Epidermal growth factor-induced epithelio-mesenchymal transition in human breast carcinoma cells

PMC42-LA cells display an epithelial phenotype: the cells congregate into pavement epithelial sheets in which E-cadherin and beta-catenin are localized at cell-cell borders. They abundantly express cytokeratins, although 5% to 10% of the cells also express the mesenchymal marker vimentin. Stimulation of PMC42-LA cells with epidermal growth factor (EGF) leads to epithelio-mesenchymal transition-like changes including up-regulation of vimentin and down-regulation of E-cadherin. Vimentin expression is seen in virtually all cells, and this increase is abrogated by treatment of cells with an EGF receptor antagonist. The expression of the mesenchyme-associated extracellular matrix molecules fibronectin and chondroitin sulfate proteoglycan also increase in the presence of EGF. PMC42-LA cells adhere rapidly to collagen I, collagen IV, and laminin-1 substrates and markedly more slowly to fibronectin and vitronectin. EGF increases the speed of cell adhesion to most of these extracellular matrix molecules without altering the order of adhesive preference. EGF also caused a time-dependent increase in the motility of PMC42-LA cells, commensurate with the degree of vimentin staining. The increase in motility was at least partly chemokinetic, because it was evident both with and without chemoattractive stimuli. Although E-cadherin staining at cell-cell junctions disappeared in response to EGF, beta-catenin persisted at the cell periphery. Further analysis revealed that N-cadherin was present at the cell-cell junctions of untreated cells and that expression was increased after EGF treatment. N- and E-cadherin are not usually coexpressed in human carcinoma cell lines but can be coexpressed in embryonic tissues, and this may signify an epithelial cell population prone to epithelio-mesenchymal-like responses.

Gender differences in adherence to sodium-restricted diet patients with heart failure.

Background

Despite the importance of the sodium-restricted diet (SRD) to heart failure (HF) management, patient adherence is poor. Little is known about gender differences in adherence or factors that affect patients' ability to follow SRD recommendations. The purposes of this study were to determine whether there were gender differences in (1) adherence to the SRD; (2) knowledge about SRD and HF self-care; and (3) perceived barriers to following the SRD.
Methods and Results

Forty-one men and 27 women completed the Heart Failure Attitudes and Barriers questionnaire that measured HF self-care, knowledge, and perceived barriers to follow an SRD. Diet adherence was measured by 24-hour urinary sodium excretion (UNa). Women were more adherent to the SRD than men as reflected by 24-hour urine excretion (2713 versus 3859 mg UNa, P = .01). Women recognized signs of excess sodium intake such as fluid buildup (P = .001) and edema (P = .01) more often than men and had better understanding of appropriate actions to take related to following an SRD. There were no gender differences in perceived barriers to follow an SRD.
Conclusions

Although men and women perceived similar barriers, women were more adherent to the SRD and had greater knowledge about following an SRD. Further investigation of this phenomenon is warranted to determine if better adherence contributes to improved outcomes in women.

Induction of epithelial to mesenchymal transition in PMC42-LA human breast carcinoma cells by carcinoma-associated fibroblast secreted factors

Background
Breast carcinoma is accompanied by changes in the acellular and cellular components of the microenvironment, the latter typified by a switch from fibroblasts to myofibroblasts.


Methods
We utilised conditioned media cultures, Western blot analysis and immunocytochemistry to investigate the differential effects of normal mammary fibroblasts (NMFs) and mammary cancer-associated fibroblasts (CAFs) on the phenotype and behaviour of PMC42-LA breast cancer cells. NMFs were obtained from a mammary gland at reduction mammoplasty, and CAFs from a mammary carcinoma after resection.


