bluuebunny/crossref_metadata_2025 huggingface dataset:
A Systematic Analysis of Human Papillomavirus (HPV) E6 PDZ Substrates Identifies MAGI-1 as a Major Target of HPV Type 16 (HPV-16) and HPV-18 Whose Loss Accompanies Disruption of Tight Junctions
Authors: Kranjec Christian , Banks Lawrence
Published: December 2010

The E6 proteins from high-risk, cancer-causing types of human papillomavirus (HPV) are characterized by the presence of a PDZ (PSD95/Dlg/ZO-1) binding motif in their extreme carboxy termini, through which they interact with a number of cellular PDZ domain-containing substrates. In order to ascertain how many of these are degraded by E6in vivo, we performed an extensive analysis of the effects of E6 ablation on the expression levels of a number of previously reported E6 PDZ substrates. Using HPV type 16 (HPV-16)-positive CaSKi cells and HPV-18-positive HeLa cells, we have found that MAGI-1 is a major degradation target of both HPV-16 and HPV-18 E6. In contrast, hDlg, hScrib, PTPN3, TIP2, FAP1, and PSD95 all exhibit various degrees of susceptibility to E6-induced degradation, and a high degree of HPV type specificity is observed for certain substrates. We also show that E6 preferentially targets MAGI-1 within the nucleus and at membrane sites. One of the direct consequences of MAGI-1 degradation is a loss of tight-junction integrity, as determined by mislocalization of the tight-junction protein ZO-1. Ablation of E6 expression restores tight junctions, and this restoration is dependent on the presence of MAGI-1. These results demonstrate that oncogenic HPV E6 proteins disrupt cellular tight junctions through the degradation of MAGI-1, and they provide further evidence of how the PDZ binding potential of E6 can contribute to HPV-induced malignancy.
Impact of Valency of a Glycoprotein B-Specific Monoclonal Antibody on Neutralization of Herpes Simplex Virus
Authors: Krawczyk Adalbert , Krauss Jürgen , Eis-Hübinger Anna M. , Däumer Martin P. , Schwarzenbacher Robert , Dittmer Ulf , Schneweis Karl E. , Jäger Dirk , Roggendorf Michael , Arndt Michaela A. E.
Published: December 2010

Herpes simplex virus (HSV) glycoprotein B (gB) is an integral part of the multicomponent fusion system required for virus entry and cell-cell fusion. Here we investigated the mechanism of viral neutralization by the monoclonal antibody (MAb) 2c, which specifically recognizes the gB of HSV type 1 (HSV-1) and HSV-2. Binding of MAb 2c to a type-common discontinuous epitope of gB resulted in highly efficient neutralization of HSV at the postbinding/prefusion stage and completely abrogated the viral cell-to-cell spreadin vitro. Mapping of the antigenic site recognized by MAb 2c to the recently solved crystal structure of the HSV-1 gB ectodomain revealed that its discontinuous epitope is only partially accessible within the observed multidomain trimer conformation of gB, likely representing its postfusion conformation. To investigate how MAb 2c may interact with gB during membrane fusion, we characterized the properties of monovalent (Fab and scFv) and bivalent [IgG and F(ab′)2] derivatives of MAb 2c. Our data show that the neutralization capacity of MAb 2c is dependent on cross-linkage of gB trimers. As a result, only bivalent derivatives of MAb 2c exhibited high neutralizing activityin vitro. Notably, bivalent MAb 2c not only was capable of preventing mucocutaneous disease in severely immunodeficient NOD/SCID mice upon vaginal HSV-1 challenge but also protected animals even with neuronal HSV infection. We also report for the first time that an anti-gB specific monoclonal antibody prevents HSV-1-induced encephalitis entirely independently from complement activation, antibody-dependent cellular cytotoxicity, and cellular immunity. This indicates the potential for further development of MAb 2c as an anti-HSV drug.
INFLUENCE OF POROSITY OF MATERIALS ON REDISTRIBUTION OF DOPANT DURING MANUFACTURING OF DIFFUSION-JUNCTION RECTIFIERS IN SEMICONDUCTOR HETEROSTRUCTURES
Authors: PANKRATOV E. L.
Published: December 2010

In this paper, influence of porosity of epitaxial layer on the depth of p–n junction in semiconductor heterostructures and the homogeneity of dopant distribution in enriched areas has been analyzed. Some conditions on technological process and materials of heterostructures to obtain the maximal compromise between the above effects have been formulated.
Cu0.5K0.25Tl0.25Ba2Ca3Cu4O12-δ SUPERCONDUCTOR AND ITS DIELECTRIC PROPERTIES
Authors: YOUNIS ADNAN , KHAN NAWAZISH ALI
Published: December 2010

Cu 0.5 K 0.25 Tl 0.25 Ba 2 Ca 3 Cu 4 O 12-δ superconductor samples were synthesized and their dielectric properties were measured between 80 K and 290 K by means of capacitance (C) and conductance (G) measurements with the test frequency (f) in the range of 10 KHz to 4 MHz. A negative capacitance (NC) occurrence was observed, which most likely arose from the superior Fermi level of ceramic superconductor samples than metal electrodes. Also the NC may be due to the space charge situated at the multiple insulator–superconductor interfaces (grain boundaries) in the materials. The negative dielectric constant (ε′) and loss factor ( tan δ) show strong dispersion at low frequencies. The lower thermal agitation at 80 K may boost the polarizability and hence the dielectric constants (ε′ and ε″).
Heuristic Decision Making
Authors: Gigerenzer Gerd , Gaissmaier Wolfgang
Published: December 2010

