Goodbye 2009, Goodbye California

Above: Sunset in San Martin on my last day in California 2009.

It's the end of a long year. I'm going to take a break from blogging for awhile. I'll update in a few weeks, until then I'll be hard at work in my second semester of vet school.
Hermit Thrush

Updated-- I'll do my best to keep writing. It's a nice way to keep in touch with people and I love that some complete strangers read me and offer support. Thanks all. But it is tough when faced with the onslaught of my second semester.

San Martin-- Arabians, Bucks And Cowboys

Above: View of San Martin from SelfSustainableNurse's kitchen. It's not easy to piece together a panoramic view like that from multiple photos-- I'm sure there has to be an easier way to do it than how I did it.

I plan to spend my last hours in the Bay in San Martin. I've roamed the Bay, from San Martin to San Anselmo (given a few more days I would have extended my range South to Monterey, possibly even to Big Sur, and to Point Reyes in the North). The two ends of the Bay are my favorite-- the coast of Monterey bay and Point Reyes National Seashore. Two of my favorite places on this planet. (My other two being the forest in central North Carolina where I grew up and Maayan Tsvi in Northern Israel, overlooking the Mediterranean ocean). And of course I love San Jose, the perfect mid-point, in particular the trails and hills of Almaden Quicksilver.

I made SelfSustainableNurse and her husband laugh a good deal on my visit. I wasn't even trying to be funny. I was just studying. Part of what I have to learn for my 'Veterinarians and Society' course, which specializes in ethics this block/semester, are the different breeds of horses, cows, sheep, goats and pigs (do not ask what this has to do with ethics-- I've long since stopped trying to make sense of my courses and accepted that they are beyond ecclectic in the mix of material covered). I've always found horse breeds especially difficult to distinguish, even way back in tech school. While looking over Arabians, I asked SelfSustainableNurse if she'd ever owned an Arabian. She and her husband just about fell off their chairs in the kitchen laughing. When she regained her breath she explained that both her horse, Percy, and her husband's horse, Phoenix, are Arabians. So yes, two of the horses that I looked at all winter and spring are Arabians. Oops. SelfSustainableNurse loves Arabians because she says they have such distinct individual personalities. But she admits that they are easily spooked/very reactive, which is why I am wary of them.

Next, I was looking out the back kitchen window and saw the new, registered Nigerian Dwarf goat that SelfSustainableNurse recently purchased. I commented, "There's your new ram!" To which she replied, laughing, "You mean buck!" Right. I do remember memorizing that, as well as other livestock terms. Obviously it didn't stick.

One thing I love about San Martin-- the cowboys. There are lots of people out on horseback. SelfSustainableNurse distinguishes between the real cowboys and the macho Mexicans on stallions foolishly showing off just to be cool. She assured me that the photo below was of a real cowboy.

Working Emergency Over The Holidays

Above: That's how I felt at the end of three shifts in a row at the emergency clinic!

I worked Wednesday, Christmas Eve and Christmas. Although everyone has been complaining that business has been slow this year, it was pretty busy. I had a hard time keeping up with the pace-- it's been a year since I've worked as a technician and to top that off everything had moved (those of you who have worked emergency know that there is nothing more frustrating than not being able to find what you need quickly-- I couldn't even find the muzzles as they were in a completely different place than last time I had worked there!)

We saw a lot of chocolate toxicities, which is typical of this time of year. Giving charcoal or UAA gel to animals is one of my least favorite things to do as a technician. Not because it is messy but because I am terrified of my patients aspirating. I've seen a few charcoal aspiration pneumonias that have been referred to us for overnight care and none of them have lived. I especially dislike giving charcoal when my patient is still heavily sedated from the drugs used to induce emesis or is struggling with me fiercely. In fact, I had one very stubborn (but otherwise totally sweet) chihuahua fight me so much that I told the veterinarian I could not get the full dose into her patient. She then came over to help me and found the same thing to be true with both of us working on getting the charcoal into this dog. She commented that one way to get veterinarians to realize that what they are asking is impossible is to make them help. I know that I am just working relief and so I don't really have the doctors' trust the way a regular employee would... but still I hope that if/when someday I am a veterinarian that I trust my technicians' judgment and don't push them to do things that might jeopardize my patients' health.

I also saw one marijuana toxicity. Classic signs-- ataxic, acting as if it is reacting to something when there is no stimuli, low heart rate, peeing all over the floor. The receptionist asked me to triage the dog and after doing a quick once over (pink mm, normal capillary refill time, low heart rate, acted like it had neurological disease and/or was hallucinating) I asked the owners point blank, "Do you have any marijuana in your house?" I think my bluntness caught one of the teenagers off guard and she nodded. Mom was ready to kill. I felt badly and explained we had no interest in the legality of the matter but that it would be much easier to treat her dog if we knew what it had eaten.

