Tag: chimeras

Bioethics News

Legal status of human-animal chimeras – hybrid embryos

In addition to the biomedical problems raised by human-animal hybridization, there are also objective legal problems.

A recent article in the Journal of Medical Ethics (2014; 40, 284-285) reviewed this topic following a debate in the United Kingdom (UK) House of Lords in December 2012. The underlying problem is to determine whether hybrids containing human biological material, mainly DNA, should be considered partially human and if so, what their legal status should be.

See our Special Report New advances and challenges in the production of human-animal chimeras

The Human Fertilisation and Embryology Act 2008 (HFE Act 2008) regulates the legal aspects of human-animal hybrids. These hybrids refer to any embryo containing human nuclear or mitochondrial DNA as well as animal nuclear or mitochondrial DNA, but in which the animal DNA is not predominant. Other categories of hybrids can be legally regulated by the “Animal Act 1986”.

However, deciding which of the two categories into which hybrid embryos should fall is not that easy.

The English Health Minister, Lord Darzi of Denham, stated that hybrid embryos should be regulated by human statutes when they are considered to be “predominantly” human, which is not easy to determine. In fact, a chimeric embryo in which non-human cells were initially predominant could continue to develop into a hybrid in which human cells predominate.

Lord Darzi also stated that chimeric embryos that are “functionally” predominantly human should also be considered as human. However, the term “functionally human” is ambiguous, which complicates the issue of its legal status.

It was therefore concluded that the UK parliament needs to more definitively determine the legal status of embryos containing human and animal genetic material, following an extensive, in-depth debate that must take into account public opinion on this matter.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

No Pain, All Gain: The Case for Farming Organs in Brainless Humans

Guest post by Ruth Stirton, University of Sussex (@RuthStirton) and David Lawrence, Newcastle University (@Biojammer)

It is widely acknowledged that there is a nationwide shortage of organs for transplantation purposes.  In 2016, 400 people died whilst on the organ waiting list.  Asking for donors is not working fast enough.  We should explore all avenues to alleviate this problem, which must include considering options that appear distasteful.  As the world gets safer, and fewer young people die in circumstances conducive to the donation of their organs, there is only so much that increased efficiency in collection (through improved procedures and storage) can do to increase the number of human organs available for transplantation. Xenotransplantation – the transplantation of animal organs into humans – gives us the possibility of saving lives that we would certainly lose otherwise.

There are major scientific hurdles in the way of transplanting whole animal organs into humans, including significant potential problems with incompatibility and consequent rejection.  There is, however, useful similarity between human and pig cells, which means that using pigs as the source of organs is the most likely to be viable.  Assuming, for the moment, that we can solve the scientific challenges with doing so, the bigger issue is the question of whether we should engage in xenotransplantation.

A significant challenge to this practice is that it is probably unethical to use an animal in this way for the benefit of humans. Pigs in particular have a relatively high level of sentience and consciousness, which should not be dismissed lightly. 

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Ten years since the discovery of iPS cells. The current state of their clinical application

Photo Neurons derived from human iPS cells Stem Cells Australia

Background

Few biomedical discoveries in recent decades have raised so many expectations as the achievement of adult reprogrammed cells or induced pluripotent stem (iPS) cells.1

Pluripotent cells are obtained from adult cells from various tissues that, after genetic reprogramming, can dedifferentiate to a pluripotency state similar to that of embryonic cells, which allows for subsequent differentiation into different cell strains.2,3

In our opinion, this discovery is relevant not only to biomedical issues but also to ethical ones, given that iPS cells could replace human embryonic stem cells (see HERE) – whose use raises numerous ethical problems – in biomedical experimentation and in clinical practice. However, after the last 10 years, the use of iPS cells has still not been clarified. A number of expectations have been met, but other mainly clinical expectations are still far from being achieved.

Current research limitations with iPS cells

There is a notable low efficacy in the techniques employed for obtaining a sufficient proportion of iPS cells, which represents a difficulty in its clinical application.4  Another limitation is the incomplete reprogramming, which depends on the type of cell employed,5 and the problems of mutagenesis resulting from inserting exogenous transcription-factor coding genes, which can cause tumors in the employed cells used.6 Recent studies aim to mitigate this effect.7 A clinical trial for treating macular degeneration with retinal pigment epithelium cells derived from autologously obtained iPS cells has recently been halted.8 After an initially successful experience with the first treated patient, the genetic sequencing of the iPS cells obtained from the second patient revealed mutations in 3 different genes, one of which was classified as oncogene in the Catalogue of Somatic Mutations in Cancer.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Do Extended Pluripotent Stem Cells Raise Ethical Issues?

On April 6, the journal Cell published work (subscription or online article purchase required) from the Salk Institute in San Diego, in which scientists have created a new “reprogrammed” stem cell.

These cells are called “extended pluripotent stem cells” or “EPS” cells.  They are different from embryonic stem (ES) cells, which are removed from intact embryos that arise from fertilization—typically requiring specific creation and destruction of an embryo.   Of course, ES cells can be human or non-human, depending on the source.

EPS cells are similar to “induced pluripotent stem cells,” or iPSCs, invented in 2006.  The latter are generated from adult skin cells that have been reprogrammed, using genetic alterations.

