Friday, October 31, 2014

WILTIMS #206: Witches' warts for Halloween!

And so the lame-duck week has come to an end. When crazy tests are put on a Wednesday, I don't think anyone expects much to get done on Thursday and Friday. Very few people stuck around for lecture and the presentations were held to mostly introductory topics. We learned our first 3 of untold scores of virus categories today: papillomavirus, polyomavirus, and adenovirus.

HPV by electron microscopy
The only one of these you're likely to know is (human) papillomavirus, aka HPV. These viruses can cause warts (yes those warts too), a slimy infection of mucous membranes (yes those membranes too), and cervical cancer (there's only one cervix, but for the sake of completeness: yes that cervix too).

TIL: The way HPV can cause such diverse conditions is that each subtype of virus encodes a specific subset of genes from its tiny genome. Subtypes 16 and 18 cause cancer because they express genes for three oncoproteins. These use the same techniques as cancer to convince the infected cell to replicate unchecked. The virus doesn't actually care if the cell divides and/or becomes cancerous; it just needs the cell to replicate its own DNA so the virus can then use the cell's replicative machinery to reproduce itself.

WILTYIMS #205: Thank you, sir, may I have another?!

Yesterday was another marathon exam session (hence my silence earlier in the week (actually, my posts are almost always silent (wait! I found an exception!))). We had exams from 9 to 5 with an hour lunch spent cramming for the tests we hadn't yet taken. Livin' life to the fullest right here.

Anyways we did, in fact, have class today because reasonable recovery time is for losers, apparently. We started our final chunk of microbiology with lectures on fungi today to be followed by an introduction to viruses tomorrow (or mycology and virology, respectively). To be honest, I don't think my brain had fully reset yet before lecture today and I retained absolutely nothing from sitting in class. But for the sake of you, my determined reader, I dug back through the lecture slides* and found a thing:

TIL: Ringworm is a complete misnomer. Unlike roundworms, pinworms, and hookworms, which are all horribly gross macroscopic worms that can live, grow and breed inside people, ringworms are not actually worms. Ringworm is the colloquial term for a large group of cutaneous (skin) infections caused by fungi. Amusingly though, the colloquial term has its origin in the actual medical name for the disease.

The different types of ringworm are classified by the Latin word tinea, followed by the Latin term for the body part they infect. So athlete's foot, which is a type of ringworm is called tinea pedis, which literally means "foot worm" even though there is no worm involved.

* Dug all the way to slide number 3
 Seriously, wear shoes or larvae will puncture your bare feet, swim to your lungs, crawl out of your trachea, to be swallowed into your intestines and grow into worms that feed and grow while releasing eggs in your poo. Yay parasites!

Friday, October 24, 2014

WILTIMS #204: ✌♒ These aren't the symptoms you're looking for...

Today I spent far more time with my study group than in class and here is the result of 3½ hours of work:

Totally makes sense, right? Myeloid neoplasms still to come...

TIL: "B symptoms" are a weird term for symptoms used in lymphoma staging. They include intermittent fever, night sweats, and unintentional weight loss. If those are the 'B symptoms', what are the 'A symptoms'? you might reasonably ask. There aren't any! Or, more precisely, "A" indicates the lack of symptoms. So a stage IIA lymphoma is less severe than a stage IIB which presents with some or all of the symptoms listed above.

Say you want to check if a CT scanner malfunctioned during a scan or you're treating a nuclear power facility worker who was briefly exposed to a radioactive source. How could you tell if damage was done when outwardly these patients look and feel totally fine? Well, it turns out that the most sensitive cells to a massive full-body radiation exposure are leukocytes (T cells, B cells and natural killer cells of the immune system). So by doing a complete blood count (CBC) you can quickly see if these canaries in the proverbial coal mine have keeled over, indicating more serious systemic cell death to come.

WILTYIMS #203: Translocate THIS

T At some point IL and today IL more about: There are a whole slew of chromosomal translocations that cause leukemias and lymphomas. These dangerous mutations occur when one gene, usually involved with cell proliferation, is grafted into another locus that encodes for some highly expressed protein.

