1 Nov
2011

Obvious (or not so obvious…) Questions In Science: How do cortisone injections work?

Note: November is National Novel Writing Month! I am hard at work on an oral history/satire of Scientology this year, so if writing here becomes more scant, or shorter, you know why.

In the ongoing saga of my toe, yesterday I got a cortisone shot into the joint. It was neither the least nor the most comfortable experience in my life, but as with any medical incident I end up in, I wanted to know exactly how it worked. So how does a cortisone injection work? What does it do? What is it going to help in my toe?

I was diagnosed with inflammation in the joint as well as a bone contusion. The injection isn’t going to do anything for the contusion, but it will help the inflammation. Cortisone is actually a steroid that the human body produces in the adrenal gland; it gets released, along with adrenaline, when we are stressed. We don’t get injected with human cortisone, however; the stuff that they use is synthetic, and is designed to be longer-acting than natural cortisone.

Cortisone has a lot of usages, as steroids do. There are several ways of taking it; itch cream, for when you get a bug bite, has cortisone in it, but it can also be taken orally or intravenously. I got a small injection right into the joint, myself.

Its function is to suppress the immune system, which ends up reducing inflammation. It does not directly reduce pain (like a numbing agent might). Inflammation is often the cause of pain, because tissue is swelling against itself and causing pressure, which is painful. Now here’s where I’m going to be honest with you: I don’t know how this bit works. I really wanted to find out the chemical processes that make this happen, but type in “cortisone suppressing immune system” into Google and all you get is a ton of woo from acupuncture people saying you shouldn’t use cortisone because YOUR IMMUNE SYSTEM WILL DIEEEEEEEE. I don’t have much patience for that sort of thing, so you’ll have to forgive me.

There is a very, very small grain of truth (that the woo people blow out of proportion) to the immunosuppressant dangers. If you’re immunocompromised in any other way, or have a fungal infection, or another infection, or get a live vaccine (etc), then it is possible that cortisone is going to suppress the immune system further. This is more the case in long-term treatment with cortisone.

To me, the larger danger of cortisone is using it in the wrong situations. There are some things, like overuse injuries, that people get injections for, and continue to get injections for, where the shot doesn’t work. This is mostly because overuse injuries are not always the result of inflammation. Pain is not always the result of inflammation, either, so asking for a cortisone shot whenever you’re in pain is not really the best of ideas, especially if it’s because of something like tendinitis. I would also hypothesize that getting a shot for pain relief without, say, physical therapy to fix the underlying problem would lead to more damage in the long run.

A cortisone injection was a good option for me because at least some of the pain in my toe was due directly to inflammation. The cortisone will reduce that swelling, giving me some pain-free time (during which I am not allowed to immediately go back to my own tricks, damn), and hopefully the inflammation will go away permanently.

The result? Yesterday I was sore from the injection. Today my toe is already feeling a lot better. Hurrah for modern science!

 

NECESSARY DISCLAIMER: I am NOT A DOCTOR. I have had no medical training. My injection was the result of a discussion with my foot specialist doctor, several imaging sessions, and thought. Talk to your own doctor if you have pain; don’t just go in requesting an injection, even if you think it may be inflammation. Talk with several doctors, if you want. But always make informed decisions within the advice of a professional.

 

Sources:

 

http://orthopedics.about.com/cs/paindrugs/a/cortisone.htm

http://en.wikipedia.org/wiki/Cortisone

http://www.drugs.com/mtm/cortisone.html

http://well.blogs.nytimes.com/2010/10/27/do-cortisone-shots-actually-make-things-worse/

29 Oct
2011

Popcorn Science: Week of 23-29 Oct

Tasty links for you to pop and enjoy!

25 Oct
2011

Obvious Questions in Science: How do fish drink?

(site is back up: yay!)

