User:Z3415141

From Embryology

Welcome to the 2014 Embryology Course!

Links: Timetable | How to work online | One page Wiki Reference Card | Moodle
  • Each week the individual assessment questions will be displayed in the practical class pages and also added here.
  • Copy the assessment items to your own page and provide your answer.
  • Note - Some guest assessments may require completion of a worksheet that will be handed in in class with your student name and ID.
Individual Lab Assessment
  1. Lab 1 Assessment - Fertilization References
  2. Lab 2 Assessment - Uploading a Research Image
  3. Lab 3 Assessment - Researching your Project Sub-Heading
  4. Lab 4 Assessment - Cord Stem Cells
  5. Lab 5 Assessment - Abnormalities
  6. Lab 6 Assessment - Group Work (As announced in the lecture, No individual assessment item for this Lab, but I do expect you to have added content to your Group project by tomorrow's Lab.)
  7. Lab 7 Assessment - Endocrine+Teeth
  8. Lab 8 - Genital
  9. Lab 9 - Peer Assessment
  10. Lab 10 - Sensory Development
  11. Lab 11 - Stem Cells
  12. Lab 12 - Stem Cells Presentation (see preparation information)
Lab 12 - Stem Cell Presentation Assessment More Info
Group Comment Mark (10)
1/8
  • Lots of effort to place article in larger context
  • Slide lay out could be improved: lots of empty space, use larger images and talk through them
  • Results presentation a bit convoluted. Try to finish discussion of each experiment with a clear conclusion.
  • Repetition of information towards the end
  • One presenter had an unprofessional style of presentation
7
2
  • Good well-structured presentation
  • Good introduction
  • Methods discussed separately. Try to avoid this, and incorporate in discussion of experiments. Not sure if technology was understood very well.
7.5
3
  • Good well-structured presentation
  • Do not discuss methods as a separate section
  • Discussion of results not always very clear, comprehension?
7.5
4
  • Good well-structured presentation
  • Lots of text on slides, improve talking through images, blow up images
  • Good discussion
8.5
5
  • Good well-structured presentation, amount of text on slides relatively good.
  • Figures too small, discussion bit convoluted
  • Slightly over time
8.5
6
  • Good comprehension and well-structured presentation.
  • Too much text on slides
  • Experiments discussed in a lot of detail. Try to be more concise and discuss aim of experiment, approach, summarize results, conclude.
  • No talking through figures
8.5
7
  • Good well-structured presentation, great introduction, inclusion of images in presentation done relatively well.
  • Methods discussed separately. Incorporate methods in discussion of the experiments in the results section.
  • Try not to depend too much on text on your slides
  • Talking through results images was not very clear, comprehension?
7.5
More Useful Links
Student Projects
Group 1 Respiratory User:Z3330991 User:Z3332339 User:Z3333429 User:Z3372817
Group 2 Renal User:Z3463310 User:Z3465141 User:Z3465654 User:Z5030311
Group 3 Gastrointestinal User:Z3414515 User:Z3375627 User:Z3415141 User:Z3415242
Group 4 Genital User:Z3415716 User:Z3416697 User:Z3417458 User:Z3417753
Group 5 Integumentary User:Z3417796 User:Z3417843 User:Z3418340 User:Z3418488
Group 6 Endocrine User:Z3418702 User:Z3418837 User:Z3418698 User:Z3414648
Group 7 Neural User:Z3418981 User:Z3419587 User:Z3422484 User:Z3374116
Group 8 Musculoskeletal User:Z3418779 User:Z3418718 User:Z3418989
Student Projects Fetal Development of a specific System.
2014 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
Student Projects - Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6 | Group 7 | Group 8 | Moodle


Lab Attendance

Lab 1--Z3415141 (talk) 12:48, 6 August 2014 (EST)

Lab 2--Z3415141 (talk) 11:15, 13 August 2014 (EST)

Lab 3--Z3415141 (talk) 11:13, 20 August 2014 (EST)

