311 research outputs found

    An α-helical domain within the carboxyl terminus of herpes simplex virus type 1 (HSV-1) glycoprotein B (gB) is associated with cell fusion and resistance to heparin inhibition of cell fusion

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    Previous studies from our laboratory indicated that a 28-amino-acid carboxyl-terminal truncation of gB caused extensive virus-induced cell fusion (Baghian et al., 1993, J Virol 67, 2396-2401). We tested the ability of additional truncations and mutations within gB to cause cell fusion in the recently established virus-free cell fusion assay (Turner et al., 1998, J. Virol. 72, 873-875). Deletion of the carboxyl-terminal 28 amino acids of gB (gBΔ28), which removed part of the predicted α-helical structure H17b, caused extensive cell fusion. A gB truncation specified by gBΔ36, which removed the entire H17b domain, caused as much cell fusion as the gBΔ28 truncation. Similarly, gB(A874P) containing a substitution of an Ala with Pro within H17b caused cell fusion. Heparin, a gB-specific inhibitor of virus-induced cell fusion, inhibited both wild-type gB and gB(syn3)-mediated cell fusion. In contrast, fusion of cells transfected with gB(Δ28), gB(Δ36), or gB(A874P) was resistant to heparin inhibition of cell fusion. We concluded the following: (1) The predicted α-helical structure of H17b within the carboxyl terminus of gB is involved in both virus-induced and virus-free cell fusion. (2) Heparin is a specific inhibitor of gB-mediated fusion in both systems. (3) Resistance to heparin inhibition of gB-mediated cell fusion is associated with the predicted α-helical structure H17b within the carboxyl terminus of gB. © 2001 Academic Press

    The effect of four commercially available steel decontamination processes on the performance of external coatings

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    External coatings used for corrosion protection often have to perform under severely corrosive environments. One major concern regarding coating performance is the negative effect of soluble salts on the steel substrate at the time of coating application, particularly for marine maintenance coating applications. These salts impact the ability of the applied coating systems to protect the steel in several ways including osmotic coating blistering, promotion of under-film metallic corrosion and coating disbondment. This paper focuses on removal of soluble salts contamination by commercially available decontamination processes in relation to external coating systems. We directly compare the effectiveness of four cleaning methods with the performance of ten coating systems. The methodology of surface contamination and preparation of test panels is discussed. After cleaning, sample evaluation for chloride ion contamination levels was carried out using Field method (commercial chloride ion test kit for surfaces) and Ion Chromatography method. Additionally, Scanning Electron Microscopy Energy Dispersive X-ray Spectroscopy (SEM/EDX) and elemental surface mapping analysis were carried out. Laboratory testing of coating systems included Adhesion, Porosity, Electrochemical Impedance Spectroscopy (EIS) analysis and cyclic UV/Salt Fog exposure. The performance of the ten coatings on all the substrates was good, but there were differences in gloss retention and on the degree of checking of the different coatings. The only significant difference in performance of the coatings compared to the method used for cleaning the substrate was higher undercreep observed for most of the coatings applied to the ultra-high pressure water jetted system. This shows the importance of substrate preparation due to the sensitivity of the coatings to even low levels of salt. Two coatings did not show increased undercreep and these may be more applicable for offshore maintenance applications where dry abrasive blasting is sometimes not used. The chemical treatment cleaning method used prior to coating application did not show any significant positive or negative effect on the performance of the applied coatings. The fact that the only differences in performance for the coatings applied to the differently prepared substrates was seen for undercreep suggests that the difference may be exacerbated for immersion situations. A follow up study to this one will examine the performance of internal coatings using immersion tests, and it will be interesting to see if these show increased effect on coating performance

    Photoacoustic Sentinel Lymph Node Imaging with Self-Assembled Copper Neodecanoate Nanoparticles

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    Photoacoustic tomography (PAT) is emerging as a novel, hybrid, and non-ionizing imaging modality because of its satisfactory spatial resolution and high soft tissue contrast. PAT combines the advantages of both optical and ultrasonic imaging methods. It opens up the possibilities for noninvasive staging of breast cancer and may replace sentinel lymph node (SLN) biopsy in clinic in the near future. In this work, we demonstrate for the first time that copper can be used as a contrast metal for near-infrared detection of SLN using PAT. A unique strategy is adopted to encapsulate multiple copies of Cu as organically soluble small molecule complexes within a phospholipid-entrapped nanoparticle. The nanoparticles assumed a size of 80–90 nm, which is the optimum hydrodynamic diameter for its distribution throughout the lymphatic systems. These particles provided at least 6-fold higher signal sensitivity in comparison to blood, which is a natural absorber of light. We also demonstrated that high SLN detection sensitivity with PAT can be achieved in a rodent model. This work clearly demonstrates for the first time the potential use of copper as an optical contrast agent

    Imaging Long-Term Fate of Intramyocardially Implanted Mesenchymal Stem Cells in a Porcine Myocardial Infarction Model

