Difference between revisions of "User:Z3332337"
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Revision as of 21:41, 2 October 2012
Lab 1 --Z3332337 11:49, 25 July 2012 (EST)
Lab 2 --Z3332337 10:15, 1 August 2012 (EST)
Lab 3 --Z3332337 10:17, 8 August 2012 (EST)
Lab 4 --Z3332337 10:24, 15 August 2012 (EST)
Lab 5 --Z3332337 10:19, 22 August 2012 (EST)
Lab 6 --Z3332337 10:15, 29 August 2012 (EST)
Lab 7 --Z3332337 10:16, 12 September 2012 (EST)
Lab 8 --Z3332337 10:10, 19 September 2012 (EST)
Lab 9 --Z3332337 10:03, 26 September 2012 (EST)
Lab 1 Assessment
Effect of the method of conception and embryo transfer procedure on mid-gestation placenta and fetal development in an IVF mouse model.
This article discusses the effects of using In Vitro Fertilisation (IVF) against "In Vivo" mouse models on the fetal development, using birthweight as the a quantifiable variable.
This article showed that IVF fetuses had a lower birthweight than fetuses from In vivo pregnancies.
They implanted sites for all IVF mice had similar implantion sites, however this study shows that IVF mice have higher abortion rates along with a lower birthweight when compared with in vivo embryos. It shows here that IVF embryos are more likely to be delayed in reaching the blastocyst stage when compared to "in vivo". They also show delayed development after the blastocyst stage which may be related to the low birthweight of IVF embryos.
Reference: Delle Piane, L., Lin, W., Liu, X., Donjacour, A., Minasi, P., Revelli, A., Maltepe, E. and Rinaudo, P.F. (2010). Effect of the method of conception and embryo transfer procedure on mid-gestation placenta and fetal development in an IVF mouse model. European Society of Human Reproduction and Embryology , 25 (8), 2039-2046.
IVF Nobel Prize
Professor Robert Edwards won the Nobel Prize in Medicine in 2010.
Lab 2 Assessment
Detection of methylation by zygote staining
Asymmetric anti-5meC staining of the male and female pronucleus after acid-pretreatment has been reported , , ,  yet was not confirmed by this study. The zygotes used in past studies were commonly generated by in vitro fertilization or subjected to culture in vitro (which provides logistic advantages for the feasibility of such studies). After antigenic unmasking with acid, the smaller (female) pronucleus in zygotes produced by in vitro fertilization (Fig 7A1) and or cultured in vitro (Fig 7A3) showed more anti-5meC staining compared to those collected directly from the oviduct (Fig 7A5). After antigenic unmasking by acid and trypsin, however, high levels of anti-5meC staining were consistently observed in both pronuclei of IVF (Fig 7A2), cultured (Fig 7A4) and fresh PN5 zygotes (Fig 7A6). Analysis of metaphase zygotes showed that culture from the early zygote stage caused variable levels of anti-5meC staining to persist in acid-only treated zygotes (Fig 7B). The level of methylation was assessed further by comparing staining with anti-MBD1 and anti-5meC in fresh and cultured zygotes (Fig 7C). This analysis showed that a similarly high level of MBD1 staining was observed in PN5 cultured (Fig 7C1) and fresh (Fig 7C3) zygotes, yet 5meC staining persisted in an asymmetrical fashion in cultured (Fig 7C7) but not fresh (Fig 7C9) zygotes. After acid and trypsin unmasking the MBD1 staining was lost from both treatments (Fig 7C2,4) and resulted in a similarly high level of staining with anti-5meC in both cultured and fresh zygotes (Fig 7C8,10). No staining was detected with non-immune control antisera for either antibody (Fig 7C5,6 and C11,12). The current results show that manipulation of the early embryo interferes with the maturational changes in zygotic chromatin that results in acid-resistant antigenic masking of 5meC, and this reduced level of masking was greatest in the female pronucleus giving an artifactual appearance of asymmetric demethylation.
