176 research outputs found
Explantation of infected thoracic endovascular aortic repair
Prosthetic graft infection is a rare and serious complication of thoracic endovascular aortic repair associated with high mortality and posing unique challenges for treatment. The prosthetic graft infection is often identified late as patients present with mild nonspecific symptoms. We describe the successful medical management and surgical explantation of an infected thoracic endograft with an aorta-bronchial fistula, using an inline reconstruction with an antibiotic-soaked synthetic graft. In this report, we provide an example of a patient with an infected thoracic endograft and how inline reconstruction combined with appropriate medical management is an acceptable treatment strategy
Innominate Artery Pseudoaneurysm From a Salter-Harris Fracture of the Sternoclavicular Joint
Fractures and dislocations of the sternoclavicular joint (SCJ) are uncommon, accounting for \u3c5% of all shoulder girdle injuries. They are relatively more common in the pediatric population than in the adult population and can often present concurrently as a posteriorly displaced medial clavicular dislocation with a fracture through the unfused physis. It is especially important to recognize this injury, because its management and potential sequelae are very different from those for fractures of the clavicle shaft. This type of injury frequently requires closed or open operative management because fracture-dislocation of the SCJ can be associated with potentially serious complications such as pneumothorax, brachial plexus injury, vagus nerve injury, tracheal injury, and vascular compromise. Few case reports describe fracture-dislocation of the SCJ resulting in vascular injuries. We describe the case of a 17-year-old boy who sustained a blunt hockey injury resulting in a right physeal fracture-dislocation of the SCJ causing an innominate artery pseudoaneurysm. This was treated with excision of the pseudoaneurysm, bovine pericardial patch angioplasty repair of the innominate artery, and open reduction and internal fixation of the medial clavicular physeal fracture
Recommended from our members
Pan-viral serology implicates enteroviruses in acute flaccid myelitis.
Since 2012, the United States of America has experienced a biennial spike in pediatric acute flaccid myelitis (AFM)1-6. Epidemiologic evidence suggests non-polio enteroviruses (EVs) are a potential etiology, yet EV RNA is rarely detected in cerebrospinal fluid (CSF)2. CSF from children with AFM (nβ=β42) and other pediatric neurologic disease controls (nβ=β58) were investigated for intrathecal antiviral antibodies, using a phage display library expressing 481,966 overlapping peptides derived from all known vertebrate and arboviruses (VirScan). Metagenomic next-generation sequencing (mNGS) of AFM CSF RNA (nβ=β20 cases) was also performed, both unbiased sequencing and with targeted enrichment for EVs. Using VirScan, the viral family significantly enriched by the CSF of AFM cases relative to controls was Picornaviridae, with the most enriched Picornaviridae peptides belonging to the genus Enterovirus (nβ=β29/42 cases versus 4/58 controls). EV VP1 ELISA confirmed this finding (nβ=β22/26 cases versus 7/50 controls). mNGS did not detect additional EV RNA. Despite rare detection of EV RNA, pan-viral serology frequently identified high levels of CSF EV-specific antibodies in AFM compared with controls, providing further evidence for a causal role of non-polio EVs in AFM
A glycine zipper motif mediates the formation of toxic Ξ²-amyloid oligomers in vitro and in vivo
Characterization of M,L and T dwarfs in the Sloan Digital Sky Survey
An extensive sample of M, L and T dwarfs identified in the Sloan Digital Sky
Survey (SDSS) has been compiled. The sample of 718 dwarfs includes 677 new
objects (629 M dwarfs, 48 L dwarfs) together with 41 that have been previously
published. All new objects and some of the previously published ones have new
optical spectra obtained either with the SDSS spectrographs or with the Apache
Point Observatory 3.5m ARC telescope. Spectral types and SDSS colors are
available for all objects; approximately 35% also have near-infrared magnitudes
measured by 2MASS or on the Mauna Kea system. We use this sample to
characterize the color--spectral type and color--color relations of late type
dwarfs in the SDSS filters, and to derive spectroscopic and photometric
parallax relations for use in future studies of the luminosity and mass
functions based on SDSS data. We find that the (i*-z*) and (i*-J) colors
provide good spectral type and absolute magnitude (M_i*) estimates for M and L
dwarfs. Our distance estimates for the current sample indicate that SDSS is
finding early M dwarfs out to about 1.5 kpc, L dwarfs to approximately 100 pc
and T dwarfs to near 20 pc. The T dwarf photometric data show large scatter and
are therefore less reliable for spectral type and distance estimation.Comment: 46 pages, 14 figures (24 pages of figures), Accepted for publication
in the Astronomical Journa
Route knowledge and configural knowledge in typical and atypical development: a comparison of sparse and rich environments
Background:
Individuals with Down syndrome (DS) and individuals with Williams syndrome (WS) have poor
navigation skills, which impact their potential to become independent. Two aspects of navigation were investigated
in these groups, using virtual environments (VE): route knowledge (the ability to learn the way from A to B by
following a fixed sequence of turns) and configural knowledge (knowledge of the spatial relationships between
places within an environment).