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    The long-term fate of stem cells after intramyocardial delivery is unknown. We used noninvasive, repetitive PET/CT imaging with [18F]FEAU to monitor the long-term (up to 5 months) spatial-temporal dynamics of MSCs retrovirally transduced with the sr39HSV1-tk gene (sr39HSV1-tk-MSC) and implanted intramyocardially in pigs with induced acute myocardial infarction. Repetitive [18F]FEAU PET/CT revealed a biphasic pattern of sr39HSV1-tk-MSC dynamics; cell proliferation peaked at 33–35 days after injection, in periinfarct regions and the major cardiac lymphatic vessels and lymph nodes. The sr39HSV1-tk-MSC–associated [18F]FEAU signals gradually decreased thereafter. Cardiac lymphography studies using PG-Gd-NIRF813 contrast for MRI and near-infrared fluorescence imaging showed rapid clearance of the contrast from the site of intramyocardial injection through the subepicardial lymphatic network into the lymphatic vessels and periaortic lymph nodes. Immunohistochemical analysis of cardiac tissue obtained at 35 and 150 days demonstrated several types of sr39HSV1-tk expressing cells, including fibro-myoblasts, lymphovascular cells, and microvascular and arterial endothelium. In summary, this study demonstrated the feasibility and sensitivity of [18F]FEAU PET/CT imaging for long-term, in-vivo monitoring (up to 5 months) of the fate of intramyocardially injected sr39HSV1-tk-MSC cells. Intramyocardially transplanted MSCs appear to integrate into the lymphatic endothelium and may help improve myocardial lymphatic system function after MI

    ccdc80-l1 Is Involved in Axon Pathfinding of Zebrafish Motoneurons

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    Axon pathfinding is a subfield of neural development by which neurons send out axons to reach the correct targets. In particular, motoneurons extend their axons toward skeletal muscles, leading to spontaneous motor activity. In this study, we identified the zebrafish Ccdc80 and Ccdc80-like1 (Ccdc80-l1) proteins in silico on the basis of their high aminoacidic sequence identity with the human CCDC80 (Coiled-Coil Domain Containing 80). We focused on ccdc80-l1 gene that is expressed in nervous and non-nervous tissues, in particular in territories correlated with axonal migration, such as adaxial cells and muscle pioneers. Loss of ccdc80-l1 in zebrafish embryos induced motility issues, although somitogenesis and myogenesis were not impaired. Our results strongly suggest that ccdc80-l1 is involved in axon guidance of primary and secondary motoneurons populations, but not in their proper formation. ccdc80-l1 has a differential role as regards the development of ventral and dorsal motoneurons, and this is consistent with the asymmetric distribution of the transcript. The axonal migration defects observed in ccdc80-l1 loss-of-function embryos are similar to the phenotype of several mutants with altered Hedgehog activity. Indeed, we reported that ccdc80-l1 expression is positively regulated by the Hedgehog pathway in adaxial cells and muscle pioneers. These findings strongly indicate ccdc80-l1 as a down-stream effector of the Hedgehog pathway

    word~river literary review (2013)

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    wordriver is a literary journal dedicated to the poetry, short fiction, and creative nonfiction of adjunct, part-time and fulltime instructors teaching under a semester or yearly contract in our universities, colleges, and community colleges worldwide. Graduate student teachers who have used up their teaching assistant time and are teaching with adjunct contracts for the remainder of their graduate program are also eligible. We’re looking for work that demonstrates the creativity and craft of adjunct/part-time instructors in English and other disciplines. We reserve first publication rights and onetime anthology publication rights for all work published. We do not accept simultaneous submissions.https://digitalscholarship.unlv.edu/word_river/1004/thumbnail.jp

    Toxicology of chemically modified graphene-based materials for medical application.

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    This review article aims to provide an overview of chemically modified graphene, and graphene oxide (GO), and their impact on toxicology when present in biological systems. Graphene is one of the most promising nanomaterials due to unique physicochemical properties including enhanced optical, thermal, and electrically conductive behavior in addition to mechanical strength and high surface-to-volume ratio. Graphene-based nanomaterials have received much attention over the last 5 years in the biomedical field ranging from their use as polymeric conduits for nerve regeneration, carriers for targeted drug delivery and in the treatment of cancer via photo-thermal therapy. Both in vitro and in vivo biological studies of graphene-based nanomaterials help understand their relative toxicity and biocompatibility when used for biomedical applications. Several studies investigating important material properties such as surface charge, concentration, shape, size, structural defects, and chemical functional groups relate to their safety profile and influence cyto- and geno-toxicology. In this review, we highlight the most recent studies of graphene-based nanomaterials and outline their unique properties, which determine their interactions under a range of environmental conditions. The advent of graphene technology has led to many promising new opportunities for future applications in the field of electronics, biotechnology, and nanomedicine to aid in the diagnosis and treatment of a variety of debilitating diseases
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