281 research outputs found
Transcriptional Basis of Psoriasis from Large Scale Gene Expression Studies: The Importance of Moving towards a Precision Medicine Approach
Transcriptome profiling techniques, such as microarrays and RNA sequencing (RNA-seq), are valuable tools for deciphering the regulatory network underlying psoriasis and have revealed large number of differentially expressed genes in lesional and non-lesional skin. Such approaches provide a more precise measurement of transcript levels and their isoforms than any other methods. Large cohort transcriptomic analyses have greatly improved our understanding of the physiological and molecular mechanisms underlying disease pathogenesis and progression. Here, we mostly review the findings of some important large scale psoriatic transcriptomic studies, and the benefits of such studies in elucidating potential therapeutic targets and biomarkers for psoriasis treatment. We also emphasised the importance of looking into the alternatively spliced RNA isoforms/transcripts in psoriasis, rather than focussing only on the gene-level annotation. The neutrophil and blood transcriptome signature in psoriasis is also briefly reviewed, as it provides the immune status information of patients and is a less invasive platform. The application of precision medicine in current management of psoriasis, by combining transcriptomic data, improves the clinical response outcome in individual patients. Drugs tailored to individual patient's genetic profile will greatly improve patient outcome and cost savings for the healthcare system
Thermal Particle Creation in Cosmological Spacetimes: A Stochastic Approach
The stochastic method based on the influence functional formalism introduced
in an earlier paper to treat particle creation in near-uniformly accelerated
detectors and collapsing masses is applied here to treat thermal and
near-thermal radiance in certain types of cosmological expansions. It is
indicated how the appearance of thermal radiance in different cosmological
spacetimes and in the two apparently distinct classes of black hole and
cosmological spacetimes can be understood under a unifying conceptual and
methodological framework.Comment: 17 pages, revtex (aps, eqsecnum), submitted to PRD, April 199
Inflationary Reheating in Grand Unified Theories
Grand unified theories may display multiply interacting fields with strong
coupling dynamics. This poses two new problems: (1) What is the nature of
chaotic reheating after inflation, and (2) How is reheating sensitive to the
mass spectrum of these theories ? We answer these questions in two interesting
limiting cases and demonstrate an increased efficiency of reheating which
strongly enhances non-thermal topological defect formation, including monopoles
and domain walls. Nevertheless, the large fluctuations may resolve this
monopole problem via a modified Dvali-Liu-Vachaspati mechanism in which
non-thermal destabilsation of discrete symmetries occurs at reheating.Comment: 4 pages, 5 ps figures - 1 colour, Revtex. Further (colour & 3-D)
figures available from http://www.sissa.it/~bassett/reheating/ . Matched to
version to appear in Phys. Rev. let
Male mice with deleted Wolframin (Wfs1) gene have reduced fertility
Background: Wolfram Syndrome (WS) is an autosomal recessive disorder characterised by non-autoimmune diabetes mellitus, optic atrophy, cranial diabetes insipidus and sensorineural deafness. Some reports have described hypogonadism in male WS patients. The aim of our study was to find out whether Wfs1 deficient (Wfs1KO) male mice have reduced fertility and, if so, to examine possible causes.
Methods: Wfs1KO mice were generated by homologous recombination. Both Wfs1KO and wild type (wt) male mice were mated with wt female mice. The number of litters and the number of pups were counted and pregnancy rates calculated. The motility and morphology of the sperm and the histology of testes were analysed. Serum testosterone and FSH concentrations were also measured.
Results: The pregnancy rate in wt females mated with Wfs1KO males was significantly lower than in the control group (15% vs. 32%; p < 0.05), but there was no significant difference in litter size. Analysis of male fertility showed that, in the Wfs1KO group, eight males out of 13 had pups whereas in the control group all 13 males had at least one litter. Sperm motility was not affected in Wfs1KO mice, but Wfs1KO males had less proximal bent tails (14.4 +/- 1.2% vs. 21.5 +/- 1.3 p < 0.05) and less abnormal sperm heads (22.8 +/- 1.8 vs. 31.5 +/- 3.5, p < 0.05) than wt males. Testes histology revealed significantly reduced number of spermatogonia (23.9 +/- 4.9 vs. 38.1 +/- 2.8; p < 0.05) and Sertoli cells (6.4 +/- 0.5 vs. 9.2 +/- 1.0; p < 0.05) in Wfs1KO mice. Serum testosterone and FSH concentrations did not differ between the two groups.
