Charlie goes to Medical School

So, I am a few weeks behind on posts and I have successfully lost the post-it with four back posts that I need to write.  I know that one of those posts was to be about the last module and our upcoming module, so I think that would be a good checkpoint to go back and talk about.  This post will be a two part post with the first talking about the end of the Fundamentals module which completed a couple of weeks ago along with what was covered as well as the upcoming module that I am actually about to have the first test for, Tissues/Muscloskeletal.

There was also a family day event which I will talk about in more detail in the next post which marked the end of our first module as well as the first month of medical school, but more about that later.

Fundamentals module did wrap up two weeks ago.  Looking back at the material, I can see everything from a much different perspective especially since the material was so well integrated.  Even though the lectures were covered in a somewhat discrete manner, the lecturers that we had did an excellent job of conveying a concept in a manner that would lead up to future topics and tie in to stuff from previous lectures.  This also speaks to the success of the faculty in organizing the new integrating curriculum.

It’s funny when you think of my high school freshman Advanced Biology class starting on the macromolecules, AP Biology, Gen Bio I and Biochem in post-bacc.  The first few days at medical school were exactly the same…macromolecules.  Well, maybe it was a bit more in depth.  We covered a good deal of biochemistry, genetics and cell biology.  All of the material was tied into clinically relevant correlations and vignettes.  In total, it was five weeks of material with two tests.  Everyone in my class successfully completed the module and the director for the module said that the average for the second test was pretty high.

So what’s next?  Well, we are starting on the systems-based modules which will continue for the rest of this year.  First up, we are learning about Tissues and the Musculoskeletal system.  The landmark event here is that we are starting our labs, both histology (i.e. microscopes) and gross anatomy.  In lecture, we are starting to cover a bit more development and physiology as well as moving right into the cellular biology coverage of tissues.  Following this, we are going to jump right into energy metabolism including glycolysis and Krebs/TCA.  From a physiological/histological perspective, we will be learning about osteons and sarcomeres.  So far, we have just been learning about tissue types and more specifically epithelial and connective tissues.  Histo lab has followed this along pretty closely.

I’ll talk more about gross anatomy lab later.  It is obviously a delicate and important subject.  Someone left their body to the school so that I could learn medicine.  Gross anatomy lab is so important to medical students that I feel like I would need to cover it here, but in doing so I must be respectful of that gift.  We have been told to treat our subject like our first patient, so I won’t be discussing any details of the subject.  I will be covering some of the process involved in the dissection, but in the most respectful way that I can.

Histo labs are a little less intense.  It is basically sitting in a room with fifty other students looking through a microscope while our instructor guides us over a PA system.  My one real disappointment here is that we don’t get to do any of the mounts.  So far, I’ve only ever done wet mounts.  The slides that we are reviewing have all been fixed to preserve them before staining and mounting.  There is a great video of this during a CSI episode that I saw one time.  Sorry I can’t remember which one.

Alright, I have to get back to studying.

WOW!!! I got my first commented which asked me a direct question about medicine.  I think I’ll overreact.

Our first…er…only piece of viewer mail comes from Commenter Evan:

Since I’m going to be working on enteropathogenic bacterial infections in my postdoctoral fellowship, I’d love to hear what you fancy medical students are being taught about the subject…

Well Commenter Evan, we actually haven’t learned a whole lot.  Our first year focuses more on the function of a healthy human body and less on the actual medical conditions and diseases.  The purpose of that is to show us how things work before showing us how they can get messed up.  However, since the step 1 boards focus more on clinical knowledge, a lot of the time the way we learn the proper function is by how it can break.  The end result of this is that while I don’t know a lot about enteropathogenic bacteria right now, I have learned a few mechanisms which are specifically affected by certain bacteria.

One of clinical vignettes that we have had is the way that Vibrio cholerae stimulates the activity of adenylate cyclase and what that results in.  V. cholerae releases a toxin which binds to the GM1 ganglioside receptor at the mucosal surface of the intestine.  This binding releases a piece of the toxin (the A1 subunit) which catalyzes a reaction which transfers ADP-Ribose from NAD to the the Gs-alpha subunit of the Gs protein.

