The Sweetest Thing

gene wilder willy wonkaWe need sweetness. Yeah, you heard me (well you hear me in your head). I’m not here to bore you with another article about why sugar is bad for you. We get it. As an information saturated society we know more about nutrition today than any other time in the unabridged history of the human race. Yes, sugar is bad for you BUT we still need to sweeten things from time to time. We have evolved taste buds on our tongues for sweet things. Every culture on the planet, from the bleakest deserts to the darkest rain forests, eats sweets. So when sugar is no longer lead singer on the sweetener stage who do we turn to?

Let’s get artificial! 

The term “Artificial sweetener” has always bothered me for some reason. It just makes it seem as though we are lying to our tastebuds but the only lie is in thinking that sugar is the basis of our perception of sweetness. Sweetness is in the brain. To understand sweetness think about locksmiths. Yes, every lock needs the right key to open it. A chemical doesn’t have to be  table sugar ( C12H22O11 )to have the right molecular structure to unlock our taste buds.

Pictures-of-the-tongue-and-taste-buds

Taste buds, making flavors known for more than 165 million years

A word or two about taste receptors…

The many protruding papillae structures on the surface of our tongue contain receptors that constitute our infamous taste buds. All of these protrusions create a massive amount of surface area around the tongue, providing many points of contact for the foods entering our mouths to make their flavors known. These taste bud receptors have a direct line to the gustatory (feeding related) areas of the brain where we interpret and experience those tastes. Just like sight and smell, taste is largely in the brain. This is why the smell or taste of fresh baked cookies or whatever can conjure up vivid memories of a time and place (rolls from the oven make me think of Grandma’s house).

Humans have big ole brains and those brains are powered by calories. Yes it takes calories to power the brain (roughly 20% of our total intake at rest) just like any other organ in the body. Sweet things tend to have a lot of calories. So it would make a lot of sense that, calorically speaking, sweet things would be so appealing (I see you over there cinnamon roll. How you doing?) What if the pleasure we get from two scoops of ice cream is really a deeply rooted feeling of security that we’ve met our body’s caloric demands?

Saccharin how do you do it?

C7H5NO3S or Miss Jackson if you’re nasty…

When I say “artificial sweetener” do you think of little, bright pink packets? It’s ok, we all do. Saccharin (commercially known as Sweet n Low) has been cluttering breakfast tables like confetti for decades but has been in use for more than a century. Of course saccharin meets and greets the same taste receptors on our tongue as table sugar but it’s 300x sweeter per serving. Where does it get its mutant flavor powers?It’s not fully understood but part of the answer is solubility my friends.

In order for us to taste anything, some portion of that substance needs to dissolve in water so that a sample of it’s molecules can shake hands (on the molecular level) with our taste buds. Saccharin in the form of a salt (sodium saccharin) dissolves in water like a champion and thanks to it’s shape, the molecule has a high affinity for the taste receptors on the tongue. I mean where sugar shakes hands with our taste buds saccharin goes in for the long, awkward hug.

hugs

Yeah…Saccharin is “that guy.”

BUT…. is it safe?

Gandalf-2You just had to ask that question didn’t you? To be honest (always) the topic of saccharin toxicity is a murky one. It has been investigated more than some organized crime bosses. There are definitely concerns about sodium saccharin’s toxicity. In some laboratory trials high doses of saccharin have been linked to bladder cancer in test rats. Now please keep in mind that they were testing lab rats and not humans. We are yet to find definitive proof that saccharin causes cancer in humans. It was for this reason that saccharin was removed from the U.S. National Toxicity Program’s Report on Carcinogens in 2000 where it had been listed since 1981. Also, the rats in those studies received high concentrations of sodium saccharin. They weren’t casually sipping Crystal Light after working in a few laps on the hamster wheel. For the sake of a toxicity study researchers are looking for toxic effects. So they test and test and test until they find some. A researcher measures those effects at different concentrations under a variety of conditions. In contrast, the amount of saccharin in your packet of sweetener was only intended to make that cup of old, burned coffee easier to drink while you wait for your car at the Jiffy Lube.

So no, I’m not here to defend the little pink packets (though I will accept cash or personal checks if they would like me to.) You will simply have to use your own judgement. However, I will leave you with this thought…

Can a substance that contains no calories or nutritional value still be considered food, and if not, why are we putting it in our mouths?

