Tag Archives: Biology

Medical Microfiction: Stromatolites

The architects that built the world are long gone. Many aeons ago, they lived, labored, and died in mats in the shallows. Their offspring, architects also, plied the family trade atop the graves of their forebears, until they too passed. And so one biofilm atop the next, strange, striped stones emerged.

We remember them for the rocks, but the architects left something greater still. Together those venerable microbes spun sunlight into atmosphere, shaping the very air into the element which gives voice to speech and song.

We stand not on the backs of giants, but on the bones of bacteria.

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English: Stromatolites growing in Hamelin Pool...
Stromatolites: they’re rocks, but they deserve a little respect. They oxygenated the atmosphere! (Photo credit: Wikipedia)

Stromatolites are not technically “medical”, but they’re certainly a nifty piece of science, and one I was dying to share with you! First, let’s dissect the word. “Stroma” comes from a Greek word meaning mattress  or bed. “Lite” comes from the Greek for stone. As the story describes, stromatolites are fossilized stones that were formed by thin layers of bacteria dying off atop one another over a huge period of time. Think of them as something like coral reefs, but far older.

One of the most important ancient sources of stromatolites were the cyanobacteria responsible for transforming much of the methane in Earth’s atmosphere into oxygen, thus allowing creatures like ourselves to live, love, and breathe. We owe a lot to these little guys, and I wanted to take a moment to remember their inestimable contribution to our lush, green Earth. Those of you who have been reading my blog from the very beginning may recall that I’ve mentioned the Great Oxygenation Event once before, but I thought they were interesting enough to bring up again. I think it’s important to remember that while human beings dominate the planet now, all our accomplishments rest on the shoulders of those that did the work before us. Even the air we breathe is something to be grateful for; it came from somewhere.

What other parts of the natural world deserve our gratitude? What tends to get overlooked in our day-to-day shuffle?

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Medical Microfiction: Multicellularity

The Multicellularity Defense

The papers called Eddie the “Monsoon Killer” because he liked to bathe in the blood of his victims.

Really. He had an extra hot tub installed just for that purpose. At five quarts of blood per person, he racked up quite the headcount.

Eddie spent 10 years in lockup while they tallied the bodies.

Just what he wanted.

Court Day arrives, and in strolls Eddie. He denies none of the evidence but claims innocence anyway. Calls it the Multicellularity Defense: “We’re just made of cells, and cells don’t live long. All my guilty cells are dead. Therefore, you must acquit!”

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Cell Biology
Cells all on the same team. (Photo credit: ex_magician)

You probably know today’s word, multicellularity, but do you ever stop to think how dang strange it is that we’re walking colonies of cells? And that these cells are always dying off, and yet somehow we don’t completely lose our sense of identity when they do?

Most life on Earth gets only one cell to live. For the bacteria, archaea, and protists among us, life begins with one cell and ends when that cell dies. If you’re lucky, you get a chance to divide before that happens, thereby passing on your genes to the next generation.

Multicellular organisms like ourselves get to live longer than that. If one cell dies, it’s not the end of the world. We go on. Most of the cells in our body get replaced on a rolling basis depending on the cell type. Red blood cells kick along for about four months, while skin cells get a few weeks to live. The nerve cells that make up the brain have the longest lifespan, and can last up until your death.

That means it’s only fair to convict Eddie’s brain of the crimes. Don’t punish the poor, innocent epidermis though!

As an added Easter Egg, did you guys catch the reference to the Chewbacca Defense at the end there? You must acquit!

Medical Microfiction: Keratinocytes

The Little Dutch Girl

“We’ll draw straws. Long straws stay. Short fixes the hull.”

“Sounds fair.”

Olga proffered a fistful of sticks to her crewmates. Hal, Zarina, and Ken drew one apiece. There was a sharp intake of breath as they opened their palms.

Olga grimaced. “Guess it’s me. Let’s roll. We’re losing oxygen.” She stepped over the airlock threshold. She scanned the area and gasped in surprise. “Wait. Where are the tools? Where’s my space suit?”

