Interacting

Distribution by Scientific Domains
Distribution within Life Sciences

Terms modified by Interacting

  • interacting agent
  • interacting component
  • interacting effects
  • interacting factor
  • interacting gene
  • interacting groups
  • interacting locus
  • interacting molecule
  • interacting partner
  • interacting protein
  • interacting species
  • interacting system

  • Selected Abstracts


    The experiences and perceived changes of Chinese ex-mental patients attending a holistic psychiatric rehabilitation programme: a qualitative study

    JOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 6 2008
    A. L. LUK
    The paper reports a study on the subjective experiences and perceived personal changes of Chinese ex-mental patients attending a psychiatric holistic rehabilitation programme. The programme adopted a self-help group approach in which holistic aspects of physical, psycho-social and spiritual needs are emphasized. There are different rehabilitation programmes for chronic mental patients. However, spiritual element is not consciously included in most of these programmes. Furthermore, few studies document the changes of participants attending psychiatric rehabilitation adopting self-help and holistic care principles. A qualitative approach using an in-depth interview was adopted. A total of 20 members from the programme, which was about one-sixth of all the regular group members were recruited. All interviews were audiotaped and transcribed. Data were coded, categorized and developed to different themes using content analysis. Totally, there were 52 themes developed from the data. However, only 13 themes on experiences in the group and nine themes on the perceived personal changes were reported. By attending the programme, participants had positive feelings and gained many positive learning opportunities when interacting with peers. Interacting with group counsellors was also very beneficial to them. Though there were only some improvements physically, there were clear perceived positive changes in the psychological, social and spiritual dimensions. These findings are consistent with those found in the quantitative measures reported previously. The subjective experiences of the participants were positive and they perceived positive personal changes after joining the group. The findings support the effectiveness of the long-term nature of self-help group. Furthermore, the holistic programme helps members rediscover meaning and purpose of life and the religious practices in the group can be regarded to be a protective factor to stress not only to those believers but also to the non-believers. [source]


    Grafted Polymer Chains Interacting with Substrates: Computer Simulations and Scaling

    MACROMOLECULAR THEORY AND SIMULATIONS, Issue 9 2008
    Radu Descas
    Abstract We review scaling methods and computer simulations used in the study of the static and dynamic properties of polymer chains tethered to adsorbing surfaces under good solvent conditions. By varying both the grafting density and the monomer/surface interactions a variety of phases can form. In particular, for attractive interactions between the chains and the surface the classical mushroom-brush transition known for repulsive substrates splits up into an overlap transition and a saturation transition which enclose a region of semidilute surface states. At high grafting densities oversaturation effects and a transition to a brush state can occur. We emphasize the role of the critical adsorption parameters for a correct description and understanding of such polymer adsorption phenomena. [source]


    A Finite Interface Crack Interacting With A Subinterface Crack In Metal/Piezoelectric Ceramic Bimaterial

    PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003
    Wen-Ye Tian
    The "pseudo-traction-electric-displacement' method was adopted to solve the interaction problem between a finite interface crack and a subinterface crack in metal/piezoelectric bimaterial. After deriving the fundamental solutions for a finite interface crack and a special subinterface crack respectively loaded by the normal and tangential concentrated tractions and the concentrated electric displacement, the present interaction problem was reduced to a system of integral equations, which may be solved numerically. The crack tip mode I stress intensity factor was calculated and detailed comparisons of the results derived under the compound mechanical-electric loading conditions and those derived under the purely mechanical loading condition are performed. [source]


    Anomalous Behavior of Atomic Hydrogen Interacting with Gold Clusters.

    CHEMINFORM, Issue 5 2004
    Stefan Buckart
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    Activin/nodal signaling modulates XPAPC expression during Xenopus gastrulation

    DEVELOPMENTAL DYNAMICS, Issue 3 2008
    Xin Lou
    Abstract Gastrulation is the first obligatory morphogenesis during vertebrate development, by which the body plan is established. Nodal signaling is a key player in many developmental processes, including gastrulation. XPAPC has been found to exert its biological function through modifying the adhesion property of cells and interacting with other several important molecules in embryos. In this report, we show that nodal signaling is necessary and sufficient for XPAPC expression during Xenopus gastrulation. Furthermore, we isolated 4.8 kb upstream DNA sequence of Xenopus XPAPC, and proved that this 4.8-kb genomic contig is sufficient to recapitulate the expression pattern of XPAPC from gastrula to tail bud stage. Transgene and ChIP assays indicate that Activin/nodal signaling participates in regulation of XPAPC expression through a Smad binding element within the XPAPC promoter. Concomitant investigation suggests that the canonical Wnt pathway-activated XPAPC expression requires nodal signaling. Developmental Dynamics 237:683,691, 2008. © 2008 Wiley-Liss, Inc. [source]


    Development and evaluation of a cd-rom to support student learning in dentist,patient communication

    EUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 2 2003
    J. T. Newton
    The interaction between dentist and patient is central to the provision of effective healthcare. A multidisciplinary team containing expertise in the social and behavioural sciences, medicine, dentistry, education and information technology was formed to design a CD-ROM to support more traditional teaching and learning in this area. The final version of the program consists of a ,virtual' patient from whom students are asked to take a medical history. The ,patient' interacts with the student and responds to the style of their questioning by changes in anxiety, or degree of annoyance. To date, the CD-ROM has been evaluated in two stages. The first stage was a predictive formative evaluation by the research/development team, and the second stage was a formative evaluation by 144 dental students of the first full prototype. A third stage, to be conducted next year, will involve measuring the longer term impact of the CD-ROM through the assessment of students' abilities to communicate with patients. The evaluation had two components: students made rates of how useful and easy to use they found the program, and students' attitudes towards interacting with patients were evaluated adopting constructs from the theory of Planned Behaviour. Students were positive about the use of the CD-ROM, though they requested some changes in the functionality of the program. Compared to a sample of students who had not used the CD-ROM, the students who used the CD-ROM felt more positive about communicating with their patients, at the end of the course, and expressed stronger intentions to communicate well with patients. We conclude that the CD-ROM we have developed in a useful adjunct to learning in dentist,patient communication. [source]


    Treating [K4(H2O)0.5][SnTe4] with PPh4+ or AsPh4+: Formation of a Highly Air-Stable Tellurostannate Salt, a Tellurolate with One-Coordinate Te Atoms, and a Polytelluride Salt with ,1[Te4(H2O)2]2, Chains,

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2007
    Eugen Ruzin
    Abstract In reactions of potassium orthotellurostannates with EPh4Cl (E = P, As), different single-crystalline products are obtained. An air-stable dimeric tellurostannate forms by partial replacement of strongly interacting K+ cations by weakly interacting or noninteracting [PPh4]+ ions. For E = As, an equally air-stable tellurophenolate, in which Te has the rare coordination number 1, results upon As,C bond cleavage at a tetraphenylarsonium cation. Oxidation of the air-sensitive [Sn2Te6]4, anion and Te2, by O2 (air) affords a tetratelluride salt with strands of H2O-bridged [Te4]2, anions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    The Vps4 C-terminal helix is a critical determinant for assembly and ATPase activity and has elements conserved in other members of the meiotic clade of AAA ATPases

    FEBS JOURNAL, Issue 7 2008
    Parimala R. Vajjhala
    Sorting of membrane proteins into intralumenal endosomal vesicles, multivesicular body (MVB) sorting, is critical for receptor down regulation, antigen presentation and enveloped virus budding. Vps4 is an AAA ATPase that functions in MVB sorting. Although AAA ATPases are oligomeric, mechanisms that govern Vps4 oligomerization and activity remain elusive. Vps4 has an N-terminal microtubule interacting and trafficking domain required for endosome recruitment, an AAA domain containing the ATPase catalytic site and a , domain, and a C-terminal , helix positioned close to the catalytic site in the 3D structure. Previous attempts to identify the role of the C-terminal helix have been unsuccessful. Here, we show that the C-terminal helix is important for Vps4 assembly and ATPase activity in vitro and function in vivo, but not endosome recruitment or interactions with Vta1 or ESCRT-III. Unlike the , domain, which is also important for Vps4 assembly, the C-terminal helix is not required in vivo for Vps4 homotypic interaction or dominant-negative effects of Vps4,E233Q, carrying a mutation in the ATP hydrolysis site. Vta1 promotes assembly of hybrid complexes comprising Vps4,E233Q and Vps4 lacking an intact C-terminal helix in vitro. Formation of catalytically active hybrid complexes demonstrates an intersubunit catalytic mechanism for Vps4. One end of the C-terminal helix lies in close proximity to the second region of homology (SRH), which is important for assembly and intersubunit catalysis in AAA ATPases. We propose that Vps4 SRH function requires an intact C-terminal helix. Co-evolution of a distinct Vps4 SRH and C-terminal helix in meiotic clade AAA ATPases supports this possibility. [source]


    Supramolecular Soft Adhesive Materials

    ADVANCED FUNCTIONAL MATERIALS, Issue 11 2010
    Jérémie Courtois
    Abstract The rheological and adhesive properties of bis-urea functionalized low-molecular-weight polyisobutylenes (PIBUT) are investigated. The polymers, which can interact through supramolecular hydrogen bonds, can self-organize over times of the order of days at room temperature. This organized structure has been identified by small angle X-ray scattering (SAXS) and its rheological properties indicate the behaviour of a soft viscoelastic gel. The ordered structure can be disrupted by temperature and shear so that at 80,°C, the material behaves as a highly viscoelastic fluid and no SAXS peak is observed. When cooled back at room temperature, the PIBUT retrieves its ordered structure and gel properties after 20 h of annealing. This very slow molecular dynamics gives PIBUT a highly dissipative nature upon deformation, which combined with strongly interacting moieties results in very interesting adhesive properties both on steel surfaces but more importantly on typical low adhesion surfaces such as silicone. A strategy based on the controlled incorporation of supramolecular bonds in a covalently crosslinked network appears promising for the development of a new generation of highly interacting and dissipative soft adhesives. [source]