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

Me Talk Pretty – Hypnic Jerk

Soul-Train-Dancers2_Soul-Tr

One day I will grow the Soul Train afro of my dreams.

Pre-season’s greetings my fellow information seekers! No no, I’ve missed you more. We’re shining this week’s E-Hollywood spotlight on the “hypnic jerk”. While it may sound like a funky, dance from the 70’s, it describes a far more psychedelic physiological phenomenon. Can you dig it? I knew you could.

When I first heard about the “hypnic jerk” I was…

17 years old or so, nodding off in statistics class to that dream where I’m giving my Nobel Prize speech and no one in the audience is laughing at my jokes because I’m not wearing any pants. Anyway, in the dream the floor of the stage suddenly collapsed and I fell into this bottomless pit of my subconscious. At that very moment I was in fact sliding out of my desk. My arms and legs flailed wildly, like a cat trying not to take a bath, knocking my textbooks onto the floor and waking me from my pants-less slumber. What I didn’t know then was that this phenomenon is actually experienced by many people (the falling feeling, not the no pants thing).

Hypnic Jerk

kick2

The Mayo Clinic recommends not taking naps near the Jacuzzi.

In the movie “Inception” (kick-ass movie btw) they refer to it as “the kick,” that moment while asleep when the sudden sensation of falling jolts you awake. Most of us have experienced this at some point and the feeling is anything but pleasant. What I experienced that day in high school was actually a rare scenario of dream incorporation.

The funny thing about R.E.M. is…

You may not know this but during the surprisingly brief stage of R.E.M sleep, where all of our dreaming takes place, your body is temporarily paralyzed. It’s quite normal, and when you think about it, evolutionarily advantageous not to be able to act out your dreams. Otherwise, we would be jumping out the window every time we’re chased by zombie hordes in our sleep. In fact the only motor function that doesn’t seem to be impaired during this stage of sleep is our eye movement. This is how the R.E.M. stage or rapid eye movement gets its name.

Of course, the line separating the dream state from the waking state is notoriously blurry and it is proposed that the hypnic jerk phenomenon occurs during that awkward intermediate stage where the region of our (brain beneath the cortex) most active when we are awake intrudes on our sleepy-time region of the brain (ventrolateral preoptic nucleus, or VLPO) that manipulates our sleep. I will affectionately refer to this region of the brain as “Vilpo” that’s right,…Vilpo Baggins.

Stay with me this gets interesting…

The VLPO region of the brain is practically next door neighbors with the optic nerve (anterior of the hypothalamus). Why so close? The theory is that during the day Vilpo is busy collecting information from our eyes about light levels (time of day) and it uses this solar sense of time to direct our sleep cycle. Yeah..sounds good, but more importantly it is neurotransmitters like serotonin and adenosine that activate the VLPO. These crafty neurotransmitters accumulate throughout the day until they reach a concentration that causes us to turn in for the night. While we sleep the VLPO releases it’s own neurotransmitters that inhibit the neurons that are most active and frisky when we’re awake so that we can stop being so frisky and get some rest. So neurotransmitters encourage sleep and neurotransmitters keep us asleep.

Sleep is not passive. To sleep and to wake means that there is always some element that must actively be kept under control. 

While we are awake the VLPO is inhibited by opposing neurotransmitters. When we are awake our reticular activating system, R.A.S is awake. This region of the brain is BFF’s with the cortex, hypothalamus, and cerebellum which control basically every conscious and semi-conscious thing we do (walking, eating, SEX, etc.). So one cluster of neurons inhibits another cluster of neurons in a daily battle of sleep and wakefulness where both sides win and both sides lose.

So here’s the deal…

Hypnic jerks seem to occur as a kind of involuntary hiccup of motor control during the crossing over phase into sleep paralysis. The mechanism behind this is still poorly understood but it is the last gasp of waking motor function. It is a paradoxical, involuntary muscle reflex (Myoclonus) and it is pretty common in healthy people. We do know that these episodes can be triggered by persistent stress and anxiety, which is never good. It is also indicated that strenuous activity throughout the day can trigger an episode. It may sound paradoxical but you can actually be “too tired” to get a good night’s sleep and you can cheat your body out of its natural progression into the stages of sleep by being either too exhausted or too wired before you cut out the lights.

