Genomic profiling of a Hepatocyte growth factor-dependent signature for MET-targeted therapy in glioblastoma.

BACKGROUND: Constitutive MET signaling promotes invasiveness in most primary and recurrent GBM. However, deployment of available MET-targeting agents is confounded by lack of effective biomarkers for selecting suitable patients for treatment. Because endogenous HGF overexpression often causes autocrine MET activation, and also indicates sensitivity to MET inhibitors, we investigated whether it drives the expression of distinct genes which could serve as a signature indicating vulnerability to MET-targeted therapy in GBM. METHODS: Interrogation of genomic data from TCGA GBM (Student's t test, GBM patients with high and low HGF expression, p ≤ 0.00001) referenced against patient-derived xenograft (PDX) models (Student's t test, sensitive vs. insensitive models, p ≤ 0.005) was used to identify the HGF-dependent signature. Genomic analysis of GBM xenograft models using both human and mouse gene expression microarrays (Student's t test, treated vs. vehicle tumors, p ≤ 0.01) were performed to elucidate the tumor and microenvironment cross talk. A PDX model with EGFR(amp) was tested for MET activation as a mechanism of erlotinib resistance. RESULTS: We identified a group of 20 genes highly associated with HGF overexpression in GBM and were up- or down-regulated only in tumors sensitive to MET inhibitor. The MET inhibitors regulate tumor (human) and host (mouse) cells within the tumor via distinct molecular processes, but overall impede tumor growth by inhibiting cell cycle progression. EGFR (amp) tumors undergo erlotinib resistance responded to a combination of MET and EGFR inhibitors. CONCLUSIONS: Combining TCGA primary tumor datasets (human) and xenograft tumor model datasets (human tumor grown in mice) using therapeutic efficacy as an endpoint may serve as a useful approach to discover and develop molecular signatures as therapeutic biomarkers for targeted therapy. The HGF dependent signature may serve as a candidate predictive signature for patient enrollment in clinical trials using MET inhibitors. Human and mouse microarrays maybe used to dissect the tumor-host interactions. Targeting MET in EGFR (amp) GBM may delay the acquired resistance developed during treatment with erlotinib.

Effects of Recreational Camping on the Environmental Values of National Parks in Sri Lanka.

Camping is a popular activity in the contemporary nature-based tourism domain and rapidly gaining momentum as a key recreational activity in Sri Lanka's national parks (NPs). Recreational uses such as camping in natural areas can induce significant and often localised resource impacts that can affect soil, vegetation, wildlife and water, with the severity of such impacts varying according to the intensity of use. Hence, monitoring of the biophysical conditions of campsites has become an important component in the reserve management agenda in many places, especially in developed countries. To the best of our knowledge, this is the first study to examine the biophysical impacts associated with the recreation ecology of camping in Sri Lanka. Ten campsites from three dry zone NPs were selected to assess biophysical impacts of camping activities. Field measurements were based on the fixed radial transect method. Gathered data included the total area of the campsite, erosion potential measured as the area of exposed soil (devoid of vegetation or organic litter), number of exposed roots and human damage to trees, number of fireplaces/ fire scars on the ground, visual counts of litter, soil compaction measured by penetrometer, loss of woody debris. This study reports significant levels of environmental degradation related to all the indictors of biophysical impacts at both high and low use campsites. There was no evidence for any difference in the level of environmental degradation associated with high and low use campsites. The loss of natural values associated with campsites negatively impacted visitors' nature-based experience. These findings highlight the importance of managing biophysical impacts in campsites to provide a high-quality visitor experience, while sustainably managing tourism activities in NPs.

Comparing hiking, mountain biking and horse riding impacts on vegetation and soils in Australia and the United States of America.

Hiking, horse riding and mountain biking are popular in protected areas in Australia and the United States of America. To help inform the often contentious deliberations about use of protected areas for these three types of activities, we review recreation ecology research in both countries. Many impacts on vegetation, soils and trails are similar for the three activities, although there can be differences in severity. Impacts include damage to existing trails, soil erosion, compaction and nutrification, changes in hydrology, trail widening, exposure of roots, rocks and bedrock. There can be damage to plants including reduction in vegetation height and biomass, changes in species composition, creation of informal trails and the spread of weeds and plant pathogens. Due to differences in evolutionary history, impacts on soil and vegetation can be greater in Australia than in the USA. There are specific social and biophysical impacts of horses such as those associated with manure and urine, grazing and the construction and use of tethering yards and fences. Mountain bike specific impacts include soil and vegetation damage from skidding and the construction of unauthorised trails, jumps, bridges and other trail technical features. There are gaps in the current research that should be filled by additional research: (1) on horse and mountain bike impacts to complement those on hiking. The methods used need to reflect patterns of actual usage and be suitable for robust statistical analysis; (2) that directly compares types and severity of impacts among activities; and (3) on the potential for each activity to contribute to the spread of weeds and plant pathogens. Additional research will assist managers and users of protected areas in understanding the relative impacts of these activities, and better ways to manage them. It may not quell the debates among users, managers and conservationists, but it will help put it on a more scientific footing.