As reflected in the amount of controversy, few areas in psychology have undergone such dramatic conceptual changes in the past decade as the emerging science of heuristics. Heuristics are efficient cognitive processes, conscious or unconscious, that ignore part of the information. Because using heuristics saves effort, the classical view has been that heuristic decisions imply greater errors than do “rational” decisions as defined by logic or statistical models. However, for many decisions, the assumptions of rational models are not met, and it is an empirical rather than an a priori issue how well cognitive heuristics function in an uncertain world. To answer both the descriptive question (“Which heuristics do people use in which situations?”) and the prescriptive question (“When should people rely on a given heuristic rather than a complex strategy to make better judgments?”), formal models are indispensable. We review research that tests formal models of heuristic inference, including in business organizations, health care, and legal institutions. This research indicates that (a) individuals and organizations often rely on simple heuristics in an adaptive way, and (b) ignoring part of the information can lead to more accurate judgments than weighting and adding all information, for instance for low predictability and small samples. The big future challenge is to develop a systematic theory of the building blocks of heuristics as well as the core capacities and environmental structures these exploit.
Early Care, Education, and Child Development
Authors: Phillips Deborah A. , Lowenstein Amy E.
Published: December 2010

Children growing up in the United States today typically spend a substantial portion of their early childhood years in early care and education (ECE) settings. These settings are thus an essential element of any effort to understand the ecology of early development. Research aimed at identifying the short- and long-term impacts of ECE experiences has a long history, the results of which now point to three key conclusions. (a) Although parents are the most important influence on children's development, ECE experiences have both short- and long-term impacts on a wide range of developmental outcomes that are best understood in interaction with family effects. (b) The quality of adult-child interactions in ECE settings is the most potent source of variation in child outcomes, although the amount of exposure to these settings also plays a role, perhaps especially with regard to social-emotional development. (c) Some children, notably those growing up in poverty, appear to be more vulnerable to variation in the quality of ECE settings than do other children. The frontiers of ECE research are addressing individual differences in children's responses to child care and approaching these settings both as sites for intervention research and as part of a wider web of important settings in young children's lives.
Psychological Perspectives on Pathways Linking Socioeconomic Status and Physical Health
Authors: Matthews Karen A. , Gallo Linda C.
Published: December 2010

Low socioeconomic status (SES) is a reliable correlate of poor physical health. Rather than treat SES as a covariate, health psychology has increasingly focused on the psychobiological pathways that inform understanding why SES is related to physical health. This review assesses the status of research that has examined stress and its associated distress, and social and personal resources as pathways. It highlights work on biomarkers and biological pathways related to SES that can serve as intermediate outcomes in future studies. Recent emphasis on the accumulation of psychobiological risks across the life course is summarized and represents an important direction for future research. Studies that test pathways from SES to candidate psychosocial pathways to health outcomes are few in number but promising. Future research should test integrated models rather than taking piecemeal approaches to evidence. Much work remains to be done, but the questions are of great health significance.
Peer Contagion in Child and Adolescent Social and Emotional Development
Authors: Dishion Thomas J. , Tipsord Jessica M.
Published: December 2010

In this article, we examine the construct of peer contagion in childhood and adolescence and review studies of child and adolescent development that have identified peer contagion influences. Evidence suggests that children's interactions with peers are tied to increases in aggression in early and middle childhood and amplification of problem behaviors such as drug use, delinquency, and violence in early to late adolescence. Deviancy training is one mechanism that accounts for peer contagion effects on problem behaviors from age 5 through adolescence. In addition, we discuss peer contagion relevant to depression in adolescence, and corumination as an interactive process that may account for these effects. Social network analyses suggest that peer contagion underlies the influence of friendship on obesity, unhealthy body images, and expectations. Literature is reviewed that suggests how peer contagion effects can undermine the goals of public education from elementary school through college and impair the goals of juvenile corrections systems. In particular, programs that “select” adolescents at risk for aggregated preventive interventions are particularly vulnerable to peer contagion effects. It appears that a history of peer rejection is a vulnerability factor for influence by peers, and adult monitoring, supervision, positive parenting, structure, and self-regulation serve as protective factors.
Attitudes and Attitude Change
Authors: Bohner Gerd , Dickel Nina
Published: December 2010

Attitudes and attitude change remain core topics of contemporary social psychology. This selective review emphasizes work published from 2005 to 2009. It addresses constructionist and stable-entity conceptualizations of attitude, the distinction between implicit and explicit measures of attitude, and implications of the foregoing for attitude change. Associative and propositional processes in attitude change are considered at a general level and in relation to evaluative conditioning. The role of bodily states and physical perceptions in attitude change is reviewed. This is followed by an integrative perspective on processing models of persuasion and the consideration of meta-cognitions in persuasion. Finally, effects of attitudes on information processing, social memory, and behavior are highlighted. Core themes cutting across the areas reviewed are attempts at integrative theorizing bringing together formerly disparate phenomena and viewpoints.
Long-Term Impact of Prevention Programs to Promote Effective Parenting: Lasting Effects but Uncertain Processes
Authors: Sandler Irwin N. , Schoenfelder Erin N. , Wolchik Sharlene A. , MacKinnon David P.
Published: December 2010