    The AdS/CFT correspondence in the PP-wave limit

    FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 6-7 2004
    M. Petrini
    We consider the correspondence between IIB string theory on the maximally supersymmetric PP-wave and the BMN sector of ,, = 4 SYM theory. At the level of the interacting (string) theory, the matching between these two descriptions is not yet fully understood. Here we review the tests supporting the simple proposal that relates the 3-string interaction to the correlation functions among the BMN operators. [source]


    Lectures on the plane-wave string/gauge theory duality

    FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 2-3 2004
    J.C. Plefka
    Abstract These lectures give an introduction to the novel duality relating type IIB string theory in a maximally supersymmetric plane-wave background to ,, = 4, d = 4, U(N) super Yang-Mills theory in a particular large N and large R-charge limit due to Berenstein, Maldacena and Nastase. In the first part of these lectures the duality is derived from the AdS/CFT correspondence by taking a Penrose limit of the AdS5 × S5 geometry and studying the corresponding double-scaling limit on the gauge theory side. The resulting free plane-wave superstring is then quantized in light-cone gauge. On the gauge theory side of the correspondence the composite super Yang-Mills operators dual to string excitations are identified, and it is shown how the string spectrum can be mapped to the planar scaling dimensions of these operators. In the second part of these lectures we study the correspondence at the interacting respectively non-planar level. On the gauge theory side it is demonstrated that the large N large R-charge limit in question preserves contributions from Feynman graphs of all genera through the emergence of a new genus counting parameter , in agreement with the string genus expansion for non-zero gs. Effective quantum mechanical tools to compute higher genus contributions to the scaling dimensions of composite operators are developed and explicitly applied in a genus one computation. We then turn to the interacting string theory side and give an elementary introduction into light-cone superstring field theory in a plane-wave background and point out how the genus one prediction from gauge theory can be reproduced. Finally, we summarize the present status of the plane-wave string/gauge theory duality. [source]


    EXPLORING THE CONNECTIONS: LAND TENURE, SOCIAL IDENTITIES, AND AGROBIODIVERSITY PRACTICES IN GHANA

    GEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2009
    Louis Awanyo
    ABSTRACT. This article employs qualitative and quantitative evidence from primary social research in Ghana to examine the link between land tenure security and social identities (of wealth/income and gender), and how they condition farmers' investments in practices that contribute to the rehabilitation of tree biodiversity (agrobiodiversity). Statistical analyses of the significance of the effects of farmers' de jure land tenure security regimes, and income and gender on agrobiodiversity practices were inconclusive. The conventional causation link between investments and more secure formal land tenure rights, for instance, was confirmed in investments in four out of eight agrobiodiversity practices. Testimonial-based evidence of farmers provided a clearer concept of land tenure security and an explanatory framework about the interacting and complex effects of income and gender on land tenure security. The theoretical and empirical argument developed from these testimonies portrays land tenure as embodying negotiated social processes, influenced by gender and income of individuals, whereby breadth of land rights, duration of rights over land, and assurance of rights are established, sustained, enhanced or changed through a variety of strategies to shape tenure security. These processes , tenure building and renewal processes , are critical because all farmers have lingering anxiety about land tenure rights, even among farmers with more secure formal rights. Investments are made in agrobiodiversity practices as a strategy to strengthen land tenure security and thereby minimize anxiety, leading to reverse causation effects between land tenure, social identities, and investments. [source]


    Human inhibitor of growth 1 inhibits hepatoma cell growth and influences p53 stability in a variant-dependent manner,

    HEPATOLOGY, Issue 2 2009
    Zhi Zhu
    Inhibitor of growth 1 (ING1) is a type II tumor suppressor that affects cell function by altering chromatin structure and regulating transcription. Recently, three ING1 splice variants have been cloned, but their roles in apoptosis and p53 regulation in human hepatocellular carcinoma (HCC) have not been fully elucidated. The present study found that ING1, in a variant-dependent manner, inhibited hepatoma cell proliferation and colony formation, induced apoptosis and cell cycle arrest at G0/G1 phase, and postponed tumor formation in nude mice. Expression of p33ING1b and p24ING1c variants, but not p47ING1a, was markedly reduced in HCC samples. Reverse transcription polymerase chain reaction and western blotting analysis revealed that ectopic overexpression of p33ING1b or p24ING1c variant increased the expression of p53 downstream genes such as p21waf1 and bax, and repressed bcl-2 expression (P < 0.01), whereas p47ING1a inactivated p21waf1 promoter (P < 0.01). Furthermore, we found that p33ING1b and p24ING1c repressed Mdm2 expression (P < 0.01) and competed with Mdm2 for binding to p53. Interestingly, p33ING1band p24ING1c did not directly bind to Mdm2 protein but strongly increased p14arf expression (P < 0.01) and interacted with p14arf protein to stimulate p53. Moreover, we found that ectopic overexpression of p33ING1b or p24ING1c significantly induced p53 protein acetylation at Lys-373/Lys-382 residue, but did not alter the phosphorylation status of p53. Conclusion: ING1 variants p33ING1b and p24ING1c may modulate p53 activity and subsequently inhibit hepatoma cell growth by at least two possible mechanisms: interacting with Mdm2 and p14arf to stabilize and activate p53, or increasing p53 acetylation. (HEPATOLOGY 2009.) [source]


