Housewatch episode 4.12

Last night's solution to House was incredibly easy to understand, so I'll focus a bit on physiology instead.

The woman (Sarah Silverman's sister for those of you not watching the credits) had nephroptosis, or floating kidney. Everytime she stood up, her kidney slid down lower into her pelvis. She lost blood pressure, and she fainted and her breathing stopped. It's called orthostatic hypotension. The kidney is suspended in the pelvis by connective tissue. It can move easier than most organs. Since we can bend at the waist, this is a good thing.

So, why were they saying everything was backwards? In a healthy person, when you stand up your heart rate and blood pressure go up a little. If they didn't, you'd faint. With the head now above the heart, it takes more work to get blood to the brain, so the heart pushes a little harder, and then circulatory system tightens up a little, so the blood is less likely to trickle backwards.

Housewatch 4.10

It's been such a long time since a new episode of House, M.D., I almost forgot about my resolution to try and explain some of the science and medicine behind the show.

This week, the woman had breast cancer. But it wasn't in her breasts, it happened to be behind her knee. So how did it get there? It wasn't metastasis. Rather, it was a developmental abnormality that left her with some breast tissue that should have been resorbed before she was born.

So, we have to digress into embryology and teratology, which is embryology gone wrong. Many tissues are created, sorted out, grown, trimmed and pruned as an embryo becomes a fetus and then a baby. In the woman's case, a small patch of breast tissue wasn't properly disposed of during development, and it later became cancerous. 35 is young for breast cancer, but they did mention her mother died of it and that the patient had a prophylactic double mastectomy.

Was that really breast milk House extracted from the knee? Yes. Risperidone can stimulate breast tissue to produce milk.

So the women's treatment became a standard course of surgery and chemotherapy.

Finally, it's worth mentioning osteopetrosis (literally, bonestone). It's rare, basically the osteoclasts, which are supposed to clip and remodel bone, are defective. Or carbon anhydrase deficiency can lead to mildly acidic blood, which alters bone metabolism.

Housewatch - Episode 4.8

A little bit delayed, since I knew this would be an unusual episode to explain. (I have kept it very simple. Many of the dirty immunological details have been ignored.) Anyway, the patient had lupus, which is an autoimmune disease. The body's immune system loses its ability to distinguish self from non-self, and attacks its own tissues.

Why was it so hard to catch? Basically, he didn't show the usual symptoms, including the characteristic "butterfly" rash, which spreads across the face under the eyes. In the patient's case, a transfusion of improperly matched blood was affecting his blood cells, which was causing most of his symptoms, and masking or overlapping many of the lupus symptoms.

The explanation was really rushed at the end, but the ultimate problem was the patient had type A blood, while they thought he had AB. So, when given AB, he had a violent reaction to it, which was causing all the bloody episodes. They gave him type A blood and steroids to control the lupus, and he recovered.

Like I said, a lot of immunological difficulties have been swept under the rug.

Random speculations: Big Love got the axe this week, and was turfed for disloyalty. A little surprising, I thought his religion would keep him in. I think 13 is next. If she has Huntington's, she's out of there. Either way, she appears to have a fatal flaw that will get her kicked out soon. I presume the plastic surgeon will go, due to age, leaving us with Amber and Kutner to form the new team, along with Foreman.

Housewatch - Episode 4.7

A great convergence of ideas this week on House, M.D., but probably not the way the producers intended.

This week's patient had Lyme disease, an infection you get through tick bites. The tick carries a bacteria that it gets from deer and other large forest creatures. It's named for Lyme, Connecticut, and is prevalent throughout New England.

The disease wasn't found very quickly, because the characteristic bulls-eye rash at the site of the bite was hidden under his hair.

Sound familiar? It should. Scrubs used the exact same plot three weeks ago.

Convergent evolution? Two shows of writer independently coming up with the same idea? Unlikely. Most likely, the writers and medical advisers read the same news story or journal article and thought that would make a good story.

One can only imagine the groans from the staff of House, M.D., as they realize Scrubs has beat them to the plot!