This article reviews findings from 46 randomized experimental trials of preventive parenting interventions. The findings of these trials provide evidence of effects to prevent a wide range of problem outcomes and to promote competencies from one to 20 years later. However, there is a paucity of evidence concerning the processes that account for program effects. Three alternative pathways are proposed as a framework for future research on the long-term effects of preventive parenting programs: (a) through program effects on parenting skills, perceptions of parental efficacy, and reduction in barriers to effective parenting; (b) through program-induced reductions in short-term problems of youth that persist over time, improvements in youth adaptation to stress, and improvements in youth belief systems concerning the self and their relationships with others; and (c) through effects on contexts in which youth become involved and on youth-environment transactions.
Speech Perception
Authors: Samuel Arthur G.
Published: December 2010

Speech perception has been studied for over a half century. During this time, one subfield has examined perception of phonetic information independent of its contribution to word recognition. Theories in this subfield include ones that are based on auditory properties of speech, the motor commands involved in speech production, and a Direct Realist approach that emphasizes the structure of the information reaching the perceiver. A second subfield has been less concerned with the acoustic-phonetic properties of speech and more concerned with how words are segmented and recognized. In this subfield, there has been a focus on the nature of communication among different levels of analysis (e.g., phonetic and lexical). In recent years, there has been a growing appreciation of the need to understand how the perceptual system dynamically changes in order to allow listeners to successfully process the variable input and new words that they constantly encounter.
Psychological Wisdom Research: Commonalities and Differences in a Growing Field
Authors: Staudinger Ursula M. , Glück Judith
Published: December 2010

Wisdom represents a fruitful topic for psychological investigations for at least two reasons. First, the study of wisdom emphasizes the search for the continued optimization and the further cultural evolution of the human condition. Second, it exemplifies the collaboration of cognitive, emotional, and motivational processes. The growth and scope of psychological wisdom research over the past few decades demonstrate that it is possible to investigate this complex construct with empirical rigor. Since the 1970s, five main areas have been established: lay definitions of wisdom, conceptualizing and measuring wisdom, understanding the development of wisdom, investigating the plasticity of wisdom, and applying psychological knowledge about wisdom in life contexts.
Anion exchanger 1b, but not sodium-bicarbonate cotransporter 1b, plays a role in transport functions of zebrafish H+-ATPase-rich cells
Authors: Lee Yi-Chun , Yan Jia-Jiun , Cruz Shelly A. , Horng Jiun-Lin , Hwang Pung-Pung
Published: December 2010

Similar to mammalian proximal tubular cells, H+-ATPase rich (HR) cells in zebrafish skin and gills are also responsible for Na+ uptake and acid secretion functions. However, the basolateral transport pathways in HR cells are still unclear. In the present study, we tested the hypothesis if there are specific slc4 members involved in basolateral ion transport pathways in HR cells. Fourteen isoforms were identified in the zebrafish(z) slc4 family, and the full-length cDNAs of two novel isoforms, z slc4a1b (anion exchanger, zAE1b) and z slc4a4b (Na+/HCO3− cotransporter, zNBCe1b), were sequenced. mRNA signals of z slc4a1b and z slc4a4b were mainly detected in certain groups of ionocytes in zebrafish skin/gills. Further double immunocytochemistry or in situ hybridization demonstrated that zAE1b, but not zNBCe1b, was localized to basolateral membranes of HR cells. Acclimation to low-Na+ or acidic environments stimulated the mRNA expression of z slc4a1b in zebrafish gills, and loss-of-function of zslc4a1b with specific morpholinos caused significant decreases in both the whole body Na+ content and the skin H+ activity in the morphants. On the basis of these results, it was concluded that zAE1b, but not zNBCe1b, is involved in the basolateral transport pathways in Na+ uptake/acid secretion mechanisms in zebrafish HR cells.
Placenta growth factor expression is regulated by hydrogen peroxide in vascular smooth muscle cells
Authors: Shaw Jennifer H. , Xiang Lingjin , Shah Anu , Yin Wei , Lloyd Pamela G.
Published: December 2010

When supply arteries become occluded, blood is diverted through preexisting collateral vessels. Shear stress arising from this increase in blood flow provides the initial physiological stimulus for expansion of the collateral circulation, a process termed arteriogenesis. Endothelial cells (EC) respond to increased shear stress by releasing a variety of mediators that can act on underlying smooth muscle cells (SMC). Placenta growth factor (PLGF) is known to mediate certain aspects of arteriogenesis, such as recruitment of monocytes to the vessel wall. Therefore, we tested whether SMC PLGF expression is influenced by mediators released by EC. We used A10 SMC cultured with medium that had been conditioned by EOMA EC for 4 days as a model. We found that EC-conditioned medium is able to upregulate PLGF gene expression in A10 SMC. Further experiments identified hydrogen peroxide (H2O2) as a key mediator of this response. We confirmed the physiological relevance of this mechanism in primary human coronary artery SMCs by demonstrating that exogenous H2O2 specifically upregulates PLGF gene and protein expression. We also demonstrated that the physiological stimulus of shear stress raises endogenous H2O2 levels in media into the range found to increase PLGF expression. In this study, we demonstrate that EC-released H2O2 acts as a positive regulator of PLGF gene and protein expression in vascular SMC. To our knowledge, this is the first study to describe H2O2 as a regulator of PLGF expression and therefore an upstream mediator of PLGF-driven arteriogenesis.
Increased matriptase zymogen activation in inflammatory skin disorders
Authors: Chen Cheng-Jueng , Wu Bai-Yao , Tsao Pai-In , Chen Chi-Yung , Wu Mei-Hsuan , Chan Yee Lam E. , Lee Herng-Sheng , Johnson Michael D. , Eckert Richard L. , Chen Ya-Wen , Chou Fengpai , Wang Jehng-Kang , Lin Chen-Yong
Published: December 2010