Results
We found greater expression of myofibroblastic markers in CAFs than in NMFs. Medium from both CAFs and NMFs induced novel expression of α-smooth muscle actin and cytokeratin-14 in PMC42-LA organoids. However, although conditioned media from NMFs resulted in distribution of vimentin-positive cells to the periphery of PMC42-LA organoids, this was not seen with CAF-conditioned medium. Upregulation of vimentin was accompanied by a mis-localization of E-cadherin, suggesting a loss of adhesive function. This was confirmed by visualizing the change in active β-catenin, localized to the cell junctions in control cells/cells in NMF-conditioned medium, to inactive β-catenin, localized to nuclei and cytoplasm in cells in CAF-conditioned medium.


Conclusion
We found no significant difference between the influences of NMFs and CAFs on PMC42-LA cell proliferation, viability, or apoptosis; significantly, we demonstrated a role for CAFs, but not for NMFs, in increasing the migratory ability of PMC42-LA cells. By concentrating NMF-conditioned media, we demonstrated the presence of factor(s) that induce epithelial-mesenchymal transition in NMF-conditioned media that are present at higher levels in CAF-conditioned media. Our in vitro results are consistent with observations in vivo showing that alterations in stroma influence the phenotype and behaviour of surrounding cells and provide evidence for a role for CAFs in stimulating cancer progression via an epithelial-mesenchymal transition. These findings have implications for our understanding of the roles of signalling between epithelial and stromal cells in the development and progression of mammary carcinoma.

Properties of slow- and fast-twitch muscle fibres in a mouse model of amyotrophic lateral sclerosis

This investigation was undertaken to determine if there are altered histological, pathological and contractile properties in presymptomatic or endstage diseased muscle fibres from representative slow-twitch and fast-twitch muscles of SOD1 G93A mice in comparison to wildtype mice. In presymptomatic SOD1 G93A mice, there was no detectable peripheral dysfunction, providing evidence that muscle pathology is secondary to motor neuronal dysfunction. At disease endstage however, single muscle fibre contractile analysis demonstrated that fast-twitch muscle fibres and neuromuscular junctions are preferentially affected by amyotrophic lateral sclerosis-induced denervation, being unable to produce the same levels of force when activated by calcium as muscle fibres from their age-matched controls. The levels of transgenic SOD1 expression, aggregation state and activity were also examined in these muscles but there no was no preference for muscle fibre type. Hence, there is no simple correlation between SOD1 protein expression/activity, and muscle fibre type vulnerability in SOD1 G93A mice.

LAN cafes: cafes, places of gathering or sites of informal teaching and learning?

Despite the interest of sociologists and educational researchers in Internet café as sites for new cultural and social formations and informal learning, thus far little attention has been paid to the function of café owners, managers and other staff in the mediation and co-construction of those spaces. Drawing from interviews with managers of commercial Internet café in Australia specialising in LAN (Local Area Network) gaming, this article seeks to examine their role and their attitudes more closely; in particular with regard to school-aged users of their facilities. We contend that LAN café are liminal spaces situated at the margins of Australian culture and located at the junctions between home, school and the street, online and offline spaces, work and play. The roles of LAN café managers are similarly ambiguous: in many ways they can be regarded as informal teachers facilitating the process of informal learning.

Relationship of heart failure patients' knowledge, perceived barriers, and attitudes regarding low-sodium diet recommendations to adherence.

The purposes of this study were to describe heart failure patient perceptions regarding instructions received for following a low-sodium diet and the benefits, barriers, and ease and frequency of following the diet. A total of 246 patients with heart failure referred from academic medical centers in the United States and Australia participated in the study. A subset of 145 patients provided 24-hour urine samples for sodium excretion assessment. While most (80%) patients reported receiving recommendations to follow a low-sodium diet, their recall of specific instructions was poor. Although the majority (75%) reported following a low-sodium diet most or all of the time, 24-hour urine sodium excretion indicated that only 25% of patients were adherent. Patients who reported being more adherent, however, had lower urine sodium excretion levels. Attitudes regarding difficulty in and perceived benefits of following the diet were not related to sodium excretion. Data on attitudes and barriers provided guidance for strategies to improve adherence.

