bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flavonoid Dimers as Bivalent Modulators for P‐Glycoprotein‐Based Multidrug Resistance: Structure–Activity Relationships
Authors: Chan Kin‐Fai , Zhao Yunzhe , Chow Toby W. S. , Yan Clare S. W. , Ma Dik Lung , Burkett Brendan A. , Wong Iris L. K. , Chow Larry M. C. , Chan Tak Hang 
Published: March 2009

AbstractBivalent modulators of P‐glycoprotein: A small library of flavonoid homodimers and heterodimers was synthesized, and their in vitro activity in reversing paclitaxel resistance was evaluated along with structure–activity relationships. SAR trends indicate that flavonoid dimers with nonpolar, hydrophobic, less bulky substituents generally show more potent reversing activity. This will help guide future efforts in the search for more potent compounds.magnified imageWe recently described the modulatory activities of apigenin homodimers linked by ethylene glycol units in multidrug‐ resistant breast cancer and leukemic cells overexpressing ABCB1 (P‐glycoprotein, P‐gp). To further improve the potency of these dimers, a small library of flavonoid homodimers and heterodimers were synthesized, and their in vitro activity in reversing cellular resistance to paclitaxel, along with structure–activity relationships (SAR), were evaluated using a P‐gp‐expressing human breast cancer cell line. Among these synthesized homodimers, many showed more potent reversing activity than that of the parent compound and verapamil. Two compounds in particular showed promising reversing activity at sub‐micromolar concentrations with no cytotoxic effects. Regarding SAR trends, flavonoid dimers with nonpolar and hydrophobic substituents (e.g., methyl and ethyl groups) generally showed more potent resistance‐reversing activity than that of dimers with polar and hydrophilic substituents (e.g. hydroxy groups) at the C3, C6, and C7 positions, but not at C5. In terms of substituent steric bulk at C6, it was found that the flavonoid dimer with methyl groups was optimal, with bulkier substituents leading to lower reversing activity. Comparisons of flavonoid heterodimers with the corresponding homodimers revealed that the two binding sites on P‐gp for flavonoid moieties are quite similar to each other. Besides paclitaxel, these new compounds also increased drug accumulation and enhanced the cytotoxicity of other cancer drugs such as doxorubicin, vincristine, and vinblastine by decreasing the IC50values 4–45‐fold.
Phagocytosis and postphagocytic reaction of cord blood and adult blood monocyte after infection with green fluorescent protein‐labeled Escherichia coli and group B Streptococci
Authors: Gille Ch. , Leiber A. , Mundle I. , Spring B. , Abele H. , Spellerberg B. , Hartmann H. , Poets Ch. F. , Orlikowsky Th. W. 
Published: March 2009

AbstractBackground:Neonatal sepsis is characterized by an excessive inflammatory response induced by immune cells (monocytes). We investigated the initial stage of monocyte‐pathogen interaction, i.e. bacterial ingestion and degradation at the single‐cell level, by comparing a new flow cytometric procedure with culture methods. We also examined the hypothesis that, in terms of phagocytosis‐induced cell death (PICD), phenotype, or cytokine production, cord blood monocytes (CBMO) differ from monocytes derived from adults (peripheral blood monocytes, PBMO).Methods:Phagocytosis and intracellular degradation were assessed by means of flow cytometry and bacterial cultures of green fluorescent protein‐labeled group B Streptococci (GBS) and Escherichia coli. The production of reactive oxygen species (ROS) was measured through luminol‐enhanced chemiluminescence. Apoptosis, phenotype, and cytokine production were assessed through flow cytometry.Results:Flow cytometry and bacterial cultures showed no difference between phagocytosis and degradation of GBS and E. coli by PBMO and CBMO. A high correlation between both methods was observed. No difference in ROS production was evident. In comparison with PBMO, CBMO apoptosis was lower after exposure to GBS and E. coli. Similarities were found between nonapoptotic monocytes and pro‐inflammatory monocytes.Conclusions:PICD is lower in CBMO during the early stages of monocyte‐pathogen interaction. Our results emphasize that monocyte apoptosis has a potential role in tailoring the immune response in neonatal sepsis. © 2009 Clinical Cytometry Society
Management implications of the relationships between water chemistry and fishes within channelized headwater streams in the midwestern United States
Authors: Smiley Peter C. , Gillespie Robert B. , King Kevin W. , Huang Chi‐hua 
Published: March 2009

