This blog has moved!

I am now writing at Dogs on Ice! Go ahead, check it out, and update your feeds!

Photo credit: Herbert Ponting

More cheetah-speed notes

  • Last Friday I attended the “HOT” (Human Origins Topic) event at the Smithsonian, where Dr. Jibril Hirbo and Felicia Gomez gave a talk about genetic variation in african populations and its possible correlation with cultural and linguistic spread. The speakers were very gracious and interesting. I will bring up their papers in a future post.

  • I also bought these three books in the Smithsonian bookstore: The Dolphin in the Mirror (Diana Reiss), The Whale – in Search of the Giants of the Sea (Philip Hoare), and Giant Pandas – Biology and Conservation (collection edited by Donald Lindburgh and Karen Baragona). I just finished reading the dolphin book, and I am very intrigued by the mirror test (a form of testing for an animal’s self awareness) when applied to  bottlenose dolphins. More soon.

 

 

Sci- Halloween Part Deux

I’ve already given a few Halloween costume ideas for the science aficionados, but here’s a few more!

Dress like a Hubble photograph (by Christopher Kane):

Turn your kids into Stegosaurs (Pip and Bean):

Find where the wild things are with a Max outfit (Etsy):

Turn into this dubious Optimus Prime – Supergirl and Captain America had to loan pieces of their costumes – from Amazon: (I am actually embarrassed to post this)

But not too embarrassed to post this:

Ring a bell?

But if you can’t make a trip to the costume shop, or prefer the DIY route, Harrison Krix of Volpin Props has a detailed how-to Big Daddy (of Bioshock), inspired by this:

and following this scheme…

plus 247.8 easy steps (seriously, click on the link, it is unbelievable), and voila:

Easy as pumpkin pie! Happy Halloween!

Lungs in a box – Part II

This is a follow up to the Lungs in a Box story (click here for Part I) and also a collaborative post with guest Dr. Silvana Russo. Quick recap:

On the new season of House, in an episode named “Transplant”, the doctors place the lungs in this plexiglass box, so they can look at it, treat it, make jokes, say their lines, misdiagnose it a few times, harass the patient’s family, etc., before transplanting it into the patient. Here’s the team gathered around the boxed lungs:

And I also told you how that is laughable: an organ for transplant will be cooled in iced bags full of fluids. Outside of the donor’s body, the organ will die, so I showed you the biochemistry behind keeping it alive, as well as practical aspects (rushing it through traffic to deliver it to the patient, or even flying in commercial airlines!).

But that is when I came across this image, of real lungs in a box:

At first I thought it was very hard to believe and thought it had to be a joke. There is even a video of a set of lungs “breathing” inside a box (be advised before you click on it: not for the squeamish):

After a little more research, I found an LA Times article from earlier this year  describing “XVIVO”: a device with the purpose of keeping lungs alive for longer than hypothermia and preservative solutions can.

When consulted on his opinion of  XVIVO, Dr. Airton Schneider, thoracic surgeon and chief of surgery at the Lutheran Hospital in Porto Alegre, Brazil, stated “the lungs are placed in perfusion and ventilation for a few hours, which decreases injury. The results are exciting. It means we can transplant almost in an elective way. There is less rejection and the chance of reperfusion injury is decreased”.

Coincidently or not, XVIVO is part of the research from Brazilian surgeon Marcelo Cypel, now working in Toronto. He published his research results at the New England Journal of Medicine. In the paper, titled “Normothermic Ex Vivo Lung Perfusion in Clinical Lung Transplantation”, the XVIVO device (actually called “normothermic ex vivo lung perfusion”, or EVLP) is used in 20 lung transplants. This new technique can be applied for lungs that could have been discarded due to tissue damage (which  can be repaired while in the perfusion system), and can store it for at least 12 hours at room temperature. The group observed similar results when compared to transplants with conventionally selected lungs. This way, lungs can be kept alive for longer until crew is gathered; can be repaired, and more donors can be used.

There is no mention of cost in this technique. In Brazil, despite shortage in resources, almost all transplants are covered by the universal healthcare system, who pays the hospital approximately 70.000 reais (equivalent to 35.000 U.S. dollars) for a lung or liver transplant (if you think about it, hospitalization due to pneumonia in the US costs “merely” 20.000). This amount covers the surgery, staff, and immunosuppressant drugs. Factoring the XVIVO would undoubtedly increase this cost, but in the other hand would keep lungs alive for longer, and be able to use more donors. Apparently, the system is already in use in the developed world (with the exception of the US, where XVIVO is still waiting for FDA approval).

For Dr. Schneider, XVIVO is “the future, but right now. Imagine removing an organ in one major city, packaging it and shipping to a different city. Then perfuse, transplant, go.”

It seems Dr. House was not so absurd after all. Shame on me.

Lungs in a box

I’ve been always irritated at the level of nonsense in House episodes. I still enjoy the writing, the characters, and many great story arcs (like the one where House is in a rehab facility), but can’t avoid suffering through ridiculous diagnoses and stupid tests. In the “Transplant” episode of the new season, I thought they reached a whole new level of absurdity. I couldn’t find an image online, so I captured a screen shot: lungs in a box.

Dr. House is brought to diagnose lungs and treat them before they can be transplanted. The lungs rest quietly inside glass boxes and they have 12+ hours before the next patients dies. Or something. This image made me laugh. In real life, donor organs are prepared and placed in ice bags inside old storage boxes and hauled immediately for transplant. Organs do not last long outside the donor’s body, so they are quickly cooled to slow down metabolism and extend their lifetime. But placed in a glass box? B-movie type science fiction.

