Intimate Interactions (intimate + interaction)

Distribution by Scientific Domains

Selected Abstracts

Glioblastoma cells incorporate into tumor vasculature and contribute to vascular radioresistance

Candice A. Shaifer
Abstract Glioblastoma multiforme (GBM) remains the most devastating neoplasm of the central nervous system and has a dismal prognosis. Ionizing radiation represents an effective therapy for GBM, but radiotherapy remains only palliative because of radioresistance. In this study, we demonstrate that glioma cells participate in tumor vascularization and contribute to vascular radioresistance. Using a 3-dimensional coculture system, we observed an intimate interaction of glioma cells with endothelial cells whereby endothelial cells form vascular structures, followed by the recruitment and vascular patterning of glioma cells. In addition, tumor cells stabilize the vascular structures and render them radioresistant. Blocking initial endothelial vascular formation with endothelial-specific inhibitors prevented tumor cells from forming any structures. However, these inhibitors exhibited minimum effects on vascular structures formed by tumor cells, due to the absence of the targeted receptors on tumor cells. Consistent with the in vitro findings, we show that glioma cells form perfused blood vessels in xenograft tumor models. Together, these data suggest that glioma cells mimic endothelial cells and incorporate into tumor vasculature, which may contribute to radioresistance observed in GBM. Therefore, interventions aimed at the glioma vasculature should take into consideration the chimeric nature of the tumor vasculature. [source]

Participatory planning, management and alternative livelihoods for poor wetland-dependent communities in Kampala, Uganda

Robert Kabumbuli
Abstract The paper is based on an on-going 3-year study in the wetland communities of Kampala. The study uses participatory methods and aims to contribute to (i) the development of low-income wetland communities, (ii) to prepare these communities to become less dependent on wetlands without receding into poverty, and (iii) the better management of the wetlands. The communities in direct dependence and intimate interaction with Nakivubo wetlands are mainly poor, live and work under hazardous conditions, and their activities pose a threat to the ecological function of the wetlands. Yet these wetlands are important for filtering the city's waste and storm water before it flows into Lake Victoria's Murchison Bay, which is Kampala's source of piped water. Government approaches to the problem of wetland encroachment have largely failed because they are confrontational, and are not consistent or participatory. The study has in the first year conducted a series of activities including stakeholder analysis, resource analysis, livelihood analysis, a questionnaire survey and action planning. Preliminary data show that wetland dependency is very high among the poor nearby communities. They practice cultivation, brick-making and harvesting of wetland vegetation. However, these activities are under threat because wetland resources are dwindling due to increasing population and over-use. Livelihoods are threatened not only by the decreasing productivity of the wetland, but also by the ever-present government threat to evict wetland encroachers to restore its ecology. The study therefore works with communities to prepare for less dependence on wetlands so that they do not suddenly recede into worse poverty if they are evicted. They formulate strategies to enhance alternative livelihood, and for management of the wetland. Action plans have been formulated to address the situation through a newly created association. [source]

Mammalian prenatal development: the influence of maternally derived molecules

BIOESSAYS, Issue 9 2009
Ccile Fligny
Abstract Normal fetal development is dependent upon an intricate exchange between mother and embryo. Several maternal and embryonic elements can influence this intimate interaction, including genetic, environmental or epigenetic factors, and have a significant impact on embryo development. The interaction of the genetic program of both mother and embryo, within the uterine environment, can shape the development of an individual. Accumulating data from animal models indicate that prenatal events may well initiate long-term changes in the expression of the embryo genetic program, which persist, or may only become apparent, much later in the individual's life. Also, environmental conditions during prenatal development may prompt the adoption of different developmental pathways, leading to alternative life histories. This review focuses on environmental factors, specifically maternally derived molecules, to illustrate how they can influence in utero embryonic development and, by extension, adult life. [source]

Self-Assembled In-Plane Growth of Mg2SiO4 Nanowires on Si Substrates Catalyzed by Au Nanoparticles

Zhou Zhang
Abstract In-plane growth of Mg2SiO4 nanowires on Si substrates is achieved by using a vapor transport method with Au nanoparticles as catalyst. The self-assembly of the as-grown nanowires shows dependence on the substrate orientation, i.e., they are along one, two, and three particular directions on Si (110), (100), and (111) substrates, respectively. Detailed electron microscopy studies suggest that the Si substrates participate in the formation of Mg2SiO4, and the epitaxial growth of the nanowires is confined along the Si <110> directions. This synthesis route is quite reliable, and the dimensions of the Mg2SiO4 nanowires can be well controlled by the experiment parameters. Furthermore, using these nanowires, a lithography-free method is demonstrated to fabricate nanowalls on Si substrates by controlled chemical etching. The Au nanoparticle catalyzed in-plane epitaxial growth of the Mg2SiO4 nanowires hinges on the intimate interactions between substrates, nanoparticles, and nanowires, and our study may help to advance the developments of novel nanomaterials and functional nanodevices. [source]

