Information and Answers to Questions
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Mini Med School 2007 Information and Answers to Questions |
If you're interested, you can browse the questions & answers from the 2006 Mini Med School by clicking here.
Anatomy and Physiology
Q: What's the story about coughing to prevent a heart attack?
A: “The American Heart Association does not endorse "cough CPR," a coughing procedure widely publicized on the Internet. As noted in the American Heart Association's textbook Basic Life Support for Healthcare Providers, the American Heart Association DOES NOT TEACH THIS AS PART OF THE CORE CURRICULUM IN ANY COURSE.
During a sudden arrhythmia (abnormal heart rhythm), it may be possible for a conscious, responsive person to cough forcefully and maintain enough blood flow to the brain to remain conscious for a few seconds until the arrhythmia disappears or is treated. Blood flow is maintained by increased pressure in the chest that occurs during forceful coughs. This has been mislabeled "cough CPR," although it's not a form of traditional resuscitation.
This coughing technique to maintain blood flow during brief arrhythmias has been useful in the hospital, particularly during cardiac catheterization. In such cases the patient's ECG is monitored continuously, and a physician is present.
During cardiac catheterization, patients may develop sudden arrhythmias. If a life-threatening arrhythmia is detected within the first 10 to 15 seconds and before the patient loses consciousness, a physician or nurse may tell the patient to cough. Repeated, forceful coughing can help the person stay conscious until the arrhythmia disappears or is treated.
Therefore, the usefulness of "cough CPR" is generally limited to monitored patients with a witnessed arrest in the hospital setting.” from the AHA
If you are having a severe arrhythmia or heart attack, the best thing by far to do with what may be limited time before you pass out, is call for help from someone nearby or 911.
Incidentally, there is a new idea that "chest-only" CPR may be just as useful in a heart attack situation as the combination of chest compression and mouth-to-mouth breathing, especially for those of us that are not expert in the technique: read an article about it here.
Q: Is Restless Legs Syndrome real? How is it treated?
A: Restless legs syndrome (RLS) is one of the most common movement disorders, affecting about 5 to 10 percent of the general population. Clinical criteria established by the International Restless Legs Syndrome Study Group include a set of four symptoms that establish the diagnosis of RLS: (1) a desire to move the limbs, often associated with unpleasant sensations; (2) restlessness: (3) worsening of symptoms at rest and at least temporary relief with movement; and (4) worsening of symptoms in the evening or night.
The cause is unknown; there is a genetic component but it is not strong. Some reports of abnormalities in iron metabolism have appeared, and iron supplements will help in iron-deficient patients. Drug therapy may be with dopamine agonists some of which are also used for Parkinson's disease: gabapentin, pramipexole dihydrochloride, carbidopa/levodopa, ropinirole hydrochloride . These drugs have side effects of some concern, so you must follow your health care provider's advice carefully.
Q: What about repositioning the head to move the little stones around in the labyrinth to treat dizziness?
A: For a chronic condition of dizziness that does not have a more serious cause, repositioning therapy may be tried. There is a slide show about it from the Mayo Clinic; click here. It sure sounds like fun.
Q: A lot of bodily problems seem to involve inflammation. (e.g., I am a transplant patient and rejection seems to be a form of inflammation.) What exactly is inflammation? What causes it?
A: BIG question! Inflammation was known to the ancient Greeks, who applied the terms rubor (redness), calor (heat), dolor (pain), and tumor (swelling). We still think this way. Inflammation is the body’s way of getting healing agents to a local area where they are needed. Local damage causes release of molecules from the affected cells which: make the local blood vessels get bigger (dilate) so that the area becomes red and warm; make the vessels become leaky, so that fluid and white blood cells can get more easily into the tissues (swelling and pain). All this helps to resolve the problem. Trouble begins when for some reason the problem can’t be resolved, for example if the inciting agent can’t easily be removed (a transplanted organ, for example). Then the inflammation can become chronic; and there is an excess of inflammatory signals, which affect the whole body.
If you are curious, JJ Cohen and his daughter Zoë, both of whom are teaching courses in inflammation/ immunology (she's at U. of Arizona) have their students contribute to an inflammation Blog, which anyone is welcome to read: click here.
Q: Are you sure that climbing 3 flights to your office only burns 2 Calories?