“Sorry, Olga,” said Zarina.

The airlock whooshed shut.

Hal shut his eyes as Olga’s body, distorted by the vacuum of space, plugged the breach in the hull.

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ISS science officer and flight engineer, astro...
When you go outside the airlock, don’t forget your space suit. (Photo credit: Wikipedia)

If I were a cell in the human body, I think one of the most miserable work environments would be the epidermis, also known as your skin. Your skin’s your body’s biggest organ, and one of the most important ones. It keeps the bad stuff out and the good stuff in and represents the boundary between the body and the environment.

Given that important role, it’s still a raw deal to be a keratinocyte, the type of cell that makes up 95% of the epidermis. Keratinocytes are born deep in the basal layer (the stratum basale) of the skin. There they spend a short childhood multiplying before they’re shoved upwards toward the surface of the skin. As they rise in rank, they’re cut off from the nourishing blood supply found in the deeper layers. Eventually they die off and are packed full of keratin, which hardens them and makes them waterproof. By the time they reach the surface of your skin, their dead bodies form a tough, waterproof wall that keeps all the living cells in your body protected from the outside world.

Keratinocytes are born to die. It’s a heroic deed, yes, but still a raw deal. Much like being thrown out of the airlock to plug the breach in the hull.

In case you’re not familiar with it, the title and inspiration for this story comes from an American folk tale called The Little Dutch Boy. In this story, a young boy becomes a hero by using his finger to plug a leak in a dike. Of course, the big difference between the boy of this story and keratinocytes is that the boy got to choose his fate!

Medical Microfiction: Apoptosis

Mother Knows Best

Mike mimicked his mother’s tremulous voice: “‘Be safe. Call me the moment you get there.’” She must think he’d jump off a cliff if she didn’t mention safety to him. He stomped the accelerator. And why did he have to phone her, anyway? The ritual was so superstitious. As if not calling would break some spell.

He seethed with teenage rebellion. So when he reached the theater, Mike conveniently “forgot” to call his mom. Minutes passed. He was halfway across the parking lot when he dissolved with a pop into a squirming heap of frogs, snails, and puppy tails.

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Apoptosis: a cell suicide program. (Photo credit: Futurama)

Why do cells die? It sounds like an obvious question. All things die eventually. But why do cells die, if they haven’t been traumatized or diseased? The answer lies in apoptosis, which is the medical term for programmed cell death. Every cell in your body comes with a “use-by” date of sorts, a built-in suicide program. When the proper signal reaches the cell, it self-destructs, and its parts are recycled by your body.

Today’s story illustrates one way apoptosis might occur. For Mike, a phone call to his mom acts as a signal that it’s not Apoptosis Day for him. If he doesn’t make the call, the process is interrupted and he self-destructs into his raw materials.

And as we know, boys are made of frogs, snails and puppy tails.

Apoptosis sounds like an awfully violent process at first. I don’t relish the idea that my cells are exploding willy-nilly when I could still get a little more mileage out of ’em. But it’s better to think of it like leaves dropping off a tree. Sometimes you just need to shed cells when you’re done with them. In fact, that’s what the word literally means: “dropping off”, as of with leaves.

The effect of lack of programmed cell death (S...
The effect of lack of programmed cell death (Specifically apoptosis) on the toes of a human. A mutation caused the middle two toes to remain connected. (Photo credit: Wikipedia)

This regular suicide program serves an important function in the body. When cells age, mutations are more likely to occur, which would then be passed to the next generation of cells. In fact, when a mutation occurs that prevents a cell from undergoing apoptosis, it often leads to mutations, cancer, and autoimmune disease. The immortal cell starts multiplying like crazy, and will not respond to the body’s signals to stop.

Interestingly, chemotherapy works because it forces the target cells to self-destruct. It makes me think of ninjas breaking into a fortress at night to administer poison to the bad guys.

Moral of the story: listen to your mom.

Was/is your mom much like Mike’s? What’s the best advice you’ve gotten from your mother, or someone in your life who’s like a mother?