Lab 4--Z3415141 (talk) 13:01, 27 August 2014 (EST)

Lab 5----Z3415141 (talk) 13:04, 3 September 2014 (EST)

Lab 6--Z3415141 (talk) 11:19, 10 September 2014 (EST)

Lab 7--Z3415141 (talk) 12:08, 17 September 2014 (EST)

Lab 8--Z3415141 (talk) 14:15, 24 September 2014 (EST)

Lab 9--Z3415141 (talk) 12:13, 8 October 2014 (EST)

Lab 10--Z3415141 (talk) 11:51, 15 October 2014 (EST)

Lab 11--Z3415141 (talk) 12:26, 22 October 2014 (EST)

Online Assessment

Online Assessment 1

Valerie L Baker, Christopher A Jones, Kevin Doody, Russell Foulk, Bill Yee, G David Adamson, Barbara Cometti, Gary DeVane, Gary Hubert, Silvia Trevisan, Fred Hoehler, Clarence Jones, Michael Soules A randomized, controlled trial comparing the efficacy and safety of aqueous subcutaneous progesterone with vaginal progesterone for luteal phase support of in vitro fertilization. Hum. Reprod.: 2014, 29(10);2212-20 PubMed 25100106


Some women for personal reasons prefer to take subcutaneous progesterone for luteal phase support when undergoing in vitro fertilization (IVF) in an attempt to avoid some of the side effects of vaginal progesterone. In attempting to work out whether the luteal phase of IVF better supports the ongoing pregnancy rate with the use of either the new aqueous preparation of subcutaneous progesterone or vaginal progesterone 800 random women aged between 18-42 years undergoing IVF received an embryo transfer where 3 oocytes were randomly placed in either a preparation progesterone administered subcutaneously or vaginal progesterone. If a viable pregnancy was to occur, then progesterone treatment continued for up to 12 weeks of the gestation process.

It was found that the pregnancy rate for vaginal progesterone (44.4%) in comparison to subcutaneous progesterone (41.6%) was consistently higher. While luteal phase support has clearly shown to improve pregnancy rates in women in the past this research shows that those women whom chose to go with the subcutaneous progesterone preparations are less likely to have a successful pregnancy than those who go with the traditional vaginal progesterone in supporting the luteal phase of IVF. It is important to note though due to the relatively small sample and dosage sizes of this study and the fairly small difference between the two groups shows that more testing should be completed before the results of this study should be considered fully conclusive.


Chung-Hoon Kim, You-Jeong Lee, Kyung-Hee Lee, Su-Kyung Kwon, Sung-Hoon Kim, Hee-Dong Chae, Byung-Moon Kang The effect of luteal phase progesterone supplementation on natural frozen-thawed embryo transfer cycles. Obstet Gynecol Sci: 2014, 57(4);291-6 PubMed 25105102


A women’s worst nightmare is the sign of vaginal bleeding symbolism what may be a miscarriage. This study examined the effects of progesterone supplementation during the luteal phase on the possibility of miscarriage and live birth rate in natural frozen-thawed embryo transfer (FTET) cycles 228 women who underwent FTET cycles over a period between 2009- 2012 were examined.

The women were split up into two groups where one would receive progesterone support during the luteal phase and another that did not receive any progesterone support during the pregnancy. Overall there were no major differences in the women’s characteristics. This included the number of oocytes received, matured and fertilised. However, miscarriage rate was significantly lower in the group that received the progesterone as well as the live birth rate in comparison to those that did not receive any progesterone. The implications of this study loom large for women undergoing FTET cycles as it shows that if the luteal phase is supported with progesterone than the probability of a women’s worst nightmare can be decreased.

