Mucin-Inspired Thermoresponsive Synthetic Hydrogels Induce Stasis in Human Pluripotent Stem Cells and Human Embryos.

Human pluripotent stem cells (hPSCs; both embryonic and induced pluripotent) rapidly proliferate in adherent culture to maintain their undifferentiated state. However, for mammals exhibiting delayed gestation (diapause), mucin-coated embryos can remain dormant for days or months in utero, with their constituent PSCs remaining pluripotent under these conditions. Here we report cellular stasis for both hPSC colonies and preimplantation embryos immersed in a wholly synthetic thermoresponsive gel comprising poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) [PGMA55-PHPMA135] diblock copolymer worms. This hydroxyl-rich mucin-mimicking nonadherent 3D gel maintained PSC viability and pluripotency in the quiescent G0 state without passaging for at least 14 days. Similarly, gel-coated human embryos remain in a state of suspended animation (diapause) for up to 8 days. The discovery of a cryptic cell arrest mechanism for both hPSCs and embryos suggests an important connection between the cellular mechanisms that evoke embryonic diapause and pluripotency. Moreover, such synthetic worm gels offer considerable utility for the short-term (weeks) storage of either pluripotent stem cells or human embryos without cryopreservation

Disruptive conservation in the material transmission of past to future

When objects move into museums, the location and nature of their associated power shifts. For example, a confederate statue may be removed from the public square and placed in a museum to ‘neutralise’ its symbolism. The symbolism of the statue is mediated by this curated public space, and the power shifts and changes in form, passing in some form to the museum impacting on all acts of its operations from the staff to its reputation. When an object is ‘collected’ during an imperial conquest that transference is not simply a matter of the location of the art but rather it is symbolic of the destruction of a culture and the dominance of another.1 Removing the power of association of things to place is a symbol of control and domination and is an act intimately connected with colonialism. Museums use objects to transmit stories,when those stories tell stories of violence and oppression those who work in museums must consider this in their actions

Finding our place - people and things in urban citizen belonging

This paper concerns the ways we each find our selves in our cities, how we find selfhood and community in the changing fluid spaces of cultural ebb and flow that constitute contemporary urban landscapes. Technologically infused infrastructures of buildings, transport and communication together with time based obligations of work and recreation intertwines with the physical spaces of built environment and human coexistence to create complex layers of 'being' in place. Continuously reconstituting our expectations, adapting to the fluctuating rules of changing roles, language, hidden meanings and socio-cultural historical inference, identity becomes an adventure of performative camouflage. Who do I need to be today? Who and what do I trust? Is it safe? This maze of physical, digital and cultural urban existences has variously been described as a happenstance of metaphors, an unknowable labyrinth, a memory machine and a drama in time. We have begun to explore being and belonging in place through the exploration of self through literature in the context of a student-tutor research partnership entitled Reading and Writing the City, based in a final year undergraduate study module. This study module poses the question 'what does it mean to belong to a place' and we supplement this question for our research project with 'what might being and belonging mean in a digitally augmented urban lifeworld' that further contributes to the research area for digital lifeworld being and belonging in place and the city. Though space is limited in this short paper, we attempt to outline key concepts and terrain related to 'Reading and Writing the City'. Discussion takes in the idea of research partnerships in a speculative university of knowledge for its own sake, what it might mean to belong to places, future cities based in a sustainable ecology of care, the nature and role of 'things' in belonging, and how digital augmentation of self, objects and environment impact identity and belonging.peer-reviewe

Detecting Genetic Mosaicism in Cultures of Human Pluripotent Stem Cells.

Genetic changes in human pluripotent stem cells (hPSCs) gained during culture can confound experimental results and potentially jeopardize the outcome of clinical therapies. Particularly common changes in hPSCs are trisomies of chromosomes 1, 12, 17, and 20. Thus, hPSCs should be regularly screened for such aberrations. Although a number of methods are used to assess hPSC genotypes, there has been no systematic evaluation of the sensitivity of the commonly used techniques in detecting low-level mosaicism in hPSC cultures. We have performed mixing experiments to mimic the naturally occurring mosaicism and have assessed the sensitivity of chromosome banding, qPCR, fluorescence in situ hybridization, and digital droplet PCR in detecting variants. Our analysis highlights the limits of mosaicism detection by the commonly employed methods, a pivotal requirement for interpreting the genetic status of hPSCs and for setting standards for safe applications of hPSCs in regenerative medicine

Enabling consistency in pluripotent stem cell-derived products for research and development and clinical applications through material standards

