Tuesday, December 30, 2008

Walk-In Clinics Need To Educate Their Patients

In the medical community, there seems to be a stigma that walk-in clinic physicians only care about money and not the well being of their patients. I have primarily heard this generalization from patients who have gone to a walk-in clinic and felt rushed through their examination. I believe that walk-in clinics serve a good purpose because they allow people to see a doctor for non emergent situations that occur when their family doctor's office is closed, like on a weekend.

Recently, a friend of mine went to a walk-in clinic because he was having groin pains. The doctor diagnosed him with an inguinal hernia, which occurs when your peritoneal sac obstructs your inguinal canal. However, my friend called me after the meeting with his doctor to ask "what is a hernia?" and "why do I need surgery for it?".

Sure, my friend should have asked the doctor these questions, but I would argue that the doctor should make sure his patient understands what kind of hernia he has, what a hernia is, and why he requires surgery to fix it. Answering these questions would only take 2 minutes of the doctor's time, so there really isn't any excuse to not explain the diagnosis.

Now maybe the doctor thought that inguinal hernias were common knowledge, but I really hope that isn't the case.

Monday, December 29, 2008

Corey Hill's Leg Break Hypothesis

Corey Hill is a giant in the UFC. He is 6'4" and fights at a mere 155 lbs according to Sherdog. Some may say that this is understandable because he is a professional athlete and probably has only 1% body fat. However, Barack Obama is 6'1" and weighs 180 lbs! Now, unless you think Obama is stacked like a body builder or you think he is obese (either conclusion would make me question your ideas about body image), you will agree that Corey Hill is REALLY light for his height.

Being so light probably suggests that his bone density is relatively low. I really have not learned anything about bone density, so I don't have any science to back this conclusion up...but it makes sense considering his BMI is 18.9 (probably not entirely true because I'm sure Corey Hill, like most UFC fighters cuts weight to fight in his weight division, however, I doubt that he cuts more than 10-15 lbs). Keep in mind, Hill IS an athlete, so he has a fair amount of lean muscle mass, which is relatively dense, i.e. heavy.

So, if his bone density IS relatively low, that would explain this:

Corey Hill Leg Break

I'm sure I'll eventually learn more about measuring bone density and in the future I'll be able to understand if my hypothesis about Corey Hill really explains his leg break. For now, I'm just going to drink a lot of milk.

Sunday, December 28, 2008

HIIT: High Intensity Interval Training Myth

High intensity interval training (HIIT) is one of the new fad training techniques that promises quick strength gains and immediate weight loss. HIIT is a training technique that involves many strenuous, short intensity workouts, such as doing wind sprints and super sets. In this post, I'll explain the magic behind the weight loss involved in HIIT.

From my experience, most people who follow HIIT believe that HIIT is the best, most efficient workout when it comes to burning fat. This belief is supported by the fact that they end up losing 5-10 lbs in their first week of HIIT. This doesn't happen with most workout plans, so HIIT must be the real thing! Most horses can't answer math questions, but that doesn't mean Clever Hans could do arithmetic. The secret behind the quick weight loss resulting from HIIT can be found by looking at the fuel you burn when you are doing high intensity exercises.

During high intensity exercises, your muscles' demand for oxygen exceeds your body's supply of oxygen. Thus, your body must create energy, ATP, anaerobically (without oxygen). This means your muscles burn glucose, which is stored in the body as glycogen, instead of fat (as mentioned in an earlier post, you need oxygen to get energy from fat). Glucose and glycogen are polar molecules, which means they attract and hold onto water molecules.

In HIIT, the high intensity exercises burn your glycogen stores. Without the glycogen holding onto the water molecules, your body excretes water that was held by the glycogen as urine, sweat, or moisture in your breath (yes, technically you lose weight whenever you breathe...or talk...explains why my girlfriend is so skinny). This loss of water is responsible for the immediate weight loss seen in HIIT. Ironically, for those people who think that HIIT burns fat, the high intensity exercises cause your muscles to stop burning fat and to start burning glucose.

I'm not saying that HIIT doesn't help you lose weight. Obviously, I just stated that it initially results in the loss of water weight; however, as far as I'm concerned, exercise is exercise and burning calories doing HIIT will result in weight loss, just like burning calories any other way will result in weight loss. People should just realize that there are no easy ways to make your body instantaneously lose 20 pounds of fat. The most effective way to lose weight is to find a workout routine that is both strenuous and fun, something maintainable that you can do for an extended period of time. Of course if that doesn't work, just try talking more.

Tuesday, December 23, 2008

House MD: Merry Little Christmas Error

I was doing what every med student does in place of studying, learning from House, when I noticed an error in the medicine on the show. I'm fairly certain the writers get their medical advice from real doctors, so this is actually quite surprising. However, there is also a good chance the writers get their information from wikipedia, so maybe the American healthcare system has nothing to worry about (on the flip side, that means us medical students DO have something to worry about because wikipedia is THE source for PBL info...haha, just kidding of course...).

In the episode, "Merry Little Christmas", the patient, Abigail, has both liver problems and lung problems. House advises Foreman to get ahead of the disease and look at the pancreas. I have no idea whether this is good advice or not...I'm a first year student, I can barely spell pancreas! However, Foreman follows this advice by testing for alpha-1 antitrypsin deficiency. When Cuddy and Wilson question him about the test, they ask why he suspects a problem with the pancreas.

The problem with this sequence of events is that the pancreas is not related to alpha-1 antitrypsin deficiency. Alpha-1 antitrypsin is a protein that is created by the liver and its function is to protect the lungs. Genetic mutations that lead to alpha-1 antitrypsin deficiency result in defective alpha-1 antitrypsin being created in the liver. The liver is unable to secrete this protein into the blood stream and it ends up accumulating in the liver cells and damages them. The absence of alpha-1 antitrypsin also results in lung damage because the protein is not present to protect the lungs. Thus, alpha-1 antitrypsin deficiency is a good diagnosis for the liver and lung damage...but has absolutely nothing to do with the pancreas.

Seriously...if House can't get this right, where am I supposed to learn about medicine?

Saturday, December 20, 2008

Exams: Med Exams + Bad Luck = Hilarious

Exams often induce a lot of stress in any university student. Sometimes students stress out and have an anxiety attack or an emotional breakdown. Sometimes, it seems, the universe conspires to ensure that you have a panic attack, aka, you have bad luck.

As I mentioned in my previous post, we recently had our first set of finals in med school. Most of us didn't really know what to expect from these exams, so that caused a couple people to pull all out study sessions the night before the exam (I don't know how people do this...personally, I need my sleep before an exam). However, an all-nighter was nothing compared to what happened to one of my friends.

Our final was at 9 a.m. on the day after a snowstorm, my friend, "John", calls me an hour before the exam freaking out because his car won't get out of his driveway. He was trying to pull out of his parking garage and while he was trying to go up the relatively steep driveway, his car lost traction due to the ice and he slid backwards into the garage's gate. Luckily, the resulting dent was on his already dented bumper, which he thankfully had not had time to replace yet.

Obviously, John was worried he was going to be late for the exam, but fortunately, he only missed the first 5 minutes. Unfortunately, we were given the exam's instructions during those first 5 minutes. Eventually John heard the "15 minutes left in the exam" warning and he noticed that he still had 70 questions left and started panicking. He began to fly through the questions as quickly as he could, but 10 minutes later he still had 40 questions left. At this point, he was in fight or flight mode, John was sweating, shaking, and could barely focus. He ended up asking a TA how much time he had left. Well, that was a bit of a lie, he TRIED to ask a TA how much time he had left, but he lost the odd syllable in his panic. Anyhow, the TA looked at his exam...and told him that HE had 1 hour and 5 minutes left, it was the DENTISTS that had 5 minutes left.

