152 research outputs found
Persistent left superior vena cava: a case report and review of literature
Persistent left superior vena cava is rare but important congenital vascular anomaly. It results when the left superior cardinal vein caudal to the innominate vein fails to regress. It is most commonly observed in isolation but can be associated with other cardiovascular abnormalities including atrial septal defect, bicuspid aortic valve, coarctation of aorta, coronary sinus ostial atresia, and cor triatriatum. The presence of PLSVC can render access to the right side of heart challenging via the left subclavian approach, which is a common site of access utilized when placing pacemakers and Swan-Ganz catheters. Incidental notation of a dilated coronary sinus on echocardiography should raise the suspicion of PLSVC. The diagnosis should be confirmed by saline contrast echocardiography
Expert Consensus Recommendations for the Suspicion and Diagnosis of Transthyretin Cardiac Amyloidosis
Cardiomyopathy is a manifestation of transthyretin amyloidosis (ATTR), which is an underrecognized systemic disease whereby the transthyretin protein misfolds to form fibrils that deposit in various tissues and organs. ATTR amyloidosis is debilitating and associated with poor life expectancy, especially in those with cardiac dysfunction, but a variety of treatment options have recently become available. Considered a rare disease, ATTR amyloidosis may be more prevalent than thought, particularly in older persons. Diagnosis is often delayed because of a lack of disease awareness and the heterogeneity of symptoms at presentation. Given the recent availability of effective treatments, early recognition and diagnosis are especially critical because treatment is likely more effective earlier in the disease course. The Amyloidosis Research Consortium recently convened a group of experts in ATTR amyloidosis who, through an iterative process, agreed on best practices for suspicion, diagnosis, and characterization of disease. This review describes these consensus recommendations for ATTR associated with cardiomyopathy as a resource to aid cardiologists and others in the recognition and diagnosis of ATTR associated with cardiomyopathy. Included in this review is an overview of red flag signs and symptoms and a recommended diagnostic approach, including testing for monoclonal protein, scintigraphy, or biopsy and, if ATTR associated with cardiomyopathy is identified, TTR genotyping
Genome prediction of PhoB regulated promoters in Sinorhizobium meliloti and twelve proteobacteria
In proteobacteria, genes whose expression is modulated in response to the external concentration of inorganic phosphate are often regulated by the PhoB protein which binds to a conserved motif (Pho box) within their promoter regions. Using a position weight matrix algorithm derived from known Pho box sequences, we identified 96 putative Pho regulon members whose promoter regions contained one or more Pho boxs in the Sinorhizobium meliloti genome. Expression of these genes was examined through assays of reporter gene fusions and through comparison with published microarray data. Of 96 genes, 31 were induced and 3 were repressed by Pi starvation in a PhoB dependent manner. Novel Pho regulon members included several genes of unknown function. Comparative analysis across 12 proteobacterial genomes revealed highly conserved Pho regulon members including genes involved in Pi metabolism (pstS, phnC and ppdK). Genes with no obvious association with Pi metabolism were predicted to be Pho regulon members in S.meliloti and multiple organisms. These included smc01605 and smc04317 which are annotated as substrate binding proteins of iron transporters and katA encoding catalase. This data suggests that the Pho regulon overlaps and interacts with several other control circuits, such as the oxidative stress response and iron homeostasis
Advancing cyanobacteria biomass estimation from hyperspectral observations: Demonstrations with HICO and PRISMA imagery
Retrieval of the phycocyanin concentration (PC), a characteristic pigment of, and proxy for, cyanobacteria
biomass, from hyperspectral satellite remote sensing measurements is challenging due to uncertainties in the
remote sensing reflectance (āRrs) resulting from atmospheric correction and instrument radiometric noise.
Although several individual algorithms have been proven to capture local variations in cyanobacteria biomass in
specific regions, their performance has not been assessed on hyperspectral images from satellite sensors. Our work leverages a machine-learning model, Mixture Density Networks (MDNs), trained on a large (N = 939) dataset of collocated in situ chlorophyll-a concentrations (Chla), PCs, and remote sensing reflectance (Rrs) measurements to estimate PC from all relevant spectral bands. The performance of the developed model is demonstrated via PC maps produced from select images of the Hyperspectral Imager for the Coastal Ocean (HICO) and Italian Space Agencyās PRecursore IperSpettrale della Missione Applicativa (PRISMA) using a matchup dataset. As input to the MDN, we incorporate a combination of widely used band ratios (BRs) and line heights (LHs) taken from existing multispectral algorithms, that have been proven for both Chla and PC estiļæ½mation, as well as novel BRs and LHs to increase the overall cyanobacteria biomass estimation accuracy and reduce the sensitivity to āRrs. When trained on a random half of the dataset, the MDN achieves uncertainties of 44.3%, which is less than half of the uncertainties of all viable optimized multispectral PC algorithms. The MDN is notably better than multispectral algorithms at preventing overestimation on low (10 mg mā 3).