    An explicit formulation for the evolution of nonlinear surface waves interacting with a submerged body

    INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2007
    Christopher P. Kent
    Abstract An explicit formulation to study nonlinear waves interacting with a submerged body in an ideal fluid of infinite depth is presented. The formulation allows one to decompose the nonlinear wave,body interaction problem into body and free-surface problems. After the decomposition, the body problem satisfies a modified body boundary condition in an unbounded fluid domain, while the free-surface problem satisfies modified nonlinear free-surface boundary conditions. It is then shown that the nonlinear free-surface problem can be further reduced to a closed system of two nonlinear evolution equations expanded in infinite series for the free-surface elevation and the velocity potential at the free surface. For numerical experiments, the body problem is solved using a distribution of singularities along the body surface and the system of evolution equations, truncated at third order in wave steepness, is then solved using a pseudo-spectral method based on the fast Fourier transform. A circular cylinder translating steadily near the free surface is considered and it is found that our numerical solutions show excellent agreement with the fully nonlinear solution using a boundary integral method. We further validate our solutions for a submerged circular cylinder oscillating vertically or fixed under incoming nonlinear waves with other analytical and numerical results. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Pml and TAp73 interacting at nuclear body mediate imatinib-induced p53-independent apoptosis of chronic myeloid leukemia cells

    INTERNATIONAL JOURNAL OF CANCER, Issue 1 2009
    Jin-Hwang Liu
    Abstract Bcr-abl signals for leukemogenesis of chronic myeloid leukemia (CML) and activates ras. Since the function of promyelocytic leukemia protein (pml) is provoked by ras to promote apoptosis and senescence in untransformed cells, the function is probably masked in CML. Imatinib specifically inhibits bcr-abl and induces apoptosis of CML cells. As reported previously, p53wild CML was more resistant to imatinib than that lacking p53. Here, we searched for an imatinib-induced p53 independent proapoptotic mechanism. We found imatinib up-regulated phosphorylation of p38 mitogen-activated protein kinase (MAPK), checkpoint kinase 2 (chk2) and transactivation-competent (TA) p73; expression of pml and bax; formation of PML-nuclear body (NB); and co-localization of TAp73/PML-NB in p53-nonfunctioning K562 and p53mutant Meg-01 CML cells, but not in BCR-ABL - HL60 cells. In K562 cells, with short interfering RNAs (siRNAs), knockdown of pml led to dephosphorylation of TAp73. Knockdown of either pml or TAp73 abolished the imatinib-induced apoptosis. Inhibition of p38 MAPK with SB203580 led to dephosphorylation of TAp73, abolishment of TAp73/PML-NB co-localization, and the subsequent apoptosis. Conversely, interferon ,-2a (IFN,), which increased phosphrylated TAp73 and TAp73/PML-NB co-localization, increased additively apoptosis with imatinib. The imatinib-induced TAp73/PML-NB co-localization was accompanied by co-immpunoprecipitation of TAp73 with pml. The imatinib-induced co-localization was also found in primary CML cells from 3 of 6 patients, including 2 with p53mutant and one with p53wild. A novel p53-independent proapoptotic mechanism using p38 MAPK /pml/TAp73 axis with a step processing at PML-NB and probably with chk2 and bax being involved is hereby evident in some imatinib-treated CML cells. © 2009 UICC [source]


    ACE4k: An analog I/O 64×64 visual microprocessor chip with 7-bit analog accuracy

    INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 2-3 2002
    G. Liñán
    Abstract This paper describes a full-custom mixed-signal chip which embeds distributed optical signal acquisition, digitally-programmable analog parallel processing, and distributed image memory cache on a common silicon substrate. This chip, designed in a 0.5 µm standard CMOS technology contains around 1.000.000 transistors, of which operate in analog mode; it is hence one the most complex mixed-signal chip reported to now. Chip functional features are: local interactions, spatial-invariant array architecture; programmable local interactions among cells; randomly-selectable memory of instructions (elementary instructions are defined by specific values of the cell local interactions); random storage/retrieval of intermediate images; capability to complete algorithmic image processing tasks controlled by the user-selected stored instructions and interacting with the cache memory, etc. Thus, as illustrated in this paper, the chip is capable to complete complex spatio-temporal image processing tasks within short computation time (<300 ns for linear convolutions) and using a low power budget (<1.2 W for the complete chip). The internal circuitry of the chip has been designed to operate in robust manner with >7-bits equivalent accuracy in the internal analog operations, which has been confirmed by experimental measurements. Such 7-bits accuracy is enough for most image processing applications. ACE4k has been demonstrated capable to implement up to 30 template,-either directly or through template decomposition. This means the 100% of the 3×3 linear templates reported in Roska et al. 1998, [1]. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    The , point interaction two-center system

    INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 7 2009
    H. Hogreve
    Abstract Motivated by the behavior of molecules in strong magnetic fields, we study the quantum system consisting of a particle (electron) interacting with two fixed (nuclear) centers by ,-type point interactions. Spectral properties and resonances of this model as a function of the internuclear separation are investigated qualitatively and quantitatively. We prove analyticity, monotonicity, and other features, compare them with corresponding attributes of related Coulomb systems, and point out the consequences for molecules. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source]


    Thinking inside the box: Novel linear scaling algorithm for Coulomb potential evaluation

    INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4 2006
    David C. Thompson
    Abstract Beginning with the Poisson equation, and expanding the electronic potential in terms of sine functions, the natural orbitals for describing the particle-in-a-box problem, we find that simple analytic forms can be found for the evaluation of the Coulomb energy for both the interacting and non-interacting system of N -electrons in a box. This method is reminiscent of fast-Fourier transform and scales linearly. To improve the usefulness of this result, we generalize the idea by considering a molecular system, embedded in a box, within which we determine the electrostatic potential, in the same manner as that described for our model systems. Within this general formalism, we consider both periodic and aperiodic recipes with specific application to systems described using Gaussian orbitals; although in principle the method is seen to be completely general. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source]


    RANKL Treatment Releases the Negative Regulation of the Poly(ADP-Ribose) Polymerase-1 on Tcirg1 Gene Expression During Osteoclastogenesis,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2006
    Guillaume E Beranger
    Abstract The Tcirg1 gene encodes the osteoclast-specific a3 isoform of the V-ATPase a subunit. Using the mouse osteoclastic model RAW264.7 cells, we studied Tcirg1 gene expression, and we identified PARP-1 as a transcriptional repressor negatively regulated by RANKL during osteoclastogenesis. Introduction: The TCIRG1 gene encodes the a3 isoform of the V-ATPase a subunit, and mutations at this locus account for ,60% of infantile malignant osteopetrosis cases. Using RAW264.7 cells as an osteoclastic differentiation model, we undertook a transcriptional study of the mouse Tcirg1 gene focused on the 4-kb region upstream of the transcription starting point. Materials and Methods: The promoter activity of serial-deletion fragments of the Tcirg1 gene promoter was monitored throughout the RAW264.7 cell differentiation process. We next performed EMSA, UV cross-linking, affinity purification, mass spectrometry analysis, gel supershift, and siRNA transfection experiments to identify the factor(s) interacting with the promoter. Results: The ,3946/+113 region of the mouse Tcirg1 gene displayed a high basal promoter activity, which was enhanced by RANKL treatment of RAW264.7 cells. Constructs deleted up to ,1589 retained this response to RANKL. A deletion up to ,1402 induced a 3-fold enhancement of the basal activity, whereas RANKL response was not affected. EMSA experiments led us to identify within the ,1589/,1402 region, a 10-nucleotide sequence, which bound a nuclear protein present in nondifferentiated RAW264.7 cells. This interaction was lost using nuclear extracts derived from RANKL-treated cells. Affinity purification followed by mass spectrometry analysis and gel supershift assay allowed the identification of poly(ADP-ribose) polymerase-1 (PARP-1) as this transcriptional repressor, whereas Western blot experiments revealed the cleavage of the DNA-binding domain of PARP-1 on RANKL treatment. Finally, both PARP-1 depletion after siRNA transfection and RAW264.7 cell treatment by an inhibitor of PARP-1 activity induced an increase of a3 mRNA expression. Conclusions: We provide evidence that the basal transcription activity of the Tcirg1 gene is negatively regulated by the binding of PARP-1 protein to its promoter region in mouse pre-osteoclast. On RANKL treatment, PARP-1 protein is cleaved and loses its repression effect, allowing an increase of Tcirg1 gene expression that is critical for osteoclast function. [source]


    HSP70 interacts with TRAF2 and differentially regulates TNF, signalling in human colon cancer cells