See, the part that John missed in the instructions was that the dentists, who are in most of our classes, had 2 hours to complete their exam. We had 3 hours to complete our exams because we had 60 extra questions for our Family Practice course, which the dentists did not take during the term. After John heard that he had over an hour left to finish the final, he was speechless from sheer joy. The TA felt so bad for John that he gave him a pat on the back and reached into his pocket and gave John a halls.

Friday, December 19, 2008

Exams: Engineering vs. Medicine

Having just completed my first exams in med school, I have a fresh appreciation for the differences between finals in engineering and finals in medicine. I thought I'd share...to save any poor engineering student who thinks switching over to medicine is a good idea (kidding of course!).

When studying for the finals, I would:

Engineering Exams
1. Start studying 2 days before the exam.
2. Make sure I understood general concepts and how to represent physical phenomena through mathematic formulas.
3. Catch up on a lot of missed tv shows.
4. Work out regularly.
5. Review the worksheets we were given throughout the term, 1-2 times.
6. Have a restful sleep the night before.
7. Walk into the exam confident I would do well.
8. Finish the 10-15 written questions with 30-45 minutes to spare, so that I could check over my work.

Medicine Exams
1. Start studying 2 weeks before the exam.
2. Make sure I memorized general concepts and specific details, like the recurrence probability of having a second child with down syndrome due to a 14, 21 Robertsonian translocation in either a man or a woman.
3. Blow up my tv to make sure I couldn't get distracted.
4. Get fat...(an effective studying technique because now my muscle cells can meet their basal metabolic needs longer due to the extra fat, which saves more glucose for my brain...wow, who thinks like that, seriously...this is what med school has done to me!)
5. Run through every word in every notes package, workshop, and handout atleast 5-6 times...and there are a lot of handouts in med school. I'm pretty sure we're single handedly responsible for the deforestation of the temperate rainforests in BC.
6. Take up 5 new religions the night before, so that I have more gods to watch my back during the exam.
7. Walk into the exam happy that the system is pass/fail (well...for the moment anyways, I'm not really sure I see how a pass/fail system benefits our medical system).
8. Finish the 200+ multiple choice questions* with 5 minutes to spare, but my brain is too fried to look over much of my work...it was a 4 hour exam (Yes the MCAT was longer, but it had breaks...and was MUCH easier).

*Note: This isn't your regular a to e multiple choice exam...some questions were a to p! We even had a multiple choice question that had 11 possible answers...and we had to pick 7 correct options!

Surprisingly, I didn't walk out of the exam thinking that the concepts we had to learn were more difficult than the material I learned in engineering. In fact, I actually feel like the concepts we learned in engineering were more difficult to understand (keep in mind this opinion may change since I finished 4 years of engineering...but I've only written ONE medical exam...the easiest one I will ever write apparently). However, I do think the exams in med school are much more stressful than any exam I wrote in engineering.

All this being said, I wouldn't discourage anyone from going to med school if being a doctor is what they really want to do. As much as I complain about the exam, it really wasn't that bad, and it's worth it considering this is what I want to do. Of course, maybe I'm just a massochist...don't ever trust anyone on the internet ;)

Saturday, November 29, 2008

The Internet Is Not A Doctor

One of the cool things about working at Microsoft was that I was able to talk to the people working in Microsoft Research(MSR). MSR is basically a playpen where researchers come up with cool ideas, research them, and hope to make a product out of their findings. Only 1 in 100 ideas even get OUT of MSR and fewer still make it to production, but MSR did give birth to a couple of great ideas like the surface top computer.

Anyhow, MSR recently published a paper about cyberchondria, which is basically "internet hypochondria". The premise is that if you wake up with a head ache and search for "head aches" online, you will often find links that state head aches are a symptom of a brain tumour (which can be true). However, you, not being a doctor, don't realize that "brain tumour" is not the only diagnosis for a patient presenting with a headache. In fact, when you consider your age and medical history...brain tumour may be (and often is) the LEAST likely diagnosis. It could just be...that you have a head ache.

Now, don't get me wrong, being curious about your illness and doing some research regarding your symptoms is a great idea. You should also feel comfortable telling your doctor about your concerns if you're worried your symptoms are indicative of a specific illness. However, there IS a problem with doing online research about your symptoms if you're the type of person to panic because some pretend med student wrote an article that makes you think you have brain cancer because you woke up with a little head ache. Long story short...don't blow your life savings because the internet made you think you're going to die soon.

Thursday, November 27, 2008

OSCE = Standardized Waste Of Time?

OSCE stands for Official Structured Clinical Exam. This is an exam that tests a physicians clinical abilities. Forget that book learning, this is where we prove we can interview patients and perform clinical procedures (like a chest exam).

Although I think testing med students on their clinical abilities is essential, testing med students in the first term of their first year is pointless! They can test us on any clinical procedures because we don't know any (not entirely true, we can measure blood pressures, but they don't test us on that) so the OSCE tests our ability to do a medical interview. I think this OSCE is a waste of time because so far, in class, we've done at least 3 practice interviews in front of a tutor and several classmates. We've also had plenty of experience doing interviews when we went out to work in the clinics throughout the term. We really do know how to do these interviews, if we didn't, the faculty would have heard about it by now!

I had to drive all the way out to VGH to do a simple 8 minute interview where we get to know a standardized (read: actor) patient, ask him about his chief presenting complaint, and see how he feels about it. Seriously...I had to drive out their for 8 minutes of chit chat! Yes...I realize that there are BIGGER problems in the world I could be complaining about, but I'm pretty sure this is a close second to obstetric fistula (maybe not, but I thought I'd raise some awareness while I had the chance).

Now I understand that schools live to examine students, so maybe we HAD to have an OSCE, but at least make the OSCE a challenge! Let us practice our complete history taking skills, I've already shown you that I can FIFE! Wait...am I complaining about an easy exam?! Ok, I'm sorry...I take it back!

Something that I found funny was how I was a victim of standardized examination. In the OSCE, our tutors have a list of questions we are supposed to ask. These range from asking the patient for his/her name and age to asking about how the patient's complaint is effecting their daily function. My patient was a 28 year old professional soccer player who came in with a knee injury. During the feedback session, my tutor told me I aced the OSCE except for the one question I missed...I didn't ask the patient if he was in a relationship. Ok...on what planet would that have been a relavent piece of information in THIS case?! (Turns out my tutor also didn't ask this question when she did a practice run earlier that day...well, at least I'm in good company!)

Tuesday, November 25, 2008

Listening > Teaching

The other day I volunteered to do blood pressure workshops for some less fortunate people. All of the people who attended the workshop were either homeless or lived in low income housing.

These blood pressure workshops are run regularly and usually get a strong turnout. Unfortunately, this workshop was on the Saturday after Welfare Wednesday. In BC, people on welfare receive their cheques once a month. The government seems to think that giving people who are addicted to alcohol or hard drugs (certainly not true of all people on welfare, but often is for the people who attend these workshops) a fat cheque once a month is a brilliant way to help them out. Oddly enough, it turns out that most of these people take their cheques to the liquor store or the shady looking guy on the corner of the block and blow all of their cash on booze and drugs. They end up drunk or high through the rest of the week and end up missing my blood pressure workshops, which, let's be honest, would probably solve all of the problems in their lives. Anyhow, since I'm only a pretend doctor and not a pretend politician, I'll keep my opinions about how I think we should fix this problem to myself.

