Mosquito Profiling?

mosquito_sick

Observe, the enemy!

So I feel a little awkward asking you this but…do you often have this feeling you just can’t shake that someone, somewhere is out to get you? Does it seem like trouble follows you wherever you go? I know your friends and family think you’re paranoid (I’ve heard them talking) but listen, I believe you. There is an ancient evil lurking in the shadows that is out to get all of us and it is a fraction of a centimeter in size. That’s right, I am talking about mosquitoes, the phantom buzz in your ear that wakes you on summer nights, those bite-sized bio-terrorists that have spread disease over the millennia. I know what you’re saying, “what does this have to do with physiology? Have you been drinking?” No, but thank you for asking. The truth is some of us DO get singled out by these tiny demons more than others. What is it about us that draws them to us like…little old ladies to a yard sale…no wait, like a wrestling team to half-priced burger night? Let’s talk some physiology!

Know the Enemy

Once upon a time called 170 million years ago a family of tiny flies (Culicidae) made a bold, annoying, adaptive leap in their evolution. It discovered an inexhaustible, readily accessible food source, human blood, and they’ve been tailgating our cookouts for as long as we’ve been drawing doodles on cave walls. That’s right, they are flies, meaning that they have an additional set of modified wings along their metathorax (oh, you care). Of course, there are more species of mosquito than YouTube Harlem shake videos but one characteristic they all seem to share is that the females are the blood drinkers. They have hungry mouths to feed after all, hundreds of tiny eggs that they can lay on the surface of still, stagnant water. Their versatility is our problem. Mosquito larva are aquatic and don’t require large ponds to spawn. In fact, their breeding sites can range from ponds to plastic kiddie pools, to a neglected paint bucket left out in the rain. The point is mosquitos are opportunists who will go after the easiest meal they can get and let’s face it..we’re pretty easy.

But why me?!

Oh if you want theories I’ve got theories, but how about we stick to statistics for now. They seem to prefer pregnant women, obese individuals, and adults over children. Mosquitoes are tiny beings flying around in an enormous space. They use their sense of smell, sensitivity to movement, and Jedi mind powers (aka unknown factors) to detect our body heat, movement, and CO2 production. Adults produce more CO2 and conserve more heat than children. Of course, some people naturally have higher body temperatures and children are constantly in motion so it really depends on who is hiking with you. Pregnant women also produce more CO2, their body heat spikes, and they have an increase in the amount of circulating blood. Mosquitoes also love us after a good workout. They have a demonic sense of smell and many compounds such as lactic acid are excreted in our sweat that draw them in like a terriyaki
marinade. Our body heat also spikes when we workout but I didn’t have to tell you that.

Picky Eaters?

They also seem to have a preference for blood type. People like myself with type O blood are far more likely to get bitten (mama told me I was special). If you’ll recall, type O blood cells lack the surface antigens A or B. The absence of those antigens or “O” is how it get’s it’s name. Why don’t you meditate on that for a while.
Studies have also shown that blood cholesterol levels are a factor which is just another reason to skip that drive-thru on the way home and stick to your New Year’s resolutions…that’s right, we all heard you.

Stay curious, stay classy, and never stop learning my friends 🙂

 

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Fun Facts – Last Call

beer glassesHappy Late Patty’s Day everybody! If you’re town was anything like mine, you’ve probably seen your fair share of blissfully intoxicated co-eds in electric green t-shirts, shiny green beads, and glazed over smiles, glittering the local bar patios like grass clippings. Speaking of blissfully intoxicated…

What do yeast, fruit flies, and human beings all have in common? We can all hold our alcohol. More accurately, we each come equipped with our very own alcohol dehydrogenase enzymes that allow us to convert that toxic, nasty ole alcohol into more user-friendly byproducts that our cells can use.

In case you didn’t know, alcohol is toxic to the body. [That’s right, I’m looking at you, Ethanol…I haven’t forgotten about New Year’s!] Not only do our bodies have no real nutritional use for it (which is why you won’t find it in your Flintstone vitamins) but when set loose in the body it can sabotage our organ systems one by one.

speed-bomb-diffusion

this is how I feel trouble-shooting my high-speed internet

Luckily, we have a generous helping of miracle-working, alcohol converting enzymes in our liver and stomach to soften the blow. We actually have 3 different enzymes in our anti-alcohol arsenal but the vast majority of the damage control is carried out by that smooth talker, alcohol dehydrogenase. These 80 kilodalton molecules step in like a bomb squad to disarm the alcohol molecules by stripping away their hydrogen atoms (that’s why we call them de-hydrogenases). This converts them into acetaldehyde, but we aren’t out of the danger zone yet. The acetaldehyde (close cousin to formaldehyde) is even more toxic than the alcohol we started with. Not unlike disarming a bomb (like I’d know) just because you snipped the red wire doesn’t turn the C4 into pound cake. What is left still packs a
punch. The acetaldehyde gets converted further into acetic acid radicals (acetic acid gives us vinegar). Alcohol dehydrogenase joins those nasty radicals with Coenzyme-A molecule to form happy little Acetyl-CoA molecules that our cells can now use in their metabolism.