There is a need for physical standards (reference materials) to ensure both reproducibility and consistency in the production of somatic cell types from human pluripotent stem cell (hPSC) sources. We have outlined the need for reference materials (RMs) in relation to the unique properties and concerns surrounding hPSC-derived products and suggest in-house approaches to RM generation relevant to basic research, drug screening, and therapeutic applications. hPSCs have an unparalleled potential as a source of somatic cells for drug screening, disease modeling, and therapeutic application. Undefined variation and product variability after differentiation to the lineage or cell type of interest impede efficient translation and can obscure the evaluation of clinical safety and efficacy. Moreover, in the absence of a consistent population, data generated from in vitro studies could be unreliable and irreproducible. Efforts to devise approaches and tools that facilitate improved consistency of hPSC-derived products, both as development tools and therapeutic products, will aid translation. Standards exist in both written and physical form; however, because many unknown factors persist in the field, premature written standards could inhibit rather than promote innovation and translation. We focused on the derivation of physical standard RMs. We outline the need for RMs and assess the approaches to in-house RM generation for hPSC-derived products, a critical tool for the analysis and control of product variation that can be applied by researchers and developers. We then explore potential routes for the generation of RMs, including both cellular and noncellular materials and novel methods that might provide valuable tools to measure and account for variation. Multiparametric techniques to identify "signatures" for therapeutically relevant cell types, such as neurons and cardiomyocytes that can be derived from hPSCs, would be of significant utility, although physical RMs will be required for clinical purposes

Chronic lymphocytic leukaemia/Small lymphocytic lymphoma (CLL/SLL) associated with translocation t(1;6)(p35;p25) as part of complex karyotype

Case report of a translocation : Chronic lymphocytic leukaemia/Small lymphocytic lymphoma (CLL/SLL) associated with translocation t(1;6)(p35;p25) as part of complex karyotype

Genome-Wide Gene Amplification during Differentiation of Neural Progenitor Cells In Vitro

DNA sequence amplification is a phenomenon that occurs predictably at defined stages during normal development in some organisms. Developmental gene amplification was first described in amphibians during gametogenesis and has not yet been described in humans. To date gene amplification in humans is a hallmark of many tumors. We used array-CGH (comparative genomic hybridization) and FISH (fluorescence in situ hybridization) to discover gene amplifications during in vitro differentiation of human neural progenitor cells. Here we report a complex gene amplification pattern two and five days after induction of differentiation of human neural progenitor cells. We identified several amplified genes in neural progenitor cells that are known to be amplified in malignant tumors. There is also a striking overlap of amplified chromosomal regions between differentiating neural progenitor cells and malignant tumor cells derived from astrocytes. Gene amplifications in normal human cells as physiological process has not been reported yet and may bear resemblance to developmental gene amplifications in amphibians and insects

Feasibility of perfusion cardiovascular magnetic resonance in paediatric patients

AIMS: As coronary artery disease may also occur during childhood in some specific conditions, we sought to assess the feasibility and accuracy of perfusion cardiovascular magnetic resonance (CMR) in paediatric patients. METHODS AND RESULTS: First-pass perfusion CMR studies were performed under pharmacological stress with adenosine and by using a hybrid echo-planar pulse sequence with slice-selective saturation recovery preparation. Fifty-six perfusion CMR examinations were performed in 47 patients. The median age was 12 years (1 month-18 years), and weight 42.8 kg (2.6-82 kg). General anaesthesia was required in 18 patients. Mean examination time was 67 +/- 19 min. Diagnostic image quality was obtained in 54/56 examinations. In 23 cases the acquisition parameters were adapted to patient's size. Perfusion CMR was abnormal in 16 examinations. The perfusion defects affected the territory of the left anterior descending coronary artery in 11, of the right coronary artery in 3, and of the circumflex coronary artery in 2 cases. Compared to coronary angiography, perfusion CMR showed a sensitivity of 87% (CI 52-97%) and a specificity of 95% (CI 79-99%). CONCLUSION: In children, perfusion CMR is feasible and accurate. In very young children (less than 1 year old), diagnostic image quality may be limited

Concise Review: The Evolution of human pluripotent stem cell culture: From feeder cells to synthetic coatings

Current practices to maintain human pluripotent stem cells (hPSCs), which include induced pluripotent stem cells and embryonic stem cells, in an undifferentiated state typically depend on the support of feeder cells such as mouse embryonic fibroblasts (MEFs) or an extracellular matrix such as Matrigel. Culture conditions that depend on these undefined support systems limit our ability to interpret mechanistic studies aimed at resolving how hPSCs interact with their extracellular environment to remain in a unique undifferentiated state and to make fate‐changing lineage decisions. Likewise, the xenogeneic components of MEFs and Matrigel ultimately hinder our ability to use pluripotent stem cells to treat debilitating human diseases. Many of these obstacles have been overcome by the development of synthetic coatings and bioreactors that support hPSC expansion and self‐renewal within defined culture conditions that are free from xenogeneic contamination. The establishment of defined culture conditions and synthetic matrices will facilitate studies to more precisely probe the molecular basis of pluripotent stem cell self‐renewal and differentiation. When combined with three‐dimensional cultures in bioreactors, these systems will also enable large‐scale expansion for future clinical applications. S TEM C ells 2013;31:1–7Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94687/1/1260_ftp.pd

Derivation of the clinical grade human embryonic stem cell line RCe021-A (RC-17)

AbstractThe human embryonic stem cell line RCe020-A (RC-16) was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP) standards. The cell line was derived from a failed to fertilise oocyte voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe020-A (RC-16) shows normal pluripotency marker expression and differentiates to mesoderm and potentially ectoderm in vitro. It has an abnormal 47XX, +14, i(20)(q10) female karyotype and microsatellite PCR identity, HLA and blood group typing data is available