Biomedical application of NMR metabolomics: study of Age-related Macular Degeneration (AMD)

Conference (2012, May 08)

Biomedical image classification with random subwindows and decision trees

in Computer Vision for Biomedical Image Applications (2005)

In this paper, we address a problem of biomedical image classification that involves the automatic classification of x-ray images in 57 predefined classes with large intra-class variability. To achieve ... [more ▼]

In this paper, we address a problem of biomedical image classification that involves the automatic classification of x-ray images in 57 predefined classes with large intra-class variability. To achieve that goal, we apply and slightly adapt a recent generic method for image classification based on ensemble of decision trees and random subwindows. We obtain classification results close to the state of the art on a publicly available database of 10000 x-ray images. We also provide some clues to interpret the classification of each image in terms of subwindow relevance. [less ▲]

Biomedical risk analysis in myocardial infarction

Conference (1983, January)

Biometallurgy for a greener E-wastes recycling

Conference (2010, September 03)

Biometrological assessment of skin protectors against moderate cold threat.

in Exogenous Dermatology : Physical, Chemical, Biological (2002), 1

Background : Cold injuries represent a serious problem in winter sport practice and other outdoor activities. Some protection is expected to be achieved by specific topical preparations aiming at ... [more ▼]

Background : Cold injuries represent a serious problem in winter sport practice and other outdoor activities. Some protection is expected to be achieved by specific topical preparations aiming at decreasing heat loss by water evaporation from the skin. Objective : To compare the efficacy of 6 topical formulations enriched or not in rubefacients. The role of the vehicle was also assessed. Methods : A total of 30 trained cyclists tested the products on their forearms. The skin temperature and electrometric values were recorded at baseline following applications of the test products, and after 30 min-bicycle riding in moderately cold and humid outdoor conditions. Results : At baseline, skin temperature was increased by rubefacients dispersed a lipogel and o/w emulsion. This parameter decreased at all test sites after riding, but the values remained higher at the rubefacient-treated sites compared to the control untreated site. The oil and lipogel formulations achieved partial occlusion decreasing the transepidermal water loss. This effect was maintained after exercise without, however, hindering sweating. Conclusion : Among the presently tested formulations, the rubefacient-enriched lipogels appeared to be the most efficient formulations for maintaining skin temperature in the normal range during sport practice in a moderately cold environment. [less ▲]

Biometrology of physical properties of skin in thyroid dysfunction.

in Journal of the European Academy of Dermatology & Venereology (2008), 22(10), 1173-1177

OBJECTIVE: There is ample clinical evidence that skin is responsive to physiopathological levels of circulating thyroid hormones. The aim of the study was to assess some physical changes of the skin in ... [more ▼]

OBJECTIVE: There is ample clinical evidence that skin is responsive to physiopathological levels of circulating thyroid hormones. The aim of the study was to assess some physical changes of the skin in the presence of moderate thyroid dysfunction. SETTING: University Hospital. PATIENTS AND METHODS: A total of 119 adults suffering from hypothyroidism or hyperthyroidism and 60 healthy controls were enrolled in this study. Hormonal dosages (TSH, fT3, fT4) were assessed in the serum. A series of biometrological assessments were also performed on the volar and dorsal aspects of the forearms. These included electrometric assessments (Nova Dermal Phase Meter, Corneometer), evaporimetry (Tewameter)), colorimetry (Mexameter), ultrasound shear wave propagation (Reviscometer) and squamometry X. Correlations were searched between each of the serum hormonal dosages and each of the biometrological parameters. RESULTS: The hormonal changes in the untreated patients with thyroid dysfunction were modest in intensity. A few outlier values with regard to the normal range were found for each biometrological parameter. No correlations were found between fT3 or fT4 and each of the physical parameters. By contrast, significant negative linear correlations were found between thyroid-stimulating hormone (TSH) and skin hydration measured by the Corneometer and the Nova DPM. CONCLUSION: This multipronged exploratory study shows that direct or indirect effects of TSH may influence the stratum corneum hydration. This correlation seemed very sensitive, as no other specific biophysical parameter was significantly correlated with the thyroid hormonal concentrations in the serum. However, our findings do not exclude the possibility of some other skin changes supervening in case of more severe thyroid dysfunction. The mechanism by which TSH alters the stratum corneum hydration is yet unknown. [less ▲]

