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==='''Trisomy 21 Peer Assessment'''===   --[[User:Z3290808|z3290808]] 23:06, 21 September 2011 (EST)
'''Trisomy 21 Peer Assessment'''  --[[User:Z3290808|z3290808]] 23:06, 21 September 2011 (EST)





Revision as of 00:35, 22 September 2011


Lab 4 Online Assessment

  1. The allantois, identified in the placental cord, is continuous with what anatomical structure?
  2. Identify the 3 vascular shunts, and their location, in the embryonic circulation.
  3. Identify the Group project sub-section that you will be researching. (Add to project page and your individual assessment page)




LAB ATTENDANCE

Z3290808 12:54, 28 July 2011 (EST)

z3290808 12:32, 4 August 2011 (EST)

z3290808 11:34, 11 August 2011 (EST)

z3290808 12:25, 18 August 2011 (EST)

z3290808 11:35, 1 September 2011 (EST)

z3290808 12:29, 15 September 2011 (EST)

LAB 1 ASSESSMENT

Identify the origin of In Vitro Fertilization and the 2010 nobel prize winner associated with this technique.

  • In vitro fertilization (IVF) is a fertility technique with a history that can be traced back to as early as the 1890's when the transfer of rabbit embryos from one mother to another was achieved successfully by Walter Heape (Metro IVF, 2011). The first ever attempt to fertilize a human egg in vitro was in 1973, although this attempt was unsuccessful as the embryo failed to implant itself into the wall of the uterus. The first successful attempt at IVF was with the birth of Louise Brown on 25th July, 1978, in Oldham, Greater Manchester, UK. Brown became known as the world's first successful IVF baby conceived outside the human body (Monash IVF, 2011). Credit for this achievement was given to embryologist Dr. Robert G. Edwards and gynecologist Dr. Patrick C. Steptoe.
  • Dr. Robert G. Edwards was awarded the 2010 Nobel Prize in Medicine or Physiology for his development of IVF.


Identify a recent paper on fertilisation and describe its key findings.

  • This article’s main objective is to examine the effect of a woman’s body mass index (BMI) on ovarian response to stimulation and the outcome of IVF. Singh et al., (2011) found that oocyte quality decreased with increasing BMI; resulting in reduced clinical pregnancy rate and thus impairment of IVF outcome. It was also evident that as the woman's BMI increased, so did the required dose of gonadotropins. This increase in required gonadotropin in obese women undergoing IVF reflected a state of 'gonadotropin resistance' which was shown to lead to "increased number of days required for ovarian stimulation and higher cancellation rates, lower serum peak estradiol (E2) levels, and reduced number of oocyte retrieved" (Singh et al., 2011). Also, increasing BMI of women undergoing IVF led to a decrease in fertilization and cleavage rate, most likely due to poorer oocyte quality as a result of increased BMI. Thus, it is evident that a woman's BMI plays a considerably significant role in how successful IVF will be for her. [1]


Identify 2 congenital anomalies.

  • Trisomy 21 (Down Syndrome)
  • Polydactyly


Reference List

  1. <pubmed>21792549</pubmed>

Metro IVF. (2011). History of IVF. Retrieved August 02, 2011 from http://www.metro.com.my/historyIVF.php

Monash IVF. (2011). History of IVF. Retrieved August 02, 2011 from http://www.monashivf.edu.au/About_Monash_IVF/History_of_IVF.aspx

LAB 2 ASSESSMENT

Identify the ZP protein that spermatozoa binds and how is this changed (altered) after fertilisation.

  • The Zona Pellucida glycoprotein that acts as the primary receptor for spermatozoa binding during fertilization is ZP3.
  • Once the sperm binds to ZP3,the acrosome reaction is induced. This reaction involves the exocytosis of acrosomal enzymes which function to digest the zona pellucida, allowing proteins on the surface of sperm to bind ZP2. As a result of this, membrane fusion occurs which in turn causes membrane depolarization; the primary block to polyspermy. Once the spermatozoa fuses into the oocyte, the cortical reaction takes place. This is when the contents of the sperm's cortical granules are released and act to remove carbohydrate from ZP3 (so that it can no longer bind to the plasma membrane of the sperm) and partially cleave ZP2 (which results in hardening of the zona pellucida). These mechanisms prevent additional sperm from entering the egg. [1]

Identify a review and a research article related to your group topic.