Matriptase, a type 2 transmembrane serine protease, and its inhibitor hepatocyte growth factor activator inhibitor (HAI)-1 are required for normal epidermal barrier function, and matriptase activity is tightly regulated during this process. We therefore hypothesized that this protease system might be deregulated in skin disease. To test this, we examined the level and activation state of matriptase in examples of 23 human skin disorders. We first examined matriptase and HAI-1 protein distribution in normal epidermis. Matriptase was detected at high levels at cell-cell junctions in the basal layer and spinous layers but was present at minimal levels in the granular layer. HAI-1 was distributed in a similar pattern, except that high-level expression was retained in the granular layer. This pattern of expression was retained in most skin disorders. We next examined the distribution of activated matriptase. Although activated matriptase is not detected in normal epidermis, a dramatic increase is seen in keratinocytes at the site of inflammation in 16 different skin diseases. To gain further evidence that activation is associated with inflammatory stimuli, we challenged HaCaT cells with acidic pH or H2O2 and observed matriptase activation. These findings suggest that inflammation-associated reactive oxygen species and tissue acidity may enhance matriptase activation in some skin diseases.
Biophysical properties of normal and diseased renal glomeruli
Authors: Wyss Hans M. , Henderson Joel M. , Byfield Fitzroy J. , Bruggeman Leslie A. , Ding Yaxian , Huang Chunfa , Suh Jung Hee , Franke Thomas , Mele Elisa , Pollak Martin R. , Miner Jeffrey H. , Janmey Paul A. , Weitz David A. , Miller R. Tyler
Published: December 2010

The mechanical properties of tissues and cells including renal glomeruli are important determinants of their differentiated state, function, and responses to injury but are not well characterized or understood. Understanding glomerular mechanics is important for understanding renal diseases attributable to abnormal expression or assembly of structural proteins and abnormal hemodynamics. We use atomic force microscopy (AFM) and a new technique, capillary micromechanics, to measure the elastic properties of rat glomeruli. The Young's modulus of glomeruli was 2,500 Pa, and it was reduced to 1,100 Pa by cytochalasin and latunculin, and to 1,400 Pa by blebbistatin. Cytochalasin or latrunculin reduced the F/G actin ratios of glomeruli but did not disrupt their architecture. To assess glomerular biomechanics in disease, we measured the Young's moduli of glomeruli from two mouse models of primary glomerular disease, Col4a3−/− mice (Alport model) and Tg26HIV/nl mice (HIV-associated nephropathy model), at stages where glomerular injury was minimal by histopathology. Col4a3−/− mice express abnormal glomerular basement membrane proteins, and Tg26HIV/nl mouse podocytes have multiple abnormalities in morphology, adhesion, and cytoskeletal structure. In both models, the Young's modulus of the glomeruli was reduced by 30%. We find that glomeruli have specific and quantifiable biomechanical properties that are dependent on the state of the actin cytoskeleton and nonmuscle myosins. These properties may be altered early in disease and represent an important early component of disease. This increased deformability of glomeruli could directly contribute to disease by permitting increased distension with hemodynamic force or represent a mechanically inhospitable environment for glomerular cells.
Characterization of squamous esophageal cells resistant to bile acids at acidic pH: implication for Barrett's esophagus pathogenesis
Authors: Goldman Aaron , Chen Hwu Dau Rw , Roesly Heather B. , Hill Kimberly A. , Tome Margaret E. , Dvorak Bohuslav , Bernstein Harris , Dvorak Katerina
Published: December 2010

Barrett's esophagus (BE) is a premalignant condition, where normal squamous epithelium is replaced by intestinal epithelium. BE is associated with an increased risk of developing esophageal adenocarcinoma (EAC). However, the BE cell of origin is not clear. We hypothesize that BE tissue originates from esophageal squamous cells, which can differentiate to columnar cells as a result of repeated exposure to gastric acid and bile acids, two components of refluxate implicated in BE pathology. To test this hypothesis, we repeatedly exposed squamous esophageal HET1A cells to 0.2 mM bile acid (BA) cocktail at pH 5.5 and developed an HET1AR-resistant cell line. These cells are able to survive and proliferate after repeated 2-h treatments with BA at pH 5.5. HET1AR cells are resistant to acidification and express markers of columnar differentiation, villin, CDX2, and cytokeratin 8/18. HET1AR cells have increased amounts of reactive oxygen species, concomitant with a decreased level and activity of manganese superoxide dismutase compared with parental cells. Furthermore, HET1AR cells express proteins and activate signaling pathways associated with inflammation, cell survival, and tumorigenesis that are thought to contribute to BE and EAC development. These include STAT3, NF-κB, epidermal growth factor receptor (EGFR), cyclooxygenase-2, interleukin-6, phosphorylated mammalian target of rapamycin (p-mTOR), and Mcl-1. The expression of prosurvival and inflammatory proteins and resistance to cell death could be partially modified by inhibition of STAT3 signaling. In summary, our study shows that long-term exposure of squamous cells to BA at acidic pH causes the cells to display the same characteristics and markers as BE.
Functional analysis of the glucose transporters-1α, -6, and -13.1 expressed by zebrafish epithelial cells
Authors: Tseng Yung-Che , Lee Jay-Ron , Lee Shyh-Jye , Hwang Pung-Pung
Published: December 2010

