Saturday, June 30, 2007
One of my favorite novels is Cat's Cradle by Kurt Vonnegut. Written in 1963, it is a ridiculous over-the-top science fiction book that satirizes science, religion, war, politics, the end of the world, and midgets. One of the more amazing things is that Vonnegut describes a fictional discovery of "ice-nine." A single molecule of this substance can "teach" molecules of normal liquid water to arrange themselves as ice-nine. It is as if one molecule of ice can seed water molecules to become that exact form of ice. This, ladies and gentlemen, is exactly what a prion does. I doubt this was the first time anyone proposed this idea, but I was amazed when I realized that Vonnegut in science fiction imagined a mechanism that decades later elucidated previously inexplicable diseases. In any case, Cat's Cradle is a really entertaining, thought-provoking, and highly recommended book.
Friday, June 29, 2007
Mad Cow Disease or Bovine Spongiform Encephalopathy interests me for many reasons. It's gotten so much press and media attention despite being incredibly rare. Indeed, people actually stopped eating beef whereas something like smoking has become so ingrained in our society that we don't even think twice when we see someone light a cigarette. But prion disease (mad cow is a type) is so weird because it involves infectious proteins. What? This goes against decades of biological dogma. Infectious organisms are things like viruses, bacteria, fungi. Aren't nucleic acids the only things that can self-replicate? How does an infectious protein make more copies of itself; there's no such thing (as far as we know) as reverse translatase. And how could prion diseases be sporadic, inherited, and infectious? Prions aren't destroyed by proteases, heat, radiation, or formalin. It just seems so bizarre and scary. Now that we know the mechanism of prion diseases, it hasn't stopped fascinating me. The very concept of something creating new copies of itself makes me think of those robots-take-over-the-world movies. I really realize Nature is a brilliant, cunning, and ingenious engineer.
Thursday, June 28, 2007
Wednesday, June 27, 2007
Tuesday, June 26, 2007
Monday, June 25, 2007
Some of the issues at hand include uncertainty, whether your plans would change depending on the test, financial, family, and educational planning. You may decide not to pursue that PhD or to get fetal testing or to travel the world. On the other hand, you may rather leave it up to God (or chance). You may become incredibly depressed if you have the mutation; you may be plagued with "survivor guilt" if you don't. Maybe you think ignorance is bliss; maybe you think knowledge is intrinsically valuable.
That's a lot to think about regarding a piece of knowledge for which there is no medical treatment. Thus, genetic counseling is central to those contemplating a test. But I like looking at Huntington's disease as an example of how knowledge is not inert. Just the prospect of knowledge transforms lives. This also says a lot about determinism and inevitability. The science of Huntington's disease is based on determinism. That is, the number of trinucleotide repeats in the Huntingtin gene causally determines whether (and when) someone will get the disease. Yet the disease is not seen as inevitable unless that information is known. The disease is determined by someone's genetics regardless of whether they test positive, but the patient only considers the disease inevitable if they test positive (hence the idea that not testing is "keeping hope open"). Until recently, I linked determinism with inevitability, but Dennett's Freedom Evolves that I'm reading has led me to doubt the solidity of that claim.
Sunday, June 24, 2007
On the other hand, a person in a persistent vegetative state can appear awake. They may open their eyes, make movements, and demonstrate sleep-wake cycles. However, they are unconscious and unaware; there is no sign they can respond to outside stimuli. There are extremely rare cases of patients in persistent vegetative states that later regain consciousness. For this reason, these patients are not dead and it would be unethical for a physician to withdraw life support without consent.
Saturday, June 23, 2007
Friday, June 22, 2007
In factitious disorders, patients self-induce or make up symptoms in order to "fake" being sick. Patients with disorders like Munchausen syndrome and Munchausen's by proxy like playing the "sick" role and getting medical attention. Yet the patient might not be conscious they are doing it. Quite odd when everyone else does their best to avoid doctors. This is in contrast to malingering where someone purposely and consciously fakes symptoms in order for secondary gain like getting out of work or getting a handicap sticker. Malingering is not a psychiatric illness (though it is something doctors have to deal with).
