1,996 research outputs found
Cardioembolic but Not Other Stroke Subtypes Predict Mortality Independent of Stroke Severity at Presentation
Introduction. Etiology of acute ischemic stroke (AIS) is known to significantly influence management, prognosis, and risk of recurrence.
Objective. To determine if ischemic stroke subtype based on TOAST criteria influences mortality.
Methods. We conducted an observational study of a consecutive cohort of patients presenting with AIS to a single tertiary academic center.
Results. The study population consisted of 500 patients who resided in the local county or the surrounding nine-county area. No patients were lost to followup. Two hundred and sixty one (52.2%) were male, and the mean age at presentation was 73.7 years (standard deviation, SD = 14.3). Subtypes were as follows: large artery atherosclerosis 97 (19.4%), cardioembolic 144 (28.8%), small vessel disease 75 (15%), other causes 19 (3.8%), and unknown 165 (33%). One hundred and sixty patients died: 69 within the first 30 days, 27 within 31–90 days, 29 within 91–365 days, and 35 after 1 year. Low 90-, 180-, and 360-day survival was seen in cardioembolic strokes (67.1%, 65.5%, and 58.2%, resp.), followed for cryptogenic strokes (78.0%, 75.3%, and 71.1%). Interestingly, when looking into the cryptogenic category, those with insufficient information to assign a stroke subtype had the lowest survival estimate (57.7% at 90 days, 56.1% at 180 days, and 51.2% at 1 year).
Conclusion. Cardioembolic ischemic stroke subtype determined by TOAST criteria predicts long-term mortality, even after adjusting for age and stroke severity
A Serpin shapes the extracellular environment to prevent influenza A virus maturation
Interferon-stimulated genes (ISGs) act in concert to provide a tight barrier against viruses. Recent studies have shed light on the contribution of individual ISG effectors to the antiviral state, but most have examined those acting on early, intracellular stages of the viral life cycle. Here, we applied an image-based screen to identify ISGs inhibiting late stages of influenza A virus (IAV) infection. We unraveled a directly antiviral function for the gene SERPINE1, encoding plasminogen activator inhibitor 1 (PAI-1). By targeting extracellular airway proteases, PAI-1 inhibits IAV glycoprotein cleavage, thereby reducing infectivity of progeny viruses. This was biologically relevant for IAV restriction in vivo. Further, partial PAI-1 deficiency, attributable to a polymorphism in human SERPINE1, conferred increased susceptibility to IAV in vitro. Together, our findings reveal that manipulating the extracellular environment to inhibit the last step in a virus life cycle is an important mechanism of the antiviral response
The impact of blood pressure hemodynamics in acute ischemic stroke: a prospective cohort study
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Anatomical localization of progenitor cells in human breast tissue reveals enrichment of uncommitted cells within immature lobules
Introduction: Lineage tracing studies in mice have revealed the localization and existence of lineage-restricted mammary epithelial progenitor cells that functionally contribute to expansive growth during puberty and differentiation during pregnancy. However, extensive anatomical differences between mouse and human mammary tissues preclude the direct translation of rodent findings to the human breast. Therefore, here we characterize the mammary progenitor cell hierarchy and identify the anatomic location of progenitor cells within human breast tissues. Methods: Mammary epithelial cells (MECs) were isolated from disease-free reduction mammoplasty tissues and assayed for stem/progenitor activity in vitro and in vivo. MECs were sorted and evaluated for growth on collagen and expression of lineages markers. Breast lobules were microdissected and individually characterized based on lineage markers and steroid receptor expression to identify the anatomic location of progenitor cells. Spanning-tree progression analysis of density-normalized events (SPADE) was used to identify the cellular hierarchy of MECs within lobules from high-dimensional cytometry data. Results: Integrating multiple assays for progenitor activity, we identified the presence of luminal alveolar and basal ductal progenitors. Further, we show that Type I lobules of the human breast were the least mature, demonstrating an unrestricted pattern of expression of luminal and basal lineage markers. Consistent with this, SPADE analysis revealed that immature lobules were enriched for basal progenitor cells, while mature lobules consisted of increased hierarchal complexity of cells within the luminal lineages. Conclusions: These results reveal underlying differences in the human breast epithelial hierarchy and suggest that with increasing glandular maturity, the epithelial hierarchy also becomes more complex. Electronic supplementary material The online version of this article (doi:10.1186/s13058-014-0453-3) contains supplementary material, which is available to authorized users
Antenatal depression, treatment with selective serotonin reuptake inhibitors, and neonatal brain structure: A propensity-matched cohort study
