856 research outputs found
Transcriptomic Profiling in Childhood H1N1/09 Influenza Reveals Reduced Expression of Protein Synthesis Genes
We compared the blood RNA transcriptome of children hospitalized with influenza A H1N1/09, respiratory syncytial virus (RSV) or bacterial infection, and healthy controls. Compared to controls, H1N1/09 patients showed increased expression of inflammatory pathway genes and reduced expression of adaptive immune pathway genes. This was validated on an independent cohort. The most significant function distinguishing H1N1/09 patients from controls was protein synthesis, with reduced gene expression. Reduced expression of protein synthesis genes also characterized the H1N1/09 expression profile compared to children with RSV and bacterial infection, suggesting that this is a key component of the pathophysiological response in children hospitalized with H1N1/09 infection
Chromatic Illumination Discrimination Ability Reveals that Human Colour Constancy Is Optimised for Blue Daylight Illuminations
The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow) and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K), all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed
Beyond the required LISA free-fall performance: new LISA pathfinder results down to 20 μHz
In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20 μHz. The Letter presents the measured differential acceleration noise figure, which is at (1.74±0.05) fm s^{-2}/sqrt[Hz] above 2 mHz and (6±1)×10 fm s^{-2}/sqrt[Hz] at 20 μHz, and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency
Guillain-Barré syndrome: a century of progress
In 1916, Guillain, Barré and Strohl reported on two cases of acute flaccid paralysis with high cerebrospinal fluid protein levels and normal cell counts — novel findings that identified the disease we now know as Guillain–Barré syndrome (GBS). 100 years on, we have made great progress with the clinical and pathological characterization of GBS. Early clinicopathological and animal studies indicated that GBS was an immune-mediated demyelinating disorder, and that severe GBS could result in secondary axonal injury; the current treatments of plasma exchange and intravenous immunoglobulin, which were developed in the 1980s, are based on this premise. Subsequent work has, however, shown that primary axonal injury can be the underlying disease. The association of Campylobacter jejuni strains has led to confirmation that anti-ganglioside antibodies are pathogenic and that axonal GBS involves an antibody and complement-mediated disruption of nodes of Ranvier, neuromuscular junctions and other neuronal and glial membranes. Now, ongoing clinical trials of the complement inhibitor eculizumab are the first targeted immunotherapy in GBS
Emergence of nasal chondrosarcoma in a dog with nasal polyposis.
Whilst the malignant transformation of nasal polyps or secondary development of nasal neoplasia after chronic inflammation is likely to be relatively rare, this potential complication should be considered, and the clinician should be vigilant for evidence of malignant transformation.fals
Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics
The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, measuring 1,600 compounds. Cabbage was sampled in 2 years from one conventional and two organic farming systems in a rigidly controlled long-term field trial in Denmark. Using Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA), we found that the production system leaves a significant (p = 0.013) imprint in the white cabbage metabolome that is retained between production years. We externally validated this finding by predicting the production system of samples from one year using a classification model built on samples from the other year, with a correct classification in 83% of cases. Thus, it was concluded that the investigated conventional and organic management practices have a systematic impact on the metabolome of white cabbage. This emphasizes the potential of untargeted metabolomics for authenticity testing of organic plant products
Search for Gravitational Waves from Primordial Black Hole Binary Coalescences in the Galactic Halo
We use data from the second science run of the LIGO gravitational-wave
detectors to search for the gravitational waves from primordial black hole
(PBH) binary coalescence with component masses in the range 0.2--.
The analysis requires a signal to be found in the data from both LIGO
observatories, according to a set of coincidence criteria. No inspiral signals
were found. Assuming a spherical halo with core radius 5 kpc extending to 50
kpc containing non-spinning black holes with masses in the range 0.2--, we place an observational upper limit on the rate of PBH coalescence
of 63 per year per Milky Way halo (MWH) with 90% confidence.Comment: 7 pages, 4 figures, to be submitted to Phys. Rev.
