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Intracranial aneurysm is a critical pathology related to the arterial wall deterioration. This work is an essential aspect of a large scale project aimed at providing clinicians with a non-invasive patient-specific decision support tool regarding the rupture risk assessment. A machine learning algorithm links the aneurysm shape observed and a database of UIA clinical images associated with in vivo wall mechanical properties and rupture characterisation. The database constitution is derived from a device prototype coupled with medical imaging. It provides the mechanical characterisation of the aneurysm from the wall deformation obtained by inverse analysis based on the variation of luminal volume. Before performing in vivo tests of the device on small animals, a numerical model was built to quantify the device's impact on the aneurysm wall under natural blood flow conditions. As the clinician will never be able to precisely situate the device, several locations were considered. In preparation for the inverse analysis procedure, artery material laws of increasing complexity were studied (linear elastic, hyper elastic Fung-like). Considering all the device locations and material laws, the device induced relative displacements to the Systole peak (worst case scenario with the highest mechanical stimulus linked to the blood flow) ranging from 375 μ m to 1.28 mm. The variation of luminal volume associated with the displacements was between 0.95 % and 4.3 % compared to the initial Systole volume of the aneurysm. Significant increase of the relative displacements and volume variations were found with the study of different cardiac cycle moments between the blood flow alone and the device application. For forthcoming animal model studies, Spectral Photon CT Counting, with a minimum spatial resolution of 250 μ m, was selected as the clinical imaging technique. Based on this preliminary study, the displacements and associated volume variations (baseline for inverse analyse), should be observable and exploitable. • Numerical models revealed a safe device use for the in vivo wall characterisation. • The device's impact on luminal volume and displacements is observable through SPCCT. • The device's location and cardiac cycle timing induce significant stimulus changes. [ABSTRACT FROM AUTHOR]

Objective: As an analogy with mild cognitive impairment (MCI), the mild behavioral impairment (MBI) construct has been proposed as a diagnostic label for those presenting late-onset behavioral symptoms. To date, however, the clinical, cognitive, and structural imaging features associated with an increased risk of conversion from MBI to dementia are poorly understood.Methods: We retrospectively analyzed the cognitive performance and structural brain MRI of 113 subjects, with a clinical follow-up of at least 4 years available. Subjects were randomly assigned to a Group A (56 subjects; age: 65.4 ± 7.9 years, 15 females, MMSE score: 28.4 ± 2.3)) or to a Group B (57 subjects, age: 66.6 ± 6.4, 17 females, MMSE score: 28.0 ± 1.4). In the Group A, cognitive and structural variables were compared between converters (at 4 years) and nonconverters and then verified in the Group B group.Results: In the Group A, 14 patients converted to behavioral-variant of frontotemporal dementia (bv-FTD) and 4 to Alzheimer's Disease (AD). Converters presented at baseline lower executive function scores and total Theory of Mind (ToM scores), as well as more severe focal frontal atrophy. In the Group B, 13 subjects converted to bv-FTD and none to AD. The combination of the variables identified in the Group A significantly (p <0.001) discriminated between converters and nonconverters in the Group B with a sensitivity of 0.615 and a specificity of 1 (total accuracy 91.22%).Conclusion: The combined presence of executive deficit, impaired ToM, and presence of isolated frontal atrophy was associated with risk of progression from MBI to a clinically evident neurodegenerative condition, mainly bv-FTD, over a 4-year period. [ABSTRACT FROM AUTHOR]

Reconstructed skins have been developed to replace skin when the integrity of tissue has been compromised following severe injury, and to provide alternative methods validating the innocuousness and effectiveness of dermatological and cosmetic products. However the functional properties of tissue substitutes have not been well characterised, mainly since mechanical measurement devices have not been designed to test cell culture materials in vitro. From the mechanical standpoint, reconstructed skin is a heterogeneous multi-layer viscoelastic material. To characterise the time-dependent behaviour of reconstructed skin, spherical indentation load-relaxation tests were performed with a specific original device adapted to measure small soft tissue samples. Load-relaxation indentation tests were performed on a standard reconstructed skin model and on sub-components of the reconstructed skin (3D-scaffold alone and dermal equivalent). Generalised Maxwell and Kelvin-Voigt rheological models are proposed for analysing the mechanical behaviour of each biological tissue. The results indicated a modification of the rheological behaviour of the samples tested as a function of their biological structure. The 3D-scaffold was modelled using the one-branch Maxwell model, while the dermis equivalent and the reconstructed skin were modeled using a one-branch and a two-branch Kelvin-Voigt model, respectively. Finally, we demonstrated that skin cells contribute to global mechanical behaviour through an increase of the instantaneous relaxation function, while the 3D-scaffold alone influences the mechanical response of long relaxation times. [ABSTRACT FROM AUTHOR]