AbstractMany headwater streams in the midwestern United States were channelized for agricultural drainage. Conservation practices are implemented to reduce nutrient, pesticide, and sediment loadings within these altered streams. The impact of these practices is not well understood because their ecological impacts have not been evaluated and the relationships between water chemistry and fishes are not well understood. We evaluated relationships between water chemistry and fish communities within channelized headwater streams of Cedar Creek, Indiana, and Upper Big Walnut Creek, Ohio. Measurements of water chemistry, hydrology, and fishes have been collected from 20 sites beginning in 2005. Multiple regression analyses indicated that the relationships between water chemistry and fish communities were weak, but significant (P < 0·05). Fish communities exhibited negative relationships with ammonium and nitrate plus nitrite and positive relationships with dissolved oxygen, pH, and metolachlor. The strongest observed relationships occurred within those regression models that included a combination of nutrients, herbicides, and physicochemical variables. Multiple regression analyses also indicated that five water chemistry variables exhibited significant relationships (P < 0·05) with hydrology. Our results suggest that if water chemistry is the focus of a conservation plan, then the most effective conservation practices may be those that have a combined influence on nutrients, herbicides, and physicochemical variables. Additionally, the use of a combination of conservation practices to address physical habitat and water chemistry degradation is most likely to provide the greatest benefits for fish communities within channelized headwater streams. Copyright © 2009 John Wiley & Sons, Ltd.
Supercritical Hydrothermal Synthesis of Silicon‐Functional Metal and Metal Oxide Nanoparticles
Authors: Ogawa Takuya , Furudate Manabu , Oshima Yoshito 
Published: March 2009

AbstractA supercritical hydrothermal reaction was applied to synthesise silicon‐functional metal and metal oxide nanoparticles. The Si‐functionalised nanoparticles were formed by the hydrothermal reaction of metal salts and subsequent surface modification of the resultant particles by organofunctional silicon compounds. The metal salts studied were copper nitrate and acetate. Si‐functionalised copper nanoparticles with a size below 10 nm were formed when an epoxy‐functional silicone compound was used. The compositions, shapes and sizes of the resultant particles proved to be affected by the structures of the silicon compounds. As for the properties, the resultant particles were hydrophobic while nonfunctional particles were hydrophilic. This methodology can be potentially applied to the synthesis of Si‐based nanohybrid materials in which such surface‐modified nanoparticles are well dispersed in a polysiloxane matrix. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of the C11–C23 Fragment of the Potent Antitumor Agent Dictyostatin (Eur. J. Org. Chem. 10/2009)
Authors: Dias Luiz C. , Lima Dimas J. P. , Gonçalves Caroline C. S. , Andricopulo Adriano D. 
Published: March 2009

AbstractThe cover picture shows the intermolecular interactions between the marine‐derived dictyostatin and the β‐tubulin binding site, as well as some important molecular fragments of the required 15‐step sequence to produce the C11–C23 fragment (highlighted in blue) of dictyostatin in good overall yield. Dictyostatin, an unsaturated 22‐membered macrolactone containing 11 stereocenters, a (Z)‐alkene, and two diene systems, exhibits potent antitumoral activity as a consequence of its reversible and specific binding to the β‐tubulin cavity and modulation of microtubule function. Details of the synthesis and characterization of the C11–C23 fragment are reported in the Short Communication by L. C. Dias et al. on p. 1491 ff. The authors thank Ms. Lívia B. Salum for her contribution to the design of the cover picture.
Do schema processes mediate links between parenting and eating pathology?
Authors: Sheffield Alex , Waller Glenn , Emanuelli Francesca , Murray James , Meyer Caroline 
Published: March 2009