According to our extensive assessments, the developed model is anticipated to enable practical PC products from
PRISMA and HICO, therefore the model is promising for planned hyperspectral missions, such as the Plankton
Aerosol and Cloud Ecosystem (PACE). This advancement will enhance the complementary roles of hyperspectral radiometry from satellite and low-altitude platforms for quantifying and monitoring cyanobacteria harmful algal
blooms at both large and local spatial scales
ASNC/AHA/ASE/EANM/HFSA/ISA/SCMR/SNMMI expert consensus recommendations for multimodality imaging in cardiac amyloidosis: Part 2 of 2āDiagnostic criteria and appropriate utilization
Cardiac amyloidosis is emerging as an underdiagnosed cause of heart failure and mortality. Growing literature suggests that a noninvasive diagnosis of cardiac amyloidosis is now feasible. However, the diagnostic criteria and utilization of imaging in cardiac amyloidosis are not standardized. In this paper, Part 2 of a series, a panel of international experts from multiple societies define the diagnostic criteria for cardiac amyloidosis and appropriate utilization of echocardiography, cardiovascular magnetic resonance imaging, and radionuclide imaging in the evaluation of patients with known or suspected cardiac amyloidosis
Identification of early changes in specific symptoms that predict longer-term response to atypical antipsychotics in the treatment of patients with schizophrenia
<p>Abstract</p> <p>Background</p> <p>To identify a simple decision tree using early symptom change to predict response to atypical antipsychotic therapy in patients with (Diagnostic and Statistical Manual, Fourth Edition, Text Revised) chronic schizophrenia.</p> <p>Methods</p> <p>Data were pooled from moderately to severely ill patients (n = 1494) from 6 randomized, double-blind trials (N = 2543). Response was defined as a ā„30% reduction in Positive and Negative Syndrome Scale (PANSS) Total score by Week 8 of treatment. Analyzed predictors were change in individual PANSS items at Weeks 1 and 2. A decision tree was constructed using classification and regression tree (CART) analysis to identify predictors that most effectively differentiated responders from non-responders.</p> <p>Results</p> <p>A 2-branch, 6-item decision tree was created, producing 3 distinct groups. First branch criterion was a 2-point score decrease in at least 2 of 5 PANSS positive items (Week 2). Second branch criterion was a 2-point score decrease in the PANSS excitement item (Week 2). "Likely responders" met the first branch criteria; "likely non-responders" did not meet first or second criterion; "not predictable" patients did not meet the first but did meet the second criterion. Using this approach, response to treatment could be predicted in most patients (92%) with high positive predictive value (79%) and high negative predictive value (75%). Predictive findings were confirmed through analysis of data from 2 independent trials.</p> <p>Conclusions</p> <p>Using a data-driven approach, we identified decision rules using early change in the scores of selected PANSS items to accurately predict longer-term treatment response or non-response to atypical antipsychotic therapy. This could lead to development of a simple quantitative evaluation tool to help guide early treatment decisions.</p> <p>Trial Registration</p> <p>This is a retrospective, non-intervention study in which pooled results from 6 previously published reports were analyzed; thus, clinical trial registration is not required.</p
Olfactory dysfunction, central cholinergic integrity and cognitive impairment in Parkinsonās disease
Olfactory dysfunction is common in subjects with Parkinsonās disease. The pathophysiology of such dysfunction, however, remains poorly understood. Neurodegeneration within central regions involved in odour perception may contribute to olfactory dysfunction in Parkinsonās disease. Central cholinergic deficits occur in Parkinsonās disease and cholinergic neurons innervate regions, such as the limbic archicortex, involved in odour perception. We investigated the relationship between performance on an odour identification task and forebrain cholinergic denervation in Parkinsonās disease subjects without dementia. Fifty-eight patients with Parkinsonās disease (mean Hoehn and Yahr stage 2.5 Ā± 0.5) without dementia (mean Mini-Mental State Examination, 29.0 Ā± 1.4) underwent a clinical assessment, [11C]methyl-4-piperidinyl propionate acetylcholinesterase brain positron emission tomography and olfactory testing with the University of Pennsylvania Smell Identification Test. The diagnosis of Parkinsonās disease was confirmed by [11C]dihydrotetrabenazine vesicular monoamine transporter type 2 positron emission tomography. We found that odour identification test