Coherent anti-Stokes Raman scattering cell imaging and segmentation with unsupervised data analysis.

Coherent Raman imaging has been extensively applied to live-cell imaging in the last 2 decades, allowing to probe the intracellular lipid, protein, nucleic acid, and water content with a high-acquisition rate and sensitivity. In this context, multiplex coherent anti-Stokes Raman scattering (MCARS) microspectroscopy using sub-nanosecond laser pulses is now recognized as a mature and straightforward technology for label-free bioimaging, offering the high spectral resolution of conventional Raman spectroscopy with reduced acquisition time. Here, we introduce the combination of the MCARS imaging technique with unsupervised data analysis based on multivariate curve resolution (MCR). The MCR process is implemented under the classical signal non-negativity constraint and, even more originally, under a new spatial constraint based on cell segmentation. We thus introduce a new methodology for hyperspectral cell imaging and segmentation, based on a simple, unsupervised workflow without any spectrum-to-spectrum phase retrieval computation. We first assess the robustness of our approach by considering cells of different types, namely, from the human HEK293 and murine C2C12 lines. To evaluate its applicability over a broader range, we then study HEK293 cells in different physiological states and experimental situations. Specifically, we compare an interphasic cell with a mitotic (prophase) one. We also present a comparison between a fixed cell and a living cell, in order to visualize the potential changes induced by the fixation protocol in cellular architecture. Next, with the aim of assessing more precisely the sensitivity of our approach, we study HEK293 living cells overexpressing tropomyosin-related kinase B (TrkB), a cancer-related membrane receptor, depending on the presence of its ligand, brain-derived neurotrophic factor (BDNF). Finally, the segmentation capability of the approach is evaluated in the case of a single cell and also by considering cell clusters of various sizes.

A new blind color watermarking based on a psychovisual model.

In this paper, we address the problem of the use of a human visual system (HVS) model to improve watermark invisibility. We propose a new color watermarking algorithm based on the minimization of the perception of color differences. This algorithm is based on a psychovisual model of the dynamics of cone photoreceptors. We used this model to determine the discrimination power of the human for a particular color and thus the best strategy to modify color pixels. Results were obtained on a color version of the lattice quantization index modulation (LQIM) method and showed improvements on psychovisual invisibility and robustness against several image distortions.

Phase estimation of a 2D fringe pattern using a monogenic-based multiscale analysis.

In this paper, a multiscale monogenic analysis is applied to 2D interference fringe patterns. The monogenic signal was originally developed as a 2D generalization of the well-known analytic signal in the 1D case. The analytic and monogenic tools are both useful to extract phase information, which can then be directly linked with physical quantities. Previous studies have already shown the interest in the monogenic signal in the field of interferometry. This paper presents theoretical and numerical illustrations of the connection between the physical phase information and the phase estimated with the monogenic tool. More specifically, the ideal case of pure cosine waves is deeply studied, and then the complexity of the fringe patterns is progressively increased. One important weakness of the monogenic transform is its singularity at the null frequency, which makes the phase estimations of low-frequency fringes diverge. Moreover, the monogenic transform is originally designed for narrowband signals, and encounters difficulties when dealing with noised signals. These problems can be bypassed by performing a multiscale analysis based on the monogenic wavelet transform. Moreover, this paper proposes a simple strategy to combine the information extracted at different scales in order to get a better estimation of the phase. The numerical tests (synthetic and real signals) show how this approach provides a finer extraction of the geometrical structure of the fringe patterns.

Characterization of Color Images with Multiscale Monogenic Maxima.

Can we build a feature-based analysis that fully characterizes images? The literature answers with edge-based reconstruction methods inspired by Marr's paradigm but limited to the greyscale case. This paper studies the color case. A new sparse representation is carried out with the monogenic concept and the Mallat-Zhong wavelet maxima method. Our monogenic maxima provide efficient contour shape and color characterization, as a sparse set of local features including amplitude, phase, orientation and ellipse parameters. This rich description takes the wavelet maxima representation further towards the wide topic of keypoint analysis. We propose a reconstruction process that retrieves the image from its monogenic maxima. While known works all rely on constrained optimization, implying an iterative use of the filterbank, we propose to interpolate the data in the feature domain by exploiting the visual knowledge from the feature-set. This direct retrieval is accurate enough so that no iteration is required. The main question is finally answered with comparative experiments. It is shown that a reasonably small amount of features is sufficiently informative for visually appealing image retrieval. The features appear numerically stable to rotation, and can be intuitively simplified to perform image regularization.

Diagnosis and management of idiopathic pulmonary fibrosis: French practical guidelines.

