111 research outputs found
Origin of Cosmic Magnetic Fields
We propose that the overlapping shock fronts from young supernova remnants
produce a locally unsteady, but globally steady large scale spiral shock front
in spiral galaxies, where star formation and therefore massive star explosions
correlate geometrically with spiral structure. This global shock front with its
steep gradients in temperature, pressure and associated electric fields will
produce drifts, which in turn give rise to a strong sheet-like electric
current, we propose. This sheet current then produces a large scale magnetic
field, which is regular, and connected to the overall spiral structure. This
rejuvenates the overall magnetic field continuously, and also allows to
understand that there is a regular field at all in disk galaxies. This proposal
connects the existence of magnetic fields to accretion in disks. We not yet
address all the symmetries of the magnetic field here; the picture proposed
here is not complete. X-ray observations may be able to test it already.Comment: 18 pages, no figures; to be published in Proc. Palermo Meeting Sept.
2002, Eds. N. G. Sanchez et al., The Early Universe and the Cosmic Microwave
Background: Theory and Observation
SHOX2 DNA Methylation is a Biomarker for the diagnosis of lung cancer based on bronchial aspirates
<p>Abstract</p> <p>Background</p> <p>This study aimed to show that SHOX2 DNA methylation is a tumor marker in patients with suspected lung cancer by using bronchial fluid aspirated during bronchoscopy. Such a biomarker would be clinically valuable, especially when, following the first bronchoscopy, a final diagnosis cannot be established by histology or cytology. A test with a low false positive rate can reduce the need for further invasive and costly procedures and ensure early treatment.</p> <p>Methods</p> <p>Marker discovery was carried out by differential methylation hybridization (DMH) and real-time PCR. The real-time PCR based HeavyMethyl technology was used for quantitative analysis of DNA methylation of SHOX2 using bronchial aspirates from two clinical centres in a case-control study. Fresh-frozen and Saccomanno-fixed samples were used to show the tumor marker performance in different sample types of clinical relevance.</p> <p>Results</p> <p>Valid measurements were obtained from a total of 523 patient samples (242 controls, 281 cases). DNA methylation of SHOX2 allowed to distinguish between malignant and benign lung disease, i.e. abscesses, infections, obstructive lung diseases, sarcoidosis, scleroderma, stenoses, at high specificity (68% sensitivity [95% CI 62-73%], 95% specificity [95% CI 91-97%]).</p> <p>Conclusions</p> <p>Hypermethylation of SHOX2 in bronchial aspirates appears to be a clinically useful tumor marker for identifying subjects with lung carcinoma, especially if histological and cytological findings after bronchoscopy are ambiguous.</p
Exploring the Zoonotic Potential of Mycobacterium avium Subspecies paratuberculosis through Comparative Genomics
A comparative genomics approach was utilised to compare the genomes of Mycobacterium avium subspecies paratuberculosis (MAP) isolated from early onset paediatric Crohn's disease (CD) patients as well as Johne's diseased animals. Draft genome sequences were produced for MAP isolates derived from four CD patients, one ulcerative colitis (UC) patient, and two non-inflammatory bowel disease (IBD) control individuals using Illumina sequencing, complemented by comparative genome hybridisation (CGH). MAP isolates derived from two bovine and one ovine host were also subjected to whole genome sequencing and CGH. All seven human derived MAP isolates were highly genetically similar and clustered together with one bovine type isolate following phylogenetic analysis. Three other sequenced isolates (including the reference bovine derived isolate K10) were genetically distinct. The human isolates contained two large tandem duplications, the organisations of which were confirmed by PCR. Designated vGI-17 and vGI-18 these duplications spanned 63 and 109 open reading frames, respectively. PCR screening of over 30 additional MAP isolates (3 human derived, 27 animal derived and one environmental isolate) confirmed that vGI-17 and vGI-18 are common across many isolates. Quantitative real-time PCR of vGI-17 demonstrated that the proportion of cells containing the vGI-17 duplication varied between 0.01 to 15% amongst isolates with human isolates containing a higher proportion of vGI-17 compared to most animal isolates. These findings suggest these duplications are transient genomic rearrangements. We hypothesise that the over-representation of vGI-17 in human derived MAP strains may enhance their ability to infect or persist within a human host by increasing genome redundancy and conferring crude regulation of protein expression across biologically important regions
A Genomic Approach to Resolving Relapse versus Reinfection among Four Cases of Buruli Ulcer
YesBackground.
Increased availability of Next Generation Sequencing (NGS) techniques allows, for the first time,
to distinguish relapses from reinfections in patients with multiple Buruli ulcer (BU) episodes.
Methodology.
We compared the number and location of single nucleotide polymorphisms (SNPs) identified by genomic screening between four pairs of Mycobacterium ulcerans isolates collected
at the time of first diagnosis and at recurrence, derived from a collection of almost 5000 well
characterized clinical samples from one BU treatment center in Benin.
Principal Findings.
The findings suggest that after surgical treatment—without antibiotics—the second episodes were due to relapse rather than reinfection. Since specific antibiotics were introduced
for the treatment of BU, the one patient with a culture available from both disease episodes
had M. ulcerans isolates with a genomic distance of 20 SNPs, suggesting the patient was
most likely reinfected rather than having a relapse.
Conclusions.
To our knowledge, this study is the first to study recurrences in M. ulcerans using NGS, and
to identify exogenous reinfection as causing a recurrence of BU. The occurrence of reinfection highlights the contribution of ongoing exposure to M. ulcerans to disease recurrence,
and has implications for vaccine development.This work was supported by the UBS Optimus Foundation (Zurich, Switzerland) and the Department of Economy, Science and Innovation of the Flemish Government (Belgium). KV was supported by a VLADOC PhD scholarship of VLIRUOS (Belgium)
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
Genetic differentiation between cave and surface-dwelling populations of Garra barreimiae (Cyprinidae) in Oman
ҁUrḍī: Muʾayyad (al-Milla wa-) al-Dīn (Muʾayyad ibn Barīk [Burayk]) al-ҁUrḍī (al-ҁĀmirī al-Dimashqī)
Hungerkultur. Zur Erfahrung des Nahrungsmangels in der totalen Institution sowjetischer Kriegsgefangenenlager des Zweiten Weltkriegs
Cloning and characterization of a novel l-arabinose isomerase from Bacillus licheniformis
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