Friday, February 29, 2008

The Return of Paternalism?

Paternalism is the notion of doctors unilaterally acting on the patient's behalf. It follows in that "Father Knows Best"-type of tradition (hence, the word). In recent years though, medical ethics has veered away from the traditional paternal role of the physician towards one of neutral advisor. This new ethic placed patient's autonomy as the paramount ideal. Patients were supposed to make decisions for their own care after being presented with the options in an unbiased manner by their physicians. The physician-as-agent was supposed to merely standby and execute the patient's decision. They could offer advice if asked, but had to be careful not to advocate too forcefully, lest they violate the norm of autonomy.

Of course, most patients who are not well-versed in the issues involved still rely on their doctor's assistance in making that ultimate decision. New research in psychology and behavioral economic shows that perhaps patients do in some cases need this "nudge" in the right direction. However, as the article notes, if one cannot trust the public to act in their own interests after even a "nudge," why not do more?
Many of the suggestions in “Nudge” seem like good ideas, and even, as with “Save More Tomorrow,” practical ones. The whole project, though, as Thaler and Sunstein acknowledge, raises some pretty awkward questions. If the “nudgee” can’t be depended on to recognize his own best interests, why stop at a nudge? Why not offer a “push,” or perhaps even a “shove”? And if people can’t be trusted to make the right choices for themselves how can they possibly be trusted to make the right decisions for the rest of us?
But, therein lies the problem: if doctors push, we risk the pendulum swinging too far back towards paternalism. It seems that there is a real dilemma brewing between the necessity of paternalism and the ideal of autonomy. Modern medicine so far does not seem to have a palatable answer.

Thursday, February 28, 2008

The Perils of Organ Donation

Organ donation is clearly an area fraught with ethical dilemmas. A recent story has shed more light on the differing incentives various actors face in the organ donation decision. The story concerns a surgeon who has been accused of inappropriately prescribing medications in order to hasten a donor's death so that the organs harvested would be more viable. At first glance, it seems that the surgeon prescribed medications to ease the man's suffering as he was removed from a ventilator. However, the article goes on to note that the transplant surgeon's presence in the room violated protocol, and that while administering the medications...
According to a police interview with Jennifer Endsley, a nurse, the transplant team, including Dr. Roozrokh, stayed in the room during the removal of the ventilator and gave orders for medication, something that would violate donation protocol. Ms. Endsley, who stayed to watch because she had never participated in this type of procedure, also told the police that Dr. Roozrokh asked an intensive care nurse to administer more “candy” — meaning drugs — after Mr. Navarro did not die immediately after his ventilator was removed.
Sadly, I am more inclined to believe the nurse's version of events. It's sometimes sad to think how technology has given us this great power to save human lives, yet somehow, the entire process almost ends up being almost dehumanizing. I remember observing a liver transplant procedure and being in awe that I was seeing the inside of someone's body with this giant cavity where the liver once was, yet simultaneously, somehow detaching this from the person that lay beneath the drapes. Actually, viewing a harvest was more striking. When we first met the donor, she was in the neuro ICU, brain dead, but her heart was still beating. We went into the OR, draped her, prepped, and soon made an incision and began the harvest. Only after about an hour into it did I realize her heart had stopped beating. A necessary step, yet it seems strange that no one really gave much pause to acknowledge this event. I do not claim that all transplant surgeons / staff are like this, but I do recall having this distinct feeling as I watched the procedures and how the transplant team functioned. I think the rigors of being involved in transplant surgery forces one to compartmentalize and focus so narrowly on the harvest and transplant that one may lose sight of the humanity underneath it all.

Think there's a better way? Read about some more views on organ donation.

Wednesday, February 27, 2008

Psychiatry or Sigh-chiatry?

My first full day on my psychiatry rotation was a minor revelation. Although each specialty has its own unique culture, I think in some ways, psychiatry is, um, "uniquer." This is not meant as a criticism or derogatory in any way; I just find it very intriguing since the approach to the patient and the manner in which they are discussed seems very different to me.