Mucosal vascular addressin cell adhesion molecule-1 is expressed outside the endothelial lineage on fibroblasts and melanoma cells

Mucosal vascular addressin cell adhesion molecule-1 (MAdCAM-1) is predominantly expressed on high endothelial venules in inflamed tissues where it assists with leucocyte extravasation. Here we report that MAdCAM-1 has the potential to be more widely expressed outside the endothelial cell lineage than previously appreciated. Thus, MAdCAM-1 RNA transcripts and cell-surface protein were expressed by NIH 3T3 fibroblasts following activation with tumour necrosis factor-alpha (TNF-alpha), and by freshly isolated and cultured primary mouse splenic and tail fibroblasts in the absence of TNF-alpha stimulation. They were constitutively expressed by B16F10 melanoma cells, and expression was enhanced by cell activation with TNF-alpha. Mucosal vascular addressin cell adhesion molecule-1 was expressed on the apical surface of isolated cells, but became predominantly localized to cell junctions in confluent cell monolayers, suggesting it may play a role in the homotypic aggregation of cells. Tumour necrosis factor-alpha enhanced the expression of a firefly luciferase reporter directed by the MAdCAM-1 promoter in NIH 3T3 and B16F10 cells. A DNA fragment extending from nt -1727 to -673 was sufficient to confer cell-type selective expression. Mucosal vascular addressin cell adhesion molecule-1 expressed by NIH 3T3 cells was biologically active, as it supported the adhesion of TK-1 T cells in an alpha4beta7-dependent fashion. The expression of MAdCAM-1 by fibroblasts, and melanomas suggests MAdCAM-1 may play a role in regulating host responses in the periphery, leucocyte transmigration across nonendothelial boundaries, or the homotypic interactions of some malignant melanomas.

Promises of nanotechnology for drug delivery to brain in neurodegenerative diseases

Brain is a delicate organ, isolated from general circulation and characterized by the presence of relatively impermeable endothelial cells with tight junctions, enzymatic activity and the presence of active efflux transporter mechanisms. These formidable obstacles often block drug delivery to the brain across the blood-brain barrier (BBB). Although several promising molecules have the potential in the in vitro settings but lack of in vivo response is probably because the molecule cannot reach the brain in a sufficient concentration. Drug delivery across the BBB is a major limitation in the treatment of central nervous system (CNS) disorders and CNS infections. This review deals with the role of nanobiotechnology in CNS drug delivery, in which three categories of carbon nanotubes, nanowires and nanoparticles (NPs) are explained. The small size of the NPs makes them an ideal choice to penetrate the BBB. Several mechanisms are involved in this process and various strategies are used. There are some concerns about the safety of NP entry in the brain that need to be resolved before human use. Although there is no approved nanotechnology-based CNS drug available the future for such neuro-nanobiotechnology based delivery system developments is promising.

Exploring corrosion protection of Mg via ionic liquid pretreatment

We present the development of a 10–100 nanometer thick surface film upon pure Mg on exposure to an ionic liquid (IL) based on the bis(trifluoromethanesulfonyl)amide (TFSA) anion. This film formation is the result of the oxidative reactivity of the metal in the IL, with the subsequent effect of ultimately protecting the underlying metal from corrosion in aqueous chloride containing solution. Film formation was studied in the IL using an electrochemical droplet cell. It was seen that this film is adherent and subsequently facilitates appreciable protection against corrosion as judged by subsequent electrochemical testing in the form of potentiodynamic polarization and impedance spectroscopy, along with direct observation. The physical film morphology was studied by electron microscopy and focused ion beam.

Single molecule conductance through rigid norbornylogous bridges with zero average curvature

A new homologous series of norbornylogous (NB) bridges has been synthesized in which the average curvature of the bridges is very small. The molecules are rigid and have two thiol moieties at each end to allow them to form self-assembled monolayers (SAMs) and to connect to two gold electrodes to form a molecular junction. The SAMs formed were characterized using electrochemistry to determine the surface coverage of molecules on gold surface and to provide an indication of the packing of the NB bridges while ellipsometry and X-ray photoelectron spectroscopy (XPS) were used to provide an indication of the SAM thickness and orientation. Single molecule conductance of NB bridges was measured as a function of the molecular length. The conductance was found to decrease exponentially with the length with a decay constant that is exactly correlated with photoelectron transfer and other studies at the multiple molecule level. The molecule−electrode contact resistance was determined and compared with that of related alkanedithiol molecular junctions.