Other than the low turnout, the workshops went well. I was told that most people who attend our clinics out there tend to have high blood pressures; however, I didn't have a SINGLE patient with high blood pressure and neither did any of my colleagues. We assumed that most of the people who came out on the Saturday after Welfare Wednesday were the types of people who take pretty good care of themselves, so it made sense they had decent blood pressures. We also had a few people who were clearly high on heroine or some other downer. In their case it was obvious that the drugs were going to lower their blood pressure somewhat.

One intersting thing I realized was how our patients valued talking to us much more than they valued learning from us. I was teaching a patient about his blood pressure reading and he was clearly interested in what I had to say...but I started seeing that he just wanted to talk, he didn't really care about blood pressure. I feel stupid about not picking it up sooner...if I was wearing a shirt layered in 3 day old vomit stains, the last thing I'd want is for some pretend doctor to tell me about hypertension. From then on I decided to just chat with the patients about what was going on in their lives and hold off on the blood pressure talk until they brought it up.

Wednesday, November 19, 2008

Who Shouldn't Be Your Doctor?

Today a woman gave us a lecture that included a story about a marathon she ran. During this marathon, she didn't drink any water because "she doesn't drink water when she exercises." She also took Vioxx, a drug that has since been taken off the market in Canada because it has been found to cause extreme cardiac side effects. Vioxx is a Cox-2 inhibitor, which, long story short, causes vasodilation.

Does this sound like a bad idea? It must be...otherwise I wouldn't have anything to post about...Let's look at the perfect storm of problems she created for herself...

She ran a marathon, which means she lost a lot of fluid, through sweat. She didn't replenish these fluids because water and exercise don't mix for her. This lack of fluid would work to lower her blood pressure. She also took Vioxx, which causes vasodilation, which leads to lower blood pressure also. Thus...you guessed it...she had REALLY low blood pressure. Low blood pressure means less blood filtration occurred at the kidneys. Less blood filtration means toxins built up...

At the end of the marathon her blood pressure was 90/60 (120/80 is normal) and her serum creatinine was 230 mmol/L (65 mmol/L is normal for her).

Here's the kicker...she's a nephrologist (kidney doctor). She did all this because she wanted to run an experiment...on herself. That's all well and good...but if you want to do that, you probably shouldn't be your OWN doctor. I doubt she would even subject anyone else to these experimental conditions because they are (I'm pretty sure!) relatively dangerous. Seems like it would be a good idea to have another doctor there to tell you when you're going too far...

That being said...she didn't really get sick, her body recovered soon after she rehydrated, but still...

Saturday, November 15, 2008

Dating Patients

Dating patients is considered unethical by the profession of medicine (at least in Canada) because of the power differential in the doctor-patient relationship. The theory is that since patients trust physicians with their health and well being, physicians could manipulate patients and coerce them into a romantic relationship, which is obviously unethical (and pretty gross too!). In Canada, physicians are self regulated by the Royal College of Physicians and Surgeons (RCPS). The RCPS decides if a physician can practice within a given province, and they deal with any ethical complaints that have been raised against a physician. Thus, if a patient complains about a doctor coercing them into a relationship, they would raise that complaint with the RCPS. The RCPS would then investigate the accusation and decide if the physician is guilty. If the physician is found guilty, the RCPS also dictates the terms of their punishment, which can range from rehabilitation or suspension, to revoking the physician's license to practice.

In most cases, the rules against dating patients makes complete sense. However, as with any ethical, political, or moral stance, there are always gray areas. The other day we were taught that the RCPS has a zero tolerance policy with regards to the doctor patient relationship. This implies that if you are the only physician in a small town, you will probably be unable to date ANYone in that town, as they're most likely all your patients! That means it's a TERRIBLE idea to go to an isolated rural community and be the only physician there, unless you enjoy celibacy.

Another interesting fact is that the RCPS believes in "once a patient, always a patient". This means if you are on call and you see a patient who comes into emergency, you can NEVER have a relationship with them. If you see them again in a social situation, 4 years later, and hit it off...you can't act on it because one night, 4 long years ago, they were your patient.

Now, in practice, I'm not sure if the RCPS is as strict as we were told they are...but if so...wow...

Wednesday, November 12, 2008

Futile Care

We discussed futile care in our ethics class today. Apparently we, physicians, are ethically obligated to provide futile treatment (e.g. ventilating a brain dead patient) if the patient or their family want to continue treatment. The justification behind continuing treatment is that the treatment provides psychological benefits for the patient's family.

In a world with limitless resources, I can understand this justification. However, in the REAL world, we already have tremendous hospital wait times and not enough beds for our patients. Keeping a patient "alive" (I use quotation marks because we don't know how alive a brain dead patient truly is) means there is one less bed and fewer resources for another patient. Thus, by delaying the inevitable passing of one patient, we are prolonging the suffering of another.

Obviously, the ethical issues in this scenario are not clear cut. The family of the brain dead patient may think that they are getting air access to health care if their physician decides to terminate treatment because it is futile. Also, what if the physician is wrong (it's been known to happen) and the treatment isn't futile? Or what if you can keep the patient alive for another year, and within that time a new technology is developed that can heal the patient?

There are many interesting dilemnas involved in futile care...I wonder how my experiences through my medical training will change my views on the issue...

Saturday, November 8, 2008

Courage or Denial

We were taking a young woman's history the other day. She seemed like the average first year student. She was very cheerful, intelligent, and she had a good sense of humour. She was recently diagnosed with pelvic inflammatory disease, PID, which she informed us was caused by either sexually transmitted infections or vaginal tearing. We were all glad she explained...we're first year med students, we don't know anything! She would be lucky if one of us could SPELL pelvic inflammatory disease, much less know its causes.

Anyhow, she was telling us how she had strep throat a few weeks ago, and then a couple of days ago she was going through abdominal pain and needed to go to the emergency room (this is when she was diagnosed with PID). Then she casually mentions her house was broken into recently...and then casually states that she was sexually assaulted several weeks ago.

We were all stunned. The patient went on to tell us how she is taking some time off school to get herself together. She also told us she had found great support groups in her friends and community. All in all, she seemed to be doing AMAZING, all things considered.

After the interview was over, our class and my tutor had a discussion about her calm, casual demeanour. Was she an amazingly courageous girl who was handling everything life had to throw at her with a smile...or was she in denial and avoiding her feelings?

Thursday, November 6, 2008

Know Your Audience

A friend of mine interviewed a volunteer patient today. We do these practice interviews to sharpen our interview skills. During the interview, questions about this patients sexual health came up. We always ask any patient if they are practicing safe sex; however, this patient happened to be homosexual.

After the patient confirmed that he practiced safe sex, my friend asked..."What kind of contraception do you use?"

We all burst out laughing...even the patient...who replied, "Uh...I think you mean protection."

I don't take viagra!

You have to love a prof who is willing to make fun of himself. This week is pharmacology week. Dr. Limpman was lecturing about drug uptake and had a slide showing a drawing of an octagonal blue pill going into the bloodstream. He immediately informs us that "everyone assumes the blue pill is viagra, then they think Dr. Limpman needs viagra." He then retorts "it doesn't even make sense, viagra is diamond shaped, not octagonal!" Upon realizing that knowing the shape of the viagra pill could be consiered evidence of his use of viagra..."Wait...No, Look! This is what I do! I'm a pharmacologist...I'm SUPPOSED to know the shape of viagra!"