So, why do I say sigh-chiatry? Even though my one day of experience is hardly enough to draw any definitive conclusions, I did observe more sighing today than I feel I've seen in any other rotation. While medical specialties tend to always believe they are "more sinned against than sinning," the psychiatry team definitely bought into this to a higher degree. This is not to say that they do not provide quality care and a valuable service to their patients, or that they somehow infringe upon other services to a greater degree. In fact, to a certain extent, I agree with their claim that other services dump on them.

Yet, I feel there is more to the sighs than merely a sense of injustice. My sense is that, unlike most other specialties, psychiatry deals with the abstract, the gray areas, the parts of medicine that make most doctors uncomfortable. Doctors must acts with a presumption of infallibility to be effective. To do this, they are bolstered by hard science and objective fact. Psychiatry strives for this, but due to the complex nature of the problems they face, they are at a disadvantage. This vagueness is both a boon and a burden. It benefits psychiatry by forcing the doctors to treat their patients more holistically, but limits psychiatry's ability to offer definitive answers. The patients' frustrations to some degree become the doctors', if only due to human nature. As our attending was discussing today, the psychiatrist must integrate not only objective clinical data but also subjective emotional data. He described how humans have 'mirror neurons,' which are special neurons that respond to images of suffering (or any other emotion) by triggering an empathetic response in the viewer (think of a guy cringing when he sees another guy kicked in the groin). Furthering this idea, the human response of the doctor to the patient and his troubles is of course primarily empathy, but one cannot help share their exasperation as well.


Tuesday, February 26, 2008

Noooo! Not Diet Sodas!

I have a weakness for sodas. I wouldn't go so far to call myself an 'addict,' but perhaps that is my own denial kicking in. I used to drink Cokes like there was no tomorrow. Over time, I switched over to Pepsis, and eventually Diet Pepsis. I think I rationalized my habit by thinking that the 'diet' part made it okay. It's just flavored water! Right?

Sadly, articles like Can Sugar Substitutes Make You Fat? seem to imply that diet soda isn't as benign as I once thought it to be. The article argues that when one drinks diet soda, the body is expecting to see calories, but does not get them, requiring the person to eat even more later on to make up the perceived deficit. It's an interesting argument, and one I'm willing to buy. However, it raises two issues: first, does this mean that drinking Cokes/Pepsis is relatively better than their diet versions, since the body will receive the calories it expects and not overcompensate? Somehow, I doubt this and just assume the article means that diet sodas are not as innocuous as advertised but still better than the alternatives. Second, the article merely notes a correlation but does not really explain why the mice described would overeat to compensate. If anything, you'd expect the mice to consume more calories, but then stop once they reached the amount their bodies thought was required. Also, the mice's bodies had adapted to the decreased caloric intake, so perhaps the real issue here is not the overeating later to compensate, but rather the repression of their metabolism.

Couple this study with other concerns over sweetners (aspartame -> cancer?) and my diet soda just got a lot less appealing.

Still unconvinced? Read about the possible link between diet sodas and chronic kidney disease.

Monday, February 25, 2008

A Few Interesting Stories

Whew! Done with Step 1! I've enjoyed a few days off, but it's back to the wards tomorrow, specifically the psych wards. I don't have anything in particular to discuss today, so here's a smattering of links with interesting stories:

When a murderer becomes a medical student - a medical school in Stockholm is faced with a dilemma over what to do when a convicted murderer who has served his time is found to be in the student body.

Do statins really prolong a patient's life? - an interesting look at the issue of how to use a drug for a disease versus as prophylaxis.

Who really gets MRSA? - As reports of a new strain of MRSA among homosexual men appeared, the article notes another group that also has a high incidence of such infections.

Hoarseness on the political trail - Find out what the candidates do in their attempts to not lose their voice while being a "voice for the people."

Seven Common Medical Myths - Haha, I must admit, I have held at least 4 of these.

