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>.

Lifelong Effects

This picture was taken from the following website:
http://www.lucinafoundation.org/assets/hydrocephalus.jpg

This past Sunday, October 10th, 2010, I watched a movie with my mom and sister at home on the Hallmark Channel called "Follow the Stars Home." It was produced in 2001 and starred Kimberly Williams-Paisley. It was aired from 4:45 - 7:00 pm. Essentially, the movie started out with a romantic love story between a couple who got together after meeting when the lady did some work for her future groom's brother. Before they knew it, they found out the wife (played by Williams-Paisley) was pregnant. After one of the sonograms, they received some bad news from the doctor. The baby was discovered to have genetic defects. The bad news was, unfortunately, only confirmed when the couple got a second opinion. Upon the wife's decision to keep the baby, her husband promptly left her, claiming he didn't want to have anything less than a perfect child. He wanted her to get an abortion as soon as they found out, but she decided to continue with the pregnancy. Before the child was born, the wife's brother-in-law (who introduced the couple and was also a doctor) did a further examination on the baby still in utero. He found the baby girl, if carried to full-term, would have fluid on the brain, also known as hydrocephalus (and pictured above), in addition to spinal cord and central nervous system damage, as well as poor development of the heart and lungs. Several surgeries would be needed to induce the development necessary for the baby's correct growth. She would not be able to walk, talk, and she would have a hard time breathing. Worst of all, though, her predicted life span was a mere six years. The movie went on to show the baby and her struggle throughout her life, as well as the constant and tedious way her mother and grandmother cared for her. Eventually, the drama re-entered the movie to add to the storyline, but a synopsis of the scientific part of the movie is given above.

I learned a lot from watching this movie. First, life is never easy. My eyes were opened to the role of parents when children are at such a young age. Even working with newborn babies at the hospital has not revealed this to me. It really made me think because, as a girl, I may be in that position one day, and it caused me to ponder about what I would do if this situation occurred later in my life. The last decision is ultimately left up to me because the baby would be growing in my body, but should my opinion on this sort of issue interfere with my marriage? If so, what is the cut-off point where things should only get my opinion as compared to my husband's? If not, where do you draw the line as to what really should be considered fairly in a marriage, concerning the birth of the first child? This relates to our class, of course, because it is a genetic disease, although it was never named specifically, that affected the physical and mental development of the child. A mutation somewhere in the process of fertilization and cleavage caused a child's life to end significantly earlier than her peers. Previously in class, we also discussed some of the ethical issues that come with certain diseases -- an issue that was brought up by the viewing of this movie. I'm really glad I watched this movie, and it was nice for me to see that the things we are learning in class really do relate to life outside the classroom.

Cytoplasmic Bridges

The picture above was taken from the following website:
http://www.mc.vanderbilt.edu/histology/word/2004/
Cell%20Junctions%2004.htm

One term in our textbook that was unfamiliar to me is "cytoplasmic bridges." This term is defined as the "continuity between adjacent cells that results from incomplete cytokinesis during gametogenesis." There are cytoplasmic connections between the dividing cells during meiosis. Cytoplasmic bridges, however, are the product of meiotic cell divisions that help daughter cells remain connected. Above is a picture detailing exactly where cytoplasmic bridges can be found, connecting actin filaments.

The information referenced above was taken from the following reference: Gilbert, Scott F. "The Saga of the Germ Line - Meiosis." Developmental Biology. Vol. 9. Sunderland, MA: Sinauer Associates, 2010. 599. Print.

