Why aren't I studying? AAargh!
Seriously...I spent an hour wandering around a bookstore yesterday and more time than that today on things that had nothing to do with virology or bacteriology. Suddenly the most important thing is making dinner?! Self-control, please!
Wednesday, December 16, 2009
Thursday, December 10, 2009
Rose Waaler
The note-taking continues!
Detection of Rheumatoid Factor
Rheumatoid factor=antibody to antibody.
Sheep red blood cells are reacted with appropriate concentration of anti-SRBC antibodies, made from rabbit or dog (odd, but apparently it works).
Appropriate concentration means it won't quite agglutinate.
Dilutions of the patient's serum are added to antibody coated SRBCs, known as sensitized SRBCs.
If the patient's serum contains RF, the RF cross links with anti SRBC antibodies and the red blood cells agglutinate. If there's no antibodies in the patient, there's no agglutination.
Colostral and milk immunoglobulins:
colostrum: IgG > IgA > IgM
non-ruminant milk: IgA > IgG > IgM
ruminant milk: IgC >IgA > IgM
Detection of Rheumatoid Factor
Rheumatoid factor=antibody to antibody.
Sheep red blood cells are reacted with appropriate concentration of anti-SRBC antibodies, made from rabbit or dog (odd, but apparently it works).
Appropriate concentration means it won't quite agglutinate.
Dilutions of the patient's serum are added to antibody coated SRBCs, known as sensitized SRBCs.
If the patient's serum contains RF, the RF cross links with anti SRBC antibodies and the red blood cells agglutinate. If there's no antibodies in the patient, there's no agglutination.
Colostral and milk immunoglobulins:
colostrum: IgG > IgA > IgM
non-ruminant milk: IgA > IgG > IgM
ruminant milk: IgC >IgA > IgM
Hypersensitivies
Using the blog for notes today. (Why? Because. It's here. I like to try new note taking formats.)
Type I:
antibody: IgE
antigen: foreign
effector mechanism: Activation of mast cells and mediators
skin test is available
Time to onset: seconds to minutes
Examples of the disease: include hay fever and anaphylaxis.
Type II:
antibody: IgG and IgM
antigen: Cell or tissue antigens AND cell surface receptors work as antigens.
Effector mechanisms: Complement activation, which leads to phagocytosis; also, cell signalling altered by antibody.
No skin test available.
Minutes to hours for onset.
Examples of disease: transfusion reactions, autoimmune hemolytic anemia, pemphigus vulgaris, and some drug allergies.
Other diseases include Grave's disease, myasthenia gravis, and type 2 diabetes.
Type III:
antibody: IgG aand IgM
antigen: Immune complexes work as the antigen; they activate complement system and phagocytosis. "Why would phagocytosis or complement activation of immune defenses lead to tissue damage? Why is the pathology of mycoplasma immune-mediated? It's because mycoplasms are bound so tightly to the cells that the immune defense can't differentiate. It's bystander damage."
skin test: Arthus reaction (inject antigen and circulating antibodies bind, forming an immune complex and resulting in 'weal and flare').
Inappropriate immune response to antigen, and also excessive.
How do allergy shots, desensitization, work? Kicks the body into T helper 1 response, with IgG. This moves it away from TH2, where IgE activate mast cells for massive degranulation.
6-8 hours to see reaction.
Examples: rheumatoid arthritis, serum sickness, systemic lupus erythematosus (SLE). What is serum sickness? Let's say someone with hepatitis is discovered to have helped prepare food; everyone who ate some is given a massive dose of anti-serum to mop up the hepatitis. (And yes, I know hepatitis is technically just a word for unhappy livers)
Not all hypersensitivities are auto immune.
Type IV
Antibody: none
antigens: foreign, cell antigen...or cell associated.
Effector mechanism: macrophage activation by TH1, plus inflammation
Or CTL mediated cytotoxicity (and inflammation) (if antigen is cell associated).