Does a surgeon's gender matter? - Wow, I never would have considered to research this, but it is something to ponder, especially in gender-based operations (ex. mastectomies, prostate surgery)

Friday, February 15, 2008

The Great Pellagra Epidemic of 1915

You're thinking, "What? Pellagra Epidemic?" Yea, I did too, but apparently, this epidemic is what lead to the discovery and identification of pellagra as a disease caused by vitamin deficiency, specifically Vitamin B3. Pellagra was found to be a vitamin deficiency by Dr. Joseph Goldberger:
The puzzle of pellagra was solved by Dr. Joseph Goldberger. Dr. Goldberger was assigned in 1914 by the US Public Health Service to the South to deal with pellagra. After inspecting Southern orphanages, mental hospitals and prisons, Goldberger made the pivotal observation that the malnourished inmates of those institutions often developed pellagra while the better-fed staff did not. Pellagra, he deduced, did not arise from germs, as was commonly believed, but rather from a nutritional deficiency. To prove this, Dr. Goldberger, his assistants and even his wife engaged in experiments called "filth parties." They injected themselves with blood or ingested the scabs, feces and body fluids of patients. None developed pellagra. He also did decisive experiments with Mississippi prison inmates (who "volunteered" in return for a full pardon). Dr. Goldberger fed them a poor diet that he believed caused pellagra and within months, many developed the disease. He then added meat, fresh vegetables and milk to their diet and reversed all of the signs and symptoms of pellagra. Dr. Goldberger never identified the dietary principle that had this extraordinary effect. He died in 1929 (of kidney cancer). Eight years later, the factor was found to be niacin. This discovery was made in 1937 at the University of Wisconsin. Niacin is abundant in red meat, fish, poultry, and green leafy vegetables. Niacin can prevent pellagra (and can cure it).

Another point of interest: the name "pellagra" comes from the Italian "pelle", skin + "agra", rough = rough skin, referring to the skin problems in pellagra.

Want to read more? Italians also were involved with atropine, as well as pretty women.

Thursday, February 14, 2008

The Fibromyalgia Fallacy?

Fibromyalgia has been a mystery to me as a medical student. Luckily, I am not alone as rheumatologists seem perplexed by this entity as well. The recent NYTimes article Drug Approved. Is Disease Real? describes Pfizer's release of the first drug approved to treat fibromyalgia, Lyrica. The piece raises the issue of whether pharmacological treatments should be developed for conditions that are not yet well-defined. The most telling quote in the article came from Dr. Frederick Wolfe:

Dr. Frederick Wolfe, the director of the National Databank for Rheumatic Diseases and the lead author of the 1990 paper that first defined the diagnostic guidelines for fibromyalgia, says he has become cynical and discouraged about the diagnosis. He now considers the condition a physical response to stress, depression, and economic and social anxiety.

“Some of us in those days thought that we had actually identified a disease, which this clearly is not,” Dr. Wolfe said. “To make people ill, to give them an illness, was the wrong thing.”

If the researchers who helped define a disease no longer consider it one, one must wonder about the motives underlying the pharmaceutical industry's push into this area. As interesting as the diseases treated in rheumatology are from a pathophysiological point of view, these endless "clinical criteria conditions" that are diagnosed by criteria instead of by signs/symptoms ultimately make it unappealing to me. While I am sympathetic to people who suffer from the constellation of symptoms we term 'fibromyalgia,' scientists should be careful to not overly define an entity that is not yet fully understood as this may do more harm than good. If the cause of the disease is not well-known, then what exactly are these new drugs targeting in the body? Without having a better idea of how these drugs work, and having other options available, the use of the new pharmaceuticals seems a bit dubious to me.

Wednesday, February 13, 2008

Who is Dr. Bert O'Malley? And What Does He Have To Do With Roger Clemens?