Think of it as though some cellular proteins are painstakingly made by hand while others are mass-produced on an assembly line. Then some cancerous businessman comes in and finds a way to slip the blueprints for the handmade protein into the assembly line. Suddenly the shoddily made copies of the rare protein flood the market using the machinery of a simpler (gene) product.

In real life the assembly line protein is some important part of the immune system, like a piece of the antibody molecule of which we need to be able to produce immense quantities to fight infections. Then a mutation swaps-in a normally highly regulated molecule that controls cell growth and division, like cyclin D. The growth protein is then made at levels reserved for antibodies causing cells to divide in the uncontrolled manner of cancer.

The image to the right (from Wikipedia, amazingly) is a nice graphic showing the locations of the chromosomal fragments that swap, as connected by the disease that the swap causes. Notice that a bunch of diseases are connected to chromosome 14; this is where the immunoglobulin heavy chain (IgH), a part of all antibodies, is normally encoded. A translocation between part of chromosome 8 and this region of chromosome 14, or put more succinctly t(8;14), causes Burkitt's lymphoma. t(11;14) causes mantle cell lymphoma and t(14;18) causes follicular lymphoma.

The t(9:22) translocation is particularly interesting. This is called the Philadelphia chromosome (after the city of its discovery) and it's associated with chronic myelogenous leukemia.  Here, the gene that's swapped in is not just expressed more but, due to some convenient splicing, actually made more potent. The gene product is a tyrosine kinase, an enzyme that phosphorylates other proteins, and because of this translocation it is constitutively turned on, having widespread and, it turns out, cancerous results.

Thursday, October 23, 2014

WILTIMS #202: Shivers and smiles

Today was not a productive day. Well, it wasn't a productive day toward the goal of passing my upcoming exams, but I did do couple things. I started by giving a presentation on preventing lung cancer to a class of middle schoolers through our school's Cancer Education Awareness Program. It's always fun to scare some silence into a rambunctious class by pulling out my cancer souvenirs.

Then my team played our last flag football game of the season. It was 50-something degrees with 20+ mph winds and somewhere between drizzle and teeming rain. Ever since high school and rainy water polo games (yes, east coast people, we always played outdoors), I've thought rain makes any game more epic. But even though this was a playoff game, this just felt fun. The team we played was from our year and we all knew each other. Everyone was cold, drenched and just wanted to put in our hour on the field and go warm up at home.

But home is not where I went. Tonight was our weekly volunteer evening at the juvenile detention center. So I dug out a towel from the trunk of my car*, changed into drier clothes and headed over to the facility to spend some time with a very different set of kids than the ones I had taught this morning. Though I love giving my little cancer spiel for CEAP, playing games with the kids at the detention facility is probably more fun and possibly more rewarding for everyone involved.

TIL: (and I am literally looking this up right now so that I have something to show for the day, knowledgewise) Elephantiasis is caused by the parasite Wuchereria bancrofti. These roundworms are introduced into the bloodstream by a mosquito bite and then travel to lymph nodes to mature, mate and reproduce. After repeated cycles of reproduction, the dead remains of older generations of worms block the lymphatic drainage resulting in edema (swelling) of the lower extremities and scrotum (on persons with scrotums).

Also learned elephantiasis is called elephantiasis not elephantitis. Just now.
♒☆ The more you know! ♒☆

*This is one frood who always knows where his towel is.

Wednesday, October 22, 2014

WILTYIMS #201: FCM and a comic

Today was a full day of FCM (Fundamentals of Clinical Medicine, the "how to be a doctor" class). We had a brief lecture on how to talk to difficult patients, for instance patients who you suspect of prescription drug abuse or who decide to pursue a treatment plan other than the one you recommend. The latter is often called "patient non-compliance" which has become a sort of dirty word due to the obviously negative connotation. The doctor and patient need to be a team and come to a joint decision on the best course of action for that individual based both on medical science and the personal or cultural considerations of the patient.

