User:Z5088434: Difference between revisions

From Embryology
No edit summary
No edit summary
Line 149: Line 149:
==Lab 7 - Online Assessment==
==Lab 7 - Online Assessment==
''1. 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.''
''1. 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>26319183/pubmed>
PMID 26319183


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


==References==
==References==
PMID 26193891 PMID 26161332 PMID 25935518 PMID 26168107 PMID 22723007 PMID 24515905 PMID 20966459 PMID 23242925 PMID 22735930  PMID 15185170 PMID 21331089 PMID 23940636 PMID 22438645 PMID 23949966 PMID 24124047 PMID 22931925 PMID 26332872
PMID 26193891 PMID 26161332 PMID 25935518 PMID 26168107 PMID 22723007 PMID 24515905 PMID 20966459 PMID 23242925 PMID 22735930  PMID 15185170 PMID 21331089 PMID 23940636 PMID 22438645 PMID 23949966 PMID 24124047 PMID 22931925 PMID 26332872 PMID 26319183

Revision as of 16:32, 22 September 2015

--Mark Hill (talk) 17:16, 5 August 2015 (AEST) Well done, you were first! We will be talking more about this in the Practical on Friday.

Please do not use your real name on this website, use only your student number.

2015 Course: Week 2 Lecture 1 Lecture 2 Lab 1 | Week 3 Lecture 3 Lecture 4 Lab 2 | Week 4 Lecture 5 Lecture 6 Lab 3 | Week 5 Lecture 7 Lecture 8 Lab 4 | Week 6 Lecture 9 Lecture 10 Lab 5 | Week 7 Lecture 11 Lecture 12 Lab 6 | Week 8 Lecture 13 Lecture 14 Lab 7 | Week 9 Lecture 15 Lecture 16 Lab 8 | Week 10 Lecture 17 Lecture 18 Lab 9 | Week 11 Lecture 19 Lecture 20 Lab 10 | Week 12 Lecture 21 Lecture 22 Lab 11 | Week 13 Lecture 23 Lecture 24 Lab 12 | 2015 Projects: Three Person Embryos | Ovarian Hyper-stimulation Syndrome | Polycystic Ovarian Syndrome | Male Infertility | Oncofertility | Preimplantation Genetic Diagnosis | Students | Student Designed Quiz Questions | Moodle page

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Test student 2015

Lab Attendance

Lab 1 --Z5088434 (talk) 13:46, 7 August 2015 (AEST)

Lab 2 --Z5088434 (talk) 12:07, 14 August 2015 (AEST)

Lab 3 --Z5088434 (talk) 12:21, 21 August 2015 (AEST)

Lab 4 --Z5088434 (talk) 12:12, 28 August 2015 (AEST)

Lab 5 --Z5088434 (talk) 12:05, 4 September 2015 (AEST)

Lab 6 --Z5088434 (talk) 12:12, 11 September 2015 (AEST)

Lab 7 --Z5088434 (talk) 12:16, 18 September 2015 (AEST)

Lab 1 - Online Assessment

Summary of Article I

Low-dose growth hormone supplementation increases clinical pregnancy rate in poor responders undergoing in vitro fertilisation[1]

PMID 26193891

The aim of the prospective, self-controlled study was to investigate the impact of low-dose growth hormone (GH) supplementation for patients undergoing in vitro fertilization (IVF) with poor ovarian response (POR), which is defined as IVF incidence rates between 9 and 24%. GH is known to participate in follicular development by regulating gonadotropins in granulosa cells which in turn regulate the synthesis of IGF-I. This growth factor plays a major role in the synthesis of sex steroids and, thus, oocyte maturation. GH has been administered to POR patients since the 1990s, however, with mixed, mostly positive, results. Therapeutic advantages were largely established in women of advanced reproductive age. A possible reason for this unsuccessful administration is proposed to be the GH dose; the majority of doses used for POR patients is equal to those used in patients with GH-deficiency. However, POR patients are usually not GH-deficient, which leads to the investigation of the effects of lower dose GH supplementation to POR patients. A lower dosage is safer, since occurrence of side effects correlates with the dose of GH. In addition, it offers a more economic treatment strategy.

This study recruited 64 women with history of POR and an absence of pregnancy in at least two previous IVF cycles who were given GH during their third cycle. Certain factors, such as high BMI, different diseases, or surgeries lead to exclusion of the prospectus patient. The included patients underwent an ovarian stimulation protocol. This protocol involved ovarian hyperstimulation using a GnRH agonist to control for any differences besides Non-GH- and GH-cycle. A dose of 0.5 IU GH was supplemented while the GnRH agonist was given until human chorionic gonadotropin (hCG) was administered. 36h after hCG administration oocytes were retrieved and standard IVF procedures were performed. The clinical pregnancy rates, the number of retrieved oocytes, and obtained embryos, embryo quality, and cycle cancellation rate of the Non-GH- and the GH-cycle were then statistically analyzed.