The big Roger Clemens hearing is today. Both sides have a lot of witnesses with conflicting statements. As I was reading in one report on, a doctor who had reviewed Clemens' medical records did not contain any indications of steroid use:
In a late addition to its case, Clemens' camp planned to submit to the committee on Wednesday a letter from a Baylor College of Medicine professor who examined medical records supplied by Hardin's office. The physician, Dr. Bert O'Malley, wrote that the records, which covered Clemens' time with four baseball clubs from April 1995 to August 2007, were "devoid of suspicious indications" of steroid use, such as high blood pressure or cholesterol, increased recovery time from injuries, increased muscle size, mood swings and numerous other symptoms.
O'Malley also said he saw no record of abscesses, which contradicts a claim by McNamee that Clemens had an abscess on his buttocks while with the Yankees as the result of an injection. Clemens' camp told ESPN's T.J. Quinn that O'Malley was asked to review the records, but he was not paid.
But who is Dr. Bert O'Malley of Baylor College of Medicine? The name definitely struck my eye because I felt I had heard it before, but not in a medical context. Rather, I recalled my parents, who are in research, mentioning his name in the context of their work. A quick Google search later, it turns out, Dr. Bert O'Malley is primarily a researcher! Although he does have an M.D. from the University of Pittsburgh, he is now the chairman of the Department of Molecular and Cellular Biology at BCM. Um, this man probably has not seen the inside of a hospital in 20 years. Even if he does go in occasionally, shouldn't a clinician in sports medicine be the person reviewing Roger Clemens' medical records? Kinda shady, Roger. Kinda shady.

Update: Just to be clear, I'm not questioning Dr. O'Malley's background or credibility. He's a well-known endocrinologist; the issue is more about Clemens' medical history. When the committee subpoenaed Clemens' full medical record, there was an MRI of a buttock abscess:
Clemens’s medical records showed that he might have received an injection of vitamin B12 about 10 days before he met with Taylor on July 28, 1998, to discuss the injury on his buttocks. 
At the time, the infection was serious enough that Taylor started Clemens on antibiotics and asked that an M.R.I. be performed on the infected area. The procedure showed that the infection was probably caused by an attempted deep muscular injection. 
The committee, as part of its investigation, spoke with Dr. Mark Murphey, a radiology expert, who reviewed the notes from the examination of Clemens’s buttocks. 
Murphey told the committee staff that it was highly unlikely that the infection was caused by vitamin B12, a well-tolerated substance. 
Murphey said it appeared, as McNamee had said, that the infection was caused by Winstrol, which has been known to cause infections if not administered properly.
Taylor told the committee that he had given about 1,000 injections of vitamin B12 in his 30 years in baseball, and that he did not remember a player developing any type of infection from it.
So yea, clearly there is some discrepancy here. The only explanations I can think of would be either Clemens did not turn this over to O'Malley, or O'Malley did not interpret this data properly, or the radiologist Dr. Murphey's assessment is wrong.

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Tuesday, February 12, 2008

Tyramine and the Cheese Syndrome

Just a little anecdote about why tyramine can cause a hypertensive crisis:
In humans, if monoamine metabolism is compromised by the use of monoamine oxidase inhibitors (MAOIs) and foods high in tyramine are ingested, a hypertensive crisis can result as tyramine can cause the release of stored monoamines, such as dopamine, norepinephrine, epinephrine. The first signs of this were discovered by a neurologist who noticed his wife, who at the time was on MAOI medication, had severe headaches when eating cheese. For this reason, the crisis is still called the "cheese syndrome," even though other foods can cause the same problem.
Foods high in tyramine include cheese, wine, many meats, chocolate and soy. So yea, basically everything has tyramine in it. Good luck, people on MAO inhibitors.

Pope's Blessing Vs. Claw Hand

A friend recently pointed me towards the First Aid Errata (2007 Edition). Most of the errors were minor typos that would not affect one's learnin. However, I would say about 10% of the errors were significant in terms of content. While I have the 2006 edition, the page was still useful as there will still significant errors in the document that existed in my edition.

One error it noted related to claw hand. The concept of claw-hand had always confused me a little bit, and the mislabeled diagram did not help matters. I was surprised to not find a single good site online that explained the two. This might be more due to my googling skills, but I figured I'd write up what I found.

