FGF's

This picture was taken from the following website:
http://unachivablelover.files.wordpress.com/2009/
01/daddy-girl-brunette.jpg?w=325&h=325

This Wednesday, my dad was taking me to school and we were chatting in the car. We started out talking about medical school, but somehow, the conversation trailed off into physical disabilities. There is a pediatric cardiologist who is a friend of the family. He, apparently, has an arm that is shorter than the other. While discussing his difficulties of trying to get into surgery, this also served as a learning experience for my dad. I told him all about the FGF family, from when we were studying cell signaling pathways. I also told him the handicap was probably due to a mutation in this pathway, which causes shortness of limbs (something I remembered from a test). More than anything, it was fun for me to be able to share knowledge with my dad. (Usually, it goes the other way around.) In turn, I think he was proud of how much I had learned (and I'm actually applying) from this class. Also, the social implications of diseases were once again brought to my attention, making me realize how lucky I should be to be considered "normal."

Allantois

This picture was taken from the following website:
http://www.aps.uoguelph.ca/ANSC*2340/LEC3/PS23.gif

I first came across the word "allantois" in class during a lecture in the past two weeks, and the term reappeared during the reading portion of lab this week, so I decided to really find out what it means. The term is defined as "the extraembryonic membrane found in amniotes that forms off the hindgut of the embryo. It stores nitrogenous waste and, in the chick, will eventually fuse with the chorion to form the chorioallantoic membrane. It is vascularized and is formed from the splanchnopleure, a layer made up of endoderm and splanchnic lateral plate mesoderm." Essentially, the allantois is the precursor of the gut in the chick embryo. Above is a picture detailing the allantois in a sheep embryo.

The information above was taken from the following reference: http://labs.devbio.com/protected/resources/modules/LabBook/Tyler_LabManual_Complete_2010.pdf.

Chalaza

This picture was taken from the following website:
http://www.geauga4h.org/poultry/egg_labeled.gif

Yesterday, in lab, I came across the word "chalaza" while looking at an egg yolk under the microscope. Not only was I confused as to what this word meant, but I also had no idea to pronounce it. "A chalaza (plural chalazae) is a structure inside an egg which helps to keep the yolk in place. The chalazae attach to either end of the yolk and anchor to the inside of the eggshell, essentially suspending the yolk. Chalazae prevent the yolk from being damaged, promoting the healthy development of the embryonic bird. This structure is also present in some plants, performing a similar function in plant ovules." A chalaza, then, is the visibly white part attached to the egg yolk, helping to anchor the yolk. It is pronounced "kuh-LEY-zuh," emphasis provided by: http://dictionary.reference.com/browse/chalaza.

The information was sourced from the following website:
http://www.wisegeek.com/what-is-chalaza.htm.

Stem Cells for the Brain



This picture was taken from the following website:
http://www.clipartguide.com/_named_clipart_images/
0511-0811-1701-0815_Cartoon_of_a_Man_Listening_to_
the_Radio_While_Driving_clipart_image.jpg

Yesterday, I was listening to the radio, 103.5 FM, with my dad in the car and I heard a news story on stem cells acting on the brain. Scientists (at one university I can't recall the name of) injected embryonic stem cells into a human with brain cancer. The hES cells were injected with medication needed to target the brain cells. These injected cells were attracted to the mutated cells in the brain, being the cancerous cells, and changed the fate of the cells. They became specialized as fully functioning neurons, and because the medication was targeted specifically to that area, the hopes are that the tumor will diminish greatly, if not disappear completely. This was really interesting to me because hES cells are powerful in that they are totipotent. They can become anything, relating to autonomous specification that we learned about previously in class. The really unique feature of these cells, however, is that they also exhibit conditional specification because they become the cells they are around. For example, hES cells in the brain become neurons. It will be interesting to see if this experiment works, and if so, how much cancer will be treated in the future.

Epiboly



This picture was taken from the following website:
http://worms.zoology.wisc.edu/frogs/gast/epiboly.gif

During a fierce round of tic-tac-toe yesterday in class, I came across the word epiboly. I had first discovered the term in the textbook, but yesterday's discussion made me realize how important it is in Development Biology. The term is defined as "the movement of epithelial sheets (usually of ectodermal cells) that spread as a unit (rather than individually) to enclose the deeper layers of the embryo. Epiboly can occur by the cells dividing, by the cells changing their shape, or by several layers of cells intercalating into fewer layers. Often, all three mechanisms are used." Essentially, during epiboly, a sheet of cells spreads by thinning to cover the embryo.

The information referenced above was taken from the following reference: Gilbert, Scott F. "Early Development in Selected Invertebrates - Gastrulation." Developmental Biology. Vol. 9. Sunderland, MA: Sinauer Associates, 2010. 164. Print.

Reflection

This picture was taken from the following website:
http://www.photoshopessentials.com/images/type/
effects/text-reflection/photoshop-text-reflection.jpg

I still believe this class is helping me learn information that is relevant to my career goals of becoming a pediatrician. Because I am learning about how development takes place, I will have a better understanding of how to aid those with developmental malfunctions. The information in this course most closely relates to the information I am learning in Genetics, but this week, it related to Organic Chemistry as well. In chemistry this week, we were learning about step-wise reactions, which related to the signal transduction cascades in the major pathways. I usually learn best by writing information down as I hear it -- taking notes in a sense. Since the beginning of this class, however, I have now incorporated visual learning into my learning style. It helps me a lot now to be able to see a diagram or a figure of what we are discussing in class. Sometimes, it's hard for me to understand what is really being talked about unless I am able to see these picture references. I am proud that I am able to alter my learning style after so many years of getting into specific habits. I feel this will help me, both in future classes, as well as outside of the education field as it shows that I can adapt to the environment around me...given enough time. One of the most important things I have learned during the course of this class has been the development process, from fertilization to fully developed organism. Everything in this class relates to the process, and it helps to know it backwards and forwards for reference purposes. The other thing I'm glad I learned has to do with lab. Never before, in any of my science classes, have I had such involved labs. I am glad I am learning the entire lab process from setting up the experiment, performing it, recording data, and writing the lab report. It makes the process seem fuller and more meaningful. Again, I feel this will help me, not only further in my education, but after I am out of school as well. One of the things that is most confusing to me is the difference between induction and specification. These seem like one in the same process to me, and I still need to clarify the minute differences between the two terms. This is the topic we are currently discussing, however, so I am sure more discussion will help my understanding. Taking this class has really opened my eyes as to how such a small thing, like a small mutation, can affect the quality of someone's life for the rest of their life. It's unbelievable to me that so many of us turn out "normal" when there are so many things that  can go wrong during the development process. The information I've learned in class has impacted my life in a positive way. I am definitely more aware and considerate when I notice people with diseases or malformations. I feel like I am a better person for this.

Horseshoe Crabs

This picture was taken from the following website:
http://www-tc.pbs.org/wnet/nature/files/2008/06/590_crash_blood.jpg

This past Sunday, October 17, 2010, I watched a Nature documentary on WETA's PBS from 6-7 pm called "Crash: A Tale of Two Species." This program was interesting to me because it directly addressed my interest in biomedical advantages and using animals to our (the human) advantage. I feel like animals have a lot of unknown benefits, and they are able to survive in much harsher climates, yet for some reason, humans have not exhausted this resource. The dilemma comes when these animals are potentially harmed for our use. I struggle with this in the fact humans should not cause harm to animals, while I see no harm in using them to our benefit. After all, with as many dysfunctions as humans have, we could use all the help we can get. The problem, however, is that there is often a fine line that comes between those two areas.