A: One of the many things I love about Mini Med School: I just got a note from Brandt Levitt, a MM student, saying that according to Teh, K. C. and A. R. Aziz. "Heart rate, oxygen uptake, and energy cost of ascending and descending the stairs." Med. Sci. Sports Exerc., Vol. 34, No. 4, pp. 695-699, 2002, it would actually be more like 6 Calories! I had calculated it from first principles (how much energy does it take to lift my 75 kg up 14 meters?) but Teh and Aziz actually measured the energy cost metabolically; people are not as efficient as physics equations!
Q: I understand that one can get plaque buildup in the arteries, however, is there any way to get rid of this buildup through diet and exercise? Is surgery the only answer?
A: There is peer-reviewed evidence that strict adherence to a very low fat diet can actually reverse atherosclerotic plaque, and also improve survival rates. The best studied such diet is the Ornish Diet. The Ornish diet is 10% fat, 20% protein, and 70% carbohydrates. The typical American diet is 40% fat, 20% protein and 40% carbohydrates. To complement his suggested diet, Dr. Ornish advocates physical activity and meditation. You can listen to Dr. Ornish discuss diet very intelligently on a video by clicking here.
Cell Biology
Q: In last night's lecture (Cell Biology), the importance of wearing sunscreen was brought up. I was always a big proponent until I read an article in Smithsonian magazine about the use of "nano-particles" in most sunscreens. These are particles made extremely small (man-made that way) for which science doesn't completely understand the long-term effect. In studies on mice, the particles are so small that they pass through the blood-brain barrier and collect in the brain, causing damage. Sounds plausible and scary. What do you think about our bodies and nano-particles?
A: Nanoparticles have been around since before the Earth solidified! So you can't escape them, and for the most part, there is nothing to fear. They are just a form of matter of a certain size (generally smaller than 100 nM, some in the 1-10 nM range; very small.) The ancient Egyptians found that very fine gold particles suspended in colorless glass made it a deep red, so when you look at a stained glass window, you are seeing nanoparticles. Some can interact with light in curious ways, and they can bridge the divide between the Newtonian and quantum worlds. But they are not inherently dangerous, just as “chemicals” are not inherently dangerous; or liquids, which the TSA seems to think are in some way special threats, though most of the explosives we've heard of are solids.
Q: If we wanted to take a few supplements (i.e. Vitamin B, Calcium, etc) is there a website or information tool that we can use to find out if the vitamin/mineral is fat or water soluble as well as the side effects on over consumption of certain vitamins/minerals?
Q: If we take certain supplements (i.e. enzymes) everyday will our body slowly learn not to make these supplements since it thinks that we are consuming it daily? If so, then will the body know how to make them if we stop taking these supplements?
A: Enzymes aren't supplements in any way that makes sense to a nutrition expert. They are only prescribed when a person has a known inability to make one, which is not common. For anyone else, depending on the enzyme, they may just change the nature of your diet a bit; that is, if you take lactase, you will get more glucose and galactose, and less lactose, from which those two sugars are derived.
Q: Since trans-fats are such stable molecules, does our body know how to decompose it? Or does it remain in our body forever?
A: They are stable to air oxidation, which is why you can keep them in the closet. But the body can metabolize them as well as cis fatty acids. However, for reasons not yet fully understood, they raise LDL (bad cholesterol) and lower HDL, and the more trans FA in the diet, the higher the risk of cardiovascular disease.
Q: I understand that there are many environmentally induced defects in cell biology, but do you think that over time, our bodies will evolve and learn to protect itself from these environmental factors?
A: That's the rule in evolution, so, the answer is yes. Will we be here when it happens? Uh-uh.
Q: How is it that a person with pica can swallow such large objects?
A: I don't know; it's a compulsive eating disorder, usually of strange objects or substances, so you'd expect some strange behaviors.
Q: For a person with Prader Willi syndrome, can a part of the brain be stimulated to help them?
A: This is a rare syndrome of continuous hunger and compulsive eating, in which the patients can become vastly obese. It is due to a large genetic deletion, and is transmitted by the father (if the same deletion is transmitted by the mother, the syndrome is Angleman's.) There is no cure, only symptomatic and behavioral treatment for the many deficits these unfortunate kids suffer from.
Link to the Prader Willi association.
Q: What can be done for a person who aspirates continually?
A: Get to a doctor NOW.
Q: What determines the need for dialysis, and how does dialysis cleanse the blood?
A: The kidneys keep the blood composition within normal limits, so when they are no longer able to do that, we must take over some of that function. Dialysis is a way of getting some soluble molecules out of a solution, in this case the plasma. There is peritoneal dialysis, where a buffered saline is instilled into the abdominal cavity; metabolites diffuse into it, and after a time the fluid is withdrawn and discarded. And there are machines which take blood, dialyze it, and return it to a vein.
