User:Z3370664: Difference between revisions

From Embryology
Line 14: Line 14:


Lab 7 --[[User:Z3370664|Z3370664]] 10:20, 12 September 2012 (EST)
Lab 7 --[[User:Z3370664|Z3370664]] 10:20, 12 September 2012 (EST)
Lab 8 --[[User:Z3370664|Z3370664]] 10:09, 19 September 2012 (EST)


==Lab 1 Online Assessment==
==Lab 1 Online Assessment==

Revision as of 11:09, 19 September 2012

Lab Attendance

Lab 1 --Z3370664 11:49, 25 July 2012 (EST)

Lab 2 --Z3370664 10:09, 1 August 2012 (EST)

Lab 3 --Z3370664 10:28, 8 August 2012 (EST)

Lab 4 --Z3370664 10:24, 15 August 2012 (EST)

Lab 5 --Z3370664 10:12, 22 August 2012 (EST)

Lab 6 --Z3370664 10:13, 29 August 2012 (EST)

Lab 7 --Z3370664 10:20, 12 September 2012 (EST)

Lab 8 --Z3370664 10:09, 19 September 2012 (EST)

Lab 1 Online Assessment

Assignment Task 1:

Origin of In Vitro Fertilisation

In the 1890s, Walter Heape researched about reproduction in animals, and tried embryo transplantation in rabbits. This was the first ever reported case of an attempt at in vitro fertilisation. [1]

In 1948, Miriam Menken and John Rock exposed many eggs to a large number of spermatozoa in vitro to test what happens. They published their reports in Journal of Obstetrics and Gynecology.

The first successful report of IVF was in 1959, by Chang. Rabbits were the first mammals to give birth by IVF. [2]


In 1973, the first ever pregnancy through IVF was achieved by an experiment conducted by Monash University, but this resulted in a miscarriage. [3]


In 1978, the first ever human birth by IVF occurred in England. [4]


In 1980, the first ever human IVF birth in Australia occurred. [5]


Over the years, more development in IVF technology occurred. [6]


2010 Nobel Prize Winner

Sir Robert Geoffrey Edwards won the Nobel prize in Phsiology or Medicine in 2010 for his development in In Vitro Fertilisation by the successful birth of the first test tube baby, Louise Brown in 1978. [7]

Source: http://www.nobelprize.org/nobel_prizes/medicine/laureates/2010/press.html


Assignment Task 2:

Recent PubMed article on fertilisation

PubMed reference link: http://www.ncbi.nlm.nih.gov/pubmed/22842703

Full article was redirected to: http://www.nature.com/aja/journal/vaop/ncurrent/full/aja201258a.html

Summary of article:

The title of this article is: Sperm counts and sperm sex ratio in male infertility patients. [8] This article was published on 30th of July, 2012.

The investigators of this research had noticed that the number of male births had declined over the years in industrialized nations. The investigators wanted to find out whether males produced less Y chromosome, which is the determining factor in whether a baby will become a boy. In their research, 185 men went through a semen fluorescence in situ hybridization (FISH). The result was analysed to compare the gender ratios (Y chromosome number versus total number of sex chromosomes in each men) The overall sperm ratio of Y versus X for the cohort of men tested was 51.4 : 48.6.

Men with a lower semen volume had a lower proportion of Y chromosomes. The conclusions of the study showed that men who had a lower production of semen, thus had a lower production of Y-chromosome sperms, compared to men who have normal sperm production. However, the researches are unsure whether their results are biased, since many couples who were asked to take part in this research experiment refused to participate. Most of the couples who participated in this experiment are those who failed to have successful IVF. Hence, it is unclear whether the findings of this research would apply to all men in general. Hence, further research needs to be conducted for more reliable results.


Lab 2 Online Assessment

Assignment Task 1:

Gene expression in morula

Gene morula.JPG


Assignment Task 2:

Bystin is a trophinin associated protein, which is believed to be involved with forming cell adhesion between trophoblast and endometrial epithelial cells, and thus plays a role in implanation process of the embryo with the uterus wall. Bystin contains 306 amino acids [9]






Lab 3 Online Assessment

Assignment Task 1:

Gestational age is the period of time that passes since the first day of the mother's last menstrual cycle before she became pregnant. [10]

Post-fertilisational age is the period of time that passes since the sperm fertilizes the egg, up until birth.[11] The foetus grows and develops in the mother's womb during the post-fertilisational age.