What I enjoyed the most on my shifts was the two things I've always liked best as a technician-- lab work and anesthesia. It was rewarding to find that after not working for so long I still knew what I was seeing under a microscope. I found tons of giardia on a direct fecal smear from a puppy that had projectile, watery diarrhea and had just been treated (suprise, surprise) for giardia. It's been a long time since I've seen that alien face-like trophozoite staring back at me through the microscope, flagella undulating wildly. I also found schistocytes on a blood smear from another patient when doing a differential-- I called out from lab to the vet, "Hey, has this dog had a splenectomy?" To which she replied from her desk, "No, why?" Well, it turns out the dog had splenomegaly. Hmm...

I had a cat with rouleaux on the blood smear, differential was a classic stress leukogram. Nothing too remarkable in my book as far as blood work goes in an emergency clinic. The vet later told me she suspected FIP based on a constellation of signs-- uveitis, high globulins, not responding to treatment. When I showed her the lab work she noted that rouleaux is often found in cats with FIP, has something to do with the elevated globulins. I thought that was interesting.

I also got to be the anesthetist for two difficult anesthesias. The first was a geriatric dog, which made me nervous as after not doing any anesthesia for a full year the last thing I wanted was for my first patient to be old and sick! And it was not a smooth anesthesia-- the dog was too light once the vet started doing something painful, and when I deepened the anesthesia the dog got too deep and so we partially reversed its premed dose of hydromorphone. The vet joked, "This dog either wants to walk off the table or die." No fun. But the veterinarian got her job done in a hurry and I turned off the anesthetic gas expecting a fast recovery. Twenty-five minutes later I was still monitoring an intubated patient on oxygen. Realizing that the patient was not going to wake up on its own, I asked the veterinarian if we could reverse the rest of the hydromorphone. She agreed. About one minute after I gave the naloxone to the dog intraveneously, it woke up. Amazing. In all the years I've worked emergency this is the _only_ case where I've ever had to reverse a premedication.

My other anesthesia was a c-section. I had trouble intubating (super elongated soft palate!) and was nervous because there were no premedications on board and a masked induction, which can make for a rocky anesthesia. Plus, I wanted to keep my patient as light as possible so that the puppies would not be too anesthetized themselves when delivered. My patient's blood pressure tanked and wouldn't come back up no matter what I did-- lighten the anesthesia, bolus fluids, give hetastach... you name it. So finally, once all the puppies were out, the veterinarian had me give a dose of hydromorphone to see if that would help. As soon as I had injected the hydro IV, the dog began to tremor violently. I don't know what was going on. I've never seen anything quite like it (although I did once have a dog seize on a propofol induction). My first panicked thought was that my patient was going agonal, but the continuous, steady heart rate and regular, spontaneous respirations did not support that. Eventually she stopped shaking. (Of course then I was shaking from the adrenaline rush that came from thinking my patient was dying). She had a smooth recovery and went home with her pups the next morning.

I went home at 4:30 am Christmas morning after being on since 5:30 pm Christmas eve. That's emergency. And I came back the same day at noon. Now you know why I konked out like the puppy in the picture after I was done working!

Random Useless Information, Results Pending On Post-Mortem

I was extremely lucky to make it back to California last night after an extended stay in the Syracuse airport thanks to the blizzard that wreaked havoc on air travel. I think it is just plain luck that accounts for me getting the last seat on a flight to San Francisco after missing my connection to San Jose.

I'm back, but none the wiser. I find that I know a lot of useless information:

• When I saw a logo with a woodchuck, I thought of what lesions from hepatitis and lymphoma look like on necropsy of a woodchuck. How's that? Cornell has a breeding colony of captive woodchucks that they use for research (apparently a good animal model of hepatitis?)

• When merle coat color in dogs came up, I knew that it arises from a SINE_Cf insertion.

• When a melanoma in a grey horse was mentioned I thought of the connection between grey coat color and the eventuality of developing melanomas and knew that both grey coat color and melanomas also result from a specific insertion (read more here).

• When my dad mentioned an epidemiological study on statins to me on, I immediately thought of how statins are contraindicated during pregnancy based on the discovery (by Cornell veterinarians) that Veratrum californicum is the cause of cyclopia in ewes that ingested it around the second week of gestation. The biological mechanism underlying the teratogenicity of Veratrum has to do with hedgehog and patched signaling and cholesterol hence the concern that statins would also be teratogenic.

