User:Z3418702

From Embryology
Revision as of 12:58, 3 September 2014 by Z3418702 (talk | contribs)

--Z3418702 (talk) 12:45, 6 August 2014 (EST)

Lab attendance

Lab 1----Z3418702 (talk) 12:57, 6 August 2014 (EST)

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

Pubmed

PMID25084016

<pubmed>25084016</pubmed>

Lab 2 --Z3418702 (talk) 12:20, 13 August 2014 (EST)

Lab 3 ----Z3418702 (talk) 13:08, 20 August 2014 (EST)

Lab 4- --Z3418702 (talk) 12:34, 27 August 2014 (EST)

Lab 5 --Z3418702 (talk) 12:58, 3 September 2014 (EST)

Online Assessments

Lab 1

Article 1: <pubmed>24592092</pubmed>

This study was conducted by the IVF Center at Kocaeli University, Turkey. It aimed to test the effect of biochemical markers in follicular fluid, such as nitrous oxide (NO), reduced glutathione (GSH) and malondialdehyde (MDA) on the outcome of in vitro fertilisation. The researchers selected 62 infertile women, all of whom were aged between 25 and 32, were non-smokers, had no systemic diseases, and were suffering from unexplained infertility with no signs of hormonal or ovulatory issues.

Ovulation was first induced in the women using long and short agonists along with a microdose flare-up, after which an oocyte was collected. This was followed by intracytoplasmic sperm injection (ICSI) as the preferred method of fertilisation, then the transfer of the embryo took place. To collect the FF samples, the dominant follicles were chosen and samples were centrifuged, supernatants were removed and stored.

To measure MDA levels, MDA was mixed with thiobarbaturic acid (TBA) which reacted to form a red compound. This mixture was incubated, cooled and assayed to read the absorbance of the butanol phase, and results were expressed in micromoles of MDA. Similarly, levels of GSH were measured in micromoles/L after being supplemented with metaphosphoric acid and assayed. However, NO levels were measured indirectly by measuring the nitrate and nitrite sample concentrations, deproteinising the sample, then measuring absorbance at 545nm using Griess reagent, expressing NO levels in nanomoles/L.

The embryos were then graded in terms of the size of the blastomere and degree of fragmentation, into Grades A-C, A being an even blastomere with <10% fragmentation. A single Grade A embryo was then transferred into each woman on Day 3 of the trial, after which they were categorised into 2 groups based on blood concentration of human chorionic gonadotropin; successful pregnancy (Group 1) and unsuccessful pregnancy (Group 2).

Finally, to analyse these results, the researchers used the women’s pregnancy status following IVF as the primary outcome measure. Statistic analysis was carried out according to non-parametric Mann-Whitney U test. The study found that the successful pregnancy group had significantly lower levels of fluid NO and significantly higher levels of fluid MDA than the unsuccessful pregnancy group. In analysing the correlation between IVF parameters and oxidative stress, the findings showed a positive weak correlation of MDA with fertilisation rate and the number of Grade A embryos. Also, ROC curve analysis implicated MDA as a highly sensitive predictor of pregnancy. Due to this significant difference in MDA levels between groups 1 and 2, the study concluded that MDA was the most suitable indicator of IVF success out of the 3 biochemical markers chosen for analysis.


Article 2: <pubmed>24914407</pubmed>

The objective of this study was to research the possible association between levels of plasma D-dimer, a haemostatic marker, and the success or failure of pregnancy in women undergoing IVF. The researchers selected 105 infertile women from the Ortona General Hospital’s Assisted Reproduction Unit who were undergoing IVF, indicated by factors such as tubal factor, endometriosis, male factor, anovulation and unexplained infertility.

The participants underwent ovarian stimulation by receiving daily subcutaneous injections of recombinant FSH (follicle stimulating hormone) with doses varying based on basal FSH level, the age of the woman and antral follicle count. This stimulation was begun upon complete pituitary suppression on the 3rd day of the menstrual cycle, and throughout the stimulation, hormonal fluctuations of luteinising hormone (LH) were controlled by injecting agonists and antagonists of GnRH.