We were all 100% attentive after that line, out of respect...

Tuesday, November 4, 2008

Prescribing Pharmacists

The provincial government in British Columbia (BC) is planning on giving pharmacists the right to modify and refill prescriptions. They made this decision without consulting the British Columbian Medical Association (BCMA), which is the association representing the doctors in BC. The BCMA has since convinced the government that they need to discuss this paradigm shift with doctors in order to ensure patient safety.

Currently, pharmacists can only fill perscriptions. Their primary role is to ensure the prescribed drug will not have any unwanted side effects, like dosage toxicity or drug interactions. Pharmacists also teach their clients how/when to take the prescribed drug.

The new legislation would allow pharmacists to modify precriptions to a different, but similar drug or refill a perscription for upto a year. The former would be done if the initially perscribed drug was not working effectively or had unwanted side effects.

This legislation was proposed to counteract the doctor shortage we face in BC. If doctor's are not spending time refilling or changing perscriptions, then they can see more patients. This leglislation would also be more convenient for patients because they would not have to wait to see their doctor in order to get a quick refill.

The BCMA has a problem with the legislation because they feel that it will damage patient care. Many patients are given a limited prescription because the doctor wants to see them again quickly. For example, a diabetic may be given a 3 month perscription so that doctor will be able to see him again in 3 months and perform another checkup. If patients are getting their perscriptions refilled by their pharmacists, they may not bother to see their doctor for upto a year, which may be unnacceptable depending on their state of disease. From my time in the family clinic, I have seen many patients, usually men, come in for a prescription refill and then they bring up a number of serious health concerns. Do you think these guys would come to their doctor's office if they didn't have the pretense of needing a refill?

Another concern is miscommunication, if a pharmacist modifies the prescription drug or dosage, then the doctor may not be aware of this change when he is seeing his patient. I think this is a lesser concern because I'm sure that doctors and pharmacists would work together to establish a protocol to ensure these miscommuncations would not happen.

The BCMA is advising the government to modify the legislation because they are concerned with will negatively effect patient care. The pharmacists were supposed to gain prescribing power in January...we'll see what happens.

Monday, November 3, 2008

Metabolism VIII: Low Carb Fad Diets

First off, I'm going to push the disclaimer that I do NOT support low carb diets. There is a substantial amount of literature available online that supports low carb diets, and there is an equally substantial amount against low carb diets. I'm a first year med student; I still don't know how to do a chest exam; you should not be consider this post serious, medical dietary advice.

Now that I've got the disclaimer out of the way, let's take a look at the science behind a low carb diet. Low carb diets can be high protein diets (Atkins) or high fat diets or a combination of high fat/high protein. The key is to reduce your carbohydrate intake.

If you have ever seen someone on any variation of the carb diet, you may have heard them tell you that they have seen immediate results, such as losing 5-10 lbs in a week. You should realize that if you ever lose weight this quickly, unless there is an extreme circumstance, you have lost water weight, not fat. Low carb diet results in water shedding because your glycogen stores are burned (see the previous metabolism post) and not replenished. One molecule of glycogen normally carries 3 molecules of water with it; thus, if you have less glycogen in your body, you have less water in your body. This depletion of glycogen is responsible for the immediate weight loss.

The low carb diet can lead to fat loss in the long run. Low carb means low sugar, and low sugar means low insulin. Insuling promotes fat storage and prevents fat cells from releasing fat into the blood. Without sugar, fat is released to the blood and used by most cells to generate energy. Also, protein and fat lead to satiety (feeling full), so having a high fat/high protein diet can cause you in eating fewer calories overall.

Again, I am NOT suggesting that you start a low carb diet. Altering the proportions of your diet to include more fat or protein can lead to alternate health risks in extreme cases. Too much protein in your diet can cause nitrogen related damage. Too much fat in your diet can cause blood fat to increase, which can cause cardiovascular health concerns. So in the end, if you want to lose weight, talk to your family doctor!

Metabolism VII: The Feed/Fast Cycle

The feed/fast cycle refers to the chain of events that occur after you have eaten a meal. It is a look at the big picture with regards to metabolism. Let's look at the feed fast cycle looking at an average timeline after you have eaten a meal.

0 - 4 hrs
After you have just eaten a meal, your body absorbs the sugar into the blood, which causes your blood sugar to spike up. This stimulates your pancreas to release insulin, which causes most cells in your body to take in glucose from the blood.

4 - 24 hrs
Insulin levels have dropped because the glucose from the meal is gone. Most cells are using fat as their main energy source; glucose is being reserved primarily for the brain. Now blood glucose is maintained by the liver, through the breakdown of glycogen stores. These stores are normaly depleted within 24 hrs.

1 - 2 day
After the glycogen stores are gone, the liver maintains blood glucose levels through gluconeogenesis. Thus, the liver makes glucose from either fat or proteins. Making glucose from protein means the body is breaking down muscle tissue and other essential proteins because the body does not store any protein as an intended energy reserve.

2 days - several weeks
As the fat cells release more fat into the blood, the liver starts to release ketone bodies. The brain begins to use ketone bodies for energy and thus, requires less glucose. This fall in glucose depend results in less gluconeogenesis, which means less protein breakdown.

After the fat reserves are depleted (timeline depends on individual body fat), the sole method of blood glucose maintenance is through the breakdown of proteins. The body basically cannabilises itself. People that die from starvation do not die because they run out of protein; they die because they eat away essential proteins like the heart. Note, many people die from complications of starvation before they get to this point.

That sums up the feed/fast cycle. The next metabolism post will talk about the science behind the Atkins diet and other low carb weight loss gimicks

Metabolism VI: Metabolism and Exercise

If you are trying to burn fat, you may have been advised to work out at medium intensity for an extended period of time (e.g. 60 minutes on the stairmaster), as opposed to having a short, intense workout (e.g. 10 minutes of windsprints). This post will discuss the science supporting this advice.

Exercise metabolism focusses on the metabolism of muscle, which is the primary tissue involved in exercise. Muscle requires ATP (energy) to function and stores enough ATP to last 5 to 10 seconds. Next, muscle transforms another chemical, creatine phosphate, into enough ATP to last 10 to 20 seconds. After that, the muscle uses glucose, which is broken down from the muscle's glycogen stores, to generate ATP. The muscle's glycogen stores can last about 5-10 minutes.

After the muscle's glycogen stores are depleted, it creates ATP from either blood glucose or fat. Oxygen is the deciding factor that causes the muscle to either use blood glucose or fat. If the muscle is not receiving enough oxygen, it will take in blood glucose, which probably originated from the liver, and create ATP. Thus, during short, intense exercise, muscle cells are burning glucose/glycogen stores. However, during medium intensity workouts, muscles decide to burn fat because they are receiving oxygen.

Thus, if you want to burn fat, then exercise metabolism seems to support that longer, medium intensity workouts make sense. Remember, you will need to make sure you can sustain the exercise for more than 5-10 minutes straight because you will not be burning any fat until that point.