Even though a greater number of oocytes and embryos were obtained in the GH-cycles and the cycle cancellation rate was lower in GH-cycles, the differences were not statistically significant. However, the number of top quality embryos obtained was significantly higher in the GH-cycles. The clinical pregnancy rate for the GH-cycles was 34.4%. These results align with prior knowledge about the mechanism and role of GH for follicular development. The evidence for ovarian GH receptors and this study's observation of its correlation with improved pregnancy rates and embryo quality may indicate that GH effects oocyte maturation. Additionally, low GH dosage was proven to be successful for POR patients' IVF outcome and, thus, may offer a safer and more economic treatment strategy.

Summary of Article II

Artificial oocyte activation in intracytoplasmic sperm injection cycles using testicular sperm in human in vitro fertilization[2]

PMID 26161332

The study aims to evaluate artificial oocyte activation (AOA) with a calcium ionophere as an effective method for severe male factor infertility patients with non-motile spermatozoa after pentoxifylline (PF) treatment. In the case of male factor infertility intracytoplasmic sperm injection (ICSI) is applied. The majority of failures of this method can be traced back to oocytes remaining inactivated despite appropriate injection of spermatozoa, with more than 80% of unfertilized oocytes being arrested at metaphase II stage. During oocyte activation intracellular calcium concentrations rise drastically in form of calcium oscillations. These oscillations are presumed to be triggered by certain spermatozoa factors delivered to the oocyte upon membrane fusion and cause the resumption of meiosis and multiple events of oocyte activation. In cases of non-motile spermatozoa PF is commonly used to induce motility and AOA is applied in cases where PF does not restore motility. However, the combination of both fertility methods is relatively unexplored. This study, therefore, explores the combined efficiency of PF and AOA on fertilization and pregnancy rates after ICSI.

29 patients were included who underwent AOA with a calcium ionophore after ICSI. In addition, a control group of 480 patients who only underwent ICSI without AOA was included in the study. All ICSI cycles involved male factor infertility. Oocytes and testicular spermatozoa extraction were conducted using conventional IVF methods. Non-motile spermatozoa were treated with 5mM PF to induce motility and were injected into the oocytes. 30 minutes post-ICSI the oocytes were exposed to 10uM calcium ionophere for 5 minutes and conventional IVF procedures were resumed. Embryo quality, pregnancy, and delivery rate were statistically analyzed. In addition, the effects of AOA and PF were assessed individually.

The quality of embryos was significantly lower in the AOA group compared with the control group. Similarly, delivery rates were lower in the AOA group than in the control group. Fertilization rates, however, did not account for significant differences. Prior studies have shown that DNA damage and constrained spermatozoa motility are negatively related; this potentially accounts for the decreased embryo quality in the AOA group. Within the AOA group in 17 cases sperm motility was not restored after PF exposure. Nevertheless, there was no difference between the motile and non-motile spermatozoa in fertilization, pregnancy, or delivery rate. AOA may, therefore, be useful in patients with low fertilization rate or total failure fertilization rate as it ensures fertilization regardless of the success of PF treatment.


--Mark Hill (talk) 17:38, 3 September 2015 (AEST) These are good summaries of the papers. (5/5)

Lab 2 - Online Assessment

Different Stages of Embryo Development.jpeg

Different Stages of Embryo Development[3]

PMID 25935518

--Mark Hill (talk) 17:40, 3 September 2015 (AEST) Image uploaded with reference, copyright and student template. Would have been good if you had also indicated that this was a human embryo somewhere. (5/5)

Lab 3 - Online Assessment

<pubmed>26168107</pubmed> This article reviews the cytogenetic techniques and embryo biopsies required for PGD & PGS and gives an account on the differences in PGD for single gene defects and chromosomal translocations.


<pubmed>22723007</pubmed> This article gives relatively recent and detailed information on the three types of biopsy performed on embryos at different stages of development (before conception, after fertilization, and early cleavage or blastocyst stage)


<pubmed>24515905</pubmed> This article reviews indications for PGD focusing on single gene disorders.


<pubmed>20966459</pubmed> This article gives detailed laboratory instructions and guidelines for PGD procedures, which might be useful for the methodological part of the website


The following articles are about diseased cells/embryos derived from PGD procedures for further research: <pubmed>23242925</pubmed> <pubmed>22735930</pubmed>

Other articles <pubmed>21748341</pubmed>

<pubmed>26259216</pubmed>

<pubmed>26258137</pubmed>

<pubmed>22404048</pubmed>

<pubmed>26238130</pubmed>


--Mark Hill (talk) 17:45, 3 September 2015 (AEST) These are relevant to your project. I hope you get to use some in the final project. (5/5)


Lab 4 - Online Assessment

Fertilization Quiz

1 Which of the following statements about female and male gametogenesis is incorrect:

While male meiosis is completed in days or weeks, female meiosis is delayed for months or years.
Male meiosis produces four gametes, whereas female meiosis produces only two.
In oogenesis meiosis is initiated once in a finite cell population, while in spermatogenesis meiosis is continuously initiated in a stem cell population.
Male gamete differentiation occurs after meiosis ends, whereas in oogenesis this occurs earlier during the first meiotic prophase.

