A letter to a loved one

February 28, 2007

her high school pictureDear Internets,

I think you know that I love you. That, I think, goes without typing. I remember when I received my first computer so that I could visit you. It was seventh grade and I was fascinated with your bounty of porn. I learned HTML and Javascript and began making webpages to impress you. We shared some great times that summer, away from the sun and all the people that didn’t understand our love.

I was certain we would be together forever. I was going to go to college to get a Masters in computers, you were going to keep searching for new things to share with me. We would strike out west to California and start a life together. It was all going to be so perfect, but you just couldn’t wait.

“Things weren’t moving fast enough,” you said. You were leaving me to see the coast on your own. Yes, you were outgrowing me and yes, I wanted you all to myself. Looking back, I know that you were too beautiful to keep all bottled up, but you never had to be so harsh about it, leaving without saying goodbye and taking the mouse (even though we bought him together).

I remember growing jealous as older men (with their fancy Computer Science degrees) ran off to the Silicon Valley with their signing bonuses and their shiny cars, whispering “dot com” and you ate it all up. I had to sit on the sidelines and watch. Year after year, I sat in the classroom still convinced that I wasn’t going to be too late, that I’d get my degree in time before you promised yourself to someone else. I mashed my teeth and watched as the money grew and you changed.

Every quarter, things just getting better and better for you and all the new people in your life. Oh, it was so fabulous what with all the free giveaways and the new software and the fancy CSS. It made me so mad inside to see you so happy without me, I wished for all sorts of horrible things to happen.

I know it was a rough time in your life, but I smiled from ear to ear for weeks when the Bubble burst and you came crashing down to earth with the rest of us.

I know now that my response was out of jealousy. You see, I called Al Gore and got some help. He knew your type and helped me see that if we were meant to be, then we would be. So I took some time to work on some “me” issues, you know, really explore some deep places and try to understand my feelings. That was several years ago.

Well I’m older now, in the 18th grade, and you’ve settled down quite a bit. I was only half surprised to run into you at the WiFi Starbucks; I felt like fate was waiting for the right time. I feel like we’re finally starting to connect in all the ways we couldn’t before. We were both young and immature and that you grew up so much faster was sure to create problems but I’m glad that’s all behind us and that you’ve come around. It’s been a long wait.

These last few years have been great. You have more facets than I could ever explore, your mystery is boundless and that is part of why I love you so much. But lately, I’m feeling a little tired. I want to keep up with you, but it’s almost too much. I come home after a long day of work and I know that you’ve been waiting for me so that you can tell me about Britney Spears’ day or that funny thing that Bush said but didn’t mean, he thinks. I know that nothing would make you happier than if we both sat down in front of the Tube to watch every show you taped for me, but I just can’t.

No no, baby. I’m not saying that I don’t love you anymore. Yes, I’m still in love with you, but you have too much energy for me and if we continue like this, I think it might turn into resentment on both our parts. We’ve come so far and I’d hate to see it all get mixed up again. I’m not saying we should break up. That is not what I am saying. What I think would be best, for both of us, would be if we took just a tiny break. You know, recharge our batteries and rediscover all the reasons we came together in the first place.

Anyway, that’s my idea. That’s how I feel. I still love you, Internets, it’s just that I can’t spend every moment with you anymore.

I think we need some space.

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Antiarrhythmials

February 27, 2007

Poking around the Student Doctor Network, I saw a neat question and just decided to have fun with it.  I’m playing with the idea of tackling a few topics in this manner, complete with Podcasts so that you can listen along (and I don’t have to type so much).  If this sound like something you’d use, let me know; Ill let the interest drive it.

To everyone else, sorry to bore you to death.

 

Quote:

Originally Posted by guitarguy09 View Post

I noticed FA 2007 p.255-256 lists “amiodarone” as being both a Class Ia and Class III antiarrhythmic, while Lippinocott’s and Wikipedia list is being solely Class III. Does it act in some other way aside from blocking K+ channel outflow during phase 3 (prolonging the AP and effective refractory period)? Lippincott’s says that it has Class I, II, III, and IV actions, but that it is unlike Class I because it does not prolong the QT interval (although it’s listed with the other Class III antiarrhythmics as increasing QT in FA). What’s up with this??

Awesome question with a cool answer. Unfortunately, it requires some detail to explain. Here’s a table I made when I was sorting it out for myself.