Pope's Blessing / Hand of Benediction
Nerve: Median
Lesion Location: Proximal (near the elbow) [1]
Deficiency: When the patient tries to make a fist, they are unable to flex the index and middle fingers due to loss of lateral lumbrical action, leading to the hand of benediction. The fingers are extended due to unopposed radial nerve action on the finger extensors. I believe the finger will also be adducted due to loss of abducens pollicis brevics (although abducens pollicis longus should still function).

Notes: This lesion is also related to ape hand due to the fact that loss of opponens pollicis means one has an unopposable thumb (like an ape). It seems some also believe the term ape hand refers to the thenar atrophy, but I like the first explanation better.

Claw Hand

Lesion Location: Medial epicondyle fracture or Guyon Canal entrapment.
Deficiency: There is clawing of the index and middle fingers due to weakness of the ulnar-supplied interossei muscles. [2]

Notes: I think the confusion really starts here since it seems there are two entities discussed: claw hand and ulnar claw hand. The image at right is claw hand as described above. Ulnar claw hand seems to be a late stage of ulnar nerve entrapment in which the ring and little fingers are permanently clawed. It has also been termed "papal claw." I honestly still do not know what someone means when they simply refer to "claw hand."

While I know this post has not been definitive, hopefully it clarified the cause of the confusion here. Clearly, there are still some sources that say pope's blessing / hand of benediction is an ulnar lesion [3 and comments below], but I am still unconvinced. If anyone has a more definitive answer / clarification of what I have written, please comment about it. Thanks!



Updated 2008-08-24: I have made the references clearer so you know where the information is coming from.
Updated 2015-12-08: Updated links

Monday, February 11, 2008

"Entertainment Tonight" Can Cause Seizures

Seizures can have a wide variety of triggers. In an old report, apparently Entertainment Tonight's host Mary Hart's voice was shown to have caused seizures:
Mary Hart may have been asking herself last week why it couldn't have been Barbara Walters, or maybe Vanna White. In an article in The New England Journal of Medicine, Dr. Venkat Ramani, a professor of neurology at the Albany Medical College, told of a highly unusual case in which a woman's epileptic seizures were triggered by the sound of Ms. Hart's voice. Neither Ms. Hart nor her show, "Entertainment Tonight," were mentioned in the article, but Dr. Ramani confirmed that his patient's "reflex seizures" were indeed brought on by Ms. Hart's voice. He said that when the patient first came to him he asked what set off the seizures. "With great hesitation," he recalled, "she said 'You're not going to believe it.' " Dr. Ramani said that her epilepsy predated her watching "Entertainment Tonight," and that the connection between the seizures and Ms. Hart's voice was a mystery. A spokeswoman for the show said that Ms. Hart had no comment.
I came across this piece while reading about strange celebrity insurance policies. Apparently, Mary Hart had her legs insured. Anyway, it should be noted that the article appeared in 1991. Who knows how many other seizures Mary Hart has caused since then?

8 Phun Pharmacology Phacts

Here are some random drug facts/trivia/history I picked up while studying pharmacology. Some of them are well-known; some, perhaps not so much. Anyway, here are 8 "phun pharmacology phacts":

Q: Why do diuretics trigger sulfa allergies?

A: The observation that patients treated with sulfonamides developed a hyperchloremic metabolic acidosis led to the development of acetazolamide and subsequently the thiazide diuretics. (Note: loop diuretics also trigger sulfa allergies, but I am not sure why)

Q: Which drug used to treat hypertension was noted to have a side effect that some middle aged men might find beneficial?

A: Minoxidil was found to cause hypertrichosis (increased hair growth), so a less potent form was marketed as the anti-balding agent Rogaine.

Q: A patient presents with hypotension, weakness, disorientation, psychosis, and a breath that smells like bitter almonds. Which antihypertensive drug might the patient have been on?

A: The bitter almond breath is due to cyanide toxicity, a side effect of nitroprusside. The metabolism of nitroprusside releases cyanide.

Q: Why should people on Viagra not take nitrates?