Let’s say you let 6 hours of YouTube videos play on your laptop while you typed up a research paper, opened 20 website browsers, and then shut your computer without shutting anything down. It may sound like a lousy way to treat your computer but we do it to our brains all the time…we don’t “go to bed” we just slam our laptops shut without “shutting down” first.

Hypnic Jerks seem to serve as a haunting reminder of the gaps in our understanding of the mechanism of sleep.

Human beings make straight lines and sharp angles. Our buildings have perfect triangles, solid walls, and mathematically proportional rectangles and squares. We believe in boundary lines and cut off points but the human brain itself, with its mosaic of soft tissue and blood vessels, is not confined by the same boundaries. You have to consider that perhaps no one portion of the brain is designated strictly to sleeping or waking but that these two states of consciousness are far more intimately connected, perhaps even dependent on each other. The phenomenon of sleep could be nothing less than an infinitely complex culmination of subtle details and relationships within the vast landscape of the brain.

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

Secret Life of Yawns

coffee_dogs_yawns_1440x900_63105

9 out of 10 Beagles prefer French roast

I have to be honest with you my friends, after many hours of extensive research (2 whole hours) I just can’t wrap my head around this topic. I’ve flipped through page after page of neurophysiology, human anatomy & physiology, and re-runs of Bill Nye the Science Guy. All the while this topic mocks me from across the room, laughing and pointing at me while I stand vulnerable with my intellectual fly open. Yes my friends, the question of why we yawn is quite the physiological puzzler. So allow me to share what I’ve learned so far.

PANDICULATION! (get your minds out of the gutter…I was here first)

Pandiculation refers to the act of yawning and stretching at the same time. It’s that moment we’ve all witnessed when a dog first wakes from his nap. They’ll stretch out onto their paws in that awkward straddle that always reminds me of yoga on stilts. They then open their jaws impossibly wide and yawn. We may not be as cute as our fury friends when we do this but all the tell tale signs are there. Also, have you ever noticed how unsatisfying a yawn without stretching is? In fact, it is suggested that this is one of the main advantages of this activity. What other involuntary responses to stress, fatigue, and boredom do you know of that simultaneously stretch your jaw, tongue, throat, and eardrums aside from dry heaving?

So what does yawning do for us?

Here’s where the theories rear their ugly, wishy-washy heads. As you know, it has always been my mission to give you the facts – raw, unfiltered, with no artificial fillers or sweeteners, but surprisingly, there are more theories on this subject than Rihanna has hairstyles. So here are my top 3 favorite explanations:

Theory #1 – Increased CO2

This charming little theory has been circulating like an urban legend for eons. It suggests that yawning is triggered by a shift in the concentration of CO2 in the blood. Remember that breathing is a kind of constant exchange of oxygen for CO2 and it is just as vital to rid the body of the CO2 generated during the daily metabolism of our cells as it is to take in oxygen. So the idea that the sudden and deep inhalation of air taken in during a yawn is the body’s way of self-regulating for these shifts makes perfect sense to me.

Upon experimental investigation with test subjects however, increasing oxygen and reducing CO2 seemed to have no measurable effect on the incidences of yawning. Sorry CO2, you can take away our polar caps but not our right to yawn.

Theory #2 – Brain Temperature

This theory suggests that yawning is a means of cooling off the brain. As a fan of Sci-fi I dig this explanation because I like to imagine the brain overheating like a high-tech super computer developed in a secret government lab. So in order to keep our test tube, android bodies from nuclear meltdown we have to yawn occasionally.

So it’s not more oxygen that our yawns are bringing in but cooler air to lower our body temperature. When you think about it, the hypothalamus of the brain regulates body temperature anyway. Yawning could just be a sign that our internal thermostat is kicking in. Since body temperature fluctuates with our sleep cycles, it is believed that cooling off the brain heightens alertness and mental efficiency. In fact Alertness ties in beautifully with our third and final explanation….

Theory #3 – Alertness

This is my favorite (my blog defies science and thus picks favorites). This theory argues that yawning is an activity evolved to promote not only alertness but a kind of group vigilance.

fun fact – I yawned approximately 17 times in the process of editing this article.

