User:Z3418340
--Z3418340 (talk) 12:45, 6 August 2014 (EST)
Lab Attendance
Lab 1 - --Z3418340 (talk) 12:53, 6 August 2014 (EST) Lab 2 - --Z3418340 (talk) 11:13, 13 August 2014 (EST) Lab 3 - --Z3418340 (talk) 13:48, 20 August 2014 (EST) Lab 4 - --Z3418340 (talk) 12:39, 27 August 2014 (EST) Lab 5 - --Z3418340 (talk) 11:37, 3 September 2014 (EST) Lab 6 - --Z3418340 (talk) 11:12, 17 September 2014 (EST) Lab 7 --Z3418340 (talk) 13:10, 17 September 2014 (EST)
Individual Assessment 1
ARTICLE 1
<pubmed>24302192</pubmed>
Inositol is an important factor with in the follicular environment, high levels have been associated with improved development of the oocyte. This particular study aims to understand the effects of treatment with inositol on oocyte quality in patients undergoing ICSI.
The researchers selected 149 patients undergoing ICSI cycles between June 2012 and May 2013, all of whom where aged under 40, had at least one previously failed attempt at ICSI and were diagnosed with polycystic ovary syndrome (PCOS). Patients were randomly divided into two groups. Group 1 consisting of 58 patients were treated with both folic acid (400 mg/day) and inositol (2000 mg/day of myo-inositol, D-chiro-inositol 400 mg/day) for 3 months prior to the ISCI cycles. Group 2 consisted of 91 patients who were treaded with folic acid (400 mg/day) alone, this group acted as the control.
(1.) The standard of IVF using ICSI was employed. Oocyte quality was routinely checked by making observations using an inverted microscope. The oocyte’s stage of maturity, size and shape, cytoplasmic characteristics and extracytoplasmic characterises were noted. (2.) Post-implantation assessments were made regarding embryo quality in light of the following parameters; number of blastomeres, degree of fragmentation and size of blastomeres. (3.) Finally at 14 days from Embryo-Transfer execution, quantitative blood detection of β-hCG is performed in order to biochemically determine pregnancy. This is followed by a final diagnosis of clinical pregnancy with ultrasound visualization.
(1.) No significant difference was found in the number of mature oocytes taken and in the number of immature oocytes taken. However the the results did show that a greater proportion of Group 1 oocytes displayed features that typical of excellent and good quality oocytes. (3.) In terms of the number of positive biochemical pregnancies there was again no statistically significant difference between Group 1 and Group 2. However Group 1 did show a statically significant increase in the number of clinical pregnancies detected.
The article is concluded discussing and highlighting the improvement in the overall quality of oocytes and parallel increase in the number of clinical pregnancies as a result of treatment with inositol.
ARTICLE 2
<pubmed>25077107 </pubmed>
The investigation was carried out on IVF patients from Mount Sinai Hospital, Toronto, Ontario. Candidates selected for the study were aged 18-41 years, with base line levels of FSH (on Day 3 of Cycle) and the ability to provide informed consent. Researchers included 173 female patients, who then underwent IVF cycles as per standard procedure.
Serum 25-hydroxy-vitamin D (25[OH]D) levels were measured one week prior to oocyte retrieval, these measurements taken in order to determine the initial Vitamin D status. Patients were either classified as having sufficient (≥ 75 nmol/L) or insufficient (< 75 nmol/L) 25(OH)D levels.
Standard IVF procedures followed; oocyte retrieval, fertilisation, growth and embryo transfer. An ultrasound was then taken 4-5 weeks after the embryo was transferred and implantation success was monitored, as indicate by the presence of a gestational sac, visible by ultrasonography. The implantation rate was calculated as the number of gestational sacs observed by ultrasonography divided by the number of embryos transferred, multiplied by 100.
With in this cohort 45.1% had sufficient levels of 25(OH)D, while 54.9% had insufficient levels. The study found a 52.5% clinical pregnancy rate per IVF cycle among women with sufficient levels of 25(OH)D levels. This was significantly higher than compare to a rate of 34.7% the among women with insufficient levels of 25(OH)D.
--Mark Hill Your summaries of these 2 selected articles are concise and accurate. You might want to also think about exploring the discussion part of the papers for additional information about the future direction of the research. (5/5)
Individual Assessment 2
Image:Abnormal heart and caudal fin development in zebrafish due to Rap 1 knock down[1]
Individual Assessment 3
Fetal Development - Time Line
Historic Findings
[1] [2] https://www.youtube.com/watch?v=WXLPxjJszio
Individual Assessment 4
PART 1 - Identify a paper that uses cord stem cells therapeutically and write a brief (2-3 paragraph) description of the paper's findings.