A: Sildenafil (Viagra) and nitrates act synergistically. Nitrates activate guanylate cyclase to increase cyclic GMP; sildenafil inhibits phosphodiesterase V to inhibit break down of cGMP. Together, the drugs markedly increase cGMP which leads to massive vasodilation and hypotension. Not exactly the best way to rekindle one's marriage, huh?

Quick note: One of the side effects of Viagra is difficulty with blue-green color discrimination, just like the color of the pills.

Q: What are "poppers"?

A: Per PharmCards, poppers are "street forms of amyl nitrates used to produce giddiness and enhance sexual perfomance via release of NO in the corpora cavernosa." The drug is related to nitroglycerin.

Q: What drug was initially discovered by William Wuthering as a treatment for dropsy, an old term for edema?

A: Digoxin is a purified extract of the foxglove plant, also known as digitalis.

Another quick note: One of digoxin's side effects is blurry yellow vision (think Van Gogh).

Q: Why are tricyclic antidepressants sedating?

A: They were first developed as antihistamines.

Q: How was penicillin discovered?

A: Penicillin was included in this list of 10 notable accidental inventions. As the story goes:
Everybody knows the story – or at least, should – the brilliant yet notoriously absent-minded biologist Sir Alexander Fleming was researching a strain of bacteria called staphylococci. Upon returning from holiday one time in 1928, he noticed that one of the glass culture dishes he had accidentally left out had become contaminated with a fungus, and so threw it away. It wasn’t until later that he noticed that the staphylococcus bacteria seemed unable to grow in the area surrounding the fungal mould.
Fleming didn’t even hold out much hope for his discovery: it wasn’t given much attention when he published his findings the following year, it was difficult to cultivate, and it was slow-acting – it wasn’t until 1945 after further research by several other scientists that penicillin was able to be produced on an industrial scale, changing the way doctors treated bacterial infections forever.

Can't get enough? Check out why Italian women love atropine, or the top 5 medical urban legends.

Friday, February 08, 2008

A Real Life Case for "House, MD"

Dr. Gregory House is the main character of Fox's sitcom House MD. As most of you likely know, each week, he takes his, um, unorthodox approach, makes a few wild guesses, and generally solves some obscure medical mystery. What cracks me up the most about this show is that the entire hospital is apparently run by perhaps 7 doctors max, who are there all the time, do ALL the procedures AND all the lab work, yet still have time to randomly leave the hospital to investigate whatever random hypothesis they have. Anyway, this week, the NYTimes has a case made just for Greg House.

In the article A Medical Mystery Unfolds in Minnesota, the author describes a mysterious illness that has befallen some residents of a small town near Rochester, MN (home of the Mayo Clinic). What the residents had in common is that they all worked at the local meatpacking plant, the aptly named Quality Pork Processors. The patients had similar symptoms: "fatigue, pain, weakness, numbness and tingling in the legs and feet." The nurses at the meatpacking plant noticed the pattern. Doctors and officials in the plant contacted the Minnesota Department of Health as well as the CDC. The Department of Health decided to investigate. Here's what they found:
On Nov. 28, Dr. DeVries’s boss, Dr. Ruth Lynfield, the state epidemiologist, toured the plant. She and the owner, Kelly Wadding, paid special attention to the head table. Dr. Lynfield became transfixed by one procedure in particular, called “blowing brains.”
As each head reached the end of the table, a worker would insert a metal hose into the foramen magnum, the opening that the spinal cord passes through. High-pressure blasts of compressed air then turned the brain into a slurry that squirted out through the same hole in the skull, often spraying brain tissue around and splattering the hose operator in the process.
The brains were pooled, poured into 10-pound containers and shipped to be sold as food — mostly in China and Korea, where cooks stir-fry them, but also in some parts of the American South, where people like them scrambled up with eggs.
Okay, let's stop everything right here. I'm not even sure why this is a mystery anymore. The clues are staring me in the face. I'm no Sherlock Holmes, but just look at the evidence!

1. The place was called "QUALITY" Pork Processors. Come. On. Since when has the word "Quality" meant quality? Can you imagine buying another product.. oh say.. a car from a company called "Quality Car Company"? Anyway, so we've already established that sanitation is probably not Job #1 at QPP.

