So it begins.

We have come to yet another week of exams. Seems like that's all I do sometimes. Next week I will answer over 300 multiple choice questions on two major subject tests and two cumulative finals. Should I survive, I will finally be done with Physio and Biochem. Then I get an entire 2 day weekend before starting block three!

See y'all in Behavioral and Neuroscience!

WILTIMS #114: Now you CME, now you don't

This evening I attended a showing of Dr. Kildare's Strange Case (1940) put on by my school as part of a continuing medical education (CME) series. CME requirements are credits that doctors are required to amass throughout their careers to maintain their licensure. CMEs can be everything from classes, to research conferences, to (apparently) educational movie nights. After the showing there was a panel-led discussion of the movie and medical issues it presented.

Of particular interest was the use of insulin shock therapy to treat a patient with schizophrenia. This was a positively medieval treatment used from around 1935 to 1960, to little proven effect. In the words of one of the panelists, "the reason insulin shock therapy was perceived as working on schizophrenic patients was that, for the first time, someone was actually trying to kill the patient."

The bizarre idea was to put the patient into a hypoglycemic coma and see if she or he is better when you wake them back up (if you can wake them back up). This only seems humane compared to the alternative treatments of electroshock therapy and lobotomy. Amusingly, electroshock is still in use as a last line intervention, although using much more compassionate methods.

I think my favorite quote from the movie was from the chief nurse: "Nurses are just like husbands. You can abuse them, insult them, work 'em to death, jump all over 'em. They'll take it. But give 'em a bad cup of coffee and you got a revolution on your hands."

TIL: Adenosine deaminase deficiency is the cause of ~15% of severe combined immunodeficiency (SCID), the disease made famous by the "bubble boy."

WILTIMS #113: Let talk about...

Yay sex! Not gonna lie; it was an interesting day. I can't tell if everyone is actually getting more mature or if we've just gotten better at holding back the giggles. Maybe that's all maturity is.

TIL: Sperm are not transported to the site of fertilization by their own means (e.g. their flagellate tail). An inert particle placed at the vaginal opening of the cervix will get to the site of fertilization just as fast as a sperm. The tail is used for smaller distances like getting to the egg once in the general vicinity and for penetrating the egg's membranous defenses.

Calcium intake has to be closely watched during pregnancy. If the mother cannot provide enough calcium from the diet, her body with start breaking down bone to fill the gap.

The placenta is very cancer-like. It grows rapidly, produces hormones in proportion to its own size, and is autologous (unresponsive to all normal feedback loops). It is only stopped by being removed during parturition (the time leading up to and including labor and delivery).

So to recap, pregnancy is like growing a parasite within a bubble of cancer inside your body. Yay!

Physiologists are terrible at drawing breasts. The lactating breast is like a bunch of grapes still connected to the stem. The stems are the lactiferous sinuses and ducts that branch out from the opening of the nipple. The grapes are alveoli that secrete milk and, upon manual stimulation of the areola*, can pump milk into the ducts in preparation for lactation. Suckling by the infant causes the release of the hormone oxytocin which feeds back to the alveoli causing contraction and release of milk. If the baby is not switched between the breasts when feeding, the unused breast can eventually begin leaking milk from over-stimulation by oxytocin.

Babies do not suck milk out of the breast. The ducts have very weak walls that would instantly collapse if placed under negative pressure. Instead a baby pinches the nipple in its mouth and rhythmically squeezes the breast tissue, quite literally milking it. There is probably some sucking going on, but that's not the principle means of excretion.

For some humor on the topic of maturity and breasts, enjoy this song by Tim Minchin (contains some explicit and inappropriate language):
                                                                                                                        

*I had thought that areolus was the singular, but in fact areola is the singular and areolæ is the plural. Learned all sort of things today!

WILTIMS #112: A case of the Mondays

Today was a long day. Who holds a quiz on Monday morning?

After class there was a screening of the documentary Fire in the Blood about the unavailability of affordable antiretroviral drugs for the African countries with the highest rates of HIV infection. As with most documentaries I was shocked, appalled and a tad skeptical about some of the more extreme claims presented. Well worth the watch though, if you find the time.

TIL: The release of luteinizing hormone (LH) and testosterone in pubescent boys occurs exclusively during nightly sleep. Getting a full night's sleep as a teenager is important!

WILTIMS #111: Conflict of disinterest

Last night, or in the wee hours of this morning, there was an interesting debate going on in the private Facebook group for first years at my medical school. A student club had just been posting about their campaign to educate our class about the rampant conflict of interest in the medical field, specifically from physicians who receive compensation from drug companies. Fitting perfectly into their narrative, some overly prepared student looking over the upcoming lectures for today noticed that one of our lecturers not only had a slide announcing a conflict of interest, but seemed to have used an entire presentation put together by a pharmaceutical company.

