User:Z3374215

From Embryology
Revision as of 12:50, 1 October 2012 by Z3374215 (talk | contribs)

Lab Attendance

Lab 1 --Z3374215 11:49, 25 July 2012 (EST)

Lab 2 --Z3374215 10:06, 1 August 2012 (EST)

Lab 3 --Z3374215 10:06, 8 August 2012 (EST)

Lab 4 --Z3374215 12:01, 15 August 2012 (EST)

Lab 5 --Z3374215 10:05, 22 August 2012 (EST)

Lab 6 --Z3374215 10:08, 29 August 2012 (EST)

Lab 7 --Z3374215 10:14, 12 September 2012 (EST)

Lab 8 --Z3374215 11:34, 19 September 2012 (EST)

Lab 9 --Z3374215 10:10, 26 September 2012 (EST)

Lab 1 Assessment

1) Identify the origin of In Vitro Fertilization and the 2010 nobel prize winner associated with this technique and add a correctly formatted link to the Nobel page.

The Nobel Prize for physiology or medicine in 2010 was awarded to Robert G. Edwards for his efforts in the development of In Vitro fertilization. Robert G. Edwards developed the idea of In Vitro fertilization since the 1950s. He first made fundamental discoveries in the life cycles of human eggs and the optimal time for fertilization before pairing with a gynecologist, Patrick Steptoe, and eventually seeing to the successful birth of an IVF baby in 1978. [1].


2) Identify and add a PubMed reference link to a recent paper on fertilisation and describe its key findings (1-2 paragraphs). "The relative contributions of propulsive forces and receptor-ligand binding forces during early contact between spermatozoa and zona pellucida of oocyte" was published by the Journal of Theoretical Biology in Nov. 2011 [2]. This report discusses the two main ways in which spermatozoa penetrate the zona pellucida of oocytes. The sperm utilize propulsive forces to assist in penetration. This is achieved through the motion of the flagella. The other factor important to penetration is the binding of sperm to ligands on the surface of the zona pellucida of the oocyte (ZP3). The report addresses the question of which of the cofactors is most imperative to the successful fertilization of the oocyte. A biomechanical model of the sperm-oocyte process was developed. It predicted that during early penetration the propulsive forces were stronger than the biochemical ligand binding. It was also predicted that the constant movement and overpowering force of the propulsion of sperm would make binding to ZP3 ligands difficult, making the large number of ZP3 receptors on the head of the sperm significantly important at this early stage.


References

Lab 2 Assessment

1) Upload an image from a journal source relating to fertilization or the first 2 weeks of development as demonstrated in the practical class. Including in the image “Summary” window: An image name as a section heading, Any further description of what the image shows, A subsection labeled “Reference” and under this the original image source, appropriate reference and all copyright information and finally a template indicating that this is a student image.

Image: Expression of Endometrial CD98 in implantation[1]

Alt
Expression of Endometrial CD98 in implantation

2) Identify a protein associated with the implantation process, including a brief description of the protein's role (1-2 paragraphs).

A study has identified trophinin as a protein important to the adhesion implantation process. It is believed to be a single intrinsic protein that spans the membrane due to hydrophobic tendencies. This molecule can adhere without the aid of calcium unlike many cell adhesion molecules. Trophinin molecules bind with other trophinin molecule in trans structure on the cell surface. Immunostaining showed that antigens specific to the trophinin molecule can be found in both trophoblast cells and in the maternal epithelium near implantation sites of the embryo. The protein has been found to be encoded in the short arm of the X chromosome. It is also present in the mouse, sheep and bovine, along with monotremes and marsupials. It appears that the binding of the trophectoderm (consists of trophoblasts and is the connection between the blastocyst and the maternal cells) is essential to invasion and proliferation of cells. In embryonic cells trophinin induces and promotes invasion and proliferation. In maternal cells the same protein promotes apoptosis (controlled cell death) so as to allow the acceptance of the embryo. Therefore it is a dual signalling molecule. [2]

Reference

  1. <pubmed>20976164</pubmed>
  2. <pubmed>22717627</pubmed>

Lab 3 Assessment

1) Identify the difference between "gestational age" and "post-fertilisation age" and explain why clinically "gestational age" is used in describing human development.

The gestational age refers to the time since the last normal menstruation period[1]. Whereas post-fertilisation age is calculated from the time of fertilization. There can be confusion between the terms espcially as gestational age is two weeks longer than post-fertilisation age[2]. Although in itself the term gestation age is confusing as there is no actual conceptus in until fertilisation but it is accepted by clinicians through widespread use[3]. As exact post-fetilisation age would be difficult to determine gestational age is used clinically. In assisted reproduction cases post-fertilisation age can be accurately determined but 2 weeks are generally added to age for ease of understanding[4].

2)Identify using histological descriptions at least 3 different types of tissues formed from somites

Somites form the dermis of the dorsal epithelium, skeletal muscles and some connective tissue, specifically, the vertebrae and ribs.[5]

References

  1. Moore, K.L., 2011 The Developing Human 9th ed. W.B. Saunders
  2. <pubmed>15520122,</pubmed>
  3. <pubmed>16006453</pubmed>
  4. <pubmed>15520122,</pubmed>
  5. Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. Paraxial Mesoderm: The Somites and Their Derivatives. Available from: http://www.ncbi.nlm.nih.gov/books/NBK10085/

Lab 4 Assessment

1) Identify the 2 invasive prenatal diagnostic techniques related to the placenta and 2 abnormalities that can be identified with these techniques. Prenatal placental biopsy an invasive diagnostic technique for genetic abnormalities (such as trisomy 21) in the fetus. A karyotype is constructed allowing analysis of the chromosomes. It is used in the second and third trimester of pregnancy to confirm suspected malformations. Placental biopsies are sonographically guided[1]. Chorionic villus testing is another invasive technique carried out transcervically in the first trimester to detect inherited disorders such as haemophilia [2]


2) Identify a paper that uses cord stem cells therapeutically and write a brief (2-3 paragraph) description of the paper's findings. Mesenchymal stem cells derived from the human umbilical cord have been used as a therapeutic treatment for neuromyelitis optica. Neuromyelitis optica is an autoimmune inflammatory disease that effects the optic nerve and spinal cord. Stem cells have been seen to provide differentiation potential to neural cells, secrete necessary factors and help regulate immunological function. Five patients were treated with stem cell injections and then monitored for 18 months to analyse the effects both adverse and any improvements. Four out of the five patients gained some relief following treatment. Signs and symptoms decreased and the frequency of relapse was lessened. The neurological lesions also decreased in volume and severity as seen by MRI. The paper summarised that human umbilical cord stem cells were an appropriate therapy technique[3].

References

  1. <pubmed>2712602</pubmed>
  2. <pubmed>22250892</pubmed>
  3. <pubmed>22873728</pubmed>

Lab 7 Assessment

1. (a) Provide a one sentence definition of a muscle satellite cell

Muscle satellite cells are progenitor cells and are involved in muscle growth and repair as they can induce regenerated muscle and additional satellite cells[1]

(b) In one paragraph, briefly discuss two examples of when satellite cells are activated.

A study investigating exercised induced satellite cell activation in skeletal muscle of growing and mature rats concluded that satellite cells are activated by acute sessions of prolonged eccentric exercise. It also concluded that exercise affected the proliferation of young mitotically active satellite cells[2]. Satellite cells are also activated when damage occurs. A study indicated that two variants of the IGF-I gene are necessary for activation of satellite cells. The study examined induced lesions to the anterior tibialis muscle of rats. The results showed that one variant of the gene which gives rise to a growth factor, MGF, is initially produced after injury and it activates satellite cells then IGF-IEa is expressed to maintain the repair process [3]


2. In one brief paragraph, describe what happens to skeletal muscle fibre type and size when the innervating motor nerve sustains long term damage such as in spinal cord injury.