Context
The use of umbilical chord derived stem cells for therapeutic purposes is certainly widespread and has served as an effective tool for the treatment of cancers, heart disease and many other conditions.
This particular study aims to further investigate the potential use of Mesenchymal stem cells (MSC)derived from chord blood, this time looking at potential use as a promoter of wound healing in diabetic patients. In these patients incomplete healing of wounds is primarily associated with poor revascularization and decreased production of growth factors in the damaged area. Since MSCs are multipotent they hold a great promise for tissue regenration and .
The main advantage of investigation into such therapies lies in the fact that MSCs can be easily isolated and refined from chord blood as oppose to any other sources.
Study and Findings
This study was conducted on genetically diabetic mice who showed delayed would healing. A wound was induced followed by subcutaneous injection of Conditioned-MSCs (CM-MSC), UC-MSC (Umbilical cord derived MSCs) or control PBS (Phosphate buffer solution).
Wound healing was reported as a percentage of the initial would that had reepitheliasized. Time taken for complete reepitheliasized was accelerated from 14 days in the PBS group, down to 4 days; following the initial injection of CM-MSC. Histological examination of would margins at 14 days revealed that CM-MSC treated wounds had relatively enhanced repiehtelizsation, a thiner layer of dense granulation tissue and increased vascularisation. Further more Immunohistological staining also showed higher capillary density in CM-MSC treated wounds compared to both the UC-MSC and PBS treated groups. Finally the PCR analysis of RNA was extracted from the CM-MSC treated mice revealed significantly higher levels of factors promoting aniogenesis such as; VEGF, PDGF, and KGF.
It was concluded that both the transplantation of UC-MSCs and CM-MSCs accelerates wound closure, increases angiogenesis and directly stimulates transrciption of vascular growth factors (VEGF, PDGF, and KGF).
Reference
<pubmed>3781996</pubmed>
PART 2 - Identify the developmental vascular "shunts" present in the embryo shunts and their anatomical location.
The three "shunts" are alternate paths for blood flow with in the circulatory system of the embryo.
Two of these shunts have the role of diverting blood from the pulmonary to the systemic circuit. The third connects the umbilical vein to the inferior vena cava.
1. The foramen ovale - An opening in the interatrial septum that allows blood to flow from the right atrium to the left atrium. Closes to leave the fossa ovale 2. The ductus arteriosus - A short, muscular vessel that connects the pulmonary trunk to the aorta. Degenrates to from the ligamentum arteriosum. 3. The ductus venosus - A temporary blood vessel that branches from the umbilical vein, allowing much of the freshly oxygenated blood from the placenta—the organ of gas exchange between the mother and fetus—to bypass the fetal liver and go directly to the fetal heart. Degenerates to become the ligamentum venosum.
Individual Assessment 5
Normal Pancreatic Development - During the fifth week of gestation one dorsal and two ventral evaginations (buds) appear on the wall of the developing foregut. Selective expansion of the duodenum causes fusion of the two ventral buds. During the seventh week of development the gut undergoes rotation and the ventral bud rotates with the gut. As the ventral bud passes behind the duodenum it fuses with the dorsal bud.
Annular pancreas (AP) results when ventral bud fails to rotate with with the duodenum. As a result the ventral bud essentially envelopes the rotating duodenum and forms a ring of pancreatic tissue surrounding the duodenum, known as a annulus.
Complete annular pancreas - pancreatic parenchyma or annular duct is seen to completely surround the 2nd part of duodenum
Incomplete annular pancreas - annulus does not surround the duodenum completely, giving a 'crocodile jaw' appearance Annular pancreas is associated with excess amniotic fluid during pregnancy (polyhydramniosis) and is often coupled with other congenital abnormalities of the gastrointestinal tract.
<pubmed>21386643</pubmed>
Individual Assessment 6 - Lab 7
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.
It is suspected that exposure to Endocrine Disrupting Chemicals (EDCs) disrupts normal thyroid development. This study investigates the effects of pre-conceptual, gestational, and continuous maternal exposure to sewage sludge on fetal thyroid gland development and the levels of circulating thyroid hormones in the exposed ovine fetus.
Pre-conceptual and gestational exposure in the fetuses; the first exposed throughout their lives prior and post mating (TT).
Exposure only until mating, but not thereafter (TC) resulting in exclusively pre-conceptual exposure.
Exclusively gestational exposure was achieved by exposure between mating and euthanasia (CT).