Reflection



This picture was taken from the website: http://2.bp.blogspot.com/_tqy4jJBa2DM/
TFg2JlPtefI/AAAAAAAAAYw/qaaEGkupGzc/s1600/thinking-outside-the-box.jpg

 I love being in this class for the sole reason that I feel like I am finally learning something useful. This is the point at which we have enough foundational knowledge from core concepts to apply it what we encounter in the everyday world. My future career goal is to be a pediatrician, so it is very important to me to learn about developmental diseases, how the develop, why they occur, and how they can be treated. What better class to cover all these topics? Learning about gametogenesis and the difference between mitosis and meiosis in males and females has also helped me in my Genetics class. I am able to understand, now, why mutations occur, as well as the effect they have on an individual. It is nice to learn about an entire concept, especially through the use of two classes. I learn best by writing things down, which includes both visual and audio learning. Taking notes and doing the various assignments for this class, especially since they have been in paper format up to this point, have been very helpful for me. I am working on incorporating other learning styles into my learning, but this has worked for me so far because this is what I have encountered. The two most important things I have learned about so far are spermatogenesis and oogenesis. Understanding how, when, and why these processes take place is key to understanding the development of some diseases, as well as the seeing the large number of mutations that can occur along the way. The ethical side of these processes becomes confusing for me, especially concerning genotypes of individuals. If there is a mutation somewhere in development and an individual ends up with three alleles instead of two, I am still confused as to how society should treat this person, mainly with isues concerning their personal rights. I need to study this more on my own to decide on these issues and take a clear stance on them. This class has opened my eyes to the world around me. Individuals with physical disabilities now peak my interest rather than scare me because of the nature of their disease and how it developed. It automatically becomes a new research project. This has opened my eyes to my future as well. A lot of individual research time will benefit me because I will no longer be ignorant to these issues. I will, instead, be aware and informed of them.

Down Syndrome and Mutations




This picture was taken from the following website:
https://cornellbiochem.wikispaces.com/file/view/
downsyndrome1.jpg/66756907/downsyndrome1.jpg

 
Recently in class, we have been talking about mutations. We were assigned to do a project on a specific disease, and I chose to do mine on Down syndrome. This is an abnormality caused by nondisjunction in fertilization, or the failure of homologous chromosomes to separate as they should during reproduction, resulting in an extra copy of a chromosome. This is a mutation in the sense that, normally, only two chromosomes would develop in a zygote, whereas three chromosomes develop with this syndrome. A picture of a child with Down syndrome is posted above.

One of our class textbooks, "Mutants" by Leroi, describes two noteworthy details about mutations. First, our faces seem to be the most vulnerable body part in displaying mutation's effects (Leroi). This was apparent to me because one of my sources for my project was MedLine Plus, an online journal. On this website, symptoms of Down syndrome are listed, but nearly all of them are facial disfigurements. It describes an abnormally shaped head, a flattened nose, separated brain sutures, small ears, a small mouth and upward slanting eyes (MedLine Plus). Also, it stated that Down syndrome is mainly apparent to doctors at birth because of its distinct physical abnormalities (MedLine Plus). I had noticed this during my project, but as I read from my textbook, it became more apparent to me. So my question is this: why are our faces so vulnerable to mutation? What about our faces makes mutations almost attract the area? Is there a genetic reason for this? Does the environment play a role?

The other detail Leroi suggests in his coverage of mutations is that "more than 70% of spontaneously aborted fetuses bear severe chromosomal abnormalities" (Leroi). Leroi adds, "it is now widely supported that miscarriage is an evolved device that enables mothers to screen for, and rid themselves of, genetically impaired progeny." Also while doing my project, I found that it was very common for mothers to have abortions, or miscarriages, after they got positive results from testing their babies for Down syndrome. If more than half of spontaneous abortions occur because of genetic abnormalities, such as the one that causes Down syndrome, why does it not account for fetuses with this anomaly? This suggests that spontaneous abortion must have sort of a "cut-off point," in which it can no longer occur. If not, at least some of these fetuses would have spontaneously aborted, especially more than enough to allow Down syndrome to be the "most common single cause of human birth defects" (MedLine Plus). This also peaked my interest. We have answers to the more basic questions concerning spontaneous abortion, such as how and why it happens, but we still do not have all the answers. When does it take place during the pregnancy? Does it stop after a certain point? Are there other criteria? Does the mother have to have specific qualities that allow this process to continue in her? Or is it normally built in to every female? Does it stop after the female reaches a certain age?