The Na+ channels of the SA and AV nodes are always firing (more or less) and are termed “active”. This is in contrast to the Na+ channels of the ventricles that are usually off or “inactive”. This all makes sense when you remember that the slow depolarization of the SA/AV is via Na+ channel, whereas the Na+ channels of the ventricles are off except for a very brief phase 0 upstroke (not a lot of time for a drug to take effect).

So, what makes a Class I a Class I is its action on these active Na+ channels. From this, you expect their action to be in the nodes and not in the ventricles. What makes Quinidine a Ia is its additional K+ action. In the SA/AV, this would prolong repolarization. In the ventricles, this would also prolong repolarization. Now, the prolonged QT, the slowing HR, etc begin to make sense.

If you can keep the differences between the SA/AV and the Ventricles straight AND commit the table I included to memory, then the effects of these drugs start to come together. Shockingly, more detail up front requires less memorization later on and leads to a real understanding of antiarrhythmials.

So when people say that Amiodarone is also a Class I, they’re missing it! Amiodarone doesn’t have the basic action that makes a Class I a Class I, and instead includes the actions that make a Ia and a Ib different from a standard Class I.

Lot of details, but interesting nonetheless. The only thing I’ll add is that the Na+ channel in the SA/AV is a “funny” channel and that the Ca2+ channel in the SA/AV is an L-type channel. Why do you care? Well, the actions of Beta-Blockers don’t make sense otherwise. Beta-blockers like Propranolol can act at the Funny channel and the L-type channels in the SA/AV, and can also act at the Ca2+ in the ventricle, but you don’t see them affect the Na+ channel in the ventricles.

You should be able to piece together the rest. In the meantime, here are the bullet points.

Block: Effect

K+: Delays repolarization ↑AP duration, ↑ ERP, ↑ QT interval (risk for Torsade de pointes)
Na+ (SA/AV): ↓ automaticity, ↓ slope of phase 4, ↓ cell excitability
Na+ (Vent) : ↓ conduction, ↓ slope of phase 0 depolarization
Ca2+: ↓ conduction (SA/AV), ↓ slope of phase 4, ↓ phase 2 plateau (Vent), ↓ contractility, ↓ QT interval
Beta-receptor: Na+ (SA/AV)-block and Ca2+-block; negative chronotropic, dromotropic, and inotropic

Mg2+: Functional Ca2+ blocker; first line in Torsades de Pointes, Digitoxin toxicity
Adenosine: Receptors on SA and AV node; ↑ K+ and ↓ Ca2+ conductance, hyperpolarizes; may cause AV block; DOC in diagnosing/abolishing AV nodal arrhythmias. Toxicity: flushing, chest burning. t1/2 = 10s.

Hope it helps, topher.


Errors in First Aid for the USMLE (2007): Gastrointestinal System

February 27, 2007

As always … corrections, suggestions and additions are welcome in the comments.

