Sunday, November 25, 2007

Retention

As I cast my mind back over the past weeks and try to remember some of the anatomy I fought long and hard to learn, I come up blank in a lot of areas. I can, of course, remember the major things, big muscles etc.., but I can't recall necessarily the spinal segment of a given nerve, or the course of the lesser occipital nerve, or which muscles articulate the thumb. Even metabolism is fading, and it's only been a week since my last exam. I don't recall all the details of gluneogenesis regulation for example. Medical school is a process of cramming, literally. Recall those days in school right before a final exam when you were trying desperately to remember some fact only for the exam. That's how I study, only all the time. I don't know how long term retention is possible, given the pace and quantity of information to learn. I think the theory is that I will now have a context of information that I will reinforce during the last two years of school and eventually in residency. It's a sound idea in principle, and the quantity of information makes this system necessary, but it is quite frustrating to study 50-70 hours a week and not remember the things that took so much effort to learn.

The metabolism unit here is in dire need of reworking. The previous course director left and is in Atlanta now, but he would have been gone anyway because the students collectively upbraided him year after year in course evals. The resulting course that I have endured, is a hodgepodge of biochem and nutrition with some esoteric diseases thrown in for interest. I currently don't really think I could give decent nutritional advice to a patient based on information I learned here that I didn't already know from the Cheerio's box. That's not saying I haven't learned, but the things I have learned don't seem to be really applicable. Yes, I might understand the mechanism of non-classical galactosemia, but I can't explain in layman's (or Laman's as Aaron would say) terms how diabetes works, or the regulation of protein v. fat v. sugar usage in the body, or how satiety and appetite are currently understood, or the role of exercise on the whole system at a biochemical level. Some of this will hopefully be elucidated in the subsequent 4 weeks, but I'm not too sanguine. Perhaps, again, the current classes are laying a foundation for the GI unit next year and the wards in later years. If so, patience is in order, but the current unit is still a disjointed conglomeration of lectures loosely based on metabolism.
-Spiff

Free Money!!!!

So, out of the blue, the financial aid department decided to bequeath me $5000. I just got the email and out of the goodness of their hearts decided to give me some money. Very much appreciated (WooHoo!!!)I don't know why, but now I have a scholarship.

In other news, I did nothing all week. I have a flight simulator game that I have been playing all week and will be loath to put down once school starts again. Mindy and I went to the Missouri history museum which was moderately interesting. It was a pretty laid back vacation, with lots of lounging around doing nothing. I'm normally not a fan of that kind of leisure, but it was very restful after 14 weeks of craziness. I now have 4 more weeks of cell bio and metabolism, but then 2 weeks of vacation! whohoo!
that's all folks!

Tuesday, November 20, 2007

Vitamin C prophylaxis debunked

A large meta analysis was just published in the Cochrane Database of Systematic Reviews to determine the effectiveness of mega-dosage vitamin C (>0.2 g/day). For the those unfamiliar, a meta-analysis is a compilation of many researcher's work combined mathematically to yield results. In essence it combines many large studies into one huge study. The end result: large dosage vitamin C was ineffective in preventing or shortening to any significant degree the incidence of the common cold. Believe me? here's the abstract:

BACKGROUND: The role of vitamin C (ascorbic acid) in the prevention and treatment of the common cold has been a subject of controversy for 60 years, but is widely sold and used as both a preventive and therapeutic agent. OBJECTIVES: To discover whether oral doses of 0.2 g or more daily of vitamin C reduces the incidence, duration or severity of the common cold when used either as continuous prophylaxis or after the onset of symptoms. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2006); MEDLINE (1966 to December 2006); and EMBASE (1990 to December 2006). SELECTION CRITERIA: Papers were excluded if a dose less than 0.2 g per day of vitamin C was used, or if there was no placebo comparison. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed trial quality. 'Incidence' of colds during prophylaxis was assessed as the proportion of participants experiencing one or more colds during the study period. 'Duration' was the mean days of illness of cold episodes. MAIN RESULTS: Thirty trial comparisons involving 11,350 study participants contributed to the meta-analysis on the relative risk (RR) of developing a cold whilst taking prophylactic vitamin C. The pooled RR was 0.96 (95% confidence intervals (CI) 0.92 to 1.00). A subgroup of six trials involving a total of 642 marathon runners, skiers, and soldiers on sub-arctic exercises reported a pooled RR of 0.50 (95% CI 0.38 to 0.66).Thirty comparisons involving 9676 respiratory episodes contributed to a meta-analysis on common cold duration during prophylaxis. A consistent benefit was observed, representing a reduction in cold duration of 8% (95% CI 3% to 13%) for adults and 13.6% (95% CI 5% to 22%) for children.Seven trial comparisons involving 3294 respiratory episodes contributed to the meta-analysis of cold duration during therapy with vitamin C initiated after the onset of symptoms. No significant differences from placebo were seen. Four trial comparisons involving 2753 respiratory episodes contributed to the meta-analysis of cold severity during therapy and no significant differences from placebo were seen. AUTHORS' CONCLUSIONS: The failure of vitamin C supplementation to reduce the incidence of colds in the normal population indicates that routine mega-dose prophylaxis is not rationally justified for community use. But evidence suggests that it could be justified in people exposed to brief periods of severe physical exercise or cold environments.