These questions, along with those above have yet to be answered and are useful for more research in the scientific world.

The book "Mutants" is a scientific book written in 2003 by Armand Marie Leroi as a means of finding a "direct way into the human genome and the human body" through the discovery of mutants. Leroi is an evolutionary developmental biologist, and thus, has ample experience and knowledge to write such a book. It is informative and does not take sides. Rather, it seeks to provide a new way of thinking: all humans are mutants, not merely those with severe physical disfigurements that we may more often assume. This is, therefore, a trustworthy source.

The other source I used is from an online, peer-reviewed, scientific, medical journal, and as such, does not give a specific author's name. The website is the following: http://www.nlm.nih.gov/medlineplus/ency/article/000997.htm and again, the source is informative. It does not take sides, but merely seeks to inform the public, or whoever may read this journal, of the symptoms of this disease. This website is a service of the United States National Library of Medicine, and the National Institutes of Health. Therefore, all the information posted on this site are reviewed by individuals of appropriate authority in terms of knowledge on the subject. This also, therefore, is a trustworthy source.

Cleft Palate

This picture was taken from the following website:
http://news.wustl.edu/news/Pages/20173.aspx

This past Sunday, September 12, I had the unfortunate task of attending the funeral of a close family friend. While it was slightly expected, death always seems to come at an unfortunate time, and it proved very hard for all the close family members. One of the people who spoke had an especially hard time. This was partly due to the fact that he had been given the task of speaking at his friend's funeral, however, the tears shed did not help. As he continued to speak, however, it was noticeable why he had such a hard time speaking, as well as why it was so hard to understand him. He had a cleft palate. This led to his slight speech impediment, as well as resulting in the slight difficulty others had when understanding him. After some research, I found the following information.

"We all start out life with a cleft lip and palate. During normal fetal development between the 6th and 11th weeks of pregnancy, the clefts in the lip and palate fuse together. In babies born with cleft lip or cleft palate, one or both of these splits failed to fuse." A cleft palate is a split or separation in the oral cavity. This is one of the most common birth defects, and affects about one in 1,000 babies. Children born with this disorder have struggles with eating, breathing and speaking. The cause of this anomaly is unknown, although genes and environment are suspected precursors. Surgeries provide the best results for treating clefts, however complications may be lifelong, such as they were in my encounter.

More than anything else, my eyes were opened to the social detriments birth defects can cause, even at the mature adult stage. At the funeral, even after this person had become an adult, it was apparent to the audience that something was wrong. It is hard to comprehend how such a small abnormality, that doesn't even have a known cause yet, can cause so much potential damage. Birth defects, in particular, are hard for me to understand because babies have done nothing to deserve them. We should be in constant appreciation of the fact that God has truly created our bodies more intricately than we will ever know.

The information in the second paragraph was taken from the following website: http://www.entnet.org/HealthInformation/cleftLipPalate.cfm.

Teratogens

The above picture was taken from the following website: 
http://www.learn.ppdictionary.com/prenatal%20development.htm

This week in class, we were discussing developmental anatomy. Along with the normal developmental anatomical structures, we discussed developmental abnormalities. A new word I learned while learning about these abnormalities was "teratogens." The word is derived from the Greek and literally translates to "monster-formers." Teratogens are the "exogenous agents that cause disruptions in development, resulting in teratogenesis, or the formation of congenital defects. Teratology is the study of birth defects and of how environmental agents disrupt normal development." Teratogens are substances, such as alcohol, drugs, hormones, cigarettes, lead mercury and radiation, that cause developmental, anatomical abnormalities. Above is a picture showing the different types of teratogens and their possible harmful effects on the fetus during development.


The information referenced above was taken from the following reference: Gilbert, Scott F. Developmental Anatomy - Medical Embryology and Teratology." Developmental Biology. Vol. 9. Sunderland, MA: Sinauer Associates, 2010. 28. Print