AbstractObjectiveAdverse parenting experiences are commonly linked to eating pathology. A schema‐based model of the development and maintenance of eating pathology proposes that one of the potential mediators of the link between parenting and eating pathology might be the development of schema maintenance processes—mechanisms that operate to help the individual avoid intolerable emotions.MethodTo test this hypothesis, 353 female students and 124 female eating‐disordered clients were recruited. They completed a measure of perceived parenting experiences as related to schema development (Young Parenting Inventory‐Revised (YPI‐R)), two measures of schema processes (Young Compensatory Inventory; Young–Rygh Avoidance Inventory (YRAI)) and a measure of eating pathology (Eating Disorders Inventory (EDI)).ResultsIn support of the hypothesis, certain schema processes did mediate the relationship between specific perceptions of parenting and particular forms of eating pathology, although these were different for the clinical and non‐clinical samples.DiscussionIn those patients where parenting is implicated in the development of eating pathology, treatment might need to target the cognitive processes that can explain this link. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.
Forest blowdown impacts of Hurricane Rita on fluvial systems
Authors: Phillips Jonathan D. , Park Lisa 
Published: March 2009

AbstractHurricane Rita, a category three hurricane which struck the US Gulf Coast near the Louisiana/Texas border in 2005, did not cause extensive river flooding. However, the storm did result in extensive forest damage and tree blowdown. High‐resolution post‐storm aerial photography allowed an inventory of river bank trees blown into the channel along the lower Neches and Sabine Rivers of southeast Texas and southwest Louisiana. Blowdowns directly into the channel averaged 9·3 per kilometer in the lower Neches and 13·4 in the lower Sabine River, but individual reaches 10 to 20 km in length had rates of 20 to 44 blowdowns per kilometer. Though large woody debris (LWD) from Hurricane Rita was widely perceived to reduce the capacity of channels to convey flow, no strong evidence exists of increased flooding or significant reductions in channel conveyance capacity due to LWD from the storm. The Rita blowdown inventory also allowed an assessment of whether similar blowdown events could account for major logjams and rafts on Red, Atchafalaya, and Colorado Rivers on the Gulf Coast, which blocked navigation from tens to hundreds of kilometers in the 1800s. Results from Hurricane Rita suggest that blowdown into channels alone – not withstanding blowdown elsewhere in the river valleys or along tributaries which could deliver LWD to the river – is sufficient to completely block channels, thus providing a plausible mechanism for initiating such (pre)historic log rafts. Copyright © 2009 John Wiley & Sons, Ltd.
Functional and effective connectivity of visuomotor control systems demonstrated using generalized partial least squares and structural equation modeling
Authors: Lin Fa‐Hsuan , Agnew John A. , Belliveau John W. , Zeffiro Thomas A. 
Published: March 2009

AbstractTasks employing parametric variation in movement rate are associated with predictable modulations in neural activity and provide a convenient context for developing new techniques for system identification. Using a multistage approach, we explored the functional and effective connectivity of a visuomotor control system by combining generalized partial least squares (gPLS) with subsequent structural equation modeling (SEM) to reveal the relationships between neural activity and finger movement rate in an experiment involving visually paced left or right thumb flexion. The gPLS in the first analysis stage automatically identified spatially distributed sets of BOLD‐contrast signal changes using linear combinations of sigmoidal basis functions parameterized by kinematic variables. The gPLS provided superior sensitivity in detecting task‐related functional activity patterns via a step‐wise comparison with both classical linear modeling and behavior correlation analysis. These activity patterns were used in the second analysis stage, which employed SEM to characterize the areal regional interactions. The hybrid gPLS/SEM procedure allowed modeling of complex regional interactions in a network including primary motor cortex, premotor areas, cerebellum, thalamus, and basal ganglia, with differential activity modulations with respect to rate observed in the corticocerebellar and corticostriate subsystems. This effective connectivity analysis of visuomotor control circuits showed that both the left and right corticocerebellar and corticostriate circuits exhibited movement rate‐related modulation. The identification of the functional connectivity among regions participating particular classes of behavior using gPLS, followed by the estimation of the effective connectivity using SEM is an efficient means to characterize the neural interactions underlying variations in sensorimotor behavior. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Functional abnormalities in the dyslexic brain: A quantitative meta‐analysis of neuroimaging studies
Authors: Richlan Fabio , Kronbichler Martin , Wimmer Heinz 
Published: March 2009

