Hybrid cell cycle

A. Requirements for the Establishment of a Neio Hybrid Cell Cycle ... 

Before this statement is further elaborated, we should like to reemphasize the distinction we make between the (positive) signal which initiates (synchronous) DNA synthesis, and the factors which define the duration of the new hybrid cell cycle to be eflEective, the former requires only that the nuclei (or karyomeres) reside in the same cytoplasm, while the latter requires the enclosure of the chromosomes within a single nucleus. 

The cause of protracted and possibly lethal asynchrony may reside in the formation of some hybrid molecules. The data presented in Section III, C suggest that, in interspecific hybrids, numerous (interspecific) hybrid molecules are formed. If it is assumed that the establishment of a coordinated hybrid cell cycle requires, at some point, the intervention of hybrid molecules, then the fusion product, which is really a mosaic, may not be synchronized until the molecules of parental types are diluted out by hybrid ones (hybrid membranes as well as hybrid enzymes may possibly be significant). 

Spellman, P. T., Sherlock, G., Zhang, M. Q., Iyer, V. R., Anders, K., Eisen, M. B., Brown, P. O., Bot-stein, D. and Futcher, B. (1998), Comprehensive identification of cell cycle-regulated genes of the yeast Saccharomyces cerevisiae by microarray hybridization , Mol Biol. Cell, 9, 3273-3297. 

For the hybrid sulphur cycle, current researches are focused on the SDE cell development to overcome the sulphur deposition in cathode. The next step should be ILS experiments followed by a MW-scale pilot plant. 

Other processes considered worth of further investigation are the so-called Westinghouse process, a sulphuric acid hybrid (HyS) cycle where the low-temperature step mns in an electrolysis cell to produce the hydrogen, the CuCl cycle, a lower temperature (< 500°C) hybrid cycle investigated at ANL, or the so-called UT-3 process based on a four-step cycle with calcium and bromine. 

The present modeling approach to circadian cancer chronotherapy is based on an automaton model for the cell cycle. Continuous approaches to cell cycle progression have also been used to study the link between cell proliferation and circadian rhythms [44] and to determine, in conjunction with optimal control theory, the most efficient circadian schedules of anticancer drug administration [45]. Including more molecular details of the cell cycle in continuous models for cell populations represents a promising line for future research. Hybrid models incorporating molecular details into the automaton approach presented here will also likely be developed. 

Spellman PT, Sherlock G, Zhang MQ, Iyer VR, Anders K, Eisen MB, Brown PO, Botstein D, Futcher B. Comprehensive identification of cell cycle-regulated genes of the yeast Saccha-romyces cerevisiae by microarray hybridization. Mol. Biol. Cell 1998 9 3273-3297. 

A tissue microarray study using immunohistochem-istry and in situ hybridization to observe cell cycle and apoptosis regulating genes has shown multiple alterations in cell cycle checkpoints and major tumor suppressor pathways, some of which are linked to survival as well as EBV positivity. 

Speel JM, Herbergs J, Ramaekers CS, Hopman AHN (1994) Combined immunocytochem-istry and fluorescence in situ hybridization for simultaneous tricolor detection of cell cycle, genomic, and phenotypic parameters of tumor cells. J Histochem Cytochem 42 961-966... 

A EXPERIMENTAL FIGURE 12-22 The movement of human hnRNP Al protein between nuclei in a heterokaryon shows that it can cycle in and out of the cytoplasm, but human hnRNP C protein, which showed no such movement, cannot. Cultured HeLa cells and Xenopus cells were fused by treatment with polyethylene glycol, producing heterokaryons containing nuclei from each cell type. The hybrid cells were treated with cycloheximide Immediately after fusion to prevent protein synthesis. After 2 hours, the cells were fixed and stained with fluorescent-labeled antibodies specific for human hnRNP C and Al proteins. These antibodies do not bind to the homologous Xenopus proteins, (a) A fixed preparation viewed by phase-contrast microscopy Includes unfused HeLa cells (arrowhead) and Xenopus cells (dotted arrow), as well as fused heterokaryons... 

DiFrancesco, L.M., Murthy, S.K., Luider, J., and Demetrick, D.J. (2000) Laser capture microdissection-guided fluorescence in situ hybridization and flow cytometric cell cycle analysis of purified nuclei from paraffin sections. Mod Pathol 13, 705-11. 

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