The rest of the morning we practiced these skills in small groups with standardized patients. Though the actors' stories are theoretically "standardized," it was interesting hearing from different groups about how uniquely each actor played their part. Some were defiant but willing to budge, others were argumentative and some sounded downright hostile. Our Step II clinical board exams after 3rd year will have similarly difficult patients, but thankfully the vast majority of real world patients will be much more willing to work with us to navigate treatment decisions.

Finally, the afternoon was taken up by our first preceptor session of the year. During each of our first two years we are assigned a local doctor to shadow and learn from for an afternoon every 3-4 weeks. This year I am learning in Mount Vernon, a city in Westchester County just over the county line from the Bronx. Last year I did pediatrics, so it's nice to mix it up and see adults this year.

This first visit was once again frustrating because we have yet to learn much of pathology, but it was already so much better that last year when we were truly useless. I enjoyed talking with patients and riddling through the doctors questions for me about topics I haven't covered in enough detail yet. Hopefully by the end of the year I will feel more comfortable before actually starting our clinical education in July.

TIL: Hypertension (high blood pressure) can come in several forms. One categorization is of whether the increase in pressure is seen in systole (heart contraction) or diastole (heart filling). The former is usually seen in older patients (>50yo) due to atherosclerosis (hardening) of the aorta from the accumulation of plaques. Each time the heart pumps blood out the aorta pushes back and these plaques make it less accommodating, thereby putting pressure on the heart to pump harder. Hypertension caused by other chronic conditions usually increases the diastolic pressure and these conditions are often seen at an earlier age.

Monday, October 20, 2014

WILTIMS #200: Writings, reminiscence, and zombie amoebae

Bicentennial post! My blog now has as many med school posts as the US had years of existence in the seventies! That's a terrible comparison but I'm going to run with it. Both started at dubiously defined times (US: Declaration of Independence vs ratification of the Constitution; WILTIMS: move-in week rather than day 1 of classes), both didn't align with the larger time division (US: 200yrs in 1976; WILTIMS: #200 in October), and both very nearly didn't make it this far (US: Civil War; WILTIMS: neuro... ugh neuro). And yet, here we are!

Amusingly, today was the release date of our school's student journal the Quill & Scope in which my remarks from the Convocation of Thanks were reprinted. That was one of my most meaningful moments of the past 200 school days and it was all thanks to this blog. Writing every day, even if it's only short paragraphs filled with sesquipedalian (needlessly multisyllabic (apparently there is no word for this that isn't self-descriptive)) scientific words, is the only reason I was able to write that piece (though clearly I haven't learned to control my use of parentheses (or irony)).

A second throwback milestone for the day was learning in pharmacology about the chemotherapy that I was taking just over two years ago. It was very surreal watching classmates take notes on the symptoms that I knew - and still remember - all too well. Nausea is three-pronged: pre-treatment, acute, and delayed. Hair-loss sucks. We were told that low blood cell counts can leave you immunocompromised or anemic, but they didn't mention the psychologic distress of waiting for permission from the lab tech to get the treatment you hate.

I am still so glad I wrote about chemo as I was going through it because, as we broach these topics as student clinicians, I can integrate my experiences with my medical education and that of my friends. Also, I have a head start on the material!

TIL: Naegleria fowleri is a single celled parasite found in warm freshwater that will eat your brain! These creatures get into your head when the unsuspecting swimmer gets water way up his or her nose. The amoeba then burrows up through the very thin cribriform plate of the skull and starts munching on the brain. The amoebae don't want or need to live off of a human host, but when life gives you brains, make brain-ade? Unfortunately for us, infections are almost always fatal.

Alkylating chemotherapy agents are derived from the chemicals in mustard gas from WWI. Well, it does kill cells.

Thursday, October 16, 2014

WILTIMS WILYIMS #199: Short week recap

As we again have Thursday and Friday off this week thanks to obscure Jewish holidays, I thought I'd spread out my three blog posts a bit and publish this one today. I, in no way, just didn't write anything yesterday due to being lazy and/or enjoying date night with the SO. Nope. Wasn't that at all...

Anyways, though this week was fewer in days, it was all the denser in interesting experiences.