Articles on Fragile X Syndrome:

- This review focuses on the molecular and biochemical pathways shown to be relevant in the Fragile X Syndrome. It describes that a mutation in the FMR-1 gene was found to lead to Fragile X Syndrome due to excessive repeats of the trinucleotide sequence CGG which is known to inactivate the FMR-1 gene, making the X chromosome fragile and prone to breakage. This review article also demonstrates the many vital functions of the FMR-1 gene such as its role in RNA transport and stability, thus absence of the protein transcribed and translated from this gene is thought to affect brain development and thus leads to signs of mental retardation. [2]


- This research article explores the two molecular differences of the FMR-1 gene in normal individuals vs. those with Fragile X Syndrome. These differences are an increase in size of an FMR-1 exon containing a CGG repeat and abnormal methylation of a CpG island 250 bp proximal to this repeat. This research article also shows how these two abnormalities repress transcription of the FMR-1 gene, leading to the absence of the FMR-1 protein which is thought to be the contributing factor to the Fragile X phenotype. [3]

Reference List

  1. <pubmed>20831819</pubmed>
  2. <pubmed>21196228</pubmed>
  3. <pubmed>1301913</pubmed>


LAB 3 ASSESSMENT

What is the maternal dietary requirement for late neural development?

The maternal dietary requirement for late neural development is Iodine. Iodine deficiency induces neonatal hypothyroidism (cretinism). This ultimately leads to impairments of cerebellar development as sufficient thyroid hormone is vital for the normal development of the cerebellum during late neural development. [1]

Reference List

  1. <pubmed>21611807</pubmed>

Sample Picture Upload (Done In Lab).

Differentially expressed RefSeq genes in human trisomy 21


Differentially expressed RefSeq genes in human trisomy 21.jpg


File:Differentially expressed RefSeq genes in human trisomy 21


Upload a picture relating to your group project.

FMR4 is silenced in fragile X syndrome

FMR4 is silenced in fragile X syndrome.jpg

File:FMR4 is silenced in fragile X syndrome

--Mark Hill 11:15, 14 August 2011 (EST) Well done. You can also link the reference from the figure legend, like the example below.

FMR4 is silenced in fragile X syndrome [1]

References

  1. <pubmed>18213394</pubmed>

LAB 4 ASSESSMENT

The allantois, identified in the placental cord, is continuous with what anatomical structure?

  • The allantois, originating from the endodermal layer of the trilaminar embryo, is continuous with the superior end of the developing bladder.

Identify the 3 vascular shunts, and their location, in the embryonic circulation.

  • Foramen Ovale: connects the right and left atria.
  • Ductus arteriosus: connects the pulmonary artery and descending aorta.
  • Ductus venosus: connects the umbilical and portal veins to the IVC.

Identify the Group project sub-section that you will be researching.

  • Recent Research with a focus on the relationship between Autism and Fragile X Syndrome.


LAB 5 ASSESSMENT

Which side (L/R) is most common for diaphragmatic hernia and why?

  • 85% of Congenital diaphragmatic hernias (CDH) are left sided. The most common form of CDH is the classic posterolateral or Bochdalek hernia. Bochdalek hernia is a congenital anomaly which occurs as a result of the protrusion of intra-abdominal organs (such as the intestines and stomach) into the thoracic cavity (causing the lungs to compress) via an abnormal opening in the infant’s diaphragm. The reason why it is most common on the left side is most probably due to the earlier closure of the right pleuroperitoneal opening. [1]

--z3290808 22:21, 31 August 2011 (EST)

Reference List

  1. <pubmed>12359645</pubmed>


LAB 6 ASSESSMENT

What week of development do the palatal shelves fuse?

The fusion of the two palatal shelves occurs in week 9 of embryonic development. During this period of time, the secondary palates fuse with each other as well as with the primary palate. [1]

What early animal model helped elucidate the neural crest origin and migration of neural crest cells?

Studies using the chicken model helped to explain the neural crest origin and migration of neural crest cells. Also, in the 1980’s, LeDouarin carried out transplantation experiments on chicken/quail chimeras that aided in the understanding of neural crest migration by identifying the migration path and final destination of the neural crest cells that were transplanted. [2]

What abnormality results from neural crest not migrating into the cardiac outflow tract?

Failure of the neural crest to migrate into the cardiac outflow tract may result in an abnormality such as Tetralogy of Fallot. Other abnormalities that may occur as a result of this include persistent truncus arteriosus, mispositioning or elongation of the outflow tract as well as cushion hypoplasia. [3]

--z3290808 09:38, 15 September 2011 (EST)

Reference List


LAB 7 ASSESSMENT

Trisomy 21 Peer Assessment --z3290808 23:06, 21 September 2011 (EST)


Introduction:

  • The introduction is not very well structured. It does not give an overview of what is to come and does not initially evoke the reader.
  • I like the internal links used on this page such as “nondisjunction” which takes you directly to the glossary section. This saves the reader time and effort instead of having to look up the meaning of the unfamiliar words.
  • “Aneuploidy is the term used to describe any abnormal number of chromosomes either an increase or decrease in total number.” This sentence seems out of place. Perhaps an internal link to the glossary (like that of the word “nondisjunction” used earlier) should have been provided as it does not link in with the rest of the introduction- the word was not even mentioned anywhere else in this introduction.
  • I like the extra links provided at the end of the introduction which allow the reader to read up on some extra information, however, some links are repeated in both “genetic links” and “diagnosis links” such as “prenatal diagnosis.” Also, some links are not very related to Trisomy 21- these may confuse the reader and we don’t want them to completely deviate away from the subject at hand.
  • I like the image – it helps to visualise the genetic abnormality of Trisomy 21. The image, however, is lacking a name at the bottom. Also the image does not contain a copyright notice!
  • There is only one reference in this whole introduction- not good enough. 1st, 3rd and 4th paragraphs are not even cited!

