Abstract We live in an era of an important turning point in the relationship between ethics or, more accurately, bioethics and science, notably due to both public interest and the gradual tightening of the gap in time between scientific discoveries and ethical reflection. The current bioethics debates of emerging situations pluripotent stem cells, gene therapy, nanotechnology have undoubtedly contributed to this change.
Consistently linked with exposure at relevant levels of exposure with confounding and background exposures assesseda Effect Consistently linked with increased risk with confounding and effect modifying factors assessed Susceptibility Can distinguish subgroups at risk given specific exposure a Biomarkers of exposure may also be validated by establishing a constant link to an adverse health effect or to the concentration of the chemical in the target organ.
This applies to any form of exposure. It is due to intervening host factors that vary between individuals such as breathing rate and capacity, activation, detoxification, elimination, DNA repair, etc.
Thus a high correlation between exposure and the marker may not always be observed and an exposure-response relationship may vary between people.
It is therefore important to identify and adjust for factors that can influence an exposure-response relationship. For example, to validate hydroxy-ethyl haemoglobin adducts as exposure biomarkers for ethylene oxide at low dose, investigators adjusted for age, smoking, and education in a linear regression model Schulte et al.
Additionally it may be useful to consider effect modifying factors, such as metabolic polymorphisms Bois et al.
There are some exceptions to the validation strategy that focuses on the demonstration of a correspondence between a biomarker of exposure and external exposure. Alternative ways to validate biomarkers include the assessment of their relationship with the concentration in the critical organ e.
Indeed, a good biomarker of exposure should be useful to predict adverse effects, rather than exposure levels. This may be especially the case when accurate and valid measurements of the "true" exposure are difficult or impossible to obtain use of protective devices, multiple pathways of uptake, etc.
It is possible to apply qualitative tests to determine whether external exposure or an exposure biomarker would be a better predictor for disease Steenland et al.
One test involves determining if the biomarker is more highly correlated or associated with the disease than external exposure.
A second test is whether, given the same level of exposure, those with higher levels of the biomarkers are more likely to develop the disease. When absorption mainly occurs through the dermal route or when individual protective devices are used, biomarkers of exposure can provide reliable measurements of internal dose, which are useful to assess dose-response relationships.
On the basis of the parameters of the logistic regression, the calculated benchmark dose corresponds to 0. In evaluating the role of metabolic polymorphisms, the presence of a range of doses in which the modifying effect of metabolic enzymes could be seen, is a major issue.
A pertinent example comes from a study on the urinary excretion of 1-hydroxypyrene in traffic police officers Merlo et al. Once validated, these markers can serve as surrogates for disease, albeit with some probability functions since generally not all people with a given biomarker will develop the disease, but the groups with the high levels generally will be at greatest risk.
A good example comes from a recent prospective study on the association between cytogenetic biomarkers and cancer risk Hagmar et al. This study, which followed five European cohorts has shown that subjects in the group with the highest frequency of chromosomal aberrations experienced an overall cancer risk more than double with respect to the lowest frequency group.
In the same study, no association was observed between sister chromatid exchange SCE frequency and cancer risk, whereas inconclusive results were found for the micronucleus assay.
More recently, a nested case-control study found that the association between chromosomal aberrations and cancer appeared to be independent of host factors like age and sex, and could not be explained by exposure to identified human carcinogens Bonassi et al.
The lack of validation of most biomarkers of intermediate effect is probably the most critical impediment to the broad use of biomarkers in risk assessment. The prospective epidemiological study is the gold standard for validation effect biomarkers.
The timing and frequency of specimen collection in prospective studies are important and can influence the validation.Report of the National Bioethics Advisory Commission, on Cloning Human Beings. It provided a general overview of the science and ethics of cloning humans but stopped short of a specific theological verdict.
Protestant-organized ecumenical bodies such as the World Council of Churches (, , ) and the National Council of Churches of. Animal transgenesis and cloning (p. ). Chichester: Wiley and Sons Publisher. It has become possible to identify all of the genes in a number of species through the science of genomics.
It is possible to read any given genetic message and to predict the chemical structure of the corresponding protein. In Ethics of science and. Its theories provide a self-centered conception of ethics because human flourishing is seen as an end in itself and does not sufficiently consider the extent to which our actions affect other people.
D., Virtue Ethics A collection of contemporary work on virtue ethics, including a comprehensive introduction by Statman, an overview by. This report contains the collective views of international groups of experts and does not necessarily represent the decisions or the stated policy of the United Nations Environment Programme, the International Labour Organization, or the World Health Organization.
“de-extinction” refers to the process of resurrecting extinct species by genetic methods. This science-fiction-sounding idea is in fact already in early processes of scientific implementation. Although this recent “revival of the dead” raises deep ethical questions, the ethics of de.
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