Nov
18
2009

Stem Cell Panel with Mark Noble

Mark Noble (Univesrity of Rochester, Stem Cell and Regenerative Medicine Institute) was the first speaker in a panel that followed the keynote (Dr. Capecchi).  Dr. Nobel talked about what is it about stem cells and sem cell research that we should include in our biology teaching.  He suggests that it is critical that we teach the difference between evidence-based thinking and belief-based thinking.  The difference between science and not-science.

He sees the biology of stem cells as the greatest opportunity for teaching about evolution.He referred to a very disconcerting Scientific American map, rating the evolution treatment in state public school science standards.

Tissue specific stem cells give rise to the cells of a single tissue by first generating restricted progenitor cells that only can generate some of the cell types in any given tissue.  Important to remember that its the progenitor cells that are the real work horses of developmental biology – and this, says Dr. Noble, is a medical revolution. He pointed out some interesting medical applications you don’t hear much about.  For instance, a succesful tracheal replacement with stem cells, grown on trachael-shaped biomaterials, and a similar procedure for bladder reconstruction.

Another teaching opporutnity – stem cells and cancer.  Dr. Nobel reminds us that cancer uses the same tricks as developmental biology.  Every therapy we have is targetted at removing the tumor – but if you leave the cancer stem cells, the tumor grows back.  Now our treatments are focused on killing the cancer stem cells.

Another teaching opportunity with stem cells – toxicology.  The World Health Organization estimates that 30 -40% of the burden of disesae is due to environmental factors.  Dr. Nobel explains that there are 80-150k registered chemcials relesased into the environment for which we have no information (an assumption of safety).  We have 100′s of these chemiscals in our bodies.  But stem cell science helps us to  figure out what these chemicals do.  For instance lead inhibits frature repiar by inhiting mesenchymal stem cell fucntion.  Other toxicants alter development of the nervous system or are risk factors for disbetes or alzheimer’s.

Dr. Nobel suggests that questions about the beginnings of “human-ness” are at the heart of the controversy over stem cell research. There are differeing scientific perspectives on the beginnings of human-ness – conception, 40-days post conception, 120-days post conception.  Do iPS and reprogramming technologies offer us a way to side-step these controversies? Ethics exist along a temporal continuim. For instance, what should happen to blastocysts, frozen in IVF clinics, that are currently targeted for destruction?

Dr. Nobel also suggests including the exmination of false claims in our biology teaching. For instance, “Adult-derived cells have successfully treated more than 70 diseases.”   But if you spend time with the list of diseases, most of them are bone marrow trasnplants.  So that is a false claim and its interesting to investigate the claim with students to watch them get at exactly why that claim is wrong.

Written by rheyden in: Biology Teaching | Tags:
Nov
18
2009

Tropical Rainforests

Bruce Calhoun, Save the Rainforest

Bruce Calhoun, Save the Rainforest

Bruce Calhoun (President of Save the Rainforest, Inc, Las Cruces, New Mexico) gave a terrific talk on Saturday morning – Tropical Forest and the New Climate Change Agreement.  He showed some fabulous photographs of rainforest jaguars, cougars, pigmy opossums, bats, katydids, bromeliads, passion flowers, orchids, frogs,

You can watch online videos of Bruce, giving his rainforest talk to students.

Written by rheyden in: Biology Teaching | Tags:
Nov
18
2009

Stem Cell Education Summit

Mario Cappechi's Stem Cell Keynote Address

Mario Capecchi's Stem Cell Keynote Address

It’s Saturday morning in Denver – and its cold.  We went from 70 degree temperatures to 30 degrees in one day and there’s a light dusting of snow.

This morning started early with the Stem Cell Education Summit.  The keynote speaker, Mario Capecchi, is the molecular geneticist best known for his work with knock out mice, for which he was the co-winner of the 2007 Nobel Prize. The title of the talk was “Stem Cell Therapy:  Hype or Reality?”  He started his talk with the answer to that titular question  - ‘There’s alot of hype, a little reality, and a tremendous amount of potential.”

Diseases that may be treatable by stem cell therapies:  Parkinson’s, Alzheimer’s, insulin dependent diabetes, spinal cord injuries, and heart disease. Dr. Cappechi pointed out that it’s not all future – that stem cell therapies that have been used for a long time with bone marrow transplants for leukemia patients.

He then went on to explain stem cells to the audience – they are unspecialized cell types in the human body that are capable of becoming a specialized cell type.  Stem cells are capable of self renewal and differentiation.  There are two major classes of stem cells – embyonic (extremely rapid growth and very versatile, pluripotent) and adult (slower growing, restricted and require a niche)

Embryonic mouse cells can be harvested, reintroduced, and functon to create mouse tissue.  We’re not there yet with humans and that’s why these stem cell therapies are still outside of our reach.

