401 research outputs found
Identifying protective <i>Streptococcus pyogenes</i> vaccine antigens recognized by both B and T cells in human adults and children
No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well-conserved among different GAS strains, upregulated in host-pathogen interaction studies, and predicted to be extracellular or associated with the surface of the bacteria. The antigens were tested for both antibody recognition and T cell responses in human adults and children. The antigenicity of a selected group of antigens was further validated using a high-density peptide array technology that also identified the linear epitopes. Based on immunological recognition, four targets were selected and tested for protective capabilities in an experimental GAS infection model in mice. Shown for the first time, three of these targets (spy0469, spy1228 and spy1801) conferred significant protection whereas one (spy1643) did not
An F2 pig resource population as a model for genetic studies of obesity and obesity-related diseases in humans:design and genetic parameters
Obesity is a rising worldwide public health problem. Difficulties to precisely measure various obesity traits and the genetic heterogeneity in human have been major impediments to completely disentangle genetic factors causing obesity. The pig is a relevant model for studying human obesity and obesity-related (OOR) traits. Using founder breeds divergent with respect to obesity traits we have created an F2 pig resource population (454 pigs), which has been intensively phenotyped for 36 OOR traits. The main rationale for our study is to characterize the genetic architecture of OOR traits in the F2 pig design, by estimating heritabilities, genetic, and phenotypic correlations using mixed- and multi-trait BLUP animal models. Our analyses revealed high coefficients of variation (15–42%) and moderate to high heritabilities (0.22–0.81) in fatness traits, showing large phenotypic and genetic variation in the F2 population, respectively. This fulfills the purpose of creating a resource population divergent for OOR traits. Strong genetic correlations were found between weight and lean mass at dual-energy x-ray absorptiometry scanning (0.56–0.97). Weight and conformation also showed strong genetic correlations with slaughter traits (e.g., r(g) between abdominal circumference and leaf fat at slaughtering: 0.66). Genetic correlations between fat-related traits and the glucose level vary between 0.35 and 0.74 and show a strong correlation between adipose tissue and impaired glucose metabolism. Our power calculations showed a minimum of 80% power for QTL detection for all phenotypes. We revealed genetic correlations at population level, for the first time, for several difficult to measure and novel OOR traits and diseases. The results underpin the potential of the established F2 pig resource population for further genomic, systems genetics, and functional investigations to unravel the genetic background of OOR traits
Effect of endurance versus resistance training on quadriceps muscle dysfunction in COPD:a pilot study
INTRODUCTION: Exercise is an important countermeasure to limb muscle dysfunction in COPD. The two major training modalities in COPD rehabilitation, endurance training (ET) and resistance training (RT), may both be efficient in improving muscle strength, exercise capacity, and health-related quality of life, but the effects on quadriceps muscle characteristics have not been thoroughly described. METHODS: Thirty COPD patients (forced expiratory volume in 1 second: 56% of predicted, standard deviation [SD] 14) were randomized to 8 weeks of ET or RT. Vastus lateralis muscle biopsies were obtained before and after the training intervention to assess muscle morphology and metabolic and angiogenic factors. Symptom burden, exercise capacity (6-minute walking and cycle ergometer tests), and vascular function were also assessed. RESULTS: Both training modalities improved symptom burden and exercise capacity with no difference between the two groups. The mean (SD) proportion of glycolytic type IIa muscle fibers was reduced after ET (from 48% [SD 11] to 42% [SD 10], P<0.05), whereas there was no significant change in muscle fiber distribution with RT. There was no effect of either training modality on muscle capillarization, angiogenic factors, or vascular function. After ET the muscle protein content of phosphofructokinase was reduced (P<0.05) and the citrate synthase content tended increase (P=0.08) but no change was observed after RT. CONCLUSION: Although both ET and RT improve symptoms and exercise capacity, ET induces a more oxidative quadriceps muscle phenotype, counteracting muscle dysfunction in COPD
Haplotypes on pig chromosome 3 distinguish metabolically healthy from unhealthy obese individuals