Methods:
Typically developing (TD) children aged 5 to 11 years (N = 93), individuals with DS (N = 29) and individuals
with WS (N = 20) were presented with a sparse and a rich VE grid maze. Within each maze, participants were asked to
learn a route from A to B and a route from A to C before being asked to find a novel shortcut from B to C.
Results:
Performance was broadly similar across sparse and rich mazes. The majority of participants were able to learn
novel routes, with poorest performance in the DS group, but the ability to find a shortcut, our measure of configural knowledge, was limited for all three groups. That is, 59 % TD participants successfully found a shortcut, compared to 10 % participants with DS and 35 % participants with WS. Differences in the underlying mechanisms associated with route knowledge and configural knowledge and in the developmental trajectories of performance across groups were observed. Only the TD participants walked a shorter distance in the last shortcut trial compared to the first, indicative of
increased configural knowledge across trials. The DS group often used an alternative strategy to get from B to C, summing the two taught routes together.
Conclusions:
Our findings demonstrate impaired configural knowledge in DS and in WS, with the strongest deficit in DS. This suggests that these groups rely on a rigid route knowledge based method for navigating and as a result are
likely to get lost easily. Route knowledge was also impaired in both DS and WS groups and was related to different underlying processes across all three groups. These are discussed with reference to limitations in attention and/or visuo-spatial processing in the atypical groups
Epitaxial Growth and Processing of Compound Semiconductors
Contains an introduction and reports on six research projects.Defense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research University Research Initiative Subcontract N00014-92-J-1893Joint Services Electronics Program Grant DAAH04-95-1-0038National Center for Integrated Photonics Technology Contract 542-381National Science Foundation Grant DMR 92-02957MIT Lincoln Laboratory Contract BX-6085National Center for Integrated Photonics Technology Subcontract 542-383U.S. Air Force - Office of Scientific Research Grant F49620-96-1-0126U.S. Navy - Office of Naval Research Grant N00014-91-J-1956National Science Foundation Grant DMR 94-0033
Restricting Dosage Compensation Complex Binding to the X Chromosomes by H2A.Z/HTZ-1
Dosage compensation ensures similar levels of X-linked gene products in males (XY or XO) and females (XX), despite their different numbers of X chromosomes. In mammals, flies, and worms, dosage compensation is mediated by a specialized machinery that localizes to one or both of the X chromosomes in one sex resulting in a change in gene expression from the affected X chromosome(s). In mammals and flies, dosage compensation is associated with specific histone posttranslational modifications and replacement with variant histones. Until now, no specific histone modifications or histone variants have been implicated in Caenorhabditis elegans dosage compensation. Taking a candidate approach, we have looked at specific histone modifications and variants on the C. elegans dosage compensated X chromosomes. Using RNAi-based assays, we show that reducing levels of the histone H2A variant, H2A.Z (HTZ-1 in C. elegans), leads to partial disruption of dosage compensation. By immunofluorescence, we have observed that HTZ-1 is under-represented on the dosage compensated X chromosomes, but not on the non-dosage compensated male X chromosome. We find that reduction of HTZ-1 levels by RNA interference (RNAi) and mutation results in only a very modest change in dosage compensation complex protein levels. However, in these animals, the X chromosomeβspecific localization of the complex is partially disrupted, with some nuclei displaying DCC localization beyond the X chromosome territory. We propose a model in which HTZ-1, directly or indirectly, serves to restrict the dosage compensation complex to the X chromosome by acting as or regulating the activity of an autosomal repellant
IMI - Myopia Genetics Report
The knowledge on the genetic background of refractive error and myopia has expanded
dramatically in the past few years. This white paper aims to provide a concise summary of
current genetic findings and defines the direction where development is needed.
We performed an extensive literature search and conducted informal discussions with key
stakeholders. Specific topics reviewed included common refractive error, any and high
myopia, and myopia related to syndromes.
To date, almost 200 genetic loci have been identified for refractive error and myopia, and risk
variants mostly carry low risk but are highly prevalent in the general population. Several
genes for secondary syndromic myopia overlap with those for common myopia. Polygenic
risk scores show overrepresentation of high myopia in the higher deciles of risk. Annotated
genes have a wide variety of functions, and all retinal layers appear to be sites of expression.
The current genetic findings offer a world of new molecules involved in myopiagenesis. As
the missing heritability is still large, further genetic advances are needed. This Committee
recommends expanding large-scale, in-depth genetic studies using complementary big data
analytics, consideration of gene-environment effects by thorough measurement of environmental exposures, and focus on subgroups with extreme phenotypes and high familial
occurrence. Functional characterization of associated variants is simultaneously needed to
bridge the knowledge gap between sequence variance and consequence for eye growth
- β¦