When an organ is removed from a donor’s body, circulation stops and the tissues become deprived of oxygen and nutrients. This stage is named “ischemia” and it is the main cause of injury to the organ tissues. The longer the organ stays ischemic, the more extensive the injury will be. To slow down this process, the organ is cooled to hypothermia, which can also cause injuries. After transplant, function is restored and the blood flow restarted in an event named reperfusion – actually the most significant cause of injury.

Ischemia, hypothermia and reperfusion can each trigger a cascade of events. Most importantly, cellular membrane permeability is increased, which contributes to cell swelling due to indiscriminate entry of several molecules. This completely throw off the chemical balance inside a cell, where proteins and enzymes malfunction; intracellular pH decreases; ionic composition of the cell changes (potassium moves out of the cell and sodium floods in); calcium pours in. During reperfusion, oxygen free radicals are generated, causing cellular injury. Phew, how’s that for a chain reaction?

According to Mukjerjee et al, cooling the organ from 37°C to 0°C slows metabolism by a factor of 12. Besides cooling, the organ is also flushed with a preservative solution, to help counteract the injuries mentioned above, and placed in sterile bag filled with crushed ice. Many preservative solutions have been devised, but they mostly contain a cocktail of substances: osmotic agents (to prevent cell swelling), electrolytes (to regulate osmotic effect), metabolic inhibitors (to suppress degradation of cellular proteins), antioxidants (to capture free radicals) and many others. Studies have shown that, in presence of the Euro-Collins preservative solution (high concentration of potassium, phosphate and glucose), organs last longer than in hypothermia alone.

Unlike Dr. House’s lungs, the storage time (in hypothermia) for organ varies is about 5 hours for heart, 40-50 hours for kidneys; 5-15 hours for pancreas and 6-12 hours for liver. In the case of the lung, Mukjerjee states that “the maximum safe interval for the lung to remain ischemic, even when cooled, has not been defined, but 6 hours is the selected limit, and the longest cold ischemic time was 9-10 hours”.

So you can see how crucial it is to get the organs to patients immediately. Due to short time of organ storage, transplant is an urgent procedure. It then becames a logistic problem, where hospital, surgeons, staff and equipment have to be available and ready to go. In the US and in most of the developed world, many hospitals have their own helicopters or private jets equipped to fly to the donor and bring the organs back. In other places, they are not so lucky.

Dr. Silvana Russo (does this name sound familiar? She is my sister), worked as an anesthesiologist in liver and kidney transplants for Hospital de Clinicas in Porto Alegre, Brazil. Dr. Russo believes a lung has to be transplanted within 4 hours of removal, but the actual limits are unknown: everybody tries to do it as urgently as they can. When a donor is found, surgeons and crew are immediately put on call. The time spent between removal and transplantation then depends on variables as mundane and unpredictable as traffic. (Brazilian traffic is now so bad that motorcycle messengers are the norm. Even firefighters and first responders use motorcycles to escape horrible Brazilian traffic).

For example, a transplant group in St Louis has their private jet with a dedicated pilot. However, the situation in Brazil is radically different: the surgeon himself would go to the neighboring town to pick up the organ, and bring it back in a cooler. (Surgeons prefer to fetch and harvest the organ themselves, in order to avoid removal mishaps: other doctors might cut arteries short, making it difficult to place the organ into a new patient). Dr Russo has heard of a case where a donor liver was available in the Amazon (yes, she means the rainforest, more than 4000 miles away from the hospital). The liver was placed in a cooler and flown in via commercial airline, with the surgeon waiting for it in the airport arrivals.

By now we have imagined the scene: lungs in coolers, being rushed in airplanes and motorcycles. So, lungs resting in a box.. Science fiction, right? That’s when I came across this picture online from Science Daily:

Image from University Health Network

Hoax? Reality? Does life imitate art, or even, does life imitate House episodes? I’ll elucidate that question in tomorrow’s post, where I will also show a video (not for the faint of heart) of lungs breathing in a box!

Update: Part II is posted here.

Forensic Friday

Forensic Fridays, phot by the author

I stopped by the Smithsonian National Museum of Natural History for Forensic Friday, where I talked to paleobiologist David Bohaska. He showed me 6 million year old fossilized vertebra from whales and dolphins. Last Friday’s theme was “Marine debris & ocean life”, and the scientists brought in a few marine mammals (whale, dolphin and manatee) bones, used to speculate the animal’s cause of death. I photographed the bones and injury sites, but I’m not sure yet if I  am allowed to publish the images. The fossils are part of off-the-shelf collections, not available to the general public, so I will need to clear it with the Smithsonian first. Regardless of publishing the photos, I can’t wait to share the stories I heard about those animals lives…

Sci- Halloween

This halloween, you can dress your dog like an AT-AT (by Katie Mello, via Mike):

Go outside wearing your shark’s hat (from the Georgia Aquarium):

Dress your child with the T-rex from Amazon:

Your kids can also match your love for TIE fighter piloting (even though they are too shy to be on camera):

Get yourself a dinosaur, kangaroo or panda jumper from Fred Flare:

And in the absence of a stormtrooper costume, pose with one:

Make your dog miserable and have him pose with you: