Vincent Menuz

Protection of C. elegans from anoxia by HYL-2 ceramide synthase

Oxygen deprivation is rapidly deleterious for most organisms. However, Caenorhabditis elegans has developed the ability to survive anoxia for at least 48 hours. Mutations in the DAF-2/DAF-16 insulin-like signaling pathway promote such survival. We describe a pathway involving the HYL-2 ceramide synthase that acts independently of DAF-2. Loss of the ceramide synthase gene hyl-2 results in increased sensitivity of C. elegans to anoxia. C. elegans has two ceramide synthases, hyl-1 and hyl-2, that participate in ceramide biogenesis and affect its ability to survive anoxic conditions. In contrast to hyl-2(lf) mutants, hyl-1(lf) mutants are more resistant to anoxia than normal animals. HYL-1 and HYL-2 have complementary specificities for fatty acyl chains. These data indicate that specific ceramides produced by HYL-2 confer resistance to anoxia.

Knowledge Dissemination Interventions: A Literature Review

This literature review seeks to examine knowledge dissemination interventions (KDIs) implemented in health research and gauge their effectiveness on three kinds of outcomes: (a) knowledge acquisition, (b) changes in attitudes, and (c) changes in practice. MEDLINE and Cumulative Index to Nursing and Allied Health Literature databases from 2006 to 2011 were searched. Nineteen articles were retrieved. Most of the KDIs that were evaluated had a positive impact on knowledge acquisition and changes in attitudes, but a limited one on practice. KDIs are diverse in terms of knowledge, actors, contexts, and dissemination methods. They cannot be readily applicable to other projects.

Inclusion and Exclusion in Nutrigenetics Clinical Research: Ethical and Scientific Challenges

Background/Aims: There are compelling reasons to ensure the participation of ethnic minorities and populations of all ages worldwide in nutrigenetics clinical research. If findings in such research are valid for some individuals, groups, or communities, and not for others, then ethical questions of justice – and not only issues of methodology and external validity – arise. This paper aims to examine inclusion in nutrigenetics clinical research and its scientific and ethical challenges. Methods: In total, 173 publications were identified through a systematic review of clinical studies in nutrigenetics published between 1998 and 2007. Data such as participants’ demographics as well as eligibility criteria were extracted. Results: There is no consistency in the way participants’ origins (ancestry, ethnicity, or race) and ages are described in publications. A vast majority of the studies identified was conducted in North America and Europe and focused on ‘white’ participants. Our results show that pregnant women (and fetuses), minors, and the elderly (≧75 years old) remain underrepresented. Conclusion: Representativeness in nutrigenetics research is a challenging ethical and scientific issue. Yet, if nutrigenetics is to benefit whole populations and be used in public and global health agendas, fair representation as well as clear descriptions of participants in publications are crucial.

Is Human Enhancement also a Personal Matter

Emerging technologies are increasingly used in an attempt to “enhance the human body and/or mind” beyond the contemporary standards that characterize human beings. Yet, such standards are deeply controversial and it is not an easy task to determine whether the application of a given technology to an individual and its outcome can be defined as a human enhancement or not. Despite much debate on its potential or actual ethical and social impacts, human enhancement is not subject to any consensual definition. This paper proposes a timely and much needed examination of the various definitions found in the literature. We classify these definitions into four main categories: the implicit approach, the therapy-enhancement distinction, the improvement of general human capacities and the increase of well-being. After commenting on these different approaches and their limitations, we propose a definition of human enhancement that focuses on individual perceptions. While acknowledging that a definition that mainly depends on personal and subjective individual perceptions raises many challenges, we suggest that a comprehensive approach to define human enhancement could constitute a useful premise to appropriately address the complexity of the ethical and social issues it generates.

Why Do We Wish to be Enhanced

Recent progress in the fields of nanotechnology, biotechnology, information technology and cognitive science1 has led to a growing debate concerning the use of these technologies to increase, among other things, individuals’ cognitive and physical capacities, as well as their longevity. In Western countries, new philosophical movements, such as the transhumanists,2 speculate on the possibilities of using these technologies to dramatically ‘enhance’ human beings (Bostrom, 2005). For such thinkers, humanity is moving towards a post-human condition where biotechnologically enhanced humans will bypass the standard Darwinian concept of evolution (Harris, 2007). They argue that ultimately, technological progress will lead these post-humans to reverse the ageing process and to experience extreme longevity, if not immortality (de Grey, 2005; Kurzweil and Grossman, 2009). The idea of such a radical transformation of human beings is not just a curious idea shared by a small group of eccentric thinkers. Nowadays, many widely circulated magazines are voicing transhumanist ideas,3 while institutes specifically dedicated to the development of technologies to modify human beings are opening their doors.4