• Perhaps most disturbing of all, while watching a TV documentary on Jack the Ripper (article here), I understood why the coroner estimated that it took at least fifteen minutes for Jack the Ripper to severely mutilate his victims' bodies. It's not that easy to cut up a dead body. It takes skill. Which is perhaps why profilers also suggest that Jack the Ripper knew some basic anatomy and perhaps worked in a mortuary. Kind of disturbing that I followed all the profilers' thought processes. If you've never cut up a large dead body (I'm thinking alpaca, horse or cow) then you don't know what hard work you're in for. You have to repeatedly sharpen your knife with that kind of sustained effort (which is another reason the profilers suspect Jack worked in a mortuary-- he'd have access to the kind of instruments needed to quickly and effectively disfigure a body).

And speaking of post-mortems... Back when I was a first year in college I got placed in a special advanced chemistry intro class that was mostly quantum mechanics. It was legendary for being incredibly difficult and for being next to impossible to get an A in (though I did achieve that much to my surprise). The first exam was so tough I still remember questions off of it-- like this one "Prove that orbitals are symmetrical." Uh-huh. I was convinced that I had flunked and I remember telling that to my professor as he prepared to leave the exam room with our stack of papers. He said coolly, "Wait and see what the post-mortem shows." Which, like most exams in my life, yielded a grade much better than my wildest expectations.

So now I always associate grading exams with the word "post-mortem." The problem with Cornell is the time it takes them to do a post-mortem is maddeningly long. I took a midterm at the beginning of December. I will not get it back until I return to school in January. Given that this waiting game makes me extremely anxious, I decided to institute some ground rules for myself to help manage this anxiety. Rule one: do not look up answers after leaving the exam. I can often recall almost every question on an exam just after finishing and would look up ones I was unsure of. This only heightened my anxiety when looking up something made me realize I got that question wrong, especially if I realized I had gotten several questions wrong. Rule two: do not, DO NOT, think about the exam. At all (if possible). Forcing myself to stop thinking about the exam when I find myself worrying about my grade also helps.

Winter Rebirth

alone in the library late at night
snug in my jacket, legs curled under me
a heavy book
(pathologic basis of disease)
half-balanced against the chair's armrest
there is the low background hum
of computers, printers, fluorescent lights
and outside snow falling under a street light

stepping into the parking lot
everything is coated anew
with fine powder

the white layer covering the ground
unblemished
like the smooth skin of a
newborn

there is no ice, no treachery
the fresh snow is crunchy underfoot
like styrofoam packing peanuts

and i think
what better reminder that every moment
i start anew, afresh

i'm starting over, tonight
is the first moment
of my new life
there is no trace of the old
scars and worn ruts of bad habits
i couldn't break

soon this new snow will be marred too
with footprints (already I see dog pawprints by the back door)
soot from car exhaust
and mud from the sludge of soaked soil underneath

but for now i am reborn
silent, in awe
like a puppy taking its first breath

8 Nights Of Hanukah, 12 Days Of Christmas And 13 Ways Of Looking At A Blackbird

It's the first night of Hanukah. I took my block 2 midterm this morning. In just over a week I fly back to California.

I want to celebrate with Wallace Stevens' poem "Thirteen Ways Of Looking At A Blackbird." I hadn't thought of this poem in awhile, but yesterday while composing my own (yes, I wrote "Frozen"), I remembered how much I had loved this poem and realized how well suited it is for December in Ithaca.

Thirteen Ways Of Looking At A Blackbird

I.
Among twenty snowy mountains,
The only thing moving
Was the eye of the blackbird

II.
I was of three minds,
Like a tree
In which there are three blackbirds.

III.
The blackbird whirled in the autumn winds
It was a small part of the pantomime.

IV.
A man and a woman
Are one.
A man and a woman and a blackbird
Are one.

V.
I do not know which to prefer,
The beauty of inflections,
Or the beauty of innuendos,
The blackbird whistling
Or just after.

VI.
Icicles filled the long window
With barbaric glass.
The shadow of the blackbird
Crossed it, to and fro.
The mood
Traced in the shadow
An indecipherable cause.

VII.
O thin men of Haddam,
Why do you imagine golden birds?
Do you not see how the blackbird
Walks around the feet
Of the women about you?

VIII.
I know noble accents
And lucid, inescapable rhythms;
But I know, too,
That the blackbird is involved
In what I know.

IX.
When the blackbird flew out of sight,
It marked the edge
Of one of many circles.

X.
At the sight of blackbirds
Flying in a green light,
Even the bawds of euphony
Would cry out sharply.

XI.
He rode over Connecticut
In a glass coach.
Once, a fear pierced him,
In that he mistook
The shadow of his equipage
For blackbirds.

