167 research outputs found

    An empirical evaluation of nuclei segmentation from H&E images in a real application scenario

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    Cell nuclei segmentation is a challenging task, especially in real applications, when the target images significantly differ between them. This task is also challenging for methods based on convolutional neural networks (CNNs), which have recently boosted the performance of cell nuclei segmentation systems. However, when training data are scarce or not representative of deployment scenarios, they may suffer from overfitting to a different extent, and may hardly generalise to images that differ from the ones used for training. In this work, we focus on real-world, challenging application scenarios when no annotated images from a given dataset are available, or when few images (even unlabelled) of the same domain are available to perform domain adaptation. To simulate this scenario, we performed extensive cross-dataset experiments on several CNN-based state-of-the-art cell nuclei segmentation methods. Our results show that some of the existing CNN-based approaches are capable of generalising to target images which resemble the ones used for training. In contrast, their effectiveness considerably degrades when target and source significantly differ in colours and scale

    Scene-specific crowd counting using synthetic training images

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    Crowd counting is a computer vision task on which considerable progress has recently been made thanks to convolutional neural networks. However, it remains a challenging task even in scene-specific settings, in real-world application scenarios where no representative images of the target scene are available, not even unlabelled, for training or fine-tuning a crowd counting model. Inspired by previous work in other computer vision tasks, we propose a simple but effective solution for the above application scenario, which consists of automatically building a scene-specific training set of synthetic images. Our solution does not require from end-users any manual annotation effort nor the collection of representative images of the target scene. Extensive experiments on several benchmark data sets show that the proposed solution can improve the effectiveness of existing crowd counting methods

    On The Potential of Image Moments for Medical Diagnosis

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    Medical imaging is widely used for diagnosis and postoperative or post-therapy monitoring. The ever-increasing number of images produced has encouraged the introduction of automated methods to assist doctors or pathologists. In recent years, especially after the advent of convolutional neural networks, many researchers have focused on this approach, considering it to be the only method for diagnosis since it can perform a direct classification of images. However, many diagnostic systems still rely on handcrafted features to improve interpretability and limit resource consumption. In this work, we focused our efforts on orthogonal moments, first by providing an overview and taxonomy of their macrocategories and then by analysing their classification performance on very different medical tasks represented by four public benchmark data sets. The results confirmed that convolutional neural networks achieved excellent performance on all tasks. Despite being composed of much fewer features than those extracted by the networks, orthogonal moments proved to be competitive with them, showing comparable and, in some cases, better performance. In addition, Cartesian and harmonic categories provided a very low standard deviation, proving their robustness in medical diagnostic tasks. We strongly believe that the integration of the studied orthogonal moments can lead to more robust and reliable diagnostic systems, considering the performance obtained and the low variation of the results. Finally, since they have been shown to be effective on both magnetic resonance and computed tomography images, they can be easily extended to other imaging techniques

    Electrostatic interactions contribute to the control of intramolecular thiol-disulfide isomerization in a protein

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    The roles of structural factors and of electrostatic interactions with the environment on the outcome of thiol–disulfide exchange reactions were investigated in a mutated immunoglobulin domain (I27*) under mechanical stress. An extensive ensemble of molecular dynamics trajectories was generated by means of QM/MM simulations for a total sampling of 5.7 μs. A significant number of thiol–disulfide exchanges were observed, and the Cys32 thiolate preferred to attack Cys55 over Cys24, in agreement with previous experimental and computational studies. The structural features as well as electronic structures of the thiol–disulfide system along the reaction were analyzed, as were the electrostatic interactions with the environment. The previous findings of better accessibility of Cys55 were confirmed. Additionally, the reaction was found to be directed by the electrostatic interactions of the involved sulfur atoms with the molecular environment. The relationships of atomic charges, which stem from the electrostatic interactions, lead to the kinetic preference of the attack on Cys55. Further, QM/MM metadynamics simulations of thiol–disulfide exchange in a small model system with varied artificial external electric potentials revealed changes in reaction kinetics of the same magnitude as in I27*. Therefore, the electrostatic interactions are confirmed to play a role in the regioselectivity of the thiol–disulfide exchange reactions in the protein