The aim of this propensity-matched cohort study was to evaluate the impact of prenatal SSRI exposure and a history of maternal depression on neonatal brain volumes and white matter microstructure. SSRI-exposed neonates (n = 27) were matched to children of mothers with no history of depression or SSRI use (n=54). Additionally, neonates of mothers with a history of depression, but no prenatal SSRI exposure (n=41), were matched to children of mothers with no history of depression or SSRI use (n=82). Structural magnetic resonance imaging and diffusion weighted imaging scans were acquired with a 3T Siemens Allegra scanner. Global tissue volumes were characterized using an automatic, atlas-moderated expectation maximization segmentation tool. Local differences in gray matter volumes were examined using deformation-based morphometry. Quantitative tractography was performed using an adaptation of the UNC-Utah NA-MIC DTI framework. SSRI-exposed neonates exhibited widespread changes in white matter microstructure compared to matched controls. Children exposed to a history of maternal depression but no SSRIs showed no significant differences in brain development compared to matched controls. No significant differences were found in global or regional tissue volumes. Additional research is needed to clarify whether SSRIs directly alter white matter development or whether this relationship is mediated by depressive symptoms during pregnancy
Inherent colistin resistance in Genogroups of the <i>Enterobacter cloacae</i> complex:epidemiological, genetic and biochemical analysis from the BSAC Resistance Surveillance Programme
A novel source of arterial valve cell linked to bicuspid aortic valve without rephe in mice
Abnormalities of the arterial valve leaflets, predominantly bicuspid aortic valve, are the commonest congenital malformations. Although many studies have investigated the development of the arterial valves, it has been assumed that, as with the atrioventricular valves, endocardial to mesenchymal transition (EndMT) is the predominant mechanism. We show that arterial is distinctly different from atrioventricular valve formation. Whilst the four septal valve leaflets are dominated by NCC and EndMT-derived cells, the intercalated leaflets differentiate directly from Tnnt2-Cre+/Isl1+ progenitors in the outflow wall, via a Notch-Jag dependent mechanism. Further, when this novel group of progenitors are disrupted, development of the intercalated leaflets is disrupted, resulting in leaflet dysplasia and bicuspid valves without raphe, most commonly affecting the aortic valve. This study thus overturns the dogma that heart valves are formed principally by EndMT, identifies a new source of valve interstitial cells, and provides a novel mechanism for causation of bicuspid aortic valves without raphe.British Heart Foundation RG/12/15/29935 Lorriane Eley Rachel V Richardson Lindsay Murphy Bill Chaudhry Deborah J Henderson; British Heart Foundation PG/15/46/31589 Lorriane Eley Bill Chaudhry Deborah J Henderson; Ministerio de Ciencia, Innovacion y Universidades of Spain CB16/11/00399 (Ciber Cardiovascular) Donal MacGrogan Alejandro Salguero-Jimenez Jose Luis de La Pompa; Ministerio de Ciencia, Innovacion y Universidades of Spain SAF2016-78370-R Donal MacGrogan Alejandro Salguero-Jimenez Jose Luis de La Pompa; Ministerio de Ciencia, Innovacion y Universidades of Spain RD16/0011/0021 (Red de Terapia Celular, TERCEL) Donal MacGrogan Alejandro Salguero-Jimenez Jose Luis de La Pompa; The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.S
The Metal-rich Globular Cluster NGC6553: Observations with WFPC2, STIS, and NICMOS
We present a HST study of the metal-rich globular cluster NGC6553 using
WFPC2, NICMOS and STIS. Our primary motivation is to calibrate the STIS
broad-band LP magnitude against and magnitudes for stars of
known metallicity and absolute (visual) magnitude, for application to our study
of LMC globular clusters. NGC6553 has been shown in earlier studies to have a
very unusual colour-magnitude diagram, so we also use our data to investigate
the reddening, distance, luminosity function and structure of this cluster. We
deduce a higher metallicity and smaller distance modulus than did some previous
studies, but emphasise that very large patchy extinction on small angular
scales prohibits accurate determination of the parameters of this cluster. The
horizontal branch of NGC6553 in () is tilted at an angle close to that
of the reddening vector. We show that extinction does not, however, explain the
tilt, which is presumably a metallicity effect. The colour-magnitude diagram
shows an apparent second turnoff some 1.5 magnitudes fainter than that of the
cluster. We show that this is most likely the background Galactic bulge:
however, in that case, the colour-magnitude diagram of NGC6553 is not a good
match to that of the field bulge population. The cluster is probably more
metal-rich than is the mean field bulge star.Comment: 29 pages (Latex), 13 figs (PS, in document), 10 figs (JPEG format,
outside document, degraded from original to save download time), accepted for
pub. in A
Does having a twin-brother make for a bigger brain?