XII.
The river is moving.
The blackbird must be flying.

XIII.
It was evening all afternoon
It was snowing
And it was going to snow.
The blackbird sat
In the cedar-limbs.

Frozen

frozen inside myself
all day long i have not spoken
one word
out
loud

i have not seen another
soul

birds, yes
(aren't they souls?)

house finch, chickadee
tufted titmouse chattering wildly
and the striking yet furtive white-breasted nuthatch

they keep me company

i feed them in this barren landscape
buried under snow

in return they unknowingly
keep me alive

i practice in my head
words i might say
hello?
how are you?
hi!

longing to connect
locked inside myself

I'm Going To Nevada With Rural Area Veterinary Services

On a day when it feels like my world is ending, it's grey, snowing, and I've spent almost the entire day sitting at home studying minutiae that isn't falling into place for me...

I get an email with a ray of sunshine. I got accepted to go on a RAVS trip to Nevada in March. I'll be working with a team of veterinarians, veterinary students and veterinary technicians to provide free veterinary care to pets on Native American reservations.

I can't believe I got picked.

I have one week to respond. I will think it over, but I think this is a go. Gets me out of Ithaca in the snowy spring and gets me going someplace I've never been before and working with people I've never met. Exciting.

Please G-d, just let enough of this cell-signaling, apoptosis and necrosis pathway stuff sink into my head for me to not be a total failure on my exam on Friday.

If I can only hang onto the feeling of hope for the future.

Getting this email makes me so happy I want to sing, so I put on one of my favorite songs to sing along to (only it makes me homesick for California and my friend LaMexicana who also loves Juanes and was surprised to hear me listening to him, white girl that I am)

A Dios Le Pido
I ask of G-d

Que mis ojos se despiertan con la luz de tu mirada yo
That my eyes wake up to the light of your gaze I
a Dios le pido
ask of G-d
Que mi madre no se muera y que mi padre me
That my mother doesn't die and that my father
recuerde a Dios le pido
remembers me I ask of G-d
Que tu quedes a mi lado y que mas nunca te me vayas
That you stay by my side and never again leave me
mi vida a Dios le pido
my life I ask of G-d
Que mi alma no descanse cuando de amarte se trate
That my soul never rests when it comes to loving you
mi cielo a Dios le pido
my sky I ask of G-d
Por los dias que me quedan y las noches que aun no
For those days that I have left and the nights yet to
llegan yo a Dios le pido
arrive I ask of G-d
Por los hijos de mis hijos y los hijos de tus hijos a
For the children of my children and the children of your children
Dios le pido
I ask of G-d
Que mi pueblo no derrame tante sangre y se levante
that my village doesn't shed so much blood and that will rise again
mi gente a Dios le pido
my people I ask of G-d
Que mi alma no descanse cuando de amarte se trate
that my soul never rests when it comes to loving you
mi cielo a Dios le pido
my sky I ask of G-d

Un segundo mas de vida para darte y a tu lado para
One more second of life to give to you and by your side
siempre yo quedarme
to stay forever
Un segundo mas de vida para darte y mi corazon
One second more of life to give to you my heart
entero entregarte
delivered whole
Un segundo mas de vida yo a Dios le pido
One second more of life I ask of G-d

Y que si me muero sea de amor
And if I die let if be because of love
y si me enamoro se de vos
and if I fall in love may it be with you
y que de tu voz se este corazon
and that of your voice this heart can be
todos los dias a Dios le pido
every day I ask of G-d

Out For A Walk In The Snow

It was sunny (SUNNY!) today and so I went out for a hike where I used to run before it snowed. I'm with Coral, my landlord's dog. (Over the years I have been blessed with sundry canine companions, none actually my own dogs so I never have any real canine responsibilities, just companionship for those long solo hikes and runs that I love to take. I look forward to the day eight or nine years down the road when I finish my schooling and will actually have a schedule that will allow me to be a good dog owner).

You might recognize the photo below from a photo earlier this year on my blog-- back then there were still leaves on the trees but it is the same trailhead. I took the shot of Coral because I didn't know if I would run into any other hikers to take a picture of me (but I did, as you can tell).

Collagen Related Diseases And Odd Facts About Guinea Pigs

I'm studying for my block II exam. It's not a disease course, but we are expected to know the diseases that arise from different molecular etiologies.

There are quite a few diseases having to do with collagen defects.