Biomimetic approaches to understand how mycosubtilin, an antifungal lipopeptide, can interact with cytoplasmic membranes

Poster (2009)

Mycosubtilin is a natural cyclic lipopeptide characterized by its strong antifungal activities. It has been demonstrated that the cytoplasmic membranes of the sensitive cells are the target of this ... [more ▼]

Mycosubtilin is a natural cyclic lipopeptide characterized by its strong antifungal activities. It has been demonstrated that the cytoplasmic membranes of the sensitive cells are the target of this antifungal lipopeptide. In spite of the fact that some properties of mycosubtilin have been highlighted, the molecular mechanism of its biological action remains partially understood. In view of this, we investigated the interactions between mycosubtilin and cytoplasmic membranes by using biomimetic systems such as lipid monolayers at the air-water interface and lipid multilayers. These interactions were examined by different methods (pressure/area isotherms, kinetic measurements of the interfacial adsorption, Brewster angle microscopy, infrared and NMR spectroscopies). We showed that mycosubtilin does not interact strongly with the C=O ester residues of phospholipids in multilayers, while it modifies the transition temperature of the alkyl chains. It was also demonstrated that these interactions depend on the phospholipid phase. Varying the lipid composition of monolayers allowed us to demonstrate an original behavior of mycosubtilin in the presence of sterol. This suggests a mycosubtilin-sterol affinity. [less ▲]

A biomimetic synthesis of coelenterazine analogs

in Tetrahedron Letters (2002), 43(17), 3161-3164

N-(Trifluoroacetyl)dehydrodipeptides 2–3 were coupled to aminomethylene dimethylacetal derivatives 4–5. The resulting pseudo-tripeptides 6 were stepwise deprotected (carbonyl function (7) then amine ... [more ▼]

N-(Trifluoroacetyl)dehydrodipeptides 2–3 were coupled to aminomethylene dimethylacetal derivatives 4–5. The resulting pseudo-tripeptides 6 were stepwise deprotected (carbonyl function (7) then amine function) and in situ cyclized into imidazolopyrazines 1. [less ▲]

Biomolecular comparison of bacteriological caecal flora with and without Epizootic Rabbit Enteropathy (ERE) contamination

Poster (2009, April 01)

Biomolecules in multilayer film for antimicrobial and easy-cleaning stainless steel surface applications

in Biofouling (2010), 26(6), 645-656

Microorganisms are able to attach to, grow on, and ultimately form biofilms on a large variety of surfaces, such as industrial equipment, food contact surfaces, medical implants, prostheses and operating ... [more ▼]

Microorganisms are able to attach to, grow on, and ultimately form biofilms on a large variety of surfaces, such as industrial equipment, food contact surfaces, medical implants, prostheses and operating rooms. Once organized into biofilms, bacteria are difficult to remove and kill, which increases the risk of cross-contamination and infection. One way to address the problem may thus be to develop antibacterial, anti-adhesion, ‘easy cleaning’ surfaces. In this study, stainless steel (SS) surfaces with antibacterial properties were created by embedding several antimicrobial peptides in a multilayer film architecture. The biocidal effect of these surfaces was demonstrated against both Gram-positive and Gram-negative bacteria according to two ISO tests. Also, coating SS surfaces with either mucin or heparin led to a reduction of <i>S. epidermidis</i> adhesion of almost 95% <i>vs</i> the bare substratum. Finally, by combining both antibacterial and anti-adhesion biomolecules in the same multilayer film, SS surfaces with better cleanability were produced. This surface coating property may help to delay the buildup of a dead bacterial layer which is known to progressively reduce exposure of the coating, leading to an undesirable decrease in the antibacterial effect of the surface. [less ▲]