Lastly, we talked a little bit about personality disorders, a blurry subject due to the wide range of personalities and cultures that exist. Some odd or eccentric patients have paranoid or schizoid personalities while others are dramatic with borderline or narcissistic personalities while yet others act anxious and are avoidant or dependent. It's important for all physicians to learn how to identify these patients, work with them, and care for them. While I am unlikely to go into psychiatry, all of this stuff on human nature and the diversity of normal and abnormal is fun to learn.
Thursday, June 21, 2007
Tuesday, June 19, 2007
For some reason, in thinking about and studying hallucinations and delusions, I thought of the art of Salvador Dali. "The Persistence of Time" (1931) is hauntingly beautiful and curiously bizarre. I really can't interpret or say much about it, but it's so mesmerizing.
Monday, June 18, 2007
Sunday, June 17, 2007
The service was an hour long and everyone (including schools of dentistry, nursing, and pharmacy) was invited to submit poems, reflections, or artwork. I wrote a poem for the occasion. This is a poem about departure.
The nicest receptions are the awkward ones
before the most serious of ceremonies.
This, in particular, was the immortal congregation
where Pluto was to be excommunicated
from this celestial council.
We never really noticed him, the other planets whispered.
but he didn’t say anything.
Wasn’t he just a rock too cold to socialize?
Too weak to fight off the pitchfork physicists
seeking to dethrone and tame him?
Holding a plate of pomegranate and the stem of a flute,
I gaze at the portrait of Pluto, looking past the icy exterior
and poorly defined surface details. For wasn’t Pluto
also sometimes a dog? Sometimes a God?
Sometimes an element found in nuclear bombs.
Is losing your planethood really losing everything?
You catch me malingering into the night,
fabricating stories of this man whose exterior we have
only begun to know, whose interior we have only
begun to infer.
He leaves tomorrow for a light year cruise,
ironic because he was once the gatekeeper for the place he’s going.
Now he cannot wait to cloister himself with Persephone,
and in front of the gathered planets, he recites a poem:
Run, star princess, run with me,
satchel in hand, let us go to the sea,
stare upon the waves, those starry starry waves
that, moonlit coerced, reflect those graves
so wet with temptation, that in the gloomy dusk
we shell out the cocoon, shed the husk.
You look into the water, rippled and pine
as I trace your image, finger running a line
that parts the sea, so walk with me
out of those stone walls, the entropy.
Sleep, star princess, sleep with me,
constellation made from a plea,
hand in hand, we sink together,
as the satchel releases the worldly tether.
Saturday, June 16, 2007
Speaking of cases, I really enjoy them. In small groups for BMB, we've been getting pretty interesting patient scenarios and generating lists of possible etiologies as random and diverse as Lyme disease, psychosomatic disorders, neurosyphilis, multiple sclerosis, and bipolar disease. Then we order a certain number of tests to narrow down our differential. Finally, we decide how to treat the patient and, like "Choose Your Own Adventure," the different choices lead to different outcomes. It's fun.
Friday, June 15, 2007
Thursday, June 14, 2007
There have been a lot of fascinating therapies developed for pain. We talked about ideas as diverse as acupuncture, hypnosis, placebo, deep brain electrical stimulation. Now what's interesting is that opioids (like morphine) are blocked by the pharmacologic antagonist naloxone (narcan). But, the pain relief effects of placebo and acupuncture are also blocked by naloxone, even though there are no exogenous opiates administered. The hypothesis is that these placebo-type interventions cause release of endogenous opioids, which is what relieves pain. I never really realized that placebo drugs have a physiologic effect; it really demonstrates how mind influences body. Oddly enough, hypnosis is not blocked by naloxone, and the hypothesis of how that works has to do with decreasing the emotional content in pain. If you're thinking about how much something is going to hurt, it's going to hurt. But the same stimulus might hurt less if the patient is hypnotized.