Gastrointestinal

  1. P.280, Abdominal layers
    1. Not necessary, but I’m just begging you to change this image. In contrast to a typical cross-section on CT, this image is flipped over its axis. This means that with left body on right page, we are looking from head-to-toe and not toe-to-head (as in a CT) and the anterior abdominal wall is placed below the spine on the page instead of above (as in a CT). The simplest solution is to remove all the labels, flip the image across its horizontal axis (as opposed to rotation which would place the IVC and Aorta incorrectly), and then reapply the labels.
  2. P.281, Femoral triangle
    1. The Femoral nerve is not labeled correctly as a nerve. Instead, the “Femoral a.” and “Femoral v.” labels are both pointing to the Femoral nerve. The Femoral artery and Femoral vein are not labeled. This image is also missing the “Empty space and lymphatics” of the femoral triangle.
  3. P.282, Inguinal canal
    1. The “Deep inguinal ring” label is not labeling anything. I think a bar pointing to the ring should be added.
    2. The label “Medial umbilical ligaments” is pointing to one (of two) of the medial umbilical ligaments and (incorrectly) to the median umbilical ligament. The labeling should change appropriately.
    3. The labels “Deep inguinal ring” and “External inguinal ring” are not consistent with the next page, and I think the small changes to “Internal (deep) inguinal ring” and External (superficial) Inguinal ring” would clear up any confusion and bring it in line with the descriptions on the following page.
  4. P.284, Salivary secretion
    1. I think a fourth bullet point with “Lingual lipase begins TAG digestion; activated at low pH on reaching stomach” should be added. This offers a contrast to the activation and action of alpha-amylase.
  5. P.285, GI hormones
    1. I think it’s worth mentioning that Gastrin’s effects are inhibited by Somatostatin. According to Costanzo (BRS Phys), it is a pH of 3 (not 1.5 ) which is the checkpoint for the gastrin/acid-secretion feedback loop between the antrum and the body of the stomach.
      1. Vagal stimulation of gastric acid secretion is due to ACh (as listed on P.284), but no mention is made that vagal stimulation of gastrin secretion from G cells is due to Gastrin Releasing Peptide (GRP). Because this explains why anti-muscarinics do not prevent the secretion of gastrin, I think it should be mentioned.
    2. Cholecystokinin should include “(CCK)” since this abbreviation is not stated elsewhere and is used within the same row of the table. It is also worth mentioning that CCK potentiates Secretin’s effect on pancreatic HCO3- secretion.
    3. Secretin’s effect on increased bile production is not mentioned.
    4. I think it’s worth adding the second-messenger systems used by each hormone. Since Gs, Gi and Gq were previously covered (P.214) I think it’s helpful enough to list the following next to each hormone:
      1. Gastrin (Gq)
      2. CCK (Gq)
      3. Secretin (Gs)
      4. Somatostatin (Gi)
      5. GIP (Gs)
      6. VIP (Gs)
      7. NO (cGMP)
  6. P.286, Regulation of gastric acid secretion
    1. The pattern established by this figure is that each drug with a line towards a receptor is inhibitory for that receptor. This is not the case for Misoprostol, which is a PG analog and stimulatory at the receptor. To avoid any confusion, I think that + and – signs are more appropriate here.
  7. P.294, Alcoholic hepatitis
    1. Changing the mnemonic from “You’re toASTed with alcoholic hepatitis” to “ToASTed, Sam GOT alcoholic hepatitis” helps you remember that SGOT is also known as AST (which is easy to forget).
  8. P.296, Primary sclerosing cholangitis
    1. I had no idea what an ERCP was, nor would I expect most other second-years to know it. If it’s going to be mentioned, I think it should be spelled out to “endoscopic retrograde cholangiopancreatogram (ERCP)”
  9. P.296, Reye’s syndrome
    1. In the way that acute pancreatitis is associated with gallstones and ethanol (for example), Reye’s is not associated “with viral infection … and salicyclates;” it is associated with the combination. It’s subtle but important. I think “and” should be changed to “treated with“.

Return to First Aid Errors page.


Errors in First Aid for the USMLE (2007): Neurology

February 27, 2007

As always… all suggestions, additions, corrections are welcome.

