The Word Of The Day Is Gynandromorph And The Disease Of The Day Is Blastomycosis

In a conservation genetics lecture this morning (wrapping up our week of medical genetics-- never say vet school isn't fast paced) I learned of the existence of gynandromorphs-- animals that exhibit have both male and female sexual traits because they have cells with both male and female sex chromosomes. In the case of birds, gynandromorphs may have bilateral symmetry-- with one side of the animal having male coloring/features and the other half being female. This presents a problem in chickens because the male half of the head is much larger so the skull ends up being deviated to one side. I have pictures in my notes of a gynadromorph eclectus parrot and zebra finch ("Neural, not gonadal, origin of brain sex differences in gynandromorphic finch" Agate et al. PNAS 2003). Gynandromorphs arise from a non-disjunction event post-fertilization and are not viable in mammals but in addition to birds also occur among butterflies, insects and crustaceans. (Just for kicks, avian gynandromorphs have cells with the sex chromosomes Z and ZWW; a typical female bird has sex chromosomes ZW and a male ZZ. In insects and butterflies gynandromorphs possess sex chromosomes X and XYY whereas a typical male has sex chromosomes XX and a female is XY. Bilateral gynandromorphs arise from a non-disjuction in the first division after fertilization because unlike mammals, in insects the cells are determinate even at this earliest stage and each cell will go on to form the left and right half of the body respectively).

At lunch I went to a lecture titled, "Atypical presentation of a fungal infection in an upstate NY dog." It was a great medical mystery-- a thriller on par with the best whodunit. Of course, it is a bit of a spoiler when the senior pathology resident is one of the three speakers presenting on the case-- you kind of know from the get-go that the patient died and that the mystery was only solved post-mortem. I learned that systemic fungal infections are distinguished not just based on morphological or other features but that they are localized to specific geographic regions. Blastomycosis is a reportable disease in Minnesota and is also endemic to Wisconsin and parts of Canada. Needless to say the dog's history involved travel and the infection was not acquired in the Ithaca area. I also learned that one should never-- I mean NEVER-- try to culture Blastomyces dermatitidis in one's hospital as it will potentially infect everyone if it grows because it will convert from the budding yeast form which is not contagious to people to the hyphae form which is spread by inhalation. You can also accidentally inoculate yourself if you puncture yourself with a contaminated sharp instrument.

The presentation can be quite confusing. Treatment of choice is itraconazole and the dog often gets sicker in the initial days of treatment.

And finally, I ended my Friday in the farrier's shop. My favorite quotation from our hour of instruction-- when asked how much physical strength is required to do the job (note-- asked by a classmate and not me), the farrier responded by saying: "Women don't have the testosterone so they think their way through situations that men just bully through." Although the profession seems like it would require a bit of bulk, apparently 50% of applicants to farrier schools are now women and so that profession is seeing the same shifting demographic that has occurred in veterinary schools. Pretty cool.

Random Tidbit: How Spider Silk Forms And Why That Has Anything To Do With Prions And Alzheimer's

According to my notes, the formation of spider silk involves a conversion from the globular, alpha helical conformation of the silk protein to an insoluble, beta pleated sheet conformation of the silk protein. This is somehow accomplished by the spider "spinning" the silk protein.

You might wonder how this is highly relevant to veterinary medicine. It was cited in my notes on transmissible spongiform encephalopathies as another example of proteins changing conformation. The more clinically relevant example is the conversion of the prion protein from an alpha helical conformation to a beta sheet conformation that induces other prion proteins to change conformation, which leads to the formation of incredibly stable fibrils that accumulate in plaques visible on stained sections of diseased brain.

The formation of amyloid (insoluble plaques of the beta sheet conformation of a protein) is also a hallmark of other neurodegenerative diseases, such as Alzheimer's disease and Huntington's disease. Although not my area of expertise, I worked in a lab that studied Alzheimer's disease and so am familiar with both it and prions circa 2000 or so. (In fact, geek that I am, I used to have a depiction of the prion protein from a biochemistry article hanging in my bedroom in college-- at least I put up artwork then. Now my walls are bare).

I'm surprised to learn that there haven't been any significant breakthroughs in either field since my college days. The closest we've come to a treatment for prion diseases is curing yeast of a prion-like protein, the extrachromosomal element PSI+. The experiment identified a chaperone involved in thermotolerance in yeast that was able to cause the PSI+ protein to convert back to its normal conformation. It's a long way from yeast to mammals and this was all work done before 2000.