The point of learning this was to demonstrate the cycle of the heterotrimeric (three-different parts) G protein.  A G protein is a common second messenger of cell signaling pathways.  G proteins are controlled by molecules of GTP and GDP.  Without going too much into describing what GTP and GDP are, they are basically chemicals which cells use to store energy (like ATP).  When a G protein has a GTP, it is turned on.  G proteins like Gs get GTPs at signal receptors on the surface of the cell.  When a G protein has a GDP, it is turned off.  This actually occurs when the G protein catalyzes the loss of a P from the GTP (GTP to GDP, Triphosphate to Diphosphate).

Cholera toxin affects the ability of this G protein subunit to catalyze this reaction.  Because it cannot do this, the G protein subunit gets stuck with a GTP molecule and is always on.  This activated G protein subunit stimulates the adenylate cyclase which then creates compounds called cAMP…a lot of them.  This the drives an ensuing signal cascade which then pumps sodium ions into the lumen of the small intestine.

Actually, this was the part that they were fuzzy on, so I am not sure if this was sodium or another electrolyte which is pumped out first.  Basically the common motif for moving water around the body is moving either sodium or chloride ions (or some other electrolytic ion) out of a cell.  This will then cause then cause an electrostatic pull for an ion of the opposite charge which can then tag along across the surface of the cell.  So lets say it starts with a sodium ion.  That will then pull a chloride ion.  This people may recognize as salt.  Eventually you will get a really salty solution.  This salty solution is sitting across the membrane from a very watery solution.  This situation is resolved by water passing into the lumen, chasing the salt.

Again, we haven’t covered the exact mechanism here with cholera toxin, but one electrolyte (say Sodium) is pumped out which is followed by more electrolytes (Chlorine) which is then followed by water.

Excess water in the lumen of the intestine results in extremely watery diarrhea resulting in dehydration.  Treatment for the condition is supportive (oral rehydration therapy), although a drug like morphine can be used to inhibit the activity of adenylate cyclase counteracting the effects of the activated Gs alpha protein.

So that is one way that a bacterial can affect you through while residing in your intestine.  This may not be the only mechanism by which bacteria can affect you (maybe it is…I haven’t gotten that far yet), but water loss and diarrhea are one common theme among enterobacteria.

Since our last test, we have started our new modules.  The first module was on fundamentals, the basic stuff.  It involved a lot of biochem and genetics, and some cell biology.  This week starts our Muscle and Skeleton module.  With it comes the start of a ritual which has become synonymous with first year medical students, Gross Anatomy Lab.

I’m more excited about this that I thought I would be.  Last night I was throwing together my spare pannier with sets of scrubs and nitrile gloves, and I couldn’t believe how psyched reviewing the instructions for today got me.

Wife is obviously less than thrilled with the smells of formaldehyde (which apparently still gets used) or whatever chemical preservative we are using.  She has insisted on a biohazard-like containment system next to the washer and dryer.  I am even wearing old shoes (which apparently have had the padding worn out of…I think I did a 10k in these shoes).

I would like to note that today starts a period where I am benefiting from the generosity of an individual who has allowed his or her remains to be used for this purpose.  The school, much like most others, has a strict code concerning how the subjects are to be treated.

Ultimately it does come down to respect as far as the code is concerned, but I am also very thankful for the gift.  While I will treat the subject with respect, I don’t think that respect alone covers the gratitude I feel for the opportunity to learn.  The school hosts memorial events for when the remains are returned to their loved ones.  I hope that I get a chance to thank the friends and family for the gift.

I have to run.  Class is starting soon and I have to bike to class.  I hope everyone has a great day.

Pretty much the opposite of this guy.

So, this is the first in a series of catch up posts.  I’ve gotten far enough behind that I am afraid of dropping a few posts that I’ve been meaning to write.  But, I’ve got a list here that I’m going to start scratching things off of.