The hexose supply and subsequent metabolism are crucial for the operations of the iono- and osmoregulatory mechanisms in fish, but how hexose is transported and supplied to cells of the ionoregulatory epithelia is unknown. Three zebrafish glucose transporters (zGLUTs), zGLUT1a, -13.1, and -6, were previously found to respectively be expressed by ionocytes (Na+-K+-ATPase-rich, Na+-Cl−cotransporter-expressing, and H+-ATPase-rich cells) and adjacent energy-depositing cells [glycogen-rich (GR) cells] in zebrafish skin and gills ( 32 ). The present study aimed to test if the transport kinetics of these three zGLUTs differ, and if the transport functional differences are of physiological relevance to the respective functions of epithelial cells. The three zGLUTs expressed by Xenopus laevis oocytes revealed different d-glucose transport kinetics; zGLUT13.1 showed the lowest Michaelis constant ( Km), whereas zGLUT6 had the highest Kmand maximal velocity. In morpholino injection experiments, translational knockdown of zGLUT1a and -13.1, respectively, impaired Cl−/Ca2+and Na+/Ca2+uptake, but loss-of-function of zGLUT6 did not cause a significant effect on ion uptake functions in zebrafish. Based on these results, zGLUT1a and -13.1 appear to be superior to zGLUT6 in competing for glucose under a situation of low blood glucose due to extensive energy consumption, whereas, in a high blood glucose situation, zGLUT6 is able to absorb the excess glucose for energy deposition. The timely and sufficient supply of energy to ionocytes so that they can carry out ion regulation is definitely a more important event than storing energy in GR cells, particularly when acute environmental change disturbs the ion balance in zebrafish.
Role of spinal V1a receptors in regulation of arterial pressure during acute and chronic osmotic stress
Authors: Veitenheimer Britta , Osborn John W.
Published: December 2010

Vasopressinergic neurons in the paraventricular nucleus project to areas in the spinal cord from which sympathetic nerves originate. This pathway is hypothesized to be involved in the regulation of mean arterial pressure (MAP), particularly under various conditions of osmotic stress. Several studies measuring sympathetic nerve activity support this hypothesis. However, the evidence that spinal vasopressin influences MAP under physiological or pathophysiological conditions in conscious animals is limited. The purpose of this study was to investigate, in conscious rats, if the increases in MAP during acute or chronic osmotic stimuli are due to activation of spinal vasopressin (V1a) receptors. Three conditions of osmotic stress were examined: acute intravenous hypertonic saline, 24- and 48-h water deprivation, and 4 wk of DOCA-salt treatment. Rats were chronically instrumented with an indwelling catheter for intrathecal injections and a radiotelemeter to measure MAP. In normotensive rats, intrathecal vasopressin and V1a agonist increased MAP, heart rate, and motor activity; these responses were blocked by pretreatment with an intrathecal V1a receptor antagonist. However, when the intrathecal V1a antagonist was given during the three conditions of osmotic stress to investigate the role of “endogenous” vasopressin, the antagonist had no effect on MAP, heart rate, or motor activity. Contrary to the hypothesis suggested by previous studies, these findings indicate that spinal V1a receptors are not required for elevations of MAP under conditions of acute or chronic osmotic stress in conscious rats.
Potent cardiovascular effects of homologous urotensin II (UII)-related peptide and UII in unanesthetized eels after peripheral and central injections
Authors: Nobata Shigenori , Donald John A. , Balment Richard J. , Takei Yoshio
Published: December 2010

We cloned cDNAs encoding urotensin II (UII)-related peptide (URP) and UII in Japanese eel, Anguilla japonica , the former being the first such cloning in teleost fishes. Unlike the exclusive expression of UII in the urophysis, the URP gene was expressed most abundantly in the brain (medulla oblongata) followed by the urophysis. Peripheral injections of URP into eels increased blood pressure by 16.1 ± 0.8 mmHg at 0.1 nmol/kg in ventral aortic blood pressure (PVA) and with similar potency and efficacy to that of UII (relative potency of URP to UII = 0.83). URP/UII and ANG II preferentially acted on the branchial and systemic circulations, respectively, and the duration of effect was distinct among the three peptides in the order of UII (60 min) >URP (30 min) >ANG II (14 min) in PVA. Urantide, a mammalian UII receptor antagonist, inhibited the URP effect (−63.6 ± 5.2%) to a greater extent than for UII (−39.9 ± 5.0%). URP and UII constricted isolated eel branchial and systemic arteries, showing their direct actions on the vascular smooth muscle. Central injection of URP increased blood pressure by 12.3 ± 0.8 mmHg at 50 pmol/eel in PVAand with similar efficacy but less potency (relative potency = 0.47) and shorter duration compared with UII. The central actions of URP/UII were more potent on the branchial circulation than on the systemic circulation, again opposite the effects of ANG II. The similar responses to peripheral and central injections suggest that peripheral hormones may act on the brain. Taken together, in eels, URP and UII are potent cardiovascular hormones like ANG II, acting directly on the peripheral vasculature, as well as a central vasomotor site, and their actions are mediated to different degrees by the UII receptor.
Calcium sensitivity of dicarboxylate transport in cultured proximal tubule cells
Authors: Hering-Smith Kathleen S. , Schiro Faith R. , Pajor Ana M. , Hamm L. Lee
Published: December 2010