Scoping Recreational Disturbance of Shorebirds to Inform the Agenda for Research and Management in Tropical Asia.

In addition to scoping the impacts of the four most reported sources of recreational disturbance on shorebirds, this study also advances the concept of Tropical Asia (TA) to collectively describe tourist destinations in the ecologically and geopolitically diverse part of the planet that incorporates the tourism megaregion of South and Southeast Asia. At a time of growing global concern about the rapid decline of shorebird populations, many governments in TA are embracing and capitalising on the exponential growth in demand for coastal recreation and tourism across the region. This political response is partly driven by efforts to deliver economic development, aligned to the United Nations Sustainable Development Goals, in order to secure the livelihoods of people living in less developed coastal areas. However, the rapid increase in visitor numbers and the development of infrastructure to support the booming demand for coastal tourism destinations in TA are further exacerbating the pressures on shorebird populations across the region. Despite these growing pressures and the wealth of research reporting on shorebird populations across the Asian flyways, this scoping study identified surprisingly little research that reports on the recreational disturbance (RD) of shorebirds in TA. While undertaken to inform future research, this study also provides a synthesis of management strategies reported in the global literature into a set of management recommendations for coastal destinations in TA.

Molecular dynamics simulations of mass transfer resistance in grain boundaries of twinned zeolite membranes.

The net mass transfer resistance for gas molecules permeating through zeolite membranes includes contributions from intracrystalline diffusion and contributions from interfacial effects. These interfacial effects can arise either from gas-zeolite interfaces or from interfaces that exist within zeolite crystals due to grain boundaries. We present the first atomically detailed simulations that examine interfacial mass transfer resistance due to internal grain boundaries in zeolites that are relevant for membrane applications. Our calculations examine twinned silicalite crystals in crystallographic configurations that have been identified in previous experiments. We used the dual control volume grand canonical molecular dynamics method to simulate the permeance of CH(4) and CF(4) through thin twinned silicalite crystals. The magnitudes of the grain boundary resistances are quite substantial, at least for the thin crystals that are accessible in our simulations.

A novel zinc compound (zinc monocysteine) enhances the antioxidant capacity of human retinal pigment epithelial cells.

PURPOSE: The aim of this study was to document the effect of a novel zinc amino acid combination on the concentrations of important antioxidants in cultured human retinal pigment epithelial (hRPE) cells. METHODS: Primary confluent hRPE cells were treated with 30 microM of zinc acetate, zinc chloride, zinc cysteine, and zinc sulfate. The antioxidants catalase, glutathione, glutathione peroxidase, and metallothionein were measured. MTT assays were performed to determine the relative protection of the zinc compounds from the cytotoxic effects of H202 and t-butyl hydroperoxide. RESULTS: Catalase and glutathione peroxidase activities were increased by the zinc formulations compared with the untreated control. Glutathione and metallothionein content were also increased. The greatest increases occurred with zinc conjugated to the amino acid cysteine. The MTT assays showed that zinc monocysteine protected cultured RPE cells from the toxicity of H2O2 and t-butyl hydroperoxide. CONCLUSIONS: Our results demonstrate that zinc treatment of RPE cells increases antioxidants and protects cultured RPE cells from the cytotoxic effects of H2O2 and t-butyl hydroperoxide. The results show that zinc conjugated to cysteine offers greater benefits than either zinc salts or cysteine alone.

Understanding the conflicting values associated with motorized recreation in protected areas.

The International Union for the Conservation of Nature World Parks Congress in 2014 reported that the quality of management of protected areas is crucial in halting the loss of the world's biodiversity and meeting global environmental challenges. However, increasingly high-impact activities, including motorized recreation are occurring in protected areas such as national parks, creating an ongoing clash of values and further compromising protected area management. This paper discusses the values of protected areas in the context of increasingly high-impact motorized usage, the impact of divergent values placed on green spaces such as national parks, and perceptions about these spaces. Given the changing global context of this millennium, and increasing populations requiring space for high-impact activities including motorized recreation, rethinking recreation in protected areas is needed. A protected area classification to accommodate high-impact activities away from vulnerable natural areas may assist in maintaining protected area quality.

