269 research outputs found
Interferon block to HIV-1 transduction in macrophages despite SAMHD1 degradation and high deoxynucleoside triphosphates supply
International audienceBackgroundInterferon-α (IFN-α) is an essential mediator of the antiviral response, which potently inhibits both early and late phases of HIV replication. The SAMHD1 deoxynucleoside triphosphate (dNTP) hydrolase represents the prototype of a new antiviral strategy we referred to as "nucleotide depletion". SAMHD1 depletes dNTP levels in myeloid cells below those required for optimal synthesis of HIV viral DNA. HIV-2 and its SIVsm and SIVmac close relatives encode a protein termed Vpx, which counteracts SAMHD1. The potentiality of IFN-α to cooperate with nucleotide depletion has been poorly investigated so far. Here we wondered whether IFN-α affects SAMHD1 expression, Vpx-induced SAMHD1 degradation, Vpx-mediated rescue of HIV-1 transduction and the dNTP supply in monocyte-derived macrophages (MDMs).ResultsIFN-α inhibited HIV-1 transduction in monocytes and in MDMs while SAMHD1 expression was not up-regulated. Vpx triggered SAMHD1 degradation in IFN-α treated cells, and weakly restored HIV-1 transduction from the IFN-α block. Vpx helper effect towards HIV-1 transduction was gradually inhibited with increasing doses of IFN-α. dNTP levels were not significantly affected in MDMs and CD4+ primary activated T lymphocytes by IFN-α and, in correlation with SAMHD1 degradation, restoration of dNTP levels by Vpx was efficient in MDMs treated with the cytokine. In contrast, IFN-α inhibited Vpx-mediated SAMHD1 degradation in THP-1 cells, where, accordingly, Vpx could not rescue HIV-1 transduction.ConclusionOur results suggest that the early antiviral effect of IFN-α results from a mechanism independent of nucleotide depletion in MDMs. In addition, they indicate that the macrophage-like THP-1 cell line may provide a system to characterize an IFN-α-induced cell response that inhibits Vpx-mediated SAMHD1 degradation
The Retroviral Restriction Ability of SAMHD1, but Not Its Deoxynucleotide Triphosphohydrolase Activity, Is Regulated by Phosphorylation
SummarySAMHD1 is a cellular enzyme that depletes intracellular deoxynucleoside triphosphates (dNTPs) and inhibits the ability of retroviruses, notably HIV-1, to infect myeloid cells. Although SAMHD1 is expressed in both cycling and noncycling cells, the antiviral activity of SAMHD1 is limited to noncycling cells. We determined that SAMHD1 is phosphorylated on residue T592 in cycling cells but that this phosphorylation is lost when cells are in a noncycling state. Reverse genetic experiments revealed that SAMHD1 phosphorylated on residue T592 is unable to block retroviral infection, but this modification does not affect the ability of SAMHD1 to decrease cellular dNTP levels. SAMHD1 contains a target motif for cyclin-dependent kinase 1 (cdk1) (592TPQK595), and cdk1 activity is required for SAMHD1 phosphorylation. Collectively, these findings indicate that phosphorylation modulates the ability of SAMHD1 to block retroviral infection without affecting its ability to decrease cellular dNTP levels
Diet quality in childhood: the Generation R Study
Purpose: We aimed to evaluate diet quality of 8-year-old children in the Netherlands, to identify sociodemographic and lifestyle correlates of child diet quality, and to examine tracking of diet quality from ea
Spectral Topography of the Subthalamic Nucleus to Inform Next-Generation Deep Brain Stimulation.
BACKGROUND
The landscape of neurophysiological symptoms and behavioral biomarkers in basal ganglia signals for movement disorders is expanding. The clinical translation of sensing-based deep brain stimulation (DBS) also requires a thorough understanding of the anatomical organization of spectral biomarkers within the subthalamic nucleus (STN).
OBJECTIVES
The aims were to systematically investigate the spectral topography, including a wide range of sub-bands in STN local field potentials (LFP) of Parkinson's disease (PD) patients, and to evaluate its predictive performance for clinical response to DBS.
METHODS
STN-LFPs were recorded from 70 PD patients (130 hemispheres) awake and at rest using multicontact DBS electrodes. A comprehensive spatial characterization, including hot spot localization and focality estimation, was performed for multiple sub-bands (delta, theta, alpha, low-beta, high-beta, low-gamma, high-gamma, and fast-gamma (FG) as well as low- and fast high-frequency oscillations [HFO]) and compared to the clinical hot spot for rigidity response to DBS. A spectral biomarker map was established and used to predict the clinical response to DBS.
