Cell division and differentiation

The change in cells undergoing normal, controlled cell division and differentiation to cells that are transformed, dividing without check, and are undifferentiated or abnormally differentiated, does not appear to occur as a single step that is,... 

Transcription of growth-promoting genes leading to cell division and differentiation... 

Eflornithine (Vaniqa) is an irreversible inhibitor of ornithine decarboxylase, which catalyzes the rate-limiting step in the biosynthesis of polyamines. Polyamines are required for cell division and differentiation, and inhibition of ornithine decarboxylase affects the rate of hair growth. Topical eflornithine has been shown to be effective in reducing facial hair growth in approximately 30% of women when applied twice daily for 6 months of therapy. Hair growth was observed to return to pretreatment levels 8 weeks after discontinuation. Local adverse effects include stinging, burning, and folliculitis. 

Wu, J. Ohta, N. Zhao, J.L. Newton, A. A novel bacterial tyrosine kinase essential for cell division and differentiation. Proc. Natl. Acad. Sci. USA, 96, 13068-13073 (1999)... 

Tuber structure in cross section from exterior to interior can be separated into the epidermis, cortex, outer medulla, inner medulla, and pith (Mazza, 1985). Relatively little is known about the temporal sequence of cell division and differentiation leading up to bulking. Sink capacity is a function of the combined vacuolar volume of the tubers, the location of fructan synthesis and storage within the cells (Darwen and John, 1989 Keller et al., 1988 Pollock, 1986). Vacuolar volume is a function of cell size and number. The size of individual cells within the tuber varies with tissue type cortex (286 cells per 10 mm2), extension zone (145 cells per 10 mm2), storage tissue (85 cells per 10 mm2), and pith (149 cells per 10 mm2) (Schubert and Feuerle, 1997). The extent that cell number and size increases after the initial formation of the tuber has not been adequately documented. 

Immediately inside the endodermis is the pericycle, which is typically one cell thick in angiosperms. The cells of the pericycle can divide and form a meristematic region that can produce lateral or branch roots in the region just above the root hairs. Radially inside the pericycle is the vascular tissue. The phloem generally occurs in two to eight or more strands located around the root axis. The xylem usually radiates out between the phloem strands, so water does not have to cross the phloem to reach the xylem of a young root. The tissue between the xylem and the phloem is the vascular cambium, which through cell division and differentiation produces xylem (to the inside in stems and older roots) and phloem (to the outside in stems and older roots). 

The alkoxyacid metabolites appear to be responsible for the toxic effects reported in the testes, bone marrow, and embryo. The testes, bone marrow, and embryo contain large numbers of rapidly dividing and differentiating cells, and it is possible that one or more processes of cell division and differentiation are affected. It has been hypothesized that alkoxyacetic acids may be introduced into the Krebs cycle by formation of methoxy- or ethoxyacetyl-CoA and by formation of methoxy- or ethoxycitrate by mitochondrial enzymes. 

Stinchcomb, D. (1995) Constraining the cell cycle Regulating cell division and differentiation by gene therapy. Nature Med. 1, 1004-1006. 

The post-peel mask cream contains retinol microencapsulated in a cyclodextrin. Vitamin A is involved in the processes of cell division and differentiation that help the epidermis regenerate after the peel from the cells of the basal layer. 

Jones, R.W. and M.N. Huffman. Fish embryos as bioassay material in testing chemicals for effects on cell division and differentiation. Trans. Am. Microsc. Soc. 76 177-183, 1957. 

Similar results have been obtained with mitochondrial fractions from eggs and whole embryos of the surf clam Spisula solidissima. Specific activities of cytochrome oxidase, succinate-cytochrome c reductase, and NADH-cytochrome c reductase were found to be constant during the period from fertilization through the development of swimming stages. Cell division and differentiation apparently entailed neither a significant increase in the total content of. . . mitochondria nor a differentiation of these particles with respect to (their) enzymatic components (Stritt-... 

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