Go Little Giant Cells!
First up was the annual first-year vs second-year powderpuff flag-football game. We became the first class to go 2-0 in school history (after being the only class to upset the second-years, last year). It's a good thing we don't generally have competitive teams for med school students because if a "friendly" competition between classes at the same school is this contentious, I'm pretty sure interschool games would turn bloody.

Earlier that day we had an unusual standardized patient (SP) interaction where rather than each of us dressing up in white coats and interviewing one of these actor-instructors individually, we met as a group and interviewed a SP en masse. They had each student ask one question and then the next person was supposed to proceed logically and continue the interview. That was weird. Props to the two SPs we had for staying in character despite the ludicrous situation of being interviewed simultaneously by 8 unqualified med students in neon pink football paraphernalia.

LEFT HEAD: In that case I shall have to kill you.
RIGHT HEAD: Oh, I don't think so.
MIDDLE HEAD: Well, what do I think?

The takeaway lesson from this for me was that asking all the appropriate questions in succession will do you no good if you don't listen and adapt to the patient. That's the skill that's hard to learn. Anyone can read a checklist and write down answers, but learning how to disarm and effectively communicate with a stubborn or defensive patient takes people skills and practice. This is almost impossible to do as an eight-headed med student monster.

Yesterday we had our last required microbiology lab session (though there is an optional lab manual for "How to make pale ale" for when we start studying fungi). We did several stains on tiny bacteria and could only see a haze of red or speckles of blue, neither of which we were supposed to see. The picture below was the most interesting thing we observed all day. What an interesting bacterial growth pattern, you might think. Actually, that growth is the inorganic crystals of the very appropriately named crystal violet dye that we use to perform a Gram-stain. It's an artifact of poor staining technique and it was absolutely fascinating compared to the reddish wisps that were all over the rest of the slide.

The Artifact (nothing to see here)
Lastly, today I got to be a patient again but still learned a thing or two. It was interesting going back to my oncologist for my 4 month check-up, now that we are learning about lymphomas in pathology. Since it's common knowledge amongst my classmates that I had Hodgkin's lymphoma a few years ago, I've had quite a few friends ask excitedly which subclass of the disease I had. Somewhat embarrassingly, I had no idea, so I was looking forward to my appointment today to ask my doc for the details on my long past diagnosis. Then I got a kind reminder that the stuff that we work so hard to learn these first two years is sometimes absolutely useless when it comes to the real world treatment of patients.

TIL YIL: Turns out that with one rare exception, the subtypes of Hodgkin's lymphoma are clinically irrelevant because the treatment, ("ABVD" chemo +/- radiation) is exactly the same regardless of cellular pathology. That doesn't mean I won't be memorizing those subtypes for my exams!

Wednesday, October 15, 2014

WILTIMS #198: Tardy as usual...

Apologies once again. I failed miserably at writing a post yesterday. And it was a fantastically eventful day too! But occasionally sleep wins out. I shall make it up to you today/tomorrow. 'Til then, here's a tidbit to tide you over:

A smudge cell surrounded by healthy RBCs
TIL: One test that is run to diagnose hematopathology disorders (anemias and blood/lymph cancers (leukemias and lymphomas)) is a peripheral blood smear. This one doesn't really need translating. Lab techs literally take blood from a peripheral blood sample and smear it onto a slide. They can then look at the composition of cells and their morphology to try to see if either the comparative amounts of different cells or the shapes of one particular cell type explains a patient's symptoms.

One such morphological indicator is the presence of "smudge cells." This actual scientific term is used to describe diseased B-cell lymphocytes (a kind of white blood cell) that are so fragile that when they are smeared across the slide their cell membrane shreds apart, leaving behind a highly stained blob of DNA from their nuclei. The presence of smudge cells is diagnostic for chronic lymphocytic leukemia (CLL).

Monday, October 13, 2014

WILTIMS #197: Mmm mmm, parasites!