Neurology

  1. P.345, Basal ganglia
    1. I think this image is confusing and could benefit from a few additions. Specifically, I think it should be made clear that neurons from the SNc are synapsing on neurons in the Striatum. The Striatal neurons are currently labeled as “Putamen” which would lead to confusion if a test stem referenced the “striatal neurons” that are the sites of Huntington’s lesions.
    2. I think it is appropriate in this section to repeat that Dopamine is inhibitory through its D2 receptor (currently unmentioned) and stimulatory through its D1 receptor.
    3. The light and dark shading of the pathways is not very intuitive, and I think a return to + and – signs might be worthwhile.
  2. P.349, Spinal tract anatomy and functions
    1. Under 3rd-order neuron, “sensory cortex” is listed for the Dorsal column-medial lemniscus tract. The third order neuron is actually that neuron originating in the thalamus (receiving the 2nd-order neuron as described) and then projecting to the sensory cortex. It is the 4th order neuron (within the sensory cortex) that is the end-point of this tract and responsible for any conscious experience. “sensory cortex” should be changed to “ascends from VPL of thalamus to sensory cortex.”
    2. This same criticism applies to “sensory cortex” listed for Spinothalamic tract.
  3. P.357, Visual field defects
    1. The 6th bullet for “Left hemianopia with macular sparing” should include the “(PCA)” since this is the most commonly cited cause. The image should also include a bar across the fibers in the posterior part of the optic radiation. As it stands, “6” is the only number in the figure without a bar marking the site of the disruption.
  4. P.359, Aphasia
    1. Just for the repetition, I think the following should be added here:
      1. Broca’s (44,45)
      2. Wernicke’s (22)
  5. P.363, Primary brain tumors
    1. Childhood peak incidence
      1. F. Pilocytic (low grade): this tumor is correctly described as being found most often in the posterior fossa, however, it is drawn in the anterior fossa and supratentorial. Further, the image of the brain is backwards from what is traditionally shown, which may have led to some confusion during the illustration.
  6. P.364, Tabes dorsalis
    1. Because space is not an issue here and the term has not been used recently, I think it might be worth extending “DTRs” to “deep tendon reflexes”.
  7. P.365, Brown-Sequard syndrome
    1. First bullet point is followed by “not shown”. Similarly, the fifth bullet point is also not shown on the diagram. I do not understand this, since the territory of “Ipsilateral UMN signs” is identical to the territory of “Ipsilateral loss of tactile, vibration, proprioception sense”. It seems the labeling could read “1,2” instead of just “2”. My point is similar for bullet points “4,5” instead of “4” when describing the territories of “Ipsilateral loss of all sensation at level of lesion” and “LMN signs at level of lesion”.
  8. P.366, Facial lesions
    1. Instead of the current mnemonic “ALexander Bell with STD: AIDS, Lyme, Sarcoid, Tumors, Diabetes” I suggest the shorter “BLASTeD: Bell’s palsy from Lyme, AIDS, Sarcoid, Tumors, Diabetes”. A small change, but somewhat easier to remember. Or, if you like, “Bell-LASTeD“.
  9. P.367, Parkinson’s disease drugs
    1. When describing bromocriptine, I think it’s important to say that it is not simply a “partial dopamine agonist”. It is instead a selective dopamine agonist at the D2 receptor, and has its action not in stimulating the direct pathway of the basal ganglia, but instead suppresses the indirect pathway.
  10. P.370, Anesthetics – general principles
    1. The line beginning “Drugs with [up arrow] solubility…” could use a little changing. I suggest beginning with the reciprocal relationship between MAC and potency, followed by the conclusion. I also believe that MAC is not Minimal Anesthetic Concentration but Minimal Alveolar Concentration. The distinction is important as the two are not the same.
      1. MAC = Minimal Alveolar Concentration. Potency = 1/MAC. [up arrow] solubility = [up arrow] potency = [down arrow] MAC.
  11. P.371, Intravenous anesthetics
    1. I propose an alternative for the mnemonic “B.B. King on OPIATES PROPOses FOOLishly” for memorizing Barbiturates, Benzodiazepines, Ketamine, Opiates and Propofol.
      1. KOPs keep them BEhind BARs: Ketamine, Opiates, Propofol, BEnzodiazepines, BARbiturates.
        1. Bonus: …where they are put to sleep by IV anesthetics.
  12. P.371, Local anesthetics
    1. In the second bullet point, when dealing with the order of nerve blockade, the small myelinated/unmyelinated fibers of the ANS could be included “temperature > ANS > touch”

Return to First Aid Errors page.


God I Love Medical School

February 24, 2007

More funny lines from Veritography (in the middle of a month of tests):

Last night, I was trying to memorize my dreams. I’ve never been able to remember my dreams. But right now my brain is so wired for intake of data that any experience I have is something I assume I’m going to be tested on later.

Cat said it right: Studying in medical school is like having sex while you are drunk. You never actually finish, you just keep going until it’s not worth it anymore.

God I love medical school.


Real Med Students of Genius

February 24, 2007

This sent me into a giggle-fit.  Horribly off-key spoof of the Bud Light “Real Men of Genius” campaign.  Courtesy of The Ramble Strip.

  1. Mr. Always Late to Small Groups Guy (guilty)
  2. Mr. Will This be on the Exam Asker
  3. Mr. Always Prepared For Everything Guy
  4. Mr. Awesome Floor Team Avoider
  5. Mr. Really Bad With Children Guy
  6. Mr. Walk Behind the Lecturer Guy
  7. Mr. Falls Asleep During Everything Guy (guilty)
  8. Mr. Accidental Scrub Out Guy

How to Prepare for the USMLE: Should I Take a Prep Course?

February 23, 2007

“Should I take a prep course?”

Shrug. I don’t know if you should or shouldn’t. The best I can do is tell you why I didn’t. Comprehensive review courses make a few implicit promises that include:

  1. Structured lecture, pacing of material, routine
  2. A community of other serious students
  3. A one-stop-shop for your review materials
  4. Some diagnostic component
  5. Confidence that you’re studying the right way

If you’re thinking about taking the Kaplan course, this is more or less what you’ll get. A great many of my classmates went this route and chose the Step 1 Prep Retreat which includes a full-service hotel setting and costs $5,599. That’s a lot of money. I could have chosen to take out a “bridge” loan for $6000 to cover it, but I decided to make damn sure that it was worth it before I added to my debt.