The 1AM hubub was considerable because we had, up until today, never had any presentation that wasn't, with admittedly varied degrees of success, directly put together by one of our professors. How is it that we were already being brainwashed by Big Pharma when we weren't even through our first year of medical school? Why are we paying tuition for a presentation paid for by industry?

When the lecture finally started, no one actually cared about the topic of presentation because we all just wanted to see if the lecturer was the Pharma stooge we had painted him to be that morning. Turns out the presentation was 90% super dry background slides about the physiological basis for the disease process and then a couple case studies of patients that had successfully been treated with the drug. He did a pretty good job of pointing out that the drug in question isn't always right for every patient, though since this topic was his primary area of research, he was solidly in favor of treatment when indicated.

The presenter did seem arrogant and kinda sleazy, but we all agreed it wasn't because of the presentation - that was just him. And like every other presenter we've had, he thought very highly of his own research. Am I glad he had to disclose his conflict of interest? Of course. But am upset that he used a slideshow put together by a drug company that was paying him? Meh. It just showed that he was too lazy to make one himself. I am proud that my classmates and I are involved enough in our own education to have this discussion.

TIL: Artificial growth hormone replacement works really well, sometimes. World renowned endocrinologists can be unpleasant people. All the money in the world still can't buy an interesting presentation.

WILTIMS #110: A tasty, tasty lie

Sometimes the body is stupid. The α-cells of the islets of Langerhans of the pancreas produce glucagon, the hormonal opposite of insulin. Whereas insulin decreases blood sugar levels, glucagon increases it. Ideally, you'd like the cells that make each of these hormones to be able to sense the amount of sugar in the blood, to see if they are needed. The β-cells, which make insulin, can detect blood sugar through GLUT2 glucose transporters. The α-cells, however, use an insulin sensitive glucose transporter, GLUT4, that requires insulin to function.

So, imagine you have type I diabetes. Sorry. Your β-cells don't produce enough insulin, so your blood sugar is always high. The lack of insulin turns off the GLUT4 transporters, convincing the α-cells that you are hypoglycemic when you are in fact quite the opposite. The α-cells release loads of glucagon to fix the imagined problem, stimulating the liver and other tissues to release even more sugar into the blood, making all of your problems worse. As I have said before, 'intelligent design' my ass.

TIL: One protein that promotes fatty acid transport is called, seemingly unimaginatively, fatty acid transporter. But this is conveniently abbreviated as FAT.

The actual cause of death for starvation is typically respiratory failure. In the body's desperate search for energy, it turns from burning the last stores of sugar and fat to breaking down protein, which is mostly found in skeletal muscle. When the diaphragm, the muscle responsible for the bulk of our breathing, is degraded to the point that it can't sufficiently do its job, the person dies.

WILTIMS #109: T4: Judgement Day

Medical euphemisms are interesting. Today we were discussing hypothyroidism, which when left untreated causes physical and mental symptoms that were once referred to as cretinism. This is where we get the word cretin. Well, that's actually tricky because the term vastly predates our understanding of the illness, so in a way the disease was named for the people described by the word. Like spastic, crippled, moron, and many other terms, cretinism was once perfectly acceptable but has become politically incorrect.

The word retarded is particularly interesting because it has a very literal meaning that is still used extensively in medicine, among other places. Retard simply means to slow, e.g. fire retardant slows the spread of a fire. So to say that a child is mentally retarded literally means that their mental faculties are developing slowly. This has become taboo to say outside of a strict medical setting, so we've had to come up with new euphemisms like developmentally delayed. It still means the same thing but hasn't been used as a derogatory slur... yet.

TIL: Competency is a legal distinction determined by a court. Capacity is a medical distinction determined by medical professionals. The latter can be used as evidence of the former. In every other way these two words are synonymous in regards to medical ethics.

T4 - Note the 4 iodine atoms

Thyroid hormone comes in two active flavors, T3 and T4, which differ only by the number of iodine atoms bound to the molecule. T3 is the more active of the two but T4 is both more prominent in the circulating blood and the preferred hormone given orally for thyroid replacement therapy. This is the case because T4 has a half-life of about a week, compared to T3's paltry 1 day. This increased retention allows thyroid hormone levels to remain more constant.

This related tidbit was something I learned while volunteering at a cancer screening clinic last year. The iodine used in the synthesis of thyroid hormone is actually the reason we make and consume iodized salt. The thyroid is the only organ that uses this trace but essential nutrient. This provides a surprisingly easy target for treating thyroid cancers. By injecting radioactive iodine, you can use the body's own natural pathways to target the radiation directly to the thyroid.