Patients with BRAF V600E mutant melanoma are typically treated with targeted BRAF kinase inhibitors, such as vemurafenib and dabrafenib. Although these drugs are initially effective, they are not ...curative. Most of the focus to date has been upon genetic mechanisms of acquired resistance; therefore, we must better understand the global signaling adaptations that mediate escape from BRAF inhibition. In the current study, we have used activity-based protein profiling (ABPP) with ATP-analogue probes to enrich kinases and other enzyme classes that contribute to BRAF inhibitor (BRAFi) resistance in four paired isogenic BRAFi-naïve/resistant cell line models. Our analysis showed these cell line models, which also differ in their PTEN status, have considerable heterogeneity in their kinase ATP probe uptake in comparing both naïve cells and adaptations to chronic drug exposure. A number of kinases including FAK1, SLK, and TAOK2 had increased ATP probe uptake in BRAFi resistant cells, while KHS1 (M4K5) and BRAF had decreased ATP probe uptake in the BRAFi-resistant cells. Gene ontology (GO) enrichment analysis revealed BRAFi resistance is associated with a significant enhancement in ATP probe uptake in proteins implicated in cytoskeletal organization and adhesion, and decreases in ATP probe uptake in proteins associated with cell metabolic processes. The ABPP approach was able to identify key phenotypic mediators critical for each BRAFi resistant cell line. Together, these data show that common phenotypic adaptations to BRAF inhibition can be mediated through very different signaling networks, suggesting considerable redundancy within the signaling of BRAF mutant melanoma cells.
Functionalized Xenon as a Biosensor Spence, Megan M.; Rubin, Seth M.; Dimitrov, Ivan E. ...
Proceedings of the National Academy of Sciences - PNAS,
09/2001, Letnik:
98, Številka:
19
Journal Article
Recenzirano
Odprti dostop
The detection of biological molecules and their interactions is a significant component of modern biomedical research. In current biosensor technologies, simultaneous detection is limited to a small ...number of analytes by the spectral overlap of their signals. We have developed an NMR-based xenon biosensor that capitalizes on the enhanced signal-to-noise, spectral simplicity, and chemical-shift sensitivity of laser-polarized xenon to detect specific biomolecules at the level of tens of nanomoles. We present results using xenon "functionalized" by a biotin-modified supramolecular cage to detect biotin-avidin binding. This biosensor methodology can be extended to a multiplexing assay for multiple analytes.
In this paper the results of experimental tests in a boundary layer wind tunnel aimed at direct comparison of the two main methods used to estimate the wind loads acting on tall buildings are ...presented. The tests were performed on two different models of tall buildings: a regular one with a prismatic shape; an irregular one whose external shape was inspired by that of Bank of China Tower in Hong Kong. The two models have the same square footprint and height. The two methods used to measure the wind effects were: the high frequency force balance, which allows to directly measure the global base reactions (two forces in the plane of the base, the two overturning moments and the torsional moment around the vertical axis); the synchronous multi-pressure sensing system, which measures the pressure in several points on the surface of the model, and allows, by means of numerical integration, to estimate both the floor loads and the base reactions. In order to perform a comparison between the results obtained by the high frequency force balance and synchronous multi-pressure sensing system a statistical analysis of the results was carried out; in particular, higher order moments were investigated. Moreover the spectra and the correlation structure of the loads were studied.
Abstract Context The Centers for Medicare & Medicaid Services have elected to include a bereaved family member survey in public reporting of hospice quality data as mandated in the Affordable Care ...Act. However, it is not known what time point after death offers the most reliable responses. Objectives To examine the stability of bereaved family members' survey responses when administered three, six, and nine months after hospice patient death. Methods Bereaved family members from six geographically diverse hospices were interviewed three, six, and nine months after patient death. All respondents completed a core survey. Those whose family member died at home, in a freestanding inpatient unit, or in a nursing home also completed a site-specific module. Stability was based on top-box scoring of each item with kappa statistics, and multivariable regression models were used to assess directionality and predictors of change. To analyze the effects of grief, we assessed response stability among respondents at least one SD from the mean change in grief between three and six months. Results We had 1532 surveys (536 three-month surveys, 529 six-month surveys, and 467 nine-month surveys) returned by 643 respondents (average age 61.7 years, 17.4% black, and 50.5% a child respondent) about hospice decedents (55.3% females, average age 78.6 years, 57.0% noncancer, and 40.0% at home). The average kappa for core items between three and nine months was 0.54 (range 0.42–0.74), 0.58 (0.41–0.69) for home-specific items, and 0.54 (0.39–0.63) for nursing home. Even among individuals demonstrating large grief changes, core items demonstrated moderate to high stability over time. Conclusion Bereaved family member responses are stable between three and nine months after the death of the patient.
