Density-dependent inhibition

Density-dependent inhibition of growth reduced or lost... 

Density-dependent inhibition of powth Mitotic inhibition correlated with increased cell density. 

Density-dependent inhibition is a term describing the phenomenon in which crowded cells stop dividing (Campbell et al., 1999). When cells divide to the point that they touch each other and fill the available space, they automatically stop dividing. When cells die and cause a hole to form, adjacent cells begin to divide until they again fill the space. This occurrence is apparently due to inadequate amounts of nutrients and growth factors when the cells are crowded (Campbell et al., 1999). 

What effects do you suppose that growth factors, density-dependent inhibition, and anchorage dependence would have on attempts to grow somatal cells in vitro ... 

Takahashi, K. and K. Suzuki. 1996. Density-dependent inhibition of growth involves prevention of EGF receptor activation by E-cadherin-mediated cell-cell adhesion. Exp Cell Res 226 214-222. 

Chemical interference must be distinguished from resource competition. The studies of Nilsson and colleagues in which PVC pipes were used to reduce belowground competition, and activated carbon was used to reduce allelopathy, illustrate one approach to this problem. Muller s application of manure to bare zones in the chaparral represents another. Demonstrating density-dependent inhibition of growth offers another means of distinguishing the operation of these interference mechanisms. The probability that allelopathy and resource competition together cause the observed inhibitory effects (Nilsson 1994) must be kept in mind. 

Andrews, Fi.E., Bruckdorfer, K.R., Dunn, R.C. and Jacobs, M. (1987). Low-density lipoproteins inhibit endothelium-dependent relaxation in rabbit aorta. Nature (Lond.) 327, 237-239. 

Buckley, C, Bund SJ, McTaggart F et al. Oxidized low-density lipoproteins inhibit endothelium-dependent relaxations in isolated large and small rabbit coronary arteries. J. Auton. Pharmacol. 16,... 

Assumption 5 states that the endpoints measured in the toxicity tests on which the SSD is based must be ecologically relevant. Mortality is the most frequently studied endpoint in laboratory tests. In chronic tests, endpoints such as reproduction and inhibition of growth are also studied. Forbes et al. (2001a) argued that individual-level endpoints like survival, fecundity, and growth may not reflect effects at the population level (Assumption 5). They recommended that additional consideration be given to the relative frequency of different life cycle types, to the proportion of sensitive and insensitive taxonomic groups in communities, and to the role of density-dependent influences on population dynamics (see also Forbes and Calow 2002). 

Figure 7.15 Winand diagram. Depending on current density and inhibition activity, Fischer classified four structural types of preferential observation a base-oriented reproduction type BR, a field-oriented texture type FT, an un-oriented dispersion type UD, and the field-oriented isolation type FI, which is near the origin of deposition or formation of isolated crystals and is not often observed.

These results provide experimental confirmation of the role of the puberty inhibiting pheromone as a density dependent factor regulating populations of house mice. 

Administration of Cediranib produced dose-dependent inhibition of tumor growth in a range of histologically distinct human tumor xenografts (lung, colon, breast, prostate, and ovarian) and also decreased primary tumor growth, metastasis, and microvessel density in an orthotopic model of murine renal cell carcinoma (Drevs et al. 2004). 

The functions g,- derived from experimental thermal conductivity data and, indeed, the mean free-path parameters, are, naturally, different from those derived from viscosity data because of the inevitable failure of the Enskog theory to represent either property accurately. This fact inhibits the transposition of information on the density dependence of one property to the prediction of the second but is otherwise not significant in the prediction process. 

The molecular structure and dynamics of the ice/water interface are of interest, for example, in understanding phenomena like frost heaving, freezing (and the inhibition of freezing) in biological systems, and the growth mechanisms of ice crystals. In a series of simulations, Haymet and coworkers (see Refs. 193-196) studied the density variation, the orientational order and the layer-dependence of the mobilitity of water molecules. The ice/water basal interface is found to be a relatively broad interface of about... 

---