2 Where does fertilization usually occur:

Ovaries
Upper uterine cavity
First 1/3 of uterine tube
Last 1/3 of uterine tube
Lower uterine cavity

3 The acrosome reaction...:

Helps spermatozoa to penetrate the zona pellucida
Initiates ovulation
Allows spermatozoa movement by stimulating the mitochondria
Is responsible for ZP2 expression in the zona pellucida
all of the above


--Mark Hill (talk) 17:50, 3 September 2015 (AEST) Q1 and Q2 are too easy and require simple guesses. You have not explained why the other options are incorrect in your answer and could have linked to further resources. (8/10)


ANAT2341 Student 2015 Quiz Questions

Lab 5 - Online Assessment

Interferon Regulatory Factor-6 and Cleft Lip and/or Palate

Orofacial clefts such as cleft lip and/or palate are common structural birth defects with birth prevalence ranging from 1/500 to 1/2,000 in different populations. The failure in growth of the frontonasal prominence, the paired mandibular processes, the paired maxillary processes, and the medial and lateral nasal processes in week 4, together with the failure in fusion of the lateral nasal processes with the maxillary processes, and the medial nasal processes in week 6 and 7 results in orofacial clefting of the upper lip and/or primary palate. Clefts in the secondary palate may arise due to failure in several developmental steps after week 6, such as palatal shelves elevation or migration[4].Their complex etiology is not fully understood and both genetic and environmental causes have been established to be involved in cleft lip and/or palate development. Many aberrations in different genes have been found to correlate with cleft occurrence. One pivotal gene appears to be located on chromosome 1 at the 1q32 region, which encodes interferon regulatory factor-6 (IRF6)[5], an important member of the IRF family involved in oral and maxillofacial development[6].

Mutations in IRF6 were first identified in patients suffering from Van der Woude syndrome, who often display orofacial clefts in addition to other symptoms. In several subsequent research studies SNPs in IRF6 were also detected in some non-syndromic cleft lip and/or palate. Irregularities in IRF6, therefore, are considered risk factors for cleft lip and/or palate development[7]. The phenotypic heterogeneity of Van der Woude syndrome in comparison to non-syndromic cleft lip and/or palate is hypothesized to be caused by different types of mutations of IRF6 resulting in either a partially or fully nonfunctional protein[8]. In addition, the phenotype might be influenced by the site of mutation[9]. Mutations on a specific sequence variant about ten kb upstream of its transcription start site have been found to keep transcription factor AP-2α from binding and, therefore, influencing IRF6 expression[7].

Many animal models have given rise to several hypotheses about how IRF6 irregularities may affect development on a molecular level. For instance, IRF6 mutations caused a hyper-proliferative epidermis in mice. This will induce a failure of terminal differentiation in the respective epidermis and generate epithelial adhesions that can clog the oral cavity and create a cleft palate further on during development. IRF6 also has been identified as a key determinant of keratinocyte proliferation, oral periderm formation, and its spatio-temporal regulation. Additionally, IRF6 in interaction with other transcription factors has been studied widely. For example, p63 activates IRF6 transcription and is mutated in many malformation syndromes that display cleft lip and/or palate. This emphasizes IRF6's role in facial development and in the etiology of orofacial clefts[7]. Studies in zebrafish and frog embryos have provided information about the interaction between IRF6 and Grainyhead-like 3 (Grhl3), which has effects on regulation of the epidermal permeability barrier and on periderm differentiation. IRF6 seems to directly active Grhl3 expression by binding to its promotor. This Grhl3 promotor binding association has also been observed in humans[10]. Several other hypotheses of IRF6's involvement in the etiology of cleft lip and/or palate have been proposed, however, the precise mechanisms are not known and more research is needed to establish a full understanding[11].

Lab 7 - Online Assessment

1. 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>26319183/pubmed> PMID 26319183

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

References

PMID 26193891 PMID 26161332 PMID 25935518 PMID 26168107 PMID 22723007 PMID 24515905 PMID 20966459 PMID 23242925 PMID 22735930 PMID 15185170 PMID 21331089 PMID 23940636 PMID 22438645 PMID 23949966 PMID 24124047 PMID 22931925 PMID 26332872 PMID 26319183

  1. <pubmed>26193891</pubmed>
  2. <pubmed>26161332</pubmed>
  3. <pubmed>25935518</pubmed>
  4. <pubmed>24124047</pubmed>
  5. <pubmed>15185170</pubmed>
  6. <pubmed>23940636</pubmed>
  7. 7.0 7.1 7.2 <pubmed>21331089</pubmed>
  8. <pubmed>22438645</pubmed>
  9. <pubmed>23949966</pubmed>
  10. <pubmed>22931925</pubmed>
  11. <pubmed>26332872</pubmed>