Yes I do love a happy ending, but just because a few fancy-pants liver enzymes allow us to convert ETOH (alcohol) into useful cellular byproducts doesn’t mean we can go out chugging margaritas like protein shakes. Be safe. Hey, look at me….I care.

Stay curious, stay classy, and never stop learning my friends 🙂

Medical Marvels – the Bayer facts (see what I did there)

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First a little history…

The story of Aspirin is an old one. I know you’re probably tired of

giving credit to the ancient Greeks for every little thing just

because they wrote everything down, but as early as 5th century B.C.

good folks like Hippocrates, in their flowing togas were describing

miracle pain relieving powders made from ground willow bark. Now let’s

fast-forward to the 18th century where scientist representing three

corners of the globe were playing around with salicin, as if it were

an Olympic sport. First a German named Johann Andreas Buchner

identified the compound salicin as the active ingredient to that wacky

Willow powder I mentioned earlier. Back in France, Henri Leroux was

figuring out ways to produce larger, biggie-sized quantities of the

compound. The cool kids (scientists) figured out along the way that

salicin gets it’s medicinal potency from being converted into

salicylic acid (its metabolite) by the body. Though this form can also

be found in plants a crafty Italian by the name of Raffaele Piria

would later figure out a way to convert salicin to salicylic acid in

his lab.

Turning down the volume….

I won’t bore you in this article with feedback mechanisms (I’ll bore

you in another article). Let’s just say that for many of the chemical

signals that our cells produce there is usually a mechanism to

interfere, inhibit, or amplify that signal. In the case of pain our

body really wants to get that message across loud and clear. There is

a family of cellular messengers called prostaglandins that, among other

things, switches our neurons on to pain. The enzyme cyclooxygenase

(COX-2) increases the production of these pain happy molecules during

inflammation. Salicylic acid blocks the expression of COX-2 (as in

it’s gene expression into protein). It’s kind of like throwing water

over the logs so the fire never gets a chance to start.

The trouble with Sally is…

Despite its magical pain relieving and anti-inflammatory properties,

salicylic acid could be pretty harsh on the stomach lining. In fact, a

lot of people suffered from intestinal bleeding after taking the

powder (Now that’s harsh). Along comes this hot-shot chemist out of

Germany, Felix Hoffman who decides that it’s the “acid” portion of

salicylic acid that’s the problem. After performing a little

biochemical black magic (Adding an acetyl group like acetyl chloride

to the compound to take the edge off a little) Felix produces a more

user friendly compound that his employer Friederick Bayer & Co would

later market as “the wonder drug.” When the biochemical nerd dust

settled we were left with Acetylsalicylic acid (ASA), or Aspirin.

Stay curious, stay classy, and never stop learning my friends 🙂

Me Talk Pretty – Cross extensor reflex

That’s right party people we’re not done. You get two zesty physiology terms relating to the body’s response to pain for the price of one. Now that’s a value! Ok maybe I was just too lazy to include this one in our last brief chat about pain. I’m only human. Don’t make it awkward (I can feel you judging me and it’s so cold).

Well in addition to our lighting quick withdrawal from pain (NFR) orchestrated by sensory neurons, interneuron connections, and the spinal column, our body takes counter measures to maintain balance and stability. That’s right while one foot dodges sharp objects the other foot plants firmly on the ground to keep balance. Like the withdrawal reflex, this occurs within a fraction of a second as well. It is an opposing process. While flexor muscles on one side contract (for example hamstring muscles on the side of injury) the extensor muscles on the opposite side relax (quadriceps of the supporting leg relaxes to fully extend and support the weight). Once the pain receptors on the effected side are triggered by a pain stimulus (broken glass, sharp nail, etc) that signal flows down the sensory neuron like telephone wire to the spinal chord. From there the signal crosses over to the opposite side of the spinal chord to an excitatory interneuron. An alpha neuron takes it from there to its final destination, the neuromuscular junction controlling the extensor muscles in the opposite leg. This allows the weight to be evenly distributed to the support leg thereby taking pressure off of the injured side, minimizing further injury. I love a happy ending.

Stay curious, stay classy, and never stop learning my friends :-)