On inverse analysis and robustness evaluation for biological structure behaviour in FE simulation. Application to the liver

To prevent abdominal organs traumas, the definition of efficient safety devices should be based on a detailed knowledge of injury mechanisms and related injury criteria. In this sense, FE simulation coupled to experiment could be a valuable tool to provide a better understanding of internal organs behaviour under crash conditions. This work proposes a methodology based on inverse analysis which combines exploration process optimisation and robustness study to obtain mechanical behaviour of the complex structure of the liver through FE simulation. The liver characterisation was build on Mooney Rivlin hyperelastic behaviour law considering whole liver structure under uniform quasi-static compression. With the global method used, the model fits experimental data. The variability induced by modelling parameters is quantified within a reasonable time. Liver compression, FE simulation, inverse analysis, robustness analysis

Ionic contrast terahertz time resolved imaging of frog auricular heart muscle electrical activity

International audienceThe authors demonstrate the direct, noninvasive and time resolved imaging of functional frog auricular fibers by ionic contrast terahertz (ICT) near field microscopy. This technique provides quantitative, time-dependent measurement of ionic flow during auricular muscle electrical activity, and opens the way of direct noninvasive imaging of cardiac activity under stimulation. ICT microscopy technique was associated with full three-dimensional simulation enabling to measure precisely the fiber sizes. This technique coupled to waveguide technology should provide the grounds to development of advanced in vivo ion flux measurement in mammalian hearts, allowing the prediction of heart attack from change in K+ fluxes. Cop. 2006 American Institute of Physics

Modélisation du comportement effectif du combustible MOX par une analyse micromécanique en champs de transformation non uniformes

La répartition hétérogène du plutonium dans le combustible nucléaire MOX implique que la modélisation de son comportement, durant l'irradiation, passe par la construction de lois macroscopiques faisant intervenir les effets microstructuraux. Pour homogénéiser ce problème local, nous avons choisi une méthode d'analyse par champs de transformation non uniformes, abrégé anglais NTFA (cf-Michel, Suquet IJSS 2003). Nous présentons donc ici, les travaux menés sur ce modèle pour l'adapter au comportement du MOX, et les résultats effectifs et locaux de celui-ci par rapport à des calculs de références

Expression of a Set of Synthetic Suppressor tRNAPhe Genes in Saccharomyces cerevisiae

ynthetic ochre and amber tRNA suppressor genes derived from the yeast tRNAGAAPhe sequence have been constructed. They were efficiently transcribed in vitro and expressed in vivo via a synthetic expression cassette. tRNAUUAPhe and tRNAUUAPheDelta IVS (IVS = intervening sequence) are relatively inefficient ochre suppressors. They are toxic to the cell when expressed on a multicopy plasmid, and they do not suppress at all when present as single copies. The intron does not seem to have any effect on suppression. In contrast, the amber suppressor tRNACUAPheDelta IVS is efficient when expressed from a single-copy plasmid, while its efficiency is reduced on a multicopy vector

Cancer risk in immune-mediated inflammatory diseases (IMID).

Inflammation and cancer have a profound yet ambiguous relationship. Inflammation - especially chronic inflammation - has protumorigenic effects, but inflammatory cells also mediate an immune response against the tumor and immunosuppression is known to increase the risk for certain tumors.This article reviews current literature on the role of inflammation in cancer and the cancer risk in immune-mediated inflammatory diseases (IMIDs). We discuss the effect on cancer risk of different drug classes used in the treatment of IMIDs treatment, including biologicals such as tumor necrosis factor (TNF) inhibitors.Overall cancer incidence and mortality risk are similar to the general population in inflammatory bowel disease (IBD), and slightly increased for rheumatoid arthritis and psoriasis, with risk profiles differing for different tumor types. Increased risk for non-melanoma skin cancer is associated with thiopurine treatment in IBD, with the combination of anti-TNF and methotrexate in rheumatoid arthritis and with PUVA, cyclosporine and anti-TNF treatment in psoriasis. Data on the safety of using biologic or immunosuppressant therapy in IMID patients with a history of cancer are scarce.This review provides clinicians with a solid background to help them in making decisions about treatment of immune-mediated diseases in patients with a tumor history.This article is related to another review article in Molecular Cancer: http://www.molecular-cancer.com/content/12/1/86.Peer reviewe

Comparative proteome analysis of human epithelial ovarian cancer

<p>Abstract</p> <p>Background</p> <p>Epithelial ovarian cancer is a devastating disease associated with low survival prognosis mainly because of the lack of early detection markers and the asymptomatic nature of the cancer until late stage. Using two complementary proteomics approaches, a differential protein expression profile was carried out between low and highly transformed epithelial ovarian cancer cell lines which realistically mimic the phenotypic changes observed during evolution of a tumour metastasis. This investigation was aimed at a better understanding of the molecular mechanisms underlying differentiation, proliferation and neoplastic progression of ovarian cancer.</p> <p>Results</p> <p>The quantitative profiling of epithelial ovarian cancer model cell lines TOV-81D and TOV-112D generated using iTRAQ analysis and two-dimensional electrophoresis coupled to liquid chromatography tandem mass spectrometry revealed some proteins with altered expression levels. Several of these proteins have been the object of interest in cancer research but others were unrecognized as differentially expressed in a context of ovarian cancer. Among these, series of proteins involved in transcriptional activity, cellular metabolism, cell adhesion or motility and cytoskeleton organization were identified, suggesting their possible role in the emergence of oncogenic pathways leading to aggressive cellular behavior.</p> <p>Conclusion</p> <p>The differential protein expression profile generated by the two proteomics approaches combined to complementary characterizations studies will open the way to more exhaustive and systematic representation of the disease and will provide valuable information that may be helpful to uncover the molecular mechanisms related to epithelial ovarian cancer.</p

Cursive Eye-Writing With Smooth-Pursuit Eye-Movement Is Possible in Subjects With Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder causing a progressive motor weakness of all voluntary muscles, whose progression challenges communication modalities such as handwriting or speech. The current study investigated whether ALS subjects can use Eye-On-Line (EOL), a novel eye-operated communication device allowing, after training, to voluntarily control smooth-pursuit eye-movements (SPEM) so as to eye-write in cursive. To that aim, ALS participants (n = 12) with preserved eye-movements but impaired handwriting were trained during six on-site visits. The primary outcome of the study was the recognition of eye-written digits (0–9) from ALS and healthy control subjects by naïve “readers.” Changes in oculomotor performance and the safety of EOL were also evaluated. At the end of the program, 69.4% of the eye-written digits from 11 ALS subjects were recognized by naïve readers, similar to the 67.3% found for eye-written digits from controls participants, with however, large inter-individual differences in both groups of “writers.” Training with EOL was associated with a transient fatigue leading one ALS subject to drop out the study at the fifth visit. Otherwise, itching eyes was the most common adverse event (3 subjects). This study shows that, despite the impact of ALS on the motor system, most ALS participants could improve their mastering of eye-movements, so as to produce recognizable eye-written digits, although the eye-traces sometimes needed smoothing to ease digit legibility from both ALS subjects and control participants. The capability to endogenously and voluntarily generate eye-traces using EOL brings a novel way to communicate for disabled individuals, allowing creative personal and emotional expression