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2010
    Shengming Dai
    Abstract Members of tumour necrosis factor (TNF) family usually trigger both survival and apoptotic signals in various cell types. Heat shock proteins (HSPs) are conserved proteins implicated in protection of cells from stress stimuli. However, the mechanisms of HSPs in TNF,-induced signalling pathway have not been fully elucidated. We report here that HSP70 over-expression in human colon cancer cells can inhibit TNF,-induced NF,B activation but promote TNF,-induced activation of c-Jun N-terminal kinase (JNK) through interaction with TNF receptor (TNFR)-associated factor 2 (TRAF2). We provide evidence that HSP70 over-expression can sequester TRAF2 in detergent-soluble fractions possibly through interacting with TRAF2, leading to reduced recruitment of receptor-interacting protein (RIP1) and I,B, kinase (IKK) signalosome to the TNFR1,TRADD complex and inhibited NF,B activation after TNF, stimuli. In addition, we found that HSP70,TRAF2 interaction can promote TNF,-induced JNK activation. Therefore, our study suggests that HSP70 may differentially regulate TNF,-induced activation of NF,B and JNK through interaction with TRAF2, contributing to the pro-apoptotic roles of HSP70 in TNF,-induced apoptosis of human colon cancer cells. [source]


    Dual action of apolipoprotein E-interacting HCCR-1 oncoprotein and its implication for breast cancer and obesity

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 9b 2009
    Seon-Ah Ha
    Abstract Obese women have an increased risk for post-menopausal breast cancer. The physiological mechanism by which obesity contributes to breast tumourigenesis is not understood. We previously showed that HCCR-1 oncogene contributes to breast tumourigenesis as a negative regulator of p53 and detection of HCCR-1 serological level was useful for the diagnosis of breast cancer. In this study, we found that the HCCR-1 level is elevated in breast cancer tissues and cell lines compared to normal breast tissues. We identified apolipoprotein E (ApoE) interacting with HCCR-1. Our data show that HCCR-1 inhibits anti-proliferative effect of ApoE, which was mediated by diminishing ApoE secretion of breast cancer cells. Finally, HCCR-1 induced the severe obesity in transgenic mice. Those obese mice showed severe hyperlipidaemia. In conclusion, our results suggest that HCCR-1 might play a role in the breast tumourigenesis while the overexpression of HCCR-1 induces the obesity probably by inhibiting the cholesterol-lowering effect of ApoE. Therefore, HCCR-1 seems to provide the molecular link between the obesity and the breast cancer risk. [source]


    Inclusion of the ligand field contribution in a polarizable molecular mechanics: SIBFA-LF,

    JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 16 2003
    Jean-Philip Piquemal
    Abstract To account for the distortion of the coordination sphere that takes place in complexes containing open-shell metal cations such as Cu(II), we implemented, in sum of interactions between fragments ab initio computed (SIBFA) molecular mechanics, an additional contribution to take into account the ligand field splitting of the metal d orbitals. This term, based on the angular overlap model, has been parameterized for Cu(II) coordinated to oxygen and nitrogen ligands. The comparison of the results obtained from density functional theory computations on the one hand and SIBFA or SIBFA-LF on the other shows that SIBFA-LF gives geometric arrangements similar to those obtained from quantum mechanical computations. Moreover, the geometric improvement takes place without downgrading the energetic agreement obtained from SIBFA. The systems considered are Cu(II) interacting with six water molecules, four ammonia or four imidazoles, and four water plus two formate anions. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 1963,1970, 2003 [source]


    Sequential radiation of unrelated organisms: the gall fly Eurosta solidaginis and the tumbling flower beetle Mordellistena convicta

    JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 5 2003
    W. G. Abrahamson
    Abstract Host shifts and the formation of insect-host races are likely common processes in the speciation of herbivorous insects. The interactions of goldenrods Solidago (Compositae), the gall fly Eurosta solidaginis (Diptera: Tephritidae) and the beetle Mordellistena convicta (Coleoptera: Mordellidae) provide behavioural, ecological and genetic evidence of host races that may represent incipient species forming via sympatric speciation. We summarize evidence for Eurosta host races and show that M. convicta has radiated from goldenrod stems to Eurosta galls to form host-part races and, having exploited the galler's host shift, has begun to differentiate into host races within galls. Thus, host-race formation has occurred in two interacting, but unrelated organisms representing two trophic levels, resulting in ,sequential radiation' (escalation of biodiversity up the trophic system). Distributions of host races and their behavioural isolating mechanisms suggest sympatric differentiation. Such differentiation suggests host-race formation and subsequent speciation may be an important source of biodiversity. [source]