Q: When the gall bladder is removed, where does the liver store the bile?
A: Apparently the liver doen't really need to store bile, it can usually make enough on the fly. But lowering fat in the diet (the main reason we need bile is to emulsify fat) is a very good idea, especially post-gall bladder surgery.
Q: Why is hair in the ears necessary for good sound reception?
A: First we hear of this.
Microbiology and Immunology
Q: When you get sick with a virus, how important is rest and how (why) is it helpful? Would we all be better off if people stayed home for a day or two when really sick vs. coming to work/school and "sharing?"
A: Yes, I think you are right. There is even a new word: “presenteeism” to describe people who go to work sick (a peculiarly USA problem, apparently; we all seem to work too hard.) If nature has made us feel like we want to stay in bed when we're ill, there is probably a really good reason for it. Stay home, drink plenty of fluids, take a couple of aspirin, and call me in the morning.
Q: 30+ years ago, I was vaccinated for yellow fever, typhoid fever and other nasty stuff -- does my body still have the antibodies for these diseases?
A: It might. We are finding that about a quarter of people who were vaccinated for smallpox 25+ years ago are still fully immune, and the rest would get it back very quickly with a “booster” shot. Still, if you plan to go to a place where those are prevalent, I'd ask my health care specialist about booster shots to be on the safe side.
Q: How much is the world's populations at risk to designer diseases?
A: I'm not sure what those are: wearing too much Armani? There was a rumor that the CIA was developing an “ethnic virus” that would only affect certain racial groups; but I don't think they are smart enough to do that, since it would be impossible.
Q: Why can't medical science cure the rheumatic diseases which have been around for years and affect so many people?
A: Not smart enough, not enough funding, hard to work with people since they are outbred and thus unpredictable, we already do a pretty good job treating them, they are very complex, progress is being made, stay tuned.
Q: Why doesn't the immune system eliminate constant, low grade infections in the body, for example staph in the skin or subclinical gum infections? These infections always seem "active" when present rather than going into some "latent" stage.
A: Bugs are very clever at exploiting design weaknesses in the human body. For example, the gingival crevice, between tooth and gum, is neither inside nor outside the body; it is not washed by antibacterial saliva, but T cells can't get there, either. So bugs find it just the right niche; warm, wet, full of nutrients, but low on defenses. They settle down and you have periodontal disease. The skin also has issues; it has to support more bacteria than there are people in the world, because they are good for it; so bad bugs exploit this hospitality.
Q: Why do some vaccines require boosters (subsequent shots) and how is it determined how much time should pass between an initial vaccine and a booster?
A: All of that is empirical: they are tested initially in various ways and their efficacy determined. In general we try to keep it as simple as possible, so most people will comply, even if another shot might add some protection.
Q: Have there been any studies done with a connection of cancer treatment i.e. chemo , radiation, meds, etc and a person with lupus?
A: Not that we are aware of. Some of the drugs used for cancer treatment are also used for lupus and other autoimmune diseases, since both have a problem with dividing cells; cancer cells, or overstimulated lymphocytes.
Q: What causes lupus "flare ups"? Can they be prevented?
A: Almost all autoimmune diseases are “relapsing-remitting.” We don't know why, except some can be worsened by physical or emotional stress; and there may be environmental triggers of flare-ups that we haven't yet identified. Proper treatment should minimize flare ups but can't completely eliminate them.
Q: Are the different auto immune diseases related? Can you comment on "natural immunity" - is it simply that you didn't know that you have had the disease and produced antibodies?
A: There is a relationship; if one family member has an autoimmune disease, first-degree relatives are at higher risk for a variety of conditions than are unrelated people. Good website: http://www.nlm.nih.gov/medlineplus/autoimmunediseases.html Natural immunity is a vague term; we think you don't make much of a response unless you've been exposed, though you may have been unaware of it.
Q: When somatic hyper mutation occurs, is it possible for that to generate auto-immunity?
A: No one thinks that's an important risk mechanism. If the B cell happens to mutate to bind self, it will not get help from an antiself T cell (T cells do not hypermutate) so is likely to stop dividing and may die.
Q: I know of a man who got West Nile Virus and then was bitten by a 2nd infected mosquito, leading to severe and long lasting symptoms, including cognitive problems. His doctor said it was an antibody cascade. Why would this cause long lasting problem?