EPS cells may be made by reprogramming ES cells or skin cells or, if I understand the work correctly, iPSCs.  In this case, the reprogramming is done with a cocktail of chemicals in the lab.

But EPS cells are more capable than iPSCs.  Unlike iPSCs, which can give rise to many different types of cells but not all—including not a placenta and not an entire intact new individual—EPS cells can do all of that.  They are totipotent, meaning they can make all the cells of an individual from their species.  Moreover, they are quite long-lived in the laboratory.  EPS cells from one species—e.g., humans—can be placed into non-human (e.g., mouse) embryos to make hybrid animals that, it appears, survive quite well and can breed.  And, remarkably, the authors of the Cell paper report (again, if I understand correctly, and I think I do) that they were able to use a mouse EPS cell to give rise to a whole new mouse, not “just” a laboratory tissue hybrid.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

New advances and challenges in the production of human-animal chimeras

They had overcome the obstacle of using human embryonic stem cells, but that even so, a ethical difficulty remained with the producing organs formed almost entirely of human cells in experimental animals.

It seems a little excessive that, in less than two months, we have dedicated three reports to the latest studies by Juan Carlos Izpisúa and his group. Nonetheless, we believe that the importance of his work merits this level of interest.

In our first report, we referred to a study published in Nature, which describes — among other breakthroughs — the production of human-animal chimeras in order to generate quasi-human organs for use in transplantation. In the report, we mentioned the ethical difficulties evident in the study as a result of the use of human embryonic stem cells.

In the second, we discussed the new steps taken in the production of human organs in animals, in connection with an interview by Izpisúa published in Investigación y Ciencia (the Spanish version of Scientific American). In the interview, Izpisúa particularly stressed that, from an ethical point of view, they had overcome the obstacle of using human embryonic stem cells, but that even so, a potential ethical difficulty remained with the possibility of producing organs formed almost entirely of human cells in experimental animals.

Now, we evaluate these experiments by analysing the latest findings published in an article in scientific journal Cell (see HERE).  We also discuss another paper by a different research group, in which the authors also describe the production of human-animal chimeras, likewise with the intention of producing organs for transplantation.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Should a Human-Pig Chimera Be Treated As a Person?

Julian Savulescu writes, “Scientists in the United States are creating so-called “human-pig chimeras” which will be capable of growing the much-needed organs. These chimeras are animals that combine human and pig characteristics. They are like mules that will provide organs that can be transplanted into humans.”

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Ethics & Society Newsfeed: February 3, 2017

Image via

Politics

Betsy DeVos’s ethics review raises further questions for Democrats and watchdogs
Betsy DeVos, Trump’s nominee to lead the Education Department, promised to divest from more than 100 entities to avoid potential conflicts of interest with her new job. Questions left unanswered.

Donald Trump warned over ‘unprecedented’ plan to appoint cabinet without ethics office checks, emails reveal
Disclosed emails from the head of the ethics office warn President aides staffing a cabinet with robust oversight is a ‘tradition evolved as a result of hard lessons’

South Dakota Governor Signs Measure Reversing Voter Ethics
Governor of South Dakota signed a bill Thursday overturning an anti-corruption measure passed by a majority of voters in November, to the consternation of government watchdog groups.

Trump And His Organization Lawyer Up For The Ethics War Ahead
President Trump and the Trump Organization are beefing up their legal teams against an expected surge of conflict-of-interest allegations.

Teaching Ethics In The Trump Era
Graduate-level professor asks how to tell students ethics is important when “nothing around them feels ethical” re: Trump administration and conflicts of interest.

Bioethics

Human-pig hybrids might be unsettling. But they could save lives.
A new study out of California unsettled a lot of people last week after revealing that scientists had, for the first time, made part-human, part-pig embryos — referred to as “chimeras.” Raises ethical questions.

Could changing the way doctors are paid help narrow health disparities?
A study suggests that changing the way doctors and hospitals are paid could narrow some of the health disparities between poorer and wealthier patients.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

What’s the Benefit in Making Human-Animal Hybrids?

February 3, 2017

(The Conversation UK) – The chimeric pig foetuses produced by Juan Izpisua Belmonte, Jun Wu and their team at the Salk Institute were not allowed to develop to term, and contained human cells in multiple tissues. The actual proportion of human cells in the chimeras was quite low and their presence appeared to interfere with development. Even so, the study represents a first step in a new avenue of stem cell research which has great promise. But it also raises serious ethical concerns.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Can We Be Okay With Chimeras?

In a post yesterday, Jon Holmlund, in typically erudite fashion, addressed the ethical issues that arise from the findings of a published study which looked at the potential use of genome technologies to (someday) produce human organs in animals. I will begin by saying that I have no particular disagreement with Jon’s assessment. There is a lot that is troubling in this research, as much good… // Read More »

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Chimeras with benefits? Transplants from bioengineered human/pig donors

By Brad Segal In January of this year, Cell published a study modestly titled, Interspecies Chimerism with Mammalian Pluripotent Stem Cells. It reports success bioengineering a mostly-pig partly-human embryo. One day before, Nature published a report that scientists had grown … Continue reading

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.