Remember that your body is very complex and I don't think burning fat is as simple as exercising for more than 5-10 minutes. Diet, genetics, basal metabolism all come into play too. Also, I think you should focus on burning calories, not burning fat, because in the long run it doesn't really matter WHERE you burn the calories from, as long as they are burned. For example, if you burn 100 calories of glycogen, the next time you have a meal, the first hundred calories of sugar you eat will be turned into glycogen and NOT fat. However, if you burn 100 calories of fat, then the next time you have a meal, the first hundred calories of sugar you eat will be turned into fat because your glycogen stores will be full as they have not been burned. So, my advice in the end...do whatever exercise you enjoy enough to do often, oh, and watch what you eat too.

In the next post, I will talk about the feed/fast cycle.

Wednesday, October 29, 2008

Metabolism V: Aerobic Metabolism vs. Anaerobic Metabolism

This will be a quick post comparing aerobic and anaerobic metabolism. Aerobic metabolism refers to metabolism that requires oxygen and anerobic metabolism refers to metabolism that does not require oxygen.

Aerobic glucose metabolism (aerobic glycolysis) is the most common form of glucose metabolism in our bodies. Fat metabolism also falls into the aerobic glycolysis pathway; thus, fat metabolism requires oxygen also.

Anaerobic glucose metabolism (anaerobic glycolysis) occurs in oxygen deprived cells and cells which cannot preform aerobic glycolysis (e.g. red blood cells). A byproduct of anaerobic glycolysis is lactic acid, which we will discuss more in a later post.

Aerobic glycolysis generates almost 10 times as much energy as anaerobic glycolysis. This is the principle reason we die if we don't have enough oxygen.

Next time, I will talk about how metabolism plays a role in exercise.

Metabolism IV: The Role of the Liver

The liver has a number of different purposes within the body. One of its key functions is to maintain metabolic nutrient levels in the blood. When blood sugar is high, the liver stores glucose. When blood sugar is low, the liver releases glucose from these glucose stores. The liver can also convert some fats and proteins into glucose, which it releases into the blood stream.

The next post will compare aerobic vs. anaerobic metabolism.

Sunday, October 19, 2008

Metabolism Part III: How and Why Our Bodies Use Fat

Our bodies use fat for energy for two main reasons.

The first reason is cyclic. We use fat for energy because when we have an abundance of energy, such as after we have had a meal, we store the excess carbs and proteins as fat. We convert the excess carbs and proteins into fat for storage because fat is a very efficient storage medium. One hundred calories of fat has less mass and volume than one hundred calories of carbohydrate.

The second reason is that the brain uses primarily glucose as its fuel source. The brain does not use fat as an energy source because fat cannot cross the blood brain barrier. Since the brain is kind of important, when blood glucose levels are not high, other cells in the body switch fuel sources from blood glucose to fat. Thus, the blood glucose is saved for the brain.

As a side note, during starvation, when blood glucose levels drop, the brain can use ketone bodies as a secondary fuel source. Ketone bodies are derived from fatty acids. However, even during starvation, the brain gets at least 25% of its energy from glucose.

In my next post, I will discuss the liver's role in maintaining blood glucose levels.

Saturday, October 18, 2008

Metabolism Part II: Regulation

In part one of my discussion about metabolism I discussed the different fuel sources. In part two, I will discuss metabolic regulation, starting with hormones. Hormones are biological compounds made in one part of a body to control another part of the body. The two main hormones that regulate metabolism are insulin and glucagon.

Insulin is secreted from the pancreas and signals muscle cells and fat cells to get their energy from blood glucose. Insulin also signals fat cells to convert excess blood sugar into fat and muscle cells to store excess blood glucose as glycogen (Don't know what glycogen is? Don't worry, glycogen will be discussed later).

Glucagon, which is also secreted from the pancreas, signals actions that oppose insulin. Glucagon inhibits fat and glycogen production. Glucagon signals muscle cells and fat cells to get their energy from stored fat. Thus, glucagon promotes fat breakdown (lipolysis).

There are other hormones that regulate metabolism. They all work similarly to glucagon and oppose the actions of insulin. However, I will not be discussing them here because they go beyond the scope of my talk about metabolism.

Insulin AND glucagon are ALWAYS present in your blood (assuming you're health, i.e. not a Type 1 diabetic). Their effect on your metabolism are dependent on their relative ratio. If you have more insulin than glucagon in your blood, then your body is probably making fat. If you have less insulin than glucagon in your blood, then your body is probably burning fat.

As you can imagine, immediately after a meal, your pancreas secretes more insulin. Your body wants to get its energy from the recently consumed sugars instead of its own energy stores (your fat). However, when you haven't eaten for a while, your pancreas secretes glucagon. This is because it wants your muscle and fat cells to get their energy from your fat stores, not your blood sugar. I'll discuss why in my next post.

Thursday, October 16, 2008

Metabolism Part I: Fuel Sources

We're learning about metabolism this week. Personally, I find the subject interesting because understanding metabolism can put a lot of fad diets and workout myths to rest. I've looked up information regarding these workout myths before, but never found a single source of information that discussed them.

Remember, I'm learning about metabolism for the first time right now and we are learning just a BRIEF overview of metabolism right now. That is to say, the concepts I am describing in the next few posts have been simplified and gloss over the true complexity of our metabolism.

This first post will describe fuel sources. Our bodies need energy. In our bodies, energy is ATP, a molecule that is used to power many cellular reactions. ATP can come from carbohydrates, proteins, and fats.

Sugars are carbohydrates. There are several different kinds of sugar, but the main one that is discussed with regards to metabolism is glucose. The process of turning sugars into ATP is called glycolysis. Glycolysis can occur with or without oxygen. However, more ATP are generated when glycolysis occurs with oxygen because one of the products of glycolysis can go onto generate further ATP when oxygen is present.

Fats are made up of fatty acids and a molecule called glycerol. Glycerol can be converted to glucose and make ATP through glycolysis. Fatty acids can make ATP through a different process called beta oxidation. Beta oxidation requires oxygen.

We generally do not want our bodies to use protein as a fuel source because proteins have many other tasks in our body. Proteins are responsible for cell stability, building muscles, and many other tasks. However, some proteins can be transformed into glucose and generate energy through glycolysis. Other proteins can generate ATP through the oxygen dependent path discussed with carbohydrates.

Next, I'll discuss hormones.

Sunday, October 12, 2008

Exercise: Taking Your Health Into Your Own Hands

When you see a doctor because you are ill, your doctor will provide you with a list of suggestions to help make you healthy again. These suggestions can range from taking antibiotics to fight an infection, to icing a sprained elbow. One common suggestion on every list, regardless of the illness, is exercise. Even if you have a torn ligament or broken bone, your doctor will suggest that you, in time, exercise the injured body part.

In family practice, I was interviewing a patient who had migraines. These migraines were excruciating and he said he would do anything to stop them from happening. He told me that the migraines came on after bouts of insomnia. He was also pre-hypertensive, which means his blood pressure is slightly higher than it should be. Now, considering exercise can help reduce blood pressure, and regular exercise can help regulate your sleeping cycle, I asked about the patient's current exercise regime. Turns out that he does not exercise, at all. It turned out that my preceptor (the doctor who runs the practice) had suggested exercise to this patient in the past, many times, without success. This patient would rather try a boatload of different pills than exercise 3 times a week.

The sad part is that this is not an uncommon occurrence among patients. Many patients do not exercise regularly, even when their chief health complaint may be solved by regular exercise. People would rather take medication with all kinds of scary side effects than jog around the block a couple times a week. Even more frightening, I say this living on the west coast, where we supposedly have a healthier style of living than our fellow Canadians living on the east coast.

