394 research outputs found
Literature-based discovery of diabetes- and ROS-related targets
Abstract Background Reactive oxygen species (ROS) are known mediators of cellular damage in multiple diseases including diabetic complications. Despite its importance, no comprehensive database is currently available for the genes associated with ROS. Methods We present ROS- and diabetes-related targets (genes/proteins) collected from the biomedical literature through a text mining technology. A web-based literature mining tool, SciMiner, was applied to 1,154 biomedical papers indexed with diabetes and ROS by PubMed to identify relevant targets. Over-represented targets in the ROS-diabetes literature were obtained through comparisons against randomly selected literature. The expression levels of nine genes, selected from the top ranked ROS-diabetes set, were measured in the dorsal root ganglia (DRG) of diabetic and non-diabetic DBA/2J mice in order to evaluate the biological relevance of literature-derived targets in the pathogenesis of diabetic neuropathy. Results SciMiner identified 1,026 ROS- and diabetes-related targets from the 1,154 biomedical papers (http://jdrf.neurology.med.umich.edu/ROSDiabetes/). Fifty-three targets were significantly over-represented in the ROS-diabetes literature compared to randomly selected literature. These over-represented targets included well-known members of the oxidative stress response including catalase, the NADPH oxidase family, and the superoxide dismutase family of proteins. Eight of the nine selected genes exhibited significant differential expression between diabetic and non-diabetic mice. For six genes, the direction of expression change in diabetes paralleled enhanced oxidative stress in the DRG. Conclusions Literature mining compiled ROS-diabetes related targets from the biomedical literature and led us to evaluate the biological relevance of selected targets in the pathogenesis of diabetic neuropathy.http://deepblue.lib.umich.edu/bitstream/2027.42/78315/1/1755-8794-3-49.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/2/1755-8794-3-49-S7.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/3/1755-8794-3-49-S10.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/4/1755-8794-3-49-S8.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/5/1755-8794-3-49-S3.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/6/1755-8794-3-49-S1.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/7/1755-8794-3-49-S4.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/8/1755-8794-3-49-S2.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/9/1755-8794-3-49-S12.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/10/1755-8794-3-49-S11.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/11/1755-8794-3-49-S9.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/12/1755-8794-3-49-S5.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/13/1755-8794-3-49-S6.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/14/1755-8794-3-49.pdfPeer Reviewe
Debris Disks: Probing Planet Formation
Debris disks are the dust disks found around ~20% of nearby main sequence
stars in far-IR surveys. They can be considered as descendants of
protoplanetary disks or components of planetary systems, providing valuable
information on circumstellar disk evolution and the outcome of planet
formation. The debris disk population can be explained by the steady
collisional erosion of planetesimal belts; population models constrain where
(10-100au) and in what quantity (>1Mearth) planetesimals (>10km in size)
typically form in protoplanetary disks. Gas is now seen long into the debris
disk phase. Some of this is secondary implying planetesimals have a Solar
System comet-like composition, but some systems may retain primordial gas.
Ongoing planet formation processes are invoked for some debris disks, such as
the continued growth of dwarf planets in an unstirred disk, or the growth of
terrestrial planets through giant impacts. Planets imprint structure on debris
disks in many ways; images of gaps, clumps, warps, eccentricities and other
disk asymmetries, are readily explained by planets at >>5au. Hot dust in the
region planets are commonly found (<5au) is seen for a growing number of stars.