Idiopathic pulmonary fibrosis (IPF) is the most frequent chronic idiopathic interstitial pneumonia in adults. The management of rare diseases in France has been organised by a national plan for rare diseases, which endorsed a network of expert centres for rare diseases throughout France. This article is an overview of the executive summary of the French guidelines for the management of IPF, an initiative that emanated from the French National Reference Centre and the Network of Regional Competence Centres for Rare Lung Diseases. This review aims at providing pulmonologists with a document that: 1) combines the current available evidence; 2) reviews practical modalities of diagnosis and management of IPF; and 3) is adapted to everyday medical practice. The French practical guidelines result from the combined efforts of a coordination committee, a writing committee and a multidisciplinary review panel, following recommendations from the Haute Autorité de Santé. All recommendations included in this article received at least 90% agreement by the reviewing panel. Herein, we summarise the main conclusions and practical recommendations of the French guidelines.

Impact of comorbidities on COPD-specific health-related quality of life.

BACKGROUND: Comorbidities are frequent in subjects with COPD, but their contribution to health-related quality of life (HRQoL) impairment is not clearly established. METHODS: Cross-sectional analysis of data from the French COPD cohort Initiatives BPCO. Data were recorded in stable state and included spirometry, dyspnea (modified Medical Research Council - mMRC-scale), mood disorders (hospital anxiety-depression scale) and physician-diagnosed comorbidities including diabetes, hypertension, coronary artery disease, chronic heart failure, venous thromboembolism. HRQoL was assessed using the disease-specific St. George's Respiratory Questionnaire (SGRQ). Stepwise forward and backward multiple regression analyses were performed to examine the contribution of comorbidities to SGRQ scores. RESULTS: Data are median [IQR]. 326 COPD subjects were analyzed: male 77%, age 65.0 [57.0; 72.0] years, FEV(1) 48.9 [34.7; 65.9]% predicted. SGRQ total score was 44.2 [30.0; 61.2]. In univariate analysis, positive correlations were found between SGRQ total scores and dyspnea and exacerbations/patient/year, whereas negative correlations were found with FEV(1). SGRQ total scores were increased in women (P = 0.06), and in subjects with low BMI, anxiety or depression (each analysis, P < 0.001), but not in subjects with cardiovascular comorbidities or diabetes. In multivariate analyses, major independent determinants of SGRQ total score included dyspnea, exacerbations/patient/year and depression. Low BMI, coronary artery disease and FEV(1) were also independently associated with SGRQ total score, but their contribution was only modest. CONCLUSIONS: These data suggest that in the presence of dyspnea and exacerbation, depression is the most important contributor to HRQoL impairment measured by SGRQ in COPD subjects, whereas other comorbidities and FEV(1) have only limited impact.

Vector extension of monogenic wavelets for geometric representation of color images.

Monogenic wavelets offer a geometric representation of grayscale images through an AM-FM model allowing invariance of coefficients to translations and rotations. The underlying concept of local phase includes a fine contour analysis into a coherent unified framework. Starting from a link with structure tensors, we propose a nontrivial extension of the monogenic framework to vector-valued signals to carry out a nonmarginal color monogenic wavelet transform. We also give a practical study of this new wavelet transform in the contexts of sparse representations and invariant analysis, which helps to understand the physical interpretation of coefficients and validates the interest of our theoretical construction.

Association between occupational exposure and the clinical characteristics of COPD.

BACKGROUND: The contribution of occupational exposures to COPD and their interaction with cigarette smoking on clinical pattern of COPD remain underappreciated. The aim of this study was to explore the contribution of occupational exposures on clinical pattern of COPD. METHODS: Cross-sectional data from a multicenter tertiary care cohort of 591 smokers or ex-smokers with COPD (median FEV1 49%) were analyzed. Self-reported exposure to vapor, dust, gas or fumes (VDGF) at any time during the entire career was recorded. RESULTS: VDGF exposure was reported in 209 (35%) subjects aged 31 to 88 years. Several features were significantly associated with VDGF exposure: age (median 68 versus 64 years, p < 0.001), male gender (90% vs 76%; p < 0.0001), reported work-related respiratory disability (86% vs 7%, p < 0.001), current wheezing (71% vs 61%, p = 0.03) and hay fever (15.5% vs 8.5%, p < 0.01). In contrast, current and cumulative smoking was less (p = 0.01) despite similar severity of airflow obstruction. CONCLUSION: In this patient series of COPD patients, subjects exposed to VDGF were older male patients who reported more work-related respiratory disability, more asthma-like symptoms and atopy, suggesting that, even in smokers or ex-smokers with COPD, occupational exposures are associated with distinct patients characteristics.

Asthma unmasked with tumor necrosis factor-α-blocking drugs.