The idea of megadosage became popular in 1970 when Linus Pauling the two time nobel laureate advocated its usage. Subsequent studies have had mixed results in substantiating his theory, and as this meta analyis proves, there really isn't any theraputic benefit, regarding colds at least. Most americans would probably not be hurt, however, by ingesting more fruit, even if it were in the mistaken belief that it would fortsall the dreaded cold.

Saturday, November 17, 2007

At least it's done

Score:
Metabolism: 0 George: 1
Cell Biology: 1 George: 0

I was wayyyy overprepared for metabolism, or at least so prepared the thing was a cakewalk excepting the few questions that were on stuff we never covered, not even mentioned in the syllabus. Cell Bio was like a stay in a Turkish jail. Unpleasant, to put it nicely. BUT, they're both done, and now I have a week off.

Friday, November 16, 2007

Saturation Point

It's 9:45 on Friday night. I spent all day studying since we didn't have class. Tomorrow I have my first saturday exam of medical school. They are de rigeur next year, but this is the first so far. The curriculum deans decided to rearrange the schedule such that we have a week off for thanksgiving rather a the cost of having a saturday exam. I am desperately looking forward to a break. I haven't ever had so much consecutive school. 15 weeks straight. This week has been particularly brutal. Yesteray we (Aaron, Dan and I) started reviewing histology slides at school at 630. My study day ended at 10pm, with about 30 minutes off for lunch and some miscellaneous breaks. Today wasn't much better, but at least we started at 8.

I have finally put all the pieces together for the regulation of glycolysis, gluconeogenesis, TCA cycle, oxidative phosphorylation, the pentose shunt, glycogenolysis, glycogen synthesis and some other miscellaneous junk. These processes govern how and when sugar is both broken down and synthesizd. Mostly they follow common theme of phosphorylation inducing activation or inactivation of a particular key enzyme. It's a complex system of switches, where by inactivating one enzyme, you can activate another which deactivates a third, and allows the process to go. The logic of it can be kind of hard to get, but after taking genetics at UO, this makes a lot more sense.


To bring some clinical relevance to this very dry biochem, they bring up obscure metabolic anomalies with defects in these enzymes. For example, Galactosemia illustrates the importance of having a galactose-1 phospho uridyl transferase or a galactose kinase enzyme. Without one of these, an infant cannot process lactose in its mother's milk (lactose is a disaccharide made of galactose and glucose). The infant becomes severely hypoglycemic (CBG of ≈ 10 mg/dl), has seizures, coma, and if the deficiency isn't caught within 3 days, irreparable brain damage. Useful in real life? hmmmm. The pediatrician in the case we studied (this happened at SLU) hadn't ever seen it in 20 years. It has an incidence of 1/62,000. Useful for USMLE step 1, most definitely.

This is what's been on my mind all month, so now it's on yours.

And now I lay me down to sleep
my pile of textbooks at my feet
If I should die before I wake,
that's one less test I'll have to take.

Tuesday, November 13, 2007

Phrase of the week

Rather than bore you with my whining about how impenetrable some of my syllabus pages are, I thought I'd give a sample:

"Conversion of phosphorylase A to phosphorylase B is by protein phosphatase, which dephosphorylates phoshporylase A, resulting in the inactivation of this enzyme. Phosphorylase kinase activates glycogen phosphorylase by serine phosphorylation."

After many tortuous hours of study and some fortuitous revelation, I can now tell you what this means. The readable version would be this:

Conversion of A ---> B happens by addition of a phosphate group.

The reverse, B ---->A, occurs by the removal of this phosphate group.

2 different enzymes participate in these reactions.

Phosphatase kinase adds phosphate to B, making A.

Protein Phosphatase removes phosphate from A, making B.

A is active, B is inactive.

Active protein has a phosphate then.

Tell me which is clearer.

Monday, November 12, 2007

I'm sick of glucose metabolism

There, I've said it, and I don't feel bad about it. The metabolism unit here at school needs some serious re-working. The first two weeks after anatomy were really easy. The first lecture was ridiculous in fact. It was "this is where the elements come from ." I have taken genchem, thank you. Is the fact that Iodine is only made in supernovae relevant? NO! Do we need a lecture on peptide bonds? NO! we have all taken organic chemistry to get to medical school! DO we need a very general lecture on DNA transcription regulation when we have an entire 8 weeks of molecular biology in January? NO! Because the first two weeks were so general, they have really piled on the lectures in the last two weeks. 3 hours of lecture straight? no problem! 4? sure! Hey, and while you're at it, why don't we go to an IDIOTIC "interdisciplinary" class for two hours after spending 3 hours learning detailed glucose metabolism regulatory pathways!

