192 research outputs found
Focal Cerebral Infarction in Newborn: Description of Three Cases:
We observed 3 full-term newborns with focal ischemic injury of the middle cerebral artery (MCA), in which diagnosis of MCA stroke was suspected by US and confirmed by CT scan and MRI. A four-year follow-up was carried out to study the effect of neonatal stroke on neurodevelopmental outcome. All children had a history of pre-perinatal risk factors: neonatal cerebral infarction in term infants, in fact, has many possible causes, including bacterial meningitis, inherited or acquired coagulopathies, trauma and hypoxia-ischemia. The prognosis of neonatal MCA infarction depends on early diagnosis, on the CNS plasticity mechanism and, finally, on medical therapy and neuropsychological rehabilitation
Critical structure factor in Ising systems
We perform a large-scale Monte Carlo simulation of the three-dimensional
Ising model on simple cubic lattices of size L^3 with L=128 and 256. We
determine the corresponding structure factor (Fourier transform of the
two-point function) and compare it with several approximations and with
experimental results. We also compute the turbidity as a function of the
momentum of the incoming radiation, focusing in particular on the deviations
from the Ornstein-Zernicke expression of Puglielli and Ford.Comment: 16 page
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Elevated Stearoyl-CoA Desaturase in Brains of Patients with Alzheimer's Disease
The molecular bases of Alzheimer's disease (AD) remain unclear. We used a lipidomic approach to identify lipid abnormalities in the brains of subjects with AD (N = 37) compared to age-matched controls (N = 17). The analyses revealed statistically detectable elevations in levels of non-esterified monounsaturated fatty acids (MUFAs) and mead acid (20:3n-9) in mid-frontal cortex, temporal cortex and hippocampus of AD patients. Further studies showed that brain mRNAs encoding for isoforms of the rate-limiting enzyme in MUFAs biosynthesis, stearoyl-CoA desaturase (SCD-1, SCD-5a and SCD-5b), were elevated in subjects with AD. The monounsaturated/saturated fatty acid ratio (‘desaturation index’) – displayed a strong negative correlation with measures of cognition: the Mini Mental State Examination test (r = −0.80; P = 0.0001) and the Boston Naming test (r = −0.57; P = 0.0071). Our results reveal a previously unrecognized role for the lipogenic enzyme SCD in AD
Modulation of Statin-Activated Shedding of Alzheimer APP Ectodomain by ROCK
BACKGROUND: Statins are widely used cholesterol-lowering drugs that act by inhibiting HMGCoA reductase, the rate-limiting enzyme in cholesterol biosynthesis. Recent evidence suggests that statin use may be associated with a decreased risk for Alzheimer disease, although the mechanisms underlying this apparent risk reduction are poorly understood. One popular hypothesis for statin action is related to the drugs' ability to activate α-secretase-type shedding of the α-secretase-cleaved soluble Alzheimer amyloid precursor protein ectodomain (sAPP(α)). Statins also inhibit the isoprenoid pathway, thereby modulating the activities of the Rho family of small GTPases—Rho A, B, and C—as well as the activities of Rac and cdc42. Rho proteins, in turn, exert many of their effects via Rho-associated protein kinases (ROCKs). Several cell-surface molecules are substrates for activated α-secretase-type ectodomain shedding, and regulation of shedding typically occurs via activation of protein kinase C or extracellular-signal-regulated protein kinases, or via inactivation of protein phosphatase 1 or 2A. However, the possibility that these enzymes play a role in statin-stimulated shedding has been excluded, leading us to investigate whether the Rho/ROCK1 protein phosphorylation pathway might be involved. METHODS AND FINDINGS: We found that both atorvastatin and simvastatin stimulated sAPP(α) shedding from a neuroblastoma cell line via a subcellular mechanism apparently located upstream of endocytosis. A farnesyl transferase inhibitor also increased sAPP(α) shedding, as did a dominant negative form of ROCK1. Most conclusively, a constitutively active ROCK1 molecule inhibited statin-stimulated sAPP(α) shedding. CONCLUSION: Together, these data suggest that statins exert their effects on shedding of sAPP(α) from cultured cells, at least in part, by modulation of the isoprenoid pathway and ROCK1
Complications of mechanical thrombectomy for acute ischemic stroke: Incidence, risk factors, and clinical relevance in the Italian Registry of Endovascular Treatment in acute stroke