Data from a survey to determine visitor attitudes and knowledge about the provisioning of wild dolphins at a marine tourism destination.

In the Austral summer of 2014-2015 we surveyed visitors at the popular marine tourism destination of Koombana Bay, Bunbury, Western Australia to investigate resident and visitor attitudes towards the provisioning of the wild dolphins and their knowledge about the legal, social and environmental repercussions arising from the unregulated provisioning of the dolphins. We report the data collected in our survey along with our preliminary statistical analyses and the survey instrument we utilized to collect the data.

Fibroblasts Enhance Migration of Human Lung Cancer Cells in a Paper-Based Coculture System.

A multilayered paper-based platform is used to investigate the interactions between human lung tumor cells and fibroblasts that are isolated from primary patient tumor samples.

Predictive assessment of surface resistances in zeolite membranes using atomically detailed models.

The diffusive transport of molecules through nanoporous membranes is determined by both intracrystalline diffusion and mass transport resistances associated with entering and leaving the membrane material. We compare two methods for assessing the relative importance of these resistances based on atomically detailed descriptions of the membrane material. For extremely thin membranes, net transport can be assessed using dual control volume grand canonical molecular dynamics (DCV-GCMD). We show that previous implementations of this technique may have been influenced by nonisothermal effects in interfacial regions and suggest a simple remedy to this situation. We also introduce an approximate method that uses information only from equilibrium MD simulations, which avoids the significant computational expense associated with DCV-GCMD. This approximate method can be used to rapidly assess the importance of interface-related resistances to mass transport over broad ranges of membrane operating conditions. This method will be useful in allowing a rapid determination of whether these interface resistances are significant in practical experimental situations. These two methods are compared by considering the transport of CH(4) and CF(4) through defect-free silicalite membranes.

Synthesis and Quasi-Static Compressive Properties of Mg-AZ91D-Al2O3 Syntactic Foams.

Magnesium alloys have considerably lower density than the aluminum alloy matrices that are typically used in syntactic foams, allowing for greater specific energy absorption. Despite the potential advantages, few studies have reported the properties of magnesium alloy matrix syntactic foams. In this work, Al2O3 hollow particles of three different size ranges, 0.106-0.212 mm, 0.212-0.425 mm, and 0.425-0.500 mm were encapsulated in Mg-AZ91D by a sub-atmospheric pressure infiltration technique. It is shown that the peak strength, plateau strength and toughness of the foam increases with increasing hollow sphere wall thickness to diameter (t/D) ratio. Since t/D was found to increase with decreasing hollow sphere diameter, the foams produced with smaller spheres showed improved performance-specifically, higher energy absorption per unit weight. These foams show better performance than other metallic foams on a specific property basis.

Design, Synthesis, and Structure-Activity Relationships of Pyridine-Based Rho Kinase (ROCK) Inhibitors.

The Rho kinases (ROCK1 and ROCK2) are highly homologous serine/threonine kinases that act on substrates associated with cellular motility, morphology, and contraction and are of therapeutic interest in diseases associated with cellular migration and contraction, such as hypertension, glaucoma, and erectile dysfunction. Beginning with compound 4, an inhibitor of ROCK1 identified through high-throughput screening, systematic exploration of SAR, and application of structure-based design, led to potent and selective ROCK inhibitors. Compound 37 represents significant improvements in inhibition potency, kinase selectivity, and CYP inhibition and possesses pharmacokinetics suitable for in vivo experimentation.

A paper-based invasion assay: assessing chemotaxis of cancer cells in gradients of oxygen.

This work describes a 3D, paper-based assay that can isolate sub-populations of cells based on their invasiveness (i.e., distance migrated in a hydrogel) in a gradient of concentration of oxygen (O2). Layers of paper impregnated with a cell-compatible hydrogel are stacked and placed in a plastic holder to form the invasion assay. In most assays, the stack comprises a single layer of paper containing mammalian cells suspended in a hydrogel, sandwiched between multiple layers of paper containing only hydrogel. Cells in the stack consume and produce small molecules; these molecules diffuse throughout the stack to generate gradients in the stack, and between the stack and the bulk culture medium. Placing the cell-containing layer in different positions of the stack, or modifying the permeability of the holder to oxygen or proteins, alters the profile of the gradients within the stack. Physically separating the layers after culture isolates sub-populations of cells that migrated different distances, and enables their subsequent analysis or culture. Using this system, three independent cell lines derived from A549 cancer cells are shown to produce distinguishable migration behavior in a gradient of oxygen. This result is the first experimental demonstration that oxygen acts as a chemoattractant for cancer cells.