We started a new section on microbiology today with lectures on parasitology. The two main types of medically relevant parasites are so different from each other that it's amazing they are associated. Whereas the various bacteria I've talked about in the past few weeks are all fairly closely related, protozoa and helminths are in different kingdoms. In a well played joke, our professor pointed out that helminths are more closely related to parasitic members of congress (or any of the rest of us) than to protozoa.

TIL: Mycobacteria are tiny - so tiny in fact that they were once thought to be viruses. One of the benefits of their diminutiveness is that, unlike typical bacteria, they don't have a cell wall and are thusly resistant to antibiotics that target cell wall formation such as penicillins, cyclosporins and vancomycin.

Tetracycline antibiotics are not recommended for pregnant women and children younger than 9 years old because they will stain a child's still-implanted permanent teeth gray.

Superinfection is super-awful. That's the term for when you already have one infection and, before you've had a chance to recover, you get a second one. We see this with things like C. difficile where the patient is being treated for one infection and the prescribed antibiotics allow for C. diff. to rear its "difficult" head.

Another example of superinfection we learned of today is when the parasite, Strongyloides stercoralis or threadworm, causes repeated infection in its host through autoinfection. Normally, roundworms transmit to new hosts by releasing eggs through the feces of their current hosts. But threadworms jump the gun and develop to the infectious larval stage before they are excreted... meaning that they can chew into the colon and/or anal region of the host that is already infected.

Sorry about that last tidbit... and just be glad I didn't share any pictures.

Thursday, October 9, 2014

Bonus Post: Dancing the night away

I once again forgot to mention in yesterday's post that I have a couple extra days off this week due to some lesser known Jewish holidays. In fact both this week and next week I have 4-day weekends, so there will be a few fewer WILTIMS posts in the near future. But to make up for my lack of warning, here's a bonus fact:

TIL: St. Vitus is the patron saint of actors, dancers and epileptics. Why would I bring this up? In order to be given a diagnosis of rheumatic fever, which is caused by a systemic infection of Streptococcus pyogenes, the patient is required to present with at least 2 major symptoms or one major and 2 minor symptoms from the Jones criteria. The major symptoms (as listed in the order of a cute mnemonic) are:

  • Joints (polyarthritis)
  • (carditis)
  • Nodes (subcutaneous nodules)
  • Erythema marginatum rash
  • Sydenham's chorea
That last one is the modern term for a neurologic condition involving uncoordinated movements of the limbs. The old name? Saint Vitus Dance.

WILTIMS #196: Known unknowns

Today was a lecture-free day, with 3+ hours of micro lab followed by two more of nutritional pathology case studies. The former was work-intensive and ended with the assignment of "unknown" samples for each student to identify by next week. This, though a little gimmicky, is one of my favorite activities for any lab class because it proves that each of us has actually learned some set of identifying procedures (that we may never be called upon again to physically perform, but still).

TIL: I have a knack for spotting barely something floating in a sea of almost nothing.

An array of TSI test results from Wikipedia
The TSI slant is a very useful test for differentiating between gram-negative bacteria. It uses a diagonally set gel to demonstrate the sugar fermentation, iron oxidation, gas production and aerobic/anaerobic properties of each bacterium. The top, slanted portion is appropriately called the slant while the bottom is the butt. When you are talking to each other about stabbing the butt, context is everything.

If the gel turns yellow it indicates the production of acid through fermentation of one or more sugars. Black indicates the reduction of thiosulfate and production of ferrous sulfide. Bubbles or raising of the agar indicates hydrogen gas production.

Wednesday, October 8, 2014

WILTIMS #195: Mama bears

TIL: If a UTI spreads up from the bladder into the ureters and kidneys, normal UTI antibiotics will no longer effectively treat the infection. This is because they often clear from the bloodstream very quickly and concentrate in the bladder (this is why we use them for UTIs). But since they clear so well through the kidneys, they never reach a high enough concentration to kill the bacteria there before moving straight down the urinary tract.

Aicardi syndrome is a genetic condition caused by a malformation of the brain. Specifically, the corpus callosum which connects the two hemispheres of the brain, is absent. Children born with this syndrome often have severe seizures and very specific retinal tears called lacunae. The incidence if about 1 in every 150,000 live births and the prognosis for development and lifespan is generally very poor.

