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.