Tissue culture definition

The use of appropriate experimental design can provide definitive evidence that P-gp-mediated efflux is altering the transport of a compound and can provide further mechanistic information regarding the transport of a compound. Recently it has been appreciated that P-gp efflux can be a potential source for chug interactions and in vitro experimentation can be very helpful to understand potential liability. The techniques described in this section can be used with any tissue culture transport model. 

A tissue culture dish or flask is not an inert plastic without biological relevance, but is rather a complex physicochemical substrate having definite effects on cell morphology and growth. It is important to be aware of the characteristics of various tissue culture surfaces so that experiments can be appropriately designed and interpreted (Grinnell, 1978). 

Parathyroid implantation (B2) and tissue culture experiments (Gl, G2) have shown that the secretion of the parathyroid glands exerts a direct action on bone which results in resorption and destruction. Injection of the hormone produces definite cellular changes within a few hours in the osteoblasts and osteocytes (H3). There is also an increase in the number of osteoclasts. It is impossible to say, however, whether bone mineral or organic matrix is primarily affected, as they appear to be mobilized simultaneously (C6, M5). 

The terpenoid indole alkaloids are a group of plant bases derived by multiple variation on the strictosidine [(79) p. 20] skeleton. Arguably the most important work in the past five years has been done on these alkaloids with enzyme preparations from plant tissue cultures, and the research is of great potential significance for other studies in alkaloid biosynthesis. The results have allowed close definition of the early stages of biosynthesis (this Report, p. 19). Use of crude enzyme preparations in this way has been extended to the study of benzylisoquinoline biosynthesis, with enzyme-catalysed formation of norlaudanosoline-1-carboxylic acid [(57) p. 16] this compound had earlier been identified as the first of the benzylisoquinolines (this Report, p. 15). It seems that amino-acids of this general formula (6) are key intermediates in the biosynthesis of all isoquinoline alkaloids. Lophocereine (7) is exceptional in that two routes (from leucine and mevalonate) may lead to it, only one of which potentially involves an acid like (6). ... 

Some clinicians are critical of the use of amniotic material as described above and prefer to use cells which are more definitely foetal in origin. Therefore, more rapid assay procedures have been developed by increasing the sensitivity of the enzyme assays and reducing the number of tissue culture passages (Brady, 1978). 

The most recent results [179, 180] have been obtained chiefly using enzyme preparations from plant tissue cultures, and they are most impressive allowing clear definition of the early stages of... 

Possibly relevant (a) HTLVl viral myelopathy is at least partly dysimmune [60] (see above) and (b) previously occult oncornavirus manifested morphologically as definite viral-type particles in "normal" chick embryo tissue-cultured... 

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