205 research outputs found

    LightDepth: Single-View Depth Self-Supervision from Illumination Decline

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    Single-view depth estimation can be remarkably effective if there is enough ground-truth depth data for supervised training. However, there are scenarios, especially in medicine in the case of endoscopies, where such data cannot be obtained. In such cases, multi-view self-supervision and synthetic-to-real transfer serve as alternative approaches, however, with a considerable performance reduction in comparison to supervised case. Instead, we propose a single-view self-supervised method that achieves a performance similar to the supervised case. In some medical devices, such as endoscopes, the camera and light sources are co-located at a small distance from the target surfaces. Thus, we can exploit that, for any given albedo and surface orientation, pixel brightness is inversely proportional to the square of the distance to the surface, providing a strong single-view self-supervisory signal. In our experiments, our self-supervised models deliver accuracies comparable to those of fully supervised ones, while being applicable without depth ground-truth data

    BCR-ABL induces the expression of Skp2 through the PI3K pathway to promote p27Kip1 degradation and proliferation of chronic myelogenous leukemia cells

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    Chronic myelogenous leukemia (CML) is characterized by the expression of the BCR-ABL tyrosine kinase, which results in increased cell proliferation and inhibition of apoptosis. In this study, we show in both BCR-ABL cells (Mo7e-p210 and BaF/3-p210) and primary CML CD34+ cells that STI571 inhibition of BCR-ABL tyrosine kinase activity results in a G(1) cell cycle arrest mediated by the PI3K pathway. This arrest is associated with a nuclear accumulation of p27(Kip1) and down-regulation of cyclins D and E. As a result, there is a reduction of the cyclin E/Cdk2 kinase activity and of the retinoblastoma protein phosphorylation. By quantitative reverse transcription-PCR we show that BCR-ABL/PI3K regulates the expression of p27(Kip1) at the level of transcription. We further show that BCR-ABL also regulates p27(Kip1) protein levels by increasing its degradation by the proteasome. This degradation depends on the ubiquitinylation of p27(Kip1) by Skp2-containing SFC complexes: silencing the expression of Skp2 with a small interfering RNA results in the accumulation of p27(Kip1). We also demonstrate that BCR-ABL cells show transcriptional up-regulation of Skp2. Finally, expression of a p27(Kip1) mutant unable of being recognized by Skp2 results in inhibition of proliferation of BCR-ABL cells, indicating that the degradation of p27(Kip1) contributes to the pathogenesis of CML. In conclusion, these results suggest that BCR-ABL regulates cell cycle in CML cells at least in part by inducing proteasome-mediated degradation of the cell cycle inhibitor p27(Kip1) and provide a rationale for the use of inhibitors of the proteasome in patients with BCR-ABL leukemias

    Circulating hematopoietic stem cells and putative intestinal stem cells in coeliac disease

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    Background: The intestinal stem cells (ISC) modulation and the role of circulating hematopoietic stem cells (HSC) in coeliac disease (CD) are poorly understood. Our aim was to investigate the longitudinal modifications in peripheral blood HSC traffic and putative ISC density induced by gluten-free diet (GFD) in CD. Methods: Thirty-one CD patients and 7 controls were enrolled. Circulating CD133+ and CD34+ HSC were measured by flow cytometry, at enrolment and after 7 days and 1, 3, 6, 12, and 24 months of GFD. Endoscopy was performed at diagnosis and repeated at 6, 12, and 24 months following GFD. We used the Marsh-Oberhuber score to evaluate the histological severity of duodenal damage; immunohistochemistry was employed to measure the intraepithelial lymphoid infiltrate (IEL, CD3+ lymphoid cells) and the putative ISC compartment (CD133+ and Lgr5+ epithelial cells). Results: At enrolment, circulating HSCs were significantly increased in CD patients and they further augmented during the first week of GFD, but progressively decreased afterwards. CD patients presented with villous atrophy, abundant IEL and rare ISC residing at the crypt base. Upon GFD, IEL progressively decreased, while ISC density increased, peaking at 12 months. After 24 months of GFD, all patients were asymptomatic and their duodenal mucosa was macroscopically and histologically normal. Conclusions: In active CD patients, the ISC niche is depleted and there is an increased traffic of circulating HSC versus non-coeliac subjects. GFD induces a precocious mobilization of circulating HSC, which is followed by the expansion of the local ISC compartment, leading to mucosal healing and clinical remission

    Evolution after Anti-TNF Discontinuation in Patients with Inflammatory Bowel Disease: A Multicenter Long-Term Follow-Up Study