RESULTS
The STN shows a heterogeneous topographic distribution of different spectral biomarkers, with the strongest segregation in the inferior-superior axis. Relative to the superiorly localized beta hot spot, HFOs (FG, slow HFO) were localized up to 2 mm more inferiorly. Beta oscillations are spatially more spread compared to other sub-bands. Both the spatial proximity of contacts to the beta hot spot and the distance to higher-frequency hot spots were predictive for the best rigidity response to DBS.
CONCLUSIONS
The spatial segregation and properties of spectral biomarkers within the DBS target structure can additionally be informative for the implementation of next-generation sensing-based DBS. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
2017-2018 Mostly Music: Franz Joseph Haydn
https://spiral.lynn.edu/conservatory_mostlymusic/1029/thumbnail.jp
Software Startups -- A Research Agenda
Software startup companies develop innovative, software-intensive products
within limited time frames and with few resources, searching for sustainable
and scalable business models. Software startups are quite distinct from
traditional mature software companies, but also from micro-, small-, and
medium-sized enterprises, introducing new challenges relevant for software
engineering research. This paper's research agenda focuses on software
engineering in startups, identifying, in particular, 70+ research questions in
the areas of supporting startup engineering activities, startup evolution
models and patterns, ecosystems and innovation hubs, human aspects in software
startups, applying startup concepts in non-startup environments, and
methodologies and theories for startup research. We connect and motivate this
research agenda with past studies in software startup research, while pointing
out possible future directions. While all authors of this research agenda have
their main background in Software Engineering or Computer Science, their
interest in software startups broadens the perspective to the challenges, but
also to the opportunities that emerge from multi-disciplinary research. Our
audience is therefore primarily software engineering researchers, even though
we aim at stimulating collaborations and research that crosses disciplinary
boundaries. We believe that with this research agenda we cover a wide spectrum
of the software startup industry current needs
Recommended from our members
Predicting breast cancer response to neoadjuvant treatment using multi-feature MRI: results from the I-SPY 2 TRIAL.
Dynamic contrast-enhanced (DCE) MRI provides both morphological and functional information regarding breast tumor response to neoadjuvant chemotherapy (NAC). The purpose of this retrospective study is to test if prediction models combining multiple MRI features outperform models with single features. Four features were quantitatively calculated in each MRI exam: functional tumor volume, longest diameter, sphericity, and contralateral background parenchymal enhancement. Logistic regression analysis was used to study the relationship between MRI variables and pathologic complete response (pCR). Predictive performance was estimated using the area under the receiver operating characteristic curve (AUC). The full cohort was stratified by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status (positive or negative). A total of 384 patients (median age: 49 y/o) were included. Results showed analysis with combined features achieved higher AUCs than analysis with any feature alone. AUCs estimated for the combined versus highest AUCs among single features were 0.81 (95% confidence interval [CI]: 0.76, 0.86) versus 0.79 (95% CI: 0.73, 0.85) in the full cohort, 0.83 (95% CI: 0.77, 0.92) versus 0.73 (95% CI: 0.61, 0.84) in HR-positive/HER2-negative, 0.88 (95% CI: 0.79, 0.97) versus 0.78 (95% CI: 0.63, 0.89) in HR-positive/HER2-positive, 0.83 (95% CI not available) versus 0.75 (95% CI: 0.46, 0.81) in HR-negative/HER2-positive, and 0.82 (95% CI: 0.74, 0.91) versus 0.75 (95% CI: 0.64, 0.83) in triple negatives. Multi-feature MRI analysis improved pCR prediction over analysis of any individual feature that we examined. Additionally, the improvements in prediction were more notable when analysis was conducted according to cancer subtype
An evaluation of purified Salmonella Typhi protein antigens for the serological diagnosis of acute typhoid fever.