Could I accomplish everything the review course was offering on my own? The structured lecturing was out of the question. I didn’t go to class for the first two years, so taking a live lecture course made little sense for me. I’ve written about it before, but believe me when I tell you that my ears are stupid. I’ve never been the type to sit passively and absorb information; I instead need to be actively involved by rewriting the material (time-consuming) or teaching it.

As far as the pacing goes, I got a hold of the Kaplan lecture schedule just to see how much weight they gave to each section. Then, I just picked something upon which to base a schedule (First Aid), looked at how many days I had to study, and made one for myself. It wasn’t that hard to do. Sticking to it is often a pain, but chances are that every time I want to fall behind my study partner is keeping pace. At this point, my competitive nature takes over and I buckle down.

Daily routine has been incredibly important and we screwed it up. Trying to find a good place to study is hard in the winter when all the public libraries keep banker’s hours and all the academic ones are for students only. Having to sneak in, find parking a mile away, and worry about freezing to death all got in the way for us. Eventually, we found a great library and have been going there every day from 8am-6pm, but we wasted about four weeks trying to find it. So far, wasting that time has been one of my biggest mistakes. Things would have been so much easier if I was the type that could get work done at home.

I couldn’t exactly get a community of students around me, but I thought that might be a good thing. As it stands, I struck a deal with my roommate: I’ll make you study if you make me study. We shook on it and things have been going well for six weeks now. I recently spoke with a classmate of mine at the Kaplan Retreat in Alabama and found out how different it is.

“Kaplan Spring Break 2007! WOO!” I was afraid of that, to be honest. So many medical students reliving their dorm days sounds like a recipe for distraction. “We all wake up for eight hours of lecture with an hour break for lunch and by the end of it, we’re too tired to do anything else. We either spend the rest of the day watching a movie, going to the hotel bar, or lifting weights and relaxing in the indoor pool. It’s pretty great.” All that’s missing is a few testimonials about all the hot singles waiting for your call and a 900 number. I’m glad I passed.

As my roommate Kelly put it, “This is two months of your life where you make yourself a deal: life is going to suck, you’re going to work, you will have no fun so that after it’s over you don’t have to regret any of it.” Sounded good to me.

Being on your own outside of a class also means having to figure which books to get. There’s a great book called The Paradox of Choice that I recommend, but the nuts and bolts of it is that by having so many options and having the time to compare them against each other, we end up paralyzing ourselves and no matter what we choose (even if it’s better than what we would have chosen without all the options) we’re more unhappy with it. Such is life when buying review books. I thought I had a handle on it but have since learned that the books everyone else thinks are great I think are shit, and that no matter what happened I wouldn’t have had the time to find the “right” ones anyway.

So if you get the Kaplan books when you take the Kaplan class, you’ll probably be really happy with them. I have been unhappy with mine because I can compare them against other books to see their strengths and weaknesses. Ignorance is bliss. If I had to do it all over again, I might have just gone to Amazon.com, looked at a list of books I should buy, and then done so without questioning.

As far as the diagnostic component goes, I started studying for the USMLE thinking that the Kaplan QBank was the only game in town. I’ve since discovered quite the opposite and ended up going with USMLE WORLD. You have to wonder how many people never investigate and end up going with Kaplan classes because of how famous the Kaplan QBank is.

The last one is a doozy: confidence that you’re studying the right way. I struggled with this one before beginning. Ultimately, I looked at my last two years in school and decided that I had done enough things correctly that I could fake my way through preparing for the Boards. It also helped that I found the Step1Blog and talked to a few successful people a year ahead of me that also studied on their own. I’ve tried to figure out the best way to cover the material and I’ve failed at it more than a few times but I’ve also had some success and now I’m in my stride. Good thing since the test is now three weeks away.

In all, I’ve lived at my roommates house rent free, paid for gas, spent $500 on books ($200 of which I wasted on the Kaplan Lecture Notes), $200 on warm clothes because Cincinnati is freezing, and spent $700 to register for the actual exam. That comes to the grand total of $1500. What am I doing with the extra $4000 that I didn’t spend on a course?

My own Kaplan Spring Break 2007!

  • Flight from Midwest, USA to Bangkok, Thailand on March 27th.
  • Canon D60 digital camera with two Sigma lenses
  • Northface backpack (I will be living from this)
  • Flight home, May 8th

WOO!

Return to USMLE Step 1 page.