Subject cells

Subjecting cells to oxidative stress can result in severe metabolic dysfunctions, including peroxidation of membrane lipids, depletion of nicotinamide nucleotides, rises in intracellular free Ca ions, cytoskeletal disruption and DNA damage. The latter is often measured as formation of single-strand breaks, double-strand breaks or chromosomal aberrations. Indeed, DNA damage has been almost invariably observed in a wide range of mammalian cell types exposed to oxidative stress in a number... 

Table 13.2 Methods used to subject cells to oxidative stress that has produced increased intracellular DNA damage (see Halil well and Aruoma, 1991)...

Essentially, this method is based on subjecting cell membranes to a short external electric field pulse of an intensity comparable to the electric field strength of the membrane 77). Under these conditions the membrane breaks down locally and becomes permeable. This process is reversible, i.e. the membrane reconstitutes its original properties in time intervals which can be experimentally controlled. 

Subjecting cells to various forms of stress has been shown to dramatically reorganize IF networks, concomitant with the redistribution of normally soluble aB-crystallins to these networks, resulting in resistance to... 

Araghi-Niknam M, Fatemi SH (2003) Levels of Bcl-2 and P53 are altered in superior frontal and cerebellar cortices of autistic subjects. Cell Mol Neurobiol 23 945-952. 

Experimentally there are two important ways of detecting anti-tumour activities of Vinca alkaloids. One way deals with healthy animals. Products with potencies in cell growth inhibition may first suppress fast growing cells. For this purpose the cells of the circulatory system may serve as subject cells. In healthy mice, rats, guinea pigs, rabbits, or other small animals, the normal blood cell count (red and white cells) is easily established. Any significant drop in the blood cell count after single or repeated doses of substances with possible anti-tumour activities can indicate that these substances are worth further study. The second step involves evaluation of these substances in experimental tumours. One of the most useful models is the P 1534 leukemia in DBA/2 mice, which has... 

In both methods, cultured animal cells must be treated to facilitate their initial uptake of a recombinant plasmid vector. This can be done by exposing cells to a preparation of lipids that penetrate the plasma membrane, Increasing Its permeability to DNA. Alternatively, subjecting cells to a brief electric shock of several thousand volts, a technique known as electroporation, makes them transiently perme able to DNA. Usually the plasmid DNA Is added In sufficient concentration to ensure that a large proportion of the cultured cells will receive at least one copy of the plasmid... 

An increasing interest is being shown in the polysaccharides of fungi. In particular, chemistry and biochemistry of the intra-or exo-cellular polysaccharides have been studied by several workers. The relationship between taxonomy and chemical structure of fungal polysaccharides is an interesting subject. Cell wall chemistry and taxonomy of fungi were reviewed by Bartnicki-Garcia... 

The mode of action of many cell disrupters is to subject cells to very high pressures (up to 2,700 bar). If this high-pressure fluid is in contact with an... 

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