From imitation to conversation: the first dialogues with human neonates

Emese Nagy
Abstract The functional maturity of the newborn infant's brain, the resemblances between neonatal imitation and imitation in adults and the possibly lateralized neonatal imitation suggest that the mirror neuron system may contribute to neonatal imitation. Newborn infants not only imitate but also initiate previously imitated gestures, and are able to participate in overlapping imitation,initiation communicative cycles. Additionally, these social responses in neonates are faster than previously thought, and may enable them to have long-lasting intimate interactions much before language develops. Infants are equipped with a powerful, innate, reciprocal communicative ability already at birth. The earliest communication originates from imitation and this communicative ability presumably later evolves to language. Copyright 2006 John Wiley & Sons, Ltd. [source]

The properties of reactive hot melt polyurethane adhesives modified with novel thermoplastic polyurethanes

Tae K. Kim
Abstract A reactive hot melt adhesive (RHMA) consisting of thermoplastic polyurethane (TPU) was modified with sodium montmorillonite (Na-MMT) intercalated with poly(ethylene glycol) (PEG), and their effects on the adhesion, rheological, and mechanical properties of the RHMA were examined. The Na-MMT intercalated with PEG (Na-MMT/PEG) effectively enhanced the initial bond strength development of the RHMA, although the amounts of Na-MMT/PEG in the RHMA were less than 0.2%. The increase of the complex viscosity and pseudo-solid like behavior observed at low shear rate indicates that there are intimate interactions between the RHMA molecules and Na-MMT/PEG. The improved modulus and tensile strength of the cured RHMA film in the presence of Na-MMT/PEG demonstrates that Na-MMT/PEG effectively reinforced the RHMA. 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

Functionalization of Shortened Single-Walled Carbon Nanotubes with Poly(p -dioxanone) by "Grafting-From" Approach

Kuk Ro Yoon
Abstract Summary: It has been a real challenge to form carbon nanotube (CNT)/polymer composites where CNTs are well-dispersed in the polymer matrix and the interactions between CNTs and polymers are effectively strong. In this paper, we applied surface-initiated, ring-opening polymerization (SI-ROP) of p -dioxanone (PDX) to shortened single-walled carbon nanotubes (s-SWCNTs) and successfully formed s-SWCNT/PPDX composites (see Figure). Due to intimate interactions between s-SWCNTs and PPDX, we observed dramatic changes in PPDX properties upon the formation of the composites: 10%-weight-loss-temperature of PPDX increased by 20,C (measured by thermogravimetric analysis) and the patterns of Tg and Tm were greatly altered. We did not observe any noticeable peaks from the composite up to 120,C in differential scanning calorimetry (DSC), while DSC data of PPDX itself showed Tg and Tm at ,13.4 and 103,C respectively. Schematic representation of the procedure for formation of s-SWCNT/PPDX composites. [source]

Beyond empathy: clinical intimacy in nursing practice

Timothy W. Kirk PhD
Abstract Understanding, shared meaning, and mutual trust lie at the heart of the therapeutic nurse,patient relationship. This article introduces the concept of clinical intimacy by applying the interpersonal process model of intimacy to the nurse,patient relationship. The distinction between complementary and reciprocal behaviours, and between intimate interactions and intimate relationships, addresses background concerns about the appropriateness of intimacy in nursing relationships. The mutual construction of meaning in the interactive process between nurses and patients is seen to lie at the heart of clinical intimacy as a hermeneutic enterprise. Intimacy is distinguished from empathy based on intentionality and the status and location of meaning. Reasons for continued investigation into clinical intimacy as an explanatory model for nursing as a hermeneutic practice are presented. [source]

Induced fit in guanidino kinases,comparison of substrate-free and transition state analog structures of arginine kinase

Mohammad S. Yousef
Abstract Arginine kinase (AK) is a member of the guanidino kinase family that plays an important role in buffering ATP concentration in cells with high and fluctuating energy demands. The AK specifically catalyzes the reversible phosphoryl transfer between ATP and arginine. We have determined the crystal structure of AK from the horseshoe crab (Limulus polyphemus) in its open (substrate-free) form. The final model has been refined at 2.35 with a final R of 22.3% (Rfree = 23.7%). The structure of the open form is compared to the previously determined structure of the transition state analog complex in the closed form. Classically, the protein would be considered two domain, but dynamic domain (DynDom) analysis shows that most of the differences between the two structures can be considered as the motion between four rigid groups of nonsequential residues. ATP binds near a cluster of positively charged residues of a fixed dynamic domain. The other three dynamic domains close the active site with separate hinge rotations relative to the fixed domain. Several residues of key importance for the induced motion are conserved within the phosphagen kinase family, including creatine kinase. Substantial conformational changes are induced in different parts of the enzyme as intimate interactions are formed with both substrates. Thus, although induced fit occurs in a number of phosphoryl transfer enzymes, the conformational changes in phosphagen kinases appear to be more complicated than in prior examples. [source]