A Genome-Wide Analysis of Promoter-Mediated Phenotypic Noise in Escherichia coli
Gene expression is subject to random perturbations that lead to fluctuations in the rate of protein production. As a consequence, for any given protein, genetically identical organisms living in a constant environment will contain different amounts of that particular protein, resulting in different phenotypes. This phenomenon is known as “phenotypic noise.” In bacterial systems, previous studies have shown that, for specific genes, both transcriptional and translational processes affect phenotypic noise. Here, we focus on how the promoter regions of genes affect noise and ask whether levels of promoter-mediated noise are correlated with genes' functional attributes, using data for over 60% of all promoters in Escherichia coli. We find that essential genes and genes with a high degree of evolutionary conservation have promoters that confer low levels of noise. We also find that the level of noise cannot be attributed to the evolutionary time that different genes have spent in the genome of E. coli. In contrast to previous results in eukaryotes, we find no association between promoter-mediated noise and gene expression plasticity. These results are consistent with the hypothesis that, in bacteria, natural selection can act to reduce gene expression noise and that some of this noise is controlled through the sequence of the promoter region alon
Pigmentation plasticity enhances crypsis in larval newts: Associated metabolic cost and background choice behaviour
In heterogeneous environments, the capacity for colour change can be a valuable adaptation enhancing crypsis against predators. Alternatively, organisms might achieve concealment by evolving preferences for backgrounds that match their visual traits, thus avoiding the costs of plasticity. Here we examined the degree of plasticity in pigmentation of newt larvae (Lissotriton boscai) in relation to predation risk. Furthermore, we tested for associated metabolic costs and pigmentation-dependent background choice behaviour. Newt larvae expressed substantial changes in pigmentation so that light, high-reflecting environment induced depigmentation whereas dark, low-reflecting environment induced pigmentation in just three days of exposure. Induced pigmentation was completely reversible upon switching microhabitats. Predator cues, however, did not enhance cryptic phenotypes, suggesting that environmental albedo induces changes in pigmentation improving concealment regardless of the perceived predation risk. Metabolic rate was higher in heavily pigmented individuals from dark environments, indicating a high energetic requirement of pigmentation that could impose a constraint to larval camouflage in dim habitats. Finally, we found partial evidence for larvae selecting backgrounds matching their induced phenotypes. However, in the presence of predator cues, larvae increased the time spent in light environments, which may reflect a escape response towards shallow waters rather than an attempt at increasing crypsisFinancial support was provided by the Spanish Ministry of Science and Innovation (MICINN), Grant CGL2012-40044 to IGM, and by the Universidad Autónoma de Madrid, Short Stay Grant to NPC. Additional financial support was provided by the MICINN, Grant CGL2015-68670-R to NP
A randomised, double-blind, placebo-controlled trial of repeated nebulisation of non-viral cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy in patients with cystic fibrosis
BACKGROUND: Cystic fibrosis (CF) is a chronic, life-limiting disease caused by mutations in the CF
transmembrane conductance regulator (CFTR) gene leading to abnormal airway surface ion transport,
chronic lung infections, inflammation and eventual respiratory failure. With the exception of the
small-molecule potentiator, ivacaftor (Kalydeco®, Vertex Pharmaceuticals, Boston, MA, USA), which is
suitable for a small proportion of patients, there are no licensed therapies targeting the basic defect.
The UK Cystic Fibrosis Gene Therapy Consortium has taken a cationic lipid-mediated CFTR gene therapy
formulation through preclinical and clinical development.
OBJECTIVE: To determine clinical efficacy of the formulation delivered to the airways over a period of
1 year in patients with CF.
DESIGN: This was a randomised, double-blind, placebo-controlled Phase IIb trial of the CFTR gene–liposome
complex pGM169/GL67A. Randomisation was performed via InForm™ version 4.6 (Phase Forward
Incorporated, Oracle, CA, USA) and was 1 : 1, except for patients in the mechanistic subgroups (2 : 1).
Allocation was blinded by masking nebuliser chambers.
SETTINGS: Data were collected in the clinical and scientific sites and entered onto a trial-specific InForm,
version 4.6 database.
PARTICIPANTS: Patients with CF aged ≥ 12 years with forced expiratory volume in the first second (FEV1)
between 50% and 90% predicted and any combination of CFTR mutations. The per-protocol group
(≥ 9 doses) consisted of 54 patients receiving placebo (62 randomised) and 62 patients receiving gene
therapy (78 randomised).
INTERVENTIONS: Subjects received 5 ml of nebulised pGM169/G67A (active) or 0.9% saline (placebo) at
28 (±5)-day intervals over 1 year.
MAIN OUTCOME MEASURES: The primary end point was the relative change in percentage predicted FEV1
over the 12-month period. A number of secondary clinical outcomes were assessed alongside safety
measures: other spirometric values; lung clearance index (LCI) assessed by multibreath washout; structural
disease on computed tomography (CT) scan; the Cystic Fibrosis Questionnaire – Revised (CFQ-R), a
validated quality-of-life questionnaire; exercise capacity and monitoring; systemic and sputum inflammatory
markers; and adverse events (AEs). A mechanistic study was performed in a subgroup in whom transgene
deoxyribonucleic acid (DNA) and messenger ribonucleic acid (mRNA) was measured alongside nasal and
lower airway potential difference.
RESULTS: There was a significant (p = 0.046) treatment effect (TE) of 3.7% [95% confidence interval (CI)
0.1% to 7.3%] in the primary end point at 12 months and in secondary end points, including forced vital
capacity (FVC) (p = 0.031) and CT gas trapping (p = 0.048). Other outcomes, although not reaching
statistical significance, favoured active treatment. Effects were noted by 1 month and were irrespective
of sex, age or CFTR mutation class. Subjects with a more severe baseline FEV1 had a FEV1 TE of 6.4%
(95% CI 0.8% to 12.1%) and greater changes in many other secondary outcomes. However, the more
mildly affected group also demonstrated benefits, particularly in small airway disease markers such as LCI.
The active group showed a significantly (p = 0.032) greater bronchial chloride secretory response. No
difference in treatment-attributable AEs was seen between the placebo and active groups.
CONCLUSIONS: Monthly application of the pGM169/GL67A gene therapy formulation was associated with
an improvement in lung function, other clinically relevant parameters and bronchial CFTR function,
compared with placebo.
LIMITATIONS: Although encouraging, the improvement in FEV1 was modest and was not accompanied by
detectable improvement in patients’ quality of life.
FUTURE WORK: Future work will focus on attempts to increase efficacy by increasing dose or frequency,
the coadministration of a CFTR potentiator, or the use of modified viral vectors capable of
repeated administration.
TRIAL REGISTRATION: ClinicalTrials.gov NCT01621867
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