Thursday, April 14, 2011

Highlights From Experimental Biology 2011

by Chris Masterjohn

I arrived in Washington, DC on Friday evening to meet with 13,000 other biological scientists for the Experimental Biology 2011 meeting and just got home Wednesday night.  

I was there to give a 15-minute presentation on how I fed an overdose of fructose to a couple dozen rats and it didn't do any of the nasty things I expected it to.  You'll be hearing lots more about fructose from me in the near future as I try to figure out what happened.

One of the coolest presentations I saw was a talk Peter Friedl of the German Nijmegen Center for Molecular Life Sciences gave entitled "Dynamic imaging of cancer invasion, plasticity, and resistance."  This was the first talk I saw of the conference, on Saturday morning.  Friedl showed textbook images of cancer metastasis, which show isolated cells dropping off from a cancer and then making their lonely but merry way to invade other tissues.  Then he showed videos proving it was false.

His remarkable live streaming images showed that cancers actually send forth highly organized finger-like projections like these:

Those bright strands  are highly organized projections made up of individual and continuously dividing cells.  A minority of their expansion is due to the fact that they are traveling forward, led by a small cluster of a few cells or sometimes an individual cell at the tip, while the majority of their growth comes from the fact that they are actively dividing, pushing forward as they do so.

Sunday I gave my own talk and later I was student chair of the fourth Dietary Bioactive Components session, focusing on antioxidant and anti-inflammatory compounds.  Little did I realize that the job of the student chair would be to manage the twitter feed.

And of course there was way too much stuff going on at this conference for anyone to possibly see it all, so check out the #eb2011 hashtag on twitter to find other tweets and blog posts, or maybe search Google.

The best talk I saw was on Monday.  Paul Kubes of the University of Calgary gave a talk entitled "Sterile versus infectious inflammation... an identical immune response?"  Kubes has a hilarious sense of humor, which livened up the talk a bit, but the content was simply astounding.  In his presentation he showed that immune cells called neutrophils respond to bacterial infection by spilling out their DNA to form webs that catch bacteria.  

Here are some neutrophils:

When they are exposed to Staphylococcus aureus, they start spilling out their DNA, shown in green:

Over time, these nets greatly expand:

Through electron microscopy we can see that these DNA-nets form lattice-like webs that catch Staph aureus just like spider webs catch insects:

Other images show that these nets protrude out of a small bubble on the surface of the neutrophil's membrane, kind of like how Spider Man shoots webs out of his wrist.

What was particularly amazing was watching live streaming video of this process, where the denucleated neutrophils could be seen crawling around eating the bacteria they had caught in their DNA-webs.  

Conclusion?  Neutrophils are kind of like spiders.  Err, I guess they are kind of superheroes so maybe they are more like Spider Man.

And man, with all these live streaming photos of fluorescing molecules, who wouldn't want to get into this line of work?  Oh right, I almost forgot.  For a few hundred reasons why no one in their right mind would get into this line of work, check out PhD Comics.

Although, this Lady Gaga rendition sums it up rather succintly:

On Tuesday, I went to a special session put on by the Institute of Medicine's Food and Nutrition Board (FNB) about the new DRIs for calcium and vitamin D.  They focused mostly on vitamin D.  Presenters included the chair of the FNB, Dennis Bier, the director of the FNB, Linda Meyers,  the chair of the committee that wrote the vitamin D report, Catherine Ross, and several other people involved in writing the vitamin D report such as Christine Taylor, Patsy Brannon, and Susan Mayne.

Mayne, a cancer epidemiologist from Yale, discussed a list of what she considered myths floating around the internet and elsewhere about the vitamin D report:

You can click the picture to enlarge it.

And here are the facts, as she saw them:

I apologize the photos are kind of blurry.

Regardless of whether the IOM's FNB got the best estimate of the vitamin D requirement exactly right, I agreed with the gist of Payne's talk.  I got the impression as soon as I started reading the 999 page report that there was an awful lot of misunderstanding about the report and its purpose.

When I'm done reading it, I'll post my analysis on my other blog, Mother Nature Obeyed.

Unfortunately, I missed the Wednesday session entitled, "Exploring the Factors That Impact Blood Cholesterol and Heart Disease Risk: Is Dietary Cholesterol as Bad For You as History Leads Us to Believe?"  The director of our graduate program here at UConn, gave a talk entitled, "Rethinking Dietary Cholesterol: A Critical Review of Existing Lieterature."

She told me the moderated question and answer session produced quite a lively debate.

The best part of the conference was meeting new friends.  I met nutrition journalist David Despain on Saturday night.  Here's a picture of Melissa, David, and me parting at the subway after chowing down on some delicious Mexican food together:

Without love and friendship, science would be pretty boring.

Read more about the author, Chris Masterjohn, PhD, here.


  1. This stuff is fascinating Chris.

    Cancerous finger-like projections? Wild!

    Neutrophils shooting out DNA webs at bacteria... this is better than science fiction.

    Looking forward to hearing your thoughts on the IOM vitamin D report too.


  2. Shou-Ching Jaminet does work on cancer call communication and microtubules (or maybe even filaments) I believe. Fascinating about the spiderwebs!

  3. If the Neutrophils are attacking with DNA webs, where is the Nitric Oxide? Are they a different branch of the immune system?

  4. Cool stuff... A bunch of people from my lab went, but I doubt your talks of interest overlapped!

    I've always wondered how useful rats are for fructose modeling (as well as some aspects of alcohol induced pathology modeling for that matter) because they possess uricase, which humans lack.

  5. Your blog definitely stands out from the rest. I enjoy the unique integration of biochemistry and nutrition that other sources lack, and believe this gives you a more credible foundation to work from. Thanks for keeping us so (scientifically) informed!

  6. The vit D report on the DRI you discussed did consider all (or at least most) of the evidence.

    However, they considered only very birefly (and then dismissed) the best evidence existing that vit D supplementation prevents cancer. That evidence is Lappe's randomized placebo controlled trial finding a 77% reduction in cancer for subjects getting vit as compared to placebos.

    They ultimately dismissed Lappe's trial because it was inconsistent with Trivedi's early RCT finding a null effect of vit D on cancer...

    This dismissal despite:

    1. Trivedi used a 100,000 IU bolus of vit D once per quarter year in a older cohort...

    2. Trivedi's study did not show harm.

    3. Lappe's massive reductions in the incidence of cancer, if true, has the potential to be such a profound game-changer, that it warrants much more discussion than the paragraph they gave it.

    Hard to consider the report fair when they ignore the best evidence, right? Moreover, unless you sign on to the dismissal of Lappe's trial, you really shouldn't support the results of the report in my opinion.

    And, if you do think it was appropriate to dismiss Lappe's trial, I am dying to know why (because I very much value your opinion).

  7. Sounds like a facinating conference.

    Neutrophil extracellular traps (NETs) and their role in capturing bacteria are a interesting discovery. I have not seen them visualised before.

    There was an interesting recent paper showing that statins alter neutrophil function causing them to release more NETs.

    "One remarkable observation to emerge from several clinico-epidemiological studies is that patients receiving statin therapy may experience reduced infection-associated mortality due to pneumonia, bacteremia or sepsis."

    NETs may also be involved in the pathogenesis of the autoimmune disease lupus.

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