Specificity, causation

The book begins with a discussion of the theories of error causation and then goes on to describe the various ways in which data can be collected, analyzed, and used to reduce the potential for error. Case studies are used to teach the methodology of error reduction in specific industry operations. Finally, the book concludes with a plan for a plant error reduction program and a discussion of how human factors principles impact on the process safety management system. 

The mucopolysaccharidoses share a common mechanism of causation, as illustrated in Figure 48-10. They are inherited in an autosomal recessive manner, with Hurler and Hunter syndromes being perhaps the most widely studied. None are common. In some cases, a family history of a mucopolysaccharidosis is obtained. Specific laboratory investigations of help in their diagnosis are urine testing for the presence of increased... 

How well can causation be inferred from correlation The problem is akin to inferring the design of a microprocessor based on the readout of its transistors in response to a variety of inputs. The task is impossible in a strict mathematical sense, in that the microprocessor layout could be arbitrarily complicated, but is likely to prove at least somewhat tractable in a more constrained biological setting, especially when combined with ways to cut specific wires in biological circuits using antisense and related techniques. 

About 23% of regular users of hallucinogens report experiencing flashbacks. These have been classified as perceptual (visual effects), somatic (numbness), or emotional (reexperience of a disturbing emotion). Many theories about their causation remain unproved. Usually they fade with time, and no specific treatment is needed (49). 

A major reason for this lies in methodological problems connected with the observation and description and the nature of human behaviour itself. In order to asses causation and function of behaviour we rely on an observational device. The process of information reduction which is applied to the study of behaviour results in highly variable observations. The assessment of meaning and function rarely produces reproducible results, and different signals especially in human communication seem to take many meanings which are context-specific. Partially this might be due to the observational approaches used for coding behaviour. 

Previous discussion has dealt with diseases caused by an alteration in a single gene or in a specific chromosome. Most common diseases heart disease, cancer, diabetes, etc.) have substantial genetic components, but their causation is complex. This chapter reviews some basic principles of the genetics of common, complex diseases. 

This use of animal evidence is based, in part, upon its scientific standing, but it is also based upon a science policy decision - it is one of the defaults present in the risk assessment process. Even in the absence of specific knowledge that the response detected in a toxicology study is relevant to humans, it will be assumed to be so -unless other data arrive to demonstrate that it is not relevant to humans (see below what is meant by other data ). Regulators and public health policies generally call for action even when the evidence regarding adverse health effects does not rise to the level necessary to establish causation in humans. 

Even when Mr. Z s expert makes the case for specific causation, it remains possible that there are other medical and exposure issues that make alternative causes even more likely than benzene. Possible alternative causes are always in the spotlight, at least among defendants. 

Nevertheless, depressive episodes among alcohol-dependent men and women are heterogeneous in terms of both causation and clinical course. Studies have shown differences between patients with the onset of major depression before alcohol dependence or during a long abstinence period (i.e., independent major depression) versus those who experience depressive symptoms only in association with alcohol use ( 34). Specifically, the former are more likely to ... 

For causation see Vivian Nutton, The Seeds of Disease An Explanation of Contagion and Infection from the Greeks to the Renaissance , Medical History, 27 (1983), 1-34 Margaret Felling, Contagion/Germ Theory/Specificity , in William Bynum and Roy Porter (eds.). Companion Encyclopedia of the History of Medicine, i (1993), 309-34, esp. 315. 

Future predictions are improved by the inclusion of TIE and CBR analyses. TIEs have been and continue to be used to establish causality based on the toxicity of sediment interstitial pore waters (Ankley and Schubauer-Berigan, 1995 Stronkhorst et al., 2003). However, because interstitial water testing may overestimate toxicity of non-persistent, readily water soluble substances (e.g., ammonia) and underestimate toxicity of persistent, poorly water soluble substances, the focus of TIEs is shifting to studies of whole sediments (Burgess et al., 2000, 2003 Ho et al., 2002). TIEs have been used as part of the SQT to determine causation (Hunt et al., 2001). The information provided regarding specific contaminants responsible for observed toxicity provides additional information for predictions related to changes in loadings of contaminants such as metals, which are not metabolized. 

Although it has been postulated that the presence of amyloid protein in the Alzheimer s brain could be specifically involved in the causation of the... 

Page GP, George V, Go RC, Page PZ, Allison DB. Are we there yet Deciding when one has demonstrated specific genetic causation in complex diseases and quantitative traits. Am J Hum Genet 2003 73 711-719. 

---