Project description:Generation of neurons in the embryonic neocortex is a balanced process of proliferation and differentiation of neuronal progenitor cells. Canonical Wnt signalling is crucial for expansion of radial glial cells in the ventricular zone and for differentiation of intermediate progenitors in the subventricular zone. We detected abundant expression of two transcrtiption factors mediating canonical Wnt signalling, Tcf7L1 and Tcf7L2, in the ventricular zone of the embryonic neocortex. Conditional knock-out analysis showed that Tcf7L2, but not Tcf7L1, is the principal Wnt mediator important for maintenance of progenitor cell identity in the ventricular zone. In the absence of Tcf7L2, the Wnt activity is reduced, ventricular zone markers Pax6 and Sox2 are downregulated and the neuroepithelial structure is severed due to the loss of apical adherens junctions. This results in decreased proliferation of radial glial cells, the reduced number of intermediate progenitors in the subventricular zone and hypoplastic forebrain. Our data show that canonical Wnt signalling, which is essential for determining the neuroepithelial character of the neocortical ventricular zone, is mediated by Tcf7L2.
Project description:To investigate the cellular basis of tissue integrity in a vertebrate central nervous system (CNS) tissue, we eliminated Müller glial cells (MG) from the zebrafish retina. For well over a century, glial cells have been ascribed a mechanical role in the support of neural tissues, yet this idea has not been specifically tested in vivo. We report here that retinas devoid of MG rip apart, a defect known as retinoschisis. Using atomic force microscopy, we show that retinas without MG have decreased resistance to tensile stress and are softer than controls. Laser ablation of MG processes showed that these cells are under tension in the tissue. Thus, we propose that MG act like springs that hold the neural retina together, finally confirming an active mechanical role of glial cells in the CNS.
Project description:BackgroundFilamentation temperature-sensitive H (FtsH) is an ATP-dependent zinc metalloprotease with ATPase activity, proteolysis activity and molecular chaperone-like activity. For now, a total of nine FtsH proteins have been encoded in rice, but their functions have not revealed in detail. In order to investigate the molecular mechanism of OsFtsH2 here, several osftsh2 knockout mutants were successfully generated by the CRISPR/Cas9 gene editing technology.ResultsAll the mutants exhibited a phenotype of striking albino leaf and could not survive through the stage of three leaves. OsFtsH2 was located in the chloroplast and preferentially expressed in green tissues. In addition, osftsh2 mutants could not form normal chloroplasts and had lost photosynthetic autotrophic capacity. RNA sequencing analysis indicated that many biological processes such as photosynthesis-related pathways and plant hormone signal transduction were significantly affected in osftsh2 mutants.ConclusionsOverall, the results suggested OsFtsH2 to be essential for chloroplast development in rice.
Project description:BackgroundThis article is based upon data gathered during a study conducted in partnership with the World Intellectual Property Organization on the patent status of products appearing on the World Health Organization's 2013 Model List of Essential Medicines (MLEM). It is a statistical analysis aimed at answering: in which developing countries are patents on essential medicines being filed?MethodsPatent data were collected by linking those listed in the United States and Canada's medicine patent registers to corresponding patents in developing countries using two international patent databases (INPADOC and Derwent) via a commerical-grade patent search platform (Thomson Innovation). The respective supplier companies were then contacted to correct and verify our data. We next tallied the number of MLEM patents per developing country. Spearman correlations were done to assess bivariate relationships between variables, and a multivariate regression model was developed to explain the number of MLEM patents in each country using SPSS 23.0.ResultsA subset of 20 of the 375 (5%) products on the 2013 MLEM fit our inclusion criteria. The patent estate reports (i.e., the global list of patents for a given drug) varied greatly in their number with a median of 48 patents (interquartile range [IQR]: 26-76). Their geographic reach had a median of 15% of the developing countries sampled (IQR: 8-28%). The number of developing countries covered appeared to increase with the age of the patent estate (r = .433, p = 0.028). The number of MLEM patents per country was significantly positively associated with human development index (HDI), gross domestic income (GDI) per capita, total healthcare expenditure per capita, population size, the Rule of Law Index, and average education level. Population size, GDI per capita, and healthcare expenditure (in % of national expenditure) were predictors of the number of MLEM patents in countries (p = 0.001, p = 0.001, p = 0.009, respectively). Population size was the most important predictor (β = 0.59), followed by income (GDI per capita) (β = 0.32), and healthcare expenditure (β = 0.15). Holding the other factors constant, (i) 14.3 million more people, (ii) $833.33 more per capita (GDI), or (iii) 0.88% more of national spending on healthcare resulted in 1 additional essential medicine patent.ConclusionPopulation was a powerful predictor of the number of patent filings in developing countries along with GDI and healthcare expenditure. The age and historical context of the patent estate may make a difference in the number of patents and countries covered. Broad surveillance and benchmarking of the global medicine patent landscape is valuable for detecting significant shifts that may occur over time. With improved international medicine patent transparency by companies and data available through third parties, such studies will be increasingly feasible.
Project description:Forkhead box O1 (FoxO1), a member of the Forkhead box-containing O family of transcription factors, is a key regulator of numerous genes that govern a wide array of cellular functions, including differentiation, homeostasis, and survival. However, the role of FoxO1 in development remains elusive. Here, we describe an essential and previously undefined role for FoxO1 in placental development. We demonstrate that FoxO1-null embryos up to embryonic day 9.0 (E9.0) are indistinguishable, including their morphology, cardiovascular structure, and vascular gene expression, from wild-type (WT) littermates. However, FoxO1-nulls manifested a profoundly swollen/hydropic allantois, which failed to fuse with the chorion, a phenotype that leads to subsequent cardiovascular malformation, progressive apoptotic cell death, and embryonic lethality at E10.5. Quantitative RT-PCR analysis of genes involved in placental development revealed significant attenuation of VCAM1 expression in FoxO1-null embryos. Using immunohistochemical, transcriptional, and chromatin immunoprecipitation assays, we further discovered that FoxO1 is an essential upstream regulator of the VCAM1 gene. Collectively, our findings provide critical molecular insight into a unique FoxO1-VCAM1 axis that governs placental morphogenesis, a process that is essential for subsequent normal cardiovascular development and fetal life.