OBJECTIVES: The diagnosis of typhoid fever is a challenge. Aiming to develop a typhoid diagnostic we measured antibody responses against Salmonella Typhi (S. Typhi) protein antigens and the Vi polysaccharide in a cohort of Bangladeshi febrile patients. METHODS: IgM against 12 purified antigens and the Vi polysaccharide was measured by ELISA in plasma from patients with confirmed typhoid fever (n = 32), other confirmed infections (n = 17), and healthy controls (n = 40). ELISAs with the most specific antigens were performed on plasma from 243 patients with undiagnosed febrile disease. RESULTS: IgM against the S. Typhi protein antigens correlated with each other (rho > 0.8), but not against Vi (rho 0.85, respectively. Applying a dynamic cut-off to patients with undiagnosed febrile disease suggested that 34-58% had an IgM response indicative of typhoid. CONCLUSIONS: We evaluated the diagnostic potential of several S. Typhi antigens; our assays give good sensitivity and specificity, but require further assessment in differing patient populations
The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry
The developments of the open-source OpenMolcas chemistry software environment since spring 2020 are described, with a focus on novel functionalities accessible in the stable branch of the package or via interfaces with other packages. These developments span a wide range of topics in computational chemistry and are presented in thematic sections: electronic structure theory, electronic spectroscopy simulations, analytic gradients and molecular structure optimizations, ab initio molecular dynamics, and other new features. This report offers an overview of the chemical phenomena and processes OpenMolcas can address, while showing that OpenMolcas is an attractive platform for state-of-the-art atomistic computer simulations
Global, regional, and national disability-adjusted life-years (DALYs) for 359 diseases and injuries and healthy life expectancy (HALE) for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017.
How long one lives, how many years of life are spent in good and poor health, and how the population's state of health and leading causes of disability change over time all have implications for policy, planning, and provision of services. We comparatively assessed the patterns and trends of healthy life expectancy (HALE), which quantifies the number of years of life expected to be lived in good health, and the complementary measure of disability-adjusted life-years (DALYs), a composite measure of disease burden capturing both premature mortality and prevalence and severity of ill health, for 359 diseases and injuries for 195 countries and territories over the past 28 years. Methods We used data for age-specific mortality rates, years of life lost (YLLs) due to premature mortality, and years lived with disability (YLDs) from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 to calculate HALE and DALYs from 1990 to 2017. We calculated HALE using age-specific mortality rates and YLDs per capita for each location, age, sex, and year. We calculated DALYs for 359 causes as the sum of YLLs and YLDs. We assessed how observed HALE and DALYs differed by country and sex from expected trends based on Socio-demographic Index (SDI). We also analysed HALE by decomposing years of life gained into years spent in good health and in poor health, between 1990 and 2017, and extra years lived by females compared with males. Findings Globally, from 1990 to 2017, life expectancy at birth increased by 7·4 years (95% uncertainty interval 7·1-7·8), from 65·6 years (65·3-65·8) in 1990 to 73·0 years (72·7-73·3) in 2017. The increase in years of life varied from 5·1 years (5·0-5·3) in high SDI countries to 12·0 years (11·3-12·8) in low SDI countries. Of the additional years of life expected at birth, 26·3% (20·1-33·1) were expected to be spent in poor health in high SDI countries compared with 11·7% (8·8-15·1) in low-middle SDI countries. HALE at birth increased by 6·3 years (5·9-6·7), from 57·0 years (54·6-59·1) in 1990 to 63·3 years (60·5-65·7) in 2017. The increase varied from 3·8 years (3·4-4·1) in high SDI countries to 10·5 years (9·8-11·2) in low SDI countries. Even larger variations in HALE than these were observed between countries, ranging from 1·0 year (0·4-1·7) in Saint Vincent and the Grenadines (62·4 years [59·9-64·7] in 1990 to 63·5 years [60·9-65·8] in 2017) to 23·7 years (21·9-25·6) in Eritrea (30·7 years [28·9-32·2] in 1990 to 54·4 years [51·5-57·1] in 2017). In most countries, the increase in HALE was smaller than the increase in overall life expectancy, indicating more years lived in poor health. In 180 of 195 countries and territories, females were expected to live longer than males in 2017, with extra years lived varying from 1·4 years (0·6-2·3) in Algeria to 11·9 years (10·9-12·9) in Ukraine. Of the extra years gained, the proportion spent in poor health varied largely across countries, with less than 20% of additional years spent in poor health in Bosnia and Herzegovina, Burundi, and Slovakia, whereas in Bahrain all the extra years were spent in poor health. In 2017, the highest estimate of HALE at birth was in Singapore for both females (75·8 years [72·4-78·7]) and males (72·6 years [69·8-75·0]) and the lowest estimates were in Central African Republic (47·0 years [43·7-50·2] for females and 42·8 years [40·1-45·6] for males). Globally, in 2017, the five leading causes of DALYs were neonatal disorders, ischaemic heart disease, stroke, lower respiratory infections, and chronic obstructive pulmonary disease. Between 1990 and 2017, age-standardised DALY rates decreased by 41·3% (38·8-43·5) for communicable diseases and by 49·8% (47·9-51·6) for neonatal disorders. For non-communicable diseases, global DALYs increased by 40·1% (36·8-43·0), although age-standardised DALY rates decreased by 18·1% (16·0-20·2)
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