Noninvasive estimation of tumour viability in a xenograft model of human neuroblastoma with proton magnetic resonance spectroscopy (1H MRS)

The aim of the study was to evaluate proton magnetic resonance spectroscopy (1H MRS) for noninvasive biological characterisation of neuroblastoma xenografts in vivo. For designing the experiments, human neuroblastoma xenografts growing subcutaneously in nude rats were analysed in vivo with 1H MRS and magnetic resonance imaging at 4.7 T. The effects of spontaneous tumour growth and antiangiogenesis treatment, respectively, on spectral characteristics were evaluated. The spectroscopic findings were compared to tumour morphology, proliferation and viable tumour tissue fraction. The results showed that signals from choline (Cho)-containing compounds and mobile lipids (MLs) dominated the spectra. The individual ML/Cho ratios for both treated and untreated tumours were positively correlated with tumour volume (P<0.05). There was an inverse correlation between the ML/Cho ratio and the viable tumour fraction (r=−0.86, P<0.001). Higher ML/Cho ratios concomitant with pronounced histological changes were seen in spectra from tumours treated with the antiangiogenic drug TNP-470, compared to untreated control tumours (P<0.05). In conclusion, the ML/Cho ratio obtained in vivo by 1H MRS enabled accurate assessment of the viable tumour fraction in a human neuroblastoma xenograft model. 1H MRS also revealed early metabolic effects of antiangiogenesis treatment. 1H MRS could prove useful as a tool to monitor experimental therapy in preclinical models of neuroblastoma, and possibly also in children

Enhancing the species: genetic engineering technologies and human persistence

Many of the existing ethical analyses of genetic engineering technologies (GET) focus on how they can be used to enhance individuals—to improve individual well-being, health and cognition. There is a gap in the current literature about the specific ways enhancement technologies could be used to improve our populations and species, viewed as a whole. In this paper, I explore how GET may be used to enhance the species through improvements in the gene pool. I argue one aspect of the species that may be desirable to enhance is ‘persistence’ or long-term viability. I then look at some of the ways in which GET could be used to improve human persistence and argue that the use of GET to secure benefits for individuals may compromise persistence. This suggests conflicts between uses of GET to enhance individuals and uses to promote the persistence of the species may occur. As GET are further developed, the likelihood that these conflicts will actually arise, and how we should resolve them if they do, will need to be considered

The ethics of human life extension: the second argument from evolution

One argument that is sometimes made against pursuing radical forms of human life extension is that such interventions will make the species less evolvable, which would be morally undesirable. In this paper I discuss the empirical and evaluative claims of this argument. I argue that radical increases in life expectancy could, in principle, reduce the evolutionary potential of human populations through both biological and cultural mechanisms. I further argue that if life extension did reduce the evolvability of the species this will be undesirable for three reasons: (1) it may increase the species’ susceptibility to extinction risks, (2) it may adversely affect institutions and practises that promote well-being, and (3) it may impede moral progress

Valuable and valueless diversity

In “Imposing Diversity” Robert Sparrow illustrates that objections to genetic selection based on diversity can have counterintuitive implications. Through a series of thought experiments designed to overcome any status quo bias that may be affecting our assessment of the value of diversity, Sparrow argues that valuing genetic diversity is more problematic than is generally recognized. In this commentary I argue a well-developed account of the value of genetic diversity can lead to less problematic implications, and remain an important consideration when considering the ethics of genetic selection. For reasons of space I will only discuss two of Sparrow’s thought experiments “Imposing Disability” and “Genetic Scapegoat”.</p

Enhancing the species: genetic engineering technologies and human persistence

Many of the existing ethical analyses of genetic engineering technologies (GET) focus on how they can be used to enhance individuals—to improve individual well-being, health and cognition. There is a gap in the current literature about the specific ways enhancement technologies could be used to improve our populations and species, viewed as a whole. In this paper, I explore how GET may be used to enhance the species through improvements in the gene pool. I argue one aspect of the species that may be desirable to enhance is ‘persistence’ or long-term viability. I then look at some of the ways in which GET could be used to improve human persistence and argue that the use of GET to secure benefits for individuals may compromise persistence. This suggests conflicts between uses of GET to enhance individuals and uses to promote the persistence of the species may occur. As GET are further developed, the likelihood that these conflicts will actually arise, and how we should resolve them if they do, will need to be considered

Ethics of genomic passports: should the genetically resistant be exempted from lockdowns and quarantines?

Lockdowns and quarantines have been implemented widely in response to the COVID-19 pandemic. This has been accompanied by a rise in interest in the ethics of ‘passport’ systems that allow low-risk individuals greater freedoms during lockdowns and exemptions to quarantines. Immunity and vaccination passports have been suggested to facilitate the greater movement of those with acquired immunity and who have been vaccinated. Another group of individuals who pose a low risk to others during pandemics are those with genetically mediated resistances to pathogens. In this paper, we introduce the concept of genomic passports, which so far have not been explored in the bioethics literature. Using COVID-19 as an illustrative example, we explore the ethical issues raised by genomic passports and highlight differences and similarities to immunity passports. We conclude that, although there remain significant practical and ethical challenges to the implementation of genomic passports, there will be ways to ethically use them in the future