AbstractThis study used foci from 17 original studies on functional abnormalities in the dyslexic brain to identify brain regions with consistent under‐ or overactivation. Studies were included when reading or reading‐related tasks were performed on visually presented stimuli and when results reported coordinates for group differences. Activation likelihood estimation (ALE) was used for quantification. Maxima of underactivation were found in inferior parietal, superior temporal, middle and inferior temporal, and fusiform regions of the left hemisphere. With respect to left frontal abnormalities, we found underactivation in the inferior frontal gyrus to be accompanied by overactivation in the primary motor cortex and the anterior insula. Tentative functional interpretations of the activation abnormalities are provided. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Functional interactions guiding adaptive processing of behavioral significance
Authors: Diekhof Esther Kristina , Falkai Peter , Gruber Oliver 
Published: March 2009

AbstractThe ability to quickly decide on the nature of unexpected environmental changes is vital for adaptive behavior. Converging evidence suggests that the orbitofrontal cortex plays an important role in the rapid assignment of motivational significance and goal relevance to environmental stimuli. However, its putative role as a central part of a network involved in the prioritization of attentional selection, particulary when significant environmental changes occur unexpectedly or outside of attentional focus, remains to be established. Therefore, we used functional magnetic resonance imaging with a subsequent psychophysiological interaction analysis to reveal the functional connectivity of the right posterior orbitofrontal cortex (pOFC) in a context, in which subjects had to adjust goal‐directed behavior to behaviorally relevant events presented outside of the current attentional focus. As expected, an increased functional interaction between pOFC and regions involved in the modulation of selective attention (pulvinar nucleus and inferior parietal lobule) and processing of “bottom‐up” salience (substantia nigra) could be observed when unattended, but significant changes were relevant for behavior. Moreover, a positive correlation between level of accuracy and an increased functional connectivity between pOFC and extrastriate cortex suggested that a motivationally‐triggered signal from pOFC may have increased visual processing of the relevant but currently unattended stimulus attribute. These data provide evidence that the interplay between the pOFC and these regions underlies a mechanism by which organisms rapidly achieve voluntary control of attentional resources to deal with behaviorally significant changes that occur outside of current attentional focus. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Estimating the effectiveness of a rotational irrigation delivery system: A case study from Pakistan
Authors: Zardari Noor ul Hassan , Cordery Ian 
Published: March 2009

AbstractIn this study, basic principles of the rotational irrigation water delivery system of Pakistan (i.e. the warabandi) and the performance of the warabandi system under current socio‐economic conditions have been investigated from a farmers' survey completed from 154 farmers located on five watercourses of the lower Indus River Basin. It is shown that irrigation water allocation based on very limited criteria does not give much incentive to the farmers for improving agricultural income. Also, the survey results suggest that the productivity of limited irrigation water could not be maximized under the warabandi system. We have therefore suggested the basic principles of the warabandi system should be revised by making them suitable for the current socio‐economic conditions. We propose that the existence or non‐existence of fresh groundwater resources along with other critical variables should be taken into consideration when making canal water allocation decisions. A framework to allow distribution equity and efficiency in water allocations – such as considering the gross area of a tertiary canal, sensitivity of crop growth stage to water shortage, crop value, bias of allocation towards most water use efficient areas, the potential losses from water deficiency, etc. – should be developed as a tool to improve water productivity for Pakistan and for individual farmers. The contribution of groundwater in the farmers' income from agriculture and the economic value of irrigation water have also been estimated. Copyright © 2009 John Wiley & Sons, Ltd.
Head ditch hydraulics and the variability of inflows to irrigation furrows
Authors: Smith R. J. , Gillies M. H. 
Published: March 2009