    A measure of food seeking in individuals with Prader,Willi syndrome

    JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 1 2006
    J. Young
    Abstract Background Individuals with Prader,Willi syndrome (PWS), a chromosome 15 genetic disorder, often have a significant preoccupation with food and problem behaviour related to food seeking is often prevalent. Methods In the present study, we compared how individuals with PWS responded on a survey regarding the acceptability of food in various locations that varied according to degree of appropriateness for human consumption (e.g. food on a plate, food in a garbage can). For a subgroup of participants, we observed how they actually responded when placed in a room with food items placed in the same locations depicted in the survey. In the first part of the study, three groups (25 typically developing individuals, 7 individuals with intellectual disability (ID), and 19 individuals with PWS) responded to a visual survey to determine the degree of acceptability of food items in various locations (e.g. on a table near a hairbrush, on the floor behind a toy box, in a trash can). In the second part of the study, these food items (popcorn, jelly beans) were placed in the 12 locations described above. Nine individuals diagnosed with PWS (deletion type) and three individuals with ID were given some break time in the room for 15 min. The amount of food consumed, the time spent food seeking, and time spent interacting with materials were measured. Results Results of the survey indicated that the PWS group differed significantly with regard to how they responded on the survey from the typically developing group, but did not differ significantly from the ID group. Results of the food seeking observations indicated that only three individuals with PWS ate a significant number of items. The three individuals did not differ from the rest of the group according to IQ or compulsivity score; however, they had significantly lower body mass index (BMI) scores and were younger than the other participants. Conclusions The findings from the survey indicate that individuals with PWS are able to discriminate the appropriateness of eating items in more or less contaminated areas; however, the amount of time spent seeking food and the amount of food covertly consumed appeared to depend more directly on age and BMI. [source]


    N,N -dimethyl-thioamphetamine and methyl-thioamphetamine, two non-neurotoxic substrates of 5-HT transporters, have scant in vitro efficacy for the induction of transporter-mediated 5-HT release and currents

    JOURNAL OF NEUROCHEMISTRY, Issue 5 2008
    Marco Gobbi
    Abstract We studied two non-neurotoxic amphetamine derivatives (methyl-thioamphetamine, MTA and N,N- dimethylMTA, DMMTA) interacting with serotonin (5-HT) transporters (SERTs) with affinities comparable to that of p- Cl-amphetamine (pCA). The rank order for their maximal effects in inducing both [3H]5-HT release from rat brain synaptosomes or hSERT-expressing HEK-293 cells, and currents in hSERT-expressing oocytes, was pCA » MTA , DMMTA. A correlation between drug-induced release and currents is also strengthened by the similar bell shape of the dose,response curves. Release experiments indicated that MTA and DMMTA are SERT substrates although MTA is taken up by HEK-293 cells with a Vmax 40% lower than pCA. The weak effects of MTA and DMMTA in vitro might therefore be due to their properties as ,partial substrates' on the mechanisms, other than translocation, responsible for currents and/or release. After either local or systemic in vivo administration, MTA and DMMTA release 5-HT in a manner comparable to pCA. These findings confirm that the neurotoxic properties of some amphetamine derivatives are independent of their 5-HT-releasing activity in vivo. It is worth noting that only those amphetamine derivatives with high efficiency in inducing 5-HT release and currents in vitro have neurotoxic properties. [source]


    GABAA receptor associated proteins: a key factor regulating GABAA receptor function

    JOURNAL OF NEUROCHEMISTRY, Issue 2 2007
    Zi-Wei Chen
    Abstract ,-Aminobutyric acid (GABA), an important inhibitory neurotransmitter in both vertebrates and invertebrates, acts on GABA receptors that are ubiquitously expressed in the CNS. GABAA receptors also represent a major site of action of clinically relevant drugs, such as benzodiazepines, barbiturates, ethanol, and general anesthetics. It has been shown that the intracellular M3-M4 loop of GABAA receptors plays an important role in regulating GABAA receptor function. Therefore, studies of the function of receptor intracellular loop associated proteins become important for understanding mechanisms of regulating receptor activity. Recently, several labs have used the yeast two-hybrid assay to identify proteins interacting with GABAA receptors, for example, the interaction of GABAA receptor associated protein (GABARAP) and Golgi-specific DHHC zinc finger protein (GODZ) with , subunits, PRIP, phospholipase C-related, catalytically inactive proteins (PRIP-1) and (PRIP-2) with GABARAP and receptor ,2 and , subunits, Plic-1 with some , and , subunits, radixin with the ,5 subunit, HAP1 with the ,1 subunit, GABAA receptor interacting factor-1 (GRIF-1) with the ,2 subunit, and brefeldin A-inhibited GDP/GTP exchange factor 2 (BIG2) with the ,3 subunit. These proteins have been shown to play important roles in modulating the activities of GABAA receptors ranging from enhancing trafficking, to stabilizing surface and internalized receptors, to regulating modification of GABAA receptors. This article reviews the current studies of GABAA receptor intracellular loop-associated proteins. [source]


    Melatonin antagonizes the intrinsic pathway of apoptosis via mitochondrial targeting of Bcl-2