In a study involving 12 human patients suffering from spinal cord injuries a section of the vastus lateralis muscle was biopsied at 3 intervals within the first 6month following injury. From 6-24 weeks after injury they showed 27-56% atrophy of Type I, IIa and IIax+IIx fibers. There was increased conversion between muscle types, type IIa decreased and type IIax+IIx increased. However there was little change in proportion of tpye I fibers during this period[4]

Reference

  1. <pubmed>12757751</pubmed>
  2. <pubmed>3693217</pubmed>
  3. M Hill1, A Wernig, G Goldspink Muscle satellite (stem) cell activation during local tissue injury and repair Journal of Anatomy:2003, 203(1);89-99
  4. <pubmed>9887150</pubmed>


Lab 8 Assessment - Peer Review

Vision

The layout of the page is relatively good. If anything it appears little too image heavy at the moment. On the note of images, the referencing is good but don't forget to include the student template note with each image. The inclusion of some student drawn images in great to see but it might be an idea to make the labels larger as they are hard to read. The use of subheadings is great, a really logically well set out page. The references need a bit of work, some are spread sporadically throughout the page and some in the references section just list the URL along with the error on reference number 13.

The introductory is brief but alright. However the first two images are largely similar, not sure why both need to be included. Perhaps if possible it would be nice to link each of the main anatomical bullet points you have listed in your introduction to their associated developmental paragraph further down the page.

The History of development is coming along nicely but perhaps would be easier to read if it was in the format of a table. Also the Atlas of the Development of Man needs to be properly referenced with the author in the reference section. It would be nice to have some information relating to the pictures uploaded in this section.

The section on Development is well done and it is interesting to look at the individual development of each structure. It might be an idea to include some more references to when each structural development occurs. Current Research really needs some more content. The glossary is a nice addition and helpful.

Somatosensory

This page has made good use of subheadings ensuring that the main topics are easily accessible from the contents box. The project appears a little text heavy, it may help to include some other images. Also don't forget to add the student template note on the student drawn image. The reference list at the end is not particularly extensive. Perhaps this can be worked on by collecting the loose references in the text and adding them to the final reference section. Overall some sections of the page seem to have little to with embryology and more focused on adult function.

The introduction, while good, seems to lack any original voice, rather seeming to consist almost entirely of research done by others. The referencing in this section is also confusing with (Lagercrantz, Hanson, Evrard & Rodeck, 2001) being listed before any text. Referencing in this format also makes the page seem like a report or essay rather than a web page. There is also mention of a picture that does not exist. The historic section is brief and rather hard to digest as it is just a chunk of text. Perhaps putting this information into a table and developing it a little would help here.

The section on Central Somatosensory Differentiation was particularly well done. The inclusion of the student drawn image making all the difference. The general structure of this section is also commendable.

The subtitles "Touch", "Pain", "Heat/Cold" and "Pressure" are somewhat abrupt and don't particularly indicate what the section is discussing. This section in particular could do with the addition of some images. The information under Touch could perhaps be a little more heavily researched but is generally well written. Breaking the Pain section into some smaller paragraphs could be useful. The Hot/Cold and Pressure sections are well done excepting the random references to some articles.

Current research section could do with some more information. There are several words throughout the content that could do with being linked to an explanation in the glossary such as the "dorsal column-medial lemniscal system". The external links section is a good addition but it might be helpful to explain more clearly what each links to, especially the last three.

Taste

Initially the page seems to have a good balance between text and diagrams/photographs. However the figures included are not properly labelled once you click on the file and some of them don't appear to have any copyright information included. Some of the pictures could do with being a bit smaller as they take up a large proportion of the page. The student drawn image of the tongue is particularly impressive but does still need to have the student template included. The references seem limited in comparison to other groups perhaps suggesting a lack of depth or variety of research. There also appears to be a coding problem relating to reference number 5. The general layout and use of subheadings is great. It may be useful to link the words in the glossary to their occurrence in the text.

The introductory paragraphs are very well written. They are easy to understand and interesting and give a good overview of how taste functions. Similarly the section on taste map is well written clearly explaining the neurological factors associated with taste. However the presence of the picture in isolation is confusing as it is representing an the old method of taste association. Perhaps this would be resolved if a diagram of the newer taste map was also included. Also you say that the old taste map has been disproved by recent research but that research is not referenced. In fact it appears that very little of that section is referenced. The section on cortical areas is well done.

The timeline of developmental processes is good, the table an easy visual format and the information concise and effective. The only point of contention would be the direct quote in Wk8-9 which seems out of place in comparison to the remainder of the entries which are nicely paraphrased. The history section is similarly well done being extensive and comprehensive. That is excepting some Pub Med references which are just placed in the text rather than in the reference list at the bottom. While interesting and well written the part detailing the Adult Tongue and Taste Buds seems out of place in a embryology course.

