Category Archives: Human Impacts
Yesterday, the European Court of Justice banned the issuing of patents for embyronic stem cell research, stating:
“A process which involves removal of a stem cell from a human embryo at the blastocyst stage, entailing the destruction of that embryo, cannot be patented.“
The decision has caused widespread concern amongst European stem cell researchers, yet has been welcomed by other groups on moral, ethical or religious grounds.
So why is it such a hot topic?
Use the resources here, and others that you can find, to discuss the following questions in your group. Be prepared to feed back to the class with a summary of no more than 5 minutes.
- What are (embryonic) stem cells and how do their properties facilitate research?
- Where are stem cells found? Are they all the same?
- How do stem cells eventually become differentiated and specialised?
- Outline at least one recent successful therapeutic use of stem cells.
- Identify a range of stakeholders in the debate. What are their views and reasons for them?
- Can you propose potential solutions or workable compromises that could reduce the impact of the ban on scientific research?
Some write-ups on this news story here:
About Stem Cells:
- Cell Theory, topic 2.1 resources by MrT
- Loads of interactive resources from Learn.Genetics
- SEED Magazine’s Stem Cells Cribsheet
- Stem Cell Differentiation (animation) from MCB Harvard
- Stem Cell Basics, from the National Institutes of Health
- StemCells: Seeds of Hope? video from Teachers Domain
- NewScientist special reports on Stem Cells
- Stem Cells transplants in lymphoma (animation)
Theory of Knowledge
The embryonic stem cell debate generates strong and emotive knowledge issues, which is evidenced by the fact that the case was passed all the way up to the European Court of Justice. There are many stakeholders in embryonic stem cell research, each with their own knowledge claims and beliefs.
With this recent ban on patenting methods based on the destruction of embryonic stem cells, we add the elements of patenting and intellectual ownership (and of course the knock-on effects to funding, progress and public perception).
To what extent does the embryonic stem cell debate highlight potential conflicts between the areas of knowledge of the natural sciences and ethics and between the ways of knowing of emotion and reason?
After reading through, understanding and discussing the resources, what knowledge issues can you identify?
This follows on from a related story in the USA last year:
Comments have been disabled on this post, but are open on the TOK page for the same content.
“This turtle gonna go to rehab, to make its flippers go, go, go…*”
In a recent BBC documentary, Stephen Fry and Mark Carwardine head to the USA to see the damage and recovery from the Deepwater Horizon oilspill:
“Stephen Fry loves Louisiana. Four months after the BP oil spill, dubbed the worst ecological disaster in the history of America, Fry returns to the Deep South together with zoologist Mark Carwardine, to see what the impact has been on the people, the vast wetlands and the species that live there. What they find both surprises and divides the travelling duo.”
From the BBC Website (you might get it in your area)
The Deepwater Horizon spill would make a great foundation for an interdisciplinary science unit or Group 4 project, looking at ocean chemistry, waves and dispersal, remote sensing technologies, geological resources, ecology, marine biology and food chains, economics, politics, ethics and much more.
*Amy Winehouse, if you didn’t get it.
This is the predictable and perennial question that comes up from at least one student when we are looking at stem cells, genetic engineering, cell differentiation and transplanting. Until now, the answer has (perhaps in an oversimplified way) been ‘no’.
We can use stem cell transplants to treat lymphoma. Recently a young woman had a trachea transplant based on stem cell technology. Skin grafts from a patient’s own cultured cells are also possible, as are stem cell-based bladders. However, these are all rather simple technologies.
To treat lymphoma, bone marrow cells are replaced, and are all the same. The trachea transplant was a pre-existing trachea simply coated in the patient’s stem cells to prevent immune rejection. Skin transplants are basically sheets of epidermis that cover a wound, yet do not have the intricate functions of original skin: temperature regulation, secretion, senses. The bladder is a bag.
The challenge with using stem cells to transplant a more complex organ, such as a heart, is that it is not a simple sheet made of one type of cell. It is complex 3D structure, with a range of cells performing specific tasks within the organ. These cells have differentiated to perform their functions: cardiomyocytes (beating cells), vascular endothelial cells (smooth internal surfaces) and smooth muscle cells (blood vessel walls).
How can we get the stem cells to become the right type of cell, in the right position?
The answer to this question could be the key to opening up new doors in the search for viable transplantable organs in medicine, and bears much in common with the trachea case. It also marks a return to form for the NewScientist YouTube channel, who have this short clip of the new hearts in action:
A full article to accompany the footage is here.
In a nutshell:
1. Find a suitable transplant organ, such as a pig’s heart.
2. Strip of all cells and DNA, using a detergent. Only the collagen ‘scaffold’ remains, as in the image of the decellularised heart to the right.
3. Coat the scaffold with the recipient’s stem cells.
4. Ensure that the blood supply is adequate and will provide the right signals for differentiation.
What is amazing in this case is how the cells ‘knew’ what specialised cells to become. The leader of the research group, Dr. Doris Taylor, puts it down to the mechanical stimulus of the pressure of the blood in the vessels and chambers and chemical signals from growth factors and peptides that remained on the stripped heart structure.
They even went as far as replacing a healthy rat’s heart with one of these new hybrid hearts. The rat survived for the trial, but she says they need to focus on producing more muscular hearts in order to ensure long-term survival of transplant recipients.
Food for thought:
Read the whole article and some of the links within it. Discuss these questions:
1. What are the potential uses for this kind of transplant technology?
2. What are the current limitations of this method and how might they be overcome?
3. What are the ethical issues related to using hybrid (pig-human) organs in medical transplants? How would you feel if you were the patient?
4. Who are the various stakeholders in this technology and what are their viewpoints?
Dr Doris Taylor’s research page from the University of Minnesota
NewScientist Article: Hybrid hearts could solve transplant problem
BioAlive stem cells links and resources
Can stem cells repair a damaged heart? from the NIH
Research reveals how stem cells build a heart, from Harvard news.