User:Z3465654

Online Assessment

Lab 1 Assessment

Article 1

<pubmed>24760595</pubmed> The following case study investigated the effects of hepatitis B virus (HBV) infection on sperm parameters, ovarian stimulation, and outcomes of in vitro fertilization (IVF) and embryo transfer, as the impact of HBV on human infertility was questionable. During this study, a total of 224 couples were identified, where either one or both partners were HBsAg-seropositive, and were undergoing their first IVF and embryo transfer cycle. The morphology of their sperm was analysed, as was the quality of their embryo rate, the duration of infertility and their fertilization rates, and then compared to those of 448 HBsAg-seronegative couples. In all four cases, the results of the HBsAg-seropositive couples were inferior to those of the HBsAg-seronegative couples, expressing significantly lower normal sperm morphology, top-quality embryo rate and fertilization rates, and significantly prolonged durations of infertility. It was noted however, that in regard to clinical pregnancy rates, there was no significant difference between the two groups. Based on the case study results, it was concluded that HBV infection was likely to cause infertility.

Article 2

<pubmed>24602756</pubmed> The following case study sought to investigate whether assisted reproductive technology (ART) treatments had any impact on the sex ratio of babies born. Using the United Kingdom records of women who have conceived children between 2000 and 2010 using intrauterine insemination, IVF, or intracytoplasmic sperm injection (ICSI), the records of a total of 106,066 babies born to 76,994 mothers were analysed. The results showed that each form of ART resulted in a varied sex ratio, the most significant variation occurring from IVF with 52.1% of babies born male, and the least variation occurring from ICSI embryo transfer, with 49.3% of babies being born male. It was also found that when the embryos were transferred during the blastocyst stage in ICSI and IVF, as opposed to during the early cleavage-stage ET, it resulted in approximately 6% more males being born. It was concluded however, that due to the significantly increasing number of babies born using ART treatments, more research was needed into the causes of the gender bias after such treatments.

Lab 2 Assessment

These histological views show the morphology of the kidneys of wildtype mice (left) compared to those of transgenic line A homozygous mice (right) that have been injected with Gremlin, an embryonic gene that plays a role in nephrogenesis. These images show what can occur to the morphology of the kidney if this gene is over-expressed.

<pubmed>25036148</pubmed>

Lab 3 Assessment

The kidneys first develop in the embryo by a process called nephrogenesis, in which self-renewing mesenchymal renal stem cells produce nephrons to form a simple embryonic kidney, called the pronephros. Nephrons are the main functional unit of the kidney.

<pubmed>24855634</pubmed>

An embryonic gene named gremlin (GREM1) has been found to play a key role in the formation of the kidneys and nephrogenesis in general. When fully formed, the expression of this gene is relatively low in an adult. However, it is thought that many renal diseases and their progressions are linked to an overexpression of this gremlin gene.

<pubmed>25036148</pubmed>

Nephrogenesis is stimulated by the signaling between the epithelial ureteric buds and progenitor cells, causing nephrons to develop and the ureteric buds to branch.

<pubmed>24656820</pubmed>

At birth, although the infant’s kidneys are developed enough to maintain homeostasis and are sufficient for growth and development, their functional capabilities are decreased. This is a result of the transition from depending on the placenta to maintain homeostasis of fluid and electrolyte balance while in-utero, to maturation of the neonatal glomeruli once born.

<pubmed>24781774</pubmed>

<pubmed>24623338</pubmed>

<pubmed>24488483</pubmed>

Determining nephron number is important: it can show the success/extent of nephrogenesis, and thus be used to determine if any and what genes and environmental factors may aid this process; a low nephron count has been linked to multiple cardiovascular and renal disease later in life.

<pubmed>24022365</pubmed>

<pubmed>24011574</pubmed>

The overexpression of the gremlin gene (GREM1) has been found to be a cause of renal disease.

<pubmed>25036148</pubmed> <pubmed>24500691</pubmed>

Lab 4 Assessment

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

<pubmed>25130827</pubmed> A study was conducted to determine whether the combination of umbilical cord mesenchymal stem cells (UC-MSC) with haploidentical hematopoietic stem cells (haplo-HSCT) would produce a more effective outcome and positive result when transplanted into patients suffering from refractory/relapsed myeloid leukemia. Using results obtained from January 2007 to June 2013, the data of 36 patients who received such treatments were analysed with respect to the engraftment (the rate at which the stem cells are able to reproduce new cells), graft versus host disease ((GVHD) a condition in which the donor stem cells attack the recipient’s body), and their two-year overall survival.

After reviewing and analysing the results, it was determined that the average engraftment time of neutrophils was 12 days, while the average time for platelets was 14 days. The cell counts of both, however, were well below that of the normal range of a healthy individual. In terms of GVHD, 5 of the 36 patients suffered grade III to IV acute GVHD, 12 of 32 suffered chronic GVHD, 2 patients had extensive chronic GVHD, and 3 patients relapsed. Despite this, the two-year OS rate was calculated to be 76.9%, with the final assessment concluding that the combination transplantation of stem cells was a good therapeutic method, especially as an alternative to patients with high risk or unsuitable donors.

There are a number of developmental vascular "shunts" present in the embryo that are closed postnatally. Identify these shunts and their anatomical location.

<pubmed>3052747</pubmed> There are three developmental vascular ‘shunts’ present during embryo and fetal development:

• Ductus arteriosus – it connects the pulmonary artery with the descending portion of the aortic arch, and works to ‘shunt’ the majority of the output from the right ventricle away from the undeveloped lungs.

