Tissue repairs

Tissue repairs Tissues Tissue stains Titan... 

MetaHoelement complexes may be useful for the post-irradiation treatment of radiation injury, based on the observation that several of these compounds accelerate recovery of, among other things, lympho/hemopoiesis. Preirradiation Mn2(0)(DIPS)g increases the survival of y-irradiated mice (103). Treatment of mice that have been exposed to an LD q q dose of y-rays plus Mn2(0)(DIPS)g either 1 or 3 h after irradiation also increases survival, which supports the hypothesis that this compound is an effective radiorecovery agent (105). Again, this increase in survival may result from the resynthesis of radiation-depleted Mn-dependent enzymes that facHitate the recovery of immunocompetence and tissue repair, as reported for Cu(II)2(DIPS)4. 

Amino acids promote the production of proteins, enhance tissue repair and wound healing, and reduce the rate of protein breakdown. Amino acids are used in certain disease states, such as severe kidney and liver disease, as well as in TPN solutions. (See the last section of this chapter for a more detailed discussion of TPN.) TPN may be used in patients with conditions such as impairment of gastrointestinal absorption of protein, in patients with an increased requirement for protein, as seen in those with extensive bums or infections, and in patients with no available oral route for nutritional intake ... 

Chitosan freeze-dried fleeces support chondrocyte attachment and synthesis of extracellular matrix [344]. Chitosan was used to assist the spontaneous tissue repair of the meniscus [345]. The repair of the cartilage and the prevention of its degradation in osteoarthritis is, however, possible with the association of glucosamine sulfate salt and chondroitine sulfate, the latter being particularly effective [346]. 

In critically ill patients, may give protein calories in excess of energy requirements in order for this macronutrient to be utilized for tissue repair and synthesis (controversial)... 

Mutsaers SE, Bishop JE, McGrouther G, Laurent GJ. Mechanisms of tissue repair from wound healing to fibrosis. Int J Biochem Cell Biol 1997 29(1) 5-17. 

Bucala R, Spiegel LA, Chesney J, Hogan M, Cerami A. Circulating fibrocytes define a new leukocyte subpopulation that mediates tissue repair. Mol Med 1994 1(1) 71—81. 

T cell and cytokine regulation of enterocyte apoptosis may also be important in the expulsion of nematodes, in particular T. spiralis and T. muris, which inhabit an intracellular niche. Certainly an increase in the number of apoptotic cells within the epithelium is observed around the period of expulsion of T. muris in resistant mouse strains (D. Artis, C.S. Potten and R.K. Grencis, unpublished). Apoptosis of host enterocytes may dislodge the nematode or perhaps expose vital feeding organs to immune attack, and so enhance expulsion. Whether enterocyte apoptosis results from the burrowing action of the worms or a tissue repair mechanism, or is involved in expulsion, remains to be investigated. 

Bioactive ceramics have already played an important role in bone repair in the clinical fields because of their ability to bond to living bone. However, the use of these bioactive ceramics is limited because of their brittleness and higher Young s modulus than bone. The combination of ceramic and organic components provides us with a design for novel tissue-repairing materials. The establishment of these techniques promises a novel bone repairing material. 

PDGF plays an important role in the wound healing process. It is released at the site of damage by activated platelets, and acts as a mitogen/chemoattractant for many of the cells responsible for initiation of tissue repair. It thus tends to act primarily in a paracrine manner. It also represents an autocrine/paracrine growth factor for a variety of malignant cells. 

Inflammation is the normal host response to infection or injury that mediates immune elimination of pathogens and tissue repair. Inflammatory processes include increased production of cytokines, chemokines, nitric oxide, and eicosanoids by the innate immune system in conjunction with altered leukocyte homing, all of which greatly impact acquired immunity. Aberrant inflammatory responses evoke both acute injury such... 

Thus, the role of cytokines in inflammation, immune-cell function and tissue repair is varied and complex. Later sections of this book explore the cytokines generated by neutrophils during inflammatory challenge ( 7.3.4), the regulation of neutrophil function by cytokines ( 7.2.1) and human diseases associated with neutrophil dysfunction in which cytokines may play important roles ( 8.2.5, 8.8). 

Valine A branched-chain essential amino add that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway. [NIH]... 

Valine (Val or V) ((5)-2-amino-3-methyl-butanoic acid) is a nonpolar, neutral, aliphatic amino acid with the formula HOOCCH(NH2)CH(CH3)2. Along with Leu and He, Val is a branched-chain amino acid and is found in high concentrations in the muscles. Val is needed for muscle metabolism and coordination, tissue repair, and for the maintenance of proper nitrogen balance in the body. ° The steric hindrance present in Val and He (caused by branching) lowers the rate of coupling reactions, resulting in an increase in side reactions. ... 

The best-known effect of APOE is the regulation of lipid metabolism (see Fig. 10.13). APOE is a constituent of TG-rich chylomicrons, VLDL particles and their remnants, and a subclass of HDL. In addition to its role in the transport of cholesterol and the metabolism of lipoprotein particles, APOE can be involved in many other physiological and pathological processes, including immunoregu-lation, nerve regeneration, activation of lipolytic enzymes (hepatic lipase, lipoprotein lipase, lecithin cholesterol acyltransferase), ligand for several cell receptors, neuronal homeostasis, and tissue repair (488,490). APOE is essential... 

Nenss, S., Becher, E., Woltje, M., Tietze, L. and Jahnen-Dechent, W. (2004) Eunctional expression of HGF and HGE receptor/c-met in adult human mesenchymal stem cells suggests a role in cell mobilization, tissue repair, and wound healing. Stem Cells 22, 405 414. 

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