554 research outputs found

    Directed differentiation of porcine epiblast-derived neural progenitor cells into neurons and glia

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    AbstractNeural progenitor cells (NPCs) are promising candidates for cell-based therapy of neurodegenerative diseases; however, safety concerns must be addressed through transplantation studies in large animal models, such as the pig. The aim of this study was to derive NPCs from porcine blastocysts and evaluate their in-vitro differentiation potential. Epiblasts were manually isolated from expanded hatched blastocysts and cultured on MEF feeder cells. Outgrowth colonies were passaged to MS5 cells and rosettes were further passaged to Matrigel-coated dishes containing bFGF and EGF. Three NPC lines were established which showed expression of SOX2, NESTIN and VIMENTIN. One line was characterised in more detail, retaining a normal karyotype and proliferating for more than three months in culture. Following differentiation, TUJI was significantly up-regulated in protocol 2 (RA and SHH; 58% positive cells) as were NF and TH. In contrast, MBP was significantly up-regulated in protocol 3 (FGF8 and SHH; 63% positive cells), whereas, GFAP was significantly up-regulated in protocols 1–4 (33%, 25%, 43% and 22%). The present study provides the first report of a porcine blastocyst-derived NPC line capable of differentiating into both neurons and glia, which may be of paramount importance for future transplantation studies in large animal models of neurodegenerative diseases

    Early embryonic development, assisted reproductive technologies, and pluripotent stem cell biology in domestic mammals

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    Over many decades assisted reproductive technologies, including artificial insemination, embryo transfer, in vitro production (IVP) of embryos, cloning by somatic cell nuclear transfer (SCNT), and stem cell culture, have been developed with the aim of refining breeding strategies for improved production and health in animal husbandry. More recently, biomedical applications of these technologies, in particular, SCNT and stem cell culture, have been pursued in domestic mammals in order to create models for human disease and therapy. The following review focuses on presenting important aspects of pre-implantation development in cattle, pigs, horses, and dogs. Biological aspects and impact of assisted reproductive technologies including IVP, SCNT, and culture of pluripotent stem cells are also addressed. © 2013 Elsevier Ltd

    Organelle reorganization in bovine oocytes during dominant follicle growth and regressionOrganelle reorganization in bovine oocytes during dominant follicle growth and regression

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    BACKGROUND: We tested the hypothesis that organelles in bovine oocytes undergo changes in number and spatial distribution in a manner specific for phase of follicle development. METHODS: Cumulus-oocyte-complexes were collected from Hereford heifers by ultrasound-guided follicle aspiration from dominant follicles in the growing phase (n = 5; Day 0 = ovulation), static phase (n = 5), regressing phase (n = 7) of Wave 1 and from preovulatory follicles (n = 5). Oocytes were processed and transmission electron micrographs of ooplasm representing peripheral, perinuclear and central regions were evaluated using standard stereological methods. RESULTS: The number of mitochondria and volume occupied by lipid droplets was higher (P < 0.03) in oocytes from regressing follicles (193.0 ± 10.4/1000 μm(3) and 3.5 ± 0.7 %) than growing and preovulatory stages (118.7 ± 14.4/1000 μm(3) and 1.1 ± 0.3 %; 150.5 ± 28.7/1000 μm(3) and 1.6 ± 0.2 %, respectively). Oocytes from growing, static and preovulatory follicles had >70 % mitochondria in the peripheral regions whereas oocytes from regressing follicles had an even distribution. Oocytes from growing follicles had more lipid droplets in peripheral region than in central region (86.9 vs. 13.1 %). Percent surface area of mitochondria in contact with lipid droplets increased from growing (2.3 %) to static, regressing or preovulatory follicle stage (8.9, 6.1 and 6.2 %). The amount, size and distribution of other organelles did not differ among phases (P > 0.11). CONCLUSIONS: Our hypothesis was supported in that mitochondrial number increased and translocation occurred from a peripheral to an even distribution as follicles entered the regressing phase. In addition, lipid droplets underwent spatial reorganization from a peripheral to an even distribution during the growing phase and mitochondria-lipid contact area increased with follicle maturation

    Trophectoderm differentiation in the bovine embryo: characterization of a polarized epithelium.

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    Blastocytst formation is dependent on the differentiation of a transporting epithelium, the trophectoderm, which is coordinated by the embryonic expression and cell adhesive properties of E-cadherin. The trophectoderm shares differentiative characteristics with all epithelial tissues, including E-cadherin-mediated cell adhesion, tight junction formation, and polarized distribution of intramembrane proteins, including the Na-K ATPase. The present study was conducted to characterize the mRNA expression and distribution of polypeptides encoding E-cadherin, beta-catenin, and the tight junction associated protein, zonula occludens protein 1, in pre-attachment bovine embryos, in vitro. Immunocytochemistry and gene specific reverse transcription--polymerase chain reaction methods were used. Transcripts for E-cadherin and beta-catenin were detected in embryos of all stages throughout pre-attachment development. Immunocytochemistry revealed E-cadherin and beta-catenin polypeptides evenly distributed around the cell margins of one-cell zygotes and cleavage stage embryos. In the morula, detection of these proteins diminished in the free apical surface of outer blastomeres. E-cadherin and beta-catenin became restricted to the basolateral membranes of trophectoderm cells of the blastocyst, while maintaining apolar distributions in the inner cell mass. Zonula occludens protein 1 immunoreactivity was undetectable until the morula stage and first appeared as punctate points between the outer cells. In the blastocyst, zonula occludens protein 1 was localized as a continuous ring at the apical points of trophectoderm cell contact and was undetectable in the inner cell mass. These results illustrate that the gene products encoding E-cadherin, beta-catenin and zonula occludens protein 1 are expressed and maintain cellular distribution patterns consistent with their predicted roles in mediating trophectoderm differentiation in in vitro produced bovine embryos