Molecular xenomonitoring (MX)-pathogen detection in the mosquito rather than human-is a promising tool for lymphatic filariasis (LF) surveillance. In the Recife Metropolitan Region (RMR), the last LF ...focus in Brazil, Culex quinquefasciatus mosquitoes have been implicated in transmitting Wuchereria bancrofti parasites. This paper presents findings on the ideal mosquito collection method, mosquito dispersion, W. bancrofti infection in mosquitoes and W. bancrofti antigen in humans to aid MX development.
Experiments occurred within two densely populated urban areas of Olinda, RMR, in July and August 2015. U.S. Centers for Disease Control and Prevention (CDC) light traps were compared to battery-powered aspirators as collection methods, and mosquito dispersion was measured by mosquito mark release recapture (MMRR). Female Cx. quinquefasciatus were tested by PCR for W. bancrofti infection, and study area residents were screened by rapid tests for W. bancrofti antigen.
Aspirators caught 2.6 times more total Cx. quinquefasciatus, including 38 times more blood-fed and 5 times more gravid stages, than CDC light traps. They also collected 123 times more Aedes aegypti. Of the 9,644 marked mosquitoes released, only ten (0.01%) were recaptured, nine of which were < 50m (34.8m median, 85.4m maximum) from the release point. Of 9,169 unmarked mosquitoes captured in the MMR, 38.3% were unfed, 48.8% blood-fed, 5.5% semi-gravid, and 7.3% gravid. PCR on 182 pools (1,556 mosquitoes) found no evidence of W. bancrofti infection in Cx. quinquefasciatus. Rapid tests on 110 of 111 eligible residents were all negative for W. bancrofti antigen.
Aspirators were more effective than CDC light traps at capturing Ae. aegypti and all but unfed stages of Cx. quinquefasciatus. Female Cx. quinquefasciatus traveled short (< 86m) distances in this urban area. Lack of evidence for W. bancrofti infection in mosquitoes and antigen in humans in these fine-scale studies does not indicate that LF transmission has ceased in the RMR. A MX surveillance system should consider vector-specific collection methods, mosquito dispersion, and spatial scale but also local context, environmental factors such as sanitation, and host factors such as infection prevalence and treatment history.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Neuronal cell networks have been reconstructed on planar microelectrode arrays (NMAs) from dissociated hippocampal pyramidal neurons. Microcontact printing (pCP) and a photoresist-liftoff method were ...used to selectively localize poly-L-lysine (PLL) on the surface of NWAs. Haptotaxis led to the organization of the neurons into networks localized adjacent to microelectrodes. Various grids of PLL with 2-25-pm-wide lines spaced by 50-200 pm with 15-25-pm nodes at intersection points were used to guide cell body attachment and neurite outgrowth. Bursting activity with spike attenuation was observed, and multichannel recordings detected instances of coincident firing activity. Finally, we present here an extracellular recording from a -2 pm bundle of guided neurites.
Riboswitches are structural RNA elements that are generally located in the 5' untranslated region of messenger RNA. During regulation of gene expression, ligand binding to the aptamer domain of a ...riboswitch triggers a signal to the downstream expression platform. A complete understanding of the structural basis of this mechanism requires the ability to study structural changes over time. Here we use femtosecond X-ray free electron laser (XFEL) pulses to obtain structural measurements from crystals so small that diffusion of a ligand can be timed to initiate a reaction before diffraction. We demonstrate this approach by determining four structures of the adenine riboswitch aptamer domain during the course of a reaction, involving two unbound apo structures, one ligand-bound intermediate, and the final ligand-bound conformation. These structures support a reaction mechanism model with at least four states and illustrate the structural basis of signal transmission. The three-way junction and the P1 switch helix of the two apo conformers are notably different from those in the ligand-bound conformation. Our time-resolved crystallographic measurements with a 10-second delay captured the structure of an intermediate with changes in the binding pocket that accommodate the ligand. With at least a 10-minute delay, the RNA molecules were fully converted to the ligand-bound state, in which the substantial conformational changes resulted in conversion of the space group. Such notable changes in crystallo highlight the important opportunities that micro- and nanocrystals may offer in these and similar time-resolved diffraction studies. Together, these results demonstrate the potential of 'mix-and-inject' time-resolved serial crystallography to study biochemically important interactions between biomacromolecules and ligands, including those that involve large conformational changes.
•We investigate regolith composition with proton albedo.•We find that fluxes of these albedo protons peak near the lunar poles.•The results cannot be due to heavy element enrichment or deeply buried ...hydrogenous material.•The latitudinal distribution does not correlate with that of epithermal or high-energy neutrons.•We find evidence for a top layer (∼10cm) of hydrated material in the lunar regolith.
We find evidence for hydrated material in the lunar regolith using “albedo protons” measured with the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO). Fluxes of these albedo protons, which are emitted from the regolith due to steady bombardment by high energy radiation (Galactic Cosmic Rays), are observed to peak near the poles, and are inconsistent with the latitude trends of heavy element enrichment (e.g., enhanced Fe abundance). The latitudinal distribution of albedo protons anti-correlates with that of epithermal or high energy neutrons. The high latitude enhancement may be due to the conversion of upward directed secondary neutrons from the lunar regolith into tertiary protons due to neutron–proton collisions in hydrated regolith that is more prevalent near the poles. The CRaTER instrument may thus provide important measurements of volatile distributions within regolith at the Moon and potentially, with similar sensors and observations, at other bodies within the Solar System.
Background: HIV-stigma can influence engagement in care and viral suppression rates among persons living with HIV (PLWH). Understanding HIV-provider level stigma and its associated factors may aid in ...development of interventions to improve engagement in care. Methods: We assessed HIV-related stigma, provider knowledge, and practices and beliefs among healthcare providers using an online survey tool. Generalized linear modeling was used to determine factors associated with HIV-stigma score. Results: Among 436 participants, the mean age was 42.3 (SD 12.3), 70% female, 62% white, 65% physicians, and 44% worked at an academic center. The mean HIV Health Care Provider Stigma Scale (HPASS) score was 150.5 (SD 18.9, total = 180 higher score = less stigma) with factor subscale scores of 67.1 (SD 8.2, total = 78) prejudice, 51.3 (SD 9.7, total = 66) stereotyping, and 32.1 (SD 5, total = 36) discrimination. Female sex and comfort with talking about sex and drug use had 4.97 (95% CI 0.61, 9.32) and 1.99 (95% CI 0.88, 3.10) estimated higher HPASS scores. Disagreement/strong disagreement versus strong agreement with the statement that PLWH should be allowed to have babies and feeling responsible for talking about HIV prevention associated with −17.05 (95% CI −25.96, −8.15) and −2.16 (95% CI −3.43, −0.88) estimated lower HPASS scores. Conclusions: The modifiable factors we identified as associated with higher HIV related stigma may provide opportunities for education that may ameliorate these negative associations.
Climate change effects on coastal ecosystems vary on large spatial scales, but can also be highly site dependent at the regional level. The Wadden Sea in the south-eastern North Sea is warming faster ...than many other temperate coastal areas, with surface seawater temperature increasing by almost 2 °C over the last 60 years, nearly double the global ocean mean increase. Climate warming is accompanied by rising sea levels, which have increased by approximately 2 mm yr
−1
over the last 120 years. For this sedimentary coast, the predicted acceleration of sea-level rise will have profound effects on tidal dynamics and bathymetry in the area. This paper synthesises studies of the effects of ocean warming and sea level rise in the northern Wadden Sea, largely based on research conducted at the Wadden Sea Station Sylt of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research. An increasing rate of sea level rise above a critical threshold will lead to coastal erosion and changes in sediment composition, and may cause the transition from a tidal to lagoon-like environment as tidal flats submerge. This involves changes to coastal morphology, and the decline of important habitats such as muddy tidal flats, salt marshes and seagrass meadows, as well as their ecological services (e.g. carbon sequestration). Ocean warming affects plankton dynamics and phenology, as well as benthic community structure by hampering cold-adapted but facilitating warm-adapted species. The latter consist mostly of introduced non-native species originating from warmer coasts, with some epibenthic species acting as ecosystem engineers that create novel habitats on the tidal flats. Warming also changes interactions between species by decoupling existing predator–prey dynamics, as well as forming new interactions in which mass mortalities caused by parasites and pathogens can play an understudied but essential role. However, Wadden Sea organisms can adapt to changing abiotic and biotic parameters via genetic adaptation and phenotypic plasticity, which can also be inherited across generations (transgenerational plasticity), enabling faster plastic responses to future conditions. Important research advances have been made using next-generation molecular tools (-omics), mesocosm experiments simulating future climate scenarios, modelling approaches (ecological network analysis), and internet-based technologies for data collection and archiving. By synthesising these climate change impacts on multiple levels of physical and biological organisation in the northern Wadden Sea, we reveal knowledge gaps that need to be addressed by future investigations and comparative studies in other regions in order to implement management, mitigation and restoration strategies to preserve the uniqueness of this ecosystem of global importance.
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