    Efficacy of the combination of cisplatin with either gemcitabine and vinorelbine or gemcitabine and paclitaxel in the treatment of locally advanced or metastatic non-small-cell lung cancer: a phase III randomised trial of the Southern Italy Cooperative Oncology Group (SICOG 0101)

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    Triplet regimens were occasionally reported to produce a higher response rate (RR) than doublets in locally advanced or metastatic non-small-cell lung cancer (NSCLC). This trial was conducted to assess (i) whether the addition of cisplatin (CDDP) to either gemcitabine (GEM) and vinorelbine (VNR) or GEM and paclitaxel (PTX) significantly prolongs overall survival (OS) and (ii) to compare the toxicity of PTX-containing and VNR-containing combinations

    Fluoro-edenitic fibres in the sputum of subjects from Biancavilla (Sicily): a pilot study

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    BACKGROUND: An excess of mortality for malignant neoplasms of the pleura in Biancavilla, promoted an investigation for pleural mesothelioma, disclosing 17 cases. As the absence of known sources of asbestos exposure, a local stone quarry, located near the inhabited area, used for the extraction of building materials, was investigated. Amphibolic fibres were found in the quarry and identified as fluoro-edenite "new end-member of the edenite / fluoro-edenite series" and recognized as the fluoro-edenite holotype by International Mineralogical Association – Commission on New Minerals and Mineral Names. A pilot study was performed to verify the feasibility of using spontaneous sputum as an exposure indicator for these fibres, in a context in which the use of aerosol-induced sputum technique would not be easily accepted. METHODS: Hypothesizing a behaviour of the new fibre analogous to that of asbestos, the determination of the free fibres and the ferruginous bodies in spontaneous sputum was carried out. Phase Contrast Optical Microscope and an Environmental Scanning Electron Microscope fitted with X-ray energy dispersive analysis system (micro-analysis) were used to examine the samples. The criteria for inclusion in the study were: 1) subjects hospitalized for exacerbation of chronic obstructive pulmonary disease symptoms, 2) age ≥ 45 years, 3) residence in Biancavilla for at least 30 years. RESULTS: The preliminary findings are related to 12 subjects (7 females and 5 males). Uncoated fibres (with length > 5 μm, diameter < 3 μm, aspect ratio 3.1) and ferruginous bodies were searched. Six out of twelve subjects (4 females, 2 males) had at least one of the three samples positive for the presence of fluoro-edenite, confirmed by micro-analysis. The fibre concentration found in the sputum ranged from 0.04 to 10 fibres/g; the length from 20 to 40 μm, the diameter was < 0.5 μm. No ferruginous bodies were found in any of the samples. The four women with a positive sample were housewives. Of the two men with a positive sample, one was a farmer and the other a mason. Therefore, it may be assumed that the exposure to fluoro-edenitic fibres was mainly environmental. CONCLUSION: The occurrence of the pleural mesothelioma cases and the presence of fluoro-edenitic fibres in spontaneous sputum, evidence the need to study the biological activity of fluoro-edenitic fibres and the implementation of epidemiological monitoring systems

    Accumulation of neutral lipids in peripheral blood mononuclear cells as a distinctive trait of Alzheimer patients and asymptomatic subjects at risk of disease