BACKGROUND: There are limited data concerning procedure-related complications of endovascular thrombectomy for large vessel occlusion strokes. AIMS: We evaluated the cumulative incidence, the clinical relevance in terms of increased disability and mortality, and risk factors for complications. METHODS: From January 2011 to December 2017, 4799 patients were enrolled by 36 centers in the Italian Registry of Endovascular Stroke Treatment. Data on demographic and procedural characteristics, complications, and clinical outcome at three months were prospectively collected. RESULTS: The complications cumulative incidence was 201 per 1000 patients undergoing endovascular thrombectomy. Ongoing antiplatelet therapy (p < 0.01; OR 1.82, 95% CI: 1.21-2.73) and large vessel occlusion site (carotid-T, p < 0.03; OR 3.05, 95% CI: 1.13-8.19; M2-segment-MCA, p < 0.01; OR 4.54, 95% CI: 1.66-12.44) were associated with a higher risk of subarachnoid hemorrhage/arterial perforation. Thrombectomy alone (p < 0.01; OR 0.50, 95% CI: 0.31-0.83) and younger age (p < 0.04; OR 0.98, 95% CI: 0.97-0.99) revealed a lower risk of developing dissection. M2-segment-MCA occlusion (p < 0.01; OR 0.35, 95% CI: 0.19-0.64) and hypertension (p < 0.04; OR 0.77, 95% CI: 0.6-0.98) were less related to clot embolization. Higher NIHSS at onset (p < 0.01; OR 1.04, 95% CI: 1.02-1.06), longer groin-to-reperfusion time (p < 0.01; OR 1.05, 95% CI: 1.02-1.07), diabetes (p < 0.01; OR 1.67, 95% CI: 1.25-2.23), and LVO site (carotid-T, p < 0.01; OR 1.96, 95% CI: 1.26-3.05; M2-segment-MCA, p < 0.02; OR 1.62, 95% CI: 1.08-2.42) were associated with a higher risk of developing symptomatic intracerebral hemorrhage compared to no/asymptomatic intracerebral hemorrhage. The subgroup of patients treated with thrombectomy alone presented a lower risk of symptomatic intracerebral hemorrhage (p < 0.01; OR 0.70; 95% CI: 0.55-0.90). Subarachnoid hemorrhage/arterial perforation and symptomatic intracerebral hemorrhage after endovascular thrombectomy worsen both functional independence and mortality at three-month follow-up (p < 0.01). Distal embolization is associated with neurological deterioration (p < 0.01), while arterial dissection did not affect clinical outcome at follow-up. CONCLUSIONS: Complications globally considered are not uncommon and may result in poor clinical outcome. Early recognition of risk factors might help to prevent complications and manage them appropriately in order to maximize endovascular thrombectomy benefits
CTCF Prevents the Epigenetic Drift of EBV Latency Promoter Qp
The establishment and maintenance of Epstein-Barr Virus (EBV) latent infection requires distinct viral gene expression programs. These gene expression programs, termed latency types, are determined largely by promoter selection, and controlled through the interplay between cell-type specific transcription factors, chromatin structure, and epigenetic modifications. We used a genome-wide chromatin-immunoprecipitation (ChIP) assay to identify epigenetic modifications that correlate with different latency types. We found that the chromatin insulator protein CTCF binds at several key regulatory nodes in the EBV genome and may compartmentalize epigenetic modifications across the viral genome. Highly enriched CTCF binding sites were identified at the promoter regions upstream of Cp, Wp, EBERs, and Qp. Since Qp is essential for long-term maintenance of viral genomes in type I latency and epithelial cell infections, we focused on the role of CTCF in regulating Qp. Purified CTCF bound ∼40 bp upstream of the EBNA1 binding sites located at +10 bp relative to the transcriptional initiation site at Qp. Mutagenesis of the CTCF binding site in EBV bacmids resulted in a decrease in the recovery of stable hygromycin-resistant episomes in 293 cells. EBV lacking the Qp CTCF site showed a decrease in Qp transcription initiation and a corresponding increase in Cp and Fp promoter utilization at 8 weeks post-transfection. However, by 16 weeks post-transfection, bacmids lacking CTCF sites had no detectable Qp transcription and showed high levels of histone H3 K9 methylation and CpG DNA methylation at the Qp initiation site. These findings provide direct genetic evidence that CTCF functions as a chromatin insulator that prevents the promiscuous transcription of surrounding genes and blocks the epigenetic silencing of an essential promoter, Qp, during EBV latent infection
Non-alcoholic fatty liver disease induces signs of Alzheimer’s disease (AD) in wild-type mice and accelerates pathological signs of AD in an AD model
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