Urinary citrate is an important inhibitor of calcium nephrolithiasis and is primarily determined by proximal tubule reabsorption. The major transporter to reabsorb citrate is Na+-dicarboxylate cotransporter (NaDC1), which transports dicarboxylates, including the divalent form of citrate. We previously found that opossum kidney (OK) proximal tubule cells variably express either divalent or trivalent citrate transport, depending on extracellular calcium. The present studies were performed to delineate the mechanism of the effect of calcium on citrate and succinate transport in these cells. Transport was measured using isotope uptake assays. In some studies, NaDC1 transport was studied in Xenopus oocytes, expressing either the rabbit or opossum ortholog. In the OK cell culture model, lowering extracellular calcium increased both citrate and succinate transport by more than twofold; the effect was specific in that glucose transport was not altered. Citrate and succinate were found to reciprocally inhibit transport at low extracellular calcium (<60 μM), but not at normal calcium (1.2 mM); this mutual inhibition is consistent with dicarboxylate transport. The inhibition varied progressively at intermediate levels of extracellular calcium. In addition to changing the relative magnitude and interaction of citrate and succinate transport, decreasing calcium also increased the affinity of the transport process for various other dicarboxylates. Also, the affinity for succinate, at low concentrations of substrate, was increased by calcium removal. In contrast, in oocytes expressing NaDC1, calcium did not have a similar effect on transport, indicating that NaDC1 could not likely account for the findings in OK cells. In summary, extracellular calcium regulates constitutive citrate and succinate transport in OK proximal tubule cells, probably via a novel transport process that is not NaDC1. The calcium effect on citrate transport parallels in vivo studies that demonstrate the regulation of urinary citrate excretion with urinary calcium excretion, a process that may be important in decreasing urinary calcium stone formation.
A PPARγ agonist inhibits aldosterone-induced mesangial cell proliferation by blocking ROS-dependent EGFR intracellular signaling
Authors: Yuan Yanggang , Zhang Aihua , Huang Songming , Ding Guixia , Chen Ronghua
Published: December 2010

Mesangial cell (MC) proliferation is a key feature in the pathogenesis of a number of renal diseases. Peroxisome proliferator-activated receptor-γ (PPARγ) has attracted considerable attention for its effects on stimulating cell differentiation and on inducing cell cycle arrest. We previously showed that aldosterone (Aldo) stimulates MC proliferation via the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway, which was dependent on reactive oxygen species (ROS)-mediated epithelial growth factor receptor (EGFR) transactivation (Huang S, Zhang A, Ding G, and Chen R. Am J Physiol Renal Physiol 296: F1323–F1333, 2009). In this study, we examined whether the PPARγ agonist rosiglitazone inhibited Aldo-induced MC proliferation by modulating ROS-dependent EGFR intracellular signaling. Rosiglitazone at 1–10 μM dose dependently inhibited Aldo-induced MC proliferation of cultured mouse MCs. The inhibitory effect was blocked by the PPARγ antagonist PD-68235, indicating that the rosiglitazone effect acted through PPARγ activation. Rosiglitazone also arrested Aldo-induced cell cycle progression and suppressed expression of cyclins D1 and A. Moreover, rosiglitazone dose dependently blocked Aldo-induced ROS production, EGFR phosphorylation, and PI3K/Akt activation. These results suggest that the PPARγ agonist rosiglitazone may inhibit Aldo-induced MC proliferation directly, by affecting ROS/EGFR/PI3K/Akt signaling pathways and cell cycle-regulatory proteins. PPARγ might be a novel therapeutic target against glomerular diseases.
Impaired endothelial proliferation and mesenchymal transition contribute to vascular rarefaction following acute kidney injury
Authors: Basile David P. , Friedrich Jessica L. , Spahic Jasmina , Knipe Nicole , Mang Henry , Leonard Ellen C. , Changizi-Ashtiyani Saeed , Bacallao Robert L. , Molitoris Bruce A. , Sutton Timothy A.
Published: December 2010