Among many unanswered questions in the field, the one I most expected to be answered by now was what is the role of the normally folded prion protein in the body? Genetic knockouts didn't show any abnormalities so this remains a mystery. But prions are conserved in all vertebrates so they must have played an important evolutionary role at some point in time.

On a simpler note, one thing that I've never understood-- prion stands for proteinaceous infectious particle. How does one get prion out of three words that have the acronym PIP?

Perhaps tomorrow I will write what little I know about Alzheimer's disease.

Oh yeah, in case you are wondering what falls under the category of transmissible spongiform encephalopathies:

Creutzfeldt-Jacob disease (familial and the sporadically occuring variant), which is the same as Kuru
Bovine Spongiform Encephalopathy aka "Mad Cow Disease"
Chronic Wasting Disease (found in cervids-- deer)
Transmissible Mink Encephalopathy
Feline Spongiform Encephalopathy
Gerstmann-Straussler-Schneinker Syndrome
Scrapie
and my all-time personal favorite--
Fatal Familial Insomnia

Lucky White Rabbit Numero Dos

Last time I posted a picture of a white rabbit on my blog I had to go looking for one. This one just fell into my lap. Well, kind of. I'd explain but I can't. Let's just say I got to spend the evening doing physical exams on animals that were not patients at Cornell's hospital or part of the low-income clinic and leave it at that.

If that sounds scintillating, then you'll probably drool over my plans for tomorrow evening-- practicing suturing! As anyone who has had to learn to suture knows, it's not nearly as easy as it looks. I've actually sutured live animals before-- it's allowed for licensed technicians to suture skin under the practice act in California. I'm hoping that if I get in a good review tomorrow night then the veterinarians will let me suture on the shifts I picked up over winter break.

Did you notice my hair cut? I can't decide if I like it-- short is easy and my motto is no muss, no fuss, but my identity is all wrapped up in having long hair... A lot of my classmates have complimented me on the new look, which is nice. Although several people think it makes me look younger!&($%@

One more funny thing-- the car I parked next to in the vet school parking lot this morning had a bumper sticker that said, "Ithaca, 10 square miles surrounded by reality." That made me laugh. EB and D always used to say that Northampton was La-La land. I think Ithaca is even more out there. At least someone else had a similar thought-- enough so to make a bumper sticker.

Fun For The Whole Family

That's me with EB, D and a very squirmy Ianite over Thanksgiving vacation. And a photo of Ian and his dad in which you can actually see Ian:


Here Ian is walking around with a block, showing off one of many pieces of canine-themed clothing I purchased for him back in California.


I wish I could have another two weeks of vacation. It was great to see my parents, EB, D, Ian (he's a real little person now, no more baby) and their finally renovated new old house.

It was also great to get out of Ithaca even if just for a few days. The sun is so much brighter in North Carolina! (Just before I left I began using a light box to try to make up for my sunlight deficit so hopefully that will help me continue to feel good now that I'm back).

Not to mention that I made out like a bandit-- I got my mom and dad each to buy me a piece of warm winter clothing as a holiday/early birthday present and my mom also gave me a book that I love even though I am only a few pages into it-- Something for the Pain: Compassion and Burnout in the ER by Paul Austin. It's tales from human emergency medicine-- hauntingly similar to veterinary medicine in some respects and completely different in other ways. I'm riveted.

Thanks everyone!

Round One: I Advance

I got back my final exam yesterday, but waited to open it until this morning. People were opening theirs in the hallway at school and there was a lot of talking about grades and how people did and how they felt about how they did. I don't think there is anything wrong with this sort of thing. But I was certain I did badly and didn't want to show my emotions at school. Then, last night, before going to bed, I was worried it would keep me from falling asleep if I looked.

Needless to say, my classmates and roommate were shocked by my self-restraint. Last night as I sat studying at my desk, my roommate asked inredulously, "You mean you don't know what grade you got yet?" And I said calmly, "No, I haven't looked."

This morning I woke up with butterflies in my stomach. I ate my cereal, fed my cats, and took out the thick manila envelope.

I was shocked. I got exactly the grade I was aiming for. Not an A, but a very respectable grade at Cornell. The class average was a C, and I wanted to be above that.

I have no idea how they graded as I am certain that my raw points should not add up to my grade, but I'm grateful.

