837 research outputs found
Angiogenic regulatory influence of extracellular matrix deposited by resting state asthmatic and non‐asthmatic airway smooth muscle cells is similar
The extracellular matrix (ECM) is the tissue microenvironment that regulates the characteristics of stromal and systemic cells to control processes such as inflammation and angiogenesis. Despite ongoing anti-inflammatory treatment, low levels of inflammation exist in the airways in asthma, which alters ECM deposition by airway smooth muscle (ASM) cells. The altered ECM causes aberrant behaviour of cells, such as endothelial cells, in the airway tissue. We therefore sought to characterize the composition and angiogenic potential of the ECM deposited by asthmatic and non-asthmatic ASM. After 72 hours under non-stimulated conditions, the ECM deposited by primary human asthmatic ASM cells was equal in total protein, collagen I, III and fibronectin content to that from non-asthmatic ASM cells. Further, the matrices of non-asthmatic and asthmatic ASM cells were equivalent in regulating the growth, activity, attachment and migration of primary human umbilical vein endothelial cells (HUVECs). Under basal conditions, asthmatic and non-asthmatic ASM cells intrinsically deposit an ECM of equivalent composition and angiogenic potential. Previous findings indicate that dysregulation of the airway ECM is driven even by low levels of inflammatory provocation. This study suggests the need for more effective anti-inflammatory therapies in asthma to maintain the airway ECM and regulate ECM-mediated aberrant angiogenesis
General Analysis of Antideuteron Searches for Dark Matter
Low energy cosmic ray antideuterons provide a unique low background channel
for indirect detection of dark matter. We compute the cosmic ray flux of
antideuterons from hadronic annihilations of dark matter for various Standard
Model final states and determine the mass reach of two future experiments
(AMS-02 and GAPS) designed to greatly increase the sensitivity of antideuteron
detection over current bounds. We consider generic models of scalar, fermion,
and massive vector bosons as thermal dark matter, describe their basic features
relevant to direct and indirect detection, and discuss the implications of
direct detection bounds on models of dark matter as a thermal relic. We also
consider specific dark matter candidates and assess their potential for
detection via antideuterons from their hadronic annihilation channels. Since
the dark matter mass reach of the GAPS experiment can be well above 100 GeV, we
find that antideuterons can be a good indirect detection channel for a variety
of thermal relic electroweak scale dark matter candidates, even when the rate
for direct detection is highly suppressed.Comment: 44 pages, 15 Figure
Injectable Poly-l-Lactic Acid: A Novel Sculpting Agent for the Treatment of Dermal Fat Atrophy After Severe Acne
Acne vulgaris affects up to 80% of people 11 to 30 years of age, and scarring can occur for up to 95% of these patients. Scarring may be pitted or hypertrophic in nature, although in most cases it is atrophic. Atrophic acne scarring follows dermal collagen and fat loss after moderate to severe acne infection. Injectable poly-L-acid (PLLA) is a biocompatible, biodegradable, synthetic polymer device that is hypothesized to enhance dermal volume via the endogenous production of fibroblasts and, subsequently, collagen. The gradual improvements in cutaneous volume observed after treatment with injectable PLLA have been noted to last up to 2 years. The case studies presented describe the use of injectable PLLA to correct dermal fat loss in macular atrophic acne scarring of the cheeks. Two female patients underwent three treatment sessions with injectable PLLA over a 12-week period. At each treatment session, the reconstituted product was injected into the deep dermis under the depressed portion of the scar. Both patients were extremely pleased with their results at, respectively, 1- and 4-year follow-up evaluations. Patients experienced minimal swelling and redness after injection and no product-related adverse events such as papule and/or nodule formation. The author believes these data suggest that injectable PLLA is a good treatment option for the correction of macular atropic scarring with thin dermis (off-label use), particularly compared with other injectable fillers currently used for this indication that have shorter durations of effect
Towards strange metallic holography
We initiate a holographic model building approach to `strange metallic'
phenomenology. Our model couples a neutral Lifshitz-invariant quantum critical
theory, dual to a bulk gravitational background, to a finite density of gapped
probe charge carriers, dually described by D-branes. In the physical regime of
temperature much lower than the charge density and gap, we exhibit anomalous
scalings of the temperature and frequency dependent conductivity. Choosing the
dynamical critical exponent appropriately we can match the non-Fermi liquid
