A model for the compressible, viscoelastic behavior of human amnion addressing tissue variability through a single parameter

A viscoelastic, compressible model is proposed to rationalize the recently reported response of human amnion in multiaxial relaxation and creep experiments. The theory includes two viscoelastic contributions responsible for the short- and long-term time- dependent response of the material. These two contributions can be related to physical processes: water flow through the tissue and dissipative characteristics of the collagen fibers, respectively. An accurate agreement of the model with the mean tension and kinematic response of amnion in uniaxial relaxation tests was achieved. By variation of a single linear factor that accounts for the variability among tissue samples, the model provides very sound predictions not only of the uniaxial relaxation but also of the uniaxial creep and strip-biaxial relaxation behavior of individual samples. This suggests that a wide range of viscoelastic behaviors due to patient-specific variations in tissue composition

Early prediction of anthracycline induced cardiotoxicity

Aim: The purpose of this study is to evaluate echocardiographically determined cardiac functions with serum levels of brain natriuretic peptide (BNP), cardiac troponin I (cTnI) and total antioxidant status (TAOS) in childhood leukemia treated with chemotherapeutics containing anthracyclines. Methods: A study group of 29 patients who have been followed for acute lymphoblastic leukemia (ALL) and administered a treatment protocol containing chemotherapy of anthracyclines were included in the analysis. Levels of BNP, cTnI and TAOS were studied in serum samples of the patients. Results: We demonstrated that as the drug dosage increased, systolic ejection fraction (EF) and shortening fraction (FS) values decreased (EF r2 = 0.2327, FS r2 = 0.251). On the other hand, increased dosage of anthracycline therapy was associated with significant raise in plasma BNP levels (r 2 = 0.246) and significant decrease in serum TAOS levels (r 2 = 0.317) without any change in serum cTnI levels. Conclusion: Our study suggest that serum TAOS and BNP levels may be useful as an early and sensitive indicator of anthracycline induced cardiotoxicity. © 2007 The Author(s)