I love to hear left-wing tubthumping about health care reform! Please, explain to me how obesity is an inquity in health care when it is mostly lifestyle derived (excepting the few with hormone problems). Oh, I see. You like Popeye's Fried Fat more than spinach. Well, it's just not fair now, is it? Those nasty goverment people, snatching you out of your house and forcing fried food down your throat against your will. No, no wait. YOU chose to eat that. You chose to smoke. You chose to sleep with 8 people a night, and now you're an STD poster child. (yes, I used D for disease, not the new politically correct "I" for infection. Syphyllis is a disease!) How the heck can it be an inequity if you chose something with poor consequences for your health? AUGGH.

This "interdisciplinary" class is really really annoying. It's the first year they've tried it and I have nothing but bad things to say for the experience. It's two hours I waste every week. The ostensibly interdisciplinary part comes because there are nursing students and social work students thrown in with the med-students. One curious observation is that the nursing students are extremely quick to tell us that they're 'accelerated nursing students', meaning they have a bachelors and will get a BSN in 1 year. I have spoken to several students who, right after we introduced ourselves, told me that they were accelerated nursing students. I don't know why, though. It's not like they've somehow gained or lost stature in my eyes because now I know that they'll have a BSN really quickly. Perhaps they're intimidated by a medstudent who is all but clueless? Generally, the nursing students are pretty bright, thought there are a few exceptions, though the same is true for my classmates. They seem to have a bit of a chip on their shoulders, however, at least from the few interactions I've had with them in small groups. Ok, now I've wasted 20 minutes venting online. Back to learning why cAMP and PKA upregulate the genes for PEPCK and increase the rate of gluconeogenesis.

Sunday, November 11, 2007

In Flanders Fields

In Flanders fields the poppies blow
Between the crosses row on row,
That mark our place; and in the sky
The larks, still bravely singing, fly
Scarce heard amid the guns below.

We are the Dead. Short days ago
We lived, felt dawn, saw sunset glow,
Loved and were loved, and now we lie
In Flanders fields.

Take up our quarrel with the foe:
To you from failing hands we throw
The torch; be yours to hold it high.
If ye break faith with us who die
We shall not sleep, though poppies grow
In Flanders fields.

- Lieutenant Colonel John McCrae, MD (1872-1918)
Canadian Army

Colonel McCrae died of pneumonia he contracted while sleeping year round in a tent, eschewing the huts his fellow officers lived in, as a show of solidarity for his comrades on the front. He wrote Flanders Fields after 17 hellacious days in an aid station at the second battle of Ypres in 1915. 69,000 Allied troops died during month long battle.

Saturday, November 03, 2007

Returns on investment

For the crew at mission control in Eugene, I have officially passed Anatomy. With a Z score of a whopping +0.2. Simply stunning. That means I was slightly above the median score. Sadly, however, I didn't honor, for reasons discussed previously. I don't think I've ever had a class with such a low (study time)/(grade) ratio. I must have put in nearly 70 hours a week, more in exam weeks. I have, however, learned, that outlines, even exhaustively thorough ones, aren't as useful to me as a textbook with real english prose to read. I just do better when there are full sentences. I
wish, however, that the phrasing were less dry. I know, it's not 'scientific', but with history books it's so much easier to remember what you read because the phrasing can be varied and interesting.

I also took my one and only exam in Epidemiology and Biostatistics. It was a pretty dull class, but one of the most useful I'm told. It was a very qualitative, nearly non-mathematical version of biostats. I can at least understand more of what I read in the primary literature now.

We are also taking a new class called Critical Issues in Health Care, which is mercifully only once a week, and is 'inter-disciplinary', which means there are nursing and social work students in there with us. There is still a 3:1 ratio of medical to nursing students however. The class is supposed to make us aware of issues in american health care delivery. The first class didn't tell me anything I didn't already know, which is that things are pretty well screwed up. The lecturer for the first three lectures is some bigwig at the Missouri Foundation. He's a big proponent of a single payer system, and promised more polemical tubthumping next week. It's axiomatic among medical students at least, that a single-payer system is generally a bad idea, though I'm insufficiently familiar with its implementation in other countries to judge. I'm interested to see if this gentleman has any data to substantiate his position, or if he's just giving his opinions as fact. If the last lecture is anything to go by, I'm not too sanguine. The essence of his talk was that things have been broken since the 1930's, and fixing them isn't very feasible. He also talked about how our system is heavily weighted towards tertiary, high tech, expensive intervention based medicine rather than preventative primary care. He also talked about the fact that primary care docs are becoming increasingly hard to come by...

I have some major bones to pick with his last assertions: Why do you think that newly graduated physicians are drawn to choose tertiary specialties? For myself, my contracts with Total Higher Education Lenders influence those decisions heavily. My classmates and I borrow $65K a year, most of it at 6-8% interest. The principal alone is $260K for all 4 years, but at the end of a residency, the total will be in the 450K range. The ability to repay that in a timely manner most definitely is a factor in planning a career. If school were cheaper, there would definitely not be the disincentive to choose primary care. I'll have to update this as the class progresses because it'll be interesting to see how the various lecturers approach the problems in our system.