From the moment we wake our inner clock is ticking, counting down the hours until sleep. As the light changes throughout the day, adenosine (neuron inhibiting, smooth talker that gets your central nervous system into bed) accumulates in our cells like sand at the bottom of an hour glass. Your awareness to stimuli, reaction time, and perception of subtle changes in the environment becomes muffled and muddy. Staying vigilant is crucial in a prehistoric wilderness of dire wolves and sabertoothes that think of homo sapiens as walking, P.F. Chang appetizers (I like the spring rolls).

earlymanSo there you are, standing guard by the cave with your hairy arms and caveman abs. Having just chowed down on grilled mastodon your eyes start to droop. Your respiration shallows and your body temperature fluctuates, but just then, you hear bushes rattle in the distance. The sudden sound makes your shoulders jump (known as a hypnic jerk), jolting you back into consciousness. You smell the distinct musk of a predator dangerously close by. Reaching for your flint tipped spear you start to…yawn? The other members of your tribe also reach for their weapons. Women gather up the little ones and they too begin to yawn (a phenomenon of contagious yawning observed primarily among relatives and close friends rather than strangers). The yawning stretches the jaw, tongue, eardrums, and throat. Arterial blood flow is increased, allowing the brain to cool, prompting arousal just in time to perceive the threat of wolves approaching…or so the theory goes.

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

 

 

 

Crash Course – Epidemiology

this is how I feel when someone coughs without covering their mouth

this is how I feel when someone coughs without covering their mouth

Alright party people, let’s get right down to it. The Ebola outbreak is on everyone’s mind right now and I felt obligated as your friend and favorite science blogger (let me have my dream) to clear up a few key concepts that get tossed out by the media like candy wrappers. Epidemiologists (scientists who study disease) have their own technical lingo when it comes to disease and GOSH DARNIT I want you to know it too. Hey, look at me…I care.

The terms of the trade…

Agent – the thing that causes the disease, or put another way, the element that is always present with the onset of the disease and whose presence is essential for the disease to occur.

Reservoir – the habitat where the infectious agent lives and thrives. This can be a stagnant, jungle pond or the intestinal tract of a human being

Carrier – person or critter (bat, monkey, bird) that can harbor the infectious agent and is capable of giving it to others. The carrier often lacks any signs or symptoms of having the disease.

Host – Any living thing that can be infected by a disease causing agent under normal conditions. If it’s a brisk November morning and you’re reading “Horton Hears a Who” to a small room of kindergartners on the carpet and half of them have the sniffles, then you are the perfect host for the Rhinovirus (cold). All the conditions are perfect.

Vector – living intermediary between a reservoir and a host. Mosquitoes are classic vectors, especially since they’ll suck blood from a variety of victims. They are equal opportunity pains in the butt.

Transmission – the mode or mechanism by which the disease causing agent is spread (air, water, food, person to person contact, contact with object)

Virulence – refers to the infectious agent’s ability to cause disease. I think of it as a measure of potency. On the other hand, infectivity describes that pathogen’s ability to spread disease to other hosts. When Chicken Pox shows up at a party it doesn’t just stand in the corner by itself. It turns the music up, heads to the center of the floor, and tries to dance with everybody.

Zoonoses – infectious diseases that are transmissible from animals to humans.
It’s funny just how foreign this term is for many of us, since there are so many devastating diseases to the human population (Avian flu, Swine Flu, Black Plague, Rabies, Lyme’s) that we acquire from other species.

Morbidity – is essentially an assessment of just how sick the disease in question makes you. It also has a statistical value representing the relative occurrence of disease in a population.
The definition of morbidity has a wonderfully legal sound to it, but the further a disease moves you away from your normal, healthy physical or mental state the higher the morbidity of that disease is. It is the degree of transformation your body goes through in the course of a disease.

Let’s put it all together…

Gina flew in yesterday from Boston on a late flight back to Georgia. The 5 year old behind her showed her all of his limited edition Shrek action figures on the ride back. One of them was sticky from the gummy worms he’d eaten earlier. She’d gotten back at 10pm but her college peeps were in town and the beers at Karma Mike’s Grill were still half priced until midnight. Work came way too early that next day. She only slept 3 hours and the AC in her office was at full blast.
By noon the sneezes started and her nose would not stop running. Around 2:30 all the name brand, instant coffee in the world could not keep her eyes open to read through all her emails. Later that night her throat felt scratchy and her muscles ached as if she’d lost a cage match. That’s when she remembered the kid on the plane and the suspiciously sticky Shrek. Suddenly Gina understood everything that was happening to her.

