Category Archives: Defense Against Infections Diseases
Ebola: What’s Going On?
Ebola is making headlines at the moment – in this task we’ll learn more about how it works and what is being done to stop it. Refer to this excellent resource from the Center for Disease Control (CDC). These short videos also give some background.
………..o0O0o………..
Goal: Produce a poster, blog post or short presentation to communicate accurate information regarding Ebola.
Role: You are science communicators.
Audience: Your peers – high school students and teachers.
Scenario: Ebola is making the news in a big way – and so is misinformation about it. You need to find and present accurate information about Ebola, including potential risks and what is being done to combat it.
Product: Large visual poster, blog (500 words with media) or short presentation (4-5 mins).
……….o0O0o……….
Required information
- Describe the pathogen of Ebola, including type of pathogen, characteristics and ‘behaviour’.
- Outline the effects of Ebola on the patient: symptoms, damage, cause of death.
- Outline how Ebola is transmitted, including risk factors for transmission.
- Explain why patients who survive Ebola infection become immune to future infections.
- Describe current treatments for Ebola, including their effectiveness.
- Describe how an outbreak of Ebola might be controlled.
- Outline how a vaccine for Ebola might be created.
- Evaluate the current level of ‘panic’ about Ebola. To what extent is it justified in our context?
- Define any new or technical terms used (or discovered in your research) for the audience.
Going Further
- Compare Ebola and other viral infections.
- Discuss the origins of Ebola, including how it is thought to have become able to infect humans.
………..o0O0o……….
Teacher Notes
- This could be used to reinforce the diseases unit.
- Students should be vigilant on student use of resources: there are many conspiracy theories out there clouding the issue.
………..o0O0o……….
Harvard Stem Cells Breakthrough: Diabetes
This recent news from Harvard is a perfect fit for the IBBio course, connecting lots of what we have learned in the course. Watch this short TED Talk from Prof. Doug Melton on how they are using stem cells to create new insulin-producing beta cells. Then read this article from the Harvard Gazette on the most recent developments in their work.
………..o0O0o………..
Goal: Produce a poster, blog post or short presentation to communicate Melton’s team’s breakthrough, including connections to the IBBio course.
Role: You are science communicators.
Audience: Your peers – high school students and teachers.
Scenario: Stem cells and diabetes are both headline-grabbing stories. As we develop more treatments for diseases using stem cells, the public need to be well informed of the reality of what is happening – and inspired by the future.
Product: Large visual poster, blog (500 words with media) or short presentation (4-5 mins).
……….o0O0o……….
Required information
- Explain that Type 1 diabetes is “an autoimmune metabolic condition in which the body kills off all the pancreatic beta cells that produce the insulin needed for glucose regulation in the body.” [article, paragraph 14]
- Outline the usual treatment needed for type 1 diabetes.
- Outline the properties of stem cells.
- Explain how stem cells differentiate to become differentiated cells.
- Describe the work of Melton’s team to create beta-cell lines derived from stem-cell lines.
- Outline the proposed treatment for type 1 diabetes through implanting the newly-produced beta-cells.
- Discuss any caveats or limitations to the method.
- Discuss any ethical implications for the use of stem cells in this manner.
- Define any new or technical terms used (or discovered in your research) for the audience.
Going Further
- Distinguish between type 1 and type 2 diabetes.
- Evaluate whether this method would be as effective for type 2 diabetes as for type 1, with reasons.
………..o0O0o……….
Teacher Notes
- This could be used to teach part of the homeostasis topic once students know about stem cells, or as a review tool for later in the course.
- Students should refer to the subject guide to check their use of terminology and to regulate the depth of explanation.
………..o0O0o……….
Connecting Type II Diabetes
Here is Doug Melton talking about how we might use hormones to treat Type II diabetes:
Ed Yong’s TED Talk: Suicidal crickets, zombie roaches and other parasite tales
“Are there any parasites that are influencing our behaviour without us knowing it?”
When I started this blog back in 2007, Ed Yong was a fledgling science writer gaining an audience with his Not Exactly Rocket Science wordpress blog; clear and engaging online articles that opened up primary research to a wider audience. You’ll find many links to his writing throughout this site, connecting the concepts of the IB Biology course to current science and ‘the wow beat’. He has since had a book and is resident at NatGeo’s Phenomena Salon, after moving through Science Blogs and Discover.
He continues to inspire me as a writer and this week he gave his TED Talk, a funny and fact-packed tour of the sinister side of parasites. Enjoy! You will even be able to find some links out to further reading and references.
If you don’t already, you should subscribe to the Phenomena blogs, and if you’re a teacher or student whose schedule are as packed a mine, I highly recommend Ed’s weekly ‘Missing Links‘ roundup of science news and writing – they make for my Sunday morning reading!
Biology4Good Charity Focus | Hope HIV
Thanks Kasia from Hope HIV for getting in touch and sending this video, that outlines the great work that they do with the donations people make. They focus on the idea of ‘using who you are to make a difference,’ which is perfect for IB students and teachers. Visit this page in particular to see some stories of people that they have hope in – and then if you feel like making a donation, please visit my JustGiving page for Hope HIV here.
For more resources on HIV and how it connects to our curriculum, visit the page for 6.3 Defense Against Infectious Disease here.
And this one outlines their amazing work and growth since 2000.
15 year-old develops effective, cheap test for pancreatic cancer [TED Audition]
Wow. Here’s Jack Andraka’s TED Audition for a talk on his work developing a carbon nanotube and antibody-based test for pancreatic cancer.
Jack won the 2012 Gordon E. Moore Award ($75,000) at the Intel International* Science and Engineering Fair for the same work:
Read more about him, his work and the work he built it on here on Forbes.com.
*Yup – you can have a go too.
The End of AIDS?
World AIDS Day is almost upon us again: 1st December. This video was tweeted by @StephenFry today – give it a look over to see how ARV drugs may be used in prevention as well as treatment.
[vimeo 32317889]To find out more, visit the End to AIDS website, where you can also read a history of World AIDS Day.
How We’ll Stop Polio for Good
This TED Talk by Bruce Aylward is amazing – watch it! Particularly important for HL Biology students.
Find out more about the work of the Global Polio Eradication Initiative. You can donate through Rotary International or click on the map below to track their progress.
2006 Map of Global Polio, from the Global Polio Eradication Initiative.
Hybrid Hearts: Stem Cell Transplants 2.0
“Can we use stem cells to make a new heart/eye/lung/liver etc?”
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:
Decellularised pig heart: the scaffold (NewScientist)
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?
Useful Sources:
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.
Pandemic II: Educational Flash Game
Pandemic II: Spread the World
Thanks to the excellent NotExactlyRocketScience blog for posting the link to this game. Pandemic II is a complex flash game based on strategy, evolution (though more like design) and the spread of disease. The premise is simple – take a pathogen (bacteria, virus or parasite), and watch its spread across the globe. Along the way you can alter the pathogen to change its properties, making it more infectious, more lethal or less noticeable. The aim of the game is to wipe out the population of the world.
It is easy to save using Firefox add-ons.
Check out the game here: http://www.crazymonkeygames.com/Pandemic-2.html
And the tutorials here:
Is it better than the addictive Magic Pen Game or Foldit?
Have a go!
i-Biology 