    JOURNAL OF PINEAL RESEARCH, Issue 3 2008
    Flavia Radogna
    Abstract:, We have recently shown that melatonin antagonizes damage-induced apoptosis by interaction with the MT-1/MT-2 plasma membrane receptors. Here, we show that melatonin interferes with the intrinsic pathway of apoptosis at the mitochondrial level. In response to an apoptogenic stimulus, melatonin allows mitochondrial translocation of the pro-apoptotic protein Bax, but it impairs its activation/dimerization The downstream apoptotic events, i.e. cytochrome c release, caspase 9 and 3 activation and nuclear vesiculation are equally impaired, indicating that melatonin interferes with Bax activation within mitochondria. Interestingly, we found that melatonin induces a strong re-localization of Bcl-2, the main Bax antagonist to mitochondria, suggesting that Bax activation may in fact be antagonized by Bcl-2 at the mitochondrial level. Indeed, we inhibit the melatonin anti-apoptotic effect (i) by silencing Bcl-2 with small interfering RNAs, or with small-molecular inhibitors targeted at the BH3 binding pocket in Bcl-2 (i.e. the one interacting with Bax); and (ii) by inhibiting melatonin-induced Bcl-2 mitochondrial re-localization with the MT1/MT2 receptor antagonist luzindole. This evidence provides a mechanism that may explain how melatonin through interaction with the MT1/MT2 receptors, elicits a pathway that interferes with the Bcl-2 family, thus modulating the cell life/death balance. [source]


    Inquiry in interaction: How local adaptations of curricula shape classroom communities

    JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 9 2004
    Noel Enyedy
    In this study, we seek a better understanding of how individuals and their daily interactions shape and reshape social structures that constitute a classroom community. Moreover, we provide insight into how discourse and classroom interactions shape the nature of a learning community, as well as which aspects of the classroom culture may be consequential for learning. The participants in this study include two teachers who are implementing a new environmental science program, Global Learning through Observation to Benefit the Environment (GLOBE), and interacting with 54 children in an urban middle school. Both qualitative and quantitative data are analyzed and presented. To gain a better understanding of the inquiry teaching within classroom communities, we compare and contrast the discourse and interactions of the two teachers during three parallel environmental science lessons. The focus of our analysis includes (1) how the community identifies the object or goal of its activity; and (2) how the rights, rules, and roles for members are established and inhabited in interaction. Quantitative analyses of student pre- and posttests suggest greater learning for students in one classroom over the other, providing support for the influence of the classroom community and interactional choices of the teacher on student learning. Implications of the findings from this study are discussed in the context of curricular design, professional development, and educational reform. ? 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 905-935, 2004. [source]


    Design, technology, and science: Sites for learning, resistance, and social reproduction in urban schools

    JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 7 2001
    Gale Seiler
    The teaching of science through activities that emphasize design and technology has been advocated as a vehicle for accomplishing science for all students. This study was situated in an inner7-city neighborhood school populated mainly by African American students from life worlds characterized by poverty. The article explores the discourse and practices of students and three coteachers as a curriculum was enacted to provide opportunities for students to learn about the physics of motion through designing, building, and testing a model car. Some students participated in ways that led to their building viable model cars and interacting with one another in ways that suggest design and technological competence. However, there also was evidence of resistance from students who participated sporadically and refused to cooperate with teachers as they endeavored to structure the environment in ways that would lead to a deeper understanding of science. Analysis of in-class interactions reveals an untapped potential for the emergence of a sciencelike discourse and diverse outcomes. Among the challenges explored in this article is a struggle for respect that permeates the students' lives on the street and bleeds into the classroom environment. Whereas teachers enacted the curriculum as if learning was the chief goal for students, it is apparent that students used the class opportunistically to maintain and earn the respect of peers. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 746,767, 2001 [source]


    Text-based video content classification for online video-sharing sites

    JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 5 2010
    Chunneng Huang
    With the emergence of Web 2.0, sharing personal content, communicating ideas, and interacting with other online users in Web 2.0 communities have become daily routines for online users. User-generated data from Web 2.0 sites provide rich personal information (e.g., personal preferences and interests) and can be utilized to obtain insight about cyber communities and their social networks. Many studies have focused on leveraging user-generated information to analyze blogs and forums, but few studies have applied this approach to video-sharing Web sites. In this study, we propose a text-based framework for video content classification of online-video sharing Web sites. Different types of user-generated data (e.g., titles, descriptions, and comments) were used as proxies for online videos, and three types of text features (lexical, syntactic, and content-specific features) were extracted. Three feature-based classification techniques (C4.5, Naïve Bayes, and Support Vector Machine) were used to classify videos. To evaluate the proposed framework, user-generated data from candidate videos, which were identified by searching user-given keywords on YouTube, were first collected. Then, a subset of the collected data was randomly selected and manually tagged by users as our experiment data. The experimental results showed that the proposed approach was able to classify online videos based on users' interests with accuracy rates up to 87.2%, and all three types of text features contributed to discriminating videos. Support Vector Machine outperformed C4.5 and Naïve Bayes techniques in our experiments. In addition, our case study further demonstrated that accurate video-classification results are very useful for identifying implicit cyber communities on video-sharing Web sites. [source]