Lethal event

Also, in the treatment with BLM, 150 SSBs and 30 DSBs are formed at the LD37 level of survival (Ward 1988). It has hence be concluded that the cellular repair enzymes can cope very efficiently with these simple lesions, and much more complex lesions (clustered lesions, above the level of a DSB, see below) are required to cause a lethal event. This is supported by the observation that densely ionizing radiations show a higher RBE then low-LET radiation (Goodhead 1994). 

The action by H202 produces per lethal event five times fewer DSBs than X-rays (Prise et al. 1989). In contrast to ionizing radiation, H202 does not create DNA-protein cross-links (Bradley and Erickson 1981) and causes very few if any mutations (Thacker 1975 Thacker and Parker 1976 Bradley and Erickson 1981). 

Potentially, the most lethal events can occur in those laboratories where chemicals and biologically active materials are being handled. As mentioned above, in the UK... 

A 60-year-old man developed angioedema after taking two doses of rofecoxib 12.5 mg 18 and 12 hours before (133). Despite intensive treatment he developed pulmonary hemorrhagic edema and died a day later. He had fibrotic lung disease, which may have predisposed him to the lethal event. 

Jobses I, Martens D Tramper J (1991) Lethal events during gas sparging in animal cell culture. Biotechnology and Bioengineering 31 484-490. 

Episodes that lead to acute, non-lethal events are many and varied. They range from accidents in the home with household products to consumption of plant and animal toxins from industrial and transportation accidents to skin contact with certain plants such as poison ivy from consumption of too much alcohol to inhaling of certain air pollutants, both outdoors and indoors, that have for some reason accumulated to unusually high levels. 

ALS is also inhibited by a number of compounds which are structurally unrelated to the sulfonylureas. These include two other classes of herbicides the imidazolinones (5) and the triazolopyrimidines (Hawkes, T.R. Howard, J.L. Pontin, S.E. In Herbicides and Plant Metabolism, in press). LaRossa et al. have speculated on why ALS is such an effective target for so many inhibitors (6). Blocking ALS leads to the buildup of the toxic substrate a-ketobutyrate. The elevated levels of this metabolite combined with the reduced levels of the branched chain amino acids appear to make the inhibition of ALS a particularly lethal event. 

Lichtenstein, S., Slovic, P., Fischoff, B., Lajrman, M., and Combs, B., Judged frequency of lethal events. Journal of Experimental Psychology Human Learning and Memory 4... 

This experiment provided compelling evidence that a solitary intrastrand d(GpG) adduct can be a lethal event in a single-stranded bacteriophage. The extent to which the other adducts, formed by cis- and Iraw-DDP on DNA, affect replication and survival is currently being addressed by studies of other site-specifically platinated genomes. 

Kiein, F., Karwan, A., and Winterberger, U. (1990). Pedigree analyses of yeast cells recovering from DNA damage allow assignment of lethal events to individual post-treatment generations. Genetics 124, 57-65. 

S. Lichtenstein, P. Slovic, B. Fischhof, M. Layman, B. Combs (1978) Judged liequeney of lethal events. J. Exp. Psychol. Human Learning Mem., 4, 551-578. 

M. G. Morgan, Engineering and Public Policy/Carnegie-Mellon University Graduate Research Methods Class (1983) On judging the frequency of lethal events a replication. Risk Anal, 3, 11-16. 

The total average number of lethal events induced by a particular pattern of particle traversals is then calculated by numerical integration ... 

Empirical experiments by psychologists have found that lay people are unable to accurately judge the frequency of hazards that they face. Moreover, there are some systemic biases in the way that people misperceive risk frequencies. The seminal work is Lichtenstein et al. (1978). Lay people were told the actual annual number of fatalities in America for either electrocution (about 1,000 per year) or motor vehicle accidents (50,000 per year). The respondents then had to give their estimates for the annual number of deaths for forty other lethal events. The plot of results is shown in figure 5.1. 

Lichtenstein, Sarah, Paul Slovic, Baruch Fischhoff, Mark Layman and Barbara Combs. (1978). "Judged frequency of lethal events." Journal of Experimental Psychology Human Learning and Memory, vol. 4(6), pp. 551-578. 

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