--Mark Hill I had not previously copied my comments onto your page. There are both good summaries of fertilisation related articles. (5/5)

Online Assessment 2

Oviduct Ligation Oviduct Ligation .png

--Mark Hill You should have included the reference legend under the figure with a reference link (as I have shown below. (4/5)

Oviduct Ligation .png

Oviduct Ligation

Estrella Jiménez-Trigos, José S Vicente, Francisco Marco-Jiménez Live birth from slow-frozen rabbit oocytes after in vivo fertilisation. PLoS ONE: 2013, 8(12);e83399 PubMed 24358281


Online Assessment 3

Midgut Formation during the development of the human fetus

1. Nicole M Davis, Natasza A Kurpios, Xiaoxia Sun, Jerome Gros, James F Martin, Clifford J Tabin The chirality of gut rotation derives from left-right asymmetric changes in the architecture of the dorsal mesentery. Dev. Cell: 2008, 15(1);134-45 PubMed 18606147

2. Won Kyu Kim, Hyun Kim, Dae Ho Ahn, Myoung Hee Kim, Hyoung Woo Park Timetable for intestinal rotation in staged human embryos and fetuses. Birth Defects Res. Part A Clin. Mol. Teratol.: 2003, 67(11);941-5 PubMed 14745932

3. Mirjana Abramovic, Goran Radenkovic, Aleksandra Velickov Appearance of interstitial cells of Cajal in the human midgut. Cell Tissue Res.: 2014, 356(1);9-14 PubMed 24414177


--Mark Hill These are relevant references to GIT development. A single descriptive sentence for each would have been useful. (4/5)

Online Assessment 4

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

The neuroprotective mechanisms and effects of implanted cord-derived msenchymal stem cells from a human umbilical cord(hUC-MSCs) were examined in ischemic stroke. An improvement in infarct volume and neurobehavioral function in the hUC-MSCs was discoverewd.

To do so the hUC-MSCs were cultured after they were isolated from the subendothetelial/endothelial layers of the umbilical cord of a human. Twenty days after the of induction of in vitro neuronal differentiation the cultured hUC-MSCs showed morphological features similar to those neurons. However there was no detection of functional neuron type channels.

From the discovery that the morphological differences meant that the cells were now able to produce neurotrophic factors but had not become active neuronal cells it was concluded that this may be related to the neuroprotective effects of hUC-MSCs.

Seong-Ho Koh, Kyung Suk Kim, Mi Ran Choi, Kyoung Hwa Jung, Kyoung Sun Park, Young Gyu Chai, Wonjae Roh, Se Jin Hwang, Hyun-Ju Ko, Yong-Min Huh, Hee-Tae Kim, Seung Hyun Kim Implantation of human umbilical cord-derived mesenchymal stem cells as a neuroprotective therapy for ischemic stroke in rats. Brain Res.: 2008, 1229;233-48 PubMed 18634757


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

Ductus Venosus: Joins the descending aorta and left pulmonary artery.

Ductus Arteriosus: connects the pulmonary artery directly to the ascending aorta.

Foamen Ovale: An opening between the septum of the left and right atria of the heart.

--Mark Hill This is a relatively old paper and its findings while interesting do not add to a therapeutic application. The shunts are correct (4/5)

Online Assessment 5

Extrahepatic Billary Atresia is categorised by destruction of the Billary tree due to an ascending inflammatory localised process. As an irreversible condition, it is a lethal abnormality and patients left untreated can yield to complications of end-stage liver disease and Billary cirrhosis.

The abnormality is not greatly understood currently. It is believed that a multiple of causes are responsible for the inflammatory condition and research has shown that females are slightly more likely than males to be affected. Parental factors, infectious triggers and genetics are currently assumed to be the cause of the condition.

Ulrich Baumann, Benno Ure Biliary atresia. Clin Res Hepatol Gastroenterol: 2012, 36(3);257-9 PubMed 22609296


--Mark Hill Biliary has only one "L" and you should read what you have written for correct grammar. While I did ask for only a few paragraphs, this is a very short description and I wanted more in your summary. You have not even given me the incidence rates (1 in 10,000 to 1 in 15,000 live births) or listed the causes. (3/5)

Online Assessment 6

Worked on group task.