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    <p>Abstract</p> <p>Background</p> <p>Alzheimer's disease is the most common progressive neurodegenerative disease. In recent years, numerous progresses in the discovery of novel Alzheimer's disease molecular biomarkers in brain as well as in biological fluids have been made. Among them, those involving lipid metabolism are emerging as potential candidates. In particular, an accumulation of neutral lipids was recently found by us in skin fibroblasts from Alzheimer's disease patients. Therefore, with the aim to assess whether peripheral alterations in cholesterol homeostasis might be relevant in Alzheimer's disease development and progression, in the present study we analyzed lipid metabolism in plasma and peripheral blood mononuclear cells from Alzheimer's disease patients and from their first-degree relatives.</p> <p>Methods</p> <p>Blood samples were obtained from 93 patients with probable Alzheimer's disease and from 91 of their first-degree relatives. As controls we utilized 57, cognitively normal, over-65 year-old volunteers and 113 blood donors aged 21-66 years, respectively. Data are reported as mean ± standard error. Statistical calculations were performed using the statistical analysis software Origin 8.0 version. Data analysis was done using the Student t-test and the Pearson test.</p> <p>Results</p> <p>Data reported here show high neutral lipid levels and increased ACAT-1 protein in about 85% of peripheral blood mononuclear cells freshly isolated (<it>ex vivo</it>) from patients with probable sporadic Alzheimer's disease compared to about 7% of cognitively normal age-matched controls. A significant reduction in high density lipoprotein-cholesterol levels in plasma from Alzheimer's disease blood samples was also observed. Additionally, correlation analyses reveal a negative correlation between high density lipoprotein-cholesterol and cognitive capacity, as determined by Mini Mental State Examination, as well as between high density lipoprotein-cholesterol and neutral lipid accumulation. We observed great variability in the neutral lipid-peripheral blood mononuclear cells data and in plasma lipid analysis of the subjects enrolled as Alzheimer's disease-first-degree relatives. However, about 30% of them tend to display a peripheral metabolic cholesterol pattern similar to that exhibited by Alzheimer's disease patients.</p> <p>Conclusion</p> <p>We suggest that neutral lipid-peripheral blood mononuclear cells and plasma high density lipoprotein-cholesterol determinations might be of interest to outline a distinctive metabolic profile applying to both Alzheimer's disease patients and asymptomatic subjects at higher risk of disease.</p

    Final results of the TANIA randomised phase III trial of bevacizumab after progression on first-line bevacizumab therapy for HER2-negative locally recurrent/metastatic breast cancer

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    BACKGROUND: The randomised phase III TANIA trial demonstrated that continuing bevacizumab with second-line chemotherapy for locally recurrent/metastatic breast cancer (LR/mBC) after progression on first-line bevacizumab-containing therapy significantly improved progression-free survival (PFS) compared with chemotherapy alone (hazard ratio [HR]=0.75, 95% confidence interval [CI] 0.61-0.93). We report final results from the TANIA trial, including overall survival (OS) and health-related quality of life (HRQoL). PATIENTS AND METHODS: Patients with HER2-negative LR/mBC that had progressed on or after first-line bevacizumab plus chemotherapy were randomised to receive standard second-line chemotherapy either alone or with bevacizumab. At second progression, patients initially randomised to bevacizumab continued bevacizumab with their third-line chemotherapy but those randomised to chemotherapy alone were not allowed to cross over to receive third-line bevacizumab. The primary end point was second-line PFS; secondary end points included third-line PFS, combined second- and third-line PFS, OS, HRQoL and safety. RESULTS: Of the 494 patients randomised, 483 received second-line therapy; 234 patients (47% of the randomised population) continued to third-line study treatment. The median duration of follow-up at the final analysis was 32.1 months in the chemotherapy-alone arm and 30.9 months in the bevacizumab plus chemotherapy arm. There was no statistically significant difference between treatment arms in third-line PFS (HR=0.79, 95% CI 0.59-1.06), combined second- and third-line PFS (HR=0.85, 95% CI 0.68-1.05) or OS (HR=0.96, 95% CI 0.76-1.21). Third-line safety results showed increased incidences of proteinuria and hypertension with bevacizumab, consistent with safety results for the second-line treatment phase. No differences in HRQoL were detected. CONCLUSION: In this trial, continuing bevacizumab beyond first and second progression of LR/mBC improved second-line PFS but no improvement in longer-term efficacy was observed. The second-line PFS benefit appears to be achieved without detrimentally affecting quality of life. CLINICALTRIALSGOV: NCT01250379
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