Expression of metallothionein isoforms in human chorioretinal complex.

PURPOSE: To determine the relative expression of metallothionein isoforms and their differential induction by oxidative stress in cultured RPE cells and to localize the isoforms in the human chorioretinal complex. METHODS: Total RNA was isolated from cultured human retinal pigment epithelial cells using TRI-Reagent. An "anchor-oligo-dT primer" was used for the synthesis of cDNA, reverse transcribed using avian reverse transcriptase and subsequently subjected to PCR analysis using oligonucleotides specific for metallothionein (MT) I, MT II, and MT III. The selected transcripts were then used to assess the expression of the above elements in fixed tissue sections by in situ hybridization. Cultured RPE cells were allowed to phagocytose bovine photoreceptor outer segments (ROS) or were treated with H(2)O(2) for 6 hours and then analyzed by RT-PCR or in situ hybridization to ascertain the effect of oxidative stress on metallothionein mRNA isoform expression. RESULTS: Relative density analysis of amplified products demonstrate the presence of MT I, MT II and MT III in RPE cells, with an apparent relative expression MT II > MT I > MT III [corrected]. Expression of MT I and MT II mRNA was increased by both phagocytosis and hydrogen peroxide, however MT III was not induced by either stress. In situ hybridization corroborated the findings of the RT-PCR analysis and showed that MTs were mainly localized in the RPE and the photoreceptor layer of the retina. CONCLUSIONS: The localization of MT and the response of MT to oxidative stress are consistent with a role for MT as an antioxidant in the RPE and retina. Studies are ongoing to determine the specific mechanisms of action of these antioxidants in RPE cells.

An electrophoretic method to deliver topical drugs to the eye.

It is possible that many patients avoid complete ophthalmic exams because pupil dilation is slow, reversal sluggish, and vision blurred. Others experience incomplete dilation during exams or prior to surgery when good dilation is essential to successful outcome. Iontophoresis, the application of low-level electrical current to promote traversal of desired molecules across a boundary, has been used for many years and has recently become common in transdermal drug delivery. We now investigate iontophoresis as a method of accelerating drug absorption into the ocular anterior segment. In vivo rabbit studies assessed iontophoresis effects on the performance of dilators and constrictors. 1-mA and 4-mA direct current levels applied for 2-minute durations yielded dilation time-history measurements. Subsequent in vitro tests at a wide range of current densities showed minimal chemical modifications in ocular pharmaceuticals. Drug samples processed through high-performance liquid chromatography (HPLC) pinpointed minimal structural changes. Detailed in vivo rabbit testing is under way. Using 2 dilators and constrictors in crossed testing with 0.5-mA to 1.25-mA current levels and 20-sec to 60-sec durations, we recorded dilation progress by digital photography. Initial studies showed faster, larger dilations and quicker reversal using iontophoresis. Drug testing showed chemical structures remaining constant for clinically useful current levels, < or = 1 mA (< or = 1.25 mA/cm2 current density). Drug pH and HPLC retention times were constant within this range, and resistivity varied linearly as expected for increasing current. Rabbit testing will quantify improved drug speed and efficacy, validate the charge delivery electrode design, and indicate iontophoretic current and duration for further use. Tested ocular drugs showed no degradation when exposed to clinically useful iontophoretic currents. Preliminary results indicate significant time reductions for dilation and reversal, plus increases in maximum dilation. This procedure may aid clinicians by allowing more rapid complete examinations and surgical preparations for patients. Making dilation more convenient will also improve patient acceptance of exams, aiding earlier detection and treatment of ocular disease.

Impact of technical assistants for venepuncture and intravenous cannulation on overall emergency department performance.

OBJECTIVE: The objective of the article was to determine the effect of a technical assistant for venepuncture and i.v. cannulation on triage performance and patient length of stay in an ED. METHODS: An observational study of daily ED performance was conducted at an inner city tertiary referral ED. Over a period of 158 consecutive days, data on triage performance and average length of stay were collected. A technical assistant was employed for 8-10 h per day to perform venepuncture, i.v. cannulation and electronic order entry. Study groups compared were days staffed by a technical assistant and days that were not staffed. RESULTS: Days staffed by a technical assistant were associated with significantly higher triage performance for triage category three (mean 0.66, 95% CI 0.63-0.69 vs 0.58, 95% CI 0.54-0.62; P=0.003) and lower average length of stay per patient for triage category two patients (mean length of stay 390 min, 95% CI 369-411 vs 425 min, 95% CI 399-451; P=0.04). Triage performance thresholds for triage category three (75% of patients seen within 30 min) were met over twice as often on staffed days compared with control (39/96 [38%]vs 10/62 [16%], P=0.004). CONCLUSION: Staffing the ED with a technical assistant was associated with improved ED performance for triage category three and average length of stay for triage category two patients.

