373 research outputs found

    Transfection of primary human skin fibroblasts by electroporation

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    Primary human skin fibroblasts are an accessible source of phenotypically and karyotypically normal human cells, but are difficult to transfect with exogenous DNA. Here we demonstrate that both transient expression and stable transformation can be carried out by the method of electroporation. Highly efficient transient chloramphenicol acetyltransferase expression was shown after transfection with plasmid pRSVCAT. Stable transformation of human skin fibroblasts to G418 resistance was obtained after electroporation with neo-containing plasmids at an efficiency of approximately 1.4 x 10-5/[mu]g DNA. The ability to easily transfect these cells with exogenous DNA may have important applications in the study of human genetic diseases and cancer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27179/1/0000177.pd

    Calsyntenin-1 mediates axonal transport of the amyloid precursor protein and regulates Aβ production

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    Understanding the mechanisms that control processing of the amyloid precursor protein (APP) to produce amyloid-β (Aβ) peptide represents a key area of Alzheimer's disease research. Here, we show that siRNA-mediated loss of calsyntenin-1 in cultured neurons alters APP processing to increase production of Aβ. We also show that calsyntenin-1 is reduced in Alzheimer's disease brains and that the extent of this reduction correlates with increased Aβ levels. Calsyntenin-1 is a ligand for kinesin-1 light chains and APP is transported through axons on kinesin-1 molecular motors. Defects in axonal transport are an early pathological feature in Alzheimer's disease and defective APP transport is known to increase Aβ production. We show that calsyntenin-1 and APP are co-transported through axons and that siRNA-induced loss of calsyntenin-1 markedly disrupts axonal transport of APP. Thus, perturbation to axonal transport of APP on calsyntenin-1 containing carriers induces alterations to APP processing that increase production of Aβ. Together, our findings suggest that disruption of calsyntenin-1-associated axonal transport of APP is a pathogenic mechanism in Alzheimer's disease

    Growing Three-Dimensional Corneal Tissue in a Bioreactor

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    Spheroids of corneal tissue about 5 mm in diameter have been grown in a bioreactor from an in vitro culture of primary rabbit corneal cells to illustrate the production of optic cells from aggregates and tissue. In comparison with corneal tissues previously grown in vitro by other techniques, this tissue approximates intact corneal tissue more closely in both size and structure. This novel three-dimensional tissue can be used to model cell structures and functions in normal and abnormal corneas. Efforts continue to refine the present in vitro method into one for producing human corneal tissue to overcome the chronic shortage of donors for corneal transplants: The method would be used to prepare corneal tissues, either from in vitro cultures of a patient s own cells or from a well-defined culture from another human donor known to be healthy. As explained in several articles in prior issues of NASA Tech Briefs, generally cylindrical horizontal rotating bioreactors have been developed to provide nutrient-solution environments conducive to the 30 NASA Tech Briefs, October 2003 growth of delicate animal cells, with gentle, low-shear flow conditions that keep the cells in suspension without damaging them. The horizontal rotating bioreactor used in this method, denoted by the acronym "HARV," was described in "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662), NASA Tech Briefs, Vol. 16, No. 5 (May, 1992), page 150

    Three dimensional optic tissue culture and process

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    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix

    The meaning and importance of dignified care: Findings from a survey of health and social care professionals

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    This article is available through the Brunel Open Access Publishing Fund. Copyright © 2013 Cairns et al.; licensee BioMed Central Ltd.There are well established national and local policies championing the need to provide dignity in care for older people. We have evidence as to what older people and their relatives understand by the term 'dignified care' but less insight into the perspectives of staff regarding their understanding of this key policy objective.This research was supported by the Dunhill Medical Trust [grant number: R93/1108]

    Emollient bath additives for the treatment of childhood eczema (BATHE): multi-centre pragmatic parallel group randomised controlled trial of clinical and cost-effectiveness