We report five cases of asthma unmasked by anti-tumor necrosis factor (TNF)-α-blocking drugs. Asthma symptoms appeared within an average of 4 months (range 1-24 months) after starting the anti-TNF-α treatment for inflammatory disease. The patients did not appear to be predisposed to asthma except for one patient who had asthma during childhood. Four patients stopped anti-TNF-α-blocking drugs with an improvement of symptoms within 1 to 5 months. In the patient with a history of childhood asthma, respiratory symptoms recurred when another anti-TNF-α therapy was started. Asthma control was achieved with inhaled steroids, allowing anti-TNF-α treatment to continue. The biotherapy was maintained for the fifth patient in association with inhaled steroids. The pathophysiologic mechanisms are unknown but are probably more complex than the T helper 1/T helper 2 imbalance suggested in the literature, and further studies are required.

Cough and sputum production are associated with frequent exacerbations and hospitalizations in COPD subjects.

BACKGROUND: Epidemiologic studies indicate that chronic cough and sputum production are associated with increased mortality and disease progression in COPD subjects. Our objective was to identify features associated with chronic cough and sputum production in COPD subjects. METHODS: Cross-sectional analysis of data were obtained in a multicenter (17 university hospitals in France) cohort of COPD patients. The cohort comprised 433 COPD subjects (65 +/- 11 years; FEV(1), 50 +/- 20% predicted). Subjects with (n = 321) and without (n = 112) chronic cough and sputum production were compared. RESULTS: No significant difference was observed between groups for age, FEV(1), body mass index, and comorbidities. Subjects with chronic cough and sputum production had increased total mean numbers of exacerbations per patient per year (2.20 +/- 2.20 vs 0.97 +/- 1.19, respectively; p < 0.0001), moderate exacerbations (1.80 +/- 2.07 vs 0.66 +/- 0.85, respectively; p < 0.0001), and severe exacerbations requiring hospitalizations (0.43 +/- 0.95 vs 0.22 +/- 0.56, respectively; p < 0.02). The total number of exacerbations per patient per year was the only variable independently associated with chronic cough and sputum production. Frequent exacerbations (two or more per patient per year) occurred in 55% vs 22% of subjects, respectively, with and without chronic cough and sputum production (p < 0.0001). Chronic cough and sputum production and decreased FEV(1) were independently associated with an increased risk of frequent exacerbations and frequent hospitalizations. CONCLUSIONS: Chronic cough and sputum production are associated with frequent COPD exacerbations, including severe exacerbations requiring hospitalizations.

The effect of an information leaflet upon knowledge and awareness of COPD in potential sufferers. A randomized controlled study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is markedly under-diagnosed, which may be related to the under-reporting of symptoms and poor awareness of the disease. We hypothesized that written information on COPD may help increase awareness of the disease in people at risk of developing it. OBJECTIVES: To evaluate the impact of an information leaflet sent by postal mail on the level of knowledge of COPD in subjects with or at risk of COPD. METHODS: A total of 860 subjects with or at risk of COPD were selected by using a phone questionnaire. All subjects who reported a known diagnosis of COPD, a chronic cough and sputum production, or a smoking history of at least 15 pack-years were eligible for selection. Their knowledge of COPD was assessed during a telephone interview (baseline). They were randomized into 2 groups, with only 1 group receiving the information leaflet, and were then contacted 3 months later for a second interview. The changes in the knowledge of COPD from baseline were compared between subjects who reported receiving and reading the leaflet (true sensitized group) and subjects to whom the leaflet was not sent (control group). RESULTS: At the follow-up interview, the proportion of patients who spontaneously mentioned 'respiratory difficulties', when asked about the meaning of COPD, significantly increased in the true sensitized group (+11.9%) compared with the control group (+2.6%, p < 0.05). In addition, the frequency of patients who cited lung function test as the primary diagnostic tool for COPD increased by +14.4% in the true sensitized group versus+2.0% in the control group (p < 0.05). However, there was no short-term leaflet-dependent improvement in smoking behaviour or utilization of health-care resources. CONCLUSIONS: This study shows that an information leaflet sent by postal mail to subjects with or at risk of COPD can significantly improve their knowledge of COPD; however, it has no significant impact on their behaviour.

3-D discrete analytical ridgelet transform.

In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines: 3-D discrete radial lines going through the origin defined from their orthogonal projections and 3-D planes covered with 2-D discrete line segments. These discrete analytical lines have a parameter called arithmetical thickness, allowing us to define a 3-D DART adapted to a specific application. Indeed, the 3-D DART representation is not orthogonal, It is associated with a flexible redundancy factor. The 3-D DART has a very simple forward/inverse algorithm that provides an exact reconstruction without any iterative method. In order to illustrate the potentiality of this new discrete transform, we apply the 3-D DART and its extension to the Local-DART (with smooth windowing) to the denoising of 3-D image and color video. These experimental results show that the simple thresholding of the 3-D DART coefficients is efficient.