A: He was one smart guy to know this had happened, since there would be no way of knowing whether a mosquito that bit you was carrying virus, unless this was all done in a lab. It is possible, but also possible that the disease just was getting worse and the second bite was irrelevant.
Q: How and/or why does vitamin C help your immune system? What are the structural factors or chemical properties that help your immune system?
A: Vitamin C does not help your immune system; it helps your financial system if you happen to be selling it for that purpose. We never see scurvy any more! There is no such thing as an “immune booster” and we mostly have immune systems that are just fine. There are real immunodeficiencies, but they are rare. If your body is healthy, so is your immune system. If it isn't, it needs working up by a clinical immunologist, and not by the person at the health food store.
Pathology (and some leftovers!)
Q: I have a quick question from last Wednesday's immunology presentation in the Museum of Natural Sciences. There was some discussion with regards to the evolution of man and how our life span has improved through the ages in part due to advances in medicine, water treatment, nutrition, hygiene, etc. Is there any supporting evidence that our immune system has "evolved" to some extent and man is less likely to succumb to certain illnesses which may have previously caused an epidemic? It seems if our bodies are full of such a wide variety of lymphocytes in adulthood and only a fraction of our resistance may be innate or transferred from our mothers in early childhood, a certain amount of our immune response may have originated generations ago and are eventually coded for. I understand evolution and developmental factors may be random and caused from mutations or genetic variability over an extended period of time. Is it fair to say future generations will have an immune response to pathogens of present day provided the individuals do not lack a normal immune system? Obviously, as various organisms change and mutate, their virulence may also follow suit leaving man just as susceptible to new / future illnesses we may not have experienced to date. But in your own words, "bring it on" because we have quite a regiment ready to defend our bodies to foreign invaders.
A: This is a great question and I sure can’t answer it. Evolution takes longer that human history, so I doubt that any major changes have happened in the last 10,000 years. Also, there are so many of us now it is hard to imaging an exciting new genetic invention spreading through the species, as it might have done when the world had only a few hundred thousand people. But the secret of our success is something I didn’t spend much time on: the way we generate all those antibodies (and T cell receptors) involves randomization processes during the rearrangement of the DNA segments. So each antibody will have an unexpected amino acid here, several over there, a replacement here, and so on; it generates a potential thousand million billion different antibodies! Likely to be enough to keep us healthy as long as we take care of our environment and keep it healthy, too.
Q: Is an autopsy always done in a case of suicide? If so, Why?
A: All suicide and homicide victims are “coroner’s cases” in Colorado. The coroner can decide whether an autopsy must be done; if the cause of death is considered to be known or obvious, the coroner can decide to forgo an autopsy.
Q: We have students here at the Anschutz-Fitzsimons site who are invited to attend a histology/histotechnology career day on October 29 -- can you tell them a little bit about "histology/histotechnology."
A: The National Society for Histotechnology describes their profession better than we can, at http://www.nsh.org/organizations.php3?action=printContentItem&orgid=111&typeID=1158&itemID=14718
Q: The last time I was in a hospital lab, at Children's, they had a lab test that could determine how likely a patient was to develop allergies, and what allergies they might develop. How does that work?
A: You are probably referring to two tests. The first measures total serum IgE, the class of antibodies that are the cause of allergies. It is not very definitive, since you can have specific allergies without an elevation in the total. The other is called RAST: Radio Allergo Sorbent Test. This measures the amount of IgE antibody directed against a specific allergen, so you can test against peanuts, penicillin, molds, ragweed, and so on. It does not detect “unknown” allergens, only ones for which an allergen preparation and a RAST is available. The ones that are tested are usually ones that are suspect from the patient’s history.
Q: Is it your job to look at the genetic markers associated with cancer?
A: Yes, when that is done clinically (as opposed to for research) it is pathologists who do the testing. Histopathology technicians may do the actual work, and together with the pathologist, interpret the results.
Q: How hard is it to get into medical school?
A: Easier than you would think. This is from the Association Of American Medical Colleges, October 2007: “The 2007 entering class to U.S. medical schools is the largest in the nation's history, according to data released by the AAMC last week. The number of first-year enrollees totals almost 17,800 students, a 2.3 percent increase over 2006. More than 42,300 individuals applied to medical school this year, an increase of 8.2 percent. Nearly 32,000 were first-time applicants, the highest number on AAMC record. The 2007 medical school applicant pool also included more individuals from racial and ethnic minorities. The number of black male applicants and Hispanic male applicants, for example, both increased this year by 9.2 percent.”