Our Cast…

Gina – Host

5 year old – Asymptomatic carrier

Shrek action figure – mode of indirect transmission

Respiratory tract – reservoir of virus

Rhinovirus – infectious agent

I hope this helps. Stay curious, stay classy, and never stop learning my friends 🙂

That Carpal Tunnel Thing…

Body parts are like politicians. You don’t really think about what they do until something goes wrong. Consider the median nerve. “What’s that?” Well it’s only the peripheral nerve responsible for sensation and motor control of the fingers within the palms of each hand (except for the little finger, but pinkies have problems with authority).

"You say it your way and I shall say it mine."

“You say it your way and I shall say it mine.”

Don’t feel bad if you’re not facebook friends with the median nerve. It never really hits the news until it gets squeezed. Yes, squeezed. Everyone has heard of Carpal Tunnel syndrome, Carpal Tunnel, or “Copper tunnah” if you were raised in the land of sweet tea and magnolias.

The carpal tunnel is a narrow channel of ligaments and bone in the wrist that the median nerve passes through like the DC metro train. In carpal tunnel syndrome this space begins to narrow, compressing the median nerve which leads to numbness and chronic pain in the hand, fingers, and wrist.

What causes the squeeze?

_CARPTUN

I really wanted to give this diagram a high five just now. Weird, I know.

Did I mention that the carpal tunnel is narrow? No space is wasted in the body and the median nerve isn’t just floating happily in first class with all the leg room in the world. It is literally surrounded on all sides by 9 flexor tendons, vessels, small muscles, and of course, the carpal bones of the hand. In such a tight space if any one of those tendons decides to swell (and you know how tendons can get) the median nerve will get squeezed tighter than a dachshund wrestling a Saint Bernard for a bean bag chair.

I’ll just give you a moment to absorb that imagery…

Risk Factors

“Risk” is just a sly statistical term to describe how much wiggle room an individual has in avoiding a disease or condition. In this case, risk factors include any condition that could significantly alter the space within the carpal tunnel.

Injury – wrist fractures, and dislocation of the carpal bones of the wrist

Chronic Illness – Diabetics or anyone with an increased risk of nerve damage, Impaired kidney function, obesity, prolonged fluid retention during pregnancy, or persistent inflammatory conditions

and then there are the Statistically cursed…

fibro-wrist-pain-400x400

“Why did I play World of Warcraft for 7 hours Yesterday?”

Statistically women are 3 times more likely than men to develop CTS, possibly due to their smaller carpal tunnels. Of course, those women who do develop CTS could have any combination of the risk factors that I mentioned above. So I wouldn’t go out making predictions at the bar with your tape measure just yet. A perfectly healthy woman or man with no signs of CTS could have smaller wrists than a woman with CTS.

Work Related? – There are a lot of people (including myself) who associate CTS with mind-numbingly repetitive tasks, such as typing or assembly line work. We can’t start pointing the finger at any one profession (and I know you want to). We can’t just say, for example, that packaging chicken parts for Tyson causes carpal tunnel syndrome. However, it has been established that CTS is three times more common among assembly line workers than individuals who perform data entry.

Any prolonged activity that puts stress on the wrist could easily exacerbate an underlying condition that could lead to CTS. Even if you have wrists the size of tree trunks I wouldn’t compete in any 3 day, speed origami marathons until all the facts are in.

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

 

 

Me Talk Pretty – Syndromes

Hello party people! I know it’s been many moons since I’ve posted an article but hey, let’s not dwell on the past. It’s bad for your complexion. In this episode of Me Talk Pretty I would like to introduce a topic that has wandered the deserts of obscurity for eons in need of clarity, and today we’re gonna make it rain. For many of us, the definition of a syndrome is as elusive as the lyrics to Tiny Dancer (hold me closer Tony Danza..I’m cold). Let’s clear a few things up shall we.

Syndrome versus Disease…FIGHT!

The classifications for diseases and syndromes are so closely related that they could be wearing the same underwear (like 100% cotton with no room to breath). There is a somewhat reliable consensus that a disease is classified as – having recognizable signs and symptoms which have a consistent anatomical or physiological effect on the body and are linked to a KNOWN CAUSE, a.ka etiologic agent. For example, Bacterial Meningitis is the inflammation of the protective layer of the brain in response to some nasty ole bacterial infection in the blood stream.