Some Recent Findings:

  • Firstly, I don’t think this section should be placed here. I think it should appear later on the page, possibly towards the end?
  • I like how this section is arranged structurally, however there are some issues. Firstly, it is not sufficient to merely quote the information as a whole. If a quote is required, it should not make up the bulk of the information. This information should have been put into your own words. Also, the references should be placed directly after the quote (not as done here).
  • This is a good image; however I don’t think it belongs under this heading as it does not display any recent findings. I think it more shows some of the facial phenotypic characteristics of the disease. I think it should be in the signs and symptoms section of this page – however the dilemma I found is that this page actually lacks a specific “signs and symptoms” subheading which I think is imperative, especially for this specific genetic disorder which shows many phenotypic characteristics. From the looks of it the image has been referenced appropriately with the inclusion of the copyright notice.

Trisomy 21 (Down Syndrome) Karyotypes:

  • The two images are good and referenced adequately. Do they need a copyright notice however? They help to visualise the genetic abnormality of chromosome 21 associated with this disorder in both males and females which is good.
  • The description below could be more targeted at the images above. An explanation of the difference between the male and female karyotype would have also been good.
  • It just seems like this section is slightly too brief, although it does get the message across.
  • Lack of references of the text in this section!

Associated Congenital Abnormalities:

  • To make it look more professional, the first letter after the bullet point should be a capital.
  • Only one reference for this whole list?
  • I like the “(More? Hearing Abnormalities)” section for readers who are interested in reading further.
  • The image in this section is too small as a thumbnail. It also has no title so the reader does not know what they are obtaining from the image before they click onto it. The image is not referenced appropriately. I think the image does not need to be there- it does not seem to complement the adjacent text of this section.

Heart Defects:

  • Links are good, however same issue as above – would look more professional with the bullet point starting with a capital letter.
  • No references in this section which is worrying considering you have provided percentages that need to be justified with an appropriate citation.

Limb Defects:

  • Quite a brief section but is okay in structure.
  • Only one reference for this section?
  • Image is appropriate and complements the writing of this section. It also has a title, thus the reader knows before even clicking onto it what it encompasses. Image reference seems adequate.

American College of Obstetricians and Gynecologists Recommendations:

  • This section is overall good, however I am not too sure if it is appropriate to dedicate an entire section to this?

Prevalence:

  • Interesting section- it says “Listed below are some sample data from different world regions” although the reader is only provided with data based on Ireland and USA. If it’s possible to obtain, more data on many other countries would be good to allow the reader to gain insight into the prevalence of the disorder worldwide.
  • References have been included which is good.

Down's syndrome Screening:

  • This section is possibly too long and dense with information – you may lose the reader!
  • I don’t think the image of “John Langdon Down” is appropriate for this section on screening of down’s syndrome. Maybe this could go in the introduction? Also this image has not been properly referenced and no copyright notice has been displayed.
  • The image of the “Tandem SNP Analysis Process” seems appropriate for this section and is satisfactory referenced.
  • Parts of this section are not referenced.

Meiosis I and Meiosis II:

  • “A recent study[19] has analysed two large USA studies…” I do not think this should be a section on its own. It could very well be added into the “Some recent findings” section.

Aneuploidy:

  • Firstly, no references in this section!
  • Secondly, as with the previous section, I do not believe this information should be dedicated an entire subheading. It could easily be incorporated into the glossary via an internal link such as the one used in the introduction.


Trisomy 21 Growth Charts:

  • “Data from this paper…” Which paper? Please reference exactly which paper and include authors of paper as well as year published.
  • Once again I do not think this should be dedicated to an entire sub heading. It does not seem directly relevant.
  • Nevertheless, graph charts are good with appropriate references and titles.
  • As I have mentioned in a previous comment, it is not very good to quote a whole paragraph. Try to put this in your own words and maybe only quote a vital piece of information.

References + Glossary:

  • References seem to be formatted correctly. However, I think 20 references is insufficient for this amount of information and data.
  • Too many subheadings for individual forms of references. This may overwhelm the reader!
  • Glossary is good and in alphabetical order so it is made easier for the reader to locate the word.
  • The Glossary links section at the bottom is good.

Overall Comment:

  • Structure needs refining and referencing was a consistent issue. Creator needs to read over the page and edit where appropriate. Otherwise, sound and interesting information on Trisomy 21 has been provided for the reader.

--z3290808 23:06, 21 September 2011 (EST)

LAB 8 ASSESSMENT

LAB 9 ASSESSMENT

LAB 10 ASSESSMENT

LAB 11 ASSESSMENT

LAB 12 ASSESSMENT