--Mark Hill Yes.

Online Assessment 7

1. Daniel Wreschnig, Hamid Dolatshad, Fred C Davis Embryonic development of circadian oscillations in the mouse hypothalamus. J. Biol. Rhythms: 2014, 29(4);299-310 PubMed 25238858

This study examined the point in development in which the suprachiasmatic nucleus (SCN) first has the capacity to generate circadian oscillations. Using mice to track the circadian clock protein, PER2. The hypothalamic explants expressed consistent oscillations firstly when isolated between 15 and 16 days postfertilisation. Explants from any other brain area were shown to not express any oscillations. It was concluded that within a day of genesis around the same age of the first trimester in humans, the autonomously develops mechanisms sufficient to couple and synchronise its cells and also the SCN gains the ability to express circadian oscillations.


--Mark Hill An interesting neuroendocrine study related to diurnal rhythms. Tooth origins was also part of this assessment. (3/5)

Online Assessment 8

1. Provide a brief time course and overview of embryonic development of either the human testis or ovary. (2-3 paragraphs)

Human Testes Embryonic Development It is towards the seventh week of development that the male gonad develops into the testis. Before this time the gonads of both sexes are identical as they are undifferentiated. It is the differentiation which is dependant upon the XY chromosomes that determines whether the gonads turn into testes or ovaries. Fertilisation determines the genetic sex and a male be complete with the XY chromosome complex[1].The Y chromosome is the key for the testes formation. It has a testis-determining effect on the medulla of the undifferentiated gonad as it contains the Y-linked gene SRY which produces the protein product Testis Determining Factor (TDF). TDF upregulates other transcription factors including SOX9. The SOX-9 is said to work with Sf1 to produce AMH (Anti-Müllerian hormone) in sertoli cells to inhibit female reproductive system creation[2].

Ultimately the expression of the SRY protein leads to the development of primary sex cords which proliferate from the coelomic epithelium and then extend and condense into the medulla of the gonad. These cords then branch and their ends become the rete testes. The more present sex cords then become the seminiferous cords which then form the tunica albuginea after they loose their connection with the germinal epithelium. The cords then develop into the seminiferous tubules. These tubules then become separated by mesenchyme which allows the interstitial cells of leydig to arise. Because the seminefrous tubules come from a dual origin on a cellular level their walls are composed of both the supporting sertoli cells which come from the germinal epithelium and the undifferentiated male germ cell spermatagonia which come from the primordial germ cells. Further down the track of development the germinal epithelium is flattened to form the mesothelium on the surface of the testis. The rete testis become continuous with the persistent mesonephric tubules. These tubules are involved in the formation of the excretory tracts of the testis forming the efferent ductules which open into adjacent mesonephric ducts[3].


References

  1. Yen-Shan Chen, Joseph D Racca, Nelson B Phillips, Michael A Weiss Inherited human sex reversal due to impaired nucleocytoplasmic trafficking of SRY defines a male transcriptional threshold. Proc. Natl. Acad. Sci. U.S.A.: 2013, 110(38);E3567-76 PubMed 24003159
  2. P De Santa Barbara, N Bonneaud, B Boizet, M Desclozeaux, B Moniot, P Sudbeck, G Scherer, F Poulat, P Berta Direct interaction of SRY-related protein SOX9 and steroidogenic factor 1 regulates transcription of the human anti-Müllerian hormone gene. Mol. Cell. Biol.: 1998, 18(11);6653-65 PubMed 9774680
  3. Samadhan K Phuge, Narahari P Gramapurohit Gonadal sex differentiation, development up to sexual maturity and steroidogenesis in the skipper frog, Euphlyctis cyanophlyctis. Gen. Comp. Endocrinol.: 2013, 181;65-71 PubMed 22944459

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

Persistent portions of the mesonephros in the male

Bailey309.jpg

Diagram persistent portions of the mesonephros


--Mark Hill This is much better than earlier assessment items, well done. (5/5)