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    Objectives: To determine the clinical and cost-effectiveness of including emollient bath additives in the management of childhood eczema. Trial design: Pragmatic randomised open-label superiority trial with two parallel groups. Setting and recruitment: 96 general practices in Wales, West of England and Southern England. Invitation by personal letter or opportunistically by usual clinical team. Participants: Children were eligible to participate if aged over 12 months and less than 12 years, fulfilling UK Diagnostic Criteria for Atopic Dermatitis. Children with inactive or very mild eczema (5 or less on Nottingham Eczema Severity Scale) were excluded, as were children who bathed less than once a week, or whose carers were not willing to accept randomisation. 483 were randomised and one withdrew, leaving 482 children in the trial: 51% female, 84% white, mean age 5 years. Interventions: The intervention group were prescribed emollient bath additives by their usual clinical team and were asked to use them regularly for 12 months. The control group were asked to use no bath additives for 12 months. Both groups continued with standard eczema management and were given standardised advice on how to wash. Primary outcome: Eczema control measured by Patient Oriented Eczema Measure (POEM, range 0-28) weekly for 16 weeks. Secondary outcomes: Eczema severity over 1 year (4-weekly POEM from baseline to 52 weeks); number of eczema exacerbations resulting in primary healthcare consultation; disease-specific quality of life (QOL) (Dermatitis Family Impact); generic QoL (Child Health Utility-9D); resource utilisation; type and quantity of topical corticosteroid/calcineurin inhibitors prescribed. Randomisation: 483 children were randomised (1:1) using online software, stratified by recruiting centre. Results: 95.6% (461/482) of participants completed at least one post-baseline POEM, so were included in the analysis, and 76.8% (370/482) of participants completed questionnaires for more than 80% of the time points for the primary outcome (12/16 weekly questionnaires to 16 weeks). The mean Baseline POEM was 9.5 (s.d. 5.7) in the bath additives group and 10.1 (s.d. 5.8) in the no bath additives group. The mean POEM over the 16-week period was 7.5 (s.d. 6.0) in the bath additives group and 8.4 (6.0) in the no bath additives group. There was no statistically significant difference in weekly POEM scores between groups over 16 weeks. After controlling for baseline severity and confounders (ethnicity, topical corticosteroid use, soap substitute use) and allowing for clustering of participants within centres and responses within participants over time, POEM scores in the no bath additive group were 0.41 points higher than in the bath additive group (95% CI -0.27 to 1.10), below the published minimal clinically important difference for POEM of 3 points. There was no difference between groups in secondary outcomes, economic outcomes or in adverse effects. Conclusions: This trial found no evidence of clinical benefit from including emollient bath additives in the standard management of childhood eczema. Further research is needed into optimal regimens for leave-on emollient and use of soap substitutes for children with eczema

    A novel somatic mutation achieves partial rescue in a child with Hutchinson-Gilford progeria syndrome.

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    BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS) is a fatal sporadic autosomal dominant premature ageing disease caused by single base mutations that optimise a cryptic splice site within exon 11 of the LMNA gene. The resultant disease-causing protein, progerin, acts as a dominant negative. Disease severity relies partly on progerin levels. METHODS AND RESULTS: We report a novel form of somatic mosaicism, where a child possessed two cell populations with different HGPS disease-producing mutations of the same nucleotide-one producing severe HGPS and one mild HGPS. The proband possessed an intermediate phenotype. The mosaicism was initially discovered when Sanger sequencing showed a c.1968+2T>A mutation in blood DNA and a c.1968+2T>C in DNA from cultured fibroblasts. Deep sequencing of DNA from the proband's blood revealed 4.7% c.1968+2T>C mutation, and 41.3% c.1968+2T>A mutation. CONCLUSIONS: We hypothesise that the germline mutation was c.1968+2T>A, but a rescue event occurred during early development, where the somatic mutation from A to C at 1968+2 provided a selective advantage. This type of mosaicism where a partial phenotypic rescue event results from a second but milder disease-causing mutation in the same nucleotide has not been previously characterised for any disease.Progeria experiments were funded by The Progeria Research Foundation grants PRF-2002-CB and PRF-2002-MRD (JFB, WEN, SEC, LBG), and by the Medical Research Council UK grant MR/L019116/1 (DL). Core and general laboratory grants are as follows: Kilguss Research Core of Women & Infants Hospital of Rhode Island through an Institutional Development Award from the NIGMS of the NIH (P30GM114750), intramural funds to the NHGRI (ZIA-HG200305), Cancer Research UK programme grant C6/A18796 and Wellcome Trust (WT092096)

    Fish and macroinvertebrate assemblages reveal extensive degradation of the world's rivers

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    Rivers suffer from multiple stressors acting simultaneously on their biota, but the consequences are poorly quantified at the global scale. We evaluated the biological condition of rivers globally, including the largest proportion of countries from the Global South published to date. We gathered macroinvertebrate- and fish-based assessments from 72,275 and 37,676 sites, respectively, from 64 study regions across six continents and 45 nations. Because assessments were based on differing methods, different systems were consolidated into a 3-class system: Good, Impaired, or Severely Impaired, following common guidelines. The proportion of sites in each class by study area was calculated and each region was assigned a Köppen-Geiger climate type, Human Footprint score (addressing landscape alterations), Human Development Index (HDI) score (addressing social welfare), % rivers with good ambient water quality, % protected freshwater key biodiversity areas; and % of forest area net change rate. We found that 50% of macroinvertebrate sites and 42% of fish sites were in Good condition, whereas 21% and 29% were Severely Impaired, respectively. The poorest biological conditions occurred in Arid and Equatorial climates and the best conditions occurred in Snow climates. Severely Impaired conditions were associated (Pearson correlation coefficient) with higher HDI scores, poorer physico-chemical water quality, and lower proportions of protected freshwater areas. Good biological conditions were associated with good water quality and increased forested areas. It is essential to implement statutory bioassessment programs in Asian, African, and South American countries, and continue them in Oceania, Europe, and North America. There is a need to invest in assessments based on fish, as there is less information globally and fish were strong indicators of degradation. Our study highlights a need to increase the extent and number of protected river catchments, preserve and restore natural forested areas in the catchments, treat wastewater discharges, and improve river connectivity

    Hundreds of variants clustered in genomic loci and biological pathways affect human height

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    Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
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