1,266 research outputs found
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Genetically engineered human cortical spheroid models of tuberous sclerosis.
Tuberous sclerosis complex (TSC) is a multisystem developmental disorder caused by mutations in the TSC1 or TSC2 genes, whose protein products are negative regulators of mechanistic target of rapamycin complex 1 signaling. Hallmark pathologies of TSC are cortical tubers-regions of dysmorphic, disorganized neurons and glia in the cortex that are linked to epileptogenesis. To determine the developmental origin of tuber cells, we established human cellular models of TSC by CRISPR-Cas9-mediated gene editing of TSC1 or TSC2 in human pluripotent stem cells (hPSCs). Using heterozygous TSC2 hPSCs with a conditional mutation in the functional allele, we show that mosaic biallelic inactivation during neural progenitor expansion is necessary for the formation of dysplastic cells and increased glia production in three-dimensional cortical spheroids. Our findings provide support for the second-hit model of cortical tuber formation and suggest that variable developmental timing of somatic mutations could contribute to the heterogeneity in the neurological presentation of TSC
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Genetic Analysis of the X Chromosomes of Man and Mouse
A detailed man-mouse comparative map aids the identification of mouse models for human inherited diseases and provides insight into the chromosomal rearrangements which have occurred during evolution. The man-mouse comparative map of the X chromosome is known to comprise at least eight conserved segments. Four of these lie in the human proximal short arm (Xp) in the CYBB-centromere region. Three share homology with the proximal, and one with the distal, region of the mouse X chromosome.
To improve the man-mouse comparative map of proximal Xp detailed recombination mapping has been performed. Panels of mice with recombination events in regions of the mouse X chromosome which share homology with human proximal Xp have been identified from laboratory M. musculus x M. spretus backcrosses. A high resolution map of the DXWas70 to Cybb region of the mouse X chromosome was created by analysis of additional recombination from the European Collaborative Interspecific Backcross. The order of loci and the position of evolutionary breakpoints (EBs) in human proximal Xp was established as: DMD - EB - XK - PFC - EB - GATAI - NPHL - EB - DXS674/DXS679 - ALAS2 - EB - DXF34.
Detailed physical analysis of the DXWas?0 to Cybb interval of the mouse X chromosome was carried out using YAC clones. YACs were analysed using PCR, PFGE and Southern and in situ hybridisation and as a result of these analyses, three YAC contigs were constructed. These include twelve YACs and may contains sequences at 2-3 evolutionary breakpoints. They may also contain the genes involved in the mouse mutant phenotypes tattered and scurfy
Peroxisome abundance and lipid-toxicity of pancreatic B-cells in response to saturated fats
PhD ThesisLipotoxicity results from the accumulation of fats within nonāadipose tissue, and is one
of the causes of insulin resistance and Ī²ācell dysfunction in type 2 diabetes. Recently
candidate gene studies have identified a gene variant at the PEX11Ī± gene locus which
is associated with reduced Ī²ācell function. PEX11Ī± and PEX11Ī² encode proteins
involved in the division and proliferation of peroxisomes, which are responsible for the
initial oxidation of very long chain and long chain fatty acids prior to complete
oxidation in the mitochondria. The aim of this thesis was to explore the impact of
altered PEX11Ī± and PEX11Ī² expression on peroxisome abundance and insulin
secretion in cultured pancreatic Ī²ācells. siRNAs specific for PEX11Ī± and PEX11Ī² were
used to knock down expression in MIN6 cells.
Transfection resulted in 70% knockdown of PEX11Ī± at all time points examined. There
was no significant difference in the levels of insulin secreted at 25mM glucose between
the PEX11Ī± knockdown and the scrambled control cells. At 25mM glucose, 250Ī¼M
palmitate decreased insulin secretion by 50% compared with the BSA control in the
scrambled control cells. This was unchanged by PEX11Ī± knockdown. Transfection with
siRNA specific for PEX11Ī² resulted in >80% reduction in expression at all time points
examined. At 96hrs a 35% reduction in PMPā70 protein levels, a marker of peroxisome
abundance, was also seen. Incubation with palmitate in the PEX11Ī² knockdowns
resulted in a significant increase in insulin secretion at 25mM glucose compared with
the scrambled palmitate control.
