Muscle, basic properties

Adult stem cells, also known as postnatal stem cells, have been isolated from other mesenchymal tissues, such as umbihcal cord blood (Mareschi et al., 2001), fat (Zuk et al., 2001), muscle (Collins et al., 2005), synovium (De Bari et al., 2001), and dental pulp (Gronthos et al., 2000, Miura et al., 2003). Although the cell characteristics of stem cells derived from different tissues are not identical, they all share the two basic properties of stem cells, self-renewal and pluripotency, like the BMSC populations. 

Contractility not only plays a prominent role in muscle but it is a basic property of all protoplasm. Because muscle is made of protoplasm, which is highly contractile, a muscle fiber may contract to one-tenth of its original length, a contraction of 90% and a deformability equal to that of the best rubber. 

A wide variety of compounds containing the basic 1-pyrindine skeleton have found applications in the biomedical field.50-52, 102 Compounds 52 and 53 described above, possess valuable biological activities similar to mepyrapone which has been found to act as a specific 1 l-j8-hydroxylase inhibitor in the biosynthesis of corticoid hormones in man as well as in animals.51 Antishock activity has been found in a series of octahydro- and decahydrobenzo[a]cyclopenta[/]quinolizenes (12) and (13).151tt The cardiovascular and potent antishock properties of 2,3,3a,5,6,ll,12,12a-octahydro-8-hydroxy-l/7-benzo[a]cyclopenta[/]-quinolizinium bromide (12a),151b as well as its positive inotropic effect on the cat papillary muscle preparation,1510 have been reported. Methods of synthesis for a series of these compounds and tests of their relative antishock activity have been described.151 Although some compounds were active, comparison of these results pointed up the lack of structure-activity relationships in the seven compounds tested. 

The basic building blocks of the nervous system are cells called neurons. Neurons are similar to other cells in the human body, such as blood cells or muscle cells, but they have the unique feature of being able to communicate with each other. The structural properties of neurons provide us with some clues to the nature of the neural transmission process. 

Because altered sodium channels have been implicated in kdr and kdr-like resistance phenomena in insects, basic research on the biochemistry and molecular biology of this molecule, which plays a central role in normal processes of nervous excitation in animals, is of immediate relevance. The results of recent investigations of the voltage-sensitive sodium channels of vertebrate nerves and muscles have provided unprecedented insight into the structure of this large and complex membrane macromolecule. Sodium channel components from electric eel electroplax, mammalian brain, and mammalian skeletal muscle have been solubilized and purified (for a recent review, see Ref. 19). A large a subunit (ca. 2 60 kDa) is a common feature of all purified channels in addition, there is evidence for two smaller subunits ( Jl and J2 37-39 kDa) associated with the mammalian brain sodium channel and for one or two smaller subunits of similar size associated with muscle sodium channels. Reconstitution experiments with rat brain channel components show that incorporation of the a and pi subunits into phospholipid membranes in the presence of brain lipids or brain phosphatidylethanolamine is sufficient to produce all of the functional properties of sodium channels in native membranes (AA). Similar results have been obtained with purified rabbit muscle (45) and eel electroplax (AS.) sodium channels. 

After establishing the basic principles of polymer chemistry, the book pinpoints the dynamic properties of the more useful conducting polymers, such as polypyrroles, polythiophenes, and polyanilines. It then demonstrates how the control of these properties enables cutting-edge applications in nano, biomedicine, and MEMS as well as sensors and artificial muscles. Subsequent chapters discuss the effect of nanodimensionai control on the resultant properties. 

Mephenesin carbamate (Tolseram) Basically a muscle relaxant with some tranquilizing properties... 

An additional substrate recognition motif appears to be contained somewhere within subdomains 1 and 2 of RLC (Zhi etai, 1994). Skeletal muscle myosin RLC is a poor substrate for the smooth muscle MLCK (Table I). Substitution of glutamate at the P-3 position for an arginine improves the ability of the skeletal muscle myosin RLC to be phosphorylated by the smooth muscle kinase however, the Pmax m ratio is only 0.06 compared to 3.4 for the wild-type smooth muscle RLC. Thus, a basic residue at the P-3 position is important, but is not the sole determinant for substrate specificity. This fact is further illustrated by the poor kinetic properties for phosphorylation of a chimera RLC contain-... 

Basically, there are three major groups of proteins in muscle tissue (a) the sarcoplasmic proteins of the muscle cell cytoplasm, (b) the myofibrillar proteins, soluble at high ionic strengths, that make up the myofibril or contractile part of the muscle, and (c) the stromal proteins comprised largely of the connective tissue proteins, collagen, and elastin. The myofibrillar proteins and the stromal proteins are fibrous and elongated they form viscous solutions with large shear resistance. These properties coupled with other lines of indirect evidence indicate that the physical properties of the myofibrillar and stromal proteins are directly related to the texture and tenderness of meat (34). 

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