179 research outputs found

    A prescription for the Epley maneuver: www.youtube.com?

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    OBJECTIVES: Video-sharing Web sites are being used for information about common conditions including dizziness. The Epley maneuver (EM) is a simple and effective treatment for benign paroxysmal positional vertigo (BPPV) of the posterior canal. However, the maneuver is underused in routine care. In this study, we aimed to describe and analyze the available information about the EM on youtube.com. METHODS: A YouTube search was performed on August 31, 2011, for videos that demonstrated the entire EM. Detailed data were abstracted from each video and corresponding Web site. Videos were rated on the accuracy of the maneuver by 2 authors, with differences resolved by adjudication. Comments posted by viewers were assessed for themes regarding video use. RESULTS: Of the 3,319 videos identified, 33 demonstrated the EM. The total number of hits for all videos was 2,755,607. The video with the most hits (802,471) was produced by the American Academy of Neurology. Five of the videos accounted for 85% of all the hits. The maneuver demonstration was rated as accurate in 64% (21) of the videos. Themes derived from the 424 posted comments included patients self-treating with the maneuver after reviewing the videos, and providers using the videos as a prescribed treatment or for educational purposes. CONCLUSION: Accurate video demonstration of the Epley maneuver is available and widely viewed on YouTube. Video-sharing media may be an important way to disseminate effective interventions such as the EM. The impact of video Web sites on outcomes and costs of care is not known and warrants future study

    Solar-electric-propulsion cargo vehicles for split/sprint Mars mission

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    In support of the proposed exploration of Mars, an unmanned cargo ferry SEMM1 (Solar Electric Mars Mission) was designed. The vehicle is based on solar electric propulsion, and required to transport a cargo of 61,000 kg. The trajectory is a combination of spirals; first, out from LEO, then around the sun, then spiral down to low Mars orbit. The spacecraft produces 3.03 MWe power using photovoltaic flexible blanket arrays. Ion thrusters using argon as a propellant were selected to drive the ship, providing about 60 Newtons of thrust in low Earth orbit. The configuration is based on two long truss beams to which the 24 individual, self-deployable, solar arrays are attached. The main body module supports the two beams and houses the computers, electrical, and control equipment. The thruster module is attached to the rear of the main body, and the cargo to the front

    Multimodal MRI as a diagnostic biomarker for amyotrophic lateral sclerosis

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    Objective Reliable biomarkers for amyotrophic lateral sclerosis ( ALS ) are needed, given the clinical heterogeneity of the disease. Here, we provide proof‐of‐concept for using multimodal magnetic resonance imaging ( MRI ) as a diagnostic biomarker for ALS . Specifically, we evaluated the added diagnostic utility of proton magnetic resonance spectroscopy ( MRS ) to diffusion tensor imaging ( DTI ). Methods Twenty‐nine patients with ALS and 30 age‐ and gender‐matched healthy controls underwent brain MRI which used proton MRS including spectral editing techniques to measure γ‐aminobutyric acid ( GABA ) and DTI to measure fractional anisotropy of the corticospinal tract. Data were analyzed using logistic regression, t ‐tests, and generalized linear models with leave‐one‐out analysis to generate and compare the resulting receiver operating characteristic ( ROC ) curves. Results The diagnostic accuracy is significantly improved when the MRS data were combined with the DTI data as compared to the DTI data only (area under the ROC curves ( AUC ) = 0.93 vs. AUC  = 0.81; P  = 0.05). The combined MRS and DTI data resulted in sensitivity of 0.93, specificity of 0.85, positive likelihood ratio of 6.20, and negative likelihood ratio of 0.08 whereas the DTI data only resulted in sensitivity of 0.86, specificity of 0.70, positive likelihood ratio of 2.87, and negative likelihood ratio of 0.20. Interpretation Combining multiple advanced neuroimaging modalities significantly improves disease discrimination between ALS patients and healthy controls. These results provide an important step toward advancing a multimodal MRI approach along the diagnostic test development pathway for ALS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106065/1/acn330.pd

    Overview of the Role for Calreticulin in the Enhancement of Wound Healing through Multiple Biological Effects