scalings, such as linear resistivity, observed in strange metal regimes. As
part of our investigation we outline three distinct string theory realizations
of Lifshitz geometries: from F theory, from polarised branes, and from a
gravitating charged Fermi gas. We also identify general features of
renormalisation group flow in Lifshitz theories, such as the appearance of
relevant charge-charge interactions when . We outline a program to
extend this model building approach to other anomalous observables of interest
such as the Hall conductivity.Comment: 71 pages, 8 figure
A novel malaria vaccine candidate antigen expressed in Tetrahymena thermophila
Development of effective malaria vaccines is hampered by the problem of producing correctly folded Plasmodium proteins for use as vaccine components. We have investigated the use of a novel ciliate expression system, Tetrahymena thermophila, as a P. falciparum vaccine antigen platform. A synthetic vaccine antigen composed of N-terminal and C-terminal regions of merozoite surface protein-1 (MSP-1) was expressed in Tetrahymena thermophila. The recombinant antigen was secreted into the culture medium and purified by monoclonal antibody (mAb) affinity chromatography. The vaccine was immunogenic in MF1 mice, eliciting high antibody titers against both N- and C-terminal components. Sera from immunized animals reacted strongly with P. falciparum parasites from three antigenically different strains by immunofluorescence assays, confirming that the antibodies produced are able to recognize parasite antigens in their native form. Epitope mapping of serum reactivity with a peptide library derived from all three MSP-1 Block 2 serotypes confirmed that the MSP-1 Block 2 hybrid component of the vaccine had effectively targeted all three serotypes of this polymorphic region of MSP-1. This study has successfully demonstrated the use of Tetrahymena thermophila as a recombinant protein expression platform for the production of malaria vaccine antigens
Human Immunity and the Design of Multi-Component, Single Target Vaccines
BACKGROUND: Inclusion of multiple immunogens to target a single organism is a strategy being pursued for many experimental vaccines, especially where it is difficult to generate a strongly protective response from a single immunogen. Although there are many human vaccines that contain multiple defined immunogens, in almost every case each component targets a different pathogen. As a consequence, there is little practical experience for deciding where the increased complexity of vaccines with multiple defined immunogens vaccines targeting single pathogens will be justifiable. METHODOLOGY/PRINCIPAL FINDINGS: A mathematical model, with immunogenicity parameters derived from a database of human responses to established vaccines, was used to predict the increase in the efficacy and the proportion of the population protected resulting from addition of further immunogens. The gains depended on the relative protection and the range of responses in the population to each immunogen and also to the correlation of the responses between immunogens. In most scenarios modeled, the gain in overall efficacy obtained by adding more immunogens was comparable to gains obtained from a single immunogen through the use of better formulations or adjuvants. Multi-component single target vaccines were more effective at decreasing the proportion of poor responders than increasing the overall efficacy of the vaccine in a population. CONCLUSIONS/SIGNIFICANCE: Inclusion of limited number of antigens in a vaccine aimed at targeting a single organism will increase efficacy, but the gains are relatively modest and for a practical vaccine there are constraints that are likely to limit multi-component single target vaccines to a small number of key antigens. The model predicts that this type of vaccine will be most useful where the critical issue is the reduction in proportion of poor responders
The Impact of Combination Antiretroviral Therapy and its Interruption on Anxiety, Stress, Depression and Quality of Life in Thai Patients
OBJECTIVE: Investigation on anxiety, stress, depression, and quality of life (QoL) within STACCATO, a randomised trial of two treatment strategies: CD4 guided scheduled treatment interruption (STI) compared to continuous treatment (CT). PARTICIPANTS: Thai patients with HIV-infection enrolled in the STACCATO trial. METHODS: Anxiety, depression assessed by the questionnaires Hospital Anxiety and Depression Scale (HADS) and DASS, stress assessed by the Depression Anxiety Stress Scale (DASS), and QoL evaluated by the HIV Medical Outcome Study (MOS-HIV) questionnaires. Answers to questionnaires were evaluated at 4 time-points: baseline, 24 weeks, 48 weeks and at the end of STACCATO. RESULTS: A total of 251 patients answered the HADS/DASS and 241 answered the MOS-HIV of the 379 Thai patients enrolled into STACCATO (66.2 and 63.6% respectively). At baseline 16.3% and 7.2% of patients reported anxiety and depression using HADS scale. Using the DASS scale, 35.1% reported mild to moderate and 9.6% reported severe anxiety; 8.8% reported mild to moderate and 2.0% reported severe depression; 42.6% reported mild to moderate and 4.8% reported severe stress. We showed a significant improvement of the MHS across time (p=0.001), but no difference between arms (p=0.17). The summarized physical health status score (PHS) did not change during the trial (p=0.15) nor between arm (p=0.45). There was no change of MHS or PHS in the STI arm, taking into account the number of STI cycle (p=0.30 and 0.57) but MHS significant increased across time-points (p=0.007). CONCLUSION: Antiretroviral therapy improved mental health and QOL, irrespective of the treatment strategy