Acute kidney injury induces the loss of renal microvessels, but the fate of endothelial cells and the mechanism of potential vascular endothelial growth factor (VEGF)-mediated protection is unknown. Cumulative cell proliferation was analyzed in the kidney of Sprague-Dawley rats following ischemia-reperfusion (I/R) injury by repetitive administration of BrdU (twice daily) and colocalization in endothelial cells with CD31 or cablin. Proliferating endothelial cells were undetectable for up to 2 days following I/R and accounted for only ∼1% of BrdU-positive cells after 7 days. VEGF-121 preserved vascular loss following I/R but did not affect proliferation of endothelial, perivascular cells or tubular cells. Endothelial mesenchymal transition states were identified by localizing endothelial markers (CD31, cablin, or infused tomato lectin) with the fibroblast marker S100A4. Such structures were prominent within 6 h and sustained for at least 7 days following I/R. A Tie-2-cre transgenic crossed with a yellow fluorescent protein (YFP) reporter mouse was used to trace the fate of endothelial cells and demonstrated interstititial expansion of YFP-positive cells colocalizing with S100A4 and smooth muscle actin following I/R. The interstitial expansion of YFP cells was attenuated by VEGF-121. Multiphoton imaging of transgenic mice revealed the alteration of YFP-positive vascular cells associated with blood vessels characterized by limited perfusion in vivo. Taken together, these data indicate that vascular dropout post-AKI results from endothelial phenotypic transition combined with an impaired regenerative capacity, which may contribute to progressive chronic kidney disease.
Leg vasoconstriction during head-up tilt in patients with autonomic failure is not abolished
Authors: Groothuis Jan T. , Thijssen Dick H. J. , Lenders Jacques W. M. , Deinum Jaap , Hopman Maria T. E.
Published: December 2010

Maintaining blood pressure during orthostatic challenges is primarily achieved by baroreceptor-mediated activation of the sympathetic nervous system, which can be divided into preganglionic and postganglionic parts. Despite their preganglionic autonomic failure, spinal cord-injured individuals demonstrate a preserved peripheral vasoconstriction during orthostatic challenges. Whether this also applies to patients with postganglionic autonomic failure is unknown. Therefore, we assessed leg vasoconstriction during 60° head-up tilt in five patients with pure autonomic failure (PAF) and two patients with autonomic failure due to dopamine-β-hydroxylase (DBH) deficiency. Ten healthy subjects served as controls. Leg blood flow was measured using duplex ultrasound in the right superficial femoral artery. Leg vascular resistance was calculated as the arterial-venous pressure gradient divided by blood flow. DBH-deficient patients were tested off and on the norepinephrine pro-drug l-threo-dihydroxyphenylserine (l-DOPS). During 60° head-up tilt, leg vascular resistance increased significantly in PAF patients [0.40 ± 0.38 (+30%) mmHg·ml−1·min−1]. The increase in leg vascular resistance was not significantly different from controls [0.88 ± 1.04 (+72%) mmHg·ml−1·min−1]. In DBH-deficient patients, leg vascular resistance increased by 0.49 ± 0.01 (+153%) and 1.52 ± 1.47 (+234%) mmHg·ml−1·min−1 off and on l-DOPS, respectively. Despite the increase in leg vascular resistance, orthostatic hypotension was present in PAF and DBH-deficient patients. Our results demonstrate that leg vasoconstriction during orthostatic challenges in patients with PAF or DBH deficiency is not abolished. This indicates that the sympathetic nervous system is not the sole or pivotal mechanism inducing leg vasoconstriction during orthostatic challenges. Additional vasoconstrictor mechanisms may compensate for the loss in sympathetic nervous system control.
The role of intrinsic factors in control of arm movement direction: implications from directional preferences
Authors: Dounskaia Natalia , Goble Jacob A. , Wang Wanyue
Published: December 2010

The role of extrinsic and intrinsic factors in control of arm movement direction remains under debate. We addressed this question by investigating preferences in selection of movement direction and whether factors causing these preferences have extrinsic or intrinsic nature. An unconstrained free-stroke drawing task was used during which participants produced straight strokes on a horizontal table, choosing the direction and the beginning and end of each stroke arbitrarily. The variation of the initial arm postures across strokes provided a possibility to distinguish between the extrinsic and intrinsic origins of directional biases. Although participants were encouraged to produce strokes equally in all directions, each participant demonstrated preferences for some directions over the others. However, the preferred directions were not consistent across participants, suggesting no directional preferences in extrinsic space. Consistent biases toward certain directions were revealed in intrinsic space representing initial arm postures. Factors contributing to the revealed preferences were analyzed within the optimal control framework. The major bias was explained by a tendency predicted by the leading joint hypothesis (LJH) to minimize active interference with interaction torque generated by shoulder motion at the elbow. Some minor biases may represent movements of minimal inertial resistance or maximal kinematic manipulability. These results support a crucial role of intrinsic factors in control of the movement direction of the arm. Based on the LJH interpretation of the major bias, we hypothesize that the dominant tendency was to minimize neural effort for control of arm intersegmental dynamics. Possible organization of neural processes underlying optimal selection of movement direction is discussed.
Coupled Coincidence Point and Coupled Common Fixed Point Theorems in Partially Ordered Metric Spaces with "Equation missing" -Distance
Authors: Abbas Mujahid , Ilić Dejan , Khan MuhammadAli
Published: December 2010

We introduce the concept of a "Equation missing"-compatible mapping to obtain a coupled coincidence point and a coupled point of coincidence for nonlinear contractive mappings in partially ordered metric spaces equipped with "Equation missing"-distances. Related coupled common fixed point theorems for such mappings are also proved. Our results generalize, extend, and unify several well-known comparable results in the literature.
On Certain Classes of p‐Valent Functions by Using Complex‐Order and Differential Subordination
Authors: Tehranchi Abdolreza , Kılıçman Adem
Published: December 2010