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    OBJECTIVES:The aims of this study were to assess the risk of relapse after discontinuation of anti-tumor necrosis factor (anti-TNF) drugs in patients with inflammatory bowel disease (IBD), to identify the factors associated with relapse, and to evaluate the overcome after retreatment with the same anti-TNF in those who relapsed.METHODS:This was a retrospective, observational, multicenter study. IBD patients who had been treated with anti-TNFs and in whom these drugs were discontinued after clinical remission was achieved were included.RESULTS:A total of 1, 055 patients were included. The incidence rate of relapse was 19% and 17% per patient-year in Crohn''s disease and ulcerative colitis patients, respectively. In both Crohn''s disease and ulcerative colitis patients in deep remission, the incidence rate of relapse was 19% per patient-year. The treatment with adalimumab vs. infliximab (hazard ratio (HR)=1.29; 95% confidence interval (CI)=1.01-1.66), elective discontinuation of anti-TNFs (HR=1.90; 95% CI=1.07-3.37) or discontinuation because of adverse events (HR=2.33; 95% CI=1.27-2.02) vs. a top-down strategy, colonic localization (HR=1.51; 95% CI=1.13-2.02) vs. ileal, and stricturing behavior (HR=1.5; 95% CI=1.09-2.05) vs. inflammatory were associated with a higher risk of relapse in Crohn''s disease patients, whereas treatment with immunomodulators after discontinuation (HR=0.67; 95% CI=0.51-0.87) and age (HR=0.98; 95% CI=0.97-0.99) were protective factors. None of the factors were predictive in ulcerative colitis patients. Retreatment of relapse with the same anti-TNF was effective (80% responded) and safe.CONCLUSIONS:The incidence rate of inflammatory bowel disease relapse after anti-TNF discontinuation is relevant. Some predictive factors of relapse after anti-TNF withdrawal have been identified. Retreatment with the same anti-TNF drug was effective and safe

    Interchromosomal Duplications on the Bactrocera oleae Y Chromosome Imply a Distinct Evolutionary Origin of the Sex Chromosomes Compared to Drosophila

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    BACKGROUND: Diptera have an extraordinary variety of sex determination mechanisms, and Drosophila melanogaster is the paradigm for this group. However, the Drosophila sex determination pathway is only partially conserved and the family Tephritidae affords an interesting example. The tephritid Y chromosome is postulated to be necessary to determine male development. Characterization of Y sequences, apart from elucidating the nature of the male determining factor, is also important to understand the evolutionary history of sex chromosomes within the Tephritidae. We studied the Y sequences from the olive fly, Bactrocera oleae. Its Y chromosome is minute and highly heterochromatic, and displays high heteromorphism with the X chromosome. METHODOLOGY/PRINCIPAL FINDINGS: A combined Representational Difference Analysis (RDA) and fluorescence in-situ hybridization (FISH) approach was used to investigate the Y chromosome to derive information on its sequence content. The Y chromosome is strewn with repetitive DNA sequences, the majority of which are also interdispersed in the pericentromeric regions of the autosomes. The Y chromosome appears to have accumulated small and large repetitive interchromosomal duplications. The large interchromosomal duplications harbour an importin-4-like gene fragment. Apart from these importin-4-like sequences, the other Y repetitive sequences are not shared with the X chromosome, suggesting molecular differentiation of these two chromosomes. Moreover, as the identified Y sequences were not detected on the Y chromosomes of closely related tephritids, we can infer divergence in the repetitive nature of their sequence contents. CONCLUSIONS/SIGNIFICANCE: The identification of Y-linked sequences may tell us much about the repetitive nature, the origin and the evolution of Y chromosomes. We hypothesize how these repetitive sequences accumulated and were maintained on the Y chromosome during its evolutionary history. Our data reinforce the idea that the sex chromosomes of the Tephritidae may have distinct evolutionary origins with respect to those of the Drosophilidae and other Dipteran families

    Smoking cessation opportunities in severe mental illness (tobacco intensive motivational and estimate risk — TIMER—): study protocol for a randomized controlled trial

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    There is an increased risk of premature death in people with severe mental illness (SMI). Respiratory disorders and cardiovascular disease are leading causes of increased mortality rates in these patients, and tobacco consumption remains the most preventable risk factor involved. Developing new tools to motivate patients towards cessation of smoking is a high priority. Information on the motivational value of giving the lung age and prevention opportunities is unknown in this high-risk population. In the context of community care, screening and early detection of lung damage could potentially be used, together with mobile technology, in order to produce a prevention message, which may provide patients with SMI with a better chance of quitting smoking.This study receives funding by the Spanish Ministry of Economy, Industry and Competitiveness, Instituto Carlos III (FIS PI16/00802)

    Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment

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    The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 3σ\sigma (5σ\sigma) level, with a 66 (100) kt-MW-yr far detector exposure, and has the ability to make strong statements at significantly shorter exposures depending on the true value of other oscillation parameters. We also show that DUNE has the potential to make a robust measurement of CPV at a 3σ\sigma level with a 100 kt-MW-yr exposure for the maximally CP-violating values \delta_{\rm CP}} = \pm\pi/2. Additionally, the dependence of DUNE's sensitivity on the exposure taken in neutrino-enhanced and antineutrino-enhanced running is discussed. An equal fraction of exposure taken in each beam mode is found to be close to optimal when considered over the entire space of interest

    Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

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    Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42\ub74% vs 44\ub72%; absolute difference \u20131\ub769 [\u20139\ub758 to 6\ub711] p=0\ub767; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5\u20138] vs 6 [5\u20138] cm H2O; p=0\ub70011). ICU mortality was higher in MICs than in HICs (30\ub75% vs 19\ub79%; p=0\ub70004; adjusted effect 16\ub741% [95% CI 9\ub752\u201323\ub752]; p<0\ub70001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0\ub780 [95% CI 0\ub775\u20130\ub786]; p<0\ub70001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status. Funding: No funding
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