I think I'm most proud of my laboratory section. There are many people who said they scored roughly 50% on their lab portion. It was incredibly difficult. People were crying during it. I started in the hardest section of all and was just trying not to panic for the first hour. Even now, people are talking about how they left that section almost entirely blank. Well, I struggled to put down an answer for everything, even when I had no idea what I was looking at, but I really felt like it threw me for the rest of the exam and like I was so shaken I could barely think. But I did perform well under pressure (my lab % was 75%, pretty amazing).

In other news, I've been feeling really sad lately. Depressed. It could have something to do with daylight savings and be related to seasonal affective disorder. There's other things going on in my life that have made me feel sad, but I don't want to go into them here.

I'm now solidly into block II, Cell Biology and Genetics. I like basic science a lot. We're currently studying cell signaling, which is super complex and kind of confusing but I am trying to focus on the major themes. When we started the section on cell-signaling this week our professor put up a slide of a painting by Hieronymous Bosch and said we might feel like we've entered one of his paintings and arrived in a very strange world filled with minutiae. He then put up another slide by Bosch, of Saint Anthony being tortured, and said that we might even feel like our professors are trying to torture us just like Saint Anthony was suffering in the painting. Kind of bizarre. I know the pathologist I worked for over the summer is famous for saying to students, "This isn't meant to be mental torture." Maybe this guy thinks the opposite. I certainly hope our final is not as brutal as the one I just got back, I don't want to take another exam that hard for a long time!

East Coast Medicine

There are certain diseases and problems that are more common in certain regions of the country. California is famous for foxtails. I've seen them in just about every place imaginable, including in the urethra of the penis of a 12 year old blocked cat (that was an unusual blocked cat case just to prove you never quite know what to expect even with something you see all the time).

In the Bay area I also saw a lot of snail bait toxicity, specifically metaldehyde toxicity. And quite a bit of hyperthermia (the only time we ever closed the doors to the emergency clinic was on a weekend where it stayed over 115F and we literally had no more room for bodies, dead or alive, pretty horrific).

Things on the East coast are a little different. For example, I'd never seen a dog with a face full of porcupine quills before I came here (the paws were covered too).

Today I went to an emergency medicine lunch lecture titled "The Perils Of Winter." The speaker covered hypothermia, ethylene glycol toxicity and house fire (for reasons I do not completely understand, house fires are more common in the winter).

I guess winter emergency medicine will be a whole new brand of medicine for me. I haven't seen an ethylene glycol toxicity in quite awhile, California had the good sense to mandate that manufacturers add a bittering agent to any product sold in the state. In fact, a similar proposal is currently on the table nationally, HR 615, but apparently only Republicans support it so far????? Here's another article I found on the subject, "With antifreeze, bitter is better." It seems crazy to me that such legislation has yet to be passed when ethylene glycol toxicity has killed children, not just pets, who ingested even tiny amounts of the sweet substance. When I have time maybe I'll write to my representative and voice my opinion on the matter. I encourage you to do the same if you are at all so inclined.

In other news, I've started block 2. Cell biology. Lots of my classmates are whining about this class but since I love basic science I am enjoying the material.

I'm still learning lots about cows, and other species, but not allowed to post any pictures.

And tonight I went to the low-income clinic again and saw some interesting cases but can't write about the details here. It is nerve-wracking seeing a patient with no one to follow you up. I feel like I must be missing something important every time I do a physical exam and can only hope that I'm not missing anything important.

And the rumor is that if the administration hasn't contacted you yet then you passed your exam and are not on academic probation. I don't totally believe it-- and I won't till I actually have my exam back, but every day that passes works in my favor and means it is more likely I was in the passing range.

Survive And Advance

One of the second year vet students likened vet school to an NCAA tournament. He said, "The goal is to survive and advance [to the next round]. How much you win by does not matter."

I've achieved step one-- I survived block I, and all five days of my final exams. Now I have to wait two weeks to see if I advance to the next round. At this point, I don't care if I get a D or an A as long as I pass. Of course, it is preferable _not_ to be on academic probation, but the end result is the same if I get a D or an A-- I advance.

I've posted the picture of me with a white rabbit because I don't want to be outdone by my sister. She thinks she can keep up with me by posting some photos of her and her daughter with a plastic cow. So I had to find a white rabbit (his name is Gideon) to prove I can keep up with her photos of my niece with a white rabbit!

Now, let's hope I can pull a passing grade in this class just like I pulled this white rabbit out of a hat!