Reproducible measurement of macular light flash recovery time using a novel device can indicate the presence and worsening of macular diseases.

PURPOSE: To determine the safety, sensitivity, and specificity of a novel flash photorecovery timing instrument with response verification in differentiating normal from abnormal maculae, and in detecting worsening macular disease. METHODS: Right and left eye photorecovery times were determined at baseline and after 5 min using a xenon arc, flash filtered for infrared, ultraviolet, and visible short wavelengths, delivered through an aperture in a hand-held tube. A push-button actuated timer and flash and stopped timer when lighted numbers became visible post-flash. A numeric keypad verified responses. Normal subjects (two eyes tested, n = 144; one eye tested, n = 108) ranged in age from 15 to 84. Photorecovery times were measured in one eye of subjects with small drusen and 20/20 acuity (53-55 correct ETDRS letters; n = 57); in both eyes of subjects with dry age-related macular degeneration (AMD; n = 118); wet AMD with (n = 19) or without (n = 17) macular fluid; and eyes of diabetics with background retinopathy with (n = 19) or without (n = 17) macular retinal thickening. Once-weekly photorecovery measurements for 6 months in each eye of 10 dry AMD subjects and 10 dry diabetic maculopathy subjects provided longitudinal data. RESULTS: Normal subjects' mean right eye recovery time was 9.6 sec (+/- 1.9 SD); left 10.8 sec (+/- 1.0 SD). Photorecovery lengthened after age 55, nearly doubling that of young subjects by age 80. Macular edema, serous macular detachment, or worsened dry AMD were accompanied by prolonged photorecovery (p < .01). When abnormal new vessels or retinal thickening appeared in three serially followed patients, photorecovery at least doubled (p < .01). In all three, photorecovery prolongation occurred without clinical symptoms. None of the 499 tested subjects reported adverse events due to the flash testing. CONCLUSIONS: These findings support the usefulness of a reproducible light flash macular vision recovery measurement as an indicator of macular pathology and worsening disease.

A randomized, prospective, placebo-controlled clinical trial of a novel zinc-monocysteine compound in age-related macular degeneration.

PURPOSE: To test the hypothesis that daily use of zinc-monocysteine (ZMC) supplement will be well tolerated and result in improved macular function in persons with dry age-related macular degeneration (AMD). METHODS: Eligible, consenting subjects were randomized to either ZMC 25 mg or placebo twice daily for 6 months. Both ZMC and placebo groups enrolled 40 participants, with best corrected visual acuity 20/25 to 20/70, macular drusen, and pigment changes. Masked personnel determined baseline, 3- and 6-month best-corrected visual acuity, contrast sensitivity, and light flash recovery time. Differences between ZMC and placebo were analyzed by a one-sided unpaired t-test of the paired differences between baseline and 3- and 6-month timepoints for right and left eyes separately. RESULTS: By 6 months the ZMC group showed improved visual acuity (p < 0.0001) and contrast sensitivity (p < 0.0001). Macular light flash recovery time shortened in the ZMC group at 3 months by 2.1 sec (left eye, p = 0.0001) to 3.6 sec (right eye, p < 0.0001), and at 6 months by 7.2 sec (left eye, p < 0.0001) to 7.4 sec (right eye, p < 0.0001). This variable had no improvement in the placebo group. ZMC had a gastrointestinal irritation rate of under 2%. CONCLUSION: ZMC 25 mg twice daily was well tolerated and was associated with improved macular function in comparison to a placebo in persons with dry AMD.

Influences of interfacial resistances on gas transport through carbon nanotube membranes.

Carbon nanotubes have significant promise as gas separation membranes. Gas permeation through nanopores involves mass transfer resistances from molecules entering and leaving pores (so-called surface resistances) and diffusion within the pores. We use molecular simulations to give the first estimates of surface resistances for gas transport through nanotubes. For CH4 transport through (20,0) carbon nanotubes at 300 K, surface resistances are small for nanotubes 5-10 mum in length but can be significant for shorter nanotubes.