Online Assessment 9

Group 1 This is a really good project. First thing noticeable on the page is the amount of information you have which is great. The introduction is really well written and I like the fact that you have included images in this part as it makes it so much easier to understand. I also found it quite easy to grasp the difference in fetal and embryonic periods so well done as this is an important part of the project. This table of the lung development stages is great and really well done. One thing you could maybe do here is add a few diagrams. I know you have more diagrams down below but I think it’s something that might make it even easier to follow. You obviously haven’t found any current models at the moment. Don’t know if this helps but it may for the models: PMID: 22876201. Current research and finings again is good.

Something which seems to be reoccurring with your page is the fact that the references are spread all over the page. I think it would look much better if all the references were at the bottom of the page as this makes you page look more professional and aesthetically pleasing. Also maybe add some student drawings as I think this would more interesting for your page and be a bit more unique. Something else to note is the abnormalities part.

It’s great that you have a lot of different abnormalities but I feel as though some of them such as cystic fibrosis and laryngeal atresia could have been given a bit more of information to supplement what you are saying. Also adding a diagram would be good to make it easier for the viewer to understand. Overall it’s a well presented page with some quality information. Maybe look at your referencing technique, adding some more student images and a bit more detail to the abnormalities to take what at the moment is a good project to a great project. Best of luck!!


Group 2 This so far is a really good. You have all obviously done your research as well as you have got a lot of references throughout your page which again is great. The introduction is well done, clear and concise which is good. Maybe think about adding an image to make it a bit more appealing. You will obviously need to add some historic findings, but I’m sure your aware of that. The developmental timeline I think could be improved if you were to tabulate it as other projects have done that and it looks really good and more professional. The referencing is well done as it looks good having all the references down the bottom of the page. There are some refercnes over the page which have just been listed so it may be a good idea to change this so that they are all down the bottom.

You have made a good start on the current research models. Note the buy in the line ‘One recent research paper buy Al-Odat et al.’ should be by. I don’t think you should actually reference the paper in your writing either. You should reference it but do so by using a footnote rather than actually saying the names of the people. The development of the kidney image has not worked so look at the formatting of that image. On the biiger picture of this project something that I have noticed is that the balance of writing to images is heavily towards the information writing side. So I think it would be good if you were able to tip this balance with a few more pictures as it would make the page more appealing. I think in doing so you could add some student images as this will make the page more interesting, Also spacing your information out as at times when you look at a whole chink of writing you don’t feel like reading it, so I think spacing it out more will help.

Overall though it is a well done project. A few things such as the references that have been just listed on the page that need to go down the bottom, inclusion of some more student images, and tipping the balance of your page more in favor of images would go a long way in making your project even better. But you have done a good job so far and best of luck with the rest of it.


Group 4 Overall this is a good project, and it is evident that you all have put a great deal off effort into researching this developmental stage. I enjoy the use of diagrams, especially the diagrams which you have drawn yourself- as it shows that you have a clear understanding of the topic at hand and eases our understanding of a complex topic. Although, I must comment that the first diagram you have used- whilst extremely helpful, is a bit pixelated and I think that if this is changed it will greatly aid the look of your project.

I found your project to be a bit too wordy. I understand that genital development is a complex topic since you have to cover two different methods of development, however I think that the use of tables and dot points will greatly aid the clarity of your work. I think that “System Development” is off to a good start, and once the formatting issues are resolved, the table will be a good way to express the development.

I enjoyed the diagrams in current research models, however I think the presentation of your work overall can be improved. For example try scanning in the picture instead of taking a photo showing the background. Further, the paragraphs are a bit too long to retain interest and I think this section can benefit from shorter dot points or a time line.

Again, the historic findings seems very well researched, however for this purpose it is a little *too* exhaustive. I think it would be a better idea to cut back on so much detail and make it easier to read. Or consider formatting your work in a different manner so as to appeal to the reader.

