T.H. Satoh², T.A. Surmacz³, O. Nyormoi⁴, C.M. Whitacre¹

BIOCELL, Vol.27, No.1, pp. 47-55, 2003, DOI:10.32604/biocell.2003.27.047

Abstract This study shows a strong association between cell attachment to substratum and activation of β1-integrin-signaling with resistance to the camptothecin derivative topotecan (TPT) in breast cancer cells. We propose a mechanistic-driven approach to sensitize the cells to camptothecins. ZR-75-1 anchoragedependent breast cancer cell line, its derivative 9D3S suspension cells (9D3S-S), and 9D3S cells attached to fibronectin-coated plates (9D3S-A) were treated with TPT (1 µM) or CPT-11 (40 µM) for 48 h. Programmed cell death (PCD), as shown by poly(ADP-ribose) polymerase (PARP), pro-caspase-3 and pro-caspase-9 cleavage, was observed in 9D3S-S cells but not in ZR-75-1 or More >

A. Sánchez Riera, A. Daud, A. Gallo, S. Genta, M. Aybar, S. Sánchez

BIOCELL, Vol.27, No.1, pp. 37-46, 2003, DOI:10.32604/biocell.2003.27.037

Abstract Amphibians respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretion. Most humoral defense proteins are synthetized in the skin. In this study we isolated two β-galactoside-binding lectins with molecular weights of 50 and 56 KDa from the skin of Bufo arenarum. These lectins have significant hemagglutination activity against trypsinized rabbit erythrocytes, which was inhibited by galactose-containing saccharides. They are water-soluble and independent of the presence of calcium. The antimicrobial analysis for each lectin was performed. At µmolar concentration lectins show strong bacteriostatic activity against Gram negative bacteria (Escherichia coli K12 4100 More >

R. Yunes, G.F. Doncel, A.A. Acosta

BIOCELL, Vol.27, No.1, pp. 29-36, 2003, DOI:10.32604/biocell.2003.27.029

Abstract Our objective was to study the incidence of sperm-tail phosphotyrosine immunoreactivity in normozoospermic and asthenozoospermic human sperm samples, its association with sperm motion parameters, particularly hyperactivated motility, and its potential involvement in the pathogenesis of asthenozoospermia. The work was conducted as a prospective experimental study in the Sperm Biology and Andrology laboratories of the Jones Institute, a medical school-based fertility center. The study subjects were healthy fertile male donors (normozoospermic samples) and infertile patients (asthenozoospermic samples) attending the center. Recently ejaculated semen samples were washed twice to eliminate seminal plasma and a swim-up was performed… More >

F. Auricchio¹, L. Petrini², R. Pietrabissa³, E. Sacco⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 365-380, 2003, DOI:10.3970/cmes.2003.004.365

Abstract Since 80’s many devices were developed to exploit the unique blend of mechanical and biocompatibility properties of shape memory alloys in orthodontic applications. It results in a high clinical effectiveness, but also in a spreading of technical knowledge on the properties of the single appliances. The goal of the present contribution is to contrast this sense of bewilderness and to prepare the basis for a simulationtool able to support the orthodontist choice. In particular a finite-element beam with a one-dimensional constitutive law, able to describe the SMA super elasticity and shape memory effect, is presented: More >

M.C. Ho Ba Tho¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 489-496, 2003, DOI:10.3970/cmes.2003.004.489

Abstract The objective of the paper is to address the methodology developed to model bone and joints with individualised geometric and material properties from medical image data. An atlas of mechanical properties of human bone has been investigated demonstrating individual differences. From these data, predictive relationships have been established between mechanical properties and quantitative data derived from measurements on medical images. Subsequently, geometric and numerical models of bones with individualised geometrical and mechanical properties have been developed from the same source of image data. The advantages of this modelling technique are its ability to study the More >

M. Thiriet¹, S. Naili², C. Ribreau²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 473-488, 2003, DOI:10.3970/cmes.2003.004.473

Abstract The laminar steady flow of incompressible Newtonian fluid is studied in rigid pipes with cross configuration of a collapsed tube to determine both the entry length and the wall shear stress (WSS). The cross section shapes have been defined from the collapse of an infinitely long elastic tube subjected to an uniform transmural pressure. Five characteristic collapsed configurations, from the unstressed down to the point-contact states, with a finite and infinite curvature radius at the contact point, are investigated, although the wall contact is not necessary observed in veins. Such collapsed shapes induce cross gradient More >

A.R.Skovoroda¹, R.V.Goldstein²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 457-472, 2003, DOI:10.3970/cmes.2003.004.457

Abstract We discuss the inverse problem of the recovery of the distribution of the elastic moduli of a stratified layer, based on measurements of the surface displacement under localized surface loads. A general parametric solution and a numerical procedure for computing the parameters are presented. Examples of numerical results are given. The problem and its solution are related to the monitoring of elastic properties of living tissues. More >

B. Mochnacki¹, E. Majchrzak²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 431-438, 2003, DOI:10.3970/cmes.2003.004.431

Abstract In the paper the analysis of transient temperature field in the domain of biological tissue subjected to an external heat source is presented. Because of the geometrical features of the skin the heat exchange in domain considered is assumed to be one-dimensional. The thermophysical parameters of successive skin layers (dermis, epidermis and sub-cutaneous region) are different, at the same time in sub-domains of dermis and sub-cutaneous region the internal heat sources resulting from blood perfusion are taken into account. The degree of the skin burn results from the value of the so-called Henriques integrals. The More >

Jun Liu¹, Mauro Ferrari¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 421-430, 2003, DOI:10.3970/cmes.2003.004.421

Abstract A microstructure-accounting mechanical field theory approach is applied to the problem of reflection from a granular thin layer embedded between two solid substrates to study the direct relationship of the micro-structural parameters and the overall reflection coefficients of the thin layer. The exact solution for plane wave reflection coefficients is derived under the new theoretical framework giving quantitative relations between the macroscopic reflection coefficients and a set of micro structural/physical parameters including particle size and micromoduli. The model was analyzed using averaged material properties of biological tissue for the granular thin layer. It was demonstrated More >

Francesco Genna¹, Corrado Paganelli², Stefano Salgarello³, Pierluigi Sapelli²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 405-420, 2003, DOI:10.3970/cmes.2003.004.405

Abstract We study the mechanical behavior of a prototype osseointegrated dental implant containing a thin internal layer, designed in such a way as to simulate the existence of the periodontal ligament (PDL). Experimental stress-strain curves suggest that the behavior of the PDL can be simulated by means of a compressible hyperelastic constitutive model, at least for short-term loading. We have adopted one such a model to describe the mechanical behavior of the internal layer in the prototype implant design, studied by means of several 3--D Finite Element analyses. The results indicate that the presence of such More >