Then there’s the idea of reprogramming somatic cells to function as a different type of cell.  There are two techniques for this – the first is nuclear transfer (remove the current nucleus and put in a different one). That technique is very inefficient (low success rates) and the resulting organism is fragile.  The second is the Yamanaka method (inducing a forced exprssion of certain genes in a fibroblast) to create induced pluriplotent stem cells.

Dr Capecchi then turned his attention to stem cell work in the small intestine. The intestinal epithelium is the most rapidly self-renewing tissue (turns over every 5 days) in adult mammals. The stem cells of the small intestine are made in the crypt (at the base of the villus).  Interestingly, the small intestine almost never gets cancer, while the colon (which doesn’t regnerate like this) is a common cancer site. The gut has many different types of absorbing cells, as you move along the length of the intestine. So, it turns out there are a number of different stem cell populations in the small intestine – multiple populations making one tissue type – an added complexity that is critical to understand. Though this system had been studied for year, they didn’t have a marker.  A marker is really important for geneicsts because that’s their way in.

When asked how close are we to the clinic with this research, Dr. Capecchi said that  ”the safe answer is 20 years” and then went on to reiterate how complex this research is. He explainted that we’re going to hear a lot of claims in the coming years and, unfortunately, most of those successes won’t be real.  Even worse, it will be difficult to know whether or not the claims are valid .  He reminds us that there are cancer patients who get better, even wtihout therapy, so, in some cases, you won’t know whether the improvement with cancer patients is due to the stem cell therapy or some other factor. But he concluded by saying that there is tremendous potential here – that stem cell research will provide cellular solutions for cellular problems.

Written by rheyden in: Biology Teaching | Tags:
Nov
15
2009

NABT Town Hall

One of the unique features of NABT is the ability of members to have a face-to-face meeting with the Board of Directors and “talk back” as it were.  I’ve attended several of these meetings and quite frankly, some have been rather contentious.  This year, however, was not one of “those” meetings. John Moore, this year’s President made a presentation bringing folks up to date about the state of the organization and generally explained the situations and decisions made this past year. Needless to say, 2009 has been a monumental year for NABT.  The economy has hit all non-profits hard and NABT is no different.  But when given lemons, you best make lemonade and the year has been full of tough decisions and hard work to re-structure for the future.  One bit of especially good news: we planned the conference based on a projected attendance of 850 and as of Saturday morning had over 1100 registered attendees.  Special kudos to the Colorado Biology Teachers Association for their volunteer efforts.  Some 70 CBTA members worked registration and handled AV needs for the conferenceIMG_5016

But the dialog is not one-way at the Town Hall.  Members can ask any question, challenge any decision, and offer suggestions as they see fit.  This year offered some good suggestions about potential future convention sites, member recruitment, NABT merchandise sales, and the annual banquet, which were dutifully recorded by yours truly to be posted to the Board of Directors and added to the ongoing discussion.

The Town Hall ended with Past President Todd Carter presenting outgoing President John Moore with a plaque to commemorate his year of service to NABT.

Written by bobmelton in: Conference Info,NABT News | Tags:
Nov
15
2009

Using a Digital Camera in the Classroom

DSCN1774

Digital Camera Use Workshop

I stopped in time to catch the tail-end of a workshop on using digital cameras in teaching, given by Brian Gross, Mike Kittel, and Brian Heeney.  They had some great ideas for using digital cameras in the classroom.

One of my favorites was a new piece of hardward I’d never heard of called the Eye-Fi. This is a wireless device that allows you to automatically and wirelessly download photos from your camera to your computer.  No more cables, no more fussing around.  Instant access to the photos on your camera. There’s a range of options – they recommnded the Eye-Fi Pro (which is $140) which functions without a router (the others, that are less expensive must traffic through a router). With this technology, you can use the pictures you take in class and instantly have them up there on the screen – “Look at Suzy’s concept map!”  or “Everyone look up here to see what group 3 figured out.”

As for digital camera recomendations – Brian says it’s hard to go wrong these days. You can get a perfectly good camera for $99.  If your camera is capable of taking photos at 8 or 10 megapixel resolution, they recommend reducing the resolution to 3-4 mega pixels as that is perfectly sufficient for most classroom or web use and the photos download much faster. If you are buying a bunch of cameras for student use, they do recommend getting cameras that take double A batteries, so that it’s easy to replace them (without having to recharge).

Tiger Direct is a web site they recommend for good deals on electronic equipment.  They also provided the link to a wiki site they built full of teaching resources.