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    Calreticulin (CRT), an intracellular chaperone protein crucial for the proper folding and transport of proteins through the endoplasmic reticulum, has more recent acclaim as a critical regulator of extracellular functions, particularly in mediating cellular migration and as a requirement for phagocytosis of apoptotic cells. Consistent with these functions, we show that the topical application of CRT has profound effects on the process of wound healing by causing a dose-dependent increase in epithelial migration and granulation tissue formation in both murine and porcine normal and impaired animal models of skin injury. These effects of CRT are substantiated, in vitro, as we show that CRT strongly induces cell migration/wound closure of human keratinocytes and fibroblasts, using a wound/scratch plate assay, and stimulates cellular proliferation of human keratinocytes, fibroblasts, and vascular endothelial cells, providing mechanistic insight into how CRT functions in repair. Similarly, in both animal models, the histology of the wounds show marked proliferation of basal keratinocytes and dermal fibroblasts, dense cellularity of the dermis with notably increased numbers of macrophages and well-organized collagen fibril deposition. Thus, CRT profoundly affects the wound healing process by recruiting cells essential for repair into the wound, stimulating cell growth, and increasing extracellular matrix production

    Nanoparticles decorated with proteolytic enzymes, a promising strategy to overcome the mucus barrier

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    The intestinal mucus gel layer represents a stumbling block for drug adsorption. This study is aimed to formulate a nanoparticulate system able to overcome this barrier by cleaving locally the glycoprotein substructures of the mucus. Mucolytic enzymes such as papain (PAP) and bromelain (BRO) were covalently conjugated to poly(acrylic acid) (PAA). Nanoparticles (NPs) were then formulated via ionic gelation method and characterized by particle size, zeta potential, enzyme content and enzymatic activity. The NPs permeation quantified by rotating tube studies was correlated with changes in the mucus gel layer structure determined by pulsed-gradient-spin-echo NMR (PGSE-NMR), small-angle neutron scattering (SANS) and spin-echo SANS (SESANS). PAP and BRO functionalized NPs had an average size in the range of 250 and 285 nm and a zeta potential that ranged between -6 and -5 mV. The enzyme content was 242 μg enzyme/mg for PAP modified NPs and 253 μg enzyme/mg for BRO modified NPs. The maintained enzymatic activity was 43% for PAP decorated NPs and 76% for BRO decorated NPs. The rotating tube technique revealed a better performance of BRO decorated NPs compared to PAA decorated NPs, with a 4.8 fold higher concentration of NPs in the inner slice of mucus. Addition of 0.5wt% of enzyme functionalized NPs to 5wt% intestinal mucin led to c.a. 2 fold increase in the mobility of the mucin as measured by PGSE-NMR indicative of a significant break-up of the structure of the mucin. SANS and SESANS measurements further revealed a change in structure of the intestinal mucus induced by the incorporation of the functionalized NPs mostly occurring at a lengthscale longer than 0.5 μm. Accordingly, BRO decorated NPs show higher potential then PAP functionalized NPs as mucus permeating drug delivery systems

    EEA1, an early endosome-associated protein: EEA1 is a conserved α-helical peripheral membrane-protein flanked by cysteine fingers and contains a calmodulin-binding IQ motif

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    Early endosomes are cellular compartments receiving endocytosed material and sorting them for vesicular transport to late endosomes and lysosomes or for recycling to the plasma membrane. We have cloned a human cDNA encoding an evolutionarily conserved 180-kDa protein on early endosomes named EEA1 (Early Endosome Antigen1). EEA1 is associated with early endosomes since it co-localizes by immunofluorescence with the transferrin receptor and with Rab5 but not with Rab7. Immunoelectron microscopy shows that it is associated with tubulovesicular early endosomes containing internalized bovine serum albumin-gold. EEA1 is a hydrophilic peripheral membrane protein present in cytosol and membrane fractions. It partitions in the aqueous phase after Triton X-114 solubilization and is extracted from membranes by 0.3 M NaCl. It is a predominantly cu-helical protein sharing 17-20% sequence identity with the myosins and contains a calmodulin-binding IQ motif. It is flanked by metal-binding, cysteine ''finger'' motifs. The COOH-terminal fingers, Cys-X(2)-Cys-X(12)-Cys-X(2)-Cys and Cys-X(2)-Cys-X(16)-Cys-X(2)-Cys, are present within a region that is strikingly homologous with Saccharomyces cerevisiae FAB1 protein required for endocytosis and with Caenarhabditis elegans ZK632. These fingers also show limited conservation with S. cerevisiae VAC1, Vps11, and Vps18p proteins implicated in vacuolar transport. We propose that EEA1 is required for vesicular transport of proteins through early endosomes and that its finger motifs are required for this activity

    Intracellular coexpression of CXC- and CC– chemokine receptors and their ligands in human melanoma cell lines and dynamic variations after xenotransplantation

