Connective tissue replacement

Well-known products include wound dressing, temporary skin, and connective-tissue replacement (BioFill , Gengiflex ) [7]. Numerous groups are working on these applications and investigating the healing effect of this external BC material (Table 2). 

The neuromuscular complications of diabetes mellitus are most often neuropathic in origin, with distal sensorimotor polyneuropathies being the most common. In addition, ischemic infarction of skeletal muscle may occur due to occlusive vascular disease, with small and medium-sized arterioles particularly affected. This occurs in poorly-controlled diabetes and affects thigh, muscles in most cases. In acute stages, muscle biopsy findings are those of widespread muscle necrosis, edema, and phagocytic cell infiltration. Muscle regeneration may be incomplete and increased fibrous connective tissue may replace lost muscle tissue. 

The citric acid cycle is the final common pathway for the aerobic oxidation of carbohydrate, lipid, and protein because glucose, fatty acids, and most amino acids are metabolized to acetyl-CoA or intermediates of the cycle. It also has a central role in gluconeogenesis, lipogenesis, and interconversion of amino acids. Many of these processes occur in most tissues, but the hver is the only tissue in which all occur to a significant extent. The repercussions are therefore profound when, for example, large numbers of hepatic cells are damaged as in acute hepatitis or replaced by connective tissue (as in cirrhosis). Very few, if any, genetic abnormalities of citric acid cycle enzymes have been reported such ab-normahties would be incompatible with life or normal development. 

Mucosa. The innermost layer of the wall is the mucosa, which consists of a mucous membrane, the lamina propria, and the muscularis mucosa. The mucous membrane provides important protective and absorptive functions for the digestive tract. The nature of the epithelial cells lining the tract varies from one region to the next. Rapidly dividing stem cells continually produce new cells to replace worn out epithelial cells. The average life span of these epithelial cells is only a few days. The lamina propria is a thin middle layer of connective tissue. This region contains the capillaries and small lymphatic vessels that take up the digested nutrient molecules. The muscularis mucosa is a thin layer of smooth muscle. Contraction of this muscle may alter the effective surface area for absorption in the lumen. 

Cirrhosis A liver disease commonly associated with chronic alcohol misuse and characterised by the replacement of once-healthy hepatocytes with abnormal connective tissue. 

Ethanol-related high levels of NADH+H and acetyl-CoA in the liver lead to increased synthesis of neutral fats and cholesterol. However, since the export of these in the form of VLDLs (see p. 278) is reduced due to alcohol, storage of lipids occurs (fatty liver). This increase in the fat content of the liver (from less than 5% to more than 50% of the dry weight) is initially reversible. However, in chronic alcoholism the hepatocytes are increasingly replaced by connective tissue. When liver cirrhosis occurs, the damage to the liver finally reaches an irreversible stage, characterized by progressive loss of liver functions. 

Carbon-epoxy plates are now used in bone surgery replacing the titanium plates that had been employed. Usually a layer of connective tissue forms around the composite plate. 

Meat proteins comprise a water-soluble fraction (containing the muscle pigment myoglobin and enzymes), a salt-soluble fraction composed mainly of contractile proteins, and an insoluble fraction comprising connective tissue proteins and membrane proteins. As reviewed by Dierckx and Huyghebaert [107], HPLC analysis of meat proteins has been successfully applied to evaluate heat-induced changes in the protein prohle, to detect adulterations (addition of protein of lower value, the replacement of meat from high-value species with meat from lower-value species, etc.), and for specie identification in noncooked products (also for fish sample). 

Persikov, A. V., Pillitteri, R. J., Amin, P., Schwarze, U., Byers, P. H., and Brodsky, B. (2004). Stability related bias in residues replacing glycines within the collagen triple helix (Gly-Xaa-Yaa) in inherited connective tissue disorders. Hum. Mut. 24, 330-337. 

Muscular Dystrophy. A striking feature of muscular dystrophy is the extensive loss of contractile proteins and their replacement by fat and connective tissue. The involvement of proteases in the degradation of... 

Tht fatty liver condition can be described as follows. With alcohol consumption, the liver s main source of energy (fatly acids) is replaced by alcohol. This results in accumulation of unused fatty acids, in the form of triglycerides, with the consequent deposition of these TGs as fat. This mechanism is different from the fatty liver provoked by kwashiorkor, where a fatty liver results from the failure to synthesize the apoHpopioteins needed for exporting TGs from the liver. The fatty liver of kwashiorkor is not associated with cirrhosis, but that of alcoholism is associated with conversion of stellate cells to cells resembling those of connective tissue, i-c-, fibroblasts, Stellate cells are fat-storing cells that occur In the interstitial space between the capillaries and hcpalocytcs, called the space of Disse. 

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