Conclusion: The impaired fertility of Wfs1KO male mice is most likely due to changes in sperm morphology and reduced number of spermatogenic cells. The exact mechanism through which the Wfs1 gene influences sperm morphology needs to be clarified in further studies
Sphagnum bleaching:Bicarbonate ‘toxicity’ and tolerance for seven Sphagnum species
Growth and functioning of Sphagnum mosses are closely linked to water level and chemistry. Sphagnum mosses occur in wet, generally acidic conditions, and when buffered, alkaline water is known to negatively impact Sphagnum. The effects of time, dose and species-specific responses of buffered, alkaline water on Sphagnum are largely unknown. We investigated the effects of bicarbonate and calcium on the survival, growth and physiological functioning of seven Sphagnum species occurring in contrasting environments, from raised bogs to (rich) fens. Mosses were submerged in different concentrations of bicarbonate and calcium solutions for 10 weeks under climate-controlled circumstances. After 2 weeks, all species exposed to the high bicarbonate treatment (2.0 mM) showed severe potassium leakage and swift discoloration. In contrast, species showed differential responses to the intermediate bicarbonate treatment (0.8 mM), some with a later onset of potassium leakage. S. squarrosum, S. teres & S. contortum generally persisted the longest, with all species dying after 6 to 10 weeks. Calcium alone, in contrast, negatively affected S. squarrosum, S. teres & S. contortum, causing discoloration and potassium leakage. Our study shows enrichment with bicarbonate, but not calcium, is detrimental for most Sphagnum species tested. A mechanistic model was developed that is consistent with dose and duration dependence and the species specificity. Future conservation and restoration measures for Sphagnum-dominated habitats and Sphagnum farming (cultivation, production and harvest of Sphagnum moss biomass) should limit flooding with bicarbonate-rich waters while investigating new management options, like acidifying surface waters to lower bicarbonate levels
Unsupervised machine learning identifies distinct ALS molecular subtypes in post-mortem motor cortex and blood expression data
Amyotrophic lateral sclerosis (ALS) displays considerable clinical and genetic heterogeneity. Machine learning approaches have previously been utilised for patient stratification in ALS as they can disentangle complex disease landscapes. However, lack of independent validation in different populations and tissue samples have greatly limited their use in clinical and research settings. We overcame these issues by performing hierarchical clustering on the 5000 most variably expressed autosomal genes from motor cortex expression data of people with sporadic ALS from the KCL BrainBank (N = 112). Three molecular phenotypes linked to ALS pathogenesis were identified: synaptic and neuropeptide signalling, oxidative stress and apoptosis, and neuroinflammation. Cluster validation was achieved by applying linear discriminant analysis models to cases from TargetALS US motor cortex (N = 93), as well as Italian (N = 15) and Dutch (N = 397) blood expression datasets, for which there was a high assignment probability (80–90%) for each molecular subtype. The ALS and motor cortex specificity of the expression signatures were tested by mapping KCL BrainBank controls (N = 59), and occipital cortex (N = 45) and cerebellum (N = 123) samples from TargetALS to each cluster, before constructing case-control and motor cortex-region logistic regression classifiers. We found that the signatures were not only able to distinguish people with ALS from controls (AUC 0.88 ± 0.10), but also reflect the motor cortex-based disease process, as there was perfect discrimination between motor cortex and the other brain regions. Cell types known to be involved in the biological processes of each molecular phenotype were found in higher proportions, reinforcing their biological interpretation. Phenotype analysis revealed distinct cluster-related outcomes in both motor cortex datasets, relating to disease onset and progression-related measures. Our results support the hypothesis that different mechanisms underpin ALS pathogenesis in subgroups of patients and demonstrate potential for the development of personalised treatment approaches. Our method is available for the scientific and clinical community at https://alsgeclustering.er.kcl.ac.uk
Global supply-chain effects of COVID-19 control measures