AbstractThe spatial variability and temporal variation of furrow inflows have a major impact on the performance of furrow irrigation, as indicated by the usual measures of application efficiency and uniformity. They also cause difficulties in determining the soil infiltration characteristic through inverse solution techniques and in selecting preferred values for the operational variables of flow rate and time to cut‐off to give maximum performance at the field scale.In this paper a steady spatially varied flow analysis is performed to predict the steady water surface profiles in a typical head ditch and the subsequent spatial variability of the furrow inflows, for both pipe or siphon and sill or bankless‐type water application systems. The resulting patterns were very similar to those seen in the spatially varied pipe flow in gated pipe, with depths and outflows increasing toward the downstream end of the channel. It is shown that it is feasible to design head ditches to minimise the variability in outflows. An unsteady analysis of the same head ditch illustrated the variation of outflows with time caused by the time taken to fill the channel. Copyright © 2009 John Wiley & Sons, Ltd.
An AC electrokinetic method for enhanced detection of DNA nanoparticles
Authors: Krishnan Rajaram , Heller Michael J. 
Published: March 2009

AbstractIn biomedical research and diagnostics it is a challenge to isolate and detect low levels of nanoparticles and nanoscale biomarkers in blood and other biological samples. While highly sensitive epifluorescent microscope systems are available for ultra low level detection, the isolation of the specific entities from large sample volumes is often the bigger limitation. AC electrokinetic techniques like dielectrophoresis (DEP) offer an attractive mechanism for specifically concentrating nanoparticles into microscopic locations. Unfortunately, DEP requires significant sample dilution thus making the technology unsuitable for biological applications. Using a microelectrode array device, special conditions have been found for the separation of hmw‐DNA and nanoparticles under high conductance (ionic strength) conditions. At AC frequencies in the 3000–10 000 Hz range, 10 μm microspheres and human T lymphocytes can be isolated into the DEP low field regions, while hmw‐DNA and nanoparticles can be concentrated into microscopic high field regions for subsequent detection using an epifluorescent system. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Compartmentalization of epidermal growth factor receptor in liver plasma membrane
Authors: Wang Ye , Posner Barry I. , Balbis Alejandro 
Published: March 2009

AbstractWe have investigated epidermal growth factor (EGF)‐induced compartmentalization and activation of the EGF receptor (EGFR) in rat liver plasma membrane (PM) raft subfractions prepared by three different biochemical methods previously developed to characterize the composition of membrane rafts. Only detergent‐resistant membranes (DRMs) possessed the basic characteristics attributed to membrane rafts. Following the administration of a low dose of EGF (1 µg/100 g BW) the content of EGFR in PM–DRMs did not change significantly; whereas after a higher dose of EGF (5 µg/100 g BW) we observed a rapid and marked disappearance of EGFR (around 80%) from both PM and DRM fractions. Interestingly, following the administration of either a low or high dose of EGF, the pool of EGFR in the PM–DRM fraction became highly Tyr‐phosphorylated. In accordance with the higher level of EGFR Tyr‐Phosphorylation, EGF induced an augmented recruitment of Grb2 and Shc proteins to PM–DRMs compared with whole PM. Furthermore neither high nor low doses of EGF affected the caveolin content in DRMs and PM. These observations suggest that EGFR located in DRMs are competent for signaling, and non‐caveolae PM rafts are involved in the compartmentalization and internalization of the EGFR. J. Cell. Biochem. 107: 96–103, 2009. © 2009 Wiley‐Liss, Inc.
The perinucleolar compartment
Authors: Pollock Callie , Huang Sui 
Published: March 2009

AbstractThe perinucleolar compartment (PNC) is a distinct nuclear body that localizes to the nucleolar periphery. The PNC is predominantly found in cancer cells, and recent evidence suggests that PNC prevalence can be a pan‐cancer marker for tumors of solid tissue origin. The PNC is a heritable structure enriched with newly transcribed pol III RNAs and RNA‐binding proteins, which exchange rapidly with the surrounding nucleoplasm. The structural integrity of the PNC is dependent upon the continuous transcription of pol III RNA and an intact DNA structure. Although the complete structure and function of the PNC remains to be resolved, much progress has been made in the characterization of the PNC in recent years. Here we summarize our current understanding of the dynamics, structure and function of the PNC. J. Cell. Biochem. 107: 189–193, 2009. © 2009 Wiley‐Liss, Inc.