Fish are truly remarkable animals. First off, the question of what a fish is is a pretty tricky one, because fish are defined by what they’re not, namely mammals, reptiles, amphibians, or birds. Secondly, they breathe by doing a direct gas exchange, but only in the region of their gills, unlike water-dwelling amphibians. Anyone who’s had a pet goldfish has watched it swim round, opening its mouth to pass water through, looking like it’s taking big drinks. In all that water, how do fish maintain the proper levels of hydration? After all, everything needs water to survive. How do fish drink?

The answer is: it depends.  Read More »

25 Oct
2011

Late OQIS

I have no idea why, but I can’t access the site from anything but my iPhone. I’m working on getting it back again. Sorry for the delay!

21 Oct
2011

No lit review today

Sorry guys, I am off to guide a climbing trip! Next week!

18 Oct
2011

Obvious Questions in Science: Are all snowflakes unique?

Image from SnowCrystals.com

You may or may not know that I work for a Major Outdoor Retailer. Regardless, in the retail world, winter begins in, oh, August. But being a snowboarder, when they start busting out the boards and skis in my store, I start thinking dreamily of days on the slopes, or gliding through quiet forests. I probably won’t be doing much of it for some time, but hey, a girl can dream!

That being said, let’s talk about the thing that makes winter worthwhile: snow. And let’s all take a moment to pray to the snow gods that we get dumped on this season (sorry, Southern Hemisphere friends!).

Done? Good. Oh wait, I’m supposed to be an atheist. Oh well!

Fight Club says it best: “You are not a beautiful and unique snowflake.” But this begs the question: what is so unique and beautiful about snowflakes, anyway? Is it true that each one is unique? And if so, why? Read More »

15 Oct
2011

Popcorn Science: week of 9 – 15 Oct

Popcorn Science is a compendium of all sorts of cool little sciencey bits I find around the web. They’re small, poppable, and tasty. Have two or three.
Cuttlefish (Broadclub Cuttlefish) - Sepia latimanus - P6042161
(photo by Jan Messersmith)

  • The Ice Age might still be going on inside China’s deepest caves: courtesy of Demosthenes, this is an awesome finding. There are some seriously weird nettles going on in these caves that might be indicative of plant life during the Ice Age. Or they might be completely unique. Either way, nifty nettles!
  • Climate shifts sparked 17th century conflict: yay Wired. Turns out conflict in the 17th century (including plagues, wars, famines, etc) can be correlated to climate shifts. Also turns out the authors didn’t extend their argument to today. Oh well. Still cool.
  • Early paint making found in Africa: really cool stuff. It turns out there were Homo sapiens making paint from ochre 100,000 years ago, a good 40,000 years before any other discovered workshop. It begs the question why we attribute pyramids and stuff to aliens when our own species has done so many cool things…
  • There isn’t an ancient, artistic kraken: at the Geological Society of America meeting this week, Mark McNemanin gave a presentation about how the only explanation for a set of octopus fossils neatly arranged was that an ancient giant kraken artistically arranged them there on purpose. This story got a lot of popular press, but guess what–no plausible evidence. PZ explains it handily, and NatGeo gives credit where credit is due.
  • There aren’t enough cuttlefish in your life, and NPR agrees with me.
  • Pitchers in baseball retaliate more readily in heat, and while more research is needed, one wonders what’s going to happen with global warming…
  • There exists a Dance your Ph.D. Contest, and I’m pretty sure every Ph.D. candidate out there needs to go enter RIGHT NOW.

 

 

 

14 Oct
2011

Lit Review: fish clocks!

(Source article: Cavallari N, Frigato E, Vallone D, Fröhlich N, Lopez-Olmeda JF, et al. 2011 A Blind Circadian Clock in Cavefish Reveals that Opsins Mediate Peripheral Clock Photoreception. PLoS Biol 9(9): e1001142. doi:10.1371/journal.pbio.1001142. Can be found for free here, because the Public Library of Science (PLoS) is a boss.)