We have established a pig resource population specifically designed to elucidate the genetics involved in development of obesity and obesity related co-morbidities by crossing the obesity prone Göttingen Minipig breed with two lean production pig breeds. In this study we have performed genome wide association (GWA) to identify loci with effect on blood lipid levels. The most significantly associated single nucleotide polymorphisms (SNPs) were used for linkage disequilibrium (LD) and haplotype analyses. Three separate haploblocks which influence the ratio between high density lipoprotein cholesterol and total cholesterol (HDL-C/CT), triglycerides (TG) and low density lipoprotein cholesterol (LDL-C) levels respectively were identified on Sus Scrofa chromosome 3 (SSC3). Large additive genetic effects were found for the HDL-C/CT and LDL-C haplotypes. Haplotypes segregating from Göttingen Minipigs were shown to impose a positive effect on blood lipid levels. Thus, the genetic profile of the Göttingen Minipig breed seems to support a phenotype comparable to the metabolic healthy obese (MHO) phenotype in humans
Quantification of DNA-associated proteins inside eukaryotic cells using single-molecule localization microscopy
Development of single-molecule localization microscopy techniques has allowed nanometre scale localization accuracy inside cells, permitting the resolution of ultra-fine cell structure and the elucidation of crucial molecular mechanisms. Application of these methodologies to understanding processes underlying DNA replication and repair has been limited to defined in vitro biochemical analysis and prokaryotic cells. In order to expand these techniques to eukaryotic systems, we have further developed a photo-activated localization microscopy-based method to directly visualize DNA-associated proteins in unfixed eukaryotic cells. We demonstrate that motion blurring of fluorescence due to protein diffusivity can be used to selectively image the DNA-bound population of proteins. We designed and tested a simple methodology and show that it can be used to detect changes in DNA binding of a replicative helicase subunit, Mcm4, and the replication sliding clamp, PCNA, between different stages of the cell cycle and between distinct genetic backgrounds
a controlled multicenter study with assessment of echocardiographic reference values, and the frequency of dilatation and aneurysm in Marfan syndrome
Background Echocardiographic upper normal limits of both main pulmonary artery
(MPA) diameters (MPA-d) and ratio of MPA to aortic root diameter (MPA-r) are
not defined in healthy adults. Accordingly, frequency of MPA dilatation based
on echocardiography remains to be assessed in adults with Marfan syndrome
(MFS). Methods We enrolled 123 normal adults (72 men, 52 women aged 42 ± 14
years) and 98 patients with MFS (42 men, 56 women aged 39 ± 14 years) in a
retrospective cross-sectional observational controlled study in four tertiary
care centers. We defined outcome measures including upper normal limits of
MPA-d and MPA-r as 95 quantile of normal persons, MPA dilatation as diameters
> upper normal limits, MPA aneurysm as diameters >4 cm, and indication for
surgery as MPA diameters >6 cm. Results MPA diameters revealed normal
distribution without correlation to age, sex, body weight, body height, body
mass index and body surface area. The upper normal limit was 2.6 cm (95%
confidence interval (CI) =2.44-2.76 cm) for MPA-d, and 1.05 (95% CI =
.86–1.24) for MPA-r. MPA dilatation presented in 6 normal persons (4.9%) and
in 68 MFS patients (69.4%; P < .001), MPA aneurysm presented only in MFS (15
patients; 15.3%; P < .001), and no patient required surgery. Mean MPA-r were
increased in MFS (P 1.05 were equally frequent in 7
normal persons (5%) and in 8 MFS patients (10.5%; P = .161). MPA-r related to
aortic root diameters (P = .042), reduced left ventricular ejection fraction
(P = .006), and increased pulmonary artery systolic pressures (P = .040). No
clinical manifestations of MFS and no FBN1 mutation characteristics related to
MPA diameters. Conclusions We established 2.6 cm for MPA-d and 1.05 for MPA-r
as upper normal limits. MFS exhibits a high prevalence of MPA dilatation and
aneurysm. However, patients may require MPA surgery only in scarce
circumstances, most likely because formation of marked MPA aneurysm may
require LV dysfunction and increased PASP
The Computational 2D Materials Database: High-Throughput Modeling and Discovery of Atomically Thin Crystals
We introduce the Computational 2D Materials Database (C2DB), which organises
a variety of structural, thermodynamic, elastic, electronic, magnetic, and
optical properties of around 1500 two-dimensional materials distributed over
more than 30 different crystal structures. Material properties are
systematically calculated by state-of-the art density functional theory and
many-body perturbation theory (GW\!_0 and the Bethe-Salpeter Equation
for 200 materials) following a semi-automated workflow for maximal
consistency and transparency. The C2DB is fully open and can be browsed online
or downloaded in its entirety. In this paper, we describe the workflow behind
the database, present an overview of the properties and materials currently
available, and explore trends and correlations in the data. Moreover, we
identify a large number of new potentially synthesisable 2D materials with
interesting properties targeting applications within spintronics,
(opto-)electronics, and plasmonics. The C2DB offers a comprehensive and easily
accessible overview of the rapidly expanding family of 2D materials and forms
an ideal platform for computational modeling and design of new 2D materials and
van der Waals heterostructures.Comment: Add journal reference and DOI; Minor updates to figures and wordin
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