Skin test: most certainly. It takes 48-72 hours (though the TB skin test in cattle can be nicely simulated in under an hour by using chicken blood cells. On the other hand, you can also induce anaphylaxis, hypersensitivity type I, with chicken cells...apparently reversible).
Examples: contact dermatitis, tuberculin reaction, type 1 diabetes, multiple sclerosis. CTL mediated: acute graft rejection ("omg alien invasion kill kill kill!" scream the CTLs)
Hemolytic disease in newborns: the mother makes antibodies to the fetal antigens (just think of the fetus as an allograft; this is why pregnant women are immunosuppressed). This is a problem for horses; the mare concentrates antibodies in her colostrum. The foal is born without any problems and nurses, and ingests what is essentially anti-foal colostrum. The complicated bit is that this doesn't happen with the first foal she has by that stallion; it takes that first pregnancy to introduce her immune system to the foreign genetics. By breeding her to a different stallion each time, she never builds up the antibody response. The other option is to feed the foal colostrum from a different mare. HOWEVER, the replacement colostrum should be from a mare on the same farm. Horses develop very localized immunity; the endemic pathogens of one farm are not the same as what may be endemic on a different farm.
Type I:
antibody: IgE
antigen: foreign
effector mechanism: Activation of mast cells and mediators
skin test is available
Time to onset: seconds to minutes
Examples of the disease: include hay fever and anaphylaxis.
Type II:
antibody: IgG and IgM
antigen: Cell or tissue antigens AND cell surface receptors work as antigens.
Effector mechanisms: Complement activation, which leads to phagocytosis; also, cell signalling altered by antibody.
No skin test available.
Minutes to hours for onset.
Examples of disease: transfusion reactions, autoimmune hemolytic anemia, pemphigus vulgaris, and some drug allergies.
Other diseases include Grave's disease, myasthenia gravis, and type 2 diabetes.
Type III:
antibody: IgG aand IgM
antigen: Immune complexes work as the antigen; they activate complement system and phagocytosis. "Why would phagocytosis or complement activation of immune defenses lead to tissue damage? Why is the pathology of mycoplasma immune-mediated? It's because mycoplasms are bound so tightly to the cells that the immune defense can't differentiate. It's bystander damage."
skin test: Arthus reaction (inject antigen and circulating antibodies bind, forming an immune complex and resulting in 'weal and flare').
Inappropriate immune response to antigen, and also excessive.
How do allergy shots, desensitization, work? Kicks the body into T helper 1 response, with IgG. This moves it away from TH2, where IgE activate mast cells for massive degranulation.
6-8 hours to see reaction.
Examples: rheumatoid arthritis, serum sickness, systemic lupus erythematosus (SLE). What is serum sickness? Let's say someone with hepatitis is discovered to have helped prepare food; everyone who ate some is given a massive dose of anti-serum to mop up the hepatitis. (And yes, I know hepatitis is technically just a word for unhappy livers)
Not all hypersensitivities are auto immune.
Type IV
Antibody: none
antigens: foreign, cell antigen...or cell associated.
Effector mechanism: macrophage activation by TH1, plus inflammation
Or CTL mediated cytotoxicity (and inflammation) (if antigen is cell associated).
Skin test: most certainly. It takes 48-72 hours (though the TB skin test in cattle can be nicely simulated in under an hour by using chicken blood cells. On the other hand, you can also induce anaphylaxis, hypersensitivity type I, with chicken cells...apparently reversible).
Examples: contact dermatitis, tuberculin reaction, type 1 diabetes, multiple sclerosis. CTL mediated: acute graft rejection ("omg alien invasion kill kill kill!" scream the CTLs)
Hemolytic disease in newborns: the mother makes antibodies to the fetal antigens (just think of the fetus as an allograft; this is why pregnant women are immunosuppressed). This is a problem for horses; the mare concentrates antibodies in her colostrum. The foal is born without any problems and nurses, and ingests what is essentially anti-foal colostrum. The complicated bit is that this doesn't happen with the first foal she has by that stallion; it takes that first pregnancy to introduce her immune system to the foreign genetics. By breeding her to a different stallion each time, she never builds up the antibody response. The other option is to feed the foal colostrum from a different mare. HOWEVER, the replacement colostrum should be from a mare on the same farm. Horses develop very localized immunity; the endemic pathogens of one farm are not the same as what may be endemic on a different farm.