Abstract: Normal skin ageing is characterised by an alteration of the underlying connective tissue with measurable consequences on global skin biophysical properties. The cutis laxa syndrome, a rare genetic disorder, is considered as an accelerated ageing process since patients appear prematurely aged due to alterations of dermal elastic fibres. In the present study, we compared the topography and the biomechanical parameters of normal aged skin with an 17 year old cutis laxa patient. Skin topography analyses were conducted on normal skin at different ages. The results indicate that the skin relief highly changes as a function of ageing. The cutaneous lines change from a relatively isotropic orientation to a highly anisotropic orientation. This reorganisation of the skin relief during the ageing process might be due to a modification of the skin mechanical properties, and particularly to a modification of the dermis mechanical properties. A specific bio-tribometer, based on the indentationtechnique under light load, has been developed to study the biophysical properties of the human skin in vivo through two main parameters: the physico-chemical properties of the skin surface, by measuring the maximum adhesion force between the skin and the bio-tribometer; and the bulk mechanical properties. Our results show that the pull-off force between the skin and the biotribometer as well as the skin Young's modulus decrease with age. In the case of the young cutis laxa patient, the results obtained were similar to those observed for aged individuals. These results are very interesting and encouraging since they would allow the monitoring of the cutis laxa skin in a standardised and non-invasive way to better characterize either the evolution of the disease or the benefit of a treatment. [Copyright &y& Elsevier]

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Snake venoms are rich mixtures of polypeptides, which target, among other physiological networks, the cardiovascular system. Snake toxins such as phospholipase A2 (PLA2), natriuretic peptides (NPs), and bradykinin-potentiating peptides (BPP) exert various effects with vascular consequences (hypotension, vasorelaxation...). Some of these toxins have been developped as drugs with antihypertensive properties, such as Captopril™. We have previously shown that the venom of Montivipera bornmuelleri induces the relaxation of rat aortic rings. Here, we aim to identify and characterize the vasoactive compounds of this venom. The venom was fractionated by HPLC. The fractions were assayed on the endothelial cell line, Mile Sven 1 (MS1) and two different cell lines, which stably expressed muscarinic receptors M1 and M3. We screened for compounds able to inhibit acetylcholine-induced intracellular Ca2+ rise, using the fluorescence probe FURA-2. Wire myography on isolated mesenteric arteries was used. Proteomic analysis was performed to characterize selected fractions. Among 23 fractions of the M. bornmuelleri venom, one fraction was selected for its ability to reduce acetylcholine-induced Ca2+ rise in MS1 cells. The proteomic analysis led to identify a novel peptidyl toxin, homologous to a vascular endothelial growth factor toxin from Macrovipera lebetina. However, this novel toxin was unable to antagonize acetylcholine-induced Ca2+ rise in cells expressing muscarinic receptors M1 or M3, suggesting that this peptide acts indirectly on the Ca2+ signaling pathway in endothelial cells. In myography, the crude venom exhibited a vasorelaxant effect on mesenteric arteries, but the isolated peptide did not. The M. bornmuelleri venom exerts a vasorelaxant effect on mesenteric arteries. We found a novel toxin homologous to a vascular endothelial growth factor snake toxin, which modulates Ca2+ signaling pathway in endothelial cells. [ABSTRACT FROM AUTHOR]