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    BackgroundChemokines have been implicated in tumor progression and metastasis. In melanoma, chemokine receptors have been implicated in organ selective metastasis by regulating processes such as chemoattraction, adhesion and survival.MethodsIn this study we have analyzed, using flow cytometry, the systems formed by the chemokine receptors CXCR3, CXCR4, CXCR7, CCR7 and CCR10 and their ligands in thirteen human melanoma cell lines (five established from primary tumors and eight established from metastasis from different tissues). WM-115 and WM-266.4 melanoma cell lines (obtained from a primary and a metastatic melanoma respectively) were xenografted in nude mice and the tumors and cell lines derived from them were also analyzed.ResultsOur results show that the melanoma cell lines do not express or express in a low degree the chemokine receptors on their cell surface. However, melanoma cell lines show intracellular expression of all the aforementioned receptors and most of their respective ligands. When analyzing the xenografts and the cell lines obtained from them we found variations in the intracellular expression of chemokines and chemokine receptors that differed between the primary and metastatic cell lines. However, as well as in the original cell lines, minute or no expression of the chemokine receptors was observed at the cell surface.ConclusionsCoexpression of chemokine receptors and their ligands was found in human melanoma cell lines. However, this expression is intracellular and receptors are not found at the cell membrane nor chemokines are secreted to the cell medium. The levels of expressed chemokine receptors and their ligands show dynamic variations after xenotransplantation that differ depending on the origin of the cell line (from primary tumor or from metastasis)

    Can bryophyte groups increase functional resolution in tundra ecosystems?

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    Funding Information: This study was supported by a grant to SL from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie, Grant No. 797446 and by the Independent Research Fund Denmark, Grant no. 0135-00140B. Funding from the Academy of Finland (grant 322266), National Science Foundation (1504224, 1836839, PLR-1504381 and PLR-1836898), Independent Research Fund Denmark (9040-00314B), Moscow State University, (project No 121032500089-1), Natural Sciences and Engineering Research Council of Canada, ArcticNet, Polar Continental Shelf Program, Northern Science Training Program, Polar Knowledge Canada, Royal Canadian Mounted Police, Tomsk State University competitiveness improvement program and the Russian Science Foundation (grant No 20-67-46018) are gratefully acknowledged. Matthias Ahrens provided valuable insights on the cushion growth form, and we are most thankful. We thank Gaius Shaver and two anonymous reviewers for providing valuable critique and input to earlier versions of this manuscript. Publisher Copyright: © the author(s) or their institution(s).The relative contribution of bryophytes to plant diversity, primary productivity, and ecosystem functioning increases towards colder climates. Bryophytes respond to environmental changes at the species level, but because bryophyte species are relatively difficult to identify, they are often lumped into one functional group. Consequently, bryophyte function remains poorly resolved. Here, we explore how higher resolution of bryophyte functional diversity can be encouraged and implemented in tundra ecological studies. We briefly review previous bryophyte functional classifications and the roles of bryophytes in tundra ecosystems and their susceptibility to environmental change. Based on shoot morphology and colony organization, we then propose twelve easily distinguishable bryophyte functional groups. To illustrate how bryophyte functional groups can help elucidate variation in bryophyte effects and responses, we compiled existing data on water holding capacity, a key bryophyte trait. Although plant functional groups can mask potentially high interspecific and intraspecific variability, we found better separation of bryophyte functional group means compared with previous grouping systems regarding water holding capacity. This suggests that our bryophyte functional groups truly represent variation in the functional roles of bryophytes in tundra ecosystems. Lastly, we provide recommendations to improve the monitoring of bryophyte community changes in tundra study sites.Peer reviewe

    Locus coeruleus imaging as a biomarker for noradrenergic dysfunction in neurodegenerative diseases.

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    Pathological alterations to the locus coeruleus, the major source of noradrenaline in the brain, are histologically evident in early stages of neurodegenerative diseases. Novel MRI approaches now provide an opportunity to quantify structural features of the locus coeruleus in vivo during disease progression. In combination with neuropathological biomarkers, in vivo locus coeruleus imaging could help to understand the contribution of locus coeruleus neurodegeneration to clinical and pathological manifestations in Alzheimer's disease, atypical neurodegenerative dementias and Parkinson's disease. Moreover, as the functional sensitivity of the noradrenergic system is likely to change with disease progression, in vivo measures of locus coeruleus integrity could provide new pathophysiological insights into cognitive and behavioural symptoms. Locus coeruleus imaging also holds the promise to stratify patients into clinical trials according to noradrenergic dysfunction. In this article, we present a consensus on how non-invasive in vivo assessment of locus coeruleus integrity can be used for clinical research in neurodegenerative diseases. We outline the next steps for in vivo, post-mortem and clinical studies that can lay the groundwork to evaluate the potential of locus coeruleus imaging as a biomarker for neurodegenerative diseases.Includes MRC, NIHR, Wellcome Trust, H2020 and FP7
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