This dust usually originates in an outer belt (e.g., from exocomets), although
an asteroid belt or recent collision is sometimes inferred.Comment: Invited review, accepted for publication in the 'Handbook of
Exoplanets', eds. H.J. Deeg and J.A. Belmonte, Springer (2018
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Stabilization of long-looped i-motif DNA by polypyridyl ruthenium complexes
A spectroscopic study of the interactions of Î- and Î-[Ru(phen)2(dppz)]2+ with i-motif DNA containing thymine loops of various lengths. In the presence of i-motifs, the luminescence of the Î enantiomer was enhanced much more than the Î. Despite this, the effect of each enantiomer on i-motif thermal stability was comparable. The sequences most affected by [Ru(phen)2(dppz)]2+ were those with long thymine loops; this suggests that long-looped i-motifs are attractive targets for potential transition metal complex drugs and should be explored further in drug design
Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers
We present a review of the interplay between the evolution of circumstellar
disks and the formation of planets, both from the perspective of theoretical
models and dedicated observations. Based on this, we identify and discuss
fundamental questions concerning the formation and evolution of circumstellar
disks and planets which can be addressed in the near future with optical and
infrared long-baseline interferometers. Furthermore, the importance of
complementary observations with long-baseline (sub)millimeter interferometers
and high-sensitivity infrared observatories is outlined.Comment: 83 pages; Accepted for publication in "Astronomy and Astrophysics
Review"; The final publication is available at http://www.springerlink.co
The Vega debris disc: A view from Herschel
We present five band imaging of the Vega debris disc obtained using the Herschel Space Observatory. These data span a wavelength range of 70â500âÎźm with full-width half-maximum angular resolutions of 5.6â36.9â. The disc is well resolved in all bands, with the ring structure visible at 70 and 160âÎźm. Radial profiles of the disc surface brightness are produced, and a disc radius of 11â (~85âAU) is determined. The disc is seen to have a smooth structure thoughout the entire wavelength range, suggesting that the disc is in a steady state, rather than being an ephemeral structure caused by the recent collision of two large planetesimals
Bisphenol A-Mediated Suppression of LPL Gene Expression Inhibits Triglyceride Accumulation during Adipogenic Differentiation of Human Adult Stem Cells
The endocrine disrupting chemical, bisphenol A (BPA), has been shown to accelerate the rate of adipogenesis and increase the amount of triglyceride accumulation during differentiation of 3T3-L1 preadipocytes. The objective of this study was to investigate if that observation is mirrored in human primary cells. Here we investigated the effect of BPA on adipogenesis in cultured human primary adult stem cells. Continuous exposure to BPA throughout the 14 days of differentiation dramatically reduced triglyceride accumulation and suppressed gene transcription of the lipogenic enzyme, lipoprotein lipase (LPL). Results presented in the present study show for the first time that BPA can reduce triglyceride accumulation during adipogenesis by attenuating the expression of LPL gene transcription. Also, by employing image cytometric analysis rather than conventional Oil red O staining techniques we show that BPA regulates triglyceride accumulation in a manner which does not appear to effect adipogenesis per se
Pain control after total knee arthroplasty: a randomized trial comparing local infiltration anesthesia and continuous femoral block
Local infiltration analgesia (LIA) is a new multimodal wound infiltration method. It
has attracted growing interest in recent years and is widely used all over the world for
treating postoperative pain after knee and hip arthroplasty. This method is based on
systematic infiltration of a mixture of ropivacaine, a long acting local anesthetic,
ketorolac, a cyclooxygenase inhibitor (NSAID), and adrenalin around all structures
subject to surgical trauma inknee and hip arthroplasty.
Two patient cohorts of 40 patients scheduled for elective total knee arthroplasty
(TKA) and 15 patients scheduled for total hip arthroplasty (THA) contributed to the
work presented in this thesis. In a randomized trial the efficacy of LIA in TKA with
regard to pain at rest and upon movement was compared to femoral block. Both
methods result in a high quality pain relief and similar morphine consumption, but
fewer patients in the LIA group reported pain of 7/10 on any occasion during the 24 h
monitoring period (paper I).
In the same patient cohort the maximal total plasma concentration of ropivacaine was
below the established toxic threshold for most patients although a few reached
potentially toxic concentrations of 1.4-1.7 mg/L. The time to maximal detected
plasma concentration was around 4-6 h after release of tourniquet in TKA (paper II).
All patients in the THA cohort were subjected to the routine LIA protocol. In these
patients both the total and unbound plasma concentration of ropivacaine was
determined. The concentration was below the established toxic threshold. As
ropivacaine binds to a-1 acid glycoprotein(AAG) we assessed the possibility that
increased AAG may decrease the unbound concentration of ropivacaine. A40 %
increase in AAG was detected during the first 24 h after surgery, however the
fraction of unbound ropivacaine remained the same. There was a trend towards
increased C max of ropivacaine with increasing age and decreasing creatinine
clearance but the statistical power was too low to draw any conclusion (paper III).
Administration of 30mg ketorolac according to the LIA protocol both in TKA and
THA resulted in a similar Cmax as previously reported after 10 mg intramuscular
ketorolac (paper II, paper IV). Neither age, nor body weight or BMI, nor creatinine
clearance, correlates to maximal ketorolac plasma concentration or total exposure to
ketorolac (AUC) (paper IV).
In conclusion, LIA provides good postoperative analgesia which is similar to femoral
block after total knee arthroplasty. The plasma concentration of ropivacaine seems to
be below toxic levels in most TKA patients. The unbound plasma concentration of
ropivcaine in THA seems to be below the toxic level.