Wednesday, June 13, 2007
Tuesday, June 12, 2007
Monday, June 11, 2007
Sunday, June 10, 2007
I wrote something last year when I hardly understood the gravity of rhetoric and the opposite of fate: "In a blink, a heartbeat, it'll all be over, dust in the air, words pluming from my mouth, hyperventilating incoherence. A word, two, a hundred, a thousand - but even photographs are futile attempts to stop this magnificent mane-throwing beast, charging one-way and never looking back. When you draw optics ray diagrams in physics, you see that the beams converge and diverge, each following its own self-illuminated path. Here we come, focused, interlocking, hands reaching out. Can I grasp yours? Will you hold on? Will I swing you around, Texas Tommy, or latch onto your shoulders, Atlas of the blue cap? Is my influence so great? Are my crutches so weary? And yet, I ask these questions knowing far too well that the interwoven strands of Fate gaze down upon us, intolerable and reminding. How far can these manacles extend? How tight are the knots of this rope? Will I succumb to the fear that I shall be cast away an empty shell, a satellite orbiting the past, letting gravity like wine seep through my fingers as I try to find meaning and place in this beautiful, lonely world?"
Congratulations. I defer to the unyielding mistress of time. Goodbye.
Friday, June 08, 2007
We've had a few patients come in to talk about their experience with different neurologic diseases. A woman with a congenital dystrophy talked about how she was unable to run her entire life and is now nearly bound to a wheelchair. A man discussed how he is able to be a high-functioning lawyer despite multiple sclerosis. Two great old men who had experienced strokes entertained us with humor and hope as they described how they became best friends at the stroke rehabilitation facility. They bantered, joked around, and really got us to laugh.
We've also seen several patients struggling with psychiatric disorders. A woman with "double depression" (dysthymia plus major depressive disorder), a patient with bipolar disease, a man who jumped off Golden Gate Bridge in a suicide attempt. Only about 20 of the 1500+ people who've attempted suicide off the bridge have survived, and he was one of them. Just today, we had a patient with a borderline personality disorder and another with Huntington's disease.
Honoring patient privacy, I won't elaborate on any individual stories. But I've learned an incredible amount from these brave and fantastic people. Illnesses don't characterize them. They are characterized by an indomitable spirit facing adversity we cannot even imagine. They stride into the classroom, enrapture us with their tale of ongoing struggle with a chronic disease. They teach us, they cry with us, they laugh with us, and they remind us why we chose to become physicians.
Thursday, June 07, 2007
And you thought it was hard to get published in NEJM.
Wednesday, June 06, 2007
"Although strong emergence is logically possible, it is uncomfortably like magic. How does an irreducible but supervenient downward causal power arise, since by definition it cannot be due to the aggregation of the micro-level potentialities? Such causal powers would be quite unlike anything within our scientific ken" (Mark Bedau).
I believe strong emergence may explain a lot of scientific phenomena. A single neuron can't "think." It's just made up of cell membrane and mitochondria and sodium channels. It fires all-or-nothing action potentials. It's pretty dumb. But you take a few of them and have them interact. They can start to do cool things, modulating each other's signals, affecting each other's growth. Wikipedia says there are anywhere from 100 billion to 100 trillion synapses. Maybe - just maybe - that's enough to create these unbelievably remarkable properties "thinking" and "consciousness." These higher level functions somehow result from the interactions of all the neurons, though no individual cell has such properties.
I've spent a considerable amount of time thinking about this topic. It has become the mainstay for explaining a ridiculous number of things, from how ant colonies work to architecture to friction. It seems like a simple idea, yet it has fundamental implications about science. If certain properties of a system emerge from complex interactions of its constituents, then "reductionist" science of breaking down problems into its parts will give little insight into the emergent properties. Indeed, in the last decade or so, there has been a great interest in "systems biology" because of this.