Considering the economic slowdown we are facing, I wonder how many health care tax dollars could be better used elsewhere if people would just exercise more often.

Saturday, October 4, 2008

First Year Med Student vs. Instructor

If you've ever been to university, or talked to anyone who has gone to university, you have probably heard about the keeners who try to show off their knowledge by attempting to outsmart their professor. This can vary from asking an on-topic question from an article that was just published the day before to asking a question that is completely unrelated to the subject of the course. The bottom line is, the keener never looks smart; in fact, the person asking these questions are often privately despised by most of the class an often the professor too. On the bright side, hating the keener brings everyone else together, so really, they help to unite a class.

Now, the behaviour I just mentioned generally occurs in third or fourth year, when the undergraduate students have a good fundamental understanding about the area they are studying. Many of these keeners are in fact smart (academically, not socially), and if they are keeners in biology, they often find their way into medical school. The problem is, at this point, they've developed this keener behavior and they cannot stop trying to show off how smart they are. However, what they don't seem to grasp is that they are first years again, not third years who understand the fundamentals. This can lead to a beautiful moment if you have a professor who is not willing to be patient with this kind of immaturity.

Scenario 1

Keener 1: "Question, I see the thymus gland is located on the chest wall, this is different than in a fish, why is that?"

Professor: "Get a life (whispering to himself)...I'm sorry, I'm not a marine biologist, nor do I study evolution. In fact, I'm pretty sure I introduced myself as a medical doctor at the beginning of the lecture."

Note, whispering to yourself is not effective when you are presenting to a class of 300 student and thus, you have a microphone stuck to the side of your head.

Scenario 2

Professor: "Now, can anyone tell me what would make you suspect a pregnant woman is carrying a fetus with a tracheoesophageal fistula (a condition wherein your food pipe, the esophagus, is not a single pipe, but instead is interconnected with your wind pipe, the trachea)?

Keener 2: "Use an ultrasound?"

Professor: "evil laugh...Without using any technology...this is the art of medicine folks, we can't always rely on our toys!"

...nobody knows...

Professor: "If the mother's belly is larger than you'd expect, this would lead me to suspect there is amniotic fluid (fluid in the placenta that surrounds the fetus, it contains fetal waste and also nourishes the fetus too...yeh I know, gross!) buildup, and that is a sign the fetus has a tracheoesophageal fistula!" (because the fetus is not absorbing the amniotic fluid because it cannot swallow it properly)

Keener 3: Trying to prove how smart she is by proving the professor is wrong "Um...obviously you still need an ultrasound because the stomach would also be bigger if the mother was having twins!" self satisfied grin

Professor: "No. You can palpate to see how many fetuses the mother is carrying. Want to try again? Seriously, I can do this all day.

First year med students need to realize they don't know anything compared to their profs...asking questions is great. You are at school to learn. However, trying to show off is arrogant and pointless. It wastes EVERYone's time, including your own!

Friday, October 3, 2008

More Efficient Doctors = Bad For More Vulnerable Populations

As first year med students, we have a class called Doctor, Patient, and Society. The main goal of this class is to discuss social and ethical issues facing doctors and what their role is with their patient, in a community, and in society at large.

The other day we were talking about vulnerable populations. The focus of the lecture was a discussion about sub groups of patients that are more general than an average patient. Examples are immigrants, poor patients, and children.

An interesting issue that was brought up was that the government is demanding doctors see more patients per hour than before. On the surface, this seems like a decent idea because Canada is facing a doctor shortage; thus, getting each existing doctor to see more patients helps reduce this problem. However, making doctors see more patients per hour turns out to have negative consequences for immigrant populations. Immigrants, who don't speak english fluently, have a much harder time communicating with their physician. Thus, it takes much longer for a doctor to see an immigrant for a regular visit. In order for doctor's to see more patients in a shorter period of time, they need to see patients who can present their problems quickly. That kind of patient is usually a person who is well educated and fluent in english.

In order to help the majority, the minorities suffer. It's unfortunate that sometimes vulnerable populations just become more vulnerable, even when we are trying to help.

Thursday, September 25, 2008

Anxiety Tremors

I went out on my first family practice visit this week. This is part of a course wherein we work with a preceptor at his family practice and get some hands on experience doing patient interviews and taking vital sign readings.

During this visit, I learned that patients can develop tremors that come on due to anxiety. When I saw the tremors, I immediately thought Parkinson's (mostly because it was the only cause of tremors I had known about at the time); however, these tremors were physically different than Parkinson's tremors. Instead of the trademark wrist grind of Parkinson's, anxiety tremors are a constant shaking. Also, anxiety tremors do not go away when the afflicted individual attempts to do something this his hands, whereas in Parkinson's the tremors often go away when the individual uses their hand (e.g. reaching for a glass).

Anyhow, these anxiety tremors, often caused by depression, are brought on solely by anxiety. The emotional stress induced by constant anxiety causes the brain to lose control over the body's nervous system and causes neurons in the arms to fire, causing them to shake.

I'm not sure WHY anxiety causes this to happen...I'm also not sure if I don't know because I'm an ignorant 1st year medical student, or if I don't know because the mechanism behind anxiety tremors hasn't been discovered yet. Anyhow, I just thought I'd mention the phenomenon.

Monday, September 22, 2008

Referred Pain

Referred pain is an interesting phenomenon where your body is injured or damaged in one location and you feel pain in a completely different location. For example, often when a patient has a damaged diaphragm (muscle located just above your abs) they go to their doctor complaining about shoulder pain.

To understand why this happens you need to look at the anatomy of the nervous system. The nervous system can be divided into somatic and autonomic systems. The somatic nervous system involves the nerves that react to external sensations, like the touch receptors all along our skin. The autonomic nervous system involves nerves that we cannot consciously control, like the nerves that tell our heart to beat.

The diaphragm is a muscle that helps us breathe, and though we CAN consciously control it, it also runs automatically so we don't have to consciously think about taking a breath all the time (good news for all those people who can't multitask...imagine talking on the phone, while surfing the web and watching the t.v. if you had to remember to breath every 5 seconds). The diaphragm is innervated by the phrenic nerve (an autonomic nerve), which comes out of the spine at the same level as the the somatic nerves that innervate the shoulder (nerves C3, C4, and C5 for those who care).

If the diaphragm is injured, the autonomic nerves that warn the brain about this problem start firing. However, on the way to the brain, they get to the spine and mix with the somatic nerves that innervate the shoulder. NORMALLY, somatic nerves warn the brain about pain because somatic nerves are the pain recepters in our skin...where pain will most often happen. Since the brain isn't used to having the autonomic nerves complain about pain, it just assumes that the pain is coming from the somatic nerves. Those somatic nerves are connected to the shoulder, so the brain thinks the shoulder hurts.

Of course...if you just dislocated your shoulder, don't assume your diaphragm is the reason you want to cry.

Saturday, September 20, 2008

Buying a Stethescope

One piece of equipment every doctor medical student needs is a stethoscope. Fortunately, our school organizes a medical equipment night every year. This is a mutually beneficial relationship between the students and the medical equipment manufacturers because they can present to all 300 of us at once and we can cash in on high purchase volume discounts. Unfortunately, this equipment night is held before any of us have a clue how to even use the equipment, so we are just a flock of blind geese and the salespeople are basically hawks out to get us. At our medical equipment night, we had Company A, Company B, and Company C. Most students who attended the night were only looking for stethoscopes; however, diagnostic sets and blood pressure cuffs were also being offered.