The aim of the present paper is to study the p‐valent analytic functions in the unit disk and satisfy the differential subordinations z(ℐp(r, λ)f(z)) (j+1)/(p − j)(ℐp(r, λ)f(z)) (j)≺(a + (aB + (A − B)β)z)/a(1 + Bz), where Ip(r, λ) is an operator defined by Slgean and β is a complex number. Further we define a new related integral operator and also study the Fekete‐Szego problem by proving some interesting properties.
Studying the Attribution of LiF in OLED by the - Characteristics
Authors: Zhang Chun-lin , Wang Fang-cong , Zhang Yong , Li Hai-xia , Liu Su
Published: December 2010

The organic light-emitting device (OLED) with simple structures of indium tin oxide (ITO)/tris(8-quinolinolato) aluminum (Alq3)/LiF/Al and ITO/Alq3/Al was fabricated to analyze the contribution of LiF in OLED. We used the - characteristics to investigate the contribution of LiF in OLED and found that the capacitance of the above-mentioned structures was 12.5 nF and 77.5 nF, respectively. It is shown that the LiF layer affects the property of OLED resulting in the change of the capacitance of the device.
Validation of the HIRHAM‐Simulated Indian Summer Monsoon Circulation
Authors: Polanski Stefan , Rinke Annette , Dethloff Klaus
Published: December 2010

The regional climate model HIRHAM has been applied over the Asian continent to simulate the Indian monsoon circulation under present‐day conditions. The model is driven at the lateral and lower boundaries by European reanalysis (ERA40) data for the period from 1958 to 2001. Simulations with a horizontal resolution of 50 km are carried out to analyze the regional monsoon patterns. The focus in this paper is on the validation of the long‐term summer monsoon climatology and its variability concerning circulation, temperature, and precipitation. Additionally, the monsoonal behavior in simulations for wet and dry years has been investigated and compared against several observational data sets. The results successfully reproduce the observations due to a realistic reproduction of topographic features. The simulated precipitation shows a better agreement with a high‐resolution gridded precipitation data set over the central land areas of India and in the higher elevated Tibetan and Himalayan regions than ERA40.
Studies on the Photoinduced Interaction between Zn(II) Porphyrin and Colloidal TiO2
Authors: Huang Heyong , Zhou Jiahong , Zhou Yan , Zhou Yanhuai , Feng Yuying
Published: December 2010

The interaction of Zn(II) porphyrin (ZnPP) with colloidal TiO2was studied by absorption and fluorescence spectroscopy. The fluorescence emission of ZnPP was quenched by colloidal TiO2upon excitation of its absorption band. The quenching rate constant (kq) is1.24×1011 M−1 s−1. These data indicate that there is an interaction between ZnPP and colloidal TiO2nanoparticle surface. The quenching mechanism is discussed on the basis of the quenching rate constant as well as the reduction potential of the colloidal TiO2. And the mechanism of electron transfer has been confirmed by the calculation of free energy change(ΔGet)by applying Rehm-Weller equation as well as energy level diagram.
Exponential Admissibility and Dynamic Output Feedback Control of Switched Singular Systems with Interval Time‐Varying Delay
Authors: Lin Jinxing , Fan Chunxia
Published: December 2010

This paper is concerned with the problems of exponential admissibility and dynamic output feedback (DOF) control for a class of continuous‐time switched singular systems with interval time‐varying delay. A full‐order, dynamic, synchronously switched DOF controller is considered. First, by using the average dwell time approach, a delay‐range‐dependent exponential admissibility criterion for the unforced switched singular time‐delay system is established in terms of linear matrix inequalities (LMIs). Then, based on this criterion, a sufficient condition on the existence of a desired DOF controller, which guarantees that the closed‐loop system is regular, impulse free and exponentially stable, is proposed by employing the LMI technique. Finally, some illustrative examples are given to show the effectiveness of the proposed approach.
Adaptive Probabilistic Broadcasting over Dense Wireless Ad Hoc Networks
Authors: Gau Victor , Hwang Jenq-Neng
Published: December 2010

We propose an idle probability-based broadcasting method,iPro, which employs an adaptive probabilistic mechanism to improve performance of data broadcasting over dense wireless ad hoc networks. In multisource one-hop broadcast scenarios, the modeling and simulation results of the proposediProare shown to significantly outperform the standard IEEE 802.11 under saturated condition. Moreover, the results also show that without estimating the number of competing nodes and changing the contention window size, the performance of the proposediProcan still approach the theoretical bound. We further applyiProto multihop broadcasting scenarios, and the experiment results show that within the same elapsed time after the broadcasting, the proposediProhas significantly higher Packet-Delivery Ratios (PDR) than traditional methods.
The Basic Differential Equations of Self‐Anchored Cable‐Stayed Suspension Bridge
Authors: Hui-Li Wang , Si-Feng Qin , Zhe Zhang , Cai-Liang Huang , Wen-Jun Xu
Published: December 2010

The static behavior of self‐anchored cable‐stayed suspension bridge under vertical load is described with the continuum method. Based on the partition generalized variation principle, considering the compression‐bending coupling effect of the main girder and the tower, the large displacement incomplete generalized potential energy functional of three‐span self‐anchored cable‐stayed suspension bridge is established. Then, the basic differential equations of self‐anchored cable‐stayed suspension bridge are derived through constraint variation. Taking a self‐anchored cable‐stayed suspension bridge with main span 100 m, for example, the results by the proposed analytic method agree with that of numerical analysis. Therefore, the basic differential equations proposed in this paper could be applied to the preliminary analysis of self‐anchored cable‐stayed suspension bridge. The equations also provide a theoretical basis to describe the static behavior of this type of bridge.