Real-time observation of fiber network formation in molecular organogel : supersaturation-dependent microstructure and its related rheological property

Low-molecular mass organic gelators self-organizing into three-dimensional fiber networks within organic solvents have attracted much attention in recent years. However, to date, how the microstructure of fiber network is formed in a gelation process and the key factors that govern the topological structure of a gel network remain to be determined. In this work, we address these issues by investigating the in situ formation of the gel networks in the N-lauroyl-l-glutamic acid di-n-butylamide (GP-1)/propylene glycol (PG) system. By using optical microscopy, the time evolution of the gel network microstructure was investigated under various supersaturation conditions. It is found that supersaturation is one of the key factors that govern the topological structure of a gel network. In particular, the creation of the junctions turns out to be supersaturation-dependent. The rheological experiments further revealed the correlation between topological structure and mechanical properties. It suggests that the rheological properties can be effectively modified by tuning the microstructure topology of the gel network. Our results reported here provide new physical insight into the formation kinetics of a molecular gel. Furthermore, this work could be important in constructing and engineering a supramolecular structure for the purpose of applications.

Achieving a chromium rich surface upon steels via FBR-CVD chromising treatments

Surface alloying via fluidised bed reactor (FBR) chemical vapour deposition (CVD) can be used to produce adherent and highly corrosion resistant surface layers. In this work, 304, 316, and 409 stainless steels and 1020 steel were chromised, producing distinct surface layers tens of micrometres thick. The composition and surface of these layers was characterised using microscopy, GDOES, and XPS. Surfaces were highly enriched in Cr and displayed improved corrosion resistance as determined by electrochemical evaluations. This work demonstrates that it is possible to form continuous, functional and corrosion resistant Cr-rich surface layers via FBR-CVD on a variety of steels.

Detection of curved edges at subpixel accuracy using deformable models

One approach to the detection of curves at subpixel accuracy involves the reconstruction of such features from subpixel edge data points. A new technique is presented for reconstructing and segmenting curves with subpixel accuracy using deformable models. A curve is represented as a set of interconnected Hermite splines forming a snake generated from the subpixel edge information that minimizes the global energy functional integral over the set. While previous work on the minimization was mostly based on the Euler-Lagrange transformation, the authors use the finite element method to solve the energy minimization equation. The advantages of this approach over the Euler-Lagrange transformation approach are that the method is straightforward, leads to positive m-diagonal symmetric matrices, and has the ability to cope with irregular geometries such as junctions and corners. The energy functional integral solved using this method can also be used to segment the features by searching for the location of the maxima of the first derivative of the energy over the elementary curve set.

Harvesting waste thermal energy using a carbon-nanotube-based thermo-electrochemical cell

Low efficiencies and costly electrode materials have limited harvesting of thermal energy as electrical energy using thermo-electrochemical cells (or “thermocells”). We demonstrate thermocells, in practical configurations (from coin cells to cells that can be wrapped around exhaust pipes), that harvest low-grade thermal energy using relatively inexpensive carbon multiwalled nanotube (MWNT) electrodes. These electrodes provide high electrochemically accessible surface areas and fast redox-mediated electron transfer, which significantly enhances thermocell current generation capacity and overall efficiency. Thermocell efficiency is further improved by directly synthesizing MWNTs as vertical forests that reduce electrical and thermal resistance at electrode/substrate junctions. The efficiency of thermocells with MWNT electrodes is shown to be as high as 1.4% of Carnot efficiency, which is 3-fold higher than for previously demonstrated thermocells. With the cost of MWNTs decreasing, MWNT-based thermocells may become commercially viable for harvesting low-grade thermal energy.