• Ductus venosus – it connects the portal sinus to the inferior vena cava, allowing oxygenated blood received from the umbilical vein to rapidly enter the central circulation by diverting around the liver.

• Foramen ovale – it connects the right atrium to the left atrium, allowing oxygenated blood from the former to enter the latter.

Lab 5 Assessment

Cystic Fibrosis

Cystic fibrosis (CF) is a hereditary abnormality affecting 1 in 2500 infants born in Australia [1]. It results from a mutation within the CF gene which is responsible for encoding a protein called cystic fibrosis transmembrane regulator (CFTR), and is located on chromosome 7 [2]. As the CFTR protein is responsible for the proper functioning of chloride channels within a cell, its defect results in an increased diffusion of salt and water across the cell, affecting the secretory glands of the body [1][2]. This causes the glands to produce increasingly salty sweat, as well as a very thick, sticky mucus, the main detriment to CF sufferers, as it causes significant impacts to several organs such as the pancreas, liver, intestines, sinuses, sex organs, and primarily the lungs [1][2][3].

The production of this thick, sticky mucus can result in blockages within the ducts and airways of the lung, causing bacteria to be trapped within. This would result in inflammation and infections capable of causing serious and permanent damage to the lungs [1][2][3]. These blockages would also result in the impaired function of digestive organs, such as the pancreas, as the enzymes produced cannot reach their destination, therefore resulting in vitamin deficiency and malnutrition [1][2].

As this abnormality is obtained genetically, both mother and father would need to be carriers for the gene, with a one-in-four chance that a child produced would inherit both copies, resulting in a positive diagnosis for CF [3]. While there is no cure for CF, there are a number of treatments available that can help to prolong their life, including salt and vitamin supplements, exercise and physiotherapy to clear lungs, and mist inhalations to open airways [1].

[1] Cystic Fibrosis Australia, 2014, About Cystic Fibrosis, [Online], Available: http://www.cysticfibrosis.org.au/all/learn/

[2] MedicineNet, 2014, Cystic Fibrosis Facts, [Online], Available: http://www.medicinenet.com/cystic_fibrosis/article.htm

[3] NHS Choices, 2014, Cystic Fibrosis – Causes, [Online], Available: http://www.nhs.uk/Conditions/cystic-fibrosis/Pages/Causes.aspx

Lab 7 Assessment

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.

<pubmed>24814991</pubmed> The following research article is an update to a previous discovery within the developing adrenal gland, providing additional information as to the organization of its various zones. It is well known that the adrenal cortex of an embryonic mammal will differentiate into three distinctive layers: the zona glomerulosa (zG), the zona fasciculata (zF), and the zona reticularis (zR), each of which have their own secretions. It was in 1994 however, that a fourth zone was identified located between zG and zF. This new zone was named the ‘undifferentiated cell zone (zU)’ as no significant endocrine functions were found to exist in this area. BrdU was incorporated to this zone, demonstrating that active cell division was occurring at the outer and inner regions of zU and as they proliferated, these cells migrated in two directions: towards zG and towards zF. It was proposed that these cells were stem/progenitor cells. With recent studies however, it was identified that Sonic Hedgehog existed within the cells of zU, a very important factor in embryonic development, and that these cells migrated bidirectionally as well.

Identify the embryonic layers and tissues that contribute to the developing teeth.

<pubmed>18794902</pubmed> The teeth are proposed to have originated from two main embryonic layers: the epithelium of tooth enamel is derived from the ectoderm, while the dentin and pulp of the tooth have originated from neural crest derived mesenchyme. However, the teeth are capable of being endodermal in origin, or a mixture of both endo- and ectoderm, if the oropharyngeal membrane, the membrane that separates the two layers, is broken.

Lab 8 Assessment

Provide a brief time course and overview of embryonic development of either the human testis or ovary.

Embryonic Development of the Testes The process of gonad development is one controlled by genetics. It is the presence or absence of the Y chromosome that will determine whether the gonads of the embryo will form into testis or ovaries during week 7 of the embryonic period, in particular the SRY gene located on this chromosome. This is because the presence of this gene upregulates the expression of SOX-9 , a transcription factor that causes the differentiation of the support cells (Sertoli cells). Once these cells are developed, they in turn begin to produce anti-Müllerian hormone (AMH) in order to promote the regression of the Müllerian duct, establishing the male phenotype .

The differentiation of the Sertoli cells also causes two main compartments to be formed within the developing testes: the testes cords (consist of clusters of germ cells surrounded by Sertoli cells, further surrounded by myoid cells) and the testis interstitium (includes the Leydig cells and the testis vasculature) .

Include an image from the historic genital embryology section of the online notes in your description

Remnant of the Wolffian Body

Lab Attendance

Lab 1 --Z3465654 (talk) 12:45, 6 August 2014 (EST)

Lab 2 --Z3465654 (talk) 11:18, 13 August 2014 (EST)

Lab 3 --Z3465654 (talk) 11:16, 20 August 2014 (EST)

Lab 4 --Z3465654 (talk) 11:06, 27 August 2014 (EST)

Lab 5 --Z3465654 (talk) 11:42, 3 September 2014 (EST)

Lab 6 --Z3465654 (talk) 11:40, 10 September 2014 (EST)

Lab 7 - Did Not Attend

Lab 8 --Z3465654 (talk) 11:08, 24 September 2014 (EST)

http://www.ncbi.nlm.nih.gov/pubmed

PubMed