomponent enzyme) and Bio‐Feed Plus (a multicomponent preparation with different enzymatic activities) efficiently degraded the autoclaved rye bran AX into lower‐molecular‐weight fragments. As much as 70% of the xylose residues and 58% of the arabinose residues in the autoclaved bran were soluble after treatment with Bio‐Feed Plus; the weight—average molecular weight of the detectable portion of these soluble polymers was 104 000 Da. Grindamyl H 640 solubilised only a small fraction of the AX in autoclaved rye bran; the molecular weight of these soluble fragments was higher than that of those released by the Bio‐Feed xylanases. Addition of laccase during treatment with Bio‐Feed Wheat or Grindamyl H 640 decreased the yield of water‐soluble AX.© 2003 Society of Chemical Industry
Textural, histological and biochemical changes in cucumber (Cucumis sativus L) due to immersion and variations in turgor pressure
Authors: Sajnín C , Gamba G , Gerschenson L N , Rojas A M 
Published: April 2003

AbstractTextural, histological and biochemical characteristics of cucumber (Cucumis sativus L) under different tissue turgor pressures were studied after equilibration of mesocarp tissue cylinders in various polyethylene glycol 400 (PEG) solutions. Tissue swelling was observed for all hypotonic solutions. Cell membrane vitality was detected in all cucumber tissues where significant values of initial firmness (fi) and residual relaxation force (FR) were found. Good turgor status was also associated with higher values of these parameters, observing higher values of the textural parameters for higher turgor. Cell wall integrity was observed through Calcofluor fluorescence assay in tissue equilibrated in hypotonic, isotonic and hypertonic solutions, although a lower fluorescence intensity was observed in tissue equilibrated with 0 mol m−3 PEG solution, probably owing to some cell bursting. Calcium bridges between pectic polymers were proven to be responsible for cell–cell adhesion and tissue integrity of cucumber mesocarp tissue. Compression curves obtained for raw tissue showed a stage of fracture, and its loss after immersion might be attributed to cell–cell adhesion weakness due to immersion in calcium‐free PEG solutions. Peroxidase and polygalacturonase increased after cucumber equilibration in the solutions, probably expressing tissue injury. Cucumber textural behaviour was very much affected by immersion in calcium‐free solutions, determining the loss of fracture stage and a great influence of turgor pressure on the textural response of soaked tissue.© 2003 Society of Chemical Industry
Dehydration kinetics of red pepper (Capsicum annuum L var Jaranda)
Authors: Sanjuán N , Lozano M , García‐Pascual P , Mulet A 
Published: April 2003

AbstractShredded and whole red pepper samples were dehydrated in a laboratory drier with a through‐flow air velocity of 0.5 m s−1 at 50, 55, 60 and 70 °C. Shredded peppers dried faster than whole peppers. The drying behaviour of whole samples was characterised by a constant‐ and a falling‐rate drying period, whilst that of shredded samples was characterised by a falling‐rate drying period only. The mass transfer coefficient for whole samples during the constant‐rate period was computed experimentally. The effect of temperature on the mass transfer coefficient was described by the Arrhenius model. The activation energy was 58 kJ mol−1. In the falling‐rate period the mass transfer was described by a diffusional model, and the effective diffusion coefficient at each temperature was determined. Diffusion coefficients were estimated to lie between 4.38 × 10−11 and 10.99 × 10−11 m2 s−1 for whole peppers and between 37.23 × 10−11 and 99.61 × 10−11 m2 s−1 for shredded peppers. The effect of temperature on the effective diffusion coefficient was described by the Arrhenius equation, with an activation energy of 44 kJ mol−1 for whole peppers and 56 kJ mol−1 for shredded peppers.© 2003 Society of Chemical Industry