A) This disease has a known cause – playa hating bacterial infection by the bacteria Neisseria meningitidis (or any number of known pathogens)

B) This disease has a recognizable physiological effect on an organ/organ system – inflammatory response within the meninges of the brain and infiltration of cerebrospinal fluid leading to systemic central nervous system infection.

C) This disease has consistent, recognizable pattern of signs and symptoms – mind numbing headaches, neck stiffness, fever, altered mental state.

Here’s where it gets tricky…

I would like to tell you that a syndrome is distinguishable from a disease by – having recognizable signs and symptoms which have a consistent anatomical or physiological effect on the body but have NO KNOWN CAUSE. However, we know that Acquired Immunodeficiency Syndrome (AIDS) is linked to an infection with HIV (Human immunodeficiency virus) which attacks our CD4 T-cells. AIDS is classified as a syndrome because the condition has such a broad spectrum of symptoms and complications resulting from the breakdown of the immune system that it can not be classified as a single disease process. On the other hand, Carpal Tunnel Syndrome (the chronic pain and impaired functionality of the hand and wrist associated with the constriction of the medial nerve of the wrist) has a consistent pattern of symptoms and physiological effects BUT the causes of carpal tunnel are highly debatable.

So I would like to be so bold as to say that as a general rule of thumb – what makes a syndrome a syndrome is in the complicated nature of identifying a single, consistent cause for a pattern of signs and symptoms that typically appear together.

I know I know…this one is a little messy. So let’s think of it abstractly.

One afternoon I walk outside and notice that everyone is wearing bright green t-shirts, and walking in groups along the sidewalks with four leaf clovers painted on their faces, carrying mugs of bubbly green liquid. As I walk past restaurants I see lunch specials for corned beef and cabbage. Based on these signs and symptoms I immediately check the calendar (March 17th) and quickly diagnose the phenomenon as St. Patrick’s day. It has been well established that these patterns of behavior only occur together on this particular day. So based on what I’ve told you, would you classify this holiday as a disease or a syndrome?

How about this one – One afternoon I walk outside and there’s a parking ticket on my windshield. Later that day I crack the screen to my smart phone and can no longer make calls which causes me to miss a crucial text message about a party that night. Based on these signs and symptoms I immediately look at the calendar (Friday 13th) and I quickly diagnose the phenomenon as Bad luck. The association of these patterns of behavior are both poorly understood and highly debatable. If bad luck were an illness would you classify it as a disease or a syndrome? (yeah I know that’s a lousy example but humor me)

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

Malaria II – Full Circle

dex2Hello party people! So we’re back to finish up our chat about malaria. Last week I took you behind the scenes with the curious parasite (Plasmodium falciparum) that causes malaria, and its obnoxious insect carrier, with the face for radio, the Anopheles mosquito. Today I want to focus on the disease itself. Sure, having a parasite that rapidly divides in the liver and spreads through the blood stream clearly doesn’t sound as fun as dinner and a movie but how exactly does our body respond to these microscopic freeloaders?

Fun fact – Mosquitos do not depend on blood as their primary food
source. Most of the time they eat like vegan, yoga instructors,
feeding on sap and flower nectar for carbohydrate fuel to power their
airborne lifestyle. Blood becomes a necessary source of protein for
developing eggs. So it is actually the female Anopheles that goes buzz
in the night.

Act I – Incubation stage

o-MOVING-INTO-APARTMENT-facebookI don’t know about you, but if I just moved into a new apartment I need a few days to get settled in, unpack some boxes, and tape my Marley posters to the wall before I throw a party. Plasmodium falciparum is no different. At this point the Plasmodium is still hanging out in the liver cells. It can take up to 30 days after the
initial infection before the first symptoms appear, and those range in severity.

Act II – Blood stage

a closer look at the hemoglobin protein. P. falciparum converts the heme subunit to hemozoin.

a closer look at the hemoglobin protein. P. falciparum converts the heme subunit to hemozoin.

The chaos ensues once the Plasmodium disperses from the liver and begins circulating in the blood stream. It’s the hemoglobin protein in our blood that they’re after. I don’t want to wander too deep into biochemistry, but if you recall from my earlier article on blood, each hemoglobin protein contains a vital compartment called a heme group. This contains a tiny molecule of iron at its core. This is what binds

the oxygen in our blood. Heme is also toxic when it is released from the hemoglobin. To get around this toxicity the Plasmodium can store heme molecules in their single-celled body in an insoluble, crystallized form called hemozoin. Inevitably the red cells lyse,
releasing the plasmodium along with all the waste products leftover from their hemoglobin feeding frenzy, to include hemozoin. This becomes bad news for us.