If caught in time, Lyme Disease is treatable with antibiotics. If you want to hear an endless "he said, she said" debate, google "post-Lyme syndrome".

Housewatch - Episode 4.4

This week on House, the girl was unfortunate enough to have ergotism, a historically common, but now rare, disease.

Ergotism is a result of poisoning by ergot, a fungus (Claviceps purpurea) that grows in rye, and other cereals. In this episode, the patient was baking her own organic rye bread at home. So, she ate it, and the toxins produced by the fungus caused the illness.

The mold can continue to grow in the rye, and secrete a toxin that causes a variety of neurological effects, which can lead to seizures and hallucinations, both of which the patient had. It's also possible to have vascular effects, such as the bleeding the patient had. In worse cases, limbs can fall off.

There isn't a specific antidote, but it can be controlled with drugs that help the blood flow and sedatives for cases of hallucination.

Recently (OK, 1976), ergotism has been as a suggested cause of the Salem Witch Trials (original scientific journal article here). (I was just in Salem.) Briefly, in 1692 a bunch of girls accused people of being witches. Twenty people (men and women) died, 19 by hanging, and 1 by crushing.

Ergot poisoning has been a suggested cause, which largely, but not completely, accounts for the symptoms demonstrated by the girls. Others think they were just evil bitches.

And now, some speculation on what doctors will remain. Amber (blonde doctor) will survive, because she's been given a lot of lines, seems about as amoral as House, and is very ambitious, all traits that House will like. (Or perhaps she could be too similar, and get turfed like the old guy did this week.) The Indian guy will survive, because I've seen him in other shows, or movies. I don't remember. He's not a nobody. The black guy will probably end up part of the team too, because House can pick on him for religion, and therefore have a few religious dilemmas this season. And they wouldn't want to have a team of all-white doctors. That begs the question, where are the Asian doctors? (I can't recall ever seeing an Asian doctor on the show), who tend to have the highest marks on entering and leaving medical school.

The white guy disappears, because he's hardly said a word. The brunette doctor disappears because there can't be two women on the team, though I could see her staying on because she's the most attractive of the group. And the surgeon goes, because he's already a doctor and can simply return to practice.

Another moment of hilarity: Chase suddenly being a accomplished surgeon. Fine for tv, but in the real world, I don't think people realize just how far apart surgery and medicine are. Surgery is carpentry and sewing, medicine is pills, IVs and tests.

Housewatch - Episode 4.3 http://www.blogger.com/img/gl.link.gif

Another episode of House, another post. This time, the patient had the misfortune to suffer from spinal muscle atrophy. In his case, it was ascending, which means it started at his feet, and slowly worked its way up his body. Like last week's disease, it's genetic. But SMA is recessive, which means you need two copies of the bad gene, instead of just one, as in von Hippel-Lindau.

SMA kills motoneurons, which are the nerve cells that control muscles. Related diseases include amyotrophic lateral sclerosis, aka Lou Gehrig's Disease, and Parkinson's. In SMA, the mutated gene (SMN1, or survival motor neuron 1) makes a protein that is essential for nerve cell maintenance. Without it, the nerve cells shrink and die, and without stimulation, the muscles atrophy.

They called what actually killed him by two names, threadworm and Strongyloides. This was very confusing, since they are different, but related diseases. Both are caused by a worm infection. In each case, the 1-cm worms can easily be seen in the stool. That's why the male team wanted a stool sample.

Threadworm, or pinworm, is a very common illness. As this article notes, one course of treatment is usually sufficient to cure the disease. (The patient did not have this.)

Ickiness from Wikipedia:

Reproduction

Pinworm eggs are easily seen under the microscope.