The use of ketorolac in LIA may not be safer than other routes of administration, and
similar restrictions should be applied in patients at risk of developing side effects
Inducible viral receptor, A possible concept to induce viral protection in primitive immune animals
A pseudolysogen (PL) is derived from the lysogenic Vibrio harveyi (VH) which is infected with the VHS1 (Vibrio harveyi Siphoviridae-like 1) bacteriophage. The lysogenic Vibrio harveyi undergoes an unequivalent division of the extra-chromosomal VHS1 phage genome and its VH host chromosome and produces a true lysogen (TL) and pseudolysogen (PL). The PL is tolerant to super-infection of VHS1, as is of the true lysogen (TL), but the PL does not contain the VHS1 phage genome while the TL does. However, the PL can become susceptible to VHS1 phage infection if the physiological state of the PL is changed. It is postulated that this is due to a phage receptor molecule which can be inducible to an on-and-off regulation influence by an alternating condition of the bacterial host cell. This characteristic of the PL leads to speculate that this phenomenon can also occur in high organisms with low immunity such as shrimp. This article proposes a hypothesis that the viral receptor molecule on the target cell can play a crucial role in which the invertebrate aquaculture animals can become tolerant to viral infection. A possible mechanism may be that the target cell disrupts the viral receptor molecule to prevent super infection. This concept can explain a mechanism for the prevention of viral infection in invertebrate animals which do not have acquired immunity in response to pathogens. It can guide us to develop a mechanism of immunity to viral infection in low-evolved-immune animals. Also, it can be an additional mechanism that exists in high immune organism, as in human for the prevention of viral infectio
Observation of shell effects in superconducting nanoparticles of Sn
In a zero-dimensional superconductor, quantum size effects(QSE) not only set
the limit to superconductivity, but are also at the heart of new phenomena such
as shell effects, which have been predicted to result in large enhancements of
the superconducting energy gap. Here, we experimentally demonstrate these QSE
through measurements on single, isolated Pb and Sn nanoparticles. In both
systems superconductivity is ultimately quenched at sizes governed by the
dominance of the quantum fluctuations of the order parameter. However, before
the destruction of superconductivity, in Sn nanoparticles we observe giant
oscillations in the superconducting energy gap with particle size leading to
enhancements as large as 60%. These oscillations are the first experimental
proof of coherent shell effects in nanoscale superconductors. Contrarily, we
observe no such oscillations in the gap for Pb nanoparticles, which is ascribed
to the suppression of shell effects for shorter coherence lengths. Our study
paves the way to exploit QSE in boosting superconductivity in low-dimensional
systems
Herschel images of Fomalhaut An extrasolar Kuiper belt at the height of its dynamical activity
Context. Fomalhaut is a young (2 Âą 1 Ă 108 years), nearby (7.7 pc), 2 Mâ star that is suspected to harbor an infant planetary system, interspersed with one or more belts of dusty debris.
Aims. We present far-infrared images obtained with the Herschel Space Observatory with an angular resolution between 5.7â˛â˛ and 36.7â˛â˛ at wavelengths between 70 Îźm and 500 Îźm. The images show the main debris belt in great detail. Even at high spatial resolution, the belt appears smooth. The region in between the belt and the central star is not devoid of material; thermal emission is observed here as well. Also at the location of the star, excess emission is detected. We aim to construct a consistent image of the Fomalhaut system.
Methods. We use a dynamical model together with radiative-transfer tools to derive the parameters of the debris disk. We include detailed models of the interaction of the dust grains with radiation, for both the radiation pressure and the temperature determination. Comparing these models to the spatially resolved temperature information contained in the images allows us to place strong constraints on the presence of grains that will be blown out of the system by radiation pressure. We use this to derive the dynamical parameters of the system.
Results. The appearance of the belt points toward a remarkably active system in which dust grains are produced at a very high rate by a collisional cascade in a narrow region filled with dynamically excited planetesimals. Dust particles with sizes below the blow-out size are abundantly present. The equivalent of 2000 one-km-sized comets are destroyed every day, out of a cometary reservoir amounting to 110 Earth masses. From comparison of their scattering and thermal properties, we find evidence that the dust grains are fluffy aggregates, which indicates a cometary origin. The excess emission at the location of the star may be produced by hot dust with a range of temperatures, but may also be due to gaseous free-free emission from a stellar wind
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