The wave phenomenon in free surface media stems from the propagation of mode grouping. Due to the nature of propagation in a given medium, this phenomenon expresses different types of dependence on the medium's properties and represents its mechanical admittance. In contrast with body wave propagation, dependencies related to surface propagation in a medium can be described by spatial-temporal characteristics. These characteristics can be obtained by performing appropriate experiments and do not require prior knowledge of the physical properties of the medium. In this study, we propose an original surface wave investigation and a phenomenological analysis approach adapted to the mechano-bio-structural states evaluation of in vivo human skin. Two objectives are sought with the method proposed: the first concerns the development of a non-invasive device for generating and tracking surface waves in human skin called Free-Skin-Surface-Wave (FSSW); the second concerns the adaptation of the Multi-Chanel Analysis of Surface Waves (MASW) method to evaluate the mechano-bio-structural states of human cutaneous tissue in vivo on the basis of the propagating phenomena observed. As an illustration of the proposed method application, we have done an in vivo evaluation, on intern-forearm of female volunteers population. In addition, we proposed a study of the aging effect and a comparison with ultrasound B-Mode technique, to validate the method sensitivity to follow the mechano-morphological properties of the in vivo human skin. In this study, our medium of application was human skin in vivo , but it is conceivable to extend this application to other soft biological media. [ABSTRACT FROM AUTHOR]

Skin ageing is a complex process which strongly impacts the three skin layers (epidermis, dermis, hypodermis) both functionally and structurally. Of particular interest are the effects of ageing on the dermis biomechanics and how this evolution can impact the reorganization of the cutaneous lines which compose the skin relief. It has been argued that the skin relief could reflect the underlying mechanical condition of the skin. Nevertheless, there is not yet conclusive evidence of the existence of such a link. This work aims at experimentally studying, in vivo , the correlation between the anisotropy of human skin biomechanics and skin topography as a function of ageing. The study was conducted on a panel of 20 men divided into 4 groups according to age (from 23 to 64 years old). The measurements were performed on the right volar forearm of each volunteer. For the biomechanical measurements, an innovative contactless bio-rheometer was developed. It allows access to the mechanical behaviour of the skin in several directions. This device generates an air blast without any contact with the skin area and measures its dynamic response (evaluation of speed of wave propagation) with a linear laser. Moreover, a turntable enables measurements to be made in different angular directions. To analyse the topography of skin relief, we proposed a new method, based on watershed and linear radon transformations. First, an optical analysis of a replica of the skin relief is performed. Then, from the skin image obtained, the density of the cutaneous lines is calculated in different directions using watersheld transformation. The orientation of the detected lines is then estimated with an algorithm based on linear radon transformation. The results observed show a good correlation between the skin relief and the mechanical properties of the skin all along the ageing process. For both topography and mechanical properties, there is a transition from an almost isotropic mechanical behaviour to an anisotropic one as a function of ageing process. Thus, we might conclude that the skin relief reflects the underlying mechanical conditions of the skin. Image 1 [ABSTRACT FROM AUTHOR]

Objectif Dans la littérature, peu de données existent à ce jour concernant les complications non métaboliques des pompes à insuline. L'objectif de ce travail était d'évaluer dans le réseau Provence la fréquence et la gravité des complications matérielles liées aux pompes à insuline en 2014. Matériels et Méthodes Lors de chaque incident matériel, une feuille de déclaration d'incident technique était remplie par le prestataire et envoyée au médecin de suivi et au fabricant. Étaient relevés : la date de survenue, le type d incident, le type de pompe, le mode de déclaration, les conséquences cliniques. Ces données étaient secondairement croisées aux fiches d'évaluation annuelle des centres initiateurs afin de collecter l'ensemble des données patients. Résultats 279 déclarations de matériovigilance ont été réalisée du 1 er janvier au 31 Décembre 2014, 271 incidents liés aux pompes, seulement 8 déclarations liées aux cathéters, soit une prévalence de 16,3 % d'incidents déclarés sur l'ensemble des pompes à insuline du réseau Provence en 2014. Le signalement de l'incident était fait dans 48 % des cas lors du suivi du prestataire, dans 45 % des cas par appel du patient, 4 % des cas par appel du médecin de suivi, 1 % des cas par un mail du patient. Les incidents les plus fréquemment recensés étaient des anomalies de l'affichage de l'écran dans 21 % des cas, des fissures du boitier ou du compartiment des piles dans 26 % des cas, alarme intempestive dans 13 % des cas, autonomie des piles dans 6,5 % des cas et problème de touches dans 9 % des cas. Les conséquences cliniques de ces incidents étaient rares : aucune conséquence dans 87,2 % des cas, hyperglycémie dans 6,2 % des cas, hypoglycémie dans 1,1 % des cas, acétone dans 1,1 % des cas et hospitalisation dans 0,7 % des cas. Conclusions Les incidents matériels liés aux pompes à insuline restent fréquents en dépit du développement constant des matériaux. Ces incidents sont essentiellement mineurs et ont peu de conséquences cliniques pour les patients. Il est nécessaire d'améliorer la déclaration des incidents de cathéter. [ABSTRACT FROM AUTHOR]