    Effect of nutrition and superovulation on oocyte morphology, follicular fluid composition and systemic hormone concentrations in ewes

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    The objective was to determine the effect of dietary intake on follicle and oocyte morphology in unstimulated and superovulated ewes. Fifty-four ewes were fed grass meal at 0.5, 1.0 or 2.0 times maintenance energy requirements (M) for 32 days. Oestrous cycles were synchronized using progestagen pessaries and either unstimulated or superovulated with 200 mg pig FSH. The ewes were killed and ovaries were collected either 36 or 12 h before the anticipated LH surge. Serum progesterone concentrations in ewes on day 10 after withdrawal of the pessary were lower in ewes fed 2.0M than in ewes fed 0.5M or 1.0M (P /= 3 mm) were observed when the animals were killed in ewes fed 2.0M (3.5 +/- 0.3) than in ewes fed 0.5M (2.4 +/- 0.3) or 1.0M (2.4 +/- 0.5; P < 0. 05). Fewer follicles were observed in superovulated ewes on 0.5M (7. 5 +/- 1.2) than in ewes on 1.0M (12.0 +/- 0.5) or 2.0M (12.3 +/- 1. 4; P < 0.05). Follicular fluid progesterone concentrations were higher in ewes fed 0.5M compared with those fed 1M or 2M (P < 0.05). Insulin-like growth factor (IGF)-I concentrations were higher in follicular fluid from ewes on 1M compared with either those on 0.5M or 2M (P < 0.05), whereas IGF-II concentrations were lower in follicular fluid from ewes on 2M compared with those on 1M or 0.5M (P < 0.05). Superovulation increased follicular fluid progesterone, oestradiol, IGF-I and IGF-II concentrations (P < 0.01). Concentrations of the 34, 22 and 20 kDa IGF binding proteins were lower in follicles from superovulated ewes compared with unstimulated ewes (P < 0.05). Oocytes from superovulated ewes showed abnormalities such as premature activation of cumulus expansion and vacuolation of the nucleolus and increased frequency of detachment of interchromatin-like granules from the nucleolar remnant. Collectively, these results indicate that both high and low dietary intakes can alter systemic and follicular fluid hormone concentrations. Relative to dietary effects, the effects of superovulation were greater and involved substantial increases in follicular fluid hormone concentrations and abnormal oocyte morphology

    Cerebral near-infrared spectroscopy monitoring (NIRS) in children and adults: a systematic review with meta-analysis

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    Background: Cerebral oxygenation monitoring utilising near-infrared spectroscopy (NIRS) is increasingly used to guide interventions in clinical care. The objective of this systematic review with meta-analysis and Trial Sequential Analysis is to evaluate the effects of clinical care with access to cerebral NIRS monitoring in children and adults versus care without. Methods: This review conforms to PRISMA guidelines and was registered in PROSPERO (CRD42020202986). Methods are outlined in our protocol (doi: 10.1186/s13643-021-01660-2). Results: Twenty-five randomised clinical trials were included (2606 participants). All trials were at a high risk of bias. Two trials assessed the effects of NIRS during neonatal intensive care, 13 during cardiac surgery, 9 during non-cardiac surgery and 1 during neurocritical care. Meta-analyses showed no significant difference for all-cause mortality (RR 0.75, 95% CI 0.51-1.10; 1489 participants; I2 = 0; 11 trials; very low certainty of evidence); moderate or severe, persistent cognitive or neurological deficit (RR 0.74, 95% CI 0.42-1.32; 1135 participants; I2 = 39.6; 9 trials; very low certainty of evidence); and serious adverse events (RR 0.82; 95% CI 0.67-1.01; 2132 participants; I2 = 68.4; 17 trials; very low certainty of evidence). Conclusion: The evidence on the effects of clinical care with access to cerebral NIRS monitoring is very uncertain. Impact: The evidence of the effects of cerebral NIRS versus no NIRS monitoring are very uncertain for mortality, neuroprotection, and serious adverse events. Additional trials to obtain sufficient information size, focusing on lowering bias risk, are required. The first attempt to systematically review randomised clinical trials with meta-analysis to evaluate the effects of cerebral NIRS monitoring by pooling data across various clinical settings. Despite pooling data across clinical settings, study interpretation was not substantially impacted by heterogeneity. We have insufficient evidence to support or reject the clinical use of cerebral NIRS monitoring
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