2. The process was called "Blowing Brains." Um, that by itself says enough. I mean, what else was on this assembly line? "Feces fling"? They might as well have had the workers just gnaw all the unnecessary parts off the carcass in terms of exposing them to whatever the pigs carried.

3. Blasting air into a hole with no other (significant) hole for it to escape from is a dumb idea. Period.

4. Spraying bits of brain matter is a dumb idea. Period.

5. To be fair, by itself, the spraying may not have necessarily caused disease, but:
The person blowing brains was separated from the other workers by a plexiglass shield that had enough space under it to allow the heads to ride through on a conveyor belt. There was also enough space for brain tissue to splatter nearby employees.
“You could see aerosolization of brain tissue,” Dr. Lynfield said.
The workers wore hard hats, gloves, lab coats and safety glasses, but many had bare arms, and none had masks or face shields to prevent swallowing or inhaling the mist of brain tissue.
So, basically, these workers might as well have been licking the insides of the skulls clean themselves. Genius.

Anyway, to make a long story short, once the workers were away from the plant, they recovered, but not fully. The disease (which sounds like some kind of mix between Guillain-Barre Syndrome and a prion disease to my still-in-training eye) was hypothesized to have been caused by an immune reaction the patients were having to the pig brain matter itself.

The real lesson here though?

Don't aerosolize dead animals!

In case you're not familiar with the show, you can purchase the season DVDs on Amazon: House MD:

Updated 2015-12-08

Thursday, February 07, 2008

Take Wikipedia With A Grain Of Salt

While doing some Step I practice questions, I learned that furosemide blocks the Na+ transporter of the macula densa along with the Na/K/2CL transporter of the thick ascending limb. Upon discussion with a friend, we realized we had a difference of opinion as to where the macula densa was located. I believed it was in the distal convoluted tubule, whereas they placed it at the distal convoluted tubule. I figured a quick Wikipedia search would resolve this. However, I was surprised at what I saw:
In the kidney, the macula densa is an area of closely packed specialized cells lining the wall of the thick ascending limb of Henle (TALH) at the point of return of the nephron to the vascular pole of its parent glomerulus glomerular vascular pole.
I was a bit chagrined to see this, but the article referenced Junquiera's Basic Histology, so I figured I'd bust out my copy to see what it actually said. Here's what I found:
In this juxtaglomerular region, cells of the distal convoluted tubule usually become columnar and closely packed together. Most of the cells have a Golgi complex in the basal region. This modified segment of the wall of the distal convoluted tubule, which appears darker in microscopic preparations because of the close proximity of its nuclei, is called the macula densa.
Source: Junquiera, LC, Carneiro J. Basic Histology, 11th. ed. 2005, p. 379
I suppose some might argue that this is semantics as I believe the macula densa is located at the end of the TALH and at the beginning of the DCT, so perhaps it is in the transition zone between the two. Obviously, the terms are human definitions, and kidneys could care less about those.


Still, I'll take the histology book as the authority, so I went ahead fixed the macula densa page on Wikipedia, but it was a little surprising to me. I know Wikipedia is not flawless but I figured the more specialized the article, the more likely someone who knew something about it wrote it, and the less likely there would be an error. Oh well... I'll still use it, but I guess when there's a doubt, I'll still have to go back to the original sources.

Want more? Read about my initial views on Wikipedia or more renal stuff about how colas affect the kidney.

Wednesday, February 06, 2008

Who Was Typhoid Mary?