Which takes us to today’s interesting medical mystery …actually a series of cases presented to a small group of first year medical students.  For the first time, they will be responsible for driving the conversation forward and interpreting the information at hand.

This is actually the way that the small groups are run for the second year students.  Cases are presented to the group by a student, designated the reader.  The group will ask for one piece of information at a time until the case has been run through.  A second student will take notes on the board, and the rest will shoot ideas faster than the scribe can write.

So how does a Doctor think?  Well, it is a lot like any scientific endeavor.  What you do know is important.  However, what is probably more important is what you don’t know.  Most of the time, a patient actually will come in and directly tell you what is wrong with them.  However, whether the patient actually does or not, each piece of information should be considered carefully.  What questions does a piece of information lead to?  What do you actually know?  What do you definitely not know?  What does it mean?

As the conversation progresses, a physician takes the entire set of known medical conditions and starts removing things from possibility…or rather probability.  The picture becomes clearer as the case progresses.  Specific conditions become more or less likely.

The two skilled physicians who facilitate our group tell us repeatedly that we know more than we think we do, which is true.  They also take some time to laugh at the things that we don’t actually get right.

The board that we write on is black and white, so graying out an option is not really an option.  I get dinged once or twice for wanting to remove a condition from our list of possible causes for a patient’s symptoms. The second time, I tell them that scratching from the board does not mean that I have dismissed a hypothesis completely.  However, it does mean that it may not make my top five.

At the end of the first case, we look to them for the right answer.  But the point of the exercise is not an answer.  One of them points up at the board where we have written what we know, what we don’t and what our hypotheses are, and they tell us that we have a reasonably well-performed differential diagnosis.  We have six to ten hypotheses on the board, some of which are scratched out or have a finger rubbed through them.  Three or four remain, and one of them could be the condition causing the patient’s symptoms.

Of course, we don’t know how to perform a physical.  We are inexperienced at taking histories.  We have no idea what tests to run.  And, we aren’t allowed to treat them.

But we were able to run down a top five.

This image and House are copyright of Fox or Universal or whoever makes that show.  Please check and episode of it out since I am using the picture.  Check your local listings or hulu.  I think there are new episodes in a week or two.

Medical school is like getting shot in the face with knowledge.  Just a quick study break before going back to the flashcards.

I’ve made so many that I’ve only been able to solidly go through them once.  This second go-round is the highlights.  I’m definitely doing this wrong.  Next module, I’m going to take a different tack and consolidated my lecture materials into subjects before making study notes.  I feel like we’ve covered a number of topics in several different lectures.

I also haven’t been sleeping super great.  Luckily, this is just good training for the next…well…rest of my life when I don’t get to sleep a lot.  I have tempered my caffeine intake today in hopes of getting to sleep when I lie down tonight.  It’s just pretty hard to relax when you are excited about your new career.  Luckily, that also makes it easy to get up in the morning.

I do have quite the grip on this material though.  A lot of interesting stuff.

Alright, more flashcards.

I’m a little too busy to track down the picture that I have of a 3×5 index card, but I’ve gone through roughly 500 of them.  I have a test on Friday and it is only marginally more material than last time, but has somehow generated a great deal more notecards.  I spent the entire weekend writing flash cards…with the exception of Friday evening when my eyes were dilated from an eye exam.

We are covering a lot of genetics, regulation of gene expression, molecular biology techniques (including a lot of leading edge stuff that is pretty new), a lot of cancer stuff (oncogenes vs. tumor suppressors, apoptosis) and some cell biology (endomembranes and cytoskeleton).

A lot of stuff is running together.  We are covering a lot of the same genetic diseases in the different lectures, so the clinical vignettes are bleeding together.  Even some of the lecture material gets repeated a good bit.

I have a handful of posts that are waiting to be written.  I’m going to queue up some quick drafts to encourage me to write them after the test.  I had a good one that I was trying to write on some of our lecturers which isn’t turning out how I liked.  I’m going to rework it later as well as some other ones.  I’ll try to post some quick stuff this week.

Anyway, I hope all is well with everyone.  I’m going to go flip through some cards.