Gestational age is most commonly used clinically in describing human development because it is easier to calculate, since the mother normally remembers the day her last periods started, rather than trying to figure out which day the sperm fertilized the egg.


Assignment Task 2:

The three different tupes of tissues formed from somites are the:

1. Dermis of the dorsal skin (dermatome)[12] is the skin on the back. [13]

2. Skeletal Muscles (myotome)[14] of the ribs cage, limbs, abdominal wall, back and tongue. [15]

3. Vertebrae and rib cartilage (sclerotome)[16] [17]



Lab 4 Online Assessment

Assignment Task 1:

1. Identify the 2 invasive prenatal diagnostic techniques related to the placenta and 2 abnormalities that can be identified with these techniques.


Answer:

Amniocentesis

Amniocentesis is an example of a prenatal diagnostic technique used to find abnormalities in the placenta. It is usually performed at 16 weeks of pregnancy, by using a needle which goes through the skin of the pregnant mother, through the walls of the uterus, and taking a sample of fluid that surrounds the baby. It does not touch the baby or the placenta. This fluid is then tested to see abnormalities in the chromosomes of the baby, figure out if the baby has genetic disorders such as Down's Syndrome or Cystic fibrosis. [18]


Chorionic villus sampling

This is also another technique used to detect chromosomal disorders such as Down's Syndrome.[19] It is done before 15 weeks of pregnancy. A small sample of 'chorion' (placental tissue) is taken from the inside the pregnant mother's uterus, using a needle which penetrates the skin of the mother's abdomen and goes in through the walls of the uterus. [20]

References: Alfirevic Z, von Dadelszen P (2003). Alfirevic, Zarko. ed. "Instruments for chorionic villus sampling for prenatal diagnosis" [21]


http://www.medicinenet.com/chorionic_villus_sampling/article.htm


Assignment Task 2:

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

Answer:

"Successful stem cell therapy using umbilical cord blood-derived multipotent stem cells for Buerger's disease and ischemic limb disease animal model."

by: Kim SW, Han H, Chae GT, Lee SH, Bo S, Yoon JH, Lee YS, Lee KS, Park HK, Kang KS.

The scientists who wrote this paper used Umbilical Cord Blood (UCB) derived mesenchymal stem cells (MSC) and transplanted them into four men as part of their study. These men had a disease called "Buerger's Disease", also known as thromboangiitis obliterans. This disease is characterised by "acute inflammation and thrombosis (clotting) of the arteries and veins in the hands and feet."[22] This disease currently has no cure. Hence the researchers were using the stem cells to test whether they could provide therapy with success. These men had necrotic skin lesions due to their disease. After being treated with the stem cells, their skin lesions had healed after 4 weeks. They also had newly formed blood vessels which were normal. Due to this, their ischemic rest pain was also cured after being treated with the stem cells. There were no side effects noticed after their therapy with stem cells.

The conclusion made by the researchers was that stem cell therapy can be used for therapy for Buerger's disease and other such similar ischemic disease.


Source of article: http://www.ncbi.nlm.nih.gov/pubmed/16497946


Lab 7 Online Assessment

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

Answer: Muscle satellite cells are myogenic cells with single nuclei, which are found between the basement membrane and sarcolemma of muscle fibers, and are involved with repair and regeneration of damaged muscle fibers. [23]

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

Answer: Muscle satellite cells are activated when the muscle fibers are damaged by injury. They are involved with repairing and regenerating the damaged muscle fibers. [24] When satellite cells are activated, they proliferate and form myoblasts to to replace damaged muscle fibers by cell differentiation and fusing with the damaged myofibers. [25] [26] After fusion with the myofibers, there is no further division by mitosis. [27]


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?

Answer: The skeletal muscle fibres increase in tension when there is injury for the motor nerves to sustain spinal cord injury. This occurs due to activation of stretch reflex. [28] There is an increase in type II fibres compared to type I fibres. [29] Hence there is an increase in fast type fibres when there is an increase in passive tension. [30] An example of a motor disorder is spasticity. When this disorder occurs, the muscle tone increases, which is called hypertonia. [31] Tardieu et al (1982) reported that the muscle fibres shorten in length in patients with spasticity. [32] However, another study shows that the variability of fiber size increases in muscles of spasticity patients. [33] When normal skeletal muscles are studied in biopsies, they appear to be tightly packed, with polygon shaped fibers.[34] Spastic patients on the other hand, showed an increase in fiber size, with more "round" shaped fibers. In some patients, there is also an increase in intercellular space.[35]