• Osteogenesis imperfecta aka Brittle Bone Disease or Lobstein syndrome results from a mutation in collagen type I that substitutes another amino acid for glycine (which is the simplest, smallest amino acid), and as a result the triplet of alpha helices which make up collagen cannot pack as tightly.
• Ehlers-Danlos syndrome can manifest in many different forms. The host of possible problems include abnormally flexible joints, loose joints, abnormally stretchy skin, fragile skin and blood vessels and poor wound healing.
• Dystrophic epidermolysis bullosa involves a mutation in collagen type VII, the anchoring type of collagen, which links the basement membrane of the epidermis to the fibrillar collagens in the dermis. There is a recessive and dominant form. The disease causes severe blistering and skin wounds heal extremely slowly.

As far as I can tell OI, EDS and DEB all affect both dogs and humans. I'm not sure about other species.
Note: Epidermolysis bullosa simplex is a disease of cattle (and humans) that involves a mutation in keratin 5. Keratin is an intermediate filament, not a collagen.

Scurvy is a disease that is caused by a deficiency of vitamin C. Humans get this disease because they cannot synthesize their own vitamin C. Vitamin C is a co-factor required for the hydroxylation of prolines and lysines on the alpha helices of collagen. Without hydroxylation, the alpha helices don't form the triplet superstructure of which collagen is composed and so you can't make collagen. This results in problems any place in the body that needs new collagen formation-- hence the resulting clinical signs of fragile skin and blood vessels, bleeding, loose teeth and impaired wound healing.

Guinea pigs and primates are the only animals that aren't able to synthesize their own vitamin C. (I can't find anything about guinea pigs' larger South American relative, the capybara-- which is the largest rodent in the world. I wonder if they can make vitamin C?)

So here are the ood facts I know about guinea pigs so far from vet school and the clinic:

• Guinea pigs are not able to make vitamin C and so must have it supplemented in their diet.
• Guinea pigs' bronchoesophageal artery often branches off the right subclavian artery whereas in dogs and other domestic species the bronchoesophageal artery branches off the right fifth intercostal artery (yes, that was in my block I notes on embryology)
• You should not use Clavamox or other cephalosporins in guinea pigs because it will affect their gut flora (I'll never forget an exotics vet that I did an internship with back in tech school ranting about a general practice vet prescribing Clavamox for one of her cavy patients)
  

From Sunny To Snow

This is me headed out on a walk this afternoon with my landlord's dog, Coral. I'm also testing out one of my new coats and found it works great (thanks!). It arrived just in time for today's snowfall.

Yesterday it was sunny and warm and snowless. I went for a hike after class with two of my classmates in an area that I discovered on my return from my Thanksgiving travel. Crossing the suspension bridge we had the view below:

I guess the weather changes pretty quickly here in Ithaca.

I composed the beginning of the following poem in my head after making a trip to the farmer's market this morning, heading home in the snow:

cocooned in confetti
white specks against a grey sky
falling silently

My post on blastomycosis generated more responses than I anticipated (not everyone posts comments, sometimes I get emails etc from those who know me). The lecture wasn't actually part of my cell biology course, it was open to the whole college. I don't know if we cover blastmycosis in our disease course, I won't take it until next year. The talk didn't go much into treatment so I had no idea it took so long to treat, thanks for the info, Ceres.

This was the first case of blastomycosis that has presented to the Cornell hospital in recent years. It wasn't treated as blastomycosis because no one realized that was the organism causing the dog's illness until the dog had died and was sent to necropsy (by the time this dog was referred to Cornell it was too late in the course of the disease to have any real shot at a successful treatment judging by the pathology report-- there were blasto yeast buds in the brain, not to mention everywhere else, and the dog was only hospitalized a brief time before death so those lesions were likely there on presentation). The reason that it was not diagnosed as blastomycosis was because the presentation was anything but classic. I wonder how many cases of blastomycosis are atypical and don't present with a cough? I was also impressed by how difficult it is to accurately diagnose blastomycosis-- I remember the resident saying that to get a sample one must typically do a lymph node or lung aspirate, that tracheal washes aren't usually sufficient. Yuck. It seems like a pretty nasty disease all around.

For those of you looking for some interesting reading, check out _The Medical Detectives_ by Berton and Boueche. It is a compilation of puzzling human medical cases and includes one that involved a systemic fungal infection. I won't tell you which one that is, I don't want to spoil it. I did get to show off though during my orientation week when the dean of learning picked this case to use as a model to teach us how to tackle problem based learning and I knew the answer. I kept quiet until the end of her presentation, after my classmates had taken their best stab at it, and then I raised my hand and gave the answer. It was quite satisfying, although she would point out that problem based learning is not about the answer at all but rather about the process. Bah humbug.

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