Hormone Level
Maternal and fetal blood samples were obtained and concentrations of T3,T4 and TSH were determined. Hormone level analysis revealed that treatment had no significant effect on maternal t3/T4 ratios. There was also no change in plasma levels of these hormones in maternal blood compare to the control group. Furthermore, no significant correlation of any kind was found between maternal TSH and fetal thyroid hormone levels.
Morphometric Analysis
Thyroid tissue sections were analysed and the follicle number, size and epithelial height were determined. All groups showed inter-animal variability, the phenomenon is most pronounced in the TT group . Treatment groups presented with a lower follicle count, and both groups with preconceptual exposure showed a higher percentage distribution of medium-sized follicles. The height of the follicular epithelium was unchanged and no changes in follicular resorption vacuoles was observed.
In addition morphological analysis shows a change in the relative distribution of small and large blood vessels. Smaller blood vessels representing more than 80% of all blood vessels in the thyroid tissues were predominantly affected. Female fetuses consistently show a reduction in the percentage of small blood vessel after pre-conceptual exposure and an exclusive and significant increase in thyroid cell proliferation in both groups CT and TC. Male fetuses showed significantly reduced follicle counts in both cross-over groups (CT, TC) and revealed highest thyroid cell proliferative activity in the TT group.
<pubmed>23291342</pubmed>
2.) Identify the embryonic layers and tissues that contribute to the developing teeth
Tooth development begins when dental lamina proliferates to form two horseshoe-shaped structures corresponding to the future dental arcades, this structure originates from the ectodermal layer. Enamel organs develop in the dental lamina; each swelling is the future site of a single tooth. The enamel organ exerts an organizing influence over the development of the mesodermal portions of the tooth. Gradually becoming cup-shaped, the enamel organ partially encloses an adjacent mesodermal structure which goes on to from the the dental papilla. Unenclosed mesoderm of the dental papilla contributes surrounding structures.
Source: http://www.britannica.com/EBchecked/topic/1512077/tooth-germ <pubmed></pubmed>
Individual Assessment 7 - Lab 8
Provide a brief time course and overview of embryonic development of either the human testis or ovary. (2-3 paragraphs) Include an image from the historic genital embryology section of the online notes in your description.
The the male testis is derived from three embryonic cell layers (origins).
- The first layer in the mesothelium, linked to the posterior abdominal wall.
- The next is the underlying layer of mesencyme, which develops into embryonic connective tissue.
- Finally the primordial germ cells, which are the earliest undifferntiated sex cells.
During week 5 of embryonic development, a thickened area develops on the medial side of the mesonephros due to proliferation of epithelium and the underlying mesencyme layers - genital ridge. Epithelial chords from the mesothelium project then into the underlying mesencyme - genital chords. The gonad is now established, consisting of an external cortex and an inner medulla.In male embryos with an XY sex chromosome complex, the medulla differntiates, giving rise to the testi while the cortex degenerates.
In conjunction with the formation of genital ridges, primordial germ cells are developing in the umbilical vessicle at week 4 of embryonic development. During the folding phase, these umbilical vessicles are incorporated into the embryo (hind gut region).The primordial germs cells are now able to migrate along the dorsal mesentery from the hind gut into the genial ridges. By week 6 the germ cells have been incorporated the mesencyme via the genial chords.
The embryonic development of the early genital system beings is identical for males and females until week 7, when the of morphological characteristics begin developing. The male Y chromosome has a sex-determining region known as the SRY gene which stimulates production of Testes-Determining Factor, determines testicular differentiation. Organisation factors and TDF stimulate differentiation of gonadal chords and into seminiferious chords. At this point a thick fibrous cap envelops the developing tubules - tunica albuginea . As testis gradually enlarges, it looses its connection to the mesonephros and is suspended by the mesochorium.
The seminiferous chords continue to develop, giving rise to the Leydige cells and Sertoli cells by week 8 of embryonic development. Leydig cells being producing androgens such as Testosterone. While Sertoli cells are producing Anti-Mullerian Hormone (AMH) which prevents simultaneous development of female internal genial tract.
Week 4 - Primordial Germ Cells - differentiated Week 5 - Formation of Genital Ridges and Genital Chords - establish gonad stucture Week 6 - Primordial Germ Cells migrate into the Genial Ridges and are incorporated into the mesncyme Week 7 - Expression of the SRY gene- Increased TDF Week 8 - Differentiation of Leydig and Sertoli cells - Coupled with production of Testosterone and AMH
Pub Med
http://www.ncbi.nlm.nih.gov/pubmed/25084016
<pubmed>25084016</pubmed>