Reference: Li, Y., & O'Neill, C. (2012). Persistence of cytosine methylation of DNA following fertilisation in the mouse. PLoS One., 7(1), e30687. Epub 32012 Jan 30626. Copyright Li, O'Neill. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Identify a Protein Associated with Implantation
A protein associated implantation is Proprotein 6 Convertase (PC6), a serine protease. It is involved in endometrial receptivity and is integral for cellular remodelling by cleavage of scaffolding protein ezrin-radixin-moesin binding phosphoprotein 50 (EBP50). Cleavage event allows for the ezrin protein to integrate the actin cytoskeleton and the plasma membrane, increasing chances of binding and therefore implantation. Knockout mice were used to down-regulate PC6 and results in failure of cleavage of EBP50 and therefore a decrease of healthy embryo implantation when compared to the wild type mice.
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" is any time between conception and birth, typically measured from the woman's last menstrual period until the current time. Whereas, "post-fertilisational age" is specifically the time after the ovum is fertilised.
"Gestational age" is used to in describing human development because it is measures pregnancy in weeks, as a pregnancy typically lasts 38-42 weeks.
2. Identify using histological descriptions at least 3 different types of tissues formed from somites.
Somites which develop from the paraxial mesoderm, give rise to 3 different types of tissues: dermatome, myotome and sclerotome tissues.
Dorsolaterally there is the: Dermatome which forms the dermis and and contributing fibroblasts, & Myotome which forms the myoblasts (primordial muscle cells).
Ventromedially there is the: Sclerotome which forms the vertebrae and the ribs.
Lab 4 Assessment
Amniocentesis: is where amniotic fluid is extracted with a needle is inserted into the amniotic cavity through the abdominal wall, guided by an ultrasound. This test detects for levels of metabolic by-products, including alpha-fetoprotein. This test is usually administered between 14-16 weeks gestation.
Elevated levels of the afore-mentioned protein may indicate abnormalities regarding the neural tube, such as spina bifida (unfused vertebrae over spinal cord) and anencephaly (the end of the neural tube fails to fuse).
Chorionic Villus Sampling (CVS): is where tissue is removed from the chorion layer of the uterine wall, by a needle or a catheter through the cervix, also guided by an ultrasound. This tissue is then karyotyped for molecular and genetic testing, for abnormalities such as Trisomy 21 (aka: Down Syndrome). This test is administered usually in weeks 10-12 of gestation.
It should be noted that abnormalities detected in CVS may be confirmed through amniocentesis.
Reference: Larsen's human embryology 4th ed. Schoenwolf, Gary C; Larsen, William J, (William James). Philadelphia, PA : Elsevier/Churchill Livingstone, c2009.
2) Identify a paper that uses cord stem cells therapeutically and write a brief description of the paper's findings.
Roura, Santiago, Josep-Maria Pujal, and Antoni Bayes-Genis. "Umbilical Cord Blood for Cardiovascular Cell Therapy: From Promise to Fact." Annals of the New York Academy of Sciences 1254, no. 1 (2012): 66-70.
Umbilical Cord Blood (UBC) is a valuable stem cell source and has a great potential for vascular growth and repair. This article indicated that UBC may be used as an alternate source of hematopoietic cytokines (CD133+) which stimulate angiogenesis.
It has been indicated in the therapy for an array of diseases including the reconstitution of a defective immune system, neurological improvement of cerebral palsy, and possibly the treatment of type 1 diabetes. It has also shown improvements in reducing 'graft vs. host' disease in transplant patients due to the presence of Multipotent Stromal Cells (MSCs) found in UCB. MSCs are also found in bone marrow.
Research on animal models through fluorescent angiography has shown that UCB may improve, if not recover, endothelial function from "UCB-MSC differentiation and new microcirculatory vessel formation".
Lab 7 Assessment
(a) Provide a one sentence definition of a muscle satellite cell (b) In one paragraph, briefly discuss two examples of when satellite cells are activated?
a) Muscle satellite cell: Is a normally quiescent myogenic cell which holds a reserve stem cell population and becoming activated when muscle is injured.
b) Satellite cells are activated when new skeletal muscle is being generated of in the instance that muscle is damaged or injured.
(c) 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?
c) When there is long term damage to motor nerve cells which prevent normal functioning of the musculoskeletal system the affected muscles generally undergo the process of 'atrophy', or a "wasting away". This is not the muscle dying, but the muscle cells are reducing in size because of a lack of use. Muscle fibre type also changes from fast-twitch fibres to slow twitch.