Monday, December 7, 2009
Doctors and doctors-to-be
Nowadays when I have a doctor's appointment, I find an opportunity to tell the doctor that I'm a vet student. I'm sure some level of my brain does this because it doesn't want the doctor to think it is a silly brain for using medical terms. Everyone knows that patients find medical terminology to be incomprehensible jargon, so the patients who try putting forward a vocab word or two of their own probably spent an hour of quality time with some medical websites.
But Mayo's help page does not a doctor make...so I try to clarify where I got my information. Otherwise, we get conversations like this:
Me: "So, I suppose one of the things that could be causing stomach pain, if it's not just stress related, could be Crohn's?"
Doctor: "Ah, so you've been doing some reading online, then?"
"Um...we went over it in class a month ago. Did I mention what I'm in school for?"
Granted, vets aren't supposed to diagnose human disease. We had a session on this today: if a woman comes in with a ringworm positive cat, and she has what is obviously a ringworm lesion on her forearm, you are allowed to diagnose the cat and start it on treatment, but you can't tell the woman anything beyond, "Maybe you should go see your doctor."
But Mayo's help page does not a doctor make...so I try to clarify where I got my information. Otherwise, we get conversations like this:
Me: "So, I suppose one of the things that could be causing stomach pain, if it's not just stress related, could be Crohn's?"
Doctor: "Ah, so you've been doing some reading online, then?"
"Um...we went over it in class a month ago. Did I mention what I'm in school for?"
Granted, vets aren't supposed to diagnose human disease. We had a session on this today: if a woman comes in with a ringworm positive cat, and she has what is obviously a ringworm lesion on her forearm, you are allowed to diagnose the cat and start it on treatment, but you can't tell the woman anything beyond, "Maybe you should go see your doctor."
Saturday, December 5, 2009
How to relax (or not)
Perhaps reading about how smallpox hasn't really been eradicated after all is not the best way to relax. However, the fun part of reading "Demon in the Freezer" is realizing that now I know some of the techniques used in those high-biosecurity labs.
It's been a hard week, what with getting exams back and having papers to turn in. I reviewed my e-mails to non-vet people one day, as well, and found out my writing has deteriorated badly since the beginning of the semester. As the months go by, everything unrelated to infectious disease becomes incoherent and disjointed, and I start talking about salmonella and flaviviridae with increasing fervor.
I talked to the supervisor at work about fixing the on-call schedule so we don't get called in for twenty-four hour stretches. The alternative was probably going to be me giving two month notice and resigning. In some ways, that was an attractive option. I find being on-call to be a loathsome experience. The pager is like a black box of portable stress. If it doesn't go off, I'm worried I might have missed it, so I have to keep checking for the little blinking light. There's always the one long moment where you look at it and wait for it to blink.
If it does go off, that's the next four hours (at minimum).
Some of the people who no longer do this job assure me that, well yes, there are crazy times when you get called in the entire night every time you're on call. But then there are stretches where nothing happens at all! They say this as if it makes everything okay. "There might be times you don't get called in, isn't that awesome?!" Although to be honest, getting called in is not really the problem. Surgeries are exciting, and you learn a little more every time you help with one. No, the problem is cleaning up after the surgery, because then there is no more excitement and it usually takes about as long as the surgery itself. I like to think that it is a less important part of education at this stage; at any rate, I would rather be studying bacteria.
It's been a hard week, what with getting exams back and having papers to turn in. I reviewed my e-mails to non-vet people one day, as well, and found out my writing has deteriorated badly since the beginning of the semester. As the months go by, everything unrelated to infectious disease becomes incoherent and disjointed, and I start talking about salmonella and flaviviridae with increasing fervor.
