China
Africa
Explore chapters and articles related to this topic
Extracellular Matrix–Derived Biomaterials: Molecularly Defined Ingredients and Processing Techniques
Published in Gilson Khang, Handbook of Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine, 2017
H.R. Hoogenkamp, L.R.M. Versteegden, T.H. van Kuppevelt, W.F. Daamen
The last major adhesive glycoprotein is fibrinogen. Fibrinogen is a large (349 kDa), soluble and complex protein consisting of three different subunits (Aα, Bβ, and γ) varying in amino acid length (610, 461, and 411, respectively) linked by disulfide bonds.97 Fibrinopeptides on the soluble fibrinogen can be cleaved by thrombin to convert fibrinogen into insoluble fibrin. Fibrin molecules assemble to form a protofibril, which subsequently aggregate into larger fibers. A 3D network, or a fibrin clot, is formed which is capable of catching blood platelets to promote aggregation. This is essential for forming a hemostatic barrier and the newly formed network offers temporary scaffolding for cells involved in wound healing. Transglutaminase (factor XIIIA) crosslinks the glutamine and the lysine residues in the fibrin clot which temporarily stabilizes the network against chemical, mechanical, and proteolytic degradation.98 Fibrin, or forming fibrin clots, also has affinity for some plasma proteins such as fibronectin and albumin, which have influence on properties like fibril thickness and density.99 Other (glyco)proteins like thrombospondin, von Willebrand factor, and fibulin bound to the fibrin clot increase the affinity for blood platelets. Moreover, growth factors like FGF-2 and VEGF are also bound to stimulate swift remodeling of the damaged site. It is noteworthy, that because of the presence of other proteins, clots formed in vivo have different properties compared with clots formed with purified components.
Asbestos exposure and mesothelioma
Published in Dorsett D. Smith, The Health Effects of Asbestos, 2015
The small increase in survival seen in some recent series, may be due to earlier detection with the advent of computed tomography (CT) and positron emission tomography scanning. (Helland A, Solberg S, Brustugun OT. Incidence and survival of malignant pleural mesothelioma in Norway: A population-based study of 1686 cases. J Thorac Oncol 2012;12:1858–61.) Attempts at early detection via blood tests and pleural effusion analysis, have been largely unsuccessful, but continued attempts to find suitable biomarkers, such as mesothelin, osteopontin, and more recently fibulin-3, look promising. (Pass HI, Levin SM, Harbut MR et al. Fibulin-3 as a blood and effusion biomarker for pleural mesothelioma. N Engl J Med 2012;367:1417–27.) The most recent epidemiological studies from the Centers for Disease Control, reveal that the incidence of mesothelioma is falling in men and is remaining stable in women. (Henley SJ, Larson TC, Wu M et al. Mesothelioma incidence in 50 states and the District of Columbia, United States, 2003–2008. Int J Occup Environ Health 2013;19(1):1–10.)
Adverse cardiovascular effects of exposure to cadmium and mercury alone and in combination on the cardiac tissue and aorta of Sprague–Dawley rats
Published in Journal of Environmental Science and Health, Part A, 2021
Sandra Arbi, Megan Jean Bester, Liselle Pretorius, Hester Magdalena Oberholzer
Oxidative stress mechanisms have been shown to affect elastin synthesis[5] and in Sprague–Dawley rats, as a result of oxidative insult, elastin and increased SMC were observed in the tunica intima creating neointimal tissue masses.[56] Similarly, the present study showed areas of neointimal formation in the groups exposed to Hg (Figure 5e,f) and the co-exposed group (Figure 5g,h). Alterations to elastin structure have been reported to decrease arterial compliance. Studies have shown that mice and humans reduced levels of fibulin-5 causes a reduction in arterial compliance, which is correlated with hypertension, reduced cardiac function and an increased risk of death from CVD.[57] In fibulin–5 deficient mice, elastin staining was reduced due to elastin fibers fiber fragmentation visible with electron microscopy.[57] In the present study, for all groups the intensity of the staining was the same. Altered elastin arrangement were observed all groups, with this effect being the most obvious in the Hg (Figure 6f) and co-exposed groups (Figure 6g). Compared with the Hg group, co-exposure to Cd and Hg resulted in increased elastin fibers linking between the lamellae. In contrast, Cd caused interruptions in the elastin lamellae (Figure 6d), while the presence of collagen bundles (Figure 7b) possibly contributed to elastic lamellae displacement.