lab 1 --Z3331951 11:49, 25 July 2012 (EST)
Lab 2 - Z3331951 10:01, 1 August 2012 (EST)
Lab 3 - Z3331951 10:08, 8 August 2012 (EST)
Lab 4 - Z3331951 10:23, 15 August 2012 (EST)
Lab 1 Assessment
The 2010 Nobel prize was awarded to Robert Edwards for his pioneering work in developing in vitro fertilisation. Details can be seen on this page
An interesting article regarding fertilisation was authored by Eisenberg et al and published in July 2012, titled Sperm counts and sperm sex ratio in male infertility patients. The paper attempts to partially account for the recent decline in male births in some industrialised societies. In order to do this, they have collected sperm samples from both fertile and infertile men. The proportion of X and Y chromosome carrying sperm was them investigated for each of the samples. This is relevant as it is the sperm that determine the sex of the zygote. Eisenberg and his team found that motile and fertile sperm actually have a predisposition to carrying the Y chromosome, indicating that the higher a mans reproductive potential, the greater his chances of having a male child.
Lab 2 Assessment
The endometrial glands secrete fibronectin. This extracellular matrix protein interacts with integrin receptor proteins on trophoblast cells to form a bond. This is one of the initial bonds between the blastocyst and the uterine wall
Lab 3 Assessment
Amniocentesis is an invasive procedure where a needle is passed into the amniotic cavity of the foetus and a collection of the amniotic fluid is taken. Out of this fluid, foetal cells can be isolated and grown for testing. Occurs between 14 and 20 weeks gestation. Chromosomal analysis of the cells can identify the trisomy 18 (Edwards’s syndrome) defect, along with other chromosomal defects.
Chorionic villus sampling uses a catheter to sample cells of the chorionic villi, a key component of the placenta. Similar to amniocentesis, it is primarily used to identify the karyotype of the foetus. An example of a disorder that can be identified with this procedure is trisomy 21 (Downs’s syndrome).
The team of Zhu et al studied the potential use of umbilical cord blood mesenchymal stem cells (UCB-MSC) in the treatment of gastric cancer, which is quite resistant to the classical methods of treating cancer. The procedure used the stem cells as vehicles to deliver signalling molecules to the tumour. This is due to UCB-MSC’s ability to migrate into the site of cancer and begin to proliferate. Using recombination and other methods, the stem cells were engineered to secrete LIGHT, a member of the TNF family of receptor molecules. LIGHT is able to stimulate both antitumour immunity, and also the apoptosis of cancerous cells themselves. Nude mice were given gastric cancer as a live model to test the efficacy of the stem cell treatment. LIGHT was shown to convey a strong antitumour effect, primarily through the induction of apoptosis. The development of techniques like this is novel and exciting, allowing a tailored and specific route of treatment for many hard to treat diseases, like gastric cancer. However, the acquisition of the UCB-MSC’s may be a restraining factor.