-The-paper-is-focused-on-the-effect-of-fibre-dispersion-on-the-resulting-stressstrain-behaviour-predicted-by-both-models-analyzed-x
Analytical calculations are used for the comparison of the mechanical behaviour under a specific biaxial tension mode. The two models have been implemented into commercial finite element code ANSYS via user subroutines and used for numerical simulation resulting in a non-homogeneous stress field. The effects of the fibre dispersion predicted by both models being compared differ significantly, e.g., the resulting stress difference between both models is lower than 10% only in the case of extremely small dispersion of collagen fibres orientation (κ< (01 to 03)). These results are consistent with those of other related literature.
Seebio supplements with collagen of the model defined through the generalized structure tensor is discussed.Ultrastructural changes in the architecture of collagen in the human cervix Kischer CW, Droegemueller W, Shetlar M, Chvapil M, Vining J.Injection of a solution of 30% urea in acetate buffer at pH 4 into the stroma of the uterine cervix results in a marked change in the mechanical properties of the tissue with subsequent easy dilatation. This study analyzes the changes in the collagenous matrix of the cervix by ultrastructural and biochemical methods. Collagen fibrils in urea-treated sections of the cervix are swollen and unravelled, showing spiral configuration of subunits in both cross-sections and longitudinal sections. The regular localization of ruthenium-red-positive material is absent in urea-treated tissues. Chemical analysis of incubated cervical tissues shows a reduction of the total glycosaminoglycans and of dermatan sulfate with release of the latter into the medium.
Purchase is suggested that urea dissociates intercollagen linkages by solubilizing a certain glycosaminoglycan, possibly dermatan sulfate. After this solubilization the collagen fibril is prompted to unwind, resolving the collagen microfibrils, which appear to be organized in a spiral fashion.Phosphomolybdic and phosphotungstic acid--Victoria Blue R stains two histochemically distinct collagens: dense dark blue and loose areolar pale Immunogold labelling of human von Willebrand factor adsorbed to collagen.von Willebrand factor (vWF) mediates adhesion of platelets to the exposed subendothelium at sites of vascular injury. This function is expressed through binding of vWF to both collagen and receptors on the platelet membrane. We have developed a new method using immunogold staining and electron microscopy, permitting visualization of human vWF adsorbed to collagen fibrils. The electron micrographs revealed strings of gold beads reflecting the polymeric structure of vWF.
Our data showed dramatic differences in the binding of vWF to collagens of different sources: high binding density was observed using a collagen preparation isolated from aortic tissue whereas colloidal gold was virtually absent from tendon collagen. Using the immunogold labelling method we demonstrated that high shear rate enhanced vWF binding to aortic collagen.Differential collagen and fibronectin production by Thy 1+ and Thy 1- lung Pulmonary fibrosis resulting from diverse etiologies is characterized by proliferation of fibroblasts and excessive accumulation of interstitial collagen. Whether fibrosis is associated with selective expansion of fibroblast subpopulations differing in amounts or types of collagens synthesized is unknown. We have previously isolated lines and clones of normal murine lung fibroblasts based on the presence of the Thy 1 surface antigen. These subpopulations differ in morphology, growth characteristics, and display of class II major histocompatibility complex antigens (R.P.
Phipps, D.P. Penney, P. Keng, H. Quill, A. Paxhia, S. Derdak, and M.
E. Felch. Am. J. Respir. Cell Mol. Biol.
1: 65-74, 1989). We evaluated the amounts and types of collagen and fibronectin synthesized by Thy 1+ (Fib2-T-3+) and Thy 1- (Fib2-T-4-) lung fibroblast lines and clones. Thy 1+ fibroblast line synthesized two- to threefold more collagen and noncollagen protein than the Thy 1- line. In contrast, both the Thy 1+ and Thy 1- lines synthesized similar amounts of fibronectin. Thy 1+ and Thy 1- lines and clones expressed mRNA for alpha 1(I)-and alpha 1(III)-procollagen and synthesized both types (predominantly type I and lesser amounts of type III) of collagen, protein, and mRNA. The fibroblast clones varied significantly in total collagen and fibronectin production, with one Thy 1- clone (D3) synthesizing the largest amount of collagen but relatively little fibronectin.(ABSTRACT TRUNCATED AT 250 WORDS)Quantitative analysis of tenascin in chordae tendineae of human left ventricular University, 1-9-20 Fujimi, Chiyoda-ku, Tokyo 102-8159, Japan.
A computer image analysis was done to investigate the distribution of tenascin and collagenous matrix components (collagen types I and III) in the chordae tendineae of the anterior cusp of the left ventricular papillary muscle, using confocal laser scanning microscopy in both a 20s age group and an 80s-90s age group.