The sections on the effect of gene expression on the formation of taste abnormalities and current research are good. However it may be useful to put the information regarding each picture as a caption rather than plain text.

It will be interesting to see what is put in the section "Image Gallery"

Abnormal Vision

Your introduction is relatively well written and the brief explanation of new terms such as microphthalmia was particularly useful. Perhaps it would be possible to break the text into two paragraphs to make reading easier. It is really good to see a section included about normal eye development as it provides a basis of understanding for the remainder of the page. Concise and to the point and not too complex, it's great. Only suggestion would be to place it in a table perhaps with each Carnegie stage a new entry.

Layout of abnormalities is very logical covering the main areas of developmental abnormalities. However it is slightly confusing that immediately under the title Abnormal Lens Development more information on normal development is given. Allocating the defects to their associated individual genes is good but perhaps instead of a dotpoint a subheading would be of more use. The actual information is clearly and effectively written. The inclusion of the pictures clearly illustrates the abnormalities but their placement is a little odd. Perhaps they are too large. The captions on the pictures are appropriate and the pictures are appropriately referenced and it is great that the link to the picture contains more information.

Under the title "Ocular Manifestations" perhaps indicate what the two sections are, just so the following on sections make sense and don't appear disjointed. The sections on the genetic caused abnormalities is fascinating and very well written. The timeline included in the information about Leber Congenital Amaurosis is particularly interesting. The spacing in the section on genes associated with Anophthalmia and Microphthalmia appears slightly strange. The figures included are particularly illustrative and appropriate. Similarly the section on environmentally caused abnormalities is really well written and interesting.

Perhaps a more extensive section on current research could be included. If possible, link the words in the glossary to where they appeared in the text. This is the coding if you don't have it Words for Glossary. Just add that in place of the word when you first mention it in the text. The citing and referencing is really well done. It also shows a great depth of research. The figures/photographs so far included are brilliant but the inclusion of a student drawn diagram somewhere if possible would be effective. Also try and fix the general layout of the project, possibly including some more subheadings. In general the content relates to the the course and is pitched at an appropriate level. Hope this helps.

Hearing

Firstly the use of humour in this page is brilliant! Makes for an interesting and engaging read. The use of photographs and figures are particularly useful to help understand the topic but don't forget that the student template notice needs to be added to each photograph/diagram that you include. The referencing is great and extensive, perhaps though it might be an idea to see what is going on with reference number 56. The general layout of the page is really attractive too with a good balance of images and text, tables and especially the colourful Summary box. The content seems to address the course aims and requirements.

The introductory paragraph is to the point, well written and engaging. Similarly the structure and content included in the historic section is detailed and easy to read due to the table layout. The section about the development of the inner is well written but is somewhat overwhelming to look at just because of the amount of text. Maybe this could be combated by separating it into a few more paragraphs. The inclusion of genetic information in this area is great. The information under the subheading "The Otic Placode" onwards is particularly well done.

I like how the section on abnormalities is set out. However one problem with the area is the NOTE just before the table of genetic syndromes, I don't understand its purpose. Similarly the link in Goldenhar Syndrome entry appears random in comparison to the remainder of the entries. Perhaps some more images in the abnormality section would be beneficial in breaking up the text. The paragraph discussing Rubella has two sentences in brackets at the bottom. Not sure why they are there either. If possible make "Infections" and "Drugs" into subheadings. I assume that information is still forthcoming for the section on Isotretinoin.

"Technologies to detect" is a good entry but perhaps consider changing subheading title as it is a little vague and incomplete. Also with this section there are loose references which should be included in the reference list at the bottom of the page rather than in the middle of the text. The information on hearing technology is brief but to the point. Again with the section on current research it may be an idea to include subheadings rather than bullet points, just so it is more easily accessed from the contents box at the top of the page.

Lab 9

1) Identify and write a brief description of the findings of a recent research paper on development of one of the endocrine organs covered in today's practical.

2) Identify the embryonic layers and tissues that contribute to the developing teeth.