When it comes to our immune system our blood stream is a small town
and our white cells hate strangers with a passion. Eventually,
wandering T-cells with the right receptors will encounter Plasmodium
merozoites in the bloodstream (by detecting dsDNA on their membrane
surface) which triggers the release of pro-inflammatory cytokines. However the hemozoin that is released when the red cell ruptures seems to trigger an immune response on its own.

Unfortunately, our immune response is not always strong enough to
completely clear the infection. This is partly due to the many changes
the plasmodium goes through in its life cycle that allows it to dodge
the immune response. It goes through 7 stages, altering its
biochemistry a little each time.

 

One of the classic presentations of this disease is intermittent
fevers. Typically when your fever stops you start to feel better, but
with a malarial infection fevers often occur in waves every 48-72
hours. This is the result of the rupturing of blood cells as the
parasites continue to multiply and invade new cells.

Signs and Symptoms

 

That's right, I know what you really really want...

That’s right, I know what you really really want…

Think back to the last time you or someone you’re close to had the
flu. When you get hit with the flu you typically look awful, drunk, and exhausted like you haven’t slept since the Spice Girls were last on tour. During classic cases of P. falciparum infections, patients will present with “flu-like” symptoms of high, persistent fever, headaches, chills, sweats, anemia, and vomiting. Remember that during the blood stage of the infection blood cells are being destroyed. So the patient is weak and essentially poorly oxygenated. It is basically a parasite-linked anemia.

Malaria can become deadly if left untreated when infected cells begin to clock capillaries of the brain (cerebral malaria). This can ultimately lead to brain damage, coma, or death.

Testing Methods

We can identify malaria directly from a peripheral blood smear where a
giemsa stain is added to a drop of infected blood on a glass slide and
examined under the microscope. This kind of testing is wonderfully
direct. The problem with poorly developed countries is that proper
testing facilities, microscopic equipment, and trained professionals
who know what to look for are in short supply. So there are RDT’s
(rapid diagnostic tests) available that can identify specific malarial
antigens in patient blood samples. Much like a Strep or flu test, the
patient’s sample is combined with a reagent in a tube or cassette
where a qualitative reaction (positive or negative) can be observed.
However, depending on the concentration of Plasmodium in the blood a
patient may have a false negative. So there is still a need for
confirmatory testing, especially in areas of the world (I’m looking at
you Africa) where drug resistant cases are high.

Treatment

Good Ole Chloroquine…

So we know the plasmodium needs to break down the hemoglobin in order to use those lip-smacking amino-acids while not poisoning themselves with the heme that gets released. So they form hemozoin crystals of the heme to disarm its toxicity.
Welcome to the wonderfully clever world of chloroquine. This drug diffuses into the Plasmodium, halting their ability to form hemozoin crystals. This allows the heme to build up in their nasty little bodies, shutting down their metabolism. Sadly, chloroquine resistant malaria is common place in malarial hot zones. In these cases patients require drug combinations like quinine sulfate and tetracycline. 

You also have to manage the mosquito side of the disease. Spraying for mosquitos to control the population has been effective in many urban settings. We also have to understand the behavior of the mosquito. Anopheles prefers to feed at night until the wee hours of the morning. So distributing sleeping nets in malarial hot zones can literally save lives.

The CDC has mapped out malarial zones around the globe. So travelers are encouraged to seek malarial prophylaxis to prevent infections.

Here’s the bad news you already know..

– Children are the most at risk from malaria. In fact it kills more children globally than anything else.

– Diseases thrive in areas where the population is dense and the
availability of adequate healthcare is scarce. This creates a scenario
where the mosquitos are more likely to bite infected individuals. An
infected population left untreated inevitably leads to a more
resistant disease.

Luckily we don’t live in a vacuum and we can contribute. There are a number of organizations out there committed to finding solutions for this global problem. Here’s one organization I happen to like (no, I’m not affiliated with them)

http://www.malarianomore.org/pages/the-challenge

Hopefully I cleared a few things up about this topic. If you have questions please leave me a comment.

As always, stay curious, stay classy, and never stop learning my friends 🙂