Countries have sought to stop the spread of coronavirus disease 2019 (COVID-19) by severely restricting travel and in-person commercial activities. Here, we analyse the supply-chain effects of a set of idealized lockdown scenarios, using the latest global trade modelling framework. We find that supply-chain losses that are related to initial COVID-19 lockdowns are largely dependent on the number of countries imposing restrictions and that losses are more sensitive to the duration of a lockdown than its strictness. However, a longer containment that can eradicate the disease imposes a smaller loss than shorter ones. Earlier, stricter and shorter lockdowns can minimize overall losses. A ‘go-slow’ approach to lifting restrictions may reduce overall damages if it avoids the need for further lockdowns. Regardless of the strategy, the complexity of global supply chains will magnify losses beyond the direct effects of COVID-19. Thus, pandemic control is a public good that requires collective efforts and support to lower-capacity countries
BEC Collapse and Dynamical Squeezing of Vacuum Fluctuations
We analyze the phenomena of Bose Novae, as described by Donley et al [Nature
412, 295 (2001)], by focusing on the behavior of excitations or fluctuations
above the condensate, as driven by the dynamics of the condensate (rather than
the dynamics of the condensate alone or the kinetics of the atoms). The
dynamics of the condensate squeezes and amplifies the quantum excitations,
mixing the positive and negative frequency components of their wave functions
thereby creating particles which appear as bursts and jets. By analyzing the
changing amplitude and particle content of these excitations, our simple
physical picture (based on a test field approximation) explains well the
overall features of the Bose Novae phenomena and provide excellent quantitative
fits with experimental data on several aspects, such as the scaling behavior of
the collapse time and the amount of particles in the jet. The predictions of
the bursts at this level of approximation is less than satisfactory but may be
improved on by including the backreaction of the excitations on the condensate.
The mechanism behind the dominant effect -- parametric amplification of vacuum
fluctuations and freezing of modes outside of horizon -- is similar to that of
cosmological particle creation and structure formation in a rapid quench (which
is fundamentally different from Hawking radiation in black holes). This shows
that BEC dynamics is a promising venue for doing `laboratory cosmology'.Comment: Latex 36 pages, 6 figure
Polymorphisms in the interleukin-10 gene cluster are possibly involved in the increased risk for major depressive disorder
<p>Abstract</p> <p>Background</p> <p>Innate immune inflammatory response is suggested to have a role in the pathogenesis of major depressive disorder (MDD). Interleukin (IL)-10 family cytokines IL-10, IL-19, IL-20, and IL-24 are all implicated in the inflammatory processes and polymorphisms in respective genes have been associated with various immunopathological conditions. This study was carried out to investigate whether single-nucleotide polymorphisms (SNPs) in these genes are also associated with MDD.</p> <p>Methods</p> <p>Case-control association study was performed with seven SNPs from the <it>IL10 </it>gene cluster. 153 patients with MDD and 277 healthy control individuals were recruited.</p> <p>Results</p> <p>None of the selected SNPs were individually associated with MDD. The linkage disequilibrium (LD) analysis indicated the existence of two recombination sites in the <it>IL10 </it>gene cluster, thus confirming the formerly established LD pattern of this genomic region. This also created two haplotype blocks, both consisting of three SNPs. Additionally, the haplotype analysis detected a significantly higher frequency of block 2 (<it>IL20 </it>and <it>IL24 </it>genes) haplotype TGC in the patients group compared to healthy control individuals (P = 0.0097).</p> <p>Conclusion</p> <p>Our study established increased risk for MDD related to the <it>IL20 </it>and <it>IL24 </it>haplotype and suggests that cytokines may contribute to the pathogenesis of MDD. Since none of the block 2 SNPs were individually associated with MDD, it is possible that other polymorphisms linked to them contribute to the disease susceptibility. Future studies are needed to confirm the results and to find the possible functional explanation.</p
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