Company A was a German, family run business. Their marketing strategy was to have a 30-something year old, very attractive, blond woman tell us about their products. This same marketing tactic has done wonders for Budweiser, Bacardi, Axe, etc. However, considering most of our class is comprised of women and not the male, 18-24 demographic that the aforementioned companies have been successful in targeting, Company A really needs to rethink their sales pitch. Another fatal mistake by Company A was that they spent most of their allotted time pushing their diagnostic sets, which range in the $700 region, and they barely talked about their stethoscopes (the only product most of us were planning on buying that night). How the brilliant minds at Company A don't realize that new medical students, who are paying medical tuition and buying medical text books for the first time, probably can't part with $700, is beyond me.

Company B was next, they were the Canadian branch of a worldwide, originally American, conglomerate. Their marketing strategy was to have a man, dressed as a used car salesman, pitch their only products, stethoscopes, in the most monotonous tone ever. Either he is completely dispassionate about his job and wants to quit 2 years ago, or he has some kind of illness which leads to extreme fatigue. I realized that I'd be unable to help him in either case because I'm not a career counsellor and neither of the two diseases I can diagnose at this point present with fatigue (I probably can't even diagnose THOSE diseases correctly, but that's not the point), so I decided to take a nap through his presentation.

Company C, an American owned family company (I don't know why A and C kept stating they were family owned, it really doesn't make me any more or less likely to buy their product) was next. Their marketing strategy was the paradigm of American capitalism. Their salespeople were all dressed in Company C golf shirts. Their presenter was loud, concise, and kept pushing their products. They had sales pitches left, right, and center. For example, they offered an opthalmoscope for $25 if we bought a diagnostic set (not a big deal considering a diagnostic set is $700). They also offered a free penlight if we bought a diagnostic set and a blood pressure cuff (even less of a big deal since we were already given free penlights...and let's be honest, a free penlight is hardly a good motivator to part with $700). They also had a random prize giveaway where they gave 20 lucky students a free stethoscope with a $50 coupon for another stethoscope, which they could give to a friend.

After these three presentations, I was ready to buy a Company C stethoscope. Their tight sales pitch made me feel like they had their act together; I also thought that a company like Company C really cared about their reputation, so they would be sure to help me if I ever had any problems with their product in the future.

Next came the product demonstrations. The three companies took up space in our atrium and we were allowed to try out their equipment. Company A didn't even have any demo stethoscopes, so I didn't bother going to their booth (if you can figure out who Company A is, and you work for them, seriously...get a new sales staff). Company B had their stethoscopes on display and they even had a CD of heart sounds with a device we could use to try to listen for wheezing, heart murmurs, etc. (a brilliant idea in general, wasted on us since we know next to nothing about listening for heart sounds). Company C had the sales army on overdrive. They were talking us into trying out their diagnostic equipment, which again was useless since we didn't know what to look for even after they showed us how to use an opthalmoscope. Another pro for Company C's stethoscopes was that they had adjustable ear pieces, so we could change the size of the stethoscope to fit our heads without worrying about doing any damage to the equipment.

The problem with the Company C stethoscope...it sucked. The sound quality it provided was terrible. They had me sold with their marketing campaign, but their product was sub optimal. I'm sorry, but what is the point in dropping all those dollars into sales if the customer is disappointed the second he tries your product?

I guess the lesson in all this is to skip the sales pitches and try the product. I ended up getting a Littman Cardiology III. I really didn't want to get one initially because this is what EVERY med student gets, but clearly the reason for that is the sound quality it provides.

Note, HalfMD disagrees with me.

Sunday, September 14, 2008

More Medical Students = Worse Doctors?

It is a well documented fact that both Canada and the USA are dealing with a shortage of physicians. This is best noticed in the primary care field because fewer and fewer people actually have a family doctor. Most people rely on walk-in clinics for their medical needs and thus do not build a long term relationship with a physician, which results in poor continuity of care. The physician shortage is also seen in other specialties where patients have to wait months before they can meet with a neurologist, nephrologist, etc.

One solution to this problem is to open up more seats in medical school and pump out more doctors. This seems like a brilliant idea because it means we can ensure that these new doctors are trained in an accredited school (i.e. exactly how we (the Canadian Medical Association) want them to be trained).

The potential problem that this can cause is that opening up more seats does not NECESSARILY mean that you will have more qualified applicants that graduate to become excellent doctors.

One key attribute I want in my doctor is intelligence. Now, becoming a physician requires a lot more than just intelligence, a doctor also has to be good with people, organized, caring, etc. However, intelligence IS still a key attribute that I would want ALL of my doctors to possess. My fear is that creating more seats may result in a lower bar to get into medical school, which in turn leads to the production of less capable doctors. I am fairly confident that I will be able to accurately judge the quality of any doctor my friends or family are going to see within four years, after I complete med school. However, I sincerely doubt that the average patient will be able to accurately judge a physician's competence without having an extensive medical background themselves. Thus, I wonder how much creating more medical students will help our nations medical problems.

Obviously, the problem I am discussing here disappears if every single med school seat is filled with a brilliant, qualified applicant, or if the unqualified applicants who do get in do not make it through the arduous journey of medical school (though it is very difficult to fail out of med school, which I will discuss later). Also, remember that this is just an issue I am thinking out loud about at this point. After only three weeks of medical school, I am hardly qualified to judge the state of the Canadian medical education program :)

Another issue that I think may reduce the quality of our next generation of medical doctors is the medical school admissions committee's focus on diversity. However, due to the controversy surrounding that topic, I am going to hold off on that post for a while!

Wednesday, August 27, 2008

Role Playing

Today, in our 3rd day of med school, we were introduced to clinical role playing. Clinical role playing is a form experiential teaching where the students act out a particular scenario with a standardized patient (an actor).

Today the clinical role playing focused on harrasment. For example, one scenario involved a patient who wanted to meet with her doctor privately to discuss a personal issue. Upon meeting with the doctor, she professed that she was in love with him and wanted to begin a romantic relationship (this violates all kinds of doctor/patient boundaries of course). One of us played the role of the doctor in this situation and the actor was the patient. The scene played out, the actor left, and then we discussed what we thought about the situation, provided feedback to the student who played the doctor, and discussed different ways to deal with this kind of scenario (which apparently happens more than I would expect).

I am interested in seeing how well this "clinical role playing" training prepares us for similar real-world scenarios. I certainly do believe that role playing the scenario is better than simply reading the scene and then having a discussion. However, I think it is much easier to act out a scene in the ideal, ethical way, and it is much more challenging to follow the same course of action when we are actually living the scenario.

For example, in the aforementioned scene with the female patient, we did not have to worry about hurting the patient's feelings when we refused her requests because we knew she was an actor. If the scenario was real, we would have to worry about our patient's future medical care after rejecting her because she would obviously need to see a new doctor after coming admitting her feelings. I suppose the clinical role playing is aimed at getting us to think about these kinds of issues, but I still think role playing will give some of us a false sense of confidence in our abilities to handle the scenarios once we are out seeing patients.

Monday, August 25, 2008

The Beginning

This blog is titled "Medgineer's Corner". As an engineer, I only have the "gineer" part of the title done. So for that reason, and that reason alone ;), I left my job as a software developer and I enrolled in medical school.

