Biological modeling

Cryptands, 7, 731-761 alkali metal complexes NMR, 7, 740 reactivity, 7, 743-744 alkaline earth complexes reactivity, 7, 743-744 anion complexes, 7, 747-748 applications, 7, 753-761 as biological models, 7, 753-754 bis-tren... 

Ochrymowycz and his coworkers have also prepared a number of polysulfur macrocycles for use in biological or biological model systems . The synthetic methodology is essentially similar to that described above except that certain of the sulfur containing fragments were prepared by addition reactions to ethylene. Two examples of this approach, taken from ref. 59, are shown in Eq. (6.9). 

Spivak, C. C Albuquerque, E. X. In Progess in Cholinergic Biology Model Cholinergic Synapses Hanin, I. Goldberg, M., Eds. Raven Press New York, 1982, 323. 

Hu, C. et al., Black rice (Oryza sativa L. indica) pigmented fraction suppresses both reactive oxygen species and nitric oxide in chemical and biological model systems, J. Agric. Food Chem., 51, 5271, 2003. 

Specific culture conditions are essential to ensure that the biological model maintains unchanged, as long as possible, its intrinsic characteristics in terms of biological response and cell function. 

Wang JF, Li PP et al. Signal transduction abnormalities in bipolar disorder in Bipolar Disorder Biological Models and their Clinical Application (Joffe RT and Young LT, Eds), Marcel Dekker, New York 1997, pp 41-79. 

Fig. 5. Retention of 144Ce in lung, liver, skeleton, and soft tissue remainders of Beagle dogs after inhalation of l44Ce chloride in Cs chloride aerosol particles. Average values and total ranges of data are shown in the upper figure along with solid line curves which were projected from the biological model, all of which include physical decay. The lower figure shows the same model projections only corrected for physical decay.

Fig. 17. Biological model recommended for describing the uptake and retention of cerium by humans after inhalation or ingestion. Numbers in parentheses give the fractions of the material in the originating compartments which are cleared to the indicated sites of deposition. Clearance from the pulmonary region results from competition between mechanical clearances to the lymph nodes and gastrointestinal tract and absorption of soluble material into the systemic circulation. The fractions included in parentheses by the pulmonary compartment indicate the distribution of material subject to the two clearance rates however, these amounts will not be cleared in this manner if the material is previously absorbed into blood. Transfer rate constants or functions, S(t), are given in fractions per unit time. Dashed lines indicate clearance pathways which exist but occur at such slow rates as to be considered insignificant compared to radioactive decay of the cerium isotopes.

S. Archer, Measurement of nitric-oxide in biological models. Faseb J. 7, 349-360 (1993). 

T. Ohsaka, F. Matsumoto, and K. Tokuda, An electrochemical approach to dismutation of superoxide ion using a biological model system with a hydrophobic/hydrophilic interface, in Frontiers of Reactive Oxygen Species in Biological and Medicine (K. Asaka and T. Yoshikawa, eds), pp. 91—93. Elsevier Science B.V. Oxford (1994). 

Keywords biological model control decontamination indication toxic chemical material... 

Table 1 Studies that use transcriptional profiling to compare biological models... 

N. Sekkat, R. H. Guy, Biological Models to Study Skin Permeation , in Pharmacokinetic Optimization in Drug Research Biological, Physicochemical and Computational Strategies , Eds. B. Testa, H. van de Waterbeemd, G. Folkers, R. Guy, Verlag Helvetica Chimica Acta, Zurich, 2001, p. 155- 172. 

This permeability barrier shows selectivity in that small hydrophobic molecules can partition into and diffuse across the lipid bilayer of the cell membrane, whereas small hydrophilic molecules can only diffuse between cells (i.e., through the intercellular junctions). In addition, the presence of uptake and efflux transporters complicates our ability to predict intestinal permeability based on physicochemical properties alone because transporters may increase or decrease absorptive flux. The complexity of the permeability process makes it difficult to elucidate permeability pathways in complex biological model systems such as animals and tissues. For this reason, cultured cells in general, and Caco-2 cells in particular, have been used extensively to investigate the role of specific permeability pathways in drug absorption. 

The first step in progressing from in vitro mobilization experiments to clinical trials is the setting up of biological model systems (356). Next comes the testing of oral efficacy in animals such as mice, rats, and rabbits (43,249), alongside toxicity studies. We cite a few of the... 

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