Following the collection of oocytes, intracytoplasmic sperm injection (ICSI) was used to perform IVF and an embryo transfer was carried out, 14 days after which a pregnancy test was taken. The presence of a gestational sac with a fetal heartbeat after 7 weeks of gestation was the criterion for a clinical pregnancy.This ovarian stimulation protocol was followed by a venous blood sample to test D-dimer concentrations, where a latex quantitative assay was used with 200ng/mL being the threshold level for an abnormal D-dimer level. These assay levels were statistically analysed using a Mann-Whitney U-test and T-test.

The results of the study indicated significantly higher levels of circulating D-dimer in women with a failed pregnancy following IVF in comparison to those with a clinical or successful pregnancy. This difference was statistically valid even when taking age and vascular risk factors into account. It was found that women with concentrations of D-dimer above the threshold had a more dismal pregnancy outcome, and that D-dimer levels increased after the one-week administration of GnRH. Overall, only 38% of the participants had achieved a clinical pregnancy and the study concluded that high D-dimer concentrations are implicated in a higher risk of a failed pregnancy following IVF. This was consistent with previous postulations that a possible mechanism for failure is unsuccessful implantation and placentation, owing to a hypercoagulable vascular state, leading to increased risk of thrombolic events in maternal vessels to the placenta.

Lab 2

Fertilisation of medusa eggs by spermatozoids in vitro in sea water.png

Fertilisation of medusa eggs by spermatozoids in vitro in sea water[1]

--Mark Hill (talk) 16:28, 21 August 2014 (EST) This is all correct, I have fixed the reference link below. Please in future use a shorter image title and do not use .jpg in the image description above (I have removed for you).

  1. <pubmed>23185235</pubmed>| [1]

Lab 3

Adrenal gland

<pubmed>7011178</pubmed> <pubmed>24116052</pubmed>

Gonad development

<pubmed>17237341</pubmed> <pubmed>7623307</pubmed>

Placenta

<pubmed>10419690</pubmed> <pubmed>7673080</pubmed>

Lab 4

Summary of research article

This study by Chang et al. observed the effect of varying the intratracheal transplantation time of umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) on the attenuation of hyperoxic lung injury in neonatal rats. It was concluded that the optimal time window for stem cell transplantation was narrow; efficient only during the early but not late phases of inflammation. The findings were in line with previous research that the anti-inflammatory properties of UCB-derived MSCs play a crucial therapeutic role in the alleviation of bronchopulmonary dysplasia (BPD), through reducing hypoxia-induced injuries including increased apoptosis and impaired alveolarisation.

Tissue sampling and analysis of lung histopathology found that the Hypoxia Control (HC) group showed fewer, larger and more abnormally-sized alveoli compared to the Normoxia Control (NC) group. However, upon transplantation of UCB-derived MSCs, these alveolar impairments and changes in morphology were attenuated, especially when added on post-natal day 3 (HT3) than on post-natal day 10 (HT10).

The study’s comparison of the levels of pro-inflammatory cytokines such as IL-6α, IL-6β and TNF-α before and after the addition of the UCB-derived MSCs found that such molecular markers were significantly lower after HT3 transplantation than HT10 transplantation. These levels were much lower than the initial starting levels exhibited by the NC group, indicating the therapeutic effect of the cord cells. Furthermore, the hypoxia-induced reduction in VEGF and HGF levels and increase in lung collagen levels were both attenuated by the addition of the MSCs.

These findings led to the conclusion that the therapeutic efficacy of UCB-derived MSCs on treating BPD is indeed time-dependent; having potent effects in the early inflammatory process, which is then reduced in later stages. The study also tested any potential synergistic effects of combined early and late MSCs intratracheal transplantation, but none were found.

<pubmed>23349686</pubmed>

Vascular shunts

The 3 developmental vascular shunts in the fetal circulation that close postnatally are:

a) Ductus arteriosus (Ductus Botalli): Connects the pulmonary artery to the proximal descending part of the aortic arch and prevents the output of the right ventricle from entering the unexpanded fetal lung, which is fluid-filled and non-functioning. This shunt transfers medium oxygen saturated blood and becomes the ligamentum arteriosum after closing at birth.

b) Ductus venosus: Shunts blood from the left umbilical vein to the inferior vena cava. This carries well-oxygenated blood and allows placental blood to bypass the liver ultimately to the fetal brain.

c) Foramen ovale (Foramen Botalli): Shunts blood that is highly saturated with oxygen from the right atrium to the left atrium and becomes the fossa ovalis after closing at birth.