After mating, the male dies. The female migrates to the anus and emerges, usually during the night, to deposit about 10,000 to 20,000 eggs in the perianal area (around the anus). She then secretes a substance that causes a very strong itching sensation, inciting the host to scratch the area and thus transfer some of the eggs to the fingers. Eggs can also be transferred to cloth, toys and the bathtub. Once ingested orally, the larvae hatch and migrate back to the intestine, growing to maturity in 30-45 days. The eggs can survive from 2 to 3 weeks on their own outside of the human body. It is also in some cases where the larva will hatch around the skin of the anus and travel back inside the anus, up the rectum and back into the intestines where it matures. (SOURCES: Rudolph's Pediatrics - 21st Ed. 2003; Current Medical Diagnosis & Treatment - 45th Ed. 2006)

The patient actually had Strongyloides, which involves a different worm that can infect dogs and be transmitted between humans and dogs. This article is very informative. Like a lot of parasites, it has a bizarre life cycle.

But it's easy to treat with a dose or two of ivermectin, which is why everybody was upset at the end that it wasn't caught. Or that it was caught, and the medicine wasn't delivered.

And what about the dog? The dog died because it ate the ivermectin pills intended for the patient. Collies react unusually to it (J Vet Intern Med. 2002 Jan-Feb;16(1):89-94. Ivermectin toxicity in 17 collies. Hopper K, Aldrich J, Haskins SC.).

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House is now HouseMD

In accordance with several suggestions, tags for the television show House, M.D., are now tagged as HouseMD. House music is retaining house.

Housewatch, episode 4.2

Last night on House, M.D., the young Air Force pilot was finally diagnosed with Von Hippel-Lindau disease, a rare genetic disorder that causes abnormal growths throughout the body. The process, called angiomatosis, leaves the patient with cysts or tumors scattered throughout the body. The pilot happened to have hers in the liver and brain, although the blood vessels, kidney, pancreas and retina of the eye are common locations too. It occurs worldwide, in about 1 in 32,000 people.

The gene that causes the disease is located on chromosome 3. It is a tumor suppressor gene, which, when lost, lets cellular division go out of control. This can lead to the overgrown blood vessels, which turn into cysts and in the worst cases, cancer. It is an autosomal dominant disorder, which means only one copy is needed for the disease to occur.

Chase showed up to posit that the pilot's panic attacks were caused by a pheochromocytoma, a known early sign of Von Hippel-Lindau. (One researcher has suggested pheochromocytomas aggravated the Hatfield-McCoy feud. ) A pheochromocytoma is a small tumor in the adrenal glands on top of the kidneys that secretes too many stimulating hormones, like adrenaline, into the bloodstream. This is logical, considering VHL can often cause abnormal growths in the kidneys.

The pilot's original complaint was synesthesia, which is a confusion or overlapping of the senses. The most common form is associating sounds with colors. For instance, a flute would be associated with bright red. I searched PubMed for "synesthesia and von" and "synesthesia and hippel". Both came up with zero results, so I wonder if the writers just made that up.

Addendum: Given that Cameron was only onscreen for 60 seconds, she still managed to be quite annoying. House was right, she did look like a cheap hooker. Dark hair and blue eyes is a much better combination.

Housewatch, episode 4.1

I've decided to start explaining (or trying to) episodes of House, M.D. I like the show, medicine and Hugh Laurie.

Now, last night's episode was a case of mistaken identity. Not very medical.

Perhaps the most interesting medical hypothesis was crush syndrome, which I had never heard of. Basically, you get crushed by a building or other heavy object and unsurprisingly, it's not very good for you. It's common after earthquakes, but was first described during the Blitz, in London, (Bywaters EGL, Beall D. Crush injuries with impairment of renal function. BMJ 1941; 1: 427-32.) when buildings were falling left and right.

During crush syndrome, the large muscles of the body get compressed. Cutting off the blood supply causes cells to weaken, since they don't have the energy to maintain themselves, and they release potassium, phosphate, enzymes and the muscle protein myoglobin into the bloodstream. Ultimately, it's bad for the kidneys. But the brain and muscles can suffer too, often leading to amputation of a limb.

The patient also had acute respiratory distress syndrome. It's a little less interesting. When you have lots of other problems, it's not very surprising that the lungs get a little stressed and can fail when they fill with fluid.

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