Project description:Nsun5 gene, encoding a cytosine-5 RNA methyltransferase, is deleted in about 95% patients with Williams-Beuren syndrome (WBS). WBS is a neurodevelopmental disorder and characterized by cognitive disorder. We generated single-gene Nsun5 knockout (Nsun5-KO) mice and reported that the Nsun5 deletion leads to deficit in spatial cognition. This study focused on investigating the influence of Nsun5 deficiency in the development of cerebral cortex. In comparison with wild-type littermates, the cortical thickness in postnatal day 10 Nsun5-KO mice was obviously reduced with an abnormal laminar organization, and the processes of pyramidal cells were shorter and finer. Nsun5 was selectively expressed in radial glial cells (RGCs) of cerebral cortex from embryonic day (E) 12.5 to E16.5, but not in intermediate progenitor cells (IPCs) or neocortical neurons. The Nsun5 deletion did not alter proliferation of RGCs or differentiation of RGCs into IPCs. Notably, the ablation of Nsun5 disrupted the growth of radial glial scaffolds, thus numerous basal processes of RGCs failed to reach pial basement membrane. Level of cell polarity regulator Cdc42 protein in radial glial scaffolds of E14.5 Nsun5-KO mice was reduced, but the level of Cdc42 mRNA was unchanged. The dysfunction of glial scaffolds impeded the radial migration of upper-layer and deeper-layer neurons to cause their subcortical accumulation and apoptosis, resulting in an obvious thinness of the cortical plate in E18.5 Nsun5-KO mice. These findings establish a critical role of Nsun5 in development of cerebral cortex through regulating radial glial scaffolds of RGCs to control migration of neocortical neurons.
Project description:BackgroundThe ability to give and receive feedback effectively is a key skill for doctors, aids learning between all levels of the medical hierarchy, and provides a basis for reflective practice and life-long learning. How best to teach this skill?DiscussionWe suggest that a single "teaching the skill of feedback" session provides superficial and ineffective learning in a medical culture that often uses feedback skills poorly or discourages feedback. Our experience suggests that both the skill and the underlying attitude informing its application must be addressed, and is best done so longitudinally and reiteratively using different forms of feedback delivery. These feedback learning opportunities include written and oral, peer to peer and cross-hierarchy, public and private, thereby addressing different cognitive processes and attitudinal difficulties.SummaryWe conclude by asking whether it is possible to build a consensus approach to a framework for teaching and learning feedback skills?
Project description:This will be a descriptive study designed to evaluate the propensity for hospitalized pediatric patients treated adequately with Clinolipid or standard of care for up to 90 days to develop Essential Fatty Acid Deficiency (EFAD). Additionally, this study design will evaluate the safety and efficacy of using Clinolipid in a pediatric population.
Project description:During neurogenesis, proliferating neural precursor cells (NPC) exit the cell cycle and differentiate into postmitotic neurons. The proteins that regulate cell survival through the stages of differentiation, however, are still poorly understood. Here, we examined the roles of the anti-apoptotic Bcl-2 proteins, Mcl-1 and Bcl-xL, in promoting survival as cells progress through the stages of neurogenesis in the mouse embryonic central nervous system. We used Nestin-mediated, nervous system-specific conditional deletion of mcl-1, bcl-x or both to identify their distinct and overlapping roles. Individual conditional deletion of mcl-1 (MKO) and bcl-x (BKO) suggested sequential roles in promoting cell survival during developmental neurogenesis. In the MKO embryo, apoptosis begins at embryonic day 10 (E10) in the proliferating NPC population throughout the entire developing nervous system. In the BKO embryo, apoptosis begins later at E11 within the postmitotic neuron populations. In the double (mcl-1 and bcl-x) conditional knockout (DKO), cell death extended throughout both proliferating and non-proliferating cell populations resulting in embryonic lethality at E12, earlier than in either the MKO or BKO. Apoptotic cell death of the entire central nervous system in the DKO demonstrates that both genes are necessary for cell survival during developmental neurogenesis. To determine whether Mcl-1 and Bcl-xL have overlapping anti-apoptotic roles during neurogenesis, we examined the impact of gene dosage. Loss of a single bcl-x allele in the MKO embryo exasperated apoptotic cell death within the NPC population revealing a novel anti-apoptotic role for Bcl-xL in proliferating NPCs. Cells were rescued from apoptosis in both the MKO and BKO embryos by breeding with the Bax null mouse line indicating that Mcl-1 and Bcl-xL have a common pro-apoptotic target during developmental neurogenesis. Taken together, these findings demonstrate that Mcl-1 and Bcl-xL are the two essential anti-apoptotic Bcl-2 proteins required for the survival of the developing mammalian nervous system.
Project description:Policy Points That child and adolescent mental health services needs are frequently unmet has been known for many decades, yet few systemic solutions have been sought and fewer have been implemented at scale. Key among the barriers to improving child and adolescent mental health services has been the lack of well-organized primary mental health care. Such care is a mutual but uncoordinated responsibility of multiple disciplines and agencies. Achieving consensus on the essential structures and processes of mental health services is a feasible first step toward creating an organized system.