Friday, July 21, 2006

End of the First Week

We had our third PSS today, and again, it went fairly smoothly. We finished all of the questions a few minutes early, actually. Afterward, we were discussing how things went this week with our facilitator, and several of us (including me!) felt that we understood the things that we had looked up ourselves well. But we had to go back later and read the questions that the other subgroup was working on later, because we weren't getting it during class. That being said, on Monday most of us felt like we didn't get much of anything at the time, and I for one feel that getting half of the material during class is better than getting none. We decided that now that we have some experience with PSS, we would like to try to work together as a big group again on Monday. If it doesn't work, we can always go back to dividing up the work again.

After PSS, we had our first journal club (JC) meeting. The way JC works is that the entire class is divided into two groups of 16, and two people present within each group every week. Each student gets 45 minutes total to present, including audience questions and discussion. There is a different faculty moderator in charge each week, and they are the ones who assign the papers to us. The papers are chosen based on their impact, their intensity, and on what topics we are covering in class that week. We were learning about intracellular transport and endocytosis this week, so the paper was about a potential method to treat a lysomal storage disease called Niemann-Pick disease. Fortunately the type A form of this disease is rare, because it is lethal and currently untreatable. Basically what happens is that people who are affected by Niemann-Pick disease are missing an enzyme called acid sphingomyelinase (ASM). This enzyme hydrolyzes a lipid called sphingomyelin, and so people who don't have the enzyme wind up storing these lipids in all kinds of bad places in their cells and tissues since they can't break them down. What the study authors wanted to do was to give them ASM and get their cells to take up the enzymes in a specific manner so that the cells would now be able to break down the lipids. So far this has been done in animals, but not yet in people. It's a neat idea, though.

At the end of the presentations, we had a brief discussion about what the presenter did well, and what he could have done better. This week it was a professor who presented to give us an idea about how we should do our own presentations. The first students will be presenting next week. My group will be doing one paper about a protein called VEGF, and the other is about the VEGF receptor. I'll tell you more about them next Friday.


sara said...

That is really cool that you are studying basic research topics. We never did that in med school. :)

Sarah said...

Neimann-Pick Disease sounds really interesting. What else did you learn about it? Who typically gets the type A form? What makes that form so rare as opposed to the others? Are there hereditary factors? Hum...interesting stuff.

CCLCM Student said...

Hi Sarah,

Great questions! Our focus was more on the fact that NPD A and B were lyosomal storage diseases rather than on the disease itself; there are actually a bunch of similar diseases where people can't process lipids, and their severity can range from mild to lethal. I'll do my best to answer your questions though:

1) Type A disease is the most severe form that is due to ASM deficiency, and it usually occurs in Ashkenazi Jews. (These are Jews from Eastern European countries.) This ethnic group tends to have other lipid processing disorders with neurological involvement too, like Tay-Sach's disease. Kids with Type A NPD or Tay-Sach's diseases usually die at a very young age.

2) Yes, there are two other forms. Type B occurs in all ethnic groups and is a relatively mild (compared to Type A) form that leads to, among other things, pulmonary problems. The study authors were actually hoping to treat the type B form, because of course you can't get proteins like enzymes across the blood-brain barrier easily. (That would be necessary to treat Type A disease.) There is currently no cure for Type A disease.

There is also a Type C NPD, but that is actually caused by a problem with a completely different pathway. (If you're interested, it's a problem with the LDL internalization pathway. Basically what happens is that cholesterol winds up getting stored in the cells, which it is not supposed to do.) Even though it has nothing to do with ASM deficiency, the net phenotype is the same for all three types of diseases (i.e., storage of lipids in organs where it doesn't belong). Type C also has neurological involvement and it is also lethal.