The question was asked, how about having the students use the cameras in their cell phones if you can’t afford to buy classroom sets of digital cameras? One of the speakers said, yes, if you have excellent classroom management and set up the expectations in advance.  The other said that he doesn’t open the door to that.

Some of their ideas for using the camera:

- pictures of procedures in a lab

- pictures of students on the first day of class

- take pictures of students goofing off or sleeping, encourages more compliant behavior (thye cautioned that you do need waivers, avoid putting student photos online, and tellt he students that if they don’t want pictures taken of them, to just request it)

- pictures of models that the students assemble

- students taking pictures of their lab results

Good stuff.

Written by rheyden in: Biology Teaching | Tags:
Nov
13
2009

Lessons Learned from Marine Mammals

Today was a pretty full agenda but I did get an opportunity to meet a young man who is living his dream as muscle physiologist studying marine mammals.  I got to introduce Dr. Shane Kanatous, an Assistant Professor in the biology Department at Colorado State University in Fort Collins. As a youngster, Dr. Kanatous was influenced by Jacques Cousteau and his long running series that ran as National Geographic Specials on PBS.  He was determined to become a oceanographer/ marine biologist and has studied across the country to achieve that dream.kanatous

His primary research animal is the Weddell Seal, a 400-600 Kg. penniped found in Antarctica.  They have the remarkable ability to make deep, long dives in the search for food.  Such dives last over 20 minutes to depths of as much a 2,000 ft.  They can do so because of their unique distribution of mitochondria in their muscle tissue as well as their unique capillary distribution and use of myoglobin.  Shane had us imagine ourselves driving to Wal-Mart, hyperventilating 5-6 times as  we walked to the door, then exhaling all the air from our lungs and closing our eyes as we entered the store and pass the greeter on our way to pick up and purchase our groceries, not opening our eyes or breathing until we exit the store.  Weddell Seals do that  process 60-80 times a day as they dive in search of codfish and squid at depths that collapse their lungs.

You can follow Dr. Kanatous and his research through his Polar Science 2009 project.  His presentation today was made possible by the American Physiological Society

Written by bobmelton in: Biology Teaching | Tags: ,
Nov
12
2009

Cellular Respiration Lab

Brad Williamson and his microrespirometers

Brad Williamson and his microrespirometers

Our fearless AP Bio Listserv moderator and the organizer of this NABT Bio Blog, Brad Williamson, gave an interesting workshop this afternoon.  He showed us how to build microrespirometers for a cellular respiration lab out of 1-ml syringes, plastic capillary tubes, germinated seeds (he used cabbage seeds), 15% KOH solution, and some homemade manometer fluid (soapy water with red food coloring).  All 30 teachers in the room got them working perfectly!  Here’s a link to a more fulsome description of the lab on his Exploring Life author web site.  Nice job, Brad :-)

Written by rheyden in: Biology Teaching | Tags:
Nov
12
2009

AP Biology Teachers’ Open Forum

Still blogging from the 2009 NABT….I just attended an Open Forum run by the Development Committee for Advanced Placement Biology  – Franklin Bell (Mercersburg Academy) and Domenic Castignetti (Loyola University), along with Eileen Gregory (Rollins College), the current Chair of the Committee.

Franklin and Domenic gave us some helpful background on how the AP exam items are developed (lots of discussion and collaboration, the entire committee must come to agreement on each one) and they reviewed the 2009 exam results (there were 159,000 students who took the AP Bio exam in 2009). The results are all up on AP Central, but they spent some time going over the four free-response questions from the exam.

2009 AP Biology Exam Results Breakdown

Question 1: Experimental design (fish tank), mean = 5.49
Question 2: ATP, mean = 2.92
Question 3: Phylogeny, mean = 5.33
Question 4: Structural and Physiological adaptations, mean = 3.29

There was some discussion about the lower than expected mean on the ATP questions. Some of the teachers in the room suspected that it was due to the fact that this is a topic covered early in the year. That brought out a discussion about the importance of review and teachers offered some of their creative ideas for reviewing. One of my favorites was you have the students close their eyes, open their textbook at randomly and point to something. Write down that word or phrase. Then close the book and do it again. Then they have to come up with a connection between the two things they pointed to.

Some other good suggestions that came out of the forum….assign a unit over the summer and students write journal entries about it or email in summaries to the instructor. One teacher assigns a summer reading book (maybe Sean Carroll’s Into the Jungle or Neil Shubin’s, Your Inner Fish ) and give them a list of questions to answer, via email, over the course of the summer.

Another nice spring suggestion was to assign each student a tree or bush bud, somewhere on the school grounds, to monitor over a couple of weeks.  They make daily observations, take measurements, even document with digital photos.

Written by rheyden in: Biology Teaching | Tags: