S-motility

Anuras S Motility Disorders of the Gastrointestinal Tract. New York, Raven Press, 1992. 

Fractal pattern reminiscent of that formed by P. dendritiformis was observed in other bacteria that exhibit collective motility such as S. marcescens and P. mirahilis [80], and some mutants of M. xanthus defective in S motility (see Section 5) [75]. This latter case represents a new class of pattern-forming strains that seem to be unmasked by mutation. 

Fontes and Kaiser [33] described a special case of tactic behavior in M. xanthus. They showed that the cells respond to stress in the agar. This response (elasticotaxis) depends on A-, but not on S-motility. According to Wolgemuth et al. [131], elasticotaxis arises from the tendency of the polyelectrolyte chains of extruding slime to align with polymer chains in the agar. 

The Dif system is required for production of peritrichous cell-surface appendages called fibrils [134, 135]. These are flexible filaments, 10-30 nm in diameter and up to many times the length of the cell [28, 65], composed of approximately equal amounts of polysaccharide and protein [3, 4]. A fibril protein was recently identified as a zinc metalloprotease [61]. Under the microscope, the fibrils appear to coat the cells and form a cohesive interconnective matrix ([58], Figure 10). Chemical disruption of the fibrils, like that of the pili, results in defective S-motility [2]. In... 

They also are important portals for systemic therapy. However, many variables can influence dmg dissolution and absorption ia these areas, including rate of gastric emptying, intestinal motility, mass and pH of intestinal contents, and condition of the absorbiag surfaces (15—17). These variables, ia turn, can be affected by the patient s disease, posture, and eating habits, and even by such aspects of the treatment as the timing of doses (11). 

Constipation, caused by a decrease in intestinal motility, may occur in tiiose taking one of tiiese drag s on a regular basis. Drowsiness may occur widi die use of diese dm, but at times tins adverse reaction is desirable Fbr example when atropine is used preoperatively to reduce die production of secretions in die respiratory tract, drowsiness is part of die desired response... 

Vale, R.D., Reese, T.S., Sheetz, M.P. (1985a). Identification of a novel force generating protein, kinesin, involved in microtubule-based motility. Cell 42,39-50. 

Cooper, M.S., Schliwa, M. (1986). Motility of cultured fish epidermal cells in the presence and absence of direct current electric fields. J. Cell Biol. 102, 1384-1399. 

Smith, S.J. (1988). Neuronal cytomechanics The actin-based motility of growth cones. Science 242, 708-715. 

Preston, T.M., King, C.A., Hyams, J.S. (1990). The Cytoskeleton and Cell Motility, Blackie, Glasgow. 

Figure 13, A schematic diagram of the motility assay. Myosin molecules (HMM or S-1 are also used) stick to glass coverslips coated with nitrocellulose. Actin, in solution, is then added to the glass coverslip and it binds to the myosin molecules. When ATP is added, actin can move over the surface, propelled by the myosin molecules.

The interactions between the endocrine and neural systems of the GIT are complex, include shared signaling molecules, and can be hard to separate. Therefore, it is likely that the influence(s) of some phytochemicals will cross over between neural and non-neural pathways. Corresponding with this, lumenal administration of capsaicin interacts with visceral neurons to increase GIT motility (Zittel et al., 2001 Topcu et al, 2002) and abrogates the decreased electrolyte and fluid secretion caused by piperine (Capasso et al., 2002). 

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