Palmitate incubation decreased insulin secretion at 25mM glucose in untransfected
control cells. However, PEX11Ī± knockdown did not alter insulin secretion in the
presence or absence of palmitate. PEX11Ī² knockdown resulted in a decrease in PMPā
70 protein. Unexpectedly, PEX11Ī² knockdown led to the partial recovery of the
inhibitory effect of palmitate on insulin secretion.BBSR
The construction and evaluation of a measure of auditory comprehension,
Thesis (M.A.)--Boston Universit
Managing the Technology Life Cycle - a Contextual Approach to Analysis
Organisations need to understand and manage the technology life cycle in order to deliver their business objectives. Technology and systems have an increased role in all organisational forms. Failure to realise the benefits here can have severe impact on these entities and, in the case of the emergence of disruptive technologies in the sector, the business can be destroyed and customers move to competitors, who have embraced these technologies - for example the UK travel industry, evidenced by recent high profile failure [1]. The critical role of IS and IT in the value chain has increased the importance of good management of this area. This paper considers the main factors for managing the life cycle, in terms of the implementation, support, renewal and disposal of technology. This is based on analysis of key literatures and an empirical study of technology leadership in energy sector projects. The aim is to improve understanding and awareness of this critical area, providing insights into these factors, which are categorised as 'evolutionary' and 'revolutionary'. These factors are viewed as 'drivers' of the technology life cycle, creating its character and duration also embracing the 'triggers for change', promoting the replacement of the technology and recommencement of the cycle. The critical stages are discussed with the contextual influences, in order to analyse this area, discerning the relevant rationale, as summarised in a conceptual model. Recommendations for good practice are elicited from this study in terms of identifying the key decisions and thus analysing and managing technological change
Citizensā Juries: When Older Adults Deliberate on the Benefits and Risks of Smart Health and Smart Homes
open access articleBackground: Technology-enabled healthcare or smart health has provided a wealth of
products and services to enable older people to monitor and manage their own health conditions at
home, thereby maintaining independence, whilst also reducing healthcare costs. However, despite
the growing ubiquity of smart health, innovations are often technically driven, and the older user does
not often have input into design. The purpose of the current study was to facilitate a debate about
the positive and negative perceptions and attitudes towards digital health technologies. Methods:
We conducted citizensā juries to enable a deliberative inquiry into the benefits and risks of smart health
technologies and systems. Transcriptions of group discussions were interpreted from a perspective
of life-worlds versus systems-worlds. Results: Twenty-three participants of diverse demographics
contributed to the debate. Views of older people were felt to be frequently ignored by organisations
implementing systems and technologies. Participants demonstrated diverse levels of digital literacy
and a range of concerns about misuse of technology. Conclusion: Our interpretation contrasted
the life-world of experiences, hopes, and fears with the systems-world of surveillance, e ciencies,
and risks. This interpretation o ers new perspectives on involving older people in co-design and
governance of smart health and smart homes
A short guide to hereditary diffuse gastric cancer
Hereditary diffuse gastric cancer (HDGC) is the only known predisposition syndrome dominated by carcinoma of the stomach and with a recognised genetic cause. Germline mutations in the E-cadherin gene (CDH1) co-segregate with the disease in about half of the families with multiple diffuse gastric cancer. In these families, identification of the CDH1 mutation allows for clinical measures to be taken. Importantly, clinical intervention is likely to be therapeutic and associated with tolerable morbidity. This review is thus aimed at providing a current overview of the clinical management and the underlying biology of HDGC
An Integrated Analysis of Maternal-Infant Sleep, Breastfeeding, and Sudden Infant Death Syndrome Research Supporting a Balanced Discourse
Breastfeeding and the place of sleep for the mother and the infant have been controversial internationally due to reported concerns regarding infant deaths despite the known benefits of exclusive and prolonged breastfeeding, which are increased by breastfeeding at night. The aims of this integrated analysis were to (a) review breastfeeding and maternal and infant sleep research literature via historical, epidemiological, anthropological, and methodological lenses; (b) use this information to determine where we are currently in safeguarding both infant lives and breastfeeding; and (c) postulate the direction that research might take from this point forward to improve our knowledge and inform our policy and practice. Despite well-meaning but unsuccessful campaigns in some countries to dissuade parents from sleeping with their babies, many breastfeeding mothers and caregivers do sleep with their infants whether intentionally or unintentionally. Taking cultural contexts and socio-ecological circumstances into consideration, data supports policies to counsel parents and caregivers on safe sleep practices, including bed-sharing in non-hazardous circumstances, particularly in the absence of parental smoking, recent parental alcohol consumption, or sleeping next to an adult on a sofa. Further research with appropriate methodology is needed to drill down on actual rates of infant deaths, paying close attention to the definitions of deaths, the circumstances of the deaths, and confounding factors, in order to ensure we have the best information with which to derive public health policy. Introduction and use of the concept of ābreastsleepingā is a plausible way to remove the negative connotations of āco-sleepingā and redirect ongoing data-driven discussions and education of best practices of breastfeeding and sleep
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