I talked to the supervisor at work about fixing the on-call schedule so we don't get called in for twenty-four hour stretches. The alternative was probably going to be me giving two month notice and resigning. In some ways, that was an attractive option. I find being on-call to be a loathsome experience. The pager is like a black box of portable stress. If it doesn't go off, I'm worried I might have missed it, so I have to keep checking for the little blinking light. There's always the one long moment where you look at it and wait for it to blink.
If it does go off, that's the next four hours (at minimum).
Some of the people who no longer do this job assure me that, well yes, there are crazy times when you get called in the entire night every time you're on call. But then there are stretches where nothing happens at all! They say this as if it makes everything okay. "There might be times you don't get called in, isn't that awesome?!" Although to be honest, getting called in is not really the problem. Surgeries are exciting, and you learn a little more every time you help with one. No, the problem is cleaning up after the surgery, because then there is no more excitement and it usually takes about as long as the surgery itself. I like to think that it is a less important part of education at this stage; at any rate, I would rather be studying bacteria.
Sunday, November 29, 2009
Pathology 1, me 1
After about a month, we got back our scores on the previous path exam, on which I got an amazing beyond-a-B A! And then we got back our scores on the most recent exam, which completely kicked my butt and handed me an amazingly low 64. Which once again puts me at the very bottom of the class. Granted, this was the section where I was horribly sleep deprived for most of the lectures, had no lab partner for half the labs (because she didn't "like the disgusting pictures"), and was called in for fifteen hours a few days before the exam. I shouldn't blame my lab partner, of course, but seeing as she obviously did better on the exam than I did, I feel a little bitter.
Oh well, back to work.
Thursday, November 26, 2009
TGIT
I am enjoying the absence of people. My parents headed off to Vegas the night I got called in for five hours. I gripe SOOO much when I get called in, my poor boyfriend doesn't know if he's supposed to tell me when the clinic has left a message with him (I was on my way home and missed the call). And then I spend the first hour going "hatehatehate", the second hour "I'm missing bellydance, aargh!" and then the rest of the evening is fine because I've missed bellydance and how much worse could it possibly get? Well, there weren't any emergency back surgeries that came in, so it didn't get any worse, but I was fully expecting one might roll in any moment. As opposed to weekend before last, where I got to spend ten hours of quality time with the surgeon and anesthesiologist. And an additional five hours of quality time with the cartloads and cartloads of bloody instruments that all needed to be cleaned. I got home at five a.m.
But now I'm not on call for a couple of weeks, which lightens my heart. As for today, no school! As I mentioned, the parental units are off seeking sunshine, and my boyfriend went home with his family, which leaves me with the farm full of dogs and cats (who I can hug because my cat-allergic boyfriend is not around). The bedrooms at the farm were cold, so last night I slept on the couch, which Nanner acting as a very localized heat blanket. Nanner has really mastered the art of staying inside as soon as it gets cold. She finds the person least likely to kick her out and cuddles up quietly, and if they show signs of impatience she starts purring. Since I was the only one home, it was an easy sell.
School switched into high gear the last month, or maybe I did. I think I have passed the most recent round of exams with grades more toward the middle of the pack, which pleases me greatly. A's are awesome, but I am perfectly happy with B's. Even a high C does not offend my sensibilities. (Really hoping the bacteriology exam turned out at least that well). About a month ago I had one weekend with nothing else scheduled, but to study...it was bliss. Since then it has been more of a marathon, with me swearing on a daily basis to never volunteer again, since there's always something else that comes up too. So I'm not too distressed at having nothing going this weekend, although I have a long list of errands I would like to run. Alas, I do not want to go anywhere near the stores tomorrow, but I'm pretty sure it's not a good idea to buy glasses online.
And now I have to go take care of all the animals I promised to take care of today.
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