This documentary described the function of the horseshoe crab in biomedical advantages such as drug testing and treating burns, while it also serves to be part of the red knot's diet through the source of its eggs. Basically, horseshoe crabs have a compound in their blood called LAL that clots to viruses and bacteria by binding to it. This substance is a natural compound in the crab that helps it fight off the many infections of the ocean environment. LAL is harvested, and is now required to test bacterial contamination by the FDA in pacemakers, IV solutions, and any other device implanted inside the human body. This spiked my interest because of how the LAL is harvested. The horseshoe crabs are harvested and bled. About one third of their blood is harvested and used to test human devices. After being "bled," the crabs are released into their natural environment, where they supposedly regain their blood volume in a week. LAL manufacturers claim that there is no long-term injury to the animals, and animals are not killed to harvest their blood, which accounts for a wealthy $15,000 for every quart harvested. The process brings concerns, however, because recent studies have found that about 10-15% of the crabs do not survive the bleeding procedure, while the LAL manufacturers claim that less than 3% of the crabs are lost to mortality. It has also been proposed that it takes a few months, as opposed to just 1 week, for the crabs to regain their original amount of blood cells. This procedure could take a bigger toll on the crabs than we realize. By potentially harming so many crabs for our benefit, it also poses a potential threat to our ecosystem. The red knot, a small bird common to the seaside, depends on the horseshoe crab for its eggs as food. An increase in bleeding of the crabs leads to less crabs, which produces less eggs for the birds to consume, which then leads to less birds being able to "bulk up" during their optimal seasons and fly south for survival. Perhaps the biggest use of horseshoe crabs is as bait in the commercial fishing industry. This is where this process sparked my interest. I didn't realize that the FDA required almost every product to be be tested because they realize how useful the substance is, and yet it poses such a large threat to these animals, and yet even a larger threat to the ecosystem that I'm not sure it's really worth it.

The other source I found on this issue is from the Fish and Wildlife Service. It talks about the many threats posed to horseshoe crabs, mainly due to humans. Most of these include basic reasons such as beach development, recreational vehicle traffic, and oil spills. Lucky for these animals though, their biomedical and ecological advantages have been noted for their great importance, and measures have been taken to protect them before their untimely demise. These measures, however, have not recently increased the crab population as much as previously estimated. Again, this spiked my interest because I'm not sure if we should still be using these crabs so much to our advantage if we are also causing them so much harm.

The documentary listed above is from a peer-reviewed source. The WETA and PBS services have qualified reporters with ample education and knowledge to have produced such a program. It directly involved science correspondents through the use of interviews. The documentary was published in 2008, although it was aired in 2010 on our local network. The documentary was only biased in the medical sense. It proved all the uses and advances these animals have in the medical world without adequately addressing the harm caused to the animals themselves. It did talk about some of the bias felt by the LAL manufacturers, but those details would have been easily glossed over unless they were being paid careful attention. As anyone trying to prove a point, no, it did not admit this bias. The citation for the documentary is as follows: "Crash: A Tale of Two Species -- The Benefits of Blue Blood -- Horseshoe Crabs." Nature. PBS. WETA, Washington, DC, 17 Oct. 2010. Television. Later on, I was able to find a synopsis of the documentary on the following website: http://www.pbs.org/wnet/nature/episodes/crash-a-tale-of-two-species/the-benefits-of-blue-blood/595/.

The website I cited from is also a credible source because it is national association. The government would only allow people with ample education and knowledge on a specific subject to report on these issues. The website was published in August of 2006, but was again, written by science correspondents. The United States Fish and Wildlife Association sponsored and published the site. This article was biased as well, seeking to prove the disastrous effects humans have on horseshoe crabs. It never admitted this bias, and depicted this information as fact. The full citation for the website is as follows: "The Horseshoe Crab -- Limulus Polyphemus -- A Living Fossil." FWS.gov. United States Fish & Wildlife Service, Aug. 2006. Web. 18 Oct. 2010. <http://www.fws.gov/northeast/pdf/horseshoe.fs.pdf>.