The abnormalities was well done, and I think its on the right track with the use of subheadings to break up the work. I understand there is a lot to talk about in this section, but the paragraphs are not succinct enough to retain my attention throughout the entire piece.

Overall, the grammar and punctuation is quite well done, I think that the project as a whole needs some cutting down and tightening to make it more easy to read, but off to a good start.


Group 5 This is a really well done project. You have made sure that that you have ticked all the boxes as well that Mark has asked for. The abnormalities section is really good. You have done well with most of your images as when you click on them there is a good description and they are well referenced. The development overview table is exceptional and makes the project easy to understand. For the week 22 maybe include the study in which you got your information from.

Apart from the abnormalities section it appears as though the referencing is a bit all over the place. Need to follow the abnormalities section and put references into the specific parts of the information you are using it for. Because otherwise it becomes difficult to know exactly where you got your information from. The historic findings are really good and well done however there is probably a space for more information to be included as I feel as though some of the findings are a bit hard to follow at times. It may have just been my computer I couldn’t see the picture of ‘fetal hair development’.

I think it would give a nice touch to the project if you were to add some student images because it would give the page a more ‘student’ and also make it easier to understand. Don’t mind the purple background on the ‘some recent findings’ part but it just looks a bit out of the blue. It’s certainly unique and attracts the eye but it puts a lot of emphasis on this section which I’m not entirely sure you want. Overall though a really good project with excellent information. There needs to be a bit more focus on referencing technique, some minor edits which I have mentioned and maybe introduce some student pictures to make the project more student-like.


Group 6 So far you have made a good start. The introduction is a really important part of the project so it’s important that you get that down. The pineal gland part has made a good start but it would be good if some more hormones could be added. I think it would be good maybe if you all combined all of your times line and put them at the top of the page. You could maybe do this in a table form, but it’s certainly something that would make the project more succinct. Also instead of having references spread all over the page it would be a good idea to put the all of them at the page to make the page look more neat and tidy.

The hypothalamus part also needs to add extra information on the hormone part and add their illustration. I think it may be a good idea to add a student image because this makes the page more interesting and people looking at the page will be instantly attracted to this. Something that is really important and goes for the whole page is that you need to do in text referencing, as having the references at the end of the writing is tough because we don’t know which parts came from where.

Its good that there is recent findings in the hypothalamus part but I think this probably highlights the biggest issue with your project, being that It probably doesn’t link with all parts that well. I think it would be good if you could link all parts of the endocrine system together to make it easier to understand. For example, if you put the recent findings as a whole new part then everyone puts their recent findings in there it will make it easier to understand and look more collaborative. Also there is an imbalance in written information to pictures which tips in favor of the information. While it’s great to have a lot of information it becomes a bit boring just reading all the time so I think adding more images, particularly student drawn images would be something that would definitely improve the page.

Overall it has been a good start but the main points that need to be focused on are to finish off the information, make sure you correctly reference with footnotes and putting the references at the end of the page, and adding more images to make it more interesting. Good luck with the rest of the project.


Group 7 This is a really good project so far. The introduction is really well done and I especially like that you have included a diagrams in it. The brain development is good, however I’m not completely sure about the dot points. It would look better if they were not there.

Well done with the images that you have got there they all appear to be well described and referenced when you click on them. Only problem with the images is that there is a lack of them. It appears that there is an imbalance between written information and images tipping in favor of the information. I think it would be a good idea to add some more images to elicit more excitement in the page. Student images are a good idea as they highlight that it is a student project and make it more interesting for the viewer.

The current research models and findings shouldn’t be left like it is at the moment. You will need to go into more detail and reference properly. While on referencing it is important that you put all your references at the bottom of the page. You only have 20 at the bottom at the moment and it is clear that you have used many more than twenty. Also you need to add in text citations so that we know exactly where you have got your information from.

The current research part is good with plenty of information, but again look at adding more images to make it a bit more interesting. There are obviously some parts that you need to finish off which I’m sure your aware of.