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A simple and versatile 2-dimensional platform to study plant germination and growth under controlled humidity
We describe a simple, inexpensive, but remarkably versatile and controlled growth environment for the observation of plant germination and seedling root growth on a flat, horizontal surface over periods of weeks. The setup provides to each plant a controlled humidity (between 56% and 91% RH), and contact with both nutrients and atmosphere. The flat and horizontal geometry of the surface supporting the roots eliminates the gravitropic bias on their development and facilitates the imaging of the entire root system. Experiments can be setup under sterile conditions and then transferred to a non-sterile environment. The system can be assembled in 1-2 minutes, costs approximately 8.78 per experiment in disposables), and is easily scalable to a variety of plants. We demonstrate the performance of the system by germinating, growing, and imaging Wheat (Triticum aestivum), Corn (Zea mays), and Wisconsin Fast Plants (Brassica rapa). Germination rates were close to those expected for optimal conditions
Electrocortical evidence for long-term incidental spatial learning through modified navigation instructions
© Springer Nature Switzerland AG 2018. The use of Navigation Assistance Systems for spatial orienting has become increasingly popular. Such automated navigation support, however, comes with a reduced processing of the surrounding environment and often with a decline of spatial orienting ability. To prevent such deskilling and to support spatial learning, the present study investigated incidental spatial learning by comparing standard navigation instructions with two modified navigation instruction conditions. The first modified instruction condition highlighted landmarks and provided additional redundant information regarding the landmark (contrast condition), while the second highlighted landmarks and included information of personal interest to the participant (personal-reference condition). Participants’ spatial knowledge of the previously unknown virtual city was tested three weeks later. Behavioral and electroencephalographic (EEG) data demonstrated enhanced spatial memory performance for participants in the modified navigation instruction conditions without further differentiating between modified instructions. Recognition performance of landmarks was better and the late positive complex of the event-related potential (ERP) revealed amplitude differences reflecting an increased amount of recollected information for modified navigation instructions. The results indicate a significant long-term spatial learning effect when landmarks are highlighted during navigation instructions
EGFRvIV: a previously uncharacterized oncogenic mutant reveals a kinase autoinhibitory mechanism
Tumor cells often subvert normal regulatory mechanisms of signal transduction. This study shows this principle by studying yet uncharacterized mutants of the epidermal growth factor receptor (EGFR) previously identified in glioblastoma multiforme, which is the most aggressive brain tumor in adults. Unlike the well-characterized EGFRvIII mutant form, which lacks a portion of the ligand-binding cleft within the extracellular domain, EGFRvIVa and EGFRvIVb lack internal segments distal to the intracellular tyrosine kinase domain. By constructing the mutants and by ectopic expression in naive cells, we show that both mutants confer an oncogenic potential in vitro, as well as tumorigenic growth in animals. The underlying mechanisms entail constitutive receptor dimerization and basal activation of the kinase domain, likely through a mechanism that relieves a restraining molecular fold, along with stabilization due to association with HSP90. Phosphoproteomic analyses delineated the signaling pathways preferentially engaged by EGFRvIVb-identified unique substrates. This information, along with remarkable sensitivities to tyrosine kinase blockers and to a chaperone inhibitor, proposes strategies for pharmacological interception in brain tumors harboring EGFRvIV mutations.Goldhirsh FoundationNational Cancer Institute (U.S.) (CA118705)National Cancer Institute (U.S.) (CA141556)National Cancer Institute (U.S.) (U54-CA112967
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