Humans have lived under the rhythm of the sun for as long as we’ve been around, in whatever shape we’ve been in. Sure, the advances of modern life and the ability to turn on the lights after dark has messed with this a bit, but ask anyone the day after Spring Forward if they’re still affected by circadian rhythms and they’ll give you a sleepy, grumpy “Yes.”

The cool thing is, there is actually a biological reason that we have a circadian rhythm, which is defined as a rhythmic response to light and dark. Light will activate different triggers in your body that will lead you to be more awake; lack of it will shut those triggers down and make you go to sleep. This is why you shouldn’t watch TV before bed.

So what happens when you have an organism that has evolved for millions of years with no light at all? What happens to those triggers, and to the rhythm they engender? Enter the cavefish. Read More »

11 Oct
2011

Obvious Questions in Science: How do MRIs work?

I happen to be injured right now, a story in its own right, but not the point. So this morning I woke up early to go get an MRI. This is the third time I’ve had one, and they’re always accompanied by a long questionnaire on your health history, especially any contact with metal. When you get an MRI, you have to lie very still for at least 30 minutes while the machine works, giving you a lot of time to wonder how this damn big contraption surrounding you works, what all the loud banging noises me, and, if you’re me, singing to Bohemian Rhapsody.

When you get an x-ray taken, a beam of high-energy photons (x-rays, with wavelengths of .01 to 10 nanometers, much shorter than visible light) is shot at the part of your body you’ve hurt. X-rays penetrate flesh but reflect off bone, making them ideal for imaging broken bones. X-rays can also do damage to your DNA if you’re exposed to too much of them, but the amount used in imaging is perfectly safe.

Sometimes, though, the injury isn’t in the bone: it’s in some part of the soft tissue, which an x-ray can’t show. This is where MRI, or magnetic resonance imaging, comes in.
The MRI Machine is part of an equipment grant program to the VMMC that started in 2003.
(Image by US Embassy in Manila)

An MRI machine is comprised of several parts. The whole casing is basically a huge magnet, one strong enough to generate a stable magnetic field. Most MRIs use a superconducting magnet, which is essentially a giant electromagnet. Let’s flash back to high school science for a second: passing a current through a coil of wire will produce a magnetic field (just as passing a magnet through a core of wire will produce an electric current—this is how stoplights know you’re coming). The wires in an MRI are supercooled by liquid helium—the colder the wire, the better the conductivity, and the stronger magnetic field the device can produce. There are also smaller magnets involved, called gradient magnets, which can produce variations in the magnetic field to allow different parts of the body to be scanned. The final component involved are the coils that you put whatever part of your body you’re scanning into; these transmit radiofrequency waves into the body.

Pop quiz: how many protons does a hydrogen atom have?

If you answered one, you’re right. Hydrogen is key in imaging with an MRI. There is a ton of the first element in our bodies, mostly because we’re made of a lot of water and fat. When you put hydrogen in a magnetic field, it aligns with the direction of the magnetic field. Normally, the hydrogen atoms in your body are just chilling, out, spinning whatever way they please. When you’re in an MRI, most of the protons in the hydrogen atoms in your body will align in one way or the other, pointing either up toward your head or down toward your feet. In fact, a huge fraction of them will cancel each other out: for each proton pointing toward your head, there’s one pointing toward your feet, and vice versa. However, there are a few—enough to image with—that don’t get canceled out.

These protons are what we’re looking for. The machine next applies a radio frequency specific to hydrogen, which makes the hydrogen atoms spin in a different direction again. In conjunction with this, the gradient magnets are used to pick out a really specific part of the body—a slice, if you will—by changing the local magnetic field. This allows for really precise imaging, which is super cool. When the radiofrequency pulse is turned off, the hydrogen protons will realign with the rest of the field, and in the process of doing so, they release the energy they absorbed from the pulse. This energy radiates back into the machine, and from this we get an image. The energy the machine receives back tells the machine what type of tissue it was in—any abnormalities are going to put out a different frequency than expected. The signal is received as mathematical data, which is put through a Fourier transform and translated into an image—essentially, frequencies are translated into the picture we see.