Overall it is a really good project with the potential to be excellent because of the amount of effort you have put into the research. Just make sure you change your references so that they are all down the bottom and have in text citations, add more images and maybe student images as well to make your page more presentable. Very well done so far and good luck with finishing the project off.

--Mark Hill Very good peer assessment, you have kept it brief and specific. (10/10)

Online Assessment 10

Identify a recent research paper on sensory development (not hearing) and write a brief summary (several paragraphs) of the research methods and findings. Include at the end a link to the relevant wiki sensory notes page.

Development and aging of visual hemifield asymmetries in contrast sensitivity

One eye from 258 participants aged from 8-65 performed contrast sensitivity testes where they had one of their eyes examined in a darkened room under monocular conditions. All participants were recruited as volunteers. Neuro-opthalmological examinations were completed on all participants. These tests consisted of ocular tensions, slit lamp biomicroscopy and fundus examinations, and visual acutity using snellen charts. Participants that were not up to the standard required were excluded. These participants had criteria such as neurological and retinal diseases, pathology of optic nerve, diabetes, high ammetropy and significant media opacities.

All participants were right handed and had normal or corrected to normal visual acuity. The low-level contrast sensitivity behavioral tasks were then performed on these participants. Two distinct spatiotemporal frequency channels were probed, one of intermediate spatial and null temporal frequency and one of low spatial and high temporal frequency. The participants were split into four groups depending on age to observe the patterns.

Within the four different age groups different patterns were observed. It was found that there was an advantage in left visual hemifield/right hemisphere for only the intermediate special frequency channel that was present early in life and this remained stable throughout adulthood. However, asymmetrical inferior/superior visual hemifields were found for both spatiotemporal frequencies with the advantage of the inferior hemifield emerging early in life and persisting throughout the ageing process. Therefore, this shows that the dominant left and right hemispheric and dorsal retinotopic patterns in low-level vision hold steady throughout aging after they emerge from an early age.


Maria Fatima Silva, Otília C d'Almeida, Bárbara Oliveiros, Catarina Mateus, Miguel Castelo-Branco Development and aging of visual hemifield asymmetries in contrast sensitivity. J Vis: 2014, 14(12); PubMed 25326605


[1]

--Mark Hill I would have preferred to see some "prenatal" studies that would relate more to the course. Minor, again some typos in your written answer, please check your work. (4/5)

Online Assessment 11

Tissue-Engineered Vascular Grafts Created From Human Induced Pluripotent Stem Cells

Mesenchymal markers were firstly shown to differentiate into different mesenchymal families, including chondrogenic, adipogenic and osteogeneic. Then by culturing Human induced pluripotent stem cells (hiPSC) from mesenchymal progenitor cells over 8 weeks they were able to induce the differentiation of smooth muscle cells and collagenous matrix generation in creating functional vascular grafts. Layers of calopin containing smooth muscle cells and collagenous matrix production was confirmed by histological analysis.

These grafts were then put under a number of various tests to examine their ability as vascular replacements. Mechanical examination showed that the average burst pressure of the grafts was 700 mmHg, which is around half of that of the normal veins. It was also shown that these grafts could undergo apoptosis during culturing which was leading to chromosomal abnormalities forming calcified vessel constructs. Overall this study showed the potential for hiPS cells for vascular graft generation. However, more research needs to be done into the strength of the grafts and reducing the number of abnormalities that may rise in the vessels after the grafts have been implanted.

Sumati Sundaram, Jennifer One, Joshua Siewert, Stephan Teodosescu, Liping Zhao, Sashka Dimitrievska, Hong Qian, Angela H Huang, Laura Niklason Tissue-Engineered Vascular Grafts Created From Human Induced Pluripotent Stem Cells. Stem Cells Transl Med: 2014; PubMed 25378654


--Mark Hill Very good. (5/5)

Online Assessment 12

No online assessment this week.