User:Z3332885

From Embryology
Revision as of 00:33, 19 September 2012 by Z3332885 (talk | contribs) (Lab 7 Assessment)

Lab Attendence

Lab 2 --Z3332885 10:38, 1 August 2012 (EST) Lab 3 --Z3332885 11:05, 8 August 2012 (EST) Lab 4 --Z3332885 12:10, 15 August 2012 (EST) Lab 5 --Z3332885 11:58, 22 August 2012 (EST) Lab 6 --Z3332885 10:13, 29 August 2012 (EST) Lab 7--Z3332885 11:36, 12 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

Research into controlling fertility has been going on for a while, and many experiments for IVF has been conducted since the 1960s. In 1973 the first IVF pregnancy was achieved, though baby did not survive till birth. In the 1978 the first IVF baby was born in india. The baby named "Durga" was the work of physican Kolkata using primitive methods and household refrigeration. In 1979 the world’s second baby conceived by IV was born.


In 2010, the Nobel Prize for physiology medicine was awarded to Robert G. Edwards for his contribution in the development of In Vitro Fertilization. [1]


(2)Identify and add a PubMed reference link to a recent paper on fertilisation and describe its key findings (1-2 paragraphs)

Summary

Many embryos are discarded from IVF labratories because they are considered to be poor quality. These embryos are, however, proposed to be good sources for human embryonic stem cells (heSC). This article studied whether heSC could be isolated from poor quality embryos, while also evaluating the efficiency of different isolation methods. Their experiments involved 166 embryos. The embryos were culture in a blastocyst medium for 2 days so that inner cell masses could develope. The inner masses from 32 embryo cells were then isolated, 17 using a mechanical method, the other 15 by immunosurgery. The isolated ICMs were subcultivated, and the rates of ICM colony formation was measured. Both methods had similar success rate (P>0.05). However, the cultures that did work had normal hESC differentiation ability, which indicates heSC could be derived from poor embryos. [2]

References

   1.http://en.wikipedia.org/wiki/In_vitro_fertilisation
   2.Liu W, Yin Y, Long X, Luo Y, Jiang Y, Zhang W, Du H, Li S, Zheng Y, Li Q, Chen X, Liao B, Xiao G, Wang W, Sun X.
     Derivation and characterization of human embryonic stem cell lines from poor quality embryos. J Genet Genomics. 2009 PMID: 19376483 

Lab 2 Assessment

Question 1. Upload an image from a journal source relating to fertilization or the first 2 weeks of development as demonstrated in the practical class.

Egradation of Intact Oocyte Zonae by Isolated Sperm Proteasomes.jpg


Question 2: Identify a protein associated with the implantation process, including a brief description of the protein's role.

L-selectin is an adhesion molecule belonging to the selectin family of proteins. In the implantation process, L-selectin on the uterine epithelial cells interacts with sLex molecule on the trophoblast to mediate adhesion. This interaction has also been shown to induce the subsequent apoptosis of the uterine epithelial cells. 1


References

1. Liu S, Yang X, Liu Y, Wang X, Yan Q. sLeX/L-selectin mediates adhesion in vitro implantation model. Mol Cell Biochem. 2011 Apr;350(1-2):185-92. PMID: 21197561

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.

Gestational age- time between the last menstrual period and birth (measured in weeks). Post-fertilizational age- time elasped from fertilization to birth.

Clinically, the gestational age is used to describe human development. Gestational age can easily be determined by working out the number of weeks since last menstrual period, whereas the post-fertilization age is hard often hard to determine. Knowing this number can help determine the morbidity and mortality of the baby. 1


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


Sclerotome- Vertebrae and ribs 2

Dermatome- The dermis of the dorsal skin 3

Myotome- Skeletal muscles of the back 4


References:

1. http://www.nlm.nih.gov/medlineplus/ency/article/002367.htm

2. http://en.wikipedia.org/wiki/Sclerotome

3. http://en.wikipedia.org/wiki/Dermatomal_mesenchyme

4. http://en.wikipedia.org/wiki/Myotome

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.

Amniocentesis - amniotic fluid containing fetal tissue is sampled from the amnion using a needle. The DNA from the sample is then tested for genetic abnormalities such as Down syndrome (trisomy 21) or Patau syndrome (trisomy 13). 1

Chorionic Villus Sampling - chorionic villus (placental tissue) is sampled and tested for chromosomal abnormalities. This procedure usually takes place at 10–12 weeks' gestation. Down syndrome and Tay-Sachs disease can be detected using this technique. 2


2. Identify a paper that uses cord stem cells therapeutically and write a brief (2-3 paragraph) description of the paper's findings.

This study was conducted to better understand hematopoictic and endothlial precursor cells from umbilical cord blood, and their possible use as cell-based therapies for ischemic diseases.

Results

On a growth factor depleted matrigel, ALDH(hi) cells significantly increased tube formation in Human umbilical vein endothelial cells. Transplantation of ALDH(hi) cell was also observed to significantly improve the recovery of perfusion in an ischemic limb (femoral artery ligation), corelation with an increase in murine vWF(+) blood vessel and CD31(+) capillary densities. UCB ALDH(hi) cells promote vascular regeneration and can therefore be use used to develope therapeutic strategies in treating ischemic diseases.

Reference

1. http://en.wikipedia.org/wiki/Amniocentesis

2. http://en.wikipedia.org/wiki/Chorionic_villus_sampling

3. Putman DM, Liu KY, Broughton HC, Bell GI, Hess DA. Umbilical Cord Blood-Derived Aldehyde Dehydrogenase-Expressing Progenitor Cells Promote Recovery from Acute Ischemic Injury. Stem Cells:2012,16(8)PMID: 22899443

Lab 7 Assessment

1.Provide a one sentence definition of a muscle satellite cell (b) In one paragraph, briefly discuss two examples of when satellite cells are activated ?

Myosatellite cells are mononuclear progenitor cells, found between the sarcolemma and the basement membrane of terminally differentiated muscle cells. These cells represent a population of stem cells, which are quiescent normally, but can proliferate to regenerate muscles in response to injury. Two examples of statellite cells being activated are:

Mechanical stress- strenuous exercise produce tears in the myofibers

Chronic diseases- causing hypertrophy of muscle cells.

When activated, the satellite cells enter the cell cyle to produce myoblasts that fuse/replace the damage cells.


<pubmed>17213900</pubmed>


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?

When the innervating motor nerve of skeletal muscle is damage, the muscle fiber will no longer be receiving nerve impulses to contract leading to paralysis. The inactivity of the muscle in the long term will also cause atrophy. This is marked by theloss of type I (slow) fibres and become predominantly composed of fast glycolytic type II fibres.

<pubmed>16931550</pubmed>