Since I'm studying infectious diseases, salmonella has been on my mind. Specifically, the "First Lady" of Salmonella, Typhoid Mary. Who exactly was Typhoid Mary?
Mary Mallon (September 23, 1869November 11, 1938), also known as Typhoid Mary, was the first person in the United States to be identified as a healthy carrier of typhoid fever. Over the course of her career as a cook, she infected 47 people, three of whom died from the disease. Her fame is in part due to her vehement denial of her own role in causing the disease, together with her refusal to cease working as a cook. She was forcibly quarantined twice by public health authorities and died in quarantine. It was also possible she was born with the disease, as her mother had typhoid fever during her pregnancy.
However, my research also uncovered another Typhoid Mary:
Typhoid Mary (Mary Walker), also known as Typhoid and Bloody Mary, is a fictional mutant character in the Marvel Comics universe, most commonly associated with Daredevil as a supervillainess. She first appeared in Daredevil #254, and was created by Ann Nocenti and John Romita, Jr.

Typhoid Mary is an enemy and former lover of Daredevil with low level psionic powers, including telekinesis. She has been employed by organized crime syndicates as an assassin in the past. She is also truly and gravely mentally ill.
I love how the comic Typhoid Mary does not even come close to sharing the actual disease, which is decidedly much less glamorous. Can you imagine a comic book with the real Typhoid Mary? "Oh no, Superman is ill. All he did was eat at the local cafet... oh no! Typhoid Mary strikes again!"

Anyway, back to the real Typhoid Mary. Salmonella causes enteric fever, which presents with fever (duh), abdominal pain, liver or spleen enlargement and "salmon"/rose colored spots on the abdomen. Salmonella can also cause gastroenteritis, sepsis, and osteomyelitis especially in sickle cell patients. Some individuals enter a carrier state, such as Typhoid Mary:
People catch typhoid fever after ingesting water or food which has been contaminated during handling by a human carrier. The human carrier is usually a healthy person who has survived a previous episode of typhoid fever but in whom the typhoid bacteria have been able to survive without causing further symptoms. Carriers continue to excrete the bacteria in their feces and urine and poor hygiene can lead to its introduction into food and water.
However, it fails to mention how exactly Mary achieved this. Was she a mutant, as the comic book world would like you to believe? Sadly, no. The reality is salmonella can live in the gallbladder for years, and carriers secrete the bacteria in their stool. The best part of the story to me is how Mallon continued to work as a cook even after she was quarantined! She was eventually quarantined again and died in quarantine. You've gotta love the level of denial some people have.

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Tuesday, February 05, 2008

Why Monica Bellucci Might Take Atropine

Q: Why might some Italian women be crazy?

A: Atropine makes them that way! Atropine is an anti-muscarinic agent that acts on M1 receptors in the CNS, M2 receptors in the heart, and M3 receptors in smooth muscle tissue and various glands. The drug can be used to treat bradycardia, cholinesterase inhibitor overdose, and mild cramping and urgent bladder in mild cystitis. The side effects of atropine can be remembered by the mnemonic:
  • Red as a beet - Dilation of superficial vessels leads to flushing
  • Blind as a bat - Cycloplegia and mydriasis
  • Dry as a bone - Decreased lacrimation and salivation
  • Hot as a hare - Atropine fever due to decreased perspiration
  • Mad as a hatter - Delirium and hallucinations
It was first isolated from the plant Atropa belladonna (right), so named because extracts from the plant were allegedly used by Italian women to dilate their pupils. However, my un-PC hunch is that some of the women OD'ed on the atropine causing them to be "mad as a hatter." Then again, Italy gave us Monica Bellucci, so perhaps that's an acceptable trade-off.

More anecdotes? Find out why the French are a little too familiar with a certain STD and with a certain might-as-well-be an STD.

Monday, February 04, 2008

Organ Donation Update

Following up on my ground-breaking editorial on organ donation, the NYTimes has recently published two related articles:
Check 'em out and remember: you heard the idea for an organ donation market here first!

Want more? Check out how med school affects how med students speak, or Democractic Candidate Healthcare Proposals.

Friday, February 01, 2008

Wii Memories

As The Onion reports Half of 26 year old's memories Nintendo-related:
According to an fMRI of Jenkins' brain regions during the process of memory recall, his parietal lobe registers the same amount of activity when he hears the word "mother" as it does when he hears the words "Banjo Kazooie."
Sad, and while untrue, I wouldn't be too surprised if this was essentially true for some kid out there in America.


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