Category Archives: Immunity & Immune System
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.
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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).
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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.
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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.
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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.
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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).
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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.
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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.
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Connecting Type II Diabetes
Here is Doug Melton talking about how we might use hormones to treat Type II diabetes:
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.
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.
The Transport System
These links are for the Further Human Physiology unit.
Here’s the powerpoint:
Download here: transport-system.ppt
And here’s the Click4Biology link
Medmovie.com has a large collection of animations which are great for this unit. We can’t link to them directly, but it’s worth having a look around.
The Cardiac Cycle:
Hyper Heart animation and graphs from the Chinese University of Hong Kong
Biointeractive from the Howard Hughes Medical Institute
Control of the Heart Beat:
A few good links to try from Washburn Rural High School
And don’t forget the Medmovie resource…
Atherosclerosis and Coronary Heart Disease:
Medmovie has good animations for atherosclerosis, heart attacks and heart bypass surgery. There aren’t many that are better…
Production of Tissue Fluid and Lymph:
Hydrostatic and osmotic pressure (fluid exchange) from McGraw Hill
Capillary exchange from coolschool.ca (they have other good resources, too)
Bonus features:
For a good (tricky) prac, here’s a virtual EKG package from skillstat.com
And here’s a decent heart structure tutorial from Gateway Community College
NHS Vaccinations
Nice, simple animations here:
Aimed at the panicky classes after the Wakefield/MMR-autism fiasco- so are quite basic- but raise some points for discussion.
The rest of the NHS immunisation site contains some good, clear information on vaccination schedules and the various diseases covered.
Defense Against Infectious Disease
Phagocytic leukocyte having a gobble:
Immune response animation. Good plenary.
Cell mediated immune response:
i-Biology 