And that noise? That comes from the current in the gradient magnets opposing the main magnetic field. Most of the time they give you headphones with music. Hence my Bohemian Rhapsody singalong. I figured the technician couldn’t hear it over the noise, anyway.

If I’m given a copy of my MRI images, I’ll be sure to post them here.

 

Sources:

http://en.wikipedia.org/wiki/X-ray

http://en.wikipedia.org/wiki/Electromagnet

http://en.wikipedia.org/wiki/Fourier_transform

http://science.howstuffworks.com/mri.htm

7 Oct
2011

Lit Review: Black bears and minivans in Yosemite

(Source article: Stewart W. Breck, Nathan Lance and Victoria Seher (2009) Selective Foraging for Anthropogenic Resources by Black Bears: Minivans in Yosemite National Park. Journal of Mammalogy: October 2009, Vol. 90, No. 5, pp. 1041-1044. Available for free at USDA.gov)

Alternate title: children are bear bait (just as we’ve always known).

It turns out you shouldn’t drive a minivan into Yosemite.

Black bears are resourceful animals, and can figure out a great many ways of breaking into things to get the food they want. They forage selectively, picking and choosing their meals to maximize energetic gains and minimize foraging costs. This is a natural behavior, but it’s also one that gets enhanced in proximity to humans.

Black bears also happen to live in Yosemite. Humans have loved coming to Yosemite National Park for over a century, and with little wonder: it’s a beautiful, beautiful place.

Yosemite Valley, Yosemite National Park

(image by K. Moore)

There has been ongoing conflict between humans and bears in Yosemite for as long as humans have been visiting, and it’s a real problem. A big priority for officials in the park is nonlethal management of bears. There are efforts to educate people and penalize them for breaking the rules, of course, but we can all think of instances where this has flat out failed completely.

Black Bear

(image by torhutchins)

Do you see how close that person in the background is to this bear? Not only is this breaking the rules, it’s REALLY, REALLY DANGEROUS.

All bear incidents are documented by the National Park Service. This gives a pretty nice database with which researchers can work. So Breck et al decided to look at selective foraging of vehicles by black bears, to see if one vehicle was preferred over another.

It turns out that over a period of 6 years, minivans were the vehicle of choice for black bears, coming in 1st or 2nd place for break-ins each year. In fact, they sought out minivans moreso than they did other cars, even when minivans weren’t the most available vehicles. The question is, why?

There are lots of possible reasons for why black bears selected for minivans, and it could be a combination of any of them. But here’s my favorite, in the words of the author:

[I]t is possible that minivans were more likely to emit food odors regardless of whether they contained meaningful amounts of food available. This argument is based on the fact that minivans are designed for families with children and small children in particular are notorious for spilling food and drink while riding in vehicles. Thus, vehicles transporting children would emit greater food odors, making them attractive to bears.

This is the point where I wrote “I love this author” in the margin. Of course, as they point out, this would mean that any vehicle transporting children would be targeted more by bears; this would make for a really interesting further study, I think.

Another possibility is that owners of minivans might for some reason be more likely to leave food out, despite rules to the contrary. My theory is that this has to do with them corralling their children and not focusing on what they should be doing. Otherwise, it might be that minivans are easier to break into structurally, or that this might be the learned behavior of a few bears.

Regardless of the reason, the management implications here are really interesting. I’m not suggesting that Yosemite National Park exclude all minivans from entering; on the contrary, that would probably force the bears into choosing their next most selected vehicle, the SUV. But it could focus education efforts more effectively–maybe vehicles carrying families, like minivans do, need extra education and perhaps extra enforcement as well.

I liked this study a great deal: it was very approachable, interesting, a bit humorous, and relevant. The implications for management and further study are strong, and I really look forward to seeing what is done with this information, or at least where it leads.

Then again, child-free days at the park sound pretty good, too.

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