Lab 8 Assessment
Good descriptions of individual features of the eye. But seeing how the current task is the embryological development of the eye, it seems to be the smallest section of your wiki. Possibly a flow chart would be best to demonstrate the text you have in this section. Additionally, the information presented isn’t anything new or hasn’t been learnt in intro anatomy and could go further, as your current research section is still unfinished. Needs more current journal information
The text however in all of the sections is too dense and I feel my concentration waning when reading it. And although you have already an overall picture depicting the eye and it’s anatomical features, maybe for each section highlight the area that is being referred too. The timeline is unfinished and too wordy, needs to be more succinct.
The section of development of the optic nerve was really good, but again needs images to reinforce the text. Glossary and references are good, but need to be expanded. And a timeline of development would be useful.
Summary: text overwhelms the images and isn’t balanced.
Good luck with the rest ☺
Initial impression is it’s too textual for a wiki. The lack of consistent referencing styles is hard to follow. Relates the developing somatosensation to the nervous system, which was good and very interesting. Tables and mind maps/flow carts would be beneficial in sections 1.3.1-1.3.3. And a section on abnormalities of touch would be nice and/or methods of detecting touch and pain etc (ie: clinical methods) and maybe sensitivity to touch.
However, the way this project was divided was logical and easy to follow. But more defined and succinct paragraphs need to be made as it tends to go on for a bit, but that is a sign of good research into the project.
In the section of thermoreceptors it would be better if there was an image from the article for graphical representation.
Summary: MORE IMAGES!!! Be more succinct.
Good luck with the rest ☺
WOW! I really can’t come up with anything bad to say about this wiki. Text and image are nicely balanced. Developmental timeline was very easy to follow and succinct which is always nice. It was good to have research images alongside hand drawn images. Diagnosis and treatment sections may need some expantion. List of references current and varied – always good to see.
All in all this was a very good project and congrats of the good work. Keep it up.
Good luck with the rest ☺
I really liked the way how sub-divided the different abnormalities in vision and matched them with the corresponding image. However, further headings would be better for finding specific abnormalities especially when it comes to genetic causes. Also, the addition of normal eye functioning summary is a good recap on the eye before getting to abnormalities.
The molecular pathways are a bit hard to follow and confusing, although interesting.
The images are great and balanced with text, but the set out needs to change to make it more “friendly looking”.
Your glossary is good but may need a few more additions and extensive references are excellent.
Summary: overall very good and not complaints besides maybe think about the setting of the text to pictures.
Good luck with the rest ☺
Very clever start to the page. Introductory picture and statement draws reader in. Succinct but depth of information is really good. Somewhat overwhelming, but still very good. Break up in the information a little more.
The use of tables is really good and the coloured textbox was eye-catching and informative, similar to a textbook summary and great for wiki.
Distribution of abnormalities between environmental and genetic was also very good but further subheading for each syndrome would be better for quick access to desired information.
The development of the ear section is very well researched and informative but need pictures. I see that you havn’t gotten to really uploading lots of pictures yet but it’s really quite essential for you to do this esp. for this section as it’s the main focus. A few had drawn ones would be sufficient.
The extensive references are also impressinve.
Summary: break up sections more and more hand drawn images.
Good luck with the rest ☺
Lab 9 Assessment
(a) 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.
This article indicates that the developing pancreas, both endocrine and exocrine tissue, develops from signals received from the surrounding mesenchyme to the local epithelium from the expanding progenitor cells.
They have shown that mesenchymal cells regulate ancreatic growth both in ealry and late stages of fetal development, including initial proliferation of cells and after cells have differentiated.
This was an in vivo study where they interrupted the Beta-catenin signalling pathway. Beta-catenin is involved in "regulating mesenchyme signalling and growth", therefore when interrupting this pathway blocked proper pancreas organogenesis in both early and late stages, until the end of the gestation period.
(b) Identify the embryonic layers and tissues that contribute to the developing teeth.
The tooth develops from interactions between the dorsal ectoderm within the neural tube which produces WNT6 a signalling protein which interacts with bone morphogenetic proteins (BMPs) from the neural plate. At this point, where the ectoderm and mesenchyme meet (forming ectomesenchyme) there is active cell multiplication where FOXD3 gene is expressed allowing the initial two rows of ectomesenchyme to be expressed.
Cranial neural crest (cnc) cells (also known are odontogenic cells) migrate an populate the pharyngeal arches, from which the maxilla and mandible are derived from the 1st arch.
So although it is thought that teeth arrive exclusively ectoderm, but undergo "mesenchymalisation" which give the teeth the origin of 'ectomesenchyme'.