Today was the first day, it consisted of a number of housekeeping, orientation lectures. As you can imagine, it was a relatively tame introduction to the profession of medicine. On the bright side, I met a number of interesting people.

The most noteworthy event of the day, strangely enough, involved gender segregation. We were told numerous times that we should not date anyone in our class. Then we were split into small groups (intended to make ice breakers easier). The weird thing was that these groups were either entirely male or entirely female. I guess they are really serious about curbing any potential in-class dating, starting from day 1. I wonder if they will arrange the lecture seating the same way...

Sunday, March 2, 2008

Machine Learning vs. Artificial Intelligence

Artificial Intelligence and Machine Learning are two independent topics that are often used interchangeably by the general public. Artificial intelligence, in general terms, is a field dedicated to creating autonomous machines (think robots from any science fiction movie.) Machine learning is a sub field of artificial intelligence that is primarily concerned with the development of an algorithm that allows computers to learn.

Artificial intelligence starts at the top of the complexity pyramid because it is concerned with making a machine replica of a human being. Machine learning, however, starts at the bottom because it is only concerned with giving machines the power to learn.

Machine learning algorithms have tremendous potential in medical research because if computer programs are able to learn, then they will be able to study.

For example, every day we have more and more medical research that is being produced by scientists all around the world. This is great, except that we are outputting research at a rate far greater than any human can take in and understand. Thus, there are likely related studies that are being published, but not being linked together because researchers of one study are not aware of the related studies. Imagine a study found that rats who do not eat enough carrots begin to develop a disease (exclusive to rats) which is caused from a lack of vitamin A. Imagine also, that a recent study found that a community in South America had an abnormally high rate of blindness in their elderly population. This study looked at different issues, including the diet of the community. Finally, we have a third study that indicates that vitamin A is required to maintain healthy eyes. If you had a server farm that was capable of machine learning and you dedicated this farm to studying medical research, these machines could discover that the solution to the problem faced by the community in South America was that they did not have enough carrots in their diet. The machines would be able to figure this out because they could have learned that:

1) People were going blind in South America (Study 2)
2) Eyes require vitamin A to function properly (Study 3)
3) Vitamin A is found in carrots (Study 1)

Now, this example is obviously ridiculous because it is already well documented that we need vitamin A to maintain the health of our eyes and that carrots are a source of vitamin A. However, the point is that machine learning is powerful because computers can be dedicated to studying our existing knowledge base and looking for connections that we have not yet discovered. Thousands of machines can be put to task and look for connections between existing research at a fraction of the cost a single human would demand in salary. Also, a computer can work 24 hours a day and does not need a bathroom break. I am interested in finding an algorithm that will allow us to use computers to connect medical research.

My next few posts will present some of my thoughts about machine learning.

Sunday, January 27, 2008

Brain Theory = Game Theory?

Harvard scientists are attempting to create a high resolution map of a mouse brain. They want to understand the anatomical properties of the brain and map the connections between different neurons.

Researchers all over the world are rushing to understand the brain; the problem is that they all think their method of research is the only correct method.

Connectomic researchers believe that the only way to understand the brain is by mappingnhow all the neurons interact with each other.

Geneticists believe that the path to greater cerebral understanding is by noting which genes affect brain development.

Biochemists think that we must notate every chemical path way for every brain mechanism.

Brain signal analysts feel that analyzing the brain's methods of signal processing is the only route to understand our brains.

All of these researchers have one thing in common, they are all wrong. Whatever happened to collaboration? If an ornithologist claimed that the only way to understand the ecosystem was by studying birds, and the study of any other creature was a waste of time, most people would think that ornithologist is out to lunch, right? So how can brain researcher understand the mind if they only study one of its properties?

All of the aforementioned research methods have the common goal of exploring the brain, but most researchers do not want to collaborate because they do not want to share the glory. The only way we will really begin to understand the brain is if researchers in different fields start working together and we try to learn in small, modular steps. Mapping an entire neural network is great, if you share that data with thousands of researcher groups who all look at different components and use different methods of analysis; but, it is pointless for thousands of research groups to independently study an entire neural network. Didn't Nash have a theory on this?

Thursday, January 24, 2008

Label Persistence on an Image in WPF

One of my side projects is an application that presents the user with an image of the human body with labels on different parts of the anatomy. The user can then click on the label and be presented with information about that body part. Here is an example of a skeleton with its skull labeled:

I am writing my application in Visual Basic using WPF. WPF is a very powerful technology that allows rapid user interface development; however, it does not have a native mechanism for label persistence. That is, if I label a part of an image, the label will not automatically reconfigure itself with the image if the user resizes the application. This means if the user resizes my application while it is displaying the above image, the skull label will no longer be on top of the skull in the image.

The solution to this problem turned out to be trivial, I am just surprised that Microsoft did not create a feature to handle this user scenario; a scenario that, I would think, is relatively common.
To solve this problem, I had to store several data points.
  1. The original height and width of the image.

  2. The 4 margin distances (distances between the left, right, top, and bottom of the label from the left, right, top, and bottom of the image, respectively).

  3. The width and height of the label itself.

Normally a control object in a user interface is only represented by two data points, its x and y coordinates; however, I had to represent the label with the 6 data points mentioned in 2. and 3. to maintain label persistence.

Now for the algorithm:

  1. On a resize event, I calculate the change of both the height and the width of the image.

    Dim widthMultiplier As Double = AnatomyImage.ActualWidth / oldWidth

    Dim heightMultiplier As Double = AnatomyImage.ActualHeight / oldHeight

  2. I then use these multipliers to reevaluate the margins, height, and width of the label.

    Dim x As New Thickness With {.Top = Label1.Margin.Top * heightMultiplier, _
    .Bottom = Label1.Margin.Bottom * heightMultiplier, _
    .Left = Label1.Margin.Left * widthMultiplier, _
    .Right = Label1.Margin.Right * widthMultiplier _
    Label1.Margin = x
    Label1.Width = Label1.ActualWidth * widthMultiplier
    Label1.Height = Label1.ActualHeight * heightMultiplier

Thus, the label is always in the same relative location on the image because its height, width, and margins still "own" the same relative percentage of the image.

...Seriously though, why was label persistence not a property in WPF?!

Monday, January 14, 2008

The Cocktail Party Problem

The cocktail party problem is a common problem in digital signal processing. It describes a scenario where a number of guests are in the same room at a cocktail party having simultaneous, mutually exclusive conversations. For our example, let's assume there are 5 speakers having mutually exclusive conversations. We want to record the conversations and play them at a later date.

If we place a single microphone in the middle of the room and record all of the conversations, we will hear distorted bits of different conversation when we play back the recording. We may be able to tease apart bits and pieces of the conversation from the speaker who was closest to the microphone; however, this is far from ideal and we can do much better. If we place five or more microphones in different parts of the room and record all of the conversations, then we can tease apart each conversation by analyzing the collective recordings.

This is done through Independent Componenet Analysis (ICA). ICA is a mathematical process that takes n linear equations as input and produces n linearly independent equations as output. Thus, if we take the five recordings, one from each mic, and process it through ICA, five independent speeches will be produced as output. These independent speeches correspond to the different conversations that were being recorded.

ICA is useful in EEG brain research because the EEG produces a cocktail party scenario. The brain has many componenets that may be "talking" at the same time, like the speakers at the party, and the EEG channels record voltage readings from the brain, like the microphones in the room. Thus, ICA allows us to seperate the data into independent equations that we believe correspond to different components in the brain.