Objective: Brain volume of boys is larger than that of girls by ∼10%. Prenatal exposure to testosterone has been suggested in the masculinization of the brain. For example, in litter-bearing mammals intrauterine position increases prenatal testosterone exposure through adjacent male fetuses, resulting in masculinization of brain morphology. Design: The influence of intrauterine presence of a male co-twin on masculinization of human brain volume was studied in 9-year old twins. Methods: Magnetic resonance imaging brain scans, current testosterone, and estradiol levels were acquired from four groups of dizygotic (DZ) twins: boys from same-sex twin-pairs (SSM), boys from opposite-sex twin-pairs (OSM), girls from opposite-sex twin-pairs (OSF), and girls from same-sex twin-pairs (SSF; n=119 individuals). Data on total brain, cerebellum, gray and white matter volumes were examined. Results: Irrespective of their own sex, children with a male co-twin as compared to children with a female co-twin had larger total brain (+2.5%) and cerebellum (+5.5%) volumes. SSM, purportedly exposed to the highest prenatal testosterone levels, were found to have the largest volumes, followed by OSM, OSF and SSF children. Birth weight partly explained the effect on brain volumes. Current testosterone and estradiol levels did not account for the volumetric brain differences. However, the effects observed in children did not replicate in adult twins. Conclusions: Our study indicates that sharing the uterus with a DZ twin brother increases total brain volume in 9-year olds. The effect may be transient and limited to a critical period in childhood. © 2009 European Society of Endocrinology
Using non-invasive biomarkers to identify hepatic fibrosis in people with type 2 diabetes mellitus: the Edinburgh type 2 diabetes study
BACKGROUND & AIMS: It is difficult to determine the different stages of non-alcoholic fatty liver disease without the use of invasive liver biopsy. In this study we investigated five non-invasive biomarkers used previously to detect hepatic fibrosis and determined the level of agreement between them in order to inform future research.
METHODS: In the Edinburgh Type 2 Diabetes Study, a population-based cohort aged 60-74 years with type 2 diabetes, 831 participants underwent ultrasound assessment for fatty liver and had serum aspartate aminotransferase to alanine aminotransferase ratio (AST/ALT), aspartate to platelet ratio index (APRI), European Liver Fibrosis panel (ELF), Fibrosis-4 Score (FIB4) and liver stiffness measurement (LSM) measured.
RESULTS: Literature based cut-offs yielded marked differences in the proportions of the cohort with probable liver fibrosis in the full cohort. Agreement between the top 5% of the distribution for each biomarker pair was poor. APRI and FIB4 had the best positive agreement at 76.4%, but agreement for all of the other serum biomarker pairs was between 18% and 34%. Agreement with LSM was poor (9-16%).
CONCLUSIONS: We found poor correlation between the five biomarkers of liver fibrosis studied. Using the top 5% of each biomarker resulted in good agreement on the absence of advanced liver disease but poor agreement on the presence of advanced disease. Further work is required to validate these markers against liver biopsy and to determine their predictive value for clinical liver-related endpoints, in a range of different low and high risk population groups
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