Selective killing

Although the ratios have varied from year to year since 1979, the selective herbicides used in com production have accounted for approximately 21% of herbicide use on a per crop basis (24). Herbicide use in soybean and cotton production combined account for ca 23% of the selective herbicide market. Graminicides, which selectively kill grasses, constitute 40% of the total market, leaving a market share of approximately 16% for the nonselective herbicides. 

SMITH T, MUSK s R and JOHNSON I T (1996) Allyl isothiocyanate selectively kills undifferentiated HT29 cells in vitro and suppresses aberrant crypt foci in the colonic mucosa of rats , Biochem Soc Trans, 24 381S. 

A few interesting organic molecules may possess the ability to release hydroxyl radical under physiological conditions. The most extensively studied of these is 3-amino-l,2,4-benzotriazine 1,4-dioxide (tirapazamine, 95, Scheme 8.32). Tirapazamine is a bioreductively activated DNA-damaging agent that selectively kills the oxygen-poor (hypoxic) cells found in solid tumors. The biological activity of... 

The work of Sheehy concentrated on the enhancement of oil recovery from a reservoir using microorganisms, and led to the patent, Oil Recovery Using Microorganisms [24], The main idea was to use a biocide to selectively kill certain microorganisms and then induce the growth of others by carefully controlled nutritional conditions. This idea has potential for some other applications and could be extrapolated to in situ refining. 

DeFatta, R., Li, Y., and De Benedetti, A. (2002). Selective killing of cancer cells based on translational control of a suicide gene. Cancer Gene Ther. 9, 573-578. 

Colombatti, M., Nabholz, M., Gros, O., and Brown, C. (1983) Selective killing of target cells by anti-body-ricin A-chain or antibody-gelonin hybrid molecules Comparison of cytotoxic potency and use in immunoselection procedures./. Immunol. 131, 3091. 

Ozawa, S., Ueda, M., Ando, N., Abe, O., Minoshima, S., and Shimizu, N. (1989) Selective killing of squamous carcinoma cells by an immunotoxin that recognizes the EGF receptor. Int. J. Cancer 43, 152. 

Thorpe, P.E., Mason, D.W., Brown, A.N.F., Simmonds, S.J., Ross, W.C.J., Cumber, A.J., and Forrester, J.A. (1982) Selective killing of malignant cells in a leukaemic rat bone marrow using an antibody-ricin conjugate. Nature (London) 297, 594. 

The need of designing probes for measuring in vivo temperature is primarily dictated by therapeutical purposes. In fact, useful therapies against tumors like hypertermia or thermal ablation are based on localized heating which selectively kills tumor cells. Such therapies require the achievement of well-defined temperatures that, moreover, have to be maintained constant for a given time. Therefore, a continuous temperature monitoring is essential for the success of the therapy 136). 

Different antimalarials selectively kill the parasite s different developmental forms. The mechanism of action is known for some of them pyrimethamine and dapsone inhibit dihydrofolate reductase (p. 273), as does chlorguanide (proguanil) via its active metabolite. The sulfonamide sulfadoxine inhibits synthesis of dihydrofolic acid (p. 272). Chlo-roquine and quinine accumulate within the acidic vacuoles of blood schizonts and inhibit polymerization of heme, the latter substance being toxic for the schizonts. 

Griseofirlvin used as a positive control at 5 pM since it is known to selectively kill cells with centrosome amplification. 

Shaw AT, Winslow MM, Magendantz M et al (2011) Selective killing of K-ras mutant cancer cells hy small molecule inducers of oxidative stress. Proc Natl Acad Sci USA 108 8773-8778... 

Herbicides, used to kill or damage a plant, are the most rapidly growing segment of pesticides. Prior to the 1930s, herbicides were non-specific and often very toxic to humans as well as other animals. In the 1930s, in parallel with the development of new insecticides, researchers discovered several chemicals that selectively killed plants. These chemicals are now widely used to increase food production and have been used in warfare. Herbicides come in a variety of chemical structures and mechanisms of action, so they will be discussed in only general terms. Interested readers are referred to the many web sites and extensive literature on herbicides (see below and the presentation). 

Since mitochondria are energy factories, they are essential to cellular life. This fact can be usefully exploited in drug design to enable selective killing of unwanted cell types. For example, the mitochondria of certain parasites are fundamentally different from those of the host human cells. Accordingly, it is possible to selectively kill such parasites by targeting the biochemical uniqueness of their mitochondria. Certain 4-hydroxyquinoline derivatives are effective antiparasitic agents that use this mechanism. 

DDT was not the only synthetic chemical to find a use in private and commercial gardens. Plant physiologists in the 1930s had accidentally discovered a way of selectively killing weeds in cereal crops (the dominant source of food for humans— wheat, barley, maize and rice). The plant physiologists interested in how plants controlled their growth had discovered a plant hormone—auxin (indole-3-acetic acid). Chemists soon found that, not only was it easy to make this compound, but they could also easily make... 

Stoddard solvent gives excellent selective kill of weeds in carrots when applied in pure form, but loses its selectivity when emulsified in water. The highly toxic aromatic hydrocarbons diethylbenzene, tetrahydronaphthalene, and methylnaphthalene gave excd-lent selective kill of weeds in carrots when mixed with nontoxic oil at the proper concentration. The same relative amounts of the aromatics applied emulsified in water, or pure, however, killed the carrots as well as the weeds. Attempts to obtain selective kill by reducing the quantity of the aromatic were unsuccessful. 

Nuclear radiation is focused on harmful tissue, such as a cancerous tumor, to selectively kill or shrink the tissue in a technique known as radiation therapy. This application of nuclear radiation has saved millions of lives—a clear-cut example of the benefits of nuclear technology. The inset shows the international symbol indicating an area where radioactive material is being handled or produced. 

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