scores correlated positively with acetylcholinesterase activity in the hippocampal formation (r = 0.56, P < 0.0001), amygdala (r = 0.50, P < 0.0001) and neocortex (r = 0.46, P = 0.0003). Striatal monoaminergic activity correlated positively with odour identification scores (r = 0.30, P < 0.05). Multiple regression analysis including limbic (hippocampal and amygdala) and neocortical acetylcholinesterase activity as well as striatal monoaminergic activity, using odour identification scores as the dependent variable, demonstrated a significant regressor effect for limbic acetylcholinesterase activity (F = 10.1, P < 0.0001), borderline for striatal monoaminergic activity (F = 1.6, P = 0.13), but not significant for cortical acetylcholinesterase activity (F = 0.3, P = 0.75). Odour identification scores correlated positively with scores on cognitive measures of episodic verbal learning (r = 0.30, P < 0.05). These findings indicate that cholinergic denervation of the limbic archicortex is a more robust determinant of hyposmia than nigrostriatal dopaminergic denervation in subjects with moderately severe Parkinson's disease. Greater deficits in odour identification may identify patients with Parkinson's disease at risk for clinically significant cognitive impairment
Beneath a Steel Sky: A Musical Characterisation of Class Structure
This article proposes Revolution Softwareās Beneath a Steel Sky (1994) as a starting point for the analysis of the relationship between music and social class in video games. While other issues of representation have been studied extensively within game studies (gender representation in particular), the representation of class remains an underexplored area. Furthermore, the relationship between video game music and socio-cultural aspects of video game studies is also rarely examined beyond issues of race, ethnicity, and cultural appropriation. This article draws connections between these two underexplored areas and analyses the musical characterisation of class in the 1994 cyberpunk adventure game, which takes places largely in a literally stratified metropolis where the three levels of the city act as representations of the three social classes. Here, music plays an important role in terms of environmental storytelling, both as semiotic shorthand, and as a reflection of the affordances available to the inhabitants of the city
T1 mapping in cardiac MRI
Quantitative myocardial and blood T1 have recently achieved clinical utility in numerous pathologies, as they provide non-invasive tissue characterization with the potential to replace invasive biopsy. Native T1 time (no contrast agent), changes with myocardial extracellular water (edema, focal or diffuse fibrosis), fat, iron, and amyloid protein content. After contrast, the extracellular volume fraction (ECV) estimates the size of the extracellular space and identifies interstitial disease. Spatially resolved quantification of these biomarkers (so-called T1 mapping and ECV mapping) are steadily becoming diagnostic and prognostically useful tests for several heart muscle diseases, influencing clinical decision-making with a pending second consensus statement due mid-2017. This review outlines the physics involved in estimating T1 times and summarizes the disease-specific clinical and research impacts of T1 and ECV to date. We conclude by highlighting some of the remaining challenges such as their community-wide delivery, quality control, and standardization for clinical practice
Autoradiographic quantification of muscarinic cholinergic synaptic markers in bat, shrew, and rat brain
We employed radioligand binding autoradiography to determine the distributions of pre- and postsynaptic cholinergic radioligand binding sites in the brains of two species of bat, one species of shrew, and the rat. High affinity choline uptake sites were measured with [ 3 H]hemicholinium, and presynaptic cholinergic vesicles were identified with [ 3 H]vesamicol. Muscarinic cholinergic receptors were determined with [ 3 H]scopolamine. The distribution patterns of the three cholinergic markers were similar in all species examined, and identified known major cholinergic pathways on the basis of enrichments in both pre- and postsynaptic markers. In addition, there was excellent agreement, both within and across species, in the regional distributions of the two presynaptic cholinergic markers. Our results indicate that pharmacological identifiers of cholinergic pathways and synapses, including the cholinergic vesicle transport site, and the organizations of central nervous system cholinergic pathways are phylogenetically conserved among eutherian mammals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45409/1/11064_2004_Article_BF00971334.pd
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