Things I already knew: Parents of developmentally disabled children are fiercely intimidating people. We had a panel of mothers of kids with chronic health conditions come speak to our entire class which had donned its white coats and ties (and dresses, etc.) - that's an intimidating audience! But these women had learned to manage whole teams of doctors and navigate the most confusing parts of the health system, so 200 medical students were nothing to worry over.

Tuesday, October 7, 2014

WILTIMS #194: Target aquired

TIL: Anisocytosis is the variation in size of red blood cells (RBCs). RBCs normally have a very consistent morphology, so when they look different it is an easy indicator of pathology. RBCs are recycled about every 4 months, meaning that about 1% of the circulating RBCs should be brand new immature cells. Too many young RBCs (which look bigger and greyer) mean that the body is producing more red blood cells (likely in response to their destruction in forms of anemia). To Too few immature RBCs can indicate other underproduction anemias.

Some of the morphological changes that can occur include the formation of very faint RBCs, due to disorders of hemoglobin synthesis or iron deficiency; sickle cells, which are formed due to aberrant hemoglobin polymerisation; and target cells, which produce an extra large cell membrane resulting in a extra fold that makes them look like targets.

The pictures to the right show all of the variations I described above. In order: an immature RBC (polychromatophilic macrocyte), faint RBCs from severe iron deficiency (hypochromic microcytes), sickle cells, and target cells.

Friday, October 3, 2014

WILTIMS #193: A cancerous quickie for Friday

TIL: The cancers that commonly metastasize to bone are breast, lung, thyroid, kidney and prostate. This can be remembered by the mnemonic: BLT with Kosher Pickle.

Paraneoplastic syndromes are symptoms associated with cancer that are not readily explained by the normal attributes of the tumor(s). For example, if a tumor differentiates and starts producing a hormone not normally found in that tissue, that would be considered paraneoplastic.

The TNM cancer classification system differentiates instances of cancer by tumor size, lymph nodal spread, and metastasis.

Wilms' tumor, also known as nephroblastoma, is a cancer of the kidneys that typically presents in children. It is one of the only cancers that is named after a person in addition to its anatomically descriptive name.

WILTIMS #192: Carrier has arrived

Staph. aureus from my nose!
Some weirdly stained microbe from my throat
Only 2-3 of the 23 people in our small micro lab should be nasal carriers of the sometimes dangerous but hopefully harmless Staphylococcus aureus species of bacteria. And I was one of the lucky few! Woohoo? You can see my beautiful clustered spheres in the first of my three microscope cellphone pictures on the left.
Another unknown microbe from my throat

S. aureus is the same microbe that can become MRSA, the deadly antibiotic-resistant infection often picked up in hospitals.

TIL: Plague is passed on by flea throw up from when the rapidly multiplying bacteria block the flea's mouth-straw-appendage and it is forced to cough to clear its throat-straw-thingy at the beginning of the next feeding. This transmits the plague-causing bacteria to the next host.

Thursday, October 2, 2014

WILTIMS #191: Ready for me to pick your nose?

Does that say sheep blood? Yes, yes it does.
Today we finally had a "wet" lab in microbiology, wherein we cultured actual bacteria on various media. We also learned (or relearned) how to do a Gram-stain and tried to use this technique to identify bacteria swabbed from our own throats and noses. There were definitely things there, but nobody had any idea what they were. Tomorrow, we'll get to see the results of the cultures we grew overnight. Now we're all hoping we aren't the ones carrying the most bacteria or one of the 2-3 individuals in each lab predicted to be carrying slightly scarier infections like S. aureus.

TIL: Lyme disease is only found in the northern hemisphere and then over 80% are in the New England and the mid-atlantic states. This bacterium is spread by tick bites but humans are only an incidental host, with the primary host being different depending on the species of tick. Part of the reason for the regional variation in incidence is that there are different dominant species of tick outside of the highly affected states.

Cases of Lyme disease by county, 2012

One of my microbiology professors knows very little US or world geography. Can you spot Virginia?