287 research outputs found
Identification of Genes Regulating Gene Targeting by a High-Throughput Screening Approach
Homologous gene targeting (HGT) is a precise but inefficient process for genome engineering. Several methods for increasing its efficiency have been developed, including the use of rare cutting endonucleases. However, there is still room for improvement, as even nuclease-induced HGT may vary in efficiency as a function of
the nuclease, target site, and cell type considered. We have developed a high-throughput
screening assay for the identification of factors stimulating meganuclease-induced
HGT. We used this assay to explore a collection of siRNAs targeting 19,121
human genes. At the end of secondary screening, we had identified 64 genes for
which knockdown affected nuclease-induced HGT. Two of the strongest candidates
were characterized further. We showed that siRNAs directed against the ATF7IP
gene, encoding a protein involved in chromatin remodeling, stimulated HGT by a
factor of three to eight, at various loci and in different cell types. This method thus led
to the identification of a number of genes, the manipulation of which might increase
rates of targeted recombination
Tannin-controlled micelles and fibrils of -casein
Effects of green tea tannin epigallocatechin-gallate (EGCG) on
thermal-stress-induced amyloid fibril formation of reduced carboxymethylated
bovine milk protein -casein (RCMK) were studied by dynamical light
scattering (DLS) and small angle x-rays scattering (SAXS). Two populations of
aggregates, micelles and fibrils, dominated the time evolution of light
scattering intensity and of effective hydrodynamic diameter. SAXS experiments
allowed to resolve micelles and fibrils so that the time dependence of
scattering profile revealed structural evolution of the two populations. The
low-Q scattering intensity prior to an expected increase with time due to
fibril growth, shows an intriguing rapid decrease which is interpreted as the
release of monomers from micelles. This phenomenon, observed both in the
absence and in the presence of EGCG, indicates that under thermal stress free
native monomers are converted to amyloid-prone monomers that do not form
micelles. The consumption of free native monomers results in a release of
native monomers from micelles, because only native protein participate in
micelle-monomer (quasi-)equilibrium. This release is reversible, indicating
also that native-to-amyloid-prone monomers conversion is reversible as well. We
show that EGCG does not bind to protein in fibrils, neither does it
affect/prevent the pro-amyloid conversion of monomers. EGCG hinders the
addition of monomers to growing fibrils. These facts allowed us to propose
kinetics model for EGCG-controlled amyloid aggregation of micellar proteins.
Therein, we introduced the growth-rate inhibition function which quantitatively
accounts for the effect of EGCG on the fibril growth at any degree of thermal
stress
Fatal case of hemolytic-uremic syndrome in an adult due to a rare serogroup O91 Entero hemorrhagic Escherichia coli associated with a Clostridium difficile infection. More than meets the eye
AbstractHemolytic-uremic syndrome due to enterohemorrhagic Escherichia coli, belonging to serogroup O91 has rarely been described. We report here a case of post-diarrheal HUS due to EHEC O91 in an elderly patient for whom diagnosis was delayed given a previously diagnosed C. difficile infection. This case highlights the usefulness of Shiga-toxin detection
Descriptive study of sedentary behaviours in 35,444 French working adults: cross-sectional findings from the ACTI-Cités study
International audienceBackground : Given the unfavourable health outcomes associated with sedentary behaviours, there is a need to better understand the context in which these behaviours take place to better address this public health concern. We explored self-reported sedentary behaviours by type of day (work/non-work), occupation, and perceptions towards physical activity, in a large sample of adults.Methods : We assessed sedentary behaviours cross-sectionally in 35,444 working adults (mean ± SD age: 44.5 ± 13.0 y) from the French NutriNet-Santé web-based cohort. Participants self-reported sedentary behaviours, assessed as domain-specific sitting time (work, transport, leisure) and time spent in sedentary entertainment (TV/DVD, computer and other screen-based activities, non-screen-based activities) on workdays and non-workdays, along with occupation type (ranging from mainly sitting to heavy manual work) and perceptions towards physical activity. Associations of each type of sedentary behaviour with occupation type and perceptions towards physical activity were analysed by day type in multiple linear regression analyses.Results : On workdays, adults spent a mean (SD) of 4.17 (3.07) h/day in work sitting, 1.10 (1.69) h/day in transport sitting, 2.19 (1.62) h/day in leisure-time sitting, 1.53 (1.24) h/day viewing TV/DVDs, 2.19 (2.62) h/day on other screen time, and 0.97 (1.49) on non-screen time. On non-workdays, this was 0.85 (1.53) h/day in transport sitting, 3.19 (2.05) h/day in leisure-time sitting, 2.24 (1.76) h/day viewing TV/DVDs, 1.85 (1.74) h/day on other screen time, and 1.30 (1.35) on non-screen time. Time spent in sedentary behaviours differed by occupation type, with more sedentary behaviour outside of work (both sitting and entertainment time), in those with sedentary occupations, especially on workdays. Negative perceptions towards physical activity were associated with more sedentary behaviour outside of work (both sitting and entertainment time), irrespective of day type.Conclusions : A substantial amount of waking hours was spent in different types of sedentary behaviours on workdays and non-workdays. Being sedentary at work was associated with more sedentary behaviour outside of work. Negative perceptions towards physical activity may influence the amount of time spent in sedentary behaviours. These data should help to better identify target groups in public health interventions to reduce sedentary behaviours in working adults
The era of reference genomes in conservation genomics
Progress in genome sequencing
now enables the large-scale
generation of reference genomes.
Various international initiatives
aim to generate reference genomes
representing global biodiversity.
These genomes provide
unique insights into genomic diversity
and architecture, thereby enabling
comprehensive analyses
of population and functional
genomics, and are expected
to revolutionize conservation
genomics
The era of reference genomes in conservation genomics
Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional
genomics, and are expected to revolutionize conservation genomics
How genomics can help biodiversity conservation
The availability of public genomic resources can greatly assist biodiversity assessment, conservation, and restoration efforts by providing evidence for scientifically informed management decisions. Here we survey the main approaches and applications in biodiversity and conservation genomics, considering practical factors, such as cost, time, prerequisite skills, and current shortcomings of applications. Most approaches perform best in combination with reference genomes from the target species or closely related species. We review case studies to illustrate how reference genomes can facilitate biodiversity research and conservation across the tree of life. We conclude that the time is ripe to view reference genomes as fundamental resources and to integrate their use as a best practice in conservation genomics.info:eu-repo/semantics/publishedVersio
DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France
We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon
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