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--[[User:Z8600021|Mark Hill]] 17:59, 10 September 2012 (EST) You have answered both questions well. '''10/10'''
--[[User:Z8600021|Mark Hill]] 17:59, 10 September 2012 (EST) You have answered both questions well. '''10/10'''
==Lab 7 Assignment==

Revision as of 22:55, 18 September 2012

Lab Attendance

Lab 1 --Z3220343 11:49, 25 July 2012 (EST) Lab 2 --Z3220343 10:56, 1 August 2012 (EST) Lab 3 --Z3220343 10:06, 8 August 2012 (EST) Lab 4 --Z3220343 10:05, 15 August 2012 (EST) Lab 5 --Z3220343 10:02, 22 August 2012 (EST) Lab 6 --Z3220343 10:08, 29 August 2012 (EST) Lab 7 --Z3220343 10:12, 12 September 2012 (EST)


Lab 1 Assignment

    • The history of IVF dates back to the 1890's with Walter Heape reporting embryo transplants in rabbits. It was not until 1965 that Robert Edwards, Georgianna and Howard Jones, attempted to fertilize human oocytes In Vitro. In 1973 the first IVF pregnancy was reported by Leeton and Wood at Monash University (Melbourne, Australia) but this resulted in a miscarriage. The first IVF birth was the famous Louise Brown, born in 1978. This birth was the result of the collaborate works of Robert Edwards and Patrick Steptoe. [1]
  • In 2010 Robert Edwards won the Nobel Prize in Physiology or Medicine for his work with In Vitro Fertilization. [2]

Demián Glujovsky, Debbie Blake, Cindy Farquhar ,Ariel Bardach. Cleavage stage versus blastocyst stage embryo transfer in assisted reproductive technology 11 July 2012

The purpose of this article is to determine whether implantation of a ‘cleavage stage’(2-3 days) embryo is more likely to result in a live birth or if implantation should occur later when the embryo has reached the ‘blastocysts’ (5-6 days) stage of development. While there have been papers published on the success of ‘blastocysts’ implantation, it is noted that these trials were not randomised nor a consensus about the best practice for blastocyst culture. This paper delves into the results of a clinical randomised trial on blastocysts against cleavage stage. The merits found towards blastocysts are based on 2 arguments. 1. That most successful pregnancies in vivo, the embryo does not reach the uterus at day 3, which is the typical implantation time for cleavage transfer. 2. That blastocysts have higher implantation potential as the embryo have reach the blastocysts stage, have the most potential to survive. It is this second point, the one of self-selection which is seen a negative in the use of blastocysts implantation. This study found that although the live birth rate for the randomised controlled trail for blastocysts was a small but significant difference, the miscarriage rate between cleavage stage and blastocysts remained the same. On a whole this paper found that the benefits between cleavage stage and blastocysts are still unclear. [3]

--Mark Hill 17:46, 10 September 2012 (EST) Excellent answers to both questions 10/10.

Lab 2 Assignment

  1. Image:Fly GenomeJournal.pbio.0050131.g001.png[1]
  2. Trophinin is a protein that is expressed by trophoblast cells. In vivo pattern and activity of this protein suggests that it assists in the initial attachment of trophectoderm cells into the maternal epithelia. It is also instrumental in allowing the trophoblasts to invade through the uterine wall. [2]

References

  1. Gross L (2007) Novel Technique Shows When the Fertilized Egg’s Genome Comes into Its Own. PLoS Biol 5(5): e131. doi:10.1371/journal.pbio.0050131
  2. <pubmed>17487845</pubmed>

--Mark Hill 17:52, 10 September 2012 (EST) 1. Image uploaded with all required information including copyright and student image template. 2. Trophinin protein related to implantation identified, the paper though related to cancer progression and also without description of mechanism (role). See also PMID 22717627 8/10

Lab 3 Assignment

1. Gestational Age - is the period between conception and birth. It is determined as the time form last menstrual cycle to birth and can be between 38-42 weeks.[1] Post fertilization age - is determined as time from the fertilization of the egg. This time frame is 2 weeks shorter than gestational age and in most cases must be inferred. [2]

Gestational age is used in describing human development is traditionally used as most wopmen know when their last period was and not when conception occurred. There is minor error of 4-6 days. It is also conveniently broken up into weeks.[3]

2. Somites differentiate into 2 parts:

  • The ventromedial part is the sclerotome, which cells become the vertebrae and ribs (bone).
  • The dorsolateral part is the dermomyotome, which cells from the myotome regions – muscles and the dermatome regions becomes the dermis.[4]

References

  1. http://www.nlm.nih.gov/medlineplus/ency/article/002367.htm
  2. http://www.livestrong.com/article/92683-embryo-fetus-development-stages/
  3. http://pediatrics.aappublications.org/content/114/5/1362.full
  4. The Developing Human: clinically oriented embryology 9th ed. Keith L. Moore, T.V.N. Persaud, Mark G. Torchia. Philadelphia, PA: Saunders, 2011. Chapter 5 pg 343

--Mark Hill 17:58, 10 September 2012 (EST) 1. Answer is detailed and correct. 2. You have identified 3 somite regions and histological tissue types. I would have preferred bone, skeletal muscle and connective tissue as the full histology descriptions. 9/10

Lab 4 Assignment

  1. Amniocentesis involves taking a sample of amniotic fluid transabdominally by a syringe. This treatment is done usually at week 15 or 16 but can be done at 10 to 14 but with a greater risk of complications.
This treatment can screen for the follow abnormalities:
  • Chromosomal and Neural tube defects.
Chorionic villus sampling involves taking a biopsy of tertiary villi from the chorion frondosum either transcervically or transabdominally. Unlike other methods CVS allows for earlier testing, generally between weeks 10 and 12.[1]
This treatment is used to screen for:
  • Cystic fibrosis and Down syndrome [2]
  1. Reversal of type 1 diabetes via islet β cell regeneration following immune modulation by cord blood-derived multipotent stem cells. January 10 2012
Cord-blood stem cells are being used to re-educate the lymphocytes in a type 1 diabetic patient. This treatment may also allow for a repopulation of islet beta cells in the pancreas. This method takes blood from the patient and the lymphocytes separated out. The lymphocytes are slowly passes through discs which contain adherent CB SCs and are then collected and returned to the patient’s blood. Type 1 patients after receiving this treatment has increased metabolic function and decreased autoimmune results lasting months after a single treatment. This paper states that they have data to prove that reversal of autoimmune response leads to regeneration of islet beta cells and improvement in metabolic function for long standing Type 1 patients.[3]

References

  1. Robert L. Nussbaum, Roderick R. McInnes, Huntington F. Willard, Genetics in Medicine Chapter 15 prenatal diagnosis, Saunders, 2007
  2. http://www.thewomens.org.au/ChorionicVillusSamplingCVS
  3. <pubmed>22233865</pubmed>

--Mark Hill 17:59, 10 September 2012 (EST) You have answered both questions well. 10/10

Lab 7 Assignment