Rationnel: L’apoprotéine (apo)-CIII, marqueur de risque cardiovasculaire, est augmentée dans l’obésité. La chirurgie bariatrique est associée à une diminution de la morbi-mortalité cardiovasculaire en partie grâce à une amélioration du profil lipidique. Nous avons évalué l’évolution des concentrations en apo-CIII avant et après chirurgie bariatrique en lien avec les profils lipidiques. Patients et méthodes: Évaluation des profils lipidiques et apoprotéiques, avant et 12 mois après chirurgie, chez 170 patients obèses bénéficiant d’une chirurgie bariatrique répartis en 3 groupes : anneau gastrique (AG n=27), sleeve gastrectomie (SG n=80) ou bypass gastrique (BP n=63). Résultats: Douze mois après chirurgie, on constate une diminution significative de l’IMC (AG : – 7,9 ; SG : – 11,3 et BP : – 12,5kg/m2 p<0,01), du HOMA et des triglycérides (AG : – 0,43 ; SG : – 0,59 et BP : – 0,36g/L p<0,01) dans les 3 groupes, une augmentation significative du HDL-cholestérol dans les groupes AG et SG, une diminution significative du LDL-cholestérol et du cholestérol total dans le groupe BP ainsi qu’une diminution significative des taux d’apo-CII (SG : – 7,0 et BP : – 9,1mg/L p<0,01 versus AG : – 4,8) et d’apo-CIII (SG : – 41,6 et BP : – 34,6mg/L p<0,01 versus AG : – 19,4) dans les groupes SG et BP. La diminution d’apo-CIII est significativement et positivement corrélée au cholestérol total, aux triglycérides, et à l’apo-CII. Discussion: La chirurgie bariatrique entraine une diminution des taux plasmatiques d’apo-CIII en lien avec l’amélioration du profil lipidique et la baisse des taux d’apo-CII. Cet effet sur l’apo-CIII pourrait être lié à la diminution des lipoprotéines riches en triglycérides circulantes par diminution des apports alimentaires, perte de poids et amélioration de l’insulinosensiblité. Le rôle propre de la diminution d’apo-CIII et du ratio apo-CIII/CII sur l’amélioration du catabolisme des LRT est envisageable. [ABSTRACT FROM AUTHOR]

Rationnel: Des taux plasmatiques bas de HDL-cholestérol sont couramment retrouvés dans l’obésité et représentent un facteur de risque cardio-vasculaire indépendant. Le but de cette étude était d’examiner les associations entre les taux plasmatiques du HDL-cholestérol et les profils hormonaux plasmatiques (insuline, adiponectine, résistine, leptine et ghréline) dans des sous-groupes de patients atteints d’obésité de classe II et III. Matériels et méthodes: Les taux plasmatiques à jeun de glucose, cholestérol total, LDL-cholestérol, HDL-cholestérol, triglycérides, acides gras libres, apoprotéines AI, B-100, B-48, CII, CIII, insuline, CRP, adipocytokines (adiponectine, résistine, leptine) et ghréline, ainsi que la composition corporelle et la dépense énergétique au repos ont été mesurés dans 3 sous-groupes de patients obèses : 21 obèses métaboliquement sains (OMS), 17 obèses métaboliquement anormaux (OMA) et 21 obèses avec HDL-cholestérol bas isolé (OHB) comparés à 21 sujets contrôles sains de poids normal. Résultats: La résistance à l’insuline est graduellement augmentée des patients appartenant au groupe OMS, au groupe OHB jusqu’au groupe OMA (P<0.05 pour l’index HOMA-IR entre OMS et OMA et entre OHB et OMA). En analyse par régression multiple, l’adiponectine est associée de façon positive et indépendante aux taux de HDL-cholestérol dans le groupe OMA (P<0.05) et la ghréline est associée de façon positive et indépendante aux taux de HDL-cholestérol dans le groupe OHB (P<0.05). Conclusion: Notre étude montre que, dans l’obésité, ghréline et adiponectine pourraient contribuer aux taux du HDL-cholestérol indépendamment de la résistance à l’insuline et de l’inflammation. [Copyright &y& Elsevier]